The vibration platform is special device, the main purpose of which is to seal concrete mixtures in the production of reinforced concrete, concrete panels, slabs, blocks, etc. The use of such equipment in construction extends the service life concrete products, ensures their strength and reliability.
It is possible to supply such vibrating platforms as VPK-20, VPK-15, VPK-10, and SMF vibration platform.
Vibrating blocks can be divided into subcategories according to such characteristics as load capacity, nature of vibrations, type of construction, type of installed vibrators, etc.
According to the nature of vibrations, vibration platforms can have non-harmonic shock-vibration vibrations directed vertically harmonic vibrations, circular harmonic oscillations. By design, vibrating platforms can be of block or frame type. By type of installed vibrators: vibrating platforms with electromagnetic or hydraulic vibrators, with unbalanced runners.
Vibration platforms with directed vertical harmonic vibrations operate according to the following principle: two identical vibrators are installed in one plane, which rotate in different directions, thereby creating directed horizontal vibrations. Required condition is the synchronous operation of vibrators. If the load capacity is low, unbalance shafts are installed on the vibration platform, which are located at a short distance from each other and on the same horizontal plane.
Vibration platforms with directed vertical vibrations are made of vibration blocks, electromagnets, couplings, etc. The design of the device with a load capacity of 2 tons includes a foundation and vibrating frame, a synchronizer, and an electric motor. The frames are made of rolled steel. An electric motor and a synchronizer are located on the foundation frame, and two dual vibrators are located on the vibrating frame. In the upper plane of the vibrating frame there are holes covered with flexible textures, with the help of which the vibrators are mounted and dismantled. This type vibration equipment is used for the production of concrete and reinforced concrete products measuring 3x6 meters.
The design of the vibration platforms includes a set of spring-loaded vibration pedestals mounted on a common frame. VI-107N electromechanical vibrators are installed on the vibrating tables. The uniform is not attached to such a machine. A control cabinet with starting devices is supplied separately. At the Client’s request, all vibrators or a separate group can be put into operation using one button. Protection against phase loss, overloads, short circuits, shutdowns, as well as zero protection engines are provided by electrical equipment.
For successful operation of vibration equipment, the rules of transportation, storage, installation and use must be strictly observed.
| Characteristic | VPK-10 | VPK-15 | VPK-20 |
| Load capacity, t | 10 | 15 | 20 |
| Oscillation frequency, Hz | 50 | 50 | 50 |
| Number of vibration pedestals, pcs. | 4 | 6 | 8 |
| Operating voltage, V | 380 | 380 | 380 |
| Driving force, kN | 160 | 240 | 320 |
| Rated power, kW | 17,6 | 26,4 | 35,2 |
| Weight, kg | 3080 | 4500 | 6100 |
| Overall dimensions, mm: | |||
| length | 5960 | 7700 | 9100 |
| width | 1300 | 1300 | 1300 |
| height | 800 | 800 | 800 |
| << |
Designed for the production of reinforced concrete products in metal molds, for compacting the concrete mixture in them.
They are divided into several types according to purpose, types of vibration produced and operating principle:
Vibrating table SV-1400.
Designed for the production of road and sidewalk curbs
- and single forms.
Equipped with an industrial vibrator with a power of 0.5 kW, 2800 rpm, 220 V.
Specifications:
Nominal oscillation frequency count/min – 2800
Maximum centrifugal (driving) force, kN - 5
Maximum static moment of unbalance, kg cm - 5.1
Dimensions:
Width - 500 mm
Length - 1456 mm
Height - 860 mm
Weight, kg - 150-190
Service personnel, persons — 2
Characteristics of electrical equipment:
Type of supply current - alternating
Rated voltage of the power circuit, V - 220
Rated power of the vibrator, kW - 0.5
Price 35,500 rub.
Note! As standard, one industrial vibrator with a power of 0.5 kW, 2800 rpm, 220 V is installed on the vibrating table.
We install a larger number of vibrators at the customer’s request.
Voltage 380 V is available on request.
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Vibrating table SMZh-200-2
Designed for the production of reinforced concrete products as a compaction of the concrete mixture. The vibrating table consists of a support frame on which a vibrating frame with shafts and imbalances is installed. Imbalances are subject to vibration frequency adjustment. The vibrating frame is equipped with metal stops that prevent the metal mold from shifting during vibration.
Compacts the concrete mixture in the production of reinforced concrete products. Consists of two vibrating tables SMZh-200.
Technical characteristics of one vibrating table SMZh-200-2:
— load capacity 5 tons (total 10 tons)
— engine power 18.5 kW (total 37 kW), rpm 3000.
— Platform, dimensions: length/width (mm) 2495/1730
— Dimensions of one cabinet: length/width/height (mm) 2200/2100/450
— The size of the molded product is up to 8000 mm
— Required foundation: reinforced concrete slab with a thickness of 300 mm, anchoring — 6 anchors.
Advantages of SMF-200-2:
Powerful vibration, the cabinets do not resonate.
It is possible to install a frequency converter to adjust the engine speed (vibration indicators).
It is possible to increase the carrying capacity.
Vibrating pedestals SMZh-200
| Vibrating cabinet SMZh-200 (1750*1700mm.15 kW) | 535 000 |
| Vibrating cabinet SMZh-200 (1700*1200mm.15 kW) | 535 000 |
| Vibrating cabinet SMZh-200 (2000*1700mm.18.5 kW) | 551 000 |
| Vibrating cabinet SMZh-200 (2200*1750mm.18.5 kW) | 561 000 |
| Vibrating cabinet SMZh-200 (2200*2100mm.18.5 kW) | 583 000 |
| Vibrating cabinet SMZh-200 (2500*1750mm.18.5 kW) | 599 000 |
| Vibrating cabinet SMZh-200 (2500*2100mm.18.5 kW) | 615 000 |
Vibrating platform for metal molds.
Prices of vibrating platforms for metal molds.
Vibrating platform VSM (1500x2000) (2 VI 98B vibrators included) - RUB 166,200.
Vibration platform VSM-1 (1500x3000) (3 vibrators VI 98B included) - RUB 175,700.
Vibrating platform VSM-2 (2000x3000) (4 VI 98B vibrators included) - RUB 198,300.
Vibrating platform VSM-3 (2000x4000) (6 vibrators VI 98B included) - RUB 317,250.
Vibration platform VSM-4 (2000x6000) (8 VI 98B vibrators included) - RUB 407,900.
Vibrating platform VSM-5 (2000x8300) (8 VI 98B vibrators included) - RUB 450,200.
Vibration platform VSM-6 (2000x11000) (10 VI 98B vibrators included) - RUB 566,500.
Prices for vibrating platforms for metal molds:
Vibrating platform VSM (1500x2000 mm) (2 VI 98B vibrators included) — RUB 166,200
Vibrating platform VSM-1 (1500x3000) (3 VI 98B vibrators included) — RUB 175,700
Vibrating platform VSM-2 (2000x3000) (4 VI 98B vibrators included) — RUB 198,300
Vibrating platform VSM-3 (2000x4000) (6 vibrators VI 98B included) — RUB 317,250
Vibrating platform VSM-4 (2000x6000) (8 VI 98B vibrators included) — RUB 407,900
Vibrating platform VSM-5 (2000x8300) (8 VI 98B vibrators included) — RUB 450,200
Vibrating platform VSM-6 (2000x11000) (10 VI 98B vibrators included) — RUB 566,500
Consultations on all equipment can be obtained by calling +7 912 734 45 20
Vibrating platform consists of two frames: an upper, movable one, on which a form with a concrete mixture is installed, and a lower, fixed one, fixed to the foundation. The upper frame with a vibration mechanism attached to it rests on the lower frame with the help of shock absorbers (springs, springs and elastic rubber pads) or is held on an air cushion.
The vibration mechanism is most often designed in the form of shafts with unbalances driven into rotation by an electric motor. On small vibrating platforms of the simplest type, vibrations are obtained using external vibrators attached to a movable frame. The upper frame is designed with great rigidity. In cases where the movable frame does not have sufficient rigidity, the amplitude at various points of the vibrating platform may be stationary, due to which sufficient compaction of the mixture will not be ensured in areas with a small amplitude.
The amplitude is regulated by changing the kinetic moment of the unbalances, which is equal to the product of the mass of the unbalance and the amount of displacement of its center of gravity (eccentricity). To do this, unbalances are designed in the form of two disks with weights eccentrically placed on them. By rotating one disk relative to another, fixedly mounted on the shaft, you can change the magnitude of the kinetic moment. In addition, a change in the kinetic moment can be achieved by using unbalances with replaceable weights.
According to the nature of vibrations, vibrating platforms can be with circular and directed vertical vibrations, as well as resonant or vibration-impact with nonlinear horizontal vibrations. Vibrating platforms with circular vibrations are made with one unbalance shaft, during the rotation of which the upper frame makes oscillatory movements in both vertical and horizontal planes (see figure below, pos. A, b). Vertically directed vibrations of the upper frame of the vibrating platform are obtained by installing two parallel vibrating shafts on it, rotating at the same speed in opposite directions (see figure below, pos. V). Vibrating platforms with vertically directed vibrations have a number of disadvantages: design complexity, large mass, high electric drive power, as well as noise and vibration in the workplace.
| Scheme of operation of vibrating platforms |
A- with circular vibrations; b- diagram of the action of forces of a vibrating platform with circular vibrations; V- with vertically directed vibrations; phase 1 - the centrifugal forces of the two unbalance shafts are directed upward and add up; 2 - forces are directed in different directions and mutually destroy each other; 3 - both forces are directed downward and add up; 4 - forces are directed towards each other and are mutually destroyed; G- with horizontally directed vibrations, resonant; d- the same, vibration-impact, with nonlinear vibrations; 1 - vibrator; 2 - vibrating plate; 3 - spring; 4 - movable frame with thrust frame plate; 5 - springs; 6 - elastic limiter; 7 - drummer |
Resonant ones are largely devoid of these disadvantages (see figure above, pos. G) or vibration-impact with nonlinear horizontal vibrations (see figure above, pos. d) vibration platforms. The movable frame of the vibrating platform 4 receives horizontal vibrations using directional vibrators 1, rigidly mounted on the vibrating plate 2, which is connected to the thrust plate 4 of the movable frame on springs 3. The vibration-impact vibrating platform with nonlinear oscillations also has a hammer 6 and an elastic limiter 7 on the vibrating plate on the thrust plate 5 of the movable frame. In the case when the gap between the striker and the elastic limiter is large, the vibration platform acts as a resonant one. As this gap decreases, each movement of the vibrator will be accompanied by an impact on the elastic limiter, which changes the nature of the vibration, and the operation of the vibrating platform becomes more stable.
As studies have shown, it is advisable to use vibration platforms with vertically directed vibrations when molding flat products of small thickness, and with circular and horizontal vibrations - when manufacturing structures of large thickness, when it is necessary to use vibrations of not only the mold tray, but also its side elements.
Changing the oscillation frequency of the vibrating platform can be accomplished by using two- or three-speed electric motors, as well as by regulating the current frequency using generators. In order for the vibrations of the upper frame to be completely, without loss, transmitted to the concrete mixture through the mold, the latter is securely attached to the upper frame of the vibrating platform during compaction by mechanical (wedge, eccentric and other clamps), electromagnetic and pneumatic methods (see figure below). Vibrating platforms with vertically directed vibrations with a lifting capacity of up to 10 tons are equipped with pneumatic clamps, and more than 10 tons are equipped with electromagnetic fastening of forms. Vibrating platforms with horizontal vibrations have wedge-mounted forms. The forms should be placed symmetrically on the vibrating platforms, not exceeding its rated load capacity.
The domestic industry produces standardized vibrating platforms with an amplitude of 0.3-0.6 mm and a vibration frequency of up to 50 Hz (3000 counts/min), allowing the installation of forms up to 18 m long and up to 3.4 m wide.
Vibrating platforms with vertically directed vibrations type MS-476B are designed with a load capacity of 5 tons; SMZH-66 (6668/3B) m SMZH-64 (SM-858) - 8 t; SM-615KP, SMZh-65 (5917) and SMZh-187A - 10 tons; SMZH-67 (6691-1C), SMZH-181A and SMZH-200A - 15 tons; SMZh-68 (7151/1C) and SMZH199A - 24 t and SMZh-164 - 40 t. All vibrating platforms with vertically directed vibrations, with the exception of SM-476B, SM-615KP and SMZh-66 (6668/3B), which have a solid frame, designed from 8, 14 and 16 unified vibration blocks installed on two supporting lower frames (see figure below). Vibrating platforms with horizontally directed vibrations type SMZh-80 (7452) have a load capacity of 8 tons; SMZH-198 - 15 tons. SMZH-196 and SMZH-280 - 20 tons, and the Dubrovsky reinforced concrete plant - 50 tons.
Compaction on vibrating platforms in comparison with other methods (for example, vibrating cores) requires high initial costs and high energy consumption (due to additional costs for vibration of forms), but due to high productivity, minimal manual labor and good quality of compaction, it has become widespread in enterprises prefabricated reinforced concrete.
Equipment for compacting concrete mixture
In the manufacture of reinforced concrete products and structures, the concrete mixture is compacted by vibration, centrifugation, vibration stamping, vibration rolling and pressing. The choice of method for compacting the concrete mixture depends on the configuration, design and purpose of the reinforced concrete product and the adopted technology for its production.
In transport construction, mainly two methods are used to compact concrete mixtures: vibration using special vibration mechanisms (vibrators) and centrifugation, i.e. in special machines using centrifugal force.
Vibrators used to compact concrete mixtures are classified according to the type of drive and the method of transmitting vibrations of the concrete mixture. Depending on the type of drive, they are divided into electric, pneumatic and hydraulic. Electric vibrators are divided into electromagnetic and electromechanical.
According to the method of vibration transmission, surface, external, deep and machine vibrators are distinguished.
The source of vibration of any vibrator is a vibration mechanism, the design of which depends on the purpose of the vibrator. The most common are unbalanced, electromagnetic and pneumatic vibration mechanisms.
Unbalanced vibration mechanisms are produced in two types: the first type mechanism is a hollow body, inside of which the unbalance is mounted on two ball bearings. The unbalance rotates with a rigid or flexible shaft connected to the electric motor shaft. When the unbalance rotates, circular vibrations occur, transmitted through the bearings to the housing, and from it to the concrete mixture being compacted. The vibration frequency of the housing corresponds to the number of revolutions of the shaft on which the unbalance is installed. Such vibration mechanisms are used in deep vibrators.
Rice. 1. Schemes of vibration mechanisms
Rice. 2. Diagram of the pneumatic vibration mechanism
The second type of unbalance mechanism is a hollow housing, inside of which is an electric motor with one or two unbalances. When the electric motor shaft rotates, the unbalances create circular vibrations, which are transmitted through bearings to the vibrator housing or working platform (depending on the design of the vibrator). This is the operating principle of deep, surface, external and machine vibrators.
The electromagnetic vibration mechanism is an AC electromagnet mounted on the work site. The core of the electromagnet is rigidly fixed in the center of the working platform, and the armature is connected to the working platform of the electromagnet by means of lugs and bolts with springs. An alternating electric current, passing through the winding of a coil placed on a core, creates an electromagnetic field that causes periodic attraction of the armature and the core and their repulsion under the action of a spring. The frequency of the oscillations thus created depends on the frequency of the alternating current flowing through the winding of the core coil.
Such mechanisms are used in vibrating platforms, vibrating screens and feeders.
The pneumatic vibration mechanism is a cylinder, inside of which there is a piston that performs reciprocating movements under the influence of compressed air. Compressed air enters the cylinder through the distribution box alternately from the right and left sides of the piston through the inlet ports and bypass ports. The speed of movement of the piston, and therefore the oscillation frequency of the vibration mechanism, depends on the pressure of the compressed air entering the cylinder.
The planetary vibration mechanism has a ring in its housing. A runner attached to a rod rolls along the treadmill of this ring. The rod is rotated by the electric motor shaft through a hinge.
Rice. 3. Diagram of the electromagnetic vibration mechanism
Rice. 4. Diagram of the planetary vibration mechanism
The frequency of oscillations in planetary vibration mechanisms depends on the number of revolutions of the rod on which the runner is attached, as well as on the diameter of the runner and the treadmill.
Surface vibrators transmit vibrations of the concrete mixture with their working part, which is installed directly on the surface of the compacted layer. These vibrators are used in the construction of road surfaces, floors, etc.
An electromechanical surface vibrator consists of a metal trough and an unbalanced vibration mechanism bolted to the trough.
The vibration mechanism is mounted in the housing and is an asynchronous electric motor with two unbalances.
External vibrators are mounted on the formwork of a concrete product or structure and transmit vibrations of the concrete mixture through this formwork. Such vibrators are used for the construction of columns, vaults, pipes and other monolithic reinforced concrete structures, as well as for the production of large reinforced concrete products in molds. In addition, these vibrators are used to facilitate the unloading of materials from dump trucks and bins, the passage of materials along trays and through screens.
In an external pendulum-type vibrator, the stator of an asynchronous squirrel-cage electric motor of a special design is fixed in two elongated bearing shields, which act as pendulum arms. The lower ends of these shields are connected to the vibrator support plate using bearings and an axle. Sector unbalances are installed at the output ends of the electric motor rotor shaft. They are closed with covers bolted to the bearing shields.
Deep vibrators transmit vibrations of the concrete mixture with their body immersed in the mixture. These vibrators are used to compact large masses of concrete mixture during the construction of large structures made of monolithic concrete.
An internal vibrator with a flexible shaft and an unbalanced vibration mechanism consists of a closed-type electric motor with a gearbox, a flexible shaft and a vibrating tip, inside of which an unbalanced vibration mechanism is placed.
Electromechanical vibrators are produced with a power from 0.2 to 4 kW with an oscillation frequency of 6 thousand, 10 thousand and 20 thousand per minute and a driving force from 130 to 3000 kgf. In addition, there are pneumatic vibrators with a number of vibrations from 2 thousand to 18 thousand per minute.
Rice. 5. Surface vibrator
Rice. 6. External pendulum vibrator
Rice. 7. Vibrator with flexible shaft
The concrete mixture or solution is saturated with air during the process of mixing, transportation, distribution and laying in a form (formwork). To remove air from the mixture, various mechanical methods of compaction are used. The mixture, a few seconds after the start of mechanical action on it (compression-rolling, vibration, exposure to centrifugal forces or vacuum, etc.), turns from a gelatinous state into a heavy liquid, fills all parts of the molds, envelops the reinforcement, the surface of the concrete mixture takes a horizontal position , while air bubbles rise to the top. The duration of mechanical action on the mixture depends on its hardness and usually does not exceed several minutes. If the exposure is too long, the mixture separates - the coarse aggregate sinks to the bottom of the mold, the reinforcement frame moves, etc.
During the repair and construction of buildings, vibration and, less often, vacuum methods of compacting the concrete mixture are used. Vibration compaction is based on the communication of harmonic vibrations of the concrete mixture, as a result of which, due to the impact of alternating velocities and accelerations on the components, the bonds between the components are broken. With an increase in the amplitude and frequency of vibrations, the intensity of destruction of connections between components increases, and the productivity of the vibration compactor increases.
Based on the type of vibration exciters, vibration devices are divided into eccentric devices, in which vibrations are created due to the rotation of an unbalanced mass of the unbalance, and into machines, in which vibrations are created due to the reciprocating movement of a certain mass. Vibrating devices use compressed air, electromagnetic fields or a mechanism driven by an electric, hydraulic, pneumatic motor or internal combustion engine as the driving force.
According to the shape of vibrations, vibrators are divided into vibrators with circular and rectilinear vibrations.
By design, vibration devices are divided into surface, deep with remote or with a built-in motor. Some types of vibrators are used to transmit vibrations to various devices and systems and therefore they are attached to molds for the manufacture of products, to bins, skips, etc.
The surface vibrator is a trough-shaped shield 6 with handles for moving it along the surface of the product. A vibration element is attached to the shield, consisting of an electric motor, a rotor, at the ends of the shaft of which weights in the form of a semicircle or sector are installed.
The electric motor is powered by alternating current from a safe voltage network of 36 V, 50 Hz using a plug connector. Shaft rotation speed - 2800 min-1. Vibrator weight - 53 kg, overall dimensions 1.1X0.6X0.27 m, power - 0.6 kW, disturbing force - 40...80 kN.
Rice. 8. Surface vibrator
The unbalance consists of two plates, by rotating them on the shaft relative to each other, you can change the value of the unbalanced mass from zero to maximum. As the disturbing force increases, the compaction performance increases. However, at the same time, energy consumption increases, noise and the destructive effect on the metal structure of the installation increase.
Surface vibrators are widely used in floor construction for compacting and leveling concrete mixtures with a layer thickness of up to 0.15 m.
A type of surface vibrators are vibrating slats (vibrating bars), on which several vibrators are sometimes installed. With the help of vibrating laths, it is possible to level and compact the mixture when making concrete paths, driveways, floors, corridors, etc.
A deep vibrator (vibrating mace) with a built-in electric motor is shown in Fig. 9. During operation, these vibrators are immersed in the mass of concrete mixture. The domestic industry produces vibrators weighing 9, 15 and 22 kg with a vibration frequency of 183 s-1, a housing diameter of 50, 75 and 100 mm, a disturbing unbalance force of 2.5; 5.5 y\10 kN. The vibrator consists of a cylindrical body in which an electric motor and an unbalanced shaft are mounted. The body is connected to the control handle through a rubber coupling, which weakens the vibration transmitted to the worker’s hands.
Rice. 9. Deep electromechanical vibrators:
a, b - unbalanced vibrators with built-in electric drive; c - deep-well electromechanical vibrator with a flexible shaft; d, b - vibrating tips with unbalanced runners with internal and external running-in; 1 - vibration exciter; 2 - hose with cable; 3 - switch; 4 - handle; 5 - unbalance; 6 - bearings; 7 - electric motor; 8 - flexible shaft; 9 - vibrating tip; 10 - spindle; 11 - elastic coupling; 12 - unbalance slider; 13 - running surface
Internal vibrators with a flexible shaft are widely used in the manufacture of monolithic structures. They have a small diameter and weight of the working body, which allows them to be immersed in hard-to-reach places between reinforcement bars. The vibrator consists of an electric motor with a carrying handle and a switch, which is connected via a flexible shaft to the tip. Inside the tip there is a vibration exciter of a planetary type. The exciter is made in the form of a composite cylindrical body with a massive part at the bottom, machined at the end. A bearing assembly is screwed into the upper part, through which a flexible drive shaft passes. A runner in the form of a rod is attached to the end of this shaft through a rubber coupling, at the end of which there is a conical thickening.
Rice. 10. Trowels:
a - single-bottom with elastic suspension; b - double-disc with rigid suspension; 1 - trowel discs; 2 - gearbox; 3- electric motor; 4 - control handle with fitting and valve for water supply; 5 - output shafts of the planetary gearbox
Deep vibrators used on construction sites have a mass of 26...59 kg, a vibration exciter housing diameter of 28...76 mm, a vibration frequency of 334...175 s-1 and a disturbing force of 1.8. ..4.0 kN.
In recent years, construction sites have begun to use vacuum methods for compacting and dewatering concrete mixtures with a layer thickness of up to 0.15 m. The working equipment in this case is a vacuum beam, which is a hollow structure (dimensions 3.0 × 0.3 × 0.15 m ), connected via flexible pipelines (0.06 m in diameter) to a vacuum pump with a power of about 5 kW and giving 80% vacuum. The lower part of the beam has many small holes. As the beam moves along the concrete surface, air and excess water are sucked out of the concrete mixture. After vacuum treatment, the surface can be smoothed immediately. This method of compaction is highly productive and silent, but requires additional time to complete a number of preparatory work.
After compacting the concrete mixture and checking that its surface meets the required marks, smoothing of the surface begins. Various hand-held machines are used for smoothing (troweling).
A trowel with a textolite disk working body is shown in Fig. 10. The machine is designed for smoothing a layer of plaster or, in some cases, sand-cement mortar when processing concrete surfaces. Disk diameter 0.3 m, weight about 3 kg. The machine has a pneumatic rotary four-blade engine, a two-stage planetary gearbox and a working element. The machine components are mounted in an aluminum handle housing, the configuration of which makes the machine convenient for smoothing vertical surfaces. The machine has a wetting device in the form of a tube with holes for supplying water to the surface to be smoothed. In order to obtain the required surface quality, it is necessary to use fine-grained sand for the solution, and smoothing should begin after a certain period of time for the plastered surface.
For finishing operations, a machine is used that is also intended for plastering work. It has a working body in the form of concentrically located rings with a diameter of 0.22 m and a disk with rubbing surfaces made of wood, foam plastic, chipboard, felt or nylon. The working element is driven by a high-frequency motor, the shaft of which has a gear that meshes with the internal teeth of the ring drive gear and the disk drive gear. When the electric motor is turned on, the disk and ring rotate in different directions. The machine has a fitting for supplying water to the surface to be rubbed.
Rice. 11. Manual smoothing machine
Machines of the DZM-9B type (Fig. 11) are used for smoothing the surface of freshly laid concrete floors (driveways, paths) or various monolithic concrete structures. This machine contains a high-frequency electric motor with a squirrel-cage rotor, a disk working element, a two-stage gearbox, an articulated lever with a switch, a handle for transportation and a current-carrying cord with a plug connector. To smooth, press the stopper, lower the lever and pull the trigger. During the work process, in order to achieve the required smoothing quality, the machine is given circular and translational movements. Machine weight 8…15 kg. The peripheral speed of the disk is 8...10 m/s with a diameter of 0.4...0.6 m. The required level of smoothing for surfaces to be painted or wallpapered is 0.6...1.2 mm, for floor surfaces in common areas - 0.3...0.6 mm, for floors covered with linoleum - 1.2. ..2.5 mm.
Block vibration platforms
The vibration platform SMZh-200G with a lifting capacity of 15 tons with vertically directed vibrations for molding products with a plan size of no more than 3X6 m consists of eight identical vibration blocks (maximum load capacity 2 tons) with two-shaft unbalanced vibration exciters of vertically directed action and electromagnets arranged in two rows and interconnected cardan shafts.
Rice. 12. Concrete paver type 2.296
Rice. 13. Vibrating platform CSF -200G
The vibrating platform is driven by four electric motors. All four motor shafts rotate synchronously thanks to mechanical synchronizers. A metal casing is provided to reduce noise.
The two-shaft vibration exciter is a cast steel housing in which two parallel vibrators are installed. Spherical roller bearings are used as shaft supports. On each vibration exciter shaft there are two unbalances, each of which is a sector fixed to the shaft with an attached replaceable unbalance.
For the vibration exciter bearings of the vibrating platforms, liquid lubricant is used, which is poured into the vibration exciter housing to the level of the axis of the lower bearing rollers.
The elastic suspension of the vibrating block consists of four pairs of cylindrical springs and coupling bolts with which the vibrating block is attached to the support frame. Two beams located between the lower and upper pre-compressed suspension springs reliably fix the vibration block from lateral displacements.
The electromagnet serves to attract the mold (pallet) to the surface of the vibrating block, which is the supporting surface for the mold. The electromagnet is a massive steel body in which a coil of aluminum wire is embedded. The ends of the wire are brought out into the terminal box. Using lamellas and bolts, the electromagnet housing is attached to the vibration exciter housing. The electromagnet coil is powered by 110 V DC from a selenium rectifier. The gaps between the coil and the body are filled with bitumen. For normal fastening of the form to the vibrating platform during compaction of the concrete mixture, it is necessary that the holding force of the electromagnets exceeds the force of separation of the form, which arises from the dynamic forces acting on it.
The vibrating platform SMZh-187G has a similar design, differing in the number of vibrating blocks, the distance between them and the drive power. In addition, the vibrating platform SMZH -187G, unlike the vibrating platform SMZH -200G, has a one-way drive.
Along with block vibration platforms that have vertically directed harmonic vibrations, vibration platforms SMZH -538A, SMZH -773 and SMZH -774 with shock vibrations are produced.
The SMZh-538A vibration platform has four separate vibration blocks attached to a common frame through rubber elements, located transverse to the longitudinal axis of the form. The distance between the axes of the vibrating blocks is assumed to be the same as for the vibrating plates SMF -187G and SMD -200G-1700 mm.
Each vibrating block has two thick-sheet rubber pads on top, on which the mold rests. In the SMF -538 modification, IV-96 vibrators are used as a vibration drive, two for each vibration unit; in the modification SMZH -538A, the vibrators are replaced by two rows of unbalance shafts connected to each other by cardan shafts; Each row of shafts is driven by its own electric motor.
The vibrating platform SMZH -773 is configured according to the block vibrating platform SMZH -187G, has a one-way drive from two electric motors, mutual synchronization of the rotation of two rows of vibrating shafts, electromagnetic fastening of the forms and is distinguished by half the rotation speed of the drive motor and the design of the suspension of the vibrating blocks, which ensures the shock mode of vibration.
The vibration platform SMZH -774 consists of two vibration platforms installed along a common axis with four vibration blocks in the form of transverse tables with two vibrating shafts. Each vibrator has its own drive. Vibratory blocks rest on stationary frames through an elastic suspension system. The electric motors of the drives are located at opposite edges of the vibration platform. There is no mechanical synchronization or form fastening. The form is installed on supporting elements with rubber gaskets. The elastic suspension system of the blocks ensures shock operation. Oscillation frequency 25 Hz.
Frame vibration platforms
The most common frame vibration platforms are vibration platforms with multicomponent low-frequency vibrations excited by one or two adjustable vibration exciters with a vertical shaft, designed by EKB "Vibrotekhnika" of the Poltava Civil Engineering Institute. The movable frame rests on elastic rubber-metal supports mounted on a frame mounted on the foundation. An unbalanced vibration exciter with a vertical shaft is attached to the movable frame, driven into rotation by an asynchronous electric motor through a V-belt transmission. The engine is mounted on a sub-frame mounted on the foundation.
The fundamental feature of the vibrating platform is that the plane of action of the driving force of the debalance does not coincide with the center of mass of the moving parts of the vibration system of the vibrator. The displacement in height of the vibration exciter relative to the center of mass ensures, in the presence of elastic supports, the rigidity of which is different horizontally and vertically, the multicomponent nature of vibrations of the movable frame with elliptical trajectories.
The horizontal and vertical components of the amplitudes of vibration displacements of the points of the movable frame are interconnected, their required value is achieved by regulating the static moment of the vibration exciter, and the relationship between them is by installing the vibration exciter at a certain distance from the center of mass of the vibration platform in height.
To ensure normal compaction of the concrete mixture, vibration modes are used with a vibration frequency of 20 ... 25 Hz and amplitudes of vibration movements horizontally of 0.6 ... 1.0 mm and vertically of 0.35 ... 0.45 mm.
Currently, various configurations of vibrating platforms have been developed for the formation of certain types of reinforced concrete structures that differ in weight and size.
Two types of unified vibration exciters VU-10rs and VU-25rs are used in vibration platforms.
Depending on the purpose, vibration platforms are composed of one or two vibration exciters installed at the ends, sides or in the middle part of the frame.
For ease of calculation, a shockless vibration platform with vertically directed vibrations is reduced to a linear system with one degree of freedom. The required vibration frequency and vibration displacement amplitude ua are specified by technological requirements. The total amplitude of the driving force developed by all in-phase rotating weights is
Rice. 14. Frame vibration platform
Rice. 15. Vibration exciter
1 - drive pulley; 2 - body; 3 - housing cover; 4 - unbalance shaft; 5 - removable weight; 6 - unbalance; 7 - window cover for installing replaceable weights
Molding machines and installations
The SMZH-227B machine for molding floor panels consists of a carriage, a drive for void formers, right and left chain supports, a support with sprockets, electrical equipment and stops for the pallet.
The carriage is used to install void formers into the mold and remove them from it after molding the products. It is a portal-type structure, supported by four wheels and moving on rails.
The carriage movement drive consists of a motor, a brake, a gearbox, a drive sprocket, a gear coupling, a drive shaft with a sprocket and two drive chains, the ends of which are fixed to the carriage using special rods and pins. The drive is mounted on a frame mounted on the foundation.
Rice. 16. Molding machine SMF -227B
To support the chains, channel supports are installed on the foundation, on which limit switches are placed that limit the travel of the carriage.
Changing the machine to produce a product of a new standard size involves installing void formers of the appropriate size and moving the limit switch to the required distance, which limits the travel of the carriage when introducing void formers into the mold.
The SMZH-227B machine uses vibration-free void formers designed for the use of vibrating platforms.
In the SMZH-227 machine of previous modifications, vibrating void formers are used, which ensure deep compaction of rigid concrete mixtures and immediate removal of formwork without the use of vibrating platforms at the forming stations.
The vibration void former is a steel pipe with a diameter of 159 mm and a wall thickness of 6 mm, inside which three vibration groups are placed freely with a gap of 0.5 ... 1.5 mm, consisting of two supports with unbalance shafts mounted in bearings. The vibration groups are connected to each other by shafts with centering elements and elastic couplings.
The outermost connecting shaft is connected using a coupling to the drive shaft of the fixed carriage support, on which in this case the electric drives are mounted. Under the influence of the centrifugal force that occurs during the rotation of the unbalance shafts, the supports of the vibrating groups are pressed against the inner wall of the void former body, roll in and transmit vibrations to the body.
The cassette molding plant consists of a cassette and a machine for stripping and assembling the cassettes. The installation is intended for the production of panels of internal walls and ceilings used in large-panel housing construction. The machine for stripping and assembling cassettes consists of a frame, a hydraulic cylinder, a system of locking levers with shock absorbers, adjusting screws, hydraulic equipment and electrical equipment. The frame is formed by two (front and rear) racks, interconnected by support beams, on which cassette-shaped walls are installed with their rollers. The brackets for the hydraulic drive lever system, a hydraulic cylinder and limit switches are attached to the front frame strut.
Using rods, the lever system is connected to the locking levers. Adjustment screws are installed on the rear frame post to obtain the required thickness and correct position of the bag during assembly. Shock absorbers, pivotally connected to the lever system and adjusting screws, are welded to the outer surfaces of the stationary and removable cassette walls. The hydraulic cylinder and lever system move the walls by 850 mm. The control panel and electrical cabinet are mounted next to the cassette molding unit on the service platform.
Rice. 17. Molding plant
The cassette mold is a package of metal walls and thermal compartments, between which molding compartments are formed by on-board equipment. According to their design characteristics and purpose, walls can be divided into thermal, intermediate and extreme (stationary and removable). In the assembled form, thermal walls and intermediate walls alternate. The thermal wall, to which steam is supplied to heat the concrete mixture during heat treatment, is made of two metal sheets 24 mm thick and channels attached along the contour of the wall. The thermal wall must be sealed. The outermost thermal wall is equipped with a heat-insulating shield. The intermediate walls of the cassette form are made of 24 mm thick sheet.
All walls of the mold, except for the outermost removable one, are equipped with side equipment in accordance with the thickness of the molded products. On the cantilever sections of the intermediate walls, IV-104 electromechanical vibrators are mounted on brackets on both sides, designed to vibrate the walls during the process of filling the cassette mold with concrete mixture. The vibrators are installed so that their axis is parallel to the plane of the walls. Vibrations of the intermediate wall should be considered as forced vibrations of an elastic beam placed on two pivotally fixed supports and having two consoles to which a driving force is applied. The wall oscillation frequency of 1400 kol./min corresponds to the vibrator oscillation frequency. The most effective vibration is observed when the vibrator is installed on a console 65 ... 68 cm long. The amplitude of vibration of the intermediate walls is 0.08 ... 0.30 mm.
In the upper part, the cassette form is equipped with four protective visors that prevent spillage of the concrete mixture. Steam is supplied through the hoses to the thermal compartment walls from the distribution combs. The thermal compartments have perforated tubes through which steam enters the compartment. To drain condensate, a pipe with a tap is provided in the lower part of the heating compartment. Locks 8 are installed on the walls to secure them together. The lock bar in the upper part is connected to an eccentric, when rotated it rises or lowers and at the same time connects or separates the mold compartments.
Brackets are welded to the upper end of each cassette wall on the right and left for attaching roller supports 9, designed to move the cassette walls along the machine frame guides when disassembling and assembling the cassette.
The products are manufactured as follows. The compartment formed by the outermost stationary wall and the separating sheet is prepared for molding. After cleaning the surfaces and removing concrete residues, the embedded parts and opening-forming gels are installed and secured, and the surfaces of the sheets are lubricated.
The reinforcement cage is fed into the compartment and fixed in the required position. The entire wall package is moved by a hydraulic cylinder towards the stationary wall until it stops. Using locks, a dividing wall is attached to the stationary wall, freeing it from the rest of the package, which is pulled back by the same hydraulic cylinder, revealing the next compartment for cleaning, lubricating and sewing the reinforcement frame. Then the package is brought in by a hydraulic cylinder, the next wall is left, covering the second compartment prepared for concreting, and the package is moved back, revealing the third compartment, etc. until the last compartment. The last to be installed is the removable wall. The locking levers compress the entire package.
The design of the stripping machine provides two automatic bag locking mechanisms that protect the cassette from spontaneous opening during the processes of molding and heat treatment of products.
The first mechanism that performs the primary locking of the cassette package operates as follows. Due to the displacement (eccentricity) of the folding levers from the central hinge downward relative to the axes of their outer hinges, the horizontal force from the expansion of the cassette package keeps the levers from spontaneous folding (when the pumping station drive is turned off due to the presence of the above eccentricity between the axes of the locking levers).
The second mechanism performs secondary locking of the cassette package.
The form is prepared for concreting. After feeding, the concrete mixture is compacted. Next, steam is supplied to the thermal compartments of the mold and heat treatment is carried out in accordance with the adopted regime. The form is disassembled in the same way as assembly, but in reverse order. Products are removed from the compartments using a crane.
Installations SMZH -339A, SMZH -340A, SMZH -341A and SMZH -342, SMZH -800, SMZH -801, SMZH -802 and SMZH -803 are intended for the production of volumetric reinforced concrete blocks of sanitary-technical cabins of the “cap” type and consist from a vibrating table, pressing frame, liners, external board equipment, hydraulic equipment, electrical equipment and service platforms.
The vibrating table is the core of the molding unit and contains a vibrating frame, a support frame and a hydraulic drive. There are two hydraulic cylinders on the support frame, the rods of which are pivotally connected to double-arm levers connected by a common drive shaft and ensuring synchronous lifting and lowering of the pressing frame without distortions.
The internal cavities of the cabins are formed by liners, which are an all-welded structure, the frame of which is covered with steel sheets. To form the outer contour of the product, four sides are hingedly mounted on the pressing (lifting) frame. When lifting the frame, the sides diverge using rods 6. A similar device has an installation for the production of elevator tubing.
Rice. 18. Installation for molding sanitary and technical cabins
The side walls of the product are filled with concrete mixture and compacted with the vibrator drive of the vibrating table turned on. Upon completion of the molding of the side walls, the ceiling of the sanitary cabins is molded.
After laying and vibrating compaction of the concrete mixture, heat treatment of the molded products is carried out in the installation, while steam is supplied directly to the internal cavity of the thermal compartments.
In the SMF -800 ... 804 installations, a fan-shaped scheme is used for opening the sides and pressing out the cores and void formers downwards.
A molding installation (mold) for the production of pressure reinforced concrete pipes by vibration-hydropressing consists of an outer casing and an inner core with a rubber cover. The outer casing is a composite cylinder with a longitudinal split, assembled from two or four curved steel sheets. Stiffening ribs are welded to the casing. The casing parts are fastened together using flanges with bolts and springs. The joints of the form are sealed with adhesive tape. The inner core consists of two steel cylinders: solid and perforated, as well as a rubber boot placed on the perforated cylinder. An annular gap of 6 mm is provided between the outer and inner cylinders of the core, which is filled with water when pressing the concrete mixture. A rubber socket former and a steel sealing ring are put on the outer cylinder of the core.
Rice. 19. Installation for forming pressure reinforced concrete pipes with a diameter of 500 ... 1600 mm by vibro-hydropressing:
a - assembled form; b - cross-section of the form with concrete; 1 - position before crimping; 11 - position after crimping
A thrust socket ring is installed in the socket of the mold, and a thrust ring is installed at the sleeve end, and longitudinal reinforcement rods are passed through their holes, tying them with wire to the spiral frame. The bell ring is secured to the mold with clamps. The longitudinal rods are tensioned using a hydraulic jack, while they center the spiral frame relative to the walls of the form, providing the necessary protective layer of concrete. After tensioning the longitudinal reinforcement, the gaps between its rods and the walls of the holes in the thrust rings are covered with molding clay. The outer casing of the mold is installed on the core prepared in a vertical position using a crane. The assembled form is transferred to the concreting station, where a centering ring is installed in its sleeve end, and the loading cone with a vibrator is also secured with rubber bands. Several pneumatic vibrators are attached to the mold platforms, depending on the size of the pipe being concreted.
A vibrating platform can be used to compact the concrete mixture. In this case, the vibrators are not hung.
The concrete mixture is fed into the mold through a loading cone. While feeding the mixture, pneumatic vibrators (or a vibrating platform) are turned on and the mixture is compacted. After filling the mold with concrete mixture, the loading cone and centering ring are removed, and a sealing ring with a cross is installed in their place. The form filled with concrete is transferred by an overhead crane to the crimping station.
At the crimping station, the mold is fixed in a vertical position and connected through a pipe to the water supply. The set of equipment for hydraulic sealing includes a high-pressure unit, consisting of two cylinders with a volume of 410 liters each, two pumps - high and low pressure, a compressor, a low-pressure tank and four electrical contact pressure gauges.
The essence of the process is as follows. Water is supplied under pressure into the cavity between the solid and perforated cylinders of the mold core. Penetrating through the holes in the cylinder under the rubber boot, water expands it, producing pressure testing. In this case, as a result of the compression of the bolt spring, the outer casing of the mold opens. The resulting gap reaches 12 ... 15 mm. The expansion of the mold begins at a pressure of 0.25 ... 0.3 MPa. The freshly laid concrete mixture follows the deformations of the form, pulls along the turns of the reinforcement cage and causes tensile stresses in them, thereby straining the reinforcement.
The pressure created under the rubber boot depends on the purpose of the pipes and their diameter. For pipes designed to operate at a liquid pressure of 1.0 ... 1.2 MPa, this pressure reaches 2.9 ... 3.4 MPa.
The subsequent heat treatment of the pipes, which is carried out by releasing live steam into the cavity of the inner part of the mold through a distribution ring in the lower part of the mold and under the steaming cover while maintaining a given pressing pressure, fixes the position of the reinforcement in a stretched state until the concrete acquires high strength (30.0 ... 35.0 MPa). Steaming. The cover consists of a canvas cover and a frame with a loop for connection to the overhead crane hook. After the end of the heat treatment, the steaming cover is raised, the pressure is reduced to zero and water is removed from the inside of the mold.
The mold, detached from the base, is transferred by crane to the assembly pit, where the ring with the cross is removed. A vacuum system is connected to the inside of the mold, which removes remaining water from the inner container of the mold.
Molding machines SMZH -194B and SMZH -329 for the production of concrete free-flow pipes with a diameter of 300 ... 600 mm and 800 ... 1200 mm using the radial pressing method are used in technological semi-conveyor lines.
The SMZH -194B, SMZH -329 machines consist of a traverse with a rotation mechanism, a funnel, a bell-forming mechanism, a bed with service platforms, a rotary table with a rotation drive, hydraulic cylinders, a hydraulic drive with a feeder pumping station, a feeder drive, a table clamp, a hopper, and a lifting mechanism and fixing funnels, molds and electrical equipment.
Two vertical guides are fixed to the frame, along which, with the help of plunger hydraulic cylinders, a traverse with a mechanism for rotating the roller head is raised and lowered. The traverse is a welded body; a flange motor is installed on it, the torque from which is transmitted through a gearbox to the drive shaft. To measure the shaft rotation speed, the gearbox has four pairs of replaceable gears.
The drive shaft rotates in a housing mounted on a traverse. A roller head is attached to the lower end of the shaft.
The bell-forming mechanism is installed under the rotary table on a support frame on the same vertical axis with the traverse drive shaft and moves vertically using a hydraulic cylinder along two guides fixed to the frame. A motor is installed on the mechanism body, the torque from which is transmitted through helical gear and worm gears to the vertical drive shaft.
The mold, located on the rotary table diametrically opposite to the vertical axis of the machine, is rotated on the table by 180° and installed on the vertical axis of the machine. The operator turns on the hydraulic cylinder, and the traverse, which is in the upper position, moves down. Together with the traverse, the loading hopper is lowered until the skirt of the roller head is flush with the upper surface of the pallet. Then the operator turns on the rotation drive of the socket forming mechanism with its simultaneous lifting, and the vibrators begin to work. Rotation and vibration are transmitted to the pallet. The rotation drive of the roller head is turned on, and the concrete mixture is fed from the feeder into the mold. After the socket is formed, the rotating roller head rises upward, compacting the supplied concrete mixture. After the head leaves the mold, the loading funnel rises and the mold unlocks. By turning the carousel, the mold with the product is fed to the post for removing it from the machine.
The SMZH-542 machine is designed for the production of reinforced concrete manhole rings for water supply and sewerage networks with a diameter of 700, 1000 and 1500 mm. It consists of a rotation mechanism, funnel, hopper, feeder, carousel, frame, hydraulic cylinder, pumping station, electrical equipment and equipment sets.
Rice. 20. Machine for making non-pressure pipes
The rotation mechanism consists of a three-speed four-stage gearbox, a main shaft and a roller head with three rotation speeds.
Rice. 21. Centrifuge for molding racks of lighting poles and contact networks
The rotation speed of the roller head is adjusted depending on the molding modes and the diameter of the product.
The funnel ensures the formation of the upper end of the product and the reception of excess concrete mixture after completion of molding. When the head leaves the mold, its rotation and lifting stop. The funnel rises, and the mold with the product is fed to the mold removal station by turning the carousel.
The SMZH-169B centrifuge is designed for molding racks of lighting poles and contact networks up to 15.5 m long and consists of a support frame, drive rollers, support rollers, an electric drive and a fence.
The support frame is used to install the rollers. The rollers with axes rotate in bearings installed in detachable housings, which allows them to be repaired without disrupting the regulation of the roller supports. The base of the supporting rollers can be changed, which allows you to work with forms with a bandage diameter of 490 ... 800 mm. The drive rollers of all supports are connected to each other by gear couplings and shafts. The design of gear couplings allows shaft misalignment, which should be minimal to maintain shape, reduce noise and ensure normal gear operation.
To ensure safe operation of the centrifuge and prevent the mold from swinging vertically, all supports are equipped with safety levers with rollers.
The shafts of the two extreme spans of the centrifuge are connected through gear couplings to the drive shaft carrying the pulley. The centrifuge is driven by two engines through a two-stage belt drive.
Working on a centrifuge begins with setting up the mold. Then the lever turns the rollers of the safety device and fixes it. The operator at the control panel turns on the drive motors.
At the same time, a software time relay is turned on, controlling the time required to manufacture the product. The transition of the centrifuge from the rotation speed at which the concrete mixture is distributed to the rotation speed at which the mixture is compacted is carried out using speed controllers.
When the mold stops rotating, the safety rollers are moved away from it, the guard is moved back, and the mold with the product is transferred to heat treatment by an overhead crane.
When compacting a concrete mixture, it is necessary to create conditions under which the particles of the mixture can take the most stable position relative to each other, precluding their further movement even in an unhardened state.
The strength of concrete is determined by the strength of the aggregates (crushed stone, gravel, sand), as well as the binder (cement), which should be as close as possible to the strength of the aggregates. Currently, the strength of binders is still significantly lower than the strength of aggregates used for the manufacture of reinforced concrete products, especially high grades.
The most durable concrete will be one in which large and small particles of filler will occupy almost the entire volume of the product, leaving only thin layers and tiny spaces between the densely packed filler particles that bind them into a single whole for the cement paste (and after hardening, according to the cement stone). To obtain such concrete, it is necessary to correctly select the composition of the concrete mixture and compact it efficiently.
Electromechanical manual deep vibrators are manufactured with a remote electric motor with a flexible shaft connecting the electric motor to a working vibrating tip, or with an electric motor built directly into the vibrator body.
During operation, the vibrating tip of a deep-seated manual vibrator is lowered into the layer of concrete mixture to a depth not exceeding the length of the working part, and as the mixture is compacted, it is rearranged in steps not exceeding 1.5 times the radius of action of the vibrator.
Manual internal vibrators with flexible shaft
Deep vibrators with a flexible shaft are designed for compacting concrete mixtures with a cone draft of 3-5 cm when laying them in thin-walled monolithic structures, as well as densely reinforced masses. The distance between the reinforcement bars must be at least 1.5 times the diameter of the vibrating tip.
Vibrators are equipped with an electric motor, a flexible shaft and two replaceable vibrating tips of the same standard size (the IV-47 vibrator is equipped with two flexible shafts).
At the top of the electric motor there is a packet switch PV2-25. The electric motor is installed on a base that ensures its stable position on a horizontal surface.
The torque from the electric motor shaft is transmitted to the vibrating tip spindle through the flexible shaft using a claw coupling, which allows only right rotation, corresponding to the winding of the flexible shaft.
Internal vibrators with a flexible shaft have a planetary type vibration mechanism.
Vibrators IV-17, IV-27, IV-67, IV-66 and IV-75 have runners with external running, and vibrator IV-47 has a runner with internal running.
Otherwise, the design of the vibrating tips of the vibrators is similar. Each of them is a hermetically sealed housing, inside of which there is an unbalance connected to the vibrating tip spindle by an elastic rubber-metal coupling.
When the unbalances are rolled along the bushing or core, vibration vibrations of the tips occur.
All external connections of the vibrating tip housings, as well as connections of the flexible shaft with the electric motor and the vibrating tip, have a left-hand thread.
The output power of the transformer must be at least 1 kVA for vibrators IV-17 and IV-27, and at least 1.5 kVA for vibrators IV-47.
The voltage at the electric motor terminals when the vibrating tip is operating in concrete should not be lower than 34V. When the voltage drops below 34V, increase the cable cross-section or shorten its length; If after this the voltage does not increase, it is necessary to increase the power of the transformer.
Manual deep-well vibrators with a built-in electric motor with a distance between the reinforcement rods of at least 1.5 times the outer diameter of the vibrator body.
Deep vibrators with a built-in electric motor are designed for compacting concrete mixtures with a cone draft of 1-5 cm when laying them in monolithic concrete and reinforced concrete structures.
Rice. 22. Deep vibrator IV-59
1 - body; 2 - bearings; 3 - unbalance; 4 - unbalance shaft; 5 - inclined channel of the unbalance shaft for lifting liquid lubricant; 6 - radial hole; 7 - stator; 8 - rotor; 9 - lower handle; 10 - shock absorber; 11 - rod; 12 - packet switch; 13 - upper handle; 14 - liquid lubricant
Manual deep vibrators with a built-in electric motor IV-55, IV-56, IV-59 and IV-60 are similar in design. Their working parts are a hermetically sealed cylindrical housing, inside of which electric motors and an unbalanced oscillation exciter are built.
The vibrators are equipped with a three-phase asynchronous electric motor with a squirrel-cage rotor.
During operation, vibrators IV-55 and IV-56 are held by a rubber-fabric sleeve that absorbs vibrations, one end of which is connected to the body of the vibrating tip, and the other to a sealed box in which the PVZ-25 packet switch is mounted.
For convenience of working with vibrators IV-59 and IV-60, a pipe is welded to the upper part of their body, which is the lower part of the rod, to which the upper part of the rod with a handle and a sealed box is attached using a shock absorber. A package switch PVZ-25 is mounted in the rod box. The shock absorber serves to dampen vibrations on the upper handle.
To power the electric motors of the IV-55 and IV-56 vibrators, frequency converters S-572A, I-75V, as well as a static frequency converter PChS-4-200-36, are recommended respectively.
To power the electric motors of the IV-59 and IV-60 vibrators, it is recommended to use frequency converters I-75V and ChS-7 with a step-down transformer TSPK-20A, as well as static frequency converters PChS-4-200-36 and PChS-10-200-36 with power respectively 4 and YukVa, frequency 200Hz and voltage 36V.-
The cross-section of the current-carrying core of the supply cable of vibrators IV-55, IV-56, IV-59 and IV-60 should be 1.5, respectively; 2.5; 4 and 6 mm2.
If the voltage at the vibrator switch terminals drops below 32 V, it is necessary to stop operating the vibrator and provide a voltage of 36 V by reducing the cable length, increasing the cross-section of the power cable cores or increasing the power of the frequency converter.
The length of the power cable should not exceed 5-10 m.
When operating with several vibrators from one frequency converter, the vibrators should be switched on one at a time with a delay that ensures full start-up of the vibrator motor.
You only need to remove the vibrator from the concrete mixture when the electric motor is turned on. During operation, the vibrator body should be completely immersed in the concrete mixture.
Operating the vibrator in air and with the working part not completely immersed in the concrete mixture will lead to
to the rapid destruction of winding insulation, since the electric motor is designed to operate with intensive cooling with a concrete mixture.
During operation, it is not allowed to turn off the vibrator immersed in the concrete mixture, clamp it between reinforcing bars, or press it against the formwork.
Manual pneumatic deep vibrators
Pneumatic deep vibrators S-697, S-698, S-699, S-700 and S-923 are similar in design and are a hermetically sealed cylindrical housing, inside of which a planetary pneumatic motor-vibration exciter is enclosed.
Rice. 23. Deep pneumatic vibrator S-699
1 - body; 2- nut; 3 - outer hose; internal hose; 5 - slider; 6 - hollow axis; 7 - blade; 8 - end shields with exhaust holes, 9 - tap; 10 - union nut; 11 - nipple; 12 - working chamber; 13 - exhaust chamber
The stator of the pneumatic motor in the form of a hollow axis with one blade stands motionless, and the rotor rolls planetarily around the stator, acting as an unbalance runner.
The blade divides the cavity enclosed between the runner and the axle into two chambers: working and exhaust. The runner is driven by compressed air entering the working chamber of the air motor through an internal flexible hose through a central hole drilled in the axis. Pressed against the axis under the action of centrifugal force, the runner rolls around it with a frequency depending on the air pressure in the network. The exhaust air enters the exhaust chamber and from there through the side openings in the shields through the outer rubber-fabric hose to the exhaust.
The center of gravity of the slider is shifted relative to the axis era of the internal hole, due to which the vibrator creates two-frequency vibrations.
The S-700 vibrator has handles to perceive the reactive torque and create greater ease of use.
The S-923 vibrator, instead of an external rubber-fabric hose, is equipped with a rigid rod with two handles: upper and lower. The rod consists of two parts connected to each other by a rubber shock absorber.
The vibrators are started and turned off using a tap or a special starting device.
For normal operation of internal pneumatic vibrators, you should use a hose with an internal diameter of at least 16 mm and a length of no more than 8-10 m. When increasing the length of the hose, it is necessary to increase its cross-section accordingly.
The pressure in the compressed air network must be at least 0.4 MPa.
During operation, do not allow tension or sharp bends in the hose.
When working in winter conditions at subzero temperatures, it is necessary to ensure that the compressed air is thoroughly cleaned of moisture to avoid freezing of condensate and the formation of ice plugs.
The rules for working with electromechanical vibrators when compacting concrete mixtures apply equally to pneumatic vibrators.
Suspended deep vibrators
Suspended deep-well vibrators are used both in single versions and in the form of vibration packages consisting of several vibrators.
Vibrators IV-34 (S-827) and S-649 have a planetary type vibration exciter with internal running of the runner. The electric motor of the S-827 vibrator is remote, and the S-649 vibrator is built into the housing. The vibrators are equipped with three-phase asynchronous motors with a squirrel-cage rotor.
The vibrators are united by a common frame; Each vibrator is fastened to the frame with clamps through rubber shock-absorbing pads.
The sliding frame allows you to change the distance between the vibrators.
Rice. 24. Suspended deep vibrator IV-34 (S-827)
1 - core; 2 - slider; 3 - vibrator body; 4 - rubber-metal articulated coupling; 5 - spindle; 6 - shock absorber; 7 - electric motor
Rice. 25. Pack of four vibrators S-649
1 - frame; 2 - clamp; 3 - terminal box; 4 - chain suspension; 5 - vibrators
The electric motors of the vibrators are powered from the mains through a bus box mounted on the frame.
The vibration package is suspended on the hook of a crane or other lifting device using a chain suspension.
To compact the concrete mixture, vibrators are used with a vibration frequency (usually 3000, but sometimes 15,000 per minute) and a vibration amplitude from 0.1 to 3 mm. There are surface, deep (internal), external and machine vibrators.
The basis of vibrators are vibration elements (vibration exciters): electromechanical, electromagnetic and pneumatic.
Electromechanical vibration elements can be single-shaft, double-shaft, pendulum and planetary. In a single-shaft element, counterweights (unbalances) are attached to the electric motor shaft, the rotation of which leads to vibration. The operating voltage of the element is 36 V.
The electromagnetic vibration element consists of a base with a core and an electromagnetic coil, an armature and springs. A selenium rectifier is connected to the power circuit of the electromagnetic coil, which converts alternating current into direct pulsating current. Under the influence of electromagnetic forces, the armature is attracted to the core 50 times per second. Accelerated release of the anchor is ensured by springs.
Pneumatic vibration elements are divided into piston and planetary elements. In the piston element, vibrations occur as a result of the reciprocating movement of the piston inside the housing. Compressed air enters the left side of the cylinder through the pipeline, inlet port, bypass port and moves the piston to the right. Air from the right cylinder cavity exits through the exhaust port. Having passed the middle position, the piston closes the channels and opens the channels. At the same time, compressed air begins to flow into the right cavity of the cylinder and moves the piston to the left. By adjusting the pressure in the supply pipeline, the oscillation frequency of the piston changes.
Rice. 26. Vibrating elements
a - electromechanical; b - electromagnetic; c - pneumatic piston; g - pneumatic planetary
The pneumatic planetary vibration element consists of a housing, in the end walls of which a fixed axis with a textolite blade and a rotating rotor-unbalance are fixed. The blade divides the chamber into a working and exhaust cavity. Compressed air enters the working cavity through longitudinal and radial drillings in the axis, then into the exhaust and through holes in the side walls to the exhaust.
Surface vibrators are installed directly on the concrete mixture to be compacted and moved manually during work. Such a vibrator consists of a vibration element (electromechanical or electromagnetic) mounted on a steel trough-shaped plate, a wooden platform or an I-beam (vibrating lath). The vibration frequency of the vibrator is 2800-2850 per minute.
Rice. 27. Surface vibrators
a - vibration platform; b - vpbroraika
Deep vibrators (immersed in the concrete mixture) include a vibrator with a flexible shaft and a vibrator with a built-in vibrator motor. To compact the concrete mixture in large, weakly reinforced masses, package deep vibrators are used, composed of 8-16 vibrators.
The vibrating mace shown in Fig. 28, a, consists of a steel closed housing, inside of which a shaft is placed in bearings. A counterweight (unbalance) is installed on the middle part of the shaft, and an electric motor rotor is installed on the cantilever part. The stator is mounted in a vibrator housing, which is attached to a rod with a handle and a switch. The vibrator has a working part diameter of 114 and 133 mm. The number of vibrations is 5700 per minute.
Rice. 28. Deep vibrators
a - vibrating mace; b - with a flexible shaft; c - with planetary vibration element
Vibrators with a flexible shaft are used for concreting densely reinforced structures. From the electric motor (motor head), a gear transmission transmits rotation to a flexible shaft protected by armor. A replaceable vibrating tip is screwed into the threaded bushing, which is an eccentric shaft mounted in ball bearings. The vibrator is turned on by turning the handle of the electric motor switch. The number of vibrations is 6700 and 10,000 per minute, the diameter of the vibrating tip is 51 and 76 mm.
A vibrator with a remote motor and a planetary vibration element with internal unbalance rolling is shown in Fig. 28, b. Rotation from the engine shaft is transmitted to a vertical shaft with couplings 16, allowing the lower part of the shaft 17 to deviate from the geometric axis by an angle of up to 5°.
In addition to high-frequency oscillations in planetary vibrators, oscillations occur with a frequency equal to the number of revolutions of the electric motor shaft of 3000 per minute.
