RU1775293C - Vibration platform for moulding of articles out of concrete mixes - Google Patents

Abstract

Usage: in the production of concrete and reinforced concrete. SUMMARY OF THE INVENTION: comprises movable frames mounted on the base by means of elastic stops and arranged in parallel with elastic elements on which the form is supported, vibrators connected to each other by connecting shafts, and a drive. Connecting devices are placed between the vibrators and the shafts. Each of them is made in the form of a hollow conical body, the smaller base of which is rigidly mounted on the vibrator shaft, and the larger - on the connecting shaft. In this case, the side surface of the housing is made split along its generatrix, the larger base is elastic and attached to the flange of the connecting shaft by means of a pressure disk from the cavity side. 3 ill. • W ^

Description

The invention relates to devices for vibration compaction of materials and can be used in the manufacture of concrete and reinforced concrete products.

The closest technical solution is a vibratory platform for molding concrete products, comprising movable frames mounted on the base by means of elastic supports and parallelly mounted with elastic elements, on which the form is supported, vibrators connected to each other by connecting shafts, and a drive.

The disadvantage of this device is the low efficiency of compaction of concrete mixtures,

The purpose of the invention is the intensification of the process of compaction of concrete mixture.

The goal is achieved. that a vibrating platform for molding products from concrete mixtures, comprising movable frames mounted on the base by means of elastic supports and parallelly mounted with elastic elements, on which the form is supported, vibrators connected between each other by connecting shafts, and a drive provided with vibrators and shafts located connecting devices, each of them is made in the form of a hollow conical body, the smaller base of which is rigidly fixed to the vibrator shaft, and the larger - on the connecting shaft, with the side The surface of the housing is made split along its generatrix, the larger base is elastic and attached to the flange of the connecting shaft by means of a clamping disk from the side of the cavity, and the thickness of the elastic osnop .li-; constitutes

D

where Mkr is the maximum torque on the shaft;

DB is the diameter of the shaft flange;

 permissible tangential shear stress of the elastic base,

In FIG. 1 shows the proposed device, a General view; figure 2 is a view of figure 1; in Fig.3 - view B in Fig.1,

The vibrating platform contains vibration blocks 3 mounted on the base 1 by means of elastic supports 2 and placed in parallel. Each of them includes a movable frame 4 with elastic elements 5. on which the mold is supported, and a vibrator 6, The vibrators 6 of the vibration blocks 3 are interconnected by connecting shafts 7 with a drive 8. Between the shafts 7 and the vibrator are placed connecting devices. Each of them is made in the form of a hollow conical body 9. The smaller base 10 of the housing 9 is rigidly fixed to the shaft of the vibrator 6, and the larger base 11 is fixed to the flange 12 of the connecting shaft 7 by means of the pressure disk 13. The larger base 11 is made elastic. its thickness is

l-M

l 2 - ;;

where A is the thickness of the elastic base;

MKR is the maximum torque on the shaft;

Dfl is the diameter of the shaft flange;

t is the permissible tangential shear stress of the elastic base.

The lateral surface of the hollow conical body 9 is made split along its generatrix and forms several, but not less than three, rays 14,

When choosing and calculating connecting shafts, it is necessary:

steel is taken as the material, since when 10 shaft-cycles are reached, the fatigue limit for steel is constant, which subsequently tauts the shaft operation without breakage. For shafts made of aluminum alloys, fiberglass, etc. the fatigue limit decreases after 10 cycles, which can lead to breakage;

use only light thin-walled pipes with a ratio of inner diameter d to outer D equal to about 0.9, as this reduces the inertial and dynamic loads from unbalance during installation and increases the service life of the bearings of the vibration exciter;

to eliminate harmful bending vibrations of steel connecting pipes, which can reduce the amplitude of vibrations of vibration blocks, and therefore the intensity of the vibration process of compaction of hard concrete, it is necessary to limit the maximum (critical) length L to

the formula

,5

where D is the outer diameter of the connecting shaft, cm;

p - the number of revolutions of the connecting shaft, min

The vibrating platform works as follows

way.

On the elastic members 5, e.g. resilient pads, a mold is freely set and filled with hard concrete. After turning on the electric motor 8, the torque is transmitted to the connecting shafts 7 in the form of a thin-walled tube of subcritical length L, which excludes their bending vibrations, which through the conical hollow body 9 synchronously rotate the unbalanced shafts of the vibrators b. Since there is no phase shift of the oscillations between the vibration blocks 3 due to the correctly calculated stiffness of the large base 11, determined by the thickness D, the disturbing force of all

vibration blocks 3 are simultaneously transferred to the mold with concrete, which intensifies the process of compaction of rigid mixtures, any horizontal vibrations of vibration blocks (due to deviation of verticality of shock absorbers during installation, start-up and run-out with products with different masses along the cantilever part of punches, etc.) are compensated by the elasticity of the large base 11 and increase the service life, and hence the reliability.

After compaction of the hard concrete with a given vibration intensity by synchronously operating vibration blocks, the mold is removed and fed to the steaming station.

Claims (1)

The technical and economic advantages of the proposed vibration platform are to increase the intensification of the process of compaction of rigid concrete mixtures due to synchronous and common-mode vibration excitation of the mold with concrete from all vibration units and the elimination of harmful resonant vibrations of the connecting shafts, which reduce the vibration amplitude of the vibration blocks; increasing the strength of the parts connecting the vibratory unit and the connecting shaft in the form of a thin-walled pipe by elasticizing the large base of the body, flexible in all directions and reducing dynamic loads; the use of a thin-walled tube of limited length as a connecting shaft also reduces inertial and imbalanced loads, which increases the service life of the bearings of the vibration units; simplicity of design, which does not have traditionally breaking cardan shafts, shafts of several rows, synchronizers, fewer electric motors. SUMMARY OF THE INVENTION A vibrating platform for molding articles of concrete mixtures comprising movable frames mounted on the base by means of elastic supports and parallel with elastic elements, on which the form is supported, vibrators connected to each other by connecting shafts, and a drive, characterized in that , in order to intensify the process of compaction of the concrete mixture, it is equipped with connecting devices placed between the vibrators and shafts, each of them is made in the form of a hollow conical body, smaller which is rigidly fixed on the vibrator shaft, and the larger one on the connecting shaft, while the side surface of the housing is made split along its generatrix, the larger base is elastic and attached to the flange of the connecting shaft through the pressure disk from the cavity side, and the thickness of the elastic base is where MKR is the maximum torque on the shaft; DB is the diameter of the shaft flange; d is the permissible tangential shear stress of the elastic base. 4l