RU42251U1 - VIBRATION AREA - Google Patents

Abstract

Vibration platform, consisting of a support frame, vibration blocks, synchronizers, driveshafts, electric motors, characterized in that the intersection synchronizer is equipped with a phase setting mechanism, operating on the command of a vibration field uniformity measuring device, calculated as a result of processing information about movements and accelerations at given points of the reference frame obtained from sensors mounted on a support frame.

Description

The device relates to mechanical engineering and is intended to provide a uniform vibration field in technological processes.

Currently, most reinforced concrete structures are manufactured by vibration compaction of concrete mixtures. The most characteristic equipment for compaction of concrete are vibratory platforms.

With all the variety of types of vibrating machines, each of them consists of three main elements:

working body, drive (vibration exciter) and elastic ties. The most widespread are eccentric, pneumatic, hydraulic types of drives (vibration exciters).

In eccentric vibration exciters [1], the rotational motion of the shaft is converted into oscillatory motion using a connecting rod connected to the working body of the vibrator. Such drives are used in low-frequency resonant vibration machines operating with a frequency of up to 25 Hz.

With a large number of oscillations, these drives, as a rule, are not used, since the force acting on the bearings increases significantly.

Inertial vibration exciters [2] are the most common type of vibrator drive. In them, a coercive force is created due to the rotation of one or more unbalanced masses - unbalances.

They are divided into vibration exciters with a built-in and external electric motor.

Inertial vibration exciters with small dimensions and mass of the drive provide significant forced forces.

At the same time, their use in low-frequency vibratory machines is irrational, since the mass of unbalance increases significantly, and at frequencies above 25 Hz the mass of unbalance increases significantly and the load on the bearings sharply increases.

For high-frequency vibration machines operating at small amplitudes of vibration, the most acceptable are electromagnetic vibration exciters [3].

In them, the necessary reciprocating movement is obtained without any intermediate mechanisms. They easily provide smooth adjustment of driving force. However, despite the noted advantages, the scope of their application due to

vibration mode (high frequency - small amplitude) is limited. In addition, they have a large mass, are difficult to adjust and require increased accuracy of installation work.

Pneumatic vibration exciters [4] as well as electromagnetic exciters are expediently used for high-frequency vibrating machines if their explosion safety is required. Hydraulic vibration exciters [5, p. 14] allow you to create driving forces at large amplitudes and at the same time have a simple adjustment of the operating mode. The disadvantages include the complexity of the design, heating and leakage of the working fluid.

A device is also known for compacting concrete in a sliding formwork [6].

The invention relates to the construction of monolithic reinforced concrete buildings and structures.

The device comprises jack frames with formwork shields equipped with piezoceramic concrete compaction emitters, an ultrasonic vibrations generator, a thyristor switching device and a microcontroller for control.

Piezoceramic emitters are connected to the ultrasonic oscillation generator through a thyristor switching device, the control input of which is connected to the output of the control microcontroller.

The closest solution is a vibrator, presented in [5, p. 348] (prototype).

Vibration platform - the prototype is designed for forming the outer wall panels of residential buildings.

The design of this type of vibration platform includes a support frame, vibration blocks with electromagnets, a synchronizer, drives with electric motors, cardan shafts. The molding process consists in laying the concrete mixture in special forms, distributing and compacting the mixture. The main parameters of vibration are the frequency and amplitude of the vibration. When calculating the processes of vibrational compaction, in addition to the amplitude and frequency of vibrations, the values of maximum speed, acceleration, and vibration intensity are also taken into account.

The operating experience of the indicated type showed that the form is filled unevenly in height, since the mass of the concrete mix varies with different loading, as well as due to changes in the design parameters of the vibrating platform over time.

The results of the study of existing devices (including the prototype device) showed that the uniformity of the vibration field on the vibration tables is small, the homogeneity coefficient is 41%.

Therefore, each product had to vibrate for at least 10 minutes.

The purpose of this device is to ensure a uniform vibratory field over the entire area of the vibrating platform, thereby ensuring a high degree of compaction of the concrete mix, exact conformity of the shape and size of the product to the design, good quality of the resulting surface, requiring no additional processing.

The goal is achieved by the fact that the intersection synchronizer is equipped with a phase setting mechanism, which operates on the command of a vibration field uniformity measuring device. The team is designed as a result of processing information about movements and accelerations at given points of the support frame received from the sensors.

The device is illustrated by drawings in figure 1, which shows in plan a general diagram of the proposed vibratory platform.

The device contains electric motors 1, sectional synchronizers 2, intersectional synchronizer 3, vibration blocks 4, cardan shafts 5, a support frame 6 on which the concrete form 7 is mounted, a phase 8 installation mechanism, including a system of sensors 9 of vibration measuring equipment connected to the device 10 for measuring the uniformity of the vibration field.

The vibrating platform works as follows.

Form 7 is installed on the supporting frame 6, then the concrete mixture is poured. After that, the electric motors 1 are turned on, and through the cardan shafts 5 and synchronizers 2 and 3, the vibration blocks 4 begin to work, subjecting the concrete mixture to vibration. If the concrete mixture is filled unevenly in form 7, the sensors 9 will transmit information about the movement and acceleration at predetermined points of the support frame to the device 10 for measuring the uniformity of the vibration field. It compares the vertical displacements and accelerations of the support frame 6 and calculates the phase angle, which should ensure uniformity of the vibration field.

Using the installation mechanism of phase 8, form 7 occupies a position that allows you to create a uniform vibration field.

To verify the operation of the installation, studies were made of the uniformity of the vibration field of the active vibrating tables at the precast concrete plant.

As experiments showed, the use of the proposed device allowed to reduce the vibration time by half.

List of references:

1. Spivakovsky O.A., Goncharevich I.F. Vibration Conveyors, Feeders and Accessories. - M.: Mechanical Engineering, 1972.-327 p.

2. Vibration machines in the construction and production of building materials. Handbook / Ed. V.A. Bauman et al. - M.: Mechanical Engineering, 1978.-548 p.

3. Goncharevich I.F., Strelnikov L.P. Electrovibration transport equipment. - M.: Gosgortekhizdat, 1959.-261 p.

4. Hertz EF Pneumatic drives. - M.: Mechanical Engineering, 1969.-360 p.

5. Gozbenko V.E., Control of dynamic properties of mechanical oscillatory systems. - Irkutsk: Publishing House of Irkutsk University, 2000.-412 p.

6. RF patent №21713 43. IPC E 04 G 21 / О “Device for compaction of concrete mix in sliding formwork” authors Bulgakov AG, Parshin OD, Bok T.O.

Claims (1)

Vibration platform, consisting of a support frame, vibration blocks, synchronizers, driveshafts, electric motors, characterized in that the intersection synchronizer is equipped with a phase setting mechanism, operating on the command of a vibration field uniformity measuring device, calculated as a result of processing information about movements and accelerations at given points of the reference frame obtained from sensors mounted on a support frame.