SU1322105A1 - Bench for performing impact testing - Google Patents

Abstract

The invention relates to a test apparatus, in particular to test benches. The aim of the invention is to increase the accuracy of reproduction of shock pulses with a steep falling edge. The goal is achieved due to the fact that in the stand containing a cylinder with a piston and a pneumatic actuator to disperse the piston with the product under test, an additional piston is inserted, which, after a given acceleration of the main piston is connected to it, and closes the power circuit, provides a sharp cessation of acceleration. The stand contains a cylinder 1 with a piston 2 installed in it, which is used to fasten the test product 3, a latch 4, an additional piston 5, a drive for accelerating the piston 2, including a pneumatic pressure source into the pressure chamber 6 formed by pistons 2 and 5, is installed - an axial 7 eternally movable axial direction associated with the piston 2 and a braking device. To provide the set parameters of the shock pulse before the test, an additional piston 5 is installed at a calculated distance from the main piston 2, as well as an emphasis 7 for calculating At the acceleration of the piston 2, the associated stop 7 of the specified acceleration comes into contact with the piston 5 and they begin to move together. The forces acting on the pistons are mutually balanced and acceleration stops abruptly. 1C. In the f-crystals, 3 sludge. With s / s OS K9 Yu SP

Description

The invention relates to testing equipment, in particular to stands, which are used to test products for the impact of shock loads.

The purpose of the invention is to improve the accuracy of shock pulse reproduction with a steep falling edge

The goal is achieved by the fact that in the stand containing the cylinder

The body cylinder 14 communicates with the cavity of the receiver through the holes 17.

An additional piston 5 is mounted in the cylinder 1 at an adjustable distance from the main piston 2 by means of a replaceable sleeve 18.

The proposed test bench works as follows.,

In order to ensure that the piston is formed by a piston and a pneumatic drive for a given shock impulse of additional piston acceleration, an additional piston is inserted into the test product, which after a given acceleration of the main piston is connected to it, the forces acting on the main and additional pistons cancel each other out and accelerate abruptly .

Fig. 1 shows a test stand} in Fig. 2 - a stand with a piston made in the form of a glass, a shock impulse.

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option; figure 3 is a view of forming

The stand contains a cylinder 1 with a piston 2 installed in it, which serves to fix test item 3, latch A of piston 2, additional piston 5, drive for acceleration of piston 2 including pneumatic pressure source (not shown) and chamber 6 of pressure formed by pistons 2 and 5, an axially mounted stop 7, located in the opposite pressure chamber 6 of the side of the auxiliary piston 5 and connected to the piston 2, and a braking device. The stop 7 is connected to the piston 2 by means of the rod 8, and the brake device is designed in the form of a cracking device including a sleeve 10 of plastic material fixed to the rod 8 by means of a support 9 and an annular cutter 11 mounted on the cylinder 1. In the embodiment of the stand shown 2, the piston 2 is complete in the form of a glass, on the inner surface of which the abutment 7 is installed in the required position and fixed in this position with the help of bolts 12. The braking device in this case is made in the form of a receiver 13 placed in it The cylinder 1A and the brake piston 15 connected to the main piston 2 by the rod 16 passing through the additional gear 6; The internal cavity of the auxiliary cylinder 14 communicates with the cavity of the receiver through the holes 17.

An additional piston 5 is mounted in the cylinder 1 at an adjustable distance from the main piston 2 by means of a replaceable sleeve 18.

The proposed test bench works as follows.,

To ensure the formation, the closed piston 5 is installed at a distance i from the inner end of the piston 2, a. the stop 7 is at a distance of 1 from the additional piston 5, with 5 the values of f, and 1 are calculated depending on the parameters of the required impact pulse by the formulas

where 0 is the adiabat indicator of the worker

gas (air);

g is the acceleration of the free product J IMOKC; the maximum amplitude of the shock pulse discharge; - duration of shock

impulse;

t is the rise time of the amplitude of the overload from zero to the maximum;

| - the ratio of the magnitude of the overload amplitude, equal to the ratio of the magnitude of the overload amplitude at time T to the maximum overload at time .t, vTThen pressure chamber 6 is filled with compressed air to the design pressure providing the specified overload. After that, the latch 4 is opened and the piston 2 under the action of compressed air begins to accelerate, forming a test. shock pulse. After acceleration to a given speed in time, due to the magnitude of Ij, the abutment 7 abuts against the additional piston 5, the pressure forces acting on the pistons 2 and 5 cancel each other out and the acceleration stops abruptly. Further movement of the movable parts of the stand occurs by inertia, and the accumulated kinetic energy is spent in the brake device for cjjjsaaftHe material of the sleeve 10 (in the stand version shown in figure 1) or for throttling the gas from the additional cylinder 14 to the receiver 13 through the holes 17 ( in the version of the stand shown in FIG. 2) „

By changing the value of P and, accordingly, 2 it is possible to obtain shock pulses of different duration, the form of which is shown in FIG. At the same time, due to the force closure during the interaction of the additional piston 5 with the stop 7, the termination of the overload at the end of the pulse has the nature of a cutoff, which provides an increase in the accuracy of reproduction of the shock pulse.

Claims (2)

1. A bump test bench that contains a cylinder with a piston installed in it used to secure the product under test, a piston retainer. a piston accelerating drive including a high pressure pneumatic source and a braking device, characterized in that, in order to improve the fidelity of shock pulses with a steep falling front, it is equipped with an additional piston installed in the cylinder at an adjustable distance from the main piston and forming with there is a chamber for connecting to a high pressure source, and an axially movable axially mounted stop placed in the opposite side pressure chamber of the additional EDSS and bonded with the main piston. 2. Stand non. L, characterized in that the piston is made in the form of a glass, an additional piston is placed inside the glass, and the stop is located on the inner surface of the glass. fe.2 Compiled by V. Finogenov Editor S. Patrusheva Tehred I. Popovich Corrector M. Demchik Zakag2854 / 37 Circulation 776, Subscription VNYZHEI USSR State Committee on inventions and discoveries 1J3035, Moscow, Zh-35, Raushsk nab., d.4 / 5 Production printing company, Uzhgorod, Projecto st., 4