SU1363003A2 - Braking device to stand for shock tests - Google Patents

Abstract

This invention relates to an impact test technique. The aim of the invention is to improve the accuracy of the formation of rectangular shock pulses. A brake device comprising a cylinder 1, a piston 2 installed therein, forming a cavity 3 with the cylinder, and a chamber 6 communicating with a cavity 3 connected at the end of the braking path of the piston 2 by a channel 7 in which a check valve is installed, is provided with an additional chamber 17, mounted coaxially to the cylinder, and a pipe 18 connected at one end to the cylinder at the end of the braking path of the piston. The first group of channels 15 of the cylinder, located closer to the end of the braking path of the piston, communicates the cavity of the cylinder with an additional chamber, and the channels 16 of the second group communicate with the pipeline. Improving the accuracy of the formation of rectangular pulses is provided by eliminating the rebound of the platform 12. The axes of the channels 15 can be tilted to the axis of the cylinder at a sharp angle in the direction of movement of the piston, and the axis of the channels 16 is similarly in the opposite direction. 1 hp f-ly. 1 il. I (L 12 N)

Description

The invention relates to testing equipment, in particular to brake devices to test benches.

The purpose of the invention is to improve the accuracy of the formation of rectangular shock pulses.

The drawing shows the proposed brake device.

The brake device contains a cylinder 1, installed in cylindrical piston 2, forming with it a gas-filled cavity 3 and a holder A for fixing the piston 2 in the initial position, made in the form of a flexible element connected to the rear wall of the 5th cylinder 1 and the piston 2. Parallel the cylinder has a chamber 6 communicated with the cavity 3 by means of a canal 7 at the end of the braking path of the piston 2. In channel 7 a check valve is installed, which includes a shut-off member 8 and a spring 9 and ensures gas passage from the cavity 3 to the chamber 6; 10 of which is greater than or equal to the cross section of cylinder 1. For communication with a pressure source (not shown), a hole 11 is made in cylinder 1. The braking object contains platform 12 with the product under test 13. In cylinder 1 there is an open cavity 14 along its length made the first and second groups of channels 15 and 16, evenly spaced around the circumference.

Coaxially to cylinder 1 there is an additional camera installed: 1 7, communicated with channels 15 of the first group. At the end of the braking path of the Norse 2, a pipeline 18 is connected to the cylinder 1, which communicates the cavity 3 with the channels 16 of the second group. The channels 15 are located closer to the end of the braking path and their axes are inclined at an acute angle to the axis of the cylinder 1 in the direction of movement of the piston 2, and the channels 16 of the second group are closer to the open cavity 14 and their axes are inclined similarly, but in the opposite direction. The rear wall 5 of the cylinder 1 is equipped with a damper 19.

Braking device works as follows.

Through the hole 11 cavity 3 zapol

air pressure P. The air through the channel 7 acts on the backup organ 8, which compresses the spring 9 and opens the hole 10, which communicates the cavity 3 with the chamber 6, and flows into the chamber 6 the pressure in it

until it reaches

0

15

0

25

and Pg ,, after which the channel 7 closes with the locking member 8 under the action of the spring 9. When the cavity 3 is filled with air, the piston 2 occupies the initial position in which it is held by the holder 4. At the same time the channels 15 are filled with compressed air and the additional chamber 17, After the cavity is filled 3., chambers 6 and 17 to the pressure value P, the opening 11 is blocked, and in this state the braking device is ready for testing. The pre-accelerated platform 12 with the product 13 enters the cylinder 1 where the braking process begins. Initially, air is compressed in cavity 14 to pressure P, and then

the air in cavity 3 is compressed. When the pressure exceeds P (due to two-piston 2 together with platform 12), opening 10 opens and air flows from cavity 3 to chamber b, and the volume of cavity 3 decreases, and the pressure in it chambers 6 and 17 increases to the value of R.

In a given place (shown by a dotted line in the drawing) of cylinder 1, braking of platforms-1Ы 12 (repayment of the kinetic energy stored by it during acceleration) is terminated. Immediately before this, platform 12 passes by channels 16 of the second group, opening through them the release of compressed air from cavity 3 through conduit 18 and cavity 14 to the atmosphere, as a result of which pressure in cavity 3 begins to decrease and opening 10 closes, then platform 12 passes by channels 15 of the first group, opening the outflow of air through them from the additional chamber 17 by jets moving after the platform 12, after which the platform 12 and the piston 2 slowly move by the force from the pressure of the jets to the rear wall 5 of the cylinder ra 1 and its vicinity are stopped. The speed of their movement, their movement is determined by the parameters of the pipeline 18, the additional chamber 17 and the channels 15 and 16.

35

40

45

55 By introducing an additional chamber 17, conduit 18 and two groups of channels 15 and 16, it is possible to eliminate the accelerated movement of the platform in the opposite direction (rebound) and to improve the accuracy of forcing rectangular shock pulses affecting the test item when braking the platform. In addition, the platform stops near the rear wall, which makes it easier to remove after the test.

Claims (2)

1. Brake device to the stand for impact tests according to the author, St. No. 901871, characterized in that, in order to increase the accuracy of the formation of rectangular shock pulses, it is provided with an additional camera mounted coaxially with Editor A.Revin Order 6393/30 Compiled by A. Kozin Tehred L.SerdyukovaKorrektor S.Shekmar Circulation 776 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35 Raushsk nab. 4/5 Production and printing company, Uzhgorod, Projecto st., 4 a cylinder and a pipeline, one end of which is connected to the cylinder at the end of the braking path of the piston, in the cylinder along its length there are two groups of channels, the first of which, located closer to the end of the braking path of the piston, reports the cylinder cavity with an additional chamber, and the second group of channels is connected to the pipeline. 2. The device according to claim 1, characterized in that the axes of the channels of the first group are inclined to the axis of the cylinder at an acute angle in the direction piston movements, and the axes of the channels of the second group are similarly in the opposite direction.