SU887829A1 - Hydraulic shock absorber - Google Patents

Description

one

The invention relates to mechanical engineering and can be used as a shock absorbing (braking) device in the transport and power mechanisms of machine tools and automatic lines.

Known damping device for hydraulic cylinders, containing built-in choke of the cylinder choke 1.,

The disadvantage of such a device is that in order to obtain the optimal time and path for braking in each specific condition, considerable experimental refinement is required.

The closest to the technical essence of the invention is a hydraulic shock absorber containing a hydraulic cylinder, the rod cavity of which is in communication with the drain, a supply line and a normally open throttle regulator, indicating the hydraulic cylinder cavity with the supply line.

The disadvantage of this shock absorber is that the process of braking of the depreciable masses is carried out with a constantly varying negative acceleration, which leads to a failure of the resistance force of the shock absorber.

The purpose of the invention is to provide the braking of the depreciable masses according to the law of equally slow motion.

To achieve this goal, the shock absorber is fitted with a normally closed variable pressure valve installed between the hydraulic cylinder and the supply line parallel to the throttle controller.

FIG. 1 shows the hydraulic scheme of the proposed shock absorber; in fig. 2 throttle controller and pressure valve, longitudinal, section; in fig. 3 shows section A-A in FIG. 2

The shock absorber contains a hydraulic cylinder 1, the brush 2 of which is designed to interact with the movable element

transport mechanism of the machine or automatic line (not shown).

A normally closed adjustable pressure valve 3 and parallel to it an installed and normally open throttle controller 4 are communicated with hydraulic cylinder 1.

A pressure valve, adjustable to the required pressure, includes a housing 5 (Fig. 2}, in which a spool 6 is placed, preloaded by a spring 7.

The housing 5 has a channel 8 which connects the piston cavity of the hydraulic cylinder through the cavities 9 and 10 and the channel 11 with the supply line 12. The housing 5 also has a channel 13 connecting the channel 8 with the cavity 14, the throttle controller 4 changes the fluid resistance at the moment transition of the moving parts of the shock absorber from the rest state to the motion state and adjusts to the Pressure providing a soft transition.

The throttle controller 4 includes a housing 15, in which the spool 16 is preloaded, spring-loaded 17. The channel 8 through the cavities 18 and 19 and the channel 11 communicates the piston cavity of the hydraulic cylinders with the supply line 12. The control channel 20 also has a control channel 20 with a cavity of 21. On the middle of the valve spool 16, a groove 22 is made, intended to relieve the pressure of the valve.

The pressure valve 3 and the throttle controller 4 are arranged so that channel 8 is common for the supply of fluid, and channel I1 is common for the drain.

The shock absorber works as follows.

Initially, the spools

6 and 16 are held by their springs

7 and 17 in the lower positions (Fig. 2), the spool 6 separates the cavities 9 and 10 in the housing 5, and the spool 16 forms the throttle slot 23 with the opening of the housing 15. Fluid is supplied to the supply line 12 and further along channel 11, the cavity 19, the throttle gap 23, the cavity 18 enters the piston cavity of the hydraulic cylinder 1, keeping its piston in the extreme right position (FIG. 1). When the movable element of the transfopTHoro mechanism interacts with the rod 2, the latter begins to move to the left. At the same time, at the initial moment of the piston movement, the liquid from the piston cavity

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hydraulic cylinders 1 are displaced along channel 8 to cavity 18 and from there through throttle slot 23 to cavity 19, and then to channel 11 and further to supply line 12.

At the moment of contact of the elements of the transport mechanisms on the rods 2 there is a sharp increase in the speed of movement of moving parts

10 of the shock absorber, which also leads to a sharp increase in the flow rate of fluid through the throttle slot 23, as a result of which the pressure of the fluid increases in the cavities 18, 21, 9, 14,

15 channel 8 and the piston cavity of the hydraulic cylinder 1. Under the action of increasing fluid pressure from one side to the end of the spool 16 of the throttle regulator 4, it moves up

20 and blocks the passage of fluid from the cavity 18 into the cavity 19. On the other hand, the fluid, acting on the end of the spool 6 of the pressure valve 3, opens it, and the cavity 9 communicates with the cavity 10 and then through

channel 11 — with a supply line 12,

The braking process then takes place at a predetermined constant pressure of fluid in the shock absorber.

Pressure valve: the pan 3 and the pressure regulator 4 operate in parallel, but their functions are opposed: positive, and moreover, the spool 16 starts moving with some advance in relation to the spool 6 of the pressure valve 3, as a result of which the braking process occurs gently and in accordance with the law of equal motion.

After the mobile element of the transport mechanism stops, the braking process is stopped, while the movement of fluid through the pressure head. The new valve 3 will also stop.

Since the groove 22, which connects the cavities 18 and 19, is made on the valve of the spool 16 of the throttle regulator 4, pressure from the piston cavity of the cylinder into the channel 11 and the pipeline 12 and the spools 6 and 16 under the action of their springs 7 and 17 are omitted. 2J i.e. return to their original position, thereby the spool 16 of the throttle regulator 4 opens the access of fluid from the I2 line to the piston cavity of cylinder 1, and the spool 6 of the pressure valve 3 separates the cavities 9 and 10. As soon as the resistance preventing the reverse movement of the rod is removed 2, the latter, under the action of the pressure of the fluid flowing from the supply line, will begin to move to its original position (Fig. 1).

The use of the proposed hydraulic shock absorber allows smooth, without shock, to be slowed down by moving masses moving at high speeds.

Claims (1)

1. Levitsky N.I. and others. Calculation of control devices for hydraulic actuators. M., Mechanical Engineering, 1971, p. 27.2. Patent of Germany No. 1256485, CL A7a 16/10, 1970 (prototype). sh W Lj LA 1 ff -Id a