SU1500613A1 - Hydraulic drive for mechanisms of self-propelled jib crane - Google Patents

Description

The invention relates to a lifting and transport machinery.

The purpose of the invention is to improve the management of hydraulic drive by providing a constant and independent of external 2

her load differential pressure on the control element of the distributor. The hydraulic actuator contains a pump 1, a distributor 3 with spools and a locked flow channel, the hydraulic motor

14 of the turning mechanism, hydraulic cylinders 1 5 and 1 6 of the boom lifting mechanism and the extension mechanism of the movable sections of the station wheel, respectively, the hydraulic cylinder 27 of the turning mechanism brake, valves, filter 10, tank 11, lines and pressure regulator 12 installed parallel to the pump pressure line. Line 17 of the control of the pressure regulator 12 is connected to the tank 11 through the jet 29, and with the lines of the hydraulic motor 14 and hydraulic cylinders

15 and 16 mechanisms through check valve blocks 18, 21, 24. 1 Il.

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The invention relates to lifting and transport engineering and relates to hydraulic actuators boom; self-propelled cranes.

The purpose of the invention is to improve the control of the hydraulic drive by providing a constant and independent of the external load differential pressure on the control element of the distribution of the divider.

The drawing shows a schematic diagram of the hydraulic mechanisms of the small-sized self-propelled crane.

The hydraulic actuator contains a pump 1, from 15 _<of which the fluid through the pressure line 2 enters the distributor 3. with a closed flow channel "4". In the distributor 3 there are spools · 5.6 and 7 and a safety valve 8. 20

From the distributor 3, the fluid through the drain line 9 through the filter 10 is directed to the tank 1 G. Parallel to the distributor 3 to the pressure line 2 a pressure regulator 12 is connected, from which the liquid goes through the line 13 to the discharge line 9.

The pistol 5 of the distributor 3 serves to control the hydraulic motor 14. the turning mechanism, the spool 6 to control the hydraulic cylinder 15 of the boom raising mechanism and the spool 7 ¹ to control the hydraulic cylinder 16 of the mechanism for changing the length of the telescopic boom. . .

. Line 17 of control of pressure regulator 12 is connected via block 18 of check valves to lines 19 and 20 of hydraulic motor 14, block 21 of check valves with lines 22 and 23 of hydraulic cylinder 15, through block 24 of check valves with lines 25 and 26 of hydraulic cylinder 16. Brake hydraulic cylinder 27 control The turning mechanism is produced from lines 19 and 20 through the valve type OR 28 * The control control regulator 12 pressure line 17 is connected via a jet 29 to the tank 11.

On the spools 5, 6 and 7 of the distributor 3 throttling elements 30 and 31 are implemented, allowing to ensure the regulation of the fluid flow at a certain course of the spool.

The hydraulic actuator works as follows.

When the neutral position of the spools 5, 6 and? distributor 3 taps to the motor 14 are connected to ba35

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com 11, taps to the hydraulic cylinders 15 and 16 are locked. Line 17 of the control of the pressure regulator 12 through the jet 29 is connected to the tank 11. The fluid flow from the pump 1 along the pressure line

2 enters the pressure regulator 12, moves its shut-off and regulating element to the upper position, since there is no pressure from the spring side ^ and ^{1 is} sent under low pressure along lines 13 and 9 through the filter 10 to the tank

11. This unloads the pump at the neutral position of all spools.

When lifting the boom, the spool 6 is moved to the top position. The liquid from the pump through the spool goes through line 22 to the piston cavity of the hydraulic cylinder 15. From the rod end of the hydraulic cylinder 15, the liquid goes through the line 23 to the distributor 3 and further along the drain line 9 through the filter 10 to the tank 11.

At the same time, the liquid through the block 21 of the check valves flows through line 17 to the pressure regulator 12. Due to the fact that a small part of the flow of liquid passes through the jet 29 -. The pressure in line 17 is maintained at a pressure equal to the operating pressure in line 2. The pressure drop across the throttling element 31 of the spool 6 does not depend on external loads, will always be constant and small, which allows you to adjust the flow rate and boom lifting speed • at a certain and constant during spool valve.

When lowering the boom, the spool 6 is moved to the lower position. The liquid from the pump through the valve 6 is directed along the line 23 into the rod end of the hydraulic cylinder 15. From the piston cavity, the liquid enters the line 22 into the distributor

3 and further along the drain line 9 through the filter 10 is sent to the tank 11. Under the working pressure, the liquid through the block 21 of check valves enters the pressure regulator 12 via the control line 17. A small part of the fluid at the same time through the nozzle 29 enters the tank 11, the pressure drop across the throttling element 30 of the valve 6 will be small and independent of external loads and pressure in the hydraulic system, which provides regulation

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speed at a given course of the spool valve.

The hydraulic actuator works in the same way when the hydraulic motor 14 of the turning mechanism and the hydraulic cylinder 16 of the mechanism for changing the length of the boom are turned on. The spool 5 at the neutral position connects the lines 19 and 20 of the hydraulic motor with the tank 11.

When all spools of the distributor are switched on at the same time, they are transferred to the total flow area of the throttling elements that do not allow the entire fluid flow from the pump to pressure line 17 through the check valve block from the most loaded hydraulic motor, which also determines the pressure in the pressure line 2 of the pump .

The pressure drop over the control element of the most loaded spool will be constant and slight, a. the differential pressure on the regulating elements of the other spools will be equal to the pressure difference in the pressure line of the pump and the pressure in the hydraulic motor line.

When moving all spools to full stroke, when the total flow area of the throttling elements passes the entire fluid flow from the pump and the pressure regulator does not work, the entire fluid flow is directed to the least loaded hydraulic engine as in conventional hydraulic actuators without a pressure regulator.

1500613

Connecting the control line of the pressure regulator with the tank through the jet, and with the hydraulic motor lines and ₅ hydraulic cylinders through check valve blocks, ensures a constant and independent of the external load pressure drop on the valve spool, which allows you to control the hydraulic motors of the valve mechanisms . This provides increased convenience and improved control of the '15 hydraulic drive.

Claims (1)

Formula of invention The hydraulic actuator of the mechanisms of the articulated self-propelled crane, containing at least one hydraulic motor, whose lines are connected to the pressure line of the pump and the tank through a valve made with a closed flow channel, and a pressure regulator through which the pressure line the pump is connected to the tank, and its control lines communicate respectively with the pressure line of the pump and with the master ¹ ral hydraulic motor, distinguished by the fact that, in order to improve the control of the hydraulic cylinder by ensuring a constant and independent of the external load element distributor, it is equipped with blocks "3 check valves through which the said pressure regulator control line communicates with the line . hydraulic engine, and a jet through which it communicates with the tank.