RU1805226C - Hydraulic drive for tree breaker - Google Patents

Abstract

SUMMARY OF THE INVENTION: a pump is connected through a distributor by hydraulic lines to a piston and rod cavities of a boom lift hydraulic cylinder. The cavities are interconnected via a spring-loaded on-off valve. A check valve is installed in the hydraulic line between the outlet of the distributor and the piston cavity of the hydraulic cylinder. A hydraulically controlled valve is installed in the hydraulic line between the second outlet of the distributor and the rod cavity of the hydraulic cylinder. The distributor is made hydraulically controllable from the side of the spring cavity communicated with its inlet through the throttle and directly with the inlet of the deceleration valve connected to the control cavity of the hydraulically controllable valve; a distributor with an open center is connected in parallel to the rum. 1 s.p. f-ly, 1 ill.

Description

The invention relates to forestry engineering, in particular to volumetric hydraulic drives of forestry machines.

The purpose of the invention is to increase reliability by providing automatic connection of the piston and rod cavities of the hydraulic cylinder during gravitational lowering of the boom;

The drawing shows a schematic diagram of a hydraulic drive. .

The hydraulic actuator includes a tank 1, a pump 2, connected by pipelines 3 through a distributor 4 with piston 5 and rod 6 cavities of hydraulic cylinders 7, boom lifting or hydraulic cylinders 8 lifting the handle. Moreover, between the output of the distributor 4 and the piston cavities 5, a delay valve 9 is installed, consisting of a check valve 10 and a throttle 11. The distributor 12 is made with a spring cavity 13, a hydraulic control cavity 14, which are interconnected via a throttle 15. Inlet 16 of the hydraulic control cavity 14 is connected to the piston cavity 5, and the outlet 17 through the check valve 18 to the rod cavity 6, and the spring cavity 13 using the pipe 19 to the outlet of the distributor 4 before the slow valve 9. In the pipe 20 of the rod cavity 6 installed n emy Hydraulic valve 21, a control line 22 which is connected to the piston chamber 5 through a valve 9. zamedlitelny parallel emomu Hydraulic distributor valve 21 is open center 23, which is connected to the output of the input distributor 4.

The hydraulic drive of a logging machine of manipulator type, for example, for felling and stacking trees, operates as follows.

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In the initial state, the distributor 23 is in a position connecting the outlet of the distributor 4 with a drain.

When the distributor 4 is turned on to lift the working equipment, for example, the hydraulic cylinder 7, the working fluid from the pump 2 through the distributor 4, passes the check valve 10, and enters the piston cavity 6. The hydraulic fluid displaced from the rod cavity 6 passes through the controlled valve 21, which this time is opened by the pressure of the rod cavity into the drain hydroline of the distributor 4 and then through the pipeline to the tank 1. In this case, part of the working fluid passes into the tank 1 through the open hydraulic line of the distributor 23.

Upon returning dispenser 4; the cavities 5 and 6 are locked into the neutral position, the lifting of the working equipment is stopped,

To lower the working equipment, the distributor 4 is moved to another position in which the pipeline 19 of the spring cavity 13 of the distributor 12 is connected to the tank 1. The working fluid from the control cavity 14 will begin to flow through the throttle 15 into the spring cavity 13. As a result, a pressure differential is created between the control cavity 14 and the spring cavity 13, the valve will open by connecting the inlet 16 to the outlet 17. Most of the working fluid from the piston cavity 5 of the hydraulic cylinders flows through the check valve 18 into the rod cavity 6, and less than an hour b, equal to the difference in volume between the piston and rod cavities is discharged through the inductors 15 and 11 into the tank 1, In this case hydraulic cylinder piston under the action of gravitational force moves downward (in the scheme) lowering the working machine equipment. Lowering. In this case will occur until the termination of the action of gravitational forces, for example, until it stops against an obstacle - contact with the ground level or the site of unloading of cargo.

In the described position of the distributor 4, the pump 2 is connected directly to the tank 1 and does not affect the lowering mode of the working equipment.

When the distributor 4 is installed in the neutral position, the piston 5 and the rod cavities 6 of the hydraulic cylinders are locked, lowering is stopped.

In the event that it is necessary to perform operations without using gravitational forces, for feller bunchers, such a need arises, for example, to self-extract when the tracked chassis is stuck, by switching the manipulator against the ground 8 switch the distributor 23. In this case, the output of the distributor 4 is connected directly with a rod cavity 6 of the hydraulic cylinder. Therefore, when the distributor 4 is turned on

lowering the working equipment, the working fluid from the pump 2 enters through the distributor 23 into the rod cavity b of the hydraulic cylinders, and the liquid displaced under the pressure of the pump from the piston cavity through the chokes 11 and 15, the distributor 4 enters the tank 1.

Thus, the use of a hydraulically controlled valve for communication between the piston and rod cavities

boom lift hydraulic cylinder and allows you to automate the process of connecting the cavities directly in the process of gravitational lowering, which simplifies the control of the hydraulic actuator and simplifies it

construction.

Claims (2)

1. The hydraulic drive of forestry machines of manipulator type, containing a pump communicated by hydraulic lines through a distributor with a piston and rod cavities of a boom lifting hydraulic cylinder connected to each other through a spring-loaded two-position distributor, and a retardation valve installed in the hydraulic line between the distributor output and the piston cavity of the hydraulic cylinder, characterized in that, in order to increase reliability by automatic connection of the piston cavity with the rod during gravitational lowering of the boom, it is equipped with a hydraulic valve | installed in the hydraulic line between the second outlet the distributor and the rod cavity of the hydraulic cylinder, the on-off valve is made hydraulically controlled from the side of the spring cavity communicated with its inlet through the throttle and directly with the inlet of the deceleration valve connected to the control cavity of the hydraulically controlled valve. 2. The hydraulic actuator according to claim 1, characterized in that a valve with an open center is connected in parallel with the hydraulic valve. % thirteen fifteen fifteen sixteen .nineteen twenty „ 12 / L Gf 3 2