SU1375749A2 - Bucket position control hydraulic system - Google Patents

Abstract

The invention relates to construction and road machines and improves the accuracy of bucket leveling when lifting a boom, regardless of its load. The hydraulic system includes a hydraulic valve 1 with a drain line, cylinders (C) 2 and 3 of the drive boom 7 and bucket 8, respectively. The piston cavity C 2 is working, and the rod is a drain. The hydraulic servo (SC) 9 has a spring-loaded piston and rod. It is kinematically connected to the throttle control assembly (D) 6 inertial resistance. The working surface of the SC 9 is in communication with the working cavity C 3. The working fluid is supplied to C 2, from where it is forced into the drain. The pressure propagates in SC 9 by injecting the piston with the rod. The latter turns and opens D 6. Boom 7 is raised and the bucket 8 is leveling. When digging material of SC 9, D 6 loops, and at the moment of boom lifting, piston C 2 closes line 11 connecting the working cavity C 3 to the rod cavity C 2 .1 il. with (L

Description

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The invention relates to construction and road machines, in particular to their hydraulic drives of loaders, and is an improvement of the device according to the author. No. 800306.

The aim of the invention is to improve the accuracy of the alignment of the bucket when lifting the boom, regardless of its load.

The drawing shows a schematic hydraulic diagram of bucket position control.

The bucket hydraulic control system consists of a hydraulic distributor

1with drain line, shchindry

2 actuators of the boom, the piston cavity of which is working, and the piston rod - the drain, cylinder 3 of the bucket drive, the rod cavity of which is working, and the piston - drain, check valves 4 and 5, inert resistance drops 6, ladle 8, servo 9 with spring 10 and line 11.

In the static position at neutral positions of the spool valve of the hydraulic distributor 1, the pump forces the working fluid to the drain, the cavities of the cylinder 2 and 3 are locked, the piston rod of the servoschindra 9 is retracted into the sleeve,

The subsupply element of the servo-cylinder 9 - the rod exposes the throttle-limb regulating element to the extreme position corresponding to the maximum one. opening throttle. With such a. The choke 6 skips the oil when raising the boom with an empty bucket.

The rod cavity of the servo cylinder 9, in which the spring 10 is located. Compression, is connected to the drain.

The hydraulic system works as follows.

After scooping material lifting equipment is lifted

In this case, the working fluid is supplied to the piston-cavity of the cylinder 2, the rod cavity of which is connected to the drain line. When lifting the boom in the rod end of the cylinder 3 of the bucket, the working fluid is compressed and expelled through the throttle 6, the check valve 4, the distributor section, 1 to drain.

The piston cavity of the cylinder 3 has its feed with a common drain line through the check valve 5.

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The pressure of the rod end of the cylinder 3 spreads along the line 11 into the piston cavity of the servo cylinder 9, compresses the spring 10 and raises the piston with the rod, which being structurally connected to the limb of the drossel 6, rotates it and adjusts the degree of opening depending on the bucket load . The larger the mass of the loaded material, the more the throttle 6 is covered. The law of regulation is provided by the spring 10 of compression.

The boom is raised and at the same time leveling the bucket (bucket 8 is rotated clockwise).

When scooping the material in the rod cavity of the cylinder 3, high pressures occur, due to which the servo cylinder 9 closes the throttle 6, excluding the propagation of high pressures in the rod cavity of the boom cylinder 2.

The proposed design solution provides the opportunity to work simultaneously with two cylinders 2 and 3, producing a combined operation: digging and lifting the boom.

If during the lifting of the boom 7 the latter is stopped in any intermediate position, the alignment of the bucket 8 will stop, as the control valve of the cylinder 2 will take a neutral position, disabling the rod end of the cylinders 2 and 3 from draining,

At the moment of raising the boom to the extreme upper position, the piston of the cylinder 2 closes with a limit switch (not shown) the line connecting the working cavity of the cylinder 3 with the rod end of the cylinder 2 through the throttle 6 and the check valve 4.

This eliminates the movement of the bucket 8 in the event that after stopping the boom 7 in its extreme upper position, the driver continues for some time to keep the boom cylinder control valve 2 turned on.

When you turn on the spool control cylinder 3 bucket and the supply of working fluid from the pump into the piston cavity, the bucket 8 is unloaded from the material.

After the spool is shifted to the second extreme position, the bucket 6 returns to its original position (rotates counterclockwise).

31375749

Claims (1)

The invention of the invention is made with regulatory unit, and the hydraulic system is equipped with a servo-hydraulic control system for the position of a cylinder with a spring-loaded piston bucket on auth. No. 800306, about t of l of a rod, which is kinematically related to the fact that, in order to designate a throttle control unit, To increase the leveling accuracy of the bucket, at the same time, the working cavity of the servo-cylinder when raising the boom, regardless of its pressure, is in communication with the working cavity of the loading, the throttle of the inertia sop-linder of the bucket drive.