KR101737017B1

KR101737017B1 - The hydraulic device for front loader

Info

Publication number: KR101737017B1
Application number: KR1020150076160A
Authority: KR
Inventors: 유계희
Original assignee: (주)태성공업
Priority date: 2015-05-29
Filing date: 2015-05-29
Publication date: 2017-05-18
Also published as: KR20160141240A

Abstract

More particularly, the present invention relates to a front loader hydraulic device, and more particularly to a front loader hydraulic device that connects a boom up spool of a boom cylinder and a boom up port of a boom cylinder by a first flow path and a second flow path, A third port and a fourth port are connected to a third port and a fourth port, respectively, to drive the boom and the bucket. The third and fourth flow paths are connected to each other via a relief valve and a first check valve The first check valve is configured to prevent the hydraulic fluid from flowing from the fourth flow path to the third flow path, the first extension flow path between the relief valve and the first check valve and the second flow path are connected to the second check valve, And the second check valve is configured to prevent the hydraulic fluid from flowing from the second flow path to the first extension flow path, and the relief valve is operable to discharge the hydraulic fluid whose pressure is increased at the bucket descending port Upon passage The length of the cylinder rod pulling out of the bucket cylinder is adjusted to increase the rotation range of the bucket, and at the same time, due to the shrinkage of the cylinder rod of the bucket cylinder occurring at the time of boom rising, The pressure rise of the cylinder can be solved.

Description

The hydraulic device for front loader < RTI ID = 0.0 >

The present invention relates to a front loader hydraulic device and, more particularly, to a front loader hydraulic device in which, when a boom rises, the length of the cylinder rod taken out of the bucket cylinder is adjusted to enlarge the rotating range of the bucket, The pressure increase of the front loader can be solved.

Generally, the front loader is installed in front of a tractor and is mainly used for carrying cargo or short-distance movement. The front loader is composed of a boom, a bucket and a frame, and is connected to a hydraulic control valve for supplying hydraulic pressure thereto.

In this connection, Patent Document 1 discloses a hydraulic system in which a vertical hydraulic chamber of a boom cylinder is connected to a hydraulic pump and an oil tank via a hydraulic line and a boom control valve, and a pilot valve and a pilot line are provided through a boom control valve, A bypass line is connected between the lower hydraulic pressure-side hydraulic line and the oil tank-side hydraulic line of the boom cylinder by a bypass line, and the bypass line is taken between the pilot-relief valve and the orifice to connect the upper hydraulic chamber to the hydraulic line via the check valve, And a pilot valve is connected to the pilot line in the middle of the lot line to take a pilot line in the hydraulic line and the pilot line and the relief valve are connected to the pilot line.

However, Patent Document 1 discloses a conventional hydraulic pressure flow at the time of boom lifting and bucket lifting. It is possible to solve the pressure rise inside the bucket cylinder caused by the link structure when the boom is lifted, A configuration in which the length of the bucket is adjusted to increase the rotation range of the bucket is required.

Patent Document 1: Korean Patent Publication No. 92-0005489 (published on June 07, 1992)

In accordance with the present invention, the length of the cylinder rod taken out of the bucket cylinder is adjusted to increase the rotation range of the bucket, and at the same time, the increase in pressure of the bucket cylinder can be solved by the shrinkage of the cylinder rod of the bucket cylinder The present invention is directed to providing a front loader hydraulic system having a front loader.

In order to achieve the above object, according to the present invention, a boom control spool, a boom up port of a boom cylinder, and a boom descent port are connected by a first flow path and a second flow path, respectively, and a bucket control spool and a bucket descending port And a bucket raising port connected to the boom and the bucket by a third flow path and a fourth flow path, respectively, wherein the third flow path and the fourth flow path are connected to each other by a first extension having a relief valve and a first check valve The first check valve is configured to prevent the hydraulic fluid from flowing from the fourth flow path to the third flow path, and the first extension flow path and the second flow path between the relief valve and the first check valve are provided with the second check valve And the second check valve is configured to prevent the hydraulic fluid from flowing from the second flow path to the first extension flow path, and the relief valve is configured to allow the hydraulic fluid having the increased pressure to pass through the bucket descending port Something special It is gong.

According to the present invention, when the boom rises, the operating oil whose pressure is increased at the bucket descending port is passed according to the set pressure of the relief valve, thereby the cylinder rod pull-out length of the bucket cylinder is adjusted.

Further, the present invention has the effect of relieving the pressure rise of the bucket cylinder by the shrinkage of the cylinder rod of the bucket cylinder which occurs when the boom is lifted.

In addition, the present invention has an effect of preventing the cavitation of the bucket cylinder by supplying the operating fluid whose pressure has been increased in the bucket descent port to the bucket ascending port of the bucket cylinder through the relief valve and the first check valve when the boom rises.

In addition, since part of the operating oil whose pressure is increased in the bucket descent port is supplied to the boom descent port of the boom cylinder through the relief valve and the second check valve, It has the effect of preventing the whole supply.

1 is a schematic diagram according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a configuration of a specific embodiment of the present invention will be described with reference to the accompanying drawings.

1, the front loader hydraulic device of the present invention for driving the boom 13 and the bucket 23 of the front loader includes a boom control spool A and a boom up port 11 of the boom cylinder 10, And the boom descent port 12 are connected to the first flow path 1 and the second flow path 2 and the bucket descending port 21 and the bucket ascending port 21 of the bucket cylinder 20 22 are connected to the third flow path 3 and the fourth flow path 4, respectively.

The third flow path 3 and the fourth flow path 4 are connected by a first extension flow path 5 provided with a relief valve 5-1 and a first check valve 5-2, 1 check valve 5-2 is configured to prevent the hydraulic fluid from flowing from the fourth flow path 4 to the third flow path 3. [

At this time, the relief valve 5-1 closest to the third flow path 3 and the first check valve 5-2 closest to the fourth flow path 4 are formed.

The first elongated flow path 5 and the second elongated flow path 2 between the relief valve 5-1 and the first check valve 5-2 are connected to each other through the second check valve 6-1 And the second check valve 6-1 is configured to prevent the hydraulic fluid from flowing from the second flow path 2 to the first extension flow path 5. The second check valve 6-1 is connected to the second extension flow path 6,

Here, the boom control spool A and the bucket control spool B are hydraulic control valves, which are typically 3-way or 4-way position changeover valves and are connected to a hydraulic pump and an oil tank.

The boom cylinder 10 and the bucket cylinder 20 are each provided with a piston and a cylinder rod. One of the hydraulic chambers, in which the cylinder rod protrudes and retracts around the piston, Port 22 and the other hydraulic chamber on the other side is a boom rising port 11 and a bucket lowering port 21, respectively.

Here, the first flow path 1 supplies the operating oil to the uprising port 11 of the boom cylinder 10 when the boom 13 is operated to raise the boom 13. When the boom 13 descends, A).

The second flow path 2 allows the hydraulic fluid to flow toward the boom control spool A when the boom 13 is operated to raise the boom 13. When the boom 13 descends, ).

The third flow path 3 allows the hydraulic fluid to flow to the bucket control spool B side when the bucket 23 is holding the workpiece and allows the hydraulic fluid to flow into the bucket descent port 21 when the workpiece is poured. .

The fourth flow path 4 supplies the operating oil to the bucket rising port 22 of the bucket cylinder 20 when the bucket 23 is holding the workpiece, B).

The relief valve 5-1 allows the operating fluid whose pressure has been increased in the bucket descent port 21 to pass through the relief valve 5-1 and the pressure in the bucket descent port 21 is increased when the boom 13 rises The operating fluid is supplied to the bucket raising port 22 of the bucket cylinder 20 through the relief valve 5-1 and the first check valve 5-2 and is supplied to the bucket raising port 22 of the bucket cylinder 20, Is configured to be supplied to the boom down port (12) of the boom cylinder (10) through the relief valve (5-1) and the second check valve (6-1).

The operation and effect of the embodiment of the present invention will be described as follows.

The operating oil is supplied from the boom control spool A to the boom up port 11 of the boom cylinder 10 through the first flow path 1 to raise the boom 13 as shown in Fig.

At this time, the bucket 23 is held in a state holding the workpiece or spilled on the stopper.

As a result, the bucket cylinder 20 connected to the bucket cylinder 20 is contracted to reduce the length of the bucket cylinder 20, so that the internal pressure of the bucket descent port 21 is increased. As a result, When the set pressure value of the relief valve 5-1 is reached, the relief valve 5-1 is opened and the hydraulic oil whose pressure is increased in the bucket descent port 21 passes.

At this time, the hydraulic oil flows to the bucket raising port 22 of the bucket cylinder 20 through the fourth flow path 4 connected to the first extending passage 5 while passing through the first check valve 5-2 .

That is, the relief valve 5-1 passes the operating oil whose pressure has risen in the bucket lowering port 21 according to the set pressure, so that the cylinder rod withdrawing length of the bucket cylinder 20 is adjusted, The range is enlarged.

The operating fluid whose pressure has risen in the bucket descent port 21 when the boom 13 rises flows through the relief valve 5-1 and the first check valve 5-2 to the bucket rising port (22) to prevent cavitation of the bucket cylinder (20).

A portion of the operating oil whose pressure has risen in the bucket lowering port 21 is connected to the second elongated flow path 6 through the relief valve 5-1 and the second check valve 6-1, Is supplied to the boom lowering port (12) of the boom cylinder (10) through the boom cylinder (2).

That is, the extra operating fluid remaining after filling the bucket raising port 22 of the bucket cylinder 20 is supplied to the boom down port 12 of the boom cylinder 10.

Here, the relief valve 5-1 can appropriately adjust the cylinder rod pull-out length of the bucket cylinder 20 to suit various working environments through pressure setting.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limited to the embodiments set forth herein. Various changes and modifications may be made by those skilled in the art.

1: first flow path 2: second flow path
3: Third Euro 4: 4th Euro
5: first extension passage 5-1: relief valve
5-2: first check valve 6: second extension channel
6-1: second check valve 10: boom cylinder
11: boom up port 12: boom down port
13: Boom 20: Bucket cylinder
21: bucket descending port 22: bucket ascending port
23: Bucket

Claims

The boom control spool A and the boom up port 11 and the boom down port 12 of the boom cylinder 10 are connected to the first flow path 1 and the second flow path 2 respectively and the bucket control spool B And the bucket descending port 21 and the bucket ascending port 22 of the bucket cylinder 20 are connected to the third flow path 3 and the fourth flow path 4 respectively to drive the boom 13 and the bucket 23 1. A front loader hydraulic system comprising:
The third flow path 3 and the fourth flow path 4 are connected by a first extension flow path 5 provided with a relief valve 5-1 and a first check valve 5-2, The valve 5-2 is configured to prevent the hydraulic fluid from flowing from the fourth flow path 4 to the third flow path 3,
The first elongate flow path 5 and the second elongate flow path 2 between the relief valve 5-1 and the first check valve 5-2 are connected to each other by a second extension And the second check valve 6-1 is configured to prevent the hydraulic fluid from flowing from the second flow path 2 to the first extension flow path 5,
The relief valve 5-1 passes the operating oil whose pressure has risen at the bucket lowering port 21 according to the set pressure,
A part of the operating oil whose pressure has risen in the bucket lowering port 21 is supplied to the boom lowering port 12 of the boom cylinder 10 through the relief valve 5-1 and the second check valve 6-1 And the front loader hydraulic device.

The method according to claim 1,
The operating fluid whose pressure has risen in the bucket descent port 21 when the boom 13 rises flows through the relief valve 5-1 and the first check valve 5-2 to the bucket rising port 22 of the bucket cylinder 20 To the front loader.

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