JPS61282522A - Oil-pressure operator for back hoe - Google Patents

Abstract

PURPOSE:To stabilize the turning speeds of a slewing base and an operating arm by providing a detector to detect the operations of an operating lever for a rotary operating valve and an interrupting valve to interrupt the confluence of pressure oil to a vertically rocking operation valve on the basis of information from the said detector. CONSTITUTION:In the center bypass of a rotary operation valve V9 to ratationally operate a slewing base 2 or an operating arm 15, a confluence pipeline 12 is provided such that pressure oils are joined to the vertically rocking operation base V6 of the arm 15. A sensor 23 to detect the operational condition of an operating lever 22 for the valve V9 is provided. During the operation of the lever 22 on the basis of the information from the sensor 23, the confluence of pressure oils to the base V6 is interrupted by a confluence interruption valve 24 provided to the pipeline 12. The slewing base 2 or the operating arm 15 can thus be stably operated rotationally, and the inching operability during the fine operation period can also be kept under good condition.

Description

[Detailed description of the invention] ゛ (Industrial field of application) The present invention provides a center bypass of a rotation operation valve for rotating a swivel table or a working arm to a vertical swing operation valve of the working arm. The present invention relates to a hydraulic operating section of a backhoe that is provided with a merging pipe line for merging pressure oil.

[Conventional technology]

Conventionally, in the hydraulic operation unit, the rotation operation valve and the vertical swing operation valve are operated from the rotation operation valve even when the swivel table or the work arm is simultaneously rotated while the arm is being operated. The oil lines were connected so that the two pressurized oils met at the confluence pipe.

[Problem that the invention seeks to solve]

However, when the arm is operated, the pressure in the confluence pipe becomes high, and when the swivel table or working arm is operated, the operating speed becomes faster, increasing the danger and worsening the inching operability during minute operations. There was a risk.

An object of the present invention is to prevent the operating speed of the swivel base or working arm from increasing when the arm is operated.

[Failure to solve the problem]

The characteristic configuration of the hydraulic operation section of the backhoe in the present invention is as follows:
A detector is provided to detect the operation of the operating lever for the rotation operating valve, and a merging cutoff valve is installed to cut off the flow of pressure oil to the vertical swing operating valve when the operating lever is operated based on information from the detector. The function and effect are as follows.

[For production]

In other words, if the rotation operation valve of the swivel table or work arm is operated with the operation lever while the arm is operating the vertical swing operation valve, the vertical swing operation will be performed by the merging cutoff valve installed in the merging pipe. Since the flow of pressure oil to the valve is cut off, the pressure in the merge line does not increase, and the rotational speed of the swivel table or working arm remains stable and does not increase.

〔Effect of the invention〕

Therefore, the swivel table or the working arm can be rotated stably, and the inching operability during minute operations can be maintained well, making it possible to maintain safety and good operability.

〔Example〕 Next, examples will be shown.

As shown in Figure 2, a swivel platform (2) and a dozer device (3) are attached to a crawler type traveling device (1), and a backhoe device (4), boarding and driving section (5), and driving section (6) are rotated. stand (
2) It consists of a small backhoe and a work vehicle that can be attached to a vehicle and used for soil removal work.

A hydraulic circuit for driving the traveling device (1), the swivel table (2), the dozer device (3), the backhoe device (4), etc. will be described in detail below with reference to FIG.

The first to third pumps (Pυ, (pg
).

(P9) are arranged in conjunction with the same engine, and the first traveling operation valve (V9) of the hydraulic motor (Ml) for the left and right crawlers, and the operation valve (V9) of the boom hydraulic cylinder (C1)
Vz), the operation valve (V
9) are connected in parallel to the first pump (P9) in a multiple valve type with center bypass arranged in that order. The second traveling operation valve (V4) of the hydraulic motor (Mg) for the left and right crawlers, the boom expansion operation valve (V9), the merging spacer (7), and the vertical swing operation valve of the arm hydraulic cylinder (C1) (V9), operation valve for service port (8) (
V? ) are connected in parallel to the second pump (P2) in the form of multiple valves with sensor bypass arranged in that order. Rotary operation valve (V9) of cylinder (C4)
), hydraulic motor for swivel table (M-type rotary operation valve (V9),
The operation valve (Vl+1) of the dozer hydraulic cylinder (C2) is arranged in the order of the multiple valve type with center bypass and connected in parallel to the third pump (P3).

The left and right crawler hydraulic motors (MO, 0+2> are connected separately to the first and second pumps (Pυ, (h)) in a low-speed state, and the pressure oil from both pumps (P+) and (Pt) is combined. A speed change valve (9) is provided for switching to a high speed state where the ground pressure motors (L) and (1'h) are supplied in series.

Operation valve (Vs) for swing, swivel and dozer
, (V9), and (V+.) are connected to the merging spacer (7) connected to the second pump (P2) by the merging pipe line (12), and the work is carried out by connecting the center bypass (11) of the multiple valve including When the arm (15) and the swivel table (2) are rotated, and when the def device (3) is stopped, the attachment connected to the arm (15) or the service port (8) is (h) It is constructed so that it can be driven at high speed using the pressure oil from (P3).

Main relief circuits (10) and (13) connected to the first to third pumps (P9) and (P9) respectively
.

The relief pressure (14) is set at a high pressure and at an appropriate value to prevent the engine from stopping due to overload during normal backhoe work or dozer work. still,
In Figure 1, (17) is a counterbalance valve, (1B
) is the brake valve, (19) is the oil tank, (20
) is a return oil path, and (21) is a check valve with a built-in spacer.

A detector (23) consisting of a limit switch is provided to detect the operation of the operating lever (22) for the rotary operating valve (V9) of the swivel base (2), and based on the information from the detector (23), A merging cutoff valve (24) consisting of an electromagnetic switching valve that cuts off the flow of pressure oil to the vertical swing operating valve (V9) when the operating lever (22) is operated is provided in the merging line (12), When the working arm (15) is operated to swing up and down, when the rotation operation valve (V9) is set to a medium opening degree for the rotation operation, the hydraulic pressure in the merging pipe (12) is configured so as not to increase. .

[Another example]

The detector (23) is a rotary operation valve (V9) for a rotating base.
Instead of detecting the operation of the operation lever (22), the operation of the operation lever of the swing rotary operation valve (v8) may be detected.

The backhoe of the present invention may have an automatic rotation stop mechanism, and in this case, an electromagnetic device that operates the rotation operation valve (V9) for the rotation platform (2) or the rotation operation valve (V9) for the swing The command voltage to the proportional valve is detected by a detector (23), and when the command voltage is applied to the electromagnetic valve, the merging cutoff valve (24) is configured to operate.

[Brief explanation of drawings]

The drawings show an embodiment of a hydraulic operating section of a backhoe according to the present invention, and FIG. 1 is a schematic hydraulic circuit diagram, and FIG. 2 is an overall side view of a backhoe working vehicle. (2)... Swivel base, (12)... Merging pipe, (15)... Working arm, (22)...
...operation lever, (23) ...detector,
(24)...Merge cutoff valve, (V9)...
・Vertical swing operation valve, (V9), (Vs)...
・Rotary operation valve.

Claims (1)

[Claims] The center bypass of the rotation operating valve (V_9) or (V_8) for rotating the swivel table (2) or the working arm (15) is connected to the vertical swing operating valve (V_8) of the working arm (15).
A hydraulic operation part of a backhoe which is provided with a merging pipe (12) for merging pressure oil into the rotary operation valve (V).
A detector (23) is provided to detect the operation of the operating lever (22) for (V_9) or (V_8), and the detector (23)
) A merging cutoff valve (24) is provided in the merging pipe (12) that cuts off the flow of pressure oil to the vertical swing operating valve (V_6) when the operating lever (22) is operated based on information from the merging pipe (12). The hydraulic control section of a backhoe.