JP2539479Y2 - Work vehicle hydraulic circuit operation structure - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation structure of a control valve for a service port of a construction machine such as a backhoe or a wheel loader. A service port for supplying and discharging hydraulic oil to and from the device and a variable flow control valve for the service port are provided, and an operation unit of the variable flow control valve and an operation tool provided in an operation unit are interlocked via a transmission member. The present invention relates to a hydraulic circuit operation structure of a working vehicle.

[0002] The present invention can also be applied to a work vehicle with a hydraulic drive device such as a tractor or a transport vehicle with a hydraulic lift device.

[0003]

2. Description of the Related Art This type of hydraulic circuit operation structure is, for example,
As shown in Japanese Utility Model Laid-Open Publication No. 1-167456, utilizing a method of providing a detent mechanism and interlocking a service pedal and a variable flow control valve and providing a large number of locking positions of the detent mechanism, It has been considered to adjust and set the opening and closing amount of the control valve.

[0004]

However, since the opening / closing amount of the service port control valve does not change so frequently, it is costly to construct the dedicated adjusting means as described above. Can be seen.

Accordingly, an object of the present invention is to provide an inexpensive structure for adjusting the opening and closing of a service port control valve.

[0006]

According to the present invention, there is provided a hydraulic circuit operating structure for a working vehicle, comprising: a connecting member for connecting an operating part and a transmitting member; and a connecting member for connecting an operating tool and a transmitting member. Attaching a restricting member that regulates the maximum operation amount of the operation unit to one of the connection members with the fixed unit accompanying the movement by the operation of the operation tool,
It is characterized in that the mounting position of the regulating member with respect to the connecting member is adjustable so that the maximum operation amount can be changed and adjusted.

[0007]

That is, in the case of a backhoe, for example, the operation part of the control valve provided below the floor of the operation part and the operation part of the operation part are interlocked with a wire. Are connected in an interlocked manner using a transmission member such as a rod or Bowden wire, so that the operation section and the transmission member, and the operation tool and the transmission member, are often connected and connected via the connection member.

Accordingly, at least one of the connecting members is provided with a regulating member for regulating the maximum operation amount of the operation portion by contacting the fixing portion with the movement of the operation tool, and the maximum operation amount is changed and adjusted. If the mounting position of the regulating member with respect to the connecting member can be adjusted so as to be possible, a variable adjusting means of the opening / closing amount of the control port for the service port will be configured using the connecting member which is an essential part. .

[0009]

As a result, the opening / closing adjustment structure of the service port control valve can be provided at a relatively low cost by devising a dual use of the component parts.

In the case where the opening / closing adjusting means is applied to one of the connecting members, there is an advantage that the one which can be easily arranged can be selected.
When the opening / closing adjusting means is applied to each of the two connecting members, it is convenient in practical use to set the fine adjustment on the near side and the large adjustment on the far side.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention applied to a backhoe as an example of a working vehicle will be described below with reference to the drawings. FIG. 2 shows an excavation work device W provided with a service port 2 for an attached work device such as a breaker at the tip of a boom 1 that can be moved up and down by a boom cylinder C, and a two-position switching type variable flow control valve for the service port 2. 3 shows a backhoe in which the operation unit 3 is arranged below the step 5 of the operation unit 4.

A horizontal axis P is provided below the swivel base 6 of the operating unit 4.
A service pedal (corresponding to an operating tool) 7 is provided, which can be swung. The operating portion 7A of the pedal 7 (corresponding to a connecting member) and the spool (corresponding to an operating portion) 8 of the control valve 3 are pushed. A pull-type operation cable (corresponding to a transmission member) 9 is interlocked and connected.

As shown in FIG. 1, the operation cable 9 and the spool 8 are connected and connected via an adapter (corresponding to a connecting member) 10, and the control accompanying the movement of the adapter 10 by the swing operation of the pedal 7. A bolt (corresponding to a restricting member) 12 that regulates the maximum sliding operation amount of the spool 8 by making contact with the case 11 (corresponding to a fixed portion) of the valve 3 and that allows the maximum sliding operation amount to be changed and adjusted.
The adjusting mechanism T is configured by being attached together with the lock nut 13 to the projecting piece 10a of the adapter 10.

The control valve 3 is urged to return the spool 8 to the neutral position, and the amount of sliding of the spool 8 to the pressure oil supply side position with respect to the attached working device is determined by the contact between the bolt 12 and the case 11. It is regulated by.

When the service pedal 7 is in its depressed position,
This is a two-position switching type configuration in which a stopper 14 that is rotatable about a vertical axis is extended and retained by locking, and the operating part 7 and the operation cable 9 are connected via a flexible mechanism 15 such as a winding spring. This corresponds to the stepless adjustment operation of the adjustment mechanism T of the spool 8.

[Other Embodiment] As shown in FIG. 3, an adjusting mechanism T capable of changing and adjusting the maximum sliding amount of the three-position switching control valve 3 to both sides of the expansion and contraction of the spool 8 may be constituted.

That is, the adapter 10 is interposed in a state where the protruding piece 10a is attached to the tip screw portion of the operation cable 9,
A stop nut (corresponding to a regulating member) 16 with a regulating cylinder 16a is locked to the adapter 10 by a lock nut 17, and a regulating rod (corresponding to a regulating member) 18 is screwed to the protruding piece 10a.

The operation of the lock nut 17 and the stop nut 16 adjusts the amount of pushing of the spool when the restricting cylinder 16a contacts the case 11, and the restricting rod 18 and the control valve are controlled by operating the restricting rod 18 and the protruding piece 10a. The spool withdrawal amount at the time of contact with the cable supporting bent portion (corresponding to the fixing portion) 20 of the fixing stand 19 of 3 is adjusted.

Incidentally, in the claims of the utility model registration, reference numerals are written for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings by the entry.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view showing an operation structure of a control valve.

FIG. 2 is a side view of a backhoe.

FIG. 3 is a diagram showing an operation structure of a three-position switching control valve.

[Explanation of symbols]

 2 Service Port 3 Variable Flow Control Valve 4 Operating Unit 7 Operating Unit 7A, 10 Connecting Member 8 Operating Unit 9 Transmission Member C Hydraulic Cylinder W Working Device L Regulator

Claims (1)

(57) [Scope of request for utility model registration] An operating device (W) driven by a hydraulic cylinder (C) is provided, and a service port (2) for supplying and discharging hydraulic oil to and from an attached operating device and a variable flow rate control for the service port (2). Valves (3) are provided, respectively, and an operation part (8) of the variable flow control valve (3) and an operation tool (7) provided in the operation part (4) are interlocked and connected via a transmission member (9). A hydraulic circuit operation structure for a work vehicle, comprising: a connection member (10) between the operation portion (8) and the transmission member (9); the operation tool (7); and the transmission member (9).
One of the connection members (1A) with the connection member (7A).
0 or 7A), a restricting member (L) for restricting a maximum operation amount of the operation unit (7) by contact with a fixed unit accompanying movement by operation of the operation tool (7) is attached, and the maximum operation is performed. A hydraulic circuit operating structure for a working vehicle, wherein a mounting position of the regulating member (L) with respect to the connecting member (10 or 7A) is adjustable so that the amount can be changed and adjusted.