JPH09165786A - Structure of operating lever for working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the safety for operation of a working machine such as a backhoe or the like. SOLUTION: A lever base 27 having an operating lever 16 is installed at a position near a seat 20 so that it can either be inclined or fixed. The operating lever 16 and pilot operated hydraulic control valves for controlling operations of hydraulic actuators are communicably connected through a pilot hydraulic line, and an opening/shutting value mechanism that checks transmission of fluid pressure in the pilot hydraulic line in accordance with inclination of the lever stand 27 is provided at the pilot hydraulic line. A safety lever 46 is provided in projection at the front side of the lever base 27, and the safety lever 46 is interlocked with the opening/shutting valve mechanism and furthermore, the safety value 46 is so constructed that transmission of fluid pressure in the pilot hydraulic line is checked as the operation of the safety lever 46 is shited to a release position 46-2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operating lever structure for a working machine such as a backhoe.

[0002]

2. Description of the Related Art Conventionally, a hydraulic control valve for controlling the operation of a hydraulic actuator provided in a working machine such as a backhoe,
A linkage using a rod or wire, etc., is interlockingly connected to the operating lever provided in the driver, and the lever supports the lever to support the seating or leaving of the driver. The one that can be freely tilted together with the table (Shokaisho 6
No. 0-452, No. 60-53858, No. 61
Japanese Unexamined Patent Application Publication No. 60-53859 discloses a method in which a main hydraulic circuit for operating a hydraulic actuator at the time of tilting is cut to ensure safety.

[0003]

However, in the link mechanism using a rod or the like, the resistance increases due to rusting of the connecting portion of each link member, oil shortage, etc., and the operation becomes heavy. It is difficult to perform the operation due to the non-uniformity and the occurrence of backlash due to the wear of the connecting portion, and it is difficult to perform the delicate operation.

Further, since the mechanism configured to transmit the operation by using the link mechanism can be freely tilted, the structure becomes complicated, and the operation lever can be adjusted according to the physique and preference of the driver. Could not be adjusted.

[0005]

According to the present invention, a lever base having an operating lever is tiltably fixed at a position near a seat, and the pilot lever is used to control the operation of the operating lever and a hydraulic actuator. The hydraulic control valve is connected to the hydraulic control valve via a pilot hydraulic path, and an opening / closing valve mechanism is provided in the pilot hydraulic path that blocks transmission of fluid pressure in the pilot hydraulic path due to tilting of the lever base. A safety lever is provided so as to project from the lever base side toward the front, and the safety lever and the opening / closing valve mechanism are interlockingly connected, and the pilot is accompanied by the operation of the safety lever to the release position. It is intended to provide an operating lever structure for a working machine, characterized in that it is configured to prevent transmission of fluid pressure in a hydraulic path.

Further, in the present invention, a control box is erected on the side of the seat, and a lever base having an operation lever is tiltably fixed to the control box.
On the control box side, a safety lever that opens and closes the entry / exit passage to the seat side is projected, and with the safety lever,
Another feature is that the on-off valve mechanism provided in the pilot hydraulic path is interlocked.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiment of the present invention will be described in detail with reference to the drawings. In FIG. 1, (A) shows a backhoe as an example of a working machine, and a traveling frame (2) having a crawler traveling device (1). ), The swivel base (3) is installed upright in the center of the
A turning frame (4) is mounted on the upper part of (3) so that it can turn left and right.A motor unit (5) is arranged at the rear of the turning frame (4), and an operating unit (6) is arranged at the center of the turning frame (4). A bracket (7) protrudes from the front end of the revolving frame (4) to connect the base end of the excavation work section (B).

The excavating work section (B) pivots a boom support (8) so as to be rotatable left and right on a bracket (7).
The boom (9), the arm (10) and the bucket (11) are sequentially connected in such a manner as to be vertically rotatable, and the boom (9)
(9), hydraulic cylinders (12), (13) and (14) for operating the arm (10) and the bucket (11) are provided.

[0009] A hydraulic motor (1) for turning the airframe is provided on the side of the turning frame (4) which can turn with respect to the turning base (3).
5) is provided.

At the time of excavation work, the above-mentioned hydraulic actuators, that is, the hydraulic cylinders (12), (13), (14) and the hydraulic motor (15) are most frequently used, and the operation control of these hydraulic actuators is controlled. , Driving unit (6)
The operation is performed through a pilot-actuated hydraulic control valve by the operation of left and right operation levers (16) and (17) provided in the inside.

The driving section (6) is provided with a seat (20) at the rear inside a cabin (19) having a door (18) on the left side as shown in FIG. Travel lever (21a) (21b)
The left and right control boxes (22) and (23) are erected on the left and right sides of the seat (20), and the left and right armrests (24) are located above them.
(25) is provided.

Right and left operation levers (16) and (17) are provided in front of the left and right armrests (24) and (25), respectively.
In front of 7), a meter box (26) projects from the right control box (23).

In particular, the left operating lever (16) is erected on the upper surface of a lever base (27), which will be described later.
Are disposed on the upper part of the left control box (22) so as to be tiltable, and the base end of each operation lever (16) (17) has two positions in four directions, front, rear, left and right as shown in FIG. Switching valve (28a)
(28b) (28c) (28d), (29a) (29b) (29c) (29d) are arranged in conjunction with the front, rear, left and right operations of each base end,
Each two-position switching valve (28a) (28b) (28c) (28d), (29a) (29b) (29
c) On the input side of (29d), the P port (31) communicating with the pilot hydraulic pump (30) side via the hydraulic hose (39-1) and the hydraulic oil tank (32) side and the hydraulic hose (39- A T port (31 ') communicating with the pilot-operated hydraulic control valves (33), (34), (35), and (36) is provided on the output side.
7a) (37b) and flexible hydraulic hoses (39-3) (39-4) (39-5) (39-
A V port (38) communicating through 6) is provided.

Each pilot-operated hydraulic control valve
(33) (34) (35) (36) are hydraulic pumps (40a) (40b) (4
0c) and each hydraulic actuator, ie boom,
It is interposed between the hydraulic cylinders (12) (13) (14) for arm and bucket operation and the hydraulic motor (15) for body turning, and each hydraulic control valve (33) (34) (35) (36) Pilot pressure receiver
(37a) (37b) two-position switching valve (28a) (28b) (28c) (28d), (29a)
(29b) When the pilot oil pressure from (29c) (29d) acts,
The fluid pressure causes the spools of the hydraulic control valves (33), (34), (35), and (36) to operate in conjunction with each other, and switches the oil passage to operate the hydraulic actuator.

A two-position switching valve (28a) provided in conjunction with the pilot hydraulic pump (30) and the left operating lever (16)
(28b) (28c) (28d), (29a) (29b) (29c) (29d), and pilot-operated hydraulic control valves (33) (34) (35) (36)
While connecting at (39-1), (39-2), (39-3), (39-4), (39-5), and (39-6), these form a pilot hydraulic path (30A).

A hydraulic hose (39-1) for connecting the pilot hydraulic pump (30) with the two-position switching valves (28a) (28b) (28c) (28d), (29a) (29b) (29c) (29d). ), The branch oil passage (3
9-7), the cutoff valve is switched to the hydraulic oil tank (32) without returning the pressurized hydraulic oil from the pilot hydraulic pump (30) to the two-position switching valve group. A bleed-off valve (41) for performing the above-mentioned operation is provided. When the bleed-off valve (41) is closed, pressure oil is supplied to the two-position switching valve group, and when the bleed-off valve (41) is opened, the pressure oil is released to the hydraulic oil tank (32). Thus, the operation of the two-position switching valve group is stopped.

Therefore, the bleed-off valve (41) is provided in the pilot hydraulic path (30A) as described above, and the bleed-off valve (41) is opened and closed to provide the bleed-off valve (41) in the pilot hydraulic path (30A). Position switching valve (28a) (28b) (28c)
(28d), (29a) (29b) (29c) (29d), or each pilot operated hydraulic control valve (33) (34) (35) (36) linked to the operation of the operating lever (16) , Or interlocking can be automatically interrupted.

(42) is a relief valve, (42 ') is a filter unit, (43) is a return spring of a two-position switching valve, (44) is a choke for adjusting the return operation speed of the valve, (44) 45) shows a local pilot oil passage for relating the response of the operation to the pie trot pressure.

In FIG. 4, the left control box (22)
The bleed-off valve (41) is disposed in the left control box (22), and the bleed-off valve (41) projects forward from the left control box (22). It can be operated by operating the safety lever (46).

The safety lever (46) is provided at a set position (46-1) so as to be able to open and close a boarding passage when the driver gets on and off the seat (20). Seat (2
When leaving the position (0), the safety lever (16) is rotated upward to operate the release position (46-2).

The lever base (27) on which the left operating lever (16) is erected is provided with a hinge part provided at the lower rear end of the base (27).
The hook (48) provided at the lower front end of the base (27) is provided with a pin (48) provided at the front upper end of the left control box (22). 49) to fix the tilt, and release the engagement of the hook (48) and the pin (49) by operating the lock lever (50) protruding from the lower front end of the lever base (27). The lever base (27) can be tilted.

Further, an interlocking lever (51) is provided on the inner surface of the rear side wall of the lever base (27) in front of the hinge (47), and the interlocking lever (51) is connected to the interlocking rod (52). Connect the upper end to the bell crank (55) pivotally attached to the pivot shaft (54) via the shock absorbing mechanism (53) provided at the lower end of the interlocking rod (52), and bleed the bell crank (55) and When the spool (56) of the off valve (41) is connected and the lever base (27) is tilted, the bleed-off valve (41) is bleed-off operated in conjunction with this.

The base end of the safety lever (46) is also connected to the pivot (54), so that either the tilting of the lever base (27) or the operation of the safety lever (46) can be operated. For example, the bleed-off valve (41) operates to cut off the pilot hydraulic path (30A), and the operation of the pilot-operated valve type hydraulic control valves (33), (34), (35), and (36) stops. It has a heavy safety structure.

When the lever base (27) is tilted rearward and upward, the operation does not operate because the transmission of the fluid pressure is blocked, so that the excavation work section (B) does not operate unexpectedly, and it is safe. is there.

The reason that the lever base (27) can be tilted rearward and upward is to increase the space of the approach route to the seat and to make it easier for the driver to leave and take a seat. The two-position switching valve provided in the base (27) is connected to the hydraulic hose (3
The tilting is made possible by communicating with the other using 9).

In addition, when taking off or taking a seat with the lever base (27) tilted backward, even if clothes or the like are caught on the left operation lever (16), safety is ensured by the above-described safety structure.

The left armrest (24) is also rotatable rearward and upward about the rear end.

Since the hydraulic control valves (33), (34), (35), and (36) operate with the energy of the pilot hydraulic pressure,
The operating force and stroke of the operating lever (16) can be set independently of the operating load and stroke of the spools of the control valves (33) (34) (35) (36). No comfortable operation feeling can be obtained.

In FIGS. 2 and 4, (58) indicates a throttle lever and (59) indicates a guard frame.

[0030]

According to the present invention, the operating lever and the pilot type hydraulic control valve for controlling the operation of the hydraulic actuator are communicatively coupled via the pilot hydraulic path, and in the pilot hydraulic path, Since the on-off valve mechanism that blocks the transmission of fluid pressure with the tilt of the lever base is provided, the lever base tilts backward when the driver leaves the seat, so the pilot hydraulic path does not operate, Therefore, even if the operation lever is accidentally operated, the working unit does not operate and it is safe.

Further, a safety lever is provided so as to protrude forward from a control box side having an operation lever, so that the getting-off passage can be freely opened and closed by the safety lever.
Since the safety lever and the opening / closing valve mechanism are interlockingly connected, when the driver moves away from the seat, only the safety lever is operated to the release position and the pilot hydraulic path does not operate, so that it is safe.

[Brief description of the drawings]

FIG. 1 is an overall side view of a backhoe as a working machine having an operating lever structure according to the present invention.

FIG. 2 is a perspective view of a driving unit of the backhoe.

FIG. 3 is a hydraulic circuit diagram.

FIG. 4 is a left side view of a driving unit.

[Explanation of symbols]

 (12) Hydraulic cylinder (13) Hydraulic cylinder (14) Hydraulic cylinder (15) Hydraulic motor (16) Operating lever (20) Seat (22) Control box (24) Armrest (27) Lever base (30A) Pilot hydraulic Path (33) Hydraulic control valve (34) Hydraulic control valve (35) Hydraulic control valve (36) Hydraulic control valve (41A) Open / close valve mechanism (46) Safety lever

Claims (2)

[Claims] 1. An operating lever (16) near a seat (20).
A lever base (27) having a lever is arranged so that it can be tilted and fixed, and a pilot-operated hydraulic control valve (33) (34) (35) (36) that controls the operation of the operation lever (16) and hydraulic actuator. ) And is communicatively connected via the pilot hydraulic path (30A),
Moreover, in the pilot hydraulic path (30A), the lever base (2
An on-off valve mechanism (41A) that blocks the transmission of fluid pressure in the pilot hydraulic path (30A) along with the tilting of 7) is provided, and the safety lever (46) is moved forward from the lever base (27) side. Projectingly, the safety lever (46) and the opening / closing valve mechanism (41A) are interlockingly connected, and the safety lever is also provided.
An operating lever structure for a working machine, characterized in that it is configured to prevent the transmission of fluid pressure in the pilot hydraulic path (30A) in response to the operation of (46) to the release position (46-2). 2. A control box on the side of the seat (20)
(22) is erected and a lever base (27) having an operation lever (16) is tiltably fixed to the control box (22), and a seat (20) is provided on the control box (22) side. ) Side is provided with a safety lever (46) for opening and closing the passage, and the safety lever (46) and the opening / closing valve mechanism (41A) provided in the pilot hydraulic path (30A) are linked together. Working machine operation lever structure.