JPH05311700A - Operation lever structure for working machine - Google Patents

Abstract

PURPOSE:To operate a working machine such as a back hoe in the safe state. CONSTITUTION:A lever base 27 having an operation lever 16 is tiltably and fixably arranged at a position near a seat 20, and the operation lever 16 is transferrably connected to pilot-activated hydraulic control valves 33, 34, 35, 36 controlling the operation of a hydraulic actuator via a pilot hydraulic passage 30A. An opening/closing valve mechanism 41A blocking the transfer of the fluid pressure of the pilot hydraulic passage 30A when the lever base 27 is tilted is provided in the pilot hydraulic passage 30A, a safety lever 46 is protruded forward from the lever base 27 side, and the safety lever 46 and the opening/ closing valve mechanism 41A are interlocked and connected. The transfer of the fluid pressure of the pilot hydraulic passage 30A is blocked when the safety lever 46 is operated to the 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 is interlockingly connected to the operating lever provided in the driver, and the lever supports the lever to support the seated or abandoned flight of the driver. The one that can be tilted freely with the stand
No. 0-452, No. 60-53858, No. 61
Further, there has been disclosed a safety device in which a main hydraulic circuit for operating a hydraulic actuator at the time of tilting is cut off for safety (Japanese Utility Model Laid-Open No. 60-53859).

[0003]

However, in a link mechanism using a rod or the like, the resistance increases due to rusting of the connecting portion of each link member, oil depletion, 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 one configured to transmit the operation 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. I couldn't adjust the position of.

[0005]

According to the present invention, a lever base having an operating lever is tiltably fixed to 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 via a pilot hydraulic path so that it can be transmitted, and an opening / closing valve mechanism that blocks the transmission of fluid pressure in the pilot hydraulic path due to the tilting of the lever base is installed in the pilot hydraulic path. 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 interlocked and connected. Moreover, the pilot is accompanied by the operation of the safety lever to the release position. The present invention provides an operating lever structure for a working machine, which is configured to prevent the 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 and connected.

[0007]

Embodiments 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 swivel frame (4) is mounted on the upper part of (3) so that it can swivel left and right, a prime mover section (5) is installed at the rear of the swivel frame (4), and an operating section (6) is installed at the center. A bracket (7) is provided on the front end of the revolving frame (4) so as to connect the base end of the excavation work section (B).

The excavation work section (B) pivotally supports the boom support (8) on the bracket (7) so that the boom support (8) can be rotated left and right, and the boom (8) is supported.
The boom (9), the arm (10), and the bucket (11) are connected in this order in a vertically rotatable manner.
The hydraulic cylinders (12), (13) and (14) for operating the (9), the arm (10) and the bucket (11) are interposed.

On the side of the swing frame (4) which is rotatable with respect to the swing base (3), a hydraulic motor (1
5) is provided.

During excavation work, the above hydraulic actuators, that is, the hydraulic cylinders (12), (13) and (14) and the hydraulic motor (15) are most frequently used, and the operation control of these hydraulic actuators is performed. , Driving department (6)
The operation is performed via the pilot operated hydraulic control valve by operating the left and right operation levers (16) and (17) provided inside.

As shown in FIG. 2, the operating unit (6) is provided with a seat (20) inside and rearward of a cabin (19) having a door (18) on the left side surface thereof. Travel levers (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 placed above them.
(25) is provided.

Left and right operation levers (16) and (17) are installed upright in front of the left and right armrests (24) and (25), respectively.
A meter box (26) is projected from the right control box (23) in front of 7).

In particular, the left operation lever (16) is erected on the upper surface of a lever base (27) which will be described later, and the lever base (27).
Is mounted on the upper part of the left control box (22) so that it can be tilted. At the base end of each operating lever (16) (17), there are 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 operation of the front, rear, left and right of each base end, respectively.
Two-position switching valves (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 via 2) is provided, and the pilot pressure receiving part (3) of the pilot operated hydraulic control valve (33) (34) (35) (36) is provided on the output side.
7a) (37b) and flexible hydraulic hose (39-3) (39-4) (39-5) (39-
There is a V port (38) that communicates via 6).

Each pilot operated hydraulic control valve
(33) (34) (35) (36) are hydraulic pumps (40a) (40b) (4
0c) and each hydraulic actuator, i.e. boom,
It is installed between the hydraulic cylinders (12) (13) (14) for arm and bucket operation and the hydraulic motor (15) for turning the machine, and each hydraulic control valve (33) (34) (35) (36) Pilot pressure receiver
(37a) (37b) two-position switching valve (28a) (28b) (28c) (28d), (29a)
When the pilot hydraulic pressure from (29b) (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, switching 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 operation 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), they form the pilot hydraulic path (30A).

Further, a hydraulic hose (39-1) for connecting the pilot hydraulic pump (30) and the two-position switching valves (28a) (28b) (28c) (28d), (29a) (29b) (29c) (29d) ) In the middle position, the branch oil passage (3
9-7) is provided to the cut-off valve while switching the pressurized hydraulic oil on the pilot hydraulic pump (30) side to the hydraulic oil tank (32) side without sending it to the two-position switching valve group and returning it. A bleed-off valve (41) that performs the above function is provided. Then, 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 opened to the hydraulic oil tank (32). Then, the operation of the two-position switching valve group is stopped.

Therefore, by providing the bleed-off valve (41) in the pilot hydraulic path (30A) as described above and opening and closing the bleed-off valve (41), the bleed-off valve (41) is installed 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.

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

Also, in FIG. 4, the left control box (22)
The bleed-off valve (41) is arranged 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 the set position (46-1) so that the driver can open and close the entry / exit passage when getting on / off the seat (20). Seat (2
When leaving 0), the safety lever (16) is rotated upward to operate to the release position (46-2).

The lever base (27) on which the left operation lever (16) is erected is a hinge portion provided at the lower rear end of the base (27).
A hook (48) provided at the lower front end of the base (27) is tiltable rearward and upward around the center (47), and a hook (48) provided at the front upper end of the left control box (22). 49) to lock the tilt, and release the engagement between 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.

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). The interlocking lever (51) is provided with an interlocking rod (52). Connect the upper end to the bell crank (55) pivotally attached to the pivot shaft (54) through the shock absorbing mechanism (53) provided at the lower end of the interlocking rod (52), and bleed the bell crank (55). 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 in conjunction with this.

Further, the base end of the safety lever (46) is also connected to the pivot shaft (54), and therefore 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 shut off the pilot hydraulic path (30A), and the operation of the pilot operated valve type hydraulic control valves (33) (34) (35) (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 the excavation work section (B) does not operate unexpectedly and is safe. is there.

It is to be noted that the lever base (27) can be tilted upward and rearward in order to increase the space of the entry path to the seat and to allow the driver to leave and sit. The two-position switching valve installed in the base (27) was attached to the hydraulic hose (3
By using 9) to communicate with others, the tilting is possible.

Further, in the seating area where the lever base (27) is tilted rearward, even if clothes etc. are caught on the left operation lever (16), the safety is ensured by the above safety structure.

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

Further, since the hydraulic control valves (33) (34) (35) (36) are operated by the energy of pilot hydraulic pressure,
It is possible to set the operating force and stroke of the operating lever (16) regardless of the operating load and stroke of the spool of the control valve (33) (34) (35) (36) and fatigue even during long-term operation. You can get a comfortable operation feeling.

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

[0030]

According to the present invention, the operation lever and the pilot type hydraulic control valve for controlling the operation of the hydraulic actuator are communicatively connected via the pilot hydraulic path,
In addition, since an opening / closing valve mechanism is provided in the pilot hydraulic path to prevent the transmission of fluid pressure due to the tilting of the lever base, the lever base tilts backward when the driver leaves the seat. Since the pilot hydraulic path does not operate, the working unit does not operate even if the operating lever is operated unexpectedly, which is safe.

Further, a safety lever is provided so as to project from the side of the control box having the operation lever, and the passenger can freely open and close the passage using the safety lever, and
Since the safety lever and the on-off valve mechanism are interlockingly connected, it is safe because the pilot hydraulic path does not operate when the driver leaves the seat only by operating the safety lever to the release position.

[Brief description of 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) Control 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) is provided near a seat (20).
A lever base (27) having a lever is tiltably fixed, and a pilot-operated hydraulic control valve (33) (34) (35) (36) that controls the operation of the operating lever (16) and hydraulic actuator is provided. ) 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) is provided to prevent transmission of fluid pressure in the pilot hydraulic path (30A) due to tilting of (7), and the safety lever (46) is moved forward from the lever base (27) side. Projectingly, the safety lever (46) and the on-off 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 constructed so as to prevent transmission of fluid pressure in the pilot hydraulic path (30A) in accordance with 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 operating lever (16) is tiltably fixed to the control box (22) .A seat (20) is provided on the control box (22) side. ) Side, a safety lever (46) that opens and closes the entry / exit passage is projected, and the safety lever (46) and the opening / closing valve mechanism (41A) provided in the pilot hydraulic path (30A) are linked and linked. Working machine operation lever structure.