JP2002285588A - Safety device of slewing working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce material costs and manufacturing costs of a safety device by simplifying the mechanism of an interlock between a switching lever and an unloading valve to the utmost. SOLUTION: The safety device of a slewing working machine is provided with an operating box 26 which is disposed on a slewing base 3, a pilot valve unit 33 which is housed in the operating box 26 and to which an operating lever 27 protruding outside the operating box 26 is connected swingably, the switching lever 44 which is pivoted turnably on the operating box 26, and the unloading valve 43 which raises or releases pilot pressure of the unit 33 with switching operations of the switching lever 44. A rotating shaft of the switching lever 44 is directly connected to a rotary shaft 47 which is built into the operating box 26 so as to switch an oil passage of the unloading valve 43.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a safety device for a turning work machine such as a backhoe.

[0002]

2. Description of the Related Art For example, in a backhoe, a standard machine equipped with a digging device in front of a swivel base and a small rear swing machine,
There is a micro turning machine equipped with a digging device in the center of the turning table. In each of these models, the control box of the control device is arranged in front of the driver's seat on the turning table. On the upper surface of the control box, a control lever for controlling a turn, a boom, an arm, and a bucket is erected, and the control lever is swingably connected to a pilot valve housed in the control box, The output port of the pilot valve is connected to a pilot-operated control valve constituting a control valve unit via a manifold and hydraulic piping.

[0003] In such a steering device of a turning work machine,
A safety device is incorporated to prevent the operator from accidentally touching the control lever when the driver gets out of the driver's seat and unintentionally operating the boom or arm.The safety device includes a control box. A switching lever is rotatably mounted on the side surface of the vehicle, and an unload valve is provided for raising or releasing the pilot pressure of the pilot valve in accordance with the switching operation of the switching lever (for example, See JP-A-7-180191).

[0004]

In the safety device described in the above-mentioned conventional publication, the unloading valve comprises a solenoid valve arranged inside the swivel table, and a switch for switching the solenoid valve is provided in the control box. The switch is turned on / off by a switching lever.
For this reason, a relatively expensive solenoid valve is required, electrical wiring is required between the switch in the control box and the solenoid valve in the swivel base, and a switch for turning on and off the switch is required. The structure is extremely complicated in that it is necessary to attach the operating tool to the rotation shaft of the switching lever, and the material cost and the manufacturing cost of the safety device of the turning work machine have been extremely high.

SUMMARY OF THE INVENTION In view of such circumstances, an object of the present invention is to make the interlocking mechanism between a switching lever and an unload valve as simple as possible to reduce the material cost and the manufacturing cost of a safety device for a turning work machine. And

[0006]

In order to achieve the above object,
The present invention has taken the following technical measures. That is, the present invention provides a control box disposed on a swivel base, a pilot valve unit in which a control lever housed in the control box and protruding outside the control box is swingably connected, A switching lever pivotally attached to the steering box, and an unload valve for raising or releasing the pilot pressure of the pilot valve unit in accordance with the switching operation of the switching lever;
In the safety device for a turning work machine, the turning shaft of the switching lever is directly connected to a rotary shaft for switching an oil path of the unload valve incorporated in the steering box. .

In this case, since the rotary shaft of the switching lever is directly connected to the rotary shaft for switching the oil path of the unload valve incorporated in the control box, it is necessary to use a relatively expensive solenoid valve. As a result, there is no need to electrically connect the inside of the swivel table and the inside of the control box, and there is no need to attach an operating tool for turning the switch on and off to the rotating shaft of the switching lever. Further, the interlocking mechanism between the switching lever and the unload valve can be made extremely simple.

In the present invention, the method of mounting the unload valve is not particularly limited, but if the valve is directly connected to the manifold supporting the pilot valve unit in the control box, the unload valve is fixed in the control box. No special bracket is required, and in this regard, the material cost and the manufacturing cost of the safety device can be further reduced.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 4, a small rear turning type backhoe 1 exemplified as a turning work machine is mounted on a crawler traveling device 2, a turning table 3 provided on the traveling device 2 so as to be freely rotatable, and the turning table 3. It mainly comprises an excavator 4. The crawler traveling device 2 includes a track frame 5 and side frames 6 provided on both left and right sides thereof. Each side frame 6 has a driving wheel and a driven wheel disposed at the front and rear portions thereof, and a plurality of rolling wheels disposed at an intermediate portion thereof, and is wound so as to pass from the driving wheel to the driven wheel. A rubber or iron crawler 7 is driven by a hydraulically driven traveling motor 8.

At the center of the upper surface of the track frame 5, the swivel 3 is mounted via a swivel bearing. It is pivotable around the center.
A dozer 10 is pivotally attached to the front end of the track frame 5, and the dozer 10 can be moved up and down by a dozer cylinder 11. The swivel base 3 is formed by welding a mounting frame or bracket for mounting various devices to a base plate 12 to which a swivel bearing is mounted. Inside the swivel base 3, an engine, a fuel tank, an oil tank, and the like are provided. It is installed. A rear portion of the swivel 3 is covered with a bonnet 13, and a driver's seat 14 is provided on the bonnet 13. The floor portion of the swivel base 3 in front of the driver's seat 14 is a step-in / out step, and the excavator 4 is mounted on a support bracket fixed to the front end of the base plate 12 so as to be swingable about a vertical axis.

The excavator 4 includes a swing bracket 15 supported by a support bracket via a vertical axis, a boom 16 pivotally attached to the swing bracket 15 so as to be vertically swingable, and a tip end of the boom 16. An arm 17 pivotally attached to the arm 17 and a bucket 18 pivotally attached to the distal end of the arm 17 are provided. A swing bracket 15 is provided at a front portion in the swivel 3. The swing cylinder 19 can swing right and left.
Further, the boom 16 is swung by a boom cylinder 20 erected between the swing bracket 15 and the center of the boom 16, and the arm 17 is provided between the intermediate bracket projecting from the upper surface of the center of the boom 16 and the arm 17. The bucket 18 is swung by an arm cylinder 21 erected between base brackets formed at the base end, and
7 is pivoted by a bucket cylinder 22 provided between the base end bracket and the bucket link.

At the front of the swivel table 3, the cylinders 1
A control device 25 for controlling hydraulic actuators such as 1, 19 to 22 and the like to control the crawler traveling device 1, the swivel 3 and the excavator 4 as desired is provided. 3, a control box 26 disposed in front of the floor, a pair of left and right control levers 27 housed in the control box 26 and protruding outside from the upper surface of the control box 26, and provided between the control levers 27. And a pair of left and right traveling levers 28.

As shown in FIGS. 1 and 2, the steering device 25 also includes a number of hydraulic oil control units for controlling hydraulic oil to hydraulic actuators such as the cylinders 19 to 22 that drive the swing motor 9 and the excavator 4. A control valve unit 29 in which the control valves V are concentrated is provided. Among the control members for remotely controlling the control valves V, a traveling lever 28 for left and right traveling and a pedal 30 for a dozer (see FIG. 1)
An operation member whose use frequency is relatively low, such as link 3
1 and a mechanically operated control valve Vm via the rod 32
It is linked and linked.

On the other hand, hydraulic actuators requiring frequent and delicate operations such as turning, boom, arm and bucket are controlled by a pilot-operated control valve V1 through a pilot valve unit 33 by a pair of left and right control levers 27. To V4. That is, as shown in FIG. 3, pilot valves are used for the control valves V1 to V4 for controlling the swing motor 9, the boom cylinder 20, the arm cylinder 21, and the bucket cylinder 22. The hydraulic circuit is configured to be switched by pilot pressure oil from a pilot valve unit 33 operated by the lever 27.

The left operating lever 27L of the pair of left and right steering levers 27 is pivotally operated in the front-rear direction and the left-right direction so that the left pilot valve unit 33 can be freely operated.
The casing is supported by an L casing. When the pilot valves P1 to P4 in the casing are switched, the control valve V1 for turning and the control valve V2 for the arm can be controlled. Also, the right operation lever 27R
Is supported by the casing of the right pilot valve unit 33R so as to be swingable in the front-rear direction and the left-right direction, and by switching the pilot valves P5 to P8 in the casing, the boom for the boom is operated. The control valve V3 and the packet control valve V4 can be controlled.

As shown in FIGS. 1 and 2, inside the control box 26, there are provided pilot valve units 33 each having a base end of the control lever 26 connected to be able to swing back and forth and left and right. , The manifold 3 connected to the output port of the pilot valve unit 33
4, the control valve unit 29 in which a mechanical control valve Vm and a pilot-operated control valve V1 to V4 are continuously joined in the left-right direction, and the pilot-operated control valves V1 to V4 and a manifold. 34
And a plurality of hydraulic pipes 40 for piping between them.

Among them, the manifold 34 is provided with the swivel 3
A first support plate 36 fixed to a support frame 35 provided upright and having an oil passage therein; a manual switching valve 37 fixed to the lower surface of the support plate 36;
A second support plate 38 fixed to the lower surface of the switching valve 37 and having an oil passage therein is provided. Each pilot valve unit 33 is fixed to the upper surface of both left and right ends of the first support plate 36. The control valve unit 29 is disposed in the space below the manifold 34 in the control box 26 such that the spools of the control valves V1 to V4 are oriented in the vertical direction and the inlets 39 are directed upward.

At the right end of the first support plate 36, a discharge port of an oil passage communicating with the right pilot valve unit 33R is formed downward, and a control valve V3 for the boom and a control valve V4 for the bucket are formed. Are arranged at the same plane position as the respective discharge ports. On the other hand, the left pilot valve unit 33L is connected to the left end of the second support plate 38 via the switching valve 37.
The discharge port of the oil path communicating with the arm is formed downward, and the inflow ports 39 of the control valve V1 for turning and the control valve V2 for the arm are arranged at the same plane position as the respective discharge ports.

The hydraulic pipe 40 of the present embodiment is made of a straight non-flexible pipe made of metal or hard resin. The hydraulic pipe 40 made of the non-flexible pipe is used to control the pilot-operated control valves V1 to V4. An inflow port 39 is connected to each discharge port on the manifold 34 side. As described above, according to the control device 25 of the present embodiment, the inflow ports 39 of the pilot-operated control valves V1 to V4 pointing upward are in the same plane position as the discharge ports on the manifold 34 side pointing downward. Therefore, there is no need to bend the hydraulic hose or use a bent pipe when connecting them with the hydraulic pipe 40, and the piping work for the manifold 34 is very simple in this regard.

Therefore, the control valve unit 2
9 can be easily incorporated into the control box 26, and there is no need to connect a long hydraulic hose to the manifold 34, so that the material cost and the manufacturing cost of the control device 25 can be reduced. Further, in the present embodiment, since a straight non-flexible pipe is used as the hydraulic pipe 40, the control valves V1 to V1 are connected to the connection ports at both ends thereof.
When forcibly inserting the inflow port 39 of the V4 or the discharge port of the manifold 34, the non-flexible pipe does not bend or curve due to bending, and piping for the manifold 34 is compared with the case where a hydraulic hose is used. There is also the advantage that work is easier.

In the present embodiment, the switching valve 37 for switching the oil passage is interposed between the control valves V1 and V2 for turning and the arm and the first support plate 36, so that the switching valve 37 according to the user's preference is provided. The direction of turning and the operation of the arm can be switched. Of course, the switching valve 37 may be omitted and control valves V1 and V2 for turning and arm may be directly piped to the first support plate 36, or control valves V3 and V for boom and bucket may be provided.
Also, the switching valve 37 may be interposed with respect to 4.

In the control device 25, the driver operates the driver's seat 1
The operation by the control lever 27 is permitted when the driver is seated on the driver's seat 4, and the operation is disabled when the driver gets off the driver's seat 14 to prevent the excavator 4 or the like from being operated by mistake. A safety device 42 is incorporated.
That is, as shown in the hydraulic circuit of FIG. 3, the unload valve 43 which can be switched between two positions, a pressure oil supply state and a supply stop state, is provided in the pressure oil supply path for the pilot valves P1 to P8 of each pilot valve unit 33. The unload valve 43 is directly connected to the lower surface of the first support plate 36 of the manifold 34 that supports the pilot valve unit 33 in the control box 26, as shown in FIGS. ing.

A switching lever 44 for switching the unload valve 43 is rotatably mounted on the side surface of the control box 26. The switching lever 44 moves the center of the control box 26 in the left-right direction. Are formed in a substantially U-shaped frame shape from a rotating rod 45 penetrating through the shaft and an operating rod 46 fixed orthogonally to both ends of the rotating rod 45. An intermediate portion of the rotating rod 45 is directly connected to a rotary shaft 47 for switching an oil path of an unload valve 43 incorporated in the control box 26,
The protruding end of the rotating rod 45 extends to a position protruding into a boarding passage below the driver's seat 14.

When the switching lever 44 is rotated so that the operation rod 46 extends horizontally, the unload valve 43 switches to the supply stop state, and the operation of the control lever 27 is disabled, and the operation rod 46 is turned off. When the switching lever 44 is rotated so as to be substantially vertical,
The unload valve 43 is switched to the pressure oil supply state, and the operation of the excavator 4 and the like by the control lever 27 is allowed. According to the safety device 42 of the present embodiment, since the rotating rod 45 of the switching lever 44 is directly connected to the rotary shaft 47 for switching the oil path of the unload valve 43 incorporated in the control box 26, the switching is performed. The interlocking mechanism between the lever 44 and the unload valve 43 becomes extremely simple, and the material cost and the manufacturing cost of the safety device 42 can be significantly reduced.

The unloading valve 43 is connected to the first support plate 36 constituting the manifold 34 for supporting the pilot valve unit 33 in the control box 26.
Since it is directly connected to the lower surface of the control box, a hydraulic pipe between the unload valve 43 and the manifold 34 is not required, and a special bracket for fixing the unload valve 43 in the control box 26 is not required. This also contributes to a reduction in material costs and manufacturing costs of the control device 25 or the safety device 42. The present invention can be applied not only to the small back turning type valve 1 but also to a standard type or a micro turning type backhoe.

[0026]

As described above, according to the present invention,
Since the interlocking mechanism between the switching lever and the unload valve becomes extremely simple, the material cost and the manufacturing cost of the safety device of the turning work machine can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view of a steering device and a safety device of a backhoe as viewed from a driver seat side.

FIG. 2 is a left side view of the steering device and the safety device.

FIG. 3 is a hydraulic circuit diagram of a drive system of the backhoe.

FIG. 4 is a left side view of the backhoe.

[Explanation of symbols]

 3 Turntable 26 Control Box 27 Control Lever 29 Control Valve Unit 33 Pilot Valve Unit 34 Manifold 42 Safety Device 43 Unload Valve 44 Switching Lever 47 Rotary Shaft

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G05G 1/04 G05G 1/04 Z 13/00 13/00 F term (reference) 2D003 AA01 AB02 AB03 AB04 BA07 CA01 CA04 DA03 EA03 EA04 EA05 EA06 2D015 EB00 GA01 GA02 GB01 3F205 AA07 BA06 KA10 3J070 AA03 BA41 CB01 CC62 DA21 EA31

Claims (2)

[Claims] 1. A control box (26) arranged on a swivel (3) and a control lever (27) housed in the control box (26) and protruding outside the control box (26). A pilot valve unit (33) that is swingably connected, a switching lever (44) that is pivotally attached to the control box (26), and a switching operation of the switching lever (44). An unloading valve (43) for raising or releasing the pilot pressure of the pilot valve unit (33). A safety device for a turning work machine, comprising: a rotating shaft of the switching lever (44); The unloading valve (4) incorporated in the box (26)
3) A safety device for a turning work machine, which is directly connected to a rotary shaft (47) for switching an oil path. 2. An unloading valve (43) is connected to a pilot valve unit (3) in a control box (26).
The safety device for a turning work machine according to claim 1, wherein the safety device is directly connected to a manifold (34) that supports the turning device (3).