JPH0790887A - Work machine interference preventive device - Google Patents

Abstract

PURPOSE:To enable work at a certain degree of speed even in a speed reduction area of a cab. CONSTITUTION:An interference preventive area of a single round of a cab 1 where a work machine 2 causes interference when the work machine 2 offset to the front side of the cab 1 is bent toward the cab, is stored in a controller 3, and a stopping area A where the work machine 2 stops automatically in the area and a speed reduction area B on this side are arranged respectively, and this side is set as a safe area C. First and second areas B1 and B2 are arranged to divide the speed reduction area B into the safe area C side and the stopping area A side when the work machine 2 stops in the stopping area A and gets away from the cab 1 and again approaches the cab l in the speed reduction area B, and speed of the work machine is set at medium speed in the first area B1, and it is set at low speed in the B2. Thereby, since practicability and safety in the speed reduction area can be reconciled with each other, workability around the cab can be remarkably improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a working machine interference preventing device which prevents an accident such that the working machine interferes with the cab and damages the cab when working on a vehicle for excavation and loading such as a power shovel. In particular, the present invention relates to a work implement interference prevention device capable of performing speed control when moving away from a cab and then approaching the cab again in a deceleration region after being automatically stopped.

[0002]

2. Description of the Related Art In a vehicle for excavation and loading such as a power shovel, a working machine including a boom, an arm, a bucket and the like is generally provided on an upper swing body. During work, the boom undulates with respect to the upper revolving structure, and the arm provided at the tip of the boom and the bucket at the end of the boom rotate in the front-rear direction. It doesn't interfere with the cab. However, in the case of digging the side of the vehicle, it cannot be digged by the working machine described above.
A conventional boom is divided into an offset boom 25 and a boom 26 as shown in a side view and a plan view in (b), and the offset boom 25 can be laterally offset with respect to the boom 26. . In the excavating and loading vehicle having such a mechanism, the offset boom 2
If 5 is offset toward the cab 1, the working range of the arm 27 and the bucket 30 may interfere with the cab 1. On the other hand, an interference prevention area is provided around the cab 1, and this area is stored in the controller.
A work machine interference prevention device is considered in which the operation of the work machine is stopped by a command from the controller when the work machine enters this area.

[0003]

However, in the conventional working machine interference prevention device, many operations are impossible when the working machine enters the interference prevention area, and the avoidance operation is troublesome and rapidly. When it is operated, it suddenly stops, so it is unavoidable to cause a load spill due to inertia.

As a solution to such a problem, an interference prevention area for the cab 1 is provided as shown in FIG.
In response to this, there is one in which the command pressure of the working machine control circuit is changed. That is, a stop area A near the cab 1, a deceleration area B in front of the stop area A, and a safety area C in front of the stop area A are provided. In the safety area C, a control circuit for operating boom-on-arm excavation is provided. Is set to a high pressure, the deceleration region B is set to a low pressure, and the stop region A is set to 0.

However, if there is an obstacle such as a fence in the vicinity, it is necessary to operate the work machine 2 in the deceleration area B. As shown in FIG. 6, the operation in the deceleration region B is performed when the work implement 2 is automatically stopped in front of the cab 1 as shown in FIG.
It stops when the blade edge of 0 enters the stop area A. Next, in (b), the bucket 30 avoids forward by lowering the boom 26 or operating the arm 27 toward the dump side, and the deceleration area B
The working machine 2 is temporarily stopped inside. (C) is a case where the boom 26 or the arm 27 is tried to approach the cab 1 again in the deceleration area B by the excavation operation of the arm 27. However, the approaching speed is slow, or the engine speed is slow to a normal speed in the half. It will be about 10 to 20% and it will not move. In other words, the operation around the cab 1 has a drawback that it is difficult to operate because the command pressure of the working machine control circuit is kept low in consideration of safety.

In view of the above, the present invention provides a work implement interference prevention device capable of working at a certain speed while ensuring safety even in the deceleration region of the cab, and aims to solve the drawbacks of the prior art. It was made for the purpose.

[0007]

As a means for solving the above-mentioned problems of the prior art, the present invention relates to a cab rotation which causes interference when a working machine offset toward the front side of the cab is bent toward the cab. In a work machine interference prevention device, a controller stores the interference prevention area, and a work machine automatically stops in the area, and a deceleration area is provided in front of the stop area. Item 1 defines the deceleration area into a side closer to the safety area and a side closer to the stop area when the working machine moves away from the cabin after stopping in the stop area and approaches the cab again in the deceleration area. 3. A region is provided so that the first region has a medium speed and the second region has a low speed.
Is characterized in that the speed is changed from a high speed to a low speed in the deceleration region according to claim 1 in a slanted manner.

[0008]

According to the above construction, in both claims 1 and 2, the operating speed of the working machine becomes faster even in the deceleration area near the safety area, and becomes slower when approaching the stop area. .

[0009]

1 is a circuit diagram showing an embodiment of a work machine interference prevention device according to claims 1 and 2 of the present invention, and FIG. 2 is an interference prevention of the work machine interference prevention device according to claim 1 of the present invention. FIG. 3 is an explanatory view showing an embodiment of the relationship between the range of the region and the command pressure of the control circuit (circuits 9 and 16) for operating the boom / arm excavation. FIG. 3 is a work machine interference prevention device according to claim 2 of the present invention. FIG. 4 is an explanatory diagram showing an example of the relationship between the range of the interference prevention area and the command pressure of the control circuit (circuits 9 and 16) for operating the boom on-arm excavation.

The present invention will be described below with reference to the embodiments shown in FIGS. According to the present invention, when the working machine 2 offset toward the front side of the cab 1 is bent toward the cab, the controller 3 stores the interference prevention area around the cab 1 in which the working machine 2 causes interference, and the working machine 2 stores the interference prevention area. Stop area A that automatically stops in the area, and deceleration area B in front of it
In a work implement interference prevention device having a safety area C in front of each of them, the work implement 2 once stops automatically in the stop area A, moves away from the cab 1, and again in the deceleration area B to the cab 1. When approaching, as shown in FIG. 2, the deceleration area B is divided into a side close to the safety area C and a side close to the stop area A by providing first and second areas B1 and B2. The command pressure of the control circuit (circuits 9 and 16) for operating the upper arm excavation is maintained at an intermediate pressure lower than the high pressure in the safety area C, the speed of the work machine 2 is set to the intermediate speed, and the second area B2 is on the boom. The command pressure of the control circuit (circuits 9 and 16) for operating the arm excavation is maintained at a low pressure so that the speed of the working machine 2 is set to a low speed. Automatically stop once and move away from cab 1 Ri, cab 1 again in the deceleration region B
As shown in FIG. 3, the command pressures of the control circuits 9 and 16 for operating the boom on-arm excavation are gradually changed from high pressure to low pressure in the deceleration region B from the safety region C to the stop region A, as shown in FIG. Work machine 2
The speed of is gradually reduced.

FIG. 1 shows a hydraulic circuit of an excavation and loading vehicle in which a working machine 2 offset to the front of the cab 1 can be bent toward the cab 1, and the direction is switched to supply hydraulic pressure to a desired actuator (not shown). Valves 61, 62, 63,
... is switched by the pilot pressure control valves 81, 82, 83 by the hydraulic pressure from the pilot pump 7. Among them, in the circuit 9 from the boom control valve 81 upper side to the boom direction switching valve 61 upper side, the boom top stop electromagnetic proportional valve 4 is provided in the circuit 10 from the arm control valve 82 excavation side to the arm direction switching valve 62 excavation side. The solenoid proportional valves 5 for stopping the arm excavation are connected to the respective paths, and the solenoid proportional valves 4 and 5 are connected to the controller 3. The boom control valve 81 is operated by the right operation lever 12, the arm control valve 82 is operated by the left operation lever 13, the offset control valve 83 is operated by the operation pedal 14, and the circuit 17 reaching the left side of the offset direction switching valve 63 is provided. A solenoid valve 31 is connected to the solenoid valve 31, and the solenoid valve 31 is connected to the controller 3. These control valves 81, 82, 83
Are the boom direction switching valve 61 and the arm direction switching valve 6, respectively.
2. Pilot circuits 9, 10, 15, 16, 17, and 18 are connected to the left and right ends of the offset direction switching valve 63, respectively. Discharge oil is supplied from the main pumps 19 and 20 to the respective directional switching valves 61 and 62, and discharge oil is supplied from the main pump 21 to the directional switching valve 63 through the main circuits 22, 23 and 24, respectively. The controller 3 is the work machine 2
Signal 26a provided on the fulcrum of the boom 26 and potentiometer signal 2 provided on the fulcrum of the arm 27 during operation of the
7a, the potentiometer signal 25a provided at the fulcrum of the offset boom 25 is input, and when the working machine 2 approaches the cab 1 in the preset interference prevention area, an output signal for avoiding this is issued. ing. When the electromagnetic proportional valves 4 and 5 receive the output signal from the controller 3,
It operates in proportion to the magnitude of the current, which reduces the stop shock to prevent bucket spillage and reduces variations in the stop position.The set pressure can be changed according to the speed. , When the speed is fast, the set pressure is low. When the solenoid valve 31 receives an output signal from the controller 3, it opens and closes.
Since the offset boom 25 does not offset at a high speed, it is not necessary to use a solenoid proportional valve. Further, a hydraulic lock solenoid valve 29 is provided in the middle of the circuit 28 between the control valves 81, 82, 83 and the pilot pump 7.
The valve 29 shuts off the circuit 28 when receiving the output signal from the controller 3. 30 in the figure
Is a bucket.

FIG. 2 shows an essential part of the present invention. A stop area A is provided in the front portion of the cab 1 in the width L _1, for example, and a deceleration area B is provided in the width L ₂ in front of the stop area A. It is a region C. The deceleration area B is the first on the side closer to the safety area C.
It is divided into a region B1 and a second region B2 on the side close to the stop region A, and the set pressures of the electromagnetic proportional valves 4 and 5 for boom boom and arm excavation are controlled to control the boom boom and arm excavation. As shown in FIG. 5, the command pressure of the control circuit (circuits 9 and 16) is high in the safety area C and the first area B1.
Then, in the first area B, the second area B2 becomes low in the middle area.
The inside of 1 is newly provided.

The operation will be described below. After the working machine 2 becomes the stop area A and is automatically stopped, the working machine 2 is placed in the cab 1.
When the vehicle is moved away from the vehicle, stopped in the deceleration area B, and brought closer to the cab 1, the operation is performed at the position shown in FIG. 6C. That is, in the operation in the first region B1 of FIG. 2, the set pressure of the solenoid proportional valves 4 and 5 is medium pressure, and the command pressure of the control circuit (circuits 9 and 16) for operating the boom upper / arm excavation is medium pressure. Therefore, although the operating speed of the work machine in this B1 region is slightly reduced, it does not stop, and when approaching the second region B2, the set pressure of the solenoid proportional valves 4 and 5 is low and the boom / arm excavation is performed. The command pressure of the control circuit (circuits 9 and 16) to be operated is low, and the speed of the work machine 2 is low.

According to claim 2 of the present invention, as shown in FIG. 3, according to claim 1, the deceleration region B is divided into two, while the safety region C is divided.
The width of the deceleration area B between the stop area A and the stop area A is a control circuit for operating the boom raising and arm excavation (circuits 9 and 1).
The difference is that the command pressure of 6) is shaded so that the command pressure is higher in the first area B1 closer to the safety area C as usual and lower in the second area B2 closer to the stop area A as usual. Therefore, the operating speed of the working machine becomes slower as the stop area A is approached from the side closer to the safety area C.

[0015]

As described above, according to the present invention, when the working machine offset to the front side of the cab is bent toward the cab, the controller stores the interference prevention area around the cab where the working machine interferes. In the working machine interference prevention device, a stop area in which the work machine automatically stops in the area and a deceleration area in front of the stop area are provided, and the area in front of the stop area is a safety area. 1st and 2nd, which are divided into a side close to
By providing a region, the speed of the work machine is set to medium speed in the first region, and the conventional low speed in the second region,
According to claim 2, the speed of the working machine is changed from a high speed area to a stop area in a deceleration area from a high speed to a low speed, so that the speed and the speed are gradually reduced. It is possible to significantly improve the workability in.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a work machine interference prevention device according to claims 1 and 2 of the present invention.

FIG. 2 is a diagram showing a relationship between a range of an interference prevention region of the work implement interference prevention device according to claim 1 of the present invention and a command pressure of a control circuit for operating boom raising / arm excavation.

FIG. 3 is a diagram showing a relationship between a range of an interference prevention region of a work implement interference prevention device according to claim 2 of the present invention and a command pressure of a control circuit for operating boom raising / arm excavation.

FIG. 4 shows a conventional offset excavation and loading vehicle,
(A) is a side view and (b) is a plan view.

FIG. 5 is a diagram showing a relationship between a range of an interference prevention region of a conventional work machine interference prevention device and a command pressure of a control circuit for operating boom raising / arm excavation.

FIG. 6 is a state diagram showing a posture of the work machine in the work machine interference prevention area.

[Explanation of symbols]

 1 cab 2 work machine 3 controller 4 solenoid proportional valve (for boom raising) 5 〃 (for arm excavation) 9 control circuit that operates on boom 16 control circuit that operates arm excavation A stop area B deceleration area B1 first area B2 Second area C Safety area

Claims (2)

[Claims] 1. An interference prevention area around a cab in which the working machine interferes when the working machine offset to the front side of the cab is bent toward the cab is stored in a controller, and the working machine is stored in the area. In a work machine interference prevention device in which a stop area that automatically stops and a deceleration area in front of it are provided respectively, and further in front of that a safety area, in a work machine interference prevention device, the work machine moves away from the cabin after stopping in the stop area, and the cab again in the deceleration area. When the deceleration region approaches, the first and second regions that divide the deceleration region into the side closer to the safety region and the side closer to the stop region are provided, and the first region is set to medium speed and the second region is set to low speed. Characteristic work equipment interference prevention device. 2. An interference prevention area around a cab in which the working machine interferes when the working machine offset to the front side of the cab is bent toward the cab, is stored in a controller, and the working machine is stored in the area. In a work machine interference prevention device in which a stop area that automatically stops and a deceleration area in front of it are provided respectively, and further in front of that a safety area, in a work machine interference prevention device, the work machine moves away from the cabin after stopping in the stop area, and the cab again in the deceleration area. A work implement interference prevention device, characterized in that the speed is changed in a diagonal manner such that the speed gradually decreases between the deceleration regions from the safety region side to the stop region side when approaching.