JPH084045A - Interference preventive device of work machine - Google Patents

Abstract

PURPOSE:To properly prevent the interference of a working machine and an operating room. CONSTITUTION:An abnormal intrusion decision sphere 22 and an interference preventive sphere 21 are provided from the front of an operating room 2a over to the right side part, and at the same time chamfering 22a is administered by cutting the abnormal intrusion decision sphere 22 obliquely, and these respective spheres are made to be memorized at the operation device of a controller. This operation device possesses a coordinates operation portion to calculate the tip coordinates of a bucket 6; a comparison operation portion to decide the bucket tip coordinates; and a drive control portion or the like to output a control signal to a hydraulic drive circuit, and in a case in which the tip of the bucket 6 has intruded into the interference preventive sphere 21, arm pulling, boom raising and left offset action are prohibited, and in a case in which the tip of the bucket 6 has retreated from the interference preventive sphere 21, return to normal operation is carried out. Also, in a case in which the tip of the bucket 6 has intruded into the abnormal intrusion decision sphere 22, arm pulling, boom raising and left offset action are prohibited, and even if the tip of the bucket 6 has retreated from the abnormal intrusion decision sphere 22, these actions are kept prohibited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interference preventing device for a working machine, which automatically stops the operation of the working machine when the working machine approaches the driver's cab, and avoids a collision between the two. The present invention relates to an interference prevention device for a working machine, which is suitable for use in a construction machine such as a small swing hydraulic excavator.

[0002]

2. Description of the Related Art FIGS. 12 to 14 are disclosed in Japanese Patent Application Laid-Open No. 5-272155 as a prior art of an interference prevention device for a work machine of this type. FIG. 12 is a side view of a hydraulic excavator, and FIG. Is a plan view thereof, and FIG. 14 is a plan view showing the relationship between the bucket and the interference prevention area and the emergency stop area.

In FIGS. 12 and 13, reference numeral 1 denotes a traveling body, 2
Is a revolving structure having a driver's cab 2a and arranged above the traveling structure 1. The traveling structure 1 and the revolving structure 2 form a main body of the hydraulic excavator. 3 is a first boom rotatably connected to the right side of the cab 2a, 4 is a second boom rotatably connected to the tip of the first boom 3, and 5 is a pivot to the tip of the second boom. An arm 6 that is operably connected is a bucket that is rotatably connected to the tip of the arm 5, and the boom 3, 4 and the arm 5 and the bucket 6 form a working machine 7. 8 is a boom cylinder that drives the first boom 3, 9 is an offset cylinder that drives the second boom 4,
Reference numeral 10 is an arm cylinder for driving the arm 5, 11 is a bucket cylinder for driving the bucket 6, and as shown in FIG. 13, the second boom 4 uses the offset cylinder 9 to move the arm 5 and the bucket 6 to the first boom 3. And translate in the horizontal direction. Each of these cylinders 8, 9, 10, 11
Is operated by an operating lever and an operating pedal (both not shown) arranged in the driver's cab 2a. When an operator operates the operating lever and the operating pedal as appropriate, each operator is operated based on an instruction signal corresponding to the operation amount. Cylinder 8, 9, 1
The amount of pressure oil supplied to 0 and 11 is controlled. 12
Is a boom angle sensor provided at a fulcrum of the first boom 3, and detects a relative angle between the revolving unit 2 and the first boom 3. Further, 13 is an offset angle sensor provided at a fulcrum portion of the second boom 4, and the first boom 3 and the second boom 4 are provided.
The relative angle between them, that is, the offset angle is detected. Further, 14 is an arm angle sensor provided at a fulcrum of the arm 5, and detects a relative angle between the second boom 4 and the arm 5.

In FIG. 14, reference numeral 15 is an interference prevention region set from the front side to the right side of the cab 2a, and 16
Is an emergency stop area set inside the interference prevention area 15, and is an interference prevention area 15 at the right front corner of the cab 2a.
Is chamfered 15a. These interference prevention areas 1
5 and the emergency stop area 16 are stored in a controller (not shown).
When each angle signal detected by 3, 14 is input, the posture of the work implement 7 is obtained from each angle signal, and when it is determined that the bucket 6 has entered the interference prevention area 15, the operation lever or the operation pedal is operated. Regardless of the instruction signal, the operation of each part of the working machine 7 is automatically stopped so that the bucket 6 does not approach the cab 2a any more.

That is, when the offset cylinder 9 is left offset and the bucket 6 is in front of the operator's cab 2a, if the cloud operation of the arm 5 and the raising operation of the first boom 3 are operated individually or in combination, the bucket 6 is operated. Moves toward the operator's cab 2a, but solenoid valves are provided in the left offset pilot line, the boom raising pilot line, and the arm pulling pilot line of the hydraulic circuit, respectively. When the vehicle enters the controller, the controller outputs a control signal to operate each solenoid valve, which shuts off the pressure oil in each pilot line described above, so that the left offset operation, the arm crowd operation, and the raising of the first boom are performed. Each operation is prohibited. At that time, since the front right corner portion of the interference prevention area 15 is cut by the chamfer 15a, the automatic stop at this portion is eliminated, and the work efficiency is improved. Further, when the bucket 6 does not automatically stop in the interference prevention area 15 and enters the emergency stop area 16 due to a defective stick of the solenoid valve or the like, it is provided in the pipeline between the pilot pump and each direction switching valve. Since the solenoid valve of is operated by the control signal from the controller, regardless of the operation of the operation lever and the operation pedal, the working machine 7 is shut down urgently because the supply of pressure oil from the pilot pump to each directional switching valve is cut off. .

[0006]

By the way, in the above-mentioned conventional interference preventing device for a working machine, the emergency stop region 16 is set to have a constant width from the front side to the right side of the cab 2a, and the right front corner of the cab 2a is set. Since the emergency stop region 16 of the part is angular, there is a problem that the bucket 6 enters the emergency stop region 16 and makes an emergency stop even when there is no defect such as a stick of the solenoid valve.

That is, as shown in FIG. 14, when the tip end of the bucket 6 is automatically stopped in the interference prevention area 15 in front of the operator's cab 2a in a state where the offset cylinder 9 is not operated to the left or right and the offset is zero. As described above, the left offset operation, the arm crowd operation, and the first boom raising operation are prohibited, but the other operations are permitted. Therefore, the right offset operation is performed to move the tip of the bucket 6 to the interference prevention region. When it is attempted to evacuate from 15, the bucket 6 moves in the direction of the arrow in the figure to haze the emergency stop area 16, and the working machine 7 is brought to an emergency stop.
In particular, at low temperature, the viscous resistance of the pressure oil flowing through each pilot conduit is high, and the time from the output of the control signal to each solenoid valve until the bucket 6 stops becomes long. There is a tendency to stop at a position near the emergency stop region 16 in the interference prevention region 15, and the emergency stop region 16 is often scratched by the right offset operation after the automatic stop. Therefore, in such a case, despite the fact that each part is functioning normally, it will be considered as having some defect and an emergency stop will be performed, and the cause of the defect will be investigated or normal operation will be restored. Therefore, there was a problem that a lot of time and labor were required.

The present invention has been made in view of the above circumstances of the prior art, and an object thereof is to provide an interference preventer for a working machine capable of appropriately preventing interference between the working machine and a driver's cab. To do.

[0009]

In order to achieve the above object, the present invention provides a main body having an operator's cab, and a first boom rotatably provided on the side of the operator's cab of the main body. A second boom movably connected to the first boom by an offset cylinder in a lateral direction, an arm rotatably connected to the second boom, and a arm rotatably with respect to the arm. The buckets are connected to each other, an actuator for driving a working machine including the first and second booms, an arm and a bucket, and at least a front side of the operator's cab and a side side of the first boom. And a controller for determining whether or not the working machine has entered the interference prevention area, and when the working machine has entered the interference prevention area,
The working machine is prohibited from operating in the direction in which it interferes with the cab, and when the working machine is retracted from the interference prevention area, the working machine is allowed to operate in the interference direction. In the interference prevention device, an abnormal intrusion determination area is set inside the interference prevention area, and a corner portion from the side to the front of the abnormal intrusion determination area is chamfered so that the working machine crosses the interference prevention area. The operation of the work machine in the interference direction is continued to be prohibited when the work machine enters the abnormal intrusion determination area.

[0010]

When the cloud movement of the arm and the raising operation of the first boom are operated individually or in combination while the offset cylinder is left offset, the tip of the bucket moves toward the operator's cab, and the sensors and valves are moved. If the equipment is functioning normally, it will automatically stop in the interference prevention area set around the cab, and if there is something wrong with the sensor or valves, the abnormal intrusion determination will be set inside the interference prevention area. Stop automatically in the area. When the offset cylinder was not offset and the offset was zero, the tip of the bucket automatically stopped in the interference prevention area in front of the operator's cab, and then the right offset operation was performed to retract the tip of the bucket from the interference prevention area. In this case, the tip of the bucket moves from the side to the front of the operator's cab, but the abnormal entry area of this corner is chamfered. The tip of the bucket can be easily retracted from the interference prevention area without entering the area.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of a hydraulic excavator equipped with a work implement interference prevention device according to a first embodiment of the present invention, FIG. 2 is a plan view of the hydraulic excavator, and FIG. 3 is an interference prevention region set in the hydraulic excavator. 6 is a plan view showing the relationship between the abnormal intrusion determination area and the bucket, FIG. 4 is a block diagram showing the overall configuration of the interference prevention device of FIG. 1, FIG. 5 is a circuit diagram showing a hydraulic drive circuit, and FIG.
10 is a flow chart showing the processing contents of the arithmetic unit, and the parts corresponding to those in FIGS. 12 to 14 are given the same reference numerals.

As shown in FIGS. 1 to 3, in the hydraulic excavator according to the present embodiment, the interference prevention region 21 extends from the front side to the right side of the operator's cab 2a, and the abnormal intrusion determination region is inside the interference prevention region 21. 22 are set respectively,
These areas 21 and 22 are stored in the arithmetic unit of the controller, which will be described later. The interference prevention area 21 is set to have a substantially constant width from the front side to the right side of the operator's cab 2a, but the abnormal intrusion determination area 22 is chamfered 22a obliquely cut in the front right corner of the operator's cab 2a. Has been applied. That is, the normal area and the interference prevention area 21
Is Z1 and the boundary line between the interference prevention area 21 and the abnormal intrusion determination area 22 is Z2, the boundary line Z1 intersects at a corner in the right front corner of the cab 2a, but the boundary line Z2 is It has a shape with cut corners.

In FIG. 4, reference numerals 12, 13, and 14 denote the boom angle sensor, the offset angle sensor, and the arm angle sensor, respectively, and the relative angle signals between the working machine members detected by the sensors 12, 13, and 14, respectively. θ1, θ2, θ
3 is input to the arithmetic unit 23 built in the controller. The arithmetic unit 23 calculates the coordinate of the tip of the bucket 6 from the coordinate of the predetermined point on the working machine 7, for example, the tip of the arm 5, based on the angle signals θ1, θ2, θ3.
4 and the interference prevention area storage unit 2 that stores the areas described above.
6, the abnormal intrusion determination area storage unit 27, and the coordinate calculation unit 2
The bucket tip coordinates calculated in 4 are stored in the storage units 26 and 27.
It outputs a predetermined control signal to the hydraulic drive circuit 31 based on the control signal from the comparison calculation unit 29 and the comparison calculation unit 29 which determines whether or not it is within the range and outputs the predetermined control signal according to the result. And a drive control unit 30 that operates. The hydraulic drive circuit 31 receives, in addition to the control signal from the drive control unit 30, an operating means for operating the working machine 7 arranged in the cab 2a, for example, an instruction signal from an operating lever 32, The amount of hydraulic oil supplied to each of the cylinders 8 to 11 is controlled based on these signals. When calculating the bucket tip coordinates, for example, a coordinate system whose origin is the center of rotation of the revolving unit 2 and the first boom 3 is set in advance, and the coordinate system based on the respective angle signals θ1, θ2, and θ3 is used. The coordinate value of the tip of the arm 5 may be calculated, and the coordinate value of the tip of the bucket 6 may be calculated from the coordinate value of the arm tip.

As shown in FIG. 5, the hydraulic drive circuit 31 is provided.
Are a hydraulic pump 33 and a pilot pump 34 driven by an engine, a boom directional control valve 35 for controlling the flow of hydraulic oil supplied from the hydraulic pump 33 to the cylinders 8, 9 and 10, and an offset directional control valve. 36, an arm direction switching valve 37, a boom pilot valve 38 for operating the cylinders 8, 9 and 10, an offset pilot valve 39, an arm pilot valve 40, etc., and a bucket cylinder 11, a traveling motor, etc. Other actuators are omitted from the drawing. Each pilot valve 38, 39, 40 has a left chamber and a right chamber which communicate with the pilot pump 34, and the pressure oil discharged from the pilot pump 34 is converted into an instruction signal from the operation lever 32. Depending on these, these are supplied to the left or right chamber.

The boom direction switching valve 35 has pilot chambers on both left and right sides.
5 left pilot chamber and the boom pilot valve 3
The chamber on the left side of 8 is connected by a boom raising pilot line 41, and the chamber on the right side of the direction switching valve for boom 35 and the chamber on the right side of the pilot valve for boom 38 are connected by a boom lowering pilot line 42. There is. The offset directional control valve 36 also has pilot chambers on both left and right sides.
The pilot chamber on the left side of 6 and the chamber on the left side of the offset pilot valve 39 are arranged in the right offset pilot line 43.
The pilot chamber on the right side of the offset directional control valve 36 and the chamber on the right side of the offset pilot valve 39 are connected by a left offset pilot conduit 44. Further, the arm directional control valve 37 also has pilot chambers on both left and right sides. The pilot chamber on the left side of the arm directional control valve 37 and the chamber on the left side of the arm pilot valve 40 are arm pull pilot pipes. Road 45
And the right pilot chamber of the arm directional control valve 37 and the right chamber of the arm pilot valve 40 are connected by an arm pushing pilot conduit 46.

An electromagnetic proportional pressure reducing valve 47 for a boom is provided in the boom raising pilot line 41, and an electromagnetic proportional pressure reducing valve 48 for an arm is provided in the arm pulling pilot line 45. These electromagnetic proportional pressure reducing valves are provided. 47 and 48 have ports connected to the tank. These electromagnetic proportional pressure reducing valves 47 and 48 are used for the drive control unit 30 of the arithmetic unit 23.
Is operated in proportion to the current value of the control signal output from
Normally, when the maximum level current Ia is input to fully open the boom raising pilot line 41 and the arm pulling pilot line 45 and the current Ib having the minimum current value is input as the control signal, the boom raising pilot line 41 is input. Shut off the pressure oil from the arm pull pilot line 45 and return it to the tank.
When a current Ic whose current value is between the maximum level and the minimum level is input as the control signal, the boom raising pilot line 4
1 and the arm pulling pilot line 45 to reduce the pressure oil to reduce the pilot pressure. On the other hand, an offset electromagnetic switching valve 49 is provided in the left offset pilot conduit 44, and the electromagnetic switching valve 49 has a port connected to the tank. This electromagnetic switching valve 49 is also the arithmetic unit 2
The switching operation is performed by the control signal output from the drive control unit 30 of No. 3, and only when the control signal is input, the pressure oil in the left offset pilot conduit 44 is shut off and returned to the tank.

Next, the operation of this embodiment will be mainly described with reference to FIGS.
This will be described with reference to the flowchart shown in. For normal operation in which there is no risk of contact between the tip of the bucket 6 and the cab 2a, that is, when the bucket 6 is located outside the interference prevention area 21 set around the cab 2a, The arm electromagnetic proportional pressure reducing valves 47, 48 and the offset electromagnetic switching valve 49 are all in the positions shown in FIG. In this state, for example, when the boom operation lever 32 is tilted to the left side in FIG. 5, the pressure oil discharged from the pilot pump 34 flows from the chamber on the left side of the boom pilot valve 38 to the boom raising pilot conduit 41 and the boom. Solenoid proportional pressure reducing valve 4
After being supplied to the pilot chamber on the left side of the boom direction switching valve 35 via 7, the boom direction switching valve 35 starts to operate. Then, when the boom direction switching valve 35 is switched from the neutral position to the left side position, the pressure oil of the hydraulic pump 33 is supplied to the bottom side of the boom cylinder 8 via the boom direction switching valve 35, and the boom cylinder 8 extends. Then, the first boom 3 rises. On the contrary, when the boom operation lever 32 is tilted to the right side in FIG. 5, the pilot pump 3
The pressure oil discharged from No. 4 is supplied from the chamber on the right side of the boom pilot valve 38 to the pilot chamber on the right side of the boom direction switching valve 35 via the boom lowering pilot conduit 42, and the boom direction switching valve 35 operates. Start. Then, when the boom direction switching valve 35 is switched from the neutral position to the right position, the pressure oil of the hydraulic pump 33 is supplied to the rod side of the boom cylinder 8 via the boom direction switching valve 35, and the boom cylinder 8 expands and contracts. The first boom 3 descends. Similarly, the offset cylinder 9 expands and contracts according to the amount of operation of the offset operation lever 32, and the arm 5 and the bucket 6 are laterally right- or left-offset with respect to the first boom 3, and the operation lever 32 is also operated. The arm cylinder 10 expands and contracts in accordance with the operation amount of, and the arm 5 is pulled or pushed.

At this time, the arithmetic unit 23 first determines whether or not the flag for abnormal processing is set, as shown in step S-1 of FIG. 6, and if the flag is not set, the procedure is carried out. At S-2, the relative angle signals θ1, θ2, θ3 from the boom angle sensor 12, the offset angle sensor 13, and the arm angle sensor 14 are input to the coordinate calculation unit 24, and then at step S-3, the relative angle signals θ1, θ.
After calculating the coordinates of the tip of the arm 5 from 2, 3
At -4, the bucket tip coordinates are calculated from the arm tip coordinates. Next, in step S-5, the comparison calculation unit 29 compares the bucket tip coordinates calculated by the coordinate calculation unit 24 with the interference prevention area storage unit 26, and the tip of the bucket 6 is inside the interference prevention area 21. In other words, it is determined whether or not the tip of the bucket 6 has entered the boundary line Z1.

When the result of the determination in step S-5 is NO, that is, when the tip of the bucket 6 has not entered the interference prevention area 21, the process proceeds to step S-6 and normal processing is performed. In this case, as shown in FIG. 7, the drive control unit 30 outputs the maximum level current Ia to the boom electromagnetic proportional pressure reducing valve 47 and the arm electromagnetic proportional pressure reducing valve 48, and outputs the switching signal to the offset electromagnetic switching valve 49. Boom-up pilot line 41 and arm pull pilot line 45
And the left offset pilot line 44 is fully opened. Therefore, the cylinders 8, 9 and 10 perform normal operation according to the operation amount of the corresponding operation lever 32. Also,
When the result of the determination in step S-5 is YES, step S-7
Then, the comparison calculation unit 29 compares the bucket tip coordinates with the abnormal intrusion determination area storage unit 27 to determine whether the tip of the bucket 6 is inside the abnormal intrusion determination area 22, in other words, the tip of the bucket 6. Determines whether or not has entered the boundary line Z2.

When the result of the determination in step S-7 is NO, that is, when the tip of the bucket 6 is in the interference prevention area 21, the process proceeds to step S-8 and the stop process is performed. In this case, as shown in FIG. 8, the drive control unit 30 outputs the current Ic between the maximum level and the minimum level to the boom electromagnetic proportional pressure reducing valve 47 and the arm electromagnetic proportional pressure reducing valve 48, and then outputs the minimum value. It outputs a level current Ib, which
After the pressure oil in the boom raising pilot conduit 41 and the arm pulling pilot conduit 45 is reduced to reduce the pilot pressure, the pressure oil in these pilot conduits 41, 45 is shut off and returned to the tank. The drive control unit 30 also outputs a switching signal to the offset electromagnetic switching valve 49 to shut off the pressure oil in the left offset pilot conduit 44 and return it to the tank. Therefore, the operation levers 32 are operated in a direction in which the tip of the bucket 6 approaches the operator's cab 2a, and pressure oil is supplied from the pilot pump 34 to the boom raising pilot conduit 41, the arm pulling pilot conduit 45, and the left offset pilot conduit 44. Even if supplied, since the pilot pressure does not build up in these pipelines 41, 44, 45, the working machine 7 automatically stops, and the raising operation of the first boom 3, the pulling operation of the arm 5 and the left offset operation are prohibited. It Note that this stopping process is performed by the bucket 6
Is moved in the direction away from the cab 2a, the tip of the bucket 6 is automatically released at a position retracted to the outside of the interference prevention area 21, and the above-described normal processing is performed again.

On the other hand, when the result of the determination in step S-7 is YES, that is, due to a defect in each of the sensors 12 to 14, the electromagnetic proportional pressure reducing valves 47 and 48, the electromagnetic switching valve 49, or the like,
When the tip of the bucket 6 crosses the boundary line Z2 and enters the abnormal intrusion determination area 22, the process proceeds to step S-9, and the abnormal process is performed. In this case, as shown in FIG.
0 outputs the minimum level current Ib to the electromagnetic proportional pressure reducing valve 47 for boom and the electromagnetic proportional pressure reducing valve 48 for arm, and outputs the switching signal to the electromagnetic switching valve 49 for offset, so that the interference is caused similarly to the above-mentioned stop processing. All the directional movements are prohibited and the working machine 7 is stopped urgently. Further, the abnormality processing flag is set, and an alarm such as sounding a buzzer or lighting a lamp is issued to notify the operator that there is some abnormality.

When the abnormality processing flag is set in step S-9, the tip of the bucket 6 is moved to the abnormal intrusion determination area 2
Even if it is retracted from 2 to the outside of the interference prevention area 21, the raising operation of the first boom 3, the pulling operation of the arm 5 and the left offset operation are still prohibited, and normal work cannot be performed. In such a case, with the engine stopped, the sensor or valve causing the defect is replaced with a normal one, and then the engine is restarted to return to step S-1. As described above, this procedure S
In -1, it is determined whether or not the flag for the abnormality processing is set. In this case, since the flag remains set, the procedure proceeds from step S-1 to step S-10 and the restoration processing is performed. As shown in FIG. 10, in this return processing, the drive control unit 30 causes the boom proportional electromagnetic pressure reducing valve 4 to operate.
7 and the electromagnetic proportional pressure reducing valve 48 for the arm have a minimum level current I.
By outputting b and a switching signal to the electromagnetic switching valve for offset 49, the state in which all the operations in the interference direction are prohibited is maintained, and, for example, when the abnormality recovery signal is turned on from the reset switch, the abnormality processing is performed. The flag is reset, the return process is completed, and the process returns to step S-2.

In the above-mentioned operation, after the offset cylinder 9 is not offset and the offset is zero, the tip of the bucket 6 automatically stops within the interference prevention area 21 in front of the operator's cab 2a. When the right offset operation is performed to retract the tip of the bucket 6, the tip of the bucket 6 moves in the direction of the arrow in the front right corner of the cab 2a, as shown in FIG. At this time, since the front right corner portion of the abnormal intrusion determination area 22 is chamfered 22a, the tip of the bucket 6 does not intrude into the abnormal intrusion determination area 22 more than necessary, and the tip of the bucket 6 is prevented from interfering. It is possible to easily evacuate the area 21. Therefore, even though each part is functioning normally, the number of malfunctions such as accidental stoppage in the abnormal intrusion determination area 22 is reduced, and as a result, the cause of the defect is searched for and the normal operation is restored. Wasted time and labor can be saved and work efficiency can be improved.

In the above-described first embodiment, the case has been described in which the front right corner of the abnormal intrusion determination area 22 is cut diagonally to be chamfered 22a. However, as shown in FIG. The right front corner portion of 22 may be cut into a stepped shape to be chamfered 22a, and the point is that the corner of the right front corner portion of the abnormal intrusion determination area 22 may be reduced.

[0025]

As described above, according to the present invention,
When the tip of the work implement stops automatically in the interference prevention area with zero offset, and then the right offset operation is performed to retract the tip of the work implement from this interference prevention area, the tip of the work implement is erroneously detected as an abnormal intrusion judgment area. It is possible to provide a work machine interference prevention device that can reduce the frequency of intrusion into the work machine and that has high work efficiency.

[Brief description of drawings]

FIG. 1 is a side view of a hydraulic excavator including an interference prevention device for a working machine according to a first embodiment of the present invention.

FIG. 2 is a plan view of the hydraulic excavator.

FIG. 3 is a plan view showing the relationship between the bucket and the interference prevention area and the abnormal intrusion determination area set in the hydraulic excavator.

FIG. 4 is a block diagram showing the overall configuration of the interference prevention device of FIG.

5 is a circuit diagram showing a hydraulic drive circuit provided in the interference prevention device of FIG.

6 is a flowchart showing the processing contents of a computing device provided in the interference prevention device of FIG.

FIG. 7 is a flowchart showing normal processing of the arithmetic device of FIG.

8 is a flowchart showing a stop process of the arithmetic device of FIG.

9 is a flowchart showing an abnormal process of the arithmetic device of FIG.

10 is a flowchart showing a return process of the arithmetic device of FIG.

FIG. 11 is a plan view showing a modified example of the abnormal intrusion determination area.

FIG. 12 is a side view of a hydraulic excavator including an interference prevention device for a working machine according to a conventional example.

FIG. 13 is a plan view of the hydraulic excavator.

FIG. 14 is a plan view showing the relationship between the bucket and the interference prevention area and the emergency stop area set in the hydraulic excavator.

[Explanation of symbols]

 2 Revolving structure 2a Operator's cab 3 1st boom 4 2nd boom 5 Arm 6 Bucket 7 Working machine 8 Boom cylinder 9 Offset cylinder 10 Arm cylinder 12 Boom angle sensor 13 Offset angle sensor 14 Arm angle sensor 21 Interference prevention area 22 Abnormal intrusion determination Area 22a Chamfering 23 Computing device 24 Coordinate computing unit 29 Comparison computing unit 30 Drive control unit 31 Hydraulic drive circuit 32 Operating lever 47 Boom electromagnetic proportional pressure reducing valve 48 Arm electromagnetic proportional pressure reducing valve 49 Offset electromagnetic switching valve

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Shudo Yamada 20 Ishigane, Toyama City, Toyama Prefecture Fujikoshi Co., Ltd. (72) Inventor Takashi Matsuda 20 Ishigane, Toyama City, Toyama Prefecture (72) Inventor Toshiyuki Ishizaka 20 Ishigane, Toyama City, Toyama Prefecture Fujikoshi Co., Ltd.

Claims (1)

[Claims] 1. A main body having a cab, a first boom rotatably provided on a side of the cab of the main body, and a lateral movement by an offset cylinder with respect to the first boom. A second boom connected to the second boom; an arm rotatably connected to the second boom; a bucket rotatably connected to the arm; An actuator configured to drive a working machine configured with a bucket, and an interference prevention area set at least in front of the cab and on a side facing the first boom are stored, and the working machine is stored in the interference prevention area. And a controller for determining whether or not has entered, when the working machine enters the interference prevention area,
The working machine is prohibited from operating in the direction in which it interferes with the cab, and when the working machine is retracted from the interference prevention area, the working machine is allowed to operate in the interference direction. In the interference prevention device, an abnormal intrusion determination area is set inside the interference prevention area, and a corner portion from the side to the front of the abnormal intrusion determination area is chamfered so that the working machine crosses the interference prevention area. The work machine interference prevention device is characterized in that, when the work machine enters the abnormal intrusion determination area, the work machine is continuously prohibited from operating in the interference direction.