JPH0835239A - Work machine interference prevention device - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a work machine interference prevention device that can automatically correct a forbidden area when the cab moves and reliably prevent a contact accident between the work machine and the cab. . [Configuration] A monitor point M is set at a predetermined position of the boom 3, the arm 4 and the bucket 5 which constitute the working machine 6,
At the time of operating the work implement 6, the microcomputer 30 calculates the current coordinates of the monitor point M, and the degree of deceleration according to the distance between the current coordinates of the monitor point M and the intrusion prohibited area set around the cab 2a. K is calculated, and the value of K is multiplied by the current operating speed of the actuator to decelerate or stop the actuator, and the work range is limited and controlled. Further, when the operator's cab 2a is moved in the front-rear direction by the slide cylinder 32 during the work while limiting the work range in this way, the microcomputer 30 causes the slide cylinder 32 detected by the stroke sensor 35 to move. According to the slide amount of No. 1, the already set intrusion prohibited area is corrected, and the corrected intrusion prohibited area is set around the driver's cab 2a after the movement.

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 suitable for use in a construction machine such as a hydraulic excavator for deep hole excavation, which is movable with respect to the main body.

[0002]

2. Description of the Related Art In a hydraulic excavator, a main body is composed of a traveling body and a revolving structure which is rotatably provided on the traveling body, and a boom rotatably connected to a front portion of the revolving structure and the boom. A working machine is composed of an arm and a bucket which are sequentially connected to each other, and various operations such as excavation and loading are performed by operating a bending work motion of the working machine. When performing such work, depending on the work posture of the work equipment, a part of the bucket may come into contact with the operator's cab provided on the revolving structure to damage the operator's cab or, in some cases, cause a disaster to the operator. There is also. Therefore, conventionally, as disclosed in Japanese Patent Laid-Open No. 3-217523, a hydraulic excavator is provided with an interference preventing device for a working machine, and the interference preventing device avoids a collision between the working machine and the cab. What has been done is proposed.

The work machine interference prevention device described in the above publication sets an intrusion prohibition area and a deceleration area adjacent to the operation prohibition area in advance, and when a part of the work machine enters the deceleration area, When the operating speed of the actuator that drives the work machine is reduced and a part of the work machine reaches the intrusion prohibited area,
The operation of the actuator is automatically stopped.

[0004]

By the way, in the above-mentioned conventional interference preventing device for a working machine, since the invasion prohibition area is set on the basis of the operator's cab fixed to the revolving structure, the hydraulic excavator for deep hole excavation can be prevented. As described above, when applied to a construction machine in which the driver's cab is movable on the revolving structure, the intrusion prohibition area set before moving the driver's cab position is the area originally desired to be restricted after the operator's cab is moved. This causes a problem of slipping. For example, if an intrusion prohibition area with a predetermined width is set in front of the driver's cab and the operator's cab moves forward during work, the width of the intrusion prohibition area that has already been set becomes narrow and the amount of movement of the operator's cab is large. Since the intrusion prohibited area is zero,
If the work is continued as it is, the work machine may come into contact with the cab. On the contrary, if the driver's cab moves backward during work, the already set intrusion prohibition area moves away from the operator's cab, and the width of the intrusion prevention area becomes wider than necessary. There is a problem that the work efficiency is lowered because the frequency of automatic stop after grabbing is increased.
Note that such a problem occurs not only when the cab is movable in the front-rear direction on the revolving structure but also when the cab is movable in the vertical direction.

The present invention has been made in view of the actual situation of the prior art as described above, and an object thereof is to automatically correct the intrusion prohibited area when the driver's cab is moved, and Another object of the present invention is to provide a work machine interference prevention device capable of reliably preventing a contact accident of

[0006]

In order to achieve the above object, the present invention provides a working machine comprising a main body having a movable cab and a plurality of articulated movable parts rotatably connected to the main body. And a position detecting means for detecting the position of the working machine, and when the working machine reaches an invasion prohibited area set around the driver's cab, in a direction in which the working machine interferes with the driver's cab. An interference prevention device for a working machine, the detection device detecting a movement amount of the driver's cab with respect to the main body, and correcting the interference prevention region based on a detection result of the detection device. Is characterized by.

[0007]

The joint angles of the working machine are detected by an angle sensor or the like, which is a position detecting means, and the coordinates of the monitor point set at a predetermined position of the working machine are calculated from the detection signal.
When the work machine is operated, the current coordinates of the monitor point are calculated, and when the monitor point reaches the intrusion prohibited area set around the driver's cab in advance, the operation of the actuator that drives the work machine is automatically stopped, and the work machine is stopped. The work range is limited between the control room and the cab.

Further, when an operation of moving the cab in the front-back or up-down direction with respect to the main body is performed during the work while controlling the work range as described above, the movement amount of the cab is reduced. The amount of movement is detected by the detection device and is input to the microcomputer. In the microcomputer, the already set invasion prohibited area is corrected with respect to the movement amount detected by the detection device, and the work range restriction control is performed by using the corrected intrusion prohibited area as a new intrusion prohibited area.

[0009]

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 according to a first embodiment of the present invention, and FIG. 2 is an explanatory view showing dimensions of respective parts of the hydraulic excavator. In these drawings, 1 is a lower traveling body and 2 is a moving body. An upper revolving structure having a possible driver's cab 2a, and the lower traveling structure 1 and the upper revolving structure 2 form a main body. Three
Is a boom rotatably connected to the upper revolving structure 2, 4 is an arm rotatably connected to the boom 3, and 5 is a bucket rotatably connected to the arm 4.
The working machine 6 is composed of a plurality of articulated movable parts including an arm 4 and a bucket 5. Reference numeral 7 is a boom cylinder for driving the boom 3, 8 is an arm cylinder for driving the arm 4, 9 is a bucket cylinder for driving the bucket 5, and each of these cylinders 7 to 9 is operated by an operation lever 10 provided in the cab 2a. Be operated. Reference numeral 11 is a pin connecting portion between the boom 3 and the upper swing body 2, and 12 is a boom 3 and an arm 4.
And 13 is a pin coupling portion between the arm 4 and the bucket 5. Reference numeral 14 is a boom angle sensor attached to the pin coupling portion 11 of the boom 3, and detects a relative angle between the upper swing body 2 and the boom 3, that is, a boom angle. 15
Is an arm angle sensor attached to the pin coupling portion 12 of the arm 4, and detects a relative angle between the boom 3 and the arm 4, that is, an arm angle. Reference numeral 32 denotes a slide cylinder that moves the cab 2a in the front-rear direction with respect to the upper swing body 2, and the slide cylinder 32 is operated by an operation lever 33 provided in the cab 2a.

FIG. 3 is a circuit diagram showing an interference preventive device for a working machine provided in the hydraulic excavator shown in FIG. 1. The boom cylinder 7, arm cylinder 8, bucket cylinder 9, slide cylinder 32, boom angle sensor 14 and The same reference numerals are given to the arm angle sensor 15.
In the figure, 16 and 17 are electric levers used as an example of the operation lever 10, 18 is a controller,
9 is a swing motor, 20, 21, 22, 23 and 34 are directional control valves, 24 is a prime mover, 25 is a hydraulic pump, 26 is a pilot hydraulic pump, 27 is a proportional pressure reducing valve unit, 28,
29 is a proportional pressure reducing valve which constitutes the proportional pressure reducing valve unit 27,
Reference numeral 30 is a microcomputer, 31 is a range limiting switch, 35 is a stroke sensor for detecting the stroke (slide) amount of the slide cylinder 32, and 36 is an electric lever used as an example of the operation lever 33.

Among the operating directions of the electric lever 16, the arrows V ₁ and V ₂ correspond to the bucket cylinder 9, the arrows B ₁ and B ₂ correspond to the boom cylinder 7, and the electric lever 17 is used.
Arrows A ₁ and A ₂ of the operating directions of the arm cylinder 8
And arrows S ₁ and S ₂ correspond to the swing motor 19, respectively,
Further, in the operation direction of the electric lever 36, arrows T ₁ , T ₂
Corresponds to the slide cylinder 32. Further, i ₁ and i ₂ are signals corresponding to B ₁ and B ₂ , respectively, and r ₁ and r ₂ are proportional pressure reducing valve drive signals determined based on the signals i ₁ and i ₂ and the signal y from the microcomputer 30. The proportional pressure reducing valves 28 and 29 output the output pressure based on the magnitudes of the signals r ₁ and r ₂ to the pilot receiving portion of the boom directional control valve 20. The same applies to the other directional control valves 21 to 23 and 34,
These direction change valves 21 to 23, 34 are also the controller 18
Is driven based on the magnitude of the proportional pressure reducing valve drive signal output from the proportional pressure reducing valve unit 27. The directional control valves 20 to 23, 34 control the flow of pressure oil supplied from the hydraulic pump 25 to each actuator, and, for example, as described above, output from the proportional pressure reducing valve unit 27 based on the signals r ₁ and r _2. When the direction switching valve 20 is driven by the pressure, the boom cylinder 7 is shortened or extended, and similarly, when the direction switching valve 23 is driven by the output pressure from the proportional pressure reducing valve unit 27, the upper swing body 2 revolves.

The boom angle α _B and the arm angle α _A are detected by the boom angle sensor 14 and the arm angle sensor 15, respectively, and the microcomputer 30 uses the boom angle α _B and the arm angle α _A as variables to determine the current monitor point M. Calculate the coordinates. In this embodiment, the monitor point M is the arm 4
Is set in the pin coupling portion 13 between the bucket 5 and the bucket 5 (see FIG. 1). On the other hand, the slide amount L of the slide cylinder 32
S is detected by the stroke sensor 35, and the microcomputer 30 corrects a preset intrusion prohibited area using this slide amount LS as a variable and sets this as a new intrusion prohibited area. Further, the microcomputer 30 has a built-in calculation means for calculating a deceleration degree K described later according to the distance between the latest intrusion prohibition area and the current coordinates of the monitor point M, and the value of the calculation result K is a signal. It is output to the controller 18 as y. The controller 18 multiplies the present degree of deceleration K by the current lever output signal to decelerate the operating speed of the work implement 6, and when the monitor point M reaches the intrusion prohibited area,
A stop means for multiplying K = 0 by the current lever output signal to stop the operation of the working machine 6 is incorporated.

FIG. 4 is an explanatory diagram showing the relationship between the driver's cab 2a and the intrusion prohibition area preset around the driver's cab 2a.
The slide cylinder 32 is in the most contracted state, and in this state, the entry prohibition area, the deceleration area, and the non-restriction area are set in order from the front side in front of the cab 2a. Of these areas, the non-restricted area farthest from the cab 2a is the work machine 6
The area where the operation is not restricted, the deceleration area before that is the area where the operation speed of the working machine 6 is decelerated, and the intrusion prohibition area closest to the operator's cab 2a is the area where the operation speed of the working machine 6 is zero.

In FIG. 4, straight lines representing the front surface shape of the operator's cab 2a are Z ₀ and Z ₀ ′, boundary lines between the intrusion prohibition region and the deceleration region are Z ₁ and Z ₁ ′, and the deceleration region and the non-restriction region. The border is Z
₂ and Z ₂ ′, the lower limit of the intrusion prohibition area and the deceleration area is Z =
It is a straight line of 0. Here, the straight line expressions representing Z ₀ and Z ₀ ′ are determined by the shape of the operator cab 2a, and Z ₀ : Z = k ₀ X + b ₀ Z ₀ ′: Z = k ₀ ′ X + b ₀ ′ (k ₀ , b ₀ is a constant). Z ₁ and Z ₁ ′ are Z ₀ and Z _0.
Both the distances L ₀ and L ₀ ′ to the ′ are the length LV of the bucket 5.
If the straight lines satisfying the above are satisfied and the distances between Z ₁ and Z _{0 and} between Z ₁ ′ and Z ₀ ′ in the X-axis direction are L ₁ , Z ₁ and Z ₁ ′ are _{, Z 1: Z = k 0} X + b 0 -k 0 L 1 .............................. (1) Z 1 ': Z = k 0'X + b 0'-k 0'L 1 ............ ……… (2) Further, Z ₂ and Z ₂ ′ are Z ₁ and Z ₁ ′ with deceleration distance L
It is a straight line shifted by _{2 in the} X-axis direction, and Z ₂ : Z = k ₀ X + b ₀ −k ₀ (L ₁ + L ₂ ) ... (3) Z ₂ ′: Z = k ₀ ′ X + b ₀ ′ −k ₀ ′ (L ₁ + L ₂ ) ... (4) During As a method of determining the deceleration distance L ₂ is, for example, the cloud action of the arm when performing at full speed, emits a signal to abruptly stop the arm actually arm is stopped from being generated by this signal Further, there is a method of setting the deceleration distance L ₂ to a value equal to or larger than the overrun amount in consideration of the overrun amount of the bucket movement.

In this way, setting the intrusion prohibition area in advance means that Z ₁ and Z ₁ ′ in the above equations (1) and (2) are set in the state where the slide cylinder 32 is at the minimum contraction (LS = 0). It is nothing but setting, and these equations (1) and (2) and L ₂
Since Z ₂ and Z ₂ ′ in the equations (3) and (4) are determined from the value of, the deceleration area is also set when the intrusion prohibition area is set. Further, since Z ₁ , Z ₁ ′ and Z ₂ , Z ₂ ′ determined by these equations (1) to (4) are values at LS = 0, the slide cylinder 32 extends and the cab 2a Figure 1
When moving to the front indicated by the broken line, Z ₁ , Z ₁ ′ and Z ₂ , Z ₂ ′ are Z ₁ : Z = k ₀ X + b ₀ −k ₀ (L ₁ + LS). ……………… (5) Z ₁ ′: Z = k ₀ ′ X + b ₀ ′ −k ₀ ′ (L ₁ + LS) ………… (6) Z ₂ : Z = k ₀ X + b ₀ −k _{0 (L 1 + L 2 + LS} ) .................. (7) Z 2 ': Z = k 0'X + b 0'-k 0 '(L 1 + L 2 + LS) becomes ......... (8). That is, the correction of the intrusion prohibition area means that Z ₁ , Z ₁ ′ and Z ₂ , Z ₂ ′ are calculated from the slide amounts LS of the slide cylinder 32 including these corrections (5) to (8). It is nothing but recalculation according to the formula.

Next, the operation of this embodiment will be described mainly with reference to the flowchart of FIG. First, when the operator turns on the range limiting switch 31 (S-1) and starts the work range limiting control between the working machine 6 and the operator's cab 2a, the controller 18 initializes the deceleration degree K of the actuator to 1. Set (S-2). Further, the slide amount (stroke amount) LS of the slide cylinder 32 detected by the stroke sensor 35 is always input to the microcomputer 30 (S-3), and the microcomputer 30 is preset based on this slide amount LS. The intrusion prohibited area is corrected (S-4). As described above, the correction of the intrusion prohibited area means that the slide cylinder 32 is in the most contracted state (L
This is to recalculate Z ₁ , Z ₁ ′ and Z ₂ , Z ₂ ′ determined in S = 0) according to the above equations (5) to (8).

When the operator operates the operation lever 10 (electric levers 16 and 17), as described above, the actuators such as the cylinders 7 to 9 and the turning motor 19 operate according to the operation amount, and the hydraulic excavator excavates. Work.
During such work, the boom angle α _B and the arm angle α _A detected by the boom angle sensor 14 and the arm angle sensor 15 are always input to the microcomputer 30 (S-5), and the microcomputer 30 detects these boom angle α. The current coordinates of the monitor point M are calculated using _B and the arm angle α _A as variables. The current coordinates (X _M , Z _M ) of the monitor point M are: X _M = LA · cos (α _B + α _A ) + LB · cos α _B + S ₀ (9) Z _M = −LA · sin (α) _B + α _A ) -LB · sin α _B + T ₀ (10) (Each constant in the formula is shown in Fig. 2, the boom angle is plus the boom lowering direction, and the arm angle is cloud. The direction is plus).

Although the coordinates of the monitor point M change every moment during the work, the microcomputer 30 uses the above (9),
Which of the areas (intrusion prohibition area, deceleration area, and non-limit area) the current coordinates of the monitor point M calculated by the expression (10) are calculated by the above expressions (5) to (8) Judgment, and based on the judgment result, K = [X _M − [Z _M − {b ₀ −k ₀ (L ₁ + LS)}] / k ₀ ] / L ₂ ………… (11) K = [ X _M − [Z _M − {b ₀ ′ −k ₀ ′ (L ₁ + LS)}] / k ₀ ′] / L ₂ (12) However, if K> 1, K = 1 If K <0 The degree K of deceleration is calculated according to one of the expressions represented by K = 0 (S-6), and the calculation result is output to the controller 18 as a signal y. In other words, monitoring point M for each region, when the coordinates of an intersection of the straight line Z ₁ and the straight line Z ₁ 'and (X _00, Z _00), and the boundary of the horizontal plane containing the coordinates (X _00, Z _00), Since it depends on the straight line Z ₁ and the straight line Z ₂ above it and on the straight line Z ₁ ′ and the straight line Z ₂ ′ above it, when Z _M ≧ Z ₀₀ , the degree K of deceleration is calculated according to the above equation (11). If 0 ≦ Z _M <Z ₀₀ , the above (1
The degree K of deceleration is calculated according to the equation (2). Also, Z _M
When <0, all are in the non-restricted region, so in this case, the deceleration degree K is set to K = 1.

In this way, when the degree of deceleration K is output from the microcomputer 30 to the controller 18,
The controller 18 multiplies the current lever output signal by K (S-7) and outputs a proportional pressure reducing valve drive signal corresponding to this value to the proportional pressure reducing valve unit 27 to drive the proportional pressure reducing system (S-8). As a result, the directional control valves 20 to 23 are driven according to the magnitude of the proportional pressure reducing valve drive signal, and the actuator is driven (S-9).

For example, assuming a case where the electric lever 17 is operated to perform the cloud operation of the arm 4 alone, the current coordinates (X _M , Z _M ) of the monitor point M are the coordinates (X ₀₀ ,
Z ₀₀₎ If more in the non-restricted area of the upper of the (11)
According to the formula, if it is in the lower non-restricted area, (1
The deceleration degree K is calculated according to the equation (2), and K> 1 in all of these cases, but K> 1 = 1 from the condition of K> 1 = 1.
= 1 is output to the controller 18, and the arm cylinder 8
Is driven at an operation speed corresponding to the operation amount of the electric lever 17. From this state, the cloud operation of arm 4 continues,
When the current coordinates of the monitor point M cross the boundary lines Z ₂ and Z ₂ ′ and enter the deceleration region, the deceleration degree K is calculated in accordance with the above equation (11) or (12), and 0 ≦ K ≦ 1 is output to the controller 18.
The controller 18 multiplies this K by the current operation command signal of the arm cylinder 8 which is an actuator, and outputs a proportional pressure reducing valve drive signal to the proportional pressure reducing valve 28 of the proportional pressure reducing valve unit 27 according to this value. 28 outputs the output pressure based on the magnitude of the proportional pressure reducing valve drive signal to the pilot receiving portion on the right side of the arm directional control valve 21, and the operating speed of the arm cylinder 8 corresponds to the operation amount of the electric lever 17. The cloud speed of the arm 4 becomes slower than that of the operation speed. The cloud operation of the arm 4 is further continued, and the current coordinates of the monitor point M are the boundary lines Z ₁ and Z ₁ ′.
If you enter the intrusion-prohibited area by crossing over, the same as above (1
The degree K of deceleration is calculated according to the equation (1) or (12), and in these cases, K <0, but K = 0 is output to the controller 18 under the condition of K <0 = 0. The controller 18 multiplies K = 0 by the current operation command signal of the arm cylinder 8 to minimize the proportional pressure reducing valve drive signal, and sets the directional control valve 21 to the neutral position. As a result, the operating speed of the arm cylinder 8 which is an actuator becomes 0,
The arm 4 automatically stops.

According to the above steps S-1 to S-9, the work range limiting control is performed between the working machine 6 and the operator's cab 2a, and then the range limiting switch 31 is turned off in S-10. If it is determined to be OFF, the work range limiting control is ended there (S-1).
1). Further, the range limit switch 31 is turned off in S-10.
If it is determined that it is not, the process returns to S-3 and the above-described operation is repeated. If the cab 2a moves in the front-rear direction during that time, the current intrusion prohibition area is corrected according to the movement amount, and the correction is performed. The work area restriction control is performed by setting the subsequent intrusion prohibited area as a new intrusion prohibited area.

As described above, in the first embodiment,
When the working machine 6 is operated, the current coordinates of the monitor point M set at an appropriate position of the working machine 6 is calculated by using the coordinate calculating means incorporated in the microcomputer 30, and the current coordinates of the monitor point M are calculated. In order to decelerate or stop the operation of the actuator that drives the work implement 6 in accordance with the distance from the intrusion prohibition area corrected for the slide amount LS of the slide cylinder 32, the operation lever 33 ( When the electric lever 36) is operated, the cab 2a
Even if the vehicle moves in the front-rear direction, the relative position between the driver's cab 2a and the preset invasion prohibited area around it does not change, and the contact accident between the working machine and the driver's cab is ensured without lowering the work efficiency. Can be prevented.

FIG. 6 is a side view of a hydraulic excavator according to a second embodiment of the present invention, FIG. 7 is a circuit diagram of a work machine interference prevention device provided in the hydraulic excavator of FIG. 6, and FIG. 8 is an interference prevention of FIG. It is a flowchart which shows the processing content of an apparatus, The duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol to the part corresponding to FIGS. In FIG. 6, 37 is a driver's cab 2a
Is a lift cylinder for moving the upper and lower parts with respect to the upper revolving structure 2, and the lift cylinder 37 is operated by an operation lever 38 provided in the operator's cab 2a. Further, in FIG. 7, 39 is a direction switching valve that controls the flow of pressure oil supplied to the lift cylinder 37, 40 is a lift sensor that detects the stroke of the lift cylinder 37, and 41 is the operation lever 38. This is an electric lever used as an example, and the arrows U ₁ and U _{2 in} the operating direction of the electric lever 41 correspond to the lift cylinder 37.

Next, the operation of the second embodiment thus constructed will be described with reference to FIG. The operation of the second embodiment differs from the operation of the first embodiment described above in that the operation of detecting the stroke of the slide cylinder in S-3 of FIG.
Then, we just changed the operation to detect the stroke of the lift cylinder, and the whole procedure is basically the same,
A duplicate description will be omitted. However, since the method of correcting the intrusion prohibited area is different from that of the first embodiment, the method of correcting the intrusion prohibited area will be described below.

Assuming that the lift amount of the lift cylinder 37 is LL, the side view when the lift cylinder 37 is at the minimum contraction (LL = 0) is the same as FIG. 4, and Z ₁ , Z ₁ ′ and Z ₁ at this time are the same. _The equations for determining ₂ , Z ₂ ′ are the same as the above equations (1) to (4). Here, when the lift cylinder 37 extends and the cab 2a moves upward as shown by the broken line in FIG. 6, Z ₁ , Z ₁ ′ and Z ₂ , Z ₂ ′ are Z ₁ : _{Z = k 0 X + b 0} + LL ........................ (13) Z 1 ': Z = k 0'X + b 0' + LL .................. (14) Z 2: Z = k 0 X + b 0 + LL _{........................ (15) Z 2 ':} Z = k 0'X + b 0' + LL .................. becomes (16). The lower limit of the intrusion prohibition area and the deceleration area is Z = L
Let L.

The current coordinate of the monitor point M is (X _M ,
When Z _M), the degree K of the reduction which is calculated by the microcomputer 30, if the Z _M ≧ Z ₀₀ K = _{[X M - {Z M - (} b 0 + LL)} / k 0 ] / L ₂ ... ......... (17) if the _{LL ≦ Z M <Z 00 K} = _{[X M - {Z M - (} b 0 '+ LL)} / k 0' ] _{/ L 2 ...... (18) Z} M < of LL Case K = 1 …………………………………………………… (19) However, if K> 1, K = 1 and if K <0, K = 0 To be

As described above, in the second embodiment,
When the working machine 6 is operated, the current coordinate of the monitor point M is calculated by using the coordinate calculating means built in the microcomputer 30, and the current coordinate of the monitor point M and the lift amount LL of the lift cylinder 37 are corrected. In order to decelerate or stop the operation of the actuator that drives the work machine 6 in accordance with the distance to the intruder prohibited area, the operation lever 38 (electric lever 41) is operated during the work to move the cab 2a in the vertical direction. Even if it moves to, the relative position of the driver's cab 2a and the intrusion prohibition area set around it does not change, and the contact accident between the working machine and the driver's cab can be reliably prevented without lowering the work efficiency. .

The interference preventing device for a working machine according to the present invention is not limited to the above-mentioned embodiments, and various modifications are possible. For example, in each of the above-described embodiments, the case where the electric lever is used as the operation lever has been described, but it is also possible to use a hydraulic pilot lever instead, and further, as a means for detecting each joint angle of the working machine, A cylinder stroke sensor or the like may be used instead of the angle sensor described in each of the above embodiments.

Further, in each of the above-described embodiments, the case where the switching operation of each directional switching valve is performed by the pilot pressure from the proportional pressure reducing valve unit has been described, but as a means for reducing the operating speed of the actuator, a hydraulic pump and a directional switching valve are used. A variable flow rate adjusting valve may be attached to a pipe line connecting the valve and the variable flow rate adjusting valve may be operated by a drive signal from the controller to control the pressure oil amount to the directional control valve. Alternatively, an electromagnetic switching valve that determines the flow direction of pressure oil and a variable flow rate adjustment valve that determines the flow rate of pressure oil are provided in the pipeline that connects the hydraulic pump and the actuator, and based on separate drive signals from the controller. Then, the flow and amount of the pressure oil supplied to the actuator may be controlled by switching these electromagnetic switching valves ON-OFF and variably operating the variable flow rate adjusting valve.

Further, in each of the above embodiments, the case where the monitor point is set at the pin connecting portion between the arm and the bucket has been described. However, the position and the number of the monitor points are not limited to this, and the shape and the intrusion of the working machine. It is also possible to appropriately increase or decrease according to the setting position of the prohibited area.

[0031]

As described above, according to the present invention,
If the driver's cab moves with respect to the main unit during work, the intrusion prohibition area is automatically corrected according to the amount of movement, so a proper intrusion prevention area is always set around the operator's cab after the movement. It is possible to reliably avoid a contact accident between the machine and the cab.

[Brief description of drawings]

FIG. 1 is a side view of a hydraulic excavator according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing dimensions of each part of the hydraulic excavator of FIG.

3 is a circuit diagram showing an interference prevention device for a working machine provided in the hydraulic excavator of FIG.

FIG. 4 is an explanatory diagram showing a relationship between a driver's cab and an intrusion prohibited area.

5 is a flowchart showing the processing contents of the interference prevention device for the working machine in FIG.

FIG. 6 is a side view of a hydraulic excavator according to a second embodiment of the present invention.

7 is a circuit diagram of an interference prevention device for a work machine provided in the hydraulic excavator of FIG.

FIG. 8 is a flowchart showing the processing contents of the interference prevention device of FIG.

[Explanation of symbols]

 1 Lower Traveling Body 2 Upper Revolving Body 2a Operator's Cabin 3 Boom 4 Arm 5 Bucket 6 Working Machine 7 Boom Cylinder 8 Arm Cylinder 9 Bucket Cylinder 10, 33, 38 Operating Lever 14 Boom Angle Sensor 15 Arm Angle Sensor 16, 17, 36, 41 electric lever 18 controller 19 swing motor 20, 21, 22, 23, 34, 39 directional switching valve 27 proportional pressure reducing valve unit 28, 29 proportional pressure reducing valve 30 microcomputer 31 range limiting switch 32 slide cylinder 35, 40 stroke sensor (detection) Equipment) 37 Lift Cylinder M Monitor Point

Claims (3)

[Claims] 1. A main body having a movable cab, a working machine including a plurality of articulated movable parts rotatably connected to the main body, and position detection means for detecting the position of the working machine. In the interference preventing device for a working machine, when the working machine reaches an invasion prohibited area set around the driver's cab, the working machine is prohibited from operating in a direction of interfering with the driver's cab, An interference prevention device for a working machine, comprising: a detection device that detects a movement amount of the driver's cab with respect to the main body, and the interference prevention region is corrected based on a detection result of the detection device. 2. The method according to claim 1, further comprising a slide cylinder that moves the cab in the front-rear direction with respect to the main body, and the detection device is a stroke sensor that detects a slide amount of the slide cylinder. Characteristic work equipment interference prevention device. 3. The lift sensor according to claim 1, further comprising a lift cylinder that moves the cab vertically with respect to the main body, and the detection device is a stroke sensor that detects a lift amount of the lift cylinder. Characteristic work equipment interference prevention device.