JPH0820974A - Work range limiter for construction machinery - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a work range limiting device for a construction machine, which can automatically correct an intrusion prohibited area according to the movement amount of the working machine body when the working machine body moves. [Structure] At a predetermined position of the boom 3, the arm 4 and the bucket 5 which form the front member 6, monitor points M1 to M1 are provided.
When M6 is set and the front member 6 is operated, the microcomputer 31 calculates the current coordinates of the monitor points M1 to M6, and the deceleration degree K is calculated according to the distance between these coordinates and the preset intrusion prohibition area. Then, 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 working machine main body moves during the work while limiting the working range in this way, the microcomputer 31 determines the working machine main body from the output g of the accelerometer 38 and the output θ _{0 of the} gyro 39. The movement amount is calculated, and the intrusion prohibited area is automatically corrected based on the calculation result.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work range limiting device for a front member provided in a construction machine such as a hydraulic excavator.

[0002]

2. Description of the Related Art A hydraulic excavator, which is an example of a construction machine, constitutes a working machine body with a lower traveling body and an upper revolving body rotatably provided on the lower traveling body, and rotates on the upper revolving body. A boom, an arm, and a bucket which are operably connected to each other form a front member, and various operations such as excavation and loading are performed by operating a bending work motion of the front member. However, at the work site where such work is performed, there may be obstacles such as electric wires and signs above the ground, and there may be obstacles such as gas pipes and water pipes underground. If the work is continued in a situation, the front member may damage these obstacles during the work, or even the operator may be injured. Therefore, conventionally, Japanese Patent Laid-Open No.
As disclosed in Japanese Patent No. 208923 and Japanese Patent Application Laid-Open No. 4-136324, a hydraulic excavator is provided with a work range limiting device for limiting the work range of a front member, and by this work range limiting device, the work range limiting device moves in the vertical direction, forward direction, or the like. There has been proposed a device which avoids a collision between an existing obstacle and a front member.

In the work range limiting devices described in these publications, an intrusion prohibition area is set in advance at a predetermined position, and when a part of the front member intrudes into the deceleration area on the front side of the intrusion prohibition area, the front member is closed. The operation speed of the actuator for driving the actuator is reduced, and when a part of the front member reaches the invasion prohibited area, the operation of the actuator is automatically stopped.

[0004]

By the way, in such a work range limiting device, the invasion prohibition area is set with reference to the stopped working machine body. The set intrusion prohibition area may deviate from the area you want to restrict, and if you continue to work, the front member will enter the intrusion prevention area and come into contact with obstacles. It will stop automatically before this. However, in the above-mentioned conventional work range limiting device, since no consideration is given to the movement of the working machine body after setting the intrusion prohibition area, if the working machine body moves during work, the intrusion prohibition area is set again. There is a problem in that work efficiency is reduced because it has to be redone. In addition, since it is the operator who sets the intrusion prevention area, it is possible to make a human error of forgetting to reset the intrusion prevention area after the work machine body has moved. There was a problem that it became impossible to perform limit control.

The present invention has been made in view of the circumstances of the prior art as described above, and an object thereof is to automatically correct the intrusion prohibition area when the working machine body is moved, and to perform an upward or downward movement. (EN) Provided is a work range limiting device for a construction machine capable of reliably preventing a contact accident with an obstacle existing in the vehicle.

[0006]

In order to achieve the above object, the present invention comprises a working machine main body composed of a traveling body and a revolving structure, and a plurality of articulated movable parts rotatably connected to the revolving structure. And a position detecting means for detecting the position of the front member, and when the front member reaches an intrusion prohibited area set in its operation range, the operation of the front member is stopped. In the work range limiting device, a travel movement amount detection device for detecting a travel movement amount of the working machine body and an inclination change amount detection device for detecting an inclination change amount of the work machine body are provided, and the work range is limited and controlled. While performing work, the movement state of the working machine body is detected by the traveling movement amount detection device and the inclination change amount detection device, and the intrusion prohibition is performed based on these detection results. To correct the area, and the most important features.

[0007]

Before starting the work, the operator sets an intrusion prohibited area at a predetermined position above, below or in front of the work machine body in consideration of obstacles existing at the work site. Thereafter, when the front member is operated with the work machine main body stopped, each joint angle of the front member is detected by an angle sensor or the like which is a position detecting means, and the monitor signal set at a predetermined position of the front member is detected from the detection signal. The coordinates of the points are calculated. Then, when the monitor point reaches the preset intrusion prohibition area, the operation of the actuator that drives the front member is automatically stopped, whereby the work range limiting control is performed.

Further, when the work motor is driven to move the work machine body while performing work while limiting the work range as described above, the travel movement amount and the inclination change amount of the work machine body are respectively changed. It is detected by the traveling movement amount detection device and the inclination change amount detection device and input to the microcomputer. Then, the microcomputer corrects the already set intrusion prohibition area with respect to the traveling movement amount and the inclination change amount, and performs the work range restriction control with the corrected intrusion prohibition area as a new intrusion prohibition 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 an embodiment of the present invention. In FIG. 1, 1 is a lower traveling body, 2 is an upper revolving structure having a cab 2a, and these lower traveling structure 1 and upper revolving structure are shown. The work machine body is composed of 2 and. Reference numeral 3 denotes a boom rotatably connected to the upper swing body 2, 4 denotes an arm rotatably connected to the boom 3, and 5 denotes a bucket rotatably connected to the arm 4. Arm 4
The front member 6 is constituted by a plurality of articulated movable parts including the bucket 5 and the 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. Further, M1 is a monitor point set on the upper surface of the boom 3, M2 and M3 are monitor points set at two positions at the rear end of the arm 4, and M4 is a monitor set at the highest position of the cutting edge circle of the bucket 5. A point, M5 is a monitor point that is set to the most front of the blade edge circle of the bucket 5, and M6 is a monitor point that is set to the lowest position of the blade edge circle of the bucket 5.
Note that FIG. 2 shows the dimensions of each part including the monitor points M1 to M6.

FIG. 3 is a circuit diagram showing a work range limiting device provided in the hydraulic excavator of FIG. 1, and the boom cylinder 7, arm cylinder 8, bucket cylinder 9, boom angle sensor 14 and arm angle sensor 15 described above are shown. The same reference numerals are attached. In the figure, 16 and 17 are electric levers used as an example of the operation lever 10,
18 is a controller, 19 is a swing motor, 20-23,
Reference numerals 36 and 37 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 and 29 are proportional pressure reducing valves constituting the proportional pressure reducing valve unit 27, and 30 is an intrusion prohibition. Setting device for setting the area, 31 is a microcomputer, 32 is a range limiting switch, 33 is an alarm device installed in the cab 2a, 3
Reference numerals 4 and 35 are traveling motors. Further, 38 is an accelerometer that detects the longitudinal acceleration of the working machine body (the lower traveling body 1 and the upper swinging body 2), and 39 is a gyro that detects the inclination of the working machine body. The gyro 39 constitutes a tilt change amount detection device.

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
Further, arrows S ₁ and S ₂ correspond to the swing motor 19, respectively. Further, i ₁ and i ₂ are signals corresponding to B ₁ and B ₂ , respectively, and r ₁ and r ₂ are signals i ₁ and i ₂ and the signal x from the setter 30.
And the proportional pressure reducing valve drive signal determined based on the signal y from the microcomputer 31.
Reference numerals 8 and 29 output the output pressure based on the magnitudes of the signals r ₁ and r ₂ to the pilot receiver of the boom directional control valve 20. The other directional control valves 21 to 23 are similar, and these directional control valves 21 to 23 are also driven based on the magnitude of the proportional pressure reducing valve drive signal output from the controller 18 to the proportional pressure reducing valve unit 27. Further, the direction switching valves 20 to 23 control the flow of pressure oil supplied from the hydraulic pump 25 to each actuator, and, for example, as described above, by the output pressure 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, 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. On the other hand, the direction switching valves 36 and 37 are driven by a traveling lever and traveling pilot pressure oil (not shown) to control the flow of the pressure oil supplied to the traveling motors 34 and 35. It is rotated by oil.

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 31 sets the boom angle α _B and the arm angle α _A as variables to monitor points M1 to M1. calculates the current coordinates of the M6, it incorporates a calculating means for calculating the degree of deceleration K (K ₁ ~K ₆₎ to be described later in accordance with the distance between the monitoring point M1~M6 current coordinates for each and forbidden entry area And the value of the operation result K is signal y as the controller 1
8 is output. The controller 18 multiplies the current degree of deceleration K by the current lever output signal to decelerate the operating speed of the front member, and when at least one of the monitor points M1 to M6 reaches the intrusion prohibited area, A stop means for multiplying the current lever output signal by K = 0 to stop the operation of the front member is incorporated.

Next, the operation when the present embodiment is applied to the upper range restriction will be described mainly with reference to the flowchart of FIG. 4 and the explanatory view of FIG. In FIG. 5, H _L is the height to the intrusion prohibition area, H _S is the height to the deceleration area, and θ ₀
Indicates the inclination angle of the ground.

First, before starting the work, the operator turns on the range limiting switch 32 (S-1), and then sets the intrusion prohibited area upward by the setting device 30 (S-).
2). As a method of determining the invasion prohibited area, for example, there is a method of raising the boom 3 near an obstacle above and calculating the height from the boom angle, or measuring the distance to the obstacle with a ruler or the like. In the present invention, the intrusion prohibited area means a boundary line where a part of the front member may collide with an obstacle, and is actually set in front of the obstacle in view of a certain degree of safety. Further, the intrusion-prohibited area is a surface having a constant height with respect to the horizontal reference plane. Therefore, the setting of the intrusion-inhibited area in S-2 is nothing but the setting of H _{L in} FIG. .

When the intrusion prohibition area is set in this way, a deceleration area having a constant width is also set on the front side (downward) thereof, and the controller 18 limits the upper range based on the signal x from the setter 30. the highest respectively the degree of deceleration for monitoring point and will be _{M1~M4 K 1, K 2, K} 3, is initialized to K ₄ = 1 in (S-3). When the operator operates the operation lever 10 (electric levers 16 and 17) after setting the intrusion prohibition area, the actuators such as the cylinders 7 to 9 and the turning motor 19 operate according to the operation amount as described above. However, the hydraulic excavator performs work such as excavation. During such work, the boom angle α _B detected by the boom angle sensor 14 and the arm angle sensor 15
And the arm angle α _A are always input to the microcomputer 31 (S-4), and the microcomputer 31 uses the boom angle α _B and the arm angle α _A as variables to detect the current Z-axis direction of each monitor point M1 to M4. Calculate the coordinates.

The formula for calculating the current Z coordinate (Z _M1 , Z _M2 , Z _M3 , Z _M4 ) of each monitor point _{M1 to M4} is as follows (each constant in the formula is shown in FIG. 2). And again
The boom angle is positive in the boom lowering direction, and the arm angle is positive in the cloud direction). Here, the X′-Z ′ coordinates mean the turning axis of the hydraulic excavator as the Z ′ axis, the point where the Z ′ axis intersects the lower surface of the lower traveling body 1 as the origin O, and the origin O through the origin O and the lower surface of the lower traveling body 1. Coordinates with parallel lines as the X'axis, and X-
The Z coordinate is a coordinate having a horizontal line passing through the origin O as the X axis and a vertical line passing through the origin O as the Z axis. The inclination angle θ ₀ is positive in the counterclockwise direction and negative in the clockwise direction in FIG.

First, the coordinates M1 (X _M1 ′, Z _M1 ′) and M2 of the monitor points M1 to M4 in the X′-Z ′ coordinates.
(X _M2 ′, Z _M2 ′), M3 (X _M3 ′, Z _M3 ′), M4
(X _M4 ′, Z _M4 ′) is X _M1 ′ = L _b1 · cos α _B + L _b2 · sin α _B + S ₀ Z _M1 ′ = −L _b1 · sin α _B + L _b2 · cos α _B + T ₀ X _M2 ′ ＝ -L _a1・ cos (α _B + α _A ) + L _a2・ sin (α _B + α _A ) + LB ・
cos α _B + S ₀ Z _M2 ′ = L _a1 · sin (α _B + α _A ) + L _a2 · cos (α _B + α _A ) -LB · s
in α _B + T ₀ X _M3 '=-L _a3・ cos (α _B + α _A ) + L _a4・ sin (α _B + α _A ) + LB ・
cos α _B + S ₀ Z _M3 ′ = L _a3 · sin (α _B + α _A ) + L _a4 · cos (α _B + α _A ) -LB · s
in α _B + T ₀ X _M4 ′ = LA ・ cos (α _B + α _A ) + LB ・ cos α _B + LV + S ₀ Z _M4 ′ = -LA ・ sin (α _B + α _A ) -LB ・ sin α _B + Calculated as LV + T ₀ . Then, Z _M1 obtained in this way
By converting ′, Z _M2 ′, Z _M3 ′, Z _M4 ′ into X-Z coordinates, the current Z coordinates (Z _M1 , Z _M2 , Z _M3 , Z _M4 ) of each monitor point _{M1 to M4} are Z _M1 = X _M1 ′ · sin (-θ ₀ ) + Z _M1 ′ · cos (-θ ₀ ) Z _M2 = X _M2 ′ · sin (-θ ₀ ) + Z _M2 ′ · cos (-θ ₀ ) Z _M3 = X _M3 ′ · sin (−θ ₀ ) + Z _M3 ′ · cos (−θ ₀ ) Z _M4 = X _M4 ′ · sin (−θ ₀ ) + Z _M4 ′ · cos (−θ ₀ ).

During the work, Z of each monitor point M1 to M4
Although the coordinates change every moment, the microcomputer 31
Based on the Z coordinate obtained by the above formula, each monitor point M1
The degree K ₁ ~K ₄ deceleration for ~M4 calculated according to the following formula (S-5~S-8), and outputs the result of operation to the controller 18 as a signal y.

[0019] _{K 1 = (H L -Z M1} ) / (H L -H S) .............................. However, K _{1> 1} of the case K ₁ = _1, the case of K ₁ <0 _{K 1 = 0 K 2 = (} H L -Z M2) / (H L -H S) .............................. However, in the case of _{K 2> 1 K 2 = 1} , K 2 < 0 when _{K 2 = 0 K 3 = (} H L -Z M3) / (H L -H S) .............................. However, K _3> for _{1 K 3 = 1, K 3} <0 for _{K 3 = 0 K 4 = (} H L -Z M4) / (H L -H S) .............................. However, if the _{K 4> 1 K 4 = 1} , K 4 < When 0, K ₄ = 0 In this way, when the deceleration degrees K _{1 to} K ₄ are output from the microcomputer 31 to the controller 18, the controller 18 compares the values of K _{1 to} K ₄ in S-9. Then, the minimum value among them is the degree of deceleration K = min
The current lever output signal is multiplied as (K ₁ , K ₂ , K ₃ , K ₄ ) (S-10), and a proportional pressure reducing valve drive signal corresponding to this value is output to the proportional pressure reducing valve unit 27 to output the proportional pressure reducing system. Is driven (S-11). As a result, each directional valve 20-23
Is driven according to the magnitude of the proportional pressure reducing valve drive signal to drive the actuator (S-12).

For example, as shown in FIG. 5, an intrusion prohibition region is set at a position of height H _L and a deceleration region is set at a position of height H _S , and the electric lever 16 is tilted in the direction of arrow B _{1 in} FIG. Assuming a case where the boom 3 is independently lifted in the direction of arrow A and the current height Z _M2 of the monitor point M2 does not reach H _S , ( _HL- Z _M1 )> (H _L −
Although the K _2> 1 with _{H S), K 2> 1} = 1 condition K ₂ =
1 is output to the controller 18, and the boom cylinder 7 is driven at an operating speed corresponding to the operation amount of the electric lever 16. When the raising operation of the boom 3 is continued from this state and the current height Z _M2 of the monitor point M2 exceeds H _S, that is, when the monitor point M2 enters the deceleration area, ( _HL- Z _M2 ) <( H _L -H _S) for the 0 ≦ K ₂ ≦ 1, the microcomputer 31 outputs a K ₂ which is calculated by the equation in the controller 18. The controller 18 multiplies the current operation command signal i ₁ of the boom cylinder 7 which is an actuator by this K _2, and outputs the proportional pressure reducing valve drive signal r ₁ to the proportional pressure reducing valve 28 of the proportional pressure reducing valve unit 27 according to this value. Therefore, the proportional pressure reducing valve 28 outputs the signal r
_The output pressure based on the size of ₁ is used for the boom direction switching valve 2
It is output to the pilot receiver on the right side of 0, and the operating speed of the boom cylinder 7 is reduced as compared with the operating speed corresponding to the operation amount of the electric lever 16, and the raising speed of the boom 3 becomes slow. When the raising operation of the boom 3 is further continued and the current height Z _M2 of the monitor point M2 reaches _HL , that is, when the monitor point M2 enters the intrusion prohibition area, _HL and Z _M2 in the above equation are Since K ₂ = 0 becomes equal, the microcomputer 31 outputs K ₂ = 0 to the controller 18. The controller 18 multiplies the current operation command signal i ₁ of the boom cylinder 7 by this K ₂ = 0 to minimize the proportional pressure reducing valve drive signal r ₁ and sets the directional control valve 20 to the neutral position. As a result, the operating speed of the boom cylinder 7, which is an actuator, becomes 0, and the boom 3 automatically stops.

When the boom 3 is raised from the posture shown in FIG. 5, the monitor point M3 may also enter the deceleration area or the intrusion prohibition area after the monitor point M2. In such a case, the degree of deceleration K ₃ with respect to the monitor point M3 is calculated in the same manner as above, and the controller 18 compares the value of K ₂ with respect to the monitor point M2 and the value of K ₃ with respect to the monitor point M3. , The smaller one of them is the boom cylinder 7
Multiply by the operating speed of.

Further, when the raising operation of the boom 3 and the dumping operation of the arm 4 in the direction of the arrow B are combinedly operated from the posture shown in FIG. 5, the monitor point M4 is decelerated in addition to the monitor points M2 and M3. May invade areas and intrusion-prohibited areas. In such a case, the values of K (K _{2 to} K ₄ ) calculated for the respective monitor points M 2 to M ₄ are compared, and the minimum value is multiplied by the current operating speed of the actuator.

Although the upper range is restricted by the above-described operations of S-1 to S-12, the output g detected by the accelerometer 38 and the output θ ₀ detected by the gyro 39 during such an operation. Is always input to the microcomputer 31 (S-13, S-14), and when the working machine body moves on the inclined surface during work, the microcomputer 31 uses the output g and the output θ ₀ as a basis for the work machine. The movement amount of the main body in the vertical direction is calculated (S-15), and the intrusion prohibited area set in S-2 is corrected based on the calculation result (S-1).
6).

That is, when the traveling motors 34 and 35 are driven while the upper range is being limited and the lower traveling body 1 travels on the X'axis in FIG. The movement amount j of is calculated by j = ∬gdt by integrating the output g of the accelerometer 38 twice with respect to time. Next, from this j and the output θ _{0 of the} gyro 39, the movement amount n of the working machine main body in the Z-axis direction (vertical direction) is given as n = j × sin (−θ ₀ ) ... Desired. The microcomputer 31 uses n obtained by the above equation as a correction value, and corrects _HL set in S-2 as _HL → _HL + n .... When the lower traveling body 1 travels on a horizontal plane, the relative position between the upper entry prohibition region and the working machine body does not change in the vertical direction. In that case, θ ₀ = 0 and the above equation is n = 0. Therefore, the intrusion prohibited area is not corrected as a matter of course.

By the above operations of S-13 to S-16,
The upper invasion prohibited area is corrected, and the above-described upper range restriction is continued with H _L corrected by the above equation as the height to the new intrusion prohibited area. Also,
When ending the above upper range restriction, the operator turns off the range restriction switch 32, and S-17
It is determined whether the range limiting switch 32 is turned off in step S21, and if it is turned off, the upper range limiting is ended (S-18).

Although the above-described operations of S-13 to S-18 have been described for the case where the upper range is restricted, for example, when the lower range is restricted so as to control the excavation depth, the ground surface is restricted. An intrusion-prohibited area is set below, and according to the distance between this intrusion-prohibited area and the current coordinates of the monitor point M6 set at the lowest position of the cutting edge circle of the bucket 5,
The lower range may be limited.

When the front range is restricted, an intrusion prohibition area is set in front of the front member 6, and the intrusion prohibition area and the current monitor point M5 set at the most front of the cutting edge circle of the bucket 5 are set. The forward range may be limited according to the distance from the coordinates. However, in this case, if the work machine body moves while the front range is restricted,
Since the relative position between the front intrusion prohibition area and the working machine body changes in the horizontal direction, the output g of the accelerometer 38 and the gyro 39
From the output θ _{0 of}
Is calculated as f = j × cos (−θ ₀ ) ..., and the intrusion prohibited area initially set forward is corrected using f calculated by this equation as a correction value.

Further, it is possible not only to limit the range in a single direction, but also to limit the range in a plurality of directions. For example, in the case where a breaker is attached to the tip of the front member 6 for tunnel excavation or the like, an intrusion prohibited area is set. It is set in both up and down directions and in the front, and these intrusion prohibited areas and monitor points M1 to M are set.
The range may be limited in three directions, the up-down direction and the front direction, depending on the distance from the position 6.

As described above, in the above-described embodiment, the monitor points M1 to M6 are set on the boom 3, the arm 4 and the bucket 5, which form the front member 6, respectively.
Using the coordinate calculation means built in the microcomputer 31, the current coordinates of the monitor points M1 to M6 are calculated when the front member 6 is operated, and the current coordinates are calculated according to the distance between these coordinates and a preset intrusion prohibited area. Since the deceleration process is performed, it is possible to reliably avoid contact between the obstacle existing at the work site and the front member 6. Also,
When the lower traveling body 1 moves while performing work while limiting and controlling the work range in this way, the microcomputer 31 moves the working machine body from the output g of the accelerometer 38 and the output θ _{0 of the} gyro 39. Since the amount is calculated and the intrusion prohibition area is automatically corrected based on the calculation result, there is no human error of forgetting to reset the intrusion prevention area after the work machine body has moved, and the operator has no obstacles. The work can be performed without concern about the accident of contact between the front member 6 and the front member 6, and the work efficiency can be improved.

It should be noted that the work range limiting device for the construction machine according to the present invention is not limited to the above embodiment, and various modifications are possible. For example, in the above-described embodiment, the case where the electric lever is used as the operation lever has been described, but a hydraulic pilot lever may be used instead, and as a means for detecting each joint angle of the front member, Instead of the angle sensor mentioned in the embodiment, a cylinder stroke sensor or the like can be used.

Further, in the above embodiment, the case where each directional switching valve is switched by the pilot pressure from the proportional pressure reducing valve unit has been described, but a hydraulic pump and a directional switching valve are used as means for reducing the operating speed of the actuator. A variable flow rate adjusting valve may be attached to the connected pipeline, and the variable flow rate adjusting valve may be operated by a drive signal from the controller to control the amount of pressure oil 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 the above embodiment, the case where six monitor points are set at predetermined positions of the front member has been described, but the number and positions of the monitor points are not limited to this, and the shape of the front member and the intrusion prohibited area are not limited thereto. The number may be increased or decreased as appropriate depending on the setting position and the like.

[0033]

As described above, according to the present invention,
If the work machine body moves while performing work while limiting the work range, the intrusion prohibition area is automatically corrected according to the amount of movement of the work machine body. It is possible to reliably avoid contact between the front member and the front member.

[Brief description of drawings]

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

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

3 is a circuit diagram showing a work range limiting device provided in the hydraulic excavator of FIG. 1. FIG.

FIG. 4 is a flowchart showing the processing contents of the work range limiting device in FIG.

5 is an explanatory view showing an upper range limiting operation of the hydraulic excavator of FIG. 1. FIG.

[Explanation of symbols]

 1 Lower Traveling Body 2 Upper Revolving Body 2a Driver's Cab 3 Boom 4 Arm 5 Bucket 6 Front Member 7 Boom Cylinder 8 Arm Cylinder 9 Bucket Cylinder 10 Operating Lever 14 Boom Angle Sensor 15 Arm Angle Sensor 16, 17 Electric Lever 18 Controller 19 Swing Motor 20, 21, 22, 23, 36, 37 Directional switching valve 27 Proportional pressure reducing valve unit 28, 29 Proportional pressure reducing valve 30 Setting device 31 Microcomputer 32 Position limiting switch 33 Alarm device 34, 35 Traveling motor 38 Accelerometer (traveling travel amount) Detection device) 39 Gyro (tilt change amount detection device) M1 to M6 Monitor points

Claims (3)

[Claims] 1. A work machine main body composed of a traveling structure and a revolving structure, a front member composed of a plurality of articulated movable parts rotatably connected to the revolving structure, and position detection means for detecting the position of the front member. A work range limiting device for a construction machine that stops the operation of the front member when the front member reaches an intrusion prohibited area set in the operation range, and detects the traveling movement amount of the work machine body. And a tilt change amount detecting device that detects a tilt change amount of the working machine body, and a working state of the working machine body while performing work while controlling the working range. Is detected by the traveling movement amount detection device and the inclination change amount detection device, and the intrusion prohibited area is corrected based on these detection results. Limited equipment. 2. The traveling movement amount detection device according to claim 1, further comprising an accelerometer for detecting an acceleration applied to the working machine main body, wherein the working machine main body of the working machine main body is detected based on a signal output from the accelerometer. A work range limiting device for a construction machine, which is characterized by calculating a travel distance. 3. The tilt change amount detection device according to claim 1, further comprising a gyro that detects a tilt of the working machine main body, and the tilt change amount of the working machine main body based on a signal output from the gyro. A work range limiting device for a construction machine, characterized by calculating