JPH0827841A - Restriction device of working range of construction machine - Google Patents

Abstract

PURPOSE:To prevent an operator from forgetting reset of an entrance forbidding zone when a working machine is transferred. CONSTITUTION:A monitor point is set at a specified position of a boom, an arm, and a bucket constituting a front member. A micro computor 31 operates the present coordinates of respective monitor points on controlling the front members. And the decelerating degree K is obtained in accordance with the distance of these coordinates and the preset entrance forbidding zone. This K is multiplied by the actuation speed of the present actuator to decelerate or stop the actuator and restrict the working area. When the working machine moves while restricting the working zone, the microcomputer 31 counts pulse signals from rotary encorders 38a, 38b rotating in the synchronous motion with the traveling motors 34, 35 and operates the transferred distance of the working machine body from the counted figures. An alarm device 33 is actuated on the basis of the operated 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. For example, when the work machine body moves on a sloping ground, the amount of movement of the work machine body deviates from the intrusion prohibited area in all directions, up and down, and when the work machine body moves on a flat ground, The amount of movement of the main body does not deviate from the intrusion prohibited area in the vertical direction, but it makes a large deviation from the intrusion prohibited area in the front-rear direction. The front member may enter the intrusion-prohibited area and come into contact with an obstacle, or, on the contrary, the front member may automatically stop far before the obstacle. 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 prompt an operator to reset an intrusion prohibited area by a warning when the working machine body moves, and to move in the vertical direction. Another object of the present invention is to provide a work range limiting device for a construction machine capable of reliably preventing a front member from coming into contact with an obstacle existing in the front direction, etc.

[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 detection device for detecting the traveling movement state of the working machine body is provided, and the traveling movement state of the working machine body is detected by the detection device when performing work while limiting the working range. The most main feature is that it is provided with a warning device that detects and issues a warning by a warning signal generated based on the detection result.

[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 operator operates a traveling lever or the like while performing the work while limiting and controlling the work range as described above, and the traveling motor is driven by this operation to move the work machine body, the work is performed. The movement state of the machine body is detected by a detection device such as a rotary encoder or a limit switch, and is input to the microcomputer. Then, in the microcomputer, the detection result from the detection device is compared with a preset allowable value, and when it is determined that the movement amount of the working machine body exceeds the allowable value, a warning signal is generated, and the warning signal is generated. Activate the warning device.

[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. In FIG. 1, 1 is a lower traveling body, 2 is an upper revolving structure having a driver's cab 2a, The body 2 and the working machine main body are configured. 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. The front member 6 is composed of a plurality of articulated movable parts including the arm 4 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, 21,
22, 23, 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, 30 is a setting device for setting an intrusion prohibition region, 31 is a microcomputer, 32 is a range limiting switch, and 33 is inside the cab 2a. The alarm devices, 34 and 35 installed in the vehicle are traveling motors. Also, 38a,
Reference numeral 38b is a rotary encoder as a detection device for detecting the traveling state of the working machine body. These rotary encoders 38a and 38b are traveling motors 34 and 3, respectively.
A pulse signal is generated in synchronization with the rotation of 5.

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. Further, i ₃ and i ₄ are signals corresponding to A ₁ and A ₂ , respectively, and r ₃ and r ₄ are signals i ₃ and i ₄ 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 ₃ and r ₄ to the pilot receiving portion of the arm directional control valve 21. The other directional control valves 22 and 23 are similar, and these directional control valves 22 and 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 forward range limitation will be described mainly with reference to the flowchart of FIG. 4 and the explanatory view of FIG. It should be noted that _{RL in} FIG. 5 indicates the distance to the intrusion prohibited area, and _RS indicates the distance to the deceleration area.

First, before starting the work, the operator turns on the range limiting switch 32 (S-1), and then sets the intrusion prohibited area in front by the setting device 30 (S-).
2). 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.

When the intrusion prohibition area is set in this manner, a deceleration area having a constant width is also set on the front side (front side) of the intrusion prohibition area, and the controller 18 limits the front range based on the signal x from the setter 30. each K _2, K _3, is initialized to K ₅ = 1 farthest monitoring point and can become M2, M3, M5 degree of deceleration for the 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 detected by the boom angle sensor 14 and the arm angle sensor 15
_B 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 determine the current X of each monitor point M2, M3, M5. Calculate the coordinates in the axial direction.

The formula for calculating the current X coordinate (X _M2 , X _M3 , X _M5 ) of each monitor point M2, M3, M5 is as follows (each constant in the formula is shown in FIG. 2). ,Also,
The boom angle is positive in the boom lowering direction, and the arm angle is positive in the cloud direction).

X _M2 = -L _a1 · cos (α _B + α _A ) + L _a2 · sin (α _B + α _A ) + LB · cos α _B + S ₀ …… X _M3 = -L _a3 · cos (α _B + α _A ) + L _a4・ sin (α _B + α _A ) + LB ・ cos α _B + S ₀・ ・ ・ X _M5 = LA ・ cos (α _B + α _A ) + LB ・ cos α _B + LV + S ₀ The X-coordinates of the monitor points M2, M3, and M5 change every moment during the work, but the microcomputer 31 determines each monitor point based on the X-coordinates obtained by the above formulas. M
2, M3, degree K ₂ of the deceleration for M5, K _3, K ₅ were calculated according to the following formula (S-5~S-7), and outputs the result of operation to the controller 18 as a signal y.

[0018] _{K 2 = (R L -X M2} ) / (R L -R S) .............................. However, K _2> In the case of 1 K ₂ = 1, the case of K ₂ <0 _{K 2 = 0 K 3 = (} R L -X M3) / (R L -R S) .............................. However, K _3> for _{1 K 3 = 1, K 3} < 0 Case K ₃ = 0 K ₅ = ( _RL- X _M5 ) / ( _{RL- RS} ) ………………………… However, if K ₅ > 1, K ₅ = 1 and K ₅ <0. if K ₅ = 0 Thus, the controller 18 degree K ₁ ~K ₄ deceleration from the microcomputer 31 is output, the controller 18, each of K ₂ in _{S-8, K 3, K} 5 values And the minimum value among them is the degree of deceleration K = min
The current lever output signal is multiplied as (K ₂ , K ₃ , K ₅ ) (S-9), and a proportional pressure reducing valve drive signal corresponding to this value is output to the proportional pressure reducing valve unit 27 to drive the proportional pressure reducing system. (S-10). 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-11).

For example, as shown in FIG. 5, an intrusion prohibited region is set at the position of R _L and a deceleration region is set at the position of R _S , and the electric lever 17 is tilted in the direction of arrow A _{1 in} FIG. Assuming a case where a dump operation is performed independently in the direction of arrow a,
If the current coordinate X _M5 monitor point M5 does not reach the _{R S, (R L -X M5} ) by the formula> (R _L -R _S) in K _5>
1, but K ₅ = 1 is output to the controller 18 under the condition of K ₅ > 1 = 1, and the arm cylinder 8 moves to the electric lever 1
It is driven at an operation speed corresponding to the operation amount of 7. From this state, the dump operation of the arm 4 is continued, and the monitor point M
When the current coordinate X _{M5 of} 5 exceeds R _S, that is, when the monitor point M5 enters the deceleration area, ( _RL −
X _M5) <(for a 0 ≦ K ₅ ≦ 1 with R _L -R _S), K microcomputer 31 was calculated by the equation ₅
Is output to the controller 18. The controller 18 multiplies this K ₅ by the current operation command signal i ₃ of the arm cylinder 8 which is an actuator, and according to this value the proportional pressure reducing valve drive signal r ₃ is output to the proportional pressure reducing valve 2 of the proportional pressure reducing valve unit 27.
8, the proportional pressure reducing valve 28 outputs an output pressure based on the magnitude of the signal r ₃ 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 is the electric lever 17. The operation speed is reduced as compared with the operation speed corresponding to the operation amount, and the dump speed of the arm 4 becomes slower. Further, the dump operation of the arm 4 is continued, and the monitor point M5
When the current coordinate X _M5 of R 3 reaches R _L , that is, when the monitor point M 5 enters the intrusion prohibition region, R _L and X _M5 in the above equation are equal to K ₅ = 0, so that the microcomputer 31 uses K ₅ = 0 is output to the controller 18. The controller 18 multiplies the current operation command signal i ₃ of the arm cylinder 8 by this K ₅ = 0 to minimize the proportional pressure reducing valve drive signal r ₃ 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, and the arm 4 automatically stops.

The boom 3 is not limited to the posture shown in FIG.
And the arm 4 are operated individually or in combination, and in addition to the monitor point M5, the monitor point M2 and the monitor point M
3 may also enter the deceleration area or the intrusion prohibition area. In such a case, K ₂ , K ₃ , and K ₅ are calculated for the respective monitor points M2, M3, and M5 in the same manner as described above, and the controller 18 calculates the values of these K ₂ , K ₃ , and K ₅ . Compare and multiply the current value of the operating speed of the actuator by the minimum value.

Although the forward range is restricted by the above-described operations of S-1 to S-11, the rotary encoders 38a and 38b rotate in synchronization with the traveling motors 34 and 35 during such operation, and the rotation thereof. The pulse signal generated by is always input to the microcomputer 31. The microcomputer 31 uses these rotary encoders 38
The pulse signals from a and 38b are counted (S-1
2) Then, the movement amounts d _a and d _b of the working machine main body are calculated from the count values ΔN _a and ΔN _b (S-13).

In other words, the rotary encoders 38a and 38b respectively generate pulse signals N times for one revolution of the traveling motors 34 and 35, and the traveling motors 34 and 3 are rotated.
When the distance from the central axis of 5 to the ground surface is r, when the lower traveling body 1 travels on the X axis in FIG. The moving amount d of) is obtained as d = 2πr × ΔN / N .... The microcomputer 31 compares the movement amounts d _a and d _{b of} the working machine body obtained by the above formula with the preset allowable value d ₀ (S-14), and determines both d _a and d _b . If is determined to be smaller than d ₀ , the process returns to S-3 without issuing an alarm. Also, in S-14, d _a and d _b
If any of the above is determined to be larger than d ₀ , a warning signal is generated in the controller 18, and the warning signal activates the alarm device 33 installed in the cab 2a. The alarm device 33 is a buzzer, a lamp, an electronic voice by a computer, or the like, and by using these alone or in combination, the operator is made to hear or visually recognize that the working machine main body has moved in the front-rear direction (S-15). ). When a warning is issued from the alarm device 33 in S-15, the operator is prompted to reset the intrusion prohibited area set in the front, and when the operator resets the intrusion prohibited area in the front (S-16), Controller 18
A stop signal is generated therein, the operation of the alarm device 33 is stopped by this stop signal (S-17), and the movement amount d of the working machine main body is cleared to 0 and returns to S-3.

The reason why the allowable value d ₀ is set in S-14 is, for example, the inertia when the front member 6 is operated and the working machine main body, even though the operator does not operate the traveling lever. This is because the work machine main body may slightly change its position due to vibrations and the like, and if the alarm device 33 is activated for each small position change of the work machine main body, it will rather hinder the work. Because. For this reason, in this embodiment, it is necessary to set the permissible value d ₀ as a dead zone for a minute position change of the working machine main body and judge whether the outputs from the rotary encoders 38a and 38b are in the dead zone or more. If the output from the rotary encoders 38a and 38b is about several pulses, it is determined that this is a fluctuation within the dead zone and the alarm device 33 is not activated.

FIG. 6 is a circuit diagram of a work range limiting device according to the second embodiment of the present invention. The parts corresponding to those of FIGS. 1 to 5 are designated by the same reference numerals. The second embodiment differs from the first embodiment described above in that rotary encoders 38a, 38 are used as detection devices for detecting the traveling state of the working machine body.
This is because the accelerometer 39 is used instead of b, and other configurations and operations are basically the same except for the portion (S-13 in FIG. 4) that calculates the movement amount d of the working machine body. , Duplicate description is omitted.

That is, assuming that the output of the accelerometer 39 is g, the movement amount d of the working machine main body (lower traveling body 1) is calculated by integrating the output g twice with respect to time: d = ∬gdt ... …………………, so the microcomputer 31
The movement amounts d _a and d _{b of} the working machine main body obtained by the above formula are compared with a preset allowable value d _0, and based on the comparison result, S- in FIG. 14-S-
18 operations are executed.

FIG. 7 is a circuit diagram of a work range limiting device according to a third embodiment of the present invention, in which parts corresponding to those in FIGS. The third embodiment differs from the first embodiment described above in that the rotary encoders 38a, 38 are used as detection devices for detecting the traveling state of the working machine body.
Since the potentiometers 42 and 43 are used instead of b, the other configurations are basically the same, and duplicate description is omitted.

In FIG. 7, reference numerals 40 and 41 denote traveling levers not shown in the first embodiment, and potentiometers 42 and 43 are provided on the traveling levers 40 and 41, respectively, and their inclination amounts (operation amounts) are set. To detect. As described above, when the traveling levers 40 and 41 are operated, the traveling pilot pressure oil drives the direction switching valves 36 and 37, and the traveling motors 34 and 35 rotate. Also,
q ₁ and q ₂ are output signals corresponding to the inclination amounts of the traveling levers 40 and 41, respectively, and these signals q ₁ and q ₂ are input to the controller 18.

Next, the operation in the case where the third embodiment having such a configuration is applied to the forward range limitation will be described with reference to the flowchart of FIG. In FIG. 8, S-1
Since the operations from to S-11 are the same as those in the first embodiment described above, only the operations when the working machine body after S-12 moves will be described.

That is, when the traveling levers 40 and 41 are operated to cause the lower traveling structure 1 to travel, the amount of inclination q
₁ , q ₂ are detected by the potentiometers 42, 43 (S-12), and the signals q ₁ , q ₂ output from these potentiometers 42, 43 are input to the microcomputer 31 via the controller 18. The microcomputer 31 compares these q ₁ and q ₂ with a preset allowable value q ₀ (S-13), and both q ₁ and q ₂ are q _0.
If it is determined to be smaller, S-3 without issuing an alarm.
Return to. In S-13, either q ₁ or q ₂ is q
_When it is determined that the _{value is} greater than ₀ , a warning signal is generated in the controller 18, and the warning device 33 is activated by the warning signal (S-14). Alarm device 3 at S-14
When a warning is issued from No. 3, the operator is prompted to reset the intrusion prohibited area set in the front, and when the operator resets the intrusion prohibited area in the front (S-15),
A stop signal is generated in the controller 18, and the stop signal stops the operation of the alarm device 33 (S-16).
Return to S-3. The permissible value q ₀ is set as a dead zone for a slight operation of the traveling lever,
When the operator slightly operates the traveling lever within the range of "play" and the output values from the potentiometers 42 and 43 are extremely small, it is determined that this is a variation within the dead zone and the alarm device 33 is not activated. There is.

FIG. 9 is a circuit diagram of a work range limiting device according to a fourth embodiment of the present invention, in which parts corresponding to those in FIGS. 1 to 5 are designated by the same reference numerals. The fourth embodiment differs from the first embodiment described above in that rotary encoders 38a, 38 are used as detection devices for detecting the traveling state of the working machine body.
Since the pressure sensors 44 to 47 are used instead of b, the other configurations are basically the same, and the duplicated description is omitted. The pressure sensors 44 to 47 are provided in the pilot pipes of the direction switching valves 36 and 37, and detect the pilot pressure of the traveling pilot pressure oil flowing through these pipes, and the outputs p _{1 of the} pressure sensors 44 to 47 are detected. ~
p ₄ is input to the microcomputer 31 via the controller 18. When a traveling lever (not shown) is operated, the traveling pilot pressure oil drives the direction switching valves 36 and 37, and the traveling motors 34 and 35 rotate.

FIG. 10 is a flow chart showing the operation when the fourth embodiment is applied to the forward range restriction. As is clear from the figure, this flow chart shows q ₁ and q ₂ in the flow chart of FIG. 8 as p ₁ to p ₄ , and q ₀ as p _0.
However, the other explanations are omitted here because they are the same as in the case of the third embodiment described above.

S-1 to S-1 in the first to fourth embodiments described above
The operation up to S-11 has been described for the case where the forward range limitation is performed, but each of these embodiments is also applicable to range limitations other than the forward range limitation. For example, when the lower range is restricted so as to control the excavation depth, an intrusion prohibited area is set below the ground, and the intrusion prohibited area and the monitor point M6 set at the lowest position of the cutting edge circle of the bucket 5 are set. The lower range may be limited in accordance with the distance from the current coordinates of. Further, when the range limitation in the height direction is performed, an intrusion prohibition area is set above the work machine main body, and an upper range is determined according to the distance between this intrusion prohibition area and the current coordinates of the monitor points M1 to M4. You just have to limit it. However, when the working machine body moves on a horizontal surface without any inclination, the relative position between the upper and lower intrusion prohibition areas and the working machine body does not change, and it is not necessary to reset the intrusion prohibition area. Since it is almost unlikely that there will be no inclination at the work site, it is also effective for these upper and lower range restrictions.

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. 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.

The work range limiting device for a construction machine according to the present invention is not limited to the above-mentioned embodiments, and various modifications are possible. For example, a limit switch is used instead of the potentiometer described in the third embodiment, and when the tilt amount of the traveling lever exceeds a certain value, the limit switch is turned on and a warning signal is generated by the ON signal. You can

In each of the above embodiments, the electric lever is used as the operating lever, but a hydraulic pilot lever can be used instead of the electric lever.
Further, as a means for detecting each joint angle of the front member, 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-mentioned embodiments, the case where six monitor points are set at predetermined positions of the front member has been described. However, the number and positions of the monitor points are not limited to this, and the shape of the front member and the intrusion prohibition are prohibited. It is also possible to appropriately increase or decrease according to the set position of the area and the like.

Furthermore, in each of the above-described embodiments, the case where the warning device is simply activated when the movement amount of the working machine body exceeds the predetermined value has been described. It is also possible to change the size, for example, if the buzzer is enlarged or the alarm content of the electronic voice is changed as the amount of movement of the work machine increases, the operator is notified of the necessity of resetting the intrusion prohibited area. You can inform more effectively.

[0039]

As described above, according to the present invention,
If the work machine body moves while performing work while limiting the work range, a warning prompting you to reset the intrusion prevention area is automatically issued. It is possible to prevent physical mistakes and reliably avoid contact between an obstacle existing at the work site and the front member.

[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 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 a range limiting operation in front of the hydraulic excavator of FIG. 1. FIG.

FIG. 6 is a circuit diagram of a work range limiting device according to a second embodiment of the present invention.

FIG. 7 is a circuit diagram of a work range limiting device according to a third embodiment of the present invention.

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

FIG. 9 is a circuit diagram of a work range limiting device according to a fourth embodiment of the present invention.

10 is a flowchart showing the processing contents of the work range limiting device of 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 limit switch 33 Alarm device 34, 35 Traveling motor 38a, 38b Rotary encoder (detection) Device) 39 Accelerometer (detection device) 40, 41 Traveling lever 42, 43 Photometer (detection device) 44, 45, 46, 47 Pressure sensor (detection device) M1 to M6 Monitor points

Claims (9)

[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, which 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 state of the work machine body. When the work is performed while limiting the work range, the traveling movement state of the working machine main body is detected by the detection device, and a warning is generated by a warning signal generated based on the detection result. A work range limiting device for a construction machine, which is provided with a warning device for issuing a warning. 2. The rotary encoder according to claim 1, wherein the detection device is a rotary encoder that generates a pulse signal in synchronization with rotation of a traveling motor, and detects the movement amount of the working machine main body based on the pulse signal. A work range limiting device for a construction machine, wherein the warning signal is generated when the movement amount exceeds a preset predetermined value. 3. The accelerometer according to claim 1, wherein the detection device is an accelerometer that detects an acceleration applied to the working machine body, and the movement amount of the working machine body is determined based on a signal output from the accelerometer. A work range limiting device for a construction machine, which detects the movement amount and generates the warning signal when the movement amount exceeds a preset predetermined value. 4. The potentiometer according to claim 1, wherein the detection device is a potentiometer that detects an operation amount of an operation device that commands the traveling of the traveling body, and the output value of the potentiometer exceeds a preset predetermined value. A work range limiting device for a construction machine, wherein the warning signal is sometimes generated. 5. The limit switch according to claim 1, wherein the detection device is a limit switch that is operated in accordance with an operation amount of an operation lever that commands traveling of the traveling body, and the operation amount of the operation lever is a constant amount. A work range limiting device for a construction machine, wherein a switching signal is generated from the limit switch when the limit is exceeded, and the warning signal is generated by the switching signal. 6. The pressure sensor according to claim 1, wherein the detection device is a pressure sensor that detects a pilot pressure of a directional control valve that supplies hydraulic oil to a traveling motor, and an output value of the pressure sensor is a predetermined value set in advance. A work range limiting device for a construction machine, wherein the warning signal is generated when the temperature exceeds the limit. 7. The work range limiting device for a construction machine according to claim 1, wherein the warning device is an alarm. 8. The work range limiting device for a construction machine according to claim 1, wherein the warning device is a lamp. 9. The work range limiting device for a construction machine according to claim 1, wherein the warning device is an electronic voice from a computer.