JPH0633607B2 - Construction machinery - Google Patents

Description

TECHNICAL FIELD The present invention relates to a construction machine having a work tool such as a hydraulic shovel having a bucket.

<Prior Art> FIG. 4 is a side view showing a hydraulic shovel as an example of a conventional construction machine. In this figure, 1 is a revolving structure,
Reference numeral 2 denotes a traveling body arranged below the revolving structure 1, 3 is a slewing wheel provided between the traveling structure 2 and the revolving structure 1, 4 is a boom rotatably provided on the revolving structure 1, and 5 is a boom. An arm rotatably connected to 4; a working tool for excavation, which is rotatably provided at the tip of the arm 5, namely a bucket;
Is a boom cylinder for rotating the boom 4, 8 is an arm 5
An arm cylinder for rotating the bucket cylinder, a bucket cylinder for rotating the bucket 6, and a counterweight mounted on the rear portion of the revolving unit 1. It should be noted that the boom 4, the arm 5, and the bucket 6 described above constitute one working machine.

In this hydraulic shovel, the boom 4, the arm cylinder 8, and the bucket cylinder 9 are expanded and contracted to appropriately rotate the boom 4, the arm 5, and the bucket 6, thereby excavating earth and sand. it can.

In such a hydraulic shovel, generally, a suitable capacity of the bucket 6 corresponding to the lengths of the boom 4 and the arm 5 is determined. Therefore, during normal excavation, the bucket 6 is used for excavation. However, when the work efficiency is particularly desired to be increased, the bucket 6 having a relatively large capacity may be mounted instead.

In such a case, if the reach, that is, the boom 4 and the arm 5 are extended too much in the state where the bucket 6 is fully loaded with the load, the boom 4 cannot be lifted when the work range boundary line indicated by the symbol L in FIG. 5 is crossed. This leads to matters that make it impossible to continue the work. For this reason, the present inventor has previously proposed a work range limiting control device suitable for the conventional hydraulic shovel shown in FIG. 4, for example.

This work range limiting control device is a work range limiting control command means for instructing the work tool, that is, the bucket 6 to be located within the workable range, for example, an on / off selection switch provided in the driver's cab, and the bucket 6 being the work range. Drive means including the above-described boom cylinder 7, arm cylinder 8, bucket cylinder 9 for driving the working machine, that is, the boom 4, the arm 5 and the like so as to be positioned inside, and means for supplying pressure oil to these actuators And a detection means for detecting the position of the bucket 6, for example, a boom angle meter and an arm angle meter for detecting the rotation of the boom 4 and the arm 5, and the above-mentioned switch ON signal and the boom angle meter and the arm angle meter. The control device outputs a signal for operating the above-mentioned driving means by performing a predetermined calculation process according to the signal.

<Problems to be Solved by the Invention> By the way, in the hydraulic shovel described above, since the instruction of the work range limitation control is performed by the on operation of the on / off switch provided in the operator's cab, When the switch is turned on for the purpose of this work range limiting control, even when the bucket 6 can extend the boom 4 and the arm 5 to the maximum stroke while the bucket 6 is empty, that is, the work range boundary shown in FIG. Even when the tip of the arm 5, that is, the connecting portion between the arm 5 and the bucket 6 moves to a position beyond the line L without any trouble, this work range limiting control is executed, and therefore the working range limiting control is executed. However, improvement in work efficiency cannot be expected, for example, because the traveling body 2 must be moved as necessary, and the above-mentioned repeated switching of the switch on and off In order to deal with this situation, the operation becomes complicated and the operator is tired.

The present invention has been made in view of the above-mentioned circumstances in the prior art, and an object thereof is to provide a construction machine capable of automatically executing work range limitation control only when it is necessary. .

<Means for Solving Problems> In order to achieve this object, the present invention provides a working machine including a working tool, and a driving means for driving the working machine so that the working tool is located within a workable range. A position detection means for detecting the position of the work implement, and a control device for outputting a signal for operating the drive means by performing a predetermined calculation process according to the signal output from the work range limitation control command means. A detection means for detecting the work posture of the work implement, and a control device for determining whether the work posture of the work implement is a specific work posture based on a signal output from the detection means. The controller outputs a signal for driving the drive means only when the determination means determines that the work posture is a specific work posture, and the signal output from the work range limitation control command means is input. Discrimination means When it is determined that is not a specific work posture, the driving means is controlled so as to be kept non-driving.

<Operation> Since the construction machine of the present invention is configured as described above,
While the signal is being output from the work range restriction control command means, the driving means is driven only when the work tool is judged to be in a specific work posture by the judgment means of the control device, and the work tool is positioned within the workable range. The work machine is controlled so that the work range limiting control can be automatically executed when necessary, and the work range limiting control command means can be executed when the work range limiting control is not required. Execution of the work range limiting control is automatically stopped regardless of the signal output from the device, and therefore excellent work efficiency can be secured without requiring complicated operations by the operator.

<Example> Hereinafter, the construction machine of the present invention will be described with reference to the drawings. First
1 to 3 are explanatory views showing an embodiment of the present invention, FIG. 1 is a circuit diagram showing a configuration of a main part, and FIG. 2 shows a control procedure carried out by a control device provided in this embodiment. The flow chart shown in FIG. 3 is an explanatory view showing the work posture of the bucket.

In these figures, the same members as those described above are designated by the same reference numerals.

That is, in FIG. 1 and FIG. 3, 6 is a work implement, that is, a bucket, 4, 5 are booms, arms, 7, 8 and 9 constituting a working machine together with the bucket 6, and boom cylinders, arm cylinders and bucket cylinders. is there. Reference numeral 15 is a hydraulic pilot type directional control valve for controlling the drive of the arm cylinder 8, 16 is a hydraulic pilot type directional control valve for controlling the drive of the boom cylinder 7, and 17 is a directional control valve 15.
Pilot valve for generating pilot pressure for driving
Reference numeral 8 is a pilot valve for generating a pilot pressure for driving the direction switching valve 16. Further, 19 is a shuttle valve, and this shuttle valve 19 is provided in a direction in which the arm cylinder 8 of the drive portion of the direction switching valve 15 is extended.
Is provided in a pilot pipe line which connects the drive unit for switching the valve and the pilot valve 17. Reference numeral 20 is an electromagnetic proportional pressure reducing valve arranged between the shuttle valve 19 and the hydraulic pump, that is, an EHC valve.

The direction switching valves 15 and 16 and the pilot valves 17 and 1 described above.
8, the shuttle valve 19, and the EHC valve 20, together with the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9 described above, constitute a driving unit that drives the working machine.

Reference numeral 11 is a link mechanism that transmits expansion and contraction of the bucket cylinder 9 as rotation of the bucket 6, 12 is a boom angle meter that detects the rotation angle of the boom 4, and 13 is an arm angle meter that detects the rotation angle of the arm 5. The boom angle meter 12 and the arm angle meter 13 constitute position detecting means for detecting the position of the bucket 6, that is, the position of the connecting portion between the tip of the arm 5 and the bucket 6. Numeral 14 is a detecting means for detecting that the working posture of the bucket 6 is, for example, a loading posture, for example, a bucket angle meter for detecting the rotation angle of the bucket 6.

Reference numeral 21 denotes the arm cylinder 8 of the drive unit of the direction switching valve 15.
Is a pressure detector for detecting the pressure in the line connecting the drive valve for switching the directional control valve 15 in the direction of contracting the valve and the pilot valve 17, and the pressure detector 21 has the arm 9 in the state shown in FIG. 1 to 7 constitutes an arm dump detecting means for detecting that the arm is in a rotating arm dump state as shown in FIG.

22 is the boom cylinder 7 of the drive unit of the direction switching valve 16.
Is a pressure detector that detects the pressure in the pipe line that connects the drive valve that switches the directional control valve 16 to the direction in which the boom 3 extends and the pilot valve 18. This pressure detector 22 is used when the boom 3 is in the state shown in FIG. The boom-up detecting means for detecting that the boom is in the boom-up state of rotating as shown in FIG.

Further, reference numeral 23 shown in FIG. 1 is a work range limit control command means for commanding that the bucket 6 is located within the workable range,
For example, a selection switch placed in the driver's cab and turned on / off, 24 is a position of the bucket 6 according to an ON signal of the selection switch 23, a signal output from the boom angle meter 12, and a signal output from the arm angle meter 13. It is a control device having a calculation means for calculating

The control device 24 includes a first determination unit that determines whether or not the ON signal from the selection switch 23 is output,
Second determining means for determining whether or not the boom raising operation is performed according to the signal from the pressure detector 22, and third for determining whether or not the arm dump operation is performed according to the signal from the pressure detector 21. And the bucket 6 obtained by the calculation in the above-mentioned calculating means.
Work for which the work posture of the bucket 6 is specific according to the signal output from the above-mentioned bucket angle meter 14 and the fourth judging means for judging whether or not the position is outside the preset work range boundary line. It is equipped with a fifth discriminating means for discriminating whether or not it is in a posture, for example, whether or not it is in a loaded posture, and includes a boom angle meter 12, an arm angle meter 13, a bucket angle meter 14, a signal from the selection switch 23, and a pressure detector. When the signals of 21 and 22 are input and the predetermined conditions are satisfied after the calculation in the calculation means and the judgment in each judgment means, the above-mentioned signal for driving the EHC valve 20 is output.

In the embodiment configured as described above, excavation work is performed as follows. That is, the operating lever of the pilot valve 18 shown in FIG. 1 is operated to guide the pressure oil of the pilot pump to the drive portion on the left side of the directional switching valve 16 in the figure, and the directional switching valve 16 is switched to the left position. When the operating lever of 17 is operated, the pressure oil of the pilot pump is guided to the drive portion on the right side of the directional switching valve 15 via the shuttle valve 19 and the directional switching valve 15 is switched to the right position. Is guided to the boom cylinder 7 via the direction switching valve 16 and the boom cylinder 7 contracts.
While the boom 4 is lowered, the pressure oil of the hydraulic pump is guided to the arm cylinder 8 via the direction switching valve 15 to extend the arm cylinder 8, and the arm 5 rotates downward (arm cloud). By operating a bucket pilot valve (not shown), the bucket cylinder 9 is extended, the bucket 6 is rotated clockwise in the drawing, and these booms 4,
Due to the cooperation of the arm 5 and the bucket 6, for example, the earth and sand are excavated, and the bucket 6 is in the loading posture shown by the symbol A in FIG. Further, by performing a completely opposite operation to the above, the boom 4 rotates counterclockwise in FIG. 3 (boom up), the arm 5 rotates counterclockwise (arm dump), and FIG. The bucket 6 shown in FIG. 3 rotates counterclockwise in FIG. Then, during the excavation work, the loading posture and the release posture of the bucket 6 are repeated.

When performing the work range limiting control when performing the excavation work as described above, the operator turns on the selection switch 23 in the cab. By the ON operation of the selection switch 23, the processing in the control device 24 is performed according to the processing procedure shown in FIG.

That is, in the control device 24, the first discriminating means discriminates whether or not the selective switch 23 is in the ON state according to the signal inputted from the selective switch 23 by the procedure S1 of FIG. Now that the selection switch 23 is turned on, the process proceeds to step S2. If the selection switch 23 is not turned on, it means that the work range limiting control is not intended, and the procedure moves to step S3, and the work range limiting control is not executed. In step S2, the second determination means determines whether or not the boom raising operation is performed according to the signal output from the pressure detector 22.

Here, the boom raising operation is performed, for example, when the bucket 6 shifts to an unleashed posture in a loaded state, and when the boom is raised, a pressure is generated in the pilot pipe line to which the pressure detector 22 is connected, and this pressure is increased. In response to this, a signal is output from the pressure detector 22 to the second determination means of the control device 24.

If the determination in step S2 is satisfied, step S
Go to 4. If the determination in step S2 is not satisfied, if the work range limitation control is not required, for example, when the bucket 6 is empty and is about to enter excavation, the procedure proceeds to step S3 and the work range limitation is performed. No control is exercised.

In step S4, the third discriminating means discriminates whether or not the arm dump operation is not performed according to the signal output from the pressure detector 21. Here, the state in which the arm dump operation is not performed is performed, for example, when the bucket 6 is moved to the unleashed posture in a loaded state, and in such a case, pressure is applied to the pilot conduit to which the pressure detector 21 is connected. Then, a signal is output from the pressure detector 21 to the third discriminating means of the control device 24 in accordance with this pressure.

If the determination in step S4 is satisfied, step S
Go to 5. If the determination in step S4 is not satisfied, or if work range limitation control is not required, for example, when the bucket 6 is empty and is about to enter excavation, the procedure moves to step S3 and the work range limitation is performed. No control is exercised.

In step S5, there is a known calculation for calculating the position of the bucket 6, that is, the pin position of the connecting portion between the tip of the arm 5 and the bucket 6 by the calculation means according to the signals of the boom angle meter 12 and the arm angle meter 13. It is performed using an arithmetic expression. Then, the process proceeds to step S6.

In step S6, it is judged by the fourth judging means whether or not the position obtained in step S5 is outside the work range boundary line set in advance based on the capacity of the bucket 6 and the like. If this determination is satisfied, the procedure moves to step 7.
If this determination is not satisfied, the bucket 6
The position of the bucket 6 is within the workable range even when is in the loading position, and the process proceeds to step S3, and the work range limiting control is not executed.

In step S7, the fifth discriminating means discriminates whether or not the vehicle is in the bucket loading posture based on the signal output from the bucket angle meter 14. In this case, the bucket setting angle corresponding to the preset loading attitude is compared with the signal output from the bucket angle meter 14, that is, the actual bucket angle, and when the actual bucket angle corresponds to the bucket setting angle, the loading attitude Is determined and the process moves to step S8. Note that if this determination is not satisfied, for example, when the bucket 6 is in an unleashed posture, it is not necessary to perform the work range limiting control, and the process proceeds to step S3, and the work range limiting control is not executed.

Then, in step S8, the EHC valve 20 is removed from the excavation 24.
Signal is output to the EHC valve 20 and the pressure oil of the hydraulic pump is guided to the shuttle valve 19 by this, and when the pressure of this pressure oil is sufficiently higher than the pilot pressure from the pilot valve 17. , And the directional control valve 1 shown in FIG.
5 to the drive unit on the right side of the directional control valve 15
Is switched to the right position, the arm cylinder 8 extends and becomes an arm cloud state, and accordingly, the connecting portion between the tip of the arm 5 and the bucket 6, that is, the arm tip pin is positioned at the work range boundary line. Controlled.

In the embodiment configured in this way, the selection switch 2
3, the boom 4 is being lifted, the arm dump is not being performed, the tip pin of the arm 5 is located outside the work range boundary line, and the bucket 6 is loaded. Only in some cases, the work range limiting control is automatically executed so that the bucket 6 is located within the workable range, and in other cases, for example, when the bucket 6 does not need to perform the work range limiting control in an empty state. The operation range limiting control is automatically stopped regardless of the ON signal of the selection switch 23, and therefore, the operator's complicated operation is not required.

In the above description, the bucket 6 is taken as an example of the work implement and the specific work posture is the loading posture. However, the present invention is not limited to this, and the work implement is a grasping device that grasps an object.
The specific work posture may be a posture of gripping an object.

<Effects of the Invention> Since the present invention is configured as described above, when a command is issued by the work range restriction control command means,
It is possible to automatically perform the control only when the work range limiting control is necessary, and therefore, when the work range limiting control is not necessary, the control is automatically stopped without requiring the operator's operation, The work efficiency can be improved compared to the conventional one, and during this work range limiting control,
There is no need to perform a command stop operation by the work range restriction control command means, and therefore no operator fatigue will be incurred.

[Brief description of drawings]

1 to 3 are explanatory views showing an embodiment of the construction machine of the present invention, FIG. 1 is a circuit diagram showing the configuration of the main part, and FIG. 2 is a control device provided in this embodiment. Fig. 3 is an explanatory view showing the work posture of the bucket, Fig. 4 is a side view showing a hydraulic shovel as an example of a conventional construction machine, and Fig. 5 shows the continuation of work. It is explanatory drawing which shows the work range boundary line which becomes difficult. 4 ... boom, 5 ... arm, 6 ... bucket (work implement), 7 ... boom cylinder, 8 ... arm cylinder,
9 ... Bucket cylinder, 12 ... Boom angle meter (position detecting means), 13 ... Arm angle meter (position detecting means),
14 ... Bucket goniometer (detection means), 15, 16 ...
Direction switching valve, 17, 18 ... Pilot valve, 19 ... Shuttle valve, 20 ... Electromagnetic proportional pressure reducing valve (EHC valve), 2
1, 22 ... Pressure detector, 23 ... Selection switch (working range limiting control command means), 24 ... Control device.

Claims (1)

[Claims] 1. A work machine including a work tool, a work range restriction control commanding means for instructing the work tool to be located within a workable range, and a work machine so that the work tool is located within the workable range. Predetermined arithmetic processing is performed according to the driving means for driving, the position detecting means for detecting the position of the work implement, the signal output from the work range limitation control commanding means, and the signal output from the position detecting means. In a construction machine provided with a control device for outputting a signal for operating the drive means, a detection means for detecting a work posture of the work implement is provided, and the control means is based on a signal output from the detection means. Has a determining means for determining whether the work attitude of the work implement is a specific work attitude, the control device determines that the work attitude is a specific work attitude, and the work range control is performed. Only when a signal output from the control command means is input, a signal for driving the drive means is output, and when the determination means determines that it is not in the specific work posture, the drive means is kept non-driven. A construction machine characterized by being controlled as follows.