JPH0633618B2 - 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. 5 is a side view showing a hydraulic shovel taken as an example of a conventional construction machine. In this figure, 1 is a revolving structure,
Reference numeral 2 denotes a traveling body disposed below the revolving structure 1, 3 is a revolving theory 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 An arm rotatably connected to the boom 4, 6 is a work implement for excavation provided at the tip of the arm 5, that is, a bucket, 7 is a boom cylinder for rotating the boom 4, and 8 is an arm for rotating the arm 5. A cylinder, 9 is a bucket cylinder for rotating the bucket 6, and 10 is a counterweight attached to the rear part 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 5, 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. You can

<Problems to be Solved by the Invention> By the way, in the case of the hydraulic shovel described above, in general, the bucket 6 is adjusted depending on the lengths of the boom 4 and the arm 5.
The capacity of the bucket 6 is determined, but in order to improve the efficiency of the excavation work, the bucket 6 may be provided with a special large capacity instead of the normal capacity.

However, when such a large-capacity bucket 6 is provided, the weight of the load of the bucket 6 is applied to the tip of the arm 5, so that the length of the boom 4 and the arm 5 in the horizontal plane is the same. That is, if the reach is extended too much, the boom 4 may not be able to be lifted. In such a case, the operator of the hydraulic shovel raises the boom 4. The bucket 6 must be moved so as to come to the front until the operation becomes possible, which reduces the work efficiency in another sense. Further, as described above, when the reach of the boom 4 and the arm 5 is excessively extended,
A large load is applied to the main body side, which may cause damage to the structure.

The present invention has been made in view of the above-mentioned conventional circumstances, and an object thereof is to automatically detect a limit position that causes a hindrance to work by a work tool and perform a work with the work tool without hindrance. To resist the construction machinery that can do.

<Means for Solving Problems> In order to achieve this object, the present invention provides a working machine including a working tool, a driving means for driving the working machine, and a position detecting means for detecting the position of the working tool. And a setting means for setting the work limit position of the work implement, and a comparison means for comparing the calculated value obtained by calculating the signal output from the position detection means with the work limit position set by the setting means. Then, a control device for outputting a signal for driving the drive means in accordance with the result of the comparison means, and a command connected to the control device so that the work implement is positioned within the work limit position set by the setting means Work range limitation control command means is provided, and the control device is configured to compare the comparison means based on the command signal of the work range limitation control command means.

<Operation> Since the present invention is configured as described above, the setting means of the control device sets the work limit position and the actual work tool position in advance in accordance with the command signal of the work range restriction control command means. When it is determined that the position of the work implement is in a positional relationship that interferes with the work in this comparison, a signal is output from the control means to the drive means, whereby the work machine performs the work. The tool is driven so as to reach a position where it does not hinder the work.

<Example> Hereinafter, the construction machine of the present invention will be described with reference to the 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 a configuration of a main part, and FIG. 2 is executed by a control device provided in this embodiment. FIG. 3 is a flow chart showing a control procedure to be performed, and FIG. 3 is an explanatory view showing a workable area and a workable area in this embodiment.

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

That is, in FIG. 1, 6 is a work implement, that is, a bucket, 4 and 5 are booms and arms which constitute a working machine together with the bucket 6, and 7, 8 and 9 are boom cylinders, arm cylinders and bucket cylinders. Reference numeral 13 denotes a hydraulic pilot type directional control valve (C which controls the drive of the arm cylinder 8).
/ V), 14 is a hydraulic pilot type directional control valve (C / V) for controlling the drive of the boom cylinder 7, 15 is a hydraulic pump for supplying pressure oil to the balm cylinder 7, the arm cylinder 8 and the bucket cylinder 9. Reference numeral 16 is a pilot valve for generating a pilot pressure for driving the direction switching valve 13, 17 is a pilot valve for generating a pilot pressure for driving the direction switching valve 14, and 20 is a pilot pump connected to these pilot valves 16, 17. is there. Reference numeral 18 denotes a shuttle valve. This shuttle valve 18 is a pilot conduit for connecting the pilot valve 16 with a drive portion of the drive portion of the directional switching valve 13 for switching the directional switching valve 13 in a direction to extend the arm cylinder 8. It is installed inside. Reference numeral 19 is an electromagnetic proportional pressure reducing valve, that is, an EHC valve, which is arranged between the shuttle valve 18 and the pilot pump 20 described above.

The direction switching valves 13 and 14 and the pilot valves 16 and 1 described above.
7, the shuttle valve 18, and the EHC valve 19, 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.

Further, 11 is a boom angle meter for detecting the rotation angle of the boom 4, 12 is an arm angle meter for detecting the rotation angle of the arm 5, and these boom angle meter 11 and arm angle meter 12
Thus, a detection means for detecting the position of the bucket 6, that is, the position of the tip of the arm 5 and the connecting portion of the bucket 6 is configured.

Reference numeral 21 denotes work range limiting control command means for instructing that the bucket 6 is within the work limit position, for example, within the boundary position between the workable range and the non-workable range (that is, within the workable range), for example, in the cab A selection switch arranged and turned on / off, 22 is an ON signal of the selection switch 21,
Signal output from boom angle meter 11, arm angle meter 1
2 is a control device (C / U) having a calculating means for calculating the position of the bucket 6 in accordance with the signal output from 2.

The control device 22 has a first discriminating means for discriminating whether the selection switch 21 is on or off, and a work limit position of the bucket 6 in advance, that is, a limit position of a connecting portion of the arm 5 and the bucket 6, for example, a boundary shown in FIG. Setting means set as a function corresponding to the position 30, a function corresponding to the boundary position 30 set by the setting means, that is, a work limit position, and signals output from the boom angle meter 11 and the arm angle meter 12 are calculated. And a second discriminating means for outputting a signal to the drive section of the EHC valve 19 when the calculated position is substantially equal to the work limit position.

In FIG. 3 described above, 31 is an area in which the boom cannot be raised, that is, an area in which the work with the bucket 6 is impossible, and 32 is an area in which the boom can be lifted, that is, the area with the bucket 6 is workable. It is shown.

In the embodiment configured as described above, excavation work is performed as follows. That is, the operating lever of the pilot valve 17 shown in FIG. 1 is operated to introduce the pressure oil of the pilot pump 20 to the drive portion on the left side of the directional switching valve 14 in the figure, and the directional switching valve 14 is switched to the left position. Pilot pump 20 by operating 16 control levers
When the pressure oil of the hydraulic pump 15 is guided to the drive portion on the right side of the directional switching valve 13 via the shuttle valve 18 and the directional switching valve 13 is switched to the right position, the hydraulic oil of the hydraulic pump 15 is passed through the directional switching valve 14 to the boom. Guided to cylinder 7, this boom cylinder 7
Contracts, the boom is lowered, and the hydraulic pump 1
The pressure oil 5 is guided to the arm cylinder 8 through the direction switching valve 13 and the arm cylinder 8 extends, the arm 5 rotates downward (arm cloud), and the bucket valve (not shown) for bucket is used. Bucket cylinder 9 by operation
Is extended, the bucket 6 is rotated clockwise in the drawing, and the boom 4, the arm 5, and the bucket 6 cooperate to excavate the earth and sand, for example. Further, by performing the operation completely opposite to the above, the boom 4 rotates counterclockwise (boom up), the arm 5 rotates counterclockwise (arm dump), and the bucket 6 also rotates counterclockwise. First to rotate
The posture will be as shown in the figure. During excavation work, excavation of the bucket 6, loading of the bucket 6 and dumping of soil are repeated.

Further, when performing the excavation work as described above, in order to perform the control that allows the work tool 6 to perform the work without any hindrance, that is, the work range limiting control, the operator turns on the selection switch 21 in the cab. It Here, in the setting means of the control device 22, the limit position corresponding to the boundary position 30 shown in FIG. 3 is set in advance as a function as described above.

Then, according to the ON operation of the selection switch 21 described above,
The processing in the control device 22 is performed according to the processing procedure shown in FIG.

That is, the control device 22 determines whether or not the selection switch 21 is in the ON state according to the signal input from the selection switch 21 in the first determination procedure according to the procedure S1 of FIG. Now that the selection switch 21 is on, the procedure moves to step S2. If the selection switch 21 is not turned on, the work range limiting control is not intended, and the process moves to step S3, and the work range limiting control is not executed. In step S2, the position of the bucket 6 according to the boom angle signal and the arm angle signal output from the boom angle meter 11 and the arm angle meter 12 in the calculation procedure, that is, the position of the connecting portion between the tip of the arm 5 and the bucket 6 is determined. The calculation to be performed is performed using a known calculation formula. Then, the process proceeds to step S4.

In step S4, the calculation position obtained by the calculation unit and the limit position preset by the setting unit are compared by the comparison unit, and the tip of the arm 5 is the boundary line, that is, the boundary position 30.
It is determined whether it is located outside of. If this determination is not satisfied, the bucket 6 is located in the workable area 32 shown in FIG. 3, and the procedure moves to step S3, and the work range restriction control is not executed. If the determination in step S4 is satisfied, the process proceeds to step S5.

In step S5, the control device 22 outputs a drive signal, that is, a drive current, to the drive unit of the EHC valve 20. As a result, the pressure oil of the hydraulic pump 20 is controlled to the operating force required to drive the directional switching valve 13 required to extend the arm cylinder 8, that is, the hydraulic pressure required to switch the directional switching valve 13 to the right position. Is guided to the shuttle valve 18, and when the pressure of this pressure oil is sufficiently higher than the pilot pressure from the pilot valve 16, the pressure of this pressure oil is guided to the drive section on the right side of the direction switching valve 13 in FIG. Therefore, the directional control valve 1
3 is switched to the right position, the arm cylinder 8 extends and enters the arm cloud state, and the contact portion between the tip of the arm 5 and the bucket 6 is accompanied by the boundary position 30 shown in FIG.
It is controlled to be located inside, that is, within the area 32.

In the embodiment configured in this way, the selection switch 2
When the tip of the arm 5 tries to go out of the boundary position 30 with 1 being turned on, the bucket 6 is moved to the region 3 in FIG.
2, the work range limiting control is automatically executed so that the bucket 6 is located within the workable range, and the work by the bucket 6 can be performed without any trouble.

Therefore, even if the capacity of the bucket 6 is relatively large, it is possible to automatically position the bucket 6 in the workable area 32 after the selection switch 21 is turned on without operator's operation. As a result, work cycle time is shortened and work efficiency is improved. In addition, since the boom cannot be raised, a large load is not applied to the main body side.

Although the function corresponding to the boundary position 30 in FIG. 3 is set as the limit position by the setting means of the control device 22 in the above embodiment, the present invention is not limited to this, and for example, for a small hydraulic shovel, It is also possible to set the limit position in a part of the vertical plane in the workable area, such as the boundary position 33 shown in FIG. With this setting, work in a narrow work space, especially turning, becomes easier,
It is possible to reduce operator fatigue.

In this case, it is also possible to provide a switch that can arbitrarily change the boundary position 33 and select the optimum boundary position 33 according to the work space or the like.

Further, in the above embodiment, the bucket 6 for excavation / loading is described as an example of the work tool, but the present invention is not limited to this.
In place of the excavation / loading bucket 6, a clam shell bucket, a cutting machine, and a lifting magnet may be provided.

<Effects of the Invention> Since the construction machine of the present invention is configured as described above, it is possible to automatically detect a state in which the work tool is disturbed and perform the work with the work tool without any trouble. Therefore, there is an effect that the work efficiency can be improved as compared with the conventional case.

[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 a configuration of a main part, and FIG. 2 is executed by a control device provided in this embodiment. FIG. 3 is a flow chart showing a control procedure to be performed, FIG. 3 is an explanatory view showing a workable area and a non-workable area in this embodiment, FIG. 4 is an explanatory view showing another example of the work limit position, and FIG. FIG. 6 is a side view showing a hydraulic shovel taken as an example of a conventional construction machine. 4 ... boom, 5 ... arm, 6 ... bucket (work implement), 7 ... boom cylinder, 8 ... arm cylinder,
9 ... Bucket cylinder, 11 ... Boom angle meter, 12
... Arm angle meter, 13, 14 ... Direction switching valve, 15 ...
… Hydraulic pump, 16, 17 …… Pilot valve, 18 ……
Shuttle valve, 19 ... Electromagnetic proportional valve (EHC valve), 20 ...
... Pilot pump, 21 ... Selection switch (working range limiting control command means), 22 ... Control device, 30, 33 ...
... Boundary position, 31, 32 ... area.

Claims (2)

[Claims] 1. A working machine including a working tool, a driving means for driving the working machine, a position detecting means for detecting a position of the working tool, and a setting means for setting a work limit position of the working tool. At the same time, it has a comparing means for comparing a calculated value obtained by calculating the signal output from the position detecting means with a work limit position set by the setting means, and the drive is performed according to the result of the comparing means. A control unit for outputting a signal for driving the means, and a work range limiting control commanding unit connected to the control unit for instructing the work tool to be located within the work limit position set by the setting unit. The construction machine, wherein the control device compares the comparison means based on a command signal from the work range restriction control command means. 2. The work limit position set by the setting means is a boundary position between an area where work can be performed by a work tool and an area where work cannot be performed by the work tool. Construction machinery according to item (1) of the scope.