JPH0949248A - Operation device for hydraulic shovel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve operability by operating a hydraulic actuator of a work machine attached corresponding to the contents of work using one of a pair of left, right operation levers. SOLUTION: When one of hydraulic actuators is not operated and the other one is operated using the same operation lever, a switch is operated to close a power source side contact and other contact. A solenoid of the other electromagnetic open/closure valve is energized and the valve is switched from a shut-off oil line position to an open oil line position; however, a solenoid of one of electromagnetic open/closure valves is not energized so that the shut-off oil line position can be maintained. When the operation lever is operated under such condition, the other hydraulic actuator can be operated. That is, by selecting and switching one hydraulic actuator and the other hydraulic actuator, operation can be effected using one of a pair of left, right operation levers and hence another operation lever is not needed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a construction machine such as a hydraulic excavator, an operating device provided with a pair of left and right work operating levers and a pilot valve provided near a driver's seat of a working vehicle.

[0002]

2. Description of the Related Art FIG. 3 is a hydraulic circuit diagram showing an operating device of a conventional example of a hydraulic excavator disclosed in Japanese Patent Laid-Open No. 3-21728. In the figure, 1 is a swing motor of hydraulic actuators mounted on a hydraulic excavator, 2 is a boom cylinder, 3 is an arm cylinder, 4 is a bucket cylinder, 5 _L and 5 _R are left and right traveling direction switching valves, and 6 is a swing. Pilot switching valve, 7 is a boom pilot switching valve, 8 is an arm pilot switching valve, 9 is a bucket pilot switching valve, 11 and 12 are main pumps, 13 is an oil tank, 14 _L and 14 _R are driver's seats. A pair of left and right operation levers for work provided near (not shown), 15, 16, ..., 22 are operation levers 14 _L , 14
Reference numeral 23 denotes a pilot valve for deriving the pilot secondary pressure by tilting operation of _{R in} the front-rear direction or the left-right direction, and 23 is an operation mode switching valve provided for converting the operation mode of the operation levers 14 _L , 14 _R. In the operating device shown in FIG. 3, the left operating lever 14 _L is moved in the front-back direction (AB direction).
Is operated to switch the arm pilot switching valve 8 to operate the arm cylinder 3, and the operating lever 14 _L is operated in the left-right direction (CD direction) to switch the turning pilot switching valve 6. To operate the turning motor 1, and also to operate the right operation lever 14
By operating _R in the front-back direction (EF direction), the boom pilot switching valve 7 is switched to operate the boom cylinder 2, and the operating lever 14 _R is operated in the left-right direction (GH direction). Thus, the bucket pilot switching valve 9 is switched to operate the bucket cylinder 4.

FIG. 4 is a hydraulic circuit diagram showing an earth discharging device for a bulldozer described in Japanese Utility Model Laid-Open No. 26660/1990. In the hydraulic circuit shown in FIG. 4, hydraulic cylinders 26 and 27 are connected in parallel to the output port 25 of the directional control valve 24, and electromagnetic opening / closing valves 28 and 29 are provided in the supply / discharge circuits of the hydraulic cylinders 26 and 27, respectively. ing. Therefore, the hydraulic cylinder 26 can be operated by operating the direction switching valve 24 with the electromagnetic opening / closing valve 28 in the open oil passage position and the electromagnetic opening / closing valve 29 in the shutoff oil passage position. Further, the hydraulic cylinder 27 can be operated by switching the electromagnetic opening / closing valve 28 to the shutoff oil passage position and the electromagnetic opening / closing valve 29 to the opening oil passage position and operating the direction switching valve 24.

[0004]

In a hydraulic excavator, a pair of left and right operation levers are arranged near the driver's seat and can be tilted forward and backward and left and right in a cross direction so that the operation levers can be easily and freely operated. It is provided in. Therefore, the number of hydraulic actuators that can be operated by the pair of left and right operation levers is limited to four (swing motor, boom cylinder, arm cylinder, bucket cylinder, etc.). For this reason, when a work machine equipped with another hydraulic actuator is attached to the hydraulic excavator, a separate operating lever is provided when handling work.Therefore, operating the operating lever together with the above-mentioned pair of left and right operating levers is inconvenient. Took a lot of time. Further, in the conventional hydraulic circuit shown in FIG. 4, both electromagnetic opening / closing valves 28 and 29 are switched when operating one hydraulic cylinder 27, so that the electromagnetic opening / closing valve 28 is opened when the hydraulic cylinder 26 is removed. The oil passage position remains as it is, and the condition is not good. SUMMARY OF THE INVENTION It is an object of the present invention to provide a control device capable of easily and freely operating a hydraulic actuator of a work machine mounted corresponding to the work content of a hydraulic excavator with one of a pair of left and right operation levers. .

[0005]

SUMMARY OF THE INVENTION According to the present invention, a required number of pilot switching valves for controlling the operation of a plurality of hydraulic actuators such as a boom cylinder, an arm cylinder, a bucket cylinder, and a swing motor in a hydraulic excavator, and each of these pilot switching valves. A hydraulic excavator equipped with a required number of pilot valves corresponding to the pilot ports of the switching valve and a pair of left and right operation levers for operating these pilot valves, and operating the hydraulic actuator by operating the operation levers. In the control device, other required hydraulic actuators other than the plurality of hydraulic actuators are mounted on the hydraulic excavator and the other hydraulic actuators are operated by one of the pair of left and right operation levers. Multiple that can be switched by operation One of the pilot switching valves is provided with an electromagnetic opening / closing valve in the supply / discharge circuit of the required pilot switching valve output port and the hydraulic actuator that communicates with the output port, and the one pilot switching valve output port is also provided. The other solenoid on-off valve is provided in the supply / discharge circuit that communicates with the other hydraulic actuator, and the required solenoid on-off valve of the two solenoid on-off valves is switched to open the selected solenoid on-off valve. The hydraulic actuator is operated by the operation lever. As the switching means for the two solenoid on-off valves, the solenoids of the one solenoid on-off valve and the other solenoid on-off valve and the power source are connected via a switch having a bidirectional contact, and one contact of the switch and the power source are connected. One solenoid on-off valve is energized and the other solenoid on-off valve is de-energized when the side contacts are closed, and one solenoid on-off valve is de-energized and the other solenoid is de-energized when the other contact of the switch and the power supply side contact are closed. The on-off valve was set to energize.

When it is desired to operate the other hydraulic actuator for the working machine to be newly mounted corresponding to the work content of the hydraulic excavator by using either one of the pair of left and right operation levers,
One hydraulic actuator and another hydraulic actuator are connected in parallel to the output port of the existing pilot switching valve for one existing hydraulic actuator that does not require complex operation with the other hydraulic actuator, via one and the other electromagnetic on-off valves, respectively. To do. When it is desired to operate the one hydraulic actuator, the switch is operated to close the power source side contact and the one-side contact. The solenoid of one solenoid on-off valve is energized and the solenoid on-off valve switches from the shutoff oil passage position to the open oil passage position, but the solenoid of the other solenoid on-off valve is not energized, so the other solenoid on-off valve is shut off Hold the road position. When the operating lever is operated in this state, the one hydraulic actuator can be operated. Next, if you want to operate the other hydraulic actuator with the same operating lever without operating the above one hydraulic actuator,
The switch is operated to close the power supply side contact and the other contact. The solenoid of the other energizing on-off valve energizes and the electromagnetic on-off valve switches from the shutoff oil passage position to the open oil passage position.
Since the solenoid of one of the solenoid on-off valves is not energized, the solenoid on-off valve holds the shutoff oil passage position. When the operation lever is operated in this state, the other hydraulic actuator can be operated. Therefore, the one hydraulic actuator and the other hydraulic actuator can be operated by one of the pair of left and right operation levers by selectively switching the switch.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a side view of a hydraulic excavator equipped with the control device of the present invention. In the figure, 30 is a lower traveling body of the hydraulic excavator, 31 is an upper revolving body provided above the lower traveling body 30, 32 is a revolving motor, 33 is a work attachment mounted on the front part of the upper revolving body 31, and 34 is a work. Boom of the attachment 33, 35 is an arm, 36 is a crusher which is a working machine attached to the tip of the work attachment 33, 37 is a boom cylinder, 38
Is an arm cylinder, 39 is a bucket cylinder, and 40 is a nibler cylinder provided inside the crusher 36. FIG. 2 is a circuit diagram of an essential part showing a control device of the present invention. In the figure, 41 is a boom pilot switching valve, and 42, 43.
Is an electromagnetic on-off valve, 44 is a main pump, 45 is an oil tank, 46 is one of a pair of left and right operation levers, and 47 and 48 are operation levers 46 in one direction (a front-back direction or a left-right direction) Is a pilot valve that is tilted to operate, 49 is a pilot pump that discharges pilot primary pressure, 50 is a switch, and 51 is a power supply.

Next, the structure of the control device of the present invention will be described with reference to FIGS. In the present invention, the boom cylinder 37
In order to operate the nibler cylinder 40 of the crusher 36 with the operation lever 46 that operates the boom, the boom pilot switching valve 4
No. 1 output port 52 and the boom cylinder 37 communicating with the output port 52 (supply line 53-53'-5
4 and the pipe lines 55-55'-56), an electromagnetic opening / closing valve 42 is provided, and the output port 52 of the boom pilot switching valve 41 and the nibler cylinder 40 are connected via an electromagnetic opening / closing valve 43. . Then, the solenoid valves 42 and 43
As a switching means of the above, a switch 50 having solenoids 57 and 58 of a solenoid on-off valve 42 and 43 and a power source 51, and bidirectional contacts (having one contact 60 and the other contact 61 with respect to the power source side contact 59). Wired so as to communicate with each other.

Next, the operation of the control device of the present invention will be described. Work contents of the hydraulic excavator For example, one of the pair of left and right (not shown) operation levers of the crusher 36 to be newly installed corresponding to the crushing operation (Fig. 2).
2), the boom cylinder 37 and the nibler cylinder 4 are connected to the output port 52 of the boom pilot switching valve 41 for the existing boom cylinder 37 that does not require a combined operation with the nibler cylinder 40 of the crusher 36.
0 are connected in parallel via the solenoid on-off valves 42 and 43, respectively. Therefore, when it is desired to operate the boom cylinder 37, the switch 50 is operated to close the power source side contact 59 and the one-side contact 60. The solenoid 57 of the solenoid on-off valve 42 is energized to switch the solenoid on-off valve 42 from the cutoff oil passage position to the open oil passage position, but the solenoid 58 of the other solenoid on-off valve 43 is non-energized. Hold the shutoff oil passage position. When the operating lever 46 is tilted from the neutral position N to, for example, the direction of the a position, the pilot secondary pressure is derived from the pilot valve 48, and the pilot secondary pressure is passed through the conduit 62 to the pilot of the boom pilot switching valve 41. Acts on port 63. Since the boom pilot switching valve 41 switches from the neutral position to the low position, the pressure oil from the main pump 44 flows through the pipe lines 65, 6
6, check valve 67, pipeline 68, position of boom pilot switching valve 41, pipeline 53, 53 ', solenoid on-off valve 42
Of the boom cylinder 37
Is supplied to the bottom side oil chamber 69. (Boom cylinder 3
The description of the return oil returning from the rod-side oil chamber 70 of No. 7 to the oil tank 45 is omitted. Therefore, since the boom cylinder 37 is extended, the boom 34 can be lifted.

Next, when it is desired to operate the nibler cylinder 40 with the same operating lever 46 without operating the boom cylinder 37, the switch 50 is operated to close the power source side contact 59 and the other contact 61. The solenoid 58 of the electromagnetic on-off valve 43 is energized to switch the electromagnetic on-off valve 43 from the cutoff oil passage position to the open oil passage position.
Since the solenoid 57 is not energized, the electromagnetic opening / closing valve 42 holds the shutoff oil passage position. Then, when the operation lever 46 is operated, the boom pilot switching valve 41 is switched, so that the pressure oil from the main pump 44 passes through the switching position of the boom pilot switching valve 41 and the opening oil passage position of the electromagnetic opening / closing valve 43. It is supplied to the nibler cylinder 40. Therefore, in the above case, the nibler cylinder 40 can be operated by the same operation lever 46.

[0011]

According to the present invention, in order to operate the other hydraulic actuator for the working machine, which is mounted corresponding to the work content of the hydraulic excavator, by either one of the pair of left and right operation levers, it is combined with the other hydraulic actuator. The above-mentioned one hydraulic actuator and another hydraulic actuator are connected in parallel to the output port of an existing pilot switching valve for one hydraulic actuator that does not require operation, via one and the other electromagnetic on-off valves, respectively. When it is desired to operate the one hydraulic actuator, the switch is operated to close the power source side contact and the one-side contact. The solenoid of one solenoid on-off valve is energized and the solenoid on-off valve switches from the shutoff oil passage position to the open oil passage position, but the solenoid of the other solenoid on-off valve is not energized, so the other solenoid on-off valve is shut off Hold the road position. When the operating lever is operated in this state, the one hydraulic actuator can be operated. Next, when it is desired to operate another hydraulic actuator with the same operating lever without operating one hydraulic actuator, a switch operation is performed to close the power source side contact and the other contact. The solenoid of the other solenoid on-off valve is energized and the solenoid on-off valve is switched from the cutoff oil passage position to the open oil passage position, but the solenoid of one solenoid on-off valve is not energized, so the solenoid on-off valve is closed. Hold the road position. When the operation lever is operated in this state, the other hydraulic actuator can be operated. That is, the one hydraulic actuator and the other hydraulic actuator can be operated by one of the pair of left and right operation levers by selectively switching the switch. Therefore, in the control device of the present invention, the hydraulic actuator of the working machine attached corresponding to the work content of the hydraulic excavator can be easily and freely operated by one of the pair of left and right operation levers. It is possible to improve maneuverability and eliminate the need for additional operating levers.

[Brief description of drawings]

FIG. 1 is a side view of a hydraulic excavator equipped with a control device of the present invention.

FIG. 2 is a circuit diagram of a main part showing a control device of the present invention.

FIG. 3 is a hydraulic circuit diagram showing an operating device of a conventional example of a hydraulic excavator.

FIG. 4 is a hydraulic circuit diagram of one embodiment of the prior art.

[Explanation of symbols]

1,32 Revolving motor 2,37 Boom cylinder 3,38 Arm cylinder 4,39 Bucket cylinder 7,41 Boom pilot switching valve 14 _L , 14 _R , 46 Operation lever 15, ~, 22, 47, 48 Pilot valve 25, 52 Output port 28, 29, 42, 43 Electromagnetic on-off valve 36 Crusher 40 Nibler cylinder 50 Switch 59 Power source side contact 60 One side contact 61 Other side contact

Claims (2)

[Claims] 1. A boom cylinder in a hydraulic excavator,
A required number of pilot switching valves that control the operation of multiple hydraulic actuators such as arm cylinders, bucket cylinders, and swing motors, a required number of pilot valves corresponding to the pilot ports of these pilot switching valves, and these pilot valves In a control device of a hydraulic excavator in which a pair of left and right operation levers for operating the hydraulic actuators are operated by operating the operation levers, other hydraulic actuators other than the plurality of hydraulic actuators are hydraulically operated. One of a plurality of pilot switching valves that can be switched by operating one of the pair of left and right operating levers mounted on a shovel to operate the other hydraulic actuator. Output port and its output One solenoid on-off valve is installed in the supply / discharge circuit with the hydraulic actuator leading to the port, and the other solenoid open-close valve is connected to the supply / discharge circuit communicating the output port of the one pilot switching valve with the other hydraulic actuator. A hydraulic actuator communicating the selected electromagnetic on-off valve by operating the required electromagnetic on-off valve among the above-mentioned electromagnetic on-off valves by operating the operation lever. Shovel control device. 2. The control device for a hydraulic excavator according to claim 1, wherein the solenoid and the power source of the one electromagnetic on-off valve and the other electromagnetic on-off valve are connected via a switch having bidirectional contacts. When one contact of the switch and the contact on the power supply side are closed, one electromagnetic on-off valve is energized and the other solenoid on-off valve is de-energized, and when the other contact of the switch and the power supply side contact are closed, A control device for a hydraulic excavator, characterized in that the solenoid on-off valve is set to non-energized and the other solenoid on-off valve is set to energized.