JPH0612559U - Actuator hydraulic oil switching device - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] When replacing the attachment, simply switch the oil passage switching valve to easily switch to the hydraulic circuit for the replaced attachment. [Structure] When the crusher actuator 5a is driven, the first oil passage switching valve 20 connects the operation valve 2 and the crusher actuator, and the second oil passage switching valve 21 operates the operation valve 2
Is connected to the crusher actuator, and the hydraulic pump discharge port is a low-pressure safety valve for the crusher actuator 1
5, when the breaker actuator is driven, the first oil passage switching valve 20 connects the operation valve 2 to the breaker actuator, and the breaker actuator low pressure safety valve 18, and the second oil passage switching valve 21 is the breaker. The actuator for oil and the oil tank.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention can easily switch to the hydraulic circuit for the replaced attachment by simply switching the oil passage switching valve connected to the hydraulic circuit when replacing the attachment mounted on the hydraulic excavator etc. according to the work content. it can.

[0002]

[Prior art]

 Conventionally, in a hydraulic excavator including an upper revolving structure and a lower traveling structure, a hydraulic cylinder for driving a boom, an arm, a bucket, etc., which constitutes a working machine, and a traveling motor for driving the left and right crawler tracks. A large number of hydraulic actuators are provided, and in order to freely drive each of these actuators, normally two variable displacement hydraulic pumps 1R and 1L are mounted. In addition, a crusher, a hydraulic breaker, etc. may be attached as an attachment instead of the bucket which is usually attached as a working machine to perform the crushing work of the structure, the rock mass, etc. Since each of these attachments has a different actuator for driving the attachment, the required flow rate of the actuator also differs. FIG. 3 is a diagram showing an example of a conventional technique. For example, when driving a crusher, a flow rate of 2 pumps is required, and when driving a hydraulic breaker, a flow rate of 1 pump is sufficient.

On the other hand, each of the above-mentioned attachments is often used by exchanging the attachments as needed, using one hydraulic excavator. Therefore, it is required for the hydraulic excavator to be able to easily switch the flow rate supplied to the attachment so that it can be immediately adapted to the attached attachment. In response to such a demand, in the conventional hydraulic excavator, as shown in FIG. 3, the flow rate switching between one pump and two pumps is performed by operating only one of the two operating valves 2R and 2L. This is done by switching. That is, in the hydraulic circuits 3 and 4 from the outlet port of the right service valve 2R connected to the variable displacement hydraulic pump (hereinafter referred to as the main hydraulic pump) 1R to the actuator 5 of the attachment, the left service valve 2L is provided. The outlet ports of are connected so that they can merge. The hydraulic pressure of the control pump 8 held at a constant pressure by the relief valve 10 is controlled by the pilot pressure control valve 7 according to the operation amount of the pedal 6 for operating the attachment, and the pilot pressure is controlled by the left and right service valves 2R, 2L. Is configured to operate the left and right service valves 2R and 2L.

Next, when the breaker is driven as an attachment, the changeover switch 11 is set to OF F, and the low pressure safety valve changeover valve 16 and the oil cooler direct connection changeover valve 17 are changed to the a position. Therefore, the pilot switching valves 12A and 12B are in the a position, and the pilot pressure of the pilot pressure control valve 7 is supplied only to the pilot cylinder of the left service valve 2L to control the discharge oil of the main hydraulic pump 1L to control the hydraulic circuit. It is supplied to the breaker driving actuator 5 (indicated by a hydraulic motor in the figure) via 3, 4, and the oil discharged from the actuator 5 is drained from the oil cooler direct connection switching valve 17 to the tank 14 via the filter 19 and the cooler 13. As a result, the breaker driving actuator 5 is driven. Further, since the switching valve 16 for low pressure safety valve is closed, the pressure in the pipeline is controlled by the low pressure safety valve 18 for breaker.

Next, when the crusher is driven as an attachment, the changeover switch 11 is turned ON, and the low-pressure safety valve changeover valve 16 and the oil cooler direct connection changeover valve 17 are changed over to the b position. Therefore, the pilot switching valves 12A and 12B are in the b position, and the pilot pressure of the pilot pressure control valve 7 is supplied to the pilot cylinders of the left and right service valves 2R and 2L to discharge the main hydraulic pumps 1R and 1L. And supplies them to the crusher drive actuator (the actuator replaced with the breaker drive actuator 5) by merging them in the hydraulic circuits 3 and 4, and the oil discharged from the actuator 5 is supplied from the oil cooler direct connection switching valve 17 to the service valve. The crusher is driven from the 2R via the cooler 13 and directly from the service valve 2L to the tank 14. Further, since the low-pressure safety valve switching valve 16 is opened, the pressure in the pipeline is controlled by the crusher low-pressure safety valve 15 whose set pressure is lower than that of the breaker low-pressure safety valve 18.

[0006]

[Problems to be solved by the device]

 In the above-mentioned conventional technique, it is necessary to switch both the low-pressure safety valve switching valve 16 and the oil cooler direct-coupling switching valve 17 when the breaker and the crusher are exchanged and used as attachments depending on the work content. However, there is a drawback that the switching operation is troublesome.

[0007]

[Means for Solving the Problems]

 The present invention has been made in order to solve the problems in the above-mentioned conventional techniques, and the present invention is characterized in that a hydraulic pump, a first actuator driven by the hydraulic pump, and the first actuator are replaced and driven. A second actuator, an operation valve provided in a pipe line connecting the hydraulic pump and the first actuator, or the second actuator, and the operation valve and the first actuator or the second actuator. A first oil passage switching valve and a second oil passage switching valve provided in a pipe to be connected, an interlocking mechanism of the first oil passage switching valve and the second oil passage switching valve, and a low pressure for the first actuator. A pressure safety valve and a low pressure safety valve for a second actuator, and when the first actuator is driven, the first oil passage switching valve connects the operation valve and the first actuator to the second oil passage. The exchange valve connects the operation valve and the first actuator, the discharge port of the hydraulic pump is connected to the low pressure safety valve for the first actuator, and the first oil passage switching valve operates the operation valve and the second actuator when the second actuator is driven. And a second low-pressure actuator safety valve, and the second oil passage switching valve connects the second actuator and the oil tank.

[0008]

[Action]

 According to the first aspect of the present invention, when the first actuator is driven, both the first oil passage switching valve and the second oil passage switching valve are switched to a position connecting the first actuator and the operation valve, and therefore, as in a normal hydraulic circuit. The hydraulic pump is connected to the first actuator via the operation valve, and the hydraulic pump discharge port is connected to the low pressure safety valve for the first actuator. Therefore, the first actuator is driven at a speed according to the operation amount of the operation valve, and the discharge pressure of the hydraulic pump is controlled by the low pressure safety valve for the first actuator. Next, when the second actuator replaced with the first actuator is driven, the first oil passage switching valve connects the second actuator with the operation valve and the low pressure safety valve for the second actuator, and the second oil passage switching valve is Since the second actuator is switched to a position where it is connected to the oil tank, the discharge oil of the hydraulic pump is controlled by the operation valve and supplied to the second actuator via the first oil passage switching valve, and the second actuator is It is connected to the low pressure safety valve for the two actuators, and the oil discharged from the second actuator returns to the tank via the second oil passage switching valve. When the first actuator is driven and the second actuator is driven, the first oil passage switching valve and the second oil passage switching valve are switched by a one-touch operation by the interlocking mechanism, which facilitates the switching operation for the operator.

[0009]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a diagram showing a hydraulic circuit at the time of driving a crusher, which includes a hydraulic pump 1, a crusher actuator 5a driven by the hydraulic pump 1, and a hydraulic line connecting the hydraulic pump 1 and the crusher actuator 5a. Operation valves 2 provided in 3, 4 and a hydraulic oil line connecting the operation valve 2 and the crusher actuator 5a. First oil passage switching valve 20 provided in 3, 4 and second oil. A passage switching valve 21, a link mechanism 22 for interlockingly switching the first oil passage switching valve 20 and the second oil passage switching valve 21, and a limit switch 23 that is switched by a link 22a constituting the link mechanism 22. And an electromagnetic opening / closing valve 25 that is switched by the limit switch 23, a low pressure safety valve 15 for a crusher, and a low pressure safety valve 18 for a breaker.

When the crusher actuator 5a shown in FIG. 1 is driven, when the link mechanism 22 is operated in the direction of the crusher arrow, the first oil passage switching valve 20 connects the operation valve 2 and the crusher actuator 5a to the hydraulic pipe. The second oil passage switching valve 21 connects the operation valve 2 and the crusher actuator 5a through the pipe 4 via the passage 3. Further, when the limit switch 23 is turned on by the link 22a which constitutes the link mechanism 22, the voltage of the power source 24 is applied to the solenoid 25a of the electromagnetic opening / closing valve 25, so that the electromagnetic opening / closing valve 25 is opened and the hydraulic pump The discharge port of No. 1 is connected to the low pressure safety valve for crusher 15 via the electromagnetic opening / closing valve 25. In this way, the crusher actuator 5a is driven at a speed according to the operation amount of the operation valve 2, and the hydraulic pressure is regulated by the crusher low pressure safety valve 15. The return oil discharged from the operation valve 2 is drained to the tank 14 via the oil cooler 13.

FIG. 2 is a diagram showing a hydraulic circuit when the breaker is driven. The hydraulic pump 1, a breaker actuator 5b which is driven by the hydraulic pump 1 and which replaces the crusher actuator 5a, and the hydraulic pressure are used. The operation valve 2 provided in the hydraulic lines 3 and 4 connecting the pump 1 and the breaker actuator 5b, and the hydraulic lines 3 and 4 connecting the operation valve 2 and the breaker actuator 5b. A first oil passage switching valve 20 and a second oil passage switching valve 21 provided, and a link mechanism 22 for interlockingly switching the first oil passage switching valve 20 and the second oil passage switching valve 21; A limit switch 23 that is switched by a link 22a that constitutes the link mechanism 22, an electromagnetic opening / closing valve 25 that is switched by the limit switch 23, and a low pressure safety valve 15 for a crusher. , A low-pressure safety valve 18 for breaker.

When the breaker actuator 5b shown in FIG. 2 is driven, when the link mechanism 22 is operated in the direction of the breaker arrow, the first oil passage switching valve 20 causes the operation valve 2, the breaker actuator 5b, and the breaker low-pressure safety valve 18 to operate. Are connected via a hydraulic line 3, and the second oil passage switching valve 21 drains the breaker actuator 5b from the additional filter 26 and the oil cooler 13 to the tank 14 via the return line 27. Further, when the limit switch 23 is turned off by the link 22a that constitutes the link mechanism 22, the solenoid 25a of the electromagnetic opening / closing valve 25 is not applied with the voltage of the power supply 24, and thus the electromagnetic opening / closing valve 25 is in the closed position. A solenoid opening / closing valve 25 shuts off the discharge port of the hydraulic pump 1 and the low pressure safety valve 15 for the crusher. In this way, the breaker actuator 5b is driven at a speed according to the operation amount of the operation valve 2, and the hydraulic pressure is regulated by the breaker low pressure safety valve 18. Further, when the breaker is driven, dust is easily discharged from the hydraulic equipment, etc., but the dust in the discharged return oil can be almost filtered by the additional filter 26.

[0013]

[Effect of device]

 Since the present invention is configured as described above, it has the following effects. . When replacing the attachment, the operator can simultaneously switch the first oil passage switching valve and the second oil passage switching valve to switch to the oil passage for each attachment with a single touch, thus saving labor for the operator. be able to.

[Brief description of drawings]

FIG. 1 is a diagram showing a hydraulic circuit when a crusher is driven in an embodiment of the present invention.

FIG. 2 is a diagram showing a hydraulic circuit when a breaker is driven in the embodiment of the present invention.

FIG. 3 is a diagram showing a conventional technique.

[Explanation of symbols]

 1 Hydraulic Pump 2 Operation Valve 3,4 Hydraulic Pipeline 5a Crusher Actuator 5b Breaker Actuator 13 Oil Cooler 15 Crusher Low Pressure Safety Valve 18 Breaker Low Pressure Safety Valve 20 First Oil Passage Switching Valve 21 Second Oil Passage Switching Valve 22 Link Mechanism 22a lever 23 limit switch 24 power supply 25 electromagnetic on-off valve 25a solenoid 26 extension filter 27 return line

Claims (1)

[Scope of utility model registration request] 1. A hydraulic pump, a first actuator driven by the hydraulic pump, a second actuator driven in exchange for the first actuator, the hydraulic pump and the first actuator, or a second actuator. And a first oil passage switching valve provided in a pipe line connecting the operation valve and the first actuator or the second actuator, and a second valve.
An oil passage switching valve, an interlocking mechanism of the first oil passage switching valve and the second oil passage switching valve, a low pressure safety valve for a first actuator,
A low pressure safety valve for a second actuator,
When the actuator is driven, the first oil passage switching valve connects the operation valve and the first actuator, the second oil passage switching valve connects the operation valve and the first actuator, and the hydraulic pump discharge port is the first actuator. For operating the second actuator, the first oil passage switching valve connects the operation valve to the second actuator, and the second actuator low pressure safety valve, and the second oil passage switching valve connects to the second oil passage switching valve.
A hydraulic fluid switching device for an actuator, characterized in that the actuator is connected to an oil tank.