JP2549367Y2 - Pressure oil supply device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic oil supply device capable of performing a manual operation and a radio control operation for a work vehicle operated by a manual operation and a radio control operation of a small power shovel or the like.

[0002]

2. Description of the Related Art As shown in FIG. 1, a discharge passage 2 of a hydraulic pump 1 is connected to an inlet port 5 of an electric switching valve 4 by a first switching valve 3, and an outlet of the electric switching valve 4 is provided. The port 6 is connected to the pressure receiving portion 8 of the main valve 7 so that the discharge path 2 of the hydraulic pump 1 can be connected / disconnected with the first path 10 by the second switching valve 9, and the first path 10 is manually switched. Valve 11
There is known a pressure oil supply device in which an outlet port 13 is connected to a drain port 14 of an electric switching valve 4. In this pressure oil supply device, the first switching valve 3 is switched from the state shown in FIG. 1 and the switching operation of the electric switching valve 4 supplies the pressure oil to the pressure receiving portion 8 of the main valve 7 so as to supply the main valve 7. When the second switching valve 9 is switched from the state shown in FIG. 1 and the manual switching valve 11 is switched, the main valve 7 can be switched by supplying pressure oil to the pressure receiving portion 8 of the main valve 7. Operation and manual operation are possible. As shown in FIG. 2, the above-mentioned electric switching valve 4 and manual switching valve 11 are provided in parallel, and each outlet port 6, 13 is connected to the pressure receiving section 8 of the main valve 7 via the shuttle valve 15. A device is known, and this pressure oil supply device can also perform radio control operation and manual operation in the same manner as described above.

[0003]

In the case of the former pressure oil supply device, the electric switching valve 4 includes the inlet port 5 and the outlet port 6.
If the lock is stopped at the position where the valve is shut off and it does not move, the manual operation cannot be performed because pressure oil cannot be supplied to the pressure receiving portion 8 of the main valve 7 even if the manual switching valve 11 is operated. With the latter pressure oil supply device, even if the electric switching valve 4 locks at the decompression position and does not move, the manual switching valve 11 is operated to supply the pressure oil to the pressure receiving portion 8 of the main valve 7 from the shuttle valve 15. Although manual operation is possible because of the supply, the cost is high because the shuttle valve 15 is required, and the piping is complicated and troublesome.

Therefore, an object of the present invention is to provide a pressure oil supply device capable of solving the above-mentioned problems.

Means for Solving the Problems Discharge path 2 of hydraulic pump 1
, An outlet port 6 connected to the pressure receiving portion 8 of the main valve 7, and a drain port 14, the first port having the inlet port 5 always shut off and the outlet port 6 communicating with the tank port 14. , The electric switching valve 4 which is connected to the inlet port 5 and the outlet port 6 by an electric signal, and is operated at the second position for blocking the tank port 14 and the outlet port 6, and the discharge path of the hydraulic pump 1. 2 and an outlet port 13 connected to the drain port 14 of the electric switching valve 4, a third position where the outlet port 13 is connected to the tank by manual operation, the inlet port 12 and the outlet port 13. And a manual switching valve 11 which is operated to switch to a fourth position for communicating with the valve.
6. A pressurized oil supply device characterized in that it is short-circuited by a bypass path 17 having a pressure path 6.

The discharge pressure oil of the hydraulic pump 1 is supplied to the pressure receiving portion 8 of the main valve 7 by setting the manual switching valve 11 to the third position and the electric switching valve 4 to the first position and the second position. Or
The main valve 7 can be switched by connecting the pressure receiving section 8 to the tank. At this time, the pressure oil supplied to the pressure receiving portion 8 is supplied to the bypass passage 1.
7. The gas flows out to the tank via the manual switching valve 11. The throttle 16 is provided in the bypass passage 17, so that pressure is generated in the pressure receiving portion 8 so that the main valve 7 can be switched. Further, by setting the manual switching valve 11 to the third position and the fourth position, the pressure receiving chamber 8 of the main valve 7 can be communicated with the tank by the bypass passage 17, and the pressure oil can be supplied through the bypass passage 17. ,
Even when the electric switching valve 4 is locked at a position intermediate between the first position and the second position and does not operate normally, the manual switching valve 11 can be used.
The main valve 7 can be switched.

[0005]

EXAMPLE As shown in FIG. 3, the inlet side and the outlet side of the electric switching valve 4 are short-circuited by a bypass passage 17 having a throttle 16, and the pressure of the main valve 7 is passed from the manual switching valve 11 through the bypass passage 17. The pressure oil can be supplied directly to the section 8. FIG. 4 shows a first specific example, in which the electric switching valve 4 has a spool 22 fitted in a spool hole 21 of a valve body 20, and a solenoid 23 is attached to face the spool 22. Port 24 and exit port 25
The spool 22 is held in a shut-off position by a spring 27. When the solenoid 23 is energized and the spool 22 is pressed against the spring 27, the spool 22 is connected to the inlet port 24 by the small-diameter portion 26. Exit port 25
Is moved to the pressure reducing position where the
A shaft hole 29 opened to the tank port 28 is formed at the axis of the shaft 2, and the shaft hole 29 is opened to the outlet port 25 through the orifice 30 to constitute the bypass passage 17. With this configuration, even if the spool 22 is locked at the decompression position, the tank port 28 and the outlet port 25 communicate with the shaft hole 29 and the orifice 30.
8 can be supplied to the outlet port 25. FIG. 5 shows a second specific example, in which a first orifice 31 is formed on the inlet side of a shaft hole 29, and the shaft hole 29 is opened to the outlet port 25 with a second orifice 32. 1
-The consumption flow rate can be reduced without reducing the diameter of the second orifices 31, 32. FIG. 6 shows a third specific example, in which the spool 23 has a perfect circular shape, and the inlet port 24 and the outlet port 25 communicate with the shaft hole 33 and the radial hole 34. Orifice 3 opening in
5 is formed to form a bypass.

[0006]

By setting the manual switching valve 11 to the third position and the electric switching valve 4 to the first position and the second position, the discharge pressure oil of the hydraulic pump 1 is applied to the pressure receiving portion 8 of the main valve 7. Or the main valve 7 can be switched by connecting the pressure receiving portion 8 to the tank. At this time, the pressure oil supplied to the pressure receiving portion 8 flows out to the tank via the bypass passage 17 and the manual switching valve 11,
Since the throttle 16 is provided in the bypass passage 17, pressure is generated in the pressure receiving portion 8, and the main valve 7 can be switched. Further, by setting the manual switching valve 11 to the third position and the fourth position, the pressure receiving chamber 8 of the main valve 7 can be communicated with the tank by the bypass passage 17, and the pressure oil can be supplied through the bypass passage 17. The main valve 7 can be switched by the manual switching valve 11 even when the electric switching valve 4 is locked at a position intermediate the first position and the second position and does not operate normally. Moreover, the aperture 16
The cost is reduced and the piping is simple because only the bypass path 17 having the above is provided.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a conventional pressure oil supply device.

FIG. 2 is a circuit diagram of a conventional pressure oil supply device.

FIG. 3 is a circuit diagram of the pressure oil supply device of the present invention.

FIG. 4 is a sectional view showing a first specific example.

FIG. 5 is a sectional view showing a second specific example.

FIG. 6 is a cross-sectional view showing a third specific example.

[Explanation of symbols]

1 hydraulic pump, 4 electric switching valve, 5 inlet port,
6 outlet port, 7 main valve, 8 pressure receiving section, 11 manual switching valve, 12 inlet port, 13 outlet port, 14
Tank port, 16 throttle, 17 bypass.

Claims (1)

(57) [Scope of request for utility model registration] An inlet connected to a discharge path of a hydraulic pump.
Port 5 and an outlet port connected to the pressure receiving portion 8 of the main valve 7
6 and a drain port 14;
And the tank port 14 communicates with the outlet port 6.
The first port is held at the first position
5 communicates with the outlet port 6 and the tank port 14 communicates with the outlet
Electrical directional control valve operating in a second position to shut off port 6
4 and an inlet port 1 connected to the discharge path 2 of the hydraulic pump 1
2 and the drain port 14 of the electric switching valve 4
An outlet port 13 is provided.
3 communicates with the tank at the third position and the inlet port 12
Hand that operates to switch to the fourth position communicating with mouth port 13
A dynamic switching valve 11; a tank port 14 side and an outlet port of the electric switching valve 4;
6 is short-circuited by bypass 17 having throttle 16
A pressure oil supply device characterized by the above-mentioned.