JP3649342B2 - Directional control valve - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a directional control valve that controls the flow direction of hydraulic oil.
[0002]
[Prior art]
3 and 4 are cross-sectional views showing the configuration of a conventional directional control valve.
A main spool 2 is slidably incorporated in the housing 1. The main spool 2 is formed with a first annular groove 3 and a second annular groove 4. Caps 5 and 6 are attached to positions corresponding to both ends of the main spool 2, and the caps 5 and 6 serve as pilot chambers 5a and 6a. Further, a centering spring 7 is disposed in one pilot chamber 6a.
The housing 1 has a supply passage 8 into which pressure oil supplied from a pump (not shown) flows.
The housing 1 is formed with actuator ports 9 and 10, the inner end of the actuator port 9 is opened to the flow passage 11, and the inner end of the actuator port 10 is opened to the flow passage 12.
Further, the housing 1 is formed with a return passage 13 that leads to a tank (not shown).
[0003]
In the directional control valve thus configured, when the main spool 2 moves to the left, the supply passage 8 and the flow passage 12 communicate with each other via the second annular groove 4 formed in the main spool 2, while the return passage 13 and The flow path 11 communicates with the first annular groove 3 formed in the main spool 2.
Accordingly, the pressure oil supplied from a pump (not shown) is supplied to a cylinder which is an actuator (not shown) via the supply passage 8 → the second annular groove 4 → the flow passage 12 → the actuator port 10. Then, the return oil of this cylinder returns to the tank (not shown) via the actuator port 9 → the flow passage 11 → the first annular groove 3 → the return passage 13.
[0004]
On the other hand, electromagnetic proportional pressure reducing valves 14 and 15 are directly attached to the lower positions of the caps 5 and 6 of the housing 1 in the drawing. The electromagnetic proportional pressure reducing valve 15 includes a solenoid 16, a sleeve 17 mounted in the housing 1, and a pilot spool 18 slidably accommodated in the sleeve 17.
The sleeve 17 communicates with a P port 19 that communicates with the pilot supply passage 30, a relay passage 21 that communicates with the pilot chambers 5 a and 6 a, a C port 22 that communicates with the relay passage 21, and a drain port 20. And a T port 24.
The pilot spool 18 is formed with an annular groove 26 around the pilot spool 18. The annular groove 26 is always in communication with the C port 22 regardless of the movement position of the pilot spool 18. Reference numeral 23 in the figure denotes a damper orifice. Further, a communication path 27 and a central path 28 are formed in the pilot spool 18, and the annular groove 26 and the pressure chamber 29 are always in communication with each other through the paths 27 and 28.
Further, the electromagnetic proportional pressure reducing valves 14 and 15 are provided with a movable iron core 25 of a solenoid 16.
[0005]
In the electromagnetic proportional pressure reducing valve 15 thus configured, when the solenoid 16 is excited, the movable iron core 25 moves the pilot spool 18 to the left in FIG. The movement of the pilot spool 18 causes the annular groove 26 and the pilot supply passage 30 to overlap, so that the pressure oil supplied from a pump (not shown) passes through the annular groove 26 and the damper orifice 23 from the P port 19. Flow into the C port 22. At this time, the pressure oil in the annular groove 26 is guided to the pressure chamber 30 via the communication path 27 and the central path 28.
Therefore, the pilot spool 18 stops at a position where the pressure action in the pressure chamber 29 and the pressing force of the movable iron core 25 are balanced, and controls the lap amount between the annular groove and the pilot supply passage, and according to the lap amount. Control the decompression.
[0006]
[Problems to be solved by the invention]
In the conventional directional control valve as described above, since the electromagnetic proportional pressure reducing valve is used, the pressure acting on the pilot chambers 5a and 6a is always reduced, and the pressure action on the main spool is weakened accordingly. As a result, there was a problem that the responsiveness deteriorated.
An object of the present invention is to provide a highly responsive directional control valve that uses a conventional P port, a relay passage, and a drain port as they are when high responsiveness is required due to required performance of an operating machine. It is.
[0007]
In the present invention, a main spool is slidably incorporated in a housing, both ends of the main spool are exposed to a pilot chamber, and a pair of solenoid valves for controlling the pressure of each pilot chamber is provided in the housing. on the other hand, the housing includes an actuator port in communication with the actuator, in accordance with the movement of the main spool, the supply passage for communicating the actuator port to the pump communicates with the actuator port, the movement of the main spool Accordingly , a return passage for communicating with the actuator port and communicating the actuator port with the tank, a pilot supply passage for communicating with the pilot supply source, and a relay passage for communicating the pilot supply source with the pilot chamber And drain the pilot supply passage. It is intended to assume a direction control valve having a drain port for causing.
Based on the premise of the control valve, the directional control valve of the present invention is provided with a sleeve of the electromagnetic valve in parallel to the main spool in the housing, and maintains a gap between the sleeve and the main spool. A pilot spool is slidably incorporated in the sleeve, a spring chamber is provided on the opposite side of the solenoid spool from the solenoid valve, and the spring force of the spring provided in this spring chamber is applied to the pilot spool. and, on the sleeve, a pilot supply passage provided in the housing to form a port in communication with the relay passage and the drain port, the spring chamber, causes communication with the drain port through the connection path, the drain port, the especially in that the three-way valve communicates with the tank via the T port formed in the sleeve Having.
[0008]
[Action]
Since the present invention is configured as described above, either an electromagnetic proportional pressure reducing valve or an electromagnetic proportional three-way flow control valve can be attached to the same housing.
[0009]
【Example】
1 and 2 are sectional views showing an embodiment of a directional control valve according to the present invention.
A main spool 2 is slidably incorporated in the housing 1. The main spool 2 is formed with a first annular groove 3 and a second annular groove 4. Caps 5 and 6 are attached to positions corresponding to both ends of the main spool 2, and the caps 5 and 6 serve as pilot chambers 5a and 6a. Further, a centering spring 7 is disposed in one pilot chamber 6a.
The housing 1 has a supply passage 8 into which pressure oil supplied from a pump (not shown) flows.
[0010]
The housing 1 is formed with actuator ports 9 and 10, the inner end of the actuator port 9 is opened to the flow passage 11, and the inner end of the actuator port 10 is opened to the flow passage 12.
Further, the housing 1 is formed with a return passage 13 that leads to a tank (not shown).
In the directional control valve thus configured, when the main spool 2 moves to the left, the supply passage 8 and the flow passage 12 communicate with each other via the second annular groove 4 formed in the main spool 2, while the return passage 13 and The flow path 11 communicates with the first annular groove 3 formed in the main spool 2.
[0011]
Accordingly, the pressure oil supplied from a pump (not shown) is supplied to a cylinder which is an actuator (not shown) via the supply passage 8 → the second annular groove 4 → the flow passage 12 → the actuator port 10. Then, the return oil of this cylinder returns to the tank (not shown) via the actuator port 9 → the flow passage 11 → the first annular groove 3 → the return passage 13.
On the other hand, electromagnetic proportional three-way flow control valves 31 and 32 are directly attached to the lower positions of the caps 5 and 6 of the housing 1 in the figure. The electromagnetic proportional three-way flow control valve 32 includes a solenoid 16, a sleeve 33 mounted in the housing 1, and a pilot spool 34 slidably accommodated in the sleeve 33.
The sleeve 33 communicates with the P port 19 that communicates with the pilot supply passage 30, the relay passage 21 that communicates with the pilot chambers 5 a and 6 a, the C port 22 that communicates with the relay passage 21, and the drain port 20. And a T port 24.
[0012]
Further, the pilot spool 34 is formed with an annular groove 35 around the periphery, and the annular groove 35 is always in communication with the C port 22 regardless of the movement position of the pilot spool 34.
Further, the electromagnetic proportional three-way flow control valves 31 and 32 are provided with a movable iron core 25 of a solenoid 16.
A spring chamber 36 is formed at the tip of the spool 34 that is opposite to the surface that the movable iron core 25 contacts. The spring chamber 36 is filled with oil and includes a spring 38. The spring chamber 36 and the drain port 20 are connected by a connecting path 37.
[0013]
In the electromagnetic proportional three-way flow control valve 32 configured as described above, when the solenoid 16 is energized, the movable spool 25 moves the pilot spool 34 to the left in FIG. The movement of the pilot spool 34 causes the annular groove 35 and the pilot supply passage 30 to overlap, so that the pressure oil supplied from a pump (not shown) passes from the P port 19 via the annular groove 35 to the C port 22. Flow into. At this time, the spring 38 of the spring chamber 36 is pushed by the pilot spool 35 and contracts, and the oil in the spring chamber 36 passes through the connecting path 37 and is returned from the drain port 20 to the tank.
Thus, in this solenoid valve, unlike the conventional pressure reducing valve, the pressure acting on the pilot chambers 5a and 6a is not reduced.
Moreover, the position of the pilot supply passage 30, the relay passage 21, and the drain port 20 in the housing 1 is the same as that of the prior art only by adding the connecting passage 37.
[0014]
【effect】
According to the directional control valve of the present invention, the maximum secondary pressure can be increased to the pilot hydraulic pressure. Therefore, the main spool acceleration force can be utilized to the maximum, and a high response can be realized.
In addition, since the oil in the spring chamber returns to the tank from a drain port having a different oil path from the return passage, the pilot spool does not receive back pressure from the return passage. Therefore, there is no problem that the pilot spool is returned and the opening degree is reduced, so that high responsiveness can be ensured.
Furthermore, the positions of the P port, the relay passage, and the drain port in the housing remain the same as before, and an electromagnetic proportional three-way flow control valve can be attached.
In other words, the pilot spool drive system can be selected according to the required operating performance and incorporated into a conventional housing. Also, when constructing a composite multiple valve, since the positions of the relay passages and drain ports of the respective housings are exactly the same, it is possible to superimpose different pilot spool drive systems.
Furthermore, since the structure in the housing can be made common regardless of the pilot spool drive system, the manufacturing process can be standardized, and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a directional control valve according to the present invention.
FIG. 2 is a partially enlarged cross-sectional view of FIG.
FIG. 3 is a cross-sectional view showing a conventional directional control valve.
4 is a partially enlarged sectional view of FIG. 3;
[Explanation of symbols]
1 Housing 2 Main spool 5a Pilot chamber 6a Pilot chamber 8 Supply passage 9 Actuator port 10 Actuator port 13 Return passage 16 Solenoid 20 Drain port 21 Relay passage
24 T port 30 Pilot supply passage 33 Sleeve 34 Pilot spool 36 Spring chamber 37 Connection passage 38 Spring

Claims (1)

The main spool is slidably incorporated in the housing, both ends of the main spool are exposed to the pilot chamber, and the housing is provided with a pair of solenoid valves for controlling the pressure of each pilot chamber. the, an actuator port in communication with the actuator, in accordance with the movement of the main spool, the supply passage for communicating the actuator port to the pump communicates with the actuator port, according to the movement of the main spool, the A return passage for communicating with the actuator port to communicate the actuator port with the tank, a pilot supply passage for communicating with the pilot supply source, a relay passage for communicating the pilot supply source with the pilot chamber, and a pilot supply To drain the passage In the directional control valve and a drain port, to the housing is provided in parallel to the sleeve of the solenoid valve to the main spool, keeps a distance between the sleeves and the main spool, the sleeve is A pilot spool is slidably incorporated, a spring chamber is provided on the opposite side of the solenoid of the solenoid of the solenoid valve, and the spring force of the spring provided in this spring chamber is applied to the pilot spool. The sleeve is formed with a port that communicates with a pilot supply passage, a relay passage, and a drain port provided in the housing, and the spring chamber is communicated with the drain port through a connecting path, and the drain port is formed in the sleeve. and communicates with the tank via a the T port that a three-way valve Directional control valve for the butterflies.

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