JP2745652B2 - Pressure control valve - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure control valve, and more particularly to a pressure control valve suitably used for hydraulic control of an active suspension for a vehicle or the like.

[Prior Art] An active suspension uses a hydraulic cylinder instead of a conventional spring and absorber, and obtains good steering stability and ride comfort by adjusting the hydraulic pressure to the hydraulic cylinder according to the running state of the vehicle. Things.

In order to perform such control satisfactorily, a pressure control valve that controls the hydraulic pressure to the hydraulic cylinder with good responsiveness and stability is required, and since it is mounted on a vehicle, it is necessary that the pressure control valve be compact and have low driving power. .

As a conventional pressure control valve, a pilot chamber pressure for moving a main spool valve for pressure switching is changed by a pilot relief valve using a poppet valve (first conventional example, Japanese Patent Application Laid-Open No. Sho 62-17813), It is known that the pressure is controlled by a large amount of hydraulic oil with a small operating force by changing a pilot valve using a valve (second conventional example, Japanese Patent Application Laid-Open No. Sho 62-1781).

[Problems to be Solved by the Invention] However, in the first conventional example, the poppet valve which receives the secondary pressure and relieves the secondary pressure may vibrate in response to a slight change in the secondary pressure. This causes a problem that the operation of the main spool valve is unstable and the secondary pressure fluctuates greatly.

Further, in the second embodiment, the response of the pilot spool valve is difficult, and the provision of the pilot spool valve in which the plunger of the electromagnetic coil is connected in tandem with the main spool valve increases the size of the entire apparatus. There's a problem.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide a pressure control valve that is capable of performing stable pressure control with excellent responsiveness and realizing miniaturization.

[Means for Solving the Problems] The configuration of the present invention will be described with reference to FIG. 1. A primary pressure port 11 connected to a pressure source, a tank port 12 connected to a reservoir tank, and connected to an external device. Secondary pressure port 13
The pressure control valve includes a cylinder pressure chamber 1b communicating with the secondary pressure port 13, a pilot pressure chamber 1a communicating with the primary pressure port 11 via a fixed throttle 14, and both ends of the cylinder pressure chamber 1b. The main pressure chamber 11b faces the chamber 1b and the pilot pressure chamber 1a and moves in accordance with the pressure difference between the two chambers 1a, 1b to switch and connect the primary pressure port 11 or the tank port 12 to the secondary pressure port 13. A pilot having a valve 2 and a throttle passage 31 which is rotated and communicates with the tank port 12, the throttle amount of which changes according to the amount of rotation to change the pressure of the fluid that has passed through the fixed throttle 14. Valve 3
Driving means 4 for rotatingly driving the pilot valve 3
Is provided. When the internal pressure of the pilot pressure chamber 1a becomes larger than the internal pressure of the cylinder pressure chamber 1b, the secondary pressure port 13 communicates with the primary pressure port 11 and communicates with the pilot pressure chamber 1a via a fixed throttle 14, When the internal pressure of the pilot pressure chamber 1a becomes smaller than the internal pressure of the cylinder pressure chamber 1b, the secondary pressure port 13
It is configured to communicate with

[Operation] When the pilot pressure chamber 1a and the cylinder pressure chamber 1b have the same pressure, the main valve 2 is in the neutral position. In this state, the primary pressure port 11, the tank port 12, and the secondary pressure port 13 are shut off. Have been.

When the pilot valve 3 is rotated by the rotation driving means 4, the pressure of the fluid that has passed through the fixed throttle 14 is changed by the throttle channel 31 of the pilot valve 3 according to the valve rotation amount. As a result, the internal pressure of the pilot pressure chamber 1a is changed, a pressure difference is generated between the pilot pressure chamber 1a and the cylinder pressure chamber 1b, the main valve 2 moves from the neutral position, and the secondary pressure port 13 moves from the primary pressure port 11 to the tank port 12 Is switched and connected.

Thereby, the pressure of the secondary pressure port 13 is changed, and this pressure is applied and supplied to an external device,
The internal pressure of the cylinder pressure chamber 1b communicating with the secondary pressure port 13 changes. Due to this change, the difference between the internal pressure of the pilot pressure chamber 1a and the internal pressure of the pilot pressure chamber 1a becomes small, and the main valve 2 moves back toward the neutral position.

In this manner, the pressure of the secondary pressure port 13, that is, the pressure of the external device, can accurately and promptly follow the internal pressure of the pilot pressure chamber 1 a changed by the pilot valve 3.

In such a configuration, since the pilot valve 3 rotates, the responsiveness is excellent and the outer shape can be made compact. Further, since the fluid pressure acts on the pilot valve 3 which rotates, the fluid pressure acts from the direction perpendicular to the axis, so that unnecessary vibration does not occur and stable pressure control is performed.

First Embodiment Hereinafter, the structure and operation of the first embodiment of the present invention will be described together.

In FIG. 1, a valve housing 1 is a rectangular parallelepiped, and a spool valve 2 serving as a main valve is disposed at the center in the lower half so as to be horizontally movable, and is connected to the lower surface of the valve housing 1 by the spool valve 2. Primary pressure port
11, a tank port 12, and a secondary pressure port 13 are provided. The primary pressure port 11 is connected to a hydraulic pump (not shown), and the tank port 12 is connected to a reservoir tank. The secondary pressure port 13 is connected to a conduit leading to a suspension cylinder, which is an external device.

The spool valve 2 is a rod body having both ends formed into a large-diameter cylindrical shape, and coil springs 23 and 24 are inserted into the cylinder from the left and right, and are held at a neutral position in the figure. In this neutral position, each port is provided by a stepped portion on the outer periphery of the spool valve 2.
11, 12, and 13 are shut off. Each of the above coil springs 23, 24
Are supported at the other end by caps 16 for closing both ends of the valve housing 1, and these caps 16 and the spool valve 2
A pilot pressure chamber 1a and a cylinder pressure chamber 1b are formed between them. The cylinder chamber 1b communicates with the secondary pressure port 13 through flow paths 21 and 22 formed in the spool valve 2.

The internal pressure of the pilot pressure chamber 1a is
That is, when the pressure becomes larger than the internal pressure of the secondary pressure port 13, the spool valve 2 moves to the right, the secondary pressure port 13 communicates with the primary pressure port 11, and the pilot pressure passes through the flow path 102, the fixed throttle 14, and the like. Communicates with room 1a. Secondary pressure port 13
The pressure rises by communicating with the primary pressure port 11.
As a result, the internal pressure of the cylinder pressure chamber 1b increases, and the spool valve 2 moves back toward the neutral position. When the internal pressure of the cylinder pressure chamber 1b matches the internal pressure of the pilot pressure chamber 1a, the spool 2 completely returns to the neutral position.

On the other hand, when the internal pressure of the pilot pressure chamber 1a becomes smaller than the internal pressure of the cylinder pressure chamber 1b, the spool valve 2 moves to the left, the ports 12 and 13 communicate with each other, and the pressure of the port 13 decreases. Accordingly, the internal pressure of the cylinder pressure chamber 1b decreases, and when the internal pressure of the cylinder pressure chamber 1b matches the internal pressure of the pilot pressure chamber 1a, the spool 2 completely returns to the neutral position.

In this way, the pressure of the secondary pressure port 13 connected to the cylinder pressure chamber 1b and connected to the external device is controlled to follow the internal pressure of the pilot pressure chamber 1a at all times.

A cylindrical sleeve 5 is fitted in the center of the upper half of the valve housing 1, and the lower half is inserted into the sleeve 5 so that the rod-shaped pilot valve 3 is perpendicular to the spool valve 2. Is provided. The upper end of the pilot valve 3 extends into the valve drive solenoid 4, and the upper end cylindrical portion is fitted on a rod-shaped support portion 42 erected at the center of the solenoid cover 41 and is supported rotatably.

A thick plate-shaped permanent magnet 43 is provided on the outer periphery of the upper end of the pilot valve 3 and has magnetic poles at both ends (FIG. 2) forming a rectangle. Then, the electromagnetic coils 44a, 44b, respectively at four locations in the circumferential direction surrounding the permanent magnet 43,
44c and 44d are provided, and these are connected to power sources 45a and 45b in pairs, respectively. Then
By switching the energization of the pair of electromagnetic coils 44a to 44d, the pilot valve 3 having the permanent magnet 43 integrated therewith is provided.
Are rotationally positioned at right and left and up and down orthogonal positions in the figure and at an intermediate position between them. In the figure, each of the electromagnetic coils 44a to 44a
Although the power supply to 4d is performed ON-OFF by the switch, if the power supply is changed continuously, the pilot valve 3 can of course be continuously positioned.

In FIG. 1, the lower end of the pilot valve 3 has a cylindrical shape, and an annular groove 51 is formed on the inner periphery of the sleeve 5 in contact with the outer periphery thereof.
It communicates with the primary pressure port 11 through an annular groove 101 and a flow path 102. In addition, in the lower end cylinder of the pilot valve 3
Communicates with the tank port 12 through an annular groove 103 and communicates with the annular groove 51 via a throttle channel 31 provided at a position facing the upper part of the cylinder wall and a rectangular groove 52 of the sleeve 5. The annular groove 51 communicates with the pilot pressure chamber 1a via the annular groove 53 and the flow path 15.

When the pilot valve 3 is positioned at a predetermined position by the valve drive solenoid 4, the throttle flow path 31 completely matches the rectangular groove 52 (FIG. 3 (1)). Since the pressure inside the cylinder 32 of the pilot valve 3 is low, the pressure of the hydraulic oil flowing into the annular groove 51 via the fixed throttle 14 is reduced by the large opening of the throttle channel 31 to the same low pressure as the pressure inside the cylinder 32. become. As a result, the internal pressure of the pilot pressure chamber 1a also decreases, and as described above, the spool valve 2 moves to lower the pressure of the secondary pressure port 13 to the minimum pressure.

When the energization of the valve drive solenoid 4 is changed, the pilot valve 3 rotates, and as the rotation amount increases, the relative position of the throttle channel 31 with respect to the rectangular groove 52 shifts, the opening area decreases, and the flow resistance increases. I do. As a result, the pressure of the hydraulic oil in the annular groove 51 increases, and accordingly, the pilot pressure chamber
The internal pressure of 1a also increases, the spool valve 3 moves, and the pressure of the secondary pressure port 13 increases accordingly. This pressure becomes maximum when the positions of the throttle channel 31 and the rectangular groove 52 are completely displaced as shown in FIG. 3 (2).

In the above structure, since the operating oil pressure acts from the direction perpendicular to the axis of the rotating pilot valve 3, unnecessary vibration does not occur in the pilot valve 3 even if the oil pressure fluctuates. The pressure is stable.
In addition, since the pilot valve 3 that rotates is excellent in responsiveness and can be driven by the small rotary solenoid or the step motor as described above, the whole control valve can be reduced in size and weight, and power consumption is small.

Second Embodiment The main valve is not limited to the spool valve as in the first embodiment, but may be, for example, a rotary valve shown in FIG.

In the figure, the inside of the circular valve housing 1 is centered,
A pilot valve 3 having substantially the same structure as that of the first embodiment is provided, and a fan-shaped fixed wall 17 is provided at a radially symmetric position with respect to the valve 3. Between these fixed walls 17, the rotary valves 6 are rotatable around the above-mentioned center.
A and 6B are provided, and the rotary valves 6A and 6B are substantially fan-shaped plate bodies in which flow paths 61 and 62 are formed. A pilot pressure chamber 1a and a cylinder pressure chamber 1b are formed on both sides of each of the rotary valves 6A and 6B, respectively, with the fixed wall 17,
The fixed throttle 14 directly opens into the pilot pressure chamber 1a, and the secondary pressure port 13 directly opens into the cylinder pressure chamber 1b.

The figure shows a state where each of the rotary valves 6A and 6B is in the neutral position.In this state, the primary pressure port 11 and the tank port 12 are covered and closed by the rotary valves 6A and 6B. The space between the secondary pressure ports 13 is shut off. The fixed throttle 14 communicates with the primary pressure port 11 through a channel (not shown), and a throttle channel 31 of the pilot valve 3 is opened in the pilot pressure chamber 1a.

When the pilot valve 3 rotates and the opening area of the throttle passage 31 decreases, the internal pressure of each pilot pressure chamber 1a increases,
Each pilot valve 3 rotates clockwise. As a result, the primary pressure port 11 is opened, and communicates with the cylinder pressure chamber 1b and the secondary pressure port 13 opening here via the flow paths 61 and 62. The primary pressure port 11 has a fixed throttle 14 communicating therewith.
Is open to the pilot pressure chamber 1a.
The secondary pressure port 13 and the pilot pressure chamber
Also communicates between 1a. The internal pressure of the cylinder pressure chamber 1b starts to rise, and the rotary valves 6A and 6B are rotated back to the neutral position with this rise. Valve 6
A and 6B return to the neutral position.

When the pilot valve 3 rotates in the reverse direction and the opening area of the throttle channel 31 increases, the internal pressure of each pilot pressure chamber 1a decreases, and the rotary valves 6A and 6B rotate counterclockwise. Thereby, the tank port 12 is opened this time and communicates with the cylinder pressure chamber 1b and the secondary pressure port 13. Thus,
The internal pressure of the cylinder pressure chamber 1b decreases until it matches the internal pressure of the pilot pressure chamber 1a.

In this way, the pressure of the secondary pressure port 13 is changed following the internal pressure of the pilot pressure chamber 1a changed by the pilot valve 3, and the same effect as in the first embodiment can be obtained.

[Effects of the Invention] As described above, according to the pressure control valve of the present invention, the rotation of the pilot valve changes the internal pressure of the pilot pressure chamber for moving the main valve. The miniaturization of the means for rotating and driving the valve is realized. Further, since the fluid pressure acts on the pilot valve in the direction perpendicular to the axis, unnecessary valve vibration does not occur and stable pressure control is possible.

[Brief description of the drawings]

1 to 3 show a first embodiment of the present invention.
FIG. 2 is a vertical sectional view of the entire pressure control valve, FIG. 2 is a schematic plan view of an electromagnetic solenoid, FIG. 3 is a horizontal enlarged sectional view of a valve portion of a pilot valve, and FIG. It is a whole horizontal sectional view of a control valve. 1 Valve housing 1a Pilot pressure chamber 1b Cylinder pressure chamber 11 Primary pressure port 12 Tank port 13 Secondary pressure port 14 Fixed throttle 2 Spool valve (main valve) 3 …… Pilot valve 31 …… Throttle channel 4 …… Electromagnetic solenoid (Rotary driving means) 6 …… Rotary valve (Main valve)

Claims (2)

(57) [Claims] 1. A pressure control valve comprising: a primary pressure port connected to a pressure source; a tank port connected to a reservoir tank; and a secondary pressure port connected to an external device. , A pilot pressure chamber communicating with the primary pressure port through a fixed throttle, and both ends facing the cylinder pressure chamber and the pilot pressure chamber, respectively, moving according to the pressure difference between these two chambers. A primary valve for switching between the primary pressure port or the tank port and the secondary pressure port; and a rotary valve, which is operated to rotate and communicates with the tank port to change the throttle amount according to the rotation amount. A pressure control valve comprising: a pilot valve having a throttle flow path for changing a pressure of a fluid that has passed through the fixed throttle; and a driving unit that rotationally drives the pilot valve. 2. When the internal pressure of the pilot pressure chamber becomes larger than the internal pressure of the cylinder pressure chamber, the secondary pressure port communicates with the primary pressure port and communicates with the pilot pressure chamber via the fixed throttle. 2. The pressure control valve according to claim 1, wherein the secondary pressure port communicates with the tank port when the internal pressure of the pilot pressure chamber becomes smaller than the internal pressure of the cylinder pressure chamber.