JP2727701B2 - Fluid pressure servo valve - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic servo valve that operates a guide valve for switching a fluid port by a fluid pressure controlled by a nozzle flapper.

[Prior Art] FIG. 16 shows a conventional fluid pressure servo valve, which is arranged so as to be linearly movable in the horizontal direction by a nozzle flapper 4 'whose swing amount is controlled by an electromagnetic coil 3' in the upper half of the housing 1. The fluid port is switched by changing the fluid pressure at both ends of the spool type guide valve 2 'and moving the guide valve 2'. According to such a servo valve, switching of high-pressure fluid can be smoothly performed by the small-sized electromagnetic coil 3 '.

[Problems to be Solved by the Invention] However, when the conventional fluid pressure servo valve is used in a vehicle or the like, if a vibration force acts in the moving direction of the guide valve, the guide valve linearly vibrates and cannot be controlled. There was a problem.

Therefore, an object of the present invention is to solve the problem and to provide a fluid pressure servo valve in which the guide valve does not vibrate due to linear vibration input and the control becomes impossible.

[Means for Solving the Problems] To explain the configuration of the present invention, a fluid pressure servo valve according to claim 1 has a plate-shaped guide valve 2 having a partially circular shape inside a housing 1 (FIG. 1) around its center. The control ports 11A and 11B provided on the housing 1 are provided rotatably on the outer periphery of the guide valve 2 according to the valve rotation direction.
A, 12B or switching ports 21A, 21B communicating with the return ports 13A, 13B are formed, and each end face of the guide valve 2 in the circumferential direction is connected to the pressure ports 12A, 12B, 12B.
The pressure chambers P1, P2, P3, and P4, which communicate with C and 12D through throttle paths 23A, 23B, 23C, and 23D, respectively, are controlled by the drive means 3 (FIG. 4). Channel 41A, 4
A nozzle flapper valve 4 formed with 1B is provided, and as the nozzle flapper valve 4 rotates from a neutral position, each of the pressure chambers
P1 to P4 reciprocally change the communication cross-sectional area of each of the discharge flow paths 24A, 24B, 24C, 24D that make the return ports 13A, 13B communicate with each other, and each of the throttle flow paths 23A to 23D is a guide valve. 2 and these throttle channels 23A to 23D
Pressure ports 12A to 12D communicating with the pressure chamber P1
To P4, and are opened in the wall of the housing 1 facing the outer periphery of the guide valve 2 near each of the pressure chambers P1 to P4.

The fluid pressure servo valve according to the second aspect of the present invention is configured such that each of the pressure chambers P is changed with a change in the communication sectional area of each of the discharge passages 24A and 24B.
1. A connecting member 5 having an elastic restoring force for connecting the guide valve 2 which can be rotated forward and reverse by changing the acting force of P2 to the nozzle flapper valve 4 is provided.

[Operation] In the servo valve according to claim 1, when the nozzle flapper valve 4 is rotated forward and backward from the neutral position, each of the discharge passages is formed.
As a result of the communication cross-sectional areas of 24A to 24D being reciprocally changed, a difference occurs in the internal pressures of the pressure chambers P1 to P4 facing the circumferential end surfaces of the guide valves 2, and the guide valves 2 are connected to the discharge passages 24A to 24D. The control ports 11A and 11B and the pressure ports 12A and 12B or the return ports 13A and 13B are connected to each other by rotating the control ports 11A and 11B and the return ports 13A and 13B.

In the servo valve according to the second aspect, when the nozzle flapper valve 4 is rotated forward and backward from the neutral position, each of the discharge flow paths 24
As a result of the cross-sectional area of A and 24B being reciprocally changed,
A difference is generated in the pressure acting on the circumferential end face of the guide valve 2, and the guide valve 2 rotates forward and backward. With the rotation of the guide valve 2, the connecting member 5
The nozzle flapper valve 4 connected by the rotation is rotated against the driving means 3, and as a result, each of the discharge flow paths 24A, 2A
The rotation of the guide valve 2 stops at the equilibrium position where the communication cross-sectional areas of 4B become equal again. Thus, at this rotational position, the control ports 11A and 11B and the pressure ports 12A and 12B or the return port 13 are communicated.

However, according to the configuration described in each claim, since the guide valve 2 rotates, it is not vibrated by a linear vibration force, and operates stably even when mounted on a vehicle or the like.

Further, in the configuration of the first aspect, since the pressure ports 12A to 12D are respectively opened in the housing walls close to the pressure chambers P1 to P4, the pressure chambers P1 to P4 pass through the gap with the outer periphery of the guide valve 2. The same amount of pressure fluid leaks to P4, and there is no difference in pressure between the pressure chambers P1 to P4 due to uneven amounts of leakage.

First Embodiment FIG. 4 is a partial sectional side view of a servo valve, in which a valve portion, which will be described in detail later, is provided in a lower half housing 1, and an upper half portion is covered by a cover body 31. It is a torque motor section 3 as a driving means. The torque motor section 3 has a pair of front and rear permanent magnets 32A, 32B, 32C and 32D at left and right positions (FIG. 5), and electromagnetic coils 33A and 33B are provided between these permanent magnets 33A to 32D. These electromagnetic coils 33A, 33B
And an armature 34 extending in the left-right direction is provided between the opposing gaps of the permanent magnets 32A to 32D. And the nozzle flapper valve 4 as a center. One end of the armature 34 is pushed by coil springs 35A and 35B from front and rear, and the electromagnetic coils 33A and 3
In the neutral position where no current is supplied to 3B, the armature 34 is held at the neutral position corresponding to the left-right direction as shown.

When the electromagnetic coils 33A and 33B are energized and the magnetic poles shown at both ends of the armature 34 appear, the armature 34 and the nozzle flapper valve 4 integral with the armature 34 move counterclockwise until they balance the spring force of the coil springs 35A and 35B. Rotate. Then
When the amount of energization to the electromagnetic coils 33A and 33B is increased or decreased, the nozzle flapper valve 4 is rotated to an angular position corresponding thereto, and the direction of rotation is reversed by switching the energization direction.

FIG. 1 shows a horizontal section of the valve section, and FIG.
It is sectional drawing which follows the -I line. In the figure, housing 1
A guide valve 2 is disposed inside the guide valve 2. The guide valve 2 is a partially circular plate having a small circular center portion and a wing portion projecting in a fan shape to the left and right. Is rotatable around the center in the housing space.

The housing space slightly retreats at portions facing the four circumferential end faces of the guide valve 2 and further retreats at positions inside these portions to form pressure chambers P1, P2, P3, and P4. In the space communicating with the pressure chambers P1 and P3, coil springs 25A and 25B are provided between the end surface of the guide valve 2 and the wall of the housing 1.

Control ports 11A and 11B, pressure ports 12A and 12B, and return ports 13A and 13B are respectively opened in the housing 1 at point-symmetrical positions toward the left and right outer circumferences of the guide valve 2, and the guide ports 2 oppose these. Are formed with switching channels 21A and 21B.

The lower half of the nozzle flapper valve 4 is inserted into the center opening of the guide valve 2, and the outer periphery thereof is cut off in an arc shape at the left and right positions to form restricted flow paths 41 A and 41 B. This restricted channel
41A and 41B communicate with the return ports 13A and 13B by a flow path (not shown) further below the guide valve 2.

The housing 1 further has pressure ports 12C, 1
2D is provided, and each of the pressure ports 12A to 12D is opened facing the outer periphery of the guide valve 2 near each of the pressure chambers P1 to P4. In the guide valve 2, flow paths 27A, 27B, 27C, and 27D are formed at point-symmetrical positions to connect the throttle paths 23A to 23D communicating with the pressure chambers P1 to P4 and the pressure ports 12A to 12D. In addition, each of the pressure chambers P1
Discharge passages 24A, 24B, 24C, 24D are formed, and at the illustrated nozzle flapper valve neutral position, each of these discharge passages 24A to 24D has a restriction passage 41A, 41B with a half of its opening.
Leads to.

The operation of the servo valve having the above structure will be described below with reference to FIGS.

In FIG. 2, when the nozzle flapper valve 4 is rotated counterclockwise by a predetermined angle, the discharge flow paths 24A and 24B communicating with the pressure chambers P1 and P2 are opened and communicate with the restriction flow paths 41A and 41B. The communication sectional area at this time is proportional to the rotation angle of the nozzle flapper valve 4. On the other hand, the discharge channels 24C and 24D communicating with the pressure chambers P3 and P4 are closed. And the above pressure chamber
The internal pressures of P3 and P4 maintain a high pressure, but the internal pressures of the pressure chambers P1 and P2 decrease as the communication cross-sectional areas of the discharge passages 24A and 24B increase, and the guide valve 2 receives a counterclockwise rotational force. It is rotated. This rotation is continued until the discharge passages 24A and 24B are closed again and the internal pressures of the pressure chambers P1 and P2 are restored to an equilibrium state. As a result, the guide valve 4 rotates by the predetermined angle and stops. (FIG. 3).

In this state, the control ports 11A, 11B and the pressure ports 12A, 12B are communicated by the switching flow paths 22A, 22B of the guide valve 2, and a pressurized fluid is supplied to an external load. This supply amount is proportional to the rotation angle of the guide valve 2, that is, the rotation angle of the nozzle flapper valve 4.

When the nozzle flapper valve 4 is rotated clockwise, the guide valve 2 is also rotated clockwise, and the control ports 11A and 11B are connected to the return ports 13A and 13B via the switching flow paths 21A and 21B. Then, the pressurized fluid is returned from the external load.

According to this structure, at the neutral position of the nozzle flapper valve 4, the amount of fluid leaking into each of the pressure chambers P1 to P4 through the gap between the outer periphery of the guide valve 2 and the wall of the housing 1 becomes substantially equal, and the pressure between the pressure chambers P1 to P4 There is no danger that the guide valve 2 will deviate from the neutral position due to the difference.

This is the same when the internal pressures of the pressure chambers P1 to P4 are in an equilibrium state after the guide valve 2 is rotated.
Since substantially the same amount of pressure fluid leaks from P4 to the pressure ports 12A to 12D, the internal pressures of the pressure chambers P1 to P4 are kept equal, and the equilibrium position of the guide valve 2 does not collapse.

In the present embodiment, the discharge channels 24A to 24D may be completely closed at each of the neutral and equilibrium positions to cut off the communication with the restricted channels 41A and 41B.

Second Embodiment FIGS. 6 to 8 show another structure of the valve portion.
FIG. 7 is a horizontal sectional view of the valve section, FIG. 7 is a horizontal sectional view of a further lower position, and FIG. 8 is a vertical sectional view of the valve section.

6 and 7, a partition wall 6 is provided in the circular space of the housing 1, and the partition wall 6 is a cylindrical portion at the tip.
61 is positioned concentrically with the center of the circular space,
A base 62 extends in a fan shape from 61 toward the inner peripheral wall of the housing 1. The partition wall 6 includes a base 63 having a screw 63 and a pin 64 (eighth).
) Is fixed to the bottom wall of the housing 1.

A guide valve 2 is provided in an arc-shaped space formed by the partition wall 6 and the housing 1 wall so as to be rotatable and movable in the arc-shaped space along the arc-shaped space. Pressure chambers P1, P2 are formed between the walls 6. Also,
Pressure ports 12A and 12B are opened at the left and right positions on the bottom wall of the housing 1 facing the arc-shaped space, and a return port 13 is provided at a central position between the pressure ports 12A and 12B. Control ports 11A and 11B are respectively opened between the control ports 12A and 12B. The guide valve 2 is provided with pressure ports 12A and 1A.
The fan-shaped portion facing the 2B and the return port 13 is made thinner and floats from the bottom wall of the housing 1 (see FIG. 8) to form switching channels 21A, 21B and 21C (FIG. 6), respectively.

The pressure ports 12A and 12B and the pressure chambers are provided at both ends of the guide valve 2 in contact with the bottom wall of the housing 1.
Restriction channels 23A and 23B communicating P1 and P2 are formed (FIG. 7).

The cylindrical portion 61 of the partition wall 6 includes the inside of the cylinder and each of the pressure chambers P1, P2.
Discharge passages 24A and 24B communicating with the nozzle flapper valve 4 inserted in the cylinder.
The same opening area communicates with each of the outer peripheral restriction channels 41. The restriction flow path 41 communicates with the return port 13 through the flow path 42 traversing the nozzle flapper valve 4 and the opening 65 of the cylindrical portion 61. One end of a leaf spring 5 having a weak spring force is fixed to the outer periphery of the nozzle flapper valve 4 (FIG. 6). The leaf spring 5 projects from the cylindrical opening 65 and is connected to the central side wall of the guide valve 2. Fixed.

The operation of the servo valve having such a structure will be described below with reference to FIGS.
This will be described with reference to the drawings.

In FIG. 9, when the nozzle flapper valve 4 is rotated by a predetermined angle in the counterclockwise direction (arrow in the figure), the discharge flow path 24
The communication cross-sectional area between A and the restricted flow path 41 is small, and the communication cross-sectional area between the discharge flow path 24B and the restricted flow path 41 is large. And the pressure chamber
Since the internal pressure of P1 increases and the internal pressure of pressure chamber P2 decreases, guide valve 2 rotates clockwise (FIG. 10). With this rotation, the nozzle flapper valve 4 connected to the guide valve 2 by the leaf spring 5 is forcibly rotated clockwise and returns to the neutral position. The internal pressures of the pressure chambers P1, P2 return to the same pressure, and the guide valve 2 stops at this rotational angle position. In this state,
As shown in FIG. 11, the pressure port 12A is communicated with the control port 11A by the switching flow path 21A.
The control port 11B is made to communicate with the return port 13 by the switching flow path 21C, and the high-pressure fluid flows in the direction shown by the arrow in the figure. The flow rate at this time is proportional to the rotation angle of the guide valve 2, that is, the nozzle flapper valve 4.

The torque motor unit 3 for the nozzle flapper valve 4 (the fourth
When the drive shown in FIG. 1 is stopped, the leaf spring 5 returns to a linear state by its own elastic restoring force, and the nozzle flapper valve 4 rotates clockwise with this. As a result, the communication cross-sectional area of the discharge passage 24B decreases, the internal pressure of the pressure chamber P2 increases, and the guide valve 2 rotates counterclockwise to return to the neutral position shown in FIG.

Third Embodiment In a nozzle flapper valve 4 shown in FIG.
When the nozzle flapper valve 4 is rotated counterclockwise, the cross-sectional area of the restricted flow path communicating with the discharge flow path 24A is reduced, while the discharge flow path is reduced. The cross-sectional area of the restricted flow path portion to which 24B communicates increases (FIG. 13). As a result, the internal pressure of the pressure chamber P1 becomes larger than that of the pressure chamber P2, and the guide valve 2 rotates clockwise.

With this structure, the same effect as in the fourth embodiment can be obtained.

Fourth Embodiment In FIG. 14, the leaf spring 5 according to the second embodiment is described.
Instead, coil springs 7A and 7B are disposed in the pressure chambers P1 and P2 between the circumferential end surface of the guide valve 2 and the partition wall 6. When the nozzle flapper valve 4 rotates counterclockwise and the internal pressure of the pressure chamber P1 rises, the guide valve 2 rotates clockwise to a position where it is balanced with the spring force of the coil spring 7B and stops (No. 15).
Figure).

With such a structure, the same operation as in each of the above embodiments is performed.

[Effects of the Invention] As described above, in the fluid pressure servo valve according to the present invention, since the guide valve is operated to rotate, there is no problem that vibration is caused by a linear vibration input and control becomes impossible, and the vehicle is not driven. And the like to exhibit a stable control operation.

[Brief description of the drawings]

1 to 5 show a first embodiment of the present invention.
3 are horizontal sectional views of the valve section, respectively, a sectional view taken along line II of FIG. 4, FIG. 4 is a partial sectional side view of the servo valve, and FIG. 5 is a horizontal sectional view of the torque motor section. , FIG. 4 is a sectional view taken along the line VV, FIGS. 6 to 11 show a second embodiment of the present invention, and FIGS. 6 and 7 are horizontal sectional views of the valve portion. FIG. 8 is a vertical sectional view of the valve section, taken along line VI-VI and VII-VII, respectively, and FIG.
9 to 11 are horizontal cross-sectional views of the valve section, FIGS. 12 and 13 are horizontal cross-sectional views of the valve section showing a third embodiment of the present invention, and FIGS. FIG. 15 is a horizontal sectional view of a valve section showing a fourth embodiment of the present invention, and FIG. 16 is a schematic vertical sectional view of a servo valve showing a conventional example. 1 Housing 11A, 11B Control port 12A, 12B, 12C, 12D Pressure port 13A, 13B Return port 2 Guide valve 21A, 21B, 21C, 22A, 22B Switching flow path 23A 23B, 23C, 23D ... throttle flow paths 24A, 24B, 24C, 24D ... discharge flow path 3 ... torque motor section (drive means) 4 ... nozzle flapper valves 41A, 41B ... restriction flow path 5 ... leaf spring (Connecting member) P1, P2, P3, P4 ... Pressure chamber

Claims (2)

(57) [Claims] An open circular plate-shaped guide valve is provided in a housing so as to be rotatable around the center thereof, and a control port provided in the housing is provided on the outer periphery of the guide valve in accordance with the direction of valve rotation. A switching flow path communicating with the return port is formed, and each circumferential end face of the guide valve faces a pressure chamber that communicates with the pressure port through a throttle flow path, and is rotated forward and reverse by driving means. A nozzle flapper valve that forms a restricted flow path is provided, and the communication cross-sectional area of each discharge flow path that connects each of the pressure chambers to the return port is reciprocally associated with rotation of the nozzle flapper valve from a neutral position. The throttle valve is provided in the guide valve, and each pressure port communicating with the throttle channel is connected to the pressure chamber. Provided number, the fluid pressure servo valve, characterized in that each allowed openings in the housing wall which faces the guide valve periphery close to the pressure chambers. 2. A cut-out circular plate-shaped guide valve is provided in a housing so as to be rotatable around its center, and a control port provided in the housing is provided on the outer periphery of the guide valve in accordance with the direction of valve rotation. A switching flow path communicating with the return port is formed, and each circumferential end face of the guide valve faces a pressure chamber that communicates with the pressure port through a throttle flow path, and is rotated forward and reverse by driving means. A nozzle flapper valve that forms a restricted flow path is provided, and the communication cross-sectional area of each discharge flow path that connects each of the pressure chambers to the return port is reciprocally associated with rotation of the nozzle flapper valve from a neutral position. The guide valve is adapted to be changed, and the acting force of each of the pressure chambers is changed according to the change of the communication cross-sectional area of each of the discharge flow paths, so that the guide valve is rotated in the normal and reverse directions. Is coupled to the nozzle flapper valve,
A fluid pressure servo valve provided with a connecting member having elastic restoring force.