JPH0438924B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a digital valve that can control the movement position of a valve member in the axial direction using an electric pulse motor to control fluid, and in particular, This invention relates to a digital valve equipped with a neutral position setting device for a motor shaft that rotates in reverse.

[Conventional technology]

Conventionally, this type of digital valve was developed in 1988.
A configuration as shown in Publication No. 19105 is known,
Both end arms of a torsion coil spring fitted externally on the motor shaft of the electric pulse motor are engaged with two fixing pin members provided on the valve body side, and the end arms of the torsion coil spring are connected to the motor shaft side. By engaging the two provided movable pin members, the motor shaft can be set to a desired neutral position by the mounting elastic force of the torsion coil spring, and the motor shaft can be set to a desired neutral position according to the rotation of the motor shaft from the neutral position. The movable pin member is provided so that elastic force for return action can be obtained by twisting the torsion coil spring.

[Problem that the invention seeks to solve]

However, since the neutral position of the motor shaft is set by two movable pin members and a fixed pin member that engage with the arms at both ends of the torsion coil spring, the positions of the movable and fixed pin members are the same. Otherwise, there would be play in the motor shaft when setting it to the neutral position, and there would be a problem that it would be difficult to maintain the accurate setting of the motor shaft at the neutral position.

The present invention solves these problems, and has two
The neutral position of the motor shaft is set by applying the elastic forces of the two springs in opposition to each other, and the accurate setting and maintenance of the motor shaft at the neutral position can be obtained, thereby improving the accuracy of position control of the valve member in response to electric pulse signals. The company provides a digital valve with a built-in digital valve.

[Means for Solving the Problems] For this reason, the present invention provides a valve member that is fitted into a valve body and controls fluid by moving in the axial direction, and a valve member that applies elastic force to the valve member to move the valve member in one direction. an electric pulse motor that rotates forward and backward in response to an electric pulse signal; and a first spring that is connected to the motor shaft of the electric pulse motor to move the valve member in the axial direction according to the rotation of the motor shaft. a displacement member that moves to a target position; a rotation transmission member that is provided to be able to rotate integrally with the motor shaft only when the motor shaft rotates in one direction; a second spring for restoring the rotation in the first direction;
The valve member and the displacement member are arranged in eccentric engagement so that rotational force is generated in the displacement member due to the elastic force of the spring, and the rotational force due to the elastic force of the first spring and the second spring is transferred to the motor shaft. The rotational force of the second spring is made larger than the rotational force of the first spring, and the rotation of the rotation transmission member due to the elastic force of the second spring can be stopped.

[Effect]

In such a structure of the present invention, a rotational force is applied to the motor shaft in opposition due to the elastic force of the first spring applied to the valve member and the elastic force of the second spring applied to the rotation transmission member. Since the play at the neutral position can be made substantially zero, the motor shaft can be easily set and maintained accurately at the neutral position, and the accuracy of position control of the valve member in response to electric pulse signals can be improved.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIG. 1, 1 is a valve body, which has a supply flow path P for supplying pressure fluid, a pair of load flow paths A and B connected to the fluid actuator side, and a discharge flow path R connected to the low pressure side, A valve member 3 is slidably fitted into a fitting hole 2 bored inside and communicating with each flow path. The valve member 3 is provided so as to be able to switch and control the flow direction of the fluid by blocking communication between the flow paths P, A, B, and R by moving in the axial direction. 4 is the valve member 3
This is a first spring for restoring movement in one direction, and is provided so as to be fitted onto the valve member 3 so as to apply elastic force to the valve member 3 in the left direction in the figure via the spring receiving member 5. Reference numeral 6 indicates a pin member for preventing rotation of the valve member 3, and reference numeral 7 indicates a roller member, which is rotatably mounted on an axis at the end of the valve member 3 with its outer peripheral portion protruding from the end face of the valve member. Reference numeral 8 indicates a neutral position setting device for the motor shaft, reference numeral 9 indicates an electric pulse motor that rotates in forward and reverse directions according to electric pulse signals, and reference numeral 10 indicates an output shaft connected to the motor shaft 11 of the electric pulse motor 9, which is connected to the roller of the valve member 3. It is rotatably mounted to the device main body 12 through bearing members 13 and 14 at a right angle to the axis of the valve member 3 on the outside of the side having the member 7. 1
5 is a cam-shaped displacement member, which is integrally attached to the output shaft 10 so as to abut and engage with the roller member 7 of the valve member 3; The second one is designed to receive the force and generate a rotational force in the counterclockwise direction (arrow F) when viewed from above in the figure.
As shown in the figure, it is provided so as to abut and engage with the outer circumferential surface of the roller member 7 at a contact point Y. Reference numeral 17 denotes a rotation transmission member which is rotatably fitted onto the output shaft 10 through a bearing member, and when the output shaft 10 is rotated counterclockwise when viewed from above in the figure, the output shaft 10 is rotated by engagement with the pin member 16. The output shaft 10 rotates integrally with the output shaft 10.
It is provided so that it can be relatively rotated when it is rotated clockwise. The rotation transmission member 17 has a bearing member 18 eccentrically installed on its outer periphery as shown in FIG.
The elastic force of the second spring 20 is applied to the outer circumferential surface of the output shaft 10 from the radial direction via the piston member 19 to reduce the F generated on the output shaft 10 due to the elastic force of the first spring 4.
It is provided so that a rotational force in the direction of arrow F' that acts opposite to the rotational force in the direction is generated. The second spring 20 is provided so that the rotational force generated on the motor shaft 11 due to the elastic force of each spring is stronger than that of the first spring 4. Reference numeral 21 denotes a stop member screwed onto the main body 12 of the apparatus, and as shown in FIG. The rotation of the rotation transmission member 17 in the F' direction can be stopped. Note that the stop member 21 may be integrally formed with a member constituting the device main body 12.

Next, the operation of this configuration will be explained.

1 to 4 show a state in which the electric pulse motor 9 is not operated, and the motor shaft 11 receives the rotational force of the opposing action caused by the elastic force of the first spring 4 and the second spring 20, and the stop member 21 The rotation transmitting member 17 is set and held at the stop position, that is, the neutral position. The valve member 3 blocks off the flow paths P, A, B, and R. Now, from this state, when an electric pulse signal is applied to the electric pulse motor 9 and the motor shaft 11 is rotated clockwise when viewed from above in the drawing, the displacement member 15 is rotated as the output shaft 10 rotates in the same direction. The valve member 3 is pressed and moved to a target position in the right direction in the figure through the roller member 7 against the first spring 4, and the valve member 3 switches and communicates the flow paths to control the fluid. At this time, the rotation transmission member 17 remains at the position stopped by the stop member 21 because the pin member 16 is rotated in the direction in which the engagement state is released.

Next, when the applied signal to the electric pulse motor 9 is cut off, the elastic force of the first spring 4 causes the valve member 3 to move back to its original position, and rotational force is generated in the displacement member 15, so that the output shaft 10 is pinned. The member 16 rotates back to its original position where it engages with the rotation transmitting member 17, and the motor shaft 11 is set and held at the neutral position.

Further, from the illustrated state, when an electric pulse signal is applied to the electric pulse motor 9 and the motor shaft 11 is rotated counterclockwise when viewed from above in the figure, as the output shaft 10 rotates in the same direction, the first Due to the elastic force of the spring 4, the valve member 3 is moved along the cam shape of the displacement member 15 to a target position in the left direction in the figure, and performs fluid control between the flow paths P, A, B, and R, and rotates the rotation transmitting member. 17 is the output shaft 10 by engagement with the pin member 16.
The second spring 20 is rotated integrally against the rotational force caused by the elastic force of the second spring 20. At this time, the protrusion 22 of the rotation transmission member 17 rotates in a direction in which it is disengaged from the stop member 21. Next, the electric pulse motor 9
When the applied signal is cut off, the rotation force of the second spring 20 causes the rotation transmission member 17 to move along with the output shaft 10 via the pin member 16, and the protrusion 22 moves to the stop member 2.
It is rotated back to the original position where it engages with 1. Due to the return rotation of the output shaft 10, the valve member 3 is returned to its original position via the displacement member 15 against the first spring 4,
The motor shaft 11 is set and held at a neutral position.

In this operation, in order to set the motor shaft 11 of the electric pulse motor 9 to the neutral position, the motor shaft 11 is moved to the set position by stopping the rotation due to the elastic force of the second spring 20 of the rotation transmission member 17. 1 spring 4
Since this is done by rotating and stopping by the rotational force of the opposing action of the second spring 20, the play in the neutral position of the motor shaft 11 is not affected by errors in machining or assembly of each component. It is possible to make it substantially zero, and it is possible to easily maintain the accurate setting of the motor shaft 11 at the neutral position, thereby improving the accuracy of position control of the valve member 3 in response to the electric pulse signal.
Further, by providing the stop member 21 and the protrusion 22 at different contact positions, the rotation stop position of the rotation transmission member 17 is changed, and the neutral position of the motor shaft 11 can be accurately set to a desired position.

5 and 6 show other embodiments of the present invention,
The same members as in the first embodiment are given the same reference numerals, and only different points will be explained.

The rotation transmission member 23 is externally fitted onto the output shaft 10 so that it can rotate integrally only when the output shaft rotates in one direction.
A pin member 25 is provided to protrude from the outer circumferential side surface of the disc-shaped flange 24. Reference numeral 26 denotes a torsion coil spring as a second spring that applies a rotational force for a return action to the rotation transmission member 23, and has one end arm on the pin member 25 of the rotation transmission member 23 and the other end arm on the device 12 side. The rotational force in the F″ direction that acts opposite to the rotational force in the F direction generated on the output shaft 10 due to the elastic force of the first spring 4 that engages with the member 27 and applies to the valve member 3 is transmitted to the rotation transmission member. 23.The rotation transmitting member 2
3 is a torsion coil spring 26 when the pin member 25 engages with a stop member 28 provided on the device main body 12 side.
This makes it possible to stop rotation in the F″ direction.

With this configuration, the motor shaft 11 connected to the output shaft 10 receives the opposing rotational force caused by the elastic force of the first spring 4 and the torsion coil spring 26 when the electric pulse motor 9 is not operated. The rotation transmitting member 23 is stopped by the stop member 21, so that it is set and held at the neutral position, and it rotates forward and backward in response to the electric pulse signal to the electric pulse motor 9, so that the same effect as in the first embodiment is obtained. It will be done.

〔Effect of the invention〕

As described above, according to the present invention, the valve member is fitted into the valve body and performs fluid control by moving in the axial direction;
A first spring that applies an elastic force to the valve member to restore movement of the valve member in one direction, an electric pulse motor that rotates forward and backward in response to an electric pulse signal, and a motor shaft of the electric pulse motor that is connected to the first spring. a displacement member that moves the valve member to a target position in the axial direction according to the rotation of the motor shaft; a rotation transmission member that is provided so as to be able to rotate integrally with the motor shaft only when the motor shaft rotates in one direction; a second spring that applies force to the rotation transmission member to restore rotation of the rotation transmission member in one direction; and a valve member that generates rotational force in the displacement member due to the elastic force of the first spring. and a displacement member are disposed in eccentric engagement with each other, and the rotational force caused by the elastic force of the first spring and the second spring is applied oppositely to the motor shaft, and the rotational force due to the second spring is greater than the rotational force due to the first spring. By making it possible to stop the rotation of the rotation transmission member by the elastic force of the second spring, the rotational force for rotating the motor shaft to the neutral position and stopping it is reliably applied to the motor shaft, and the motor The play at the neutral position of the shaft can be made substantially zero, making it easy to accurately set and maintain the motor shaft at the neutral position, thereby improving the accuracy of position control of the valve member in response to electric pulse signals.

Furthermore, since the motor shaft can be accurately set and maintained at the neutral position, it is possible to easily set the valve performance to the optimum value depending on the application, which is an excellent practical effect.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view of a digital valve showing an embodiment of the present invention, and FIGS. 2 to 4 are lines taken along the line in FIG.
, FIG. 5 is a longitudinal sectional view of the main part of a digital valve showing another embodiment, and FIG. 6 is a sectional view taken along line - of FIG. 5. DESCRIPTION OF SYMBOLS 1... Valve body, 3... Valve member, 4... First spring, 9... Electric pulse motor, 11... Motor shaft, 15... Displacement member, 17, 23... Rotation transmission member, 20, 26 ...Second spring, 21, 28...
Stopping member.

Claims (1)

[Claims] 1. A valve member that is inserted into the valve body and performs fluid control by moving in the axial direction, a first spring that applies elastic force to the valve member to restore movement of the valve member in one direction, and an electric pulse signal. an electric pulse motor that rotates in forward and reverse directions depending on a rotation transmission member provided to be rotatable integrally with the motor shaft only when the rotation transmission member rotates, and a second spring that applies elastic force to the rotation transmission member to restore rotation of the rotation transmission member in one direction; The valve member and the displacement member are disposed in eccentric engagement so that rotational force is generated in the displacement member due to the elastic force of the first spring, and the first spring and the second spring are arranged in eccentric engagement with each other.
The rotational force caused by the elastic force of the spring is applied oppositely to the motor shaft, and the rotational force of the second spring is set to be larger than the rotational force of the first spring, so that it is possible to stop the rotation of the rotation transmission member due to the elastic force of the second spring. A digital valve characterized by the fact that it is equipped with a.