JPH06185651A - Fluid valve and its controller - Google Patents

Abstract

PURPOSE:To prevent the compressed deformation of the seated section of a pilot valve body in a flow rate regulating valve by not seating the above seated section onto a pilot valve seat under strong force. CONSTITUTION:When a stepping motor 120 is driven, the torque of its driving shaft 122 is transmitted to the friction disc 136 of a clutch mechanism 130, and further axially moves a pilot valve body 150 through a cylindrical member 140. When the pilot valve body 150 takes its seat at a pilot valve seat 102 to wholly close a pilot valve, and the torque between the friction disc 136 and the cylindrical member 140 therefore becomes above a fixed value, they slide mutually to prevent compressive force above the fixed value from acting on a seated section 159.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid valve for driving a valve body by a motor and a control device therefor.

[0002]

2. Description of the Related Art Conventionally, as a flow control valve of this type, for example, the main valve is opened and closed by opening and closing the main flow path by the main valve and adjusting the pressure of the back pressure chamber facing the main valve by the pilot valve. Those that adjust the degree are known. The pilot valve regulates the pressure in the back pressure chamber by driving the pilot valve element with a motor to sit on or away from the pilot valve seat to introduce or discharge the liquid into or from the back pressure chamber.

In such a pilot valve, a rubber seat portion provided on the pilot valve body is seated on the pilot valve seat, but a force in the valve closing direction is applied even when the pilot valve body is fully closed. If such a valve closing operation is repeated, the seating portion will be dented or damaged. Therefore, a control circuit for stopping the driving of the motor when the seat is fully closed is provided. That is, the control circuit detects the load current value of the motor, and when the value exceeds a predetermined value, determines that the motor is in the step-out state when fully closed and stops driving the motor. is there.

[0004]

However, the torque when the motor is out of step must be considerably large.
For example, in the case of a motor driven with a shaft output of 0.7 kg, a step out does not occur unless torque of 7 kg or more, which is ten times that of the motor, is applied. Therefore, when the valve is closed, the force applied to the seating portion is large, and there is a problem that the secular change is rapid.

The present invention solves the above-mentioned problems of the prior art, and provides a fluid valve and a control device for the fluid valve, in which the seating portion of the valve body does not become tired in a short period of time and has a long life. The purpose is to

[0006]

In order to solve the above-mentioned problems, the invention of claim 1 is characterized in that the valve body is moved forward and backward with respect to the valve seat provided in the flow passage by the driving force of the motor. In the fluid valve for adjusting the opening degree of the valve, the input side member that is provided between the motor and the valve body and receives the driving force of the motor, and the input side member that contacts the valve Clutch means having an output side member that moves the body forward and backward and that does not transmit a moving force to the valve body by sliding with respect to the input side member when a load larger than a predetermined value is applied. To do.

According to a second aspect of the present invention, there is provided a fluid valve for adjusting the opening degree of the flow passage by moving the valve body forward and backward with respect to the valve seat provided in the flow passage by the rotational driving force of the drive shaft of the motor. ,
The input side member connected to the drive shaft side of the motor and the input side member come into contact with each other and rotate due to the frictional force caused by the contact, and when the load exceeds a predetermined value, the input side member slides against the input side member to rotate. And a clutch means having an output side member that does not transmit power, and by changing the rotational force of the drive shaft into a moving force in the axial direction of the valve body by being coupled to the output side member, the valve body is axially moved. And a slide means for moving back and forth.

Further, the invention of claim 3 comprises the drive control means for sending a drive signal to the motor according to claim 2, wherein the drive control means calculates the amount of movement of the valve body from the current position to the changed position. And a movement amount calculation unit that performs a valve closing command, calculates the required movement amount of the valve body to the valve closed position based on the calculated value of the movement amount calculation unit, and moves the calculated value to the valve closed position by a predetermined amount. And a valve closing control unit for driving the motor by adding the amounts.

[0009]

In the fluid valve according to the first aspect of the present invention, when the motor is driven, the driving force is transmitted to the valve body through the clutch means. In the clutch means, the input side member and the output side member come into contact with each other, and the valve body advances and retracts due to the contact force. At this time, when a load larger than a predetermined value is applied to the output side member, the output side member slips with respect to the input side member and does not transmit the moving force to the valve body. Therefore, the valve body does not close with a force greater than the predetermined value against the valve seat because the valve element slides by the clutch means when a load greater than the predetermined value is applied when closing the valve.

Further, in the fluid valve according to the second aspect of the present invention, when the motor is driven, the rotational force of the drive shaft is transmitted to the input side member of the clutch means, and further, between the input side member and the output side member. The driving force is transmitted to the slide means side by the frictional force. By the sliding means, the rotational force of the output side member is converted into a moving force in the axial direction of the valve body, and the valve body moves to the valve seat side. Then, when the valve element is seated on the valve seat, the reaction force from the valve seat is applied as a braking force to the clutch means through the slide means, and when a torque exceeding the braking force is applied, the input side member is output. Slip against. Therefore,
When the valve is closed, the sliding force of the clutch means does not apply a force greater than a predetermined amount to the valve body in the advancing direction thereof, that is, the valve body is not pressed against the valve seat with a force more than the predetermined amount.

Further, the opening degree of the fluid valve in the invention of claim 3 is controlled by drive control means for sending a drive signal to the motor. The drive control unit includes a movement amount calculation unit and an opening / closing control unit. The movement amount calculation unit calculates the movement amount of the valve body from the current position to the changed position. The valve closing control unit drives the motor by adding a predetermined moving amount to the current moving amount between the valve body position and the valve closing position when the valve closing command is issued.
As described above, the opening / closing control unit drives the valve body by a predetermined movement amount more than the movement amount from the current position to the valve closing position at the time of the valve closing command, so that the valve body is pressed against the valve seat. Be sure to sit down at. At this time, the motor is driven even after the valve body is seated, but the driving force is absorbed by the slip by the clutch means, so that the valve body is not strongly pressed against the valve seat.

[0012]

Preferred embodiments of the present invention will be described below in order to further clarify the structure and operation of the present invention described above.

A diaphragm type flow control valve 1 shown in FIG.
Is a main valve mechanism 10 connected to the pipeline and the main valve mechanism 1
And a pilot valve mechanism 100 for controlling zero.

The main valve mechanism 10 includes a valve body 12 having a main flow passage 20. The main flow path 20 has an inlet 2
2 is provided with a primary side flow path 24 including an outlet (not shown), and a main valve 30 is provided between the primary side flow path 24 and the secondary side flow path 26. Main valve seat 1 for sitting
4 are provided.

The main valve 30 includes a diaphragm 32 for the main valve.
And a main valve element 34 supported at the center of the main valve diaphragm 32. Main valve diaphragm 3
2 is a step portion 15 formed on the inner peripheral portion of the valve main body 12 and an upper opening 16 formed on the valve main body 12 at the outer peripheral edge thereof.
It is attached to the valve body 12 by being sandwiched between the lid body 40 and the protruding end portion 41 of the lid body 40. Thus, the primary valve 30 is partitioned by the main valve 30 mounted on the valve body 12, and a part of the primary channel 24 serves as the back pressure chamber 27.

The main valve body 34 is provided with a base portion 35 consisting of a collar portion 37 and a protruding portion 38 protruding from the lower center portion thereof, and a main valve diaphragm 32 is held in a recess 39 at the base of the base portion 35. .

A secondary diaphragm 50 is fixed to the tip of the projecting portion 38 of the main valve body 34 by means of a screw 53 at its central portion via a pressing member 51. In addition, the peripheral portion of the secondary diaphragm 50 is the step portion 1 of the valve body 12.
8 and the disc-shaped tightening tool 60 screwed to the lower opening 17 to clamp the valve body 12 to mount the valve body 12.
The secondary side diaphragm 50 is concentrically arranged opposite to the main valve diaphragm 32, and its pressure receiving surface is formed to have substantially the same diameter as the seat diameter of the flow passage opening of the main valve seat 14.

The primary side flow path 24, the back pressure chamber 27 and the secondary side flow path 26 of the flow rate control valve 1 are connected by a small flow path. That is, the base portion 35 of the main valve body 34
A small flow passage 70 that connects the primary side flow passage 24 and the back pressure chamber 27 is formed on the outer peripheral portion of the main valve diaphragm 32. In addition, a pilot flow passage 72 is formed in the projecting portion 38 of the base portion 35 of the main valve body 34 at the center in the axial direction and further in the radial direction. The back pressure chamber 27 and the secondary side flow path 26 are connected.

The back pressure chamber 2 of the pilot flow path 72
The pilot valve seat 102 is formed on the central upper surface of the main valve body 34 on the seventh side.

The pilot valve mechanism 100 controls the pressure of the back pressure chamber 27 by controlling the opening of the flow passage opening of the pilot valve seat 102. That is, the pilot valve mechanism 100 includes the battery-driven stepping motor 120 housed in the case 124 mounted on the top of the lid 40. The drive shaft 122 of the stepping motor 120 passes through a through hole 45 formed in the partition wall 43 of the lid 40 and is connected to the pilot valve body 150 via the clutch mechanism 130 housed in the clutch chamber 132. There is.

As shown in FIG. 2, the clutch mechanism 130 is in contact with the friction disc 136 attached to the drive shaft 122 with the attachment screw 134 at the outer peripheral portion of the friction disc 136, and the female screw portion 142 is provided at the inner peripheral portion. Cylindrical member 1 provided with
40 and a pilot valve body 150. The pilot valve body 150 includes an upper disc portion 152 having an outer peripheral portion provided with a male screw portion 154 screwed into the female screw portion 142,
A rod-shaped connecting portion 156 protruding from the central portion of the upper disk portion 152, a guide protrusion 158 formed in the central portion of the connecting portion 156, and a rubber seating portion 159 attached to the tip of the connecting portion 156 are provided. I have it. The guide protrusion 158
Is the guide groove 1 of the guide portion 160 formed in the lid 40.
It is supported so as to be guided by 62.

With the structure of the clutch mechanism 130, when the stepping motor 120 rotates, the drive shaft 1
The friction disc 136 rotates via 22. When the friction disk 136 rotates, the tubular member 140 rotates due to frictional contact with the tip of the friction disk 136. When the tubular member 140 rotates, the pilot valve body 150 integrally moves forward and backward in the axial direction together with the upper disk portion 152 screwed to the female screw portion 142. That is, the pilot valve body 150 is regulated by the guide protrusion 158 in the rotation direction by the guide groove 162 of the guide portion 160, and is guided in the axial direction to move back and forth. In this way, by moving the pilot valve body 150 in the closing direction or the opening direction with respect to the pilot valve seat 102,
The opening degree of the flow path opening of the pilot valve seat 102 is changed.

Next, the operation of the flow rate control valve 1 provided with the pilot valve mechanism 100 for performing such an operation will be described. In the flow rate control valve 1, the main valve element 34 supported by the main valve diaphragm 32 changes the opening degree of the main valve seat 14 with respect to the flow passage opening, that is, by changing the opening degree of the main valve 30. The flow rate of the main flow path 20 is adjusted. Main valve 3 above
The opening degree of 0 is the main valve diaphragm 32 and the main valve body 34.
Of the back pressure chamber 27, that is, the force in the closing direction (downward force) by the pressure of the back pressure chamber 27 and the force in the opening direction (upward force) received from the liquid flowing through the main flow path 20 are determined. Here, since the force in the opening direction applied from the primary side flow passage 24 to the main valve 30 depends on the supply pressure of the primary side flow passage 24 and has a substantially constant value, the opening degree of the main valve 30 is equal to the back pressure. It is changed according to the closing force due to the pressure of the chamber 27. Back pressure chamber 2
The pressure of 7 is driven by the stepping motor 120 of the pilot valve mechanism 100 so that the pilot valve body 150 moves back and forth with respect to the pilot valve seat 102 via the clutch mechanism 130, and the opening degree of the pilot valve seat 102 with respect to the flow passage opening is increased. It is controlled by changing.

First, as shown in FIG. 1, from the state where the pilot valve body 150 closes the flow passage opening of the pilot valve seat 102, the pilot valve body 150 is retracted to open the flow passage opening of the pilot valve seat 102. Then, the case of increasing the flow rate of the main flow path 20 will be described.

When a signal is sent from the control device (see FIG. 3) to the stepping motor 120 and the drive shaft 122 and the friction disc 136 rotate, the tubular member 140 rotates and the pilot valve body 150 causes the pilot valve seat 102 to rotate. With respect to the valve opening, the flow path opening of the pilot valve seat 102 is increased. When the opening of the flow passage opening of the pilot valve seat 102 increases, the fluid in the back pressure chamber 27 flows into the secondary side flow passage 26 via the pilot flow passage 72, and the pressure in the back pressure chamber 27 decreases. As a result, the main valve 30 moves upward in the drawing to increase the opening degree of the flow path opening of the main flow path 20, and the main flow path 20
The flow rate of becomes large.

By moving the main valve 30 in the upward direction in the figure, the pilot valve seat 10 provided integrally with the main valve body 34 is provided.
Since 2 also moves to the pilot valve body 150 side, the opening degree of the flow path opening of the pilot valve seat 102 becomes small. As a result, the flow rate from the back pressure chamber 27 to the secondary side flow passage 26 side through the pilot flow passage 72 decreases, and the pressure in the back pressure chamber 27 increases. Then, the main valve 30 is stopped at a position where the force in the closing direction due to the pressure in the back pressure chamber 27 and the force in the opening direction due to the pressure in the primary side flow path 24 balance with each other to maintain the opening degree. Therefore, the flow rate of the main flow path 20 is determined by the opening degree of the main valve 30.

On the other hand, a case will be described in which the pilot valve body 150 is moved toward the closing side with respect to the flow passage opening of the pilot valve seat 102 to reduce the flow rate of the main flow passage 20. When the drive shaft 122 of the stepping motor 120 is driven in the opposite direction to the above, the operation of the clutch mechanism 130 causes the pilot valve body 150 to advance to the pilot valve seat 102 side, and the opening degree of the flow passage opening of the pilot valve seat 102 is increased. Get smaller. As a result, the flow rate from the back pressure chamber 27 to the secondary side flow passage 26 through the pilot flow passage 72 decreases. On the other hand, since the liquid in the primary side flow passage 24 flows into the back pressure chamber 27 via the small flow passage 70, the pressure in the back pressure chamber 27 rises. Therefore, the main valve 30 moves in the closing direction, and the flow rate of the main flow path 20 decreases. The flow rate of the flow rate control valve 1 is adjusted by the operation of the pilot valve mechanism 100.

When the pilot valve body 150 is seated on the pilot valve seat 102 in the valve closing operation of the pilot valve body 150, the movement of the pilot valve body 150 in the closing direction is restricted. In this state, in the clutch mechanism 130, when the torque for rotating the pilot valve body 150 exceeds the frictional force between the friction disc 136 and the tubular member 140 due to the driving force of the stepping motor 120, the friction disc 136 is rotated. The sliding member 140 slides. As a result, the pilot valve body 150 is not applied with a moving force in the direction of the pilot valve seat 102. Therefore,
When the pilot valve seat 102 is fully closed, the rubber seating portion 159 at the tip of the pilot valve body 150 receives no further moving force. Therefore, the seating portion 159 does not sag due to a strong repetitive compressive force, and thus has excellent durability.

Next, a control device for controlling the opening / closing of the flow rate control valve 1 and its control process will be described. As shown in FIG. 3, the flow rate control valve 1 is controlled by a control device including an electronic control circuit 200 and the like. The electronic control circuit 200 is
A well-known CPU 202, ROM 204, RAM 206, and input / output interface 208 are provided, and control processing is executed while inputting / outputting with an external device via the input / output interface 208. As the external device, the stepping motor 120 driven via a drive circuit 210 is used.
A water stop button 212 for outputting a command to stop the flow control valve 1, a water stop sensor 214 for detecting that the flow control valve 1 is stopped by the flow rate on the downstream side, and a flow control valve. An opening degree command unit 216 for issuing a command to increase / decrease the flow rate to 1 is provided.

The flow rate control of the flow rate control valve 1 by this control device is executed by an opening / closing process shown in the flowchart of FIG. 4 by a program stored in advance in the ROM 204. First, in the first step S100, the current opening θ
Initialization processing such as setting of 0 to 0 is performed, and step S1
Go to 05. In step S105, the water stop button 212
It is determined whether or not is turned on, and when it is determined that it is not turned on, the process proceeds to step S110.

In step S110, the deviation from the opening commanded by the previous opening commander 216, that is, the operation opening α is read. Continued Step S115
Then, the target opening θm is obtained by adding the operation opening α to the current opening θ.
Is calculated. In the next step S120, the operation opening α
The driving pulse number p to the stepping motor 120 corresponding to is calculated, and the process proceeds to step S125. Step S1
At 25, it is determined whether the target opening θm is 0 or less, that is, whether the target opening θm is fully closed. When it is determined in the process of step S125 that the command is the full close command, in step S130, the drive pulse number p is calculated by adding the added pulse number n, while it is determined that the command is not the full close command in the process of step S125. If it is done, step S1
Move to 35. In subsequent step S135, the driving pulse number p calculated in the above process is output to the stepping motor 120.

In the subsequent step S140, the water stop sensor 2
Based on the signal from 14, it is determined whether or not the water has stopped. If it is determined that the water has stopped, the current opening θ is set to 0 in step S145, and then the step On the other hand, if it is determined that the water is not stopped, on the other hand, in step S147, the current opening θ is set to
After setting the target opening θm, the process returns to step S105.

On the other hand, when it is determined in step S105 that the water stop button 212 is turned on, step S1
In step 50, the number p of drive pulses until the valve is closed corresponding to the current opening θ is calculated. After that, the process proceeds to step S130, the added pulse number n is added, and the water stop process by the stepping motor 120 from step S135 to step S145 described above is executed.

Therefore, when the water stop command is output from the opening degree command unit 216, or when the water stop button 212 is pressed, the pilot valve mechanism 100 adds the drive pulse number p until the valve is fully closed to the pulse number n added. The water stop operation will be executed with the movement amount added. Thus, the number of added pulses n
Therefore, the pilot valve body 150 of the pilot valve mechanism 100 is
2 can be completely closed in a pressed state, and water can be surely stopped. At this time, the movement amount of the pilot valve body 150 is set to be larger by the number of added pulses n. However, when the pilot valve body 150 is fully closed, the stepping motor 12
Even if 0 is driven further, this driving force slips by the clutch mechanism 130 and does not become the moving force of the pilot valve body 150. As a result, the rubber seat 159 does not receive a strong compressive force when it is fully closed, and therefore has excellent durability without sagging.

Next, another embodiment shown in FIG. 5 will be described. FIG. 5 shows an embodiment in which the clutch mechanism 180 of the pilot valve mechanism 100A is changed from a disc type to a spring type. The clutch mechanism 180 is a stepping motor 120.
Cylinder member 182 fixed to the outer periphery of the drive shaft 122, the coil spring 186 held by a step 184 formed on the inner periphery of the cylinder member 182, and the connection pressed by the lower end of the coil spring 186. The member 190, the screw member 192 that rotates integrally with the connecting member 190, and the screw member 192.
And a slide member 194 that has a female screw that is screwed into a male screw on the outer circumference of the slide member and that is slidably supported in the axial direction. The upper end of the pilot valve body 150 is fixed to the center of the slide member 194 with a fixing member 196.

With this configuration, the stepping motor 12
When 0 rotates, the tubular member 182 rotates via the drive shaft 122. By the rotation of the tubular member 182, the coil spring 1
86 rotates, and its lower end and the upper end surface 1 of the connecting member 190.
The screw member 192 rotates integrally due to the frictional force with 91. Then, the rotation of the screw member 192 causes the slide member 194 to move in the axial direction. As a result, the pilot valve body 150 moves back and forth in the axial direction.

The seating portion 1 of the pilot valve body 150
When 59 (refer to the drawing) is seated on the pilot valve seat 102 and is in the fully closed state and the load torque exceeds a predetermined value, the coil spring 186 slides with respect to the upper end surface 191 of the connecting member 190 and the pilot valve body It does not act as a moving force of 150 in the axial direction. That is, with the configuration of the clutch mechanism 180, the pilot valve body 15 can be operated when a load torque of a predetermined value or more is applied while the driving force is buffered by the coil spring 186.
It is possible to obtain the effect of not applying an excessive moving force in the axial direction to 0.

In the above embodiment, as the clutch mechanism, the disk friction means shown in FIG. 1 and the spring type friction means shown in FIG. 5 have been described. However, the present invention is not limited to this, and the load torque exceeds a predetermined value. In that case, the structure is not particularly limited as long as it does not transmit the driving force.

[0039]

As described above, according to the present fluid valve,
By providing the clutch means between the motor and the valve body, when a load more than a predetermined amount is applied to the valve body when the valve is closed,
The valve means does not sit on the valve seat with a force greater than a predetermined value due to slipping by the clutch means. Therefore, the seated portion of the valve body is not pushed against the valve seat with a strong force, and the seated portion does not sag, which is excellent in durability.

According to the invention of claim 2, there is provided a slide means for changing the rotational driving force of the motor in the axial direction of the valve body, and the clutch means is provided between the slide means and the drive shaft of the motor. Since the sliding means moves the valve body forward and backward in the axial direction with a small amount of movement, and the clutch means does not apply a valve closing force greater than a predetermined value to the valve body, the durability is excellent as in claim 1. There is.

Further, in the fluid valve according to the invention of claim 3, drive control means for sending a drive signal to the motor is provided, and the drive control means includes a movement amount calculation section and an opening / closing control section. The movement amount calculation unit calculates the movement amount from the current position of the valve body to the changed position, and the valve closing control unit determines the valve closing time based on the position of the valve body calculated by the movement amount calculation unit. ,
The motor is driven by adding a predetermined amount of movement to the current amount of movement to the valve body position and the valve closing position. In this way, the opening / closing control unit drives the valve body more than the predetermined movement amount from the movement amount from the current position to the valve closing position at the time of the valve closing command, so that the valve element is reliably pressed in the state of being pressed against the valve seat. Sit down. At this time, the motor is driven even after the valve body is seated, but the driving force is absorbed by the slip by the clutch means, so that the valve body is not strongly pressed against the valve seat.

[Brief description of drawings]

FIG. 1 is a sectional view showing a flow control valve according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a clutch mechanism of the embodiment and its peripheral portion.

FIG. 3 is a configuration diagram showing a control circuit of a flow control valve according to the embodiment.

FIG. 4 is a flowchart showing flow rate and water stop control of the flow rate control valve according to the embodiment.

FIG. 5 is a cross-sectional view showing a pilot valve and its peripheral portion in a flow rate control valve according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Flow control valve 10 ... Main valve mechanism 12 ... Valve main body 14 ... Main valve seat 15 ... Step part 16 ... Upper opening 17 ... Lower opening 18 ... Step part 20 ... Main flow path 22 ... Inflow port 24 ... Primary side flow path 26 Secondary side flow passage 27 Back pressure chamber 30 Main valve 32 Main valve diaphragm 34 Main valve body 35 Base portion 37 Collar 38 Protrusion 39 Recess 40 Lid 41 Protruding end 43 ... Partition wall 45 ... Through hole 50 ... Secondary diaphragm 51 ... Pressing member 53 ... Screw 60 ... Fastening tool 70 ... Small flow passage 72 ... Pilot flow passage 100 ... Pilot valve mechanism 100A ... Pilot valve mechanism 102 ... Pilot valve seat 120 ... Stepping motor 122 ... Drive shaft 130 ... Clutch mechanism 134 ... Mounting screw 136 ... Friction disc 140 ... Cylindrical member 142 ... Female threaded portion 150 ... Pilot valve body 152 ... Upper disc portion 54 ... Male screw part 156 ... Connection part 158 ... Guide protrusion 159 ... Seating part 160 ... Guide part 162 ... Guide groove 180 ... Clutch mechanism 182 ... Cylindrical member 184 ... Step part 186 ... Coil spring 190 ... Connection member 191 ... Upper end surface 192 ... Screw member 194 ... Sliding member 196 ... Fixing member 200 ... Electronic control circuit 202 ... CPU 204 ... ROM 206 ... RAM 208 ... Input / output interface 210 ... Drive circuit 212 ... Water stop button 214 ... Water stop sensor 216 ... Opening command Department

Claims (3)

[Claims] 1. A fluid valve for adjusting the opening degree of the flow passage by advancing and retracting the valve body with respect to a valve seat provided in the flow passage by a driving force of a motor, the valve being provided between the motor and the valve body. The input side member that receives the driving force of the motor and the input side member are brought into contact with each other, the force is applied by the contact to move the valve body forward and backward, and the input side member is moved when a load of a predetermined amount or more is applied. And a clutch means having an output side member that does not transmit a moving force to the valve body by sliding against the valve body, and a fluid valve. 2. A fluid valve for adjusting the opening degree of the flow passage by advancing and retracting the valve body with respect to a valve seat provided in the flow passage by the rotational driving force of the drive shaft of the motor, wherein An input-side member connected to the output-side member, which comes into contact with the input-side member and rotates due to the frictional force due to the contact and which does not transmit the rotational force by sliding on the input-side member when a load larger than a predetermined value is applied. And a sliding means that is coupled to the output side member and that changes the rotational force of the drive shaft into a moving force in the axial direction of the valve element to move the valve element in the axial direction. A fluid valve comprising: 3. The drive control means for transmitting a drive signal to the motor according to claim 2, wherein the drive control means includes a movement amount calculation section for calculating a movement amount of the valve body from a current position to a changed position, At the time of the valve closing command, the necessary moving amount of the valve body to the valve closing position is calculated based on the calculated value of the moving amount calculating unit, and the predetermined moving amount is added to the calculated value up to the valve closing position. A control device for a fluid valve having a valve closing control unit for driving a motor.