JP2021085418A - Electrically-driven flow regulation valve - Google Patents

Abstract

To provide a structure in which ramp control is made possible by preventing an increase of a friction force to a motor during closing of a valve body and avoiding not only a problem of current consumption but also an adverse influence on a process with heating of the motor.SOLUTION: A valve body 40 is connected to and held by a valve body holding shaft part 50 which is fitted into a holding chamber 30. The valve body holding shaft part includes an engage space part 55 and is energized closer to a valve chamber 20 constantly by a spring member 52. An actuation shaft 70 of an electric drive mechanism 60 includes a tip engage part 73 provided in a tip of a flexible wire part 72 which is connected to a forward/backward movable part 71, and engaged via the engage space part. When backward moving or stopping the valve body, the valve body holding shaft part is moved backward or stopped against an energizing force of the spring member. When forward moving the valve body, the valve body holding shaft part is moved forward together with the energizing force of the spring member. When the valve body closes a valve seat 25 with the energizing force of the spring member, in the engage space of the valve body holding shaft part, a clearance part S is generated in the tip engage part of the actuation shaft closer to the valve chamber.SELECTED DRAWING: Figure 2

Description

The present invention relates to an electric flow rate control valve, and more particularly to a flow rate control valve operated by a direct-acting stepping motor.

For example, a needle valve operated by an electric direct-acting stepping motor is known as a flow rate control valve used in semiconductor manufacturing equipment (see Patent Document 1). Since the electric type uses electricity as a drive source and is operated by electric control, there is a large degree of freedom in the maintenance of the device, and there is an advantage that the flow rate can be easily changed by remote control or process (processing target). is there.

The electric needle valve 100 shown in FIGS. 12 and 13 is integrally arranged with the diaphragm 145 in the valve chamber 120 at the front of the housing 111 by the linear motion shaft 160 of the linear motion stepping motor 170 arranged at the rear of the housing 111. This is a flow rate adjusting valve that adjusts the opening degree of the valve seat 125 by separating the needle portion 141 of the valve body 140 from the valve seat 125. Reference numeral 121 is an inflow portion of the controlled fluid, 122 is an outflow portion thereof, 146 is a diaphragm fixing member for fixing the diaphragm 145, and 147 is a ventilation hole.

A holding chamber 130 is provided at the rear of the valve chamber 120, and a shaft body portion 150 connected to the valve body 140 is fitted coaxially and retreatably in the circumferential direction by a spline fitting structure. ing. The shaft body portion 150 is connected to the linear motion shaft 160 of the linear motion type stepping motor 170 at the rear portion, and the shaft body portion 150 is always urged rearward (in the direction opposite to the valve chamber 120) by the spring member 152. Has been done. Therefore, when the linear motion shaft 160 of the stepping motor 170 advances, the shaft body portion 150 advances against the urging force of the spring member 152 by the driving force of the motor, and the valve body 140 connected to the shaft body portion 150 is valved. Bring it closer to the seat 125 direction. When the linear motion shaft 160 of the stepping motor 170 retracts, the shaft body portion 150 retracts due to the urging force of the spring member 152, and the valve body 140 retracts and separates from the valve seat 125.

In each figure, reference numeral 115 is a heat radiation groove formed in the outer wall portion 112 of the housing, and 135 is a gas inflow port that is purged as necessary so that the corrosive gas that has passed through the diaphragm does not corrode the metal motor or shaft member. Yes, 136 is also its gas outflow port. Reference numeral 151 denotes a shaft body side spring receiving portion for the spring member 152, and reference numeral 153 is a spring receiving portion on the diaphragm fixing member side. Regarding the stepping motor 170, 171 is a rotor, 172 is a shaft for advancing and retreating the linear motion shaft 160, and 173 is a wiring portion of the stepping motor 170.

In the conventional flow rate control valve 100, the shaft body portion 150 is advanced by driving the stepping motor 170, and the valve body 140 is brought close to the valve seat 125 to adjust the valve opening degree. Since it is mounted, an upward load is applied to the rotor screw portion in the motor when the motor is fully closed, and the frictional force increases. If the valve seat is excessively pressed when the valve seat is closed too tightly, problems such as durability of the flow control valve and generation of particles may occur.

Further, even when the shaft body portion 150 or the valve body 140 thermally expands in the closed state, an upward load is applied and the frictional force increases. Then, even if a drive signal (current) for moving the valve in the opening direction is supplied to the motor 170 in the next operation, the motor 170 may not move. This is so-called "step-out" in which the stepping motor loses the load and does not move.

Further, in the conventional electric flow rate control valve, the valve closing force is the force of the motor, and it is necessary to maintain the excitation of the motor in order to maintain the fully closed sealing force of the valve seat. However, this may cause not only the problem of current consumption but also the problem that when the motor heats up and the conditions are bad, the heat is transferred to the diaphragm and the temperature of the controlled fluid is raised. In the case of fluids used in semiconductor manufacturing, the chemical reaction changes depending on the flow rate, time, and temperature of the fluid, so there is a great concern that the heat generated by the motor will adversely affect the process.

From the above situation, in the conventional electric flow control valve, avoiding the valve seat fully closed, the position of the shaft body is grasped by counting the drive pulse to the origin sensor and the stepping motor, and the valve seat is fully closed. The current situation is that it is used with a "stop" just before closing. However, with such a size stop, there is a problem that it is not possible to control a minute flow rate or start up from zero flow rate.

Jitsuto 3165083 Gazette

The present invention has been made in view of the above points, and prevents an increase in frictional force on the motor when the valve body of the electric flow control valve is closed to prevent step-out, and not only a problem of current consumption. , Avoids adverse effects on the process due to heat generation of the motor, and there is no need to "stop" before the valve seat is fully closed, enabling lamp control such as minute flow rate control and start-up from zero flow rate. It provides a new structure of an electric flow rate control valve.

That is, in the invention of claim 1, the valve body arranged integrally with the diaphragm in the valve chamber at the front of the housing is advanced and retracted with respect to the valve seat by the operating shaft of the electric drive mechanism to increase the opening degree with the valve seat. In the flow control valve to be adjusted, the valve body is connected and held to a valve body holding shaft portion that is coaxially fitted into the holding chamber at the rear of the valve chamber so as not to rotate in the circumferential direction, and the valve body holding shaft portion is held. Has an engaging space at the rear portion, and is constantly urged toward the valve chamber side by a spring member interposed between the holding shaft portion side spring receiving portion and the drive mechanism side spring receiving portion. A shaft is provided at the tip of the wire portion, an advancing / retreating portion that advances / retreats in a linear direction by driving the electric drive mechanism, a flexible wire portion that is connected to the advancing / retreating portion and advances / retreats together with the advancing / retreating portion. It has a valve body holding shaft portion and a tip engaging portion that engages via an engaging space portion, and when the valve body retracts or stops, the tip engaging portion of the operating shaft engages the wire portion. By retracting or stopping through the valve body holding shaft portion and engaging with the locking portion of the engaging space portion of the valve body holding shaft portion, the valve body holding shaft portion is retracted or stopped against the urging force of the spring member. , The valve body is separated from the valve seat, and when the valve body advances, the tip engaging portion of the operating shaft is advanced via the wire portion and is positioned in the engaging space portion of the valve body holding shaft portion. Then, when the valve body holding shaft portion is advanced together with the urging force of the spring member to bring the valve body closer to the valve seat and the valve body closes the valve seat by the urging force of the spring member. The electric flow control valve is characterized in that the space of the engaging space portion of the valve body holding shaft portion is configured to have a gap portion on the valve chamber side of the tip engaging portion of the operating shaft. ..

The invention of claim 2 relates to the electric flow rate control valve according to claim 1, wherein the electric drive mechanism and the housing are separated from each other.

The invention of claim 3 relates to the electric flow rate control valve according to claim 1 or 2, wherein the advancing / retreating portion of the operating shaft is non-rotatably inserted into the shaft sliding portion of the electric drive mechanism.

The invention of claim 4 relates to the electric flow rate control valve according to any one of claims 1 to 3, wherein the wire portion of the operating shaft is slidably fitted in the protective member made of fluororesin. ..

According to the electric flow control valve according to the invention of claim 1, the valve seat is moved back and forth with respect to the valve seat by moving the valve body integrally arranged with the diaphragm in the valve chamber at the front of the housing by the operating shaft of the electric drive mechanism. In the flow control valve that adjusts the opening degree of the valve body, the valve body is connected and held to a valve body holding shaft portion that is coaxially fitted in the holding chamber at the rear of the valve chamber so as not to rotate in the circumferential direction. The valve body holding shaft portion has an engaging space portion at the rear portion, and is always urged toward the valve chamber side by a spring member interposed between the holding shaft portion side spring receiving portion and the drive mechanism side spring receiving portion. An advancing / retreating portion in which the operating shaft advances / retreats in a linear direction by driving the electric drive mechanism, a flexible wire portion connected to the advancing / retreating portion and advancing / retreating together with the advancing / retreating portion, and the wire portion. It has a tip engaging portion provided at the tip of the valve body and engaging with the valve body holding shaft portion via an engaging space portion, and when the valve body is retracted or stopped, the tip engaging portion of the operating shaft is provided. Is retracted or stopped via the wire portion and engages with the locking portion of the engaging space portion of the valve body holding shaft portion, whereby the valve body holding shaft portion is held against the urging force of the spring member. The valve body is retracted or stopped to separate the valve body from the valve seat, and when the valve body is advanced, the tip engaging portion of the operating shaft is advanced via the wire portion to engage the valve body holding shaft portion. The valve body holding shaft is moved forward together with the urging force of the spring member so as to be close to the valve seat, and the urging force of the spring member causes the valve body to move the valve. When the seat is closed, the valve body is valved because the space of the engagement space portion of the valve body holding shaft portion is configured to have a gap on the valve chamber side of the tip engaging portion of the operating shaft. It is not necessary to maintain the excitation of the motor to maintain the fully closing force with respect to the seat or the fully closing sealing force of the valve seat, the valve seat is not over-compressed, and the problems associated with this, that is, Not only the problem of current consumption but also various problems related to the temperature rise of the controlled fluid due to the heat generation of the motor can be solved at once. Further, it is not necessary to "stop" before the valve seat is fully closed as in the conventional case, and it is possible to control a minute flow rate and control the lamp such as starting from zero flow rate.

According to the electric flow rate control valve according to the invention of claim 2, in the invention of claim 1, since the electric drive mechanism and the housing are separated from each other, it is not necessary to provide heat radiating means in the housing and the structure is simplified. It is possible to reduce the size of the housing and the size of the housing, improve the replacement characteristics, and place it away from the explosion-proof area and high-temperature area. The effect can be avoided.

According to the electric flow rate control valve according to the invention of claim 3, in the invention of claim 1 or 2, the advancing / retreating portion of the operating shaft is non-rotatably fitted into the shaft sliding portion of the electric drive mechanism. Therefore, the advancing / retreating portion can be appropriately advanced / retreated in the linear direction.

According to the electric flow rate control valve according to the invention of claim 4, in the inventions of claims 1 to 3, the wire portion of the operating shaft is slidably fitted in the protective member made of fluororesin. In addition to preventing damage and deterioration of the part, the wire part is easy to slide and does not hinder the advancement and retreat.

It is the schematic of the installation state of the electric flow rate control valve which concerns on one Embodiment of this invention. It is a vertical sectional view at the time of opening of the electric flow rate control valve of FIG. It is a vertical sectional view at the time of closing the electric flow rate control valve of FIG. FIG. 2 is a cross-sectional view taken along the line AA of FIG. FIG. 2 is a cross-sectional view taken along the line BB of FIG. FIG. 2 is an enlarged cross-sectional view of a main part at the time of valve opening shown in FIG. It is an enlarged sectional view of the main part which shows the moving state of a valve body. FIG. 3 is an enlarged cross-sectional view of a main part at the time of valve closing shown in FIG. It is the schematic of the installation state of the manifold valve using the electric flow rate control valve of this invention. It is the schematic of the circuit using the electric flow rate control valve. It is a graph of the flow rate control of the circuit using the electric flow rate control valve. It is a vertical sectional view at the time of opening a conventional electric flow rate control valve. FIG. 12 is a vertical cross-sectional view of the electric flow rate control valve of FIG. 12 when the valve is closed. It is a graph which showed the control example of the "dimension stop" of the conventional electric flow rate control valve.

The electric flow rate control valve 10 according to the embodiment of the present invention shown in FIGS. 1 to 3 is a needle valve mainly arranged in a fluid pipeline of a semiconductor manufacturing factory or a semiconductor manufacturing apparatus, and is an electric drive mechanism. The valve body 40, which is integrally arranged with the diaphragm 45 in the valve chamber 20 at the front of the housing 11, is advanced and retracted with respect to the valve seat 25 by the operating shaft 70 of 60 to adjust the opening degree with the valve seat 25. ..

In the electric flow rate control valve 10, each part such as the housing 11, the valve body 40, and the diaphragm 45 is made of a material having high corrosion resistance and chemical resistance. For example, it is a fluororesin such as PTFE, PFA, PVDF and the like. The fluororesin can be easily processed into a desired shape by cutting or the like. Further, in the electric flow control valve 10, pure water, ammonia water, hydrofluoric acid, hydrogen peroxide solution, hydrochloric acid, ozone water, hydrogen water, oxygen water, chemicals such as surfactants, gases such as hydrogen and oxygen, etc. Controlled fluid is circulated.

The housing 11 has a valve chamber 20 having an inflow portion 21 of a controlled fluid on one side and an outflow portion 22 of a controlled fluid formed on the other side via a valve seat 25, and a valve chamber 20 on the rear side of the valve chamber 20. It has a holding chamber 30 and.

The valve body 40 has a needle portion 41 and a diaphragm 45, and is connected and held to the valve body holding shaft portion 50. The needle portion 41 opens and closes the valve seat 25 by advancing and retreating the valve body 40. The diaphragm 45 is made of a thin movable membrane and prevents the controlled fluid flowing in the valve chamber 20 from entering the holding chamber 30 side. Reference numeral 46 is a diaphragm fixing member for fixing the diaphragm 45.

The valve body holding shaft portion 50 is inserted into the holding chamber 30 at the rear of the valve chamber 20 so as to be coaxially advancing and retreating in the circumferential direction so as not to rotate, has an engaging space portion 55 at the rear portion, and is on the holding shaft portion side ( The valve chamber 20 is always urged by the spring member 52 interposed between the spring receiving portion 51 on the movable side and the spring receiving portion 53 on the drive mechanism side (fixed side). Examples of the shape of the valve body holding shaft portion 50 include a known spline fitting structure as shown in FIG. In the figure, reference numeral 56 is a locking portion of the engaging space portion 55 that is screwed or bonded to the valve body holding shaft portion 50, and 57 is a ventilation hole of the engaging space portion 55.

The electric drive mechanism 60 is a member that adjusts the amount of advance / retreat by controlling an appropriate arithmetic unit (not shown) to advance / retreat the valve body 40 via the operating shaft 70. The electric drive mechanism 60 is not particularly limited as long as it can accurately reproduce the advancing / retreating amount of the valve body 40, and for example, a stepping motor, a servo motor, an ultrasonic motor, or the like is preferably used. The electric drive mechanism 60 of the embodiment is a direct-acting stepping motor. Regarding the electric drive mechanism 60, 61 is a rotor, 62 is a shaft for advancing and retreating the operating shaft 70, 63 is a wiring portion, and 64 is a shaft sliding portion.

The operating shaft 70 has an advancing / retreating portion 71, a wire portion 72, and a tip engaging portion 73. The advancing / retreating portion 71 is a linear motion shaft that advances / retreats in a linear direction by being driven by the electric drive mechanism 60. Since the advancing / retreating portion 71 is non-rotatably fitted into the shaft sliding portion 64 of the electric drive mechanism 60 by, for example, a spline structure as shown in FIG. 5, the advancing / retreating portion 71 can be appropriately advanced / retreated in the linear direction. The wire portion 72 is a flexible member that is connected to the advancing / retreating portion 71 and advances / retreats together with the advancing / retreating portion 71. The wire portion 72 is slidably fitted and inserted into the protective member 75 made of fluororesin, if necessary. The protective member 75 covers the wire portion 72 to prevent damage and deterioration, and is made of fluororesin, so that the wire portion 72 easily slides and does not hinder the advancement and retreat. The tip engaging portion 73 is a portion provided at the tip of the wire portion 72 and engages with the valve body holding shaft portion 50 via the engaging space portion 55. The tip engaging portion 73 is non-rotatably fitted and inserted into the valve body holding shaft portion 50 and the engaging space portion 55 by, for example, a spline structure or the like (not shown).

Since the electric drive mechanism is electric, it usually generates heat during operation and transfers heat to the valve body side, so it is necessary to provide heat dissipation means such as forming a groove in the housing. However, the electric drive mechanism 60 is separated from the housing 11 as shown in FIGS. 1 to 3 by being configured so that the valve body holding shaft portion 50 can move forward and backward via the operating shaft 70 having the wire portion 72. The housing 11 does not need to be provided with heat radiating means, and the structure can be simplified.

Since the housing 11 and the electric drive mechanism 60 are separated from each other in this way, the housing 11 can be formed regardless of the size of the electric drive mechanism 60, so that the housing 11 can be downsized. It can be planned and the substitution characteristics can be improved. Further, when a highly corrosive controlled fluid, a high temperature fluid, or the like is used, the electric drive mechanism 60 can be arranged away from the explosion-proof area or the high temperature area, and the electric drive mechanism 60 is corroded from the controlled fluid. It is possible to avoid the influence of heat and heat.

Further, in particular, when the housing 11 and the electric drive mechanism 60 are separated from each other, the wire portion 72 of the operating shaft 70 is fitted into the protective member 75, so that the housing 11 and the electric drive mechanism 60 are separated from each other. Exposure can be prevented. At that time, since the protective member 75 is made of fluororesin, it has a shape corresponding to the positional relationship between the housing 11 and the electric drive mechanism 60 (for example, a substantially L-shaped side view as shown in FIG. 1). Is formed in. Therefore, the wire portion 72 of the operating shaft 70 moves back and forth along the shape of the protective member 75 due to its flexibility. As a result, the wire portion 72 can appropriately transmit the operation of the electric drive mechanism 60 without causing unnecessary deformation when moving forward and backward.

Here, the operation of the electric flow rate control valve 10 of the present invention will be described. The electric flow control valve 10 has a tip engaging portion 73 of the operating shaft 70 of the electric drive mechanism 60 when the valve body 40 shown in FIGS. 2 and 6 is retracted or stopped, that is, when the valve seat 25 is opened (opened). Is retracted or stopped via the wire portion 72 and engages with the locking portion 56 of the engaging space portion 55 of the valve body holding shaft portion 50, whereby the valve body holding shaft resists the urging force of the spring member 52. The portion 50 is retracted or stopped to separate the valve body 40 from the valve seat 25. When the operating shaft 70 is stopped in the open state, the valve body holding shaft portion 50 holds the stopped state against the urging force of the spring member 52 at the retracted position.

On the other hand, when the valve body 40 is advanced from the open state of the valve seat 25 to close the valve seat 25, the operating shaft 70 of the electric drive mechanism 60 is advanced as shown in FIG. When the valve body 40 shown in FIGS. 3 and 8 is advanced (when the valve seat 25 is closed (valve closed)), the tip engaging portion 73 of the operating shaft 70 is advanced via the wire portion 72 as shown in the drawing. Positioned in the engaging space 55 of the valve body holding shaft portion 50, the operating shaft 70 and the valve body holding shaft portion 50 are advanced together with the urging force of the spring member 52 without interfering with the urging force of the spring member 52. The valve body 40 is brought close to the valve seat 25, and the valve body 40 closes the valve seat 25 by the urging force of the spring member 52. At the time of this advancement, the engagement state between the tip engaging portion 73 of the operating shaft 70 and the locking portion 56 of the engaging space portion 55 of the valve body holding shaft portion 50 is maintained. Therefore, the valve body holding shaft portion 50 does not move beyond the moving amount of the operating shaft 70, and the moving amount is controlled according to the operation of the operating shaft 70.

By advancing the valve body holding shaft portion 50 in this way, as shown in FIGS. 3 and 8, the valve body 40 is brought into contact with the valve seat 25 and the valve seat 25 is closed (closed). Then, when the valve body 40 closes the valve seat 25 by the urging force of the spring member 52, the engaging space portion 55 of the valve body holding shaft portion 50 is on the valve chamber 20 side of the tip engaging portion 73 of the operating shaft 70. It is configured to have a gap S. That is, since the tip engaging portion 73 of the operating shaft 70 has a gap portion S on the valve chamber 20 side of the space 54 of the engaging space portion 55, the valve body 40 closes the valve seat 25 by the urging force of the spring member 52. After that, it is in a free state, and if necessary, the tip engaging portion 73 of the operating shaft 70 is configured to be able to move further forward in the gap portion S of the engaging space portion 55. Since the tip engaging portion 73 is non-rotatably fitted in the engaging space portion 55, it can be appropriately moved in the engaging space portion 55.

As can be understood from the figure, the valve body 40 is moved by the urging force of the spring member 52, the valve body 40 comes into contact with the valve seat 25, the valve seat 25 is closed (valve closed), and then the tip of the operating shaft 70 is closed. The fact that the engaging portion 73 has a gap portion S of the engaging space portion 55 by the electric drive mechanism 60 as an operating means and can move freely in the gap portion S means that the valve body 40 is closed. This means that collision with the seat 25, excessive friction, and the like are avoided or alleviated. Therefore, the occurrence of problems associated with these collisions, frictions, and the like can be solved at once.

Further, in the electric flow rate control valve 10, when the valve is opened after the valve is closed, the tip engaging portion 73 of the operating shaft 70 is free in the gap portion S on the valve chamber 20 side of the space 54 of the engaging space portion 55 ( It is positioned in the free) state, in other words, the motor is excited to maintain the force to fully close the valve body 40 with respect to the valve seat 25 or the fully closed sealing force to the valve seat 25 as in the conventional case. There is no need to maintain. Therefore, it is possible to solve not only the problem of current consumption but also various problems related to the temperature rise of the controlled fluid due to the heat generation of the motor. Of course, it is not necessary to "stop" the valve seat 25 before it is fully closed as in the conventional case. Furthermore, since the movement in the valve opening direction, that is, the backward movement of the operating shaft 70 can be started from a free state with no load, it is possible to control the valve opening of a minute flow rate and ramp control such as starting from zero flow rate. It becomes.

The electric flow rate control valve of the present invention can also be used for the manifold valve 10A as shown in FIG. In the manifold valve 10A, the housing 11A is integrally formed, and a valve body is provided corresponding to each flow path (inflow portion) 21, 21, 21, 21. An electric drive mechanism 60A is provided via an operating shaft 70 corresponding to each valve body. Also in this manifold valve 10A, the housing 11A and the electric drive mechanism 60A can be separated from each other by the operating shaft 70 provided with the flexible wire portion.

FIG. 10 is a schematic diagram of a circuit using the electric flow rate control valve 10, and FIG. 11 shows a graph of the flow rate control. In this example, the on-off valve 90 is arranged on the downstream side of the electric flow rate control valve 10, and as shown in FIG. 11, the fluid is stopped by opening and closing the electric flow rate control valve 10 with the on-off valve 90 open. It is possible to control the flow rate including. Here, the on-off valve 90 is closed when the circuit is shut off in an emergency or when the circuit is stopped. By the way, FIG. 14 is a graph showing a control example of "dimension stop" of the conventional electric flow rate control valve described above, but in the conventional control valve, the valve is closed or opened by the on-off valve after the dimension is stopped. ..

According to the electric flow rate control valve of the present invention, as described above, collision with the valve seat when the valve body is closed can be avoided or alleviated, and the occurrence of problems associated therewith can be suppressed. Not only that, it prevents the increase of frictional force on the motor when the valve body of the electric flow control valve is closed to prevent step-out, and not only the problem of current consumption but also the adverse effect on the process due to the heat generation of the motor. The usefulness of the electric flow rate control valve is that it is not necessary to "stop" before the valve seat is fully closed, and it is possible to control the minute flow rate and control the lamp such as starting from zero flow rate. Is to expand as much as possible.

Further, since the operating shaft of the electric drive mechanism for advancing and retreating the valve body is provided with a flexible wire portion, the electric drive mechanism and the housing can be separated from each other, and it is necessary to provide a heat radiating means in the housing. By eliminating it, the structure can be simplified and the housing can be downsized, the replacement characteristics can be improved, and it can be placed away from the explosion-proof area and high-temperature area, so that the controlled fluid for the electric drive mechanism can be used. It is possible to avoid the effects of corrosion and heat.

As described above, in the electric flow rate control valve of the present invention, when the tip system portion of the operating shaft engages with the valve body holding shaft portion via the engaging space portion and is closed by the urging force of the spring member, the valve is closed. Since the space of the engagement space of the valve body holding shaft is configured to have a gap on the valve chamber side of the tip engaging portion, the electric flow control valve can be connected to the motor when the valve body is closed. It is necessary to prevent the increase of frictional force, prevent step-out, not only the problem of current consumption, but also avoid the adverse effect on the process due to the heat generation of the motor, and "stop" before the valve seat is fully closed. It is possible to control the minute flow rate and control the lamp such as starting from zero flow rate. Therefore, it is promising as a substitute for the conventional electric flow rate control valve.

10 Electric flow control valve (needle valve)
10A Manifold valve 11 Housing 11A Manifold valve housing 20 Valve chamber 21 Inflow part 22 Outflow part 25 Valve seat 30 Holding chamber 40 Valve body 41 Needle part 45 Diaphragm 46 Diaphragm fixing member 50 Valve body holding shaft part 51 Holding shaft side spring holder Part 52 Spring member 53 Drive mechanism side spring receiving part 54 Space 55 Engagement space part 56 Locking part 57 Vent hole in engagement space 60 Electric drive mechanism (stepping motor)
60A Manifold valve electric drive mechanism 61 Electric drive mechanism rotor 62 Electric drive mechanism shaft 63 Electric drive mechanism wiring part 64 Electric drive mechanism shaft sliding part 70 Acting shaft 71 Advance / retreat part 72 Wire part 73 Tip engaging part 75 Protective member 90 On-off valve S Gap

Claims (4)

In a flow control valve that adjusts the opening degree with the valve seat by moving the valve body integrally arranged with the diaphragm in the valve chamber at the front of the housing by the operating shaft of the electric drive mechanism with respect to the valve seat.
The valve body is connected and held to a valve body holding shaft portion coaxially fitted in the holding chamber at the rear of the valve chamber so as not to rotate in the circumferential direction.
The valve body holding shaft portion has an engaging space portion at the rear portion, and is always urged toward the valve chamber side by a spring member interposed between the holding shaft portion side spring receiving portion and the drive mechanism side spring receiving portion. Has been
The operating shaft is attached to an advancing / retreating portion that advances and retreats in a linear direction by driving the electric drive mechanism, a flexible wire portion that is connected to the advancing / retreating portion and advances / retreats together with the advancing / retreating portion, and a tip of the wire portion. It has a valve body holding shaft portion and a tip engaging portion that is provided and engages via an engaging space portion.
When the valve body is retracted or stopped, the tip engaging portion of the operating shaft is retracted or stopped via the wire portion and engages with the locking portion of the engaging space portion of the valve body holding shaft portion. The valve body holding shaft is retracted or stopped against the urging force of the spring member to separate the valve body from the valve seat.
When the valve body is advanced, the tip engaging portion of the operating shaft is advanced via the wire portion and is located in the engaging space portion of the valve body holding shaft portion, and the valve body is located together with the urging force of the spring member. By advancing the holding shaft portion, the valve body is brought close to the valve seat, and the valve body is brought close to the valve seat.
When the valve body closes the valve seat by the urging force of the spring member, a gap portion is provided on the valve chamber side of the tip engaging portion of the operating shaft in the space of the engaging space portion of the valve body holding shaft portion. An electric flow control valve characterized by being configured to have. The electric flow rate control valve according to claim 1, wherein the electric drive mechanism and the housing are separated from each other. The electric flow rate control valve according to claim 1 or 2, wherein the advancing / retreating portion of the operating shaft is non-rotatably inserted into the shaft sliding portion of the electric drive mechanism. The electric flow rate control valve according to any one of claims 1 to 3, wherein the wire portion of the operating shaft is slidably fitted in a protective member made of fluororesin.

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