JPH11101352A - Flow control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a relatively inexpensive flow control valve whereby a flow amount of fluid of high purity can be surely controlled, and flow control of active gas, high temperature fluid, etc., can be surely performed. SOLUTION: A flow control valve 1 is provided with a valve casing 2 and a drive mechanism 3. The valve casing 2 is partitioned into an inner/outer chamber 7, 8 by a metal diaphragm 6. The inner chamber 7 is provided with a valve seat 11 and an orifice seat 12. The valve seat 11 has a valve hole 13. In the outer chamber 8, a valve element 16, drive shaft 19, guide member 20, and a support member 21 are received. Between the valve element 16 and the drive shaft 19, a first disk spring 23 is provided, and between the guide member 20 and the drive shaft 19, a second disk spring 24 is provided. The drive mechanism 3 is provided with a drive part 28. The drive part 28 is provided with the drive shaft 19, drive plates 34, 35, driving spring 36, and drive force generating parts 37, 38. The drive force generating part 37, 38 is provided with a diaphragm and connection members 42, 43.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow control valve suitable for supplying or discharging a high-purity fluid such as a semiconductor manufacturing apparatus and a liquid crystal manufacturing apparatus.

[0002]

2. Description of the Related Art At present, in a supply system and a discharge system of a high-purity fluid used in a semiconductor manufacturing apparatus or a liquid crystal manufacturing apparatus, a mass flow controller 171 as shown in FIG.
Controls the flow rate of the fluid.

A mass flow controller 171 illustrated in FIG. 21 includes a body block 172 and a flow detecting unit 17.
3, an electronic control unit 174, and a control valve 175. The body block 172 has an inflow-side fluid passage 176 and an outflow-side fluid passage 177 therein.
It has an inner chamber 179 and an outer chamber 180 partitioned by a diaphragm 178. The inner chamber 179 of the body block 172 has an inflow hole 18 connected to the inflow side fluid passage 176.
1 and an outflow hole 182 connected to the outflow side fluid passage 177 are opened. A valve seat 190 having a valve hole 189 is provided in the inner chamber 179, and the valve hole 189 is connected to the inflow hole 181.

The flow rate detector 173 includes a thin tube 183 having an inner diameter of, for example, 0.2 mm for bypassing a part of the fluid passing through the inflow-side fluid passage 176, and a pair of self-heating coils Type resistors 184, 185
And an electronic circuit section 186.

[0005] The flow rate detecting section 173 detects the heat detected by the self-heating resistor 184 located on the upstream side of the thin tube 183 and the heat detected by the self-heating resistor 185 located on the downstream side. The electronic circuit unit 186 calculates the flow rate of the fluid flowing in the thin tube 183, and obtains the flow rate in the mass flow controller 171. The flow rate of the fluid flowing in the thin tube 183 and the flow rate of the fluid flowing in the inflow-side fluid passage 176 can maintain a correct flow ratio in a wide flow rate range. Therefore, by calculating the flow rate flowing through the narrow tube 183 as described above, the mass flow controller 1
The flow rate flowing through the inside 71 can be obtained.

[0006] The electronic control unit 174 is provided with the flow rate detecting unit 17.
Control valve 1 according to the flow rate calculated by the electronic circuit unit 186 of FIG.
75 is controlled. The control valve 175 has a piezoelectric element 187 and a valve element 188, and the electronic control unit 1
In response to the signal from the valve 74, the valve 188
The valve 189 is operated to a closed position for closing the valve hole 189 via 78 and an open position where the diaphragm 178 is separated from the valve hole 189.

Therefore, when the valve body 188 is operated to the closed position, the fluid passage from the inflow-side fluid passage 176 to the outflow-side fluid passage 177 via the valve hole 189 is shut off, and the diaphragm 176 is closed. When operated to the open position, the fluid in the inflow-side fluid passage 176 flows into the valve hole 1.
It will flow through 89 to the outflow fluid passage 177.

[0008]

However, in the conventional mass flow controller 171, since the inner diameter of the thin tube 183 of the flow rate detecting unit 173 is about 0.2 mm, when an active gas or the like is passed, the reaction product of this gas causes Capillary 183
The inside may be clogged, and the flow rate of the fluid may not be controlled.

Further, a piezoelectric element 18 used for flow control is provided.
7 and the electronic control unit 174, etc., cannot control the flow rate of a high-temperature fluid exceeding, for example, 80 degrees because of thermal restrictions. Further, since the electronic control unit 174 is provided, the mass flow controller 171 itself is There is a problem that it becomes expensive.

Further, the illustrated mass flow controller 171 does not have the ability to close the valve hole 189, so that the controllable range is narrowed.

In order to solve the above-mentioned problem, it is conceivable to use a fluid pressure operated valve 101 shown in FIG. Fluid pressure operated valve 101 illustrated in FIG.
Are a valve box 104 having an inflow-side fluid passage 102 and an outflow-side fluid passage 103 therein; and a valve hole 109 provided inside the valve box 104 and connected to the inflow-side fluid passage 102.
a, a pressing portion 105 that comes into contact with and separates from the valve hole 109a via a diaphragm 110, and a pressing portion 105.
Drive mechanism 107 for driving the valve in the direction of coming into contact with and separating from valve seat 109
And

The drive mechanism 107 includes a cylinder housing 111 connected to the valve box 104, a piston 112 housed in the cylinder housing 111, and a drive shaft 113 for interlocking the piston 112 and the pressing portion 105.
And a spring 106 for urging the drive shaft 113 toward the pressing portion 105. When the operating fluid is introduced into the cylinder housing 111, the piston 112 is pushed up against the urging force of the spring 106, and the drive shaft 113 is separated from the pressing portion 105. Due to this separation, the diaphragm 110 is separated from the valve hole 109a, and the inflow-side fluid passage 102 and the outflow-side fluid passage 103 are communicated with each other.

By the way, this kind of fluid pressure operated valve 10
Reference numeral 1 denotes a sliding portion between the piston 112 and the cylinder housing 111 and a drive shaft 113 and the cylinder housing 11.
1 is provided with an O-ring 108 for sealing a sliding portion.

The spring 106 is provided between the upper end of the cylinder housing 111 and the piston 112, and both ends 106a, 1a of the spring 106 are provided.
06b is in contact with the upper end of the cylinder housing 111 and the piston 112.

Therefore, the conventional hydraulic pressure operated valve 101
Therefore, when the piston 112 and the drive shaft 113 are operated, a large frictional resistance is generated between the piston 112 and the drive shaft 113, and the hysteresis tends to increase in the valve characteristics shown in FIG.

The valve characteristics shown in FIG. 23 indicate the degree of opening of the hydraulic pressure-operated valve 101 with respect to the pressure of the operating fluid for operating the valve. In FIG. 23, when the valve 101 shifts from the closed state to the open state due to the above-described frictional resistance, the valve 101 shifts along the solid line J1 in the figure, and the valve 101 shifts from the open state to the closed state. In this case, the characteristic shows that the transition is made along the solid line J2.

The fluid pressure operated valve 101 is provided with a valve seat 1.
Since the pressing force (initial load) of the spring 106 is set large in order to surely close the opening 09, the off-balance O shown in FIG. 23 is large. The off-balance O indicates the operating fluid pressure from when the valve 101 starts to close to when it opens. Since the off-balance O is large in the conventional fluid pressure operated valve 101, as shown by the straight lines J1 and J2 in FIG. The change in the flow rate of the fluid reaching the passage 103 becomes very large.

Therefore, the resolution of the opening of the fluid pressure operated valve 101 becomes much larger than the resolution required for controlling the flow rate of a supply system or a discharge system of a semiconductor manufacturing apparatus or a liquid crystal manufacturing apparatus. In the fluid pressure operated valve 101, the flow rate cannot be controlled by the valve alone in the above-described supply system or discharge system.

Accordingly, an object of the present invention is to control the flow rate of a high-purity fluid used in a semiconductor manufacturing apparatus, a liquid crystal manufacturing apparatus, and the like without fail, and to provide a supply system or a discharge system for passing an active gas, a high-temperature fluid, or the like. Another object of the present invention is to provide a flow control valve which can perform flow control reliably and is relatively inexpensive.

[0020]

SUMMARY OF THE INVENTION In order to solve the above problems and achieve the object, a flow control valve according to claim 1 is provided.
A valve box having an inflow hole and an outflow hole connected to the inflow hole, a valve seat disposed in the valve box and having a valve hole positioned between the inflow hole and the outflow hole, and contacting the valve seat. A pressing portion movably supported in the separating direction, supported by the valve box, a metal diaphragm interposed between the pressing portion and the valve seat, and opening and closing the valve hole; A drive shaft that comes into contact, a drive shaft biasing unit that urges the drive shaft toward the pressing portion to press the metal diaphragm against the valve seat through the pressing portion, and an operation that is introduced from the outside A drive unit that drives the drive shaft in a direction away from the pressing unit according to the magnitude of the pressure of the working fluid,
And first urging means for urging the pressing portion toward the valve seat when the driving shaft is driven in a direction away from the pressing portion. .

A flow control valve according to a second aspect of the present invention is a valve box having an inflow hole and an outflow hole connected to the inflow hole, and is disposed in the valve box and located between the inflow hole and the outflow hole. A valve seat having a set valve hole, a pressing portion supported by the valve box movably in a direction to contact and separate from the valve seat, and the valve hole interposed between the pressing portion and the valve seat. A metal shaft that opens and closes, a drive shaft that comes into contact with and separates from the pressing portion, and a biasing force of the drive shaft toward the pressing portion, so that the metal diaphragm is connected to the valve seat through the pressing portion. A driving unit for urging the driving shaft in a direction away from the pressing unit in accordance with the magnitude of the pressure of the operating fluid introduced from the outside; In the low opening region where the shaft approaches the pressing portion, The shaft is characterized in that and a second biasing means for biasing in a direction away from the pressing unit.

According to a third aspect of the present invention, there is provided a flow control valve having a valve box having an inflow hole and an outflow hole connected to the inflow hole, disposed in the valve box, and positioned between the inflow hole and the outflow hole. A valve seat having a valve hole, a pressing portion supported by the valve box movably in a direction to come into contact with and separate from the valve seat, interposed between the pressing portion and the valve seat, A metal diaphragm that opens and closes, a drive shaft that comes into contact with and separates from the pressing portion, and a biasing force of the drive shaft toward the pressing portion allows the metal diaphragm to move to the valve seat through the pressing portion. A driving unit having: a driving shaft urging unit for pressing; a driving unit for driving the driving shaft in a direction away from the pressing unit in accordance with the pressure of the operation fluid introduced from the outside; and the driving shaft. Is driven in the direction away from the pressing section, A first urging means for urging the pressing portion toward the valve seat, and a second urging device for urging the driving shaft in a direction away from the pressing portion in a low opening degree region where the drive shaft approaches the pressing portion. 2. A flow control valve, comprising: (2) a biasing means.

According to a fourth aspect of the present invention, there is provided a flow control valve having a valve box having an inflow port and an outflow port connected to the inflow port, and disposed in the valve box and positioned between the inflow port and the outflow port. A valve seat having a valve hole, a pressing portion supported by the valve box movably in a direction to come into contact with and separate from the valve seat, interposed between the pressing portion and the valve seat, A metal diaphragm that opens and closes, a drive shaft that comes into contact with and separates from the pressing portion, a drive shaft biasing unit that biases the drive shaft in a direction away from the pressing portion, and an operating fluid that is introduced from outside. A drive unit that drives the drive shaft in a direction approaching the pressing unit according to the magnitude of the pressure, and presses the metal diaphragm against the valve seat via the pressing unit to enable the valve to be closed. And the drive shaft is driven in a direction away from the pressing portion. The pressing portion is characterized by comprising a, a first biasing means for urging the said valve seat when.

According to a fifth aspect of the present invention, there is provided a flow control valve having a valve box having an inflow port and an outflow port connected to the inflow port, and disposed in the valve box and positioned between the inflow port and the outflow port. A valve seat having a valve hole, a pressing portion supported by the valve box movably in a direction to come into contact with and separate from the valve seat, interposed between the pressing portion and the valve seat, A metal diaphragm that opens and closes, a drive shaft that comes into contact with and separates from the pressing portion, a drive shaft biasing unit that biases the drive shaft in a direction away from the pressing portion, and an operating fluid that is introduced from outside. A drive unit that drives the drive shaft in a direction approaching the pressing unit according to the magnitude of the pressure, and presses the metal diaphragm against the valve seat via the pressing unit to enable the valve to be closed. In the low opening region where the drive shaft approaches the pressing portion. There are and the drive shaft characterized by including a second biasing means for biasing in a direction away from the pressing unit.

According to a sixth aspect of the present invention, there is provided a flow control valve having a valve box having an inflow port and an outflow port connected to the inflow port, and disposed in the valve box and positioned between the inflow port and the outflow port. A valve seat having a valve hole, a pressing portion supported by the valve box movably in a direction to come into contact with and separate from the valve seat, interposed between the pressing portion and the valve seat, A metal diaphragm that opens and closes, a drive shaft that comes into contact with and separates from the pressing portion, a drive shaft biasing unit that biases the drive shaft in a direction away from the pressing portion, and an operating fluid that is introduced from outside. A drive unit that drives the drive shaft in a direction approaching the pressing unit according to the magnitude of the pressure, and presses the metal diaphragm against the valve seat via the pressing unit to enable the valve to be closed. And the drive shaft is driven in a direction away from the pressing portion. First urging means for urging the pressing portion toward the valve seat when the driving shaft is moved, and a direction in which the drive shaft is separated from the pressing portion in a low opening degree region where the drive shaft approaches the pressing portion. And a second urging means for urging the second member.

[0026] The flow control valve according to the seventh aspect is the first aspect.
7. The throttle device according to claim 6, further comprising a throttle mechanism that gradually increases a flow rate of the fluid from the valve hole to the outlet hole when the drive shaft is driven in a direction away from the pressing portion. 8. It is characterized by that.

[0027] The flow control valve according to claim 8 is provided with a valve box having an inflow hole and an outflow hole connected to the inflow hole, and disposed in the valve box and positioned between the inflow hole and the outflow hole. A valve seat having a valve hole, a pressing portion supported by the valve box movably in a direction to come into contact with and separate from the valve seat, interposed between the pressing portion and the valve seat, A metal diaphragm that opens and closes, a drive shaft that comes into contact with and separates from the pressing portion, and a biasing of the drive shaft toward the pressing portion presses the metal diaphragm against the valve seat through the pressing portion. Or a drive shaft biasing means for biasing the drive shaft in a direction away from the pressing portion, and a drive portion for driving the drive shaft according to the magnitude of the pressure of the operating fluid introduced from the outside; , And the driving shaft has the pressing portion. When driven in La away direction, characterized in that and a diaphragm mechanism to gradually increase the flow rate of the fluid reaching the outlet hole from the valve hole.

According to the flow control valve according to the first and fourth aspects, in the low opening region of the flow control valve, the first urging means urges the pressing portion toward the valve seat. Even if the drive shaft is driven in the direction away from the control unit due to the pressure fluctuation of the operation fluid supplied from the outside, even if the opening degree is several percent,
The metal diaphragm can be pressed against the valve seat via the pressing portion. Therefore, the metal diaphragm does not immediately come off the valve seat, and the opening area of the valve hole does not increase rapidly.

As described above, since the first biasing means prevents the metal diaphragm from immediately separating from the valve seat even when the driving means is driven, the opening degree of the valve with respect to the pressure change of the operating fluid particularly in the low opening degree region is reduced. This will mitigate the change.

Therefore, it is possible to ensure the resolution of the valve opening required for controlling the flow rate of the supply system and the discharge system through which high-purity fluid such as a semiconductor manufacturing apparatus and a liquid crystal manufacturing apparatus passes.

According to the flow control valve according to the second and fifth aspects, in the low opening region of the flow control valve, the second urging means urges the pressing portion in a direction away from the valve seat. Therefore, the flow control valve is easily opened, and the off-balance in the valve characteristics is reduced.

As described above, since the second biasing means reduces the off-balance, the change in the opening degree of the valve with respect to the change in the pressure of the operating fluid particularly in the low opening degree region is reduced.
Therefore, it is possible to secure the resolution of the opening degree of the valve required for controlling the flow rate of the supply system and the discharge system through which a high-purity fluid such as a semiconductor manufacturing apparatus or a liquid crystal manufacturing apparatus passes.

According to the flow control valve according to the third and sixth aspects, in the low opening region of the flow control valve, the first urging means urges the pressing portion toward the valve seat. Even if the drive shaft is driven in the direction away from the control unit due to the pressure fluctuation of the operation fluid supplied from the outside, even if the opening degree is several percent,
The metal diaphragm can be pressed against the valve seat via the pressing portion. Therefore, the metal diaphragm does not immediately come off the valve seat, and the opening area of the valve hole does not increase rapidly.

In the low opening region, the second urging means urges the pressing portion in a direction away from the valve seat, so that the flow control valve is easily opened and the off-balance in valve characteristics is reduced. It will be.

As described above, the second urging means reduces the off-balance and the first urging means prevents the metal diaphragm from being separated from the valve seat immediately after the driving means is driven. The change in the opening degree of the valve with respect to the change in the pressure of the operating fluid in the opening degree region is reduced.

Accordingly, it is possible to secure the resolution of the opening of the valve required for controlling the flow rate of the supply system and the discharge system through which a high-purity fluid such as a semiconductor manufacturing apparatus or a liquid crystal manufacturing apparatus passes.

In the flow control valve according to the seventh and eighth aspects, the throttle mechanism gradually increases the flow rate of the fluid when the drive shaft is driven in the direction away from the pressing portion. In the house opening area, the flow rate of the fluid is narrowed down.

As described above, since the restricting mechanism restricts the flow rate of the fluid, the change in the flow rate of the fluid with respect to the change in the pressure of the operating fluid particularly in the low opening region is reduced. Therefore, it is possible to secure the resolution of the opening degree of the valve required for controlling the flow rate of the supply system and the discharge system through which a high-purity fluid such as a semiconductor manufacturing apparatus or a liquid crystal manufacturing apparatus passes.

According to a ninth aspect of the present invention, there is provided a flow control valve according to any one of the first to eighth aspects, wherein the flow control valve flows out of the valve hole between the valve hole and the outflow hole. An orifice sheet having an orifice hole for keeping the flow rate of the fluid reaching the hole uniform is characterized in that it is arranged. In this case, since the orifice sheet has an orifice hole for maintaining a uniform flow rate of the fluid from the valve hole to the outflow hole, the fluid can flow smoothly.

For this reason, the resolution of the opening degree of the valve required for controlling the flow rate of the supply system and the discharge system for passing a high-purity fluid such as a semiconductor manufacturing apparatus or a liquid crystal manufacturing apparatus can be more reliably secured.

According to a tenth aspect of the present invention, there is provided the flow rate control valve according to any one of the first to eighth aspects, wherein
The drive shaft biasing means is a spring disposed coaxially with the drive shaft, and the drive shaft has a spring receiver at an end of the shaft, and the spring receiver is connected to the spring support via a bearing. Is supported.

In this case, since the drive shaft urging means, which is a spring, is supported by the spring receiver of the drive shaft via a bearing, the drive shaft urging means rotates around the drive shaft during expansion and contraction. Also, the rotation is not hindered by the bearing. For this reason, the driving means is driven smoothly, and the hysteresis in the valve characteristics can be reduced.

Therefore, it is possible to more reliably secure the resolution of the opening degree of the valve required for controlling the flow rate of the supply system and the discharge system through which a high-purity fluid such as a semiconductor manufacturing apparatus or a liquid crystal manufacturing apparatus passes.

[0044] The flow control valve according to the eleventh aspect is the flow control valve according to any one of the first to third aspects,
The drive unit of the drive unit has a fluid chamber into which the operation fluid is introduced, and a diaphragm that is displaced in a direction away from the pressing unit when the operation fluid is introduced into the fluid chamber, The diaphragm is provided with a driving force generating section connected to the driving shaft.

According to a twelfth aspect of the present invention, there is provided a flow control valve according to any one of the fourth to sixth aspects,
The drive unit of the drive unit has a fluid chamber into which the operation fluid is introduced, and a diaphragm that is displaced in a direction approaching the pressing unit when the operation fluid is introduced into the fluid chamber, The diaphragm is provided with a driving force generating portion connected to the driving shaft.

Further, the above-mentioned claim 11 or claim 1
In carrying out the invention described in Item 2, it is desirable to embed a reinforcing sheet using aramid fiber or the like inside the diaphragm, as in the invention described in Item 13.

In this case, the driving portion of the driving means drives the driving shaft in a direction away from or approaching the pressing portion by deformation of the diaphragm, so that a large frictional resistance required by the conventional piston type fluid pressure operated valve is required. O-rings to be generated can be omitted. For this reason, the driving means is driven smoothly, and the hysteresis in the valve characteristics can be reduced.

As described above, since the frictional resistance of the driving means is suppressed, the opening degree of the valve required for controlling the flow rate of the supply system and the discharge system through which a high-purity fluid such as a semiconductor manufacturing apparatus or a liquid crystal manufacturing apparatus passes. Resolution can be ensured.

Further, the above-mentioned claim 11 to claim 13
In practicing the invention described in any one of the above, it is preferable that the diaphragm has a bent portion curved in a waveform as in the invention described in the fourteenth aspect.

In this case, the diaphragm is displaced more smoothly by the introduction of the operating fluid, so that the frictional resistance of the driving means can be further suppressed. For this reason, the resolution of the opening degree of the valve required for the flow control of the supply system and the discharge system through which a high-purity fluid such as a semiconductor manufacturing apparatus or a liquid crystal manufacturing apparatus passes can be more reliably secured.

In practicing the invention as set forth in claim 11 or claim 12, as in the invention as set forth in claim 15, a plurality of the driving force generating portions are provided along the axial direction of the driving shaft. It is desirable to arrange. In this case, since the driving unit of the driving unit includes a plurality of driving force generating units arranged in the axial direction of the driving shaft, the driving shaft is pressed despite the addition of the second urging unit. In this case, it is possible to ensure a sufficient output when driving toward the drive unit, and to prevent the drive unit from being enlarged in the radial direction of the drive shaft.

According to a sixteenth aspect of the present invention, there is provided a flow control valve according to any one of the first, third, fourth and sixth aspects, wherein the first urging means comprises A spring disposed coaxially with the shaft, wherein the pressing portion has a spring receiver for supporting an end of the spring on an end face thereof, and a position along the drive shaft of the end of the spring. A first spring receiving position adjusting mechanism for adjustment is provided.

According to a seventeenth aspect of the present invention, there is provided the flow control valve according to any one of the second, third, fifth and sixth aspects, wherein the second biasing means comprises the driving means. A spring disposed coaxially with the shaft, and guide means having a spring receiver for guiding a driving direction of the drive shaft and supporting an end of the spring; A second spring receiving position adjusting mechanism for adjusting a position along the second spring receiving position.

In these flow control valves, the travel stroke of the drive shaft or the like when the valve opening is in the range of 0% to 100% may be very small, for example, 0.3 mm. The flow control valve according to claim 15 or 16 is the first flow control valve.
Alternatively, even when the dimensional error of the spring as the second urging means is very large compared to the drive stroke of the drive shaft, for example, ± 0.1 mm, the first or second spring receiving position adjusting mechanism can The position of the end of the spring as the first and second biasing means can be adjusted. Therefore, it is possible to suppress variations in the flow characteristics and the valve seat shutoff performance of each flow control valve, and to stably secure desired flow characteristics and valve seat shutoff performance.

[0055]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 1, the flow control valve 1 includes a valve box 2 and a driving mechanism 3 as driving means.

The inside of the valve box 2 is provided with an inflow-side fluid passage 4.
And an outflow-side fluid passage 5, and are separated fluid-tightly into an inner chamber 7 and an outer chamber 8 by a metal diaphragm 6 made of metal attached to the valve box 2. The inner chamber 7 has an inlet 9 and an outlet 10 which communicate with the fluid passages 4 and 5, respectively.

The inner chamber 7 has the inlet 9 and the outlet 1 therein.
0, the valve seat 11 and the valve box 2
And an orifice sheet 12 that keeps the space between them fluid-tight. The valve seat 11 is formed in an annular shape having a predetermined cross-sectional shape by a suitable elastic material such as Teflon resin, and a valve hole 13 communicating with the inflow hole 9 is opened in the center.

Further, as shown in FIG. 10A, the valve seat 11 and the orifice sheet 12 may be formed integrally from metal or the like, and as shown in FIG. The valve box 2 may be provided with a convex portion 11a or the like along the outer shape of the valve seat 11 without providing the valve seat 2 and the orifice sheet 12. As shown in FIG. A member 11 b separate from the valve box 2 along the outer shape of 11 may be swaged to the valve box 2.

As shown in FIG. 3, the orifice seat 12 has a plurality of orifice holes 14 at positions outside the valve seat 11. These orifice holes 1
Numeral 4 is for making the inflow hole 9 and the outflow hole 10 communicate with each other via the valve hole 13 when the metal diaphragm 6 is separated from the valve seat 11, and the fluid flows in the inner chamber 7 at the time of communication. Orifice holes 14 in relation to the opening position of the outlet holes 10 so that the
Are appropriately set.

With this configuration, the flow path of the fluid flowing into the inflow-side fluid passage 4 is connected from the inflow hole 9 to the valve hole 13, and the orifice hole 14 and the outflow hole 1 are connected.
0 to the outflow side fluid passage 5.

As shown in FIG. 5, a guide member 20 is accommodated in the outer chamber 8. The guide member 20 is held in the outer chamber 8 via a support member 21 screwed into the valve box 2. The guide member 20 is connected to the orifice sheet 12.
And the metal diaphragm 6 is sandwiched between the orifice sheet 12 and the outer peripheral portion thereof. The guide member 20 supports a drive shaft 19 described later so as to guide the drive in the axial direction.

The guide member 20 has a concave portion 20c at the center of the lower surface facing the orifice sheet 12. The guide member 20 includes a spring receiver 20b that supports a second disc spring 24 described later on an end surface 20a exposed to the outer chamber 8.

The recess 20c has a valve body 16 as a pressing portion.
Is arranged. The valve body 16 is made of the metal diaphragm 6.
Through the recess 20c so as to be movable toward or away from the valve seat 11.
Is housed in The valve body 16 includes a spring receiver 16b that supports a first disc spring 23 described later on an end surface 16a located on a side opposite to a surface facing the valve seat 11.

Further, as shown in FIG.
And the guide member 20, the bellows 55 may be fixedly attached, and the bellows 55 may be used to partition the inner chamber 7 and the outer chamber 8 in a fluid-tight manner. In the example shown in FIG. 11, the valve body 16 directly seals the end face of the inflow hole 9 without providing the valve seat 11 and the orifice sheet 12 in the inner chamber 7. At this time, the valve body 16 is desirably formed of resin or the like.

The drive shaft 19 is supported by the support member 21 while being guided in the axial direction. One end 17 of the drive shaft 19 penetrates the support member 21 and the guide member 20 and is introduced into the recess 20c. The drive shaft 19 is provided at one end 17 with the other end 24 of a second disc spring 24 described later.
b is provided with a stepped portion 19a opposed to b.

One end 17 of the drive shaft 19 is connected to the valve body 16.
As shown in FIGS. 4 and 5, a play 22 having a gap S along the axial direction of the drive shaft 19 is formed between the one end portion 17 and the valve body 16. ing. The play 22 is located inside the recess 20c. The interval S of the play 22 is such that the opening degree of the flow control valve 1 is 0.
% To a relatively small first predetermined opening K, for example, several%.
The interval corresponds to the drive stroke of the drive shaft 19 in the low opening region up to 1.

As shown in FIGS. 4 and 5, a first urging member for urging the valve element 16 toward the valve seat 11 is provided between the valve element 16 and the drive shaft 19. A first disc spring 23 as a means is provided. First disc spring 23
Are arranged coaxially with the drive shaft 19. First disc spring 2
Reference numeral 3 denotes a state in which one end 23a is supported on the spring receiver 16b and the other end 23b is opposed to the distal end face 19b of the drive shaft 19. As the first biasing means, a spring such as a coil spring may be used in addition to the disc spring 23 shown in the figure. Further, as the first urging means, an elastic body such as rubber or resin such as an O-ring or a rubber sheet may be used.

The first disc spring 23 has a play 22 between the drive shaft 19 and the valve body 16 so that the flow control valve 1
The valve body 16 is urged toward the valve seat 11 in a low opening range from 0% to the first predetermined opening K1.

As shown in FIG. 5, a second disc spring 24 is provided between the guide member 20 and the drive shaft 19 as second urging means. The second disc spring 24 is arranged coaxially with the drive shaft 19. The second disc spring 24 has one end 24a supported on the spring receiver 20b and the other end 24b opposed to the step 19a. As the second urging means, a spring such as a coil spring may be used in addition to the disc spring 24 shown in the figure.

The second disc spring 24 has an opening of the flow control valve 1 ranging from 0% to a relatively small value, for example, 30%, and a second predetermined opening K2 larger than the first predetermined opening K1. In the low opening degree region, the valve body 16 biases the drive shaft 19 in a direction away from the valve seat 11.

As shown in FIG. 1, the drive mechanism 3 is mounted on a wall surface 25 of the valve box 2 where the outer chamber 8 is formed. The drive mechanism 3 connects the drive shaft 19 to the valve body 16.
, Or to move away from the valve body 16. The drive mechanism 3 includes a casing 26 connected to the valve box 2, a spring cover 27 connected to the casing 26,
And a drive unit 28 housed inside the spring cover 27.

The casing 26 is provided with the support member 21.
And a drive unit 28. The partition wall 30 has an insertion hole 29 through which the drive shaft 19 is slidably inserted in the axial direction. The partition wall 30 has the drive shaft 19 inserted into the insertion hole 29 and guides the movement along the axial direction. The guide member 2
The support member 21 and the partition wall 30 constitute the guide means described in this specification. The casing 26 is provided with the valve box 2
At the same time, it is attached to the wall surface 25 so as to surround the support member 21 and the like.

The spring cover 27 has a hollow cylindrical shape whose upper surface is closed. The lower end of the spring cover 27 is attached to the upper end of the casing 26, and the inside of the casing 26 is closed with the casing 26. On the upper surface of the spring cover 27, an operation fluid pressure introduction hole 31 into which the operation fluid is introduced is provided. The spring cover 27 has an operation fluid pressure communication hole 32 inside its peripheral wall, and the operation fluid pressure communication hole 32 is connected to the operation fluid pressure introduction hole 31.

The spring cover 27 and the casing 2
6 and the valve box 2 are fixed to each other by a plurality of bolts 33 (shown in FIG. 2). In the illustrated example,
Four bolts 33 are used, two of which are used for fixing the spring cover 27 and the casing 26, and the other two are used for fixing the spring cover 27 and the valve box 2.

The drive section 28 includes drive plates 34 and 35 attached to the drive shaft 19 and the drive shaft 19 and the valve 1.
And a first and second drive force for driving the drive shaft 19 in a direction away from the valve body 16 via the drive plates 34 and 35. Generators 37 and 38 are provided.

As shown in FIG. 6, the driving force generator 3
Reference numerals 7 and 38 denote two diaphragms 40 and 41 each having a hole 39 through which the drive shaft 19 passes in the center, and a first connecting member 42 for connecting the outer peripheral portions of these diaphragms 40 and 41 to each other in a fluid-tight manner. And the diaphragm 40,
And a second connecting member 43 that connects the inner circumferences of the holes 39 in a fluid-tight manner to each other. Diaphragm 40,
41 are arranged in parallel so as to face each other in the axial direction of the drive shaft 19. These diaphragms 40, 41
Constitutes ring-shaped fluid chambers 37a and 38a in cooperation with the first connecting portion 42 and the second connecting member 43.

The first connecting member 42 communicates with the operating fluid pressure communicating hole 32 and the fluid chambers 37a, 38
A fluid introduction hole 44 that opens at a is provided. The fluid introduction hole 44 guides the operation fluid introduced into the operation fluid pressure introduction hole 31 into the fluid chambers 37a and 38a. The second connecting member 43 has a through hole 43a at the center thereof, and the drive shaft 19 is fitted into the through hole 43a.

The diaphragms 40 and 41 are provided in the fluid chamber 3
When the pressure inside 7a and 38a exceeds a predetermined pressure P (shown in FIG. 9), the elastic deformation is performed so that the interval between them becomes larger. The diaphragms 40 and 41 of the present embodiment include a bent portion 4 that is curved between the connecting members 42 and 43.
0a and 41a. These bent portions 40a, 41a
, The operating resistance when the diaphragms 40 and 41 are elastically deformed is reduced.

The diaphragms 40 and 41 are made of a flexible elastic material such as rubber, for example, and have a sheet 45 as a reinforcing sheet made of aramid fiber or the like embedded therein as shown in the figure. Is desirable. When the sheet 45 made of aramid fiber or the like is embedded therein, the mechanical strength of the diaphragms 40 and 41 increases, and the durability improves.

As shown in FIG. 1, the drive shaft 19 has a valve body 16 on the outer periphery of a central portion thereof.
When the valve seat 11 is pressed through the
A first support flange 46 which is substantially flush with the partition wall 30 is integrally formed.

On the first flange 46, a first driving force generating portion 37 on the driving shaft 19 is arranged, and further fixed on the driving shaft 19 on the first driving force generating portion 37. The first driving plate 34 thus arranged is superimposed.

The second driving force generating section 38 on the driving shaft 19 is located above the first driving force generating section 37, and the second driving force generating section 38 is mounted on the second driving force generating section 38. 19
The second driving plate 35 fixed to the second driving plate 35 is overlapped.

Between the first driving force generating section 37 and the second driving force generating section 38, an outer peripheral intermediate member 49 and an inner peripheral intermediate member 50 are arranged. The outer peripheral intermediate member 49 is
It is fixed to the inner surface of the casing 26 and is in contact with the outer peripheral portions of the first and second driving force generators 37 and 38.
The outer peripheral intermediate member 49 has a gap between the outer peripheral intermediate member 49 and the first driving plate 34 according to the driving stroke of the driving shaft 19.
The inner peripheral intermediate member 50 is fixed to the drive shaft 19,
The first driving plate 34 and the inner peripheral portion of the second driving force generating section 38 are in contact with each other. The outer peripheral portions of the first and second driving force generating portions 37 and 38 and the outer peripheral intermediate member 49 are sandwiched between the partition wall 30 of the housing 26 and the lower end of the spring cover 27.

As shown in FIG. 1, the drive shaft 19 has the other end 47 which penetrates the first and second driving force generating portions 37 and 38 and reaches the inside of the spring cover 27. A spring receiver 48 is fixed to the other end 47. The spring receiver 48 includes a support flange 48a.
The support flange 48 a is overlapped on the second drive plate 35. This second drive plate 35 is
The drive shaft 1 is disposed adjacent to the lower end of the spring cover 27 and between the spring cover 27 and the second drive plate 35.
A gap corresponding to 9 drive strokes is formed.

The driving spring 36 extends between the support flange 48 a of the spring receiver 48 and the upper wall 27 a of the spring cover 27. The driving spring 36 is in contact with the support flange 48a via a bearing 51.

The bearings 51 have end faces 36a, 36b generated when the driving spring 36 is contracted.
It absorbs frictional resistance around the axis between the support flange 48a and the upper wall 27a of the spring cover 27, and does not hinder the contraction of the driving spring 36.

According to the above-described configuration, the pressure of the operating fluid supplied from the operating fluid pressure introducing hole 37 to the fluid chambers 37a, 38a of the first and second driving force generating units 37, 38 is increased to the predetermined pressure P. 9 (shown in FIG. 9), the diaphragms 40 and 41 push up the drive plates 34 and 35, and the drive shaft 19 and the second and third drive force generation units 37 and 38
The connecting member 43, the inner peripheral intermediate member 50 and the driving plate 34,
35 are pushed together along the arrow R1 shown in FIG. Then, one end 17 of the drive shaft 19 is connected to the valve body 1.
6, the metal diaphragm 6 by the valve body 16
Is released. As a result, the metal diaphragm 6 separates from the valve seat 11, and the valve hole 13 is opened.

When the pressure of the operating fluid supplied from the operating fluid pressure introducing hole 31 becomes lower than the predetermined pressure P, the driving shaft 19 is driven by the driving spring 36.
The second connecting member 43 of the first and second driving force generators 37 and 38, the inner peripheral intermediate member 50, and the driving plates 34 and 35 are integrally pressed down along the arrow R2 shown in FIG. Therefore, one end 17 of the drive shaft 19 abuts on the valve body 16, and the metal diaphragm 6 is pressed against the valve seat 11. Therefore, the valve hole 13 is closed.

According to the present embodiment, since the drive shaft 19 is driven in the axial direction by the diaphragms 40 and 41 which are deformed in accordance with the pressure of the operating fluid, the drive portion such as between the drive shaft 19 and the casing 26 is provided. There is no need to maintain fluid tightness between the 28 members. Therefore, it is not necessary to use an O-ring or the like in the drive unit 28, and the frictional resistance when the drive shaft 19 is driven can be reduced.

A bearing 51 provided between the drive spring 36 and the support flange 48a is provided with end faces 36a and 36b generated when the drive spring 36 is contracted, the support flange 48a and the spring cover 27. Absorb the frictional resistance with the upper wall 27a.
For this reason, the resistance when the drive spring 36 contracts can be suppressed.

When the valve body 16 is pressing the valve seat 11 through the metal diaphragm 6, the first support flange 46 and the partition wall 30 are flush with each other, and the fluid chambers 37a and 38a Since the lower diaphragm 41 of the diaphragms 40 and 41 is in contact with the outer peripheral intermediate member 49 and the partition wall 30, respectively, the fluid chamber 37 is provided.
When the pressure in the a and 38a exceeds the predetermined pressure P and the diaphragms 40 and 41 are elastically deformed, only the upper diaphragm 40 is deformed so as to rise and the valve body 16 is deformed.
Displaced away from

For this reason, when the pressure of the fluid supplied to the fluid chambers 37a, 38a exceeds a predetermined pressure P (shown in FIG. 9), the drive shaft 19 of the drive mechanism 3 immediately moves along the arrow R1 in the drawing. It will be driven.

As described above, the frictional resistance which hinders the driving of the driving mechanism 3 is suppressed, and when the pressure in the fluid chambers 37a, 38a exceeds the predetermined pressure P, the driving shaft 19 of the driving mechanism 3 is immediately driven. Therefore, the driving mechanism 3 is driven smoothly, and the off-balance O2 (shown in FIG. 9) and the hysteresis (not shown) in the valve characteristics (shown in FIG. 9) can be reduced.

The off-balance O2 is defined as the valve body 1
6 presses the valve seat 11 from the state where the metal diaphragm 6
Indicates the pressure (operating fluid pressure) of the operating fluid introduced from the outside until the valve starts to separate from the valve seat 11.

The first disc spring 23 urges the valve body 16 toward the valve seat 11 in a low opening range where the opening of the valve is from 0% to the first predetermined opening K1. . For this reason,
Even when the drive shaft 19 is driven along the arrow R1, the valve body 16 does not move immediately as compared with the two-dot chain line Q shown in FIG. 8, and therefore, as shown by the solid line in FIG. The opening degree of the valve is not proportional to the movement distance of 19, and the valve is gradually opened.

The two-dot chain line Q shown in FIG. 8 has a first urging means for urging the valve element 16 such as the first disc spring 23 toward the valve seat 11. 1 does not show a conventional hydraulically actuated valve 101. As shown in the drawing, the valve opening of the conventional fluid pressure operated valve 101 is proportional to the moving distance of the drive shaft 19.

The second disc spring 24 causes the drive shaft 19 to move away from the valve seat 11 in a low opening range from the valve opening of 0% to the second predetermined opening K2. Energize. For this reason, the off-balance of the flow control valve 1 is changed from the off-balance O1 of the conventional fluid pressure operated valve 101 without the second urging means shown by the two-dot chain line Q in FIG. Is reduced to the off-balance O2 indicated by.

As described above, the second disc spring 24 reduces the off-balance and the first disc spring 23 does not immediately separate the metal diaphragm 6 from the valve seat 11 even when the drive shaft 19 is driven. Since the chambers 37a and 38a are composed of the diaphragms 40 and 41 and the like to suppress the frictional resistance, the valve characteristics of the flow control valve 1 are as shown by the solid line in FIG. 9 and the solid line in FIG. The characteristic is obtained by combining with the solid line. Therefore, a change in the opening degree of the valve in response to a change in the operating fluid pressure in the low opening degree region, that is, a change in the flow rate of the fluid is reduced.

The valve characteristic is defined as the opening degree of the valve of the flow control valve 1 with respect to the pressure (operating fluid pressure) of the operating fluid introduced from the operating fluid pressure introducing hole 31 for driving the flow control valve 1, that is, the valve hole. It shows the flow rate of the fluid from 13 to the outlet hole 10.

Accordingly, for example, the resolution of the valve opening degree which is equal to or less than 10,000 minutes of the rated flow required for controlling the flow rate of the supply system and the discharge system for passing a high-purity fluid used in a semiconductor manufacturing apparatus, a liquid crystal manufacturing apparatus, or the like. Can be secured, and the flow rate can be reliably controlled. In particular, improvement in controllability at a low opening degree is effective for liquid control, which generally has a narrower flow control range than gas control.

Further, since it is not necessary to use a device which is relatively weak to a high temperature such as a piezoelectric element and an electronic control unit, it is necessary to surely control the flow rates of a supply system and a discharge system through which a high-temperature fluid exceeding 100 ° C. is passed. Can be achieved, and soaring prices can be suppressed.

In this embodiment, the drive shaft 19
Since the two driving force generators 37 and 38 are arranged side by side in the axial direction, the pressure receiving areas of the diaphragms 40 and 41 required for driving the driving shaft 19 are surely secured.
The size of the spring cover 27 is suppressed.

Further, since the sheets 45 made of aramid fiber or the like are embedded in the diaphragms 40 and 41 made of rubber or the like in the fluid chambers 37a and 38a, the diaphragm 4 is used.
It is possible to improve the mechanical strength of 0, 41 and the durability.

Also, valves used for supplying or discharging a high-purity fluid such as a semiconductor manufacturing apparatus such as the flow rate control valve 1 and a liquid crystal manufacturing apparatus described above have an opening of 0%.
In some cases, the moving stroke of the drive shaft in the range from to 100% is very small, for example, 0.3 mm.

On the other hand, the dimensional error in the thickness direction of the disc spring used in the first and second urging means in the initial state (free state) is generally about ± 0.1 mm.

For example, the second disc spring urges the drive shaft in a direction in which the valve body separates from the valve seat in a low opening range up to a second predetermined opening such as a movement stroke of the drive shaft of 30%. In this case, it is conceivable that the range in which the second disc spring biases the drive shaft varies within the range of 0% to about 63% of the above-described movement stroke.

For this reason, it is conceivable that the flow characteristics of each flow control valve vary, and in the worst case, the valve closing performance such that the valve body does not contact the valve seat via a metal diaphragm or the like. Can be lost.

FIGS. 13 and 14 show a flow control valve 1 according to a second embodiment of the present invention which has solved the above-mentioned problems. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

The flow control valve 1 of the present embodiment comprises at least one of the two ends 23a and 23b of the first disc spring 23 and the two ends 24a and 24b of the second disc spring 23.
And first and second spring receiving position adjusting mechanisms 56 and 57 for adjusting the position of at least one end along the drive shaft 19, respectively.

The first and second flow control valves 1 shown in FIG.
The spring receiving position adjusting mechanisms 56 and 57 respectively include the spring receiving members 16b and 20b and the first and second disc springs 23 and
The spacers 58 and 5 are located between the first ends 23a and 24a.
9 and the drive shaft 1 of these one end portions 23a, 24a.
The position along line 9 is adjusted. The thicknesses of these spacers 58, 59 are respectively set to the disc springs 23, 2
It is desirable to form them according to the thickness error in the initial state of No. 4.

The flow control valve 1 shown in FIG. 14 has a support member 21 divided into an inner support member 21a and an outer support member 21b. These support members 21a and 21b are screwed together. Grooves 60a and 60b are provided. The inner peripheral support member 21a integrally includes a spring support portion 21c that supports one end 24a of the second disc spring 24. The second disc spring 24 includes a spring support 21c and a step 19a.
And is provided between them.

The flow control valve 1 adjusts the distance between the other end 24b of the second disc spring 24 in the free state and the step 19a by adjusting the screwing amount of the screw grooves 60a and 60b. The position of the other end 24b with respect to the drive shaft 19 is adjusted.

The drive shaft 19 is divided into a distal end portion 61a and a proximal end portion 61b for pressing the valve body 16, and the distal end portion 61a and the proximal end portion 61b are threaded with each other. 62a and 62b are provided. By adjusting the screwing amounts of these screw grooves 62a and 62b, the distance between the other end 23b of the first disc spring 23 in the free state and the tip end surface 19b is adjusted, and the drive shaft of the other end 23b is adjusted. Adjustment of the position with respect to 19 is performed.

The inner and outer peripheral supporting members 21a, 21b
The screw grooves 60a and 60b constitute a second spring receiving position adjusting mechanism 57. The distal end 61a, the proximal end 6
1b and the screw grooves 62a, 62b constitute a first spring receiving position forming mechanism 56.

According to the present embodiment, similar to the first embodiment, for example, the flow rate of a supply system and a discharge system required for passing a high-purity fluid used in a semiconductor manufacturing apparatus or a liquid crystal manufacturing apparatus is controlled. It is possible to ensure the resolution of the opening degree of the valve which is equal to or less than 10,000 minutes of the rated flow rate, and it is possible to reliably control the flow rate. In particular, improvement in controllability at a low opening degree is effective for liquid control, which generally has a narrower flow control range than gas control.

Further, it is possible to reliably control the flow rates of the supply system and the discharge system through which the high-temperature fluid passes, and it is possible to suppress a rise in price and increase in size, and to improve durability.

In addition, the first and second disc springs 23, 2
4 is very large compared to the moving stroke of the drive shaft 19, for example, 0.1 mm.
And the second spring receiving position adjusting mechanisms 56 and 57
Ends 23a, 23 of the first and second disc springs 23, 24
The positions of b, 24a and 24b can be adjusted. Therefore,
Variations in the flow characteristics and the valve seat shutoff performance for each flow control valve 1 can be suppressed, and the desired flow characteristics and valve seat shutoff performance can always be stably secured.

In the first and second embodiments, as shown in FIG. 12, the driving mechanism 3 includes a driving spring 36 as a driving shaft urging means, and first and second driving force generating means. The casing 37 and the spring case 27 are
It may be configured to be housed inside.

In the drive mechanism 3 shown in FIG. 12, a drive spring 36 is arranged on the partition wall 30 of the casing 26, and a bearing 51, a spring receiver 48 and a drive plate 35 are placed on the drive spring 36. First and second
Are provided. The drive spring 36 urges the drive shaft 19 in a direction away from the valve body 16.

The support flange 48a of the spring receiver 48
The drive plate 35 is disposed on the second drive force generating section 38,
It is arranged on the driving plate 35. The first driving force generation unit 37 is disposed on the second driving force generation unit 38 via the outer peripheral intermediate member 49, the inner peripheral intermediate member 50, and the driving plate 34.

First and second driving force generators 37 and 38
Includes diaphragms 40, 41 and first and second connecting members 42, 43, respectively. The diaphragms 40, 41 and the first and second connecting members 42, 43 constitute ring-shaped first and second fluid chambers 37a, 38a. The first connection member 42 is provided with a fluid introduction hole 44 that communicates with the operating fluid pressure communication hole 32 and opens to the fluid chambers 37a and 38a. Diaphragms 40, 41
Have bent portions 40a and 41a, respectively.

First and second driving force generators 37 and 38
Are provided with their respective outer peripheral ends sandwiched between the casing 26, the spring case 27, and the outer peripheral intermediate member 49. Further, the first and second driving force generating portions 37 and 38 have respective inner peripheral edges, a support flange 48 a of a spring receiver 48, a nut 63 screwed into an end of the drive shaft 19, and an inner peripheral intermediate member 50. It is attached and fixed to the drive shaft 19 in a state of being sandwiched therebetween.

The upper wall 27a of the spring case 27 has a pressure of the operation fluid supplied into the first and second drive generators 37 and 38 lower than a predetermined pressure. When the nut 63 is displaced along the arrow R1, the stopper comes into contact with the nut 63. The casing 26 has a gap between the casing 26 and the second drive plate 35 along the drive direction of the drive shaft 19 in accordance with the drive stroke of the drive shaft 19.

According to the above-described configuration, the pressure of the operating fluid supplied from the operating fluid pressure introducing hole 37 to the fluid chambers 37a, 38a of the first and second driving force generating units 37, 38 is lower than a predetermined pressure. When the height is lowered, the driving shaft 36, the second connecting member 43 of the first and second driving force generating parts 37 and 38, and the inner peripheral intermediate member 50 are driven by the driving spring 36.
The drive plates 34 and 35 are integrally pushed together along an arrow R1 shown in FIG. Then, the drive shaft 19
Of the metal diaphragm 6 by the valve body 16 is released. As a result, the metal diaphragm 6 separates from the valve seat 11, and the valve hole 13 is opened.

When the pressure of the operating fluid supplied from the operating fluid pressure introducing hole 31 becomes higher than the predetermined pressure, the diaphragms 40 and 41 push down the driving plates 34 and 35, and the driving shaft 19 and the first And second driving force generating unit 3
The second and third connecting members 43, the inner peripheral intermediate member 50, and the driving plates 34, 35 are integrally pushed down along the arrow R2 shown in FIG. Therefore, one end 17 of the drive shaft 19 abuts on the valve body 16, and the metal diaphragm 6 is pressed against the valve seat 11. Therefore, the valve hole 1
3 is closed.

As described above, in this case, the diaphragm 40,
Reference numeral 41 denotes an operating fluid having a pressure higher than a predetermined pressure.
When it is introduced into 8a, it is displaced toward the valve body 16 and drives the drive shaft 19 in a direction approaching the valve body 16.

In the first and second embodiments, when the driving shaft 19 is driven in a direction away from the valve body 16,
Throttling mechanisms 71 and 7 shown in FIGS. 15 to 17 for gradually increasing the fluid flow path from the valve hole 13 to the outflow hole 10.
Either of the diaphragm mechanisms 2 and 73 may be provided.

The first throttle mechanism 71 shown in FIG. 15 has a convex portion 74 formed on the valve seat 11 and a throttle valve element 75 attached to the valve element 16. The convex portion 74 is provided in the valve seat 1.
1 is provided on the surface facing the valve body 16 and around the valve hole 13. The convex portion 74 is formed so as to protrude toward the valve body 16 to narrow the flow path of the fluid.

The throttle valve element 75 is provided at the tip of the valve element 16 so as to project toward the valve hole 13. The throttle valve element 75 includes an umbrella section 76 and a mounting section 77 integrally. The umbrella portion 76 is formed so as to gradually taper toward the valve hole 13. The umbrella portion 76 has an outer diameter of the valve hole 1.
3 is formed slightly smaller than the inner diameter. Mounting part 77
Is formed in a column shape, and a base end thereof is attached to the valve body 16.

The throttle valve element 75 is mounted on the valve element 16 with the mounting portion 77 penetrating the metal diaphragm 6 so that the umbrella part 76 can be inserted into the valve hole 13. The throttle valve element 75 is attached to the valve element 16 with the metal diaphragm 6 interposed between the inner surface 76 a of the umbrella portion 76 and the distal end surface of the valve element 16.

The first throttle mechanism 71 includes a throttle valve 75
The umbrella portion 76 and the convex portion 74 of the valve seat 11 narrow the flow path of the fluid from the valve hole 13 to the outflow hole 10, and when the drive shaft 19 is driven in a direction away from the valve body 16, Particularly in the low opening region, the flow rate of the fluid from the valve hole 13 to the outlet hole 10 is gradually increased.

Next, the second aperture mechanism 72 shown in FIG.
Will be described. The same components as those of the first aperture mechanism 71 are denoted by the same reference numerals, and description thereof will be omitted. The second throttle mechanism 72 includes a convex portion 74 and a throttle valve element 75a.

In the throttle valve element 75a, the outer diameter of the umbrella portion 76 is formed larger than the inner diameter of the valve hole 13. Throttle valve element 75a
The umbrella portion 76 comes into contact with the convex portion 74 and narrows the flow path of the fluid from the valve hole 13 to the outflow hole 10.

The third aperture mechanism 73 shown in FIG. 17 will be described. The same components as those of the first aperture mechanism 71 and the second aperture mechanism 72 are denoted by the same reference numerals, and description thereof will be omitted. The third diaphragm mechanism 73 includes a convex part 74 and a diaphragm part 78.

The throttle portion 78 is formed by projecting toward the valve hole 13 so that a part of the metal diaphragm 6 can be inserted into the valve hole 13.
The flow path of the fluid leading to is narrowed.

These throttle mechanisms 71, 72, 73 narrow the fluid flow path from the valve hole 13 to the outlet hole 10. For this reason, as compared with the two-dot chain line Q shown in FIG. 20, the flow path of the fluid is narrowed, so that the flow control valve 1 having these throttle mechanisms 71, 72, 73
As shown by the solid line, the flow rate of the fluid is not proportional to the moving distance of the drive shaft 19, and the flow rate of the fluid gradually increases.

A two-dot chain line Q shown in FIG. 20 indicates a conventional fluid pressure operated valve 101 which does not have the throttle mechanisms 71, 72 and 73. In the conventional fluid pressure operated valve 101, the flow rate of the fluid is proportional to the moving distance of the drive shaft 19 as shown in the figure.

As described above, the aperture mechanisms 71, 72, 73
When the drive shaft 19 is driven in a direction away from the valve body 16, particularly when the drive shaft 19 is driven in a low opening degree region,
The flow rate of the fluid that reaches zero is gradually increased.

For this reason, the change in the flow rate of the fluid from the valve hole 13 to the outflow hole 10 due to the change in the operating fluid pressure in the low opening region is reduced. Therefore, it is possible to secure the resolution of the opening degree of the valve required for controlling the flow rate of the supply system and the discharge system through which a high-purity fluid such as a semiconductor manufacturing apparatus or a liquid crystal manufacturing apparatus passes.

Further, the first to third aperture mechanisms 7
1, 72 and 73, the valve seat 11 provided with the convex portion 74 is provided.
May be formed of resin or the like and fixed in the inner chamber 7 using the orifice sheet 12.
And the orifice sheet 12 may be integrally formed from metal or the like. Further, the valve seat 11 may be formed of resin or the like, and may be directly attached to the valve box 2 by caulking or the like without using the orifice sheet 12 or the like. good.

Further, in the first and second embodiments, a third disc spring 81 as a third urging means may be provided between the support member 21 and the drive shaft 19. The third disc spring 81 moves the drive shaft 19 in a region where the opening of the valve 1 is from 0% to a third predetermined opening K3, for example, 60% larger than the second predetermined opening K2 described above. Valve body 1
6 urges in a direction away from the valve seat 11.

When the third disc spring 81 is provided together with the above-mentioned second disc spring 24, the third disc spring 81 is provided in the low opening range where the opening of the valve 1 is from 0% to the second predetermined opening K2. 2
Of the disc spring 24 and the third disc spring 81 are the valve body 16 and the valve seat 1.
The drive shaft 19 is biased in a direction away from 1.

Therefore, the off-balance of the flow control valve 1 is represented by the off-balance O1 of the conventional fluid pressure operated valve 101 shown by a two-dot chain line Q in FIG. 19 and the second disc spring 24 shown by a one-dot chain line Q1 in FIG. However, the off-balance O2 is reduced to the off-balance O3 indicated by the solid line in the figure.

As described above, by using the third disc spring 81, the off-balance is further reduced, so that the change in the valve opening, that is, the change in the flow rate of the fluid with respect to the change in the operating fluid pressure in the low opening range is further reduced. Will be done.

[0146]

According to the present invention described in detail above, in the low opening region of the flow control valve, the first urging means urges the pressing portion toward the valve seat. Even if the drive shaft is driven in a direction away from the control unit due to the pressure fluctuation of the operating fluid, the metal diaphragm can be pressed down to the valve seat via the pressing unit until the opening degree is several percent. Therefore, the metal diaphragm does not immediately come off the valve seat, and the opening area of the valve hole does not increase rapidly.

In the low opening region, the second urging means urges the pressing portion in a direction away from the valve seat, so that the flow control valve is easily opened and the off-balance in valve characteristics is reduced. It will be.

In addition, since the driving section of the driving means drives the driving shaft away from the pressing section by deformation of the diaphragm, the O-ring which generates a large frictional resistance required by the conventional piston-type fluid pressure operated valve is required. Can be omitted. For this reason, the driving means is driven smoothly, and the hysteresis in the valve characteristics can be reduced.

Further, when the drive shaft biasing means constituting the drive means is a spring and is supported by a spring receiver of the drive shaft via a bearing, the drive shaft biasing means is adapted to be connected to the drive shaft during expansion and contraction. Rotation around does not hinder this rotation by the bearings. For this reason, the driving means is driven more smoothly, and the hysteresis in the valve characteristics can be further reduced.

As described above, the second urging means reduces the off-balance, and the first urging means prevents the metal diaphragm from being immediately separated from the valve seat even when the driving means is driven, and the driving means of the driving means. Since the frictional resistance is suppressed, a change in the opening degree of the valve with respect to a change in the pressure of the operating fluid particularly in a low opening degree region is reduced. Therefore, it is possible to secure the resolution of the opening degree of the valve required for controlling the flow rate of the supply system and the discharge system through which a high-purity fluid such as a semiconductor manufacturing apparatus or a liquid crystal manufacturing apparatus passes.

In particular, improvement in controllability at a low opening degree is more effective for control of a liquid having a smaller flow rate control range than control of a fluid.

Further, since the driving section of the driving means has a plurality of driving force generating sections arranged in the axial direction of the driving shaft,
Despite the addition of the second biasing means, it is possible to sufficiently secure the output when driving the drive shaft toward the pressing portion, and to increase the size of the drive portion in the radial direction of the drive shaft. There is an advantage that it can be prevented.

[Brief description of the drawings]

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

FIG. 2 is a plan view of a spring case of the flow control valve as viewed from a direction of an arrow ii shown in FIG. 1;

FIG. 3 is a cross-sectional view of the flow control valve along a line iii-iii shown in FIG. 1;

FIG. 4 is a sectional view showing a valve body and a valve seat of the embodiment shown in FIG. 1;

FIG. 5 is a sectional view showing the outer chamber of the embodiment shown in FIG. 1;

FIG. 6 is a sectional view showing the fluid chamber of the embodiment shown in FIG. 1;

FIG. 7 is a view showing the operation of the second disc spring of the embodiment shown in FIG. 1;

FIG. 8 is a view showing the operation of the first disc spring of the embodiment shown in FIG. 1;

FIG. 9 is a view showing valve characteristics of the embodiment shown in FIG. 1;

FIG. 10 is an exemplary sectional view showing a modification of the valve seat of the embodiment;

FIG. 11 is an exemplary sectional view showing a modified example of the valve body and the valve seat of the embodiment;

FIG. 12 is a sectional view showing a modified example of the drive mechanism of the flow control valve of the present invention.

FIG. 13 is a sectional view showing a main part of a flow control valve according to a second embodiment of the present invention.

FIG. 14 is a sectional view showing a modification of the main part of the flow control valve according to the second embodiment of the present invention.

FIG. 15 is a sectional view showing a first throttle mechanism of the flow control valve of the present invention.

FIG. 16 is a sectional view showing a second throttle mechanism of the flow control valve of the present invention.

FIG. 17 is a sectional view showing a third throttle mechanism of the flow control valve of the present invention.

FIG. 18 is a sectional view showing a main part of the flow control valve of the present invention provided with a third disc spring.

FIG. 19 is a view showing the operation of the third disc spring of the present invention.

FIG. 20 is a view showing the operation of the aperture mechanism of the present invention.

FIG. 21 is a sectional view showing a conventional mass flow controller.

FIG. 22 is a sectional view showing a conventional fluid pressure operated valve.

FIG. 23 is a view showing valve characteristics of the fluid pressure operated valve shown in FIG. 22.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Flow control valve 2 ... Valve box 3 ... Drive mechanism (drive means) 6 ... Metal diaphragm 9 ... Inlet hole 10 ... Outlet hole 11 ... Valve seat 12 ... Orifice sheet 13 ... Valve hole 14 ... Orifice hole 16 ... Valve ( 16a ... End face 16b ... Spring receiver 19 ... Drive shaft 20 ... Guide member 20a ... End face 20b ... Spring receiver 23 ... First disc spring (first biasing means) 24 ... Second disc spring (second) 23a, 23b ... Ends 24a, 24b ... Ends 28 ... Driving unit 36 ... Driving spring (drive shaft urging means) 37 ... First driving force generating unit 37a ... Fluid chamber 38 ... Second Drive force generating portion 38a: fluid chambers 40, 41 ... diaphragms 40a, 41a ... bent portion 45 ... sheet (reinforcement sheet) 56 ... first spring receiving position adjusting mechanism 56 ... second spring receiving position adjusting mechanism 71, 72 , 73 Iris mechanism

Claims (17)

[Claims] 1. A valve box having an inflow hole and an outflow hole connected to the inflow hole; a valve seat disposed in the valve box and having a valve hole positioned between the inflow hole and the outflow hole; A pressing portion supported by the valve box so as to be movable toward and away from the valve seat; a metal diaphragm interposed between the pressing portion and the valve seat to open and close the valve hole; A drive shaft for removably contacting the drive shaft, a drive shaft biasing means for biasing the drive shaft toward the pressing portion to press the metal diaphragm against the valve seat via the pressing portion, and an external A driving unit that drives the drive shaft in a direction away from the pressing unit in accordance with the magnitude of the pressure of the operating fluid introduced from the unit; When pressed, urges the pressing portion toward the valve seat. And a first biasing means. 2. A valve box having an inflow hole and an outflow hole connected to the inflow hole; a valve seat disposed in the valve box and having a valve hole positioned between the inflow hole and the outflow hole; A pressing portion supported by the valve box so as to be movable toward and away from the valve seat; a metal diaphragm interposed between the pressing portion and the valve seat to open and close the valve hole; A drive shaft for removably contacting the drive shaft, a drive shaft biasing means for biasing the drive shaft toward the pressing portion to press the metal diaphragm against the valve seat via the pressing portion, and an external A drive unit for driving the drive shaft in a direction away from the pressing unit according to the magnitude of the pressure of the operating fluid introduced from the unit; and a low opening in which the drive shaft approaches the pressing unit. In the area, move the drive shaft away from the pressing portion And a second biasing means for biasing the flow rate control valve. 3. A valve box having an inflow hole and an outflow hole connected to the inflow hole; a valve seat disposed in the valve box and having a valve hole positioned between the inflow hole and the outflow hole; A pressing portion supported by the valve box so as to be movable toward and away from the valve seat; a metal diaphragm interposed between the pressing portion and the valve seat to open and close the valve hole; A drive shaft for removably contacting the drive shaft, a drive shaft biasing means for biasing the drive shaft toward the pressing portion to press the metal diaphragm against the valve seat via the pressing portion, and an external A driving unit that drives the drive shaft in a direction away from the pressing unit in accordance with the magnitude of the pressure of the operating fluid introduced from the unit; When pressed, urges the pressing section toward the valve seat. A first urging means for energizing; and a second urging means for urging the driving shaft in a direction away from the pressing part in a low opening degree region where the driving shaft approaches the pressing part. A flow control valve. 4. A valve box having an inflow hole and an outflow hole connected to the inflow hole; a valve seat disposed in the valve box and having a valve hole positioned between the inflow hole and the outflow hole; A pressing portion supported by the valve box so as to be movable toward and away from the valve seat; a metal diaphragm interposed between the pressing portion and the valve seat to open and close the valve hole; A drive shaft that comes into contact with and releasable from the pressurizing unit; a drive shaft biasing unit that biases the drive shaft in a direction away from the pressing unit; Driving means for driving a shaft in a direction approaching the pressing portion, pressing the metal diaphragm against the valve seat via the pressing portion to enable a valve closed state;
A first urging means for urging the pressing portion toward the valve seat when the drive shaft is driven in a direction away from the pressing portion; 5. A valve box having an inflow hole and an outflow hole connected to the inflow hole; a valve seat disposed in the valve box and having a valve hole positioned between the inflow hole and the outflow hole; A pressing portion supported by the valve box so as to be movable toward and away from the valve seat; a metal diaphragm interposed between the pressing portion and the valve seat to open and close the valve hole; A drive shaft that comes into contact with and releasable from the pressurizing unit; a drive shaft biasing unit that biases the drive shaft in a direction away from the pressing unit; Driving means for driving a shaft in a direction approaching the pressing portion, pressing the metal diaphragm against the valve seat via the pressing portion to enable a valve closed state;
A second urging means for urging the drive shaft in a direction away from the pressing portion in a low opening degree region where the driving shaft approaches the pressing portion. 6. A valve box having an inflow hole and an outflow hole connected to the inflow hole; a valve seat disposed in the valve box and having a valve hole positioned between the inflow hole and the outflow hole; A pressing portion supported by the valve box so as to be movable toward and away from the valve seat; a metal diaphragm interposed between the pressing portion and the valve seat to open and close the valve hole; A drive shaft that comes into contact with and releasable from the pressurizing unit; a drive shaft biasing unit that biases the drive shaft in a direction away from the pressing unit; Driving means for driving a shaft in a direction approaching the pressing portion, pressing the metal diaphragm against the valve seat via the pressing portion to enable a valve closed state;
First biasing means for biasing the pressing portion toward the valve seat when the drive shaft is driven away from the pressing portion; a low opening area in which the driving shaft approaches the pressing portion; And a second biasing means for biasing the drive shaft in a direction away from the pressing portion. 7. The method according to claim 1, wherein the flow rate of the fluid from the valve hole to the outflow hole is reduced when the drive shaft is driven in a direction away from the pressing portion. A flow control valve comprising a throttle mechanism for gradually increasing the flow rate. 8. A valve box having an inflow hole and an outflow hole connected to the inflow hole; a valve seat disposed in the valve box and having a valve hole positioned between the inflow hole and the outflow hole; A pressing portion supported by the valve box so as to be movable toward and away from the valve seat; a metal diaphragm interposed between the pressing portion and the valve seat to open and close the valve hole; A drive shaft that comes into contact with and releasable from, and presses the metal diaphragm against the valve seat via the pressing portion by urging the driving shaft toward the pressing portion, or connects the driving shaft to the pressing portion. A drive unit having a drive shaft biasing unit that biases the drive shaft in a direction away from the drive unit, and a drive unit that drives the drive shaft in accordance with the magnitude of the pressure of the operation fluid introduced from the outside; When the shaft is driven away from the pressing part A throttle mechanism for gradually increasing the flow rate of the fluid from the valve hole to the outlet hole. 9. The method according to claim 1, wherein a flow rate of the fluid from the valve hole to the outlet hole is kept uniform between the valve hole and the outlet hole. A flow control valve comprising an orifice sheet having an orifice hole. 10. The drive shaft biasing means according to claim 1, wherein the drive shaft biasing means is a spring arranged coaxially with the drive shaft, and the drive shaft is A flow control valve having a spring receiver at a shaft end thereof, and the spring is supported by the spring receiver via a bearing. 11. The driving device according to claim 1, wherein the driving unit of the driving unit includes a fluid chamber into which the operating fluid is introduced, and the operating fluid in the fluid chamber. And a diaphragm that is displaced in a direction away from the pressing portion when the diaphragm is introduced, and wherein the diaphragm includes a driving force generating portion connected to the driving shaft. 12. The driving unit according to claim 4, wherein the driving unit of the driving unit includes a fluid chamber into which the operating fluid is introduced, and the operating fluid in the fluid chamber. And a diaphragm that is displaced in a direction approaching the pressing portion when is introduced, wherein the diaphragm includes a driving force generating portion connected to the driving shaft. 13. The flow control valve according to claim 11, wherein a reinforcing sheet using aramid fiber or the like is embedded in the diaphragm. 14. The flow control valve according to claim 11, wherein the diaphragm has a bent portion which is curved in a waveform. 15. The flow control valve according to claim 11, wherein a plurality of the driving force generators are arranged along an axial direction of the drive shaft. 16. The method according to claim 1, wherein the first signal is transmitted through the first terminal.
Is a spring disposed coaxially with the drive shaft, and the pressing portion has a spring receiver for supporting an end of the spring on an end surface thereof. A flow control valve comprising a first spring receiving position adjusting mechanism for adjusting a position along the drive shaft. 17. The method according to claim 2, wherein the second one of the second, third, fifth, and sixth aspects is the same as the second one.
The biasing means is a spring arranged coaxially with the drive shaft, and further comprises guide means having a spring receiver for guiding the drive direction of the drive shaft and supporting an end of the spring. A flow control valve comprising a second spring receiving position adjusting mechanism for adjusting a position of the end portion along the drive shaft.