JP7217501B2 - diaphragm valve - Google Patents

Description

TECHNICAL FIELD The present invention relates to a diaphragm valve suitable for use as a diaphragm valve for flowing liquids such as high-purity chemicals and ultrapure water in semiconductor manufacturing equipment.

Conventionally, this type of diaphragm valve includes a cylindrical housing, a diaphragm supported in the housing so as to be curved in the axial direction, and a diaphragm assembled in the housing to be curved in the axial direction. It is composed of a drive mechanism that drives like this.

Here, when the diaphragm valve is closed, the driving mechanism receives the biasing force of the coil spring and axially moves the piston together with the piston shaft toward the diaphragm, thereby bending and displacing the diaphragm in the axial direction. and seat it on the annular valve seat at its center. Further, when the diaphragm valve is opened, the piston receives air pressure and axially moves together with the piston shaft in a direction opposite to the above-described axial motion against the biasing force of the coil spring. The diaphragm is curvedly displaced in the axial direction and separated from the annular valve seat at its central portion.

When a diaphragm valve having such a configuration is used in semiconductor manufacturing equipment, highly corrosive chemicals such as strong acids and strong alkalis are used as high-purity chemicals in the cleaning and peeling processes of the semiconductor manufacturing equipment. As the material for forming the diaphragm in the diaphragm valve, it is desirable to employ fluororesin, which is excellent in chemical resistance such as acid resistance and alkali resistance.

In addition, in semiconductor manufacturing equipment, elution of metal components and organic components from diaphragm valves is not permitted, so it is desirable to employ a fluororesin having low elution properties as the material for forming the diaphragm.

Moreover, it is desirable to employ a fluororesin that has excellent flexibility and can maintain a long life in view of the construction of the diaphragm valve as described above.

For the reasons described above, it is required to employ a fluororesin, which has chemical resistance, low elution, excellent flexibility, and can maintain a long life, as a material for forming the diaphragm.

Japanese Patent No. 5286330

By the way, in the diaphragm valve having the above-described configuration, since contamination of the liquid by particles from the diaphragm valve is not allowed in the semiconductor manufacturing equipment, the liquid flowing through the flow path system in the diaphragm valve is It is necessary to isolate it from the driving mechanism, and for that purpose, it is required that the diaphragm is integrally constructed with an outer peripheral portion, a curved displacement portion and a central portion.

Here, when PTFE is adopted as the material for forming the diaphragm, since PTFE has a low melt flow rate, it is impossible to form a diaphragm of good quality by injection molding or extrusion molding. Therefore, the diaphragm is formed by cutting a compression-molded round bar of PTFE.

Although the PTFE diaphragm formed by cutting has a long service life, in a diaphragm valve using such a diaphragm, the curved displacement portion formed by cutting extends or extends on the surface as the diaphragm valve is operated. Due to the compression, fine particles are generated from the curved displacement portion. However, such dust generation is within an allowable range, for example, when the wiring pitch of a silicon wafer manufactured by a semiconductor manufacturing apparatus is larger than 10 (nm).

When PFA is used instead of PTFE as the material for forming the diaphragm, the diaphragm is formed by cutting an injection-molded round bar, a compression-molded round bar, or an extrusion-molded round bar.

The life of the PFA diaphragm formed by cutting in this way is short. In addition, in the diaphragm valve using the PFA diaphragm formed by cutting in this way, the PTFE diaphragm formed by cutting is displaced on the surface of the curved displacement portion formed by cutting along with the operation. As with the curved displacement portion, since the curved displacement portion is stretched or compressed, fine particles are generated from the curved displacement portion.

Here, when PFA is adopted as the material for forming the diaphragm, and the PFA is used to form a thick curved portion by injection molding and by cutting, the thickness of the diaphragm is formed by injection molding or compression molding. When molded into a meat shape, crystallization does not occur uniformly at the curved displacement portion, and the interface becomes a starting point of fracture and life is shortened. .

On the other hand, in recent years, there has been a demand for further miniaturization in the production of semiconductor elements, such as silicon wafers, by semiconductor production apparatuses. For example, there is a demand to reduce the wiring pitch on a silicon wafer to 10 (nm) or less. Therefore, even particles with a size of several nanometers are not allowed to be generated from the diaphragm valve.

However, as described above, in a diaphragm valve using a diaphragm formed by cutting, the surface of the curved displacement portion formed by cutting is stretched or compressed during its operation. Dust is produced, albeit minutely.

In such a case, it is not possible to cope with the situation where even particles with a size of several nanometers are not permitted to be generated from the diaphragm valve. requested.

On the other hand, since the PFA film is thin, the crystallization can be made uniform. If adopted, it was recognized that it would lead to the improvement of the above-mentioned diaphragm.

By the way, in the above-described diaphragm valve, due to its configuration, the diaphragm is connected at its central portion to the drive shaft of the drive mechanism when the diaphragm is curvedly displaced by the drive mechanism.

However, since the diaphragm is in the form of a film and is very thin as described above, it is impossible to form the connecting portion necessary for connecting with the drive shaft of the drive mechanism in the central portion of the diaphragm. Therefore, it is extremely difficult to connect the central portion of the diaphragm to the drive shaft of the drive mechanism without the connecting portion.

In order to solve this problem, it is conceivable to use a configuration of a diaphragm valve that applies laser welding according to the resin diaphragm sealing method described in Patent Document 1 above.

In the diaphragm valve disclosed in Patent Document 1, the flange portion of the diaphragm is laser-welded to the flange portion of the lower housing so as to seal the valve body chamber for the purpose of sealing. Focusing on such a fact, it is presumed that it would be possible to use laser welding to connect the central portion of the PFA diaphragm and the drive shaft of the drive mechanism.

On the other hand, for this reason, even if the connection between the central part of the PFA diaphragm and the drive shaft of the drive mechanism is realized by joining by laser welding, when the diaphragm valve is closed, the piston is attached to the coil spring. The piston shaft is seated on the annular valve seat via the central portion of the diaphragm against the hydraulic pressure according to the force. This means that the diaphragm seats in its central portion on the annular valve seat. At this time, the impact force of the piston shaft applied to the central portion of the diaphragm seated on the annular valve seat is determined by the magnitude of the spring load of the coil spring.

Here, as the spring load of the coil spring, in addition to the load required to allow the diaphragm to sit on the annular valve seat at an appropriate speed in the central portion against the pressure of the liquid, the load to even out the rough surface of the diaphragm is required. It is said that For this reason, the spring load of the coil spring inevitably increases, and along with this, the greater the spring load of the coil spring, the greater the impact force of the piston shaft applied to the central portion of the diaphragm seated on the annular valve seat. growing.

For this reason, when the above-mentioned impact force is repeatedly applied to the central portion of the diaphragm seated on the annular valve seat, the diaphragm is broken at the central portion, and the broken portion of the diaphragm accompanying the breakage is minute. It turns into fine particles and easily mixes in the liquid. This does not keep the liquid clean. This is even more pronounced if the diaphragm is thin like a film as described above. Therefore, even if the diaphragm is thin like a film, the generation of minute particles due to damage such as breakage of the central portion of the diaphragm, which tends to occur due to the above-mentioned impact force, and the mixing of the particles into the liquid are suppressed as much as possible. There is a need.

Therefore, in order to cope with the above problems, the present invention forms a film-like PFA that can ensure flexibility and long life, and a diaphragm that can suppress dust generation of about several nanometers to a minimum. In addition to selecting the material, even if the diaphragm is thin like a film, the impact force on the central part of the diaphragm due to the drive shaft of the driving means is mitigated as much as possible, and the damage to the central part of the diaphragm that tends to occur due to the impact force is caused. It is an object of the present invention to provide a diaphragm valve capable of suppressing as much as possible minute dust generation and mixing of the dust into liquid.

In order to solve the above problems, according to the description of claim 1, the diaphragm valve according to the present invention allows a high-purity chemical solution or ultrapure water to flow from the inflow side to the outflow side when the valve portion is opened, and , to block the flow of the liquid to the outflow side as the valve portion closes.

In the diaphragm valve,
A housing (100, 100a, 100b) having a cylindrical peripheral wall (130, 112) and opposed walls (110a, 140) formed on the cylindrical peripheral wall so as to close the openings at both ends in the axial direction. )and,
It is provided at an axially intermediate portion of the cylindrical peripheral wall to form a one-sided hollow portion between one of the opposed walls (140) and the other opposed wall (110a) on the other side. a partition wall (120) that partitions the interior of the cylindrical peripheral wall so as to form a hollow portion;
a driving means (300) provided in the one-side hollow portion of the cylindrical peripheral wall;
It is provided in the other side hollow portion of the cylindrical peripheral wall to form a liquid chamber (Ra) with the other opposing wall (110a) and form an air chamber (Rb) with the partition wall (120). A film-like diaphragm (200a) made of PFA that partitions the hollow part on the other side so as to
a fluororesin annular reinforcing member (200b) joined to the upper surface of the diaphragm along the outer peripheral portion by laser welding in the hollow portion on the other side of the cylindrical peripheral wall ,
The housing includes annular valve seat portions (113, 116) that face the central portion (220) of the diaphragm in the liquid chamber and constitute a valve portion together with the central portion, and the liquid flows from the inflow side through the annular valve seat portion. A one-side channel for flowing into the liquid chamber and the other-side channel for flowing out the liquid in the liquid chamber to the outflow side are provided on the other opposing wall (110a),
The drive means includes drive shafts (320, 320b, 320c) extending axially from the one-side hollow portion through the partition (120) and the air chamber (Rb) so as to face the central portion of the diaphragm; urging means (330) for urging the drive shaft toward the central portion of the diaphragm; and a buffer (340, 420) made of rubber material.

According to such a configuration, the diaphragm is formed as a film-like diaphragm with PFA. Therefore, even if the diaphragm is in the form of a film, it is formed as a diaphragm that is excellent in chemical resistance, low elution, flexibility and long life, and that can suppress dust generation to the minimum (minimum). can be
Further, as described above, the fluororesin annular reinforcing member is joined to the upper surface of the diaphragm along the outer peripheral portion thereof by laser welding. According to this, even if the diaphragm is thin like a film and is difficult to handle, the annular reinforcing body can reinforce the diaphragm with the above-described joining structure by laser welding of the outer peripheral portion of the diaphragm and the annular reinforcing body. can function. Therefore, even if the diaphragm is thin, it can be easily handled without bending.

Here, as described above, the damping body is made of an elastic rubber material and is assembled to the extended end of the drive shaft between the extended end of the drive shaft of the driving means and the central portion of the diaphragm. ing.

Therefore, when the diaphragm valve is closed, when the drive shaft receives the biasing force of the biasing means and moves against the liquid pressure in the liquid chamber toward the other opposing wall, the diaphragm moves toward the drive shaft. It is bent by being pushed by a buffer attached to the extending end of the valve, and is seated on the annular valve seat at the center. Along with this, the drive shaft applies an impact force resulting from the biasing force of the biasing means to the central portion of the diaphragm seated on the annular valve seat via the buffer.

Here, since the damping body is made of an elastic rubber material, the damping body absorbs the impact force from the drive shaft and applies it to the central portion of the diaphragm due to its elasticity.

Therefore, even if the diaphragm valve is repeatedly closed, the shock force applied from the drive shaft to the central portion of the diaphragm is mitigated by the elasticity of the shock absorber each time the valve is closed. Therefore, even if the diaphragm is thin like a film, damage to the central portion of the diaphragm due to the impact force can be minimized due to the above-described mitigation of the impact force. As a result, the generation of dust from the central portion of the diaphragm can be minimized, and the mixing of the generated dust into the liquid can also be minimized.

Further, when the damping body is pressed against the central portion of the diaphragm seated on the annular valve seat portion by the drive shaft as described above, the damping body made of elastic rubber material is pushed against the central portion of the diaphragm due to its elasticity. pressed to. Therefore, even if the upper surface of the diaphragm is roughened, the cushioning body contacts the central portion of the upper surface of the diaphragm without leveling the roughness of the upper surface of the diaphragm so as to adapt to the roughness. Therefore, if the biasing force of the biasing means is greater than the force corresponding to the hydraulic pressure, it is possible to reduce at least the biasing force required to even out the roughness of the upper surface of the diaphragm.

On the other hand, when the diaphragm valve is opened, the drive shaft pivots toward one of the opposing walls against the biasing force of the biasing means. moves away from the central portion of the diaphragm seated on the annular valve seat as the drive shaft moves toward one of the opposing walls. As a result, the diaphragm returns to its original shape and separates from the annular valve seat portion at the central portion under the action of its elasticity or both the elasticity and the hydraulic pressure in the liquid chamber. This causes the liquid to flow from the inflow side to the outflow side.

Here, the liquid minimizes the generation of dust from the diaphragm, which tends to occur when the diaphragm valve is closed, as described above. Dust generation from the central portion during separation can also be minimized because the diaphragm is made of PFA. Therefore, contamination of the diaphragm with the liquid flowing to the outflow side can be minimized. As a result, liquids used in the manufacture of semiconductor devices can be kept clean.

Further, according to the description of claim 2, the diaphragm valve according to the present invention is:
When the valve is opened, the liquid such as high-purity chemicals or ultrapure water is made to flow from the inflow side to the outflow side, and when the valve is closed, the flow of the liquid to the outflow side is blocked. .

In the diaphragm valve,
A housing (100, 100a, 100b) having a cylindrical peripheral wall (130, 112) and opposed walls (110a, 140) formed on the cylindrical peripheral wall so as to close the openings at both ends in the axial direction. )and,
It is provided at an axially intermediate portion of the cylindrical peripheral wall to form a one-sided hollow portion between one of the opposed walls (140) and the other opposed wall (110a) on the other side. a partition wall (120) that partitions the interior of the cylindrical peripheral wall so as to form a hollow portion;
a driving means (300) provided in the one-side hollow portion of the cylindrical peripheral wall;
It is provided in the other side hollow portion of the cylindrical peripheral wall to form a liquid chamber (Ra) with the other opposing wall (110a) and form an air chamber (Rb) with the partition wall (120). A film-like diaphragm (200a) made of PFA that partitions the hollow part on the other side so as to
An annular reinforcing body (410) laminated along the outer peripheral part (210) of the upper surface of the diaphragm, and a central part (220) of the diaphragm facing from the upper surface side of the diaphragm than the annular reinforcing body A buffer body (420) located on the upper side and a curved displacement portion (230 ) integrally formed between the outer peripheral portion and the central portion of the diaphragm are formed in an annular shape facing from the upper surface side of the diaphragm. It is integrally formed of an elastic rubber material so as to have a connection film (430) extending from the inner peripheral part of the reinforcing body toward the buffer body in an inclined manner and connected to the outer peripheral part of the buffer body. and a reinforcing buffer member ( 400a),
The housing includes an annular valve seat portion (113, 116) that faces the central portion of the diaphragm in the liquid chamber and constitutes the valve portion together with the central portion, and the liquid flows from the inflow side through the annular valve seat portion. A one-side channel for flowing into the chamber and the other-side channel for flowing out the liquid in the liquid chamber to the outflow side are provided on the other opposing wall (110a),
The drive means includes drive shafts (320, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b, 320b. 320c) and biasing means (330) for biasing the drive shaft toward the central portion of the diaphragm.

According to such a configuration, the diaphragm is formed as a film-shaped diaphragm with PFA, as in the invention described in claim 1. Therefore, even if the diaphragm is film-shaped, it can It can be formed as a diaphragm that is excellent in flexibility, low elution, flexibility, and long life, and that can suppress dust generation to the minimum (minimum).

Here, as described above, the reinforcing cushioning member different from the cushioning body described in claim 1 is integrally formed of an elastic rubber material so as to have the annular reinforcing body, the connecting film and the cushioning body, The reinforcing cushioning member is laminated on the upper surface of the diaphragm along the outer peripheral portion by the annular reinforcing body. In addition, the damping body is positioned above the annular reinforcing body between the driving shaft and the central portion of the diaphragm, and the connecting film is positioned on the inner peripheral portion of the annular reinforcing body so as to face the curved displacement portion of the diaphragm. and is connected to the outer peripheral portion of the shock absorber.

Here, in the reinforcing cushioning member, as described above, the annular reinforcing body is laminated on the upper surface of the diaphragm along the outer peripheral portion thereof. For this reason, even if the diaphragm is thin like a film and is difficult to handle, the annular reinforcing body is made of an elastic rubber material. Due to its resilience, the body can perform a good reinforcement function on the diaphragm.

Further, when the diaphragm valve is closed, when the driving shaft receives the biasing force of the biasing means and moves against the liquid pressure in the liquid chamber toward the other opposing wall, the reinforcing cushioning member is displaced. The shock absorber is pushed by the drive shaft while deforming the inclined connecting film in the direction of axial movement toward the other opposing wall, and the diaphragm is pushed in the pushing direction by the shock absorber at its central portion. It is pushed and seated on the annular valve seat portion while bending the bending displacement portion. Along with this, the drive shaft applies an impact force resulting from the biasing force of the biasing means to the central portion of the diaphragm seated on the annular valve seat via the cushioning body of the reinforcing cushioning member .

Here, in the reinforcing cushioning member, even if the cushioning body is integrated with the connecting film and the annular reinforcing body, the cushioning body is made of an elastic rubber material. is relaxed and added to the center of the diaphragm.

Therefore, even if the diaphragm valve is repeatedly closed, the shock force applied from the drive shaft to the central portion of the diaphragm is mitigated by the elasticity of the cushioning body of the annular reinforcing body each time the valve is closed. Therefore, even if the diaphragm is thin like a film, damage to the central portion of the diaphragm due to the impact force can be minimized due to the above-described mitigation of the impact force. As a result, the generation of dust from the central portion of the diaphragm can be minimized, and the mixing of the generated dust into the liquid can also be minimized.

In addition, in the reinforcing cushioning member as described above, when the cushioning body is pressed against the central portion of the diaphragm seated on the annular valve seat portion by the drive shaft, the cushioning body made of an elastic rubber material exhibits its elasticity. is pressed against the central portion of the diaphragm under Therefore, even if the upper surface of the diaphragm is roughened, the cushioning body contacts the central portion of the upper surface of the diaphragm without leveling the roughness of the upper surface of the diaphragm so as to adapt to the roughness. Therefore, if the biasing force of the biasing means is greater than the force corresponding to the hydraulic pressure, it is possible to reduce at least the biasing force required to even out the roughness of the upper surface of the diaphragm.

On the other hand, when the diaphragm valve is opened, the driving shaft pivots toward one of the opposed walls against the biasing force of the biasing means, and the connecting membrane is formed because the reinforcing annular body is made of an elastic rubber material. , along with the axial movement of the drive shaft toward one of the opposed walls, the buffer extends upward from the annular reinforcing member in an inclined manner and returns to its original shape, thereby displacing the buffer upwardly away from the central portion of the diaphragm. As a result, the diaphragm returns to its original shape and separates from the annular valve seat portion at the central portion under the action of its elasticity or both the elasticity and the hydraulic pressure in the liquid chamber. At this time, in the reinforcing cushioning member, the connecting membrane is formed of an elastic rubber material so that the cushioning body is positioned above the central side of the annular reinforcing body, so that the diaphragm of the drive shaft of the coupling membrane Deformation according to the direction of axial movement to the central part of the diaphragm and return to the original shape according to the axial movement of the drive shaft of the connecting film in the direction opposite to the central part of the diaphragm, the central part of the diaphragm of the buffer A displacement to and a return to the original position can be well done.

This allows the liquid to flow well from the inflow side to the outflow side.

Here, as described above, since the reinforcing cushioning member is made of a rubber elastic material and integrally composed of the annular reinforcing body, the connecting film, and the cushioning body, the annular reinforcing body has a function of reinforcing the diaphragm. can be secured satisfactorily, and the shock force from the drive shaft against the central portion of the diaphragm seated on the annular valve seat is alleviated in cooperation with the connecting film by the buffer, so that the liquid As described above, dust generation from the diaphragm, which tends to occur when the diaphragm valve is closed, is suppressed to a minimum, and when the diaphragm valve is opened, the central portion of the diaphragm separates from the annular valve seat. Dust generation can also be minimized because the diaphragm is made of PFA. Therefore, contamination of the diaphragm with the liquid flowing to the outflow side can be minimized. As a result, liquids used in the manufacture of semiconductor devices can be kept clean.

Further, according to the description of claim 3, the present invention provides the diaphragm valve according to claim 1,
The damping body includes an engaging portion (340a) that releasably engages with a concave portion (324) formed from the end face portion (323a) of the extending end portion of the drive shaft, and the engaging portion. Base portions (340c, 340d) formed integrally with and contacting the end surface portions of the extending end portion between the end surface portion of the extending end portion of the drive shaft and the central portion of the diaphragm characterized by having

According to this, the attachment of the shock absorber to the extended end portion of the drive shaft can be achieved more specifically. As a result, the effects of the invention described in claim 1 can be achieved more reliably.

According to claim 4 of the present invention, in the diaphragm valve according to claim 3, the base of the buffer may be a flat plate portion (340c).

Further, according to the description of claim 5 of the present invention, in the invention according to claim 3,
The base of the cushioning body is formed in a curved surface portion (343) convex toward the central portion at the end surface portion on the central portion side of the diaphragm,
The annular valve seat (116) is formed by the inner end opening of the other side flow path itself,
The damping body is pressed by the drive shaft to curve such that the central portion of the diaphragm is pushed into the annular valve seat portion in a curved shape.

According to this, the base of the damping body is formed on the end surface of the diaphragm on the central portion side in a curved surface portion that is convex toward the central portion, and the annular valve seat portion is formed at the inner end of the other side flow path. It is formed by the hole itself. Therefore, since the inner diameter of the annular valve seat portion is smaller than the inner diameter of the annular valve seat portion formed so as to protrude from the inner end opening portion of the other side flow path, for example, the inner diameter of the annular valve seat portion with respect to the central portion of the diaphragm , the hydraulic pressure of the liquid becomes even higher. Therefore, the diaphragm can return to its original shape much better both by its self-restoring force and by the hydraulic pressure of the liquid in the liquid chamber.

Further, according to the description of claim 6 , the present invention provides the diaphragm valve according to claim 2,
The reinforcing buffer member is fastened by a fastening member (411) to the outer peripheral portion of the other opposing wall (110a) through the outer peripheral portion of the diaphragm through the annular reinforcing body, and is attached to the buffer by the connecting membrane. It is characterized in that it is formed in such a manner that it is gradually thinned from the outer peripheral portion to the inner peripheral portion of the annular reinforcing body and is formed in a downwardly convex curved shape so as to widen toward the end.

According to this, the connecting film of the reinforcing cushioning member is formed so as to gradually become thin from the outer peripheral portion of the cushioning body to the inner peripheral portion of the annular reinforcing member and to have a downwardly convex curved shape that widens toward the end. Therefore, the connecting membrane can be easily bent and deformed with reference to the outer peripheral side of the annular reinforcing member. As a result, the effects of the second aspect of the invention can be further improved.

Further, according to the description of claim 7 , the present invention provides the diaphragm valve according to claim 1,
The drive means
It is fitted in the one-side hollow portion of the cylindrical peripheral wall between the one opposing wall and the partition wall so as to be slidable along the axial direction thereof to form a one side chamber between the one opposing wall and the other. a piston (310) that partitions the one-side hollow portion of the cylindrical peripheral wall so as to form a side chamber with the partition wall,
The biasing means is a coil spring (330) that biases the piston toward either one of the other side chamber and the one side chamber,
The drive shaft is a piston shaft (320) extending from the piston through the other side chamber so as to face the central portion of the diaphragm,
The damping body is assembled to the extending end of the piston shaft between the extending end of the piston shaft and the central portion of the diaphragm.

According to this, when the diaphragm valve is closed, the piston receives the spring load of the coil spring as an urging force, resisting the hydraulic pressure in the liquid chamber, and pushes the valve into either the other side chamber or the first side chamber. The diaphragm is seated on the annular valve seat at its central portion by the piston shaft interlocking with this sliding, through the buffer body,
On the other hand, when the diaphragm valve is opened, the piston slides against the spring load of the coil spring due to the supply of air flow to the other chamber. The shaft moves away from the central portion of the diaphragm seated on the annular valve seat together with the cushioning body, and the diaphragm returns to its original shape under the action of its elasticity or both the elasticity and the hydraulic pressure in the liquid chamber, It separates from the annular valve seat at the central portion. Thereby, the diaphragm valve functions as an air-operated diaphragm valve.

Even with such an air-operated diaphragm valve, the same effect as the first aspect of the invention can be achieved.

Further, according to the description of claim 8 , the present invention provides the diaphragm valve according to claim 2,
The drive means
It is fitted in the one-side hollow portion of the cylindrical peripheral wall between the one opposing wall and the partition wall so as to be slidable along the axial direction thereof to form a one side chamber between the one opposing wall and the other. a piston (310) that partitions the one-side hollow portion of the cylindrical peripheral wall so as to form a side chamber with the partition wall,
The biasing means is a coil spring (330) that biases the piston toward either one of the other side chamber and the one side chamber,
The drive shaft is characterized by being a piston shaft (320) extending from the piston through the other side chamber and through the buffer of the reinforcing buffer member so as to face the above-mentioned central portion of the diaphragm.

According to such a configuration, when the diaphragm valve is closed, the piston receives the spring load of the coil spring as an urging force, so that the other side chamber and the one side chamber resist the liquid pressure in the liquid chamber. It slides toward one of the chambers while being urged toward the other opposing wall side, interlocking with this sliding , the piston shaft pivots toward the central portion of the diaphragm, and the reinforcing buffer member moves. , the shock absorber is pushed by the piston shaft while deforming the inclined connecting film as the diaphragm moves toward the center, and the diaphragm is pushed by the shock absorber at its center. The bending displacement portion is seated on the annular valve seat portion while being pushed in the moving direction to bend the bending displacement portion;
On the other hand, when the diaphragm valve is opened, the piston slides against the spring load of the coil spring due to the supply of air flow to the other chamber. However, the extending end part thereof separates from the cushioning body of the reinforcing cushioning member, and along with this, the connecting membrane returns to its original shape so as to extend upward from the annular reinforcing body in an inclined manner and cushions. The body is moved away from the central part of the diaphragm and displaced upward, and the diaphragm returns to its original shape under the action of its elastic force or both the elastic force and the hydraulic pressure in the liquid chamber, and the annular valve is formed at the central part. Separate from the seat. This allows the diaphragm valve to function as an air-operated diaphragm valve.

Even with such an air-operated diaphragm valve, the same effects as those of the second aspect of the invention can be achieved.

Further, according to the description of claim 9 , the present invention provides the diaphragm valve according to any one of claims 1 to 8, wherein the diaphragm is formed into a film by extruding or compressing PFA. It is characterized by being

According to such a configuration, in the diaphragm valve, the diaphragm is formed into a film shape by extruding or compressing PFA. As a result, compared to the formation of the diaphragm by cutting, there is less dust generation, and in particular, it has a highly smooth surface that can suppress even dust generation such as particles of several nm size to the minimum (minimum). It is possible to form a diaphragm that is excellent in chemical resistance, low elution, flexibility and long life.

Further, as described above, since the diaphragm is formed into a film by extrusion molding or compression molding of PFA, the diaphragm can be uniformly crystallized around its curved displacement portion. , the life of the diaphragm can be much longer. As described above, the effects of the invention described in any one of claims 1 to 8 can be further improved.

Further, according to the description of claim 10 , the present invention provides a diaphragm valve according to claim 9 ,
The diaphragm is characterized by having a thickness within the range of 0.1 (mm) or more and 0.6 (mm) or less.

According to this, the effect similar to the effect of invention of Claim 9 can be achieved much more reliably. Here, the reason why the thickness of the diaphragm is set to 0.1 (mm) or more is that if the thickness is less than 0.1 (mm), the diaphragm is too thin and easily broken. The reason why the diaphragm is set to 0.6 (mm) or less is that if the diaphragm is thicker than 0.6 (mm), the curved displacement portion of the diaphragm becomes too hard to be sensitively displaced, and cracks occur in the diaphragm. This is because such destruction is likely to occur.

It should be noted that the symbols in parentheses of the above means indicate correspondence with specific means described in the embodiments described later.

1 is a longitudinal sectional view showing a first embodiment of a diaphragm valve according to the present invention in a closed state; FIG. 1 is a longitudinal sectional view showing a first embodiment of a diaphragm valve according to the present invention in an open state; FIG. It is a longitudinal cross-sectional view which shows the diaphragm member in the said 1st Embodiment. 4(a) is a longitudinal sectional view showing the reinforcing body of FIG. 3, and (b) is a longitudinal sectional view showing the diaphragm of FIG. 3. FIG. 2 is an enlarged side view showing the piston and piston shaft of FIG. 1; FIG. FIG. 2 is an enlarged vertical cross-sectional view showing the cushioning body of FIG. 1; FIG. 5 is a longitudinal sectional view showing a second embodiment of a diaphragm valve according to the present invention in a closed state; FIG. 5 is a vertical cross-sectional view showing a second embodiment of a diaphragm valve according to the present invention in an open state; FIG. 8 is an enlarged longitudinal sectional view showing the cushioning body of FIG. 7; FIG. 10 is a vertical cross-sectional view showing a third embodiment of a diaphragm valve according to the present invention in a closed state; FIG. 10 is a vertical cross-sectional view showing a third embodiment of a diaphragm valve according to the present invention in an open state; 11 is an enlarged side view showing the piston and piston shaft of FIG. 10; FIG. FIG. 11 is an enlarged longitudinal sectional view showing the cushioning body of FIG. 10;

Hereinafter, each embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows a first embodiment of a diaphragm valve to which the present invention is applied. As the diaphragm valve, an air-operated diaphragm valve applied to a semiconductor manufacturing apparatus for manufacturing semiconductor elements is adopted.

The diaphragm valve is installed in the piping system of the semiconductor manufacturing apparatus, and configured to cause the liquid flowing through the piping system to flow from the upstream side to the downstream side. In the first embodiment, the liquid refers to a liquid such as a high-purity chemical liquid or ultrapure water, and is supplied to the piping system from the liquid supply source of the semiconductor manufacturing apparatus. In addition, the liquid is required to be clean in view of the characteristics of the semiconductor manufacturing apparatus.

The diaphragm valve, as shown in FIG. 1 or 2, comprises a cylindrical housing 100, a diaphragm member 200 and an air-operated drive mechanism 300 assembled in the cylindrical housing 100, and is a normally closed diaphragm valve. is configured as In addition, in the first embodiment, the air-operated drive mechanism 300 is also referred to as the drive mechanism 300 hereinafter.

The tubular housing 100 is composed of a lower housing member 100a and an upper housing member 100b.

As shown in FIG. 1 or 2, the lower housing member 100a includes a bottom wall 110 and a partition wall 120. The bottom wall 110 consists of a bottom wall main body 110a, one side cylinder 110b and the other side cylinder 110c. It is composed of

The bottom wall body 110a has a rectangular cross section, and as shown in FIG. 112.

Here, the annular wall 112 extends coaxially upward from the outer peripheral portion of the lower wall 111, and the annular wall 112 is composed of an inner annular wall portion 112a and an outer annular wall portion 112b. The inner annular wall portion 112a is formed on the central side of the annular wall 112, and the outer annular wall portion 112b annularly protrudes upward from the inner annular wall portion 112a on the outer peripheral side of the inner annular wall portion 112a. is formed as

Further, the bottom wall body 110a has an annular valve seat portion 113, and the annular valve seat portion 113 is located in the central portion of the upper surface of the lower wall 111, i. It is formed so as to protrude coaxially and annularly from the end opening toward the partition wall 120 side. Here, the annular valve seat portion 113 is formed so as to communicate with the inner end opening portion of the one side flow passage portion 114 (to be described later).

The bottom wall main body 110a has a one side flow passage portion 114 and the other side flow passage portion 115, and the one side flow passage portion 114 extends from the annular valve seat portion 113 to the one side cylinder 110b within the lower wall 111. It is formed so as to extend in an L shape toward. The one-side channel portion 114 communicates with the annular valve seat portion 113 at its inner end opening.

On the other hand, the other-side channel portion 115 is formed in an L shape within the lower wall 111 so as to extend from the right side portion of the upper surface of the lower wall 111 toward the other-side cylinder 110c. Here, the other-side channel portion 115 is formed in the lower wall 111 so that the inner end opening thereof opens from the right side of the upper surface of the lower wall 111 into the liquid chamber Ra (to be described later). there is

The one-side tube 110b is formed on the lower wall 111 so as to extend outward from the outer end opening of the one-side flow path portion 114, and the one-side tube 110b is located upstream of the piping system. plays a role of communicating the one-side channel portion 114 with the . On the other hand, the other side tube 110c is formed in the lower wall 111 so as to extend outward from the outer end opening of the other side flow path section 115. The other side tube 110c is formed in the other side flow path section. 115 to the downstream side of the piping system.

The bulkhead 120 has a bulkhead body 120a and an annular flange 120b, as shown in FIG. The bulkhead body 120a is fitted at its lower portion within the outer annular wall portion 112b of the ring-shaped wall 112 of the bottom wall body 110a, and the bulkhead body 120a serves as a reinforcement for the diaphragm member 200 at its outer peripheral portion. 200b and diaphragm 200a (discussed below) rests on inner annular wall 112a.

The annular flange 120b is formed so as to annularly protrude outward along the radial direction from an axially intermediate portion of the partition wall main body 120a. It sits coaxially on portion 112b. In this manner, the partition wall 120 is coaxially attached to the bottom wall main body 110a from above via the diaphragm 200a and the reinforcing member 200b.

Further, the partition 120 has a communication path 121, and the communication path 121 is formed in an L shape within the partition 120 as shown in FIG. Here, the communicating path 121 is open to the outside of the partition 120 at its outer end opening, and the inner end opening of the communicating path 121 is located between the diaphragm 200a and the partition main body 120a. It opens into an air chamber Rb (to be described later) that is formed.

The upper housing member 100b has a rectangular cross section, and is composed of a tubular wall 130 and an upper wall 140. As shown in FIG. The cylindrical wall 130 extends downward from the upper wall 140 in a cylindrical shape, and a hollow portion 131 of the cylindrical wall 130 has a circular cross-sectional shape on the inner peripheral surface thereof. The cylindrical wall 130 is coaxially and airtightly fitted to the bulkhead main body 120a of the bulkhead 120 from above through an O-ring 123 at the extended end opening, and is seated on the annular flange 120b. ing.

The diaphragm member 200 is composed of a diaphragm 200a and a reinforcing body 200b, as shown in any one of FIGS. 1 to 4. FIG. The diaphragm 200a is sandwiched between the bottom wall main body 110a of the bottom wall 110 and the partition wall main body 120a of the partition wall 120 together with the reinforcing member 200b at the outer peripheral portion 210 thereof. Thereby, the diaphragm 200a forms a liquid chamber Ra between the inner annular wall portion 112a and the inner annular wall portion 112a on the inner peripheral side of the outer annular wall portion 112b of the annular wall 112 of the bottom wall main body 110a and the partition wall main body 120a. A space is defined between the inner annular wall portion 112a and the bulkhead main body 120a inside the lower housing member 100a so as to form an air chamber Rb therebetween.

Into the liquid chamber Ra, the liquid flowing through the one-side cylinder 110b and the one-side channel portion 114 of the bottom wall 110 flows from the upstream side of the piping system of the semiconductor manufacturing apparatus through the annular valve seat portion 113. . As a result, the liquid generates a liquid pressure acting on the lower surface 250 of the diaphragm 200a within the liquid chamber Ra. On the other hand, outside air flows into the air chamber Rb through the communication passage 121 of the partition wall 120 . As a result, the outside air generates air pressure (atmospheric pressure) that acts on the upper surface 240 of the diaphragm 200a within the air chamber Rb.

The diaphragm 200a is formed as a disc-shaped and film-shaped diaphragm from a predetermined fluororesin (see FIG. 4(b)).

In the first embodiment, the diaphragm 200a is in contact with high-purity chemicals such as highly corrosive chemicals such as strong acids and strong alkalis due to its structure as a diaphragm valve. It is desirable to have excellent chemical resistance.

In addition, since the elution of metal components and organic components from the diaphragm 200a of the diaphragm valve and other constituent members is not permitted, it is desirable to adopt a fluororesin having low elution at least as the material for forming the diaphragm.

Moreover, since the diaphragm 200a repeats bending displacement each time the diaphragm valve is opened and closed, it is desirable that at least flexibility and longevity are excellent.

Therefore, in the first embodiment, tetrafluoroethylene perfluoroalkyl, which is excellent in chemical resistance, low elution property, heat resistance and corrosion resistance and can ensure flexibility and long life, is used as the above-mentioned predetermined fluororesin. A vinyl ether copolymer (PFA) is employed. In addition, in the first embodiment, PFA is used as a material for forming the cylindrical housing 100 and the partition wall 120 as well.

In addition, the diaphragm 200a is a film-shaped diaphragm composed of the outer peripheral portion 210, the central portion 220, and the curved displacement portion 230, and has a thickness within a predetermined thickness range, for example, 0.5 (mm). It is formed integrally.

In the first embodiment, the predetermined thickness range refers to a thickness range of 0.1 (mm) or more and 0.6 (mm) or less. Here, the reason why the thickness is set to 0.1 (mm) or more is that if the thickness is less than 0.1 (mm), the diaphragm 200a is too thin and easily broken. The reason why the thickness of the diaphragm 200a is set to 0.6 (mm) or less is that if the diaphragm 200a is thicker than 0.6 (mm), the curved displacement portion of the diaphragm becomes too hard to be sensitively displaced, and cracks occur in the diaphragm. This is because such destruction is likely to occur.

The diaphragm 200a configured as described above serves as a valve body portion (hereinafter, also referred to as valve body portion 220) facing the annular valve seat portion 113 at its central portion 220. As shown in FIG. This means that the valve body portion 220 constitutes the valve portion of the diaphragm valve together with the annular valve seat portion 113 . The curved displacement portion 230 of the film-shaped diaphragm 200a refers to a film-shaped portion between the outer peripheral portion 210 and the central portion 220 of the film-shaped diaphragm 200a.

The reinforcing member 200b serves to reinforce the film-like diaphragm 200a from its outer peripheral portion 210 side. They are joined by laser welding from the 240 side. Thereby, the reinforcing body 200b is formed integrally with the outer peripheral portion 210 of the diaphragm 200a. This means that the diaphragm member 200 is integrally formed with the diaphragm 200a and the reinforcing body 200b. In addition, hereinafter, the reinforcing body 200b is also referred to as an annular reinforcing body 200b.

In the first embodiment, the annular reinforcing body 200b is formed by injection-molding PFA into a cylindrical shape and then cutting it into an annular shape (see FIG. 4A). Here, the reinforcing body 200b has an outer diameter equal to the outer diameter of the diaphragm 200a, and the axial width and thickness of the reinforcing body 200b are suitable for reinforcing the film-like diaphragm 200a and making it easy to handle. set to each value.

The drive mechanism 300 is assembled inside the housing 100 as shown in either FIG. 1 or FIG. The drive mechanism 300 is composed of a piston 310 , a piston shaft 320 , a coil spring 330 and a buffer 340 .

1 and 2, the piston 310 is hermetically and slidably fitted in the hollow portion 131 of the cylinder wall 130 of the housing member 100b via an O-ring 311. The piston 310 partitions the hollow portion 131 of the cylinder wall 130 so as to form an upper chamber 131a on the upper wall 140 side and a lower chamber 131b on the partition wall 120 side. In the first embodiment, the O-ring 311 is fitted in an annular groove 312 (see FIG. 5) formed in the axially intermediate portion of the piston 310 so that the inner peripheral surface of the cylindrical wall 130 and the piston It plays a role of maintaining airtightness with the outer peripheral surface of 310 . Also, the piston 310 is made of PFA together with the piston shaft 320 .

Here, the upper chamber 131a is open to the outside of the housing member 100b through an annular groove portion 141, a communicating passage portion 142 and an opening portion 143 formed in the upper wall 140 of the housing member 100b.

The annular groove 141 is formed coaxially and annularly in the central portion of the upper wall 140 from the upper chamber 131a side. The opening portion 143 is formed inside the outer peripheral portion of the upper wall 140 , and the communicating passage portion 142 is formed inside the outer peripheral portion of the upper wall 140 so as to communicate the annular groove portion 141 with the opening portion 143 .

On the other hand, the lower chamber 131b is connected to a compressed air flow supply source (not shown) through a communicating passage portion 133 and an opening portion 134 formed in the cylindrical wall 130. As shown in FIG. As a result, the compressed air flow from the compressed air flow supply source is supplied to the inside of the lower chamber 131b through the opening 134 and the communication passage 133 at a constant pressure. In the first embodiment, the constant pressure is set to a value greater than the spring load of the coil spring 330 so that the piston 310 can slide at an appropriate speed against the urging force of the coil spring 330. It is The opening portion 134 is formed in a part of the cylinder wall 130 below the opening portion 143 so as to communicate with the lower chamber 131b through the communicating passage portion 133. As shown in FIG. The communication passage portion 133 is formed in a portion of the cylinder wall 130 so as to communicate the opening portion 134 with the inside of the lower chamber 131b.

1, 2, 5 and 6, the piston shaft 320 is composed of an upper piston shaft portion 320a and a lower piston shaft portion 320b. The upper piston shaft 320a extends coaxially upward from the piston 310 and extends into a central hole 144 coaxially formed in the upper wall 140 of the upper housing 100b. It is slidably fitted from the upper chamber 131a.

The lower piston shaft portion 320b extends from the piston 310 into the lower chamber 131b coaxially with the upper piston shaft portion 320a. slidably extends into the air chamber Rb through a through-hole portion 122 formed in . The O-ring 321 is fitted in an annular groove 322 (see FIG. 5) formed in the axially intermediate portion of the lower piston shaft 320b. It plays a role of maintaining airtightness between the inner peripheral surface and the outer peripheral surface of the lower piston shaft portion 320b. Further, the through-hole portion 122 is formed coaxially and through the central portion of the partition main body 120a.

A coil spring 330 is fitted within the annular groove 141 of the top wall 140, as shown in either FIG. 1 or FIG. , urging the piston 310 toward the lower chamber 131b.

In the first embodiment, the spring load of the coil spring 330 is applied via a buffer 340 (described later) when the piston 320 slides at an appropriate speed against the hydraulic pressure of the liquid generated in the liquid chamber Ra. It is set to the minimum value required to seat the central portion 220 of the diaphragm 200 a on the annular valve seat portion 113 . This means that the biasing force of the coil spring 330 described above corresponds to the spring load of the coil spring 330 .

As will be described later, the damping body 340 is coaxially assembled in a disengageable manner in the retainer recess 324 of the extending end 323 (see FIG. 5) of the lower piston shaft 320b (see FIGS. 1 and 5). 2 or see FIG. 5).

As shown in an enlarged view in FIG. 6, the cushioning body 340 has a truncated cone-shaped head portion 340a, a columnar neck portion 340b, and a disk-shaped trunk portion 340c. It is made of a rubber material (e.g. elastomer).

The head portion 340a is formed in a widening shape from a small-diameter side upper end portion 341 to a large-diameter side lower end portion 342 thereof. The neck portion 340b extends coaxially and cylindrically from the large diameter side lower end portion 342 of the head portion 340a. smaller than the diameter. Further, the trunk portion 340c is connected to the extending end portion of the neck portion 340b at its central upper portion, and is formed in an inverted T shape together with the neck portion 340b.

On the other hand, as shown in FIG. 5, the retaining recess 324 is formed in a concave shape from the extending end surface 323a side in the central portion of the extending end portion 323 of the lower piston shaft portion 320b. The retaining recess 324 is composed of a housing portion 324a and an opening portion 324b. is formed to have The opening 324b is formed to have an inner diameter that is smaller than the outer diameter of the large-diameter lower end 342 of the head 340a and slightly larger than the outer diameter of the neck 340b of the cushioning body 340. As shown in FIG.

When the cushioning body 340 is assembled into the retaining recess 324 formed in this manner, the cushioning body 340 is made of an elastic rubber material. The head portion 340a is fitted into the housing portion 324a through the opening portion 324b of the retaining recess portion 324 from the small-diameter side upper end portion 341 side against the elasticity thereof. Along with this, the head portion 340a of the cushioning body 340 returns to its original shape centering on the large diameter side lower end portion 342 thereof.

As a result, the head portion 340a of the cushioning body 340 is accommodated in the accommodation portion 324a of the retaining recess 324, with the neck portion 340b positioned within the opening 324b of the retaining recess 324. As a result, the cushioning body 340 can be held in the retaining recess 324 so as to be retained by the opening 324b of the retaining recess 324 at the head 340a.

Further, by holding the buffer 340 in the retaining recess 324 of the extended end 323 of the lower piston shaft 320b in this way, the buffer 340 is supported by the body 340c of the diaphragm 200a. It is located opposite the central portion 220 .

In the drive mechanism 300 configured as described above, when the compressed air flow from the compressed air supply source is not supplied into the lower chamber 131b, the piston 310 is moved toward the lower chamber 131b by the biasing force of the coil spring 330. As it slides, the piston shaft 320 is displaced through the cushioning body 340 so as to seat the central portion 220 (valve body portion 220 ) of the diaphragm 200 a on the annular valve seat portion 113 . This means that the diaphragm valve is closed.

On the other hand, when the compressed air flow from the compressed air supply source is supplied at a constant pressure into the lower chamber 131b through the opening portion 134 and the communicating passage portion 133, the piston 310 moves in the lower chamber 131b. Under the constant pressure of the compressed air flow, the air in the upper chamber 131a is discharged outside from the annular groove portion 141, the communication passage portion 142 and the opening portion 143 against the biasing force of the coil spring 330. It slides toward the upper chamber 131a, and the piston shaft 320 interlocks in the same direction as the piston 310 slides to separate the buffer 340 from the central portion 220 of the diaphragm 200a.

In the first embodiment configured as described above, when assembling the diaphragm member 200 to the lower housing member 100a, the diaphragm 200a is positioned at the outer peripheral portion 210 with the annular reinforcing body 200b positioned on the upper side. It is fitted in the outer annular wall portion 112b of the annular wall 112 of the lower housing member 100a together with the annular reinforcing member 200b and sits on the inner annular wall portion 112a of the annular wall 112a.

In this case, in the diaphragm member 200, the annular reinforcing body 200b is joined to the outer peripheral portion 210 of the diaphragm 200a from the upper surface 240 side of the diaphragm 200a by laser welding. For this reason, even if the diaphragm 200a is thin and difficult to handle, the annular reinforcing member 200b satisfactorily exhibits a reinforcing function from the outer peripheral portion 210 side of the diaphragm 200a. Accordingly, the diaphragm 200a can be easily fitted to the inner peripheral side of the outer annular wall portion 112b of the annular wall 112 of the lower housing member 100a together with the annular reinforcing body 200b.

After that, the partition wall 120 is fitted to the inner peripheral side of the outer annular wall portion 112b of the annular wall 112 with the partition body 120a. Along with this, the partition wall 120 is seated on the inner annular wall portion 112a of the annular wall 112 with the partition body 120a through the annular reinforcing body 200b and the outer peripheral portion 210 of the diaphragm 200a. It engages on the outer annular wall portion 112b of the annular wall 112 at the annular flange 120b.

This is because, in the diaphragm member 200, the diaphragm 200a, along with the annular reinforcing member 200b joined to the upper side thereof at the outer peripheral portion 210, is connected to the outer peripheral portion of the bulkhead body 120a and the inner annular wall portion 112a of the annular wall 112. It means that the bulkhead 120 is assembled to the annular wall 112 of the lower housing member 100a so that it is sandwiched between.

1 or 2, the upper housing member 100b assembled with the drive mechanism 300 is fitted into the bulkhead body 120a of the bulkhead 120 at its open end to engage the annular flange 120b. Along with this, the lower piston shaft portion 320b of the drive mechanism 300 is slidably inserted into the through hole portion 122 of the partition wall 120 via the O-ring 321 and extends into the air chamber Rb. Thereby, the buffer 340 is held by the lower piston shaft portion 320b so as to face the central portion 220 of the diaphragm 200a.

It is assumed that the diaphragm valve assembled as described above is in the closed state (see FIG. 1) when manufacturing the semiconductor element by the semiconductor manufacturing apparatus.

At this time, in the diaphragm valve, the piston 310 slides downward within the upper housing member 110b due to the biasing force of the coil spring 330. As shown in FIG. Accordingly, the piston shaft 320 causes the diaphragm 200 a to be seated on the annular valve seat portion 113 at the valve body portion 220 , which is the central portion 220 , of the diaphragm 200 a through the cushioning body 340 .

In such a closed state of the diaphragm valve, a compressed air flow is supplied into the lower chamber 131b at a constant pressure from the compressed air flow supply source through the opening 134 and the communication passage 133 of the upper housing member 100b. On the other hand, it is assumed that liquid is supplied from the liquid supply to the upstream part of the piping system.

When a stream of compressed air is supplied into the lower chamber 131b from the source of compressed air flow as described above, the piston 310, together with the piston shaft 320, will spring out of the coil spring under the constant pressure of the compressed air stream in the lower chamber 131b. Air in the upper chamber 131a is discharged outside through the annular groove 141, the communication passage 142 and the opening 143 against the biasing force of the upper housing member 100b. slide through the streets. Along with this, the buffer 340 is integrated with the piston shaft 320 and separated from the central portion 220 of the diaphragm 200a (see FIG. 2).

On the other hand, when the liquid is supplied from the liquid supply source to the upstream portion of the piping system as described above, the liquid passes through the one-side cylinder 110b, the one-side channel portion 114, and the annular valve seat portion 113, and flows into the liquid chamber. It flows into Ra. Accordingly, the hydraulic pressure of the liquid flowing into the liquid chamber Ra acts on the diaphragm 200a from the lower surface 250 side.

Here, as described above, when the cushioning body 340 is separated from the central portion 220 of the diaphragm 200a, in the diaphragm member 200, the diaphragm 200a of the diaphragm member 200 returns to its original shape by itself toward the air chamber Rb due to its elastic force. try to. Further, as described above, the hydraulic pressure in the liquid chamber Ra acts on the lower surface 250 of the diaphragm 250a.

In such a state, if the diaphragm 200a has an elastic force capable of self-restoring to its original shape as a self-restoring force, the diaphragm 200a will be able to It can self-restore to its original shape. Further, even if the elastic force required for such self-returning of the diaphragm 200a is insufficient, the hydraulic pressure of the liquid acting on the diaphragm 200a in the liquid chamber Ra as described above assists the self-returning of the diaphragm 200a. play a role. This means that the diaphragm 200a can successfully return to its original shape without the pulling force exerted by the piston 320, both by its self-restoring force and by the hydraulic pressure of the liquid.

As described above, the diaphragm 200a can return to its original shape at the central portion 220 and the curved displacement portion 230 and can be separated from the annular valve seat portion 113 satisfactorily. This opens the diaphragm valve. As a result, the liquid flowing into the liquid chamber Ra as described above passes through the other-side channel portion 115 and the other-side cylinder 110c and flows out into the downstream portion of the piping system.

In such a state, when the diaphragm valve repeatedly closes and opens over time, the piston 310 in the drive mechanism 300 moves under the spring load of the coil spring 330 each time the diaphragm valve closes. By sliding toward the lower chamber 131 b side, the piston shaft 320 causes the central portion 220 of the diaphragm 200 a to be seated on the annular valve seat portion 113 via the buffer 340 . In other words, each time the diaphragm valve is closed, the piston shaft 320 is moved through the buffer 340 to the central portion 220 of the diaphragm 200 a seated on the annular valve seat portion 113 due to the spring load of the coil spring 330 . It will add an impact force.

Here, the diaphragm 200a is a film-like diaphragm formed by extrusion molding of PFA, as described above. Therefore, both surfaces of the diaphragm 200a are excellent smooth surfaces.

Therefore, even if the diaphragm valve is repeatedly operated by the piston shaft 320 as described above, particles such as those caused by cutting marks are separated from the diaphragm 200a by the contact of the diaphragm 200a with the liquid and enter the liquid. It goes without saying that the situation of contamination does not occur, and even contamination of minute particles of several nanometers in size into the liquid can be suppressed to the minimum (minimum).

Further, as described above, the spring load of the coil spring 330 causes the piston 310 and the piston shaft 320 to slide at an appropriate speed against the hydraulic pressure of the liquid generated in the liquid chamber Ra, causing the piston shaft 320 to slide. , is set to the minimum value required to seat the diaphragm 200a on the annular valve seat portion 113 at its central portion 220 via a buffer 340 (to be described later).

Therefore, the spring load of the coil spring 330 is reduced by at least the load required to smooth out the roughness of the surface of the diaphragm 200a. Moreover, since the buffer 340 is made of elastic rubber, the buffer 340 can exhibit soft elasticity.

Therefore, even if the impact force from the piston shaft 320 is applied to the central portion 220 of the diaphragm 200a seated on the annular valve seat portion 113 via the cushioning body 340 as described above, the impact force is mitigated by the cushioning body 340. , and joins the central portion 220 of the diaphragm 200 a seated on the annular valve seat portion 113 . Moreover, since the spring load of the coil spring 330 does not include the load required to smooth out the roughness of the surface of the diaphragm 200a as described above, the surface roughness of the central portion 220 of the diaphragm 200a may be affected by the impact force described above. However, since the cushioning body 340 has a flexible elastic force as described above, the center of the diaphragm 200a seated on the annular valve seat portion 113 is adjusted so as to adapt to the roughness of the surface of the central portion 220 of the diaphragm 200a. It comes into contact with the portion 220 .

Therefore, as described above, although the diaphragm 200a is a film-like diaphragm and is extremely thin, the impact force from the piston shaft 320 is repeatedly applied to the central portion 220 of the diaphragm 200a seated on the annular valve seat portion 113. However, the central portion 220 of the diaphragm 200a is less likely to be damaged, such as breakage, and the life of the diaphragm 200a can be maintained for a long time. never invite

As described above, the liquid flowing into the liquid chamber Ra is kept substantially clean by minimizing the contamination of even minute particles of several nanometers in size. It flows out into the downstream part of the piping system through the other side cylinder 110c.

Therefore, even if the liquid that has flowed out into the downstream portion of the piping system flows along the surface of a semiconductor wafer having a wiring pitch of 10 (nm) or less, for example, particles of several nanometers are generated in the manufacture of semiconductor devices. It does not adhere to the surface of the semiconductor wafer and cause short circuits between wirings or other abnormalities. As a result, the quality of the manufactured semiconductor device can be favorably maintained.

In addition, since the film-shaped diaphragm 200a is formed by extrusion molding using PFA, as described above, it is possible to suppress the generation of particles of several nanometers in size to a minimum, and at the same time, it has excellent flexibility and maintains a long service life. It can be formed as a flexible diaphragm. Therefore, even if a diaphragm valve having such a diaphragm 200a is applied to a semiconductor manufacturing apparatus, the diaphragm 200a maintains a favorable bending operation for a long period of time. As a valve, it can maintain good function over a long period of time.

(Second embodiment)
FIG. 7 shows a second embodiment of the invention. In the second embodiment, the air-operated diaphragm valve has a longitudinal cross-sectional shape as shown in any one of FIGS. 7 to 9 instead of the buffer 340 described in the first embodiment. is adopted. It should be noted that the cushioning body referred to in the second embodiment is also denoted by reference numeral 340, similarly to the cushioning body 340 described in the first embodiment.

The cushioning body 340 according to the second embodiment has a trunk portion 340d instead of the disk-shaped trunk portion 340c in the cushioning body 340 described in the first embodiment (FIGS. 7 to 9). ). The lower surface of the trunk portion 340d is formed to have an arcuate vertical cross-section that is convex downward, unlike the planar lower surface of the trunk portion 340c in the first embodiment. In addition, hereinafter, the arcuate lower surface of the body portion 340d in longitudinal section is also referred to as an arcuate surface 343 .

Accordingly, in the second embodiment, an annular valve seat portion 116 is employed instead of the annular valve seat portion 113 in the bottom wall main body 110a of the first embodiment. The annular valve seat portion 116 does not protrude from the inner end opening portion of the one side passage portion 114 like the annular valve seat portion 113 in the first embodiment. It is composed of the inner end opening itself. Other configurations are the same as those of the first embodiment.

In the second embodiment configured as described above, as in the first embodiment, the diaphragm valve is assumed to be in the closed state when the semiconductor element is manufactured by the semiconductor manufacturing apparatus (see FIG. 7). .

At this time, in the diaphragm valve, the piston 310 slides downward within the upper housing member 110b due to the biasing force of the coil spring 330. As shown in FIG. Accordingly, the piston shaft 320 causes the diaphragm 200 a to be seated on the annular valve seat portion 116 at the valve body portion 220 , which is the central portion 220 , of the diaphragm 200 a through the cushioning body 340 .

Here, unlike the trunk portion 340c of the damping body 340 in the first embodiment, which has a planar lower surface, the trunk portion 340d of the damping body 340 in the second embodiment has an arcuate lower surface. 343 is formed. Therefore, the damping body 340 according to the second embodiment is different from the damping body 340 according to the first embodiment. It is seated on the annular valve seat portion 116 . Moreover, unlike the annular valve seat portion 113 described in the first embodiment, the annular valve seat portion 116 does not protrude from the inner end opening portion of the one side flow passage portion 114. It is composed of the inner end opening portion of the portion 114 itself. As described above, the inner diameter of the annular valve seat portion 116 is smaller than the inner diameter of the annular valve seat portion 113 described in the first embodiment.

In such a closed state of the diaphragm valve, similarly to the first embodiment, when a compressed air flow is supplied from the compressed air flow supply source into the lower chamber 131b, the piston 310 moves along with the piston shaft 320 to Due to the constant pressure of the compressed air flow in the lower chamber 131b, the air in the upper chamber 131a is discharged outside from the annular groove 141, the communication passage 142 and the opening 143 against the biasing force of the coil spring 330. while sliding through the hollow portion 131 of the upper housing member 100b toward the upper chamber 131a. Accompanying this, the buffer 340 is integrated with the piston shaft 320 and separated from the central portion 220 of the diaphragm 200a at the arcuate surface 343 of the body portion 340d (see FIG. 8).

On the other hand, when the liquid flows into the liquid chamber Ra through the one-side cylinder 110b, the one-side channel portion 114, and the annular valve seat portion 113 as in the first embodiment, the liquid pressure of the liquid flowing into the liquid chamber Ra increases. acts on the diaphragm 200a from its lower surface 250 side.

Here, as described above, when the buffer 340 is separated from the central portion 220 of the diaphragm 200a at its arc surface 343, the diaphragm member 200:
Since the central portion 220 of the diaphragm 200a is curvedly seated on the annular valve seat portion 116 as described above, the elastic force of the diaphragm 200a causes the central portion 220 and the curved displacement portion 230 to form an air chamber. It tries to self-restore to the original shape by itself to the Rb side. Further, as described above, the hydraulic pressure in the liquid chamber Ra acts on the lower surface 250 of the diaphragm 250a.

Here, as described above, when the cushioning body 340 is separated from the central portion 220 of the diaphragm 200a at its arcuate surface 343, in the diaphragm member 200, the diaphragm 200a is separated from the central portion 220 and the central portion 220 under its elastic force. At the curved displacement portion 230, it tries to return to the original shape by itself toward the air chamber Rb side. Further, as described above, the hydraulic pressure in the liquid chamber Ra acts on the lower surface 250 of the diaphragm 200a.

In such a state, if the diaphragm 200a has an appropriate elastic force capable of self-returning to its original shape, the diaphragm 200a will return to its original shape at its central portion 220 and curved displacement portion 230. can return. Further, even if the elastic force required for the self-returning of the diaphragm 200a is insufficient, the hydraulic pressure acting on the diaphragm 200a in the liquid chamber Ra as described above plays a role of assisting the self-returning of the diaphragm 200a. .

Here, in the second embodiment, the inner diameter of the annular valve seat portion 116 is smaller than the inner diameter of the annular valve seat portion 113 in the first embodiment. The hydraulic pressure of liquid in 116 will be higher than the hydraulic pressure of liquid in annular valve seat 113 against central portion 220 of diaphragm 200a. For this reason, the diaphragm 200a has both its self-restoring force and the hydraulic pressure of the liquid in the liquid chamber Ra, and even if it does not depend on the pulling force of the piston 320, it is much better than the first embodiment. , can return to its original shape.

As described above, the diaphragm 200a returns to its original shape at the central portion 220 and the curved displacement portion 230, and can be separated from the annular valve seat portion 116 more favorably. This opens the diaphragm valve. As a result, the liquid flowing into the liquid chamber Ra as described above passes through the other-side channel portion 115 and the other-side cylinder 110c and flows out into the downstream portion of the piping system.

In such a state, when the diaphragm valve repeatedly closes and opens over time, the shock absorber 340 according to the second embodiment differs from the shock absorber 340 according to the first embodiment. , the piston shaft 320 is seated on the annular valve seat portion 116 via the buffer 340 due to the spring load of the coil spring 330 each time the diaphragm valve is closed. An impact force is applied to the central portion 220 of the diaphragm 200a.

Here, as described above, the load of the coil spring 330 causes the piston shaft 320 to slide at an appropriate speed against the hydraulic pressure of the liquid generated in the liquid chamber Ra, thereby causing the damping force referred to in the second embodiment. It is set to the minimum value required to seat the central portion 220 of the diaphragm 200 a on the annular valve seat portion 113 via the body 340 . Accordingly, the spring load of the coil spring 330 is reduced by at least the load required to smooth out the roughness of the surface of the diaphragm 200a. In addition, the buffer 340 according to the second embodiment is made of elastic rubber like the buffer 340 according to the first embodiment, so that the buffer 340 exhibits flexible elasticity. can.

Therefore, in the second embodiment as well, the impact force from the piston shaft 320 is seated on the annular valve seat portion 116 instead of the annular valve seat portion 113 in the first embodiment through the buffer 340 as described above. Even if the impact force is applied to the central portion 220 of the diaphragm 200 a , the impact force is mitigated by the buffer 340 and is applied to the central portion 220 of the diaphragm 200 a seated on the annular valve seat portion 116 . Moreover, the spring load of the coil spring 330 does not include the load required to level the roughness of the surface of the diaphragm 200a, as in the first embodiment. Although the roughness of the curved surface of the diaphragm 220 cannot be smoothed out, the cushioning body 340 has a flexible elastic force as described above. It comes into contact with the central portion 220 of the seated diaphragm 200a.

Therefore, as described above, although the diaphragm 200a is a film-like diaphragm and is extremely thin, the impact force from the piston shaft 320 is repeatedly applied to the central portion 220 of the diaphragm 200a seated on the annular valve seat portion 116. However, the central portion 220 of the diaphragm 200a is less likely to be damaged, such as breakage, and the life of the diaphragm 200a can be maintained for a long time. nor invite. Other functions and effects are the same as those of the first embodiment.

(Third embodiment)
FIG. 10 shows a third embodiment of a diaphragm valve according to the invention. In the third embodiment, instead of the piston shaft 320 in the drive mechanism 300 described in the first embodiment, a piston shaft is adopted as shown in any one of FIGS. A member 400 is employed instead of the diaphragm member 200 and the buffer 340 described in the first embodiment. The piston shaft referred to in the third embodiment is indicated by reference numeral 320, like the piston shaft 320 referred to in the first embodiment.

In the drive mechanism 300 according to the third embodiment, the piston shaft 320 is replaced with the lower piston shaft portion 320b in the piston shaft 320 according to the first embodiment, as shown in any one of FIGS. and a lower piston shaft portion 320c.

12, the lower piston shaft portion 320c has an extended end portion 325 instead of the extended end portion 323 of the lower piston shaft portion 320b of the first embodiment. It is configured. Here, unlike the extended end portion 323 of the lower piston shaft portion 320b, the extended end portion 325 of the lower piston shaft portion 320c is formed to have a planar end face portion 325a.

Along with this, the lower piston shaft portion 320c faces the central portion 220 of the diaphragm 200a at the planar end surface portion 325a of the extending end portion 325 via a buffer 420 (described later). . The extending end portion 325 of the lower piston shaft portion 320c engages with the upper surface 421 (described later) of the damping body 420 at the extending end surface portion 325a so that the damping body 420 is attached to the lower surface 422 thereof. It faces the central portion 220 of the diaphragm 200a so as to be engageable with the central portion 220 of the diaphragm 200a from the upper surface 240 side of the diaphragm 200a.

The diaphragm member 400 is composed of the diaphragm 200a described in the first embodiment and a reinforcing buffer member 400a laminated on the diaphragm 200a from the upper surface 240 side.

As shown in any one of FIGS. 10, 11 and 13, the reinforcing cushioning member 400a is made of the above-described elastic rubber so as to integrally have a reinforcing body 410, a cushioning body 420, and a connecting film 430. It is made of material.

The reinforcing member 410 serves to reinforce the diaphragm 200a from the outer peripheral portion 210 side in the same manner as the reinforcing member 200b described in the first embodiment. Although the reinforcing member 200b is made of a different material from the reinforcing member 200b described above, it is formed to have the same annular shape as the reinforcing member 200b. In addition, the reinforcing body 410 is hereinafter also referred to as an annular reinforcing body 410 .

The buffer 420 plays a role of alleviating the impact force on the central portion 220 of the diaphragm 200a in the same manner as the buffer 340 described in the first embodiment. It is made of the same material (elastic rubber material) as that of the cushioning body 340 described above, and is formed to have the same shape as that of the cushioning body 340 .

In the third embodiment, the damping body 420 is interposed so as to be positioned between the extended end portion 325 of the lower piston shaft portion 320c and the central portion 220 of the diaphragm 200a. Here, the damping body 420 is coaxially and separably engaged with the extending end surface portion 325a of the extending end portion 325 of the lower piston shaft portion 320c at its upper surface 421. The lower surface 422 of the diaphragm 420 is coaxially engageable with the central portion 220 of the diaphragm 200a.

The connecting film 430 is formed between the annular reinforcing body 410 and the damping body 420 so as to integrally connect the annular reinforcing body 410 to the annular reinforcing body 410 and the damping body 420 . The connecting film 430 is formed in a curved shape that protrudes downward from the inner peripheral edge of the annular reinforcing body 410 to the outer peripheral edge of the cushioning body 420 and tapers at the end. In other words, the connecting film 430 is formed in a curved shape that protrudes downward from the outer peripheral edge of the cushioning body 420 to the inner peripheral edge of the annular reinforcing body 410 . Thereby, the connecting film 430 is formed so as to support the cushioning body 420 above the annular reinforcing body 410 in its original shape. The reinforcing cushioning member 400a having the connecting film 430 having such an original shape is formed by injection molding using an elastic rubber material.

In addition, the connecting film 430 is formed in an annular shape in the same manner as the curved displacement portion 230 of the diaphragm 200a. It is formed so that it gradually becomes thinner toward the side. Therefore, the connecting film 430 is easily bent toward the bending displacement portion 230 of the diaphragm 200a.

In addition, the connecting film 430 has a pair of through-holes 431 , and the pair of through-holes 431 are formed at equal angular intervals in the radial direction of the connecting film 430 . ing. Here, the pair of through holes 431 play a role of connecting an air chamber Rc (described later) formed between the reinforcing buffer member 400a and the diaphragm 200a to the air chamber Rb. The outer diameter of the reinforcing buffer member 400a matches the outer diameter of the diaphragm 200a.

The reinforcing cushioning member 400a constructed in this manner is laminated on the upper surface 240 side of the diaphragm 200a in the original shape shown in FIG. At this time, the reinforcing cushioning member 400a is configured such that the cushioning body 420 and the connecting film 430 are opposed to the central portion 220 and the curved displacement portion 230 of the diaphragm 200a, respectively. is laminated from its upper side.

As a result, the connecting film 430 rises upward from the inner peripheral edge of the annular reinforcing member 410 in a downwardly convex curved shape and tapers to hold the buffer 420 directly above the central portion 220 of the diaphragm 200a. . Other configurations are the same as those of the first embodiment.
In the third embodiment configured as described above, as in the first embodiment, the diaphragm valve is assumed to be closed when the semiconductor device is manufactured by the semiconductor manufacturing apparatus.

At this time, in the diaphragm valve, the piston 310 slides downward in the upper housing member 110b based on the biasing force (spring load) of the coil spring 330, and is reinforced by the lower piston shaft portion 320c. The center portion 220 of the diaphragm 200a is seated on the annular valve seat portion 116 via the buffer body 420 of the buffer member 400a (see FIG. 10).

In such a state, in the reinforcing cushioning member 400a, the upper surface 421 of the cushioning body 420 is pressed by the extended end face portion 325a of the extended end portion 325 of the lower piston shaft portion 320c, and the connecting membrane 430 is pressed. resists its elasticity and bends and displaces the diaphragm 200a toward the bending displacement portion 230 side, and the buffer body 420 presses the central portion 220 of the diaphragm 200a with its lower surface 422 to seat it on the annular valve seat portion 113. there is

In such a closed state of the diaphragm valve, similarly to the first embodiment, when a compressed air flow is supplied from the compressed air flow supply source into the lower chamber 131b, the piston 310 moves along with the piston shaft 320 to Based on the constant pressure of the compressed air flow in the lower chamber 131b, it slides toward the upper chamber 131a through the hollow portion 131 of the upper housing member 100b, as in the first embodiment, against the biasing force of the coil spring 330. do. Along with this, the cushioning body 420 of the reinforcing cushioning member 400a separates from the central portion 220 of the diaphragm 200a according to the elasticity of the connecting film 430 (see FIG. 11). This means that the reinforcing cushioning member 400a self-restores to its original shape based on the elastic force of the connecting film 430 so as to hold the cushioning body 420 directly above the diaphragm 200a.

On the other hand, when the liquid flows into the liquid chamber Ra as in the first embodiment, the liquid pressure of the liquid flowing into the liquid chamber Ra acts on the diaphragm 200a from the lower surface 250 side. Here, as described above, when the cushioning body 420 is separated from the central portion 220 of the diaphragm 200a, since the central portion 220 of the diaphragm 200a is seated on the annular valve seat portion 113 as described above, the central portion At 220 and curved displacement portion 230, it attempts to self-return to the original shape by itself toward the air chamber Rb side under its elastic force. Further, as described above, the hydraulic pressure in the liquid chamber Ra acts on the lower surface 250 of the diaphragm 200a.

In such a state, if the diaphragm 200a has an appropriate elastic force capable of self-returning to its original shape, the diaphragm 200a will return to its original shape at its central portion 220 and curved displacement portion 230. can return. Further, even if the elastic force required for the self-restoration of the diaphragm 200a is insufficient, the hydraulic pressure acting on the diaphragm 200a in the liquid chamber Ra as described above plays a role of assisting the self-return of the diaphragm 200a. .

As a result, the diaphragm 200a can operate satisfactorily under both its self-restoring force and the hydraulic pressure of the liquid in the liquid chamber Ra without depending on the pulling force of the piston 320, as in the first embodiment. It can return to its original shape. As a result, the diaphragm valve is opened (see FIG. 11). As a result, the liquid flowing into the liquid chamber Ra as described above passes through the other-side channel portion 115 and the other-side cylinder 110c and flows out into the downstream portion of the piping system.

In such a state, when the diaphragm valve repeatedly closes and opens over time, the damping body 420 according to the third embodiment differs from the damping body 340 according to the first embodiment. 430 and the annular reinforcing body 410 integrally constitute the reinforcing cushioning member 400a, each time the diaphragm valve is closed, the piston shaft 320 is moved by the lower piston shaft portion 320c to the coil spring. Due to the spring load of 330 , an impact force will be applied through the damper 420 to the central portion 220 of the diaphragm 200 a seated on the annular seat 113 .

Here, as described above, the spring load of the coil spring 330 causes the piston 310 and the piston shaft 320 to slide at an appropriate speed against the hydraulic pressure of the liquid generated in the liquid chamber Ra. It is set to the minimum value required to seat the central portion 220 of the diaphragm 200a on the annular valve seat portion 113 via the buffer 340 described in the embodiment. Along with this, the spring load of the coil spring 330 is reduced by at least the load required to smooth out the roughness of the surface of the diaphragm 200a, as in the first embodiment. Moreover, the buffer 420 according to the third embodiment is made of an elastic rubber material like the buffer 340 according to the first embodiment. can demonstrate.

Therefore, even if the impact force from the piston shaft 320 is applied to the central portion 220 of the diaphragm 200a seated on the annular valve seat portion 113 via the buffer 420 as described above, the impact force is mitigated by the buffer 420. It joins the central portion 220 of the diaphragm 200 a seated on the annular valve seat portion 113 . Moreover, since the spring load of the coil spring 330 does not include the load required to smooth out the roughness of the surface of the diaphragm 200a as described above, the above-described impact force may cause the curved surface of the central portion 220 of the diaphragm 200a to be deformed. Although the roughness cannot be smoothed out, the cushioning body 420 has a flexible elastic force as described above. It abuts the central portion 220 of 200a.

Therefore, as described above, although the diaphragm 200a is a film-like diaphragm and is extremely thin, the impact force from the piston shaft 320 is repeatedly applied to the central portion 220 of the diaphragm 200a seated on the annular valve seat portion 113. However, the central portion 220 of the diaphragm 200a is less likely to be damaged, such as breakage, and the life of the diaphragm 200a can be maintained for a long time. nor invite.

In addition, since the impact force from the piston shaft 320 is repeatedly applied to the central portion 220 of the diaphragm 200a seated on the annular valve seat portion 113, the diaphragm 200a is a film-like diaphragm and is very thin. Even if the central portion 220 of the diaphragm 200a is damaged from its upper surface side, the particles generated by the damage are generated in the reinforcing buffer 400a each time the diaphragm valve is opened. After entering the air chamber Rb through each through-hole portion 431 of the connecting film 430 each time the diaphragm valve is closed via the air chamber Rc (see FIG. 11) formed between the portion 230 and the central portion 220. , is discharged from the air chamber Rb to the outside through the communication passage 121 of the partition wall 120 each time the diaphragm valve is opened. Therefore, the particles in the air chamber Rc do not mix with the liquid in the liquid chamber Ra. Other functions and effects are the same as those of the first embodiment.

In addition, in carrying out the present invention, the following various modifications can be given without being limited to the above embodiments.

(1) In carrying out the present invention, the diaphragm 200a described in each of the above embodiments is not limited to a diaphragm formed by extruding PFA into a film shape by extrusion molding. The diaphragm may be formed by compression molding into a shape.

The compression molding method is a method of filling PFA into a mold and compressing it into a film. It can be formed as a film-like diaphragm with excellent longevity and high smoothness that can minimize the dust generation of particles with a size of several nanometers. Also by this, the same effect as the above embodiment can be achieved.

(2) In carrying out the present invention, the drive mechanism 300 described in each of the above embodiments has the coil spring 330 arranged in the lower chamber 131b opposite to the partition wall 120, unlike the above embodiments. It may be configured to bias in the direction. This means that the diaphragm valve functions as a normally open diaphragm valve.

Thus, even if the diaphragm valve described in each of the above embodiments operates as a normally open diaphragm valve, substantially the same effects as those of each of the above embodiments can be achieved.

(3) In carrying out the present invention, the number of through-holes 431 described in the third embodiment is not limited to one pair, and may be at least one or more. The value is within the range of 0.5 (mm) to 1.0 (mm).

(4) In carrying out the present invention, an electromagnetically operated diaphragm valve may be employed instead of the air operated diaphragm valve described in each of the above embodiments. The electromagnetically actuated diaphragm valve is constructed by adopting an electromagnetically actuated drive mechanism instead of the air-actuated drive mechanism 300 in the diaphragm valves described in the above embodiments.

In the electromagnetically actuated drive mechanism, a plunger is employed in place of the piston 310 and the piston shaft 320 of the air-actuated drive mechanism 300, and the plunger replaces the coil spring 330 in each of the above embodiments. The coil spring is energized in the demagnetized state of the solenoid, and the central portion 220 of the diaphragm 200a is urged toward the annular valve seat portion via the buffer at the distal end portion, and the magnetic attraction force of the solenoid is applied. By attracting the plunger against the coil spring, the plunger is displaced together with the buffer or separated from the buffer.

Here, the plunger may be assembled with the cushioning body described in the first or second embodiment at its tip in the same manner as in the first or second embodiment. In this case, the damper is associated with the plunger. This makes it possible to achieve the same effect as described in the first or second embodiment.

Further, the plunger may be separably engaged with the damping body 420 of the reinforcing damping body 400a of the third embodiment at its tip. According to this, the plunger is separated from the buffer body 420 and attracted when it is attracted by the magnetic attraction force of the solenoid. As a result, the electromagnetically actuated diaphragm valve can achieve the same effects as those described in the third embodiment as a normally closed diaphragm valve.

Here, in the above-described electromagnetically actuated drive mechanism, when the solenoid is deenergized, the plunger is moved away from the annular valve seat by the biasing force of the coil spring together with or separated from the buffer. When the magnetic attraction force of the solenoid is generated, the plunger may cause the central portion 220 of the diaphragm 200a to be seated on the annular valve seat via a buffer. According to this, the electromagnetically actuated diaphragm valve can achieve substantially the same effect as the normally open diaphragm valve described in the third embodiment.

100... housing, 100a... lower housing member,
100b...Upper housing member, 110a...Lower wall, 112...Annular wall,
113, 116...annular valve seat portion, 110b...one side tube, 110c...other side tube,
120... Partition wall 130... Cylindrical wall 131a... Upper chamber 131b... Lower chamber,
140... Upper wall 200, 400... Diaphragm member 200a... Diaphragm,
200b... Annular reinforcing body, 300... Pneumatic drive mechanism, 310... Piston,
320... Piston shaft, 320b, 320c... Piston shaft portion,
323, 325... Extending end, 330... Coil spring,
340, 420... buffer, 400a ... reinforcing buffer member, 430... connecting film,
Ra... liquid chamber, Rb... air chamber.

Claims (10)

A diaphragm valve that allows high-purity chemicals and ultrapure water to flow from an inflow side to an outflow side when the valve portion is opened, and blocks the flow of the liquid to the outflow side when the valve portion is closed. in
a housing having a cylindrical peripheral wall and opposing walls formed on the cylindrical peripheral wall so as to close axially opposite end openings thereof;
It is provided at an axially intermediate portion of the cylindrical peripheral wall to form a one-side hollow portion with one of the two opposing walls and to form the other-side hollow portion with the other opposing wall. A partition wall that partitions the inside of the cylindrical peripheral wall so as to
a drive means provided in the one-side hollow portion of the cylindrical peripheral wall;
The hollow portion on the other side is provided in the hollow portion on the other side of the cylindrical peripheral wall so as to form a liquid chamber with the other opposing wall and to form an air chamber with the partition wall. A film-like diaphragm made of PFA that partitions ,
a fluororesin annular reinforcing body formed by laser welding to the upper surface of the diaphragm along the outer peripheral portion in the other side hollow portion of the cylindrical peripheral wall ,
The housing includes an annular valve seat portion that faces the central portion of the diaphragm in the liquid chamber and forms the valve portion together with the central portion, and the liquid flows from the inflow side through the annular valve seat portion. A one-side flow path for flowing into the liquid chamber and another-side flow path for flowing out the liquid in the liquid chamber to the outflow side are provided on the other opposing wall,
The drive means includes a drive shaft axially movably extending from the one-side hollow portion through the partition wall and the air chamber so as to face the central portion of the diaphragm; and a shock absorber made of an elastic rubber material assembled to the extended end of the drive shaft so as to face the central portion of the diaphragm. diaphragm valve. A diaphragm valve that allows high-purity chemicals and ultrapure water to flow from an inflow side to an outflow side when the valve portion is opened, and blocks the flow of the liquid to the outflow side when the valve portion is closed. in
a housing having a cylindrical peripheral wall and opposing walls formed on the cylindrical peripheral wall so as to close axially opposite end openings thereof;
It is provided at an axially intermediate portion of the cylindrical peripheral wall to form a one-side hollow portion with one of the two opposing walls and to form the other-side hollow portion with the other opposing wall. A partition wall that partitions the inside of the cylindrical peripheral wall so as to
a drive means provided in the one-side hollow portion of the cylindrical peripheral wall;
The hollow portion on the other side is provided in the hollow portion on the other side of the cylindrical peripheral wall so as to form a liquid chamber with the other opposing wall and to form an air chamber with the partition wall. A film-like diaphragm made of PFA that partitions,
An annular reinforcing body laminated along the outer periphery of the upper surface of the diaphragm, and a cushioning body positioned above the annular reinforcing body so as to face the central part of the diaphragm from the upper surface side of the diaphragm. and the curved displacement portion integrally formed between the outer peripheral portion and the central portion of the diaphragm is inclined from the inner peripheral portion of the annular reinforcing body facing from the upper surface side of the diaphragm. a reinforcing cushioning member integrally formed of an elastic rubber material so as to have a connecting film extending toward the cushioning body and connected to the outer peripheral portion of the cushioning body,
The housing includes an annular valve seat portion facing the central portion of the diaphragm in the liquid chamber and forming the valve portion together with the central portion, and the liquid is introduced from the inflow side through the annular valve seat portion. A one-side flow path for flowing into the chamber and another-side flow path for flowing out the liquid in the liquid chamber to the outflow side are provided on the other opposing wall,
The drive means includes a drive shaft extending axially movably from the one-side hollow portion through the partition wall and the air chamber to face the central portion of the diaphragm through the buffer, and the drive shaft. and biasing means for biasing toward the central portion of the diaphragm. The damping body is formed integrally with an engaging portion that is detachably engaged with a recess formed in the extending end portion of the drive shaft from the end surface side thereof, and the engaging portion. 2. The driving shaft according to claim 1, further comprising a base portion that abuts against the end face portion of the extension end portion of the driving shaft and the central portion of the diaphragm. Diaphragm valve as described. 4. The diaphragm valve of claim 3, wherein said base of said damper is a flat plate. The base portion of the cushioning body is formed on an end surface portion of the diaphragm on the central portion side to have a curved surface portion that is convex toward the central portion side,
The annular valve seat portion is formed by the inner end opening itself of the other side flow path,
4. The diaphragm valve according to claim 3, wherein the damping body is pressed by the drive shaft to bend the central portion of the diaphragm into the annular valve seat. The reinforcing cushioning member is fastened by a fastening member to the outer peripheral portion of the other opposing wall through the outer peripheral portion of the diaphragm through the annular reinforcing body, and is attached to the buffer by the connecting film. 3. The diaphragm valve according to claim 2, wherein the thickness of the diaphragm gradually decreases from the outer peripheral portion to the inner peripheral portion of the annular reinforcing member, and the diaphragm valve is formed so as to have a curved shape that protrudes downward and widens toward the end. The drive means
The one-side chamber is fitted in the one-side hollow portion of the cylindrical peripheral wall between the one opposing wall and the partition wall so as to be slidable along the axial direction of the one side chamber between the one opposing wall. a piston that partitions the one-side hollow portion of the cylindrical peripheral wall so as to define the other side chamber with the partition wall,
the biasing means is a coil spring that biases the piston toward one of the other side chamber and the one side chamber;
The drive shaft is a piston shaft extending from the piston through the other side chamber so as to face the central portion of the diaphragm,
2. The damping body according to claim 1 , wherein the damping body is assembled to the extending end of the piston shaft between the extending end of the piston shaft and the central portion of the diaphragm. diaphragm valve. The drive means
The one-side chamber is fitted in the one-side hollow portion of the cylindrical peripheral wall between the one opposing wall and the partition wall so as to be slidable along the axial direction of the one side chamber between the one opposing wall. a piston that partitions the one-side hollow portion of the cylindrical peripheral wall so as to define the other side chamber with the partition wall,
the biasing means is a coil spring that biases the piston toward one of the other side chamber and the one side chamber;
3. The drive shaft is a piston shaft that extends from the piston through the other side chamber, through the damping body of the reinforcing damping member, and so as to face the central portion of the diaphragm. 3. The diaphragm valve according to 2. The diaphragm valve according to any one of claims 1 to 8, wherein the diaphragm is formed into a film by extrusion molding or compression molding PFA . 10. The diaphragm valve according to claim 9, wherein the diaphragm has a thickness within the range of 0.1 (mm) or more and 0.6 (mm) or less .

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