JP6874232B2 - Diaphragm valve - Google Patents

Description

The present invention relates to a diaphragm valve used for transferring various fluids in various industrial fields such as semiconductor manufacturing, chemical factories, and foods, and in particular, impurities on the inner peripheral surface of the flow path due to charging of components of the diaphragm valve. It relates to a technique capable of reducing adhesion and damage to electronic devices arranged around a diaphragm valve.

When a fluid flows through the flow path inside the diaphragm valve, static electricity may be generated due to friction between the inner peripheral surface of the flow path and the fluid. Due to the generated static electricity, electrons are accumulated in the components of the diaphragm valve, and the diaphragm valve is in a charged state, which causes various problems. For example, when electrons are accumulated on the inner peripheral surface of the flow path, impurities such as particles are likely to adhere to the inner peripheral surface of the flow path, and the flow path may be contaminated. Further, for example, when electrons are accumulated on the outer surface of the diaphragm valve, the electrons are released to the electronic devices installed around the diaphragm valve through air or a person who operates the diaphragm valve, and there is a risk of damaging the electronic devices. There was sex.

Therefore, conventionally, as a diaphragm valve capable of suppressing electric charges on the components of the diaphragm valve, the flow path body made of an insulating material and having a flow path formed in contact with the fluid flowing through the flow path made of an insulating material. A diaphragm valve is proposed, which is provided with a diaphragm and a part around the flow path is formed by a thin-walled portion, a conductive layer is formed on the outer surface of the thin-walled portion, and a charge discharging means is connected to the conductive layer. (See, for example, Patent Document 1). In this fluid device, the electrons accumulated on the inner peripheral surface of the flow path when the fluid flows through the flow path are discharged to the outside of the diaphragm valve through the conductive layer and the charge discharging means, so that the electrons are accumulated on the surface of the film portion. It was said that it could be prevented from being done.

Japanese Patent No. 4990118

However, in the diaphragm valve, since a thin portion is formed in the flow path body, there is a problem that the strength of the flow path body is lowered. Further, since the thin-walled portion is located at the bottom of the recess formed in the flow path body, it is difficult to conduct the conduction, and as a result, the electrons stored inside may not be sufficiently released and the charge of the diaphragm valve may not be eliminated. there were.

An object of the present invention has been made in view of the above-mentioned problems of the prior art, and the attachment of impurities to the inner peripheral surface of the flow path due to the charging of the components of the diaphragm valve and the arrangement around the diaphragm valve. It is an object of the present invention to provide a diaphragm valve capable of reducing damage to electronic devices.

According to the invention of claim 1, a valve body in which a valve chamber and a first flow path and a second flow path communicating with the valve chamber are formed, and a bonnet made of a conductive material and connected to the valve body. A first diaphragm made of an insulating material, sandwiched between the valve body and the bonnet, and in contact with a fluid flowing through the valve chamber, and a first grounding means connected to the bonnet. A featured diaphragm valve is provided.

That is, in the invention of claim 1, since the bonnet made of a conductive material is connected to the valve body made of an insulating material and the first grounding means is connected to the bonnet, it is accumulated in the valve body. The electrons can be reliably emitted to the outside of the diaphragm valve. By discharging the electrons accumulated in the valve body to the outside of the diaphragm valve, it is possible to reduce the adhesion of impurities to the first flow path, the second flow path, the valve chamber, and the first diaphragm.

Here, in the present invention, ^{a substance having a volume resistivity of 10 11} Ωcm or more is used as an insulating material, and a substance having a volume resistivity of 10 ¹⁰ Ωcm or less is used as a conductive material.

According to the second aspect of the present invention, the valve body is made of a base plate provided at a position facing the bonnet of the valve body and a conductive material, penetrates the valve body, the bonnet and the base plate, and the valve body. A connecting member for connecting the bonnet and the base plate, and a second diaphragm made of an insulating material, interposed between the valve body and the base plate, and in contact with the fluid flowing through the valve chamber. The diaphragm valve according to claim 1, wherein the diaphragm valve is provided.

That is, in the invention of claim 2, since the valve body made of an insulating material is sandwiched between the bonnet made of a conductive material and the base plate and connected by a connecting member made of a conductive material, it is more effective. The electrons accumulated in the valve body can be discharged to the outside of the diaphragm valve.

Further, even in a diaphragm valve having two diaphragms in the valve chamber, the electrons accumulated in the valve body can be easily and effectively discharged to the outside of the diaphragm valve.

According to the third aspect of the present invention, a through hole is formed in the bonnet, the connecting member is inserted into the through hole, and one end of the first grounding means is connected to the through hole. The diaphragm valve according to claim 2 is provided.

That is, in the invention of claim 3, since the first grounding means can be connected to the through hole formed in the bonnet and into which the connecting member is inserted, a portion for connecting the first grounding means is newly formed. It is not necessary to do so, and the first grounding means can be easily connected.

According to the invention of claim 4, the first pipe having conductivity and the second pipe having conductivity are connected to the valve body, and the first pipe and the second pipe are connected to the bonnet, respectively. The diaphragm valve according to any one of claims 1 to 3, wherein the diaphragm valve is connected to and by an earth means.

That is, in the invention of claim 4, since the first pipe and the second pipe are each connected to the bonnet by the grounding means, the grounding process can be performed in the vicinity of the diaphragm valve.

According to the invention of claim 5, the diaphragm valve according to any one of claims 1 to 4, wherein the bonnet is made of polypropylene containing a carbon material or polyvinylidene fluoride containing a carbon material. Can be provided.

That is, in the invention of claim 5, since the bonnet is made of polypropylene or polyvinylidene fluoride containing a carbon material such as carbon fiber or carbon powder, it is excellent in chemical resistance and heat resistance and is used for piping in a wide range of industrial fields. Can be done. Moreover, since the bonnet can be molded by injection molding, the productivity is excellent.

According to the inventions of claims 1 to 5, it is possible to reduce adhesion of impurities to the inner peripheral surface of the flow path and damage to electronic devices arranged around the diaphragm valve due to charging of the components of the diaphragm valve. Diaphragm valves that can be provided can be provided.

It is a vertical cross-sectional view which shows the closed state of the diaphragm valve which concerns on 1st Embodiment of this invention. It is a vertical cross-sectional view which shows the open state of the diaphragm valve which concerns on 1st Embodiment of this invention. It is a schematic diagram explaining the movement of the electron accumulated in the diaphragm valve which concerns on 1st Embodiment of this invention. It is a vertical cross-sectional view which shows the closed state of the diaphragm valve which concerns on the 2nd Embodiment of this invention. It is a perspective view of the diaphragm valve which concerns on 2nd Embodiment of this invention.

Hereinafter, each embodiment of the present invention will be described with reference to the examples shown in the drawings, but it goes without saying that the present invention is not limited to each embodiment.

[First Embodiment]
The diaphragm valve 1 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a vertical cross-sectional view showing a closed state of the diaphragm valve 1 according to the first embodiment. FIG. 2 is a vertical cross-sectional view showing an open state of the diaphragm valve 1 according to the first embodiment. FIG. 3 is a schematic diagram illustrating the movement of electrons accumulated in the diaphragm valve 1 according to the first embodiment. In the first embodiment, the diaphragm valve 1 includes a valve body 2, a bonnet 3, and a first diaphragm 4, and a drive unit 5 for driving the first diaphragm 4 up and down is arranged inside the bonnet 3. Has been done. Further, a bonnet 3 is attached to the upper part of the valve body 2.

The valve body 2 is made of polytetrafluoroethylene (hereinafter, PTFE), which is an insulating material. In the valve body 2, a valve chamber 6 is formed in the center of the upper portion thereof, and a first flow path 7 and a second flow path 8 communicating with the valve chamber 6 are formed. The first flow path 7 continues from the first opening 9 formed on one side surface of the valve body 2 and communicates with the valve chamber 6 from the center of the bottom of the valve chamber 6. Around the opening on the valve chamber 6 side of the first flow path 7 (below the valve chamber 6), the first diaphragm 4 is brought into contact with and separated, and the fluid passing through the first flow path 7 can be introduced into the valve chamber 6 in an annular shape. The valve seat 11 is formed. The second flow path 8 continues from the second opening 10 formed on the other side surface of the valve body 2 and communicates with the side surface of the valve chamber 6. In the present embodiment, the flow path from the first opening 9 through the first flow path 7, the valve chamber 6 and the second flow path 8 to the second opening 10 is referred to as the internal flow path 12.

The bonnet 3 is made of carbon fiber reinforced polypropylene (hereinafter, C-PP) which is a conductive material. The bonnet 3 is composed of a first bonnet 13 attached to the upper part of the valve body 2 and a second bonnet 14 attached to the upper part of the first bonnet 13. The first bonnet 13 has a recess 15 formed on the upper surface thereof. Further, the first bonnet 13 is formed with a cylindrical portion on the bottom surface thereof into which the stem 16 is slidably inserted in the vertical direction. The second bonnet 14 is formed with a through hole on the upper surface thereof into which the guide shaft 17 is slidably inserted. A protrusion is formed on the side surface of the second bonnet 14, and the first ground means 18 is connected to the protrusion. A driving unit 5 for driving the first diaphragm 4 is arranged in the space formed by the inner peripheral surface of the recess 15 of the first bonnet 13 and the lower surface of the second bonnet 14. The first bonnet 13 and the second bonnet 14 are integrally connected to the valve body 2 with bolts and nuts made of stainless steel (hereinafter referred to as SUS) which are connecting members (not shown).

The drive unit 5 is composed of a piston 19 made of polyvinylidene fluoride (hereinafter referred to as PVDF) and a coil spring 20 made of SUS that functions as an urging member. At this time, the internal space of the bonnet 3 (the space formed by the inner peripheral surface of the recess 15 of the first bonnet 13 and the lower surface of the second bonnet 14) functions as a cylinder, and the bonnet 3 is the housing of the drive unit 5. Is functioning as.

The piston 19 has a flange-shaped piston body 21 slidably housed on the inner peripheral surface of the bonnet 3, a guide shaft 17 extending upward from the piston body 21, and downward from the piston body 21. It has a stem 16 that extends and a first diaphragm 4 is inserted at the lower end thereof. The piston 19 is arranged so that the guide shaft 17 and the stem 16 are perpendicular to the valve seat surface.

In the piston body 21, the internal space of the bonnet 3 is surrounded by the upper surface (flange-shaped upper surface) of the piston body 21, the inner peripheral surface of the bonnet 3, and the ceiling surface of the bonnet 3, and the lower surface of the piston body 21 ( It is divided into a lower space 23 surrounded by a flange-shaped lower surface), an inner peripheral surface of the bonnet 3, and a bottom surface of the bonnet 3. Here, the second bonnet 14 is formed with a vent 24 communicating with the upper space 22, and ventilation can be performed between the upper space 22 and the outside through the vent 24. Further, the first bonnet 13 is formed with a working fluid supply port 25 communicating with the lower space 23, and is configured so that the working fluid can be supplied into the lower space 23 from the working fluid supply port 25. Further, a coil spring 20 is arranged in a compressed state between the lower surface of the second bonnet 14 and the upper surface of the piston body 21.

The first diaphragm 4 is made of PTFE, which is an insulating material, and includes a valve body portion 26 and a membrane portion 27. The valve body portion 26 is formed at the center of the lower surface of the first diaphragm 4. The valve body portion 26 is formed in a substantially pyramid shape, and is arranged so that the bottom surface (top surface of the pyramid) is in contact with the valve seat 11. The membrane portion 27 extends in the outer diameter direction from the outer periphery of the base end portion of the valve body portion 26. The outer peripheral portion of the film portion 27 is sandwiched and fixed between the valve body 2 and the first bonnet 13.

Next, the operation of the diaphragm valve 1 will be described with reference to FIGS. As shown in FIGS. 1 and 2, in a normal state where the working fluid (air) is not supplied from the working fluid supply port 25 to the lower space 23, the piston 19 of the drive unit 5 is urged downward by the coil spring 20. Is pushed down. As a result, the valve body portion 26 is pressed against the valve seat 11, and the diaphragm valve 1 is closed as shown in FIG. When the working fluid is supplied from the working fluid supply port 25 to the lower space 23 in this state, the fluid pressure of the working fluid acts upward on the lower surface of the flange portion of the piston 19, and the piston 19 resists the urging force of the coil spring 20. Pushed up. At this time, the air in the upper space 22 is discharged to the outside from the vent 24. As a result, the valve body portion 26 is separated from the valve seat 11, and the diaphragm valve 1 is opened as shown in FIG. Then, when the supply of the working fluid to the lower space 23 is stopped, the piston 19 is pushed downward again by the urging force of the coil spring 20. At this time, the air in the lower space 23 is discharged to the outside from the working fluid supply port 25. As a result, the valve body portion 26 is pressed against the valve seat 11, and the diaphragm valve 1 is closed as shown in FIG.

Next, the action and effect of the diaphragm valve 1 will be described with reference to FIG. As shown in FIG. 3, when the diaphragm valve 1 is in the open state and a fluid flows through the internal flow path 12, static electricity is generated due to friction between the inner peripheral surface of the internal flow path 12 and the fluid. In particular, when the fluid has low conductivity such as an organic solvent or contains a large amount of bubbles, or when the flow velocity of the fluid is high, static electricity is likely to be generated. Further, a portion that frequently operates for adjusting the flow rate of the fluid, such as the first diaphragm 4, tends to generate static electricity because friction with the fluid increases. When static electricity is generated in the internal flow path 12, electrons are accumulated in the valve body 2 and the first diaphragm 4 constituting the internal flow path 12. In particular, when the valve body 2 and the first diaphragm 4 are formed of an insulating material, electrons are particularly likely to be accumulated.

When electrons are accumulated in the valve body 2 and the first diaphragm 4, impure parts such as particles tend to adhere to the inner peripheral surface of the internal flow path 12, which may contaminate the internal flow path 12. Further, in the diaphragm valve 1, the first diaphragm 4 may be moved up and down while flowing a fluid through the internal flow path 12 to clean the internal flow path 12, but electrons are accumulated in the valve body 2 and the first diaphragm 4. In such a state, effective cleaning may not be possible.

In the first embodiment, since the bonnet 3 made of a conductive material is connected to the valve body 2, even if the valve body 2 and the first diaphragm 4 are formed of an insulating material, the valve body 2 and the first are The electrons stored in the diaphragm 4 can be moved to the bonnet 3. The electrons transferred to the bonnet 3 are emitted to the outside of the diaphragm valve 1 via the first earth means 18 connected to the bonnet 3. As described above, in the first embodiment, the electrons accumulated in the valve body 2 and the first diaphragm 4 can be rapidly discharged to the outside, so that the electrons are accumulated in the valve body 2 and the first diaphragm 4. This can be reduced, and impurities such as particles can be reduced from adhering to the internal flow path 12.

Further, when the bonnet 3 is made of an insulating material, electrons are less likely to be emitted from the bonnet 3 and electrons are likely to be accumulated. That is, the diaphragm valve 1 tends to be in a charged state. If the diaphragm valve 1 is manually operated in this state, the electrons accumulated on the outer surface of the diaphragm valve 1 move to the operator. If the operator touches an electronic device such as a control device while the electrons are charged, the electrons moved to the operator are released to the electronic device, which may damage the electronic device. Further, when the electronic device is arranged in the vicinity of the diaphragm valve 1, the electrons accumulated on the outer surface of the diaphragm valve 1 are directly discharged to the electronic device via the air, and the electronic device may be damaged. Damage to electronic devices due to electrons accumulated in the diaphragm valve 1 is particularly likely to occur in a clean room where the humidity is adjusted to be low, or in a device in which electronic devices such as piping members and sensors are densely arranged.

In the first embodiment, since the bonnet 3 made of a conductive material is connected to the valve body 2, the electrons accumulated in the valve body 2 and the first diaphragm 4 can be quickly moved to the bonnet 3. The electrons that have moved to the bonnet 3 move to the first grounding means 18 and are emitted to the outside of the diaphragm valve 1. As described above, in the first embodiment, the electrons accumulated in the valve body 2 and the first diaphragm 4 can be rapidly discharged to the outside, so that the accumulation of electrons in the diaphragm valve 1 can be reduced. This makes it possible to reduce damage to electronic devices arranged around the diaphragm valve 1.

In the first embodiment, only the bonnet 3 is formed of the conductive material, but the piston 19 is not limited to the bonnet 3 and may be formed of the conductive material. When the piston 19 is made of a conductive material in addition to the bonnet 3, the area where the component made of the conductive material comes into contact with the component made of the insulating material such as the valve body 2 and the first diaphragm 4 is increased. Since the volume occupied by the conductive material in the diaphragm valve 1 increases, electrons can be emitted more effectively.

[Second Embodiment]
Next, the constant pressure valve 51, which is a diaphragm valve according to the second embodiment of the present invention, will be described with reference to FIGS. 4 to 5. FIG. 4 is a vertical sectional view showing a constant pressure valve according to the second embodiment. FIG. 5 is a perspective view of the constant pressure valve according to the second embodiment. In the second embodiment, the constant pressure valve 51 includes a valve body 2, a bonnet 3, a first diaphragm 4, a connecting shaft 68, a second diaphragm 53, and a base plate 52. A spring receiver 67, a piston 19, and a coil spring 20 are arranged inside the bonnet 3. A bonnet 3 is attached to the upper part of the valve body 2, and a base plate 52 is attached to the lower part (position facing the bonnet 3). The valve body 2, the bonnet 3, and the base plate 52 are integrally connected by bolts and nuts, which are connecting members made of SUS (not shown). At this time, the connecting member penetrates the valve body 2, the bonnet 3, and the base plate 52 and comes into contact with each other, or the valve body 2 is sandwiched between the bonnet 3 and the base plate 52 and comes into contact with at least the bonnet 3 and the base plate 52. ing. Further, the first pipe 54 and the second pipe 55 are connected to the valve body 2. The parts having the same functions as those in FIGS. 1 to 3 are designated by the same reference numerals, and the differences from the first embodiment will be mainly described below.

The valve body 2 is made of PTFE. The valve body 2 is formed with a valve chamber 6 having an open upper surface and a lower surface at the center thereof, and a first flow path 7 and a second flow path 8 communicating with the valve chamber 6. The valve chamber 6 communicates the first valve chamber 56 formed in the upper part of the valve chamber 6, the second valve chamber 57 formed in the lower part of the valve chamber 6, and the first valve chamber 56 and the second valve chamber 57. It is composed of a communication flow path 58 and a communication flow path 58. The first flow path 7 continues from the first opening 9 formed on one side surface of the valve body 2 and communicates with the second valve chamber 57. A valve seat 11 is formed in the upper part of the second valve chamber 57 to contact and separate the valve body portion 26 of the connecting shaft 68. The second flow path 8 continues from the second opening 10 formed on the other side surface of the valve body 2 and communicates with the side surface of the first valve chamber 56. In the present embodiment, the flow path from the first opening 9 through the first flow path 7, the valve chamber 6 and the second flow path 8 to the second opening 10 is referred to as the internal flow path 12. Further, through holes (not shown) for inserting SUS bolts and nuts connecting the valve body 2, the bonnet 3, and the base plate 52 are formed at the four corners of the valve body 2. Further, the first pipe 54 is connected to the first opening 9 of the valve body 2, and the second pipe 55 is connected to the second opening 10. The first pipe 54 and the second pipe 55 are electrically connected to the first connecting piece 60 and the second connecting piece 61 attached to the bonnet 3 via the first grounding means 18 and the second grounding means 59, respectively. Has been done.

The bonnet 3 is made of carbon fiber reinforced polyvinylidene fluoride (hereinafter, C-PVDF), which is a conductive material. The bonnet 3 is formed in a bottomed tubular body, and a space is formed inside the bonnet 3. At the center of the upper part of the bonnet 3, a working fluid supply port 25 for supplying working fluid is formed inside the bonnet 3. Through holes 62 for inserting SUS bolts and nuts that connect the valve body 2, the bonnet 3, and the base plate 52 are formed at the four corners of the bonnet 3, and the connecting members are in contact with the bonnet 3. Further, the first connection piece 60 and the second connection piece 61 are press-fitted into the two through holes 62, respectively, and the first grounding means 18 made of C-PP is inserted into the first connection piece 60 and the second connection piece 61, respectively. , The second ground means 59 are connected respectively. Since the first grounding means 18 and the second grounding means 59 can be connected to the through hole 62 formed in the bonnet 3, a new portion for connecting the first grounding means 18 and the second grounding means 59 is newly added. Does not need to be formed.

The base plate 52 is made of C-PVDF. A recess is formed in the center of the upper part of the base plate 52, and a vent is formed on the bottom surface of the recess. Through holes (not shown) for inserting SUS bolts and nuts connecting the valve body 2, the bonnet 3, and the base plate 52 are formed at the four corners of the base plate 52.

The piston 19 is made of C-PVDF. The piston 19 is arranged so as to be vertically movable inside the bonnet 3. The piston 19 is composed of a flange portion and a piston shaft provided at a lower portion of the collar portion and having a first diaphragm 4 screwed at a lower end portion. The spring receiver 67 is made of C-PVDF. The spring receiver 67 is formed in a substantially tubular body, and the inside thereof is divided into two sections, and recesses are formed on the upper surface side and the lower surface side, respectively. Further, a through hole is formed in the central portion of the section in which the columnar portion 63 of the first diaphragm 4 slides up and down. The spring receiver 67 is sandwiched and fixed between the bonnet 3 and the valve body 2. Further, a coil spring 20 made of SUS is arranged between the recess on the upper surface side of the spring receiver 67 and the lower surface of the flange portion of the piston 19.

The first diaphragm 4 is made of PTFE and includes a columnar portion 63 and a film portion 64. A piston 19 is screwed to the upper end of the cylindrical portion 63, and a connecting shaft 68 is screwed to the lower end. The film portion 64 extends in the outer diameter direction from the outer periphery of the base end portion of the columnar portion 63. The outer peripheral portion of the film portion 64 is sandwiched and fixed by the valve body 2 and the bonnet 3.

The connecting shaft 68 is made of PTFE. A first diaphragm 4 is screwed at the upper end of the connecting shaft 68, and a valve body 26 is formed at the lower end. The valve body portion 26 is formed to have a diameter larger than the inner diameter of the communication flow path 58, and is arranged in the second valve chamber 57 so that the periphery thereof is in contact with the valve seat 11. A second diaphragm 53 is screwed at the lower end of the valve body portion 26.

The second diaphragm 53 is made of PTFE and includes a shaft portion 65 and a film portion 66. The upper end of the shaft portion 65 is screwed onto the connecting shaft 68. The film portion 66 extends in the outer diameter direction from the outer periphery of the base end portion of the shaft portion 66. The film portion 66 is sandwiched and fixed by the valve body 2 and the base plate 52.

Next, the operation of the constant pressure valve 51 will be described with reference to FIGS. 4 to 5. As shown in FIGS. 4 to 5, an urging force acts upward on the valve body portion 26 of the connecting shaft 68 due to the force of the coil spring 20 and the fluid pressure on the lower surface of the first diaphragm 4. Further, an urging force acts downward due to the pressure of the working fluid on the upper surface of the first diaphragm 4. Strictly speaking, the lower surface of the valve body portion 26 and the upper surface of the thin film portion 68 of the second diaphragm 53 receive fluid pressure, but since their pressure receiving areas are set to be substantially equal, the forces of both are applied. Almost offset. Therefore, the valve body portion 26 stands still at a position where the above-mentioned three forces (the force of the coil spring 20, the fluid pressure of the first diaphragm 4, and the pressure of the working fluid on the upper surface of the first diaphragm) are balanced.

When the working fluid is supplied from the working fluid supply port 25 to the inside of the bonnet 3 and the pressure of the working fluid is increased, the force for pushing down the first diaphragm 4 increases. As a result, the valve body portion 26 and the valve seat 11 are gradually separated from each other, and the pressure in the first valve chamber 56 increases. On the contrary, when the pressure of the working fluid is reduced, the valve body portion 26 and the valve seat 11 gradually approach each other, and the pressure in the first valve chamber 56 decreases. By adjusting the pressure of the working fluid in this way, the pressure of the first valve chamber 56 can be arbitrarily set.

In this state, when the fluid pressure on the first flow path 7 side of the constant pressure valve 51 increases, the pressure in the first valve chamber 56 also increases momentarily. As a result, the force acting by the fluid on the lower surface of the film portion 64 of the first diaphragm 4 becomes larger than the operating pressure by the working fluid acting on the upper surface of the film portion 64 of the first diaphragm 4, and the first diaphragm 4 Moves upward, and the valve body portion 26 also moves upward accordingly. Therefore, the valve body portion 26 and the valve seat 11 gradually approach each other, and the fluid pressure in the first valve chamber 56 decreases. Eventually, the valve body portion 26 moves to a position where the above three forces are balanced and stands still.

On the other hand, when the fluid pressure on the first flow path 7 side of the constant pressure valve 51 decreases, the pressure in the first valve chamber 56 also decreases momentarily. As a result, the force acting by the fluid on the lower surface of the film portion 64 of the first diaphragm 4 becomes smaller than the operating pressure by the working fluid acting on the upper surface of the film portion 64 of the first diaphragm 4, and the first diaphragm 4 becomes It moves downward, and the valve body 26 also moves downward accordingly. Therefore, the valve body portion 26 is separated from the valve seat 11, and the fluid pressure in the first valve chamber 56 increases. Eventually, the valve body portion 26 moves to a position where the above three forces are balanced and stands still.

Next, the action and effect of the constant pressure valve 51 will be described with reference to FIGS. 4 to 5. As shown in FIG. 5, in the second embodiment, the valve body 2, the first diaphragm 4, and the second diaphragm 53, which are made of an insulating material, are sandwiched between the bonnet 3 and the base plate 52, which are made of a conductive material, respectively. Has been done. The bonnet 3 and the base plate 52 are connected by connecting members (bolts, nuts) made of a conductive material so that the electrons accumulated in each can move to each other. Therefore, the electrons generated in the internal flow path 12 and accumulated in the valve body 2, the first diaphragm 4, and the second diaphragm 53 can be emitted from two directions, the upper surface side and the lower surface side of the valve body 2. , It is possible to prevent electrons from being accumulated in the valve body 2. Further, in the second embodiment, the spring receiver 67 and the piston 19 are formed of a conductive material. Since the spring receiver 67 and the piston 19 are in direct contact with the bonnet 3, electrons can move to and from the bonnet 3. Therefore, by forming the spring receiver 67, the piston 19, and the bonnet 3 from the conductive material, the electrons accumulated in the valve body 2 and the first diaphragm 4 can be more effectively moved to the bonnet 3. Here, since the mechanism for discharging the electrons excessively accumulated in the valve body 2, the first diaphragm 4, and the second diaphragm 53 to the outside is the same as that in the first embodiment, the description thereof will be omitted.

Further, in the second embodiment, the first pipe 54 and the second pipe 55 made of a conductive material are connected to the valve body 2, respectively. The first pipe 54 and the second pipe 55 are connected to the first connecting piece 60 and the second connecting piece 61 attached to the bonnet 3 via the first grounding means 18 and the second grounding means 59, respectively. .. In the second embodiment, since the first grounding means 18 and the second grounding means 59 are connected to the first pipe 54 and the second pipe 55 connected to the valve body 2, respectively, the first grounding means 18 and the second grounding means 18 are connected. (Ii) The length of the grounding means 59 can be shortened, facilitating construction.

Further, in the second embodiment, the first pipe 54, the second pipe 55, and the bonnet 3 are connected by the first ground means 18 and the second ground means 59, respectively, so that the first pipe 54 and the second pipe 54 and the second pipe 54 are connected. It is electrically connected to the pipe 55. By conducting the first pipe 54 and the second pipe 55 in this way, the first pipe 54 and the second pipe 55 can be grounded together. Further, even if the final grounding location is far from the constant pressure valve 51, it is not necessary to route the first grounding means 18 and the second grounding means 59, which facilitates the construction.

In the present invention, the valve body 2 may be any insulating material, and any insulating material having physical properties suitable for the conditions and environment of use can be used. For example, resins such as PTFE, PVDF, polyvinyl chloride (hereinafter, PVC), polyethylene (hereinafter, PE), polypropylene (hereinafter, PP), and the like can be mentioned as suitable insulating materials. Further, in the present invention, the materials of the first diaphragm 4 and the second diaphragm 53 may be any insulating material, and an insulating material having physical properties suitable for the conditions of use and the environment can be used. For example, resins such as PTFE, PVDF, PVC, PE, PP, and elastomers such as fluororubber, silicone rubber, ethylene propylene diene rubber, nitrile rubber, butyl rubber, and acrylic rubber are suitable insulating materials.

In the present invention, the bonnet 3 and the base plate 52 may be any conductive material, and any conductive material having physical properties suitable for the conditions and environment of use can be used. For example, a conductive resin in which a metal such as SUS, aluminum or iron, or a resin such as PTFE, PVDF, PVC, PE or PP is added with fibers or powder made of a conductive material such as metal or carbon is suitable. Is listed as. Further, in the present invention, the materials of the piston 19, the coil spring 20, the connecting shaft 68, and the spring receiver 67 are not particularly limited, and any material having physical properties suitable for the conditions and environment of use can be used. be able to. For example, metals such as SUS, aluminum, and iron, resins such as PTFE, PVDF, PVC, PE, and PP, and conductive resins obtained by adding a conductive material to the resin are suitable materials.

In the present invention, the first pipe 54 and the second pipe 55 are not particularly limited as long as they are conductive pipes, and any pipe suitable for the conditions and environment of use can be used. .. For example, a pipe made of a conductive material, a pipe having a wire made of a conductive material inside or outside the pipe, and the like can be mentioned.

The diaphragm valve may be configured by arbitrarily combining the first to second embodiments. That is, the present invention is not limited to the diaphragm valve of the embodiment as long as the features and functions of the present invention can be realized.

1 Diaphragm valve 2 Valve body 3 Bonnet 4 1st diaphragm 5 Drive unit 6 Valve chamber 7 1st flow path 8 2nd flow path 9 1st opening 10 2nd opening 11 Valve seat 12 Internal flow path 13 1st bonnet 14 2nd bonnet 15 Recess 16 Stem 17 Guide shaft 18 First earth means 19 Piston 20 Coil spring 21 Piston body 22 Upper space 23 Lower space 24 Vent 25 Working fluid supply port 26 Valve body 27 Membrane 51 Constant pressure valve 52 Base plate 53 Second diaphragm 54 1st piping 55 2nd piping 56 1st valve chamber 57 2nd valve chamber 58 Communication flow path 59 2nd grounding means 60 1st connection piece 61 2nd connection piece 62 Through hole 63 Column part 64 Film part 65 Shaft part 66 Membrane 67 Spring receiver 68 Connecting shaft

Claims (5)

A valve body made of an insulating material and having a valve chamber and a first flow path and a second flow path communicating with the valve chamber, and a bonnet made of a conductive material and connected to the valve body, and insulating properties. It is made of a material and is characterized by having a first diaphragm sandwiched between the valve body and the bonnet and in contact with a fluid flowing through the valve chamber, and a first grounding means connected to the bonnet. Diaphragm valve. A base plate made of a conductive material and provided at a position facing the bonnet of the valve body, and a conductive material that penetrates the valve body, the bonnet, and the base plate, and the valve body and the bonnet. It is provided with a connecting member for connecting the base plate and a second diaphragm which is made of an insulating material and is interposed between the valve body and the base plate and comes into contact with a fluid flowing through the valve chamber. The diaphragm valve according to claim 1. The diaphragm valve according to claim 2, wherein a through hole is formed in the bonnet, the connecting member is inserted into the through hole, and one end of the first grounding means is connected to the through hole. A conductive first pipe and a conductive second pipe are connected to the valve body, and the first pipe and the second pipe are connected to the bonnet by a grounding means, respectively. The diaphragm valve according to any one of claims 1 to 3. The diaphragm valve according to any one of claims 1 to 4, wherein the bonnet is made of polypropylene containing a carbon material or polyvinylidene fluoride containing a carbon material.

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