JP2000065225A - Diaphragm valve structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a diaphragm from being deformed into strain due to negative pressure generated in a secondary side passage when a valve is closed, and restrain the diaphragm from being damaged by stress concentration. SOLUTION: In a diaphragm valve structure, the abuttment of a diaphragm 2 against or the separation of the diaphragm from a valve seat 5 provided at the boundary between a primary side passage 3 and a secondary side passage 4, allows a space between the passages 3 and 4 to be closed or opened. The diaphragm valve structure is provided with a closing time membrane receiver 9 for receiving the membrane part 2b of the diaphragm 2 when the valve is closed. This valve structure is also provided with an opening time membrane receiver 8 for receiving the membrane part 2b of the diaphragm 2 when the valve is opened. Since both the membrane receivers 8 and 9 are made of plastics, self-lubricity is given to the surfaces of them. Therefore, when the valve is closed, the membrane part 2b of the diaphragm 2 is received by the closing time receiver 9, and the membrane part 2b will never be pulled into the secondary side passage 4 even if the pressure of the secondary passage 4 is dropped down.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm valve structure having a diaphragm that comes into contact with and separates from a valve seat.

[0002]

2. Description of the Related Art Conventionally, in a diaphragm valve structure of this type, when the diaphragm is opened away from a valve seat, the diaphragm may expand toward the back chamber due to a positive fluid pressure. Alternatively, when the diaphragm closes against the valve seat, the diaphragm may be drawn into the secondary passage under negative fluid pressure. In general, as the fluid pressure increases, the deformation of the diaphragm increases, and the above-mentioned swelling and retraction increase. Therefore, a simple rubber diaphragm is not suitable for high-pressure fluid applications.

[0003] In view of the above, a method has been devised in which a base fabric is sandwiched between rubber diaphragms to reduce distortion of the diaphragm. However, in this type of valve structure, a large driving force is required to move the diaphragm when the base fabric leaks or the valve is opened and closed, and the diaphragm itself tends to be expensive.

On the other hand, in the valve structure disclosed in Japanese Utility Model Laid-Open No. 8-884, a diaphragm that expands toward the back chamber due to fluid pressure when the valve is opened is received by a pressure receiving plate. That is, as illustrated in FIG. 11, in order to prevent the diaphragm 31 from being distorted and deformed, the pressure receiving plate 32 is provided on the back room side of the membrane portion 31b. Then, when the diaphragm 31 is opened, as shown in FIG. 12, the membrane portion 31b of the diaphragm 31 which is about to expand toward the back chamber due to positive fluid pressure is received by the pressure receiving plate 32. According to this valve structure, a great effect is obtained for the positive pressure at the time of opening.

[0005]

However, in the conventional diaphragm valve structure, the primary passage 33 is closed when the diaphragm valve is closed.
The flow of the fluid between the fluid and the secondary passage 34 is controlled by the diaphragm 3.
When shut off at the valve section 31a, a water hammer occurs,
Immediately after closing, the pressure in the primary side passage 33 increases, and the pressure in the secondary side passage 34 decreases. When the pressure drop becomes sharp, the pressure becomes negative enough to cause liquid column separation in the fluid, which may cause damage to the piping including the passages 33 and 34. The liquid column separation occurs due to the inertial force of the fluid in the secondary side passage 34, and is more likely to occur as the pipe ends are opened and the pipes are longer.

When the diaphragm 31 is made of rubber, as shown in FIG. 13, the film portion 31 of the diaphragm 31 is caused by a negative pressure generated due to a pressure drop in the secondary passage 34.
A part of b may be drawn into the secondary side passage 34 and deformed into distortion. In FIG. 14, the opening of the primary side passage 33 included in the valve seat 35 and the secondary side passage 3 located on the outer periphery of the valve seat 35 are shown.
4 shows an opening 34a having an arc shape. Diaphragm 3
The first membrane portion 31b is drawn into the arc-shaped opening 34a, and the valve portion 31a of the diaphragm 31
Will be distorted in a state of being eccentric with respect to the valve seat 5.

[0007] The distorted deformation due to the negative pressure is particularly caused by the valve seat 3.
This is likely to occur when the eccentricity of the diaphragm 31 with respect to 5 is structurally permitted. 11 to 13, the eccentricity of the diaphragm 31 is allowed by the gap Ga between the valve portion 31 a of the diaphragm 31 and the pressure receiving plate 32. For this reason, the deformation of the diaphragm 31 is increased, and the deformation in operation is repeated, so that the diaphragm 31 may be damaged due to stress concentration. Also, in the operation process of the diaphragm 31,
The membrane portion 31 of the diaphragm 31 is contacted with the pressure receiving plate 32.
b may be worn, and the wear is
In some cases, stress concentration was promoted.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a diaphragm that is closed by a negative pressure generated due to a pressure drop in a secondary passage when the diaphragm comes into contact with a valve seat. An object of the present invention is to provide a diaphragm valve structure capable of preventing deformation due to distortion and suppressing damage to the diaphragm due to stress concentration.

[0009]

In order to achieve the above object, according to the first aspect of the present invention, a diaphragm is applied to a valve seat provided at a boundary between a primary passage and a secondary passage. In a diaphragm valve structure in which the primary side passage and the secondary side passage are closed or opened by being brought into contact with or separated from each other, when the diaphragm is closed to receive a membrane portion of the diaphragm when the diaphragm comes into contact with a valve seat when the diaphragm is closed. The purpose is to provide a film receiver.

[0010] According to the above configuration, when the diaphragm abuts on the valve seat, the diaphragm membrane is received by the membrane receiver when the diaphragm is closed. Therefore, even if a pressure drop occurs in the secondary passage, the diaphragm membrane is maintained. It is not drawn into the secondary passage.

According to a second aspect of the present invention, there is provided an opening-time membrane for receiving a membrane portion of a diaphragm when the diaphragm is opened away from a valve seat. The purpose is to establish a reception.

According to the above construction, in addition to the operation of the first aspect of the present invention, the membrane portion of the diaphragm is received by the membrane receiver at the time of opening when the diaphragm is separated from the valve seat. The membrane part does not expand toward the back chamber even if it is applied to the diaphragm.

According to a third aspect of the present invention, in order to achieve the above object, at least one of the surfaces of the film receiver at the time of closing and the film receiving device at the time of opening is lubricated. It is intended that a process having a property is performed.

According to the above construction, in addition to the effect of the first or second aspect of the present invention, at least one of the surface of the film receiver at the time of closing and the film receiver at the time of opening is subjected to a lubricating treatment. In addition, when the membrane portion of the diaphragm is received by the closed membrane receiver or the opened membrane receiver, wear of the membrane portion is suppressed.

According to a fourth aspect of the present invention, there is provided an eccentricity regulating means for regulating the eccentricity of a diaphragm with respect to a valve seat. The purpose is to provide.

According to the above construction, the eccentricity of the diaphragm with respect to the valve seat is regulated by the eccentricity regulating means, in addition to the effect of the first aspect of the present invention. When received by the membrane receiver,
The whole area of the membrane portion comes into uniform contact with the membrane receiver when closed.

In order to achieve the above object, an invention according to claim 5 is provided by bringing a diaphragm into contact with or away from a valve seat provided at a boundary between a primary passage and a secondary passage. In a diaphragm valve structure in which a portion between a primary side passage and a secondary side passage is closed or opened, an eccentricity regulating means for regulating eccentricity of a diaphragm with respect to a valve seat is provided.

According to the above configuration, the eccentricity of the diaphragm with respect to the valve seat is regulated by the eccentricity regulating means. Therefore, even if a pressure drop occurs in the secondary passage, deformation of the diaphragm in the eccentric direction is suppressed. Retraction of the membrane portion into the secondary passage is minimized.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] Hereinafter, a first embodiment of a diaphragm valve structure according to the present invention will be described in detail with reference to the drawings.

FIGS. 1 and 2 show a main part of the diaphragm valve structure according to the present embodiment. This diaphragm valve is
And a diaphragm 2. The body 1 is formed of a material (for example, plastic) having chemical resistance.
Primary side passage 3 and secondary side passage 4 formed in this body 1
A valve seat 5 is provided at the boundary between the two. FIG. 3 is a plan view showing the primary passage 3 and its opening 3a included in the valve seat 5, and the secondary passage 4 and its opening 4a located on the outer periphery of the valve seat 5. A peripheral groove 6 is formed around the valve seat 5, and the opening 4 a of the secondary passage 4 is located in the peripheral groove 6 and forms an arc shape. The diaphragm 2 is brought into contact with or separated from the valve seat 5 so that the space between the primary passage 3 and the secondary passage 4 is closed or opened.

The rubber diaphragm 2 has a valve portion 2a which can be brought into contact with the valve seat 5, a film portion 2b integrally formed around the valve portion 2a, and a film portion 2b integrally formed on the outer periphery of the film portion 2b. And a thickened edge portion 2c. The edge 2c is fixed to the body 1. A valve stem 7 extending upward is fixed to the valve portion 2a. The valve stem 7 is moved up and down by a separate driving means (not shown). When the valve rod 7 is moved up and down, the valve portion 2a of the diaphragm 2 is moved up and down, and is separated or abutted against the valve seat 5.

Above the diaphragm 2, there is provided a ring-shaped opening-time membrane receiver 8 for receiving the membrane portion 2b of the diaphragm 2 when the valve portion 2a of the diaphragm 2 is separated from the valve seat 5 and opened. Below the diaphragm 2, there is provided a closed-time membrane receiver 9 for receiving the membrane portion 2b of the diaphragm 2 when the valve portion 2a of the diaphragm 2 abuts on the valve seat 5 when closed. As shown in FIGS. 1 and 2, the closed membrane receiver 9, the diaphragm 2, and the opened membrane receiver 8 are assembled on the body 1 by being vertically overlapped and pressed by the pressing plate 10. As shown in FIG. 4 in an enlarged manner, the open membrane receiver 8 has a curved and concave contact surface 8a with the membrane portion 2b, and the closed membrane receiver 9 has a contact surface 9a with the membrane portion 2b. Is curved and bulging. These film receivers 8 and 9 are formed of a material (for example, plastic) having the self-lubricating property of the surface for suppressing the abrasion of the diaphragm 2 and the same chemical resistance as the body 1.

According to the diaphragm valve structure of the present embodiment configured as described above, as shown in FIG. 1, when the valve portion 2a of the diaphragm 2 closes against the valve seat 5, the membrane portion 2b closes. The entire surface of the contact surface 9a of the hour film receiver 9 is received. Therefore, when closed, the secondary passage 4
Even if a negative pressure is generated based on the pressure drop, the membrane portion 2b is not drawn into the secondary side passage 4. Therefore, it is possible to prevent the diaphragm 2 from being deformed into a strain due to being pulled in. Then, since there is no distortion, the occurrence of stress concentration in the diaphragm 2 can be suppressed, and breakage of the diaphragm 2 due to the stress concentration can be suppressed. In this sense, the life of the diaphragm valve can be prolonged. Moreover, since the diaphragm 2 is hardly affected by the pressure fluctuation in the secondary side passage 4 as described above, it is possible to reduce restrictions on the secondary side passage 4 and piping connected thereto and connected devices. .

On the other hand, according to the diaphragm valve structure of this embodiment, as shown in FIG. 2, when the diaphragm 2 is opened away from the valve seat 5, the membrane portion 2b of the diaphragm 2 is brought into contact with the membrane receiver 8 when opened. The entire area of the contact surface 8a is received. Therefore, even when a positive fluid pressure is applied to the diaphragm 2 at the time of opening, the membrane portion 2b does not greatly expand toward the back chamber. Therefore, abnormal expansion of the diaphragm 2 due to the action of the fluid pressure can be suppressed. Further, since no abnormal bulging occurs, the occurrence of stress concentration in the diaphragm 2 can be suppressed, and the damage of the diaphragm 2 due to the stress concentration can be suppressed. In this sense, the life of the diaphragm valve can be prolonged.

According to the diaphragm valve structure of this embodiment, since the surface of each of the membrane receivers 8 and 9 is provided with self-lubricating properties, the membrane portion 2b of the diaphragm 2 is attached to each of the membrane receivers 8 and 9.
Abrasion of the film portion 2b when the film portion 2b is received.
In this sense, stress concentration can be further reduced, and breakage of the diaphragm 2 can be suppressed.

According to the diaphragm valve structure of this embodiment, since the membrane portion 2b of the diaphragm 2 is received by the respective membrane receivers 8, 9, the fluid pressure applied to the diaphragm 2 is shared by the respective membrane receivers 8, 9. be able to. For this reason,
The working pressure range of the diaphragm valve can be expanded as compared with a valve structure without the membrane supports 8 and 9.

[Second Embodiment] Next, a second embodiment of the diaphragm valve structure of the present invention will be described with reference to the drawings. In the following embodiments including this embodiment, the same components as those in the first embodiment will be denoted by the same reference numerals, and description thereof will be omitted. Hereinafter, different points will be mainly described. Will be described.

This embodiment is different from the first embodiment in the membrane receiver 11 when closed. FIG. 5 is a sectional view corresponding to FIG. 1, and FIG. 6 is a plan view corresponding to FIG. As shown in FIGS. 5 and 6, in the diaphragm valve structure of this embodiment, the above-described peripheral groove 6 is deleted from the outer periphery of the valve seat 5, and instead, a position corresponding to the peripheral groove 6, that is, the valve seat The closed-time membrane receiver 11 is formed integrally with the body 1 on the outer periphery of the body 5. In addition, at a position corresponding to the above-described arc-shaped opening 4a, a plurality of small openings 4b are formed instead of the opening 4a.

Therefore, the same action and effect as those of the first embodiment can be obtained also by the diaphragm valve structure of this embodiment. In particular, in this embodiment, since the closing membrane receiver 11 is formed integrally with the body 1, a valve structure is configured as compared with the first embodiment in which the closing membrane receiver 9 is a separate member. The number of parts can be reduced.

In this embodiment, only a slight negative pressure acts on the membrane portion 2b of the diaphragm 2 through the plurality of openings 4b formed on the membrane receiver 11 at the time of closing.
The influence of the negative pressure acting on the membrane portion 2b can be minimized as compared with the circular opening 34 in the conventional diaphragm valve structure shown in FIGS. In that sense, occurrence of stress concentration in the film portion 2b can be suppressed.

[Third Embodiment] Next, a third embodiment of the diaphragm valve structure of the present invention will be described with reference to the drawings.

This embodiment is different from the above embodiments in the point that the membrane receiver 12 is closed. FIG. 7 is a sectional view corresponding to FIGS. 1 and 5, and FIG. 8 is a plan view corresponding to FIGS. As shown in FIGS. 7 and 8, in the diaphragm valve structure according to this embodiment, another closed-time membrane receiver 12 that forms an annular shape corresponds to the entire circumference of the circumferential groove 6 instead of the closed-time membrane receiver 9 described above. Provided. The membrane receiver 12 has a plurality of small holes 12a arranged at equal intervals around the entire circumference.

Therefore, the same functions and effects as those of the above embodiments can be obtained also by the diaphragm valve structure of this embodiment. In particular, in this embodiment, since the circumferential groove 6 is provided around the valve seat 5 as in the first embodiment, a larger fluid flow rate is secured than in the second embodiment. be able to. Further, since the small holes 12a are arranged on the entire outer periphery of the valve seat 5, the number of the small holes 12a can be increased as compared with the plurality of openings 4b in the second embodiment, and in that sense, the number of the small holes 12a is relatively large. Fluid flow rate can be ensured.

In this embodiment, the negative pressure only slightly acts on the membrane portion 2b of the diaphragm 2 through a plurality of small holes 12a formed in the closed membrane receiver 12. Moreover, since the small holes 12a are dispersedly arranged in the entire outer periphery of the valve seat 5, the influence of the negative pressure acting on the membrane 2b can be dispersed throughout the membrane 2b. Thus, the occurrence of stress concentration in the film portion 2b can be further suppressed as compared with the case of the second embodiment.

[Fourth Embodiment] Next, a fourth embodiment of the present invention will be described with reference to the drawings.

In this embodiment, as shown in FIG.
In the same valve structure as the second embodiment, the present embodiment is different from the other embodiments in that a bearing 13 is provided on the outer periphery of the valve portion 2a of the diaphragm 2 and between the diaphragm 2 and the opening-time membrane receiver 8. The bearing 13 is for regulating the eccentricity of the diaphragm 2 with respect to the valve seat 5, and corresponds to the eccentricity regulating means of the present invention.

Therefore, in the diaphragm valve structure of this embodiment, the open membrane receiver 8 and the closed membrane receiver 9 are:
The same operation and effect as those of the second embodiment can be obtained. Further, the diaphragm 2 with respect to the valve seat 5
Is restricted by the bearing 13, the axis of the diaphragm 2 always coincides with the axis of the valve seat 5. Therefore, when the membrane part 2b of the diaphragm 2 is received by the membrane receiver 9 at the time of closing, the entire area of the membrane part 2b comes into uniform contact with the membrane receiver 9 at the time of closing. That is, the wear between the membrane portion 2b and the closed-time membrane receiver 9 is made uniform and reduced over the entire area of the membrane portion 2b. in addition,
Even if a slight negative pressure acts on the membrane 2b through each opening 4b, the deformation of the membrane 2b due to the negative pressure is less likely to occur because the eccentricity of the diaphragm 2 is restricted. In this sense, it is possible to suppress the diaphragm 2 from being deformed into a strain due to the negative pressure generated in the secondary side passage 4, and it is possible to prevent the diaphragm 2 from being damaged due to stress concentration.

[Fifth Embodiment] Next, a fifth embodiment of the diaphragm valve structure of the present invention will be described with reference to the drawings.

In this embodiment, as shown in FIG. 10, a push rod 14 extending from the valve portion 2a to the primary side passage 3 is provided in a valve structure substantially the same as that of the second embodiment, and the outer periphery of the rod 14 is provided. This embodiment differs from the other embodiments in that a plurality of projections 14a protruding outward are provided. The push rod 14 with the projection 14a is for regulating the eccentricity of the diaphragm 2 with respect to the valve seat 5, and corresponds to the eccentricity regulating means of the present invention.

Accordingly, in the diaphragm valve structure of this embodiment, the open-time membrane receiver 8 and the closed-time membrane receiver 9 are:
The same operation and effect as those of the second embodiment can be obtained. Further, the diaphragm 2 with respect to the valve seat 5
Is restricted by the push rod 14 with the projection 14a, so that the axis of the diaphragm 2 always coincides with the axis of the valve seat 5. Therefore, when the membrane portion 2b of the diaphragm 2 is received by the closing membrane receiver 9 at the time of closing, the entire area of the membrane portion 2b comes into uniform contact with the closing membrane receiver 9. That is, the wear between the membrane portion 2b and the closed membrane receiver 9 can be made uniform and reduced over the entire area of the membrane portion 2b. In addition, through each opening 4b, the film portion 2b
Even if a slight negative pressure acts on the diaphragm 2, the deformation of the membrane portion 2b due to the negative pressure is less likely to occur because the eccentricity of the diaphragm 2 is restricted. In this sense, it is possible to suppress the diaphragm 2 from being deformed into a strain due to the negative pressure generated in the secondary side passage 4, and it is possible to prevent the diaphragm 2 from being damaged due to stress concentration.

It should be noted that the present invention is not limited to the above-described embodiments, and may be carried out as follows without departing from the spirit of the invention.

(1) In each of the above-described embodiments, the film receiver 8 at the time of opening and the film receiver 9 at the time of closing are formed of plastic, so that their surfaces are subjected to a self-lubricating treatment. May be subjected to a self-lubricating surface treatment, for example, Teflon coating. Or,
It is effective to apply a surface treatment to the diaphragm side. or,
As the surface treatment, application of a lubricant (grease or the like) and insertion of a lubricant (Teflon sheet or the like) may be performed.

(2) In each of the above-described embodiments, the surface of both the open membrane receiver 8 and the closed membrane receiver 9 is treated to have self-lubricating properties. 9 may be subjected to the above-mentioned surface treatment. Alternatively, these surface treatments may be omitted.

(3) In each of the above embodiments, both the open-ended membrane receiver 8 and the closed-time membrane receiver 9 are provided, but the open-time membrane receiver 8 is omitted and only the closed-time membrane receiver 9 is provided. You may.

(4) In the fourth or fifth embodiment, in the valve structure of the second embodiment, that is, the valve structure having the open-time membrane receiver 8 and the closed-time membrane receiver 9, 13
And the push rod 14 was provided. On the other hand, an eccentricity regulating means such as a bearing or a push rod may be provided in a diaphragm valve structure having neither the open-time membrane receiver nor the closed-time membrane receiver. In this case, since the eccentricity of the diaphragm with respect to the valve seat is regulated by the eccentricity regulating means, even if a pressure drop occurs in the secondary side passage,
The deformation of the diaphragm in the eccentric direction is suppressed, and the membrane portion is minimized from being drawn into the secondary passage.
In this sense, when the diaphragm is closed against the valve seat,
The diaphragm can be prevented from being deformed to be distorted by the negative pressure generated based on the pressure drop in the secondary passage, and the diaphragm can be prevented from being damaged due to stress concentration.

(5) In the fifth embodiment, the push rod 14 having a plurality of protrusions 14a on the outer periphery is arranged in the primary passage 3 as the eccentricity restricting means. However, the outer periphery of the push rod provided in the primary passage is May be provided with a circular flange, and the flange may be formed with a through hole that allows the passage of fluid.

[0047]

According to the structure of the first aspect of the present invention, the diaphragm valve structure is provided with a closing membrane receiver for receiving the membrane portion of the diaphragm when the diaphragm comes into contact with the valve seat when closing. Therefore, even when a pressure drop occurs in the secondary passage at the time of closing, the membrane portion of the diaphragm is received by the membrane receiver at the time of closing, and is not drawn into the secondary passage. For this reason, it is possible to prevent the diaphragm from being deformed into strain due to the negative pressure generated in the secondary side passage at the time of closing, and it is possible to suppress the damage of the diaphragm due to stress concentration.

According to the structure of the second aspect of the present invention, the first aspect
In the configuration of the invention, an open-time membrane receiver for receiving the membrane portion of the diaphragm when the diaphragm is opened away from the valve seat is provided. Therefore, in addition to the function and effect of the invention of claim 1, even when a positive fluid pressure is applied to the diaphragm at the time of opening, the membrane portion is received by the membrane receiver at the time of opening,
Does not swell to the back room. For this reason, it is possible to prevent the diaphragm from being deformed into a strain at the time of opening, and it is possible to suppress the damage of the diaphragm due to stress concentration.

According to the configuration of the third aspect of the present invention, the first aspect
Alternatively, in the configuration of the second aspect of the present invention, at least one surface of the film receiver at the time of closing and the film receiver at the time of opening is subjected to a treatment having lubricity. Therefore, in addition to the function and effect of the invention of claim 1 or claim 2, abrasion of the film portion when the film portion is received by the closed film receiver or the open film receiver is suppressed by the surface treatment having lubricity. . In this sense, the effect that the stress concentration can be further reduced and the breakage of the diaphragm 2 can be suppressed is exhibited.

According to the structure of the invention of claim 4, according to claim 1,
According to the third aspect of the present invention, an eccentricity regulating means for regulating the eccentricity of the diaphragm with respect to the valve seat is provided. Therefore, in addition to the functions and effects of one of the first to third aspects of the present invention, when the membrane is received by the closed membrane receiver, the entire area of the membrane comes into uniform contact with the closed membrane receiver. . Also in this sense, the effect that the strained deformation of the diaphragm can be suppressed more reliably and the damage of the diaphragm due to the stress concentration can be suppressed more reliably.

According to the fifth aspect of the invention, in the diaphragm valve structure having neither the closed membrane receiver nor the opened membrane receiver, an eccentricity regulating means for regulating the eccentricity of the diaphragm with respect to the valve seat is provided. I have. Therefore, even if a pressure drop occurs in the secondary passage, deformation of the diaphragm in the eccentric direction is suppressed, and the film portion of the diaphragm is minimized from being drawn into the secondary passage. For this reason, it is possible to prevent the diaphragm from being deformed into distortion due to the negative pressure generated in the secondary side passage at the time of closing, and it is possible to suppress the damage of the diaphragm due to stress concentration.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a diaphragm valve structure according to a first embodiment.

FIG. 2 is a sectional view showing a diaphragm valve structure.

FIG. 3 is a plan view showing openings of a valve seat, a primary passage, and a secondary passage.

FIG. 4 is an enlarged sectional view showing a part of a main part of the diaphragm valve structure.

FIG. 5 is a cross-sectional view showing a diaphragm valve structure according to a second embodiment.

FIG. 6 is a plan view showing openings of a valve seat, a primary passage, and a secondary passage.

FIG. 7 is a cross-sectional view showing a diaphragm valve structure according to a third embodiment.

FIG. 8 is a plan view showing openings of a valve seat, a primary passage, and a secondary passage.

FIG. 9 is a cross-sectional view illustrating a diaphragm valve structure according to a fourth embodiment.

FIG. 10 is a cross-sectional view showing a diaphragm valve structure according to a fifth embodiment.

FIG. 11 is a sectional view showing a conventional diaphragm valve structure.

FIG. 12 is a sectional view showing a conventional diaphragm valve structure.

FIG. 13 is a sectional view showing a conventional diaphragm valve structure.

FIG. 14 is a plan view showing a conventional diaphragm valve structure.

[Explanation of symbols]

 2 Diaphragm 2b Membrane part 3 Primary passage 4 Secondary passage 5 Valve seat 8 Open membrane receiver 9 Closed membrane receiver 11 Closed membrane receiver 12 Closed membrane receiver 13 Bearing (eccentricity regulating means) 14 Push rod (Eccentricity regulation) means)

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tetsuya Iwashita 850 Horinouchi-cho, Kasugai-shi, Aichi Prefecture Inside Kasugai Works, Inc.

Claims (5)

[Claims] A diaphragm is brought into contact with or separated from a valve seat provided at a boundary between a primary side passage and a secondary side passage, thereby closing a gap between the primary side passage and the secondary side passage. Alternatively, in the diaphragm valve structure which is opened, a diaphragm valve stopper is provided for receiving the membrane portion of the diaphragm when the diaphragm is in contact with the valve seat when the diaphragm is closed. 2. The diaphragm valve structure according to claim 1, further comprising: an open-time membrane receiver for receiving a membrane portion of the diaphragm when the diaphragm is opened away from the valve seat. Construction. 3. The diaphragm valve structure according to claim 1, wherein at least one surface of the closed membrane receiver and the opened membrane receiver is subjected to a lubricating treatment. Diaphragm valve structure. 4. The diaphragm valve structure according to claim 1, further comprising an eccentricity regulating means for regulating the eccentricity of the diaphragm with respect to the valve seat. . 5. A gap between the primary side passage and the secondary side passage is closed by contacting or separating a diaphragm with a valve seat provided at a boundary between the primary side passage and the secondary side passage. Alternatively, in the diaphragm valve structure which is opened, an eccentricity regulating means for regulating eccentricity of the diaphragm with respect to the valve seat is provided.