JP2002340203A - Diaphragm valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a diaphragm valve for obtaining a prescribed diaphragm characteristic, and stably obtaining opening-closing performance of the valve by prescribed restoring force. SOLUTION: In this diaphragm valve, a peripheral edge part 9a of a diaphragm 9 is sandwiched by a body 1 and a diaphragm presser 10, the diaphragm is allowed to abut to a valve seat 7 by a load means, the valve seat is opened by resiliency of the diaphragm itself by releasing the load means, and the peripheral edge part 9a of the diaphragm sandwiches the outer peripheral side and the inner peripheral side of an annular projection of the diaphragm peripheral edge part 9a by an annular projection 12 formed on the body 1 or the diaphragm presser 10, and an annular groove 13 formed on the diaphragm presser 10 or the body 1 on the opposite side of a position corresponding to the annular projection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm valve which opens and closes a valve with a metal diaphragm valve, and more particularly to a clamping structure for sealingly fixing a diaphragm of the diaphragm valve.

[0002]

2. Description of the Related Art FIG. 5 shows a conventional diaphragm valve of this type.
As shown in the figure, the periphery 9a of the diaphragm 9 is
1 and the flat pressing surface 54 of the diaphragm presser 53, the diaphragm 9 is disposed so as to face the valve seat and fixed, and the diaphragm is pressed by the load means provided on the upper surface of the central portion of the diaphragm 9. There is known a diaphragm valve which opens and closes a valve seat by releasing a load means and releasing the valve means by elastic deformation of the diaphragm itself to open the valve seat. FIG. 5 shows a cross section of the holding portion of the diaphragm 9 in which the peripheral edge 9a of the diaphragm 9 is provided flat and mounted on the annular projection 52, and is held between the flat surfaces 54 of the diaphragm press that matches the flat peripheral edge 9a. .

[0003]

SUMMARY OF THE INVENTION As in the above prior art,
The peripheral edge 9a of the diaphragm is received by the annular projection 52 on the lower surface, and the upper surface is pressed by the pressing surface 54 of the diaphragm press adapted to the peripheral edge 9a to clamp the diaphragm 9. In this fixing structure, the upper surface of the annular projection 52 is directly pressed by the pressing surface 54 of the diaphragm holder, and there is a problem that the upper surface of the projection 52 is damaged or deformed by the strong pressure, and the seal is broken. In particular, if the seal is broken at one end, the diaphragm holder is further pressed to attempt to correct this, and the tip of the projection 52 is deformed. Even if the diaphragm is replaced with a new one, once the seal breaks, the tip surface of the projection 52 is damaged. There was a problem that the hermetic seal could not be restored. In this fixed structure, the load-displacement (Kgf-δ) characteristic of the diaphragm is as shown in FIG. 6B. Especially when the inside of the valve is high vacuum, or when pressure is applied little by little from the load means side, it is difficult to secure a lift from the valve seat when used at the minimum value, and linear opening and closing according to the load of the load means There was a problem that performance could not be obtained.

[0004] This is caused by variations in the shape of the diaphragm 9 during molding. For example, as shown in FIG. 4A, in the case of a diaphragm provided with a flat peripheral portion 9a on the outer periphery of a diaphragm 9 having a bulging portion 9b, the peripheral portion 9a of FIG. Diaphragm 9
On the other hand, as shown in FIGS. 4B and 4C, the peripheral edge 9a is inclined at an angle θ1 or θ2 with respect to the horizontal plane, and the bulging height also varies as h1 and h2. 5, the central projection of the diaphragm is unstablely fixed because the pressing on the upper surface is flat against the annular projection 52 on the lower surface of the diaphragm sandwiching the peripheral portion 9a in FIG. The curve shown in FIG. 6B is obtained depending on the size and assembly variation and the actual opening / closing condition, making it difficult to secure a lift from the valve seat, and a linear opening / closing performance according to the load of the load means. There was a problem that it became impossible to obtain.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems, improve the sealability of the diaphragm, and always obtain uniform diaphragm characteristics even if the shape of the diaphragm varies. The amount of valve lift according to the amount of bulging, the uniform elastic deformation characteristics of the diaphragm itself are obtained, and the linear load-displacement characteristics are obtained according to the load of the load means. It is an object of the present invention to provide a diaphragm valve in which a predetermined restoring force is stably obtained, the opening / closing performance of the valve is stabilized, and the quality is eventually stable.

[0006]

In order to achieve the object of the present invention, according to the present invention, a peripheral portion of a diaphragm is sandwiched between a main body and a diaphragm retainer, and the diaphragm is brought into contact with a valve seat by a load means. In a diaphragm valve which is released to open a valve seat by a repulsive force of the diaphragm itself, a peripheral edge of the diaphragm has an annular projection formed on a main body or a diaphragm retainer and a diaphragm retainer or a diaphragm retainer on a side opposite to a position corresponding to the annular projection. A diaphragm valve characterized in that an outer peripheral side and an inner peripheral side of an annular projection on the peripheral edge of the diaphragm are sandwiched by an annular groove formed in a main body.

In the above, the height dimension of the annular projection is
0.02 to 0.2 mm, the width and the depth of the annular groove are provided to be larger than the annular protrusion, and the peripheral edge of the diaphragm is sandwiched between the annular protrusion and the annular groove. It is a diaphragm valve. Further, in the above, the height of the annular projection is provided at 0.05 to 0.1 mm, the width and the depth of the annular groove are provided at dimensions larger than the annular projection, and the diaphragm is formed by the annular projection and the annular groove. A diaphragm valve characterized in that a peripheral portion of the diaphragm valve is sandwiched. The thickness of the diaphragm is 0.0
A diaphragm valve provided with a diameter of 5 to 0.2 mm.

[0008]

According to the present invention having the above construction, the peripheral edge of the diaphragm is formed by the annular projection formed on the main body or the diaphragm retainer, and the annular groove formed on the diaphragm retainer or the main body on the side opposite to the position corresponding to the annular projection. The periphery of the diaphragm is clamped. That is, since the inner peripheral surface of the annular projection is pressed by the annular projection and the corresponding annular groove at the peripheral edge of the diaphragm, the diaphragm is stably fixed even when a load is applied to the diaphragm. Therefore, the peripheral edge 9a of the diaphragm is deformed and sealed without deforming or damaging the sealing surface at the tip of the annular projection, so that the sealing performance is good and the sealing performance can be easily and easily restored only by replacing the diaphragm. I can do it. For this reason, a uniform diaphragm characteristic can be obtained according to the amount of bulging of the diaphragm.
The lift amount of the valve according to the swelling amount, the uniform elastic deformation characteristics of the diaphragm itself, and the linear load-displacement characteristics according to the load of the load means are obtained. For this reason, even if there is some variation during molding, a constant restoring force can be stably obtained, and the opening / closing performance of the valve is stabilized. As a result, a diaphragm valve with stable quality can be obtained stably.

Usually, the height of the annular projection depends on the size of the diaphragm valve and the thickness of the diaphragm, but it has been found from the results of various experiments that 0.02 to 0.2 mm is appropriate. If it is larger than this size, deformation of the peripheral edge of the diaphragm becomes large and the seal becomes unstable, or excessive deformation stress occurs at the peripheral edge of the diaphragm and the opening / closing lift amount of the central bulge becomes unstable. If the dimension is smaller than the above range, the sealing area is increased, an excessive clamping force of the diaphragm is required, and the sealing performance may be unstable. Further, it has been found that preferably 0.05 to 0.1 mm is good with respect to the thickness of the commonly used diaphragm and the diameter of the diaphragm.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a diaphragm valve according to an embodiment of the present invention when the valve is opened, FIGS. 2 and 3 show a diaphragm holding portion, and FIG. 2 is an enlarged cross-sectional view showing a state before a peripheral edge of the diaphragm is held. FIG. 3 and FIG. 3 are enlarged cross-sectional views showing a state in which the peripheral edge of the diaphragm is sandwiched. In FIG. 1, an inflow port 2 and an outflow port 3 are formed on both sides of a main body 1, and an upward flow path 5 which is connected to the inflow port at the center of the main body 1 and has an upward flow direction is formed. A valve seat 7 is provided in the portion, and the diaphragm 9 directly contacts the upper surface of the valve seat 7 so that the valve opens and closes. A downward flow path 6 is provided on the side of the valve seat 7, and is connected to the outlet 3.

A diaphragm 9 made of a stainless steel thin plate is provided on the upper surface of the valve seat 7, and the peripheral edge of the diaphragm 9 is held by a diaphragm retainer 10. The diaphragm retainer 10 is fixed to the main body by screwing a retainer nut 4 screwed to the external thread of the main body 1. A handle 11 having a screw hole through which the valve rod 8 penetrates at the center of the diaphragm holding nut 4, and the valve rod 8 is screwed into this screw hole, and is detachably provided above the valve rod 8.
Is rotated to move the valve stem 8 up and down.

A thrust button 14 is rotatably provided on the lower end surface of the valve rod 8, and the thrust button 14 contacts the upper surface of the diaphragm 9 to press the diaphragm 9.
Open and close the valve. When the valve rod 8 is advanced downward, the central portion of the diaphragm 9 is pressed and abuts on the valve seat 7 by elastic deformation, and the upward flow path 5 is closed. When the valve rod 8 is retracted upward, the diaphragm 9 is separated from the valve seat 7 by the elastic repulsive force of the diaphragm 9 itself, the upward flow path 5 is opened, and the valve is opened.

FIG. 2 shows a sandwiching portion of the diaphragm peripheral edge 9a. As shown in FIG. 2, an annular projection 12 is integrally formed on a flat step 15 around the inside of the main body 1. As shown in FIG. The annular projection 12 gradually becomes thinner toward the distal end in the cross section, and the upper surface is formed in a trapezoidal cross section provided on a flat surface. The height h2 of the annular projection 12 is about 0.07 mm, and the width b2 of the tip of the annular projection 12 is about 0.08 mm. On this upper surface, a stainless steel diaphragm 9 having a thickness of 0.11 mm is placed. In this embodiment, the number of the diaphragm 9 is one. The peripheral portion 9a is provided flat, and the central portion is bulged in a spherical shell shape.

The cross section of the annular projection 12 is not limited to the trapezoidal cross section of the above embodiment, but may be a triangular mountain-shaped cross section or a semi-cylindrical cross section. The diaphragm retainer 10 has an annular groove 13 formed at a position corresponding to the annular protrusion 12 of the main body, and clamps the diaphragm peripheral edge 9 a with the main body 1 to fix the diaphragm 9. This annular groove 13 has a size larger than the size of the annular projection 12 and a width dimension b1 of 0.6 m.
m and the depth dimension h1 were set to 0.4 mm. Contrary to the above, the annular groove 13 may be provided on the main body side, and the annular protrusion 12 may be provided on the diaphragm holder 10 side, and the diaphragm 9 may be held therebetween.

In this embodiment, the thickness of the diaphragm is 0.1
The height h2 of the annular projection 12 is set to 0.07 mm using 1 mm.
However, if the diaphragm has a large thickness, the height h2 of the annular projection may be slightly increased. The height h2 of the annular projection 12 is preferably at most about 0.2 mm. If the height h2 is higher than this, deformation stress is applied to the peripheral edge of the diaphragm 9 to affect the sealing property, which is not appropriate. If the height h2 is 0.02 mm or less, the diaphragm peripheral edge 9
The deformation stress given to a is too small, and the sealing property is reduced.
Therefore, the thickness is preferably about 0.02 to 0.2 mm.

[0016]

As described above, the diaphragm valve of the present invention does not directly press the upper surface of the annular projection with the diaphragm holder, but seals the inner and outer peripheral surfaces of the projection except for the annular projection by sandwiching them via the diaphragm. The sealing surface at the tip of the projection is not damaged, so the sealing performance with the diaphragm is good, and the diaphragm is forcibly fixed at the sandwiching part, and the sealing performance is high, and even if the diaphragm has variations during molding, a uniform predetermined The diaphragm characteristics described above are obtained, the quality is stable, and the opening / closing performance of the valve is stable.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a diaphragm valve according to an embodiment of the present invention when the valve is opened.

FIG. 2 is a cross-sectional view of the diaphragm holding portion of FIG. 1 before holding;

FIG. 3 is a cross-sectional view showing the diaphragm holding portion of FIG. 1 after the holding;

FIG. 4 is a cross-sectional view showing various shaped variations of the diaphragm.

FIG. 5 is a diagram illustrating a relationship between a load and a displacement of a diaphragm valve for explaining a conventional technique.

FIG. 6 is a cross-sectional view showing a diaphragm holding portion of a diaphragm valve according to the related art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Main body 2 Inflow port 3 Outflow port 4 Nut 5 Up flow path 6 Down flow path 7 Valve seat 8 Valve rod 9 Diaphragm 10 Diaphragm holding 11 Handle 12 Receiving projection 13 Receiving groove 14 Thrust button 15 Step

Claims (4)

[Claims] 1. A diaphragm is sandwiched between a main body and a diaphragm presser, a diaphragm is brought into contact with a valve seat by a load means on an upper surface of the diaphragm, the load means is released, and the diaphragm is separated from the valve seat by a repulsive force of the diaphragm itself. In the diaphragm valve for opening the valve, the peripheral edge of the diaphragm has an annular projection formed on the main body or the diaphragm retainer, and an annular groove formed on the diaphragm retainer or the main body on the opposite side of the diaphragm at a position corresponding to the annular projection. The diaphragm valve is characterized in that the diaphragm is hermetically fixed by sandwiching the outer peripheral side and the inner peripheral side of the annular projection on the peripheral edge of the diaphragm. 2. The height of the annular projection is 0.02 to 0.02.
2. The structure according to claim 1, wherein the annular groove is provided with a width and a depth dimension larger than the annular protrusion, and a peripheral edge of the diaphragm is sandwiched between the annular protrusion and the annular groove. Diaphragm valve. 3. The height of the annular projection is 0.05 to 0.05.
2. The method according to claim 1, wherein the annular groove has a width and a depth larger than the annular protrusion, and the annular protrusion and the annular groove sandwich a peripheral portion of the diaphragm. 3. The diaphragm valve according to any one of claims 1 to 2. 4. The thickness of the diaphragm is from 0.05 to
4. The diaphragm valve according to claim 1, wherein said diaphragm valve is provided with a diameter of 0.2 mm.