JPH1026240A - Leak valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the leak valve which possesses a leak flow passage free of change in a leak flow rate even if there exist deformation caused by the swelling of a valve seat, the gouging by fluid, abrasion and the pressing of a diaphragm, and also possesses a structure excellent in fabrication properties for the leak flow passage. SOLUTION: In a diaphragm valve where a diaphragm 13 is pressed to a valve seat 9 so as to be closely attached by a pressing piece 16, a seat collar 8 integrally including a flange 7 at its outer circumferential lower end, is provided for the outlet opening periphery in the valve chamber bottom surface of a fluid inflow passage, the valve seat 9 higher in height than the seat collar 8 is fitted in the outer circumference of the seat collar 8 so as to be held therein, the inner circumference of a seat ring 12 provided with a fluid passing hole 11 communicated with a fluid outflow passage 3 in the circumferential direction, is coupled in the step part 10 in the outer circumference of the valve seat 9, furthermore the outer circumference of the seat ring 12 is also fitted in the inner circumference of a valve chamber 4, and a leak flow passage 17 from the fluid inflow passage 2 side to the fluid outflow passage 2 side is thereby formed in a space between the seat collar 8 and a valve chamber bottom surface or in the seat collar 8 itself.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leak valve used in a piping line of a semiconductor manufacturing apparatus, a liquid crystal manufacturing apparatus, or the like using a fluid such as an ultra-high purity gas or liquid.

[0002]

2. Description of the Related Art A conventional leak valve for the above application is a diaphragm valve in which a diaphragm is pressed and brought into close contact with a valve seat by a pressing piece, and the valve seat is caulked at the peripheral edge of an outlet opening of a fluid inflow passage. In the case of the type, as shown in FIG. 8 (a), a leak small diameter hole 20 is formed in a part of the valve box 1 from the middle of the fluid inflow passage 2 to the middle of the fluid outflow passage 3. In some cases, a capillary tube 21 is attached to the small diameter hole 20 as shown in FIG. Further, as shown in FIG. 8 (c), a block 23 having a hole 22 is fitted into a certain portion of the valve box 1 so as to communicate with the fluid inflow passage 2 to the fluid outflow passage 3 side. Some are.

When the valve seat is a replaceable seat type, a leak groove 24 is provided at the diaphragm contact portion of the valve seat 9 as shown in FIG. 9A, or as shown in FIG. A leak hole 25 is formed in the lower portion of the valve seat 9.
There are things that are burning.

[0004]

However, in these conventional leak valves, the leak flow rate changes due to swelling of the valve seat, or the leak flow rate changes due to choking, abrasion, etc. due to fluid in the valve seat. There is a problem that the leak flow rate changes due to deformation of the leak groove and the leak hole of the valve seat due to the diaphragm pressing pressure. In addition, it was troublesome to manufacture each of the leak passages.

Accordingly, the present invention has a leak flow path in which the leak flow rate does not change even if the valve seat sheet swells, is swollen by fluid, is worn, and is deformed by the pressure of the diaphragm.
Another object of the present invention is to provide a leak valve having a structure in which the leak passage is excellent in manufacturability.

[0006]

In order to achieve the above object, a leak valve according to the present invention is a diaphragm valve in which a diaphragm is pressed and brought into close contact with a valve seat by a pressing piece. The outlet opening edge is provided with a seat collar integrally having a flange at the outer peripheral lower end, and the valve seat sheet, which is taller than the seat collar, is fitted and held on the outer periphery of the seat collar. In the step,
The inner circumference of a seat ring provided with a fluid circulation hole communicating with the fluid outflow passage in the circumferential direction is fitted, and the outer circumference of the seat ring is fitted to the inner circumference of the valve chamber, so that the seat collar and the valve chamber bottom face are connected to each other. A leak passage is formed between the fluid inflow passage and the fluid outflow passage in the middle or in the seat collar itself.

In the above-mentioned leak valve, the leak passage formed between the seat collar and the bottom of the valve chamber is a groove formed on the bottom of the seat collar and a groove formed on the bottom of the valve chamber. There is. The cross-sectional shape of these grooves may be spherical, V-shaped, or square. In addition, the length of the leak passage is appropriately set in these grooves so as to bypass in the circumferential direction of the flange of the seat collar.

In the above-mentioned leak valve, the flow passage formed in the seat collar itself may be a hole formed in a flange portion of the seat collar.

In the thus constructed leak valve of the present invention, the fluid in the fluid inflow passage is leaked even when the diaphragm is pressed and adhered to the valve seat sheet by the holding piece and the outlet of the fluid inflow passage is closed. It flows to the fluid outflow passage side through the flow passage. Since the leak flow passage is formed between the seat collar and the bottom surface of the valve chamber or in the seat collar itself, deformation of the valve seat due to swelling of the valve seat, choking due to fluid, abrasion, etc. due to the diaphragm pressing pressure. Even if there is, there is no change in the leak flow rate in the leak flow passage, and the leak flow path is stable. In addition, since the leak passage is formed between the seat collar and the bottom of the valve chamber as described above, or on the seat collar itself, the leak passage is formed by forming a groove in the bottom of the seat collar or the bottom of the valve chamber, It can be easily manufactured simply by making a hole in the collar.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a leak valve according to the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a valve box, 2 denotes a fluid inflow passage, and 3 denotes a fluid outflow passage. At the outlet opening edge 6 of the fluid inflow passage 2 on the bottom surface 5 of the valve chamber 4 of the valve box 1,
A seat collar 8 having a flange 7 at an outer peripheral lower end is provided. A valve seat sheet 9 taller than the seat collar 8 is fitted and held on the outer periphery of the seat collar 8, and a step portion on the outer periphery of the valve seat sheet 9 is provided. As shown in FIG. 2, a plurality of fluid circulation holes 11 communicating with the fluid outflow passage 3 in the circumferential direction are fitted on the inner periphery of a seat ring 12 provided at equal intervals. It fits on the inner periphery of the valve chamber 4. Reference numeral 13 denotes a diaphragm which presses and adheres to the valve seat 9.
Reference numeral 3 denotes an outer peripheral edge of which is fastened and fixed to a projection 12a on an upper surface of an outer peripheral portion of the seat ring 12 through a diaphragm retainer 14 by screwing a bonnet 15 into the valve chamber 4, and a central portion is a retaining piece of a drive unit (not shown). The pressure is applied to the valve seat 9 by the pressure 16. The seat collar 8 and the valve chamber 4
A leak flow passage 17 is formed between the fluid flow passage 2 and the fluid inflow passage 3 between the bottom surface 5 and the fluid inflow passage 2. The leak passage 17 is formed with a groove 17 a formed in the bottom surface of the seat collar 8.
The cross-sectional shape of the groove 17a is spherical as shown in FIG. 3 (a).
(B) and (c) as shown in FIG.

The leak flow passage 17 in the leak valve of the above-described embodiment has a groove 17 formed in the bottom surface of the seat collar 8.
3, the leak flow passage 17 in the leak valve of another embodiment is a groove 17b formed in the bottom surface 5 of the valve chamber 4 as shown in FIG. 4, and the cross-sectional shape of the groove 17b is shown in FIG. Although it is spherical as shown in FIG. 3A, it may be V-shaped or square as shown in FIGS. 3B and 3C in consideration of leak flow rate and workability.

The leak flow passage 17 in the leak valve of each of the above embodiments is detoured in the circumferential direction of the flange 7 of the seat collar 8 as shown in FIGS. 5 (a), 5 (b) and 5 (c). Then, the length of the leak flow passage 17 is appropriately set so as to obtain a predetermined leak flow rate. (A), (b),
FIG. 6C shows the case where the groove 17a forming the leak passage 17 is formed on the bottom surface of the seat collar 8, and the case where the groove 17b forming the leak passage 17 is formed on the bottom surface of the valve chamber 4 in FIG. (A), (b) and (c) are obtained.

In a leak valve according to still another embodiment shown in FIG. 7, a leak passage 17 is formed in the seat collar 8 itself.
Is a hole 17c drilled at the portion. Other configurations are the same as those in FIG.

In the leak valve of each embodiment configured as described above, even when the diaphragm 13 is pressed and adhered to the valve seat 9 by the holding piece 16 and the outlet of the fluid inflow passage 2 is closed, The fluid in the passage 2 flows to the fluid outflow passage 3 through the leak passage 17. The leak passage 17 is formed between the seat collar 8 and the bottom surface of the valve chamber 4 and in the seat collar 8 itself.
Even if there is deformation of the valve seat 9 due to the diaphragm pressing pressure, such as swelling of the fluid, choking due to fluid, abrasion, etc., as long as the diaphragm 13 is pressed and adhered to the valve seat 9, the leak flow rate changes in the leak flow passage 17. No, the leak flow rate is stable. In each leak valve in which the leak flow passage 17 is formed by a groove, the leak flow rate can be adjusted to a target value by appropriately changing the cross-sectional shape and length of the groove.

[0015]

As can be seen from the above description, according to the leak valve of the present invention, even if the valve seat is deformed due to the diaphragm pressing pressure such as swelling of the valve seat, peeling due to fluid, abrasion, etc. As long as the pressure is kept in close contact with the valve seat, the leak flow path is stable with no change in the leak flow rate. In the case where the leak passage is formed by a groove, by appropriately changing the cross-sectional shape and length of the groove,
The leak flow rate can be set to a desired value. Furthermore, the leak passage can be formed by forming a groove in either the bottom of the seat collar or the bottom of the valve chamber, or by drilling a hole in the seat collar. it can.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part showing one embodiment of a leak valve of the present invention.

FIG. 2 is a cross-sectional plan view taken along line AA of FIG.

FIG. 3 shows a cross-sectional shape of a groove on a bottom surface of a seat collar forming a leak passage in the leak valve of FIG. 1;
(A) is spherical, (b) is V-shaped, and (c) is square.

FIG. 4 is a sectional view of a main part showing another embodiment of the leak valve according to the present invention.

FIGS. 5A, 5B, and 5C are diagrams showing examples of setting the length of a groove provided on a bottom surface of a sheet collar.

FIGS. 6A, 6B, and 6C are diagrams showing examples of setting the length of a groove provided on the bottom surface of a valve chamber.

FIG. 7 is a cross-sectional view of a main part showing still another embodiment of the leak valve according to the present invention.

FIGS. 8 (a), (b), and (c) are cross-sectional views of relevant parts showing a conventional valve seat seat caulking type leak valve.

9 (a) and 9 (b) are cross-sectional views of relevant parts showing a conventional leak valve in which a conventional valve seat is a replaceable seat type.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve box 2 Fluid inflow passage 3 Fluid outflow passage 4 Valve room 5 Bottom surface of valve room 6 Outlet opening edge 7 Flange 8 Seat collar 9 Valve seat 10 Stepped portion 11 Fluid flow hole 12 Seat ring 13 Diaphragm 16 Holding piece 17 Leak flow Road 17a Groove on bottom surface of seat collar 17b Groove on bottom surface of valve chamber 17c Hole in flange of seat collar

Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location G05D 7/01 G05D 7/01 Z // F16K 1/36 F16K 1/36 D

Claims (6)

[Claims] 1. A diaphragm valve in which a diaphragm is pressed and brought into close contact with a valve seat by a holding piece, wherein a seat collar having an integral flange at an outer peripheral lower end is provided at an outlet opening edge of a bottom surface of a valve chamber of a fluid inflow passage, The valve seat seat, which is taller than the seat collar, is fitted and held on the outer periphery of the seat collar, and a fluid passage hole communicating with the fluid outflow passage in the circumferential direction is provided in a step portion on the outer periphery of the valve seat sheet. The inner circumference of the seat ring is fitted, and the outer circumference of the seat ring is fitted to the inner circumference of the valve chamber. A leak valve having a leak passage formed in an outflow passage. 2. The leak valve according to claim 1, wherein the leak passage formed between the seat collar and the bottom of the valve chamber is a groove formed in the bottom of the seat collar. 3. The leak valve according to claim 1, wherein the leak passage formed between the seat collar and the bottom of the valve chamber is a groove formed in the bottom of the valve chamber. 4. The leak valve according to claim 2, wherein the cross-sectional shape of the groove is any one of a spherical shape, a V shape, and a square shape. 5. The leak valve according to claim 2, wherein the length of the leak passage is set such that the groove bypasses the circumferential direction of the flange of the seat collar. 6. The leak valve according to claim 1, wherein the leak flow passage formed in the seat collar itself is a hole formed in a flange portion of the seat collar.