JPH0452541Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a safety valve, particularly a type of safety valve in which the valve body is brought into contact with the valve seat with a certain biasing force to set its operating pressure. It is used as a safety valve to prevent abnormal pressure rise in pressure vessels such as hot water boilers.

[Prior art and its problems] In this type of safety valve, the main body of the safety valve is usually formed of a brass alloy. Therefore, the valve seat portion formed within the main body is also made of brass casting. However, such valve seats do not have sufficient corrosion resistance, and if used for a long period of time, they may deteriorate, especially when used in areas where fluid temperature changes or in hot water circuits.
May be partially corroded. Such corrosion leads to a lack of sealing performance.

Therefore, a safety valve that prevents the deterioration of sealing performance due to such corrosion of the valve seat is proposed and disclosed in Japanese Utility Model Publication No. 59-29182.

As shown in FIG. 6, this conventional safety valve has a safety valve main body 1 and a valve seat portion configured separately.
The outer periphery of the valve chamber 10 is caulked to an annular protrusion 16 formed at the upstream end of the valve chamber 10 in an airtight state.

Then, the valve shaft 5 of the valve body 8 that faces the valve seat 90 is connected to the lower end of the operating shaft 14 that can be raised and lowered within a certain range by an operating lever.
In the lowered position, a connection structure is adopted that allows the valve shaft 5 to rise independently within a certain range.

In this conventional type, the valve body 8 can be opened as necessary by operating the operating lever, and
When the upstream circuit of the safety valve becomes equal to or higher than the set pressure set by the spring 3, the valve opens, thereby preventing an abnormal pressure rise in the upstream device such as the hot water storage tank.

In particular, in this conventional type, the valve seat body 9 is made of stainless steel, which has excellent corrosion resistance, so that corrosion of the valve seat can be prevented as in the conventional type, and sealing performance is impaired due to partial lack of the valve seat. Such inconveniences can be resolved.

However, with this conventional one, it is difficult to ensure concentricity between the valve body 8 and the valve seat 90 of the valve seat body 9;
There is a problem that the valve body 8 may not operate smoothly and the operating pressure may not be stable.

This is because it is difficult to ensure concentricity between the support ring 4, which slidably holds the guide shaft 7 provided on the valve body 8 and is fixed on the upstream side of the valve seat body 9, and the valve seat 90. If this concentricity is not ensured, the biasing force of the spring 3 will not act uniformly on the valve seat contacting portion of the valve body 8, and the center of action of the fluid pressure and the center of action of the spring 3 will become different. This is because an eccentric force will be applied to the valve shaft 5.

That is, since the valve seat body 9 and the support ring 4 are separate bodies and are fixed to a predetermined part of the main body 1 by separate processes, eccentricity due to variations in their fixed states may occur. This eccentricity is the cause of the above problem.

[Technical Problem] The present invention is directed to a valve equipped with such a valve seat 90 in which the valve body 8 is brought into contact with the valve seat 90 with a constant biasing force by the spring 3 fitted onto the valve stem 5. The seat body 9 is configured separately from the main body 1, and is caulked to an annular protrusion 16 formed at the upstream end of the valve chamber 10 of the main body 1 in an airtight manner on the outer periphery, and the support ring 4 provided with a guide hole is attached to the annular protrusion 16 formed at the upstream end of the valve chamber 10 of the main body 1. The corrosion resistance of the valve seat 90 is improved in the safety valve which is fixed on the upstream side of the valve seat body 9 and in which a guide shaft 7 provided on the valve body 8 is slidably inserted into the guide hole. In addition to stabilizing the operating pressure of the valve body, the valve body 8, which may cause incomplete valve opening, etc.
In order to prevent eccentricity between the valve seat 90 and the guide shaft 7,
The annular projecting piece 16 of the main body 1 remains integrated with the support ring 4 that slidably supports the valve seat body 9.
To be able to fix the outer periphery in an airtight state,
This is a technical issue.

[Technical Means] The technical means of the present invention taken to solve the above-mentioned technical problems are as follows.
The valve seat body 9 is formed above the body 91 and the support ring 4 is formed at the bottom, and the valve seat 90 is formed into a dish-shaped integrally molded body with a partially open bottom. , the back surface of the valve seat 90 is used as an annular packing accommodating section, the annular packing accommodated in this accommodating section is brought into contact with the annular protrusion 16, and the lower end of the body section 91 is arranged in the dish-shaped Extension pieces 92, 92 are made to protrude from the periphery of the opening for fluid passage formed at the bottom of the body, and these extension pieces 92, 9
2 is extended outward, and the valve seat body 9 is caulked to the annular protrusion 16.

[Operation] The above technical means of the present invention operates as follows.

A guide shaft 7 connected downward from the center of the valve body 8
is inserted through a guide hole located at the bottom of a dish-shaped body attached to the annular protrusion 16.

This guide hole is formed by integrally forming the valve seat body 9 and the support ring 4, and is formed in advance by press molding so that the valve seat 90 and the guide hole are located concentrically. The guide shaft 7 inserted through this guide hole is concentric with the valve seat 90. Therefore,
The valve body 8 and the valve seat 90 are in a concentric state, and the center of action of the spring 3 acting on the valve body 8 and the centers of the valve shaft 5 and guide shaft 7 are exactly concentric, and when the valve body is operated, the valve shaft and the guide shaft are No straining force is applied to the shaft 7.

Next, since the annular packing is accommodated in a downward-opening packing accommodating portion formed on the back side of the valve seat 90, when the dish-shaped body is caulked to the annular protrusion 16, the annular packing is inserted into the annular fitting. The protruding piece 16 and the back surface of the valve seat 90 are in contact with each other, and a seal between the valve seat body 9 and the annular protruding piece 16 is ensured by this annular packing. Moreover, this packing housing portion is a hollow portion on the back surface of the valve seat 90 made of a metal plate. Since this cavity is an inevitably required part of the valve seat body 9,
There is no need to specially form a packing housing part.

Therefore, the width of the body of the dish-shaped body is determined only by the thickness of the corrosion-resistant metal plate constituting it, and no special protrusions or the like are required in the upper part of the valve seat body 9 other than the valve seat 90. .

[Effects] Since the present invention has the above configuration, it has the following unique effects.

The center of action of the spring 3 acting on the valve body 8 and the centers of the valve stem 5 and guide shaft 7 are exactly concentric, and no straining force is applied to the valve stem and guide shaft 7 when the valve body is operated, so the safety valve is The operating pressure is stabilized and malfunctions can be prevented.

The parts that are necessarily required in the valve seat body 9 are:
Since this is a gasket accommodating portion for ensuring the outer peripheral seal of the valve seat body 9, the parts other than the gasket accommodating portion, such as the body of the dish-like body, are limited only by the thickness of the corrosion-resistant metal plate that constitutes this. Therefore, even in a configuration in which a plate-shaped body separate from the main body is attached, the valve seat portion does not become unnecessarily large. In other words, the size of this valve seat portion is minimized.

Furthermore, since the valve seat body 9 and the support ring 4 are integrally formed by press molding, the valve seat body 9 and the support ring 4 can be manufactured at low cost. Also, plate-shaped extension pieces 92, 92 are molded at the same time.
Since it is attached to the annular protrusion 16 by caulking, the caulking work is also easy.

[Example] Hereinafter, an example of the present invention will be described based on FIGS. 1 to 5.

As shown in FIG. 1, this safety valve has a main body 1 having an outlet 11 on the peripheral wall of a cylindrical body with both ends open, and one open end as an inlet 12.
By screwing the valve cover 6 to the other open end,
A valve chamber 10 is configured. As shown in FIG. 4, an annular protrusion 16 is formed at the inlet of the valve chamber 10 and extends inwardly. 91,92
It is as follows.

In the safety valve of this embodiment, as shown in FIGS. 1 and 3, the above-mentioned valve seat body 9 and support ring 4 are integrally press-molded from a corrosion-resistant stainless steel plate to form a dish-shaped body S. By caulking this dish-shaped body S to the annular protrusion 16, the valve seat 90 and the guide hole 95 are arranged at predetermined positions.

As shown in FIGS. 2 to 4, the dish-shaped body S is integrally molded so that the upper part of the body part 91 becomes the valve seat body 9 and the bottom part becomes the support ring 4. Valve seat 9 having a substantially triangular cross section with a downward opening
0, and an enlarged diameter flange 94 extending from the outer peripheral edge of the valve seat 90 is formed. At the bottom of the dish-shaped body S, a central strip plate 96 is left, and both ends thereof are semicircular openings 97, 97.As shown in FIG. A guide hole 95 is provided to slidably hold the guide shaft 7. Note that the openings 97, 9
7 functions as an opening for fluid passage. Further, a pair of extension pieces 92, 92 are connected to the lower end of the body portion 91 and the periphery of the openings 97, 97, and the expanded diameter flange 94 is brought into contact with the upper surface of the annular projection piece 16. Then, the extension pieces 92, 92 are connected to the annular protrusion 16.
The plate-shaped body S is fixed to the annular protrusion 16 by caulking it so as to come into contact with the lower cut surface of the plate.
In this fixed state, as shown in FIG.
The O-ring 27 stored in the back surface of the valve seat 90 and the annular protrusion 16 are in contact with the entire circumference of the valve seat 90 and the annular protrusion 16, ensuring watertightness between the O-ring 27 and the annular protrusion 16. .

As shown in FIG. 1, the valve body 8 is disposed facing the above-mentioned valve seat 90, and the valve body 8 has a valve shaft 5 at the upper part and a guide shaft 7 at the lower part at the center. These are provided in a protruding manner, and these are screwed together in such a manner that the valve body 8 is sandwiched between flanges formed on each of them.

Further, a spring 3 is interposed between the valve body 8 and the valve cover 6 so as to fit the valve shaft 5 outwardly, and the biasing force of the spring 3 causes the valve body 8 to close to the valve body. It is in pressure contact with the seat 90. As shown in FIG. 1, this spring 3 has one end fitted tightly into a guide convex portion 60 formed on the valve cover 6, and the other end tightly fitted onto the peripheral wall of the flange portion of the valve shaft 5. It is installed,
The opposing positions of the spring 3 and the valve body 8 are arranged so as not to shift.

The upper end of the valve shaft 5 becomes an enlarged diameter portion 50, and the enlarged diameter portion 50 is loosely inserted into the hollow portion 19 of the operating shaft 14, which protrudes through the valve lid 6 in a watertight manner around the outer periphery. For this reason, the outer diameter of the enlarged diameter portion 50 is set to be slightly smaller than the inner diameter of the hollow portion 19, and the valve stem 5 has a diameter that is smaller than the inner diameter of the hollow portion 19.
Within the range of , movement in the radial direction is free. In other words, even if the axes of the dish S and the operating shaft 14 are slightly misaligned, the valve shaft 5 will be positioned in line with the guide shaft 7 inserted into the guide hole 95. That is, the valve body 8 is in pressure contact with the valve seat 90 at a predetermined position, and the biasing force of the spring 3 acts on the center thereof.

Therefore, when the pressure on the upstream side of a hot water storage tank or the like increases abnormally, the enlarged diameter portion 50 is moved against the hollow portion 19 against the biasing force of the spring 3 due to the abnormal pressure. The valve body 8 will slide, and the valve body 8 will rise. In this case, the valve body 8 and the valve seat 90
Since there is a predetermined relationship, the center of action of the fluid pressure and the center of action of the spring 3 are concentric, and no straining force acts on the valve shaft 5 and the guide shaft 7.

An operating lever 18 is provided at the upper end of the operating shaft 14.
is pivotally supported, and by swinging the operating lever 18 upward, the valve body 8 can be slightly lifted up via the operating shaft 14 by the lever action of the operating lever 18.

Incidentally, since the above-mentioned dish-shaped body S is made of a stainless steel plate with good corrosion resistance, it is difficult for the guide shaft 7 and the guide hole 95 to stick together due to corrosion, so that the valve body 8 is not easily fixed in the above-mentioned abnormal state. Inconveniences such as the valve not opening are less likely to occur.

Furthermore, even if the guide shaft 7 and the guide hole 95 become stuck due to a cause other than the above, the guide hole 9
Since the band-shaped plate 96 provided with 5 is a plate-shaped plate having a small cross-sectional area, this portion can be elastically deformed.
Therefore, when the pressure becomes higher than the set value due to the sticking, the belt-shaped plate 96 becomes integrated with the guide shaft 7, and the part that is fixed thereto rises, and the valve body 8 becomes in the open state. Become. Therefore, the worst case scenario, such as an explosion of a pressure vessel such as a hot water boiler, can be avoided.

Furthermore, as shown in FIG. 5, if wave-shaped sections 99 are formed on both sides of the guide hole 95 in the strip plate 96, the valve body 8 can easily rise due to the grooves of the wave-shaped sections 99. Therefore, safety in the event of an abnormality when the pressure exceeds the set pressure becomes higher.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a safety valve according to an embodiment of the present invention, Figs. 2 and 3 are explanatory diagrams of a dish-shaped body S in a safety valve according to an embodiment of the present invention, and Fig. 4 is an explanation of how the dish-shaped body S is attached. 5 is an explanatory diagram of another dish-shaped body S, and FIG. 6 is an explanatory diagram of a conventional example. In the figures, 1...main body, 3...spring, 4...support ring,
5... Valve shaft, 7... Guide shaft, 8... Valve body, 9...
... Valve seat body, 10 ... Valve chamber, 16 ... Annular protrusion, 9
0... Valve seat, 91... Body, 92... Extension piece.

Claims (1)

[Scope of utility model registration request] The valve body 8 is brought into contact with the valve seat 90 with a constant biasing force by the spring 3 fitted onto the valve stem 5, and the valve seat body 9 equipped with the valve seat 90 is constructed separately from the main body 1. , an annular protrusion 16 formed at the upstream end of the valve chamber 10 of the main body 1
A support ring 4, which is caulked to make the outer periphery airtight and is provided with a guide hole, is fixed on the upstream side of the valve seat body 9, and a guide shaft 7 provided on the valve body 8 is slidably inserted into the guide hole. In the safety valve that is inserted through the valve seat body 9 and the support ring 4, the valve seat body 9 and the support ring 4 are press-formed bodies made of a corrosion-resistant metal plate, and the valve seat body 9 is above the body portion 91, and the support ring 4 is the bottom portion. The valve seat 90 is formed into a dish-shaped integrally molded body with a partially open bottom, and the cross section of the valve seat 90 is formed to have a downwardly open cross-sectional shape, and the back surface of the valve seat 90 is used as an annular packing housing part. The annular packing housed in the housing portion is brought into contact with the annular projecting piece 16, and an extension piece 92 is provided at the lower end of the body part 91 and around the periphery of the opening for fluid passage formed at the bottom of the dish-shaped body. A safety valve in which the valve seat body 9 is caulked to the annular protrusion 16 by protruding the extension pieces 92 and 92 outward.