JPS5829020A - Pressure adjusting valve - Google Patents

Abstract

PURPOSE:To obtain a pressure adjusting valve with good response, by inserting a volume reduction member which largely decreases the volume of a pressure sensing chamber in a bellows. CONSTITUTION:A primary pressure for a fluid such as vapor and air to be controlled is exerted onto an inlet chamber 2. A valve stroke adjusting handle 26 is rotated to compress an adjusting spring 25 and a valve element 9 is pushed down via a volume reduction member 15 and a valve rod 16. When this spring force is larger than an upward valve closing force operated to the element 9, the valve is opened and the fluid flows to an outlet chamber 4 and the secondary pressure is operated. The fluid flowing to the outlet chamber 4 flows to a pressure sensing chamber A in a bellows 12 from an oriffice 20 of an oriffice plate 18 and a pressure difference between the secondary pressure and the air in the member 15 is operated as a reaction force to the spring 25, and the stroke of the element 9 is determined at a point balanced to the spring force and the secondary pressure of the fluid is generated in the outlet chamber 4. If the consumption of the fluid at the secondary side is greater, the pressure at the chamber A is decreased, the bellows 12 is contracted, the primary fluid flows from a valve hole 8 and the secondary pressure is decreased to the specified value.

Description

DETAILED DESCRIPTION OF THE INVENTION Conventionally, in a diaphragm pressure regulating valve, the opening degree of the valve element could be increased by increasing the diameter of the diaphragm to increase the amount of deflection when sensing pressure.

On the other hand, in bellows-type pressure regulating valves, unlike diaphragm-type ones, the amount of deflection within the elastic limit is regulated as the amount of expansion and contraction per stage of the bellows. It has the advantage that the amount of deflection required for opening is relatively easy to obtain. However, as the number of stages of the bellows is increased and the free length is extended to take up the amount of deflection, the volume of the pressure-sensitive chamber inside the bellows increases, and the ability to detect changes in the indoor pressure of the 40 chamber or the outlet chamber becomes dull.
There was a drawback that the immediacy of accurate pressure adjustment was impaired.

Therefore, the present invention was made with the aim of eliminating the above-mentioned drawbacks, and it is possible to greatly reduce the volume of the pressure-sensitive chamber inside the bellows without changing the pressure-receiving area of the bellows, thereby increasing the ability to sense pressure fluctuations. It is intended to provide a regulating valve.

Embodiments of the present invention will be described below with reference to FIG. 1.2.

Note that this embodiment is of a type in which the bellows senses the pressure inside the outlet chambers (secondary side pressure).

In the figure, l is a valve case, 2 is an inlet chamber connected to the inlet 3, 4 is an outlet chamber connected to the outlet 5, 6 is a valve seat fitted on the partition wall 7 between the two chambers 2 and 4, and in the center is a valve seat. A hole 8 is drilled. 9
A spherical valve is abutted against the inlet-side seating end surface 8a of the valve hole 8 so as to be able to be seated and removed, and is seated by a return spring 11 within the strainer 10.

Reference numeral 12 denotes a bellows, which expands and contracts by sensing the indoor pressure of the outlet chamber 4 through the lower end opening 12a.
2t) is fixed to the upper part of the valve housing 1 via gaskets 13 and 14, and its upper end 12C is closed by a reduction material 15 of T1. Reference numeral 16 denotes a valve stem, the lower end of which passes through the valve hole 8 and comes into contact with the valve element 9, and the upper end of which is an E-ring that is snap-fitted to the end of the debt reduction material 15.

The bond reducing material 15 is inserted into the bellows in order to greatly reduce the volume of the pressure sensitive chamber A inside the bellows without changing the pressure receiving area of the bellows 12, and in this embodiment, it is formed into a dish shape. ing. This debt reduction material 15 has a dish-shaped lower end central recess 15a on the lower surface of which is connected to the valve stem 16.
The upper end side outer peripheral flange 15b is in contact with the upper end of the bellows 12, and the orifice plate 18 that partitions the outlet chamber 4 and the pressure sensitive chamber A is detachably attached to the outlet chamber of the valve housing 1 by means of a C-ring shaped locking member 19. 4, an orifice 20 is formed in the plate 18 to communicate the outlet chamber 4 and the pressure sensitive chamber A, and a guide hole 2 is formed in the plate 18.
1 is bored, and the valve stem 16 is slidably housed in the guide hole 21. In addition, a support body 2 protruding from the valve housing 1
2, a valve stroke adjustment bolt 28 is rotatably supported, and the outer surface of the outer peripheral wall 24a of the spring seat 24, the center wall of which is fitted onto the threaded portion 23a of the bolt 28, is polygonal;
The inner surface of the outer circumferential wall 22& of the support body 22, which is fitted onto the outer circumferential wall so as to prevent its rotation, is also formed in a polygonal shape, and the spring seat 24 and a bond reducing member fixed to the upper end of the bellows 12 are formed. An adjustment spring 25 is interposed between the center recess 15a of 15 and the center recess 15a. 26 is a pin 27 at the upper end of the adjustment bolt 23.
Adjustment handle, 28, fixed at lower end 2 to valve housing l
2b is an atmospheric communication hole bored in the peripheral wall of the cylindrical support 22 into which the cylindrical support 22 is fitted.

Next, the effect will be explained. The primary pressure of a fluid to be controlled, such as steam or air, acts on the inlet chamber 2 . Therefore, by rotating the valve stroke adjustment handle 26, the spring seat 24 is moved downward without being rotated, compressing the adjustment spring 25 to generate a spring force, 9 is pushed down, and when the spring force becomes greater than the upward closing force acting on the valve element 9, the valve becomes open, fluid flows into the outlet chamber 4, and secondary pressure acts. Furthermore, the fluid that has flowed into the outlet chamber 4 flows into the pressure sensitive chamber A inside the bellows 12 through the orifice of the orifice plate 18 and the orifice 20, and the fluid flows into the pressure sensitive chamber A inside the bellows 12 through the orifice of the orifice plate 18 and the secondary pressure between the atmosphere and the The differential pressure acts as an upward reaction force against the adjustment spring 25, and the stroke of the valve element 9 is determined at the point where this is balanced with the spring force, and a predetermined secondary pressure of the fluid is generated in the outlet chamber 4. Furthermore, when the consumption of fluid on the secondary side increases, the pressure in the I6 pressure chamber A decreases accordingly, so the bellows 12 contracts, the valve element 9 lowers and the valve opening increases, and the primary side Fluid flows in from the valve hole 8, and the secondary side attempts to return to a predetermined secondary pressure.

Then, if the volume of the pressure sensitive chamber A is large, the outlet chamber 4
The response of the chamber pressure of the pressure-sensitive chamber A through the orifice 20 to the chamber pressure of the pressure-sensitive chamber A is delayed, and the responsiveness of controlling the valve opening degree due to the downward or upward movement of the valve element 9 due to the contraction or expansion of the bellows 12 becomes poor. .

However, since the volume of the pressure sensitive chamber A is greatly reduced by the reducing member 15, the small amount of fluid movement through the orifice 20 allows the pressure in the pressure sensitive chamber A to respond to the outlet chamber 4 and the bellows 12 It can expand and contract, and the responsiveness of valve opening control is extremely good.

In addition, although the example in which the pressure-sensitive chamber A was communicated with the outlet chamber 4 was described above, 1. Even in a structure in which the pressure sensitive chamber A is communicated with the inlet chamber 2, the bellows 12 can similarly expand and contract in response to fluctuations in the primary pressure instead of the secondary pressure.

As is clear from the above description, in the present invention, the bellows has a reducing member inserted therein which greatly reduces the volume of the pressure-sensitive chamber therein, so that the pressure-sensitive chamber and the bellows can withstand pressure fluctuations in the inlet chamber or outlet chamber. The sensing ability of
A pressure regulating valve with good responsiveness can be provided.

In addition, in the present invention, since the debt reduction material is dish-shaped, by fitting the adjustment spring into the central recess, it is possible to reduce the overall height of the valve and make it more compact. This also serves as a spring guide, making it difficult for the spring to buckle.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of an embodiment of the present invention, and FIG. 2 is an exploded perspective view of the bellows and bond reducing material. A: Pressure-sensitive chamber, ■: Benben cabinet 2-person room, 4: Exit chamber, 6:
Valve seat, 8: Valve hole, 9: Valve element, 12: Bellows, 12a:
Lower end opening, 15: Debt reduction material, 15a: Center recess, 15
b: Outer flange, 16 two valve stems, 18 nitrogen orifice plate,
19: lock member, 20 nitrogen orifice, 21 guide hole, 22: support body, 22a: outer peripheral wall thereof, 23: adjustment bolt, 23a: threaded portion thereof, 24: spring seat, 24a: outer peripheral wall thereof. Applicant Miyawaki Steam Trap Manufacturing Co., Ltd. Agent Tsunehisa Nakamura 1st rgJ 7 2nd rIJ Lda

Claims (1)

[Claims] 1. A valve element that opens and closes a valve hole formed between an inlet chamber and an outlet chamber of the valve housing, and the other end that expands and contracts by sensing the indoor pressure of the inlet chamber or the outlet chamber through the opening at one end. A pressure regulating valve having a closed bellows and a valve stem that connects the bellows and the valve element, characterized in that a volume reducing material is inserted into the bellows to greatly reduce the volume of a pressure sensitive chamber therein. Pressure regulating valve. 2. The volume reducing material is formed into a dish shape, with the center portion on one end abutting the valve stem and the outer peripheral flange on the other end being fixed to the other end of the bellows. The pressure regulating valve according to item 1.