JPS62163122A - Pressure reducing valve - Google Patents

Abstract

PURPOSE:To improve further the flow rate characteristics of a pressure reducing valve where the movable wall of an operation part is connected to an operation rod which transmits the displacement of the movable wall to a main valve body through an approximately hemispherical surface, by providing plural rectifying blades at least at the inside of the main valve port and in the axial direction. CONSTITUTION:A columnar piston rod 12 is connected to the lower end wall of a piston 120 coaxially on a hemispherical surface. A piston ring 14 serving as a packing is provided between the outer circumference of the piston 120 and a cylinder 122. An orifice 16 is formed to the lower surface side of the piston 120. The tip of the rod 12 pierces through a valve port 114 and touches a center projected bar 20 of a valve body 118. Four rectifying blades 21 are set at the outer circumference of the bar 20 equidistantly and 90 deg. spaces secured with each other. In this case, the rod 12 can be extended with addition of the rectifying blade in case a main valve projected bar is not provided.

Description

DETAILED DESCRIPTION OF THE INVENTION 1) Industrial Application Field The present invention is a pressure reducing valve, that is, a valve that changes the opening degree of the valve body by the energy of the passing fluid itself, and changes the pressure from the negative side to a predetermined secondary pressure. Related to automatic regulating valves that reduce pressure.

As a pressure reducing valve, the secondary pressure detection part itself directly
The direct-acting type is the operating part that operates the valve body, and the pilot-actuating type is the type that operates the main valve body by adjusting the pressure of the main valve body operating part using the direct pressure reducing valve as the pilot part. There is. The present invention relates to the structure of the upper protruding rod of the main valve body and the inside of the valve port, and is applicable to both straight-line type pressure reducing valves and pylob 1 to actuation type pressure reducing valves.

The present invention relates to improving the offset characteristics and rated flow characteristics of a pressure reducing valve. Air Conditioning and Sanitary Engineering Society Regulations, HASS'
106-1978, articles are defined as follows:

Minimum adjustable flow rate: The minimum flow setting pressure of the pressure reducing valve that can maintain a stable flow condition Outlet pressure offset at the minimum adjustable flow rate: - Minimum flow rate with the outlet pressure held constant When increasing the power gradually from the adjustable flow rate to the rated flow rate of the pressure reducing valve, the difference between the changing secondary pressure and the set pressure can be guaranteed within a specified offset when the rated flow rate is constant. In the above sense, a maximum flow rate reducing valve with a small offset and a large rated flow rate is better.

2) Prior Art This is a pilot-operated steam pressure reducing valve as disclosed in Japanese Patent Application No. 60-245005. A detailed explanation will be given below. (See Fig. 5) Pressure reducing valve section 101, steam/water separator section 102, and drain valve section 103
It consists of

At the valve casing 110 there is an inlet 112 . Valve port 114° Outlet 1
form 16. The inlet is connected to a high-pressure fluid source on the primary side, and the outlet is connected to a low-pressure region on the secondary side. The valve port is formed by a valve seat member.

The main valve body 118 is placed on the valve seat at the inlet side end of the valve port 114 and is elastically biased by a coil spring.

A piston 120 is slidably disposed within the cylinder 122, and the piston rod is brought into contact with the central protruding rod of the main valve body 118 through the valve port 114. Bottom surface of the piston and piston rod 1
2 are connected approximately on a hemispherical surface. Inlet 112 and piston 1
A pilot valve 126 is disposed in a primary pressure passage 124 that communicates with the upper space of 20, that is, the piston chamber. Die A7 flamm 128 is attached with its outer periphery sandwiched between flanges 130 and 132. The space below the diaphragm 128 communicates with the outlet 116 through a secondary pressure passage 134 .

The head end surface of the valve stem 136 of the pilot valve 126 is formed by die A7.
It comes into contact with the lower center surface of the flamm 128.

A pressure setting spring 140 is brought into contact with the upper surface of the diaphragm 128 via a spring seat 138. Adjustment screw 144 is threadedly connected to valve casing 110 and installed.

When the adjustment screw 144 is turned left or right, the elastic force of the force setting spring 140 that pushes down the diaphragm 128 changes. Using the elastic force of the pressure setting spring 140 as a reference value, the diaphragm 128 curves in response to the secondary pressure acting on its lower surface, displacing the valve rod 136 and opening and closing the pyrower 1 to the valve 126.

As a result, the next side fluid pressure is introduced into the piston chamber, the piston 120 is driven, the main valve body 118 is displaced, and the fluid at the inlet 112 passes through the valve port 114 to the outlet 116.
flows to This is because when the fluid pressure on the secondary side decreases, the valve port 1
14 opens and automatically operates to close when raised.

A cylindrical partition member 146 is attached below the valve port 114, and an annular space 1 is formed between it and the valve casing 110 surrounding it.
48, the upper part of which is a cone-shaped screen 1
50 to the inlet 112, and the lower part is connected to the drain valve chamber 15.
It communicates with the top of 2.

Further, the upper part of the drain valve chamber 152 communicates with the valve port 114 through the central opening of the partition member 146. A swirl vane 154 made of an inclined wall is arranged in the annular space 148.

Therefore, when the valve port 114 opens and the fluid in the inlet 112 passes through the annular space 148, its direction is bent by the swirl vanes 154 and the fluid is swirled. The liquid is swung outward, hits the inner wall of the surrounding valve casing, and flows down into the drain valve chamber 152, while the light gas swirls in the center and flows into the partition wall member 146.
from the central opening to the valve port 114 through which it flows away to the outlet 116.

A drain valve port 158 communicating with the drain port 156 is formed at the bottom of the drain valve chamber 152 . It is covered with a float cover 162 to accommodate a spherical valve float 160 in a freely displaceable manner. A ventilation hole 164 is opened in the upper part of the float cover 162.

Therefore, the valve float 160 floats up and down with the water level in the drain valve chamber 152 to open and close the drain valve port 158, and the drain valve chamber 15
2. Automatically removes water that collects in the tank.

3) Problems to be solved by the present invention The functions and effects of the hemisphere provided on the lower surface of the piston are as follows.

The fluid ejected from the valve orifice hits the connecting surface of the hemisphere and flows along that surface. At the bottom of the connecting hemisphere, the fluid velocity is high and the static pressure is low. At the top, the velocity is low and the static pressure is high. For this reason, the piston is drawn downward, ie, toward the valve port. In other words, instead of receiving the pushing up action from the jet flow from the valve port on the inner surface, it receives it lightly by the amount created by the above-mentioned static pressure difference, and is displaced that much toward the valve port, pulling the valve body away from the valve seat. , increase the valve opening.

Also, the connecting hemisphere is centered on itself with respect to the jet flow from the valve port. In other words, when the hemispherical surface is on the central axis of the jet flow, the flow velocity is the same all around, but when it deviates to the side, the flow velocity becomes uneven around the circumference, and the hemispherical surface is pushed back onto the central axis. static pressure is distributed.

Therefore, the movable wall of the operating section and the operating rod are not subjected to vibration or tilted, and are smoothly displaced along the central axis of the jet flow, so that fluctuations in the pressure on the secondary side are small. Offsera 1~ is also small.

However, the conventional internal structure of the valve port cannot fully exhibit the above effects. This is because the fluid flowing out from the valve port is at high speed and in a state of significant turbulence, so the fluid does not flow uniformly over the spherical surface.

Therefore, in order to further improve the flow characteristics, it is necessary to provide a mechanism that rectifies the fluid before it hits the hemispherical surface of the lower surface of the piston.

4) Means for solving the problems The technical means of the present invention taken to solve the above problems is that the outer periphery of the protruding rod of the main valve that receives the displacement of the piston is
It has multiple rectifying blades arranged in the axial direction.

The side wall surface of the rectifying vane is formed into a plane parallel to the axis of the protruding rod or curved.

It is desirable that the tip of the rectifying blade on the piston side has a streamlined shape with an acute angle, but it may have a right angle.

In addition, although the above-mentioned means provided a rectifying blade on the protruding rod of the main valve, other means include installing a plurality of rectifying blades in the direction of the flow path inside the valve port (or forming a plurality of rectifying holes). You may do so.

The movable wall is the diaphragm itself in a direct-type pressure reducing valve, and is the end wall of the pyrower 1 to actuated pressure reducing valve.

5) Effect The operation of the above technical means will be explained.

−8= Fluid flowing into the valve port in a turbulent state is rectified by flowing along the blades of the protruding rod of the main valve or the blades installed inside the valve port, flows out from the valve port, and flows into the piston rod. and uniformly pass through the hemispherical surface of the underside of the piston.

6) Effect of invention The present invention produces the following unique effects.

Although the effect of only the hemispherical surface of the lower surface of the piston shown in Japanese Patent Application No. 60-245005 cannot sufficiently achieve the intended purpose, the present invention provides a more stable sliding movement of the piston than that of the above-mentioned Japanese Patent Application No. 245005. I do. As a result, the piston is smoothly displaced toward the valve port, increasing the rated flow rate.

Since the piston and cylinder are not subject to vibration or inclination, fluctuations in outlet pressure are small. In addition, there is little wear on sliding parts such as the piston and cylinder, the valve body and the valve seat, and good initial operation is maintained for a long period of time.

7) Examples An example showing a specific example of the above technical means will be described.

Embodiment 1 (See Figures 1 and 2) In this embodiment, four rectifying blades are provided on the outer periphery of the protruding rod of the main valve. Portions corresponding to those in FIG. 5 are given the same reference numbers as in FIG. 5, and detailed description thereof will be omitted.

A cylindrical piston rod 12 is attached to the lower end wall of the piston '120.
are connected coaxially on a hemisphere. A backing, that is, a piston ring 14 is interposed between the outer circumference of the piston 120 and the cylinder 122, and an orifice 1 is provided on the lower surface of the piston.
Open 6 and play C. The tip of the piston rod 12 passes through the valve port 114 and comes into contact with the central protruding rod 20 of the valve body 118 . Four rectifying blades 21 are provided on the outer periphery of the protruding rod 20 at equal intervals 90 degrees apart from each other in the axial direction.

At this time, there may be no main valve protruding rod, and the piston rod 12 may be extended with a rectifying blade.

-10= Example 2 (see Figures 3 and 4) In this example, four rectifying blades are provided in the valve port. Portions corresponding to those in FIG. 5 are given the same reference numbers as in FIG. 5, and detailed description thereof will be omitted.

A cylindrical piston rod 12 is coaxially connected to the lower end wall of the piston 120 on a hemispherical surface. A backing, that is, a piston ring 14 is interposed between the outer circumference of the piston 120 and the cylinder 122, and an orifice 16 is provided on the lower surface of the piston.
open it. The valve port 114 is partitioned by four rectifying blades 22 to form four rectifying holes 23, and a hole 24 is formed in the center where the protruding rod 20 of the main valve 118 and the piston rod 12 come into contact.

It is desirable that the upper and lower portions or at least the lower portions of the rectifying blades 22 be formed in an acute streamlined shape.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of the valve port of a pressure reducing valve according to an embodiment of the present invention;
2 is a cross-sectional view of the valve port shown in FIG. 1, FIG. 3 is a vertical cross-sectional view of the valve port of a pressure reducing valve according to another embodiment, and FIG. 4 is a cross-sectional view of the valve port shown in FIG. 3. FIG. 5 is a sectional view of a conventional pressure reducing valve. 12: Piston rod 20: Main valve protrusion rod 21. 22: Rectifying vane 23: Rectifying hole 114: Valve port 118: Valve body 120: Piston

Claims (1)

[Claims] 1. In a pressure reducing valve in which the movable wall of the operating part and the operating rod that transmits the displacement of the movable wall to the main valve body are connected almost semispherically, a plurality of rectifying vanes are installed at least inside the main valve port in the axial direction. A pressure reducing valve provided.