JPS63214813A - Pressure reducing valve - Google Patents

Abstract

PURPOSE:To smoothly and safely execute the operation by providing a through hole to which a needle is inserted with a little clearance, at a communicating path to communicate the in-flow port side of a valve box and a valve body housing room and increasing an in-flow water quantity from the clearance to the valve body housing room. CONSTITUTION:An in-flow port is formed at the valve box side of a pressure reducing valve and an out-flow port is formed at other side respectively and at the bottom wall of a valve box along a valve port, a needle 15 is erected which is protruded from the valve port to an upper part room. For the needle 15, when the valve body is in a whole closed condition or an opening is in a very small fine flow quantity condition, the outer circumferential part located in a through hole 36 of a piece 37 is formed at a small diameter part 46. Fro the small diameter part 46, the upward outer circumferential part is formed at a large diameter part 47 located at the through hole 36 while the opening of the valve body is larger and the flow quantity is increased, and both parts 46-47 are continuously provided by a taper part 48. The clearance of the needle 15 and the through hole 36 is formed at a driving channel 50 to drive the water at the in-flow side to a valve body housing room.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Industrial Application Field This invention utilizes the pressure of the fluid in the pipeline, opens and closes a piston-type main valve with a pilot valve, and adjusts the pressure on the outlet side to a predetermined pressure. Prevent hunting of the pilot valve and the accompanying main valve caused by vibrations in the pressure on the outlet side of the valve box, especially when the opening of the main valve is extremely small and the opening degree of the main valve is extremely small. This invention relates to an effective pressure reducing valve.

(2), Prior art As a conventionally known pressure reducing valve of this type, U.S. Publication No. 54-10018
There is something described in the No. This is constructed as shown in FIG. In the figure, 101 is an inlet 102 on one side. A valve box having an outlet 103 on the other side, the valve box 1
Above the valve port 104 formed in 01 is a valve body storage chamber 10.
5 is provided, and a valve body 107 is housed in a movable manner. 111 is a needle installed in the valve box 101, 112
Reference numeral 114 denotes a small-diameter valve port bored in the valve body 10, and 114 a piece having a through-hole 113 of a smaller diameter around the small-diameter valve port 112 and movable in the horizontal direction by a diaphragm 116.

123 is an anti-surfacing ring, and 124 is a pilot valve, and inside the valve box 125 of the pilot valve 124 is a pressure receiving chamber 126.
is formed. The pressure receiving chamber 126 and the valve body storage chamber 105 are communicated with each other through a connecting pipe 127, while the pressure receiving chamber 126 and the valve body 1
The outlet 103 side of 01 is communicated with pilot pipe 1'28. 129 is a valve body.

This known pressure reducing valve operates as follows. That is, when pressure (primary pressure) is applied to the inlet 102 side of the valve box 101, if the pressure (secondary pressure) on the outlet 103 side is low,
The valve body 129 opens, and therefore the pressure on the inlet 102 side is applied to the gap between the through hole 113 of the piece 114 and the needle 111, the valve body storage chamber 105, the connecting pipe 127, the pressure receiving chamber 126. The water escapes to the outlet 103 side through the pilot pipe 128, and the valve body 107 is pushed up by the pressure on the inlet side, causing water to flow from the inlet side to the outlet side.At this time, the diaphragm 11
6 and the piece 114 float slightly due to the pressure on the inlet side, but since the upper surface of the piece 114 is pressed by the floating prevention ring 123, the diaphragm 116 is not cut or detached.

Then, the pressure on the outlet 103 side increases and when it reaches a predetermined pressure, this pressure on the outlet side is transmitted to the pressure receiving chamber 126 via the pilot pipe 128, and the valve body 129 is closed. As a result, the pressure applied to the upper and lower surfaces of the valve body 107 is only the pressure on the inlet side, and a downward differential pressure is generated due to the large diameter of the piston portion 106.
The valve body 107 descends and comes into contact with the valve seat 118, and the valve port 104
occlude. At this time, the volume of the valve body storage chamber 105 increases as the valve body 10 is lowered, and water corresponding to the change in volume flows into the valve body storage chamber 105 from the gap between the through hole 113 and the needle 111. This inflow amount is determined by the gap, and the descending speed of the valve body 107 is slow throughout the entire stroke of the valve body's ascent and descent to prevent sudden blockage. A water hammer phenomenon does not occur in the water supply pipe, and wear at the contact portion between the valve body 10 and the valve box valve seat 118 is reduced.

(3) Problems to be Solved by the Invention By the way, in the pressure reducing valve, in a minute flow state where the opening degree of the valve body 107 is extremely small, the bottom surface 108 of the valve body 107 is connected to the valve body valve seat 1.
1g and facing each other with a small gap, most of the water on the inlet side passes through this gap and flows to the outlet 1.
03 side in a pulsating jet state, and only a very small amount flows from the gap between the through hole 113 and the needle 1.11 to the valve body storage chamber 105 side. Therefore, this jet flow flows toward the outlet side of the valve box 101. The pressure on the outlet side continues to vibrate little by little (5Hz or more).

This pressure vibration on the outlet side is caused by the pilot valve 124.
This pressure vibration increases, and the amplitude in the pressure receiving chamber of the pilot valve that senses it causes a spring (not shown) that biases the valve body 129 of the pilot valve in the opening direction to maintain the open state. If it exceeds the range, valve body 1
29 follows the pressure vibration on the outlet side and vibrates from fully open to fully open, and transmits this vibration to the pressure vibration in the valve body storage chamber 105. As pressure vibrations are transmitted to the valve body storage chamber 105, it becomes difficult for the valve body 107 to maintain the open state, and the valve body 107 vibrates between the closed state and the open state. This vibration of the valve body 107 then induces a pressure vibration on the inlet side, causing hunting throughout the water supply pipe, which may, for example, damage the pipe or cause damage to the instantaneous water heater in use. There are problems such as the pilot flame going out and hot water spouting out intermittently from the instantaneous water heater, which is dangerous.

Therefore, the technical object of the present invention is to minimize the amplitude of the pressure vibration on the outlet side that is transmitted to the pilot valve.

(4) Means for solving the problem The technical means taken to achieve the above technical problem are:
A through hole is provided in the communication path that communicates the inlet side of the valve body and the valve body storage chamber, into which a needle installed upright on the valve body or the valve body is inserted with a small gap, so that the opening of the valve body is extremely small. The outer periphery of the needle that is located inside the through hole in a state of flow is formed into a small diameter part, and the needle that is located inside the through hole when the flow rate increases as the opening degree of the valve body increases from a state of minute flow. The outer periphery of the needle is formed into a large diameter part, so that the amount of water on the inlet side that flows into the valve body storage chamber from the gap between the small diameter part of the needle and the through hole in a minute flow state is increased.

(5) 1 action In a microflow state where the opening degree of the valve body is extremely small, the small diameter part of the needle is located in the through hole, and the flow flows into the valve body storage chamber from the gap between the small diameter part of the needle and the through hole. The amount of water on the inlet side increases.

As a result, a large amount of ice flows from the valve body storage chamber through the first pipe line into the valve box of the pilot valve, increasing the flow force and suppressing the amplitude of the outflow low side pressure transmitted into the valve box of the pilot valve. be done. Therefore, the valve body of the pilot valve may vibrate between fully closed and fully opened following the pressure vibration on the outlet side.
This eliminates the possibility that the valve body oscillates between the closed state and the open state at a small opening at a minute flow rate, causing hunting, resulting in smooth operation and high safety.

(6) Unique Effects As mentioned above, since the vibration of the pressure on the outlet side transmitted to the inside of the valve box of the pilot valve is reduced, the vibration of the pressure on the outlet side is also suppressed to a small level as a result. In addition, in a state where the opening degree of the valve body increases from a small flow rate state and the flow rate increases, that is, in a normal flow rate state controlled to a predetermined pressure, there is no need to increase the opening degree of the pilot valve. The pressing force of the spring that biases the valve body of the pilot valve in the opening direction does not become excessive, so that there is an advantage that when the valve body is fully opened, the pressure increase on the outlet side of the valve body can be suppressed to an extremely small level.

(7), Example The present invention will be explained in detail below.

In FIG. 1, 1 is a valve box, and an inlet 2 is formed on one side of the valve box 1, and an outlet 3 is formed on the other side, and a water supply pipe (not shown), for example, is connected to these. It has become.

The interior of the valve box 1 is partitioned from below into an inflow chamber 6, an outflow chamber 7, and an upper chamber 8 by a pair of horizontal partition walls 4 and 5 fixed to the inner wall of the valve box at a predetermined interval in the vertical direction. The upper partition wall 4 is provided with an opening 10 that is larger than the outer diameter of the valve body described later. A valve port 12 is bored in the lower partition wall 5, and a valve seat 13 is provided around the periphery of the valve port 12.

Further, on the bottom wall 1b of the valve box 1 facing the valve port 12, a needle 15 whose tip protrudes from the valve port 12 into the upper chamber 8 is erected and screwed into a mounting member 16 fixed to the bottom wall. There is. The amount of protrusion of the needle 15 can be adjusted by loosening the nut 17 and rotating the corner 18 with a spanner or the like. 19.20 is an annular packing. A cylinder 22 having an outward flange at its upper end is inserted into the upper chamber 8 of the valve body 1 via the flange. In the valve body storage chamber 23 formed by the cylinder 22, a valve body 25 having a piston portion 24 at its upper end is disposed so as to be movable up and down through the opening IO. The valve body 25 is hollow inside, open at the top, and has a hole 26 formed in the center of the bottom wall. Furthermore, an annular packing 27 that slides on the inner peripheral surface of the valve body storage chamber 23 is fixed to the upper end surface of the valve body 25 by a packing presser 28 . A valve seat 30 that contacts the valve seat 13 when fully closed, and a guide mounting member 31 are fixed to the lower end surface of the valve body 25. The guide mounting member 31 is the second
As shown enlarged in the figure, it has a small-diameter valve port 32 in the center through which the needle 15 passes, and a guide 33 that runs along the inner surface of the valve seat 13 is provided on the lower surface. A stepped ring-shaped piece 37 having a through hole 36 through which the needle 15 is inserted with a slight gap is arranged on the upper surface of the guide mounting member 31. A diaphragm 38 is attached to the step part of this piece 37.
are fitted, and the diaphragm 38 is fixed with a ring nut 40 via a washer 39.

An annular packing 41 is integrally connected to the outer periphery of the diaphragm 38, and this packing 41 has a through hole 42 in the center, and is attached to the upper surface of the guide mounting member 31 with a bolt 43 so as to cover the piece 37. It is accommodated in an annular groove 45 on the lower surface of the floating prevention ring 44 .

When the valve body 25 is in a fully closed state and the opening degree of the valve body 25 is in a very small flow state, the needle 15 has an outer peripheral portion located within the through hole 36 of the piece 37 formed in a small diameter portion 46;
An outer peripheral portion above the small diameter portion 46 is formed as a large diameter portion 47 that is located within the through hole 36 when the opening degree of the valve body 15 increases and the flow rate increases. 46 and the large diameter portion 47 are connected to each other by a tapered portion 48 . The gap between the needle 15 and the through hole 36, which are inserted through the small diameter portion 46 of the through hole 36 as described above, is formed into a water guide passage 50 that guides water from the inlet 2 side to the valve body storage chamber 23. . A through hole 52 is bored in the earthen wall 1a fixed to the upper end of the valve box 1 via an annular packing 51, and a transparent covered cover cylinder 53 is erected in the first through hole 52. Cover tube 5
An indicator rod 55 for instructing the opening of the valve body, the lower end of which is attached to the para-kin presser 28 via a mounting piece 54, faces through the through hole 52 inside the valve body 3. 56 is an annular packing.

A pilot valve 60 is fixed to the upper wall 1a of the valve box via a bracket 61, and a valve chamber 64 and a pressure receiving chamber 65 are provided in the valve box 62 of the pilot valve 60, which communicate with each other via a partition wall 63. There is. The chamber below the valve port 66 of the valve chamber 64 is communicated with the valve body storage chamber 23 via a pilot pipe 68, and the upper chamber is connected to a pilot pipe 7 having an on-off valve 70.
1 to the outflow chamber 7. In the valve chamber 64,
A valve body 75 is housed, which is integrally attached to a bellow ram 73 in the pressure receiving chamber 65 via a valve rod 74 passing through the partition wall 63, and which moves up and down as the bellow ram 73 operates to open and close the valve port 66. When the pressure on the outlet 3 side reaches a predetermined pressure, the valve body 75 acts on the lower surface of the bellow flap 3.

The valve port 66 is closed. Further, a spring 7f is interposed between the top surface of the bellow frame 73 and the valve box 62,
The valve body 75 urges the valve port 66 to open. 7
Numeral 8 is an adjustment bolt screwed onto the top wall of the valve box 62, which allows the biasing force of the spring 77 to be adjusted.

Next, the operation of the above-mentioned embodiment will be explained. In this explanation of the operation, there are many parts that overlap with the operation of the conventional pressure reducing valve shown in FIG. I will briefly explain the effects based on .

When the pressure on the outlet 3 side reaches a predetermined pressure, the pressure on the outlet side passes through the pilot pipe 71 to the valve chamber 6.
4, the pressure is transmitted to the pressure receiving chamber 65, which causes the bellofram 73
Since the pressure acts on the lower surface of the valve body 75, the spring 77
and closes the valve port 66. When the valve body 25 is in a state of a minute flow rate when the predetermined pressure is about to be reached, vibrations are induced in the pressure on the outlet 3 side.

This pressure vibration is transmitted to the pressure receiving chamber 65 and the valve chamber 64 of the pilot valve 60. On the other hand, the small diameter portion 46 of the needle 15 is located inside the through hole 36, and the small diameter portion 46 of the needle 15 and the through hole 36 are connected to each other. As the water guide passage 50 formed by A large amount of water flows into the valve chamber 64 of the pilot valve, and the amplitude of the pressure vibration is suppressed to a small level by this large amount of water on the inlet port 2 side where the flow force is increased. Therefore, the valve body 75 of the pilot valve vibrates between fully closed and fully opened following the pulsating pressure vibration on the outlet side.

This eliminates the possibility that the valve body 25 oscillates between the closed state and the open state at a small opening at the time of a minute flow rate, causing hunting.

When the opening degree of the valve body 25 increases from the minute flow rate state to a state where the flow rate increases, the large diameter portion 47 of the needle 15 is located within the through hole 36, and the large diameter portion 47 of the needle 15 and The water guide passage 50 formed by the through hole 36 becomes smaller. When the water guide passage 50 becomes smaller, the amount of water flowing into the valve body storage chamber 23 on the inlet side becomes smaller than in the above case, and as a result, the water flows from the valve body storage chamber 23 through the pilot pipe 68 to the valve chamber 64 of the pilot valve. The amount of water flowing inside also becomes small, and the pressure on the outlet 3 side increases. Therefore, control performance is not impaired in normal flow conditions other than the fully open state and the minute flow state.

FIG. 3 shows another embodiment, and the differences in this embodiment from the previous embodiment will be explained.

The needle 15 and the components attached thereto are omitted, and instead, the indicator rod also serves as the needle, and the upper outer peripheral part of the indicator needle 80 is connected to the small diameter part 82 through the tapered part 81. The outer peripheral portion below the tapered portion 81 is formed as a large diameter portion 83 . and,
When the valve body 25 is in the fully closed state and in the micro flow state, the small diameter portion 82 of the needle 80 is located in the through hole 84 formed at the lower end of the cover cylinder 53'. A gap between the needle 80 and the through hole 84, through which the small diameter portion 82 and the like are inserted, is formed into a water guide passage 85 that guides water from the inlet 2 side to the valve body storage chamber 23.

Therefore, the inside of the cover cylinder 53' above the through hole 84 is communicated with the flow port 2 side via a bypass pipe 87 having an on-off valve 86.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional front view showing one embodiment of the present invention, Fig. 2 is an enlarged sectional view of the same essential parts as above, Fig. 3 is a vertical sectional front view showing another embodiment, and Fig. 4 is a conventional example. FIG. 1... Valve box 2... Inlet 3... Outlet 12... Valve port 13... Valve seat 15 River needle 22...
Cylinder 23... Valve body storage chamber 24... Piston part 25... Valve body 32... Small diameter valve port
36... Through hole 37... Piece 3
8...Diaphragm 46.82...Small diameter part 47.
83...Large diameter part 48.81...Tapered part 50,
85... Water guide passage 80... Indicator rod/needle 87... Bypass pipe Patent applicant: 1 person outside Kurimoto Iron Works Co., Ltd. Figure 1 Figure 3

Claims (1)

[Claims] 1. A valve body storage chamber in which a valve body for opening and closing the valve port of the valve box is housed so as to be movable up and down is provided above the valve body, and a first pipe line communicating with the valve body storage chamber and the valve body A pilot valve is installed at the connection with the second pipe connected to the outlet side of the box,
This pilot valve is operated by the pressure on the outlet side of the valve box, and when the pressure on the outlet side reaches a predetermined pressure, it operates in the closing direction, and water from the valve body storage chamber side is transferred from the first pipe to the first pipe. 2
It prevents water from flowing into the pipe line, and operates in the opening direction when the predetermined pressure is not reached, allowing water from the valve body storage chamber side to flow from the first pipe line to the second pipe line. In the pressure reducing valve, a through hole is provided in the communication path that communicates the inlet side of the valve box and the valve body storage chamber, into which a needle provided upright on the valve body or the valve body is inserted with a slight clearance. A state in which the outer periphery of the needle located in the through hole is formed into a small diameter part in a microflow state where the opening of the body is extremely small, and the flow rate increases as the opening of the valve body increases from the microflow state. The outer periphery of the needle located in the through hole is formed into a large diameter part, and the amount of water on the inlet side that flows into the valve body storage chamber from the gap between the small diameter part of the needle and the through hole in a microflow state increases. A pressure reducing valve characterized by: