JPH0633272Y2 - Diaphragm valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a diaphragm valve in which a closing member for opening and closing a fluid passage is composed of a diaphragm, and an electromagnetically driven pilot valve is provided. , It is used to open and close the passage of the fluid system that handles the fluid.

(Prior Art) It is known that a diaphragm valve is combined with an electromagnetic pilot valve to perform fluid control as an electromagnetic opening / closing valve.

FIG. 7 shows an example of such an arrangement, which is a fluid inlet 51 and an outlet 52.
A pilot valve seat fixed at the center of the diaphragm 56, with a diaphragm 56 fixed between the valve body 54 having a valve seat 53 and a lid body 55 with a peripheral edge sandwiched therebetween.
A pilot valve body 58 in contact with 57 is attached to a plunger 61 which is attracted by a pole piece 60 installed in an electromagnetic coil 59, and the fluid at the inlet 51 is surrounded by a lid body 55 and a diaphragm 56. It is adapted to be introduced by an introduction path 64 having a manual control valve 63 at 62.

When not energized, the pilot valve body 58 of the plunger 61, which is pushed by the spring 65, contacts the pilot valve seat 57 and closes the pilot valve hole 66 that connects the back chamber 62 and the outlet 52, and also the inlet 51 and the back chamber 62. Since the fluid pressures of the
It sits on and closes the fluid passage. When the electromagnetic coil 59 is energized, the plunger 61 is attracted to the pole piece 60, so that the pilot valve body 58 separates from the pilot valve seat 57, and the fluid in the back chamber 62 is discharged to the low pressure outlet 52 through the pilot valve hole 66. As a result, the fluid pressure at the inlet 51 pushes the diaphragm 56 to separate it from the valve seat 53 and open the fluid passage.

(Problem to be Solved by the Invention) According to the above configuration, since the fluid at the inlet 51 is introduced into the back chamber 62 through the introduction passage 64 that is throttled by the manual adjustment valve 63, the degree of throttling is small. If the fluid pressure at the inlet 51 is high when the valve is closed, the diaphragm 56 will sit on the valve seat 53 at a high speed, making a loud impact noise and possibly causing a water hammer and damaging the diaphragm 56. On the other hand, if the degree of throttling is large, the diaphragm 56 can be seated on the valve seat 53 at a slow speed, but foreign matter in the fluid easily adheres to the means control valve 63, and the opening / closing operation is stable and smooth over a long period of time. Is difficult to get people to do. As a countermeasure against this, the inventor and the applicant of the present invention form a gap between the diaphragm and the peripheral edge of the diaphragm receiver stacked on the back chamber side, and
Bleed holes and through-holes for introducing the inlet fluid into the back chamber are provided in the diaphragm and the diaphragm receiver, respectively, and the throttling effect due to the diaphragm flexing in response to the inlet pressure and changing the size of the gap is used. Then, a technique has been proposed in which the valve is closed at a slow speed even when the pressure is high (see Japanese Utility Model Laid-Open No. 61-186875).

However, with this countermeasure, since the inlet fluid is introduced into the back chamber from the bleed hole only through the through hole after the gap is eliminated, if the inlet pressure is higher than the pressure that deforms the diaphragm until the gap is eliminated, However, there is a limit to the slowing of the valve closing speed because no further throttling effect can be expected, and in reality, when the pressure is high, the diaphragm is seated on the valve seat at a high speed and the purpose cannot be fully achieved. There is.

Therefore, the present invention solves such a problem, and self-controls the inlet fluid introduced into the back chamber of the diaphragm according to the pressure when the valve is closed, and the foreign matter is generated without generating a water hammer over a wide pressure range. The present invention has been devised for the purpose of providing a diaphragm valve in which the valve closing operation is performed stably and smoothly even in the case of extremely high pressure without adhering.

(Means for Solving the Problem) The present invention provides a valve main body having a fluid inlet and an outlet and a valve seat, a diaphragm arranged so as to face the valve seat and blocking or communicating the inlet and the outlet. A pilot valve seat fixed to the diaphragm having a pilot valve hole communicating with the outlet and a back chamber formed on the side opposite to the valve seat with the diaphragm interposed therebetween, and a pilot valve body provided on an electromagnetically driven plunger. In a diaphragm valve comprising a pilot valve consisting of a diaphragm valve, an outer peripheral edge portion of the diaphragm is overlapped with the diaphragm with a gap between the diaphragm and the diaphragm, and the diaphragm receiver is provided on the surface facing the gap. The diaphragm has a groove having a V-shaped cross section extending in the circumferential direction and a through hole penetrating both sides through the groove, and the diaphragm has the inlet and the back chamber. A means for solving the above problem is provided by having a configuration in which a bleed hole that communicates with and is provided at a position that corresponds to the groove and does not overlap the through hole.

(Operation) When the pilot valve is closed to close the valve from the open position,
The fluid at the inlet is introduced into the back chamber through the bleed hole, and the diaphragm is seated on the valve seat with the back chamber at the same pressure as the inlet. When the pressure of the inlet fluid is low, the gap between the diaphragm and the diaphragm receiver is maintained, but when the pressure of the inlet fluid is high, the diaphragm contacts the diaphragm receiver and the diaphragm is pressed into the groove according to the pressure, and the diaphragm is pressed into the groove. Reduce the effective area and effective cross-sectional area of the groove. Therefore, the fluid passing through the groove from the bleed hole and entering the back chamber from the through hole is restricted to a higher pressure by the groove having the V-shaped cross section narrowed by the press-fitting of the diaphragm, so that the pressure in the back chamber is not sharply increased. Therefore, regardless of the pressure of the inlet fluid, the diaphragm is seated on the valve seat at a slow speed.

(Embodiment) The present invention will be described with reference to the embodiment shown in the drawings. In FIG. 1, a valve body 4 having an inlet 1 and an outlet 2 for a fluid and an upward valve seat 3 formed therebetween, A diaphragm 6 having a peripheral edge portion sandwiched between and fixed to a lid body 5 attached to the upper portion thereof is arranged to face the valve seat 3, and
A coil case 8 having a built-in electromagnetic coil 7 is placed therein.

A space surrounded by the lid body 5 and the diaphragm 6 forms a back chamber 9, and a pilot valve seat 11 having a pilot valve hole 10 that is fixed to the center of the diaphragm 6 and connects the back chamber 9 and the outlet 2 to each other. And the back chamber 9 arranged in the center of the electromagnetic coil 7.
The pilot valve body 13 mounted on the end face of the plunger 12 protruding to the above constitutes a pilot valve 14. The plunger 12 and the pilot valve seat 11 are connected by a coil-shaped connecting spring 15, and the plunger 12 is attracted by the pole piece 16 installed in the electromagnetic coil 7 to open the pilot valve 14 or the spring 17. It is pushed by the elastic force to close the pilot valve 14.

A thick part that bulges toward the back chamber 9 at the center of the diaphragm 6.
6a is formed and a disk-shaped diaphragm support 18
Are overlapped with each other, and a gap 19 is formed between the outer peripheral edge portion 18a and the outer side portion of the thick portion 6a of the diaphragm 6. A groove 20 having a V-shaped cross section is formed in an annular shape on a surface of the outer peripheral edge portion 18a of the diaphragm receiver 18 facing the gap 19, and two through holes 21 penetrating both surfaces through the groove 20 at a center symmetrical position. Are provided at appropriate intervals.
In addition, the diaphragm 6 has two bleed holes 22 for communicating the inlet 1 and the back chamber 9 at positions where the bleed holes 22 overlap the groove 20.
It is located in the middle of 21 and is provided in a centrally symmetrical position.

In such a structure, the pilot valve 14 is closed when the electromagnetic coil 7 is de-energized and demagnetized, and the fluid pressure at the inlet 1 is introduced into the back chamber 9 through the bleed hole 22 and the diaphragm 6 is closed. Since both sides of the diaphragm 6 have equal pressure, the diaphragm 6 is seated on the valve seat 3 to close the fluid passage.

When the electromagnetic coil 7 is energized and excited, the pilot valve 14 opens and the fluid pressure in the back chamber 9 is discharged from the pilot valve hole 10 to the outlet 2
Promptly released to the diaphragm 6 and the fluid pressure at the inlet 1
Press to separate from the valve seat 3 and open the fluid passage.

Next, when the electromagnetic coil 7 is de-energized to close the fluid passage, the pilot valve 14 is closed and the fluid pressure at the inlet 1 is introduced into the back chamber 9 through the bleed hole 22 to increase the pressure in the back chamber 9. The diaphragm 6 is then seated on the valve seat 3. At this time, when the fluid pressure at the inlet 1 is low, the amount of deformation of the diaphragm 6 is extremely small, so that the gap 19 maintains an almost initial size, and most of the fluid that has passed through the bleed hole 22 in the fully opened state is directly discharged from the gap 19. It flows into the back chamber 9, so that the back chamber 9 becomes equal in pressure to the inlet 1 fairly quickly (Fig. 2). Entrance 1
If the fluid pressure in is slightly higher than the above, the diaphragm 6
Deforms more than the above and narrows the gap 19 to limit the amount flowing into the back chamber 9 (Fig. 4). When the fluid pressure at the inlet 1 further increases, the diaphragm 6 contacts the diaphragm receiver 18 to eliminate the gap 19, and the fluid passing through the bleed hole 22 enters the groove 20 and then flows into the back chamber 19 from the through hole 21. Nari (fifth
(Fig.) If the fluid pressure is higher than this, the diaphragm 6 will groove.
It is pressed into 20 (Fig. 6). In the state shown in FIG. 6, the effective area of the bleed hole 22 and the effective cross-sectional area of the groove 20 are reduced to further limit the fluid entering the back chamber 9.

That is, as the fluid pressure at the inlet 1 becomes higher, the gap 19 becomes smaller, and then the bleed hole 22 and the groove 20 become narrower to prevent a sudden pressure increase in the back chamber 9, and the diaphragm 6 is always kept at a slow speed. It is seated on the valve seat 3 and does not suddenly close the fluid passage. In this case, the higher the pressure is, the deeper the diaphragm 6 is press-fitted into the groove 20, and the groove 20 has a V-shaped cross section, so that the effective cross-sectional area is reduced at an accelerating rate and the fluid to the back chamber 9 is controlled. Even with pressure, the valve will be closed at a slow speed.

Further, since the diaphragm 6 moves every time it is opened and closed, and the fluid flows along the surface thereof to wash the bleed hole 22, foreign matter does not adhere.

In the illustrated embodiment, since the groove 20 is annular and the through hole 21 and the bleed hole 22 are provided at the central symmetrical positions, the inclination of the diaphragm 6 due to the imbalance of the fluid pressure introduced into the back chamber 9 is small and the contact surface Although the durability is improved and it is suitable for a large-diameter valve, the groove 20 may be partially formed and the through hole 21 and the bleed hole 22 may be provided only on one side.

(Effect of the Invention) According to the present invention, a bleed hole for guiding the fluid pressure at the inlet to the back chamber is provided in the diaphragm, and a groove and a through hole are provided in the outer peripheral edge of the diaphragm receiver facing each other with a gap,
The diaphragm is deformed according to the fluid pressure at the inlet to reduce the clearance or the bleed hole and groove are throttled to self-control the fluid introduced from the inlet to the back chamber. The pressure in the back chamber does not rise suddenly when the inlet pressure is high. Therefore, the inconveniences of making the valve closing speed slow and making a large impact noise, generating a water hammer, and damaging the diaphragm are eliminated, and the valve is closed smoothly. It can be expected to work. In particular, in the present invention, the groove has a V-shaped cross section, and the bleed hole is provided at a position corresponding to this groove and at a position that does not overlap the through hole. Therefore, after the clearance is eliminated, the inlet fluid is moved from the bleed hole to the groove. The effective cross-sectional area of the groove is accelerated by the diaphragm that is press-fitted according to the inlet pressure, so that high-speed valve closing can be avoided even at extremely high pressure. It is possible to perform the stable valve closing operation at a slow speed over a wide pressure range.

Further, since the bleed hole is always washed by the fluid at the inlet, foreign matter does not adhere to the bleed hole, and the opening / closing operation can be performed stably and smoothly for a long period of time.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, FIG. 2 is an enlarged partial view of FIG. 1, FIG. 3 is a partial bottom view of a diaphragm receiver, and FIGS. 4, 5, and 6 are operation. FIG. 7 and FIG. 7 for explaining the situation are vertical sectional views of a conventional example. 1 ... inlet, 2 ... outlet, 3 ... valve seat, 4 ... valve body,
6 ... diaphragm, 7 ... electromagnetic coil, 9 ... back room,
11 …… Pilot valve seat, 12 …… Plunger, 13 …… Pilot valve body, 14 …… Pilot valve, 18 …… Diaphragm receiver, 19 …… Gap, 20 …… Groove, 21 …… Through hole, 22 …… Bleed hole,

Claims (1)

[Scope of utility model registration request] 1. A valve body (4) having a fluid inlet (1), an outlet (2) and a valve seat (3), and the inlet (1) and the outlet which are arranged facing the valve seat (3). A diaphragm (6) that blocks or communicates with (2) and the valve seat (3) with the diaphragm (6) sandwiched in between.
A pilot valve seat (11) fixed to the diaphragm (6) having a pilot valve hole (10) communicating the back chamber (9) formed on the opposite side to the outlet (2) and an electromagnetically driven plunger (1
In a diaphragm valve comprising a pilot valve (14) consisting of a pilot valve body (13) provided in (2), an outer peripheral edge portion of the diaphragm (6) on the side of the back chamber (9) is a diaphragm (6). And the diaphragm receiver (18) are superposed with a gap (19), and the diaphragm receiver (18) has a groove (20) having a V-shaped section extending in the circumferential direction formed on the surface facing the gap (19). )
And a through hole (21) penetrating both sides through the groove (20), and the diaphragm (6) has a bleed hole (22) for communicating the inlet (1) with the back chamber (9). A diaphragm valve having a position corresponding to the groove (20) and not overlapping with the through hole (21).