JPH07229580A - Pilot type diaphragm valve - Google Patents

Abstract

PURPOSE:To provide sufficient water hammer suppressing effect without any reduction in a diameter of an extraction hole by arranging a projection part toward a liquid feeding part side from a diaphragm and forming the projection part of a repairable elastic member. CONSTITUTION:Toward a fluid feeding part 30, a projection part 51 is arranged in the circumference part of a diaphragm 10, and a back pressure chamber 32 and the liquid feeding part 30 are communicated with each other via a liquid feeding side passage 20 penetrating the diaphragm 10 and the projection part 51. The projection part 51 is formed of an elastic member having restorability such as rubber, and a shape of a cross section of the liquid feeding side passage 20 formed in the projection part 51 is easily deformed by a pressure difference between the liquid feeding part 30 and the back pressure chamber 32. According to the close of a diaphragm valve element 50, a pressure difference between the fluid feeding part 30 and the back pressure chamber 32 is increased, and a pressure of the fluid feeding part 30 at high pressure works on the outer circumferential face of the projection part 51, and consequently, the projection part 51 is deformed. Then, a cross sectional area of the fluid feeding side passage 20 is reduced, a flow rate of the fluid flowing into the back pressure chamber 32 from the fluid feeding part 30 is reduced, closing valve action of the diaphragm valve A is slowed, and consequently, water hammer can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pilot type diaphragm valve, and more particularly to a pilot type diaphragm valve capable of effectively reducing a water hammer when the valve is closed.

[0002]

2. Description of the Related Art Conventionally, in a pilot type diaphragm valve which controls the flow of liquid by opening and closing a pilot valve, if a water hammer is generated when the valve is closed, it not only causes a failure of pipes and instruments, but also causes noise. However, as an example of a technology to solve this problem, the actual extraction of the extraction holes (inlet orifices) by arranging them in series in duplicate, etc.
There is a technique described in Japanese Patent Publication No. 74.

[0003]

In the above-mentioned conventional pilot type diaphragm valve, the diameter of the extraction hole (inlet side orifice) is 0.47 mm, and the pressure on the water supply side (gauge pressure when water does not flow) is 7.5 kgf. Looking at the change in water pressure from the valve open state to the valve closed state in the case of / cm ² , Fig. 17 (a) (b)
It becomes as shown in (c).

According to this, the pressure difference between the back pressure chamber and the liquid supply part was a slight differential pressure (0.35 kgf / cm ² ) when the valve was open, but as the valve closes, the pressure difference between the back pressure chamber and the liquid supply part increases. The pressure difference between the water supply part and the water supply part becomes large, the value (pressure difference) becomes maximum when the valve is closed, the water supply part pressure rises to 19.21 kg f / cm ² , water hammer phenomenon occurs, and the extraction hole A sufficient effect cannot be obtained with the double arrangement.

In order to prevent the occurrence of water hammer, it is effective to dispose a filter in the extraction hole or make the extraction hole small, but if it is used for a long time, the filter or the extraction hole will be clogged and malfunction will occur. .

It is an object of the present invention to provide a pilot type diaphragm valve having a sufficient water hammer suppression effect without reducing the diameter of the extraction hole.

[0007]

According to the present invention, there is provided a liquid supply section, a liquid discharge section, a diaphragm valve body for opening and closing a communication port between the liquid supply section and the liquid discharge section, and the communication port in the diaphragm valve body. A back pressure chamber formed on the side opposite to the opening / closing surface, a drain side passage that connects the drain section and the back pressure chamber, and a liquid feed side that connects the liquid feed section and the back pressure chamber. In a pilot type diaphragm valve including a passage and a plunger that contacts the back pressure chamber side opening of the drainage side passage and opens and closes the back pressure chamber side opening, from the diaphragm toward the liquid supply portion side. While providing the protrusion, the diaphragm and the protrusion penetrate the inside to form the liquid supply side passage that communicates the liquid supply unit and the back pressure chamber, and the protrusion is connected to the back pressure chamber and the liquid supply unit. Formed from an elastic member that deforms due to the pressure difference between the two and reduces the cross-sectional area of the liquid supply side passage Those of the pilot diaphragm valve, wherein the door.

According to the present invention, in the above structure, the projecting portion has a horizontally long flat cross-sectional shape, and the cross-sectional shape of the liquid supply side passage is from the circular cross section toward the base portion from the tip end portion to the circular cross section. It is also characterized in that both side portions are expanded laterally, and the upper and lower surfaces of the same circular cross section are expanded in a vertical direction to form a substantially rhombic cross section.

According to the present invention, the protrusion has a substantially elliptical cross-section on the outer periphery thereof, the diameter is reduced from the base toward the tip, and the cross-sectional shape of the liquid supply side passage formed therein is the same. It is also characterized in that the distal end portion is circular and the shape is a substantially elliptic cylindrical shape having a uniform wall thickness that follows the outer peripheral shape toward the base portion.

[0010]

According to the present invention, as the diaphragm valve body is closed, the pressure difference between the pressure in the liquid supply section and the pressure in the back pressure chamber increases, and the liquid supply section with a high pressure is applied to the outer peripheral surface of the protrusion made of the elastic member. Pressure acts to deform the protrusion and reduce the cross-sectional area of the liquid supply side passage formed inside, reducing the flow rate of liquid flowing from the liquid supply part into the back pressure chamber, and closing the diaphragm valve. The valve operation becomes slow and water hammer is suppressed.

When the pressure difference between the liquid supply portion and the back pressure chamber disappears after the valve is completely closed, the projecting portion that has been contracted and deformed is restored to its original shape, and the liquid supply side passage is also restored to its original shape. Restore the cross-sectional area.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to a pilot type diaphragm valve A shown in the accompanying drawings.

(Explanation of Structure of Pilot Type Diaphragm Valve A) As shown in FIG. 1, the valve casing 1 has a substantially inverted T-shape. The liquid supply part 30 and the liquid discharge part 31 as a liquid discharge flow path are coaxially formed.

The liquid supply unit 30 and the liquid discharge unit 31 are communicated with each other through a communication port 33, while the communication port 33 is opened and closed by a diaphragm valve body 50.

A back pressure chamber 32 is formed on the back surface side of the diaphragm valve body 50, that is, on the side opposite to the closed surface of the communication port 33.

As shown in FIG. 1, the diaphragm valve body 50
The diaphragm disk 16, the diaphragm 10, and the thick, frustoconical diaphragm plate 17 are combined in layers.

The outer peripheral portion of the diaphragm 10 is tightly fixed between the diaphragm retainer 15 and the valve casing 1.

The back pressure chamber 32 and the drainage portion 31 are communicated with each other through a drainage side passage 19 provided in the central portion of the diaphragm disk 16.

On the other hand, the back pressure chamber 32 and the liquid supply part 30 are provided with a protrusion 51 toward the liquid supply part 30 at the peripheral edge of the diaphragm 10, and penetrate the diaphragm disk 16, the diaphragm 10 and the protrusion 51. Communication is provided through the provided liquid supply side passage 20.

As a method of forming the protruding portion 51, in the example of FIG. 2, it is provided integrally with the diaphragm 10.

Further, in the example of FIG. 3, the protrusion 51 is molded separately, the fitting hole 60 into which the protrusion 51 is fitted is provided in the diaphragm disk 16 and the diaphragm 10, and the bush 52 is used.
After fitting and tightly fitting the protrusion 51 in the fitting hole 60, the diaphragm disk 16 and the bush 52 are ultrasonically welded.

The projecting portion 51 is formed of an elastic member having a restoring property such as rubber, and the cross section of the liquid supply side passage 20 formed in the projecting portion 51 has a liquid supply portion 30 and a back pressure chamber 32. It is preferable that the shape is such that it is easily deformed by the pressure difference.

4 to 6 show an example of the shape of the protrusion 51 and the shape of the liquid supply side passage 20 formed therein.

FIG. 4 shows the appearance of the protruding portion 51. As shown in the drawing, the protruding portion 51 integrally connects the base end of a cylindrical body having a circular cross section to the bottom surface of the diaphragm 10, and the upper and lower surfaces thereof. Has a horizontally long flat cross-section that is chamfered in a taper shape that becomes thinner toward the tip.

FIG. 5 shows a core 61 for forming the liquid supply side passage 20 having an irregular cross section inside the protrusion 51 integrally formed with the diaphragm 10 when the diaphragm 10 is formed. The shape of the core corresponds to the shape of the liquid supply type passage 20.

As shown in FIG. 5, the core 61 is a V-shaped groove forming protrusion whose thickness is gradually reduced from the base end side to the tip end side symmetrically on both sides of a shaft rod 61a having a circular cross section. 61b and 61c are projected, and notch groove forming projections 61d and 61 are formed on the upper and lower surfaces thereof.
e is protruding.

6 (a), 6 (b) and 6 (c), in the natural state, that is, in the original direction in which the liquid is not deformed by the pressure difference between the liquid supply part 30 and the back pressure chamber 32, the axial direction of the protruding part 51 is shown. Fig. 6 (a) shows the root part, Fig. 6 (a) shows the cross-sectional shape when cut at intervals.
6 (b) shows the central portion, and FIG. 6 (c) shows the tip portion.

On the other hand, in FIGS. 6 (a ') (b') (c '), a pressure difference is generated between the liquid supply portion 30 and the back pressure chamber 32, and the protruding portion 51 at the same position is deformed. The cross-sectional shape of is shown.

As shown in FIG. 6 (c), at the tip of the protrusion 51, the liquid supply side passage 20 has a circular cross section with a small diameter, and the peripheral thickness is thick. Therefore, the tip portion of the protruding portion 51 has high rigidity, and even if a pressure difference occurs between the liquid supply portion 30 and the back pressure chamber 32, it is hardly deformed as shown in FIG. 6 (c ').

However, as shown in FIG. 6 (b), the protrusion 51
The center portion of the V-shaped groove 62 is symmetrically provided on both sides of the liquid supply side passage 20 so that the rigidity of the protruding portion 51 is reduced and the pressure is easily deformed by the differential pressure between the liquid supply portion 30 and the back pressure chamber 32. , 63,
The liquid supply side passage in the vertically deformed state shown in Fig. 6 (b ')
Semicircular grooves 64 and 65 for forming 20 are provided, and the liquid supply side passage 20 has a substantially rhombic cross-sectional shape. further,
Flat portions 67 and 68 are provided on the upper and lower sides so that the above-mentioned differential pressure largely acts on the connecting portions of the V-shaped grooves 62 and 63.

Further, as shown in FIG. 6A, the roots of the protrusions 51 are also symmetrically arranged on both sides of the liquid supply side passage 20.
V-shaped grooves 62 and 63 are formed so that the rigidity of 51 is lowered and the pressure is easily deformed by the pressure difference between the liquid supply section 30 and the back pressure chamber 32. The vertical deformation shown in FIG. Supply side passage 20
The semicircular grooves 64, 65 for forming the liquid supply side passage 20 are provided, and the cross section of the liquid supply side passage 20 has a substantially rhombic shape like the central portion. Further, the flat portions 67, 6 are vertically moved in the same manner as the central portion so that the differential pressure largely acts on the connecting portions of the V-shaped grooves 62, 63.
8 are provided.

Therefore, when the above-mentioned differential pressure is applied, as shown in FIGS. 6 (a ') and 6 (b'), the protruding portion extends from the central portion to the root portion.
The flat portions 67 and 68 on the outer peripheral surface of 51 are greatly deformed into a concave shape, and the cross-sectional shape of the liquid supply side passage 20 is changed from a substantially rhombic shape to a circular shape.

As shown in FIG. 6 (a), the V-shaped grooves 62, 63 at the root of the protrusion 51 have a larger angle than the central portion of the protrusion 51.

Further, another modified example of the protrusion 51 is shown in FIGS.
Shown in. In this modified example, the cross-sectional shape of the protrusion 51 is shown in FIG.
Not only the tip side of the protrusion 51 as shown in FIG.
It is characterized by having a horizontally long flat cross-sectional shape with chamfered upper and lower surfaces over the entire length of 51. The basic structure of the protruding portion 51 is the same as that of the protruding portion 51 shown in FIGS. 4 to 6 except for the cross-sectional shape, and therefore the respective constituent portions are indicated by the same reference numerals.

The projecting portion 51 is not limited to the shape shown in FIGS. 4 to 9 described above, but the differential pressure between the liquid supply portion 30 and the back pressure chamber 32 causes the liquid supply side passage 20 to flow. It includes all shapes in which the flow passage area can be changed.

Another structure of the illustrated embodiment will be described. As shown in FIG. 1, a solenoid drive device S is attached to the upper portion of the valve casing 1. The solenoid drive device S penetrates the back pressure chamber 32 and passes through the drain side passage.
A plunger 4 having a tip abutting portion 4a for abutting against the back pressure chamber side opening 34 of 19 to close the opening 34, a coil 14 for moving the plunger 4 forward and backward, and a yoke 6. And a spring 3 and the like.

(Explanation of Operation of Pilot Type Diaphragm Valve A) FIG. 1 shows a closed state of the pilot type diaphragm valve A, in which the plunger 4 is pushed down by the urging force of the spring 3 and the drain side passage 19 is closed, The back pressure chamber 32 is the liquid supply unit 30.
The same pressure as that of is acting. On the other hand, the pressure of the drainage unit 31 is lower than the pressure of the liquid supply unit 30 (usually atmospheric pressure), and the diaphragm valve body 50 is pressed downward due to the pressure difference and maintains the valve closed state.

In this state, the projecting portion 51 has its original shape, that is, as shown in FIGS. 6 (a) and 6 (b), due to its elastic force.
The cross-sectional shape shown in (c) is restored.

When the valve is opened, the magnetic force attracts the plunger 4 upward by energizing the coil 14 against the urging force of the spring 3, and the tip abutting portion 4a of the plunger 4 extends from the back pressure chamber side opening 34. When the drain side passage 19 is separated and the drain side passage 19 is opened, the liquid in the back pressure chamber 32 flows to the drain portion 31, the pressure in the back pressure chamber 32 decreases, the diaphragm valve body 50 rises, and the communication port 33 is opened. The valve is opened, and the liquid flows from the liquid supply unit 30 through the communication port 33 to the liquid discharge unit 31.

Now, the cross-sectional shapes of the protrusion 51 and the liquid supply side passage 20 are as shown in FIGS. 4 to 6, and the minimum cross sectional diameter of the liquid supply side passage 20 is 0.62 mm (FIG. 6 (c)). , The pressure of the water supply side, that is, the liquid supply part (gauge pressure when water does not flow) is 7.5 kgf / cm ²
As shown in Fig. 10 (a) (b) (c), when the water pressure changes in the case of, the back pressure chamber 32 and the liquid supply section are immediately changed from the valve opening state to the valve closing state. The pressure difference between 30 and
The pressure difference becomes maximum immediately after the valve is closed, but the value is smaller than the pressure difference in the conventional technique shown in FIG. 12, and the pressure rise in the liquid supply part is also small.

That is, the minimum cross-sectional diameter of the liquid supply side passage 20 (0.62 mm)
Is larger than the minimum cross-sectional diameter of the conventional technology (0.47 mm), the pressure rise in the liquid supply part immediately after the valve is closed is 12.18 kg / cm.
² , which is lower than the value of 19.12 kg / cm ² of the prior art, and water hammer is suppressed.

This is because the pressure on the outer peripheral surface of the protruding portion 51 is higher than the pressure inside the liquid supply side passage 20 formed inside the protruding portion 51, and the high pressure causes the protruding portion as shown in FIG. 51
Is crushed, the cross-sectional area of the liquid supply side passage 20 is reduced, the flow rate of the liquid passing through the liquid supply side passage 20 is reduced, and the valve closing operation becomes gentle.

FIG. 11 shows that the flow rate decreases as the pressure difference between the back pressure chamber 32 and the liquid supply section 30 increases.

Further, as shown in FIGS. 6 (a ') and 6 (b'), in the state where the cross-sectional area of the liquid supply side passage 20 is reduced by the differential pressure, dust and the like in the liquid is apt to be clogged, but Even when the valve closes, the pressure difference disappears when the valve is closed, and the state of FIG. 6 (a) (b) is restored. Therefore, the cross-sectional area of the liquid supply side passage 20 increases, and the clogged dust is naturally discharged. Therefore, clogging does not occur.

Another embodiment of the protrusion 51 is shown in FIGS.
Shown in.

As shown in FIG. 12, the protruding portion 51 has a diameter reduced from the root portion toward the tip portion.

As shown in FIGS. 14 to 16, the cross sectional shape thereof is a hollow, substantially elliptical shape having a uniform thin wall except for the tip. On the other hand, the tip of the protrusion 51 has a hollow circular shape.

In this case, when a differential pressure is applied, since the thickness is uniform and thin, it is easily deformed, and it is deformed from the root portion to the tip portion as shown in FIGS.
The cross section of 20 becomes smaller.

In this case, the liquid supply pressure, the back pressure chamber pressure,
The changes over time in the pressure difference between the two pressures and the relationship between the pressure difference and the flow rate have substantially the same tendency as that shown in FIGS. 10 and 11.

[0050]

According to the present invention, a protrusion is provided from the diaphragm toward the liquid supply portion side, and a liquid supply side passage is formed which penetrates the diaphragm and the protrusion and communicates the liquid supply portion and the back pressure chamber, and the protrusion thereof. The part is formed of an elastic member having a restoring property.

Therefore, when the valve is closed, the cross-sectional area of the liquid supply passage formed in the protruding portion is reduced due to the pressure difference between the liquid supply portion and the back pressure chamber.
The amount of fluid flowing into the back pressure chamber is reduced, the operation of the diaphragm valve body is slowed, and the water hammer is effectively reduced.

Further, it is possible to increase the cross-sectional area of the liquid supply side passage formed in the protruding portion, which is less likely to cause clogging, and even when clogging occurs when the cross-sectional area is reduced, when the original shape is restored. Since the cross sectional area becomes large and the liquid is washed away by the liquid flowing through the passage, no clogging occurs.

Further, the projecting portion has a horizontally long flat cross-sectional shape, and the cross-sectional shape of the liquid supply side passage is expanded from the circular cross section toward the base from the tip end portion to both side portions of the circular cross section. In addition, if the upper and lower surfaces of the same circular cross section have a substantially rhombic cross section that expands in the vertical direction, when the pressure difference occurs between the liquid supply part and the back pressure chamber, the protruding part is easily deformed. The cross-sectional area of the liquid side passage can be easily reduced.

Further, the outer periphery of the protrusion is substantially elliptical, the diameter is reduced from the base toward the tip, and the cross-sectional shape of the liquid supply side passage formed therein is such that the tip is circular. Since the thickness is made to be a substantially elliptical shape that follows the shape of the outer periphery toward the base, the protruding portion is more likely to deform when a pressure difference occurs between the liquid supply portion and the back pressure chamber, The cross-sectional area of the side passage can be easily reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional front view of a pilot type diaphragm valve according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of a diaphragm of the valve.

FIG. 3 is an enlarged sectional view of a main part of a diaphragm of the valve.

FIG. 4 is a perspective view of a protrusion attached to the back surface of the diaphragm.

FIG. 5 is a perspective view of a liquid supply side passage forming core provided on the protrusion.

FIG. 6 is a sectional view of the protrusion.

FIG. 7 is a perspective view of a protrusion attached to the back surface of the diaphragm.

FIG. 8 is a perspective view of a liquid supply side passage forming core provided on the protrusion.

FIG. 9 is a sectional view of the protrusion.

FIG. 10 is a graph showing the pressure of the liquid supply portion, the pressure of the back pressure chamber, and the pressure difference between both pressures over time.

FIG. 11 is a graph showing the relationship between pressure difference and flow rate.

FIG. 12 is a sectional front view of another embodiment of the protruding portion.

13 is a cross-sectional view taken along the line I-I of FIG.

14 is a sectional view taken along line II-II of FIG.

15 is a sectional view taken along line III-III in FIG.

16 is a view taken along line IV-IV in FIG.

FIG. 17 is a graph showing the pressure of the liquid supply portion of the conventional pilot diaphragm valve, the pressure of the back pressure chamber, and the pressure difference between both pressures over time.

[Explanation of symbols]

 A Pilot type diaphragm valve 4 Plunger 19 Drain side passage 20 Liquid side passage 30 Liquid supply part 31 Drainage part 32 Back pressure chamber 33 Communication port 50 Diaphragm valve body 51 Projection part

Claims (3)

[Claims] 1. A liquid supply part (30), a liquid discharge part (31), and a liquid supply part (30).
Diaphragm valve body (50) for opening and closing the communication port (33) between the drainage part (31) and the drainage part (31), and a spine formed on the opposite side of the opening / closing surface of the communication port (33) in the diaphragm valve body (50). A drainage side passage that connects the pressure chamber (32) with the drainage part (31) and the back pressure chamber (32).
(19), the liquid supply side passage (20) communicating the liquid supply part (30) and the back pressure chamber (32), and the back pressure chamber side opening of the drainage side passage (19). Plunger that contacts and opens and closes the opening of the back pressure chamber
In the pilot type diaphragm valve including (4), the protrusion (51) is provided from the diaphragm (10) toward the liquid supply part side, and the diaphragm (10) and the protrusion (51) are penetrated. The liquid supply side passageway (20) that connects the liquid supply section (30) and the back pressure chamber (32) is formed, and the protrusion (51) is formed in the back pressure chamber (32).
Is deformed due to the pressure difference between the liquid supply part (30) and the liquid supply side passage.
A pilot type diaphragm valve characterized by being formed from an elastic member capable of reducing and restoring the sectional area of (20). 2. The projecting portion (51) has a horizontally long flat cross-sectional shape, and the liquid supply-side passage (20) has a cross-sectional shape from a distal end portion toward a base portion from a circular cross section to both sides of the circular cross section. 2. The pilot type diaphragm valve according to claim 1, wherein the portion is expanded laterally, and the upper and lower surfaces of the circular cross section are expanded substantially vertically to form a substantially rhombic cross section. 3. A cross section of the liquid supply side passageway (20) formed inside the protrusion (51) having a substantially elliptical cross-section on the outer periphery thereof and having a diameter reduced from the base toward the tip. 2. The pilot type diaphragm valve according to claim 1, wherein the shape is a cylindrical shape having a circular shape at its tip and a substantially elliptical shape having a uniform wall thickness which follows the shape of the outer circumference toward the base.