JPS5817900B2 - valve structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention: Industrial Application Field The present invention is used in the field of controlling the flow rate of fluids such as water and air flowing through piping.

The present invention relates to a main valve structure in which the opening degree of the main valve changes depending on the opening degree of the pilot valve, and the flow rate passing through the main valve changes proportionally. A valve with an outlet open and a valve plate made of a flexible elastic material such as synthetic rubber placed facing both the inlet and outlet openings without any restraint around the valve plate. Regarding structure.

Prior art, its problems, and technical analysis Such a valve structure is shown in Japanese Patent Publication No. 48-4520 (see FIG. 8).

That is, the valve chamber 80 has a short cylindrical shape in the valve casing.
form.

A large diameter outlet 81 is formed in the bottom wall of the valve chamber.

Therefore, an annular plane is formed between the edge of the outlet and the peripheral wall of the valve chamber, and this plane becomes the outer valve seat surface 82.

A cylindrical member is placed in the center of the outlet.

The hole in the cylindrical member forms an inlet 83, and its upper end forms an inner valve seat surface 84 in an annular plane surrounding the inlet.

The inner valve seat surface 84 is located at a lower position than the outer valve seat surface 82.

The area of the inflow port 83 is extremely small compared to the outflow port 81 .

A circular recess is formed in the ceiling wall of the valve chamber 80.

Therefore, an annular plane is formed between the edge of the recess and the peripheral wall of the valve chamber, and this plane runs along the ceiling-side valve seat surface 85.

A control fluid inlet/outlet 81 is formed in the center of the four parts.

A thin and light disc-shaped valve plate 86 made of synthetic resin is arranged on the valve seat 80.

The diameter of the valve plate 86 is larger than the outlet 81 and the valve chamber 80
larger than the recess in the ceiling.

The above valve communicates the outlet 81 with the atmosphere P2 and the inlet 8
3 is connected to a fluid system with a pressure P1 higher than the atmosphere, and a slight pressure P3 higher than the atmospheric pressure P2 is applied to the back surface of the valve plate through the control fluid inlet and outlet.

That is, when the pressure acting on the back surface of the valve plate 86 is equal to atmospheric pressure, the valve plate 86 is blown up by the jet from the inlet 83, and the peripheral portion hits the ceiling-side valve seat 85 and is attracted to the ceiling. .

The fluid in the inlet 83 then flows away to the outlet 81.

When the pressure acting on the back surface of the valve plate 86 is slightly increased, the valve plate 86 descends, and the peripheral part hits the outer valve seat 82 and the center part hits the inner valve seat 84, and the inlet 83 and outlet 81 are closed. Be cut off.

In this way, when the pressure on the back surface of the valve plate 86 is changed, the space between the inlet 83 and the outlet 81 is opened and closed ON-OFF.

Since the valve plate 86 of this valve is made of a flexible elastic material, it deforms into an upwardly convex shape when the pressure of the control fluid on the back surface decreases, and the degree of deformation depends on the pressure P3 of the control fluid. Therefore, by changing the pressure P3 of the control fluid, the flow rate Q flowing from the inlet 83 to the outlet 81 can be proportionally changed.

However, when this proportional control valve is used as the above-mentioned proportional control valve, there is a problem that the range of pressure P3 in which proportional control between the control fluid pressure P3 and the flow rate Q can be performed is extremely narrow, and proportional control of an even larger flow rate cannot be performed.

The reason for this is as follows.

Note that the valve plate 86 moves up and down as a whole due to the difference in force acting on the upper and lower surfaces.

The valve plate 86 has an external force (pl) acting on the upper and lower surfaces of each part.

p2) and the elastic force (f) accompanying the deformation are balanced.

Hereinafter, the vertical component of f will be expressed as fy. From the state where the valve plate 86 is in contact with the ceiling valve seat 85 (see Fig. 8C), as the control fluid pressure P3 is gradually increased, the valve plate 86 becomes convex upward and descends (see Fig. 8C). fy+p2=p in the section
In the relationship between l and pl, pl gradually increases).

At this time, the lower the valve plate 86 is, the more the fluid on the back side goes around the outer periphery of the valve plate 86 and flows out to the outlet 81 (see FIG. 8C), so the pressure on the back side of the valve plate 86 increases. (p
l) The rate of increase becomes slower, and the flow rate Q becomes curve 5 (
sl to 82).

Then, when the peripheral portion of the valve plate 86 approaches and comes into contact with the outer valve seat 82 (see FIG. 8C), the flow that goes around the outer circumference of the valve plate 86 from the upper surface to the lower surface is suddenly throttled and blocked. The pressure (pl) on the back surface of the valve plate 86 suddenly increases, and the flow rate Q suddenly decreases as shown by curve 5 (from S2 to 53) in FIG.

Point s3 indicates a state in which the outer peripheral portion of the valve plate 86 is in contact with the outer valve seat.

When the control fluid pressure P3 is further increased, the degree of curvature of the valve plate 86 changes while the outer peripheral portion remains in contact with the outer valve seat 82, and the flow rate Q decreases in proportion to the control fluid pressure P3, as shown in FIG. curve 5 (between s3 and 84), and finally the curve shown in Fig. 8 A
becomes the state of

Furthermore, when the control fluid pressure P3 is gradually lowered from this valve closed state, the pressure (pl) on the back surface of the valve plate 86 decreases, and the peripheral part of the valve plate 86 remains in contact with the outer valve seat 82. , the central part deforms into an upwardly convex shape, and the flow rate Q becomes curve 5 (
S4 to 83).

When the control fluid pressure P3 is further lowered, the peripheral portion becomes closer to the outer valve seat 8.
At this time, the fluid on the upper surface of the valve plate 86 flows around the outer periphery of the valve plate 86 to the lower surface, so that the pressure (pl) on the upper surface of the valve plate 86 suddenly decreases.

That is, in the relationship fy + p2 = pl, pl suddenly becomes smaller and fy becomes smaller accordingly (valve plate 86
(the curvature becomes gentler).

Therefore, the valve plate 86 rises all at once and s of the curve S in FIG.
3 to s2), and then as the control fluid pressure P3 decreases, it is sucked to the ceiling side valve seat (curve S in Fig. 9).
section from s2 to sl).

In this way, when the peripheral part of the valve plate 86 separates from the outer valve seat 82, the pressure (pl) acting on the back surface of the valve plate 86 suddenly changes, so that the peripheral part of the valve plate 86 jumps from the valve seat. Since the flow rate Q changes suddenly, proportional control of large flow rates is not possible.

Therefore, the range in which the flow rate Q changes in proportion to the control fluid pressure P3 is a narrow operating range (from S3 to S4 of the curve S in FIG. (up to).

Technical problem of the present invention The technical problem of the present invention is to
The purpose is to prevent the outer peripheral portion of the valve plate from being displaced in the valve opening/closing direction with respect to the outer valve seat.

Technical Means The means of the present invention taken to solve the above problems are as follows.

(a) The valve plate is made of a flexible elastic material that does not easily deform to the extent that it is not sucked into the outlet.

(The outflow port is arranged concentrically outside the annular inflow port, the outflow port is brought sufficiently close to the inflow port, and the ratio of the opening area of the inflow port to the outflow port is made sufficiently large.

g) A passage for introducing control fluid from the high-pressure system and a passage for leading the fluid from the back side to the low-pressure system are provided on the back side of the valve plate of the valve chamber.

Action of technical means The above technical means works as follows (see Figure 1).

That is, an introduction passage 92 is provided on the back side of the valve plate 91 of the valve chamber 90.
Control fluid flows in from the high pressure system through the back side, and the fluid at the back side flows out to the low pressure system through the outlet passage 93.

An amount Q1 of fluid flowing into the back surface of the valve plate 91 of the valve chamber 90;
When one or both of the amount Q2 of fluid flowing out from the back surface is changed, the pressure acting on the back surface of the valve plate 91 (pl
) changes.

When the pressure (pl) on the back surface of the valve plate 91 is greater than a predetermined value, the valve plate 91 is in contact with both the inner valve seat 94 and the outer valve seat 95.

When the pressure on the back side of the valve plate 91 is gradually reduced from this state, the central part of the valve plate 91 bulges upward and deforms into an upwardly convex shape.
The fluid in the inlet 96 flows toward the outlet 97 away from the inlet 96 .

When the pressure (pl) on the back surface of the valve plate 91 is further reduced, the peripheral portion of the valve plate 91 is slightly separated from the outer valve seat 95.

At this point, the forces acting on the entire upper and lower surfaces of the valve plate 91 are balanced, and the peripheral portion of the valve plate 91 does not separate from the outer valve seat 95.

That is, when the pressure (pl) on the back surface of the valve plate 91 decreases and the peripheral portion tends to move away from the outer valve seat 95, the inlet port 96
Due to radial kinetic energy, a part of the fluid flowing from the to the outlet 97 passes between the outer valve seat 95 and the lower surface of the valve plate 91, goes around the outer periphery, flows into the upper surface, and the pressure on the back surface of the valve plate 91 (
pl).

This is because the outflow port 97 is brought sufficiently close to the inflow port 96 and the ratio of the opening area of the inflow port 96 to the outflow port 97 is made sufficiently large. This is because strong kinetic energy remains.

The peripheral portion of the valve plate 91 is therefore pushed back towards the outer valve seat 95.

In addition, in the periphery of the valve plate 91, pressure (p
l) is higher than the pressure (p2) acting on the lower surface, and these are the vertical components (py
), and the valve plate 9 is balanced by the relationship py + p 2 = p 1.
1 has an upwardly convex shape.

Since the flow rate Q3 between the peripheral portion of the valve plate 91 and the outer valve seat 95 is restricted as described above, the degree of curved deformation of the valve plate 71 is determined by decreasing the inflow rate Q1 or increasing the outflow rate Q2. The smaller the back pressure (pl) is, the greater it becomes, and the flow rate Q from the inlet 96 to the outlet 97 increases.

In this way, in the present invention, the valve plate changes its degree of curvature depending on the ratio of the flow rate flowing into the back surface and the flow rate flowing out, while the peripheral portion remains unchanged from the outer valve seat. The flow rate towards the outlet can be varied proportionally.

The unique effect of the present invention is to use a movable diaphragm valve plate to control the pilot control pressure (P
As a valve that proportionally controls the flow rate of the controlled fluid for The flow rate (0) can be controlled, but in this case, the movable diaphragm valve plate is restrained at its outer periphery by a collar (casing), so the movable part and fixed part (outer periphery) of the diaphragm valve plate are
During use, cracks tend to occur at these bent points, and durability is not necessarily guaranteed.

On the other hand, in the present invention, since the valve plate is not restrained in any way with respect to the casing, the diaphragm valve plate has excellent durability.

EXAMPLE Next, an illustrated example showing a specific example of the above technical means will be described.

In the embodiment shown in FIGS. 1 to 3, a valve casing 1 forms a valve chamber 2 having a cylindrical space.

The bottom surface of the valve chamber 2 forms a circular plane valve seat surface.

An annular inlet 3 is formed in the center of the valve seat surface, and an annular annular groove outlet 4 is formed around it.

The outlet 4 is placed sufficiently close to the inlet 3.

Therefore, an inner valve seat is formed between the inlet 3 and the outlet 4, and an outer valve seat is formed between the outlet 4 and the peripheral wall of the valve seat 2.

The ratio of the opening area of the outlet 4 to the inlet 3 is made small enough so that the fluid flowing from the inlet 3 to the outlet 4 has sufficient kinetic energy at the outer valve seat portion.

The valve casing 1 is provided with an inlet 6 connected to a high-pressure fluid system piping 5 and an outlet 8 connected to a low-pressure fluid system piping 7.

The inlet 6 communicates with the inlet 3 and the outlet 8 communicates with the outlet 4.

A disk-shaped valve plate made of synthetic rubber is accommodated and arranged in a valve chamber 2 in a free state with its outer periphery not restrained by the valve casing 1 at all.

The valve plate 9 has a size that extends to the outside of the outlet 4.

The valve plate 9 has a flexible elasticity that does not allow it to be sucked into the outlet 4.

An introduction passage 10 is provided for introducing a part of the fluid in the high pressure piping system 5 into the space on the back side of the valve plate 9 of the valve chamber 2, and an outlet passage 11 is provided for introducing the fluid in the back space into the low pressure system.

An introduction pilot valve 12 is connected to the introduction passage 10, and an introduction pilot valve 12 is connected to the introduction passage 10.
Attach the lead-out valve 13 to the.

The valve of the above embodiment operates as follows.

By keeping the opening of the inlet pilot valve 12 constant and changing the opening of the outlet pilot valve 13, or by operating both pilot valves in the opposite manner, the amount of fluid flowing into the back of the valve plate 9 and the amount of fluid flowing into the back of the valve plate 9 can be adjusted. The proportion of the amount of fluid flowing out from the back surface changes, and the pressure acting on the back surface of the valve plate 9 changes.

Consider a case where the opening degree of the inlet pilot valve 12 is kept constant and the outlet pilot valve 13 is gradually opened from a closed state.

When the outlet pilot valve 13 is closed, the same pressure as the inlet 3 is applied to the back surface of the valve plate 9, and the valve plate 9 is in contact with both the inner and outer valve seats.

When the pilot valve 13 is gradually opened from this state, the pressure on the back surface of the valve plate 9 gradually decreases, and the center portion of the valve plate 9 bulges upward, deforming it into an upwardly convex shape.

Then, the center part of the valve plate 9 separates from the inner valve seat, and the inlet 3
The fluid flows toward the outlet 4.

When the opening degree of the pilot valve 13 is further increased, the pressure on the back surface of the valve plate 9 is further reduced, and the peripheral portion of the valve plate 9 is slightly separated from the outer valve seat.

At this time, since the static pressure around the valve plate 9 is higher on the upper surface than on the lower surface, the valve plate 9 is maintained in an upwardly convex shape.

As the pressure on the back surface becomes smaller, the degree of deformation of the valve plate 9 becomes larger, and the flow rate from the inlet 3 to the outlet 4 increases.

Furthermore, the degree to which the peripheral portion of the valve plate 9 is separated from the outer valve seat increases, and the radial kinetic energy of the fluid flowing from the inlet 3 toward the outlet 4 also increases.

Therefore, a portion of the fluid passes between the outer valve seat and the lower surface of the valve seat 9, goes around the outer periphery, and the amount flowing into the upper surface increases.

The valve plate 9 is stabilized in a certain state depending on the ratio of the amount of control fluid flowing into the back surface of the valve plate 9 and the amount of fluid flowing out from the back surface.

If the ratio between the amount of control fluid flowing into the back surface of the valve plate 9 and the amount of fluid flowing out from the back surface is constant, when the valve plate 9 attempts to displace upward, the lower surface of the peripheral portion of the valve plate 9 The distance between the outer valve seats increases.

Then, the flow rate flowing around the outer periphery of the valve plate 9 and flowing into the upper surface increases, and the pressure on the upper surface of the valve plate 9 increases, so that the valve plate 9 is pushed back downward.

When the valve plate 9 tries to displace downward, it is pushed back upward by the opposite effect.

In this way, by increasing the valve opening degree of the pilot pilot valve 13, the flow rate from the inlet 3 to the outlet 4 increases proportionally, while the peripheral part of the valve plate 9 does not separate from the outer valve seat. , Conversely, if the valve opening is made smaller, the flow rate decreases.

Even if the back surface of the valve plate 9 is slightly away from the outer valve seat, the flow rate that passes between the peripheral part of the valve plate and the outer valve seat and wraps around to the back surface is restricted as described above. The flow rate from the inlet 3 to the outlet 4 can be proportionally changed depending on the opening degree of the valve.

4 to 6 show another embodiment in which the invention is applied to a liquid level control valve.

An O-ring gasket 61 is interposed in the upper casing 60, and the upper casing 60 is attached to the lower casing 62 with bolts (not shown).

A valve chamber 63 having a cylindrical space is formed at the joint of both casings.

The ceiling of the valve chamber 63, that is, the lower end surface of the upper casing 60 forms a circular plane valve seat surface, and has an inlet 64 in the center and a plurality of outlet ports 65 on the circumference thereof.

Inlet 64 terminates inlet 66 and outlet 65 all communicate through annular cavity 67 to outlet 68 .

The inner and outer valve seats are therefore partially continuous in the plane between the outlet 65.

The ratio of the total opening area of the outlet 65 to the inlet 64 is such that the fluid flowing from the inlet 64 to the outlet 65 has sufficient kinetic energy at the outer valve seat portion.

A disk-shaped valve plate 69 made of synthetic rubber is housed and arranged in the valve chamber 63 in a free state.

The valve plate 69 has a flexible elasticity to the extent that it will not be sucked into the inflow/outflow port 65 .

An orifice 70 is provided in the portion of the valve plate 69 facing the inlet 64.
form.

An outlet passage 71 is provided through the bottom wall of the valve chamber 63, and a pilot valve seat made of synthetic rubber is attached to the lower end of the outlet passage 71.

A float 7 is attached to the skirt portion formed on the lower casing 62.
Accommodates 2.

A pilot valve surface 73 is formed at a position facing the pilot valve seat of the float 72, a vent 74 is a vent hole, and 75 is a bolt for preventing the float from falling off.

The operation of the liquid level control valve of this embodiment is as follows.

When the liquid level in the container to which the liquid is to be supplied is high, the float 72 is in the floating position, as shown in FIG. 4, and the outlet passage 11 is blocked by the pilot valve surface 73 of the float.

Therefore, similar to the embodiment of FIGS. 1-3, the valve plate 69 abuts both the inner and outer valve seats and the inlet 69
4 is blocked.

When the amount of liquid in the container decreases and the float 72 falls with the liquid level, the valve becomes open as shown in FIG.

That is, when the outlet passage 71 is opened, the valve plate 69 is deformed and separated from the valve seat, and the inlet 6
6 flows from the inlet 64 to the outlet 65 and flows into the empty chamber 6.
7 to outlet 68 and enters the container.

In this embodiment, since the inner valve seat and the outer valve seat are partially continuous, the radial kinetic energy of the fluid flowing from the inlet 64 toward the outlet 65 is strong.

[Brief explanation of drawings]

1 to 3 schematically show an embodiment of the valve structure of the present invention, in which FIG. 1 is a sectional view of the valve in the closed state, FIG. 2 is a sectional view of the valve in the open state, and FIG. 3 is a sectional view of the valve in the open state. is a cross-sectional view along the ■-■ line in Figure 1,
4 to 6 show another embodiment in which the present invention is applied to a liquid level control valve, in which FIG. 4 is a cross-sectional view of the valve in the closed state, FIG. 5 is a cross-sectional view of the valve in the open state, and FIG. Figure 6 is a bottom view of the upper cage jig, Figure 7 is a reference diagram for detailed explanation of the present invention,
FIG. 8 (person to D) and FIG. 9 are reference diagrams for explaining the outline and operation of the structure of the prior art. 2...Valve chamber, 3...Inflow port, 4...
...outlet, 9...valve plate, 10...
Inlet passage, 11... Outlet passage, 12...
・Introduction pilot valve, 13... Outlet pilot valve, 69... Valve plate, 70... Orifice, 71... Outlet passage, 72... ...Float, 90...Valve chamber, 91...Valve plate,
96...Inflow port, 97...Outflow port.

Claims (1)

[Claims] 1 An outlet is opened around the inlet, and a valve plate made of a flexible elastic material such as synthetic rubber is placed facing both the inlet and outlet, and the area around the valve plate is completely restrained. In the valve structure, the valve plate is made of a flexible elastic material that does not easily deform to the extent that it is not sucked into the outlet, the inlet is formed in an annular shape, and the outlet is concentrically formed outside of the inlet. a passageway arranged to bring the outlet sufficiently close to the inlet, and to make the ratio of the opening area of the inlet to the outlet sufficiently large, and to introduce control fluid from the high pressure system to the back side of the valve plate of the valve chamber; A valve structure provided with a passage that leads the fluid on the back side to a low pressure system.