JPH0213196B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is installed in a gas combustion appliance, etc., and continuously controls the outlet side gas pressure (flow rate) according to the combustion load signal, that is, the hot water temperature, room temperature, etc. The present invention relates to a fluid control valve for obtaining a desired temperature, and in particular to a valve structure of a fluid control valve with a closing function, which has a fluid shutoff function added to the fluid control valve.

Conventional technology Fluid control valves with a closing function are designed to omit a dedicated closing solenoid valve by adding a fluid shutoff function to a fluid control valve, and are intended to make the fluid control system more compact and cost-effective. Some valves have an elastic member provided in the valve portion of the valve to improve the adhesion between the valve seat and the valve body. (For example, Japanese Utility Model Application Publication No. 55-49137) This conventional fluid control valve with a closing function is shown in FIGS. It has a fixed iron core 3 disposed close to the permanent magnet 1, an electromagnetic coil 4 that generates a magnetic force in a direction repelling the permanent magnet 1, and an electromagnetic coil 4 that moves the valve body 2 in the valve closing direction under the pressure of the fluid inlet 5. The electromagnetic repulsive force is controlled by controlling the current applied to the electromagnetic coil 4, and the valve body 2 is moved up and down freely.
The valve opening degree is controlled by the balance between the fluid pressure and the electromagnetic repulsion force acting through the diaphragm 6, and the fluid pressure is proportionally controlled.

In the fluid control valve with a closing function configured as described above,
When no current is applied, the force of the permanent magnet 1 being attracted to the fixed iron core 3 causes the elastic member 7 attached to the valve body 2 to be pressed against the valve seat 8, thereby closing the valve and blocking the fluid passage.

However, in this conventional example, when the valve is repeatedly opened and closed, or when vibrations, shocks, etc. are applied, the valve body 2 tilts as shown in FIG. This is because the valve body 2 is supported by a diaphragm made of a flexible material. As a result, since the contact surface of the elastic member 7 with the valve seat 8 is tapered, the shape in which the elastic member 7 contacts the valve seat 8, which is machined into a perfect circle with high precision, is an ellipse as shown in FIG. This resulted in a small gap being formed between the valve seat 8 and the elastic member 7, resulting in the inconvenience of fluid leakage.

Further, it is difficult to process the elastic member 7 to be integrated with the valve body 2. That is, adhesion, integral molding, etc. are used as a means for attaching the elastic member 7 to the valve body 2, but when adhesive is used, there is a risk that the elastic member 7 will deteriorate due to the adhesive, and the workability is poor.

On the other hand, in the case of integral molding, if the elastic member 7 is made of rubber as the material of the valve body 2, it is necessary to select a material having a heat resistance temperature higher than the vulcanization temperature of rubber, and is limited to metals. As a result, turning is required, leading to an increase in processing costs. Further, since the elastic member 7 contracts non-uniformly during cooling during integral molding, highly accurate roundness cannot be obtained, resulting in poor yield.

Problems to be Solved by the Invention In other words, in the conventional example, when the valve is repeatedly opened and closed, and when vibrations, shocks, etc. are applied, the contact position between the elastic member and the valve seat changes and the fluid is completely closed. I couldn't do it.

In addition, processability and yield were poor.

Means for Solving the Problems The present invention solves the above problems, and includes a valve seat provided between a fluid inlet and a fluid outlet, and a seal wall surface and a positioning portion provided opposite to the valve seat. a seal ring that is fitted into the seal wall of the valve body and has a spherical radius surface having a center point on the central axis of the valve seat; A ring holder is provided to hold the ring within the valve body with a predetermined amount of compression, and the ring is closed by a biasing element.

Effect This configuration prevents repeated valve opening and closing, vibration,
Even if the valve body tilts or the contact position changes due to impact, etc., the seal ring has a spherical radius surface whose center point is on the central axis of the valve seat, so the valve seat and spherical radius surface will always make close contact. Stable closure can be achieved. In addition, by placing the ring holder in contact with the positioning part of the valve body, the seal ring can be fixed with little variation and with the optimum amount of compression. can be maintained. Furthermore, after the important parts are individually machined with high precision, the seal ring is inserted into the valve body and is further held between the seal rings by the ring holder, which improves processability and assemblability, as well as yield.

Embodiment Hereinafter, an embodiment of the present invention will be described based on the accompanying drawings. FIG. 1 shows a sectional structural view of a fluid control valve with a closing function according to the present invention, and FIG. 2 shows an enlarged sectional view of a main part of the valve portion. In FIGS. 1 and 2, 9 is a valve body in which a valve seat 12 is provided between a fluid inlet 10 and a fluid outlet 11, and 13 is a membrane in which a diaphragm 14 that operates in response to pressure on the fluid inlet 10 side is provided above and below. a valve body fixedly mounted together with plates 15a and 15b by a pin 16 and a push nut 17, and provided with seal wall surfaces 18a and 18b and a positioning portion 19;
Reference numeral 20 denotes a seal ring made of an elastic member, which has a spherical rounded surface 21 having a center point P on the central axis CL of the valve seat 12, and has a uniform cross-sectional shape over the entire circumference. has an inner diameter smaller than the outer diameter D of the seal wall surface 18a.
The radial seal is created by compressing the

22 is a ring holder that abuts against the positioning part 19 and holds the seal ring 20 at a predetermined compression amount;
It is fixedly attached together with 5a and 15b by a pin 16.

23 is a biasing element that biases the valve body 13 in the valve closing direction; 24 is a yoke 25, a yoke plate 26, a coil 27;
The driving unit has a plunger 28 provided in the center of the coil 27 so as to be movable up and down. When the coil 27 is energized, an electromagnetic force is generated, and the plunger 28 is displaced downward to operate the valve body 13 and open the fluid outlet. Controls the pressure (flow rate) on the 11 side.

In the above configuration, when the current is not energized, the biasing element 23
As a result, the valve element 13 receives a valve-closing force, and the spherical rounded surface 21 is pressed against the valve seat 12, thereby closing the valve and cutting off fluid flow. Next, when the coil 27 is energized, electromagnetic force acts on the plunger 28 to displace the valve body 13 downward, and the pressure on the fluid outlet 11 side is controlled according to the amount of energization to the coil 27. It also performs the well-known governor function.

Then, when the current supply to the coil 27 is stopped again, the valve body 13 is closed by the force of the biasing element 23.
At this time, the contact position of the seal ring 20 with respect to the valve seat 12 does not necessarily match the initial state. This is due to the inclination of the valve closing force by the biasing element 23, the fact that the valve body 13 is supported by the diaphragm 14 made of a flexible material, and disturbances such as vibrations. Since the spherical radius surface 21 is provided, even if the valve body 13 is slightly tilted, the valve seat 12 and the spherical radius surface 21 are in close contact with each other, and stable closing can be achieved. Important points for closing are the roundness of the valve seat 12 and the roundness of the contact portion of the seal ring, that is, the rounded surface 21. Since the valve seat 12 can be machined, it is easy to secure it, but since the seal ring 20 is made of an elastic member, the roundness may deteriorate depending on the amount of compression. In this embodiment, since the ring holder 22 is brought into contact with the positioning portion 19 of the valve body 12 and the amount of compression can be controlled with high precision, the roundness can be maintained with high precision. FIG. 3 shows the outer diameter D of the seal wall surface 18a.
Ring holder 22 when the radial sealing ratio δs of the seal ring 20 to The ratio of compressing the seal ring 20 by the axial compression rate δr
(Here, if the axial gap formed between the seal wall surface 18b and the lower end surface of the ring holder 22 is t, and the axial height of the seal ring 20 is T, then δr=((T−
t)/T))×100(%)) and the valve seat leakage amount Qr. At this time, the material of the seal ring 20 is NBR (nitrile rubber), the valve closing force is 150 (g), and the applied fluid pressure is 500 mmH2O.

It can be seen from FIG. 3 that as the compression ratio δr increases, the valve seat leakage Qr increases. The JIS internal leakage standard for solenoid valves of 0.55 (I/hr) is satisfied when the radial seal ratio δs is within 4% and the axial compression ratio δr
is within 10%, and the seal ring 20 must be installed within this range.

As described above, according to this embodiment, the seal ring 20 having the spherical radius surface 21 having the center point P on the central axis of the valve seat 12 is constructed as a single unit, and is inserted into the seal wall surfaces 18a and 18b to determine the position. The valve body 13 is compressed by a predetermined amount by the portion 19 and the ring holder 22.
Even if the valve body 13 is slightly tilted due to repeated opening and closing of the valve or disturbances such as vibration, the valve seat 12 and the spherical radius surface 21 are in complete contact with each other to provide stable closing performance. Assembling can be performed by fitting the seal ring 20 into the valve body 13 and then fitting the ring holder 22, thereby improving the ease of assembly. Furthermore, since the important seal ring 20 has a uniform cross section over the entire circumference, it can be molded with high precision and improves workability.

Furthermore, if the seal ring 20 deteriorates, it can be replaced by removing the push nut 17, improving maintainability. In addition, in this embodiment, a driving part of the type in which the plunger 28 slides is used, and a spring is used as the biasing element 23 that acts in the direction of lifting the valve body 13 upward, so that the valve body 13 is less likely to tilt compared to the conventional example, and the closing is reliable. It has effects such as high performance.

Effects of the Invention As explained in detail above, according to the present invention, the following effects can be obtained.

(1) The seal ring has a spherical radius surface whose center point is on the central axis of the valve seat, so even if the valve body is closed in a tilted state due to repeated opening and closing of the valve or disturbances such as vibration, the spherical radius surface will remain unchanged. comes into close contact with the entire circumference of the valve seat, providing stable closing performance.

(2) A seal wall surface and a positioning section are provided on the valve body, and a seal ring is fitted into the seal wall surface to perform a suitable radial seal, and a ring holder is brought into contact with the positioning section to achieve an optimal seal with little variation. Since the seal ring can be fixed with a certain amount of compression, the spherical radius surface, which is important for closing, can be maintained with high precision, allowing reliable closing with less valve closing force. This also improves the durability of the seal ring since the amount of bite of the valve seat into the seal ring can be reduced.

(3) The ring holder securely fixes the seal ring, allowing for highly accurate and stable assembly.
Yield and mass productivity can be improved.

(4) Since reliable closing is possible with less valve closing force, the setting force of the biasing element can be reduced, and the valve can be driven with less driving force. This is suitable for automatically controlling the valve in response to an external signal.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a fluid control valve with a closing function showing an embodiment of the present invention, Fig. 2 is an enlarged sectional view of the valve section, and Fig. 3 shows the relationship between seal ring compression ratio and valve seat leakage. 4 is a cross-sectional view of a conventional fluid control valve with a closing function, and FIG. 5 is a cross-sectional view of the same essential parts.
FIG. 6 is a diagram showing the shape of contact between the valve seat and the elastic member. DESCRIPTION OF SYMBOLS 10... Fluid inlet, 11... Fluid outlet, 12... Valve seat, 13... Valve body, 20... Seal ring, 21... Spherical radius surface, 22... Ring holder, 23... Biasing element.

Claims (1)

[Scope of Claims] 1. A valve seat provided between a fluid inlet and a fluid outlet, a valve body provided opposite to the valve seat and having a seal wall surface and a positioning portion, and a valve body fitted into the seal wall surface of the valve body. a seal ring provided with a spherical radius surface having a center point on the central axis of the valve seat; a biasing element that acts in a direction to press the spherical radius surface against the valve seat; A fluid control valve with a closing function, comprising a ring holder that contacts the seal ring and holds the seal ring in the valve body at a predetermined compression amount. 2. The radial seal ratio δr of the seal ring fitted into the valve body is within 4%, and the axial compression ratio δs of the seal ring by the ring holder is within 10%. Fluid control valve with closing function.