JP2561311Y2 - Pressure proportional control valve - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure proportional control valve for controlling a gas supply amount of a gas combustor, and more particularly to a pressure proportional control valve with a closing function capable of supplying a minute flow rate from a bypass passage. .

[0002]

2. Description of the Related Art In a pressure proportional control valve, a valve seat and a valve body are connected to each other.
Wide range of control from small flow rate to large flow rate only by gap adjustment
It is difficult to reduce the flow rate
Some are secured by flowing in a passage. FIGS. 4 and 5 show a conventional pressure proportional control valve having the bypass passage . The valve box 1 is provided with a valve seat 4 communicating with the upstream passage 2 and a valve seat 5 communicating with the downstream passage 3. Installed on the same axis in series,
The valve bodies 6 and 7 facing the respective valve seats 4 and 5 are mounted on a valve rod 9, and springs 10 and 11 for urging the respective valve bodies 6 and 7 in the valve closing direction for closing the valve seats 4 and 5 are provided. Have.

[0003] A diaphragm 12 and an electromagnetic drive unit 13 are provided above the valve box 1, and the valve stem 9 is operated by these. The gas that has passed through the upstream valve seat 4 is transferred to the downstream flow path 3.
Bypass passage 14 leading to, Ru Tei provided a channel 15 communicating with the downstream side flow path 3 to the diaphragm lower chamber.

[0004] The pressure proportional control valve is connected to an electromagnetic drive unit 13.
When power is not supplied, the upstream valves are controlled by the springs 10 and 11.
The valve body 6 is mounted on the seat 4 and the downstream valve body 7 is mounted on the downstream valve seat 5.
The channels 2 and 3 are closed by pressure contact with each other.

From this state, the electromagnetic drive unit 13 is energized to
When the exciting current is increased, the diaphragm 12
The valve stem 9 retreats (moves downward in the figure), and first, the upstream valve
The valve element 6 on the upstream side is separated from the seat 4. At this time, the engaging portion 1
6 is not engaged with the valve element 7 on the downstream side,
The free downstream valve element 7 is closed by a spring 11 on the downstream side .
The gas is pressed against the valve seat 5 and the gas flows between the valve body 7 and the valve seat 5.
Do not flow.

On the other hand, when the upstream valve seat 4 and the valve body 6 are separated from each other.
As a result, the gas passing through the opening (gap)
The path passes through the path passage 14 to the downstream flow path 3. That is,
A small flow rate is supplied through the bypass passage 14 of
The supply amount is adjusted by the degree of the gap between the valve body 6 and the valve seat 4.

Next, the exciting current of the electromagnetic drive unit 13 is increased.
When the valve stem 9 is further retracted, the engaging portion 16 is moved to the downstream side.
Engage with the valve element 7 and the valve element 9 on the downstream side together with the valve rod 9 is in the same direction.
And the valve element 7 on the downstream side is separated from the valve seat 5 on the downstream side.
The main flow path from the flow path 2 to the flow path 3 is opened, and a large flow rate is
Flows. As a result, the valve stem 9 slides in proportion to the amount of current.
The amount is determined and the gap between the valve seat 5 and the valve body 7 is adjusted.
Flow rate corresponding to. At this time, the diaphragm 12
Is applied with a gas pressure, and the gas pressure is applied through the valve rod 9 in accordance with the applied pressure.
By moving the downstream valve element 7 to adjust the gap with the valve seat 5,
The gas pressure on the flow side is controlled to be constant. in this way
The function of the pressure proportional control valve is
You.

[0008]

In the prior art shown in FIG. 4, the airtight portion of the downstream valve body 7 has a gap with the valve rod 9 and a nozzle (valve body).
There are two places 7 and the gap of the valve seat 5), it is difficult to stop them simultaneously.

In the conventional example shown in FIG. 5, the gap between the valve body 7 and the valve rod 9 on the downstream side is sealed by an O-ring 17, but in this case, the sliding resistance of the O-ring 17 is large. In many cases , the downstream valve 7 opens before the engagement portion 16 hits the downstream valve 7 . Therefore , the load of the spring 11 is
It is necessary to make the sliding resistance 17 larger.

As described above, if the load of the spring 10 is increased, the electromagnetic drive unit 13 for opening the valve must be increased, so that there is a problem that the size is increased.

Also, leakage occurs from the downstream valve portion.
When the flow rate is very small , not only the bypass passage 14 but also the downstream side valve seat portion leaks at the same time, so the minute flow rate increases by the amount of the leak. Since the leakage amount varies, the accuracy of the minute flow rate deteriorates.

Further, the valve element 6 on the upstream side comes into close contact with the entire circumference of the valve seat 4 due to misalignment of the guide portion and the valve seat 4.
No leakage occurs due to one-sided contact . In order to prevent this, it is necessary to increase the processing accuracy. Further, in such a valve structure, in order to reliably close the valve , a spring 10 is required.
Must be increased, and the electromagnetic drive unit 13 for opening the valve must be increased.

An object of the present invention is to solve the above-mentioned problems of the prior art and to obtain a pressure proportional control valve with a high precision of minute flow rate without increasing the size of the electromagnetic drive unit 13 .

[0014]

In order to solve the above problems BRIEF SUMMARY OF THE INVENTION, it means this invention is taken, the Oite to a known pressure proportional control valve described above, the valve seat of the upstream side of the valve element and the upstream The guide fitted into the inner diameter surface of the
Fix the tip to the guide and move the guide together with the valve stem.
And the spring of the downstream valve element is
It was interposed between the body and the guide.

Further, a valve rubber is provided on the downstream valve body, a gap between the downstream valve body and the valve rod is sealed with an inner peripheral portion of the valve rubber, and the sealing portion is formed into a thin film to form a valve. direct the movement of the rod
This makes it difficult to transmit to the downstream valve body .

[0016]

[Action] This invention is to a configuration described above, since the upstream-side valve body is freely swing relative to the guide became fitting the upstream side of the valve seat, the valve element against the valve stem Can swing
Te, when the valve body is pressure wear on the valve seat, it relates to deflection of the valve stem
In addition, the valve body is completely in close contact with the valve seat, and the one-side contact is absorbed.

Further, the downstream side of the valve body, the gap between the valve stem is sealed by the valve rubber, leakage from the gap
Does not occur. Further, when the action of opening the thin film to stretch
To absorb changes in the gap between the valve stem and valve body,
And no leakage occurs.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment shown in FIGS. 1 to 3, parts having the same structure and function as those of the conventional example shown in FIGS.

In FIGS. 1 to 3, reference numeral 26 denotes an upstream valve body, and reference numeral 27 denotes a downstream valve body. The upstream valve body 26 is made of rubber, and a valve body receiver 29 made of a metal plate is applied to a lower portion thereof. When the valve body 26 is made of an elastic material such as rubber,
Even if the valve element 26 is tilted, the elasticity of the valve element 26 ensures the valve seat 4
There is an advantage to adhere to.

Reference numeral 30 denotes a guide, which is made of a hard material such as a metal. Three guide pieces 31 slidably contacting the inner peripheral surface of the valve seat 4 are provided at the upper part at three equal positions, and the lower part is provided at the lower part. Is the large diameter part 3
2 is provided. Recess 33 provided in the upper portion of the valve body 26 and the large diameter portion 32 Niwame, projections 3 of the inner peripheral upper portion of the concave portion 33
4 and the outer periphery of the large-diameter portion 32 are engaged with each other.

The guide 30 has a recess 36 for receiving the lower end of the valve rod 35 and a recess 37 for receiving the spring 11. A valve rubber 44 is provided on the upper portion of the downstream valve body 27 so as to be in close contact with the downstream valve seat 5. Part 4
The inner peripheral portion 40 is tightly engaged with the peripheral groove 42 on the engaging portion 41 of the valve rod 35 to seal.

The inwardly projecting rim 43 on the inner periphery of the lower end of the cylindrical wall 47 of the valve rubber 44 is fitted into the peripheral groove 45 on the outer periphery of the valve body 27. The valve body 27 is made of a hard material such as metal, and its inner periphery is freely fitted to the valve rod 35, and the above-mentioned protruding edge 43 is provided between the spring 46 and the flange 46 on the outer periphery of the upper end of the valve body 27.
Sandwich. A sufficient gap is provided between the outer periphery and upper surface of the flange 46 and the cylinder wall 42 and the valve rubber 44.

The operation of this embodiment is as described above. The operation of the spring 10 acting on the valve rod 35 via the valve body 26 when the electromagnetic drive unit 13 is not energized is closed. Thus, the upstream valve body 26 is in close contact with the upstream valve seat 4, and the valve rubber 44 of the downstream valve body 27 is in close contact with the downstream valve seat 5 by the spring 11.

[0024] Now, by energizing the electric magnetic drive unit 13 the valve stem 35
When down, first, the lower portion of the upstream-side valve body 26 you open valve down with the valve stem 35. At this time, the engaging portion 41 is connected to the valve on the downstream side.
Since it is not engaged with the body 27, the valve rod 35 and the valve rubber 44
Only the inner periphery 40 is lowered, only the thin film 39 is deformed, and the valve stem
The valve element 27 on the downstream side, which is free from 35, is
The pressure contact with the valve seat 5 on the downstream side is maintained, and the gas is
It does not flow between the body 27 and the valve seat 5.

On the other hand, the upstream valve seat 4 and the valve body 26 are separated.
As a result, the gas passing through the opening (gap)
The flow passes through the bypass passage 14 to the downstream flow passage 3. That is,
Micro flow through this bypass passage 14 as before
Supply is made. This supply amount is determined by the excitation of the electromagnetic drive unit 13.
It is adjusted by the degree of gap between the valve body 26 and the valve seat 4 based on the amount of current.
It is.

Next, the exciting current of the electromagnetic drive unit 13 is increased.
When the valve stem 35 is further retracted, the engaging portion 41 is moved downstream.
The valve element 27 on the downstream side engages with the side valve element 27 and together with the valve rod 35.
Slides in the same direction, from the downstream valve seat 5 to the downstream valve
Away body 27, the main channel from the channel 2 to flow channel 3 is opened
Large flow. As a result, the valve stem 3
5 is determined, and the gap between the valve seat 5 and the valve body 27 is reduced.
It is regulated and the corresponding flow rate flows. Also, diamond
Gas pressure is applied to the flam 12, and corresponding to the applied pressure,
By moving the downstream valve body 27 via the valve rod 35, and between the valve seat 5 and
Adjust the gap so that the gas pressure on the downstream side is constant.
You. In this way, the pressure adjusted for the flow rate is
The function of a force proportional control valve is performed.

When energization of the electromagnetic drive unit 13 is stopped , the valve stem 3
5 rises, the reverse when the above valve opening and closing the valve body 27 on the downstream side first, then the upstream-side valve body 26 is closed, the gas stream
Is shut off.

[0028]

EFFECT This invention is constructed as described above, the upstream valve seat odor Te, guides the guide which is connected to the upstream side valve body inner diameter surface of its universal swinging the guide and the upstream valve body as than was to absorb the uneven contact of the valve body, the valve can be closed with a small load.

Further, by sealing the gap between the valve body and the valve stem of the downstream side inner circumferential portion of the valve rubber, seal the gap of the valve stem and the downstream valve body can be reliably and the seal portion Thin film
Because by and by, the resistance is significantly smaller at the time of action of the valve stem.

Therefore, the present invention improves the obstruction of the downstream valve body, improves the accuracy of minute flow rate in the bypass passage, and reduces the spring load , as described above. This has the effect of reducing the size and cost.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view of an embodiment.

FIG. 2 is an enlarged vertical sectional front view of the downstream side of the above.

FIG. 3 is an enlarged vertical sectional front view of the same upstream side.

FIG. 4 is a longitudinal sectional front view of a conventional example.

FIG. 5 is a longitudinal sectional front view of another conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Valve box 4 Valve seat 5 Valve seat 9, 35 Valve stem 10 Spring 11 Spring 12 Diaphragm 14 Bypass passage 26 Upstream valve body 27 Downstream valve body 30 Guide 32 Large diameter part 33 Depression 39 Seal part (thin film) 41 Engagement Department

Claims (2)

(57) [Scope of request for utility model registration] 1. An upstream valve provided in series and coaxially in a flow path.
seat4 andDownstream valve seat5And each of these valve seats4 and 5 respectively
OppositeContactUpstream valve body26 andDownstream valve body27
And both valve bodies26, 27In the valve closing directionRespectivelyEnergize
Spring10, 11When,In the downstream flow path 3 of the downstream valve seat 5
The diaphragm 12 to which the pressure of the flow path 3 provided is applied
And the center of the downstream valve body 27 from the diaphragm 12
Penetrates to the upstream valve body 26 andDiaphragm12
The movement of both valve bodies26, 27Valve stem to tell35When,So
Through the valve stem 35 and the diaphragm 12Above both valves
body26, 27Electromagnetic drive that operates to open13And from
And the valve element on the upstream side26The above valve stem35Together with
Slide the valve element on the downstream side27Is the above valve stem35To
And freeIt is designed to slide,And above
Upstream valve body26After opening, The downstream valve body 27late
To open the valveThe engaging portion 4 that engages with the downstream valve body 27
1 to the valve stem 35Provided and also the upstream valve seat4Go through
Bypass the valve seat 5 on the downstream side and pass through the outlet sideThe minute flow rate
ShedBypass passage14EstablishedpressureProportionalcontrolSmell the valve
hand,the above Upstream valve body26 and, Upstream valve seat4On the inner surface of
Embedded guide30And swing freely, Above valve stem
35 is fixed to the guide 30 and the guide 3
0 is moved integrally with the valve stem 35,
The spring 11 of the upstream valve body 27 is connected to the valve body 27 and the guide 3.
Characterized by being interposed between 0Pressure proportional control valve. Wherein the valve rubber 44 provided in the valve body 27 of the downstream side, to seal the gap between the valve body 5 and the valve stem 35 of the downstream side in the inner peripheral portion of the valve rubber 44, the seal portion The thin film 39
The pressure proportional control valve according to claim 1, characterized in that easily transmitted to the downstream-side valve body 27 movement of the valve stem 35 directly in the.