JP2933887B2 - Flow control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow control device mainly used as a temperature control device in a gas combustion device.

[0002]

2. Description of the Related Art In order to keep a heating object in a certain temperature range,
Devices for controlling the supply amount of fuel such as city gas and LPG are known. As such a device, there is a flow control device that includes a main valve and a sub-valve, and combines a proportional control and an on-off control. A device that uses a proportional control valve as a main valve, uses a snap valve as a sub-valve, inputs pressure change information from a temperature sensor to a bellows or the like, and operates such a main valve and a sub-valve using expansion and contraction of the bellows. Is, for example,
It is also disclosed in JP-A-1-1270. The technology disclosed herein has a piston type in which a valve seat of a main valve moves in a cylinder, and includes a reversing plate of an elastic metal that instantaneously opens and closes a sub valve by displacement of the valve seat of the main valve. I have. To close the sub-valve, the main valve is pressed against the valve seat by the bellows and the main valve is closed. Opens and closes the valve instantly. A bypass path separate from the main valve is provided as a gas passage of the sub-valve, and the bypass path is provided with a device for adjusting the amount of gas passing through the sub-valve. In the device disclosed here, the valve seat of the main valve is a piston type. Therefore, in order to maintain good sealing performance of the piston, high precision is required for its processing, and care must be taken in maintenance.

On the other hand, Japanese Unexamined Utility Model Publication No. 53-151644 and Japanese Patent Publication No. 3-68296 disclose devices having different structures. This technology also includes a main valve and a sub-valve, and is a gas flow control device that combines a valve that performs proportional control and on / off control by operating a bellows, and is similar in principle to the above-described device. Structurally, these technologies provide a reversing plate inside the main valve, provide a sub-valve in part of the main valve, and have a common gas flow path for the main and sub-valves. The structure cannot adjust the gas flow rate. In addition, the operating force for opening and closing the main valve is transmitted via a reversing plate, and the main valve and its valve seat are in rigid contact, so that the valves need to be fitted together, etc. This is not always desirable. There is also a problem that it is difficult to adjust the timing of opening and closing the main valve and the opening and closing of the sub-valve.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has developed a flow control device in which these points are improved.
It is intended to provide this. That is, the objects of the present invention are as follows. (A) It operates smoothly and can be manufactured at a low cost, without using high-precision machining such that the valve seat of the main valve is a piston type. (B) The main valve and the valve seat are made of a combination of materials having a high sealing property that does not require rubbing or the like with soft touch. (C) Separate the main valve and the sub-valve, and abolish the mechanism by which the operating force of the main valve is transmitted via the reversing plate. (D) Depending on the type of burner and gas, performing flash ignition adjustment with the main valve open may cause flashback (flashback). (E) Adopt a structure that can optimize the operation timing of the main valve and the sub-valve.

[0005]

SUMMARY OF THE INVENTION The present invention relates to an improvement of a flow control device for controlling by combining a proportional control and an on / off control, and has been developed to solve the above problems.
A flow control device characterized by taking the following technical means. That is, the present invention provides a main valve provided with a valve body made of a flexible plate, a snap device opposed to the main valve via an operation gap and separate from the main valve, and a valve mounted on a reversing plate of the snap device. An auxiliary valve that is in contact with a rod and is independent of the main valve, and proportionally controls the opening of the main valve, and after closing the main valve, flexes the valve element of the main valve to contact the working gap and control the on / off of the sub valve And a control device for controlling the flow rate. In this device, the gas path of the sub-valve is provided separately from the gas path of the main valve, and a gas amount adjusting device is attached to the gas path of the sub-valve. Depending on the type of gas and the type of burner, it may be difficult to adjust the ignition, and there is a risk of flashback if the main valve is left open. As described above, the gas path of the main valve and the sub-valve are separated, and a gas amount adjusting device is provided in the gas path of the sub-valve to adjust the minimum gas flow rate (the on / off flow rate) according to the type of gas. As a result, the device is free from the possibility of flashback or the like under any use conditions, and is a general-purpose flow control device.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a flow control device for a gas combustion heating device according to an embodiment of the present invention. FIG. 2 shows FIG.
1 is a partially cutaway side view taken along arrow AA, FIG. 3 is a partially cutaway side view taken along arrow BB in FIG. 1, and FIG. 4 is a cross-sectional view taken along arrow CC in FIG.

The flow control device 1 of the present invention comprises a casing 2
The gas 100 is received from one inlet and the gas 101 is discharged from the other outlet. In addition, a port for discharging the ignition gas 102 is provided, and a push ignition device is provided. Further, a pressure control device for keeping the gas pressure constant is provided on the inlet side. The main valve 10 includes a flexible disk-shaped valve element. This valve element softly touches the valve seat 17 to always maintain good valve sealing properties, and further flexes after the valve is closed, as described later, to contribute to a mechanism for operating the opening and closing of the sub-valve. As a material of the flexible disk-shaped main valve, a natural rubber, a synthetic rubber, an elastomer, or the like, which is a gas-stable material, has elasticity and flexibility, and does not cause sag is used. It may be one containing a reinforced synthetic fiber or the like.

The amount of gas passing through the main valve 10 is adjusted by adjusting the lift of the main valve 10, and the main valve 10 comes into contact with the valve seat 17 to close and shut off the gas passage. The opening and closing of the main valve 10 and the adjustment of the lift are performed via the lever 39 by the expansion and contraction of the bellows 32. The bellows 32 has a temperature sensor, not shown,
For example, a fluid pressure 31 or the like from a thermostat is supplied. The bellows 32 expands and contracts according to the supply pressure, operates the lever 39, and swings the lever 39 so that a gas flow rate proportional to the difference between the set target temperature of the heating target and the actual measured temperature passes through the main valve. Move. The lever 39 cooperates with the spring 12 that biases the main valve 10 in the opening direction to open and close the main valve and adjust the lift to control the gas flow rate. Lever 3
9 operates only the main valve 10 in cooperation with the spring 12,
The lift of the main valve 10 can be precisely operated with an appropriate small force, and the flow rate control becomes precise and accurate.

The flexible main valve 10 is fixed to a rigid support portion 11, which is supported by the lever 39. This rigid support portion 11 is
4 is opposed to the operating rod 13 with a play interval. When the main valve 10 comes into contact with the valve seat 17 to close the main valve and is further pushed by the lever 39, the flexible disc-shaped valve element bends, and the play interval comes into contact. The movement of the rigid support 11 of the main valve activates the snap device. By appropriately selecting the material and dimensions of the flexible main valve and adjusting the dimensions of the play interval appropriately, the operation timing of the main valve and the operation timing of the snap device can be freely adjusted.

The snap device 14 includes a reversing plate 15 for performing a momentary reversing operation and a reversing mechanism 16 for performing a reversing operation, and is conventionally known. The end of the rod 22 of the auxiliary valve 20 is in contact with the reversing plate 15 of the snap device. The sub-valve 20 is urged by a spring 21 in a direction to close to the valve seat 23, and is pushed open by the rod 22 by the reversing plate 15. To control the gas flow on and off.

In the device of the present invention, as shown in FIG. 3 showing a partially cutaway cross section and FIG.
The gas 64 passing through zero flows through the bypass paths 61 and 62 different from the gas 63 passing through the main valve 10, and has a different route from the gas passing through the main valve 10. The sub-valve 20 itself is not attached to the main valve 10 and is provided at a position independent from the main valve 10. Therefore, when opening and closing the sub-valve 20, the main valve 10
Is in a completely closed state, and there is no gas leak from the main valve 10, so there is no fear of flashback or the like. Also,
An adjusting device 60 for adjusting the amount of flowing gas is attached to the gas bypass path 61 passing through the sub-valve 20. The adjusting device 60 adjusts the cross-sectional area of the gas passage by twisting the screw 65. With this adjusting device, a safe minimum flow rate can be set according to the type of burner, the type of gas, and the like.

The set target temperature of the object to be heated is set by adjusting the height of the intermediate fulcrum of the lever 39 with the knob 34. The set temperature is, for example, 50 for hot water heating.
-100 ° C, 150-210 ° C for a fryer, and 140-340 ° C for an oven. When the knob 34 is twisted in accordance with the setting scale (not shown), the rod 3
The screw bar 37 is rotated via 5 and 36, and the adjusting piece 38 screwed to the screw bar 37 is moved up and down to adjust the height position of the lever 39. The bellows 32 has a screw rod 3 at one end.
7, and the other end is housed in a stopper. This stopper is biased and fixed by a spring 33, and constitutes a safety device when an excessive pressure is applied to the bellows. When internal pressure is applied to the bellows, the screw rod 37 is pushed up, and the lever 39 is operated via the adjustment piece 38.
Therefore, the lever 39 controls the main valve 10 and performs opening and closing of the sub-valve 20 in accordance with the set temperature of the knob 34.

The apparatus of the present invention is provided with a piezo-electric device for igniting ignition, an ignition gas valve 42 for holding the valve open against a spring 41 by a magnet device 40, and a plane cock 44. These are operated via the shaft 46 and the rod 43 by operating the push knob 45 by compressing the spring 47. The apparatus of the present invention includes an inlet gas pressure adjusting device 50 as shown in FIG. The pressure regulator 50 receives the upstream gas from the gas inlet 55, detects this gas pressure by the displacement of the diaphragm 56, and controls the gas pressure supplied to the main valve by operating the gas flow path regulator 54 so as to keep the gas pressure constant. I do. The diaphragm 56 is the seat 51,
It is backed up by a spring 52 inserted between 53 and keeps balance. The pressure regulator allows the main valve to precisely control the relationship between lift and flow under constant pressure.

FIG. 5 shows an example of a characteristic curve of the flow control device of the present invention. The horizontal axis indicates the temperature of the object to be heated, and the vertical axis indicates the gas flow rate. When the heating target starts heating from a low temperature T _1,
Gas flow rate maximum flow rate Q ₂ is the flow of the main valve, the flow rate proportional to the difference between the target temperature Ts and the actual temperature of the heating target flow with increasing temperature, as the temperature of the heat target rises, the curve 7
As shown in FIG. 1, the gas flow rate decreases. Upon reaching the temperature T _2, the main valve is closed, the flow rate to Q ₁ auxiliary valve only.
Next, when the temperature further rises and reaches the set temperature Ts, the sub-valve is also closed, and the gas flow rate becomes zero. If the temperature is not gas flow is lowered to T _3, the auxiliary valve is opened instantaneously by a snap device, the gas flows flow Q _1. Further temperature is lowered and reaches the T _4, as shown in curve 72, the main valve opens. In a situation where the temperature further decreases, the lift of the main valve increases and a gas flow rate proportional to the difference from the target temperature flows. As shown in FIG. 5, the flow control valve of the present invention has almost no difference in characteristics between when the temperature rises and when the temperature falls, and has excellent flow controllability. In the example of a flow control valve for 13A for general city gas and a gas flow rate of 3 m ³ / H (ΔP = 10 mmAq) when fully opened,
The operating temperature difference (Ts−T ₃ ) of the snap device is about 4 ° C.

[0015]

Since the flow control device of the present invention is configured as described above, it operates smoothly without relying on high-precision machining, and a mechanism for transmitting the operating force of the main valve via the reversing plate. The operation of the main valve was smooth because it was abolished, and the gas path for the main valve and the sub-valve was separated, and a gas flow rate adjustment device was installed in the gas path for the sub-valve to determine the minimum gas flow rate according to the type of gas. This has an excellent effect of having a structure that can easily optimize the operation timing of the main valve and the sub-valve.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a side view, partially cut away, taken along the line AA of FIG. 1;

FIG. 3 is a partially cutaway cross-sectional side view taken along the line BB of FIG. 1;

FIG. 4 is a sectional view taken along the line CC of FIG. 1;

FIG. 5 is a graph showing flow rate characteristics of the example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flow control device 2 Casing 10 Main valve 11 Rigid support part 12 Spring 13 Operating rod 14 Snap device 15 Reversing plate 16 Reversing mechanism 17 Valve seat 20 Secondary valve 21 Spring 22 Rod 31 Fluid pressure 32 Bellows 33 Spring 34 Knob 35, 36 Rod 37 Screw rod 38 Adjusting piece 39 Lever 40 Magnet device 41 Spring 42 Valve 43 Rod 44 Plane cock 45 Knob 46 Shaft 47 Spring 50 Pressure adjusting device 51 Seat 52 Spring 53 Seat 54 Flow path adjusting unit 55 Gas inlet 56 Diaphragm 60 Adjusting device 61 , 62 bypass path 63, 64 gas 65 screw 71, 72 curve 100, 101 gas 102 ignition gas

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F23N 5/06 F16K 31/68 F23N 1/00 102

Claims (2)

(57) [Claims] 1. A main valve having a valve body made of a flexible plate, a snap device opposed to the main valve via an operating gap and separate from the main valve, and a reversing plate of the snap device. An auxiliary valve that is in contact with the valve stem and is independent of the main valve, and proportionally controls the opening of the main valve, and after closing the main valve, flexes the valve element of the main valve to contact the working gap to turn the sub valve on and off A flow control device, comprising: a control device for controlling the flow rate. 2. The flow control device according to claim 1, wherein the gas path of the sub-valve is provided separately from the gas path of the main valve, and the gas path of the sub-valve is provided with a gas amount adjusting device.