JPH0120523Y2 - - Google Patents

Description

[Detailed description of the invention] This invention uses a governor mechanism and a solenoid valve to control the combustion output of a gas burner continuously over a wide range from the minimum to the maximum, safely and accurately. Regarding equipment.

Many devices have already been devised that continuously control the gas flow rate by adjusting the back pressure of the governor mechanism. Since the back pressure must be continuously changed, many devices are equipped with a continuously changing flow rate regulating valve in the flow path leading to the back pressure chamber.

However, continuous flow rate regulating valves have the disadvantage that when electromagnetic devices are used, they are easily affected by power fluctuations, temperature changes, atmospheric pressure changes, and the like.

Therefore, the inventor developed a device that proportionally controls the gas combustion output by turning on and off a solenoid valve installed in the flow path leading to the back pressure chamber and changing the ratio of on time and off time within one cycle. It was devised in This has a bypass flow path connecting the front and back of the governor mechanism, a solenoid valve that operates on and off in this flow path, and a back pressure chamber in the downstream stage to continuously control the valve opening of the governor mechanism. .

If the outlet of the bypass passage is provided immediately after the governor mechanism, there will be a fairly long passage from the gas outlet of the control valve to the gas burner, resulting in pressure loss due to the size of the passage and pressure fluctuations due to combustion in the burner chamber. The disadvantage is that even if there is an output fluctuation, the amount of fluctuation is not immediately fed back. In particular, various gas appliances such as gas baths and gas stoves always require a gas control valve to adjust and control the gas pressure, but gas appliances and gas appliances are often manufactured by different manufacturers, so gas appliances and gas stoves are often manufactured by different manufacturers. Generally, the gas tank is manufactured separately and assembled by the equipment manufacturer. Therefore, the gas stove manufacturer needs to manufacture and deliver gas stoves that are compatible with the products of multiple gas appliance manufacturers. However, gas control valves are compatible with a wide variety of gas appliances even in a single gas tank, and in addition to differences depending on the model, even within the same model there are differences in installation location, usage conditions, etc., as well as pressure loss in piping and variations in piping. It is necessary to take into consideration the back pressure of the combustion chamber, the variation in the burner nozzle diameter, etc., and to accommodate all of these conditions.

Further, Japanese Patent Publication No. 35719/1984 is known as a control valve constituting a feedback loop. However, with this control valve, the gas flow rate is reduced when the burner is ignited, and after the burner is ignited, the gas flow rate is automatically increased gradually to a specified value.
It has no corrective effect on the feedback loop.
Therefore, this control valve is not a feedback loop in the sense of controlling the rise and fall of the outlet pressure due to some factors.

Therefore, in the present invention, the outlet of the bypass path that is continuous with the back pressure chamber is located in the gas flow path that runs from immediately after the governor mechanism to the combustion chamber that includes the gas burner, preferably at least at the rear end of the point where the pressure loss is greatest. The technical problem is to provide a gas combustion output proportional control device that expands the feedback loop by connecting at one point. This makes it possible to control pipe pressure loss, pipe variations, combustion chamber back pressure, burner nozzle diameter variations, etc.

In order to solve the above technical problems, the present invention includes a diaphragm 1 that is displaced depending on the force relationship between gas pressure and back pressure, and a diaphragm 1 that is connected to the diaphragm 1 to control the opening and closing of a valve 4 to a gas outlet 3. In a valve device equipped with a main valve element 5, a solenoid valve 9 for externally controlling back pressure is provided in a passage 14 that branches off from a gas inlet 7 and communicates with a back pressure chamber 13 of the diaphragm 1. The gas output is controlled by changes in the back pressure of the diaphragm due to changes in the on/off time or period or both, and the other end of the bypass pipe 18 extending from the back pressure chamber 13 is connected from the gas outlet 3 to the gas burner A. It is connected to at least one part of the gas flow path leading to.

Embodiments will be described in detail below with reference to drawings showing examples. The diaphragm 1 is made of an elastic material so as to respond flexibly to gas pressure or the like. A rubber membrane may also be used. At the center of the pressure-receiving surface 2 of the diaphragm 1, the upper end of a main valve element 5 for controlling the opening and closing of a valve port 4 communicating with a gas outlet 3 is fixed. The spring 6 presses the main valve body 5 toward the valve port 4, but this spring can be omitted.

Gas is pressurized into the pressure receiving chamber 8 from the gas inlet 7 . Further, the gas passes between the valve port 4 and the main valve body 5, escapes to the gas outlet 3, and is supplied to combustion equipment A such as a gas burner.

Next, a mechanism for controlling the back pressure of the diaphragm 1 will be explained.

The solenoid valve 9 is a valve plate 1 fixed to the tip of the plunger.
Raise and lower 0. When the electromagnetic valve is energized, the valve plate 10 opens the valve hole 11. When the power is turned off, the valve spring 12
The valve plate 10 closes the valve hole 11 with the elastic force. Solenoid valve 9
has only two states: energized and non-energized, that is, on and off. However, the back pressure in the back pressure chamber 13 can be controlled by changing the time or period of the on/off operation.

Fluid passing through the valve hole 11 enters the side passage hole 14 and exits through the narrow orifice hole 15 into the passageway 16. A throttle valve 17 is provided between the passage 16 and the back pressure chamber 13.

A bypass pipe 18 is provided extending from the passage 16. The other side of the bypass pipe 18 must be connected to at least one point in the main gas passage.

The other end of the bypass pipe 18 may be opened into the gas burner A in the combustion chamber B (point x). It is also possible to open the base of the gas burner A (point y). Furthermore, it may be connected at an intermediate point between the governor mechanism and the burner (point Z), or immediately after the governor mechanism (point W). Bypass piping 1
A throttle valve 22 may be added to the inlet of 8. This is effective when the flow path loss of the bypass piping 18 is small.

Furthermore, an orifice hole 19 is provided in parallel with the valve hole 11. This is to ensure that a minimum gas pressure is applied to the back pressure chamber 13 even when the valve hole 11 is closed. The governor 20 is installed in the flow path leading to the back pressure chamber 13, and is configured to control the back pressure chamber 1 due to pressure fluctuations in the supplied gas.
3 pressure is not affected. When the solenoid valve 9 is always open, the orifice hole 15 is
Set the gas flow to the desired maximum flow rate. Furthermore, if the orifice shaft 21 is provided parallel to the surface of the diaphragm 1 with a screw or the like so that it can be easily attached and detached, only the orifice shaft 21 can be replaced. Depending on the type of gas, flow rate, and type of burner, the maximum
a bypass orifice hole 19 that defines a minimum flow rate;
The dimensions of the orifice hole 15 must be changed. In this example, since only the orifice shaft 21 can be easily replaced, it is possible to respond to the user's wishes and change the gas type without impairing the basic operation of the device.

The operation of the above configuration will be explained. Gas flows from the gas inlet 7 to the gas outlet 3 via the pressure receiving chamber 8 and the valve hole 4.

When the amount of gas inflow increases, the pressure in the pressure receiving chamber 8 provided on the inlet side increases, pushing up the diaphragm 1. Then, the main valve body 5 rises and moves in a direction to close the valve hole 4. Since the gas is restricted here, the downstream pressure decreases. Therefore, the main valve body 5 descends and the valve hole 4
opens wider. By repeating this process, the amount of gas is limited to a certain range. However, even if this alone makes it possible to keep the gas amount constant, it is not possible to obtain an arbitrary gas amount necessary for proportional combustion. It is necessary to move the equilibrium point of the diaphragm 1. Therefore, the back pressure is changed.

When back pressure is applied to the back pressure chamber 13 from the passage 16, the back pressure increases and the diaphragm 1 is pushed downward. The main valve body 5 descends and the valve port 4 opens more widely. This increases the gas flow rate. In other words, the gas flow rate can be controlled by the magnitude of the back pressure.

In order to change the back pressure, the time or cycle of the on/off operation of the solenoid valve 9 may be changed. The flow is divided from the gas inlet 7 and passes through the governor 20 to the valve hole 1 of the solenoid valve 9.
The diverted gas that has passed through 1 enters the back pressure chamber 13 through a passage 14, an orifice hole 15, and a throttle valve 17. A portion flows away from the bypass pipe 18 to the outlet 3.

The cycle of on/off operation is constant and the on time is Ton
(valve hole 11 is open) and off time Toff
(The valve hole 11 is closed) may be changed. In other words, in the formula Ton + Toff = T (period), if Ton is increased, the time the solenoid valve is open becomes relatively longer, so the pressure in the back pressure chamber Pr
becomes higher.

Alternatively, if the on-time Ton is kept constant and the period T is shortened, the back pressure Pr will similarly increase.

In this way, by changing the cycle or time of the on/off operation of the solenoid valve 9, the back pressure Pr can be changed,
The gas flow rate passing through the valve port 4 can be controlled proportionally by the governor mechanism.

The important thing is that the back pressure chamber 1 is connected to the valve hole 11 of the solenoid valve 9.
A narrow orifice hole 15 and a throttle valve 17 are provided in the path leading to No. 3 to remove the influence of pulsation of the flow rate and provide a time delay.

When the flow rate is high, the inlet pressure P ₁ and the outlet pressure
Since it is close to P ₂ and the back pressure Pr is also close to both, there will be no pulsation in the back pressure Pr even if the solenoid valve is opened and closed on and off.

Generally, P ₁ > Pr > P ₂ , but when the closing time Toff of the solenoid valve becomes relatively long and the outlet pressure P ₂ becomes significantly smaller than the inlet pressure P ₁ , pulsation of the back pressure Pr becomes a problem. Back pressure chamber 13
If the volume is large, pulsation can be suppressed to some extent. However, this is a defective part, and the orifice hole 1
5. The cross-sectional area of the flow path is narrowed twice by the throttle valve 17.
Since the loss coefficient of the flow path can be increased in this way, the influence of the on/off operation of the solenoid valve can be eliminated. The flow rate, ie the amount of gas entering the back pressure chamber, is smoothed. Moreover, the opening/closing ratio of the solenoid valve 9 Ton/
Even if Toff is changed, it is not immediately transmitted to the back pressure chamber 13, and the back pressure Pr fluctuates with a certain time delay.

Therefore, the opening and closing operations of the main valve body 5 are performed slowly. It is possible to prevent backfire and misfires when the flow rate is suddenly reduced from maximum combustion or when transitioning to the minimum flow rate. Even when igniting, there is no chance of gas suddenly leaking out and causing an explosive ignition. Gentle and safe ignition can be guaranteed.

In this invention, when the bypass piping 18 that constitutes the feedback loop is connected to point X.

When the pressure in the combustion chamber B increases due to combustion heat, exhaust gas, etc., the pressure in the X section also increases.
The amount of gas flowing out is determined by the difference between the pressure at the throttle valve 17 and the pressure in the combustion chamber B, so the amount of gas flowing out is reduced. As a result, the gas pressure in the passage 16 and the back pressure chamber 1
3 increases, the main valve body 5 is pushed down by the diaphragm 1 to increase the pressure at the outlet 3, and the pressure difference between the throttle valve 17 and the combustion chamber B is automatically corrected and maintained at a constant level. do.

Conversely, when the pressure decreases, the opposite operation occurs.
In particular, during minimum combustion, if the pressure in the combustion chamber increases, the flame will go out, so the correction effect by this feedback loop is an effective means for safety measures.

When connected to something at Y, Z, and W points.

The gas flowing out from the gas outlet 3 is connected to the connecting pipe,
Pressure loss occurs due to nozzles, etc., and varies depending on the manufacturing error, but that pressure loss is transmitted to the gas outlet 3 by the feedback loop, and the pressure increases to compensate for the manufacturing error. can do.

As described above, the present invention provides a bypass pipe 18 extending to the outside in the passage 16 leading from the solenoid valve 9 through the orifice hole 15 to the back pressure chamber 13, and
The other end of this bypass pipe 18 is connected to one arbitrary position such as the middle Z of the gas flow path from the gas outlet 3 to the gas burner A, the inside X of the gas burner, or the part Y just before the gas burner. Since the gas combustion output proportional control device has an enlarged feedback loop, it can be used with various gas appliances, and it also eliminates manufacturing errors, piping pressure loss, piping variations, and combustion. This makes it possible to control the back pressure in the chamber, variations in burner nozzle diameter, etc., and standardize gas control valve specifications. In addition, it is possible to prevent backfire and misfires when the flow rate is suddenly reduced from maximum combustion or when switching to the minimum flow rate.
It is extremely effective in terms of safety measures as it eliminates the situation where gas suddenly flows out during ignition and causes explosive ignition, and ensures gradual and safe ignition.Moreover, it has a simple structure and can be implemented at low cost. It is something.

[Brief explanation of the drawing]

The drawing is a sectional view of a gas combustion output proportional control device according to an embodiment of the present invention. 1... Diaphragm, 3... Outlet, 4... Valve port, 5... Main valve body, 7... Gas inlet, 8... Pressure receiving chamber, 9... Solenoid valve, 10... Valve plate, 11 ... Valve hole, 12 ... Valve spring, 13 ... Back pressure chamber, 14,1
6... Passage, 15... Orifice hole, 17... Throttle valve, 18... Bypass piping, 19... Bypass orifice hole, 20... Governor, A... Gas burner, B... Combustion chamber, x, y , z, w...Opening point of bypass piping.

Claims (1)

[Claims for Utility Model Registration] (1) A diaphragm 1 that is displaced due to the force relationship between gas pressure and back pressure, and a main body that is connected to the diaphragm 1 and controls the opening and closing of the valve 4 to the gas outlet 3. In the valve device equipped with the valve body 5, a solenoid valve 9 for externally controlling the back pressure is provided in a passage 14 that branches off from the gas inlet 7 and leads to the back pressure chamber 13 of the diaphragm 1, and the solenoid valve 9 is turned on. ．． The gas output is controlled by changing the diaphragm back pressure due to changes in the off time or period or both, and the gas output is controlled from the solenoid valve 9 through the orifice hole 15 to the back pressure chamber 13.
A bypass pipe 18 extending to the outside is provided in the passage 16 leading to the
The other end is connected to one arbitrary position such as the middle Z of the gas flow path from the gas outlet 3 to the gas burner A, the inside X of the gas burner, or the front part Y of the gas burner. A gas combustion output proportional control device characterized by: (2) A throttle valve 17 is provided between the passage 16 and the back pressure chamber 13.
Claim 1 of said utility model registration comprising:
Gas combustion output control device as described in .