JPH0336418A - Gas flow rate control device - Google Patents

Abstract

PURPOSE:To prevent a flame failure due to excessive primary air by providing a gas expansion room connected with a gas passage on the side of downstream of a gas flow rate controller to make up for shortage of gas flow when the gas flow is abruptly throttled. CONSTITUTION:A gas expansion room 9 comprises a diaphragm 91 whose central section is reinforced by reinforcement plates 92, 93, a cover 94, a spring 95 etc., wherein the diaphragm 91 is fixed to a recess 96 formed on a device body 1 together with a cover 94. The figure shows the diaphragm 91 when the gas pressure is lower than a set value of the spring 95 and when the gas pressure rises, the diaphragm 91 is pushed to the right as shown by a chain line and at a maximum thermal power the spring takes a most contracted shape. When the gas rate is abruptly throttled and the gas pressure in the passage 13 becomes lower than the recoiling force of the spring 95, the diaphragm 91 is pushed to the left by the action of the spring. Forcing thereby the gas to the passage 13 through a branch 97, thereby shortage of gas rate due to abrupt throttling can be compensated.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an improvement in a control device for regulating the flow rate of gas supplied to a burner of a gas appliance.

<Prior Art> A burner in a gas stove or the like ejects gas from a nozzle, the flow rate of which is adjusted by a gas flow rate regulator.

The structure is such that the primary air necessary for combustion is sucked into the mixing tube and sent to the burner body. For this reason, even if the gas flow rate is rapidly reduced, the primary air will not decrease immediately due to inertia, and if there is an excess of air at times and the throttle width is large, there is a possibility of a misfire. be.

Furthermore, in order to make ignition easier, with so-called purge ignition appliances, the amount of gas is increased at the time of ignition operation even when igniting at a small flame position, the amount of gas is throttled as soon as the ignition operation is completed, so this is not the case. Similarly, there is a possibility of misfire due to excess primary air.

Conventionally, the maximum-minimum ratio was set within a range that would not cause a misfire even if the ratio was suddenly reduced from "maximum" to "minimum".
It is common practice to prevent the above problems. For example, the maximum input is 4.100.
For a kcal/h burner, the minimum input is 750
It is set at about kcal/h, 400-450kc
The heat is too strong for stewed dishes where al/h is optimal, making it difficult to use.

For this reason, two types of burners are required to cover the required range of heat power adjustment, one for large heat power and one for small heat power.In a 20-type table stove, one burner is usually used for high heat power and the other for low heat power. By doing so, the range of adjustment of firepower is expanded,
Type 10 is equipped with a double parent-child hole burner. Also, at the same time as reducing the gas amount, the damper is also reduced.
Stoves designed to reduce the amount of air are also known.

<Problem to be solved by the invention> It is inconvenient that a wide range of firepower adjustment cannot be covered without two burners, and it is not rational to set the minimum input high at the expense of burner performance. Also,
An arrangement in which the dampers are tightened at the same time requires a mechanical interlocking mechanism, resulting in a complicated structure.

The present invention has focused on this point and has been made for the purpose of preventing the burner from misfiring even if the input maximum/minimum ratio is made larger than before.

<Means for Solving the Problem> In order to achieve the above object, the present invention provides a gas expansion chamber that expands at high gas pressure and contracts at low gas pressure, and adjusts the gas flow rate of this gas expansion chamber. Connected to the gas passage downstream from the unit.

<Function> When the firepower is high, the gas pressure is high and the gas expansion chamber expands; when the firepower is reduced, the gas pressure decreases and the gas expansion chamber contracts. This compensates for the lack of gas flow rate caused by the internal gas being released into the gas passage and being rapidly throttled, and the amount of gas ejected from the nozzle changes gradually, preventing an excess air condition that would cause a misfire. It is prevented.

<Example> Next, an example shown in the drawings will be described. The embodiment is an example in which the present invention is implemented in a gas appliance tap that integrates a fire/extinguishing mechanism, a safety mechanism, and a gas flow rate adjustment mechanism. Fig. 1 is a sectional view of the main part, and Fig. 2 is an explanatory diagram of the operation. , FIG. 3 is a side view of the whole, and FIG. 4 is a front view thereof.

In the figure, 1 is the main body of the appliance tap made of die-cast aluminum, 2 is the mounting board, and 3 is the operating knob. Point/extinguishing section 6, gas flow rate adjustment section 7, gas outlet 8
etc. are integrally formed.

Or it's built in.

The safety mechanism section 5 is an electromagnetic valve that automatically closes the gas passage when the flame goes out to prevent the release of raw gas, and is activated by detecting combustion in the burner using the thermoelectromotive force of the thermocouple. 1 point/The extinguishing unit 6 is equipped with a main valve and an ignition mechanism, and the main valve is opened and closed in response to the push operation of the operating knob 3, and the ignition mechanism generates high voltage to ignite the burner. It has become.

Further, the gas flow rate adjustment section 7 includes a small gear 72 that meshes with a large gear 71 provided on the operation knob 3. This small gear 72 is provided with a double thread screw, and the rotation of the small gear 72 causes the small gear 72 to rotate. The internal needle 73 is moved in the axial direction as partially shown in FIG. The tip end portion 75 of the needle 73 and the orifice 74 provided therein connect the gas passages 11 and 12 on the upstream side and the gas passage 1 on the downstream side.
The gas flow rate is adjusted by changing the opening degree between the needles 73 and 3 according to the position of the needle 73.

The mechanisms of these parts themselves are not directly related to the gist of the present invention, and can be constructed by appropriately employing conventionally known structures.

Further explanation will be omitted. For example, JP-A-63-
Although the same type of gas appliance plug is disclosed in Japanese Patent No. 251,718, the present invention is not limited to such a gas appliance valve, but can of course be applied to various other types of gas flow rate control devices.

Reference numeral 9 denotes a gas expansion chamber provided in a portion of the device stopper main body 1 near the gas outlet 8 according to the present invention. This gas expansion chamber 9
consists of a diaphragm 91 whose central portion is reinforced with two reinforcing plates 92 and 93, a cover 94 and a spring 95, etc. The diaphragm 91 is attached together with a cover 94 to a recess 96 formed in the appliance plug body 1. The recess 96 is connected to the gas passage 13 through a branch passage 97. The cover 94 is provided with ventilation holes 98.

Further, when incorporated into a gas appliance, a nozzle 14 is attached to the gas outlet 8, and a mixing pipe 15, a damper 16, etc. are combined.

Note that the hole diameter of the nozzle 14 is set to provide the maximum input when the gas flow rate adjustment section 7 is fully open, and the hole diameter of the orifice 74 of the needle 73 is set to provide the minimum input when the gas flow rate adjustment section 7 is fully closed. It is.

This embodiment has the configuration described above, and the gas expansion chamber 9 operates as follows.

FIG. 1 shows a case where the gas pressure in the gas passage 13 is lower than the set value of the spring 95. When the gas pressure increases, the diaphragm 91 is pushed to the right in the figure as shown by the chain line, and at the maximum firepower, the spring 95 is It is in the most compressed state. Here, when the gas flow rate suddenly increases and the gas pressure in the gas passage 13 becomes smaller than the repulsive force of the spring 95, the diaphragm 91
It moves to the left in the figure and directs the internal gas to branch path 97.
The gas is forced out through the gas passageway 13, thereby compensating for the lack of gas flow rate caused by the sudden restriction.

The setting value of the spring 95 is selected to be greater than the pressure in front of the nozzle 14 at the minimum input, and usually
It is appropriately selected so as to obtain a replenishment pressure that is about 2 to 6 times the nozzle front pressure at the minimum input.

FIG. 2 is an explanatory diagram of the above operation. Solid line A shows the case where the maximum input is suddenly reduced from 4.100 kcal/h to the minimum input of 750 kcal/h.With conventional burners, if the input is reduced to a value smaller than this, there is a high possibility of misfire, so this is the limit. Met. In contrast to this, dashed line B indicates a minimum input of 400 kcal/h.
The case of the example is shown. The 0 point is the point at which the replenishment action by the spring 95 begins, and the gas flow rate decreases gradually due to the gas pushed out from the gas expansion chamber 9. Therefore, even if the aperture width is large, an excessive amount of primary air that would cause a misfire will not occur, and a stable combustion state can be maintained even if the flow rate is reduced to a smaller input than before. In addition, even in the embodiment, when the gas supplied from the gas expansion chamber 9 runs out, the pressure suddenly decreases, but this does not cause any problem because the amount of decrease is small.

It should be noted that the gas expansion chamber is not limited to the diaphragm type as in the embodiment, but may have any other suitable structure.

<Effects of the Invention> As is clear from the above-mentioned embodiments, the present invention provides a gas expansion chamber connected to the gas passage downstream of the gas flow rate @ regulator, and improves the gas flow rate when the gas flow rate is suddenly reduced. This temporarily compensates for the lack of flow rate and prevents misfires from occurring due to excess primary air.

Therefore, even if the input maximum/minimum ratio is larger than before, misfires will not occur if the flow rate is suddenly reduced or if a purge ignition device is ignited with a small flame, and it is independent of the damper. This eliminates the need for a complicated interlocking mechanism, and it becomes possible to easily obtain an easy-to-use gas appliance that can cover a wide range of firepower adjustment with a single burner.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a main part of an embodiment of the present invention, FIG. 2 is an explanatory view of the operation, FIG. 3 is a side view of the whole, and FIG. 4 is a front view of the same. DESCRIPTION OF SYMBOLS 1... Appliance plug main body, 7... Gas flow rate adjustment part, 13... Gas passage on the downstream side, 9... Gas expansion chamber, 91... Diaphragm, 95... Spring.

Claims (1)

[Claims] (1) A gas flow rate control device comprising a gas expansion chamber that expands at high gas pressure and contracts at low gas pressure, and connects this gas expansion chamber to a gas passage downstream of a gas flow rate regulator.