JPH0136046Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an ignition safety device for gas water heaters, which consists of a thermocouple that is heated by a pilot burner flame and generates a thermoelectromotive force, and an electromagnetic coil of a safety valve that opens and closes the gas passage. thermocouple safety circuit,
Before the ignition operation, the capacitor is connected to a DC power supply to keep it in a charged state. During the ignition operation, the charged capacitor is connected to the thermocouple safety circuit so that it is discharged, and the charge stored in the capacitor is discharged to the electromagnetic coil of the safety valve. This is a gas water heater equipped with a so-called quick-start ignition safety device that holds the safety valve open from the time of ignition operation and shortens the time it takes to press the ignition knob. In gas water heaters that allow one-touch ignition and extinguishing operations by pressing the ignition button (restoring the ignition button), if the ignition fails when the ignition operation is performed while water is flowing, the water pressure response device, etc. The gas valve is opened by the action of the gas valve, and the electromagnetic coil of the safety valve is energized and the safety valve is held open by attraction until the discharge current of the capacitor decreases to a value below the release level of the safety valve. As a result, a large amount of raw gas is blown out from the pilot burner and main burner, which is extremely dangerous. Further, even if the ignition operation is performed when the water is stopped, if the hot water tap is opened to start hot water supply immediately after the pilot burner is ignited, the safety valve closes, closing the gas passage and stopping combustion.

This invention was made with the aim of eliminating the above-mentioned drawbacks, and its gist is that in a quick-start ignition safety device, the charged capacitor is turned on when water is stopped, and turned off when water is flowing. The thermocouple safety circuit is connected to the thermocouple safety circuit through a parallel circuit between the switch that activates and the switch that turns OFF only when the ignition button is pressed, and when the ignition operation is performed while water is flowing, the capacitor discharge circuit is opened and the electromagnetic coil is Prevent discharge current from flowing to
The safety valve is returned to its original position and closed at the same time as the ignition button is released, and the capacitor discharge circuit is not opened when the hot water tap is opened immediately after the ignition operation.

Examples of this invention will be described below based on the drawings.

Figures 1 and 2 show an example in which this invention is applied to a gas water heater that can be turned on and off with a single touch using an ignition button and an extinguishing button. In Figure 1, A is heated by a pilot burner flame. A thermocouple safety circuit consists of a thermocouple 1 that generates a thermoelectromotive force, and an electromagnetic coil 2 of a safety valve that opens and closes the gas passage. A parallel circuit with switch 4 that operates and turns OFF only when the button (not shown) is pressed; 8 is an igniter switch that operates in conjunction with switch 4 and switches and connects the DC power source 6 to the igniter 9 only when the ignition button is pressed; Reference numeral 7 denotes a changeover switch, which is activated when the ignition button is pressed, and grounds one end of the capacitor 5, and presses the extinguishing button (not shown) (returns the ignition button to its original position).
Accordingly, one end of the capacitor 5 is connected to the DC power source 6 via the igniter switch 8. The other end of the capacitor 5 is connected to the thermocouple safety circuit A via the parallel circuit B described above. Reference numeral 10 denotes a spark plug that continuously emits sparks and ignites the pilot burner when the igniter 9 is connected to the DC power supply 6 via the igniter switch 8.

With the above configuration, when the water is stopped before the ignition operation, the water pressure switch 3 is ON and the switch 4 is ON, so the capacitor 5, water pressure switch 3, switch 4, changeover switch 7, igniter switch 8, DC power supply 6 A charging circuit is formed by the electromagnetic coil 2 and the electromagnetic coil 2, and the capacitor 5 is kept in a charged state. When ignition is performed in a water-stop state (normal operation), the safety valve that presses the ignition button is pushed open, and the gas passage to the main burner is opened by an on-off valve (not shown) that operates in conjunction with the ignition button. Switch 4 that works with the ignition button
OFF, the changeover switch 7 switches from the igniter switch 8 side to the ground side, and the capacitor 5
→Hydraulic pressure switch 3 →A discharge circuit is constructed from electromagnetic coil 2.The electric charge stored in capacitor 5 flows to electromagnetic coil 2, energizing it, and even after the pressure is released, the safety valve is held open by attraction, and the pilot Gas is supplied to the burner and also to the position of the gas valve provided in front of the main burner. In addition, when the ignition button is pressed, the igniter switch 8 is also switched from the switch 7 side to the igniter 9 side, and the DC power supply 6 is connected to the igniter 9, causing sparks to fly from the spark plug 10 and turning on the pilot burner as described above. As gas is supplied, the pilot burner is ignited,
The thermocouple 1 is heated by the pilot burner flame and generates a thermoelectromotive current. Therefore, a composite current of the thermoelectromotive current and the discharge current of the capacitor 5 flows through the electromagnetic coil 2, and the discharge current of the capacitor 5 eventually decreases, but the thermocouple 1 gradually heats up and the thermoelectromotive current generated decreases. The safety valve is held open as the When the hot water tap is opened as necessary, the gas valve is opened by the action of the hydraulic response device, gas hot water is supplied to the main burner, and is ignited by the pilot burner flame to begin hot water supply.

In addition, when the hot water tap is opened immediately after the ignition operation and hot water supply starts, the water pressure switch 3 turns off as water flows, but the switch 4 turns on at the same time as the ignition button is released, so the capacitor discharge circuit is opened. The discharge current continues to flow through the electromagnetic coil 2.
Therefore, even if the hot water tap is opened immediately after the pilot burner is ignited and before the thermoelectromotive force generated by the thermocouple 1 reaches a value sufficient to attract and hold the safety valve open, the safety valve will not close and combustion will occur. Continue.

Next, when the hot water tap is opened and water is flowing and the ignition operation is performed (misoperation), the water pressure switch 3 will be turned OFF as the water is flowing, and
When the ignition button is pressed, the switch 4 that is linked to it is turned OFF, so the parallel circuit B between the water pressure switch 3 and switch 4 is opened, and even if the ignition operation is performed while water is flowing, the capacitor discharge circuit is not configured. Since no discharge current flows through the electromagnetic coil 2 and it is not excited, when the ignition button is released, the safety valve is also closed, closing the gas passage and preventing a large amount of raw gas from being released.

To stop using the gas water heater, press the extinguish button and the switch 7 will switch from the ground side to the igniter switch 8 side, and the igniter switch 8 will switch to the switch side 7 when you release the ignition button. At the same time, when the ignition button is released, switch 4 turns on and returns to the state before the ignition operation, so capacitor 5
will start charging and prepare for the next ignition operation. In addition, the electromagnetic coil 2 is excited because a thermoelectromotive current flows for a while after the extinguishment due to the thermal penetration of the thermocouple 1, but the charging current of the capacitor 5 flows in the opposite direction to the thermoelectromotive current caused by the thermocouple 1, so the electromagnetic coil 2 The excitation is released at the same time as the extinguishing button is pressed, and the safety valve is immediately closed.

FIG. 2 shows an embodiment different from the above-mentioned embodiment, and the same parts as the above-mentioned embodiment will be described with the same reference numerals. A capacitor 5 is connected to a thermocouple safety circuit A consisting of a thermocouple 1 and an electromagnetic coil 2 via a switch 7, and a DC power supply 6 is connected in parallel to the capacitor 5 via a switch 7 and an igniter switch 8. In this configuration, a parallel circuit B of a water pressure switch 3 and a switch 4 is interposed and connected between a parallel circuit of a capacitor 5 and a DC power supply 6 and the ground. An igniter 9 emits a spark from a spark plug 10 when connected to the DC power source 6 by an igniter switch 8.

To explain the operation of the second embodiment mentioned above,
Before the ignition operation, switch 4 is ON, water pressure switch 3 is ON when water is stopped, changeover switch 7 is connected to igniter switch 8, and igniter switch 8 is connected to changeover switch 7.
A capacitor 5 connected to the side is kept in a charged state by a DC power supply 6. When operating the ignition in a water-stop state (normal operation), when the ignition button is pressed, the safety valve is pushed open, and the switch 4 turns OFF only when the ignition button is pressed, and the changeover switch 7 is placed on the thermocouple safety circuit A side. The capacitor 5 → changeover switch 7 → electromagnetic coil 2 →
The water pressure switch 3 constitutes a capacitor discharge circuit, and the electric charge stored in the capacitor 5 flows into the electromagnetic coil 2 to excite it, and even when the ignition button is released, the safety valve remains open and the pilot burner is activated. Gas is supplied to the gas valve located in front of the main burner. In addition, when the ignition button is pressed, the igniter switch 8 is also switched to the igniter 9 side, and since the water pressure switch 3 is ON, the DC power 6 is applied to the igniter 9, and the spark plug 1
The pilot burner is ignited by blowing a spark from zero, the thermocouple 1 is heated by the pilot burner flame, a thermoelectromotive current is generated, and even if the discharge current of the capacitor 5 eventually decreases, the safety valve is maintained in an open state. When the hot water tap is opened, the gas valve is opened by the action of the hydraulic response device, gas is supplied to the main burner, and the pilot burner flame ignites the hot water to start hot water supply. However, if you operate the ignition while the hot water tap is open and water is flowing (misoperation), the water pressure switch 3 will turn off.
Since the switch 4 is turned OFF when the ignition button is pressed, the discharge circuit of the capacitor 5 is not configured, and therefore no discharge current flows through the electromagnetic coil 2. The safety valve closes and the gas passage is closed, and since DC power supply voltage is not applied to the igniter 9 and no spark is emitted from the ignition plug 10, a large amount of raw gas will not be released even if the ignition operation is performed when water is flowing. It won't ignite either.

Next, when you want to stop using the gas water heater, press the extinguish button and the changeover switch 7 will switch.
The igniter switch 8 is switched to the changeover switch 7 side when the ignition button is released, and at the same time the switch 4 is turned on and returns to the state before the ignition operation, and the capacitor 5 starts charging and prepares for the next ignition operation. Become.

As mentioned above, according to this invention, even if the ignition operation is performed while water is flowing, the discharge circuit of the capacitor is opened and no discharge current flows through the electromagnetic coil, so it is difficult to press the ignition button. The safety valve closes at the same time as it is released, resulting in no energy loss and energy savings. Therefore, if the ignition operation is performed while water is flowing, the safety valve will not be energized, so a large amount of raw gas will not be released from the main burner and pilot burner. In addition, even if the ignition operation is normal and the hot water tap is opened immediately after the pilot burner is ignited (immediately after the ignition operation), the safety valve closes and closes the gas passage to stop combustion. There is no inconvenience in letting it happen. Therefore, all dangers during ignition operation can be prevented inexpensively by using electric circuits.
Safety is improved and ease of use is also improved.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the ignition safety device for a gas combustor according to this invention, and FIG. 2 is a circuit diagram showing a different embodiment. 1... Thermocouple, 2... Electromagnetic coil, 3... Water pressure switch, 4... Switch, 5... Capacitor,
6...DC power supply, A...Thermocouple safety circuit, B...
Parallel circuit of water pressure switch 3 and switch 4.

Claims (1)

[Scope of utility model registration request] In a thermocouple safety circuit A consisting of a thermocouple 1 and an electromagnetic coil 2 of a safety valve, a capacitor 5 connected to a DC power source 6 before the ignition operation is connected to the electromagnetic coil 2 so as to be discharged during the ignition operation. In a quick-start type ignition safety device, which holds the safety valve open by suction, it turns on when the water stops.
Switch 3 turns off when water is flowing, and switch 4 turns off only when the ignition button is pressed.
A parallel circuit B is provided with the capacitor 5, and the capacitor 5 is connected to the thermocouple safety circuit A through the parallel circuit B, and when the ignition operation is performed during water flow, the capacitor 5
An ignition safety device for a gas water heater, characterized in that a discharge circuit is opened.