JPH0125897Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a timer-type gas appliance, such as a gas appliance, that automatically starts at a set time.

Conventionally, in this type of gas appliance, for example, a timer-type gas rice cooker, the electric circuit for starting the gas rice cooker is turned on by the output of the timer at the set time, and this output operates each part to turn on the starter. The ignition and the main burner ignition proceed in sequence, resulting in the rice cooking state.

However, if the rice cooking timer setting operation is performed while the rice cooker remains closed,
Although the electrical system continues to operate at the set time,
Since the main gas circuit was closed, the pilot burner and main burner were not ignited, and the appliance did not start. This also occurs when air is mixed in the pilot gas circuit.

In order to prevent such starting failures, efforts have already been made to
No. 57-119050 was proposed, but in large gas appliances such as commercial gas rice cookers, startup failures are often caused by air entering the pilot gas circuit.
This is because the length of the piping from the pilot valve to the pilot burner is unavoidable due to the structure of the device, and if all of the pilot valve piping is replaced with air, the pilot burner This is because it takes a long time for the gas ejected from the air to reach a predetermined air-gas mixture state.

In the invention of the above-mentioned application, prior to setting the timer, the process up to the pilot flame ignition is performed as a test operation, but under the above conditions, the pilot flame is not ignited in one test operation and the timer set state is reached. A situation arises where this is not the case.

The object of this invention is to increase the number of test operations and reduce pilot ignition errors.

The technical means of the present invention to solve the above problems is to combine the negative output of the pilot ignition confirmation device and the negative output of a counter that measures the number of activations of the pilot ignition device and generates the same output at the second activation. The output of an AND circuit or an equivalent circuit is input to a prepurge timer, the output of the prepurge timer is input to a pilot ignition device, and an AND circuit of the output of the counter and the negative output of the pilot ignition confirmation device. This is because the output was input to the main valve switch.

According to the above technical means, in the first pilot ignition operation, if the pilot does not ignite, there is no output from the pilot ignition confirmation device, and on the other hand, there is no output from the counter. An output is generated in the AND circuit of these two negative outputs to operate the pre-purge timer, and when this output is generated, it is again input to the pilot ignition device and the device is activated to proceed with the second ignition operation.

If the pilot flame does not ignite during the second ignition operation,
An output is generated in the other AND circuit, actuating the main valve switch, and the main valve, which was previously placed in the open state, closes.

In any of the above ignition operations, when the pilot ignition is ignited, the output of the pilot ignition confirmation device is input to the pilot fire extinguishing device and the timer is started at the same time.

As described above, in the event of an ignition error, the pilot igniter operates twice, which reduces ignition errors.

The present invention has the following unique effects.

During the second ignition operation, the ignition operation is delayed by a pre-purge timer for a certain period of time, so the raw gas near the pilot burner released during the first operation will diffuse during this time, and a large amount will be generated during the second ignition operation. This prevents the inconvenience of raw gas accumulating in the ignition part and explosively igniting it.

Furthermore, since the number of operations of the pilot igniter is set to two, there is no need for the residual amount of raw gas to increase as would be the case if the number of operations is set to three or more times.

Hereinafter, embodiments of the present invention will be described based on the drawings.

The timer set switch 1 is used to set the timer to start the appliance when turned on, and may be used together with the power switch or provided separately.

The pilot ignition device 2 includes a pilot valve 4 inserted into a gas circuit to a pilot burner 3, and an igniter 6 for supplying a discharge output to a spark plug 5 provided near the pilot burner. The input to the spark igniter opens the pilot valve 4, activates the igniter 6, and discharges the pilot flame to the pilot burner 3.
As a result, the gas ejected from the pilot burner 3 is ignited.

In this embodiment, a flame rod 7 is used as the pilot ignition confirmation device 9, and the pilot ignition device 2
If a flame is not formed in the pilot burner 3 within a certain period of time after starting, there is no output from the pilot ignition confirmation device, and conversely, an output is generated only when a flame is formed.

The output of this pilot fire ignition confirmation device 9 is inputted to a pilot fire extinguishing device 12 via a fourth AND circuit 10. In addition, a pilot ignition confirmation device 9 and a counter 16
The output of
The output of is input to the third AND circuit 19.

Here, the negative output (inverted output) of the pilot spark ignition confirmation device 9 is input to the first and second AND circuits.

Next, the pilot igniter 2 is connected to the counter 16.
The counter is configured to count the number of activations of the pilot ignition device 2, and an output is generated only when two activations are counted.

As for the configuration of this counter, a configuration can be adopted in which a flip-flop circuit is used to extract the output at the moment the starting switch of the pilot ignition device 2 is turned on and input it to the input side of the flip-flop circuit. Needless to say, a circuit using a transistor can also be used.

The output of the first AND circuit 17 is input to a normally closed main valve switch 20 inserted in series in the circuit to the main valve 8, and the output from the counter 16 is also input to the pilot ignition confirmation device 9. When there is no output (that is, when there is a reverse output), the main valve switch is turned OFF.

Next, the output of the second AND circuit 18 is input to a pre-purge timer 21, and the output of the pre-purge timer 21 is fed back to the pilot ignition device 2, which includes a counter 16 and a pilot ignition confirmation device 9.
When there is no output from the second AND circuit 18, an output is generated in the second AND circuit 18 to restart the pilot igniter 2.

Furthermore, the output of the third AND circuit 19 is
When the pilot ignition device 2 is started by the output applied by the timer 11 at the set time and a flame is formed in the pilot burner 3, the pilot ignition confirmation device 9
An output is generated in the third AND circuit 19, which opens the main valve 13, and the rice cooking progresses. This operation is a rice cooking start operation by the timer 11.

Incidentally, the inverted output of the third AND circuit 19 and the output of the ignition confirmation device 9 are inputted to the fourth AND circuit 10,
The reason why the output of the fourth AND circuit is inputted to the pilot fire extinguishing device 12 is that when the pilot flame is ignited by the output of the timer 11, the pilot flame is not extinguished and the main valve 4 is opened as it is and the main burner is turned on. This fourth AND circuit 10 is used to burn the timer 11.
It functions as a switching device between the test operation when the timer 11 is set and the rice cooking operation based on the output of the timer 11.

The pilot fire extinguishing device 12 to which the output of the fourth AND circuit is input is a device for closing the pilot valve 4, thereby extinguishing the pilot burner 3.

Furthermore, the main valve 8, pilot valve 4, and main valve 13 inserted into the gas circuit are electromagnetic valves that are opened and closed by the input of electrical signals.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention, and Fig. 2 is an explanatory diagram of the gas circuit. 11...Timer, 12...Pilot fire extinguishing device, 13...Main valve.

Claims (1)

[Scope of utility model registration request] inputting the output of the timer set switch 1 for starting the timer to an ignition test operation circuit comprising a pilot ignition device 2 and a pilot ignition confirmation device 9;
In the case where the timer 11 for starting the appliance is turned on by the output from the test operation circuit, the negative output of the pilot ignition confirmation device 9 and the pilot ignition device 2
The output of the AND circuit 18 or a circuit equivalent thereto is inputted to the pre-purge timer 21, and the output of the counter 16 which measures the number of activations and generates its output at the second activation, is input to the pre-purge timer 21.
1 is inputted to the pilot ignition device 2, and further, the output of the AND circuit 17 of the output of the counter 16 and the negative output of the pilot ignition confirmation device 9 is inputted to the main valve switch 20. utensils.