KR101297526B1 - Combustion device - Google Patents

Abstract

(Problem) Provided is a combustion apparatus which suppresses shortening of battery life accompanying failure detection of a flame detection circuit using a thermocouple.
(Solution means) The flame detection signal Vtc of the thermocouple 20 is generated within a period from when the microcomputer 50 starts operation by the power supply from the battery 10 until the burner 2 is extinguished. When the state lower than the ignition level occurs, when the burner 2 is extinguished, the conduction state of the transistor 11 is canceled by the power supply holding unit 51, and the transistor 11 is turned off. When the flame detection signal Vtc of the thermocouple 20 is not lower than the ignition level within the flame detection signal, the flame detection signal Vtc of the thermocouple 20 from the time when the burner 2 is extinguished until a predetermined time elapses. ) Is provided with a thermocouple failure detection unit 53 for turning off the transistor 11 after performing the failure detection process of the thermocouple 20 after the fire extinguishing of the burner 2 to determine whether the level is lower than the ignition level.

Description

COMBUSTION DEVICE

The present invention relates to a combustion apparatus having a function of monitoring the combustion state of a burner by a thermocouple.

In the combustion apparatus which conventionally detects the combustion state of a burner by the thermocouple installed in the vicinity of a burner, when the level of the flame detection signal by a thermocouple does not fall to an extinguishing level even if predetermined time passes from the time of burner extinguishing. It is known to judge that a flame detection circuit failed (for example, refer patent document 1, 2).

Patent Document 1: Japanese Patent Application Laid-open No. Hei 8-145348 Patent Document 2: Japanese Patent Publication No. 2007-162991

In the conventional combustion apparatus, it is necessary to operate a control circuit that determines the failure of the flame detection circuit and the flame detection circuit until a predetermined time elapses after the burner is extinguished. For this reason, in the combustion apparatus which operates a flame detection circuit and a control circuit by a battery, life of a battery is extended by continuing operation | movement of a flame detection circuit and a control circuit from the time a burner is extinguished until the said predetermined time passes. There is a problem of shortening.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to provide a combustion apparatus which suppresses shortening of battery life accompanying failure detection of a flame detection circuit using a thermocouple.

The present invention has been made to achieve the above object,
A burner (2) for burning gas by ignition,
A thermocouple 20 installed near the burner 2 and detecting a combustion state;
An operation switch 5 for instructing ignition and extinguishing of the burner 2,
When the operation switch 5 is turned on by a user's ignition operation, a driving circuit for bringing the switching element 11 into a conducting state, and is connected to the battery 10 through the switching element 11, the switching element ( In the combustion apparatus having a controller (1) consisting of a control circuit for controlling the operation of the burner (2) by operating by the power supplied from the battery (10) through 11),
The control circuit,
When the switching element 11 is brought into a conductive state by the driving circuit and the power supply from the battery 10 is started, the switching element 11 is turned on regardless of the on / off of the operation switch 5. A power supply holding unit 51 for maintaining the state;
The burner 2 is ignited according to the ignition operation by the operation switch 5, and when the fire extinguishing operation is performed by the operation switch 5 during combustion of the burner 2 and the thermocouple 20 A combustion driving unit 52 for extinguishing the burner 2 when the misfire of the burner 2 is detected by the flame detection signal by the flame;
The level of the flame detection signal by the thermocouple 20 is a predetermined flame within a period from when the control circuit starts operation by the power supplied from the battery 10 until the burner 2 is extinguished. When a state out of the detection range occurs, when the burner 2 is extinguished, the conduction state of the switching element 11 is released by the power supply holding unit 51 to cut off the switching element 11. When the state where the level of the flame detection signal by the thermocouple 20 does not deviate from the flame detection range does not occur within the period, from the time when the burner 2 is extinguished until a predetermined time elapses. And a failure detection process of the thermocouple 20 after the burner 2 extinguishes to determine whether the level of the flame detection signal by the thermocouple 20 is out of a predetermined failure determination range. And a thermocouple failure detection unit 54 for releasing the conduction state of the switching element 11 by the power supply holding unit 51 to turn off the switching element 11. .

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According to the present invention, when the operation switch is turned on, the switching element is brought into a conductive state by the driving circuit, and the control circuit starts operation by electric power supplied from the battery through the switching element. Then, the switching is maintained in the conduction state by the power supply holding unit so that power supply to the control circuit is continued.

Here, when the temperature of the thermocouple is about the same as the ambient temperature when the operation switch is turned on and the thermocouple is operating normally, the level of the flame detection signal by the thermocouple before igniting the burner is out of the flame detection range. It becomes. Thus, the thermocouple fault detection unit has a state in which the level of the flame detection signal by the thermocouple is out of the flame detection range within a period from when the control circuit starts operation until the burner is extinguished. When it is possible to recognize that the thermocouple is operating normally, it is not judged whether the thermocouple has failed after the burner is extinguished, and the conduction state of the switching element is maintained by the power supply holding unit when the burner is extinguished. Is released to put the switching element in a blocked state.

Thereby, the power consumption from the battery is reduced from the time when the burner is extinguished until a predetermined time elapses, rather than always determining whether the level of the flame detection signal by the thermocouple is out of the flame detection range. Since it can reduce, the shortening of the said battery life accompanying the failure detection of the said thermocouple can be suppressed.

1 is a configuration diagram of a gas stove that is a combustion device of the present invention
2 is a first flowchart of processing by the power supply holding unit, the combustion driving unit, and the thermocouple fault detecting unit;
3 is a second flowchart of processing by the thermocouple abnormality detecting unit, the abnormality notifying unit, and the power supply interrupting unit;

Embodiments of the present invention will be described with reference to FIGS. 1 to 3.

With reference to FIG. 1, the combustion apparatus of this embodiment is a gas stove whose operation is controlled by the controller 1 which operates with the battery 10 as a power supply, and this gas stove is a user's burner 2; The operation switch 5 for instructing the ignition and extinguishing of the fire, the solenoid valve 30 provided in the gas supply passage 3 connected to the burner 2, and the burner 2 in the vicinity of the burner 2; A thermocouple 20 for detecting a combustion state of the fuel cell, an ignition electrode 22 for igniting the burner 2, and a pilot lamp 33.

The controller 1 includes a microcomputer 50, which operates by electric power supplied from the battery 10 through the transistor 11 (corresponding to the switching element of the present invention). The base terminal of the transistor 11 is connected to the drive element 12 and the drive element 16 via a resistor 13.

The input terminal of the drive element 12 is connected to the positive electrode of the battery 10 via the operation switch 5 and is grounded (connected to the 0V potential section) via the resistor 14. With this configuration, when the operation switch 5 is turned on (conducted) by the user's ignition operation, a basic current flows from the base terminal of the transistor 11 to the drive element 12 so that the transistor 11 conducts. It will be in a state (state where the emitter terminal and the collector terminal are conductive).

Moreover, when the operation switch of this invention is turned on by the operation switch 5, the drive element 12, and the resistor 14 connected between the anode of the battery 10, and the base terminal of the transistor 11, A driving circuit is set to make the conductive state.

In addition, the input terminal of the drive element 16 is connected to the output port Po1 of the microcomputer 50, and the base terminal of the transistor 11 when the output level of the output port Po1 is High (Vcc level). The basic current flows from the drive element 16 to the conduction state of the transistor 11 (a state in which the emitter terminal and the collector terminal are conductive).

In addition, when the operation switch 5 is off (open state) and the output level of the output port Po1 of the microcomputer 50 is Low (0 V level), since the basic current of the transistor 11 does not flow, the transistor (11) becomes a cutoff state (the emitter terminal and the collector terminal are blocked).

The thermocouple 20 is connected to the AD (Analog / Digital Conversion) input port Pad of the microcomputer 50 through the amplifier 21. The flame detection signal Vtc obtained by amplifying the electromotive force of the thermocouple 20 by the amplifier 21 is input to the AD input port Pad of the microcomputer 50, and is converted into a digital value to the microcomputer 50. Is read.

The ignition electrode 22 is connected to the output port Po2 of the microcomputer 50 through an igniter 23 which applies a high voltage to the ignition electrode 22 and causes spark discharge. When the output level of the output port Po2 of the microcomputer 50 is High (Vcc level), the igniter 23 is turned on, and a high voltage is applied to the ignition electrode 22, and the output level of Po2 is Low (0V). Level), the igniter 23 is turned off, and application of the high voltage to the ignition electrode 22 is stopped.

One end of the solenoid valve 30 is connected to the output port Po3 of the microcomputer 50 via the resistor 31 and the drive element 32, and the other end is grounded (connected to the 0V potential portion). When the output level of the output port Po3 of the microcomputer 50 is High (Vcc level), the solenoid valve 30 is closed. When the output level of Po3 is Low (0V level), the solenoid valve ( 30) becomes open.

One end of the pilot lamp 33 is connected to the output port Po4 of the microcomputer 50 via the resistor 34 and the driving element 35, and the other end is connected to the Vcc potential section. When the output level of the output port Po4 of the microcomputer 50 is High (Vcc level), the pilot lamp 33 is turned on. When the output level of Po3 is Low (0V level), the pilot lamp ( 33) goes out.

The microcomputer 50 executes a program for controlling the gas stove stored in the memory 55, whereby the power supply holding unit 51, the combustion driving unit 52, the thermocouple failure detection unit 53 and the thermocouple failure notification unit 54 Function as.

When the user operates the operation switch 5 while the burner 2 is in the extinguishing state, the operation switch 5 is turned on so that the transistor 11 is brought into a conductive state by the drive element 12. Then, power supply from the battery 10 through the transistor 11 to the microcomputer 50 is started, and the microcomputer 50 starts operation.

The power supply holding part 51 maintains the output level of the output port Po1 at high when it detects that the input to the input port Pi1 is High (the operation switch 5 is in the on state), whereby the transistor (11) is kept in a conducting state to maintain a state in which power is supplied from the battery 10 to the microcomputer 50.

In addition, the combustion operation unit 52, the thermocouple failure detection unit 53, and the thermocouple failure notification unit 54 execute the processing according to the flowcharts shown in Figs.

STEP1, STEP2, and STEP20 of FIG. 2 are the processes by the thermocouple fault detection part 53. As shown in FIG. The thermocouple fault detection unit 53 inputs the thermocouple 20 to the AD port Pad in STEP 1 until the ignition operation of the operation switch 5 is detected by the high level input to the input port Pi 1 in STEP 3. It is determined whether or not the flame detection signal Vtc is lower than the ignition detection level.

In addition, the state where the flame detection signal Vtc by the thermocouple 20 is lower than the ignition detection level corresponds to the state where the level of the flame detection signal by the thermocouple of the present invention is out of a predetermined flame detection range.

When the flame detection signal Vtc is lower than the ignition detection level, the thermocouple 20 and the amplifier 21 can be judged to be operating normally. Therefore, the process proceeds to STEP2, and the thermocouple failure detection unit 53 will be described later. Post-digestion check flag (indicated by post-digestion check F in the drawing), which is a flag instructing to perform fault detection of the thermocouple 20 and the amplifier 21 after extinguishing the burner 2 by STEP 14, STEP 15, and STEP 70 in FIG. ) To 0 (reset) and proceed to STEP3.

On the other hand, when the flame detection signal Vtc by the thermocouple 20 is equal to or higher than the ignition detection level, the thermocouple 20 or the amplifier 21 is broken, or the elapsed time from the last time of extinguishing the burner 2 is short. It is assumed that the temperature of the thermocouple 20 does not fall to near ambient temperature. Therefore, in this case, branching is made from STEP1 to STEP20, and the thermocouple fault detection part 53 advances to STEP3 with the post-extinguishing check flag set to 1 (set).

If the ignition operation of the operation switch (5) is detected in step 3, the process proceeds to step 4. STEP4 to STEP10 are the processes by the combustion driving part 52. The combustion driving unit 52 starts the 10 timer in STEP 4, opens the solenoid valve 30 with the output level of the output port Po3 low in STEP 5, and outputs the output port Po2 in STEP 6. By setting the level to High, spark discharge is caused to the ignition electrode 22, and the burner 2 is ignited.

In the subsequent STEP7, the combustion driving unit 52 starts the 2 second timer, and the thermocouple fault detection unit 53 determines whether there is a time up of the 2 second timer in the next STEP8, and the flame detection signal by the thermocouple 20 in the STEP30 ( It is determined whether Vtc) is lower than the ignition level.

Then, in STEP30, when the flame detection signal Vtc by the thermocouple 20 is lower than the ignition level, the flow advances to STEP31, and the thermocouple failure detection unit 53 returns the check flag to 0 after extinguishing and returns to STEP8. On the other hand, when the flame detection signal Vtc by the thermocouple 20 is equal to or higher than the ignition level, the fire extinguishing check flag is returned to STEP 8 without setting the check flag to zero.

When the 2 second timer has timed up in STEP 8, the process proceeds to STEP 9, and the combustion driving unit 52 determines whether the flame detection signal Vtc by the thermocouple 20 is equal to or greater than the ignition level. When the flame detection signal Vtc by the thermocouple 20 is equal to or higher than the ignition level and the ignition of the burner 2 is confirmed, the process proceeds to STEP 10, and the combustion driving unit 52 turns off the igniter 23 to FIG. 3. Proceed to STEP11.

On the other hand, when the flame detection signal Vtc of the thermocouple 20 is lower than the ignition level in STEP 9 and the ignition of the burner 2 is not confirmed, the combustion operation unit 52 has timed up for 10 seconds by branching to STEP 40. Determine whether or not. When the 10-second timer has not timed up, it returns to STEP9. On the other hand, when the 10 second timer has timed up, the process proceeds to STEP41, the igniter 23 is turned off, and the process proceeds to STEP54 of FIG. In this case, the combustion driving unit 52 turns off the solenoid valve 30 at STEP54 to stop the supply of fuel gas to the burner 2, and lights up the pilot lamp 33 at subsequent STEP55 to perform misfire notification.

Then, the combustion driving unit 52 starts the 60-second timer at the next STEP56, and proceeds to STEP58 when the 60-second timer has timed up at the STEP57. In step 58, the combustion driving unit 52 sets the output level of the output port Po1 to Low to cancel the maintenance of the conduction state of the transistor 11 by the power supply holding unit 51 (transistor 11 is turned off (blocking). State)) to cut off the power supply from the battery 5 to the microcomputer 50.

When the power supply from the battery 5 to the microcomputer 50 is cut off, the output level of the output port Po4 of the microcomputer 50 becomes low, and the pilot lamp 33 goes out. When the burner 2 is not ignited as described above, a misfire notification is made in which the pilot lamp 33 lights up for 60 seconds.

When the burner 2 is in combustion, the combustion operation unit 52 repeatedly executes a loop composed of STEP 11, STEP 50, and STEP 60 in FIG. 3, and in step 11, whether the burner 2 is extinguished by the operation switch 5? In addition, it is determined whether the flame detection signal Vtc by the thermocouple 20 is lower than the ignition level in STEP50.

When the extinguishing operation of the operation switch 5 is performed in STEP 11, the process proceeds to STEP 12. The combustion driving unit 52 turns off the solenoid valve 30 by setting the output level of the output port Po3 to Low, and burner. (2) to digest. STEP13 to STEP16 and STEP70 which follow are the processes by the thermocouple fault detection part 53. As shown in FIG.

The thermocouple failure detection unit 53 determines whether the check flag is 1 after extinguishing in STEP13. When the post-extinguish check flag is 1, the process proceeds to STEP 14, and the thermocouple fault detection unit 53 starts the post-digestion check timer (for example, 60 seconds is set to the timer time).

In the following loop consisting of STEP15 and STEP70, the thermocouple fault detection unit 53 determines whether the flame detection signal Vtc by the thermocouple 20 is lower than the ignition level in STEP14, and checks the post-fire extinguishing timer in STEP70. Determines whether or not timed up. In this case, the range of the ignition level or more corresponds to the failure determination region of the present invention, and the determination of whether the flame detection signal Vtc by the thermocouple 20 is lower than the ignition level is determined by the level of the flame detection signal of the present invention. Corresponds to the determination as to whether or not it is out of the failure determining station.

When the flame detection signal Vtc of the thermocouple 20 is lower than the ignition level in STEP 15, the thermocouple 20 and the amplifier 21 can be recognized as operating normally. The detection unit 53 stops supplying power to the microcomputer 50 in the same manner as in STEP58 described above, and proceeds to STEP17 to end the processing.

In addition, when the flame detection signal Vtc by the thermocouple 20 does not become lower than the ignition level in STEP15, and the check timer expires after the extinguishing in STEP70, even after some time has passed since the burner 2 is extinguished. Nevertheless, it can be determined that the thermocouple 20 or the amplifier 21 has failed because the flame detection signal Vtc is kept high.

In this case, the process proceeds to STEP71. STEP71 to STEP73 are the processes performed by the thermocouple failure notification unit 54. The thermocouple failure notification unit 54 alternately switches the output level of the output port Po4 to High and Low to flash the pilot lamp 33 to perform thermocouple failure notification. In the subsequent STEP72, the thermocouple fault notification unit 54 starts the 60-second timer, waits for the 60-second timer to time-up in STEP73, and proceeds to STEP16. Proceeds to end the processing. Thereby, the thermocouple failure notification by flashing of the pilot lamp 33 is executed for 60 seconds.

When the post-extinguish check flag is not 1 in STEP12, the normal operation of the thermocouple 20 and the amplifier 21 is confirmed in STEP2 and STEP31 of FIG. 2, and the failure detection after extinguishing the burner 2 (STEP14, STEP15) Since STEP70 becomes unnecessary, the process branches to STEP16, and the thermocouple failure detection unit 53 stops the power supply to the microcomputer 50, similarly to the above-described STEP58, and proceeds to STEP17 to end the processing.

In this case, power supply from the battery 10 to the microcomputer 50 is cut off immediately without detecting the failure of the thermocouple 20 and the amplifier 21 after the burner 2 is extinguished by STEP 14, STEP 15, and STEP 70. . Therefore, the power consumption from the battery 10 can be reduced and the failure of the thermocouple 20 and the amplifier 21 can be reduced compared to the case where the failure detection of the thermocouple 20 and the amplifier 21 after the fire extinguishing of the burner 2 is always performed. The shortening of the battery 10 life accompanying detection can be suppressed.

Next, when it is recognized in step 50 that the flame detection signal Vtc by the thermocouple 20 becomes lower than the ignition level during combustion of the burner 2, and it is recognized that the burner 2 has failed, the process proceeds to STEP 51. STEP51 is a process by the thermocouple fault detection part 53, and the thermocouple fault detection part 53 sets the post-extinguish check flag to zero.

In subsequent STEP52, the combustion driving unit 52 starts the misfire timer and returns to STEP11 until the misfire timer times up in STEP53. When the flame detection signal Vtc by the thermocouple 20 returns to the ignition level or higher at STEP50, the flame detection signal Vtc may be considered to have been temporarily reduced due to the combustion flame, etc. Then, the combustion driving unit 52 stops the misfire timer to clear the time value.

When the flame timer has timed up in STEP53, i.e., when the flame detection signal Vtc by the thermocouple 20 is lower than the ignition level, the operation proceeds to STEP54, and the combustion driving unit 52 As described above, misfire error notification is performed to terminate the process.

In addition, in this embodiment, in step 15 of FIG. 2 after the burner 2 is extinguished, the presence or absence of failure of the thermocouple 20 is determined depending on whether the flame detection signal Vtc by the thermocouple 20 is lower than the ignition level. The flame detection signal Vtc by the thermocouple 20 is, for example, lower than the failure detection determination level set lower than the ignition level or the failure detection determination level set slightly higher than the ignition level. It may be determined whether there is a failure.

In addition, in this embodiment, although the gas stove was shown as the combustion apparatus of this invention, if it is a combustion apparatus which detects the combustion state of a burner by a thermocouple, application of this invention is also applicable to other types of combustion apparatuses, such as a gas water heater.

1-controller 2-burner
5-Operation Switch 10-Battery
11-Transistor (Switching Element) 20-Thermocouple
30-solenoid valve 50-microcomputer
51-Power supply holding part 52-Combustion driving part
53-Thermocouple fault detector 54-Thermocouple fault alert

Claims (1)

A burner (2) for burning gas by ignition,
A thermocouple 20 installed near the burner 2 and detecting a combustion state;
An operation switch 5 for instructing ignition and extinguishing of the burner 2,
When the operation switch 5 is turned on by a user's ignition operation, a driving circuit for bringing the switching element 11 into a conducting state, and is connected to the battery 10 through the switching element 11, the switching element ( In the combustion apparatus having a controller (1) consisting of a control circuit for controlling the operation of the burner (2) by operating by the power supplied from the battery (10) through 11),
The control circuit,
When the switching element 11 is brought into a conductive state by the driving circuit and the power supply from the battery 10 is started, the switching element 11 is turned on regardless of the on / off of the operation switch 5. A power supply holding unit 51 for maintaining the state;
The burner 2 is ignited according to the ignition operation by the operation switch 5, and when the fire extinguishing operation is performed by the operation switch 5 during combustion of the burner 2 and the thermocouple 20 A combustion driving unit 52 for extinguishing the burner 2 when the misfire of the burner 2 is detected by the flame detection signal by the flame;
The level of the flame detection signal by the thermocouple 20 is a predetermined flame within a period from when the control circuit starts operation by the power supplied from the battery 10 until the burner 2 is extinguished. When a state out of the detection range occurs, when the burner 2 is extinguished, the conduction state of the switching element 11 is released by the power supply holding unit 51 to cut off the switching element 11. When the state where the level of the flame detection signal by the thermocouple 20 does not deviate from the flame detection range does not occur within the period, from the time when the burner 2 is extinguished until a predetermined time elapses. And a failure detection process of the thermocouple 20 after the burner 2 extinguishes to determine whether the level of the flame detection signal by the thermocouple 20 is out of a predetermined failure determination range. And a thermocouple failure detection unit 54 for releasing the maintenance of the conduction state of the switching element 11 by the power supply holding unit 51 to turn off the switching element 11. Combustion device.

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