JP2765802B2 - Combustion equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion apparatus.

[0002]

2. Description of the Related Art Conventionally, a gas burner in which gas is supplied and burned by a gas pipe provided with an electromagnetic valve, a frame rod and a thermocouple facing a flame of the gas burner, and a predetermined time (for example, 30 seconds) have elapsed since ignition. Until then, if the flame is detected by the flame rod, keep the solenoid valve open,
There is known a combustion apparatus including control means for stopping flame detection by a frame rod after a predetermined time has elapsed and for holding a solenoid valve in an open state when a thermoelectromotive force is equal to or more than a predetermined value (FIG. 12). reference).

[0003]

However, it takes a relatively long time for the thermocouple to be exposed to the combustion flame of the gas burner and to rise in temperature to output a thermoelectromotive force of a predetermined value or more. In addition, since the time varies depending on the amount of combustion, the above-described combustion apparatus needs to set the above-mentioned predetermined time longer (for example, 30 seconds) in accordance with the case where the amount of combustion is small. Therefore, it is necessary to continue the flame detection by the flame rod that consumes a relatively large amount of electric power for about 30 seconds.
In the case of using a battery as a power source, a problem was found that the battery was quickly consumed.

An object of the present invention is to provide a combustion device that consumes less power and ensures safety.

[0005]

In order to solve the above-mentioned problems, the present invention provides a gas burner to which gas is supplied via a gas pipe, an electromagnetic valve provided in the gas pipe, and a flame of the gas burner. First flame detection means for detecting the presence or absence of a flame current, with the flame rod facing, second flame detection means for causing a thermocouple to face the gas burner and outputting a thermoelectromotive force proportional to the flame temperature, Control means for controlling the opening and closing of the solenoid valve, the control means, after a predetermined time has passed since the thermoelectromotive force output by the second flame detection means has become a predetermined value or more, A configuration is employed in which the operation of the first flame detecting means is stopped and the solenoid valve is kept open while the thermoelectromotive force is maintained at or above a predetermined value.

[0006]

[0007]

The control means operates the first flame detection means and the second flame detection means. When the gas burner is ignited, first, the first flame detecting means starts detecting a flame current. The control means
The operation of the first flame detecting means is stopped after a predetermined time has elapsed after the thermoelectromotive force of the second flame detecting means has become equal to or more than a predetermined value, and the electromagnetic force is maintained while the thermoelectromotive force remains at or above the predetermined value. Hold the valve open.

[0008]

[0009]

[0010]

[0011]

Since the operation of the first flame detecting means is stopped based on the thermoelectromotive force of the second flame detecting means, the power consumption can be reduced as compared with the conventional one. The control means
After a predetermined time has passed since the thermoelectromotive force became equal to or more than the predetermined value (when the thermoelectromotive force significantly increased), the operation of the first flame detecting means was stopped, and the thermoelectric power became equal to or more than the predetermined value. During the maintenance, the solenoid valve is kept open. For this reason,
Even if the thermal electromotive force fluctuates due to the fluctuation of the combustion flame after the operation of the first flame detecting means is stopped, the electromagnetic valve does not close because the thermal electromotive force does not become less than the predetermined value.

[0012]

[0013]

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. As shown in the drawing, a gas instantaneous water heater A, which is a combustion device employing the configuration of the present invention, includes a gas burner 1, an electromagnetic valve 2 disposed in a gas pipe 11, a frame rod 3
1 for driving the frame rod circuit 3, the thermocouple 4, the solenoid valve 2, etc.
And a battery 6 and the like.

Reference numeral 71 denotes a normally open operation switch in which a contact is made conductive only when pressed, 72 denotes a heat exchange channel, 73 denotes a faucet, 74 denotes a motor, 75 denotes a position detecting means of the faucet 73,
76 is a water flow switch.

The gas burner 1 includes a heat exchanger 722 described later.
The gas is supplied by the gas pipe 11 and burns.

The solenoid valve 2 is arranged on the most upstream side of the gas pipe 11 and is controlled by the microcomputer 5 via a solenoid valve driving circuit 504.

Specifically, as shown in FIG. 6, the valve is forcibly opened for 1.6 seconds or 0.8 seconds (depending on the tapping capacity) from the completion of the ignition operation. Until the time when the electric power reaches the ignition detection level + 1 second elapses, while the flame is detected by the flame rod circuit 3, the solenoid valve 2
Is kept in the valve open state.

After one second elapses after the thermoelectromotive force reaches the ignition detection level, the solenoid valve 2 is opened while the thermoelectromotive force output from the thermocouple 4 maintains the ignition detection level. Held in state.

The flame rod circuit 3, which is the first flame detecting means, detects the presence or absence of a flame current flowing between the flame rod 31 exposed to the flame of the gas burner 1 and the frame ground when a flame exists. It is a circuit and is constituted by electronic components as shown in FIG. In addition, since high voltage needs to be applied to the frame rod 31 to detect the flame current, the consumption current is large.

As shown in FIG. 6, the flame rod circuit 3 supplies the operating power from the start of the ignition control to the point at which the thermoelectromotive force reaches the ignition detection level + 1 second after the start of the ignition control. Is detected, a detection signal is sent to the microcomputer 5.

The thermocouple 4, which is a thermocouple, faces the gas burner 1 and outputs a thermoelectromotive force proportional to the flame temperature to a thermocouple circuit 505 (second flame detection means). Further, the thermocouple circuit 505 inputs the thermoelectromotive force transmitted by the thermocouple 4 and transmits an electric output corresponding to the detected thermoelectromotive force to the microcomputer 5 (see FIG. 4).

The monitoring of the thermoelectromotive force by the microcomputer 5, as shown in FIG.
6 seconds (when tapping capacity is low) /0.8 seconds (when tapping capacity is high)
It is implemented from the time when it passed. This time coincides with the end of the forced valve holding.

Reference numeral 6 denotes a battery in which two single 1.5 V manganese dry batteries are connected in series, and has an electromotive force of 3 V.

The heat exchange channel 72 includes a water supply pipe 721, a heat exchanger 722, and a tapping pipe 723 connected in this order. Water supply pipe 72
1, a water faucet 73 is arranged at the uppermost stream, a water governor valve 77 which also functions as a water pressure responsive member is arranged downstream of the faucet 73, and a water amount regulating valve 78 is arranged downstream of the water governor valve 77.

The tapping pipe 723 is made of metal, and a downstream portion exposed outside the appliance is formed by coating a metal flexible pipe with a resin pipe, and a shower head 724 is fitted to the tip. A water flow switch 725 is assembled to the shower head 724 so that a shower or straight water flow 726 can be selected.

The gas pipe 11 includes, from the upstream side, an electromagnetic valve 2, a water pressure responsive valve 111 connected to the water governor valve 77, a gas governor valve 112, and a gas amount control valve 113.
The gas amount adjusting valve 113 is connected to the hot water temperature setting lever L together with the water amount adjusting valve 78, and the gas amount and the water amount corresponding to the sliding amount of the hot water temperature setting lever L are supplied to the gas burner 1 and the heat exchanger 722, respectively. You. When the hot water temperature setting lever L is at the left end, the water / hot water switch m is opened and the gas burner 1 is not ignited.
4 discharges water.

The position detecting means 75 detects the fully open position or the fully closed position of the faucet 73. As shown in FIG.
It is composed of a normally-open faucet switch 751 having a spring-like movable piece 751a, and a cam 752 which is fixed to a drive shaft 741 of a motor 74 and rotates.

The faucet switch 751 is arranged such that when the faucet 73 is in the closed position, the spring-like movable piece 751a is in contact with the side peripheral wall of the cam 752 (see FIG. 3A). Is in a valve open position, the movable piece 751a is brought into a press-contact state by the large-diameter portion 752a (about one third of the outer circumference) {see FIG. 3B}, which is a micro switch that closes the electrical contact. That is, when the faucet switch 751 is switched from open to closed, the faucet 73 is in the fully open position, and when the faucet switch 751 is switched from closed to open, the faucet 73 is in the fully closed position.

The cam 752 has a substantially circular cross section, and the outer periphery of the thick portion 752b is formed with a large diameter (large diameter portion 752a). When the thick portion 752b comes to the spindle position, the spindle 731 is pressed to open the faucet 73.

At the start of hot water supply, the contacts of the faucet switch 751 are kept open until the faucet 73 is fully opened (the spindle 731 of the faucet 73 is pressed most by the thick portion 752b). The motor 74 continues to rotate until the faucet 73 is fully opened (the contact of the faucet switch 76 is closed) {see FIG. 3 (b)}.

Further, at the end of hot water supply, the contacts of the faucet switch 751 are pushed to the large diameter part until the faucet 73 is fully closed (the spindle 731 of the faucet 73 is not pressed at all). The state is maintained, and the motor 74 continues to rotate until the faucet 73 reaches the fully closed position (the contact point of the faucet switch 751 is closed) (see FIG. 3A).

A control unit 50 includes a microcomputer 5, a motor drive circuit 501, and a switch circuit 50.
2, igniter circuit 503, solenoid valve drive circuit 504, thermocouple circuit 505, safety circuit 506, operation switch circuit 507, battery confirmation lamp circuit 508, buzzer drive circuit 509, frame rod circuit 3, battery voltage detection circuit 510, etc. Assembled.

When the operation switch 71 is pressed while the tapping is stopped (the faucet 73 is closed), the microcomputer 5 operates until the faucet 73 is fully opened.
01 instructs the motor drive circuit 501 to continue energizing the motor 74. When the operation switch 71 is pressed during tapping (the faucet 73 is open), the motor drive circuit 501 continues to supply power to the motor 74 until the faucet 73 is closed. To instruct.

Further, the microcomputer 5 continues to operate the faucet switch 76 even after 5 seconds from the start of energization of the motor 74.
If the contact state (state of the faucet 73) does not change,
When it is determined that the motor 74 is locked, the motor drive circuit 5
01 instructs the motor drive circuit 501 to stop energizing the motor 74. Then, when the water flow switch 76 detects the water flow while the motor power supply is stopped, the faucet switch 751
The motor 74 is energized until the contact of the opening changes from opening to closing to opening (water faucet 73 opens halfway → fully opens → fully closed).

The igniter circuit 503 is controlled by the microcomputer 5 and applies a high voltage to the igniter electrode 702 when its operation is instructed.

The water flow switch 76 is connected to the water governor valve 77 and the water pressure responsive valve 111, and when the water governor valve 77 detects flowing water in the heat exchange water passage 72, the electrical contacts are turned on.

Next, the operation of the instantaneous gas water heater A will be described with reference to FIG.
This will be described with reference to FIG. [At the start of use] When the user performs a light pressing operation on the operation switch 71, an ON signal is input to the microcomputer 5 via the operation switch circuit 507.

At step s1, the microcomputer 5
Is output to the buzzer drive circuit 509, and the buzzer sounds.

At step s2, the microcomputer 5
Determines through the switch circuit 502 whether or not the contact of the water flow switch 76 is off. If it is off (YES), the process proceeds to step s3, and if it is on (water flow detection state) (NO), it is considered that the water flow switch 76 has an ON failure and the process proceeds to step s31.

In step s3, the microcomputer 5 instructs the motor drive circuit 501 so that the motor drive circuit 501 starts energizing the motor 74.

In step s4, it is determined whether or not 5 seconds have elapsed since the start of energization of the motor 74 (after step s3 was performed).
Proceeding to 5, if 5 seconds have elapsed, it is considered that the motor 74 has locked, and the flow proceeds to step s26.

By the rotation of the motor 74, the faucet 73 is opened in step s5. In the fully opened position, the faucet switch 75
1 turns on.

At step s6, the microcomputer 5
Determines whether or not the faucet 73 has been fully opened, based on whether or not the contact point of the faucet switch 751 is ON. If the faucet 73 is fully open (if ON; YES), the process proceeds to step s7, where the valve is closed or half-opened. If the status is OFF (NO; NO), the process returns to step s3.

In step s7, the microcomputer 5 instructs the motor drive circuit 501 so that the motor drive circuit 501 stops energizing the motor 74.

At step s8, the microcomputer 5
Determines whether the contact of the water flow switch 76 is on or not via the switch circuit 502 and turns on (water flow detection state).
In the case of (YES), the process proceeds to step s9, and in the case of off (NO), it is considered that the water is shut off and the process proceeds to step s32.

At step s9, the microcomputer 5
Determines through the switch circuit 502 whether or not the water / hot water changeover switch m is closed. If it is closed (set to the hot water side; YES), the process proceeds to step s10 and is open. In the case (set on the water side; NO), the shower head 724
The water is discharged from.

At step s10, the microcomputer 5 instructs the igniter circuit 503 to apply a high voltage to the igniter electrode 702. Also, frame rod circuit 3
Then, the supply of the battery power is started to start the flame detection by the frame rod 31 ("ignition operation" in FIG. 6).

In step s11, it is determined whether or not 0.1 seconds have elapsed (from step s10). If 0.1 seconds have elapsed (YES), the process proceeds to step s12, where 0.1 seconds have not elapsed. In the case (NO), the process returns to step s10.

In step s12, the microcomputer 5 determines whether or not the output of the frame rod circuit 3 is Lo. If Lo (ignition is not detected) (YES), the microcomputer 5 proceeds to step s13. If it is Hi (ignition detection state) (NO), it is determined that the frame rod 31 or the frame rod circuit 3 has failed, and the process proceeds to step s39.

In step s13, the microcomputer 5 instructs the solenoid valve driving circuit 504 to forcibly suck and hold the solenoid valve 2 and proceeds to step s14.

At step s14, the battery voltage detection circuit 51
If 0 detects 2.1 V or more (YES), the process proceeds to step s15, and if 0 is less than 2.1 V (YES), the process proceeds to step s41.

In step s15, it is determined whether or not 0.31 seconds have elapsed from step s13. If it has elapsed (YES), the process proceeds to step s16, and if not (NO), the process returns to step s13.

In step s16, the microcomputer 5 instructs the solenoid valve drive circuit 504 to stop the forced adsorption current of the solenoid valve 2, and proceeds to step s17. Note that the solenoid valve 2 can maintain the valve open state even when the forced suction current (for example, 250 mA) stops, because the suction current (for example, 2.5 mA) flows.

In step s17, the microcomputer 5 determines whether or not the output of the flame rod circuit 3 is Hi. If the output is Hi (ignition detection state) (YES), the flow proceeds to step s18, and if it is Lo. (NO) regards non-ignition and proceeds to step s50.

In step s18, the microcomputer 5 instructs the igniter circuit 503 to stop applying the high voltage to the igniter electrode 702, and proceeds to step s19.

In step s19, it is determined whether or not 0.8 seconds (when the tapping capacity is large) /1.6 seconds (when the tapping capacity is small) has elapsed since step s13.
S) proceeds to step s20 {at "1.6 seconds later" in FIG. 6). The determination as to whether the tapping capacity is large or small is made by a capacity switching switch that is switched by operating the hot water setting lever L.

At step s20, it is determined whether or not the thermoelectromotive force is equal to or higher than the ignition detection level (see FIG. 6) based on the output of the thermocouple circuit 505, and if it is equal to or higher than the ignition detection level (elapsed time 801). (Time point; YES) proceeds to step s21, and when it is lower than the ignition detection level (N
O) proceeds to step s52.

After it is determined in step s21 that the thermoelectromotive force is equal to or higher than the ignition detection level (Y in step s20).
ES) It is determined whether or not one second has elapsed. If one second has elapsed (YES), the process proceeds to step s22. If not (NO), the process returns to step s20.

At step s22, the microcomputer 5 cuts off the supply of the battery power to the flame rod circuit 3 and stops the flame detection by the frame rod 31 (elapsed time 802).

In step s23, the microcomputer 5 determines whether or not the operation switch 71 has been continuously pressed for 10 seconds or more. If the operation switch 71 has not been continuously pressed for 10 seconds or more (NO), the microcomputer 5 proceeds to step s24. If it is continuously pressed (YES), the flow proceeds to step s53.

At step s24, it is determined whether or not the thermoelectromotive force is continuously at or above the ignition detection level. If it is continuously at or above the ignition detection level (YES), the process proceeds to step s25, otherwise (NO). ) Proceeds to step s54.

In step s25, steps 3 to 3
It is determined whether 0 minutes have elapsed, and if it has not elapsed (N
O) returns to step s24, and if it has elapsed (YE
S) proceeds to step s55.

In step s26, the motor driving circuit 501
The microcomputer 5 instructs the motor drive circuit 501 so that the power supply to the motor 74 is stopped.

In step s27, the microcomputer 5 determines whether or not the contact of the water flow switch 76 is on via the switch circuit 502. If the contact is on (water flow detection state) (YES), the flow proceeds to step s28. If it is off (a state in which no water flow is detected) (NO), the process returns to step s26.

In step s28, the motor driving circuit 501
The microcomputer 5 instructs the motor drive circuit 501 so that the power supply to the motor 74 starts.

At step s29, it is determined whether or not 5 seconds have elapsed since the start of energization of the motor 74 (after execution of step s28). If 5 seconds have not elapsed, the process proceeds to step s30, where 5 seconds have elapsed. If it has passed, step s2
Return to 6.

In step s30, the microcomputer 5 determines whether or not the contact of the faucet switch 751 has been switched from off to on to off (YES) or not (NO). If s2
Return to 8.

In step s31, the motor driving circuit 501
The microcomputer 5 instructs the motor drive circuit 501 so that the power supply to the motor 74 is stopped.

In step s32, it is determined whether or not 30 minutes have elapsed since the power supply to the motor 74 was stopped (after step s7 was performed). If 30 minutes have elapsed (Y
ES) proceeds to step s33, and if 30 minutes have not elapsed, returns to step s8.

In step s33, the motor driving circuit 501
The microcomputer 5 instructs the motor drive circuit 501 so that the power supply to the motor 74 starts.

At step s34, the microcomputer 5 starts energizing the motor 74 (step s33).
It is determined whether or not 5 seconds have elapsed since the execution of (i.e., is performed). If 5 seconds have not elapsed (NO), the process proceeds to step s35,
If 5 seconds have elapsed (YES), the flow proceeds to step s37.

By the rotation of the motor 74, step s35
, The faucet 73 is closed and the faucet switch 76 is opened.

In step s36, the microcomputer 5 determines whether or not the faucet 73 has been fully closed based on whether or not the contact of the faucet switch 751 is off. (YES) returns to step s31, and if ON (NO), returns to step s33.

At step s37, the motor driving circuit 501
The microcomputer 5 instructs the motor drive circuit 501 so that the power supply to the motor 3 is stopped.

In step s38, the microcomputer 500 determines whether or not the contact of the water flow switch 76 is off via the switch circuit 502. If the contact is off (a state in which no water flow is detected) (NO), It returns to s31, and when it is on (YES), it returns to step s33.

In step s39, it is determined whether or not two seconds have elapsed since the transition to step s10. If it has elapsed (YES), the process proceeds to step s40. If it has not elapsed (NO), the process proceeds to step s12. Return to

At step s40, the microcomputer 5 instructs the igniter circuit 503 to stop applying a high voltage to the igniter electrode 702. Further, the supply of the battery power to the frame rod circuit 3 is stopped to stop the flame detection by the frame rod 31, and the process proceeds to step s33.

At step s41, the battery voltage detection circuit 51
When 0 detects 1.9 V or more (YES), the process proceeds to step s42, and when 0 is less than 1.9 V (NO), the process proceeds to step s45.

At step s42, the microcomputer 5 instructs the battery confirmation lamp circuit 508 to blink the battery confirmation lamp r and proceeds to step s43.

In step s43, steps s14 to s14
It is determined whether or not 0 seconds have elapsed, and if it has elapsed (YE
S) proceeds to step s44.

At step s44, the microcomputer 5 instructs the battery confirmation lamp circuit 508 to turn off the battery confirmation lamp r and returns to step s15.

At step s45, the microcomputer 5 instructs the battery confirmation lamp circuit 508 to turn on the battery confirmation lamp r and proceeds to step s46.

At step s46, the battery voltage detection circuit 51
When 0 detects 1.8 V or more (YES), the process returns to step s43. When 0 is less than 1.8 V (NO), the process proceeds to step s47.

At step s47, the microcomputer 5 instructs the solenoid valve driving circuit 504 to close the solenoid valve 2.

In step s48, step s13
It is determined whether 1.6 seconds have elapsed since the transition to step, and if it has elapsed (YES), the flow proceeds to step s49.

At step s49, the microcomputer 5 instructs the igniter circuit 503 to stop applying the high voltage to the igniter electrode 702. Further, the supply of battery power to the frame rod circuit 3 is cut off, and the flame detection by the frame rod 31 is stopped.

In step s50, step s13
It is determined whether or not 0.8 seconds / 1.6 seconds have elapsed since the transition to. If it has elapsed (YES), the flow proceeds to step s51.

At step s51, the microcomputer 5 instructs the igniter circuit 503 to stop applying a high voltage to the igniter electrode 702. Further, an instruction is given to the solenoid valve driving circuit 504 to close the solenoid valve 2. Furthermore,
The supply of battery power to the frame rod circuit 3 is cut off, and the flame detection by the frame rod 31 is stopped.

In step s52, step s13
It is determined whether or not 50 seconds have elapsed since the transition to step. If it has elapsed (YES), the flow proceeds to step s53.

In step s53, the microcomputer 5 instructs the solenoid valve drive circuit 504 to stop the suction holding current of the solenoid valve 2, and returns to step s33.

In step s54, it is determined whether or not the thermoelectromotive force has changed from the ignition detection level to the ignition detection level to less than the ignition detection level after 30 seconds from step s21. If (YES), step s5
Proceed to step 5; otherwise (NO), return to step s53.

In step s55, the buzzer is sounded on the assumption that misfire or incomplete combustion has occurred, and step s53 is performed.
Return to

[During Use Stop] When the user presses the operation switch 71 during hot water supply, the operation switch circuit 5
07, an ON signal is input to the microcomputer 5.

In step S1, the microcomputer 5
Is output to the buzzer drive circuit 509, and the buzzer sounds.

At step S2, the microcomputer 5
Instructs the motor drive circuit 501 to start energizing the motor 74 and instructs the solenoid valve drive circuit 504 to close the solenoid valve 2.

In step S3, it is determined whether or not 5 seconds have elapsed since the transition to step S2. If 5 seconds have elapsed (YES), the process proceeds to step S7, and if not (NO), the process proceeds to step S7. Proceed to S4.

In step S4, the faucet 73 is closed by the rotation of the motor 74, and the faucet switch 751 is turned off.

At step S5, the microcomputer 5
Determines through the switch circuit 502 whether or not the contact point of the water flow switch 76 is off. If the contact is off (a state in which no water flow is detected) (YES), the process proceeds to step S6, and if the contact is on (NO). ) Proceeds to step S2.

In step S6, the microcomputer 5 instructs the motor drive circuit 501 so that the motor drive circuit 501 stops energizing the motor 74.

In step S7, it is considered that the motor 74 is in the locked state, and the microcomputer 5 instructs the motor drive circuit 501 so that the motor drive circuit 501 stops energizing the motor 74.

At step S8, the microcomputer 5
Determines whether the contact of the water flow switch 76 is off via the switch circuit 502 and turns on (water flow detection state).
In the case of (YES), the process returns to step S2, and in the case of off (NO), the process returns to step S6.

Hereinafter, advantages of the instantaneous gas water heater A of the present embodiment will be described. [A] 0.8 seconds from the completion of ignition operation (at high capacity) or 1.
After a lapse of 6 seconds (at low power), the microcomputer 5
Is a configuration for monitoring the thermoelectromotive force. Therefore, even if the operation switch 71 is pressed immediately after the gas burner 1 is extinguished and the ignition is missed (flame current is not detected), the electromagnetic valve 2 is closed after the forced adsorption is stopped, so that the raw gas is not released and the safety is ensured.

Further, the microcomputer 5 stops supplying power to the flame rod circuit 3 when one second has elapsed (elapsed time 802) after the thermoelectromotive force has exceeded the ignition detection level (elapsed time 801). , The operation of the frame rod circuit 3 is stopped, so that useless power is not consumed and the battery lasts longer.

[A] Also, as described above, since the delay of one second is provided, after the operation of the flame rod circuit 3 is stopped (the safety maintaining state only by the thermocouple 4), the heat is generated due to the fluctuation of the combustion flame or the like. Even if the electromotive force varies, the electromagnetic valve 2 does not close because the thermoelectromotive force does not become less than the predetermined value.

[C] As shown in steps s10 to s13, 0.1 seconds after the operation of the igniter circuit 503 (generation of high voltage for spark) and the operation of the flame rod circuit 3 (start of flame detection) are started. After a lapse of seconds, the suction and holding of the solenoid valve 2 is performed.

As a result, the inrush current does not increase.
Does not cause malfunction of each circuit (small voltage drop of battery voltage)
At the same time, since no heavy load is applied to the battery 6, the battery 6 lasts a long time.

[D] In step s12, the microcomputer 5 performs an initial check to determine whether the frame rod 31 or the frame rod circuit 3 has failed before opening the solenoid valve 2.

For this reason, explosion ignition during operation (may occur when the frame rod 31 or the frame rod circuit 3 fails)
Can be prevented.

[E] The buzzer is not sounded in the event of an ignition error,
The buzzer is sounded only when a high degree of abnormality is detected, such as when a misfire or incomplete combustion occurs, or when the user operates the operation switch 71.

Therefore, the buzzer sounds only when necessary, so that the user can be surely alerted and the battery 6 is not burdened. In addition, the operation can be confirmed.

Further, in the above embodiment, the instantaneous gas water heater is shown as the combustion device of the present invention.
Other combustion devices may be used.

In the above embodiment, the monitoring of the thermoelectromotive force by the second flame detecting means is started after a set time from the start of the ignition. However, like the first flame detecting means, the monitoring of the thermoelectromotive force is started from the start of the ignition. You may make it start.

[Brief description of the drawings]

FIG. 1 is an external view of a gas instantaneous water heater according to one embodiment of the present invention.

FIG. 2 is an explanatory view of the structure of the instant gas water heater.

FIG. 3 is an explanatory view of a position detecting means of the instantaneous gas water heater.

FIG. 4 is a block diagram of the instant gas heater.

FIG. 5 is an electric circuit diagram of a frame rod circuit of the instantaneous gas water heater.

FIG. 6 is a time chart for explaining the operation of each part of the instant gas water heater.

FIG. 7 is a flowchart showing the operation of the instant gas heater.

FIG. 8 is a flowchart showing the operation of the instant gas heater.

FIG. 9 is a flowchart showing the operation of the instant gas heater.

FIG. 10 is a flowchart showing the operation of the instant gas water heater.

FIG. 11 is a flowchart showing the operation of the instant gas heater.

FIG. 12 is a time chart for explaining a conventional technique.

[Explanation of symbols]

 A gas instantaneous water heater (combustion device) 1 gas burner 2 solenoid valve 3 flame rod circuit (first flame detection means) 4 thermocouple (thermocouple) 5 microcomputer (control means) 11 gas pipe 31 flame rod 505 thermocouple Circuit (second flame detection means)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F23N 5/12 F16K 31/06 310 F23N 5/10 320

Claims (1)

(57) [Claims] 1. A gas burner to which gas is supplied via a gas pipe, an electromagnetic valve disposed in the gas pipe, and a first means for detecting the presence or absence of a flame current by causing a flame rod to face a flame of the gas burner. A combustion detecting apparatus comprising: a flame detecting means; a second flame detecting means for causing a thermocouple to face the gas burner to output a thermoelectromotive force in proportion to a flame temperature; and a control means for controlling opening and closing of the electromagnetic valve. In the above, the control means may be configured to output the heat generated by the second flame detection means.
The operation of the first flame detecting means is stopped after a predetermined time has elapsed since the electric power has become equal to or higher than the predetermined value, and the solenoid valve is kept open while the thermoelectromotive force is maintained at or above the predetermined value. Combustion device characterized by things.