JPS63306311A - Combustion device - Google Patents

Abstract

PURPOSE:To surely keep safety and enable positive combustion in a combustion device such as hot water heater by a method wherein a fuel valve is kept open during a desired auxiliary time after ignition and this auxiliary time is extended by a desired time when ignition of a burner is confirmed. CONSTITUTION:First and second fuel valves 12A and 12B are opened under a pushing operation of a hot water feeding member 16 to its deepest position and then a pilot burner 11 is ignited. At this time, an initial opening valve holding circuit 22A of a control circuit 22 may output an auxiliary time until the opened valve of a first fuel valve 12A can be kept with an electromotive force of a first thermocouple 19 heated by a pilot burner 11 so as to assure the opened valve of the fuel valve 12A. If the ignition is confirmed with a flame rod 25 within this auxiliary time, a forced valve opening holding electrical power is supplied for a desired time. With this arrangement, it is possible to make a positive ignition while keeping safety characteristic.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to combustion devices such as water heaters, stoves, gas heating appliances, boilers, and industrial burners. A fuel valve is provided that is opened in response to an ignition operation and held in an open state against a closing force by electric power generated by a thermocouple due to heating by a burner,
An improvement in a combustion device including an initial valve opening holding circuit that supplies forced valve opening holding power sufficient to hold the fuel valve in an open state for a set auxiliary time after ignition operation by the burner ignition operating tool. Regarding.

[Conventional technology]

In the above-mentioned combustion device, after a burner ignition operation accompanied by a fuel valve opening operation, the forced valve opening holding power sufficient to close the fuel valve and hold it in the open state against the biasing force is initially set for an auxiliary time. By supplying power from the valve-open holding circuit, the fuel valve can be opened without the operator having to maintain the fuel valve open while the power generated by the thermocouple for holding the fuel valve open increases to a predetermined value. This is intended to simplify the ignition operation that accompanies the fuel valve opening operation by automatically holding the valve open, but conventionally, as shown in Figure 5, after the ignition operation, the thermocouple A time slightly longer than the time (to) required for the generated power (current 50) to reach a power value (current value ia) sufficient to close the fuel valve and keep it in the open state against the biasing force, A type that continues to supply forced valve-opening power (current i+), or, as shown in Figure 4, a forced-opening power that is sufficient to keep the fuel valve open independently for the purpose of power saving (current 1+). ), the supply time of the forced valve opening holding power (current 1+) is stopped, and then the auxiliary power (current +z ) for a predetermined period of time (t2), but in any case, the forced valve-opening power (current The above-mentioned auxiliary setting time (1+) for causing the supply of ++) to be executed by the initial valve opening holding circuit was fixedly set.

[Problem that the invention seeks to solve]

However, in order to shorten the fuel leakage time in the event that the burner does not ignite for some reason during burner ignition operation, if the above-mentioned auxiliary setting time (t1) is set as short as possible for each model, safety against fuel leakage may be reduced. Although there is no particular problem in normal use, it may be caused by various disturbance factors such as fluctuations in fuel supply pressure, fluctuations in fuel concentration, or changes in fuel ignitability due to temperature changes. When the heating property of the thermocouple changes, albeit slightly, and as a result, the rise of the thermocouple generated power (current to) becomes slower as shown by the broken line in Figures 4 and 5, the set auxiliary time (tl ) becomes relatively insufficient and the supply of forced valve-open holding power (current i+) by the initial valve-open holding circuit is stopped, the fuel valve closes due to the closing force, and as a result, the device Even though there were no major failures, there were cases in which the burner became unable to start combustion, causing inconvenience during use.

However, if the setting assistance time (t1) is set long, the burner combustion operation can be reliably started even if the rising state of the thermocouple-generated power changes slightly due to disturbances as described above, making it easier to use. However, on the other hand, the safety against fuel leakage in the event of burner misfire decreases.For this reason, in the past, in this type of combustion equipment, intermediate methods were used that sacrificed both ease of use and safety to some extent. The actual situation is that the setting assistance time 1+ is set at a certain time, and there is still room for improvement in this respect.

The purpose of the present invention is to ensure the start of burner combustion operation even in the face of some disturbance, while ensuring sufficient safety against fuel leakage in the event of burner mis-ignition, by making reasonable improvements in view of the above-mentioned actual circumstances. The aim is to improve ease of use by making it easier to use.

Means for Solving Problem c] The combustion device according to the present invention opens the valve in conjunction with the burner ignition operating tool in conjunction with the ignition operation, and closes by the electric power generated by the thermocouple due to heating by the burner. a fuel valve that is held in the open state against the burner ignition operating device, and a force sufficient to maintain the fuel valve in the open state for a set auxiliary time (1+) after the ignition operation by the burner ignition operating device; In a type that is provided with an initial valve-open holding circuit that supplies valve-open holding power, an ignition detection means for confirming ignition of the burner is provided, and after the ignition operation by the burner ignition operating tool, within the set auxiliary time (t1). When burner ignition is confirmed by the ignition detection means, the supply of forced valve-open holding power by the initial valve-open holding circuit is continued for the set auxiliary time (1+).
The present invention is characterized by the provision of a forced holding extension means that continues for a predetermined extension time (Δt) even after the elapse of .

[For production]

That is, when the burner does not ignite, there is no burner ignition confirmation information from the ignition detection means, so the supply of forced valve-open holding power by the initial valve-open holding circuit is stopped when the set auxiliary time (t1) has elapsed. In other words, the setting assistance time (t
If l) is set short, in the event of a burner misfire, the supply of power to maintain the forcibly opened valve will be cut off in that short time (tl), and the fuel valve will close and be cut off by the biasing force. Safety against fuel leakage is sufficiently ensured.

Furthermore, even if the set auxiliary time (t1) is set as short as possible for safety reasons, if burner ignition is confirmed by the ignition detection means (i.e., when there is no longer any risk of fuel leakage), the set auxiliary time (t1) will be shortened. Even after (t1) has elapsed, the supply of forced valve-opening power is continued for a predetermined time (Δt
) is extended, and the forced open holding of the fuel valve is automatically extended. The transition to the state in which the fuel valve is held open is reliably executed even if the rise of the thermocouple-generated power is somewhat delayed due to various disturbances.

In other words, the burner combustion operation can be performed reliably even in the face of some disturbance.

〔Effect of the invention〕

As a result, compared to conventional devices which sacrifice both ease of use and safety to some extent, an excellent combustion device is achieved which has higher safety against fuel leakage in the event of misfire and is also easier to use.

〔Example〕

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

Figure 1 shows a stop-start instant water heater as an example of a combustion device, in which a casing (1) includes a fin-tube heat exchanger (2) for heating water, and a main burner (3) for heating the water.
), and a flexible hot water tap (5) connected to the water heater (4) from the heat exchanger (2) extends from the lower end of the casing (1).

The water supply channel (6) to the heat exchanger (2) is equipped with a faucet (7) for intermittent water supply, a diaphragm type water governor (8), and a water volume adjustment valve (9). , the gas fuel supply passage (10) has first and second passages for intermittent fuel supply to the main burner (3) and the pilot burner (11).
fuel valve (12A), (12B), water governor (8)
) in conjunction with the diaphragm in the heat exchanger (2)
A hydraulic valve (13) that allows fuel to be supplied to the main burner (3) only when water is supplied to the main burner (3), and a gas governor (14).
) and a fuel supply amount adjustment valve (15) are interposed.

To start and stop hot water supply, use the push button hot water supply operation tool (1
Specifically, when the hot water supply operation tool (16) in the protruding position (a) is pushed to the innermost position (b), the first and second fuel valves (12A), ( 1
2B) is opened and the spark plug (17A),
(17B) starts the ignition operation for the pilot burner (11) and the main burner (3), and first, the pilot burner (11) is ignited.

Then, after pushing it to the innermost position (b), the hot water supply operation tool (
When the push operation for 16) is released, the hot water supply operation tool (1
6) self-returns to the holding position (c) and returns to the holding position (c).
The water faucet (7) is opened in conjunction with the return to the holding position (c), and accordingly, the hydraulic response valve (7) is opened.
13) is opened in conjunction with the water governor (8), the main burner (3) is ignited, hot water supply starts, and the hot water supply operation tool (16) is held at the holding position (c). Hot water continues to be supplied in this condition.

When the hot water supply operation tool (16) held in the holding position (c) is pushed again, it is allowed to be pushed to the holding release position (d), which does not reach the innermost position (b), and the holding is released. The holding of the hot water supply operating tool is released by pushing it to position (d), and when the pushing operation is released, the hot water supply operating tool (16) returns by itself to the protruding position (a), and returns to the protruding position (a). Along with this, the faucet (7) and the second fuel valve (12B) are closed, and hot water supply is stopped.

On the other hand, the water volume adjustment valve (9) and the fuel supply volume adjustment valve (15)
The readjustment valve (9) is operated by rotating the dial-type hot water temperature regulator (18).
) and (15) are linked in such a way that the opening degrees of these regulating valves (9) and (15) are adjusted in a contradictory manner, and the water supply temperature is adjusted by adjusting the opening degrees of these regulating valves (9) and (15) in a contradictory manner.

The first fuel valve (12A) has a function as a safety valve and is a closed bias type, and the pilot burner (11)
During the combustion operation of the pilot burner (11
) The electric power generated by the first thermocouple (19) closes the first fuel valve (12A) and electromagnetically holds it in the open state against the biasing force.

In addition, the coil part of the first fuel valve (12A) and the first thermocouple (1
The electrical circuit (20) connecting the main burner (3)
) is interposed with a second thermocouple (21) disposed near the heat exchanger (2) in the combustion chamber with the polarity opposite to that of the first thermocouple (19). When incomplete combustion occurs due to extinction or lack of oxygen,
As the power generated by the thermocouple (19) decreases, or when incomplete combustion occurs due to exhaust passage blockage, the power generated by the second thermocouple (21) increases accordingly, causing the first thermocouple (
By offsetting the generated electric power of 19), the first fuel valve (12A) is automatically closed by the closing biasing force.

After pushing the hot water supply operation tool (16) to the innermost position (b), that is, the first and second fuel valves (12A).

Pilot burner (11) with valve opening operation of (12B)
After the ignition operation (see Figure 4), the pilot burner (
11), the power generated by the first thermocouple (19) (current 10) becomes a power value (current value ia) sufficient to close the first fuel valve (12A) and keep it open against the biasing force. During this period (rise time to), an initial amount valve holding circuit (22A) incorporated in a separate control circuit (22) first controls the first fuel valve (12) after the pilot burner (11) ignition operation.
A), the forced valve opening holding power (current 1+) sufficient to close the valve and keep it open against the biasing force is applied for the set auxiliary time (
t1), and after supplying the forced valve opening holding power (current 1+), the first fuel valve (12A) is subsequently opened by the sum of the power generated by the first thermocouple (19) (current i0). Auxiliary power (current tz) to keep the valve open for a predetermined time (t2)
The first fuel valve (12A) is maintained in an open state against the closing force by supplying only the amount of fuel, thereby ensuring that the first thermocouple (19) generates sufficient power. Until the first fuel valve (12A) is held open by the generated electric power, the operator does not need to keep the valve open, ie, press and hold the hot water supply operating tool (16).

Also, within the set auxiliary time (1+) during which forced valve opening holding power (current L) is supplied to the control circuit (22),
When ignition of the pilot burner (11) is confirmed by the flame rod (23) serving as an ignition detection means, the initial amount valve holding circuit (22A) supplies power (current iI) to maintain the forced valve opening as shown in Fig. 4. As shown by the dashed line, a forced hold extension operation circuit (22B) that automatically continues for a predetermined extension time (Δt) even after the set auxiliary time (t1) has elapsed.
is incorporated together with an initial amount valve holding circuit (22A).

In other words, in order to shorten the fuel leakage time when the pilot burner (11) does not ignite for some reason during the ignition operation, the set auxiliary time (tl) is set as short as possible, but the set auxiliary time (1+) is set as short as possible. If it is fixedly set to a short time, it may cause fluctuations in the fuel gas supply pressure or a decrease in the fuel gas concentration (when igniting after a long period of shutdown, or if the fuel valve (12^) + The first thermocouple is caused by disturbance factors such as (caused by mixing with air that has entered the fuel supply path (10) on the downstream side of (12B)) or changes in the ignitability of the fuel gas due to temperature changes. The power generated by the first thermocouple (19) (
If the rise of the current 10) is delayed as shown by the broken line in Fig. 4, the supply of the forced valve-opening power (current 11) is stopped relatively early and the current 10) starts to rise at the point when the set auxiliary time (tl) has elapsed. 1 fuel valve (12A) has closed, and as a result,
It may become impossible to start combustion operation.

Therefore, as mentioned above, when ignition of the pilot burner (11) is confirmed by the flame rod (23), the forced holding extension operation circuit (22B) automatically extends the supply of forced valve opening holding power (current ++). By doing so, even if the rise of the power (current to) generated by the first thermocouple (19) is somewhat delayed due to various disturbances, the power (current to) generated by the first thermocouple (19) This is to ensure that the first fuel valve (12A) shifts to the state where it is held open by the sum of the auxiliary power (current tz) and the auxiliary power (current tz).

Figure 2 shows the specific configuration of the control circuit (22), and its operation (see Figures 3 and 4) is as follows: (a) When the hot water supply operating tool (16) is pushed to the innermost position (b). Then, the start switch (SWI) turns ON, and the start switch (SWI) turns ON.
When the SWI) is turned on, the first timer circuit (T1) and the second
The timer circuit (T2) is activated, thereby turning on the first contact (Sl) and the second contact (S2).

And O of the first and second contacts (Sl) and (S2)
Since the first relay (R1) and the second relay (Rz) are excited by N, and the first relay contact (r1) and the second relay contact (r2) are turned ON, the first fuel valve (12A)
Forced valve opening holding power for the coil (current L = t+
'+it) supply is started, and the hot water supply operation tool (16)
The first fuel valve (12A) opened by the pushing operation is held open, and the ignition circuit (24) is activated to start the ignition operation of the spark plugs (17A) and (17B).

Incidentally, the first timer circuit (T1) is configured to perform the above-mentioned setting auxiliary time (
1+), and the second timer circuit (T2
) is the set auxiliary time (t1) and the auxiliary power (current it
) The respective times are set so that the time-up is equal to the sum of the predetermined time (t2) for supplying.

(b) Even if the push operation on the hot water supply operating tool (16) is released and the hot water supply operating tool (16) returns to the holding device (c), the hot water supply operation is performed so that the start switch (SWI) is maintained in the ON state. Therefore, even after the hot water supply operation tool (16) returns to the holding position (c), the first relay contact (rl) and the second relay contact (r2)
remains ON, and the forced valve opening holding power (current i, = i
, "+it) to keep the first fuel valve (12A) open and the spark plugs (17A) and (17B) to ignite, respectively. While this state is maintained, the pilot Burner (11) and main burner (3) are ignited.

(c) When the pilot burner (11) ignites, the contact (SF) of the flame rod (23) circuit turns ON and the third relay (R1) is energized. The fourth relay contact (r4) is turned on and the fifth relay contact (r1) is turned off.

Then, the third and fourth relay contacts (r3), (r=
), the first extension timer circuit (T3) and the second extension timer circuit (T4) are started, and the first extension timer circuit (T4) is activated.
and a second extension timer circuit (h).

(T4) is activated, the third contact (S3) and the fourth contact (
S4) is turned ON. Also, O of the fifth relay contact (r1)
The ignition operation of the spark plugs (17^) and (17, 8) is stopped by the FF.

Note that the first extension timer circuit (T1), like the first timer circuit (TI), times up at a time equal to the setting auxiliary time (tl), and the second extension timer circuit (T4) Similarly to the 2-timer circuit (T2), each time is set so that time amplification is performed at a time (h + tz) equal to the sum of the set auxiliary time (t1) and the predetermined time (t2) for supplying auxiliary power (current iz). It is set.

) After that, when the set auxiliary time (t1) has elapsed from the time of the ignition operation, the first timer circuit (T1) times up and the first contact (Sl) turns OFF, but the first timer circuit (TI) The first extension timer circuit (T1), which started late, is still counting time and the third contact (T1) is still counting time.
S3) is ON, the first relay contact (rl) is maintained ON, and thereby the first fuel valve (12A)
The supply of forced valve opening holding power (current L=L''it) to the valve continues even after the set auxiliary time (tl) has elapsed.

In other words, the difference in startup time between the first timer circuit (T1) and the first extension timer circuit (T1), that is, after the ignition operation, the pilot burner (1) is activated by the flame rond (23).
Forced valve-opening power (current 11 = il° + t
z) supply is extended.

In a normal case, after the ignition operation, at the time when this setting auxiliary time (t1) has elapsed, the generated power (current to) of the first thermocouple (19) is equal to the ON state of the second relay contact (i). The sum of the auxiliary power (current td) supplied by the auxiliary power has increased to a value that can keep the first fuel valve (12A) open.

On the other hand, if the pilot burner (11) does not ignite for some reason during the above-mentioned main stage, the flame rond (23) does not confirm the ignition of the pilot burner (11) (contact (SF) turns ON). , activation of the first extension timer circuit (T3) (i.e., the third contact (S3)
Since there is no forced valve opening holding power (current i1 = i% + iz) after the ignition operation,
At this point when the set auxiliary time (t1) has elapsed, the first relay contact (rl) is turned OFF to stop (auxiliary power (current tz
) is continued), and as a result, the first thermocouple (19) does not generate electricity due to the misfire, so the first fuel valve (12A) is closed by the closing force at this point. .

(E) After the setting assistance time (tl) has elapsed, the above-mentioned extension time (Δt) has elapsed, and the first extension timer circuit (T
3) times out, the third contact (S3) turns OFF.
As a result, the first relay contact (r+) is turned OFF, and the forced opening holding power for the first fuel valve (12A) (current iI=
i1' + iz) is cut off.

From this point on, the auxiliary power (current ig) continues to be supplied by keeping the second relay contact (r1) ON by the second timer circuit ('h), and the power generated by the first thermocouple (19) (current io), the first fuel valve (12A) is held open.

(to) Then, the time (tl + h) from the point of ignition operation
When the second timer circuit (T2) times out, the second contact (S2) turns OFF, but the second extension timer circuit (T4), which started later than the second timer circuit (T), is still running out of time. While counting is in progress, the fourth contact (S
4) is ON, the second relay contact (rz) is O.
N, so that the supply of auxiliary power (current it) to the first fuel valve (12A) is maintained even after the second timer circuit (Tz) times out.

In other words, in case the rise of the power generated by the first thermocouple (19) (current 10) is delayed due to various disturbances, the forced valve opening holding power (current t+"il'+iz) is supplied. For the same purpose as the extension of the set auxiliary time (1+), the flame rod 7 (2
3), the supply of auxiliary power (current tz) is also extended by a time (Δt) equal to the time required until ignition of the pilot burner (11) is confirmed.

In addition, in the case of misfire in which the first fuel valve (12A) closes at the point in time (as described above), the first extension timer circuit (T3)
Similarly, since the second extension timer circuit (T4) is not activated (that is, the fourth contact (S4) is turned on), the auxiliary power (current tz) is supplied for a period of time D+ + after the ignition operation.
At this point when time (tz) has elapsed, the second relay contact (T2) is turned OFF, thereby stopping the power supply to the first fuel valve (12A) in the event of a misfire.

(g) Finally, when the second extension timer circuit (T4) times up, the fourth contact (S4) turns OFF and the second
The relay contact (T2) turns OFF and the first fuel valve (12
The supply of auxiliary power (current it) to A) is stopped.

After this, normally, the first thermocouple (19 )
The first fuel valve (12A
) is held in an open state, and hot water supply operation continues in that state.

(1) When the hot water supply operating tool (16) held at the holding position (c) in the hot water supply operation state is pushed again to stop the hot water supply operation and returns to the protruding position (a), the second fuel valve (12B ) is closed, the main burner (3) and pilot burner (11) are extinguished, and as a result, the first thermocouple (19) stops generating electricity, so the first fuel valve (12A) is closed. Closed due to force.

This concludes the explanation of the operation of the control circuit (22) incorporating the initial valve opening holding circuit (22A) and the forced holding extension operation circuit (22B). In Fig. 2, (El) and (Ez) are battery power sources. be.

Further, in FIG. 3, broken lines indicate the operation of each part when there is no ignition.

[Another example]

Next, other embodiments of the present invention will be listed.

(al In the above embodiment, the pilot burner (1
1) The thermocouple (19) generates electric power to keep the fuel valve (12A) open by heating the thermocouple (19). Even if the model is equipped with a thermocouple (19), the fuel valve (
12A) may be configured to generate electric power to keep the valve open.

(bl) In the fuel valve (12A), the coil excited by the power generated by the thermocouple (19) and the coil excited by the forced valve holding power may be separate coils, or,
It can also be used as a dual purpose coil.

(cl In the above embodiment, forced valve opening holding power (
Both the supply of current 11-I+' +tz) and the supply of auxiliary power (current tz) are extended based on burner ignition detection, but the auxiliary power supply value (current value i
z), or the time to run the auxiliary power supply (
Depending on the setting of t2), only the supply of forced valve-opening power may be extended based on burner ignition detection.

In addition, the auxiliary power (current iz) is supplied only by the fuel valve (12^)
Since the power cannot keep the valve open, the auxiliary power supply time (t2) is relatively long, taking into account the delay in the rise of the power generated by the thermocouple (19), and even if it is set fixedly. , safety against fuel leakage in the event of misfire is not compromised.

fdl Model that does not supply auxiliary power following forced valve-opening power supply (see Figure 5), that is, setting auxiliary time (tl) for supplying forced valve-opening power (current 1+)
is the rise time (to) of the thermocouple generated power (current io)
Even if the present invention is applied to a model that is set for a slightly longer period of time, the supply of forced valve-opening power is continued for a predetermined extension time (Δt) after the set auxiliary time (t1) has elapsed based on ignition detection. good. Furthermore, if the present invention is applied to this type, the setting assistance time (t1) can be set shorter than the rise time of the thermocouple.

tel In the above embodiment, the frame rod (23
), but the thermocouple (19) that generates electric power to keep the fuel valve (12A) open, or
Burner ignition may be confirmed by detecting the power generated by a thermocouple separately provided for ignition confirmation, and various types of detection mechanisms can be used as means for confirming burner ignition.

Further, the ignition detection target may be the pilot burner (11) or the main burner (3), or may be both of them.

If) After the ignition operation, the burner ignition f11 is performed by the initial valve opening holding circuit (22A) that supplies forced valve opening holding power (current L>ia) for the set auxiliary time (tl) and the ignition detection means (23). Based on the approval, the initial valve holding circuit (22
Even after the set auxiliary time (1+) has elapsed, the supply of forced valve-opening power (current i+>ia) by A) continues for a specified extension time (Δt
) is a forced hold extension operation circuit that automatically continues the extension (
22B) (Forced holding extension means) The specific circuit configuration and means configuration of each can be changed in various ways, for example, by using a control configuration using a microcomputer instead of configuring them using an analog electrical sequence circuit. It is.

(g) The present invention provides high safety <i! can be recognized, and
This has the advantage that combustion operation can be started reliably even if the rise of the thermocouple-generated power is delayed due to various disturbances, but it is not possible to absorb variations in the rise time of the thermocouples that are the equipment components. There is also the advantage that the performance of the product combustion apparatus can be made uniform by using the combustion apparatus, and in that sense, the present invention is also useful in the production of combustion apparatuses.

(hl・The present invention is based on the second fuel valve (12
It can also be applied to a model that does not include a fuel valve corresponding to B).

fil The present invention can be applied to various combustion devices such as stoves, gas heaters, boilers, industrial burners, etc. in addition to water heaters.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

Figures 1 to 4 show embodiments of the present invention; Figure 1 is a configuration diagram of a water heater, Figure 2 is a circuit diagram, Figure 3 is a time chart, and Figure 4 is a power supply configuration. This is a graph showing. FIG. 5 is a graph showing the power supply status in another type. (12A)...Fuel valve, (16)...
Ignition operating tool, (19)...Thermocouple, (22A)
...Initial amount valve holding circuit, (22B) ...
・Forced holding extension means, (23)...Ignition detection means, (tl)...Setting assistance time, (Δt)...
...Prescribed extension time.

Claims (1)

[Claims] 1. The valve is opened with the ignition operation by interlocking with the burner ignition operation tool (16), and the thermocouple (
A fuel valve (12A) is provided which is held in an open state against the closing force by the electric power generated by the burner ignition operating tool (16). The combustion apparatus is provided with an initial valve-opening holding circuit (22A) that supplies the fuel valve (12A) with forceful valve-opening power sufficient to keep it in an open state, and the combustion apparatus is provided with an initial valve-opening holding circuit (22A) for confirming ignition of the burner. An ignition detection means (23) is provided, and the ignition detection means (23) detects the ignition within the set auxiliary time (t_1) after the ignition operation by the burner ignition operating tool (16).
3), when burner ignition is confirmed, the supply of forced valve-open holding power by the initial valve-open holding circuit (22A) continues for a predetermined extension time (Δt) even after the set auxiliary time (t_1) has elapsed. A combustion device provided with a forced holding extension means (22B) to 2. After the ignition operation, the forced holding extension means (22B)
The combustion apparatus according to claim 1, wherein the predetermined extended time (Δt) is a time corresponding to the time required until burner ignition is confirmed by the ignition detection means (23). 3. The combustion apparatus according to claim 1 or 2, wherein the ignition detection means confirms burner ignition by detecting the electric power generated by the thermocouple (19).