JP4440836B2 - Gas stove - Google Patents

Description

  The present invention relates to a gas stove in which measures for preventing overheating such as a gas stove and its installation part have been taken, and is capable of promptly preventing overheating.

There is a gas stove disclosed in Patent Document 1 as a gas stove that has been provided with the above-mentioned countermeasure against overheating.
This is assembled in a state of being dropped into the countertop of the system kitchen, and a burner opening corresponding to the gas burner is opened on the stove top plate covering the upper end opening of the stove case. Further, a temperature sensor is provided in the air passage for the air flowing from the stove case to the burner opening due to the draft during burner combustion.
In this case, the gas burner is extinguished when the temperature detected by the temperature sensor provided in the air passage rises to a preset overheat prevention temperature, thereby overheating the stove case and its installation part. Is preventing.
Japanese Patent No. 3418092

However, in the conventional apparatus, the overheat prevention temperature Tmax is set to a relatively high temperature (for example, 150 ° C.) as shown in FIG. 8 in order to prevent the overheat prevention function from operating frequently.
On the other hand, in the so-called drop-in stove assembled to the countertop of the system kitchen, a storage is often provided below the countertop in a portion adjacent to the so-called drop-in stove. In this case, the negative pressure generated when the storage door is opened is transmitted into the stove case of the drop-in stove, whereby the flame of the gas burner flows backward from the burner opening into the stove case (hereinafter referred to as “back-flow combustion”). There is a case.

However, in the above-mentioned conventional one, even during reverse flow combustion, the gas burner is not extinguished until the temperature detected by the temperature sensor is raised to the overheat prevention temperature Tmax set to a high temperature, so the overheat prevention function does not work quickly and is safe. There was a problem that early return to the state could not be ensured.
This invention is made in view of this point, and makes it a subject to enable the early return | restoration to a safe state by making the said overheat prevention function work | function quickly.

1. The solution means of the invention according to claim 1 for solving the above-mentioned problem is
A plurality of gas burners disposed "in stove case,
A stove top plate that covers the upper end opening of the stove case and has an opening for the burner facing the gas burner;
A temperature sensor disposed in a ventilation path of air flowing from the stove case to the burner opening;
A gas source valve in a common gas circuit on the upstream side supplying gas to each gas burner ,
In the gas stove that prevents overheating in the stove case based on the temperature detected by the temperature sensor,
A temperature gradient determining means for determining a temperature gradient as a temporal change rate of the temperature detected by the temperature sensor;
When the temperature gradient determined by the temperature gradient determination means is larger than the reference gradient, an overheat prevention command is output, and when the temperature gradient is equal to or less than the reference gradient, a gradient comparison means that outputs a combustion continuation command;
The temperature higher than the assumed maximum value of the detection temperature of the temperature sensor during normal use is defined as the overheat suppression temperature,
A suppression temperature determination unit that outputs a combustion suppression command when the temperature detected by the temperature sensor further increases to the overheat suppression temperature after the gradient comparison unit outputs the combustion continuation command;
It said gradient comparison means to extinguish the gas burners by closing the gas valve in response to the overheating prevention command outputs Rutotomoni, the response to the fire-retardant command the suppressing temperature determining means outputs the gas burner a burner control means Ru reduce the amount of combustion comprising a "is at.
According to the above solution, for example, when the inside of the stove case is in a negative pressure state and a reverse flow combustion state occurs in which the flame of the gas burner flows back into the stove case, the temperature detected by the temperature sensor provided in the stove case increases rapidly. . In this case, a temperature gradient that is a temporal change rate of the detected temperature is determined by the temperature gradient determining unit, and when the determined temperature gradient is larger than the reference gradient, the gradient comparing unit outputs an overheat prevention command. And by this overheating prevention command, a burner control means extinguishes a gas burner and ensures a safe state.

  In this case, the gas burner is extinguished based on the temperature gradient of the temperature detected by the temperature sensor. Accordingly, in order to prevent frequent overheat prevention operation, unlike the conventional one in which the overheat prevention function does not work until the temperature is raised to the above-described overheat prevention temperature Tmax set to a high temperature, before the temperature rises to the overheat prevention temperature Tmax. But the overheat prevention function works quickly.

Moreover, according to the said gas stove, when the inside of a stove case becomes an overheated state, each gas burner can be extinguished collectively by closing a gas main valve. Therefore, when there is a possibility that other gas burners may also generate backflow combustion because the inside of the stove case is in a negative pressure state, the backflow combustion of the other gas burners can be prevented in advance, so that safety is improved.

Further, in the above-described gas stove, even in a usage mode (hereinafter referred to as “potentially abnormal use”) in which an excessive pan or iron plate that covers the upper side of the gas burner is hung, a temperature gradient is provided as long as the backflow combustion does not occur. In consideration of the fact that may be smaller than the reference gradient, it is possible to cope with the potential abnormal use.

That is, during normal use of the gas stove, the temperature inside the stove case rises to a temperature equilibrium state after the maximum temperature. On the other hand, during a potentially abnormal use where an excessive pan, iron plate, or the like is hung on the gas stove, hot air is generated in the stove case, so that the temperature inside the stove case further exceeds the maximum temperature.

Therefore, even when the temperature gradient is smaller than the reference gradient and the combustion continuation command is output from the gradient comparison means, the temperature detected by the temperature sensor is the overheat suppression temperature (the temperature during normal use) during the potential abnormal use. The temperature is raised to a temperature higher than the assumed maximum value of the detection temperature of the sensor), and a combustion suppression command is output from the overheat suppression means.
When the combustion suppression command is output, the burner control means reduces the amount of combustion of the gas burner, thereby preventing overheating in the stove case. Therefore, the gas stove can be used continuously while preventing overheating in the stove case.

4). Like the invention according to claim 2 ,
[In the gas stove according to claim 1 ,
After reducing the combustion amount of the gas burner, when the temperature detected by the temperature sensor falls to a safe temperature lower than the overheat suppression temperature, the combustion amount of the gas burner is returned to the state before the reduction. As a result of reducing the amount, if the temperature in the stove case, that is, the temperature detected by the temperature sensor falls to a safe temperature, the combustion amount of the gas burner is returned to the state before the reduction, so the combustion amount is reduced. Compared with the case where it is left unattended, precise control is possible and the convenience of the gas stove is improved.

3 . Like the invention according to claim 3 ,
[In the gas stove according to claim 2 ,
When the combustion amount of the gas burner is reduced or when the combustion amount is returned to the state before the reduction, a notification to that effect is used. In this case, the change in the combustion amount of the gas burner is not related to the intention of the stove user. It can be notified that it is based on the function. Therefore, it is possible to call attention when the change in the combustion amount of the gas burner affects the cooking, and it is possible to prevent cooking failures and the like.

4 . As in the invention according to claim 4 ,
"In gas stove according to claims 1 to claim 3,
If the detected temperature of the temperature sensor rises to an overheat prevention temperature higher than the overheat suppression temperature after reducing the combustion amount of the gas burner, the gas burner can be extinguished.
In this case, if the temperature in the stove case detected by the temperature sensor rises to the overheat prevention temperature even if the combustion amount of the gas burner is reduced, it is considered that the pan or iron plate hung on the gas stove is extremely large. , Extinguish the gas burner to maintain a safe state.

5 . As in the invention according to claim 5,
[In the gas stove according to any one of claims 1 to 4 ,
When the gas burner is extinguished, ignition of the gas burner can be prohibited until the temperature detected by the temperature sensor falls to the ignition allowable temperature or the set time has elapsed.
In this case, after the gas burner is extinguished, ignition of the gas burner is prohibited until the temperature detected by the temperature sensor provided in the stove case falls to the ignition allowable temperature or until a set time elapses. Therefore, unlike the case where reignition is allowed immediately after the gas burner is extinguished, there is no inconvenience that the gas burner is repeatedly ignited and extinguished before the overheating state in the stove case is eliminated.

The present invention has the following specific effects.
As described above, in the present invention, the temperature gradient of the temperature detected by the temperature sensor is determined to extinguish the gas burner. Therefore, in order to prevent frequent overheat prevention operation, the overheat prevention function does not work until the temperature is raised to a high temperature set overheat prevention temperature. The overheat prevention function works, and it is possible to quickly return to the safe state.
In addition , as described above, when the inside of the stove case is overheated, each gas burner is extinguished at a time.Therefore, when the inside of the stove case is in a negative pressure state, other gas burners may cause back-flow combustion. Backflow combustion of other gas burners can be prevented in advance, and safety is improved. Further, the control is simplified as compared with the case where each gas burner is extinguished individually.

In addition , when the temperature inside the stove case rises to the overheat suppression temperature, the amount of combustion is reduced without extinguishing the gas burner, so there is a possibility of potential abnormal use such as when an excessive pan or iron plate is hung on the gas stove. The gas stove can be used continuously while preventing overheating.
In the invention according to claim 2 , when the temperature detected by the temperature sensor is lowered to the safe temperature, the combustion amount of the gas burner is returned to the state before the reduction, so that the gas stove is compared with the case where the combustion amount is reduced. Convenience is improved.

In the invention according to claim 3 , since the change in the combustion amount of the gas burner is notified, it is possible to prevent a cooking failure or the like as described above, and the usability of the gas stove is improved.
In the invention which concerns on Claim 4 , even if it reduces the combustion amount of a gas burner, a gas burner is extinguished only when the temperature in a stove case rises (when an iron plate etc. are very large). Therefore, safety can be ensured when the reduction of the combustion amount of the gas burner is not possible.
In the invention according to claim 5 , as described above, there is no inconvenience that the ignition and extinguishing of the gas burner are repeated before the overheating state is eliminated.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.
[Composition of gas stove]
FIG. 1 is a perspective view of a drop-in stove exemplifying a gas stove that is an object of the present invention, that is, a drop-in stove (A) that is mounted in an open state (K1) opened in a countertop (K) of a system kitchen. FIG.

  On the stove top plate (30) that covers the top opening of the stove case (3), gas burners (31) (32) (33) with heating capacity set to large, small, and medium are located. A grill (G) is provided at the front center of the case (3).

The stove operation section (34) located on the right side of the grill (G) has a rotary operation knob (31A) that combines the point and fire extinguishing and thermal power adjustment functions of each gas burner (31) (32) (33). 32A) and (33A) are provided, and each control knob (31A), (32A) and (33A) can be turned on and extinguished to the gas burners (31), (32) and (33) by repeating the pushing operation. It has become.
On the other hand, a grill knob (35A) similar to the knob for the gas burner is also disposed in the grill operation section (10) formed on the left side of the grill (G).

FIG. 2 is a cross-sectional view taken along a line II-II in FIG.
Gotoku (38) is placed above the burner opening (300) established on the stove top (30), and the large gas burner (31) faces the burner opening (300) from below. Yes.

  A flame detector (311) and an ignition electrode (312) are disposed near the flame hole (310) of the large gas burner (31), and the peripheral side plate of the stove case (3) is cut and raised inward. A temperature sensor (21) for detecting the ambient temperature is placed on the formed sensor support piece (37). Further, the temperature sensor (21), the flame detector (311), and the ignition electrode (312) are electrically connected to the control device (5) and, as shown in FIG. 3, small and medium gas burners (32) (33 ) And the flame burner (35), flame detectors (321) (331) (351) and ignition electrodes (322) (332) (352) are also arranged, and these are also controlled by the control device (5). Is electrically connected.

  As shown in FIG. 3, from the main gas circuit (4) in which the electromagnetic gas main valve (40) is disposed, gas is supplied to the gas burners (31) (32) (33) and the grill burner (35). The branch circuits (41), (42), (43), and (45) to be supplied are branched, and each of these branch circuits (41), (42), (43), and (45) has a function for opening and closing the circuit and gas amount adjustment. Motorized valves (51), (52), (53), and (55) that have both functions are provided, and these motorized valves (51), (52), (53), and (55) have the same configuration and have the same functions. It comes to show.

  The motorized valve (51) corresponding to the large gas burner (31) includes a safety valve (511) and a gas amount control valve (512) inserted in series in the branch circuit (41), and the gas amount control valve (512) The opening degree is adjusted by the rotation of the stepping motor (513). On the other hand, the safety valve (511) is interlocked with the forward / backward movement of the valve shaft (513C) pressed by a spring (not shown) to the cam disk (513B) attached to the rotating shaft (513A) of the stepping motor (513). Open and close. The stepping motor (513) and the gas main valve (40) are electrically connected to the control device (5).

  Furthermore, a limit switch (61) (62) for detecting the pushing operation (pointing / extinguishing operation) of the operation knob (31A) (32A) (33A) or the grill knob (35A) is provided at the input section of the control device (5). ) (63) (65) output and pulse encoders (71) (72) (73) (75) that detect the amount of rotation of the operation knob (31A) (32A) (33A) and the grille knob (35A) Output is applied.

[Control operation of gas stove]
The control device (5) incorporates a microcomputer in which a program having the contents shown in the flowcharts of FIGS. Hereinafter, the control operation of the gas stove according to the present embodiment will be described based on the flowcharts of FIGS. 4 to 7 and the temperature graph of FIG.

<Explanation of temperature graph>
The normal curve X shown in FIG. 8 shows the temperature change (change in the temperature detected by the temperature sensor (21)) during normal use, which is composed of the temperature rising area (a) and the temperature equilibrium area (b) that follows this. The abnormal curve Y in the side area shows the temperature change when an excessive pan or iron plate is placed on the Gotoku (38) and heated. In addition, the reverse flow combustion curve Z with the maximum temperature gradient indicates that each gas burner (31) is in a negative pressure state (such as when the door (20) of the storage (2) shown in FIG. 1 is opened) in the stove case (3). ), (32) and (33) show changes in the temperature detected by the temperature sensor (21) when the flame flows back into the stove case (3).

  At the time of potential abnormal use such as heating an excessive pan or iron plate, hot air is generated in the stove case (3). Therefore, in the abnormal curve Y of FIG. 8, the maximum value of the normal curve X (temperature equilibrium) The temperature rises further to the overheat suppression temperature B (see R point) beyond the temperature in the region (b). However, FIG. 8 illustrates a case where the temperature gradient in the initial temperature rise region (P) of the abnormal curve Y is larger than the temperature gradient in the temperature rise region (a) of the normal curve X. Since the temperature gradient between P) and the temperature increase range (a) varies widely, the magnitude relationship between the temperature gradients may be reversed. Therefore, it is practically impossible to distinguish between normal use and potential abnormal use by the temperature gradient.

In addition, as shown in FIG. 8, the temperature in the stove case (3) rises rapidly during back-flow combustion in which the flame of the gas burner flows back into the stove case (3), so the gradient of the back-flow combustion curve Z is the largest. .
In the present embodiment, the gradient of the virtual boundary straight line W set between the backflow combustion curve Z and the abnormal curve Y is set as a reference temperature gradient K0 which is a “reference gradient” which is the invention specific matter of claim 1. .

<< Explanation of control action >>
Next, details of the control operation will be described with reference to FIGS.
In step (ST1) of FIG. 4, it is determined whether or not an ignition operation has been performed on any of the gas burners (31), (32), (33) and the grill burner (35). Specifically, the push-in operation knob (31A) (32A) (33A) or the grill knob (35A) is pulled out to the advanced position and either of the limit switches (61) (62) (63) (65) It is determined whether or not an ignition signal (for example, an OFF signal) is output. When the ignition operation is performed, the gas source valve (40) disposed in the main gas circuit (4) is opened in step (ST2), and then the ignition routine is executed in step (ST3).

FIG. 5 is a detailed view of the ignition routine.
In step (ST31), determine the output of the limit switch (61) corresponding to the operation knob (31A) of the large gas burner (31), and if the limit switch (61) outputs an ignition signal, Gas is supplied to the large gas burner (31) at (ST32). That is, the pulse motor (513) incorporated in the motor operated valve (51) for the large gas burner (31) is rotated to the position corresponding to the medium fire, and thereby the cam disk (513B) attached to the rotating shaft (513A). ) Presses the valve shaft (513C) to open the safety valve (511). In addition, the gas amount control valve (512) is set to a medium-fire opening degree. Further, the igniter (59) is operated to execute an ignition operation from the ignition electrode (312) to the large gas burner (31). Next, in step (ST33), in order to confirm the ignition operation of the middle gas burner (33), the presence or absence of an ignition signal from the corresponding limit switch (63) is determined, and if the ignition signal can be confirmed, the large gas burner ( Similarly to 31), in step (ST34), the motor operated valve (53) for the middle gas burner (33) is operated to supply gas to the middle gas burner (33). Further, the igniter (59) is operated to ignite the middle gas burner (33). Thereafter, the same control is performed to confirm the ignition operation of the small gas burner (32) and the grill burner (35), and then, in step (ST35), it is determined whether or not each gas burner has been ignited. Specifically, each gas burner is determined by the presence or absence of a flame detection signal from the flame detector (311) (321) (331) (351) corresponding to each gas burner (31) (32) (33) that has been ignited. Check if ignition was successful. If ignition cannot be confirmed, predetermined error processing is performed in step (ST36). On the other hand, if ignition is confirmed, control is transferred to step (ST4) in FIG. 4, and each gas burner (31) (32 ) (33) fire power adjustment routine is executed.

FIG. 6 is a detailed view of the heating power adjustment routine.
In step (ST41), if the limit switch (61) corresponding to the large gas burner (31) is outputting an ignition signal, the operation knob (31A) for the large gas burner (31) is output in step (ST42). The output from the corresponding pulse encoder (71) is applied to the stepping motor (513), thereby setting the gas amount adjusting valve (512) at an opening corresponding to the rotation amount of the operation knob (31A). As a result, the heating power of the large gas burner (31) is adjusted. Next, if the limit switch (63) corresponding to the middle gas burner (33) is emitting an ignition signal in step (ST43), it corresponds to the operation knob (33A) for the middle gas burner (33) in step (ST44). The output from the pulse encoder (73) is applied to the pulse motor (533) of the motor operated valve (53). Thereafter, by the same control, the heating power of the small gas burner (32) and the grill burner (35) is adjusted, and then the control is shifted to step (ST5) in FIG. 4 to execute the overheat prevention routine.

FIG. 7 is a detailed view of the overheat prevention routine.
In step (ST51), the detected temperature S (temperature in the stove case (3)) of the temperature sensor (21) is the unheated temperature Tmax shown in FIG. 8 (unconditionally when the inside of the stove case (3) is overheated). If it is determined not to have raised to the maximum temperature) for causing extinguishing each gas burner, further judgment start temperature D (e.g. 60 shown detected temperature S of the temperature sensor (21) in FIG. 8 in step (ST52) It is determined whether or not the temperature is raised to (° C). If it is determined that the temperature has risen, it is monitored in step (ST53) that the detected temperature S further rises to a determination end temperature E (for example, 70 ° C.). When the detected temperature S of the temperature sensor (21) rises to the determination end temperature E, a comparison temperature gradient K1 that is a temporal change rate of the detected temperature S of the temperature sensor (21) is calculated. Specifically, the time required for the detected temperature S of the temperature sensor (21) to rise from the determination start temperature D to the determination end temperature E is Δt, and a comparison temperature gradient K1 = (ED) / Δt is calculated. In the present embodiment, the comparative temperature gradient K1 corresponds to a “temperature gradient” which is a specific matter of the present invention. Further, the steps (ST52) to (ST54) for determining the comparative temperature gradient K1 correspond to “temperature gradient determination means” as the invention specific matter of claim 1.

  Next, in step (ST55), it is determined whether or not the comparative temperature gradient K1 exceeds the reference temperature gradient K0. In the present embodiment, the step (ST55) corresponds to the “gradient comparison means” as the invention specific matter of claim 1, and the microcomputer command to branch the control from step (ST55) to step (ST56) described later. Corresponds to the `` overheat prevention command '' as the invention specific matter, and further, the microcomputer command for branching control from step (ST55) to step (ST58) described later corresponds to the `` combustion continuation command '' as the invention specific matter To do.

Next, when it is determined in step (ST55) in FIG. 7 that the comparative temperature gradient K1 is larger than the reference temperature gradient K0 (in the case of the reverse flow combustion curve Z in FIG. 8), a speaker (not shown) The lamp is operated to report an error, and the gas main valve (40) is closed to extinguish the gas burners (31), (32), (33) and the like. Thus, in the present embodiment, the gas burner is extinguished by determining the temperature gradient of the detected temperature S of the temperature sensor (21). Accordingly, in order to prevent frequent overheat prevention operation, the temperature rises to the overheat prevention temperature Tmax, unlike the above-described conventional one in which the overheat prevention operation is not executed until the temperature is raised to the overheat prevention temperature Tmax set at a high temperature. Even before the operation, the overheat prevention function works quickly and it is possible to return to a safe state early. In addition, since all the gas burners are extinguished at once by closing the gas main valve (40), the other gas burner may cause back-flow combustion due to the negative pressure inside the stove case. Thus, the backflow combustion of the gas burner can be prevented in advance, and the safety is improved. Further, the control is simplified as compared with the case where each gas burner is extinguished individually.
In the present embodiment, the control for closing the gas main valve (40) in step (ST56) corresponds to the “burner control means” as the invention specific matter of claim 1.

  Next, when it is determined in step (ST57) that the detected temperature S of the temperature sensor (21) has become sufficiently low and has fallen to the ignition allowable temperature F (for example, 60 ° C.), the first step in FIG. Control is transferred to (ST1). In step (ST57), it may wait for a set time and wait for the temperature in the stove case (3) to drop. This prohibits ignition of each gas burner (31), (32), and (33) until the temperature inside the stove case (3) drops.Therefore, unlike the case where reignition is allowed immediately after the gas burner is extinguished, There is no inconvenience that the gas burners (31), (32), and (33) are repeatedly ignited and extinguished before the overheating state of the case (3) is resolved.

On the other hand, if it is determined in step (ST55) that the comparative temperature gradient K1 is less than or equal to the reference temperature gradient K0, the detected temperature S of the temperature sensor (21) reaches the overheat suppression temperature B (see FIG. 8) in step (ST58). It is determined whether the temperature has risen. As shown in FIG. 8, the overheat suppression temperature B (for example, 130 ° C.) is the temperature equilibrium region (b) in the normal curve X (the estimated maximum value of the temperature sensor detected during normal use). It is set to a higher temperature. Further, in this embodiment, the step (ST58) corresponds to the “suppressed temperature determination means” as the invention specific matter of claim 1 , and a microcomputer command to branch from step (ST58) to step (ST59) described later is provided. This corresponds to the “combustion suppression command” which is the above-mentioned invention specific matter.

  Next, when the detected temperature S rises to the overheat suppression temperature B (point R in FIG. 8), step (ST59) is executed to reduce the amount of combustion of the gas burner that is ignited. Specifically, for example, when the large gas burner (31) is ignited, the stepping motor (513) of the electric valve (51) corresponding to the large gas burner (31) is rotated by a predetermined angle in the gas amount throttle direction. . In step (ST59), the fact that the combustion amount has been reduced is notified by a speaker or a display lamp (not shown).

In the present embodiment, as in step (ST59), control is performed to reduce the combustion amount without extinguishing the gas burner. Therefore, unlike the case where the fire is extinguished when the temperature is raised to the overheat suppression temperature B, the gas stove can be used continuously while preventing overheating in the stove case (3).
In this embodiment, step (ST59) corresponds to “burner control means” in claim 1 .

  Next, in step (ST60), it is determined that the detected temperature S of the temperature sensor (21) has dropped to a safe temperature G (for example, 105 ° C.) lower than the overheat suppression temperature B (point Q in FIG. 8). In step (ST61), the fact that the combustion amount of the gas burner being burned is returned to the state before being reduced in step (ST59) is notified by a speaker, a lamp, etc. (not shown). In step (ST62), the combustion amount of the burning gas burner is returned to the state before the decrease. That is, for example, when the large gas burner (31) is burning, the stepping motor (513) of the motor-operated valve (51) corresponding thereto is rotated back to the position before the execution of step (ST59), thereby The combustion amount of the large gas burner (31) is returned to the state before the decrease. This ensures good usability of the gas stove without leaving it in a state where the combustion amount is reduced.

  If it is determined in step (ST60) that the detected temperature S of the temperature sensor (21) exceeds the safe temperature G, the detected temperature S of the temperature sensor (21) is further set to the overheat prevention temperature in step (ST63). When it is determined that the temperature has been raised to Tmax (which may be a temperature lower than this temperature) (point V in FIG. 8), a predetermined error is notified in step (ST64) and the gas burner is extinguished. Specifically, when the large gas burner (31) is burning, the stepping motor (513) of the electric valve (51) corresponding to the large gas burner (31) is returned to the origin position. As a result, even if the combustion amount of the gas burner is reduced, if the temperature in the stove case detected by the temperature sensor (21) rises to the overheat prevention temperature Tmax, the gas burner can be extinguished to ensure a safe state. After executing step (ST64), the same control as in step (ST57) is performed until the detected temperature S of the temperature sensor (21) decreases to the ignition allowable temperature F or until the set time elapses. The ignition of the extinguished gas burner may be prohibited.

  Next, control is transferred to step (ST6) in FIG. 4 and when the large gas burner (31) is extinguished, that is, the operation knob (31A) is pushed in and the limit switch (61) is turned on by an ignition signal (for example, , OFF signal) is not output, the corresponding stepping motor (513) is returned to the origin position. This closes the safety valve (511) and extinguishes the large gas burner (31). Similarly, when the middle gas burner (33) is extinguished in steps (ST8) and (ST9), the corresponding stepping motor (533) is returned to the origin position to extinguish the middle gas burner (33), Thereafter, the fire extinguishing operation of the small gas burner (32) and the grill burner (35) is similarly determined. After that, when all the fire extinguishing operations of each gas burner (31) (32) (33) and grill burner (35) are confirmed in step (ST10), the gas main valve (40) is closed in step (ST11). Then, return the control to step (ST1). On the other hand, if it cannot be confirmed in step (ST10) that all the gas burners have been extinguished, control is returned to step (ST3) and the subsequent controls.

  In this embodiment, a speaker or the like is notified that the combustion amount of the gas burner is reduced in step (ST59) and that the combustion amount is restored to the pre-reduction combustion amount in step (ST61). Therefore, it can be notified that the change in the combustion amount of the gas burner is based on an overheat prevention function that is not related to the intention of the stove user. Therefore, since it is possible to call attention when a change in the combustion amount of the gas burner affects cooking, it is possible to prevent a cooking failure or the like.

[Others]
1. In the above embodiment, the time required for the detected temperature S of the temperature sensor (21) to rise from the determination start temperature D to the determination end temperature E is Δt, and the comparison temperature gradient K1 = (ED) / Δt is calculated. As a result, a comparative temperature gradient K1 which is a rate of change over time of the detected temperature S of the temperature sensor (21) was obtained. On the other hand, the detection temperature S of the temperature sensor (21) after a predetermined time Δt0 has elapsed from the time when the determination start temperature D is reached is determined, and the temperature difference between the detection temperature S and the determination start temperature D is set as described above. The comparative temperature gradient K1 may be obtained by dividing by the time Δt0.

2. In the above embodiment, the gas main valve (40) is closed in step (ST56), but in the branch circuits (41) (42) (43) (45) from the main gas circuit (4), combustion The branch circuit corresponding to the gas burner inside may be individually cut off. Specifically, when the large gas burner (31) is burning, the stepping motor (513) of the motor-operated valve (51) corresponding to this is returned to the origin position, thereby closing the safety valve (511). .

3. In the above embodiment, the notification is made when the combustion amount of the gas burner is decreased in step (ST59), but the notification operation may be continued while the combustion amount of the gas burner is decreasing.
4). In the above embodiment, the case where the present invention is applied to a drop-in stove has been described by way of example, but the present invention can also be applied to various gas stoves such as a table stove.

The perspective view of the gas stove which concerns on embodiment of this invention Sectional drawing of the partial notch of the II-II line of FIG. Schematic of the control circuit of the gas stove according to the embodiment of the present invention Flowchart for control of gas stove according to an embodiment of the present invention Ignition routine flowchart Thermal power control routine flowchart Heating prevention routine flowchart Graph of temperature S detected by temperature sensor (21)

Explanation of symbols

(3) ... Stove case
(4) ... Main gas circuit
(21) ・ ・ ・ Temperature sensor
(30) ... top plate
(31) (32) (33) ・ ・ ・ Gas burner
(40) ・ ・ ・ Gas source valve
(300) ... Burner opening

Claims (5)

A plurality of gas burners arranged in a stove case;
A stove top plate that covers the upper end opening of the stove case and has an opening for the burner facing the gas burner;
A temperature sensor disposed in a ventilation path of air flowing from the stove case to the burner opening;
A gas source valve in a common gas circuit on the upstream side supplying gas to each gas burner ,
In the gas stove that prevents overheating in the stove case based on the temperature detected by the temperature sensor,
A temperature gradient determining means for determining a temperature gradient as a temporal change rate of the temperature detected by the temperature sensor;
When the temperature gradient determined by the temperature gradient determination means is larger than the reference gradient, an overheat prevention command is output, and when the temperature gradient is equal to or less than the reference gradient, a gradient comparison means that outputs a combustion continuation command;
The temperature higher than the assumed maximum value of the detection temperature of the temperature sensor during normal use is defined as the overheat suppression temperature,
A suppression temperature determination unit that outputs a combustion suppression command when the temperature detected by the temperature sensor further increases to the overheat suppression temperature after the gradient comparison unit outputs the combustion continuation command;
It said gradient comparison means to extinguish the gas burners by closing the gas valve in response to the overheating prevention command outputs Rutotomoni, the response to the fire-retardant command the suppressing temperature determining means outputs the gas burner gas stove comprising a burner control unit, the to Ru reduce the combustion amount. The gas stove according to claim 1 , wherein
A gas stove that, after reducing the combustion amount of the gas burner, returns the combustion amount of the gas burner to the state before the reduction when the temperature detected by the temperature sensor falls to a safe temperature lower than the overheat suppression temperature. In the gas stove according to claim 2 ,
A gas stove that notifies that when the amount of combustion of the gas burner is reduced or when the amount of combustion is returned to the state before the reduction. In the gas stove according to any one of claims 1 to 3 ,
A gas stove that extinguishes the gas burner when the temperature detected by the temperature sensor rises to an overheat prevention temperature higher than the overheat suppression temperature after reducing the combustion amount of the gas burner. In the gas stove according to any one of claims 1 to 4 ,
A gas stove that, when the gas burner is extinguished, ignites the gas burner until the temperature detected by the temperature sensor falls to an allowable ignition temperature or until a set time has elapsed.

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