JP6274693B2 - Gas stove - Google Patents

Description

  The present invention relates to a gas stove having a function of heating a cooking container, detecting the temperature of the cooking container, and preventing overheating based on the detected temperature.

  A gas stove that burns fuel gas with a burner and heats a cooking container such as a pan placed on Gotoku is widely used. In recent years, in order to prevent accidents such as cooking oil fires due to overheating, gas stoves are generally equipped with a temperature sensor that detects the temperature of the cooking vessel. When the detected temperature (sensor temperature) of the temperature sensor reaches a predetermined overheat prevention temperature, the combustion of the burner is forcibly stopped to prevent ignition of cooking oil. In addition, in order to avoid forcibly stopping combustion during cooking, a gas stove having a function of adjusting the burner heating power (fuel gas supply amount) so that the sensor temperature does not reach the overheat prevention temperature is known. (For example, Patent Document 1).

  In such a gas stove, when heating a cooking container containing cooking oil for frying, etc., the sensor temperature tends to be lower than the temperature of the cooking oil in the cooking container (oil temperature). Sometimes, the greater the burner thermal power setting, the greater the difference between the oil temperature and the sensor temperature. In consideration of such circumstances, the overheat prevention temperature is set to a temperature lower than the ignition temperature with a margin so that the combustion is stopped before the oil temperature reaches the ignition temperature. Further, in order to prevent the sensor temperature from reaching the overheat prevention temperature and suddenly stopping combustion during cooking, when the sensor temperature reaches a maintenance temperature lower than the overheat prevention temperature, the heating amount adjusting means causes the burner's thermal power. Is controlled.

JP 11-270854 A

  However, in order to ensure safety even when the heating amount adjusting means does not operate due to a failure or the like, it is necessary to set the overheat prevention temperature low. On the other hand, if the overheat prevention temperature is set low, the fried food There is a problem that convenience is lost in cooking and the like. This is due to the following reason. First, in fried food cooking, there is a small amount of cooking oil compared to fried food cooking, and the cooking container tends to warm up, so the sensor temperature tends to rise rapidly. If the overheat prevention temperature is set low, assuming fried food cooking with large thermal power, the sensor temperature easily reaches the overheat prevention temperature in frying food cooking with large thermal power, and combustion is forcibly stopped unintentionally. (So-called early cut) causes the inconvenience that cooking is interrupted.

  The present invention has been made in response to the above-described problems of the prior art, and ensures convenience in fried food cooking while preventing overheating in fried food cooking and ensuring safety. The purpose is to provide a gas stove that can be

In order to solve the above-described problems, the gas stove of the present invention employs the following configuration. That is,
In a gas stove that burns fuel gas with a burner and heats a cooking vessel,
Temperature detecting means for detecting the temperature of the cooking container;
Combustion suppression means for suppressing combustion in the burner when the detected temperature of the temperature detection means reaches a preset overheat prevention temperature;
When the detection temperature of the temperature detection means reaches a predetermined maintenance temperature lower than the overheat prevention temperature, the supply amount of the fuel gas to the burner is changed, and the detection temperature of the temperature detection means becomes the overheat prevention temperature. A heating amount adjusting means capable of adjusting the heating amount by the burner so as not to reach
A heating amount detecting means for detecting a heating amount by the burner;
An overheat prevention temperature setting means for setting the overheat prevention temperature based on a detection result of the heating amount detection means , and
The overheat prevention temperature setting means is configured to change the predetermined amount when the heating amount detected by the heating amount detection means does not change more than a predetermined amount after the temperature detected by the temperature detection means reaches the maintenance temperature. The overheat prevention temperature is set lower than in the case where there is the above change .

  In such a gas stove according to the present invention, whether or not the heating amount by the burner is normally adjusted can be determined based on the detection result of the heating amount detection means provided separately from the heating amount adjustment means. And by switching overheat prevention temperature between when the amount of heating by the burner is adjusted normally (when adjustment is possible) and when it is not adjusted (when adjustment is not possible), safety such as cooking of fried foods when adjustment is not possible It is possible to ensure convenience such as cooking of stir-fried food when adjustment is possible while ensuring the property.

That is, when the temperature detected by the temperature detection means reaches the maintenance temperature and the amount of heating by the burner is adjusted normally, the amount of heating detected by the heating amount detection means changes. Therefore, it can be determined that the heating amount by the burner is not normally adjusted based on the fact that the change in the heating amount equal to or greater than the predetermined amount is not detected. In this case, by lowering the overheat prevention temperature, the temperature detected by the temperature detection means can easily reach the overheat prevention temperature. Sexuality can be secured. On the other hand, when a change in the heating amount over a predetermined amount is detected, the overheating prevention temperature can be raised because the heating amount adjusting means is operating normally. As a result, the temperature detected by the temperature detecting means is less likely to reach the overheat prevention temperature, so that convenience can be ensured by preventing premature cuts during frying.

  In the above-described gas stove according to the present invention, when the amount of heating detected by the heating amount detecting means does not change more than a predetermined amount when the heating amount adjusting means decreases the amount of heating by the burner, the change more than the predetermined amount is achieved. The overheat prevention temperature may be set lower than when there is.

  When the heating amount adjusting means decreases the heating amount by the burner, a change accompanying it should appear in the heating amount detected by the heating amount detecting means. Therefore, similarly to the above, it can be determined that the heating amount by the burner is not normally adjusted based on the fact that a change in the heating amount of a predetermined amount or more is not detected.

  Such a gas stove according to the present invention may be configured as follows. First, when the detected temperature of the temperature detecting means reaches the maintenance temperature, the heating amount adjusting means increases or decreases the heating amount by the burner at a predetermined cycle. If the heating amount detected by the heating amount detector does not change more than a predetermined amount, the cycle is shortened.

  In this way, it is possible to increase the frequency of increasing / decreasing the amount of heating by the burner and to increase the chance of detecting a change in the detected amount of heating by the heating amount detecting means accompanying the increase / decrease. And it becomes possible to judge more correctly whether the heating amount by a burner is normally adjusted based on the detection result in multiple times.

  In the above-described gas stove according to the present invention, the overheat prevention temperature may be raised when the overheat prevention temperature is set low and the heating amount detected by the heating amount detection means changes by a predetermined amount or more.

  In this way, even if the detected temperature of the temperature detecting means reaches the maintenance temperature, if the heating amount detected by the heating amount detecting means does not change more than a predetermined amount, the overheat prevention temperature is set low for the time being and the fried food is cooked. If there is a change of a predetermined amount or more after emphasizing safety in such a case, it is possible to raise the overheat prevention temperature and ensure convenience in frying.

It is sectional drawing which showed the structure of the gas stove 1 of a present Example. It is explanatory drawing which showed the example in which overheat prevention control is performed based on sensor temperature. It is explanatory drawing which showed the example which made the heating power setting of the stove burner 10 larger than the example of FIG. It is a flowchart which shows the overheat prevention control process which the control part 50 of a present Example performs. FIG. 5 is an explanatory diagram showing an example in which overheat prevention control is performed according to the overheat prevention control process of FIG. 4 when the latch valve 23 operates normally. FIG. 5 is an explanatory diagram showing an example in which overheat prevention control is performed according to the overheat prevention control process of FIG. 4 when the latch valve 23 does not operate.

  FIG. 1 is a cross-sectional view showing the structure of the gas stove 1 of the present embodiment. The gas stove 1 includes a top plate 2 that covers the upper surface of the stove body (not shown), a stove burner 10 that is installed in the stove body with an upper portion protruding from a through hole 3 formed in the top plate 2, and an upper portion of the stove burner 10. In order to place a cooking container such as a pot on the top plate 2, it is equipped with Gotoku 4 installed on the top surface of the top plate 2. The stove burner 10 of this embodiment corresponds to the “burner” of the present invention.

  The stove burner 10 covers a burner body 11 in which an annular mixing chamber 11a is formed, a mixing tube 12 extending from the burner body 11 and communicating with the mixing chamber 11a, and an upper opening of the mixing chamber 11a. Thus, an annular burner head 13 placed on the burner body 11 and an annular burner cover 14 attached above the burner head 13 are provided.

  A plurality of grooves (flame grooves) are formed radially with respect to the center of the burner head 13 on the lower surface of the outer peripheral wall of the burner head 13 (the surface placed on the burner body 11). When placed on the burner body 11, a plurality of flame openings 13 a communicating with the mixing chamber 11 a is formed by the plurality of flame opening grooves and the upper surface of the burner body 11. The burner cover 14 plays a role of preventing the boiled juice from being applied to the burner head 13 when spilled from a cooking container placed on the Gotoku 4.

  An injection nozzle 25 connected to a gas passage 20 for supplying fuel gas is installed at the opening end 12a of the mixing pipe 12 extending from the burner body 11. The gas passage 20 is provided with a gas cutoff valve 21 that opens and closes the gas passage 20. A flow rate adjustment valve 22 that adjusts the flow rate of the fuel gas passing through the gas passage 20 is provided downstream of the gas cutoff valve 21. Is provided. Further, the gas passage 20 is branched into two on the downstream side of the flow rate control valve 22, a latch valve 23 as an on-off valve is provided in one passage, and the other passage is a bypass passage that bypasses the latch valve 23. 24. The gas cutoff valve 21, the flow rate adjustment valve 22, and the latch valve 23 of this embodiment are electrically connected to the control unit 50 and controlled by the control unit 50.

  When the gas shut-off valve 21 and the flow control valve 22 are opened, the fuel gas is supplied to the injection nozzle 25, and the fuel gas injected from the injection nozzle 25 flows into the mixing pipe 12 while entraining the primary air for combustion. Then, the fuel gas passing through the mixing pipe 12 and the primary air are mixed, and the mixed gas is supplied to the mixing chamber 11a. When the mixed gas in the mixing chamber 11a is ejected from the plurality of flame ports 13a and a spark is blown by a spark plug (not shown), combustion of the mixed gas is started.

  Further, the stove burner 10 includes a thermocouple 35, and the thermocouple 35 and the control unit 50 are electrically connected. The tip of the thermocouple 35 is located outside the flame port 13a of the burner head 13, and an electromotive force is generated when the tip is heated by the combustion flame of the stove burner 10. Based on the electromotive force of the thermocouple 35, the control unit 50 can detect whether the burner 10 is combusting (whether it has been extinguished) or a change in the heating power (heating amount) of the burner 10. . Note that the setting of the heating power of the stove burner 10 can be performed by adjusting the amount of fuel gas supplied by the flow rate adjusting valve 22. Further, when the latch valve 23 is closed, the fuel gas is supplied only through the bypass passage 24, and the amount of fuel gas supplied decreases, so that the heating power of the combustor 10 fluctuates by opening and closing the latch valve 23 ( Increase or decrease).

  Further, a secondary air supply passage 13h required for combustion of the mixed gas is formed in the center of the stove burner 10, and a temperature sensor 30 is installed in the supply passage 13h. The temperature sensor 30 includes a thermistor (not shown), a coil spring that urges upward, and the like, and an upper portion projects from the central opening 14 a of the burner cover 14. When the cooking container is placed on the virtues 4, the upper end of the temperature sensor 30 comes into contact with the bottom of the cooking container to detect the temperature of the cooking container. The temperature sensor 30 is electrically connected to the control unit 50, and the control unit 50, based on the cooking container temperature (sensor temperature) detected by the temperature sensor 30, cooking oil fire due to overheating of the cooking container. Control to prevent accidents such as (overheat prevention control). The temperature sensor 30 of this embodiment corresponds to “temperature detection means” of the present invention.

  FIG. 2 shows an example in which overheat prevention control is performed based on the sensor temperature. First, in the graph of FIG. 2 (a), the change in sensor temperature is indicated by the alternate long and short dash line when time is plotted on the horizontal axis and temperature is plotted on the vertical axis, and the cooking container containing cooking oil is heated in fried food cooking. Has been. Moreover, the change of the temperature (oil temperature) which measured the cooking oil in a cooking container is shown as the continuous line. As shown in the figure, the sensor temperature tends to be lower than the oil temperature, and the deviation becomes large particularly at the start of cooking. In consideration of such a difference between the oil temperature and the sensor temperature, a cut temperature Ts (for example, 230 ° C.) lower than the ignition temperature of cooking oil (about 370 ° C.) is set, and before the oil temperature reaches the ignition temperature. When the sensor temperature reaches the cut temperature Ts, the combustion oil is prevented from igniting by suppressing the combustion in the stove burner 10 such as closing the gas shut-off valve 21 and forcibly extinguishing the fire. Yes. The cut temperature in this example corresponds to the “overheat prevention temperature” of the present invention.

  Further, as shown in FIG. 2B, a latch valve operating temperature (for example, 160 ° C.) lower than the cut temperature Ts is set, and when the sensor temperature reaches the latch valve operating temperature, the latch valve 23 is operated. Let As described above, the latch valve 23 is provided in a branch passage parallel to the bypass passage 24, and the heating power of the stove burner 10 can be increased or decreased by opening and closing the latch valve 23. The operating temperature of the latch valve in this embodiment corresponds to the “maintenance temperature” of the present invention.

  A state of switching the opening and closing of the latch valve 23 is schematically shown below the graph of FIG. The latch valve 23 is energized in the valve opening direction at the start of combustion in the stove burner 10 and is in an open state. When the sensor temperature reaches the latch valve operating temperature, the valve is energized in the valve closing direction and the latch valve 23 is closed, so that the sensor temperature and the oil temperature decrease from the increase as the heating power of the burner 10 decreases. Turn. Thereafter, by periodically switching the opening and closing of the latch valve 23, the sensor temperature is maintained near the latch valve operating temperature while repeating the increase and decrease. As a result, it is possible to prevent the sensor temperature from reaching the cut temperature Ts and forcibly extinguishing the fire during cooking. Of course, the oil temperature associated with the sensor temperature does not reach the ignition temperature.

  Note that if the latch valve 23 does not operate (open / close) for some reason and the sensor temperature continues to rise, as shown in FIG. 2A, it is forcibly forced when the sensor temperature reaches the cut temperature Ts. Since the fire is extinguished, the oil temperature does not reach the ignition temperature, and the safety when the latch valve 23 is inoperative can be ensured.

  Further, in FIG. 2B, a change in sensor temperature in the case of fried food cooking is indicated by a two-dot chain line. In fried food cooking, the amount of cooking oil is less than in fried food cooking, and the cooking container is likely to warm up. Therefore, even if the heating power setting of the stove burner 10 is the same, the sensor temperature is higher in fried food cooking than in fried food cooking. The sensor temperature tends to rise rapidly. Also, in the fried food cooking, similarly to the fried food cooking, when the sensor temperature reaches the latch valve operating temperature, the sensor temperature is maintained near the latch valve operating temperature while repeating the decrease and increase by the operation of the latch valve 23. . However, in the fried food cooking, as compared with the fried food cooking, the amplitude of increase / decrease in sensor temperature tends to increase, and the cycle of increase / decrease in sensor temperature (the cycle of opening / closing the latch valve 23) tends to be longer.

  Further, FIG. 3 shows an example in which the setting of the heating power of the stove burner 10 is larger than the example of FIG. The greater the heating power setting of the stove burner 10, the greater the difference between the sensor temperature and the oil temperature during frying cooking. Therefore, when the cut temperature Ts is set based on the example of FIG. 2, in the example of FIG. 3 in which the heating power setting of the burner 10 is increased, when the sensor temperature reaches the cut temperature Ts when the latch valve 23 is inoperative. Even if the fire is forcibly extinguished, the oil temperature has already reached the ignition temperature and may ignite. In order to avoid such a situation, when increasing the heating power setting of the burner 10, it is necessary to ensure safety by setting the cut temperature low.

  However, as described above, when cooking fried food, the sensor temperature tends to increase rapidly compared to fried food cooking. Therefore, by setting the cut temperature low, the latch valve 23 is set in the fried food cooking. Even if the sensor is operating normally, the sensor temperature easily reaches the cut temperature. Therefore, in the fried food cooking, there arises a disadvantage that the cooking is interrupted by unintentionally forcibly extinguishing the fire (so-called early cutting). Therefore, in the gas stove 1 of the present embodiment, the control unit 50 executes the following overheat prevention control process in order to ensure the convenience in fried food cooking while ensuring the safety in fried food cooking. Yes.

  FIG. 4 is a flowchart illustrating the overheat prevention control process executed by the control unit 50 according to the present embodiment. This overheat prevention control process is executed by starting combustion in the combustor 10 by operating an ignition / fire extinguishing switch (not shown). In the overheat prevention control process, first, it is determined whether or not the temperature of the cooking container (sensor temperature) detected by the temperature sensor 30 has reached a predetermined latch valve operating temperature (for example, 160 ° C.) (STEP 100). If the sensor temperature has not yet reached the latch valve operating temperature (STEP 100: no), it waits until it reaches the latch valve operating temperature.

  When the sensor temperature reaches the latch valve operating temperature (STEP 100: yes), the latch valve 23 is operated (STEP 102). In the present embodiment, the latch valve 23 is closed so that the sensor temperature is maintained near the latch valve operating temperature by alternately energizing the latch valve 23 in the valve closing direction and in the valve opening direction. Switch between the open state and the open state periodically. Although the control unit 50 controls energization to the latch valve 23, it does not receive an input signal indicating operation (opening / closing) from the latch valve 23, so whether the latch valve 23 is operating normally. The control unit 50 cannot directly grasp this. Further, the latch valve 23 and the control unit 50 of this embodiment for controlling the operation of the latch valve 23 correspond to the “heating amount adjusting means” of the present invention.

  Subsequently, it is determined whether or not the heating power setting of the stove burner 10 is greater than a predetermined heating power (STEP 104). When the heating power of the burner 10 is set to a predetermined heating power or lower (STEP 104: no), the cut temperature is set to a reference value Ts (for example, 230 ° C.) (STEP 106).

  On the other hand, when the heating power of the burner 10 is set to be larger than the predetermined heating power (STEP 104: yes), the electromotive force of the thermocouple 35 is monitored (STEP 108) and is equal to or higher than a predetermined value (for example, 3 mV). It is determined whether or not a change is detected (STEP 110). As described above, the control unit 50 is electrically connected to the thermocouple 35. In the present embodiment, the control unit 50 is based on the electromotive force of the thermocouple 35 originally provided to detect the disappearance of the stove burner 10. It is possible to detect a change in the heating power (heating amount) of the stove burner 10. The thermocouple 35 of this embodiment corresponds to the “heating amount detection means” of the present invention.

  When a change of a predetermined value or more is detected in the electromotive force of the thermocouple 35 (STEP 110: yes), the cut temperature is set to Ta (eg, 260 ° C.) higher than the reference value Ts (STEP 112). On the other hand, when a change of a predetermined value or more is not detected in the electromotive force of the thermocouple 35 (STEP 110: no), the cut temperature is set to Tb (for example, 200 ° C.) lower than the reference value Ts (STEP 114). The control unit 50 of the present embodiment that sets the cut temperature (overheat prevention temperature) corresponds to the “overheat prevention temperature setting means” of the present invention.

  As described above, when the cut temperature is set in accordance with the setting of the heating power of the burner 10 and the change in the electromotive force of the thermocouple 35 (STEP 106, STEP 112, STEP 114), whether or not the sensor temperature has reached the cut temperature. Is determined (STEP 116). When the sensor temperature does not reach the cut temperature (STEP 116: no), it is subsequently determined whether or not the combustion in the stove burner 10 is stopped (STEP 118). When the combustion is continued (STEP 118: no), the process returns to STEP 116 and waits until the combustion is stopped while determining whether or not the sensor temperature has reached the cut temperature. When combustion in the burner 10 is stopped by operating an ignition / fire extinguishing switch (not shown) (STEP 118: yes), the overheat prevention control process of FIG. 4 is terminated.

  On the other hand, when the sensor temperature reaches the cut temperature (STEP 116: yes), the gas shut-off valve 21 is closed to forcibly extinguish the fire (STEP 120), and then the overheat prevention control process of FIG. In addition, the control part 50 of the present Example which controls forced extinction of the stove burner 10 is equivalent to the "combustion suppression means" of this invention.

  FIG. 5 shows an example in which overheat prevention control is performed according to the overheat prevention control process of FIG. 4 when the latch valve 23 operates normally. In the illustrated example, the heating power setting of the stove burner 10 is larger than the predetermined heating power. First, in the graph of FIG. 5A, the change in sensor temperature in fried food cooking is indicated by a one-dot chain line, and the change in oil temperature is indicated by a solid line. When the sensor temperature rises due to the start of combustion in the stove burner 10 and reaches the latch valve operating temperature, the latch valve 23 is operated. In the example of FIG. 5, the latch valve 23 operates normally and is periodically switched between a closed state and an open state, as schematically shown below the graph of FIG. Change.

  In the graph of FIG. 5 (b), the horizontal axis represents time, the vertical axis represents the electromotive force of the thermocouple 35, and the change in the electromotive force of the thermocouple 35 is shown corresponding to the opening and closing of the latch valve 23. ing. In the illustrated example, when the latch valve 23 is closed, the electromotive force of the thermocouple 35 is reduced by a predetermined value (for example, 3 mV) or more as the heating power (heating amount) of the burner 10 is reduced. In other words, the control unit 50 can indirectly grasp that the latch valve 23 is operating normally based on the detection of a decrease of the predetermined value or more in the electromotive force of the thermocouple 35. it can. In addition, from the positional relationship between the combustion flame formed outside the flame opening 13a of the burner 10 and the tip of the thermocouple 35, when the thermal power is reduced (the combustion flame is reduced), the electromotive force of the thermocouple 35 is reduced. It may increase. For example, when the tip of the thermocouple 35 heated by the inner flame of the combustion flame becomes smaller and heated by the outer flame, the temperature of the outer flame is higher than that of the inner flame. To increase. In this case, it is possible to grasp that the latch valve 23 is operating normally based on the detection of an increase of the predetermined value or more in the electromotive force.

  And if the latch valve 23 is operating normally, the heating power (heating amount) of the burner 10 is adjusted so as to maintain the sensor temperature near the latch valve operating temperature, so that the oil temperature reaches the ignition temperature. Rather, the cut temperature can be set higher than the reference value Ts (for example, 230 ° C.) and set to Ta (for example, 260 ° C.). By doing so, as shown by the two-dot chain line in FIG. 5 (a), the sensor temperature that rises sharply compared with fried food cooking becomes difficult to reach the cut temperature Ta when cooking fried food. Therefore, it is possible to ensure convenience in cooking fried food.

  On the other hand, FIG. 6 shows an example in which overheat prevention control is performed according to the overheat prevention control process of FIG. 4 when the latch valve 23 does not operate for some reason. Also in the example shown in FIG. 6, as in the example of FIG. 5, the setting of the heating power of the combustor 10 is larger than the predetermined heating power. As indicated by the alternate long and short dash line in the graph of FIG. 6A, when the sensor temperature rises during frying and reaches the latch valve operating temperature, the latch valve 23 is operated. However, in the example of FIG. 6, the latch valve 23 does not operate normally, and the latch valve 23 remains open as schematically shown below the graph of FIG.

  Further, if the latch valve 23 is not actuated, the heating power of the burner 10 is maintained, so that a large change in the electromotive force of the thermocouple 35 (for example, a decrease of 3 mV or more) as shown in the graph of FIG. Does not occur. In other words, based on the fact that a large change is not detected in the electromotive force of the thermocouple 35, the control unit 50 can indirectly grasp that the latch valve 23 is not operating.

  If the latch valve 23 does not operate, the heating power (heating amount) of the burner 10 is not adjusted, and the sensor temperature and the oil temperature continue to rise as shown in FIG. Therefore, by lowering the cut temperature from the reference value Ts (for example, 230 ° C.) and setting it to Tb (for example, 200 ° C.), the sensor temperature reaches the cut temperature Tb before the oil temperature reaches the ignition temperature. The fire is extinguished. As a result, even if the latch valve 23 is inactive, it is possible to ensure safety by preventing overheating (ignition) of cooking oil in fried food cooking.

  As described above, in the gas stove 1 of the present embodiment, whether or not the latch valve 23 is operating normally based on the electromotive force of the thermocouple 35 (whether or not the heating power of the stove burner 10 is adjusted). The cut temperature is switched between when the latch valve 23 is activated and when it is not activated. This ensures the convenience of frying when the latch valve 23 is activated, while ensuring the safety of frying cooking when the latch valve 23 is not activated, even if the heating power of the burner 10 is set large. It becomes possible to do.

  The gas stove 1 of the present embodiment described above includes the following modifications. In the following, modifications will be described focusing on differences from the above-described embodiment.

  In the above-described embodiment, control is performed to periodically switch the latch valve 23 between the closed state and the open state so that the sensor temperature is maintained near the latch valve operating temperature, and the electromotive force of the thermocouple 35 associated therewith is controlled. Based on the fact that no change is detected, it is determined that the latch valve 23 is not operating. However, since the electromotive force of the thermocouple 35 may be affected by disturbance, a change (decrease) in the electromotive force is detected every time the latch valve 23 is closed (energization in the valve closing direction). This eliminates disturbance and enables more accurate judgment.

  In the gas stove 1 of the first modified example, even if the sensor temperature reaches the latch valve operating temperature and the latch valve 23 is energized in the valve closing direction, a decrease of a predetermined value or more is not detected in the electromotive force of the thermocouple 35. Makes the cycle for switching the opening and closing of the latch valve 23 shorter than usual. By doing so, it is possible to increase the frequency of closing the latch valve 23 and increase the chance of detecting a decrease in the electromotive force of the thermocouple 35 due to the valve closing. Then, based on the detection result for each energization in the valve closing direction a predetermined number of times (for example, 5 times), it is determined whether or not the latch valve 23 is operating normally (whether the cut temperature is raised or lowered). After the determination, the opening / closing cycle of the latch valve 23 may be returned to normal.

  In the gas stove 1 of the first modified example, when the cut temperature is lowered based on the detection result for each energization in the valve closing direction a predetermined number of times (for example, 5 times), it may be lowered to Tb at a time. However, the present invention is not limited to this, and if a decrease in the electromotive force of the thermocouple 35 is not detected when energization is performed in the valve closing direction, the cut temperature may be lowered by a predetermined amount (for example, 6 ° C.) each time.

  Further, the gas stove 1 of the first modification may be configured as follows. First, if a decrease in the electromotive force of the thermocouple 35 is not detected when the sensor temperature reaches the latch valve operating temperature and the latch valve 23 is energized for the first time in the valve closing direction, safety in frying food cooking is improved. Emphasis is placed on lowering the cut temperature to Tb. Thereafter, the cut temperature is raised by a predetermined amount (for example, 15 ° C.) each time a decrease is detected in the electromotive force of the thermocouple 35 when the latch valve 23 is energized for the second and subsequent times in the valve closing direction. By doing so, it is possible to ensure the convenience in frying cooking while placing importance on the safety in frying cooking when more accurately determining whether or not the latch valve 23 is activated.

  Moreover, in the above-mentioned Example and the 1st modification, based on the electromotive force of the thermocouple 35, it was possible to detect the change of the heating power (heating amount) of the stove burner 10. However, the means is not limited to the thermocouple 35 as long as the thermal power of the stove burner 10 can be detected. In the gas stove 1 of the second modification, a change in the heating power of the stove burner 10 is detected based on the temperature of the cooking container (sensor temperature) detected by the temperature sensor 30. The temperature sensor 30 of the second modification corresponds to the “temperature detection means” of the present invention and also corresponds to the “heating amount detection means” of the present invention.

  As indicated by the alternate long and short dash line in the graph of FIG. 5 (a), if the sensor temperature rises during frying, and the latch valve 23 operates normally when it reaches the latch valve operating temperature, the latch valve 23 is closed. As the heating power (heating amount) of the stove burner 10 decreases, the sensor temperature changes from rising to falling. In other words, it is possible to grasp that the latch valve 23 is operating normally based on the fact that a predetermined change (positive or negative change in the inclination of the one-dot chain line) is detected in the sensor temperature increase rate. . In this case, since the heating power of the stove burner 10 is adjusted, the cut temperature can be raised to Ta. As a result, when fried food is cooked, the sensor temperature is unlikely to reach the cut temperature Ta as shown by the two-dot chain line in FIG. It becomes possible.

  On the other hand, as indicated by the alternate long and short dash line in the graph of FIG. 6A, when the sensor temperature rises during frying, and the latch valve operating temperature is reached, the latch valve 23 does not operate normally and remains open. If so, the heating power of the stove burner 10 is maintained, so the sensor temperature continues to rise. In other words, it can be understood that the latch valve 23 is not operating normally based on the fact that no large change (positive or negative change in the inclination of the one-dot chain line) is detected in the sensor temperature increase rate. In this case, since the heating power of the burner 10 is not adjusted, by lowering the cut temperature to Tb, the sensor temperature reaches the cut temperature Tb and the fire is forcibly extinguished before the oil temperature reaches the ignition temperature. As a result, even if the latch valve 23 is inactive, it is possible to ensure safety by preventing overheating (ignition) of cooking oil in fried food cooking.

  As described above, in the gas stove 1 of the second modified example, whether or not the latch valve 23 is operating normally based on the temperature (sensor temperature) of the cooking container detected by the temperature sensor 30 (a stove burner). It is possible to determine whether or not the heating power of 10 is adjusted. Then, by switching the cut temperature between when the latch valve 23 is activated and when it is not activated, the latch valve 23 is secured while ensuring the safety of frying cooking when the latch valve 23 is not activated, as in the above-described embodiment. It is possible to ensure the convenience of cooking the stir-fried food during the operation.

  Although the gas stove 1 of the present embodiment and the modification has been described above, the present invention is not limited to the above-described embodiment and the modification, and can be implemented in various modes without departing from the gist thereof. is there.

  For example, in the above-described embodiments and modifications, a change (decrease) in the electromotive force of the thermocouple 35 that occurs when the latch valve 23 is energized in the valve closing direction is detected. However, the present invention is not limited to this, and a change (increase) in the electromotive force of the thermocouple 35 that occurs when the latch valve 23 is energized in the valve opening direction may be detected. In this case, it may be determined that the latch valve 23 is operating normally.

  In the above-described embodiment and modification, the cut temperature is reduced to Tb as a countermeasure when the latch valve 23 is determined to be inoperative. However, the present invention is not limited to this, and the user of the gas stove 1 may be notified of the malfunction of the latch valve 23 by making a predetermined warning sound or displaying a warning, and the gas cutoff valve 21 is closed. May be extinguished by force. However, it is used in cooking such as boiled foods where the sensor temperature does not reach the cut temperature even when the latch valve 23 is inoperative by lowering the cut temperature to ensure safety as in the above-described embodiments and modifications. Therefore, the convenience of the user of the gas stove 1 can be ensured as compared with the case where the combustion is forcibly stopped.

1 ... gas stove, 2 ... top plate, 3 ... through hole,
4 ... Five virtues, 10 ... Combo burner, 11 ... Burner body,
11a ... mixing chamber, 12 ... mixing tube, 13 ... burner head,
13a ... Flame port, 13h ... Supply passage, 14 ... Burner cover,
20 ... Gas passage, 21 ... Gas shut-off valve, 22 ... Flow control valve,
23 ... Latch valve, 24 ... Bypass passage, 25 ... Injection nozzle,
30 ... temperature sensor, 35 ... thermocouple, 50 ... control unit.

Claims (4)

In a gas stove that burns fuel gas with a burner and heats a cooking vessel,
Temperature detecting means for detecting the temperature of the cooking container;
Combustion suppression means for suppressing combustion in the burner when the detected temperature of the temperature detection means reaches a preset overheat prevention temperature;
When the detection temperature of the temperature detection means reaches a predetermined maintenance temperature lower than the overheat prevention temperature, the supply amount of the fuel gas to the burner is changed, and the detection temperature of the temperature detection means becomes the overheat prevention temperature. A heating amount adjusting means capable of adjusting the heating amount by the burner so as not to reach
A heating amount detecting means for detecting a heating amount by the burner;
An overheat prevention temperature setting means for setting the overheat prevention temperature based on a detection result of the heating amount detection means , and
The overheat prevention temperature setting means is configured to change the predetermined amount when the heating amount detected by the heating amount detection means does not change more than a predetermined amount after the temperature detected by the temperature detection means reaches the maintenance temperature. A gas stove characterized in that the overheat prevention temperature is set lower than when there is a change as described above . The gas stove according to claim 1, wherein
The overheat prevention temperature setting means, when the heating amount detected by the heating amount detecting means when the heating amount adjusting means reduces the heating amount by the burner does not change more than the predetermined amount, A gas stove, wherein the overheat prevention temperature is set lower than when there is a change of the predetermined amount or more . The gas stove according to claim 1 or 2,
The heating amount adjusting means increases or decreases the heating amount by the burner at a predetermined cycle,
The period is shortened when there is no change in the heating amount detected by the heating amount detecting unit after the temperature detected by the temperature detecting unit reaches the maintenance temperature. Gas stove. The gas stove according to claim 3 , wherein
The overheat prevention temperature setting means raises the overheat prevention temperature when the heating amount detected by the heating amount detection means changes more than the predetermined amount after setting the overheating prevention temperature low. Gas stove.

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