JP3040148B2 - Abnormal overheat stove - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overheat stove, such as a gas table, provided with a tempura fire prevention device.

2. Description of the Related Art Conventionally, a stove of this type is provided with a cooking vessel 3 heated by a gas fire 2 of a gas burner 1 and a temperature sensor 4 pressed on the wall of the cooking vessel 3 as shown in FIG. The output of the temperature sensor 4 is compared with a reference temperature by a comparator 5 such as a comparator. The output of the temperature sensor 4 is taken into a control unit 6, and then the gas cock 8 is controlled by an output from the control unit 6. Abnormal overheating was prevented.

However, in such a conventional abnormal overheat stove, when the output of the temperature sensor 4 exceeds a preset reference temperature, for example, 250 ° C., the heating unit is controlled via the gas cock 8 immediately. Therefore, there were many malfunctions and there was a problem that it was not easy to use.

In other words, in a frying dish such as fried egg and fried rice, a fire hits near the temperature sensor 4 on the bottom surface of the cooking container 3 by lifting the cooking container 3 and moving the cooking container 3 up and down. The temperature often exceeds the reference temperature, and each time the cooking is interrupted, there is a problem that it is very difficult to use.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problem and to provide an overheat prevention stove that is easy to use and has little malfunction.

Means for Solving the Problems To solve the above conventional problems, an abnormal overheat prevention stove according to the present invention includes a heating unit for heating a cooking container, a temperature sensor for detecting a wall surface temperature of the cooking container, and the temperature sensor. A comparator for comparing the output of the comparator with a preset reference temperature;
Timer means for detecting the elapse of a predetermined time, and an output from the comparator and the timer means, wherein the temperature increase rate of the wall temperature when the wall temperature exceeds the reference temperature is a predetermined temperature. When the rate of increase is less than
When the wall surface temperature continuously exceeds the reference temperature for a predetermined time or more, the heating unit is controlled so as to prevent abnormal overheating, and the wall surface temperature exceeds the reference temperature. When the temperature rise rate of the wall surface temperature at the time of exceeding the temperature rise rate is equal to or more than a preset temperature increase rate, the reference temperature is updated to a preset new reference temperature, and a preset predetermined time is further set. The heating unit is updated to a preset new predetermined time, and when the wall surface temperature continuously exceeds the new reference temperature for the preset new predetermined time or more. And control means for controlling to prevent abnormal overheating.

According to the above configuration, when the temperature rise rate of the wall surface temperature when the wall temperature of the cooking vessel exceeds the reference temperature is equal to or less than the preset temperature rise rate, the cooking vessel is continuously operated for a predetermined time or more. Cooking will not be interrupted unless the wall temperature exceeds the reference temperature, so even if the fire hits the temperature sensor near the temperature sensor, especially if the cooking container is lifted in frying pan cooking, the cooking will be interrupted as usual. This eliminates malfunctions and improves usability.

When the temperature rise rate of the wall temperature when the wall temperature of the cooking vessel exceeds the reference temperature is equal to or higher than a preset temperature rise rate, for example, it is determined to be a frying dish and a new reference temperature and a new reference temperature are set. Since the new reference temperature is updated to a predetermined time and the new reference temperature is maintained for more than the new predetermined time and the wall temperature does not exceed, the cooking is not interrupted. Abnormal overheat prevention control is performed at a temperature and a new predetermined time, thereby reducing malfunctions.

Examples Hereinafter, examples of the present invention will be described with reference to the drawings. The same parts as those in the conventional example shown in FIG. FIG. 1 is an overall configuration diagram of an abnormal overheat prevention stove showing a basic schematic configuration of the present invention. In FIG. 1, 1 is a burner as a heating unit, 2 is a gas fire,
3 cooking container, 4 is a temperature sensor consisting of a thermistor for detecting the wall temperature T _m of a cooking container 3 is crimped to the cooking container 3. 5 is a comparator for comparing the output and the reference temperature T _s of the temperature sensor 4. Reference numeral 9 denotes a timer circuit which detects the elapse of a preset time t _s . Comparator 5 and the timer circuit 9 is connected to the control unit 6, an output end of the control unit 6 is connected to the gas cock 8, comparator 5 and the predetermined time t elapsed time t _c is the timer circuit by the output of the timer circuit 9 by controlling the gas cock 8 by the output of the control unit 6 _{when s} or continue to the wall temperature T _m of a cooking container 3 exceeds the reference temperature T _s controls the gas fire 2 of the burner 1, to prevent abnormal heating It has a configuration.

FIG. 2 is a flowchart showing a signal flow in the above-mentioned basic schematic configuration. In Figure 2, when the cooking is started, the timer circuit 9 is a timer reset first, in step 11, as to measure the wall temperature T _m of a cooking container 3 by the temperature sensor 4 at step 12, a timer circuit in Step 13 9 To measure the elapsed time. Further steps
The temperature determination unit 14, to the wall surface temperature T _m is higher than the reference temperature T _s, indicating that the return to the step 11 of the timer reset. Further, in the elapsed time determination unit in step 15,
Elapsed time tc indicates a return to the temperature measurement of step 12 to exceed the predetermined time t _s.

In the above configuration, the reference temperature T _s is set to 250 ° C., the predetermined time t _s of the timer circuit 9 is set to a predetermined time of 30 seconds to 2 minutes, and 300 ml to 1500 ml of tempura oil is put in the cooking vessel 3 made of iron. The cooking vessel 3 was heated by the gas fire 2 and the temperature of the tempura oil was measured. The result shown in FIG. 3 was obtained. A third figure the horizontal axis represents time, the vertical axis represents temperature (° C.), shows the wall temperature T _m of a cooking container 3 by the solid line A, the oil temperature of the cooking oil by a dotted line B, and the reference temperature by a dotted line C ing. Tempura oil temperature is 350 ℃
Never exceeded. The temperature of tempura oil is 35
It is said that it will not ignite below 0 ° C. Therefore,
It has been confirmed that the stove operates normally as an abnormal overheat prevention stove.

In addition, we cooked frying dishes such as fried egg, fried rice etc. as usual because vegetables are often cooked daily,
The results shown in FIG. 4 were obtained. Figure 4 is a time on the horizontal axis, the vertical axis represents temperature (° C.), a wall surface temperature T _m of a frying pan as a cooking container 3 by the solid line D, and shows a reference temperature by a dotted line C. Although the cooking container 3 was moved up and down, the reference temperature
T _s of 250 ° C. was not continuously exceeded for a predetermined time of 30 seconds to 2 minutes, and there was no malfunction such as interruption of cooking.

Next, examples of the present invention will be described. Figures 3 and 4
Comparing the tempura cooking and ordinary frying cooking in FIG, 250 ° C. wall temperature T _m is the reference temperature T _s of the cooking container 3
Because the rate of temperature rise when exceeding is very different,
By measuring the rate of temperature rise, it is possible to determine whether cooking is tempura or normal frying. That is, in the case of ordinary tempura cooking, the temperature rise rate does not exceed 40 ° C./min. Accordingly, the control unit 6, the temperature rise rate is, for example, 40 ° C. / long minute or more is judged that other than tempura cooking, New rata reference temperature T _s2 example is setting a reference temperature previously, updates to 280 ° C. The configuration was adopted. At this time, the predetermined time t _s was also updated to a new predetermined time t _s2 , for example, 10 seconds. FIG. 5 shows a signal flow chart in this case. In FIG. 5, steps 14 and 15 represent the temperature determination unit and the elapsed time determination unit shown in FIG. 2, respectively. Step 21 shows a temperature rise rate determination unit, and the temperature rise rate ΔT _m / Δt when the reference temperature T _s elapses is set to a preset temperature rise rate ΔT _s / Δ
If it is equal to or more than t, the process proceeds to the temperature determination unit in step 22 and means to compare with the new reference temperature T _S2 . Further, when the wall surface temperature T _m exceeds the new reference temperature T _s2 , the heating is stopped in step 16 when the temperature exceeds the new predetermined time t _s2 in step 23, and when not exceeded, the step
Return to 13 elapsed time measurement.

When the frying pan was cooked under such a configuration, malfunction did not occur easily even if the frying pan was lifted for a longer time than usual.

In addition, in the tempura cooking, the same effect as the above-mentioned basic schematic configuration was obtained.

Advantageous Effects of the Invention As described above, according to the present invention, it is possible to provide an abnormal overheat prevention stove that is easy to use, and the following effects are obtained.

(1) The oil temperature does not exceed 300 ° C during tempura cooking, and it operates safely as an abnormal overheat prevention stove.

(2) In the case of frying, etc., even if the temperature exceeds the set temperature for a short time, there is no operation, so that cooking is not interrupted and a stove that is easy to use and that is easy to use is obtained.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an overheat stove showing a basic schematic configuration of the present invention, FIG. 2 is a flowchart showing a signal flow of the basic schematic configuration of the present invention, and FIGS. FIG. 5 is a characteristic diagram showing a temperature change at the time of cooking of tempura cooking and frying pan cooking, respectively. FIG. 5 is a flowchart showing a signal flow of the embodiment of the present invention, and FIG. is there. 3 ... Cooking container, 4 ... Temperature sensor, 5 ... Comparator, 6
...... Control part, 8 ... Gas cock, 9 ... Timer circuit.

────────────────────────────────────────────────── ─── Continued on the front page (56) References 37 (Issued September 15, 1984) Reference No. 37-074 [Safety device for stove] (58) Field surveyed (Int. Cl. ⁷ , DB name) F24C 3/12

Claims (1)

(57) [Claims] A heating unit for heating the cooking container; a temperature sensor for detecting a wall temperature of the cooking container; a comparator for comparing an output of the temperature sensor with a preset reference temperature;
Timer means for detecting the elapse of a predetermined time, and an output from the comparator and the timer means, wherein the temperature increase rate of the wall temperature when the wall temperature exceeds the reference temperature is a predetermined temperature. When the rate of increase is less than
When the wall surface temperature continuously exceeds the reference temperature for a predetermined time or more, the heating unit is controlled so as to prevent abnormal overheating, and the wall surface temperature exceeds the reference temperature. When the temperature rise rate of the wall surface temperature at the time of exceeding the temperature rise rate is equal to or more than a preset temperature increase rate, the reference temperature is updated to a preset new reference temperature, and a preset predetermined time is further set. The heating unit is updated to a preset new predetermined time, and when the wall surface temperature continuously exceeds the new reference temperature for the preset new predetermined time or more. Overheating prevention stove provided with control means for controlling so as to prevent abnormal overheating.