JP2915689B2 - Automatic fire extinguisher for cooker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic fire extinguisher for a cooker which prevents the cooking pot from burning.

[0002]

2. Description of the Related Art A conventional cooker for preventing scorching of a cooking pot is disclosed in Japanese Patent Application No. Hei 3-14564 filed earlier by the present applicant.
There is No. 7. This technology detects the boiling of the food by the temperature gradient of the temperature sensor, and then passes through the boiling zone where the temperature is maintained at a substantially constant temperature. Assuming that there is no moisture in the object, the fire is automatically extinguished when the measured temperature rises by a predetermined temperature from this point of time or when a predetermined time has elapsed after exceeding a predetermined gradient.

[0003]

The above technique is not merely based on the temperature rise from the boiling temperature immediately after the start of boiling, but is based on the temperature at the time when moisture is exhausted. However, the following problems remain. In other words, when the cooking pot is lifted during cooking (so-called pan pretendation), the temperature sensor that was in contact with the bottom of the pot separates, and the temperature measured by the temperature sensor suddenly rises due to the effects of flame radiation, etc., causing automatic fire extinguishing. The device may malfunction. In addition, since the temperature rise gradient after the moisture content of the food is different depending on the content of the food, in the case of the food whose measurement temperature rises rapidly, the time to reach the fire extinguishing temperature is short, and the degree of scorching is relatively small. On the other hand, in the case of cooked food whose measurement temperature rises slowly, there is also a problem that the time required to reach the fire extinguishing temperature is long, and that the food tends to burn. Therefore, an automatic fire extinguisher of a cooker according to the present invention solves the above-described problems, reduces malfunctions caused by panning, etc., and improves the accuracy of preventing burning.

[0004]

In order to solve the above-mentioned problems, a first automatic fire extinguisher of a cooking device according to the present invention uses a temperature sensor based on a temperature measurement signal of a temperature sensor for measuring a bottom temperature of a cooking pot. Boiling detection means for detecting a first inflection point at which the temperature change rate changes, and when the sensor temperature rises from the first inflection point through a boiling zone maintained at a substantially constant temperature, the rising gradient has a predetermined rising gradient. A slope detecting means for determining whether or not the temperature exceeds a predetermined ascending slope, and comparing the sensor temperature with a fire extinguishing temperature which is set higher by a predetermined temperature than the temperature of the second inflection point which is determined to have exceeded the predetermined rising slope. An automatic fire extinguisher for a cooker for automatically extinguishing a fire, comprising a comparing means for outputting a burner extinguishing command when the temperature exceeds a fire extinguishing temperature, wherein the extinguishing temperature is set by a temperature rising gradient by the gradient detecting means. An automatic fire extinguishing system of cooking device providing the temperature setting means. Further, the automatic fire extinguisher of the second cooking device of the present invention comprises a boiling sensor for detecting a first bending point at which a temperature change rate of the temperature sensor changes from a temperature measurement signal of a temperature sensor for measuring a bottom temperature of the cooking pot. Detecting means, when the sensor temperature rises from the first bending point through a boiling zone maintained at a substantially constant temperature, a gradient detecting means for judging whether or not the rising gradient exceeds a predetermined rising gradient; and the gradient detecting means The elapsed time from the second inflection point determined to have exceeded the predetermined ascending slope is compared with a fire extinguishing standby time which is a set time from the second inflection point, and when the elapsed time exceeds the extinguishing standby time, the burner extinguishes. An automatic fire extinguishing device for a cooker that automatically extinguishes a fire, comprising a comparing unit that outputs a command, wherein a fire extinguishing standby time setting unit that sets a plurality of fire extinguishing standby times according to a temperature rise gradient by the gradient detecting unit is provided. Special An automatic fire extinguishing system of cooker to.

[0005]

The automatic fire extinguisher according to the first aspect of the present invention detects a first inflection point at which the rate of temperature change of the temperature sensor changes from a temperature measurement signal of a temperature sensor that measures the bottom temperature of the cooking pot. A boiling zone maintained at a substantially constant temperature from the first bending point is detected by the boiling detecting means. When the sensor temperature rises and the gradient detecting means for determining whether or not the rising gradient exceeds a predetermined rising gradient determines that the rising temperature has exceeded the predetermined rising gradient, the temperature rise gradient causes the fire extinguishing temperature setting means to determine the second inflection point. A fire extinguishing temperature which is set higher than the temperature by a predetermined temperature is set, and the comparing means compares the extinguishing temperature with the sensor temperature, and outputs a burner extinguishing command when the sensor temperature exceeds the extinguishing temperature. Further, the automatic fire extinguisher of the second cooker of the present invention detects a first bending point at which the temperature change rate of the temperature sensor changes from a temperature measurement signal of a temperature sensor that measures the bottom temperature of the cooking pot, A boiling zone that is maintained at a substantially constant temperature from the first bending point is detected by a boiling detection unit. When the sensor temperature rises and the gradient detecting means for determining whether or not the rising gradient exceeds a predetermined rising gradient determines that the rising gradient has exceeded the predetermined rising gradient, the temperature rise gradient causes the fire extinguishing standby time setting means to perform the second bending. A fire extinguishing standby time from the point is set, and the elapse time from the second inflection point is compared with the fire extinguishing standby time by the comparing means. When the elapsed time exceeds the fire extinguishing standby time, a burner extinguishing command is output.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Four embodiments of an automatic fire extinguisher of a cooking device according to the present invention will be described with reference to FIGS. FIG. 1 is an explanatory view showing an outline of an automatic fire extinguisher, and a cooking device 1 indicated by a dotted line.
Is provided with a gas burner 4 connected to a gas supply pipe 3 to which a shut-off valve 2 is attached in the middle, and a central portion of the gas burner 4 is in contact with the bottom of a cooking pot 5 placed on a gotoku. A temperature sensor 6 biased upward is provided. The temperature detector 8 receives a temperature measurement signal obtained by measuring the bottom temperature of the cooking pot 5 in which the food is stored by the temperature sensor 6, and transmits the temperature signal to the boiling detector 9 and the gradient detector 10. The boiling detecting unit 9 detects a boiling zone B of about 100 ° C. after the first inflection point at which the food starts boiling from the measured temperature per unit time. Reference numeral 10 denotes a gradient detector, and a boiling detector 9
Is calculated from the temperature measured by the temperature sensor 6 in the boiling zone B detected in the step (b), and it is determined that the food has passed the second inflection point when the water content of the cooked food has disappeared and the rising gradient exceeds a predetermined rising gradient. Then, the temperature and measurement time at the second inflection point and the temperature rise gradient after the second inflection point are detected. A comparison unit 11 compares a predetermined fire extinguishing temperature with a temperature measured by the temperature sensor 6 and determines whether the temperature is high or low. Reference numeral 12 denotes a temperature sensor 6
When it is determined that the measured temperature is higher than the predetermined fire extinguishing temperature,
This is a fire extinguishing section that operates the shut-off valve 2 to stop gas supply to the gas burner 4. Reference numeral 13 denotes a fire extinguishing temperature changing unit that sets or changes a predetermined fire extinguishing temperature according to the temperature rise gradient obtained from the gradient detecting unit 10. Reference numeral 14 denotes a time accumulating unit which starts accumulating from the second bending point and outputs to the comparing unit 11 whether or not a predetermined fire extinguishing standby time has elapsed.

FIG. 2 shows the heating temperature of the cooking product obtained from the bottom temperature of the cooking pot 5 measured by the temperature sensor 6 during heating.
This is a graph based on the elapse of the heating time. Here, three types of temperature transition curves (hereinafter, referred to as heating curves) are exemplified. The heating curve L2 shows an average heating curve, and the temperature rise gradient after the second inflection point C2 is larger than the gradient 2 shown by a dashed line. The heating curve L1 shows a heating curve when the temperature rise gradient is lower than the average temperature rise gradient 2 due to the properties of the cooked food and the burning time is long, and the heating curve L3 larger than the gradient 1 is a pot. It shows the heating curve at the time of the pretend operation, and the temperature rise gradient immediately after the second bending point is larger than the gradient 3 shown by the dotted line,
The measured temperature returns to the boiling zone B about 20 seconds after the detection of the second bending point.

Embodiment 1 Embodiment 1 shows a fire extinguishing method for changing a fire extinguishing temperature in response to a temperature rise gradient. FIG. 3 shows a flowchart of an automatic fire extinguishing method in a comparison unit 11.
The temperature sensor 6 initialized at the time of starting is brought into contact with the bottom of the cooking pot 5, and the heating temperature of the food is measured by the temperature detection unit 8. Based on the measured temperature sent from the temperature detecting section 8, the boiling detecting section 9 detects that the water content of the food is T1 degrees, about 100 degrees.
The first inflection point C1 at which the temperature rises to about 100 ° C. and the boiling zone B where the temperature rises to about 100 ° C.
Is detected. Also, after detecting the first bending point C1,
The gradient detecting unit 10 calculates a rising gradient from the temperature measured by the temperature sensor 6 in the boiling zone B detected by the boiling detecting unit 9 to detect the second bending point C2 and the temperature rising gradients after the second bending point. .

Next, the second bending point C is detected by the gradient detecting section 10.
When 2 is detected (step S1), it is determined whether the temperature rise gradient after the second inflection point is a steep rise as seen in pan swing (step S2), and the gradient is large as in the heating curve L3. In this case, for example, if it is not less than 50 deg / min, the fire extinguishing temperature is set to T3 ° C. higher than the second inflection point by ΔT ₃ (step S3), and the fire extinguishing temperature set at T3 ° C. is compared with the measured temperature (step S4). ). In the heating curve L2 during normal use, the temperature rise gradient is not steep, so the fire extinguishing temperature is set to T2 ° C., which is higher by ΔT ₂ than the second inflection point at which scorching starts (step S5). Then, in the comparison unit 11, the measured temperature is T3 ° C. or T2 ° C. of the fire extinguishing temperature.
Is reached, a command to cut off the supply of the gas supply pipe 2 to the shutoff valve 2 is sent out in the fire extinguishing operation section 12 (step S).
6). Also, when the cooking pot 5 is swung during cooking,
Since the temperature returns to the boiling zone B before the measured temperature reaches T3 ° C. (step S7), the information on the temperature at the second inflection point, the measurement time, and the temperature rise gradient after the second inflection point is reset (step S8). ), The second of step S1
Repeat from the detection of the inflection point. Therefore, the fire extinguishing unit 12 does not shut off the gas supply due to the pan swing.

Embodiment 2 Embodiment 2 shows a fire extinguishing method in which the fire extinguishing temperature is set to three or more types in accordance with the temperature rise gradient. FIG. 4 shows a flowchart of the automatic fire extinguishing method of the cooking device. Things. As in the first embodiment, when the second bending point C2 is detected by the gradient detection unit 10 (step S1), the temperature rise gradient after the second bending point is large or small (steps S21 and S2).
2) The extinguishing temperature is set (steps S31, S3)
2, S33). For example, in the heating curve L2 at the time of normal use shown in FIG. 2, the slope of the heating curve is not steeper than the slope 3 (step S21), and is larger than the slope 2 (step S22), so that the fire extinguishing temperature is the second time when the burning starts It is set to T2 ° C. higher by ΔT ₂ than the inflection point (step S3
2). Also, since the heating curve L3 when the cooking pot 5 is rocked during cooking has a heating curve with a gradient greater than the gradient 3 (step S21), the fire extinguishing temperature is T3 ° C. higher than T2 ° C.
Is set to (step S31). Similarly, the heating curve L
1 is smaller than the gradient 2 (step S23), and the fire extinguishing temperature is T1 ° C. higher by ΔT ₁ than the second inflection point at which burning starts.
Is set to (step S33). After the fire extinguishing temperature is set to T3 ° C., T2 ° C., or T1 ° C., respectively, in the comparing unit 11, when the measured temperature reaches the extinguishing temperature in the comparing unit 11 (step S4), the shut-off valve 2 is set in the fire extinguishing operating unit 12. A command to cut off the supply of the gas supply pipe 2 is sent (step S6). If the measured temperature is sharply increased due to rocking of the cooking pot 5 during cooking, the measured temperature returns to the boiling zone B before the fire extinguishing temperature reaches T3 ° C. (step S7). The information of the inflection point is reset (step S8), and step S1
Is repeated from the detection of the second bending point. Therefore, the gas supply is not shut off. In addition, the temperature rise gradient and the fire extinguishing temperature after the second inflection point are set in one or more multi-stages depending on the type of cooking method, the food, and the cooking pot.

Embodiment 3 Embodiment 3 shows a fire extinguishing method in which the standby time from the second bending point to fire extinguishing is set in accordance with the temperature rise gradient. FIG. 5 shows a cooker according to Embodiment 3. 2 is a flowchart of the automatic fire extinguishing method of FIG. As in the first embodiment, the second inflection point C2 is detected by the gradient detection unit 10 (step S1), and the timer as the time integration unit 14 is activated (step S2). Next, the rising slope of the measured temperature and the slope 2
(Step S3), the heating curve L2 and the heating curve L3 in which the ascending slope of the heating curve is larger than the slope 2 are set to 20 in Step S41 with the integration time by the time integration unit 14 as the fire extinguishing standby time (t3-t2). Set to seconds.
In the heating curve L1 smaller than the slope 2, the fire extinguishing standby time (t
4-t2) is set to 5 minutes (step S42). Until the elapsed time from the second bending point exceeds the set fire extinguishing standby time, it is determined whether the measured temperature has returned to the boiling zone B (step S7). Since the heating curve L3 of the pan swing has returned to the boiling zone B within 20 seconds, the information of the second bending point is reset (step S).
8), repeating from the detection of the second bending point in step S1,
Therefore, the gas supply is not shut off. Since the heating curve L2 and the heating curve L1 have not returned to the boiling zone B (step S7), the process proceeds to step S3. And
If the elapsed time from the second inflection point exceeds the set fire extinguishing standby time, a command to shut off the supply of the gas supply pipe 2 to the shutoff valve 2 is sent out in the fire extinguishing operation unit 12 (step S).
6). In the second embodiment, the time integrating unit 14 operates. However, the time integrating unit 14 may be omitted by measuring the fire extinguishing standby time by measuring the pot bottom temperature.

Embodiment 4 Embodiment 4 shows a fire extinguishing method based on a fire extinguishing temperature and a waiting time until the fire extinguishes from the second inflection point in response to a temperature rise gradient. FIG. It is the figure which showed the flowchart of the automatic fire extinguishing method of such a cooking appliance. As in the first embodiment, when the second inflection point C2 is detected by the gradient detecting unit 10 (Step S1), the temperature rise gradient of the heating curve is compared with the gradient 2 (Step S3), and the gradient of the heating curve is changed to the gradient. For the heating curve L2 and the heating curve L3 larger than 2, the elapsed time from the detection time t2 of the second inflection point to the measurement time is set to 20 seconds in step S41. For the heating curve L1 smaller than the gradient 2, the fire extinguishing temperature is set to T1 ° C. (step S42). Next, until the elapsed time from the second inflection point exceeds the fire extinguishing standby time set in step S41 or the measured temperature exceeds the fire extinguishing temperature T1 ° C. set in step S42, the measured temperature is in the boiling zone B. (Step S)
7). Here, since the heating curve L2 and the heating curve L1 have not returned to the boiling zone B (step S7), the process proceeds to step S3. Since the heating curve L3 of the pan swing returns to the boiling zone B within 20 seconds (step S
7), reset the information of the second inflection point (Step S)
8), repeating from the detection of the second bending point in step S1,
Therefore, the gas supply is not shut off. In the heating curve L2, if the elapsed time from the second bending point exceeds the set fire extinguishing standby time (step S51), or the heating curve L
In step 1, when the measured temperature exceeds the fire extinguishing temperature T1 ° C. (step S52), a command to cut off the supply of the gas supply pipe 2 to the shutoff valve 2 in the fire extinguishing operation unit 12 is sent out (step S52).
6). In the fourth embodiment, the rising slope of the measured temperature due to panning is larger than the rising slope due to scorching, and
In addition to utilizing the characteristic of returning to the boiling zone again in about a second, for normal burning, it is possible to set multiple types of fire extinguishing temperatures suitable for the rising gradient, so that the measurement temperature rise due to panning can be reduced. In about 20 seconds of the fire extinguishing standby time, it is determined that fire extinguishing is unnecessary, and a monitoring state for automatically extinguishing fire is resumed, so that the reliability as a safety device has been improved. In the fourth embodiment, the time integrating unit 14 is not used,
The fire extinguishing standby time is measured based on the measurement time. Further, the above-described embodiment is an example, and the present invention is not limited to the above-described embodiment, and the shape, the configuration, and the like thereof can be appropriately changed without departing from the purpose and spirit of the present invention.

[0012]

As described above, according to the present invention,
When the cooking pot is shaken during cooking, even if the temperature sensor in contact with the bottom of the cooking pot separates and is affected by the radiation of the flame,
High reliability as a safety device without malfunction. Therefore, it is very convenient to use the cooking device, which is frequently used, without re-ignition when fire is extinguished due to malfunction. In addition, the accuracy of preventing non-sticking can be improved even with respect to variations in the temperature rise gradient due to the properties of the food.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing an automatic fire extinguisher of a cooking device according to the present invention.

FIG. 2 is a graph in which the heating temperature of a cooking object measured by a temperature sensor during heating is plotted with time.

FIG. 3 is a flowchart of a fire extinguishing method for changing a fire extinguishing temperature according to a temperature rise gradient in a comparing unit.

FIG. 4 is a flowchart of a fire extinguishing method according to a second embodiment in which a plurality of fire extinguishing temperatures are set according to a temperature rise gradient in a comparison unit.

FIG. 5 is a flowchart of an automatic fire extinguishing method according to a third embodiment in which a standby time from the second inflection point to fire extinguishing is changed according to the temperature rise gradient.

FIG. 6 is a flowchart of a fourth embodiment in which a fire is automatically extinguished in response to a temperature rise gradient based on a fire extinguishing temperature and a standby time until the fire extinguishes from a second bending point.

[Explanation of symbols]

1. Cooker, 2. Shut-off valve, 3. Gas supply pipe, 4.
..Gas burner, 5.Cooking pan, 6.Temperature sensor, 8.Temperature detector, 9.Boiler detector, 10 ... Gradient detector, 11 ... Comparator, 12 ... Fire extinguishing operating unit .

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F24C 3/12 A47J 27/00

Claims (2)

(57) [Claims] 1. A boiling detecting means for detecting a first inflection point at which a temperature change rate of the temperature sensor changes from a temperature measurement signal of a temperature sensor for measuring a bottom temperature of a cooking pot, and substantially constant from the first inflection point. When the sensor temperature rises through the boiling zone maintained at the temperature, the gradient detecting means for determining whether or not the rising gradient exceeds a predetermined rising gradient, and a second detecting means for determining that the gradient detecting means has exceeded the predetermined rising gradient. Automatic fire extinguishing of a cooker that automatically extinguishes a fire extinguisher equipped with a comparison means for comparing a fire extinguishing temperature set by a predetermined temperature higher than the temperature of the inflection point with the sensor temperature and outputting a burner fire extinguishing command when the sensor temperature exceeds the fire extinguishing temperature An automatic fire extinguisher for a cooking appliance, comprising a fire extinguishing temperature setting means for setting a fire extinguishing temperature based on a temperature rise gradient by the gradient detecting means. 2. A boiling detecting means for detecting a first inflection point at which a temperature change rate of the temperature sensor changes from a temperature measurement signal of a temperature sensor for measuring a bottom temperature of a cooking pot, and substantially constant from the first inflection point. When the sensor temperature rises through the boiling zone maintained at the temperature, the gradient detecting means for determining whether or not the rising gradient exceeds a predetermined rising gradient, and a second detecting means for determining that the gradient detecting means has exceeded the predetermined rising gradient. A comparison means for comparing an elapsed time from the inflection point with a fire extinguishing standby time for extinguishing the fire after a lapse of a set time from the second inflection point, and outputting a burner extinguishing command when the elapsed time exceeds the extinguishing standby time. An automatic fire extinguisher for a cooker that automatically extinguishes a fire, comprising: a fire extinguishing standby time setting unit that sets a fire extinguishing standby time based on a temperature rise gradient by the gradient detecting unit. Fire apparatus.