JP2000274674A - Safety unit for cooking stove - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safety unit for cooking stove in which fire caused by missing to turn off the cooking stove can be prevented. SOLUTION: White smoke is detected by photosensors 17, 19 before oil is fired naturally. The photosensor 17 projects a specified quantity of light which is received by the photosensor 19. A decision is made that white smoke is generated from the oil if the quantity of light received by the photosensor 19 drops below a set level. Since the white smoke is generated continuously from oil, and the like, duration of white smoke is measured. When the duration of white smoke exceeds a preset time, a solenoid valve 7 is interrupted and a burner 5 is turned off automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stove safety device, and more particularly to a stove safety device for preventing a fire caused by forgetting to turn off a stove.

[0002]

2. Description of the Related Art In order to prevent a tempura oil fire from occurring, a stove oil fire prevention device as shown in FIG. 2 is provided. In FIG. 2, gas is supplied to the stove 10 from the outside via the rubber pipe opening 1. The supplied gas reaches the burner 5 via the gas pipe 3.

In the middle of the gas pipe 3, an electromagnetic valve 7 capable of shutting off gas supply is mounted. A mechanical valve 9 that can be manually opened and closed is disposed between the burner 5 and the solenoid valve 7. On the front surface of the stove 10, an ignition button 8 for igniting the burner 5, adjusting the thermal power and extinguishing the fire is provided.

On the upper part of the stove 10, a gotoku 11 has a burner 5
At the center so as to surround it from above. At the center of the burner 5, a temperature sensor 13 is provided. The temperature sensor 13 is configured to come into contact with the bottom of the pot when the pot 15 or the like of the tempura oil is placed on the pot 11. The output signal of the temperature sensor 13 is input to the control circuit 31.

[0005] In the control circuit 31, it is determined whether or not the temperature detected by the temperature sensor 13 has reached about 250 ° C. When the temperature detected by the temperature sensor 13 is about 25
When it is determined that the temperature has reached 0 ° C., the control circuit 31 closes the solenoid valve 7. When the solenoid valve 7 is closed, the gas is shut off,
The stove 10 extinguishes automatically.

[0006] In the metal pot 15, the temperature of the oil in the pot 15 and the temperature of the pot bottom substantially match. Therefore, the temperature of the oil in the pan 15 can be estimated by measuring the temperature at the bottom of the pan. The aforementioned temperature of 250 ° C. is lower than the spontaneous ignition temperature of oil and higher than the temperature range used in normal cooking.

[0007]

By the way, in the tempura oil fire prevention device using the conventional temperature sensor 13, the temperature sensor 13 which is brought into contact with the bottom of the pan may obstruct the movement of the pan 15 during cooking. Was.

The temperature sensor 13 is configured to contact the pan 15 with a constant pressure in order to accurately detect the temperature at the bottom of the pan. However, when the pan 15 is light, the stability of the pan 15 is hindered. There was a fear.

[0009] Pot (net) such as grill net cooking, roasting cooking
If the temperature of the bottom becomes high and the sensor temperature exceeds 250 ° C., there is a risk that the fire will be extinguished automatically during cooking.

Further, in the method of detecting the temperature at the bottom of the pot, in the case of a pot 15 having poor heat conduction, such as a clay pot or a glass pot, the temperature of the oil contained in the pot 15 does not match the temperature of the pot bottom. There was a possibility that it would not work.

Further, the pot 15 whose bottom is deformed and the temperature sensor 13 does not make sufficient contact is difficult to use because the safety device does not function correctly.

The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a stove safety device for preventing a fire caused by forgetting to turn off a stove.

[0013]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a gas pipe for supplying gas, a gas shut-off means disposed in the middle of the gas pipe and capable of shutting off gas supply, A burner disposed at an end portion, a virtue disposed around the burner, an object to be heated or burned by the burner placed on the virtue, and an object to be heated or the like A light projecting means for projecting light toward the emitted smoke, a light receiving means for receiving the light emitted from the light projecting means and passing through the smoke, and a light amount of the light received by the light receiving means. A light amount determining unit that determines whether the light amount is equal to or less than a predetermined set light amount value, and a duration measuring unit that measures a continuous time equal to or less than the set light amount value when the light amount is determined to be equal to or less than the set light amount value. Means, and the duration measured by the duration measuring means is predetermined. A time determining means for determining whether or not the continuous time is equal to or more than a fixed time value; and a gas supply stopping means for closing the gas shutoff means and stopping the gas supply when the continuous time is equal to or more than the set time value. And was configured.

In the middle of the gas pipe, a gas shut-off means is provided. The gas shutoff means can shut off the gas supply. A burner is provided at the end of the gas pipe. Gotoku is arranged around the burner. An object to be heated or the like is placed in this manner and heated or burned by a burner. From an object to be heated or the like, smoke is generated due to heating or the like by a burner. The light emitting means emits light toward the smoke. The light receiving means receives the light emitted from the light emitting means and transmitted through the smoke.

The light quantity determining means determines whether the light quantity of the light received by the light receiving means is equal to or less than a predetermined light quantity value.
During normal cooking, there is no obstacle between the light emitting means and the light receiving means, so that light reaches the light receiving means side. When an object to be heated or the like is overheated due to forgetting to turn off the stove or the like, oil smoke or the like becomes white smoke and blocks light, so that light does not reach the light receiving side.

The set light quantity value is a threshold value provided for distinguishing, for example, steam or smoke during normal cooking from a remarkable white smoke state generated from an object to be heated or the like due to forgetting to turn off the stove. In the duration measuring means, when the light quantity is judged by the light quantity judging means to be equal to or less than the set light quantity value, the duration time of the set light quantity value or less is measured. Then, the time determining means determines whether or not the duration measured by the duration measuring means continues for a predetermined time value or more.

A remarkable white smoke state emanating from an object to be heated or the like due to forgetting to turn off the stove continues to occur until ignition. Therefore, if the light is interrupted instantaneously, it is not determined that the smoke is white. The gas supply stopping means closes the gas shut-off means and stops the gas supply when the time determining means continues for a set time or more.

As described above, it is possible to prevent an oil fire or the like caused by forgetting to turn off the stove. Further, since the light emitting means and the light receiving means do not directly touch the smoke, deterioration of the sensor sensitivity due to water vapor, oily smoke, etc. emitted during cooking can be reduced.

[0019]

Embodiments of the present invention will be described below. FIG. 1 shows a configuration diagram of an embodiment of the present invention. Note that the same components as those in FIG. In FIG. 1, a pot 15 containing oil is placed on the gotoku 11. An optical sensor 17 corresponding to the light projecting means and an optical sensor 19 corresponding to the light receiving means are arranged so as to sandwich the oil smoke coming out of the pan 15.

The optical sensor 17 is supplied with power from the control circuit 21. The light transmitted through the oil smoke from the optical sensor 17 is received by the optical sensor 19. Optical sensor 19
Is converted into a voltage signal and input to the control circuit 21. The control circuit 21 can shut off the solenoid valve 7.

Next, the operation of the embodiment of the present invention will be described. When the oil is heated, when the temperature reaches about 250 ° C, smoke starts to appear, and when it exceeds about 300 ° C, it becomes remarkable white smoke,
The white smoke state continues until spontaneous ignition occurs.

Therefore, as shown in FIG. 1, the white smoke generated before the oil spontaneously ignites is detected by the optical sensors 17 and 19. The optical sensor 17 emits a certain amount of light. Then, the emitted light is received by the optical sensor 19. The received light is converted to a voltage and output to the control circuit 21.

For steam and smoke emitted during normal cooking,
Its concentration is clearly different from the white smoke before the oil spontaneously ignites.
Therefore, it can be distinguished by the light transmittance. For example, during normal cooking, the amount of light received by the optical sensor 19 is large. On the other hand, in the case of white smoke from oil or the like, the amount of light received by the optical sensor 19 is small. The difference in the amount of received light at this time is clear.

Therefore, in order to distinguish between the two, a set light amount value which is a threshold value is determined in advance. And the optical sensor 19
If the amount of received light is less than the set light amount, it is determined that white smoke from oil or the like is generated. The comparison of the light amounts at this time is performed by a comparator or the like (not shown) in the control circuit 21. By setting the set light amount value in this way, it is possible to prevent the safety device from malfunctioning during normal cooking.

Since the white smoke such as oil is continuously generated until the ignition, the duration of the white smoke which continues below the set light amount value at this time is measured. The solenoid valve 7 is shut off when the duration of the white smoke lasts for a predetermined time value or more. The burner 5 is automatically extinguished by shutting off the solenoid valve 7. As a result, if the light is interrupted instantaneously, it is not determined that the smoke is white smoke, so that malfunction of the safety device can be prevented.

As described above, since the temperature sensor 13 that contacts the bottom of the pot as in the related art is not required, it does not obstruct the movement of the pot 15 during cooking. In addition, since the light pan 15 is securely placed on the gorge 11, stability can be ensured.

Further, since the method detects the white smoke generated from oil instead of the method of detecting the temperature at the bottom of the pot, the fire is not automatically extinguished even in high-temperature cooking such as grilling as in the prior art. Further, the performance as a safety device can be ensured regardless of the material of the pot 15 or the shape of the pot bottom.

Further, an optical sensor 17 is used to detect white smoke.
Since the sensor 19 is used, it is not necessary to directly expose the sensor itself to smoke, and it is possible to reduce the deterioration of the sensor sensitivity due to steam, oily smoke, etc. generated during cooking. The control circuit 21
The power supply to the optical sensors 17 and 19 may be linked to the ignition and extinguishing operations of the ignition button 8 for power saving.

[0029]

As described above, according to the present invention, the light quantity of the light received by the light receiving means is equal to or less than the predetermined light quantity value and the duration measured by the duration measuring means is predetermined. Since the gas supply is stopped by the gas shut-off means when the time exceeds the set time value, it is possible to prevent an oil fire or the like caused by forgetting to turn off the stove.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 Conventional tempura oil fire prevention device

[Explanation of symbols]

 Reference Signs List 5 burner 7 solenoid valve 10 stove 11 gotoku 15 pot 17, 19 light sensor 21 control circuit

Claims (1)

[Claims] 1. A gas pipe for supplying gas, a gas cut-off means provided in the middle of the gas pipe and capable of cutting off gas supply, and a burner provided at an end of the gas pipe. Lights are emitted toward the virtues arranged around the burner, the object to be heated or burned by the burner placed on the virtues, and smoke emitted from the object to be heated or the like. A light projecting means, a light receiving means for receiving light emitted from the light projecting means and passing through the smoke, and determining whether or not a light amount of the light received by the light receiving means is equal to or less than a predetermined set light amount value. A light amount judging means for judging, a duration measuring means for measuring a duration equal to or less than the set light quantity value when the light quantity is judged to be equal to or less than the set light quantity value; It is determined whether or not the determined continuation time continues for a predetermined time value or more. A stove comprising: a time judging means; and a gas supply stopping means for closing the gas shutoff means and stopping gas supply when the duration time continues for the set time value or more by the time judging means. Safety device.