JPH02279925A - Temperature excessive rise preventing device for electric heating cooking apparatus - Google Patents

Abstract

PURPOSE:To prevent oil smoke from generating, oil from igniting by providing a temperature detector having high and low detecting temperatures to operate with an input of a temperature sensor, and human body detecting means, and switching the detecting temperature by the output of the human body detecting means. CONSTITUTION:A triac 18 conducts a heater 11 in a duty set by a driver 17. If the temperature of a cooking vessel is raised to become the detecting temperature or higher of a temperature detector 13 by a temperature sensor 12, the operation of a triac driver 17 is inhibited to stop conduction of the heater 11. The detecting tempera ture of the detector 13 is automatically set to a low temperature if a person is not located in the vicinity for a predetermined period of time or longer and to a high temperature if the person is not located in the vicinity by human body detecting means 14. Accordingly, if the person is not located in the vicinity for a predetermined period of time or longer, the absence is detected to automatically switch the detecting temperature. If it exceeds a temperature slightly higher than a water boiling tempera ture, the conduction is immediately stopped. Therefore, oil smoke is not filled in a room to adhere oil odor or contamination does hot occur.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an excessive temperature rise prevention device for electric cooking appliances used in general households.

Conventional technology Conventionally, an electric shoe heater has an electric heating element such as a sheathed heater attached to a metal body, a means for setting the energization rate such as a watt controller, and a cooking device to be heated is placed on the sheathed heater. It was then heated and cooked. Therefore, if electricity continues to be applied to a container containing oil or the like, the temperature of the container will continue to rise, and there is a risk that the oil will eventually catch fire.

In order to prevent such unsafe conditions, recently, electric heating elements with a temperature sensor attached to the center and a function to turn the electricity on and off to prevent the temperature of the container from rising too high have been made. became.

An example of such an electric heating heater is shown in FIG. In Fig. 4, 1 is an electric heating element such as a sheathed heater, 2 is a temperature sensor 3 is a triac for turning on and off the electric heating element, and 4 is a deuge for turning on and off the electric heating element. The input switch 5 is a printed board on which a temperature detection circuit operated by the output of the temperature sensor 2 and a triac drive circuit are mounted.

6 indicates a cooking container containing oil 7.

FIG. 6 is a block diagram showing the electrical configuration. Fifth
In the figure, 8 is a temperature detection circuit operated by the output of the temperature sensor 2, 9 is a duty generation circuit that generates the duty set by the input isolator 4, and 10 is a triac drive circuit.

Now, when the temperature sensor 2 on the medium heat of the electric heating element 1 on which the pot 6 containing the oil 7 is placed detects a temperature rise, the triac 3 is turned on by the output of the temperature detection circuit 8, as shown in FIG. - It is configured to turn off and control the temperature of the oil 7 in the pot 6 placed on the heater 1 at a temperature of 0, making it possible to prevent the oil from igniting.

Problems to be Solved by the Invention However, in the above configuration, the temperature O needs to be set at a high temperature that does not interfere with actual cooking, so if oil is heated to a high temperature and left unattended. There were 19 problems caused by oil smoke that filled the room. on the other hand,
If the temperature is turned off at θ, the thermistor temperature will remain high for a while, so the switch will not be accepted, and you will have to wait for the thermistor temperature to drop, making it inconvenient to use and interfering with actual cooking. Furthermore, since the temperature rise varies depending on the size of the container and the amount of oil, there remains a risk of ignition, especially when the amount of oil is small.

In view of the above problems, the present invention aims to prevent the generation of oil smoke and the ignition of oil.

Means for Solving the Problems In order to solve the above problems, the present invention provides a temperature sensor that detects the temperature of an electric heating element and a heated object, and a temperature sensor that operates based on the input of the temperature sensor and has two detection temperatures, high and low. It has a detection circuit and a human body detection means, switches the detected temperature according to the output of the human body detection means, and stops energization at a high detection temperature when the human body is detected by the human body detection means,
If no human body is detected for a certain period of time, the power is cut off at a low detection temperature.

By configuring as described above, when a person is nearby, the temperature detection circuit operates at a high detection temperature based on the output of the human body detection means, and when the temperature sensor detects an increase in oil temperature, the temperature will rise too high. In such cases, the power supply is temporarily stopped, and when the oil temperature drops, the temperature sensor detects this and the power supply is restarted.

If a person is not around for a certain period of time, the temperature detection circuit uses the output of the human body detection means to switch the detected temperature to a temperature slightly higher than the boiling temperature of water, and the temperature sensor switches the detected temperature to a temperature slightly higher than the temperature detected by the oil temperature. If this is detected, the power is cut off and the power is not turned on again even if the temperature drops.

This prevents the room from being left in a hot oil state for a long time, and prevents the room from being filled with oil smoke and getting dirty with the smell of oil. Moreover, it goes without saying that ignition of the oil is prevented, and safety is further improved in the event that a person carelessly leaves the cooking appliance.

Embodiment Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings.

FIG. 1 shows a block diagram of an electric heating cooker which is an embodiment of the present invention. In Figure 1, 6 and 11 are electric heating elements such as sheathed heaters,
A temperature sensor 12 detects the temperature of the cooking container placed on the heater. Reference numeral 13 denotes a temperature detection circuit having two detection temperatures, high and low, which is activated by the output of the temperature sensor 2, and stops power supply to the heater when the temperature of the temperature sensor exceeds the detection temperature. Reference numeral 14 denotes a human body detection means for switching the temperature detected by the temperature detection circuit 13. Reference numeral 16 designates an input switch for setting the energization rate of the heater 110, reference numeral 16 designates a duty generation circuit, and reference numeral 17 designates a drive circuit for the triac 18.

Normally, the triac 18 energizes the heater 11 at a duty set by the drive circuit 17.
When the temperature of the cooking container rises and becomes equal to or higher than the temperature detected by the temperature detection circuit 13 by the temperature sensor 12, the operation of the triac drive circuit 17 is prohibited and the power supply to the heater 11 is stopped. The temperature detected by the temperature detection circuit 13 is detected by the human body detection means 14.
If no one is around for a certain period of time, the temperature will be lower (
(approximately 120℃), high temperature (approximately 2℃) when people are nearby.
60℃).

FIG. 2 is a block diagram showing the configuration of the human body detection means 14. In FIG. 2, 19 is an LED drive circuit, 2Q is an LED, 21 is a light receiving element, and 22 is an output circuit. When a human body exists between Lli:020 and 21, the output circuit 22 is turned off, and the human body is not between 20 and 21, the output circuit 22 is turned on.

In addition to this example, the human body detection means may be realized using a weight detection means, an infrared detection means, a Doppler radar using microwaves, or the like.

FIG. 3 shows a rough 1-ware flowchart when the configuration of the present invention is implemented on a microcomputer. In FIG. 3, the first step is to determine whether the start switch has been pressed, the second step is to set the energization rate of the heater 11, and the third step is to determine the detected temperature θ at which the temperature T of the temperature sensor 12 is high. (about 2
60° C.), step 4a.
The step is to turn off the triac 18 when the temperature of the temperature sensor 12 is higher than θ, step 4b is to turn on the triac 18 when the temperature T of the temperature sensor 12 is lower than 0, and the sixth step is to turn off the triac 18 when the temperature T of the temperature sensor 12 is lower than 0. In the step of determining whether the output of temperature sensor 14 is on or off, if the human body detection means 14 is on for a certain period of time or more, it means that there is no person near the electric heating cooker, so in the sixth step, the temperature of the temperature sensor 12 is lowered. Detection temperature θ1 (about 12
0°C), and if it is higher than 01, it is set to 1 in the seventh step.
-Turn off the Liasok 18. After that, the program jumps to the input waiting routine, and the power supply is cut off. If the human body detection means 14 is off in the sixth step, it is determined whether to skip or not in the eighth step, and then immediately before the third step, the heater is energized at the detected temperature θ. continue.

As described above, according to the invention, even if oil is heated in a container, if a person is not around for a certain period of time, the absence of the person will be detected and the temperature detected by the temperature detection circuit will be automatically adjusted. When the temperature exceeds the boiling temperature of water, the power is immediately cut off, which prevents the room from being filled with oil smoke and the smell of oil, or leaving a dirty room, and also prevents oil from igniting. This can also be prevented. -!
However, if someone is nearby, the temperature detected by the temperature detection circuit is automatically switched to a higher temperature, so there is no problem with cooking, and it is safer and easier to use than conventional overheat prevention devices. It is possible to achieve good results, and its value is high.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an electric heating cooker showing an embodiment of the present invention, FIG. 2 is a block diagram showing an embodiment of the structure of the human body detection means of the present invention, and FIG. 3 is an embodiment of the present invention. FIG. 4 is a sectional view showing an example of a conventional electric cooker; FIG. 6 is a block diagram showing an example of a conventional electric cooker; FIG.
The figure is an explanatory diagram of the operation of a conventional electric cooker. 11...Electric heating element, 12...Temperature sensor 13...Temperature detection circuit, 14...Human body detection means.

Claims (1)

[Claims] It has an electric heating element, a temperature sensor that detects the temperature of the heated object, a temperature detection circuit that operates based on the input of the temperature sensor and has two detection temperatures, high and low, and a human body detection means. The detected temperature is switched according to the output, and when a human body is detected by the human body detection means, the power supply is stopped at a high detected temperature, and when a human body is not detected, the power supply is cut off at a low detected temperature. An overtemperature rise prevention device for electric heating cookers.