JPH0518021B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a fire prevention and safety device for electric stoves.

Conventional Structure and Problems Conventionally, electric heaters have been fitted with guards to prevent people's hands, objects, etc. from easily touching the heat generating part.

However, if a flammable object is placed close to the front of the guard, the heat from the heating element will heat the combustible object and reach a high temperature, which may cause a fire to the nearby flammable object or even cause a house fire. Ta.

Hereinafter, the conventional electric stove as described above will be explained with reference to the drawings.

FIG. 1 shows a cross section of a conventional electric stove, and FIG. 2 shows its electric circuit diagram.

1 is a stove housing, 2 is a reflective plate that reflects heat forward, 3 is a heating element located in front of the reflective plate 2, and 5 is located on the back of the reflective plate 2, inside the stove housing 1. The thermostat detects the temperature rise inside the stove housing and turns on electricity to the heating element 3.
Turn off.

The operation of the electric stove configured as above will be explained below. When a combustible substance or the like is applied to the upper part of the stove casing 1 and the temperature inside the casing rises abnormally, a thermostat 5 stops energizing the heating element 3.

However, in the above configuration, the thermostat 5 will not operate unless the temperature inside the stove housing 1 rises, so if a flammable object approaches the front of the stove, the temperature inside the housing will rise. Therefore, it did not work as a safety device and was not suitable as a safety device for fire prevention.

OBJECTS OF THE INVENTION In view of the above-mentioned problems, the present invention provides an electric stove that can prevent a fire when a combustible material approaches the front of a heating element.

Structure of the Invention In order to achieve this object, the present invention includes a reflector in a stove housing with an open front, a heating element disposed in front of the reflector, and a guard disposed in front of the heating element. and a temperature sensor that detects a temperature rise, and an electric circuit that controls the heating element based on a signal from the temperature sensor, the temperature sensor having a concave shape above the reflector plate and inward from the surface of the stove housing. It is located approximately at the focal point of the heat collecting plate.

With this configuration, when a combustible object comes close to the front of the heating element, the heat from the high-temperature combustible object is absorbed.
By detecting the temperature with a temperature sensor and turning off the heating element, it is possible to prevent fires caused by nearby combustible materials.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows a side cross-section of an electric stove in one embodiment of the present invention.

In FIG. 3, reference numeral 1 indicates a stove housing with a front opening, and a reflector 2 facing the front and the reflector 2.
The stove includes a heating element 3 located at the front of the stove, and a guard 4 fixed to the front opening of the stove housing 1.

Above the reflector plate 2, a thermistor 5 is fixed on the surface of the stove housing 1 as a temperature sensor, and a signal from the thermistor 5 activates the heating element 3.
An electric circuit section 6 that turns off the power to the stove is provided within the stove housing 1.

The thermistor 5 is fixed to the bottom surface 8 of the heat absorption plate 7 of the stove housing 1, and the tip of the thermistor 5 is fixed inside the surface of the stove cylinder 1.

9 in the figure is the main power switch for the heating element 3, 1
0 is a leg that supports the stove housing 1.

Further, the thermistor is located approximately at the focal point of the bottom surface portion 8 of the heat collecting plate 7, making it easier to collect heat from the front.

The operation of the electric stove configured as above will be explained below.

First, in normal use when there are no obstacles in front of the guard 4, the ambient temperature of the thermistor 5 provided on the upper surface of the stove housing 1 is low, so the resistance value does not change and the heating element 3 is energized. There is.

As shown in FIG. 4, when an obstacle 11 such as a combustible material approaches in front of the guard 4, the heat of the heating element 3 causes
The temperature of the obstacle 11 rises, the ambient temperature of the thermistor 5 rises due to the heat, the resistance value changes, and the control circuit 6 stops energizing the heating element 3.
Therefore, the obstacle 11 stops heating and can prevent ignition.

Furthermore, when the combustible material 12 falls on the top surface of the stove housing 1 as shown in FIG. increases, the resistance value changes, the electricity to the heating element 3 is stopped, and the combustible material 1
2. Prevents temperature rise and prevents ignition.

Also, when the person falls down as shown in Figure 6, the temperature of the floor 13 rises as in the case of the proximity of the obstacle 11 in Figure 4, and the temperature of the thermistor 5 rises due to the heat, causing the resistance value to rise. The temperature changes, and the electricity to the heating element 3 is stopped, thereby preventing the floor surface 13 from igniting.

Furthermore, since the thermistor 5 is provided inward from the surface of the stove housing 1, it is less susceptible to the effects of convection heat from the heating element 3 during normal use.

Furthermore, since the thermistor 5 is provided approximately at the focal point of the bottom portion 8 of the heat collecting plate 7, it is easy to collect heat from the obstacle 11, and the temperature of the thermistor 5 rises quickly.

As described above, according to this embodiment, the thermistor 5
By providing above the reflector 2 on the surface of the stove housing 1, when the obstacle 11 approaches in front of the guard 4, the temperature rise of the obstacle 11 is detected,
It is possible to stop energizing the heating element 3 and prevent the obstruction 11 from catching fire.

Also, if combustible material falls above the stove casing 1, the ambient temperature of the thermistor 5 rises, causing the heating element 3 to stop being energized. Also, if you fall,
The thermistor 5 senses the rise in temperature of the floor surface and stops energizing the heating element 3 to prevent ignition.

Further, since the thermistor 5 is located inward from the stove surface, it is not easily affected by convection heat during normal use, so the temperature tends to be low and stable.

Further, since the thermistor 5 is located approximately at the focal point of the bottom shape of the recess, it is easy to collect the heat of the obstacle, the temperature rises quickly, and the heating element 3 can be turned off before the object ignites.

Effects of the Invention As is clear from the above examples, according to the present invention, the following effects can be obtained.

(1) Since the temperature sensor is located almost at the focal point of the heat collecting plate, it is easy to collect heat from obstacles, and of course, if flammable objects come into contact with the stove body,
Even if an obstacle is close to the front of the guard, the temperature rise of the obstacle can be detected quickly.
The response speed of the temperature sensor becomes faster, making it possible to prevent objects from catching fire. Furthermore, the temperature sensor
Since it is located inward from the surface of the stove casing, it is not affected by convection heat during normal use and remains stable at a low temperature, eliminating the possibility of malfunction.

(2) If flammable materials such as towels are placed on the top of the stove, the temperature around the temperature sensor will rise, causing
It is possible to stop energizing the heating element and prevent ignition.

(3) Even if the stove falls over, the temperature sensor detects the rise in temperature on the floor and turns off the heating element to prevent ignition, eliminating the need for an overturn switch.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a conventional electric stove, Fig. 2 is its electric circuit diagram, Fig. 3 is a sectional view of an embodiment of the present invention, and Fig. 4 is a side view of the same embodiment in a state in which combustibles are in close proximity. , Fig. 5 is a side view with combustible material on the top surface, Fig. 6 is a side view of the case in an overturned state, and Fig. 7
The figure is a circuit diagram. 1...Stove housing, 2...Reflector plate, 3...Heating element, 4...Guard, 5...Thermistor (temperature sensor), 6...Control circuit (electric circuit), 7... Heat collector plate, 8... Bottom.

Claims (1)

[Claims] 1. A reflector in the stove housing with an open front, a heating element placed in front of the reflector, a guard placed in front of the heating element, a temperature sensor that detects a temperature rise, and a temperature sensor that detects the temperature rise. and an electric circuit that controls the heating element based on a signal from a sensor,
In the electric stove, the temperature sensor is located above the reflecting plate and approximately at the focal point of a heat collecting plate that is concave inward from the surface of the stove housing.