JPH08152135A - Temperature sensor for heating cooker - Google Patents

Abstract

PURPOSE: To obtain a temperature sensor which is capable of detecting temperatures with an accuracy equivalent to that in the case of normal plane- contact even when the temperature sensor is on the tilt and partly in contact with the bottom of a cooking pan. CONSTITUTION: This temperature sensor 7 to detect temperatures of the bottom of a cooling pan 1 is provided with a heat receiving element 2 that is forced by a spring 8 to come in contact with the bottom of the cooking pan 1 and a thermistor 3 to detect the bottom temperatures transferred from the heat receiving element 2. The heat receiving element 2 has a nearly flat plane 5 at the central part of a face of contact with the bottom of the cooking pan 1 and a slope 4 that stretches from the central part toward the circumference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature sensor for a heating cooker such as a table hob, and more particularly to a temperature sensor for detecting a pot bottom temperature of a cooking pot.

[0002]

2. Description of the Related Art Conventionally, a heating cooker that detects the temperature of the bottom of a cooking pot with a thermistor and stops combustion when the detected temperature is equal to or higher than a predetermined temperature in order to prevent fires such as tempura oil and burning It has been known. For example, the heating cooker shown in FIG. 5 is provided with a temperature sensor 7 having a thermistor 3 for detecting a temperature, and the thermistor 3 detects the pot bottom temperature of the cooking pot 1 to determine whether the detected temperature is a predetermined temperature or higher. The controller 27 makes a determination, and from the determination result,
It controls the opening and closing of the gas passage. Further, the temperature sensor 7 is provided with a holder 9 that is integrally formed with the heat receiving portion 2 that comes into contact with the bottom surface of the cooking pot 1 to form a cylinder.
A spring 8 is provided coaxially for urging the blade in the abutting direction of the pot bottom. When the cooking pot 1 is placed, the spring 8 is compressed by the weight of the cooking pot 1, and the holder 9 abuts the heat receiving portion 2 on the cooking pot 1 while the outer peripheral surface of the cylindrical column 10 fixed to the body. Slide down. Further, a thermistor 3 for detecting the temperature of the transferred pot bottom is provided on the back surface of the central portion of the heat receiving unit 2, and transmits the detected temperature to the controller 27. Also,
A gap is provided in the slide portion between the holder and the column 10, and the holder 9 can be slightly swung with respect to the column 10. Therefore, when the heat receiving part 2 and the bottom surface of the pan are in contact with each other with an inclination, the bottom surface of the pan and the heat receiving part 2 are in surface contact with each other by sliding the bottom surface of the pan with a spring force.

[0003]

However, the conventional heating cooker has a problem that the pan bottom temperature is detected low when the inclination of the temperature sensor 7 is not corrected. For example, the shape of the bottom of the cooking pot 1 is not only a flat bottom pot but also a round bottom pot such as a wok, or the cooking pot 1
May be placed on 20 as if it were tilted. Also, when the temperature detecting unit 7 tilts and comes into contact with the bottom surface of the cooking pot 1, the spring force tends to slide the bottom surface of the cooking pot to correct the inclination, but the bottom surface of the cooking pot 1 "burns". In some cases, it is difficult to slip due to factors such as. In such a case, the temperature sensor 7 tilts and comes into point contact with the bottom surface of the cooking pot 1, so-called one-sided contact, which makes it difficult for heat to be transferred from the cooking pot 1 to the temperature sensor 7 and the thermistor. No. 3 will detect the pot bottom temperature at a low level. as a result,
The controller 27 cannot determine the pot bottom temperature normally. The temperature sensor of the heating cooker according to the present invention solves the above-mentioned problems, and even if the temperature sensor is tilted and comes in contact with the bottom surface of the cooking pot 1, the temperature sensor can detect temperature equivalent to normal surface contact. For the purpose of providing.

[0004]

A temperature sensor for a heating cooker according to the present invention, which solves the above-mentioned problems, comprises a heat-receiving portion that abuts on the pot bottom of a cooking pot, and a spring that urges the heat-receiving portion in the pot-bottom abutting direction. , A temperature sensor provided on the back surface of the central portion of the heat receiving portion, the temperature sensor having a temperature-sensitive element for detecting the temperature of the pot bottom transferred heat, the central portion of the heat receiving portion is formed in a substantially horizontal plane, and the central portion The gist is that an inclined surface is formed in the range from to the outer circumference.

[0005]

In the temperature sensor of the heating cooker according to the present invention having the above-described structure, the central portion of the heat receiving portion that abuts on the pan bottom of the cooking pot is formed in a substantially horizontal plane, and the inclined surface is formed in the range from the central portion to the outer periphery. Form. Therefore, when the temperature sensor is in vertical contact with the pan bottom of the cooking pan, the substantially horizontal center portion of the heat receiving part is in contact with the pan bottom. Further, when the temperature sensor is tilted, an inflection part, which is a boundary between the substantially horizontal surface near the center of the heat receiving part and the inclined surface, comes into contact with the pan bottom. Also, as it leans, the inclined surface approaches the bottom of the pan. That is, when the temperature sensor is tilted, a position near the temperature sensing element in the center of the heat receiving portion comes into contact with the bottom surface of the pan. Further, as the temperature sensor is inclined, the inclined surface of the heat receiving portion is close to the bottom surface of the pan, and the gap between the inclined surface and the bottom surface of the pan becomes smaller, so that the heat transfer loss from the bottom surface of the pan to the temperature sensing element is small. Therefore, even if the heat receiving portion of the temperature sensor is tilted and hits the bottom surface of the pot, the heat receiving portion can transmit a temperature substantially equal to the pot bottom temperature to the temperature sensing element.

[0006]

EXAMPLES In order to further clarify the constitution and operation of the present invention described above, preferred examples of the temperature sensor in the heating cooker of the present invention will be described below. FIG. 5: shows the schematic block diagram of a heating cooker. The heating cooker is provided with a burner body 22 for guiding a mixture of fuel gas and primary air,
An annular burner head 21 is removably mounted coaxially with the head of the burner body 22. At the center of the burner head 21, there is provided a temperature sensor 7 that comes into contact with the bottom surface of the cooking pot 1 to detect the temperature of the bottom of the pot. And this temperature sensor 7
Is provided with a thermistor 3 that increases or decreases the electrical resistance value according to the detected temperature. The thermistor 3 is electrically connected to a controller 27 that controls combustion, and the controller 27 monitors whether the temperature detected by the thermistor 3 is equal to or higher than a predetermined temperature. Further, the controller 27 is electrically connected to the main solenoid valve 25 and the original solenoid valve 26 that open and close the gas flow path,
When it is determined that the detected temperature is equal to or higher than the predetermined temperature, a command to close the main solenoid valve 25 and the source solenoid valve 26 is issued to stop the combustion.

FIG. 1 shows an enlarged view of the temperature sensor 7. The temperature sensor 7 is provided with a cylindrical heat receiving portion 2 in a portion that comes into contact with the bottom surface of the cooking pot 1, and a thermistor 3 that detects heat transfer from the bottom surface of the pot at the center of the back surface of the heat receiving portion 2. Further, a holder 9 which is integrated with the heat receiving portion 2 to form a cylinder is provided, and a cylindrical column 10 fixed to the body is provided coaxially in the cylinder of the holder 9. The holder 9 slides up and down on the outer peripheral surface of the pipe expanding portion 11 provided at the end of the column 10. In addition, a spring 8 for urging the holder 9 in the abutting direction of the pan bottom is provided coaxially inside the pipe expanding portion 11 of the column 10. Further, a stopper portion 13 having an inner diameter smaller than the outer diameter of the pipe expanding portion 11 of the support column 10 is provided at the lower portion of the inner surface of the cylinder of the holder 9, and the stopper portion 13 and the pipe expanding portion 11 of the support column 10 come into contact with each other so that the spring 8 The holder 9 urged by is restricted from coming off. Further, when the cooking pot 1 is placed, the spring 8 is compressed by the weight of the cooking pot 1, and the holder 9 slides the pillar 10 downward while the heat receiving portion 2 is in contact with the cooking pot 1. Also, so that the heat receiving portion 2 makes surface contact with the bottom surface of the cooking pot 1,
The holder 9 is provided so as to intentionally swing around the column 10. That is, the gap between the inner diameter of the holder 9 and the outer diameter of the tube expansion portion 11 of the support column 10, and the stopper portion 1 of the holder 9.
3 A gap is provided between the inner diameter and the outer diameter of the column 10, and the swing angle of the holder 9 is determined by this gap.

When the bottom surface of the cooking pot 1 is tilted within the swinging angle of the holder 9, the holder 9 is tilted while being pressed against the bottom surface of the pot by the spring 8, so that the heat receiving portion 2 and the bottom surface of the pot directly contact each other. Be corrected as is done. However, when the heat receiving part 2 is less likely to slip due to “burn” formed on the bottom surface of the pan, the heat receiving part 2 contacts the bottom surface of the pan while tilting. For example, in the conventional example shown in FIG. 3, since the entire pan bottom contact surface of the heat receiving part 32 is a flat surface, when the heat receiving part 32 is inclined (angle θ1), the heat receiving part 32 comes into contact with the pan bottom at a portion 36 near the outer periphery thereof. . Further, an air layer in the gap of H10 is formed in the central portion of the heat receiving portion 32. Therefore, the heat of the cooking pot 1 is transferred from the bottom of the pot to the heat receiving part 32 through the air layer, and is transferred from the heat receiving part 32 to the thermistor 3 (b). Further, the heat receiving portion 3
When 2 is tilted (angle θ2), a gap of H20 is opened between the heat receiving portion 32 and the heat receiving portion 32 (c). That is, not only the heat receiving portion 32 abuts on the bottom surface of the pan at a position away from the central portion where the thermistor 3 is attached, but also the heat receiving portion 3 is placed through the air layer.
Since the heat is transferred to 2, the temperature detected by the thermistor 3 will be lower than the pot bottom temperature.

Therefore, even if the heat receiving portion 2 is inclined, in order for the thermistor 3 to accurately detect the pot bottom temperature, it is necessary to reduce the heat transfer loss from the pot bottom surface to the heat receiving portion 2. The following two points are important. First, the first important point is that the heat receiving portion 2 located as close as possible to the thermistor 3 contacts the bottom of the pan. Furthermore, the second important point is to make the gap between the heat receiving portion 2 and the bottom surface of the pan as small as possible in the case of one-sided contact. For example, in FIG.
In another conventional example shown in, the flat surface portion 45 that comes into contact with the bottom surface of the pan is provided in the range of φC which is the close position of the thermistor 3, and φC
Even if the heat receiving portion 42 is inclined, φC is provided by providing a step on the surface from the
It is designed to come into contact with the bottom of the pan within the range. However, the drawback of this shape is the step provided on the surface from φC to the outer circumference. In other words, the step is to provide an air layer having a size of the gap D, which causes a loss in heat transfer from the bottom surface of the pot to the heat receiving section 42. Therefore, in this conventional example, the first important point that the heat receiving portion 42 near the thermistor 3 abuts on the bottom surface of the pan is satisfied, but the second important point that the gap is made small is lacking.

Therefore, in order to reduce the heat transfer loss from the bottom of the pot to the thermistor 3, the heat receiving portion 2 is formed as follows. As shown in FIG. 2 (a), in the heat receiving portion 2, a substantially flat surface 5 (which may be a flat surface or a large curved surface close to the flat surface) is formed in the range of φB at the center of the pan bottom contact surface, and φ
In the φA range from the outside of the B range to the outer circumference, the inclined surface 4 (which may be a rounded curved surface) having a maximum swing angle θ2 of the holder 9 or more and an angle θ0 approximate to the maximum swing angle is provided. Set up.

When the temperature sensor 7 comes into contact with the bottom surface of the pan of the cooking pot 1 vertically, the central portion of the heat receiving portion 2 which is substantially flat comes into contact with the bottom surface of the pan. Then, when the temperature sensor 7 is tilted (angle θ1), the outer periphery of the heat receiving portion 2 does not first come into contact with the temperature sensor 7 and the boundary between the substantially flat surface 5 near the center of the heat receiving portion 2 and the inclined surface 4 changes. The curved portion 6 contacts the bottom surface 1 of the pot (b). At this time, the gap between the heat receiving portion 2 and the bottom of the pan is as small as H1 at the central portion. Further, when the heat receiving portion 2 is inclined (angle θ2), the inflection portion 6 between the substantially flat surface 5 near the central portion of the heat receiving portion 2 and the inclined surface 4 remains in contact with the pan bottom surface 1. In addition, the gap in the central portion between the heat receiving portion 2 and the bottom of the pan is H of the conventional example (Fig. 3 (c)).
20 is smaller than H20, and the gap between the inclined surface and the bottom of the pan is smaller than H41 of the conventional example (Fig. 4C) (Fig. 2).
(C)). That is, not only does it come into contact with the bottom surface of the pot at a position close to the substantially flat surface 5 at the center of the heat receiving portion 2, but the gap between the heat receiving portion 2 and the bottom surface of the pot is small, so the thermistor 3 detects temperature almost equivalent to surface contact. do. That is, it is possible to maximize the condition for reducing the heat transfer loss. Therefore, even if the temperature sensor 7 tilts and comes into contact with the bottom surface of the pan, the controller 27 can quickly determine an abnormal situation and control combustion if the pan bottom temperature exceeds a predetermined temperature.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and it is needless to say that the present invention can be implemented in various modes without departing from the gist of the present invention. Is. For example, in the heating cooker provided with the temperature sensor of the present embodiment, the temperature detected by the thermistor 3 is electrically monitored by the controller 27 and the main electromagnetic valve 25 and the main solenoid valve provided in the gas passage are provided for easy understanding of the description. Although it has been described as the heating cooker that controls the opening and closing of the electromagnetic valve 26, the magnet safety valve is manually opened, and when the detected temperature is equal to or higher than the predetermined temperature, the electric resistance is increased to reduce the electromotive force generated by the thermocouple, The magnet safety valve may be closed by eliminating the valve opening holding force.

Further, the thermistor 3 may be a temperature sensor which, when reaching a predetermined temperature, causes a predetermined stroke to close the gas flow path. For example, a material that adsorbs and desorbs, a material that expands, or a material that deforms depending on temperature, that is, a material that uses a magnet, a thermoelement, a bimetal, or a shape memory alloy may be used. Further, in the controller 27, the monitoring unit and the control unit for determining and processing the information from the thermistor 3 may be configured by a microcomputer as a main unit or may be configured by a discrete circuit. Further, the heating cooker provided with the temperature sensor may be configured to have a temperature adjusting function of keeping the heating temperature of the cooking object within a predetermined temperature range by automatically adjusting the heating power. For example, the control when a predetermined temperature is detected is
The control is not limited to stopping combustion, and control may be performed to intermittently ignite and extinguish in order to maintain the heating temperature at a constant temperature, or control may be performed to further lower the combustion flame. .

[0014]

As described above in detail, according to the temperature sensor of the present invention, even if the heat receiving portion of the temperature sensor is tilted and comes into partial contact with the bottom surface of the cooking pot, the temperature is almost the same as the surface contact. It has an excellent effect that it can be detected.

[Brief description of drawings]

FIG. 1 is an enlarged view of a temperature sensor according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a heat receiving portion of the temperature sensor according to the embodiment of the present invention and a pan bottom surface.

FIG. 3 is a diagram showing a relationship between a heat receiving part and a pan bottom according to a conventional temperature sensor.

FIG. 4 is a diagram showing a relationship between a heat receiving part and a pan bottom according to a conventional temperature sensor.

FIG. 5 is a schematic configuration diagram of a heating cooker.

[Explanation of symbols]

 1 Pan bottom 2 Heat receiving part 3 Thermistor 4 Inclined surface 5 Substantial plane 6 Inflection part 8 Spring 9 Holder 10 Strut 13 Stopper part

Claims (1)

[Claims] 1. A heat receiving portion that abuts on the bottom of a cooking pot, a spring that urges the heat receiving portion in the abutting direction of the pot bottom, and a pot bottom temperature that is provided on the back surface of the central portion of the heat receiving portion and detects heat transferred to the pot. In a temperature sensor of a heating cooker having a temperature-sensitive element, the heat-receiving part has a central part formed in a substantially horizontal plane, and an inclined surface is formed in a range from the central part to the outer periphery. Temperature sensor.