JPH08159477A - Temperature sensor of heating and cooking device - Google Patents

Abstract

PURPOSE: To provide a temperature sensor capable of correcting an inclination of a cooking pan in respect to its bottom surface, contacting with its surface and sensing its temperature in such a manner that the temperature sensor is prevented from being inclined to be irregularly contacted with the bottom surface of the cooking pan. CONSTITUTION: A temperature sensor 7 for sensing a temperature of a bottom surface of a cooking pan 1 is provided with a heat receiving part 2 biased by a coil spring 8 in such a manner that it is abutted against the bottom surface of the cooking pan 1 and with a thermistor 3 for use in sensing a temperature of the bottom surface of the pan to which heat is transferred from the heat receiving part 2. A coil diameter of the coil spring 8 is set to be 1/2 or less in respect to an outer diameter of the heat receiving part 2 and then a surface contact between the heat receiving part 2 and the bottom surface of the pan is assured with a momentum force in which the coil spring 8 may act against the heat receiving part 2 around a rotating fulcrum point of the abutting point for the bottom surface of the pan.

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. 4 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 coil 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 coil 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. In addition, a gap is provided in the sliding portion between the holder 9 and the column 10, and the holder 9 can be slightly swung with respect to the column 10, so that the bottom surface of the pot and the heat receiving portion 2 can easily contact each other. ing.

[0003]

However, the temperature sensor of the conventional cooking device has a weak correction force for the inclination of the cooking pan with respect to the bottom surface of the cooking pan, and there is a case where the temperature sensor abuts while tilting.
There was a problem to detect the pot bottom temperature at a low level. For example, the shape of the bottom of the cooking pot is not only a flat-bottomed pot but also a round-bottomed pot of a Chinese wok, or the cooking pot may be tilted and placed. Further, since the surface of the bottom of the cooking pot is less likely to slip due to "burn", the temperature sensor may tilt and come into contact with the bottom of the cooking pot. When the cooking pot and the temperature sensor are inclined and brought into contact with each other in this way, so-called one-sided contact occurs, and it becomes difficult for heat to be transferred from the bottom face of the pot to the heat receiving part, and the thermistor detects the pot bottom temperature at a low level. As a result, the controller cannot determine the pot bottom temperature normally. The temperature sensor of the heating cooker of the present invention solves the above-mentioned problems, and surely corrects the inclination of the cooking pan with respect to the bottom surface of the cooking pan so that the temperature sensor does not tilt and do not hit the bottom surface of the cooking pan. It is an object of the present invention to provide a temperature sensor capable of detecting a temperature.

[0004]

SUMMARY OF THE INVENTION A heating cooker according to the present invention which solves the above-mentioned problems includes a heat receiving portion which abuts on a bottom of a cooking pot.
A coil spring for urging the heat receiving part in the pot bottom abutting direction, and a temperature sensor of a heating cooker provided with a temperature sensing element provided on the back surface of the central part of the heat receiving part, for detecting the transferred pot bottom temperature, The gist is that the coil diameter of the coil spring is set to 1/2 or less of the outer diameter of the heat receiving portion.

[0005]

In the temperature sensor of the heating cooker according to the present invention having the above structure, the coil diameter of the coil spring is set to 1/2 or less of the outer diameter of the heat receiving portion. When the bottom of the pan tilts and comes into contact with the heat receiving part, the contact point between the bottom of the pan and the heat receiving part serves as a fulcrum, and the coil spring generates a rotational force so that the surface of the heat receiving part contacts the bottom of the pan. Then, when the heat receiving portion starts to rotate, the heat receiving portion tilts with respect to the coil spring, and the spring force acts on the heat receiving portion by breaking it up. In other words, when the heat receiving part starts to rotate, it becomes oblique with respect to the coil spring, and the coil spring restricts the operating length of the spring by the one-sided part to the heat receiving part. You can no longer expect the spring force to. Therefore, the coil spring force acts only on the part of the heat receiving part that is cut off (this cut point is called the point of action).
The rotation force is proportional to the radius of rotation from the rotation fulcrum to the point of action and the magnitude of the force acting in the rotation direction. That is, even if the spring force is the same, the larger the component force acting in the rotation direction, the more effectively the spring force acts as the rotation force. Therefore, by setting the coil diameter of the coil spring that determines the action point position to be 1/2 or less of the outer diameter of the heat receiving portion that determines the contact point position, the spring force can be effectively used as a tangential component force. It is possible to make it work and generate a sufficient rotational force in the heat receiving part. As a result, the bottom surface of the pan and the heat receiving surface surely make surface contact,
The temperature of the bottom of the cooking pot is transferred from the bottom of the pot to the heat receiving part with little heat transfer loss, and the temperature sensing element can detect the same temperature as the bottom of the pan from the heat receiving part. That is, the pan bottom temperature detected by the temperature sensor is not affected by the inclination of the cooking pan placed.

[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. 4 shows a schematic configuration diagram of the 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 electric 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 source solenoid valve 26 that open and close the gas flow path, and when it determines that the detected temperature is equal to or higher than the predetermined temperature, the controller 27 and the source solenoid valve 26 are connected. A command to close the valve 26 is issued to stop the combustion.

FIG. 1 shows an enlarged view of the temperature sensor 7 of this embodiment. The temperature sensor 7 is provided with a heat receiving portion 2 in a portion of the cooking pot 1 that abuts on the bottom surface of the cooking pot 1, and a thermistor 3 for detecting the heat transfer temperature 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. A coil spring 8 for urging the holder 9 in the pot bottom abutting direction is coaxially provided inside the pipe expanding portion 11 of the column 10. Also,
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. The stopper portion 13 and the pipe expanding portion 11 of the support column 10 are brought into contact with each other, so that the coil spring 8 attaches. Restriction of the biased holder 9 is prevented. Further, when the cooking pot 1 is placed, the coil spring 8 is compressed by the weight of the cooking pot 1,
While the heat receiving part 2 is in contact with the cooking pot 1, the holder 9 has the support 1
Slide 0 down. Further, the holder 9 is provided so as to swing intentionally with respect to the support column 10 so that the heat receiving portion 2 comes into surface contact with the bottom surface of the cooking pot 1. That is, a gap is provided between the inner diameter of the holder 9 and the outer diameter of the tube expansion portion 11 of the column 10, and a gap between the inner diameter of the stopper portion 13 of the holder 9 and the outer diameter of the column 10, and the swing angle of the holder 9 is determined by this gap. It is determined.

[0008] When the heat receiving portion 2 is unevenly contacted with the bottom surface of the pan, in order to surely make the surface contact, the inclination is corrected.
A rotational force (hereinafter referred to as a moment) having a contact point between the bottom surface of the pot and the heat receiving portion 2 as a rotation center must act on the heat receiving portion 2. Therefore, the function of the coil spring 8 that urges the heat receiving portion 2 in the pan bottom contact direction is important. The coil spring 8 has a long free length with respect to the coil diameter, and has a large so-called aspect ratio (ratio of free length to coil diameter) to facilitate swinging, and is sufficient for holding a correction force when tilted. It is necessary to set it with a bending allowance.

Further, the relative position between the coil spring 8 and the heat receiving portion 2 is important so that a large moment acts on the heat receiving portion 2. For example, in the conventional example shown in FIG. 3, it is difficult for a large moment to act on the heat receiving portion 2. This is because the coil diameter (radius R20) of the coil spring 8 is set to be substantially equal to the outer diameter (radius R0) of the heat receiving portion 2 of the temperature sensor 7. When the cooking pot 1 is placed at an angle, or when the cooking pot 1 is placed with the temperature sensor 7 tilted, the end of the surface of the heat receiving portion 2 abuts the cooking pot 1 (hereinafter, abutting). The point is called the contact point 36) (FIG. 3A).
Then, the contact point 36 between the bottom of the pan and the heat receiving portion 2 serves as a fulcrum,
The coil spring 8 generates a rotational force so that the heat receiving surface contacts the bottom surface of the pan. On the other hand, since the heat receiving portion 2 is inclined with respect to the coil spring 8, the force (F0) of the coil spring 8 is cut off at point (G) and acts on the heat receiving portion 2. That is, the operating length of the coil spring 8 is restricted at the point G of the coil spring 8 that is closest to the contact point 36, and the spring force cannot be expected at the other parts of the coil spring 8. Therefore, the rotational force is G of the coil spring 8.
A point (hereinafter referred to as an action point G) acts, and a component force (F30) of the coil spring force (F0) acts in the rotation direction (b). The magnitude of the turning force at that time is proportional to the magnitude of the turning radius at the action point and the magnitude of the tangential component force. That is, since the contact point 36 and the point of action (G) of the coil spring 8 come too close to each other in the horizontal direction in the figure (H20), the component force acting in the tangential direction is small (F30) and the moment is small (moment = F30 × L20). ). Therefore, it cannot be said that the force of the coil spring 8 effectively acts on the heat receiving part 2 so that the heat receiving part 2 and the bottom face of the pan contact each other, and a gap (E) is formed between the heat receiving part 2 and the bottom face of the pan. It will be done (ha).

Therefore, the coil diameter of the coil spring 8 (radius R
2) is set to 1/2 or less of the outer diameter (radius R0) of the heat receiving portion 2. For example, when coil springs having different coil diameters were prepared and the extent to which the heat receiving portion 2 and the bottom surface of the pot were in surface contact was experimentally confirmed, the coil diameter (radius R2) of the coil spring 8 was determined to be the outer diameter (radius of the heat receiving portion 2). 1 for R0)
Effective results were obtained when the size was set to / 2 or less. The results of this experiment can be explained as follows. As shown in FIG. 2, when the cooking pot 1 is placed, the bottom face of the pot and the heat receiving portion 2 first contact at the contact point 6. The contact 6 has a radius R1 from the center of the heat receiving portion 2 and a radius R of the coil spring 8.
Larger than 2 (H dimension) (A). Therefore, the rotational force acts on the action point (G) of the coil spring 8 and the coil spring force (F).
The component force (F3) of 0) acts in the rotation direction (b). This rotational force (F3) is larger than the rotational force (F30) of the conventional example (FIG. 3B) compared as the same coil spring force. The distance L1 from the contact point 6 to the action point G is also larger than L20 in the conventional example (FIG. 3A). That is, in FIG. 2 of the present embodiment, the contact point 6 and the point of action (G) of the coil spring 8 are separated from each other in the horizontal direction (H dimension), so that the moment becomes large (moment of this embodiment = F3 × L1). > Moment of the conventional example = F30 × L20). Therefore, it can be said that the coil spring 8 force (F0) effectively acts on the heat receiving portion 2 so that the heat receiving portion 2 and the bottom surface of the pan are in surface contact with each other (FIG. 2).
(C)).

That is, by increasing the difference (H dimension) between the outer diameter of the heat receiving portion 2 and the coil diameter of the coil spring 8 and further reducing (D dimension), the force of the coil spring 8 acts as a large moment. You can Therefore, when the temperature sensor 7 tilts and comes into contact with the bottom surface of the pan, the tilt of the heat receiving portion 2 with respect to the bottom surface of the pan is corrected by the moment of the coil spring 8 to make surface contact, and the heat receiving portion 2 has almost the same temperature as the bottom temperature of the pan. The temperature can be transmitted to the thermistor 3. As a result, the controller 27 can quickly determine an abnormal situation when the pot bottom temperature is equal to or higher than a predetermined temperature and perform combustion control.

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 according to the present embodiment, the temperature detected by the temperature sensor 7 is electrically monitored by the controller 27 and the main electromagnetic valve 25 and the original electromagnetic valve 26 provided in the gas passage are electrically monitored for easy understanding. Although it was explained as a heating cooker that controls opening and closing, the magnet safety valve is opened manually, and when the detected temperature is above a predetermined temperature, the electrical resistance is increased to reduce the electromotive force generated by the thermocouple, and the valve opening retention force is increased. May be closed and the magnet safety valve may be closed.

Further, the temperature sensor 7 may be a temperature sensor which, when reaching a predetermined temperature, causes a predetermined stroke to close the gas passage. 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. In addition, in the controller 27, the monitoring unit and the control unit that determines and processes the information from the temperature sensor 7 may be configured by a microcomputer as a main unit or may be configured by a discrete circuit. Further, the heating cooker may be configured to have a temperature adjusting function of keeping the heating temperature of the cooked food within a predetermined temperature range by automatically adjusting the heating power. For example,
The control in the case of detecting the predetermined temperature is not limited to stopping the combustion, and control for intermittent ignition / extinction may be performed to maintain the heating temperature at a constant temperature, or the combustion flame It may be possible to perform control to further reduce the heat.

[0014]

As described above in detail, according to the temperature sensor of the present invention, the inclination of the heat receiving portion of the temperature sensor with respect to the bottom of the pan is reliably affected by the coil spring force without being influenced by the inclination of the cooking pan to be placed. It has an excellent effect that it is corrected and comes into surface contact, and the temperature of the cooking pot can be accurately 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 and a pan bottom surface and a pressing coil spring according to an embodiment of the present invention.

FIG. 3 is a view showing a relationship between a heat receiving portion and a pan bottom surface of a conventional cooking device and a pressing coil spring.

FIG. 4 is a schematic configuration diagram of a heating cooker.

[Explanation of symbols]

 1 Pan bottom 2 Heat receiving part 3 Thermistor 6 This contact 7 Temperature sensor 8 Coil 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 coil spring that biases 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 the heat transferred to the pot bottom. In the temperature sensor of the heating cooker, the temperature sensor of the heating cooker is characterized in that the coil diameter of the coil spring is set to 1/2 or less of the outer diameter of the heat receiving portion.