JPH0620418B2 - Heat sensitive device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive device that senses the temperature of a heated object of a cooking appliance such as a rice cooker.

2. Description of the Related Art A conventional heat-sensitive device of this type is disclosed, for example, in Japanese Utility Model Laid-Open No. 56-721.
As shown in Japanese Patent Publication No. 0, the structure is as shown in FIGS. 5 and 6.

That is, the heat-sensitive element 1 has a sheet-shaped front electric insulator 3 located below the front heat-sensitive member 2 and a rubber back electric insulator 5 located above the back heat-sensitive member 4. The heat-sensitive member 4 was interposed, and the outer peripheral end of the heat-sensitive member 4 was placed on the upper end opening edge of the inner case 6 and joined by the outer peripheral end of the case ring 7.

Problems to be Solved by the Invention However, with such a structure, the thermosensitive element 1
However, there is a problem that the temperature of the object to be heated cannot be sensitively detected. That is, the temperature supply to the heat-sensitive element main body 8 which sends a signal according to the sensed temperature is roughly divided into three systems. In the first system, the front-side heat-sensitive member 2 makes contact with the object to be heated or via the air to obtain accurate The temperature is supplied, the temperature is supplied to the surface electric insulator 3, and the temperature is supplied to the heat-sensitive element body 8 in contact with the surface electric insulator 3. The second system is the case ring. Since 7 is in contact with only the outer peripheral edge, the temperature is not supplied from the front part from the back heat-sensitive member 4 to the heat-sensitive element body 8 which is in contact with the thick back electric insulator 5 by heat conduction. In the third system, the temperature is supplied from the heat sensitive element body 8 to the control circuit by the heat conduction from the lead wire 9 which has a very good electric conduction and heat conduction for transmitting a signal to the control circuit.

However, the lead wire 9 is lower than the temperature of the front heat-sensitive member 2, is in contact with the back electrical insulator 5 having a thick wall and poor thermal conductivity, and has a long portion in the ambient atmosphere having a much lower temperature. Since it is exposed, it becomes a low temperature, and in order to maintain the equilibrium of this low temperature, the thermosensitive element body 8 having a high temperature
On the contrary, the temperature sensing element main body 8 cannot follow the temperature of the object to be heated sensitively, and the lead wire 9 is affected by the room temperature. It depended.

The present invention solves such a problem, and an object thereof is to provide a heat-sensitive device capable of sensitively detecting the temperature of an object to be heated.

Means for Solving the Problems In order to solve the above problems, the present invention makes a lead wire of a heat-sensitive element body contact between a front heat-sensitive member and a back heat-sensitive member via an electrical insulator. It has been arranged.

Operation According to the above-mentioned configuration, the front heat-sensitive member that receives a more accurate temperature supply from the object to be heated and the back heat-sensitive member that comes into contact with the front heat-sensitive member to provide good temperature supply and have substantially the same temperature In the meantime, since the lead wire of the heat-sensitive element body is abutted through the electrical insulator, the lead wire is solid heat conduction with almost no air layer interposed between the front heat-sensitive member and the back heat-sensitive member. The temperature is directly supplied from a large heat mass, and it is slightly cooled by the surrounding atmosphere, but the temperature of the heated object can be sensed sensitively without being affected by the temperature of the lead wire outside the contact. .

Embodiment One embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIGS. 1 to 4, reference numeral 21 denotes a metal front heat-sensitive member which is contacted with an object to be heated or supplied with temperature through air, and the front heat-sensitive member 21 has a resistance on the back surface depending on the sensed temperature. A thermosensitive element body 22 composed of a thermistor whose value changes, a metal lead wire 23 led out from the thermosensitive element body 22, and a tube-shaped electrical insulation covering the thermosensitive element body 22 and the lead wire 23 in this embodiment. The object 24 is arranged.

In addition, the heat-sensitive element body 2 is attached to the back heat-sensitive member 25 made of metal.
2 into which the lead wire 23 is fitted, and lead wires 23 which are located on both sides of the body recess 26,
A lead wire recess 27 having substantially the same depth as the total thickness of the electric insulator 24 and the electric insulator 24 (for example, the lead wire 23 has a diameter of 0.6 mm, and the electric insulator 24 has a thickness of t0.5 mm, 1.6 mm). There is.

The back heat-sensitive member 25 is in contact with the front heat-sensitive member 21. The contact surface 28 is provided in addition to the recesses 26 and 27, and the outer peripheral end of the back heat-sensitive member 25 is placed on the upper opening edge of the inner case 29, and the front heat-sensitive member 2 is provided.
Mutual abutment surfaces 28 are abutted and caulked to each other by the outer peripheral end portion of 1. By coupling the front heat-sensitive member 21 and the back heat-sensitive member 25, the heat-sensitive element body 22 is held in contact with the front heat-sensitive member 21 and the main body recess 26 of the back heat-sensitive member 25 via the electrical insulator 24. And lead wire 2
3 presses the electric insulator 24 with the electric insulator 24 and contacts the lead wire recess 27 of the back thermosensitive member 25 with the electric insulator 24, and abuts with a fixed contact. Retained.

Next, the operation of the rice cooker adopting the heat sensitive device will be described.

In FIG. 4, reference numeral 41 denotes a tubular rice cooker main body. A heating body 43 is installed in an inner bottom portion of a heating chamber 42 provided in the rice cooker main body 41, and a central portion of the heating body 43 is penetrated. A hole 44 is provided, and a pan 45 which is an object to be heated is detachably mounted on the heating body 43.

The heat-sensitive device 46 described above is housed in the outer case 47 fixed to the through hole 44, and as shown in FIG.
It is located at the upper part of the inner case 29 biased upward by the coil spring 48, and contacts the pot 45 and the bottom surface with the spring force of the coil spring 48 to detect the temperature. The temperature from the pan 45 is roughly divided into the heat sensitive element main body 22 and supplied from three systems. In the first system, the surface heat-sensitive member that is in contact with the pan 45 receives an accurate temperature supply, and the electric insulator 24 that is in contact with the surface heat-sensitive member 21 is transmitted to the heat-sensitive element body 22. In the second system, the temperature of the back heat-sensitive member 25, which is in almost the same temperature by making thermal contact with the front heat-sensitive member 21 and the wide contact surface 28,
It is transmitted to the electrical insulator 24 that abuts the main body recess 26, and is supplied to the heat-sensitive element main body 22.
It can receive almost the same temperature as the first system. Further, in the third system, a large heat mass is generated from both of the front heat-sensitive member 21 and the lead wire recess 27 of the back heat-sensitive member 25 at a substantially same temperature due to the depth of the lead wire recess 27, and there is almost no air layer, and electrical insulation is achieved. The temperature is supplied to the lead wire 23 by the thermal contact pressed from both sides of the object 24, and is supplied to the heat sensitive element body 22 by the very good heat conduction of the lead wire 23. Although the portion exiting from the outlet hole is cooled by the surrounding atmosphere, the lead wire 23 in the lead wire recess 27 is not affected by the temperature of the surrounding atmosphere due to the above-mentioned configuration, and therefore the room temperature changes. There is no dependency due to.

As is clear from the above description, the temperature supply to the thermosensitive element body 22 is excellent in all three systems, and it is possible to sensitively detect and follow the temperature of the pan 45 of the object to be heated.

EFFECTS OF THE INVENTION As is clear from the description of the above embodiments, the heat-sensitive device of the present invention is arranged such that the lead wire of the heat-sensitive element body is brought into contact with the heat-sensitive display portion and the back-side heat-sensitive member via the electrical insulator. Therefore, it is possible to sensitively follow and sense an accurate temperature without causing a time lag with respect to the temperature change of the object to be heated and having no dependency on the change of the room temperature. It is a thing.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a heat-sensitive device showing an embodiment of the present invention, FIG. 2 is a top view of a back heat-sensitive member of the heat-sensitive device, FIG. 3 is a sectional view of the heat-sensitive device, and FIG. FIG. 5 is a cutaway side view of a rice cooker employing the same heat-sensitive device, FIG. 5 is a sectional view of a conventional heat-sensitive device, and FIG. 6 is an exploded perspective view of the heat-sensitive device. 21 ... Front heat sensitive member, 22 ... Heat sensitive main body, 23 ...
… Lead wire, 24 …… Electrical insulator, 25 …… Heat sensitive member on back side, 26 …… Recessed body, 27 …… Recessed wire, 28 ...
… Abutting surface.

Claims (3)

[Claims] 1. A heat-conductive front heat-sensitive member constituting a temperature sensing side, a heat-sensitive element body covered with an electric insulator, and a heat-conductive back heat-sensitive member are sequentially laminated and joined. The lead wire of the heat-sensitive element body is arranged so as to be in contact with the front heat-sensitive member and the back heat-sensitive member via the electrical insulator. 2. The heat-sensitive device according to claim 1, wherein the electrical insulator has a tube shape and is configured to integrally cover the heat-sensitive element body and the lead wire. 3. The heat-sensitive device according to claim 1, wherein the front heat-sensitive member and the back heat-sensitive member are brought into contact with each other at a portion other than a recess into which the heat-sensitive element body is fitted.