JPS6221959Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a contact temperature sensor used in electric cooking appliances such as electric rice cookers.

In recent years, various improvements have been made to electric cooking devices such as electric rice cookers, making it easier to perform various types of cooking, and their popularity has been remarkable. There has been an increasing demand for reliability in heating control from the standpoint of higher sophistication and safety measures against heat. In order to meet these demands, it goes without saying that accurate temperature sensing means is first required.

Conventionally, various temperature sensors have been used as this type of temperature detection means, but among them, a so-called diode type is widely used because it is inexpensive and has good performance. For example, the one shown in FIG. 1 is a typical example. This is done by placing a silicone rubber 2 with a relatively high heat resistance on the head side of a temperature sensor (hereinafter simply referred to as "sensor") 1, backing up the rear part of the sensor 1 with another synthetic resin material 3, and attaching these to a metal plate. The temperature of the object to be measured is measured by bringing the metal outer cover 4 on the head side of the sensor 1 into contact with the object to be measured.
Note that in FIG. 1, reference numeral 5 indicates a lead wire.

However, in such conventional sensors, since the outside is made of metal, if the object to be measured is a rigid member, the contact with the object to be measured is a point contact, resulting in insufficient heat conduction. Also, even if heat is transmitted, the specific heat is small because it is a metal outer shell.
The drawback was that the heat dissipated quickly and the true temperature was not transmitted to the sensor.

In order to eliminate such drawbacks, for example, the contents of the specification and drawings attached to the application of Utility Model Application No. 50-91408 (Utility Model Application No. 52-5576) were photographed on a microfilm. , a method has been proposed in which a heat-sensitive element is embedded in a heat-resistant elastic member such as silicone rubber.

Also, Utility Application No. 48-34544 (Utility Application No. 49-138439)
As described in the microfilm photographing the contents of the specification and drawings attached to the application in No. 2003-11-1, a method has been proposed in which the overheat protector main body and the lead wire connection part are covered with a silicon tube.

Further, it is necessary to always maintain a proportional relationship between the temperature detected by a temperature sensor used in electric cooking devices such as electric rice cookers of various sizes and the temperature of the inner pot.

However, in the above two conventional techniques,
In order to obtain a temperature sensor suitable for the size of each electric cooker such as the various large and small rice cookers, a new temperature sensor is designed and manufactured for each electric cooker of various sizes. There was a drawback that it had to be done.

The purpose of the present invention is to eliminate the above-mentioned drawbacks, and to provide a contact-type temperature sensor that can reliably perform accurate temperature detection, has a simple structure, is easy to manufacture, is inexpensive, and is less likely to malfunction. Our goal is to provide the following.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

An overview of typical technical means among the devices disclosed in this application is as follows.

That is, in a contact type temperature sensor, accurate temperature detection is achieved by embedding and fixing the temperature sensor in the temperature sensor holding space of a cover body, for example, molded silicone rubber, through a heat-resistant rubber body, for example, curable silicone rubber. The object of the present invention is to configure a contact-type temperature sensor for an electric cooker that can reliably perform the above operations and has a simplified structure.

Hereinafter, the present invention will be explained in detail with reference to Examples.

In addition, in all the figures related to the embodiment, parts having the same functions are given the same reference numerals.

FIG. 2 is a diagram showing the configuration of an embodiment of the contact type temperature sensor of the present invention, in which a lead wire 14 is connected to a sensor holding space of a silicone rubber cover body 11 formed by molding. Add 12 and then curable silicone rubber (RTV) 13
was injected and fixed. The silicone rubber cover body 11 used in this example was
The shape is as shown in the cross-sectional view in the figure.
Since silicone rubber has high rubber elasticity, it can be forcefully removed from the mold during cast molding, and the sensor holding space 15 can also be easily formed. To manufacture a contact type temperature sensor, as shown in Figure 4, the lead wire 1
4 is connected to the sensor holding space 15 of the silicone rubber cover body 11 shown in FIG. All you have to do is inject it into the gap and fix it. By doing this, the sensor 12
It is completely sealed, is temperature stable, and is not affected by water droplets or other negative effects.

When using such a contact-type temperature sensor, the head part of the silicone rubber cover body should be brought into contact with the object to be measured, such as the surface of the inner pot of an electric cooking device such as an electric rice cooker, by applying light pressure. If you set it to do so, you can perform accurate temperature detection.

The amount of heat required for the protective member of the contact sensor varies depending on the size of the electric cooking device such as an electric rice cooker, so proper temperature detection cannot be achieved unless the thickness of the protective member of the contact sensor is changed depending on the size of the electric cooking device. become unable. That is, it becomes impossible to detect the temperature while maintaining a proportional relationship between the temperature detected by the temperature detection sensor and the temperature on the inner pot side.

Therefore, according to the present invention, since the silicone rubber cover body 11 has a structure in which the thickness can be freely changed, several types of silicone cover bodies 11 having different thicknesses are prepared in advance. The overall thickness of the protective member of the contact type temperature sensor can be adjusted to the optimal thickness for each of the various large and small electric cookers by selecting the temperature sensor according to the size of the electric cooker and combining it with the sensor 12. The temperature of the inner pot of an electric cooker, etc. can be accurately detected.

Next, the reason why silicone rubber is used as the cover body of the contact type temperature sensor of the present invention will be explained.

When silicone rubber is used as the cover body of the sensor temperature detection member, (a) it has high rubber elasticity, so it makes surface contact with the object to be contacted, and heat detection becomes more complete.

(b) Among materials other than metals, it has a relatively low specific heat and high thermal conductivity.

(c) Performance is stable because it can be molded, and since the area around the sensor can be hardened with hardening silicone rubber to fix the two, it is also more stable in terms of temperature.

(d) Manufacturing costs are low.

(e) Silicone rubber has a relatively high heat resistance of approximately 200°C, so it can be used in a wide range of temperature sensors.

There are advantages as shown in (a) to (e) above.

FIG. 5 is a diagram showing the configuration of another embodiment of the present invention, in which the molded silicone rubber cover body 11 is formed into a force-fitted shape as shown in the figure, so that the hook portion 11'' is attached to the sensor support member. 17. By doing this, the contact type temperature sensor can be firmly fixed to the sensor support member 17. Also, the contact type temperature sensor can be constantly pressed against the object to be measured. In order to do this, a pressing spring 18 is provided at the upper end of the sensor support member 17. 19 is a sensor cover, 20 is a reed switch, and 21 is a magnet.

As explained above, according to the present invention, the silicone rubber cover body has a structure in which the thickness can be freely changed, so several types of silicone cover bodies with different wall thicknesses are prepared in advance. By selecting the appropriate thickness for each electric cooker of various sizes and combining it with the sensor, the overall thickness of the protective member of the contact type temperature sensor can be adjusted to the optimum thickness for each electric cooker of various sizes. Since it can be made thicker, it is possible to accurately detect the temperature of the inner pot of an electric cooker, etc. There are few breakdowns, and it can be used not only for electric cookers but also for various appliances.
It is possible to provide a contact temperature sensor that can be used in a wide temperature range of devices, etc.

It goes without saying that the present invention is not limited to the embodiments described above, and can be modified in various ways without departing from the gist thereof. For example, it goes without saying that the cover body and the heat-resistant rubber body may be of any type as long as they have these functions.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the configuration of a conventional contact type temperature sensor, Figure 2 is a diagram showing the configuration of an embodiment of the contact type temperature sensor of the present invention, and Figure 3 is a diagram showing the configuration of a contact type temperature sensor of the present invention. FIG. 4 is a perspective view of a sensor to which lead wires are connected to be inserted into the molded silicone cover, and FIGS. FIG. 3 is a diagram showing the configuration of another embodiment of the contact-type temperature sensor. 11... Molded silicone rubber cover body, 11'...
...Silicon tube, 11"...Hook part, 12...
...Sensor, 13...Curable silicone rubber, 14
... Lead wire, 15 ... Sensor holding space, 16
...Synthetic resin, 17...Sensor support member, 18
...Press spring, 19...Sensor cover,
20...Reed switch, 21...Magnet.

Claims (1)

[Scope of utility model registration request] A temperature sensor covered with a heat-resistant rubber injection body with good heat conductivity and a heat-resistant rubber cover with good heat conductivity, which has a temperature sensor holding space for holding the temperature sensor and is made of the same material as the rubber injection body, are separated. A contact-type temperature sensor for electric cooking, characterized in that the heat-conducting heat-resistant rubber injection body is embedded in the holding space.