JPH0575630U - Temperature sensor - Google Patents

Abstract

(57) [Summary] [Object] The present invention provides a thermistor 1 having a good thermal response. [Constitution] The present invention includes a bottomed case 2 and the case 2.
In the temperature sensor 1, which includes a thermistor 3 arranged inside, a lead wire 4 which connects the lead wire end portion to the thermistor 3 and is led out to the outside of the case 2, and a filling resin 8 filled in the case 2, The case 2 has a thermal conductivity of 0.5 to 0.7 (W.
m ⁻¹ · K ⁻¹ ), specific heat of 0.5 to 1 (J · g ⁻¹ · K ⁻¹ ), and the filling resin 8 has substantially the same characteristics as the material of the case 2. The resin is used. With this configuration, it is possible to provide the temperature sensor 1 having a better thermal response than in the case of using a normal resin case.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a temperature sensor used for detecting various temperatures of vending machines and the like.

[0002]

[Prior Art]

 A conventional example of this type of temperature sensor will be described with reference to FIG.

A temperature sensor 20 shown in FIG. 8 has a bottomed case 21, a thermistor 23 arranged in the case 21, and a lead wire end connected to the thermistor 23 and led out to the outside of the case 21. A lead wire 24, an undercoat resin 25 applied around the thermistor 23, an overcoat resin 26 applied around the undercoat resin 25, and a filling resin 27 filled in the case 21. There is.

As the thermistor 23, a cut-out chip product or a disk product is used. In the case of the temperature sensor 20, the thermistor 23 is insulated by the undercoat resin 25 and the overcoat resin 26, so that even if the case 21 is a copper case, there is no problem. It never happens.

FIG. 9 shows a temperature sensor 30 as another conventional example.

The temperature sensor 30 shown in FIG. 9 includes a glass diode type thermistor 23A formed in a U-shape, and both terminals of the thermistor 23A and the end portions of the lead wires 24 are caulked with the caulking portions 31a and 31b. Respectively, and further, the surroundings of the thermistor 23A and the end portion of the lead wire 24 are covered with an insulating tube 32. It is filled with the filling resin 27.

When the case 21 is a copper case, the insulating tube 32 of the temperature sensor 30 is used to insulate the thermistor 23A formed into a U shape and the caulked portions 31a and 31b.

However, when the insulating tube 32 is used, it becomes a path for moisture infiltration, which is not preferable in terms of the water resistance characteristic of the temperature sensor 30, and the manufacturing process is complicated, resulting in a high manufacturing cost. .

In the temperature sensor 30 shown in FIG. 9, the thermal time constant when the case 21 is a copper case (the time required to reach 63.2% of the temperature difference between the initial temperature and the final reached temperature) 6) shows the measurement result, and FIG. 7 shows the measurement result of the thermal time constant when the case 21 is made of a resin (ABS resin) case.

The thermal time constants shown in FIGS. 6 and 7 are obtained by immersing the temperature sensor 30 in which the case 21 is a copper case and the temperature sensor 30 in which the case 21 is a resin case in oil at 20 ° C. It was measured by the voltage-time characteristic when the oil was loaded and transferred to oil at 80 ° C.

As is clear from the results shown in FIGS. 6 and 7, the thermal time constant was 10.5 seconds in the case of the copper case and 22.0 seconds in the case of the resin case, and the resin case was used. In the case, it turns out that the responsiveness is poor.

[0012]

[Problems to be solved by the device]

 Then, this invention aims at improving a structure and providing the thermistor with favorable thermal response.

[0013]

[Means for Solving the Problems]

The present invention comprises a case with a bottom, a thermistor arranged in the case, a lead wire connecting the end of the lead wire to the thermistor and led out to the outside of the case, and a filling resin filled in the case. In the case of the temperature sensor, the case has a thermal conductivity of 0.5 to 0.7 (W · m ⁻¹ · K ⁻¹ ), a specific heat of 0.5 to 1 by adding an inorganic substance to a thermosetting resin. The filling resin is formed of a material having a characteristic of (J · g ⁻¹ · K ⁻¹ ), and the filling resin is a resin having substantially the same characteristics as the material of the case.

[0014]

[Action]

 The operation of the temperature sensor will be described below.

According to this temperature sensor, the case has a thermal conductivity of 0.5 to 0.7 (W · m ⁻¹ · K ⁻¹ ) and a specific heat of 0.5 to 1 by adding an inorganic substance to a thermosetting resin. Since it is made of a material having the characteristics of (J · g ⁻¹ · K ⁻¹ ), the thermal conductivity of the case is higher than that when using a normal resin case, and the specific heat is a normal resin case. It will be smaller than it was. Since the filling resin is a resin having substantially the same characteristics as the material of the case, the thermal characteristics of the filling resin are substantially the same as the thermal characteristics of the case.

As a result, the thermal responsiveness of this temperature sensor becomes better than in the case of using a normal resin case.

[0017]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail.

The temperature sensor 1 shown in FIG. 1 has substantially the same configuration as the temperature sensor 30 shown in FIG. 9, but includes a U-shaped glass diode type thermistor 11 and has a soft glass tube portion. An undercoat resin is applied, and both terminals of the thermistor 11 and the ends of the lead wire 4 are connected by caulking portions 12a and 12b, respectively, and the thermistor 11 is placed in the case 2 to dispose the thermistor 11 and the caulking. A filling resin 8 is filled around the processed portions 12 a and 12 b and the lead wire 4 in the case 2.

The thermistor 10 shown in FIG. 2 has a bottomed case 2, the thermistor 3 arranged in the case 2, the lead wire end portion connected to the thermistor 3, and the case 2 outside. The lead wire 4 derived, the coat resin 7 composed of the undercoat resin 5 and the top coat resin 6 applied to the surrounding of the thermistor 3, the enclosure of the coat resin 7 inside the case 2 and the lead wire 4 inside the case 2 And the filling resin 8 filled in the enclosure.

As for the material of the case 2 of the temperature sensors 1 and 10 shown in FIGS. 1 and 2, the thermal conductivity is 0.5 to 0.7 (W · m ^{− 1} · K ⁻¹ ) and a specific heat of 0.5 to 1 (J · g ⁻¹ · K ⁻¹ ).

In case 2, the above-mentioned thermal conductivity and specific heat are obtained by adding 60 to 80% by weight of an inorganic substance such as alumina, silica, or glass to the epoxy resin.

The filling resin 8 is an epoxy resin having substantially the same characteristics as the material of the case 2.

By the way, the thermal conductivity of copper is about 400 (W · m ⁻¹ · K ⁻¹ ), and the specific heat is about 0. 4 (J · g ⁻¹ · K ⁻¹ ).

In contrast, general resins have a thermal conductivity of 0.1 to 0.3 (W · m ⁻¹ · K ⁻¹ ) and a specific heat of 1 to 2 (J · g ⁻¹ · K ^{−). 1} ) It is about. Therefore, in order to improve the thermal response, it is necessary to increase the thermal conductivity and reduce the specific heat.

The measurement result of the thermal time constant of the temperature sensor 1 is shown in FIG.

FIG. 4 shows the result of the hot water boiling current test of the temperature sensor 1.

In the hot water boiling energization test shown in FIG. 4, four kinds of samples (each sample indicated by a mark, a white circle mark, a triangle mark, and a square mark) in which the undercoat resin was changed were immersed in 90 ° C. warm water, It shows the relationship between the good product residual rate and the time when a current of 0.5 mA is applied.

Further, the result of the defroster electrification test of the temperature sensor 1 is shown in FIG.

In the defroster energization test shown in FIG. 5, each sample shown by ・ mark, white circle mark, triangle mark, and square mark is passed through a current of 0.5 mA for 4 hours in water of −40 ° C. and + 60 ° C., respectively. The results are obtained when the immersion cycle is repeated many times.

As is apparent from FIG. 3, in the case of the temperature sensor 1 using the case 2 of epoxy resin, the thermal time constant is 10.0 seconds, which can be substantially the same as the case of the conventional copper case. . As a result, the temperature sensor 1 can exhibit good thermal response.

Further, as is clear from FIGS. 4 and 5, the temperature sensor 1 of the present embodiment shows a high non-defective product residual rate even in a hot water boiling energization test for a long time, and a temperature sensor for several hundred cycles. Even in the froster electrification test, it shows a high remaining rate of non-defective products, and it is possible to obtain extremely high reliability.

The temperature sensor 10 shown in FIG. 2 can also exhibit the same operational effects as those of the temperature sensor 1.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the invention.

[0034]

[Effect of the device]

 According to the present invention described in detail above, with the configuration described above, it is possible to provide a temperature sensor having excellent thermal response and capable of obtaining high reliability.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a sectional view of another embodiment of the present invention.

FIG. 3 is a graph showing measurement results of thermal time constants of the temperature sensor shown in FIG.

FIG. 4 is a graph showing the results of a hot water boiling current test of the temperature sensor shown in FIG.

5 is a graph showing the results of a defroster electrification test of the temperature sensor shown in FIG.

FIG. 6 is a graph showing a measurement result of a thermal time constant of a temperature sensor using a conventional copper case.

FIG. 7 is a graph showing measurement results of thermal time constants of a temperature sensor using a conventional resin case.

FIG. 8 is a sectional view of a conventional temperature sensor.

FIG. 9 is a sectional view showing another example of a conventional temperature sensor.

[Explanation of symbols]

 1 Temperature sensor 4 Lead wire 8 Filling resin 11 Thermistor

Claims (1)

[Scope of utility model registration request] 1. A case having a bottom, a thermistor arranged in the case, a lead wire connecting the end of the lead wire to the thermistor and led out to the outside of the case, and a filling resin filled in the case. In the temperature sensor, the case has a thermal conductivity of 0.5 to 0.7 (W · m ⁻¹ · K ⁻¹ ), a specific heat of 0.5 by adding an inorganic substance to a thermosetting resin.
To 1 (J · g ⁻¹ · K ⁻¹ ), and the filling resin is a resin having substantially the same characteristics as the material of the case.