JPH0592667U - Temperature sensor - Google Patents

Abstract

(57) [Summary] [Purpose] To satisfy both the heat cycle characteristics and water resistance characteristics of the temperature sensor. [Structure] A butadiene resin is used as the buffer resin portion 9. The butadiene resin covers at least the connection between the thermistor element body 11 of the thermistor element 10 and the lead wires 2 and 3 and the glass. Since butadiene resin is soft and hydrophobic, it works to relieve stress due to thermal changes and improve water resistance.
Both the heat cycle characteristics and the water resistance characteristics of the temperature sensor can be satisfied.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a temperature sensor used for detecting various temperatures of an air conditioner, a vending machine, and the like.

[0002]

[Prior Art]

 As a temperature sensor of this type, it is known to use a thermistor element 30 as shown in FIG. The thermistor element 30 includes a thermistor element body 31, a pair of lead wires 32 and 33 in which dumet portions 32A and 33A are connected to both ends of the thermistor element body 31, the lead wires 32 and 33, and the thermistor element body. It is composed of a cylindrical glass 34 covering the periphery of 31.

6 to 9 show a conventional temperature sensor constructed by using the thermistor element 30 as shown in FIG. Here, the temperature sensor 41 of FIG. 6 bends the thermistor element 30 and one lead wire, for example, 33 of this thermistor element 30, so as to be parallel to the other lead wire 32 in the same direction, and each lead wire 32. , 33 and two external lead wires 37 parallel to each other by caulking conductive parts 35, 36, a connecting portion between the thermistor element body 31 of the thermistor element 30 and the lead wires 32, 33, and a silicone resin covering the glass 34, etc. And a coat resin portion 40 such as an epoxy resin which covers the buffer resin portion 39 up to the end portion of the outer lead wire 37.

FIG. 7 shows another temperature sensor 43. This temperature sensor 43 is different from the temperature sensor 41 of FIG. 6 in that a soft buffer resin portion 39 such as a silicone resin system is used for the thermistor element 30. The structure that covers the whole and the end portion 37A of the external lead wire 37 is different. Further, FIG. 8 shows another temperature sensor 45, which is different from the temperature sensor 41 of FIG. 6 in that the coating resin portion 40 such as an epoxy resin is unnecessary. Furthermore, FIG. 9 shows another temperature sensor 47. Compared to the temperature sensor 41 of FIG. 6, the entire thermistor element 30 and the end portions of the external lead wires 37 are coated with resin such as epoxy resin. The structure of covering only 40 is different.

Each of the temperature sensors shown in FIGS. 6 to 9 is applied to applications in which the reliability is relatively small, such as performing room temperature control by an air conditioner.

On the other hand, a temperature sensor having a structure as shown in FIG. 10 to FIG. 13 is used as a temperature sensor applied to an application requiring relatively high reliability such as controlling the discharge temperature of an outdoor unit. It is provided. These temperature sensors 41 ', 43', 45 ', 47' are the same as the temperature sensors 41, 43, 45, 47 shown in FIGS. 6 to 9 in a bottom case 42 having good thermal conductivity such as copper. It is formed by encapsulating via a filling resin 44 such as a soft epoxy resin.

FIGS. 15 and 16 are graphs showing the results of the defroster energization test and the hot water boiling energization test of the temperature sensors 41 ', 43', 45 ', 47' shown in FIGS. Here, the defroster energization test is to test the heat cycle characteristics of the temperature sensor. A current of 0.5 mA is applied to each temperature sensor and many samples are immersed in water at -40 ° C and + 60 ° C for 4 hours each. This is the method for obtaining the residual rate of non-defective products when the above cycle is repeated many times.

The hot water boiling current test is a test for water resistance of a temperature sensor. A large number of samples, which are temperature sensors, are immersed in 90 ° C. hot water, and a current of 0.5 mA is applied to each temperature sensor. The relationship between the remaining rate of non-defective products and the time when flowing is calculated.

The heat cycle characteristics by the defroster electrification test of FIG. 15 are as follows: temperature sensor 47 ′ (characteristic D), temperature sensor 41 ′ (characteristic A), temperature sensor 45 ′ (characteristic C), temperature sensor 43 ′ (characteristic B). Is getting better in that order. This indicates that providing the soft buffer resin portion 39 such as a silicone resin is effective for improving the heat cycle characteristics.

On the other hand, the water resistance characteristics of the hot water boiling current test of FIG. 16 are as follows: temperature sensor 45 '(characteristic C), temperature sensor 43' (characteristic B), temperature sensor 41 '(characteristic A), temperature sensor 47' (characteristic). It is getting better in the order of D). This result shows a tendency almost opposite to the result of FIG. This means that providing a soft buffer resin portion 39 such as a silicon-based resin is effective in improving heat cycle characteristics because it relieves stress due to thermal change, but it is problematic in improving water resistance. Indicates that there is.

[0011]

[Problems to be solved by the device]

 As described above, the conventional temperature sensor has a problem in that it is impossible to satisfy both the heat cycle characteristics and the water resistance characteristics that affect the performance of the temperature sensor. The present invention has been made in consideration of the above problems, and an object thereof is to provide a temperature sensor satisfying both heat cycle characteristics and water resistance characteristics.

[0012]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a thermistor element in which lead wires are connected to both ends of a thermistor element body, and the periphery of the lead wire and the thermistor element body is covered with glass, and a lead wire of the thermistor element. In a temperature sensor having an external lead wire connected to, a butadiene resin that covers at least the connection between the thermistor element of the thermistor element and the lead wire and glass, and an epoxy resin or urethane resin that covers this butadiene resin. It is characterized by having.

[0013]

[Action]

 According to the structure of the present invention as set forth in claim 1, the butadiene resin is made soft and hydrophobic by covering at least the connecting portion between the thermistor element body of the thermistor element and the lead wire and the glass by using the butadiene resin. Since it is provided, by covering the butadiene resin with an epoxy resin or a urethane resin, both heat cycle characteristics and water resistance characteristics can be satisfied.

According to the configuration of the present invention as set forth in claim 2, since the epoxy resin or urethane resin covering the butadiene resin is filled in the bottomed case, a highly reliable temperature sensor can be obtained. You can

[0015]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view showing a first embodiment of the temperature sensor of the present invention. The temperature sensor 1 of this embodiment is a thermistor element having the same structure as the thermistor element 30 shown in FIG. 10 and one lead wire of this thermistor element 10, for example, 3 are bent so as to be parallel to the other lead wire 2 in the same direction, and the conductive portions 5 and 6 are caulked and connected to the lead wires 2 and 3, respectively. A two-core parallel external lead wire 7, a buffer resin portion 9 made of butadiene resin covering the connecting portion between the thermistor element body 11 of the thermistor element 10 and the lead wires 2 and 3 and the cylindrical glass 4, and this buffer resin portion. A coat resin portion 20 such as an epoxy resin that covers 9 to the end portion 7A of the external lead wire 7, a bottomed case 12 having good heat conductivity such as copper, and a filling resin 14 such as a soft epoxy resin. I have It The butadiene resin used as the buffer resin portion 9 here is soft and hydrophobic.

FIG. 2 is a cross-sectional view showing a second embodiment of the present invention. The temperature sensor 13 of the second embodiment is a silicon resin as compared with the temperature sensor 1 of the first embodiment of FIG. The structure in which the entire thermistor element 10 and the end portion 7A of the external lead wire 7 are covered with a soft buffer resin portion 9 such as a system is different, and the other structures are the same as those in the first embodiment.

FIG. 3 is a sectional view showing a third embodiment of the present invention. The temperature sensor 15 of the third embodiment is different from the temperature sensor 1 of the first embodiment in that an epoxy resin or the like is used. The structure in which the coat resin portion 20 is unnecessary is different, and the other structures are the same as those in the first embodiment.

FIGS. 4 and 5 are graphs showing the results of the defroster energization test and the hot water boiling energization test of the temperature sensors 1, 13 and 15 according to the first to third embodiments of the present invention. The conditions for each test were the same as the conventional ones.

The heat cycle characteristics by the defroster electrification test of FIG. 4 are improved in the order of the temperature sensor 1 (characteristic A), the temperature sensor 13 (characteristic B), and the temperature sensor 15 (characteristic C). As is clear from the comparison with the conventional characteristics, the temperature cycle characteristics of each temperature sensor of this embodiment are significantly improved.

On the other hand, the water resistance characteristics by the hot water boiling energization characteristics in FIG. 5 are improved in the order of the temperature sensor 15 (characteristic C), the temperature sensor 1 (characteristic A), and the temperature sensor 13 (characteristic B). As is clear from the comparison with the conventional characteristics shown in FIG. 16, the water resistance characteristics of the temperature sensors of this embodiment are remarkably improved.

That is, according to each embodiment of the present invention, by using the butadiene resin as the buffer resin portion 9, since the butadiene resin is soft and hydrophobic, the stress due to the thermal change is relaxed and Since it works to improve water resistance, both heat cycle characteristics and water resistance characteristics can be satisfied, as is apparent from FIGS. 4 and 5.

A butadiene-based urethane resin is known as a material similar to the butadiene resin, but this butadiene-based urethane resin is excellent for use as a filling resin, and as in the present invention, it is a buffer resin that is an undercoat resin. Butadiene resin is superior when used as a part. Further, the butadiene resin is also excellent in heat resistance.

In each of the embodiments, the case where the temperature sensor is configured by using the bottomed case 12 has been described, but the same effect can be obtained by applying the temperature sensor having a structure that does not use the bottomed case 12. be able to.

[0025]

[Effect of the device]

 As described above, according to the present invention, the butadiene resin is used as the buffer resin portion so as to cover at least the connecting portion between the thermistor element body of the thermistor element and the lead wire and the glass. By utilizing the rich functions, both heat cycle characteristics and water resistance characteristics can be satisfied.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of a temperature sensor of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the temperature sensor of the present invention.

FIG. 3 is a sectional view showing a third embodiment of the temperature sensor of the present invention.

FIG. 4 is a graph showing the results of a defroster electrification test of each example of the present invention.

FIG. 5 is a graph showing the results of hot water boiling energization test of each example of the present invention.

FIG. 6 is a sectional view showing a conventional temperature sensor.

FIG. 7 is a cross-sectional view showing another conventional temperature sensor.

FIG. 8 is a sectional view showing another conventional temperature sensor.

FIG. 9 is a cross-sectional view showing another conventional temperature sensor.

FIG. 10 is a cross-sectional view showing another conventional temperature sensor.

FIG. 11 is a cross-sectional view showing another conventional temperature sensor.

FIG. 12 is a cross-sectional view showing another conventional temperature sensor.

FIG. 13 is a cross-sectional view showing another conventional temperature sensor.

FIG. 14 is a sectional view showing a thermistor element used in a conventional temperature sensor.

FIG. 15 is a graph showing a result of a defroster electrification test of a conventional temperature sensor.

FIG. 16 is a graph showing the results of a hot water boiling energization test of a conventional temperature sensor.

[Explanation of symbols]

 2,3 Lead wire 4 Cylindrical glass 7 External lead wire 9 Butadiene resin (buffer resin part) 10 Thermistor element 11 Thermistor element body 12 Bottom case 14 Filling resin 20 Coat resin part

Claims (2)

[Scope of utility model registration request] 1. A thermistor element in which lead wires are connected to both ends of a thermistor element body and the periphery of the lead wire and the thermistor element element are covered with glass, and an external lead wire connected to the lead wire of the thermistor element. A temperature sensor comprising: a temperature sensor comprising at least a butadiene resin covering a connecting portion between the thermistor element body of the thermistor element and a lead wire and glass, and an epoxy resin or a urethane resin covering the butadiene resin. . 2. The temperature sensor according to claim 1, wherein the epoxy resin or urethane resin is filled in a bottomed case.