JPS5947414B2 - temperature fuse - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temperature fuse that protects equipment by cutting off an electrical circuit when a predetermined temperature is reached, and is intended to provide a temperature fuse that has extremely small variations in melting temperature and is stable against humidity. be.

Conventionally, various types of temperature fuses have been known, and there are two types: those using a low melting point alloy as a temperature sensitive material, and those using a temperature sensitive material having a predetermined melting point as a nonconductive pole.

Those using the above-mentioned low melting point alloy are themselves good electrical conductors,
Although it has the advantage of having a predetermined melting point, it has the disadvantage that the melting temperature varies depending on the manufacturing unit and that the melting temperature changes over time due to the effects of oxidation, etc., making it unreliable. There was a lack of

On the other hand, those using non-conductive temperature-sensitive materials have extremely small variations in melting temperature and are superior to those using low-melting point alloys mentioned above, but many non-conductive temperature-sensitive materials For example, since a low-molecular-weight organic compound such as co-phosphoric acid imide is used, the temperature-sensitive material itself has hygroscopic properties, and has the disadvantage that the melting temperature is lowered by moisture.

For this reason, the temperature-sensitive material of the temperature fuse must be completely isolated from the outside air and must be placed inside a sealed case.

This sealing is usually done with resin, but it is impossible to maintain a completely sealed state because the resin deteriorates over time due to temperature and humidity.

In addition, even with early temperature fuses, it was very difficult to completely seal them against water, and when left in a high humidity atmosphere, the melting point of the temperature-sensitive substance decreased, and the temperature fuse had the disadvantage of breaking earlier than the specified temperature. Ta.

The present invention eliminates the drawbacks of the conventional temperature fuses described above, reduces the hygroscopicity of the temperature-sensitive material, and provides a temperature fuse that disconnects at a predetermined temperature.

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, reference numeral 1 denotes a case, which is formed integrally with a terminal 2.

3 is the other terminal, which is electrically connected to the terminal 2 via the contact 4 and the case 1.

5 is a non-conductive temperature-sensitive material provided on the terminal side of the case 1.

This temperature-sensitive material 5 is produced by uniformly mixing temperature-sensitive material powder, such as succinimide or adipic acid, which is a low molecular weight organic compound, and water-repellent silicon compound fine powder, and then adding particles of the temperature-sensitive material powder to a water-repellent silicon compound. It is surrounded by fine powder.

6 is a spring that presses the contact 4 to the terminal 3; 7 is a spring that slides the contact 4° when the temperature-sensitive substance 5 melts; 8 and 9 are retaining plates; 10 is an insulator;
Reference numeral 11 denotes a resin for fixing, adhesively insulating, and sealing the terminal 3 and the case 1 together.

In the above configuration, when the ambient temperature reaches a predetermined temperature, the temperature-sensitive substance 5 melts, the contact 4 moves by the force of the spring 7, and the electrical circuit is interrupted.

In addition, since the temperature-sensitive material 5 is made by surrounding the temperature-sensitive material powder with fine water-repellent silicon compound powder, its hygroscopicity is reduced, and when the temperature-sensitive material 5 is molded, the fluidity and binding properties of the powder are reduced. The density of the thermosensitive material after molding becomes uniform, and the temperature at which it melts and collapses is stabilized.

Next, other embodiments of the present invention will be described.

In Figure 2, 12 is the case, 13 and 14 are the case 1
Connector 1 with the lead wires inserted from both sides of 2.
It is connected to both ends of 5 through low melting point alloys 16 and 16'.

Reference numeral 17 is a non-conductive temperature-sensitive material that melts at a temperature higher than that of the low-melting point alloy 16.degree. 16', and a hole through which the lead wire 14 passes is formed in the center.

18 is a spring, 19.20 is an insulator for fixing and insulating lead wires 13.14, and 21.21 is lead wire 1.
It is a heat-resistant resin that fixes and seals 3.14.

In the above configuration, when the ambient temperature reaches a predetermined temperature, the temperature-sensitive substance 17 melts, the connector 15 is pulled away from the lead wire 13, and the electrical circuit is interrupted.

Moreover, the temperature-sensitive material 17 was formed in the same manner as the temperature-sensitive material 5 of the previous example, and it has low hygroscopicity and has significantly improved powder fluidity and bonding properties during molding. The density after molding becomes uniform, and the temperature at which it melts and collapses is stable.

In each of the above examples, the temperature-sensitive substances 5 and 17 are obtained by mixing a water-repellent silicon compound with a temperature-sensitive substance powder, and surrounding the particles of the temperature-sensitive substance powder with a fine powder of a water-repellent silicon compound. A water-repellent silicon compound powder that melts and hardens at 70 to 150°C is uniformly mixed into a temperature-sensitive substance powder, and after molding,
A water-repellent silicon compound may be melted by heating at 70 to 150°C.

In this case, the temperature-sensitive material powder and the water-repellent silicon compound are mixed and then molded under pressure, so the water-repellent silicon compound is densely packed between the particles of the temperature-sensitive material powder, and the water-repellent silicon compound is further melted by heating. However, since it flows between the particles of the temperature-sensitive material powder and completely covers the temperature-sensitive material powder, the temperature-sensitive material does not absorb moisture even in a high-humidity atmosphere.

Alternatively, the temperature-sensitive material can be produced by molding the temperature-sensitive material powder, then immersing the molded material in a liquid water-repellent silicon compound, and surrounding the molded material with a water-repellent silicon compound. effect can be obtained.

As is clear from the above explanation, the temperature fuse of the present invention uses a temperature-sensitive material in which the temperature-sensitive material powder is surrounded by a water-repellent silicon compound, so even if the sealing resin deteriorates, the hygroscopicity of the temperature-sensitive material is low. It is a non-conductive temperature-sensitive material that can maintain its unique excellent properties for a long period of time, has extremely high reliability, and has great commercial value.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a temperature fuse showing one embodiment of the invention, and FIG. 2 is a sectional view of a temperature fuse showing another embodiment of the invention. 1... Case, 2, 3, 13, 14...
・Terminal, 4... Contact, 5, 20... Temperature sensitive substance, 7, 18... Spring.

Claims (1)

[Claims] 1. A connecting member that connects two terminals, an elastic member that biases this connecting member in a direction to separate from the one terminal, and a device that maintains this elastic member in a constant state and maintains the ambient temperature. a temperature-sensitive substance that melts upon rising to release the fixed state of the elastic material and detach the connecting member from the one terminal, the temperature-sensitive substance surrounding the temperature-sensitive substance powder with a water-repellent silicon compound; Temperature fuse formed. 2 The temperature-sensitive substance is obtained by molding a temperature-sensitive substance powder and coating this molded product with a water-repellent silicon compound.
Temperature fuses listed in section.