JPS598231A - Temperature fuse - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface tension effect type temperature fuse whose main components are an easily fusible metal and a thermoplastic resin.

Temperature heaters that utilize the effect of surface tension include structures shown in FIGS. 1 and 2. Figure 1 shows easy-fusion metal 1
Terminal wires 2, 2' are connected to both ends of the insulating case 4, and the surface of the easily fusible metal 1 is coated with a thermosoftening resin 3 having flux properties with a melting point lower than that of the easily fusible metal 1. It is housed in a container and sealed with insulating paint 5. In addition, in Figure 2, a terminal wire 2゜2' is connected to a fusible material in which an easily fusible metal 1 and a heat softening resin 3 are atomized and dispersed, and an insulating outer skin 6 is provided around the outer periphery, and the terminal wire 2゜2' is sealed with an insulating paint 5. This is what I did. When these temperature fuses reach a predetermined temperature, the easily fusible metal 1 melts as shown in FIGS. 3 and 4, and is attracted toward the ends of the opposing terminal wires 2 and 2' with the action of surface tension. It melts and melts.

Recently, with the miniaturization of electronic devices, there is a need for a compact and high-performance temperature heater, which has accurate fusing, has sufficient insulation distance after fusing, and has a large surface tension effect.
Easily fusible alloys with excellent processability are required for temperature fuses.

Conventionally, tin, lead, bismuth, cadmium, etc., and alloys of these metals have been known as easily fusible alloys for temperature heating with melting points around 140°C to 148°C.
For example, as shown in Table 1 below.

<Table 1> In the above table, AI and A2 contain bismuth as a main component, and these easily fusible alloys have hard and brittle properties.

That is, it has poor mechanical workability such as extrudability, rollability, wire drawability, and punchability, and cannot be processed into a long, thin, or thin linear or plate-like body. In addition, this easy-to-fuse alloy has a high electrical resistance, so it self-heats when energized9.
It had the disadvantage of melting at a lower temperature due to its own light heat. Therefore, this type of easily fusible metal is not suitable for small temperature fuses of the surface tension action type, but is suitable only for large elastic action type temperature fuses that utilize old-fashioned spring plates and springs.

In addition, the easily fusible alloy of flat 3 in Table 1 above has excellent mechanical workability, has relatively low electrical resistance, and exhibits sufficient surface tension when melted, but is difficult to handle because it contains a large amount of cadmium. It is undesirable for use because it has a harmful effect on the human body during work. In particular, it cannot be used in a method of manufacturing by atomizing and dispersing it as shown in FIG.

As mentioned above, conventional easily fusible alloys have some drawbacks when used in surface tension type temperature fuses.
It's inappropriate.

The purpose of the present invention is to solve these problems by improving extrudability,
It has excellent mechanical workability such as rolling properties, wire drawability, and punching properties, has low electrical resistance, is stable over time, has little harmful effect on the human body, and can accurately control the large surface tension when melted. As shown in Figures 1 and 2, it uses a highly fusible alloy with the ability to exhibit superior surface tension function. To meet the required miniaturization of temperature fuses, it is an object of the present invention to easily and inexpensively provide extremely small temperature fuses as needed.

Hereinafter, the present invention will be explained based on examples.

Therefore, it is of great industrial value as it can provide a highly reliable, compact temperature heater at a low cost.

[Brief explanation of drawings]

Figures 1 and 2 are cross-sectional views of surface tension effect temperature fuses, Figures 3 and 4 are Figures 1 and 4, respectively.
FIG. 3 is a cross-sectional view of the temperature fuse in FIG. 2 after being blown out; 1... Easily fusible metal, 2, 2'... Terminal wire, 3... Heat softening resin, 4... Insulation case, 6... ...Insulating paint, 6...Insulating outer skin.

Claims (1)

[Claims] The main component is an easily fusible alloy and a thermosoftening resin that has flux properties at a melting point lower than the melting point of the easily fusible alloy, and when the temperature exceeds a predetermined temperature, the easily fusible alloy becomes spheroidized and melts and breaks due to the action of surface tension. A temperature heater characterized in that the metal composition of the easily fusible alloy is 52 to 54% by weight of tin, 24 to 26% by weight of lead, and 21 to 23% by weight of indium.