JPH0430754Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Effects of the Invention] (Field of Industrial Application) The present invention relates to a non-resetting type temperature fuse that uses a fusible alloy as the fuse material.

(Prior Art) As shown in FIG. 3, a conventional temperature fuse includes a temperature fuse body, which is made by welding a fusible alloy 12 to the ends of a pair of parallel lead wires 11, in a case 13. The opening of the case 13 is sealed with synthetic resin, and the temperature fuse element is fixed by the sealing part 14. Said fusible alloy 1
Rosin 15 is applied to the circumferential surface of 2.

(Problems to be Solved by the Invention) When such a conventional temperature fuse reaches the operating temperature and the fusible alloy is melted and disconnected as shown in FIG. 4, the fusible alloy 12a separated on both sides ，
12b is concentrated at the tip of the lead wire 11, so the distance between the fusible alloys 12a and 12b is short;
This results in a decrease in insulation resistance.

Furthermore, if an external force such as vibration or impact is applied to the temperature fuse during melting and disconnection of the fusible alloy, the fusible alloy 12
a and 12b fall from the lead wire 11 and spread to the surrounding area, causing re-contact.

In addition, as shown in Japanese Utility Model Publication No. 60-41631, two parallel lead wires are formed with a curved portion near their tips, and both ends of each lead wire are electrically and mechanically connected to the tip of each lead wire. Consisting of a fixed shaft-shaped fusible alloy, an elastic member that preliminarily covers the fusible alloy surrounding the curved portion of the lead wire, and a hard outer resin material that is adhered and formed on the elastic member. Therefore, even if the fusible alloy repeatedly expands and contracts due to changes in ambient temperature, there are temperature fuses that can absorb this deformation with the curved part of the lead wire or an elastic member. Since the elastic member is covered by the member, the fusible alloy melted by the excessive current will be confined within the narrow flux-filled space within the elastic member, and there is a risk that the fusible alloy will come into contact again after being melted.

The purpose of the present invention is to reliably prevent poor insulation resistance between lead wires after blowout, which is a drawback of non-resettable temperature fuses, and to reliably prevent conduction due to re-contact after blowout.

[Structure of the idea]

(Means for Solving the Problems) The present invention provides a temperature fuse body made by welding a fusible alloy 23 between the ends of a pair of lead wires 22, which is inserted into a hollow case 21 and sealed. In the fuse, an inclined bent part 26 is provided by bending the lead wire 22 in the vicinity of the welded part of the fusible alloy in a hollow part 29 in the case 21. Rosin 27, 28 is applied to a certain inclined bent portion 26 and a fusible alloy 23.

(Function) The present invention has melted and disconnected fusible alloys 23a, 23.
b is the hollow part 29 of the case 21 due to the action of the rosin 27 applied to the inclined bent part 26 of the lead wire 22.
The fusible alloys 23a and 23b are dispersed over a wide area within the range of
Because it is spread thinly and uniformly over the surface of the surface, its surface tension is large and it is less susceptible to external forces such as vibrations and shocks.

(Example) Hereinafter, the present invention will be explained in detail with reference to an example shown in FIGS. 1 and 2.

As shown in FIG. 1, the hollow part 29 of the case 21
A temperature fuse element made by welding a fusible alloy 23 is inserted between the tips of a pair of lead wires 22, and the opening 24 of the case 21 is sealed with a sealing part 25 made of epoxy resin.

The lead wire 22 is bent in an inclined shape near the welded portion of the fusible alloy in a hollow part 29 inside the case to provide an inclined bent part 26. Rosin (flux) 27, 28 is applied to the curved portion 26 and the fusible alloy 23.

By providing the lead wires 22 with the inclined bent portions 26, the distance between the pair of lead wires 22 can be adjusted to the extent that the fusible alloy
This lead wire 22 is set larger than the total length of 3.
can be inserted parallel to the inner wall of the case 21 and fixed stably. Furthermore, lead wire 2
When the vicinity of the welded part of the fusible alloy of No. 2 is bent in an inclined shape to provide an inclined bent part 26, the rosin, which is heated and in a fluid state, is poured onto the upper part of this inclined bent part 26. Since this flowing rosin loosens gently at the inclined bending part 26, the rosin loosens downward from the upper part of the inclined bending part 26 and spreads over the entire inclined bending part 26, as shown in FIG. It is cured in a state where No. 27 is uniformly attached. In this way, since the rosin 27 is evenly attached to the inclined bent portion 26 of the lead wire 22, when the fusible alloy 23 is fused as shown in FIG. Part 2
The meltable alloy is efficiently sucked up by the rosin 27 of No. 6.

Then, when the fusible alloy 23 reaches the operating temperature due to excessive current and is fused as shown in FIG. The rosin 27 applied thereto is dispersed over a wide area within the hollow portion 29 of the case 21. Therefore, this fusible alloy 2
3a and 23b, only a very small amount remains at the tip of the lead wire 22 at the time of fusing. Therefore, the electrode distance between the opposing lead wires 22 is longer than that of a conventional temperature fuse, and a sufficient insulation distance is ensured, so that the insulation resistance value does not decrease as in the conventional case.

Further, the fusible alloys 23a and 23b are connected to the lead wire 22.
Since the surface of the inclined bent portion 26 is spread thinly and uniformly, its surface tension is large and it is not easily affected by external forces such as vibrations and shocks. There is no risk of this happening.

[Effect of idea]

According to the present invention, an inclined bent part is provided in the hollow part of the case near the fusible alloy welded part of the lead wire inserted into the hollow case, and rosin is also applied to the inclined bent part. Because I decided to do it,
Due to the shape of the lead wire and the action of the rosin, the fusible alloy can be widely dispersed on the surface of the lead wire in the hollow space within the case, thereby preventing a decrease in insulation resistance value and re-contact. The reliability of a non-returnable temperature fuse using this type of fusible alloy as a fuse material can be significantly improved.

In addition, by providing the lead wire with an inclined bend, the distance between the pair of lead wires is set larger than the total length of the fusible alloy, and the lead wire is inserted parallel to the inner wall of the case and inserted into the case. It is also possible to fix it stably.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of the temperature fuse of the present invention, Fig. 2 is a sectional view during its fusing operation, Fig. 3 is a sectional view of a conventional temperature fuse, and Fig. 4 is a sectional view during its fusing operation. FIG. 5 is a sectional view showing the remelted state. 21...Case, 22...Lead wire, 23...
Fusible alloy, 26... Inclined bent portion, 27, 28...
Rosin, 29...Hollow part.

Claims (1)

[Scope of utility model registration request] In a temperature fuse in which a temperature fuse body made by welding a fusible alloy between the ends of a pair of lead wires is inserted into a hollow case and sealed, the vicinity of the welded portion of the fusible alloy of the lead wires is inserted into the case. A temperature fuse characterized in that the hollow part of the case is bent in an inclined shape to provide an inclined bent part, and the inclined bent part and the fusible alloy in the hollow part of the case are coated with rosin.