JPH06290700A - Fuse - Google Patents

Abstract

PURPOSE:To enhance endothermic characteristics and to increase reliability and durability by fixing an endothermic body to a casing. CONSTITUTION:A fuse element 2 and an endothermic body 3 are installed in a housing 1 to form a fuse (A). For this purpose, the locking parts 9, 9' of the endothermic body 3 is agreed to the installing parts 5, 5' of the inserting port 1b of the housing 1. The endothermic body 3 is inserted toward a terminal connecting part 1c from the inserting port 1b. Locking nails 9a, 9a' are engaged with the engaging parts 5a, 5a' of the housing 1 to lock and fix the endothermic body 3 to the housing 1. Next, an element 2 is inserted from the inserting port 1b in such a way that the endothermic body 3 may be held between fuse-element parts 2a, 2a' to engage the locking pieces 6, 6' of the element 2 with the engaging recessed part 7 of the endothermic body 3, locking the endothermic surface 3a of the endothermic body 3 with the fuse-element parts 2a, 2a' under a contact state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a fuse in which a heat absorbing body is interposed in a fuse element which is often used in automobiles and the like.

[0002]

2. Description of the Related Art Conventionally, automobiles and the like are equipped with circuits in which a current exceeding a steady current value flows frequently for a short time, and in order to protect these circuits, a fuse is used with a heat absorber. A fuse has been proposed in which the temperature rise of the element is delayed to prevent unnecessary fusing of the fuse element.

For example, Japanese Utility Model Publication No. 59-41563 discloses a slow blow fuse H as shown in FIG. The slow blow fuse H is a plate-shaped fuse element b that is multiply bent in a casing a.
The heat absorber c fixed to the fuse element b is built in, and is connected to a predetermined circuit by the terminals d and d ′ provided at both ends of the fuse element b.

The fuse element b is embedded in the heat absorbing body c except for the fusing part e. However, in order to embed the plate-shaped fuse element b which is multiply bent into the heat absorbing body c,
As shown in FIG. 4, a groove f corresponding to the bent shape of the fuse element b is formed on the heat absorber c, the fuse element b is inserted into the groove f, and then a ceramic which is an inorganic adhesive is filled in the groove f. The fuse element b and the heat absorber c are fixed to each other by applying an adhesive or the like. g and g'are the terminals on the other side.

Therefore, in the process of manufacturing the slow blow fuse H as described above, the process of forming a complicated groove f corresponding to the bent shape of the fuse element b in the heat absorber c, or the fuse element using a ceramic adhesive agent. There is a drawback in that extremely complicated steps such as a step of embedding and fixing b are required, resulting in low productivity and high manufacturing cost.

Further, since the heat absorber c is relatively large,
When used in an electric circuit of an automobile or the like, stress is repeatedly applied to the terminals d and d'due to mechanical vibration, and distortion occurs at a connecting portion between the terminals d and d'and the fuse element b, and the terminals d and d'are deformed. For example, there is a problem that durability is lowered.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has an excellent heat absorbing property by improving the structure of the joint portion between the fuse element and the heat absorbing body in the housing. An object of the present invention is to provide a fuse having characteristics, high reliability and high durability.

[0008]

In order to achieve the above object, the present invention comprises a box-shaped housing, a fuse element having a terminal portion and a fusible body portion, and a heat absorber contacting the fuse element. A heat absorber mounting portion is provided on an inner wall of the housing, the fuse element is provided with a locking piece for the heat absorbing body, and the heat absorbing body is provided with an engaging recess for the locking piece and a locking portion for the housing. The fuse element and the heat absorber are closely attached to each other and are locked in the housing.

[0009]

In the fuse of the present invention, since the heat absorber is locked to the housing, the vibration of the heat absorber itself does not occur even if mechanical vibration is applied to the housing. Unnecessary stress due to vibration does not act, and it is possible to prevent occurrence of troubles such as deformation of the fuse element and terminals. Further, since the locking piece of the fuse element and the engaging portion of the heat absorbing body are engaged with each other so as to be in close contact with each other, a complicated process of joining the fuse element and the heat absorbing body with an adhesive is omitted. The productivity is significantly improved.

[0010]

1 is an exploded perspective view of a fuse A according to the present invention. The fuse A is a housing 1 formed of a heat-resistant synthetic resin material into a box shape by molding,
A fuse element 2 integrally formed by bending a thin plate of a soluble metal by press working, a composite material of an inorganic material and an organic material, and a heat absorber 3 formed of a heat-resistant imide resin material or the like. Has been done.

The housing 1 has an opening 1b formed at one end of an outer shell 1a having a rectangular tube shape, and a base 1c formed at the other end. On the opposing inner walls 4, 4'of the outer shell 1a, the groove-shaped heat absorber mounting portion 5, from the insertion opening 1b to the base portion 1c,
5 ′ are respectively provided, and the heat absorber mounting portions 5, 5 ′ are provided.
Locking recesses 5a, 5a 'for locking the inserted heat absorber 3 are provided at the end of the.

The fuse element 2 is formed by bending a thin plate of a soluble metal into an inverted U shape by pressing.
a, 2a 'are formed, and female terminal portions 2b, 2b' are provided at their ends, respectively, and the inverted U-shaped bent portion is formed to have a width narrower than that of the fusible body portions 2a, 2a '. The melted portion 2c is formed. Further, the terminal portions 2b, 2b 'are provided with engaging pieces 6, 6'for the heat absorber 3 which are formed by cutting and raising the back surfaces thereof, respectively.

The heat absorbing body 3 is a composite material of an inorganic material such as ceramics and an organic material such as a synthetic resin material, or a heat-resistant polyimide resin formed into a plate shape by a molding process. An engaging recess 7 for engaging the locking piece 6 of the fuse element 2 is provided at the end of the heat absorbing surface 3a.
The other end of the fuse element 2 has a blowout portion 2a.
An isolation groove 8 is formed so as to maintain a constant gap without contacting with.

At both edges 3b, 3b 'of the heat absorber 3, rib-shaped engaging portions 9, 9'for fitting into the heat absorber mounting portions 5, 5' provided on the housing 1 are provided. Locking part 9,
Both ends of 9'are engaged with engaging claws 9a, 9a 'engaging with engaging recesses 5a, 5a' of heat absorber mounting portions 5, 5 ', and ends of base 1c of housing 1. Locking claws 9b, 9
b'is projected.

The thickness of the heat absorbing body 3 is equal to the distance between the fusible body portions 2a and 2a 'formed in an inverted U shape so that the heat absorbing surface 3a and the fusible body portions 2a, 2a' of the fuse element 2 are in close contact with each other. Is formed.

In order to form the fuse A by assembling the fuse element 2 and the heat absorbing body 3 to the housing 1, first, the heat absorbing body mounting portions 5, 5'of the insertion opening 1b of the housing 1 are formed.
The engaging portions 9 and 9'of the heat absorbing body 3 are aligned with each other, the heat absorbing body 3 is inserted from the insertion port 1b toward the terminal connecting portion 1c, and the engaging claws 9a are inserted into the engaging recesses 5a and 5a 'of the housing 1. , 9a 'are engaged to fix the heat absorber 3 to the housing 1.

Next, the fuse element 2 is inserted from the insertion opening 1b of the housing 1 so that the heat absorbing body 3 is sandwiched between the fusible body portions 2a and 2a 'of the fuse element 2 and the locking pieces 6 and 6'of the fuse element 2. The engaging recesses 7 of the heat absorber 3 are engaged with each other, and the fusible body portions 2a, 2a 'are tightly locked to the heat absorbing surface 3a of the heat absorber 3.

Then, as shown in FIG. 2, the insertion opening 1b of the housing 1 is sealed with the lid 10. As described above, in the process of assembling the fuse element 2 and the heat absorbing body 3 into the housing 1, the heat absorbing body 3 is inserted from the insertion opening 1b of the housing 1.
By simply inserting the fuse element 2 and the fuse element 2 in sequence, the fuse element 2 can be securely locked to the housing 1, so that it is easy to apply to the automatic assembling process and the productivity is excellent.

[0019]

In the fuse of the present invention, since the heat absorber is fixed to the housing, even if mechanical vibration is applied to the housing, the vibration of the heat absorber itself does not occur, and therefore the fuse element is not affected by the heat absorber. The stress due to vibration does not act, and it is possible to prevent the occurrence of troubles such as deformation of the fuse element and terminals. Further, since the locking piece of the fuse element and the engaging portion of the heat absorbing body are engaged with each other so as to be in close contact with each other, a complicated process of joining the fuse element and the heat absorbing body with an adhesive is omitted. Therefore, it has advantages such as being suitable for an automatic assembling process and remarkably improving productivity.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a fuse according to an exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state in which a fuse element and a heat absorber are assembled in the housing of FIG.

FIG. 3 is a sectional view of a conventional fuse.

FIG. 4 is a perspective view of a heat absorber and a fuse element of FIG.

[Explanation of symbols]

 A fuse 1 housing 2 fuse element 2a, 2a 'fusible body portion 2b, 2b' terminal portion 3 heat absorber 5, 5'adsorber mounting portion 6 locking piece 7 engaging recess

Claims (1)

[Claims] 1. A box-shaped housing, a fuse element having a terminal portion and a fusible body portion, and a heat absorber in contact with the fuse element. A heat absorber mounting portion is provided on an inner wall of the housing, and the fuse element is provided in the fuse element. An engagement piece for the heat absorber is provided, and an engagement recess for the engagement piece and an engagement portion for the housing are provided on the heat absorber to bring the fuse element and the heat absorber into close contact with each other, and A fuse characterized by being locked to.