Electricity: electrothermally or thermally actuated switches – Electrothermally actuated switches – Fusible element actuated
Reexamination Certificate
1999-03-15
2001-09-25
Tolin, Gerald (Department: 2835)
Electricity: electrothermally or thermally actuated switches
Electrothermally actuated switches
Fusible element actuated
C337S186000, C337S159000, C337S293000
Reexamination Certificate
active
06294978
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a high-current fuse for vehicles which can restrict a temperature rise when energized.
2. Description of the Related Art Japanese Patent Application Laid-Open No. 610-66387 discloses a fuse
90
shown in FIG.
26
.
The fuse
90
comprises a pair of tab-like terminals
91
, a fusible element
92
disposed between the tab-like terminals
91
, and a resin frame
93
integrally formed around the fusible element
92
. The resin frame
93
is rectangular and includes the connecting portion between the tab-like terminals
91
and the fusible element
92
. If the value of a rated current J′ flowing through the tab-like terminals
91
is too large, the fusible element
92
generates heat and fuses with the heat. By doing so, excess current can be prevented from flowing into an auxiliary equipment (not shown) connected to the tab-like terminals
91
.
However, since the heat generated from the fusible element
92
is transmitted to the resin frame
93
, which is in contact with the fusible element
92
, there is always a possibility that the resin frame
93
melts. To prevent this, it is necessary to put restrictions on environments and conditions in which the fuse
90
can be used, and the rated current J′ flowing through the fuse
90
.
Also, if the fuse
90
is placed in a high-temperature condition, tensile stress and compressive stress act directly upon the fusible element
92
due to the difference in linear expansion coefficient between the tab-like terminals
91
and the resin frame
93
, thereby reducing the durability of the fuse
90
.
There has also been disclosed a fuse box
94
having a fuse as shown in FIG.
27
.
The fuse box
94
comprises a main box
95
, an L-shaped bus bar
96
connected to a side wall of the main box
95
, and a cover
97
attached below the main box
95
. The main box
95
is fixed to one end of the bus bar
96
, and a battery connecting portion
95
a
is attached to the other end of the bus bar
96
. The battery connecting portion
95
a
is connected to the battery post
98
a
of a battery (storage battery)
98
. A fuse
99
is inserted into the upper portion of the main box
95
, and a terminal (not shown) for the fuse
99
is inserted into the lower portion of the main box
95
.
However, the production cost of the fuse box
94
is high due to the large number of components. Also, the fuse box
94
has a drawback that the length between the battery connecting portion
95
a
and the fuse
99
is too long, because the fuse
99
is arranged in line with the bus bar
96
. Accordingly, there is always a possibility that the fuse box
94
becomes too big in size.
SUMMARY OF THE INVENTION
The principal object of the present invention is to provide a high-current fuse which can be used in less restricted environments, has high durability, consists of a small number of components, and is small in size.
To achieve the above object, the present invention provides a high-current fuse for vehicles which includes a conductive plate having a fuse and terminal connecting portion on both sides, a resin case into which the conductive plate is insert-molded, and a heat radiating portion for releasing heat generated from the fuse and the conductive plate when energized. The heat radiating portion is disposed on the outer surface of the resin case.
With this structure, the number of components can be smaller than in the prior art, and the high-current fuse can be made compact. Such a high-current fuse for vehicles can be connected with ease even in a small installation space. Also, as the heat radiating portion is disposed on the outer surface of the resin case, the heat generated from the fuse and the conductive plate can be quickly released. Thus, a temperature rise in the resin case can be restricted, and the resin case can be prevented from melting with heat. Functional deterioration of the resin case can also be prevented.
In accordance with a second aspect of the present invention, the terminal connecting portions on both sides of the conductive plate are arranged on the same line with a space in between, and the fuse is arranged in between.
With this structure, the terminal connecting portions on both sides can be brought closer, so that the high-current fuse can be made smaller.
In accordance with a third aspect of the present invention, one of the terminal connecting portions is directly attached to a battery.
With this structure, the fuse can be automatically attached directly to the battery. Accordingly, the fuse member can be easily connected to the battery, and unlike in the prior art, a failure of connecting the fuse member to the battery can be prevented.
In accordance with a fourth aspect of the present invention, the heat radiating portion comprises a plurality of thin plates arranged on the resin case at regular intervals.
With this structure, the surface area of the resin case can be increased, so that a larger area of the resin case is brought into contact with air, and that the heat radiating effect of the resin case can be improved. Accordingly, a temperature rise can be restricted at the time of energization, and the environment and the condition when the high-current fuse is used can be less restrictive. Also, a wider range of current can flow through the conductive plate.
In accordance with a fifth aspect of the present invention, the thin plates are arranged in parallel with the energizing direction so as to strengthen the resin case.
With this structure, the rigidity of the resin case can be secured. Such a high-current fuse for vehicles does not easily bend, and thus has higher reliability as a product.
In accordance with a sixth aspect of the present invention, a pair of assisting plates facing to each other are integrally formed in the middle of the conductive plate, and the fuse is disposed between the pair of assisting plates.
With this structure, the fuse can be kept away from both ends of the conductive plate by the length of the pair of assisting plates. When the conductive plate is energized from one end to the other via the fuse, a temperature rise at the terminal connecting portions is smaller than in the prior art.
In accordance with a seventh aspect of the present invention, the fuse disposed between the pair of assisting plates is in a direction perpendicular to the energizing direction of the conductive plate.
With this structure, even if the high-current fuse for vehicles is placed under a high-temperature condition, tensile stress and compressive stress caused by the difference in linear expansion coefficient between the resin case and the conductive plate do not act directly on the fusible element of the fuse. Thus, the fuse can be more durable than in the prior art at a high temperature.
The above and other objects and features of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings.
REFERENCES:
patent: 3810063 (1974-05-01), Blewitt
patent: 3883838 (1975-05-01), Bogert et al.
patent: 4050045 (1977-09-01), Motten, Jr. et al.
patent: 4216456 (1980-08-01), Hotta et al.
patent: 4263574 (1981-04-01), Mori et al.
patent: 4460948 (1984-07-01), Malola
patent: 4839625 (1989-06-01), Newbery et al.
patent: 5214565 (1993-05-01), Flores
patent: 5643693 (1997-07-01), Hill et al.
patent: 5645448 (1997-07-01), Hill
patent: 61-66387 (1986-04-01), None
patent: 62-118336 (1987-07-01), None
patent: 64-16661 (1989-01-01), None
Endo Takayoshi
Hikage Atsushi
Inaba Shigemitsu
Matsumura Norio
Onoda Shinya
Armstrong Westerman Hattori McLeland & Naughton LLP
Tolin Gerald
Vortman Anatoly
Yazaki -Corporation
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