U.S. patent application number 09/924529 was filed with the patent office on 2002-03-07 for junction box.
This patent application is currently assigned to SUMITOMO WIRING SYSTEMS, LTD.. Invention is credited to Kobayashi, Noriko, Saito, Yukitaka, Sumida, Tatsuya.
Application Number | 20020028590 09/924529 |
Document ID | / |
Family ID | 18731977 |
Filed Date | 2002-03-07 |
United States Patent
Application |
20020028590 |
Kind Code |
A1 |
Saito, Yukitaka ; et
al. |
March 7, 2002 |
Junction box
Abstract
An electrical junction box for a vehicle has a casing and in the
casing a connector circuit having first bus bars fixed on a
connector circuit substrate to connect to electrical connectors, a
fuse circuit with second bus bars on a fuse circuit substrate,
discrete from the connector circuit, to connect to fuses, and a
relay circuit having third bus bars on a relay circuit substrate,
discrete from the connector circuit, to connect to relays. The
first bus bars have welding portions welded to and the bus bars of
one of the fuse and relay circuits have welding portions opposed
thereto. At the adjacent pairs of these welded connections an
insulating partitioning member is interposed between the welded
connections so as to prevent contact between them.
Inventors: |
Saito, Yukitaka;
(Yokkaichi-city, JP) ; Sumida, Tatsuya;
(Yokkaichi-city, JP) ; Kobayashi, Noriko;
(Yokkaichi-city, JP) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 19928
ALEXANDRIA
VA
22320
US
|
Assignee: |
SUMITOMO WIRING SYSTEMS,
LTD.
1-14, Nishisuehiro-cho
Yokkaichi-city
JP
510-8503
|
Family ID: |
18731977 |
Appl. No.: |
09/924529 |
Filed: |
August 9, 2001 |
Current U.S.
Class: |
439/76.2 |
Current CPC
Class: |
H05K 3/328 20130101;
B60R 16/0238 20130101; H05K 7/026 20130101; H01R 9/2466 20130101;
H05K 1/0254 20130101; Y10S 439/949 20130101; H05K 3/4092
20130101 |
Class at
Publication: |
439/76.2 |
International
Class: |
H05K 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 9, 2000 |
JP |
2000-240655 |
Claims
What is claimed is:
1. An electrical junction box that provides electrical connection
to a plurality of electrical connectors, a plurality of fuses and a
plurality of relays, comprising; (i) a casing; (ii) a connector
circuit in said casing having at least one connector circuit
insulation substrate and a plurality of first bus bars fixed on
said insulation substrate, said first bus bars being arranged to
provide electrical connection to electrical connectors in use;
(iii) a fuse circuit in said casing having at least one fuse
circuit insulation substrate, which is discrete from said connector
circuit, and a plurality of second bus bars fixed on said fuse
circuit insulation substrate, said second bus bars being arranged
to provide electrical connection to fuses in use; and (iv) a relay
circuit in said casing having at least one relay circuit insulation
substrate which is discrete from said connector circuit, and a
plurality of third bus bars fixed on said relay circuit insulation
substrate, said third bus bars being arranged to provide electrical
connection to relays in use; wherein said first bus bars have
respective welding portions standing up from said connector circuit
insulation substrate and arranged alongside one another, and said
bus bars of one of said fuse and relay circuits have respective
welding portions standing up from the respective insulation
substrate and arranged alongside one another opposed to said
welding portions of said first bus bars, the opposed welding
portions being welded together to form a plurality of welded
connections, and wherein at at least one adjacent pair of said
welded connections one of the respective circuits provides an
insulating partitioning member which is interposed between said
pair of welded connections and prevents contact between said pair
of adjacent welded connections.
2. An electrical junction box according to claim 1, wherein said
partitioning member has at least one support portion located
rearwardly of a rear face of one of said welding portions to
provide support of the welding portion against rearward
bending.
3. An electrical junction box according to claim 2, wherein said
partitioning member has a spaced pair of said support portions
which are located respectively rearwardly of the rear faces of both
welded-together welding portions of one said welded connection.
4. An electrical junction box according to claim 2, wherein at said
welded connections, the other of the respective circuits has at
least one upstanding support member interposed between said support
portion of said partitioning member and said rear face of said
welding portion supported thereby.
5. An electrical junction box according to claim 1, wherein said
partitioning member is molded in one-piece with the respective
insulation substrate.
6. An electrical junction box according to claim 1, wherein said
fuse circuit insulation substrate and said relay circuit insulation
substrate are discrete from each other, whereby said fuse circuit
and said relay circuit constitute separate modules in said junction
box.
7. An electrical junction box according to claim 1, wherein said
fuse circuit insulation substrate and said relay circuit insulation
substrate are combined as a unitary common substrate carrying said
second bus bars and said third bus bars, whereby said fuse circuit
and said relay circuit constitute a combined module in said
junction box.
8. An electrical junction box according to claim 1, wherein said
casing comprises upper and lower case parts, which are respectively
molded synthetic resin members, at least one of said upper and
lower case parts comprising connector sockets for receiving
electrical connectors in use.
9. A vehicle having at least one electrical junction box according
to claim 1.
10. A method of assembling an electrical junction box that provides
electrical connection to a plurality of electrical connectors, a
plurality of fuses and a plurality of relays, said electrical
junction box comprising: (a) a connector circuit having at least
one connector circuit insulation substrate and a plurality of first
bus bars fixed on said insulation substrate said first bus bars
being arranged to provide electrical connection to electrical
connectors in use; (b) a fuse circuit having at least one fuse
circuit insulation substrate, which is discrete from said connector
circuit, and a plurality of second bus bars fixed on said fuse
circuit insulation substrate, said second bus bars being arranged
to provide electrical connection to fuses in use; and (c) a relay
circuit having at least one relay circuit insulation substrate
which is discrete from said connector circuit, and a plurality of
third bus bars fixed on said relay circuit insulation substrate,
said third bus bars being arranged to provide electrical connection
to relays in use; wherein said first bus bars have first welding
portions standing up from said connector circuit insulation
substrate and arranged alongside one another, and said bus bars of
one of said fuse and relay circuits have second welding portions
stand up from the respective insulation substrate, said method
including the steps of: (i) arranging said first welding portions
respectively opposite said second welding portions in position to
be welded thereto at a plurality of welding locations, with at
least one insulating partitioning member provided by one of the
respective circuits interposed between an adjacent pair of said
welding locations so as to prevent contact, during welding, between
said welding portions of one of said pair of welding locations with
said welding portions of the other of said pair of welding
locations, and (ii) after step (i), welding together said first and
second welding portions at the respective welding locations.
11. A method according to claim 10, further comprising a step of
locating at least one support portion of said partitioning member
rearwardly of a rear face of one of said welding portions at at
least one of the pair of welding locations to provide support of
the welding portion against rearward bending.
12. A method according to claim 10, wherein the welding portions at
each said welding location are joined by one of ultrasonic welding,
resistance welding, laser welding and gas welding.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates to an electrical junction box
suitable to be connected for example to a wire harness in a vehicle
such as an automobile and a method of assembling the junction
box.
[0003] 2. Description of Related Art
[0004] Recently, the increase of electrical and electronic
component parts which are mounted in a vehicle has led to increase
of circuits to be accommodated in electrical connection boxes and
junction boxes in the vehicle. Thus, when forming branch circuits
at a high density, it is necessary to mount a large number of
component parts on a junction box or the like, which causes
increase of manufacturing complexity.
[0005] In a junction box disclosed in Japanese Laid-Open Patent
Publication No. 2000-92660 and shown in FIG. 12, bus bars 5A-5D are
laminated one upon another between an upper case part 2 and a lower
case part 3, with insulation plates 4A-4E interposed between the
bus bars 5A-5D. The upper case part 2 has a connector receiving
portion 2a, a relay receiving portion 2b, and a fuse receiving
portion 2c, on which in use connectors 6, relays 7 and fuses 8 are
mounted respectively. Terminals of the connectors 6, the relays 7
and the fuses 8 are connected to tabs 5a projecting from the bus
bars directly or are connected to the bus bars through relaying
terminals. The lower case part 3 has also a connector receiving
portion 3a to connect connectors to tabs projecting from the bus
bars.
[0006] In the junction box 1, with the increase of the number of
circuits, the area and the number of layers of the bus bars
increase and thus the size of the junction box becomes large. If
the connector, relay and fuse receiving portions are arranged on
both the upper and lower case parts to connect connectors, relays
and fuses to internal circuits of the junction box, it is possible
to make the area of the junction box smaller than in the case where
the receiving portions are mounted on only the upper case part or
the lower case part.
[0007] However, if the connector, relay and fuse receiving portions
are mounted on both the upper and lower case parts such that they
are opposed vertically, the bent tabs of bus bars must overlap each
other and thus cannot be easily arranged. In this case, it is
necessary to form tabs on bus bars of other layers, which causes an
increase of number of layers of bus bars, and thus leads to the
increase of the height of the junction box. That is, the junction
box is necessarily large.
[0008] Further, the above-described junction box is so constructed
that the bus bars are connected to the connectors, the fuses and
the relays. Thus, when the specification of the connection between
the internal circuit and the fuses and/or the relays is altered, it
is necessary to alter the entire internal circuit. Consequently the
above-described junction box is incapable of allowing a circuit
alteration easily.
[0009] Some proposals have been made for replaceable modules in
electrical circuits of automobiles.
[0010] U.S. Pat. No. 5,179,503 shows a modular automobile power
distribution box having replaceable modules carrying relays or
fuses. The relays or fuses in each module are directly connected to
terminals of leads of wire harnesses. A pair of bus bars connect
power terminals to the fuses of three maxi-fuse modules. There is
no discussion of interconnection of the modules.
[0011] U.S. Pat. No. 5,581,130 discloses removable multi-function
modules in individual casings which are mounted on a circuit board.
Each module is electrically connected to the power supply
distribution layer of the board by a pin. Alternatively, three
modules are shown connected together by two electrical and
mechanical coupling bars.
SUMMARY OF THE INVENTION
[0012] It is an object of the present invention to provide a
junction box which can be made thin without increasing the number
of layers of bus bars to be accommodated therein and which can cope
with a circuit alteration easily.
[0013] According to the present invention, there is provided an
electrical junction box that provides electrical connection to a
plurality of electrical connectors, a plurality of fuses and a
plurality of relays. The electrical junction box includes
[0014] (i) a casing,
[0015] (ii) a connector circuit in the casing having at least one
connector circuit insulation substrate and plurality of first bus
bars fixed on the insulation substrate, the first bus bars being
arranged to provide electrical connection to electrical connectors
in use,
[0016] (iii) a fuse circuit in the casing having at least one fuse
circuit insulation substrate, which is discrete from the connector
circuit, and a plurality of second bus bars fixed on the fuse
circuit insulation substrate, the second bus bars being arranged to
provide electrical connection to fuses in use, and
[0017] (iv) a relay circuit in the casing having at least one relay
circuit insulation substrate which is discrete from the connector
circuit, and a plurality of third bus bars fixed on the relay
circuit insulation substrate, the third bus bars being arranged to
provide electrical connection to relays in use.
[0018] The first bus bars have respective welding portions standing
up from the connector circuit insulation substrate and arranged
alongside one another. The bus bars of one of the fuse and relay
circuits have respective welding portions standing up from the
respective insulation substrate and arranged alongside one another
opposed to the welding portions of said first bus bars. A plurality
of welded connections are formed by welding together of the opposed
welding portions.
[0019] At at least one adjacent pair of the welded connections, one
of the respective circuits provides an insulating partitioning
member which is interposed between said pair of welded connections
so as to prevent contact between the pair of adjacent welded
connections.
[0020] Preferably, the welded portions are formed by bending an end
of each of the bus bars perpendicularly to a surface of the
insulation plate, the portions being arranged in parallel or
coplanar.
[0021] According to the invention, there is also provided a method
of assembling the electrical junction box described above. The
method includes the steps of:
[0022] (i) arranging a first welding portions respectively to
opposite second welding portions in position to be welded thereto
at a plurality of welding locations, with at least one insulating
partitioning member provided by one of the respective circuits
interposed between an adjacent pair of the welding locations so as
to prevent contact during welding between the welding portions of a
first one of the pair of welding locations with the welding
portions of the other of the pair of welding locations, and
[0023] (ii) after step (i), welding together the first and second
welding portions at the respective welding locations.
[0024] The partitioning plate is erected on the insulation plate of
the connector module or the fuse module and/or the relay module in
such a way that the partitioning plate is inserted into a gap
between the aligned welding portions of the connector module or the
fuse module and/or the relay module.
[0025] The electrical junction box of the present invention has a
modular construction. As described above, in the junction box of
the present invention, the fuse circuit substrate and the relay
circuit substrate are separately provided from the connector
circuit substrate and are then joined by welding of the bus bars.
This is in contrast with the conventional method, in which
electrically conductive sheets are punched to form unitarily the
connector connection circuit, the fuse connection circuit, and the
relay connection circuit and form tabs to be connected to
connectors, tabs to be connected to fuses, and tabs to be connected
to relays and stacked in a single stack, the circuits thus being
handled and arranged in a complicated manner. Consequently, the
area of the bus bars increases and a large number of bus bars are
necessary.
[0026] On the other hand, in the present invention, because the
circuits are separately provided and welded, it is possible to
avoid the complication of tabs overlapping each other and avoid a
large number of bus bars. Thus, it is possible to form a thin or
compact junction box. Further, because the circuits of the bus bars
can be handled and arranged easily, the area of each bus bar can be
reduced. Consequently, even though the bus bars are separately
provided for the connector connections on the one hand and the fuse
connections and the relay connections on the other hand, it is
possible to reduce the total area of the bus bars and avoid
increase of the area of the junction box.
[0027] Preferably, the connector module having the connector
circuit, the fuse module having the fuse circuit, and the relay
module having the relay circuit are all separately provided i.e.
the respective insulation substrates are discrete from each other.
Thus, if any one of the specification of the connector circuit, the
fuse circuit, and the relay circuit is altered, the design of only
any one of the modules need be changed. That is, the construction
can cope with the alteration of the specification easily.
[0028] The first bus bars are provided separately from the second
or/and third bus bars but connected thereto by means of welding.
Thus this construction does not reduce reliability of the
electrical connections. The welding portions may be connected to
each other by ultrasonic welding, resistance welding, laser welding
or gas welding.
[0029] When welding the welding portions to each other, a
positioning portion of the partitioning plate is inserted into a
gap between the arranged welding portions of the connector module
or the fuse module and/or the relay module. Therefore, the welding
portions are not dislocated and can be aligned and welded to each
other, with the welding portions reliably held at a confronting
position. Further, the partitioning plate partitions the welding
portions from adjacent welding portions after they are welded to
each other. Thus, there is no possibility that flexure of the
welding portions causes adjacent welding portions to contact each
other.
[0030] Preferably, the partitioning plate has an engaging portion
which is positioned behind a rear surface of the welding portion of
the connector module or the fuse module and/or the relay module and
is capable of engaging the rear surface of the welding portion.
Thereby, when welding the mating welding portions to each other,
the engaging operation of the engaging portion prevents the mating
portions from moving apart from each other. Accordingly, it is
possible to maintain the position of the welding portions both
longitudinally and widthwise.
[0031] Preferably, a supporting strip is provided on the insulation
plate of the connector module or the fuse module and/or the relay
module in opposition to both peripheral edges of the rear surface
of the connector module or the fuse module and/or the relay module
and the engaging portion of the partitioning plate is capable of
engaging the rear surface of the welding portion of the connector
module or the fuse module and/or the relay module through the
supporting strip. This allows the superimposing position of the
welding portions to be highly accurate.
[0032] Although the fuse circuit and the relay circuit may be
separately formed, it is possible to integrate them with each other
to form a fuse/relay composite circuit which receives fuses and
relays on the same substrate which has bus bars for fuses and
relays on it. In this case, if it is necessary to connect the
circuit of any of the bus bars for fuses to any of the bus bars for
relays, the respective bus bars are welded to each other or the bus
bars may be integrally formed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Embodiments of the invention will now be described by way of
non-limitative example with reference to the accompanying drawings.
In the drawings:
[0034] FIG. 1 is a schematic exploded perspective view showing a
junction box of a first embodiment of the present invention;
[0035] FIG. 2 is a sectional view showing a state in which the
junction box of FIG. 1 has been assembled;
[0036] FIG. 3 is a sectional view showing the junction box of FIG.
2, taken along a line perpendicular to FIG. 2;
[0037] FIG. 4 is a schematic perspective view of a connector module
of the box of FIG. 1 viewed from the underside thereof;
[0038] FIG. 5 is a schematic view showing fuse connection bus
bars;
[0039] FIG. 6 is a schematic view showing a relay connection bus
bar;
[0040] FIG. 7A is a plan view showing a partitioning plate aligning
a connector module and a fuse module to be connected to each
other.
[0041] FIG. 7B is a sectional view of the construction shown in
FIG. 7A;
[0042] FIG. 8A is a plan view showing the superimposed welding
portions of a connector module and a fuse module.
[0043] FIGS. 8B and 8C are sectional views each showing stages in a
connection process;
[0044] FIG. 9 is a sectional view showing a state in which the
welding portions have been welded to each other;
[0045] FIG. 10A is a plan view of a modified embodiment in which a
connector module and a part module have been abutted to each
other;
[0046] FIGS. 10B and 10C are sectional side views each showing
stages in a connection process of the embodiment of FIG. 10A;
[0047] FIG. 11A is a plan view showing a junction box of another
embodiment of present invention;
[0048] FIG. 11B is a bottom view showing the junction box of
another embodiment of the present invention; and
[0049] FIG. 12 is an exploded perspective view showing a
conventional junction box.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0050] Exemplary embodiments of the present invention will be
described below with reference to the drawings.
[0051] FIG. 1 is a schematic exploded perspective view showing
component parts constituting a junction box 10 which, in use, is
mounted in a vehicle body and is connected to a wire harness of the
vehicle body. The box 10 has a casing formed of molded synthetic
resin including upper and lower casing parts herein called lower
case part 11 and upper case part 12. In the casing, there are a
connector module 13 constituting a connector circuit, a fuse module
14 constituting a fuse circuit and a relay module 15 constituting a
relay circuit. Although not shown in FIG. 1, the casing formed by
the lower case part 11 and the upper case part 12 accommodates an
electronic control unit 40, seen in FIGS. 2 and 3.
[0052] The lower case part 11 has a plurality of connector
receiving portions 11a in the form of sockets projecting outwardly
and a plurality of relay receiving portions 11b also in the form of
sockets arranged in a row along one longitudinal side. The upper
case part 12 has a fuse receiving portion 12a having sockets to
receive a plurality of fuses, formed at one widthwise side. The
remaining part of the upper case part 12 is formed as a closed
portion 12c which covers and contacts the upper surface of the
electronic control unit 40 housed within the case. The upper case
part 12 also has a connector receiving portion or socket 12e on the
periphery face of its other widthwise side. The lower case part 11
and the upper case part 12 are locked to each other by fitting
their peripheral walls on each other. Suitable conventional locking
fittings (not shown) may be provided. The upper case part 12 also
has fixing brackets 12d projecting from its opposite ends, for
fixing it to for example a vehicle body.
[0053] FIG. 4 is a schematic perspective view showing the bottom
side of the connector module 13 of FIG. 1. The connector module 13
has a plurality of layers of connector connection bus bars 16
laminated one upon another with interposed insulation plates in a
stack 17. In this embodiment, there are four layers of the
connector connection bus bars. In FIG. 1, the connector module 13
is schematically shown, with one insulation plate of the stack 17
as the uppermost layer. By molding in resin, it is possible to form
the insulation plate stack 17 and a multi-layer integral assembly
of the bus bars 16.
[0054] Each layer of the bus bars 16 of the connector module 13 has
circuit portions 16a having a required configuration obtained by
punching a conductive plate. At least one tab 16b stands
perpendicularly from each circuit portion 16a towards the lower
case part 11 to project through a terminal hole 11c of one of the
connector receiving portions 11a of the lower case part 11. A
connector (not shown) secured on one end of a wire harness is in
use fitted in the connector receiving portion 11a to connect a
terminal in the connector to the tab 16b.
[0055] As shown in FIG. 1, the connector connection bus bars 16
have welding tabs 16c and 16d, projecting from holes of the
insulation plate stack 17 at the upper side of the connector
circuit 13 and welding tabs 16e projecting from the periphery of
the insulation plate stack 17. The welding tabs 16c and 16e are
welded to fuse connection bus bars 20 formed on the fuse module 14.
The welding tabs 16d are welded to relay connection bus bars 30
formed on the relay module 15 which project upwardly through a slot
in the connector module 13. The welding tabs 16c and the welding
tabs 20a of the bus bars 20 are placed adjacent each other
vertically. Similarly the welding tabs 16d and the welding tabs 30a
of the bus bars 30 are placed adjacent each other extending
vertically. The welding tabs 16e are welded to welding tabs 20b of
the fuse connection bus bars 20 by laminating them on each other
vertically and horizontally. There are thus a plurality of sets of
each of the welding tabs 16c, 16d and 16e in each case parallel
with one another.
[0056] The fuse module 14, partly shown schematically in FIG. 5,
has the fuse connection bus bars 20 arranged between two
superimposed insulation plates 22A and 22B (see FIG. 1), formed by
molding resin. The fuse connection bus bars 20 in use connect to
terminals 25a or 25b of replaceable fuses 25. As shown in FIG. 5
(where the upper insulation plate is not shown), each fuse
connection bus bar 20 has horizontal portions 20e-1 and 20e-2 fixed
to the substrate 22B, terminal portions 20c-1 and 20c-2 formed by
bending the fuse connection bus bar 20 upward at one end of the
horizontal portion 20e-1 and 20e-2, and pressure connection grooves
20d-1 and 20d-2 formed at the upper end of the terminal portions
20c-1 and 20c-2 respectively to allow the terminals 25a and 25b of
the fuse 25 to be fitted in the grooves 20d-1 and 20d-2
respectively. The end of one bus bar 20 (e.g., the left one in FIG.
5) opposite to its end to be connected to the terminal 25a projects
to form the welding portion 20a. The end of the other bus bar 20
(e.g., the right one in FIG. 5) opposite to its end to be connected
to the terminal 25b projects laterally to form the welding portion
20b. The welding portion 20a is projected horizontally from one
edge of the substrate 21 in its longitudinal direction and bent
vertically upward so that in the assembled position the welding
portion 20a and the welding portion 16c of a connector bus bar 16
lie adjacent each other, as shown in FIG. 7. It is possible to fix
the bus bar 20 to the insulation plate 22B by, for example,
caulking. In this case, a caulking projection may be formed on the
insulation plate 22B and inserted through a hole formed on the bus
bar 20. Then, the caulking projection may be deformed to fix the
bus bar 20 at a predetermined position.
[0057] The relay module 15 has a construction similar to that of
the fuse module 14. More specifically, the relay module 15 has a
large number of relay connection bus bars 30 fixed between upper
and lower insulation plates 31A and 31B (see FIG. 1). The bus bars
30 are separated from each other and individually connected to
terminals of relays in use. As shown schematically in FIG. 6 (where
the insulation plate 31B is not shown), each bus bar 30 of the
relay module 15 has a horizontal portion 30b, a terminal portion
30c formed by bending the bus bar 30 upwards at one end of the
horizontal portion 30b, and a pressure connection groove 30d formed
at the outer end of the terminal portion 30c to allow a terminal
35a of a relay 35 to be fitted therein. The welding tab 30a is
formed by bending the other end of the horizontal portion 30b in
the shape of an "L" to permit the welding tab 30a and the welding
tab 16d of one of the connector bus bars 16 to be aligned adjacent
each other vertically in the assembled state.
[0058] FIGS. 7 to 9 show in detail the construction of the
connector module 13 and the fuse module 14 in the region where the
upstanding tabs or welding portions 20a of the fuse module 14 are
brought together with and joined to tabs 16c of the connector
module 13 by welding, with the fuse module 14 overlying the
connector module 13. The details shown in these figures are omitted
in FIGS. 1 to 6 for simplicity. On each module, the tabs 16c and
20a lie in a common vertical plane and are spaced laterally from
each other.
[0059] As shown in FIG. 7A, at the end of the fuse module 14 where
the welding portions 20a project, a plurality of partitioning
plates 50 are integral with the covering insulation plate 22A and
stand up on both sides of each of the welding portions 20a. Each
partitioning plate 50 is a little lower in height than the adjacent
welding portion or portions 20a. One end of each partitioning plate
50 extends behind a rear surface of each of the respective adjacent
welding portions 20a and forms a holding portion 50a for preventing
the welding portions 20a from deflecting backwards. The holding
portion 50a engages the rear surface of the welding portions 20a by
extending only minimally behind the surfaces so that the holding
portion 50a does not interfere with the contact zone of a welding
tool when the welding portion 20a is welded to the welding portion
16c.
[0060] Extending from the holding portion 50a of the partitioning
plate 50 is a positioning portion 50b which is inserted into a gap
between the respective pair of adjacent welding portions 16c on the
connector module 13. The positioning portion 50b aligns the mating
welding portions 16c and 20a confronting each other. The
partitioning plate 50 includes an engaging portion 50c formed at
the opposite end of the positioning portion 50b from the holding
portion 50a. When the mating welding portions 16c and 20a are
arranged adjacent each other, the engaging portion 50c extends
behind and supports the rear surface of the welding portion 16c.
The engaging portion 50c engages the rear surface of the welding
portion 16c by extending only minimally behind the surface so that
the engaging portion 50c does not interfere with the contact zone
of the welding tool used when the welding portions 16c and 20a are
welded to each other.
[0061] In the first embodiment, the partitioning plate 50 is
mounted on the fuse module 14 and the welding portion 16c of the
connector module 13 and the welding portion 20a of the fuse module
14 are welded to each other. The partitioning plate 50 may
alternatively be mounted on the connector module 13. Similar
partitioning plates 50 are provided on the relay module 15 where
the welding portions 16d of the connector module 13 and the welding
portions 30a of the relay module 15 are to be welded to each
other.
[0062] In assembling the junction box 10 from the above-described
component parts, initially, the fuse module 14 is disposed over one
portion of the connector module 13. In this case, as shown in FIGS.
8A and 8B, the positioning portions 50b of the partitioning plate
50 on the fuse module 14 are inserted from above into the
respective gaps between the adjacent welding portions 16c of the
connector module 13. At the same time, the fuse module 14 is
positioned (see FIG. 8C) in such a way that the engaging portions
50c engage an upper portion of the rear surface of each of the
adjacent welding portions 16c. Thus, the partitioning plates 50
prevent the welding portions 16c and 20a from moving sideways away
from each other. Further, owing to the engaging operation of the
engaging portion 50c, welding portions 16c and 20a are prevented
from moving apart backwards and separating from each other. That
is, the welding portions 16c and 20a can be reliably aligned and
maintained in position, in readiness for welding.
[0063] When the vertical welding portions 16c and 20a are aligned
next to each other, the projection P formed on the welding portion
16c maintains a required spacing between the mating surfaces of
welding portions 16c and 20a, in readiness for welding. When the
welding portions 16c and 20a are welded to each other by
compressing them with a resistance welding device (not shown), the
projection P serving as the welding point is crushed. Consequently,
as shown in FIG. 9, the welding portions 16c and 20a move to a
connection position at which the mating surfaces thereof contact
each other. In the welding operation, the partitioning plate 50
prevents the welding portions 16c and 20a from moving sideways
relative to each other. Thus, the welding portions 16c and 20a are
prevented from being dislocated.
[0064] The welding tabs are welded to each other by a suitable
welding method such as ultrasonic welding, resistance welding,
laser welding or gas welding. It is preferable to form a projection
P on one or both confronting surfaces of each of the welding
portions 16c, 20a, 16e, 20b, 30a, and 16d to increase the welding
effect at the projection P.
[0065] Further after the pair of welding portions 16c and 20a are
welded to each other, they are prevented from shifting and thus
prevented from contacting the adjacent pair of welding portions 16c
and 20a. In this manner, the connector module 13 and the fuse
module 14 are reliably connected to each other. Although detailed
description is omitted herein, the connection between the connector
module 13 and the relay module 15, when the relay module 15 is
superimposed on the lower surface of the connector module 13 to
connect the connector module 13 and the relay module 15 to each
other, can be formed in a similar manner.
[0066] As described above, the fuse module 14 is mounted over the
connector module 13 at one widthwise side thereof, and the relay
module 15 is disposed under the connector module 13 at one
longitudinal side thereof to integrate the three modules. Then,
this subassembly of the three modules 13, 14 and 15 is accommodated
in the lower case part 11. In this case, the terminal portions of
the connector module 13 are disposed in the connector receiving
sockets 11a, and the terminal portions 30c of the relay module 15
are disposed in the relay receiving sockets 11b.
[0067] Then, the electronic control unit 40 is mounted on the
connector module 13 at a portion thereof on which the fuse module
14 is not mounted (see FIGS. 2-3). The electronic control unit 40
has, at one side thereof, a connector portion 44 having bent and
projecting conductive pins 43 connected with electrical conductors
42 fixed to a substrate 41 thereof. The electrical conductors 42
are connected to tabs 16f projecting from the bus bars 16 of the
connector module 13. The conductors 42 are connected to a large
number of electronic component parts 45 mounted on the substrate
41. The electronic component parts 45 is fixed to the substrate 41,
with the electronic component parts 45 projecting downward. The
welding tabs of the bus bars 16, 20 and 30 are disposed in a dead
space below the electronic control unit 40.
[0068] After the electronic control unit 40 is mounted on the
connector module 13, the upper case part 12 is mounted on the lower
case part 11. At this time, the terminal portions 20c of the bus
bars 20 fixed to the fuse module 14 become located in the fuse
receiving portions 12a.
[0069] At this time, the connector portion 44 of the electronic
control unit 40 is fitted in a notch 12e of the upper case 12. The
assembling of the junction box 10 is completed by locking the upper
case 12 and the lower case 11 to each other.
[0070] As shown in FIGS. 5 and 6, when the fuses 25 and the relays
35 are inserted into the fuse accommodation portion 11a and the
relay accommodation portion 11b, respectively, they are fitted in
and connected to the pressure connection grooves 20d of the fuse
connection bus bars 20 and the pressure connection grooves 30d of
the relay connection bus bars 30, respectively.
[0071] FIGS. 10A and 10B show a second embodiment. The connector
module 113 is connected to a part module 114 such as the fuse
module or the relay module not by superimposing them on each other
but by butting them to each other at their edges as shown in FIG.
10C. Bus bars 116 and 120 are fixed to the surface of the
insulation plates 117 and 122 respectively. In correspondence to
the positions of holding portions 150a of partitioning plates 150,
notches 120g are formed on the base portions of the bus bars 120 of
the part module 114 to accommodate the holding portions 150a. Each
notch 120g extends rearwardly from the rear surface of the upright
welding portion 120a of the bus bar. Similar notches 116g are
formed on the base portions of the bus bars 116 of the connector
module 113 to accommodate the engaging portions 150c of the
partitioning plates 150. In the region of each notch 116g,
supporting strips 151 are formed integrally with the insulation
plate 117 and stand up adjacent to both peripheral edges of the
rear surface of the respective welding portion 116c. The supporting
strips 151 support both sides of the base portion of the bus bar
116 provided on the connector module 113, thus preventing the
welding portion 116c from moving sideways or backwards away from
the welding portion 120a. In the second embodiment, the engaging
portion 150c of the partitioning plate 150 supports the rear
surface of the welding portion 116c through the supporting strip
151.
[0072] The part module 114 is mounted on the connector module 113
by inserting partitioning plates 150 of the part module 114 between
the adjacent welding portions 116c of the connector module 113 from
above the welding portions 116c as shown in FIG. 10B. Then, the
mating welding portions 116c and 120a may be welded to each
other.
[0073] In the first and second embodiments, welding may be achieved
by ultrasonic welding, laser welding or gas welding, instead of
resistance welding.
[0074] In the embodiments described above, the fuse module and the
relay module are separate from each other. Instead, the fuse module
and the relay module may be integral with each other to form a
composite module. In this case, as shown in FIGS. 11A and 11B, a
fuse receiving portion 12a' and a relay receiving portion 12b', in
which terminal portions of bus bars of the composite module are
disposed, are formed in the upper case 12'. Formed in the lower
case 11' is a connector receiving portion 11a' in which terminal
portions of bus bars of the connector module are disposed. In the
second embodiment, the positioning plate is formed on the part
module 114. However, it could be formed on the connector module
113.
[0075] The junction box of the present invention is not limited to
the above-described embodiments. For example, each of the fuse
module and the relay module may be divided into two parts,
respectively. In this case, when the specification of any one of
the fuses or the relays is altered, it is possible to replace only
the module associated with the fuse or the relay which should be
altered. However, if the fuse module and the relay module are
divided into three or more parts, many assembling stages are
required. Thus, it is preferably to divide the fuse module and the
relay module into at most two parts, respectively, in the case of a
large junction box.
[0076] The connector connection bus bars of the connector module,
the fuse connection bus bars of the fuse module, and the relay
connection bus bars of the relay module may be welded to each other
in any of the following three patterns, selected according to the
circuit design:
[0077] (1) A connector connection bus bar and a fuse connection bus
bar are welded to each other.
[0078] (2) A connector connection bus bar and a relay connection
bus bar are welded to each other.
[0079] (3) A connector connection bus bar is welded to a fuse
connection bus bar and to a relay connection bus bar.
[0080] In case (3), the fuse connection bus bar may be welded to a
welding portion of the connector connection bus bar at one end
thereof; the relay connection bus bar may be welded to the welding
portion of the connector connection bus bar at the other end
thereof; and a tab provided at a third portion of the connector
connection bus bar may be connected to a connector.
[0081] In addition to the connector module, fuse module, relay
module and the electronic control unit, the lower and upper case
parts may accommodate a circuit consisting of electrical wires
connected to pressure contact terminals on the base circuit. The
wires may also connect to connectors which fit in the connector
receiving portion. It is also possible to add a circuit formed as
an electrically conductive portion of an FPC (flexible printed
circuit), a PCB (printed circuit board) or a highly electrically
conductive resin molded with insulating resin.
[0082] As is apparent from the foregoing description, in the
junction box of the present invention, the connector connection bus
bars are separately provided from the fuse connection bus bars and
the relay connection bus bars, using discrete substrates. Thus,
tabs for connecting the connector connection bus bars, the fuse
connection bus bars, and the relay connection bus bars to
connectors, fuses and relays, respectively are disposed at
different positions and do not overlap each other. Accordingly, it
is unnecessary to increase the number of layers of the bus bars to
provide them with tabs. Consequently, it is possible to form a thin
junction box or otherwise to achieve a compact and logical layout.
For example, in the case of the construction of the first
embodiment, the number of bus bars can be reduced from six layers
required in the conventional junction box to four layers. Thus, it
is possible to reduce the thickness of the junction box.
[0083] Further, the partitioning plate formed on one of the mating
modules partitions a plurality of the mating welding portions from
each other, thus preventing the welding portions from moving
sideways out of alignment. Thus, the welding portions can be
reliably aligned and maintained in position. Further, the engaging
portion formed on the partitioning plate is capable of engaging the
rear surface of the welding portion of the mating module, thus
preventing the welding portions from moving backwards apart from
each other. Accordingly, the welding portions can be reliably
prevented from being dislocated during welding.
[0084] Further, as described above, because the fuse connection
tabs and the relay connection tabs are separate from the bus bars
of the base circuit, it is easy to handle and arrange the bus bars
of the base circuit. Thus, it is possible to reduce the area of the
bus bars and hence the area of the junction box. Consequently, in
the case where the bus bars are divided and the ends of the bus
bars are welded to each other, the area of the entire bus bars is
not large and hence the area of the junction box is not
increased.
[0085] Further, if the specification of the fuses and the relays is
altered, the fuse module, the relay module or the composite module
of the fuse module and the relay module is replaced. Thus, it is
unnecessary to alter the entire upper and lower cases including the
base circuit. That is, the construction can permit the alteration
of the specification quickly and at low cost.
[0086] While the invention has been illustrated by the exemplary
embodiments described above, many equivalent modifications and
variations will be apparent to those skilled in the art when given
this disclosure. Accordingly, the exemplary embodiments of the
invention set forth above are considered to be illustrative and not
limiting. Various changes to the described embodiments may be made
without departing from the spirit and scope of the invention.
* * * * *