U.S. patent application number 09/962215 was filed with the patent office on 2002-03-28 for electrical connection box for a vehicle.
This patent application is currently assigned to Sumitomo Wiring Systems, Ltd.. Invention is credited to Yuasa, Eriko.
Application Number | 20020037659 09/962215 |
Document ID | / |
Family ID | 18777150 |
Filed Date | 2002-03-28 |
United States Patent
Application |
20020037659 |
Kind Code |
A1 |
Yuasa, Eriko |
March 28, 2002 |
Electrical connection box for a vehicle
Abstract
An electrical connection box for a vehicle has a casing and at
least one bus bar within the casing to which in use a high nominal
maximum voltage of not less than about 14V and not more than about
200V is applied. On the upper wall of the casing, there is a relay
accommodation structure an upstanding walls defining first and
second recesses at which positive and negative terminals of the
relay are inserted in use. The recesses are partitioned from each
other by one upstanding wall which has an upper edge at which an
inclined groove is provided for carrying away water by gravity.
Thereby risk of leak currents is minimized.
Inventors: |
Yuasa, Eriko; (Yokkaichi,
JP) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 19928
ALEXANDRIA
VA
22320
US
|
Assignee: |
Sumitomo Wiring Systems,
Ltd.
Yokkaichi-city
JP
|
Family ID: |
18777150 |
Appl. No.: |
09/962215 |
Filed: |
September 26, 2001 |
Current U.S.
Class: |
439/206 |
Current CPC
Class: |
H05K 5/069 20130101;
H05K 7/026 20130101 |
Class at
Publication: |
439/206 |
International
Class: |
H01R 004/60 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 27, 2000 |
JP |
2000-294565 |
Claims
What is claimed is:
1. An electrical connection boxcomprising a casing having an upper
wall; at least one bus bar which is mounted within said casing and
to which in use a nominal maximum voltage of not less than about
14V and not more than about 200V is applied; and on said upper wall
of said casing, a relay accommodation structure adapted to receive
in use at least one electrical relay and comprising upstanding
walls defining at least a first recess at which a positive terminal
of the relay is to be inserted and a second recess at which a
negative terminal of the relay is to be inserted, said first and
second recesses being partitioned from each other by one of said
upstanding walls which has an upper edge at which an inclined
groove is provided for carrying away water by gravity.
2. An electrical connection box according to claim 1, wherein said
nominal maximum voltage is about 42V.
3. A vehicle comprising: an electrical power source providing a
nominal maximum voltage of not less than about 14V and not more
than about 200V; an electrical connection box comprising: a casing
having an upper wall; at least one bus bar which is mounted within
said casing and to which in use a nominal maximum voltage of not
less than about 14V and not more than about 200V is applied, said
electrical power source being electrically connected to said bus
bar; and on said upper wall of said casing, a relay accommodation
structure adapted to receive in use at least one electrical relay
and comprising upstanding walls defining at least a first recess at
which a positive terminal of the relay is to be inserted and a
second recess at which a negative terminal of the relay is to be
inserted, said first and second recesses being partitioned from
each other by one of said upstanding walls which has an upper edge
at which an inclined groove is provided for carrying away water by
gravity; and an electrical relay mounted at said relay
accommodation structure and comprising positive and negative
terminals respectively received in said first and second
recesses.
4. A vehicle according to claim 3, wherein said nominal maximum
voltage is about 42V.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates to an electrical connection
box which is suitable to be mounted on a vehicle, particularly an
electrical connection box to which a high voltage is to be applied,
and to a vehicle having such a box installed.
[0003] 2. Description of Related Art
[0004] Normally one secondary, i.e. rechargeable, battery having a
rated voltage of 12V and a maximum nominal voltage of 14V is
mounted on an automobile of the internal combustion engine type. A
voltage up to the maximum voltage of 14V is applied from the
battery to a circuit composed of bus bars and the like that are
accommodated in an electrical connection box. The power supply is
distributed by the internal circuit of the electrical connection
box. The operation of electric/electronic component parts mounted
on the vehicle is controlled through electric wires connected with
the internal circuit.
[0005] On a goods vehicle, such as a lorry or truck, a rated
voltage of 24V and a maximum voltage of 28V are applied to a
circuit by a battery structure.
[0006] In recent years, electric/electronic component parts have
been mounted in increasing numbers on a vehicle, and there is an
increase in the electric current which is applied to one
electric/electronic component part. For example, the electric power
required to drive a fan is conventionally 130 watts, but has become
260 watts in recent years. At the rated voltage of 12V of the
battery, it is impossible to operate suction and exhaust devices of
an engine, electromotive power steering, and the like devices,
requiring a high voltage such as 36V. Therefore, they are
mechanically operated by the driving force of the engine.
[0007] With the increase of the electric current applied to each
electric/electronic component part, the diameter of the electric
wires used has become larger. Further, with rapid increase of the
number of electric/electronic component parts, the number of
electric wires has increased recently, which has increased the
diameter of a wire harness having a bundle of electric wires.
Consequently, the weight of the electric wires to be wired on a
vehicle body has increased.
[0008] As described above, if the power supply from the battery is
incapable of operating the suction and exhaust devices of the
engine, they are mechanically operated. In this case, it is
impossible to accomplish fine control of the operation of the
suction and exhaust devices. Further, much fuel is consumed, which
pollutes the environment. Accordingly, it is preferable to operate
the suction and exhaust devices of the engine and the like not
mechanically but electrically by the power supply from the
battery.
[0009] In the case where the circuit is so constructed that a
voltage higher than 14V can be applied to the circuit of the
electrical connection box composed of bus bars and the like, it is
possible to reduce the required electric current and thus the
diameter of the electric wires and the size of a bundle of a
plurality of electric wires (wire harness). Therefore, it is
possible to reduce the weight of the electric wires.
[0010] Further, with the application of a high voltage to a circuit
composed of bus bars and the like, it is possible to control the
operation of the suction and exhaust devices, the power steering
motor, and the like not mechanically or hydraulically but
electrically. In this case, it is possible to accomplish fine
control of the operation of suction and exhaust devices and the
like. Further, fuel consumption can be reduced, which reduces
pollution.
[0011] It is preferable to apply a high voltage of about 42V to the
electromotive power steering motor, the suction and exhaust devices
of the engine, the fan, and other devices requiring a high voltage.
On the other hand, in an automobile, it is preferable to apply the
rated voltage of 12V (maximum voltage: 14V) to signal-generating
devices of the electric/electrical component parts and coils of
relays.
[0012] Water is liable to penetrate into terminal recesses of a
relay accommodation structure at the exterior of an electrical
connection box mounted in a vehicle from a wall partitioning the
recesses from each other. In the case where a circuit to which a
high voltage of for example about 42V is applied is connected to a
relay mounted in the relay accommodation structure, a leak current
is liable to be generated between terminals of the relay to which
the high voltage of, for example, about 42V is applied. This is
because water penetrates into a positive (+) terminal insertion
portion of the relay accommodation part and a negative (-) terminal
insertion portion thereof from a partitioning wall partitioning
them from each other. From there, water may also penetrate into the
box to cause leak currents between bus bars.
SUMMARY OF THE INVENTION
[0013] Therefore, it is an object of the present invention to
reduce or avoid the risk that water penetrates into the terminal
recesses or into a gap between high-voltage bus bars from a relay
accommodation part to thereby prevent a leak current from being
generated, particularly in the case where an electrical connection
box is provided with a circuit to which a high voltage is
applied.
[0014] According to the present invention, there is provided an
electrical connection box having a casing having an upper wall, at
least one bus bar which is mounted within the casing and to which
in use a nominal maximum voltage of not less than 14V and not more
than 200V is applied and, on the upper wall of the casing, a relay
accommodation structure adapted to receive in use at least one
electrical relay and comprising upstanding walls defining at least
a first recess at which a positive terminal of the relay is to be
inserted and a second recess at which a negative terminal of the
relay is to be received, the first and second recesses being
partitioned from each other by one of the upstanding walls which
has an upper edge at which an inclined groove is provided for
carrying away water by gravity.
[0015] With this construction, water which lodges on the upper edge
of the partition wall partitioning the respective terminal
insertion recesses of the relay accommodation structure flows into
the inclined groove and moves by gravity to the exterior of the
relay accommodation structure. Accordingly, it is possible to
reduce or prevent water from penetrating into the positive (+) or
negative (-) terminal insertion recesses. Consequently, it is
possible to prevent the water from penetrating into gaps between
the high-voltage bus bars.
[0016] The groove may be formed on the upper edge or end surface of
the partition wall so as to slope in one direction only along the
wall between the terminal insertion portions, or may have a higher
central portion and extend linearly downward in two directions to
the exterior of the relay accommodation part. That is, it is
preferable to configure the groove in such a way that water which
lodges on the partitioning wall flows linearly downward through the
groove to the exterior of the relay accommodation part.
[0017] It is preferable that the high voltage to be applied to the
high-voltage bus bar is at least about 28V, particularly about 42V.
In this case, it is easy to provide the voltage applied to the
high-voltage bus bar at 42V by connecting in series three batteries
each having a rated voltage of about 12V (nominal maximum voltage:
14V) generally used in automobiles. Needless to say, it is possible
to use a single battery having a maximum voltage of about 42V. The
reason why the high voltage to be applied to the high-voltage bus
bar is set to about 42V is partly because using a voltage close to
or above 50V for the high-voltage bus bar may be dangerous. The
present inventors have conducted salt water experiments in order to
ascertain the degree of risk when applying a voltage of 42V in an
electrical junction box suitable for use in an automobile engine
compartment. The experiments were done as follows:
[0018] 1 ml of salt water was injected into each terminal hole of
the casing of a junction box which had bus bars disposed inside.
Electrical components such as relay, fuse, connectors, etc. were
mounted on the casing. A voltage of 42V was applied to bus bars of
the junction box for 8 hours and then suspended for 16 hours. This
was repeated twice. There was initially no change to the bus bars
and electrical components. After the third repetition, it was found
that extra electric current passed between the bus bars generating
heat and a portion of bus bars was melted. The heat also melted
resin around bus bars such as an insulation plate, casing and resin
portion of electrical components adjacent the casing.
[0019] Accordingly, since damage did not occur until after the
third exposure to salt water, it was confirmed that in
consideration of conditions under normal use of an automobile, the
application of the electric power at 42V to the electric/electronic
component parts should not cause a problem.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Embodiments of the present invention will now be described
by way of example with reference to drawings, in which:
[0021] FIG. 1 is a diagram showing application of an embodiment of
the present invention;
[0022] FIG. 2 is a sectional view of an electrical connection box
to which the invention is applied;
[0023] FIG. 3 is an enlarged perspective view showing a relay
accommodation structure in an electrical connection box which is a
first embodiment of the present invention;
[0024] FIG. 4A is an enlarged partial sectional view on line A-A of
FIG. 3 and
[0025] FIG. 4B is a partial side view on the right-hand side of
FIG. 3;
[0026] FIGS. 5A and 5B are enlarged sectional views showing
alternative arrangements of the groove of the relay accommodation
structure; and
[0027] FIG. 6 shows a relay accommodation structure of a further
embodiment of the present invention,
[0028] FIG. 6A being a perspective view,
[0029] FIG. 6B a sectional view on line B-B of FIG. 6A, and
[0030] FIG. 6C a sectional view on line C-C of FIG. 6B.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0031] As schematically shown in FIG. 1, in an automobile to which
the present invention is applied, an engine E mounted in an engine
compartment X provides drive of the vehicle and generates
electrical power, e.g. through a conventional alternator (not
shown). A low-voltage battery structure 1 and a high-voltage
battery structure 2 are mounted in the engine compartment X, and
are charged by the alternator. The low-voltage battery structure 1
includes a conventional general-purpose rechargeable battery having
a rated voltage 12V and a nominal maximum voltage of 14V. The
high-voltage battery 2 includes three battery units 2a, 2b and 2c
connected in series to generate a nominal maximum voltage of about
42V. Each of the three battery units, 2a, 2b and 2c have a rated
voltage of about 12V (nominal maximum 14V). Such 12V rechargeable
(secondary) battery units are conventional. Needless to say, it is
possible to use a single battery having a maximum voltage of 42V.
The batteries 1 and 2 and their connections to the alternator are
conventional and need not be described in detail here.
[0032] The low-voltage battery structure 1 is connected to
low-voltage bus bars 10 accommodated in an electrical connection
box 3 in the form of a junction box mounted in the vehicle interior
Y (or, depending on the vehicle, in the enginecompartment) to apply
a low voltage (maximum voltage: about 14V) to the low-voltage bus
bars 10.
[0033] The high-voltage battery structure 2 is connected to
high-voltage bus bars 11 accommodated in the same electrical
connection box 3 to apply a high voltage (maximum voltage: about
42V) to the high-voltage bus bars 11.
[0034] The load side of the high-voltage bus bars 11 is connected
to electrical devices or actuators to operate them electromotively.
The actuators (not shown) include a power steering motor, suction
and exhaust devices of the engine, and like devices that consume
high power. The load side of the low-voltage bus bars 10 is
connected to appliances (not shown), such as sensors, lamps, and
like devices, consuming relatively low power, such as are typically
provided in an automobile.
[0035] As shown in FIG. 2, the electrical connection box 3 has a
casing providing two compartments 4a and 4b separated by a
partition wall 3b standing up from a bottom wall 3a. The
compartment 4a accommodates insulation plates 12 carrying the
low-voltage bus bars 10 one above another, while the compartment 4b
accommodates the insulation plates 13 carrying the high-voltage bus
bars 11 also one above another.
[0036] On the outer surface of an upper wall 3c of the casing of
the electrical connection box 3, there is provided a relay
accommodation structure 5 at which in use the low-voltage bus bars
10 and electrical relays are connected to each other, and a relay
accommodation structure 6 at which in use the high-voltage bus bars
11 and electrical relays are connected to each other. In the relay
accommodation structures 5 and 6, tabs formed by bending the bus
bars 10 and 11 are connected to terminals of the relays directly or
through relay terminals. The relays, which are not shown, are
typically of a conventional type and have terminals to be inserted
at the relay accommodation structures.
[0037] As shown in FIG. 3, the relay accommodation structure 6 for
the high-voltage bus bar 11 has upstanding walls, integral with the
casing wall 5a, defining a positive (+) terminal insertion recess
6a, a vacant terminal insertion recess 6b, and a negative (-)
terminal insertion recess 6c arranged in a row in parallel with one
another, with partition walls partitioning them from one another;
and a positive (+) terminal insertion recess 6d and a negative (-)
terminal insertion recess 6e arranged in a row in parallel with one
another, with a partition wall partitioning them from each other.
Thus the terminal insertion recesses 6a, 6b, 6c, 6d, 6e and are
arranged in the shape of a letter T. The positive (+) terminal
insertion recess 6d is adjacent to all of the positive (+) terminal
insertion recess 6a, the vacant terminal insertion recess 6b, and
the negative (-) terminal insertion recess 6c through a partition
wall 7. The upstanding walls defining the insertion portions are
formed unitarily with the upper walls 3c of the box, by plastics
moulding.
[0038] As shown in FIGS. 4A and 4B, an approximately semicircular
section groove 8 (also seen in FIG. 3) is formed on the upper end
surface of a positive/negative (+-) boundary portion 7a of the
partition wall 7 partitioning the positive (+) terminal insertion
recess 6d and the negative (-) terminal insertion recess 6c from
each other by forming the central portion of the positive/negative
(+-) boundary portion 7a lower than both edges over the whole
length of the boundary portion 7a. The groove 8 extends linearly
downward to an outer surface 6i of a side wall 6g of the negative
(-) terminal insertion recess 6c perpendicular to a side wall 6f
thereof through the upper end surface of the side wall 6f
continuous with the positive/negative (+-) boundary portion 7a. The
groove 8 penetrates through the upper end surface of the side wall
6g to the outer surface 6i to form an opening 8a.
[0039] As shown in FIGS. 5A and 5B, a groove 8' is also formed on
the partition wall 7 disposed between the positive (+) terminal
insertion recess 6d and the negative (-) terminal insertion recess
6e. Both ends of the groove 8' incline downward toward the outside.
The groove 8' may be so shaped that it inclines entirely from its
center as shown in FIG. 5A or it inclines at only both ends as
shown in Fig. 5B.
[0040] With this construction, water drops which collect on the
upper edge of the positive/negative (+-) boundary portion 7a
partitioning the positive (+) terminal insertion recess 6d and the
negative (-) terminal insertion recess 6c adjacent thereto from
each other, or water drops which collect on the upper edge of the
partitioning wall 7 disposed between the positive (+) terminal
insertion recess 6d and the negative (-) terminal insertion recess
6e, pass into the groove 8 (8') and flow along the groove thus
dropping by gravity from the opening 8a toward the outer surface 6i
of the side wall 6g or at the ends of the groove 8'. Accordingly,
it is possible to prevent water drops from dropping to the positive
(+) terminal insertion recess 6d disposed at one side of the
positive/negative (+-) boundary portion 7a, the negative (-)
terminal insertion recess 6c disposed at the other side of the
positive/negative (+-) boundary portion 7a, and the negative (-)
terminal insertion recess 6e. Consequently, it is possible to
prevent generation of a leak current because the water is prevented
from penetrating into the gap between the high-voltage bus bars 11.
It is also possible to prevent the leak current from being
generated between the terminals of the relays.
[0041] FIGS. 6A, 6B and 6C show a further embodiment, in which a
groove 8" V-shaped in section may be formed on the upper end
surface of a positive/negative (+-) boundary portion 7a' of a
partition wall 7' of a relay accommodation structure 6'. On the
upper end surface of a side wall 6f' the bottom surface of the
groove 8" may incline downward toward an outer surface 6h' of the
side wall 6f' to form an opening 8a" on the outer surface 6h'. The
groove 8" may incline downward toward the opening 8a" over its
whole length. In this construction, water which collects on the
positive/negative (+-) boundary portion 7a' drops to the inclined
groove 8" and flows through the groove 8" thus dropping from the
opening 6a' to the outer surface 6h' of the side wall 6f' by
gravity. Thus it is possible to reliably prevent water from
entering the positive (+) terminal insertion recess 6d' or the
negative (-) terminal insertion recess 6c'.
[0042] The circuits 5 of these embodiments are thus applied to an
automobile on which the battery of the rated voltage of about 12V
is mounted. However, in the case where a maximum voltage of about
28V is applied to a bus bar in the automobile or a larger vehicle
such as a truck, the bus bar to which the voltage of about 28V may
be applied is the low-voltage bus bar and the bus bar to which the
voltage of about 42V may be applied is the high-voltage bus bar.
The construction of the circuit 5 and connection box in this case
is the same as that of the embodiments.
[0043] In the embodiments, the maximum voltage of about 42V is
applied to the high-voltage bus bar 11. However, needless to say, a
high voltage of 42V - 200V can be applied to the high-voltage bus
bars 11, provided that safety is ensured.
[0044] In the embodiments, the sectional configuration of the drain
groove is semicircular or V-shaped, but may be rectangular, with
its bottom surface having a plane configuration.
[0045] As apparent from the foregoing description, by the present
invention, in the case where a high voltage is applied to the
circuit of the electrical connection box accommodating the
low-voltage bus bar and the high-voltage bus bar to reduce the
diameter of an electric wire and that of a wire harness by reducing
the amount of electric current, a groove is formed on the upper
edge of the partition wall partitioning the positive (+) terminal
insertion recess of the relay accommodation structure for
connecting the high-voltage bus bar and the relay to each other
from the negative (-) terminal insertion recess of the relay
accommodation structure. The groove is formed in such a way that
the groove inclines downward the outside of the relay accommodation
structure. Therefore, water collecting on the upper edge of the
partition wall can flow downward along the groove to the outside of
the relay accommodation structure. Accordingly, it is possible to
prevent water from penetrating into the positive (+) terminal
insertion recess or the negative (-) terminal insertion recess from
the gap therebetween. Consequently, it is possible to prevent water
from penetrating into gaps between the high-voltage bus bars and
hence prevent the generation of leak currents.
[0046] While the invention has been described in conjunction with
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.
* * * * *