Electricity: conductors and insulators – Insulators – Through wall or plate
Reexamination Certificate
2002-06-10
2003-09-23
Reichard, Dean A. (Department: 2831)
Electricity: conductors and insulators
Insulators
Through wall or plate
C174S15300A, C029S760000, C029S748000
Reexamination Certificate
active
06624361
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a method of waterproofing a wire harness in which a grommet-passing portion of a wire bundle for passing through a grommet, adapted to be mounted in a through hole in a vehicle body panel of an automobile, is tied into a waterproof structure in which a gap between any two adjacent wires is closed by a water stop agent.
FIGS. 6A
,
6
B and
6
C show a related method of producing a waterproof wire harness.
The wire harness
1
is used in the electric wiring for an automobile, and when a group of wires are shaped into an arrangement form, corresponding to an arrangement form on the vehicle, a waterproofing is applied to those portions of the wires which are to be passed through a grommet
3
adapted to be mounted in a through hole formed in a vehicle body panel.
More specifically, first, the grommet
3
is mounted on a predetermined portion of the wire bundle
4
as shown in FIG.
6
A. Then a water stop agent in an unsolidified state is filled in a gap between an inner face of a harness-passing hole
3
a
in the grommet
3
and the wire bundle
4
as shown in
FIG. 6B
, and is allowed to stand for a predetermined period of time, so that the water stop agent is solidified, thereby providing a waterproof structure in which the gap between the wire bundle
4
and the grommet
3
is filled up by the solidified water stop agent
6
, as shown in FIG.
6
C.
In such a producing method, however, a very small gap remains between any two adjacent wires at the grommet-passing portion of the wire bundle
4
, and therefore there is a fear that external rain water intrudes into these gaps because of a capillary phenomenon, which has invited a problem that a sufficient waterproof effect can not be obtained.
Therefore, there has been proposed a producing method shown in
FIGS. 7
to
8
F.
The waterproof wire harness-producing method is disclosed in JP-A-10-135657. A waterproofing jig
13
is beforehand mounted on a predetermined portion of an arrangement plate
11
which is used for preforming or shaping a group of wires into an arrangement form corresponding to an arrangement form on a vehicle.
A plurality of wire group support jigs
15
a
,
15
b
,
15
c
,
15
d
,
15
e
, . . . for supporting the wire group in a branched pattern, corresponding to the predetermined arrangement form, are mounted on the arrangement plate
11
.
The waterproofing jig
13
has slits
13
c
for arranging the wires of the grommet-passing portion in a row, each of the slits being formed by a pair of opposed arms
13
a
and
13
b.
The width of the slit
13
c
is so determined as to arrange the wires of the grommet-passing portion vertically one upon another in one row.
The waterproof structure of the grommet-passing portion, utilizing the waterproofing jig
13
, is formed according to the procedure of
FIGS. 8A
to
8
F.
First, grommet-passing portions of the group of wires
16
are arranged vertically in a row in a plane by the pair of spaced-apart slits
13
, as shown in FIG.
8
A. Then, a water stop agent
19
in an unsolidified state is applied to one face of that portion of the arranged wire group
16
, disposed between the pair of slits
13
c
, by a water stop agent-coating nozzle
18
as shown in FIG.
8
B. Generally, moisture-curing silicone RTV is used as the water stop agent
19
. Then, a band of film
21
for uniting purposes is bonded to the one face of the wire group
16
, coated with the water stop agent
19
, thereby interconnecting the wires of the wire group
16
in such a manner that these wires are kept arranged in one row, and thereafter the waterproofing jig
13
is moved downward, thereby removing the wire group
16
from the waterproofing jig
13
, as shown in FIG.
8
C.
Then, the band of film
21
is wound on the wire group
16
to tie this wire group into a wire bundle of a round cross-section, as shown in FIG.
8
D. Further, a tape
23
is wound on that portion of the wire bundle, tied by the band of film
21
, thereby forming the wire bundle into such a circular cross-sectional shape that the wire bundle can be snugly fitted into a harness-passing hole in a grommet, as shown in
FIG. 8E
, and the water stop agent is solidified. Thereafter, the grommet
25
is mounted on that portion of the wire bundle having the tape
23
wound thereon, as shown in FIG.
8
F.
In the above waterproof wire harness-producing method, however, in the case where the wire group includes wires of different outer diameters, it is difficult to arrange the wires in one row, and besides it is difficult to coat the water stop agent.
When the arrangement of the wires and the coating of the water stop agent are effected satisfactorily, a gap between any two adjacent wires at the grommet-passing portion of the wire bundle can be filled up by the water stop agent. Even in such a case, however, when the group of wires
16
is tied into a bundle by the band of film
21
, the outer diameter of the resulting wire bundle is liable to vary, and in the next step of winding the tape
23
, the outer diameter of the wire bundle must be corrected into a size, corresponding to the diameter of the harness-passing hole in the grommet
25
, by adjusting the amount of winding of the tape
23
. Thus, the operation for adjusting the amount of winding of the tape
23
is required, and therefore there is problems that much time and labor are required for the operation, and that it is difficult to carry out the operation in an automated manner.
And besides, when the tape
23
is wound spirally, there is a fear that very small gaps are formed in step portions, formed by the overlapping portions of the wound tape
23
, thus lowering the waterproof performance.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a method of waterproofing a wire harness in which grommet-passing portions of a group of wires can be tied together into a waterproof structure in which interstices between the wires are filled by a water stop agent, and besides the bundle of tied wires can be highly precisely finished into a desired outer diameter without the need for a time-consuming tape-winding operation regardless of whether or not the wire bundle includes the wires of different outer diameters, and the improved productivity and the enhanced waterproof performance can be achieved.
In order to achieve the above object, according to the present invention, there is provided a method of waterproofing a plurality of wires which constitute a wire harness passed through a through hole formed in a grommet, comprising the steps of:
providing a lower mold having a first recessed portion, and a upper mold having a second recessed portion, the first recessed portion and the second recessed portion defining a cavity when the upper mold and the lower mold are integrated, such that a cross section of the cavity is substantially identical with a cross section of the through hole formed in the grommet;
placing the wires on the first recessed portion of the lower mold;
coating the wires with water stop agent;
applying vibration to the wires so as to permeate the water stop agent into a gap between the wires;
integrating the upper mold and the lower mold such that a cross section of the wire harness is matched with a cross section of the cavity; and
solidifying the water stop agent permeated into the wires.
Preferably, the cross section of the cavity is shaped into a circle. Preferably, a cross section of the first recessed portion of the lower mold is identical with a part of an inner peripheral face of the through hole formed in a grommet.
In the above construction, a grommet-passing portion of the wire harness permeated into a gap between the wires with the water stop agent, is pressed and formed into the cross sectional shape, corresponding to the cross sectional shape of the through hole of the grommet, so that the gaps between the wires are filled with the water stop agent. Further, by the press-shaping operation of integrating the upper mold and lower mold, the wire group is formed into the wire
Lee Jinhee
Reichard Dean A.
Sughrue & Mion, PLLC
Yazaki -Corporation
LandOfFree
Method of waterproofing wire harness does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of waterproofing wire harness, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of waterproofing wire harness will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3063359