JP2002134953A - Structure and method for connecting electronic unit to shield cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure superior shield performance by a simple configuration in the connection between a shield cable and an electronic unit. SOLUTION: A terminal fitting 16 is fixed to the terminal of a plurality of electric wires covered with a braid 10 for shielding, and a shield case 30 is connected to the braid 10 for shielding for fixing. Each electric wire terminal is inserted into a unit housing 40 of an electronic unit from the outside for connecting to a circuit inside the housing, and the shield case 30 is fixed onto the external surface of the unit housing 40, thus covering the connection between each electric wire 12 and the unit housing 40 from the outside, and at the same time grounding the shield case 30 and braid 10 for shielding through the unit housing 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure and a method for connecting a shielded cable, in which a plurality of electric wires are covered with a shielding braid, to an electronic unit mounted on a vehicle.

[0002]

2. Description of the Related Art When a cable is electrically connected to an electronic unit mounted on a vehicle (for example, a control box of an electric motor) and it is necessary to shield the electric wire from another circuit, A shielded cable is used as the cable. As this shielded cable,
What covered each electric wire with a flexible braid (for example, a copper braid) is often used. An example of a conventional method for connecting such a shielded cable to the electronic unit will be described below with reference to FIGS.

[0003] 1) As shown in FIG.
The terminal of each wire 12 is exposed by removing the terminal of 0 by the length L.

2) As shown in FIG. 10, the end of each electric wire 12 is peeled off to expose the inner conductor 13, and a cylindrical waterproof plug 14 made of rubber or the like is fitted from the outside immediately behind the inner conductor 13. I do. The waterproof plug 14 integrally has a small-diameter crimp portion 14a, a large-diameter main body portion 14b, and a larger-diameter flange portion 14c in this order from the distal end side.

[0005] 3) A terminal fitting 16 is fixed to the end of each electric wire 12. As shown in FIG. 10, the terminal fitting 16 includes a ring-shaped tip having a through hole 16a, a conductor barrel 16b formed behind the tip, and an insulation barrel 16c formed behind the conductor barrel 16b. The conductor barrel portion 16b is crimped around the inner conductor 13 and the insulation barrel portion 16c is crimped around the crimp portion 14a of the waterproof plug 14.
As shown in FIG. 9, a ring-shaped terminal fitting 1 is also provided at the end of the drain wire 15 connected to the shielding braid 10.
6 'is connected and fixed.

[0006] 4) As shown in FIG. 9, the terminal of each electric wire 12 (that is, the terminal fitting 16) is inserted into a cylindrical insertion portion 19 provided in a unit housing 18 of the electronic unit.
Further, the waterproof plugs 14 are press-fitted into the respective insertion portions 19 to form a waterproof structure.

5) The terminal fittings 16 of the electric wires 12 which have entered the unit housing 18 through the insertion portions 19 are
It is connected to an unillustrated electronic circuit housed in the unit housing 18.

6) A screw 22 is inserted through a terminal fitting 16 'fixed to the end of the drain wire 15 so that the unit housing 1
By screwing into the screw hole 20 provided on the outer surface of the unit 8, the terminal fitting 16 ′ is brought into contact with the outer surface of the unit housing 18 and is fixed. Thus, the shield braid 10 can be grounded through the drain wire 15, the terminal fitting 16 ′, and the outer surface of the unit housing 18.

[0009]

In the above structure and method, when fixing the terminal fitting 16 to the end of each electric wire 12, the end of the shielding braid 10 is removed by a length L to expose the electric wire end. There must be. Therefore, in the region of the length L, each electric wire 12 is exposed to the outside without being covered by the shielding braid 10, and the shielding performance is reduced by that much. In addition, braid for shielding 1
In order to ground 0, a terminal 16 for grounding is fixed to the end of the drain wire 15 separately from the terminal 16.
In addition, an operation for fixing the terminal fitting 16 'to the outer surface of the unit housing 18 is required, and this operation is troublesome, and the connection structure is complicated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a structure and a method capable of securing high shielding performance with a simple configuration at a connection portion between a shielded cable and an electronic unit.

[0011]

According to the present invention, there is provided a shielded cable in which a plurality of wires are covered with a shielding braid for connecting the wires to a circuit of an electronic unit. A terminal fitting fixed to a terminal of each of the electric wires, and connected to a circuit in the electronic unit, at least an outer surface of which is made of metal, accommodating a circuit of the electronic unit, and A unit housing having an insertion portion for inserting the terminal, and the unit housing fixed to an end of the shielding braid so as to be able to conduct with the braid, and covering each electric wire inserted into each of the insertion portions. A metal shield case fixed to the outer surface of the housing, and the shield case is fixed to the outer surface of the housing together with the outer surface of the housing. Rudokesu and shielding braid is one that is configured to allow the ground.

According to this configuration, since the connection portion between each electric wire and the unit housing is covered with the shield case, a series of shield structures from the braiding for the shield to the unit housing are continuously formed to achieve high shielding performance. Can be secured. Further, since the shield case can be grounded only by fixing the shield case to the outer surface of the unit housing, the operation is simple.

In this structure, there is provided an electric wire holder which is accommodated in the shield case and fixes a relative position between the electric wires in the shield case to a position corresponding to a relative position between the insertion portions in the unit housing. More preferred. By fixing the relative positions of the electric wires by the electric wire holder, the work of inserting each electric wire into each insertion portion of the unit housing becomes easier.

Further, in the structure in which a waterproof plug for preventing water from entering the electronic unit is interposed between the outer peripheral surface of the electric wire and the inner peripheral surface of the insertion portion, the waterproof plug being attached to each of the electric wires. The electric wire holder clamps these waterproof plugs from the outside in a lump and fixes each waterproof plug to each electric wire by this clamping, so that the waterproof plug can be fixed to the electric wire by a simple operation. Will be possible.

The present invention also relates to a method for connecting a wire of a shielded cable in which a plurality of wires are covered with a shielding braid to a circuit of an electronic unit, wherein a terminal of the shielding braid is connected to each of the wires. A step of fixing the terminal fitting to the end of each wire by retracting from the end of the electric wire, and a step of fixing a metal shield case to the end of the shielding braid, and at least the outer surface is made of metal, and A step of inserting a terminal of each electric wire into an insertion portion provided in a unit housing for housing a circuit; a step of connecting a terminal metal terminal of each electric wire inserted into the insertion portion to a circuit of the electronic unit; A shield case fixed to the terminal of the braid is fixed to the outer surface of the unit housing so that the shield case can be grounded together with the outer surface of the housing. It is intended to include and that step.

According to this method, the terminal fitting is fixed to the end of the electric wire in a state where the braided terminal is once retracted to expose each electric wire, and the shield case is fixed to the braided end by the shield case. Since the shield case is fixed to the outer surface of the unit housing so as to cover each of the electric wires, a connection structure having excellent shield performance can be constructed by a simple operation without removing the braid.

[0017]

FIG. 1 shows a first embodiment of the present invention.
A description will be given based on (a), (b), and (c). Elements that are the same as the elements shown in FIGS. 9 and 10 are given the same reference numerals, and descriptions thereof will be omitted.

The connection method between the shielded cable and the electronic unit according to this embodiment is as follows.

1) First, a shielded cable in which a sufficient gap is secured between the plurality of electric wires 12 and the shielding braid 10 covering them is manufactured. In order to manufacture such a loose shielded cable, for example, the plurality of electric wires 12
After the shielding braid 10 is formed around the wire group in which the dummy wire and the dummy wire are bundled together, the dummy wire may be pulled out. With this method, a gap can be formed inside the shielding braid 10 by the amount of the dummy wire. This gap is for facilitating the following step 2).

2) The terminal of each of the electric wires 12 is exposed by retracting the terminal of the shielding braid 10 to a position behind the terminal while leaving the electric wires 12. Then, the ends of the electric wires 12 are peeled off to expose the inner conductor 13 as shown in FIG. 10, and a cylindrical waterproof plug 14 made of rubber or the like shown in FIG. Fit from.

3) The terminal fitting 16 is fixed to the end of each electric wire 12. As shown in FIG. 10, the terminal fitting 16 also has a ring-shaped tip having a through hole 16a, a conductor barrel 16b formed behind the tip, and an insulation barrel 16c formed behind the conductor barrel 16b. The conductor barrel portion 16b is crimped around the inner conductor 13 and the insulation barrel portion 16c is crimped around the crimp portion 14a of the waterproof plug 14.

4) At the end of the shielding braid 10, FIG.
A metal shield case 30 as shown in FIG. The shield case 30 has a main body 31 having a shape that opens largely in one direction and covers the end of each electric wire 12,
On the opposite side of the opening, there is integrally formed a throttle portion 32 having an area smaller than that of the opening, and ear portions 33 projecting outward are formed on both left and right wings of the main body portion 31.
A screw insertion hole 34 is formed in the hole.

Each of the electric wires 12 is
Is inserted from the narrowed portion 32 side, and the end of the braid 10 is put on the outside of the narrowed portion 32 of the shield case 30. And
A crimping fitting 36 having a substantially C-shaped cross section (or a substantially O-shaped cross section) 36 is placed on the crimping member 36 and swaged to form the narrowed portion 3.
The braid 10 is fixed to 2 and both are made conductive (the state of FIG. 1 (c)). The shield case 30
Regardless of the specific means for fixing the braid 10, the welding or the like may be used as necessary.

5) As shown in FIG. 1 (b), a metal unit housing 40 for housing the circuit of the electronic unit
In addition, a cylindrical insertion portion 41 communicating the inside and the outside thereof is formed, and the terminal of each electric wire 12 (that is, the terminal fitting 16) is inserted into the insertion portion 41 from outside, and further, each waterproof plug 14 is inserted.
Are pressed into the respective insertion portions 41 to form a waterproof structure.

6) The terminal fitting 16 of each electric wire 12 that has entered the unit housing 40 through the insertion portion 41 is
It is connected to an electronic circuit housed in the unit housing 40.

7) Screw insertion hole 3 of each ear 33 in shield case 30 fixed to the end of shielding braid 10
4 is screwed into a screw hole 42 provided in the unit housing 40 by inserting a screw 38 from the outside,
The ear 33 is brought into contact with the outer surface of the unit housing 40 and is fixed thereto. Thereby, the connection part between each electric wire 12 and the unit housing 40 is covered from the outside by the shield case 30, and the shield case 30 and the shielding braid 10 are packaged together with the housing 40 by grounding the unit housing 40. To be ready for grounding. By this grounding, a series of shield structures from the braid for shielding 10 to the unit housing 40 via the shield case 30 can be formed, and high shielding performance can be secured at the connection portion.

FIGS. 2 to 6 show a second embodiment of the present invention.

In this embodiment, a cylindrical waterproof plug 14 is provided at a position slightly behind the end of each of the electric wires 12.
And the terminal fitting 16 is directly fixed to the end of each electric wire 12 at a position on the distal end side. At that time, the terminal fitting 16
The insulation barrel portion 16c may be pressure-bonded to the insulating coating portion of the electric wire 12 as shown. Also, a number of peripheral grooves are formed on the surface of each waterproof plug 14 to make it uneven, and a peripheral groove 14 d is formed at the rear end of the waterproof plug 14. Further, a ring-shaped waterproof plug fixing bracket 17 is disposed behind the waterproof plug 14 and fixed around the electric wire 12.

Next, each of the waterproof plugs 14 and the fixing fittings 1
7 is sandwiched from above and below, and is a half-shaped upper holder 50A.
And the lower holder 50B are combined to form a wire holder as a whole. As shown in FIG. 5, each holder 50A, 5A
0B, inwardly projecting ridges 52a and 52b fitted into the peripheral groove 14d of the waterproof plug 14 and the fixing fitting 1
Recessed grooves 54a and 54b into which 7 are fitted are formed respectively. In this state, each holder 50 is engaged.
By combining A and 50B, the relative position between the electric wires 12 can be fixed, and the relative position between the fixing bracket 17 fixed to the electric wire 12 and the waterproof plug 14 can also be fixed. That is, the upper and lower holders 50A, 50
B and the waterproof plug 14 with the fixing metal 17 as a medium
2 can be fixed.

It is preferable that each of the holders 50A and 50B is formed of an insulating material such as a synthetic resin. 6A, for example, as shown in FIG. 6A, one or a plurality of ears 17a from the ring-shaped main body.
Are projected outward, and a concave portion 56 that sandwiches the ear portion 17a is provided.
If a and 56b are formed on the upper and lower holders 50A and 50B, respectively, the rotation of the electric wire 12 can be restricted by sandwiching the recesses 56a and 56b.
The through holes 16a of the respective terminal fittings 16 fixed to the ends of the electric wires 12 can be always kept in an upward state, so that the connection work between the terminal fittings 16 and the circuit in the unit can be more easily performed. Can be easier. This effect is obtained not only by the ears 17a, but also by configuring the electric wire holders (upper and lower holders 50A and 50B in the illustrated example) so that the fixing bracket 17 is formed to have an irregular cross-sectional shape other than a circular shape and restrains the same. It is possible.

Instead of using such a fixing member 17, the waterproof plug 14 can be fixed to the electric wire 12 by directly holding the electric wire 12 between the holders 50A and 50B.

As described above, the wire holders are fitted into the main body 31 of the shield case 30 while holding the waterproof plugs 14 by the wire holders 50A and 50B. At this time,
For example, as shown in FIG. 5, the holders 50A and 50B are locked in the shield case 30 by engaging projections 51a and 51b formed on the surfaces of the holders 50A and 50B with holes provided on the shield case 30 side. It is more preferable to keep.

In this state, if the waterproof plugs 14 are pressed into the insertion holes 44 formed in the unit housing 40, the relative positional relationship of the waterproof plugs 14 is previously determined by the electric wire holder. The waterproof plug 1 is fixed to the position corresponding to the relative positional relationship.
The work of press-fitting the waterproof plug 4 becomes easier, and the work of fixing each waterproof plug 14 to each electric wire 12 also becomes very simple.

FIGS. 4 and 5 show an example of a connection structure in the unit housing 40. FIG. In the illustrated example, the unit housing 40 has a main body 45 that opens upward, and a lid 46 that opens and closes the opening. A circuit constituted by a bus bar substrate 48 is housed in the main body 45, and each terminal fitting 16 is screwed to an appropriate bus bar 48a by a screw 49.
Are joined and electrically connected.

This connection operation can be easily performed with the lid 46 opened. Thereafter, by closing the lid 46 and sealing the space between the lid 46 and the unit housing body 45 with a rubber sealing member 47 or the like, the bus bar circuit in the housing can be effectively protected from moisture outside the housing. .

Even when the holders 50A and 50B according to the second embodiment are omitted, for example, as shown in FIG.
The waterproof plug 14 having a flange 14c at its rear end is pushed into the cylindrical insertion portion 41, and the flange 14c of the waterproof plug 14 is By fixing the shield case 30 to the unit housing 40 so as to be pressed from behind by the retaining projections 31a, the waterproof plug 14 is
0 can be firmly mounted.

In addition, the present invention can take the following embodiments, for example.

(1) In the present invention, the specific shape of the shield case 30 is not particularly limited. For example, as shown in FIG. 8 as a fourth embodiment, the shield case 30 is formed in a simple cylindrical shape without the narrowed portion 32, and instead, the terminal 10a of the braid 10 is formed in a divergent shape. 30 as it is,
Alternatively, it may be fixed.

(2) The waterproof plug 14 can be omitted as appropriate according to the application. In the case of such omission, the electric wires 12 may be inserted through the insertion portion of the unit housing 40 as it is.

(3) The unit housing 40 does not necessarily have to be entirely formed of metal, but it is sufficient that at least its outer surface is formed of metal and has conductivity.

(4) In the present invention, the braid for shielding 1
The number and arrangement of the electric wires 12 covered by 0 are not particularly limited.
The shape of the shield case 30 may be appropriately set according to the arrangement of the electric wires 12.

(5) In the present invention, the shape of the terminal fitting 16 fixed to the end of each electric wire 12 does not matter. For example, a female terminal fitted to a tab terminal formed at an end of a bus bar in the electronic unit may be fixed to an end of the electric wire 12.

[0043]

As described above, according to the present invention, the shield case is connected and fixed to the terminal of the braid for shielding, and the shield case covers the connection portion between each electric wire and the unit housing while the shield case covers the connection portion. Is fixed to the unit housing, and the shield case and the braid for shielding can be collectively grounded together with the unit housing. Therefore, there is an effect that high shielding performance can be secured with a simple configuration.

[Brief description of the drawings]

FIG. 1A is a perspective view showing a state in which a terminal fitting is fixed to an end of each electric wire in the first embodiment of the present invention;
(B) is a perspective view showing a state in which a shield case is fixed to the end of the shielding braid covering the electric wire, and (c) is (b)
FIG. 4 is a sectional view taken along line AA of FIG.

FIG. 2 is a perspective view showing a state before attaching an electric wire holder to a waterproof plug of each electric wire in the second embodiment of the present invention.

FIG. 3 is a perspective view showing a state before each electric wire is inserted into an insertion hole of an electronic unit in the second embodiment of the present invention.

FIG. 4 is a sectional view showing an internal structure of the electronic unit shown in FIG.

FIG. 5 is a sectional view taken along line BB of FIG. 4;

FIG. 6A is a perspective view showing a preferred example of a fixing fitting used in the second embodiment, and FIG. 6B is a cross-sectional view showing a mounting state thereof.

FIG. 7 is a sectional view showing a third embodiment of the present invention.

FIG. 8 is a perspective view showing a fourth embodiment of the present invention.

FIG. 9 is a perspective view showing an example of a conventional connection structure between a shielded cable and an electronic unit.

FIG. 10 is a cross-sectional view showing an example of a structure in which a waterproof plug and a terminal fitting are fixed to an end of an electric wire in a shielded cable.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Braid for shielding 12 Electric wire 14 Waterproof plug 16 Terminal fitting 30 Shield case 36 Caulking fitting 40 Unit housing 41 Insertion part 42 Screw hole 44 Insertion hole (insertion part) 50A Upper holder (constituting electric wire holder) 50B Lower holder (electric wire holder) Is composed)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takashi Ota 1-7-10 Kikuzumi, Minami-ku, Nagoya City, Aichi Prefecture Inside Harness Research Institute, Inc. (72) Inventor Hiroki Hirai 1-Kikuzumi, Minami-ku, Nagoya City, Aichi Prefecture No. 7-10 F-term in Harness Research Institute, Inc. (reference) 4E352 AA06 AA18 BB02 BB15 CC02 CC12 CC22 CC34 CC56 DD01 DD11 DR02 DR14 DR40 EE10 FF04 GG04 GG17 5E321 AA01 AA14 AA24 BB41 CC21 GG05 GG09

Claims (4)

[Claims] 1. A structure for connecting a wire of a shielded cable in which a plurality of wires are covered with a shielding braid to a circuit of an electronic unit, wherein the wire is fixed to a terminal of each of the wires, and A terminal fitting connected to the circuit, a unit housing having at least an outer surface made of metal, accommodating a circuit of the electronic unit, and having an insertion portion for inserting a terminal of each electric wire; and A metal shield case fixed to an end of the braid so as to be able to conduct with the braid, and fixed to an outer surface of the unit housing while covering each electric wire inserted into each of the insertion portions; Is configured so that the shield case and the shielding braid can be grounded together with the housing outer surface in a state where the shield case and the shield braid are fixed to the housing outer surface. Connection structure between the electronic unit and a shielded cable. 2. The connection structure between an electronic unit and a shielded cable according to claim 1, wherein the relative position of the electric wires housed in the shield case and the relative positions of the electric wires in the shield case are relative positions of the insertion portions of the unit housing. A connection structure between an electronic unit and a shielded cable, comprising an electric wire holder fixed at a position corresponding to (1). 3. The connection structure between an electronic unit and a shielded cable according to claim 2, wherein each of said electric wires is interposed between an outer peripheral surface of said electric wire and an inner peripheral surface of said insertion portion and is inserted into said electronic unit. A waterproof plug for preventing intrusion of water is attached, and the waterproof plug is clamped collectively from the outside by the electric wire holder, and the waterproof plug is fixed to the electric wire side by this clamping. Connection structure between the electronic unit and a shielded cable. 4. A method for connecting an electric wire of a shielded cable in which a plurality of electric wires are covered with a shielding braid to a circuit of an electronic unit, wherein a terminal of the shielding braid is connected to a terminal of each of the electric wires. Fixing the terminal fitting to the end of each electric wire by retracting, and fixing the metal shield case to the end of the shielding braid; at least the outer surface is made of metal, and houses the circuit of the electronic unit. Inserting the terminals of the respective wires through the insertion portions provided in the unit housing, connecting the terminal fittings of the ends of the respective wires inserted into the insertion portions to the circuit of the electronic unit, and terminating the terminals of the shielding braid. Fixing the shield case fixed to the outer surface of the unit housing so that the shield case can be grounded together with the outer surface of the housing. A method for connecting an electronic unit and a shielded cable.