JP2011119038A - Water cut-off structure for electric wire, and forming method of water cut-off structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent water having infiltrated an inside of an electric wire wired in a vehicle such as a two-wheeled vehicle or a wagon, from infiltrating an inside of an electronic control unit etc. via a connecting portion of an end of the electric wire. <P>SOLUTION: A water cut-off structure for a wire wired in a vehicle includes: an intermediate exposed part 15 located near the terminal connecting portion of the end of the electric wire, with an insulating coating layer removed and core wires exposed, wherein the intermediate exposed part is covered with a heat-shrinkable tube 21; and a water cut-off part 8 formed by, with solder 20, fixing the plurality of core wires of the intermediate exposed part 15 covered with the heat-shrinkable tube 21. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a water stop structure for an electric wire to be wired to a vehicle such as a two-wheeled vehicle or a four-wheeled vehicle, and a method for forming the water stop structure, and in particular, in an electric wire to be connected to a connector of an electronic control unit, Through this, the occurrence of water intrusion into the electronic control unit is prevented.

  When a wire harness to be routed on a vehicle such as a motorcycle or an automobile is routed along a flooded area, the wire harness is connected from the electric wire side of the wire harness through the connector connection between the electronic control unit and the wire harness. It is necessary to prevent water from entering the electronic control unit.

For this reason, conventionally, the connector connection between the electronic control unit and the wire harness uses a waterproof connector with a waterproof rubber ring attached to each wire of the wire harness. In many cases, flooding to the unit is prevented.
However, when the insulating coating layer surrounding the core wire of the electric wire is damaged, the insulating coating layer is cracked, or a part of the insulating coating layer is peeled off, and this damaged portion is located in the wet area, There is a possibility that water may enter the core wire from the damaged portion, and water may enter into the gaps between a large number of strands constituting the core wire. Water that has entered the core wire may pass through the strands due to capillary action, and may enter the electronic control unit via the terminal crimping portion of the wire terminal.

Furthermore, even if the connector connected to the electronic control unit is a waterproof connector, the wire of the wire harness connected to the waterproof connector may be connected to another wire on the other end side via a non-waterproof connector. In this case, when the connection with the non-waterproof connector is covered with water, water is immersed in the core wire of the electric wire exposed by the non-waterproof connector, and similarly to the above, water is transmitted through capillarity through the gap between the core wires, There is a possibility to reach the connection with the electronic control unit. Therefore, the electric wire connected to the electronic control unit needs to be connected to another electric wire using a waterproof connector up to the other end side.
However, since the waterproof connector is larger than the non-waterproof connector, an installation space must be ensured, and it is often difficult to secure the route of the wire harness. In addition, the cost of the waterproof connector is higher than that of the non-waterproof connector.

As a connector for waterproofing without using the waterproof rubber ring, the present applicant has provided a waterproof material 100 formed mainly of silicone gel as shown in FIG. 8 in Japanese Patent Laid-Open No. 2000-144099, A waterproof connector is provided in which a waterproof material 100 is attached to a terminal insertion side surface of a connector 101, a spacer 102 is disposed on the outer surface of the waterproof material 100, and a holder 103 is engaged with the connector 101.
In this waterproof connector, the waterproof material 100 is provided with a terminal hole that penetrates the terminal 104 that is crimped to the wire terminal.

  The waterproof connector also requires a waterproof material, a spacer, and a holder, increasing the number of parts, increasing the size of the connector, and increasing the cost. In addition, if water has reached the terminal penetrating the terminal hole of the waterproof material through the conductor of the electric wire as described above by capillarity, it may not be possible to reliably prevent water from entering the electronic control unit. There is room for improvement in these respects.

JP 2000-144099 A

  The present invention has been made in view of the above problems, and it is an object of the present invention to provide a water stop structure for an electric wire that can reliably prevent water from being generated from the electric wire constituting the wire harness to the device connected to the wire harness and the connector. It is said.

In order to solve the above problems, the present invention is a water stop structure for an electric wire wired to a vehicle,
In the position close to the terminal connection portion of the terminal of the electric wire, the insulating coating layer is removed and an intermediate exposed portion where the core wire is exposed is provided.
A heat-shrinkable tube is covered on the intermediate exposed portion, and a water stop portion is provided to which a plurality of strands constituting the core wire of the intermediate exposed portion covered with the heat-shrinkable tube are fixed with solder. The water stop structure of the electric wire characterized by this is provided.

As a method for forming the water stop structure of the electric wire,
In the position close to the terminal connected to the terminal of the electric wire, the insulating coating layer is peeled off intermediately to expose the core wire,
It has a length applied to the intermediate exposed portion of the core wire and the insulating coating layers on both sides sandwiching the intermediate exposed portion, and solder is fixed to the intermediate portion of the inner peripheral surface and adhesive is applied to both side portions. The heat-shrinkable tube, the solder-fixed portion of the heat-shrinkable tube is positioned on the outer periphery of the intermediate exposed portion of the core wire, and the adhesive application portions on both sides are positioned on the outer periphery of the insulating coating layers on both sides,
Heating and shrinking the heat-shrinkable tube, melting the solder and adhesive, and infiltrating the solder between the strands of the intermediate exposed portion of the core wire to provide a water stop portion comprising a solder integral portion; and A method for forming a water-stop structure for an electric wire that blocks a gap between both end edges of the heat-shrinkable tube and the outer peripheral surface of the insulating coating layer with the adhesive is provided.

  As described above, in the present invention, instead of using conventionally used silicone or hot melt, water is used for water stoppage in the electric wires wired to a vehicle such as a two-wheeled vehicle or a four-wheeled vehicle. Adhere to the inner surface of the heat-shrinkable tube, put the heat-shrinkable tube over the intermediate exposed part of the wire, and simultaneously heat and shrink the solder to melt and expose it to the gap between the exposed core wires. It is characterized by being used as a water-stop agent.

Ring-shaped solidified solder is fixed in advance in the axial direction on the inner peripheral surface of the heat-shrinkable tube, and an adhesive is applied to the inner peripheral surface to which the solder is not fixed. ing. Therefore, cover the heat-shrinkable tube over the intermediate exposed portion, and attach both ends of the heat-shrinkable tube in the length direction by adhering to the outer peripheral surfaces of the insulating coating layers on both sides sandwiching the intermediate exposed portion with an adhesive. Can do.
Moreover, the solder melted by heating is applied to the entire outer surface of the strands constituting the core wire, and since the solder is in a ring shape, it is reliably applied to the entire outer peripheral surface. Furthermore, it penetrates into the gaps between the wires from the entire outer periphery. Thus, while the outer periphery of a core wire will be in the state sealed with solder, it permeate | transmits also into the clearance gap between strands, the path | route of the water which penetrate | invaded is interrupted | blocked reliably, and water stops.
In addition, since the molten solder has low fluidity compared to a molten water-stopping agent such as hot melt or silicone, it does not flow excessively and can be prevented from flowing out from the intermediate exposed part of the core wire to both sides. Has the advantage of being easy to handle.

In the water stop structure of the electric wire according to the present invention, since the core wire is integrally fixed by solder to form the water stop portion, the water stop portion is relatively hard. Therefore, the vibration absorption with respect to the vibration generated when the vehicle is traveling is low, and resonance tends to occur.
Therefore, it is preferable to wrap an elastic sheet having a vibration absorbing property made of a foam sheet, a rubber sheet, or a urethane sheet around the outer peripheral surface of the heat shrinkable tube that is in close contact with the outer peripheral surface of the intermediate exposed portion of the core wire.
By winding the elastic sheet described above, vibration is absorbed by the elastic sheet, the vibration of the water stop part integrated with the solder is alleviated, and water stop reliability is prevented by preventing cracks from entering the water stop part. It is preferable to increase.

  Furthermore, vibration absorbing fins may be provided on the outer peripheral surface of the elastic sheet to further enhance vibration absorption. When the vibration absorbing fin is provided, a portion where the solder and the core wire are integrally fixed is relatively hard. Therefore, it is preferable to increase the fin to enhance the vibration absorbing effect.

Moreover, it is preferable that especially the electric wire which has the water stop structure of this invention has the said water stop part in the terminal side connected to an electronic control unit.
In particular, on the side of the electric wire connected to the connector of the electronic control unit, it is preferable to provide a water stop portion that stops the core wire of the electric wire at a position closest to the connector as much as possible. The water-stopping portion eliminates the gap where the solder is attached to the strands of the intermediate exposed portion of the core wire to generate water so that even if water penetrates to the core wire position due to damage to the insulation coating layer, Can block the water. Therefore, even if the connector connected to the electronic control unit is a non-waterproof connector, it is possible to prevent water from entering the electronic control unit from the electric wire side.

The wire harness in which a plurality of electric wires connected to the connector are converged needs to be dispersed in order to insert and lock the terminals of the electric wire terminals into the respective terminal accommodating chambers of the connector on the connector connection side. If the water stop portion is provided at the position where the electric wires are dispersed, the electric wire diameter becomes large, the distance between the electric wires becomes larger than the distance between the terminal accommodating chambers of the connector, and it becomes difficult to insert the terminals into the terminal accommodating chamber.
Therefore, it is optimal to provide the water stop portion of each electric wire at the position where the electric wire group is converged from the dispersed position, that is, at the distal end side of the converging portion.

The optimum position of the water stop portion is in a range of 10 to 100 mm from the terminal insertion surface of the connector.
For example, in the case of two wires, the wire converging position from the terminal insertion surface is about 10 mm, and in the case of a multipolar connector having 30 or more poles, the wire converging position is about 100 mm.

  As described above, when the water stop portion is provided on the distal end side of the converging position of the electric wires, the terminals of the electric wire terminals can be inserted and locked smoothly without difficulty in the terminal accommodating chamber of the connector. In addition, since there is no external interference material in the range of 10mm to 100mm in the immediate vicinity of the connector, the insulation coating of the electric wire will not be damaged, and water entering the core wire can be surely ensured by performing a water stop treatment at that position. It is possible to prevent water from entering the electronic control unit.

An electronic control unit connected to a wire harness composed of a converging body of electric wires provided with the water stop portion is connected to, for example, an engine control unit, an engine fuel control unit, an ABS control unit, an air bag control unit, a travel safety control unit, It consists of a vehicle radar control unit, a night vision camera control unit, and the like.
In addition, the device connected to the electronic control unit via the wire harness is
One or more controlled devices selected from light, washers, door locks, anti-theft horns and starters controlled by an electronic control unit,
An information transmission device comprising an O ₂ sensor, a speed sensor, a knock sensor, a collision sensor, etc. and / or another electronic control unit for transmitting information to the electronic control unit;
Furthermore, it is one or more types of electrical components selected from fuses, relays, connectors, and ground members of the electrical junction box.

  Since the electric control unit described above is related to the driving safety system of the automobile, it is necessary to prevent the occurrence of water leakage from the connector connection portion with the wire harness and the malfunction of the control of the electronic control unit. . Therefore, by providing a water stop portion on the electric wire side immediately before the connector connection portion and reliably preventing the occurrence of water intrusion into the electronic control unit, it is possible to improve the reliability of traveling safety.

  As described above, in the water stop structure of the electric wire according to the present invention, since the water stop portion in which the solder is attached to the core wire of the electric wire is provided at a position close to the end of the electric wire connected to the connector, When water is penetrating between the strands at a distant position due to damage to the insulation coating of the electric wire, the water can be shut off immediately before the connector connecting portion. Therefore, when connecting with an electronic control unit etc. via a connector, even if a connector is used as a non-waterproof connector, generation | occurrence | production of the water from the electric wire side to an electronic control unit can be prevented.

1 is an overall configuration diagram showing a first embodiment of the present invention. It is a partial cross section enlarged plan view of the connector connection side of the wire harness. It is drawing which shows the water stop part of the electric wire which comprises a wire harness. (A) is the sectional view on the AA line of FIG. 3, (B) is the sectional view on the BB line of FIG. 3, (C) is sectional drawing of an axial direction. It is drawing for demonstrating the formation method of a water stop part. It is drawing which shows 2nd Embodiment. (A) (B) is drawing which shows the modification of 2nd Embodiment. It is drawing which shows a prior art example.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 to 5 show a first embodiment.
As shown in FIG. 1, the connector 3 is connected to the tip of the wire harness W / H of the embodiment. The connector 3 is for male-female connection with a connector 2 mounted on a board of an electronic control unit 1 (hereinafter referred to as ECU) mounted in an engine room of an automobile. The connector 3 is a unit coupling connector.

The electronic control unit 1 is mounted in a non-waterproof area where water is not applied, and therefore, the connection portion between the connector 2 of the electronic control unit 1 and the connector 3 of the wire harness terminal is not exposed to water. .
The ECU 1 according to this embodiment includes an engine fuel control unit. Further, the wire of the wire harness W / H connected to the ECU 1 by a connector includes an O ₂ sensor, a speed sensor, a knock sensor, a sensor S including a collision sensor, another electronic control unit E, a fuse, a relay of an electric connection box B, Connected to the connector.

The wire harness W / H winds and binds a tape T around a plurality of electric wires W, and the female terminals 5 connected to the terminals of the electric wires W are connected to the terminal accommodating chambers of the connectors 3 at the connection portion with the connector 3 at the tip. In order to insert and lock to 3a, the electric wire group is spread and dispersed in a fan shape without tape winding.
As shown in FIGS. 3 and 4, the electric wire W is composed of a round electric wire in which a core wire 11 in which a large number of strands 10 are twisted is covered with an insulating coating 12.

The terminal of each electric wire W constituting the wire harness W / H is connected to a female terminal 5 to be inserted and locked into the connector 3 by crimping, and the position (terminal) where the dimension L is 10 to 100 mm away from the insertion side end face of the connector 3. The water stop 8 is provided at a position 20 to 100 mm away from the crimping position. In this embodiment, it is 50 mm.
The position of the water stop portion 8 is at a position covered by the tip end side of the tape T wound around the electric wire group, in other words, at the connector base position of the electric wire W drawn out from the winding tip end of the tape T and spreading in a fan shape. .

The water stop portion 8 of each electric wire W has slits along the entire circumference of the insulation coating 12, and moves by pulling one insulation coating sandwiching the slit to one side (so-called skin contact), and the core wire 11 The intermediate exposed portion 15 is provided.
The intermediate exposed portion 15 is filled with solder 20 so that the solder 20 adheres to the outer peripheral surface of the core wire 11 formed by the plurality of strands 10, and the solder is infiltrated into the gaps between the strands 10. There are no gaps.

  The outer periphery of the intermediate exposed portion 15 filled with the solder 20 is covered with a heat shrinkable tube 21 from the outer periphery of the insulating coating 12 on both sides of the intermediate exposed portion 15.

The connector 3 connected to the tip of the wire harness W / H and the connector 2 of the ECU 1 which is connected to the male and female of the connector 3 are non-waterproof connectors that are not waterproof.
The connector 3 is provided with a partition wall 3c in a connector housing 3b and is partitioned to provide a terminal accommodating chamber 3a. The female terminal 5 connected to the terminal of each electric wire W of the wire harness W / H is inserted and locked in these terminal accommodating chambers 3a. A terminal locking lance (not shown) is provided on the bottom wall surrounding each terminal accommodating chamber 3 a, and the lance is locked in the locking groove of the female terminal 5.

  The connector 2 of the ECU 1 faces the connector insertion opening 1b provided in the ECU housing 1a and is located in the housing 1a. The connector 3 of the wire harness W / H is inserted into the ECU 1 from the connector insertion opening 1b, and the connector 3 is fitted and connected to the connector 2.

Next, the formation method of the water stop part 8 of the said electric wire W is demonstrated based on FIG.
First, a soldered heat shrinkable tube 30 is prepared. The soldered heat-shrinkable tube 30 has a ring-shaped hardened solder 20 fixed to an inner peripheral surface of a substantially central portion in the length direction of the heat-shrinkable tube 21 and is ring-shaped with a gap between both sides thereof. The cured adhesive 25 is fixed. The heat-shrinkable tube 30 with solder is cut in advance to a length obtained by adding the length of the intermediate exposed portion 15 of the core wire to the length of the insulation coating 12 on both sides, and the ring-shaped solder is formed at the intermediate portion in the length direction. 20 is located.
Note that the heat-shrinkable tube with solder may be configured such that instead of the ring-shaped adhesive on both sides, a ring-shaped solder similar to the center is provided and the adhesive is applied to the entire inner peripheral surface of the heat-shrinkable tube 21.

As described above, at the position close to the end of the electric wire W, a slit is made in the insulating coating 12 of the electric wire W, and one insulating coating sandwiching the slit is pulled and moved to one side, and the core wire 11 is moved. Intermediate exposed portion 15 is formed.
Next, the soldered heat-shrinkable tube 30 is covered from the terminal side of the electric wire W, and is put on the outer periphery of the intermediate exposed portion 15 and the insulating coating 12 on both sides of the intermediate exposed portion 15.
At that time, the ring-shaped solder 20 is positioned on the outer periphery of the intermediate exposed portion 15 of the core wire, the ring-shaped adhesives 25 on both sides are positioned on the outer peripheral surface of the insulating coating 12, and both sides of the heat shrinkable tube 21 are intermediately exposed. The insulating coating 12 on both sides sandwiching the portion 15 is placed over the outer peripheral surface.

Next, heating is performed at the shrinkage temperature of the heat shrinkable tube 21. By this heating, the solder 20 cured in a ring shape is melted, penetrates into the outer peripheral surface of the intermediate exposed portion 15 of the core wire and the internal gap, and is filled without a gap. In addition, the ring-shaped adhesives 25 on both sides are softened and melted to firmly fix the heat shrinkable tube 21 and the insulating coating 12.
After that, when the required time elapses, the molten solder 20 is cured, and the intermediate exposed portion 15 of the core wire becomes the water stop portion 8 in which the plurality of strands 10 are integrated with the solder 20.
The water stop portion 8 is covered with the heat shrinkable tube 21 to be insulated and waterproofed.

  As described above, in the present invention, the wire harness W / H connected to the ECU 1 is provided with the water stop portion 8 on the electric wire W at a position closest to the unit connection connector 3 connected to the ECU 1. Therefore, the insulation coating 12 of the electric wire W is damaged at a position away from the water stop portion 8, or water is generated on the connector side of the other end of the electric wire W, and the core wire 11 in the insulation coating 12 Even if water is transmitted to the connection side with the connector 3 by capillarity in the gap 10, the water stop 8 is filled with solder 20 in the gap between the strands 10. It can be reliably shut off. Therefore, it is possible to prevent water from entering the ECU 1 from the electric wire W side through the connection portion between the connector 3 and the connector 2 of the ECU 1.

FIG. 6 shows a second embodiment.
In the second embodiment, the foamed sheet 24 made of an elastic sheet having vibration absorption is wound around the outer peripheral surface of the heat-shrinkable tube 21 in close contact with the outer peripheral surface of the intermediate exposed portion 15 of the core wire. Instead of the foam sheet, a rubber sheet or a urethane sheet may be used as long as it is an elastic sheet having vibration absorption.

  The intermediate exposed portion 15 of the core wire 11 is relatively hard because the wire 10 is fixed by the solder 20. Therefore, when the foam sheet 24 made of an elastic sheet is wound around the outer peripheral surface of the heat shrinkable tube 21, the vehicle vibration can be absorbed by the foam sheet 24, and the resonance of the water stop portion 8 fixed by the solder 20 can be suppressed. As a result, it is possible to prevent cracks from occurring in the solder 20 due to vibration and a decrease in water stoppage.

  In place of the method of winding the elastic sheet having vibration absorption, as shown in FIG. 7A, an elastic covering material 26 made of a slitted tube is provided, and the elastic covering material 26 is perpendicular to the water stop portion 8. You may cover from the direction.

  Furthermore, as shown in FIG. 7B, vibration absorbing fins 27a may be provided on the outer peripheral surface of the elastic covering material 27 made of a slit tube at intervals in the circumferential direction. The vibration absorbing fins 27a gradually increase the length of the fins toward the central portion in the length direction, and the fins are made the longest at the position where they contact the outer peripheral side of the solder 20 at the center in the length direction. When the vibration absorbing fins 27a are provided in this way, the vibration absorbing fins 27a vibrate when vehicle vibration occurs, and vibrations transmitted to the water stop portion can be almost absorbed. In particular, since the vibration absorbing fins 27a are enlarged on the outer periphery of the intermediate exposed portion of the core wire that is hardened by the solder 20, the vibration damping effect can be enhanced.

In the first embodiment, the ECU 1 is an engine fuel control unit. However, a wire harness is connected to the engine control unit, ABS control unit, airbag control unit, travel safety control unit, vehicle radar control unit, and night-vision camera control unit. It is also preferably used when connecting.
The ECU is also suitably used for controlling devices for safe driving such as lights, washers, door locks, anti-theft horns, starters and the like.
Furthermore, the wire harness which concentrated the electric wire which has the water stop part formed by the water stop method of this invention is applicable not only to a motor vehicle but when connecting with a connector in the to-be-watered area | region of a motorcycle.

1 ECU (electronic control unit)
2 ECU side connector 3 Wire harness side connector 5 Female terminal 8 Water stop portion 10 Wire 11 Core wire 12 Insulation coating 20 Solder 21 Heat shrinkable tube 30 Heat shrinkable tube with solder 24 Foam sheet 27a Vibration absorbing fin W Electric wire W / H Wire harness

Claims (5)

A water stop structure for electric wires wired to a vehicle,
In the position close to the terminal connection portion of the terminal of the electric wire, the insulating coating layer is removed and an intermediate exposed portion where the core wire is exposed is provided.
A heat-shrinkable tube is covered on the intermediate exposed portion, and a water stop portion is provided to which a plurality of strands constituting the core wire of the intermediate exposed portion covered with the heat-shrinkable tube are fixed with solder. A water-stop structure for electric wires.   The water stop structure of the electric wire according to claim 1, wherein the water stop portion is provided on a terminal side connected to the electronic control unit.   The electric wire according to claim 1, wherein an elastic sheet made of a foam sheet, a rubber sheet, or a urethane sheet is wound around the outer peripheral surface of the heat-shrinkable tube, which is in close contact with the outer peripheral surface of the intermediate exposed portion of the core wire. Water stop structure.   The water stop structure for an electric wire according to claim 3, wherein vibration absorbing fins are provided on an outer peripheral surface of the elastic sheet. It is a formation method of the water stop structure of the electric wire according to claim 1,
In the position close to the terminal connected to the terminal of the electric wire, the insulating coating layer is intermediately peeled to expose the core wire to provide an intermediate exposed portion,
Next, an adhesive is applied to both side portions of the core wire having a length applied to the intermediate exposed portion and the insulating coating layers on both sides sandwiching the intermediate exposed portion, and solder is fixed to the intermediate portion of the inner peripheral surface thereof. The heat-shrinkable tube, the solder-fixed portion of the heat-shrinkable tube is positioned on the outer periphery of the intermediate exposed portion of the core wire, and the adhesive-applied portions on both sides are positioned on the outer periphery of the insulating coating layers on both sides, The shrink tube is heated to shrink, the solder and the adhesive are melted, the solder is infiltrated between the strands of the intermediate exposed portion of the core wire, and a water stop portion including a solder integrated portion is provided, and the A method for forming a water-stop structure for an electric wire in which a gap between both end edges of the heat-shrinkable tube and the outer peripheral surface of the insulating coating layer is blocked with an adhesive.

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