JPH07282894A - Waterproof structure for connector - Google Patents

Abstract

PURPOSE:To surely attain waterproofness even when the tensile force from the lateral direction is applied to an electric wire. CONSTITUTION:When the tensile force from the lateral direction is applied to an electric wire 4, the electric wire 4 is brought into contact with the inner periphery of a through hole 21, a holding member 20 is pressed in the upper direction, however the holding member 20 is kept in contact with the inner periphery of a cavity 2, and it is not moved in the upper direction. A waterproof plug 10 on the depth side of the holding member 20 is not elastically deformed, the gaps between the waterproof plug 10 and the inner periphery of the cavity 2 and between a center hole 11 and the electric wire 4 are kept at the adhesive state over the whole periphery, and the infiltration of water into the cavity 2 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof structure for a connector for preventing water from entering a cavity into which a terminal fitting is inserted.

[0002]

2. Description of the Related Art Conventionally, as a waterproof structure of a connector for preventing water from entering a cavity into which a terminal fitting is inserted, the structure shown in FIG. 10 has been used. This uses a rubber waterproof plug 90 having a cylindrical shape,
The electric wire 95 is passed through the center hole 91 of the waterproof plug 90 in advance, the electric wire 95 is crimped to the rear end of the terminal fitting 96, and then the waterproof plug 90 is moved to a position close to the terminal fitting 96, and the terminal fitting 96 is inserted into the cavity 97. Waterproof plug 9 when inserted
0 is pushed into the cavity 97 and fitted.
In the state where the waterproof plug 90 is fitted in the cavity 97 as described above, the waterproof plug 90 is compressed in the radial direction, the circumferential projection 92 on the outer circumference thereof is crushed and deformed, and the waterproof plug 90 closely contacts the inner circumference of the cavity 97. The circumferential ridges 93 of the center hole 91 are crushed and deformed to come into close contact with the outer circumference of the electric wire 95. As a result, the terminal fitting 95 in the cavity 97 is inserted from the outside through the gap between the outer circumference of the waterproof plug 90 and the inner circumference of the cavity 97 and the gap between the inner circumference of the waterproof plug 90 and the outer circumference of the electric wire 95. It is designed to prevent water from penetrating into the space on the side that is being operated.

[0003]

The conventional waterproof structure described above has the following problems. That is, the electric wire 9 which extends through the center hole 91 of the waterproof plug 90 and extends out of the cavity 97.
When a tensile force from the lateral direction acts on the waterproof plug 90 in the longitudinal direction of the waterproof plug 90, the waterproof plug 90 is elastically deformed in the radial direction by the tensile force as shown in FIG. As a result, on the side opposite to the pulling side, the inner periphery of the cavity 97 and the waterproof plug 9
0 and a ridge 92 on the outer periphery of the wire
There is also a gap between the outer periphery of the core and the ridge 93 on the inner periphery of the center hole 91, and there is a fear that water may enter the cavity 97 through these gaps.

The present invention was devised in view of the above circumstances, and it is an object of the present invention to ensure that a waterproof function can be exerted even when a lateral tensile force is applied to an electric wire. The invention of claim 2 is intended to further improve the waterproof function. In addition to the above object, the invention of claim 3 is intended to facilitate the assembling.

[0005]

As a means for solving the above-mentioned problems, a waterproof structure for a connector according to a first aspect of the present invention is a tube provided with elasticity by inserting a terminal fitting in which a wire is crimped into a cavity. The waterproof structure of the connector is designed to prevent water from entering the cavity by closely fitting the outer shape of the waterproof plug to the outer circumference of the wire and fitting it to the inner circumference of the cavity. It is characterized in that it has a fitting hole through which a holding member is fitted and a holding member fitted into the cavity is provided.

A waterproof structure for a connector according to a second aspect of the present invention is characterized in that, in the first aspect of the invention, the outer surface of the holding member facing the outside of the cavity is an umbrella-shaped tapered surface. A waterproof structure for a connector according to a third aspect of the present invention is characterized in that, in the first or second aspect of the invention, the holding member is integrally fitted to the waterproof plug.

[0007]

In the invention according to claim 1, when a tensile force from the lateral direction acts on the electric wire, the electric wire comes into contact with the inner circumference of the fitting hole and presses the holding member in the radial direction, but the holding member does not move in the cavity. Since it is fitted and does not move, the position where the wire is fitted into the fitting hole is kept constant without being displaced in the radial direction. Therefore, the pressing force in the lateral direction does not act on the waterproof plug from the electric wire on the inner side of the holding member, and the waterproof plug is not elastically deformed in the radial direction by the pressure from the electric wire.

According to the second aspect of the present invention, since the outer surface of the holding member is an umbrella-shaped tapered surface, the water on this surface flows to the outer peripheral side according to the inclination of the tapered surface. Does not accumulate. According to the third aspect of the present invention, when the holding member is integrally fitted to the waterproof plug in advance at the time of assembly, and the waterproof plug is mounted in the cavity in that state, the holding member together with the waterproof plug is provided. Is fitted into the cavity.

[0009]

As described above, according to the waterproof structure of the connector of the invention of claim 1, even if a lateral tensile force is applied to the electric wire, a pressing force is applied from the electric wire to the waterproof plug. Since it does not act, the radial elastic deformation of the waterproof plug due to the pressing force of the electric wire does not occur.
Therefore, the waterproof plug is kept in close contact with the outer circumference of the electric wire and the inner circumference of the cavity, and it is possible to reliably prevent the intrusion of water from the outside into the cavity.

In addition to the above effects, the waterproof structure of the connector according to the invention of claim 2 has a drainage function for preventing water from accumulating on the outer surface of the holding member, so that the waterproof function is improved. You can In the waterproof structure for a connector according to the invention of claim 3, in addition to the above effect, by mounting the holding member integrally with the waterproof plug in advance, the holding member can be mounted simultaneously with the waterproof plug. The workability of the assembling work is improved as compared with the case where the holding member is attached to the cavity in another process.

[0011]

【Example】

<Example 1> Hereinafter, Example 1 embodying the present invention will be described with reference to FIG.
It will be described with reference to FIG. The connector housing 1 is formed with a cavity 2 having a circular cross section that penetrates from a rear end side shown in FIGS. 4 and 5 to a front end side not shown. The terminal fitting 3 is inserted into the cavity 2 from the rear end side and is held in a predetermined position in a non-pullable manner by a locking means (not shown). A core wire 4b exposed by peeling off the coating 4a on the connection end of the electric wire 4 is crimped to the wire barrel 3a at the rear end of the terminal fitting 3, and the connection end of the electric wire 4 has a constant length. Cavity 2 across
It is designed to be inserted inside.

A substantially cylindrical waterproof plug 10 made of an elastically deformable material such as rubber is fitted to the connection end of the electric wire 4 with the electric wire 4 inserted through a central hole 11. ,
The waterproof plug 10 is fitted in the cavity 2 together with the terminal fitting 3 and the electric wire 4, and is located at the rear end portion. When the waterproof plug 10 is fitted in the cavity 2, the circumferential projection 12 formed on the outer circumference of the waterproof plug 10 is crushed and deformed, and its elastic restoring force strongly adheres to the inner circumference of the cavity 2. At the same time, the circumferential projection 13 formed on the inner circumference of the center hole 11 is crushed and deformed, and its elastic restoring force makes it strongly adhere to the outer circumference of the covering portion 4a of the electric wire 4.

Further, on the rear end surface of the waterproof plug 10, that is, the surface facing the outside from the inside of the cavity 2, two fitting projections 14,
14 are integrally formed so as to correspond to each other with the center hole 11 sandwiched therebetween. The protruding end of the fitting protrusion 14 is formed with a tapered retaining portion 15 that has a stepped diameter and expands toward the tip side. A holding member 20 is fitted in the cavity 2. The holding member 20 is made of a material such as a synthetic resin that does not easily deform, and has a circular plate shape. The thickness dimension of the holding member 20 is the same as the distance from the rear end surface of the waterproof plug 10 to the retaining portion 15 of the fitting projection 14, and the outer diameter dimension is the same as the inner diameter dimension of the rear end portion of the cavity 2. Has become. The holding member 20 is formed with a fitting hole 21 that is aligned with the central hole 11 of the waterproof plug 10, and an outer tapered edge 21 a is formed at an opening edge outside the fitting hole 21. Further, fitting holes 22 that are aligned with the fitting protrusions 14 of the waterproof plug 10 are formed on both sides of the fitting hole 21. The inner diameter of the fitting hole 22 is
It has the same size as the outer diameter of the fitting protrusion 14, and an outwardly extending tapered surface 22 a is formed at the opening edge inside the fitting hole 22 (the side facing the waterproof plug 10).

Next, the operation of this embodiment will be described. When mounting the above-mentioned members in the cavity 2, first,
The fitting hole 22 of the holding member 20 and the fitting protrusion 14 of the waterproof plug 10
The retaining member 20 and the waterproof plug 1 are aligned with the retaining portion 15 of the
When the pressing force to bring 0 into close contact with each other is applied, the retaining portion 15 is contracted and deformed and fits into the fitting hole 22 and is locked to the edge of the fitting hole 22, and the fitting hole 22 and the fitting protrusion 14 are fitted together. As a result, the holding member 20 is integrated with the waterproof plug 10 in a state where the holding member 20 is retained and retained by the retaining portion 15. This integrated waterproof plug 10
The connecting end of the electric wire 4 is passed through the center hole 11 and the fitting hole 21 of the holding member 20, and the core wire 4b of the electric wire 4 is crimped to the wire barrel 3a of the terminal fitting 3 in this state. After that, the waterproof plug 10 and the holding member 20 are moved to the terminal fitting 3 side and positioned at a predetermined position, and the waterproof plug 10, the holding member 20, the terminal fitting 3 and the connection end portion of the electric wire 4 are integrated.

Next, the integrated body is inserted into the cavity 2 with the terminal fitting 3 facing forward, and pushed in against the friction between the waterproof plug 10 and the inner periphery of the cavity 2, and finally. The holding member 20 is fitted into the rear end of the cavity 2 internally. The assembly is completed as described above. In the assembled state, the protrusions 12 on the outer periphery of the waterproof plug 10 are crushed and deformed to strongly adhere to the inner periphery of the cavity 2, and the ridges 13 on the inner periphery of the center hole 11 are crushed and deformed to cause electric wire 4 Strongly adheres to the outer periphery of the covering portion of the outer wall of the waterproof plug 10 and the outer periphery of the electric wire 4 through the gap between the outer periphery of the waterproof plug 10 and the inner periphery of the cavity 2. This prevents water from entering the cavity 2.

In this state, when a tensile force is applied to the electric wire 4 extending outside the cavity 2 from the lateral direction (upward direction in FIG. 5) with respect to the length direction of the waterproof plug 10, the electric wire 4
Contacts the inner circumference of the fitting hole 21 and presses the holding member 20 upward. However, since the holding member 20 abuts and fits the inner circumference of the cavity 2, the holding member 20 moves upward. There is no such thing. Therefore, the portion of the electric wire 4 on the inner side of the holding member 20 is kept in the same state as when the tensile force is not applied to the electric wire 4, and the waterproof plug 10 located on the inner side of the holding member 20 is elastically deformed. It never happens. Thereby, between the outer periphery of the waterproof plug 10 and the inner periphery of the cavity 2 and the center hole 1
1 and the electric wire 4 are kept in close contact with each other over the entire circumference, so that infiltration of water from the outside into the cavity 2 is prevented.

In this embodiment, since the work of assembling the waterproof plug 10 and the holding member 20 is performed first in the assembling work, the workability after that is improved. The waterproof plug 10 and the holding member 20 may be integrated at any stage of the assembling process. Further, in this embodiment, since the tapered surface 22a is formed in the fitting hole 22 of the holding member 20, the retaining portion 15 of the fitting protrusion 14 can be easily passed through the fitting hole 22. Similarly, in this embodiment, the holding member 2
Since the tapered surface 21a is formed in the fitting hole 21 of 0, when the tensile force from the lateral direction acts on the electric wire 4, the electric wire 4 is deeply bent at the corner of the hole edge of the fitting hole 21 to cover the electric wire 4. The portion 4a is prevented from being torn or the like.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIGS. 6 and 7. In this embodiment, the means for integrally fitting the waterproof plug and the holding member in the first embodiment is changed, and the other configuration and action are the same as those in the first embodiment, and therefore the description thereof will be omitted. A pair of cutouts 32, 32 with a small gap are formed at four locations at 90 ° intervals in the circumferential direction on the outer periphery of the collar 31 at the rear end of the waterproof plug 30. A fitting protrusion 33 is formed between the notches 32. On the other hand, on the outer periphery of the holding member 40, four pieces of fitting pieces 44 having fitting holes 45 that are aligned with the fitting projections 33 are formed so as to project to the side corresponding to the waterproof plug 30. When the holding member 40 is pressed against the rear end surface of the waterproof plug 30 so as to be in close contact therewith, the fitting protrusion 33 is crushed and deformed, and the fitting piece 44 is deformed outward,
The fitting piece 44 is fitted into the notches 32, 32, and the fitting projection 33 and the fitting hole 45 are fitted together, so that the waterproof plug 30 and the holding member 40 are integrated.

<Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIG. This embodiment is different from the first embodiment in that the shape of the holding member is changed and the fitting protrusion of the waterproof plug is deformed in accordance with the shape, and other configurations and operations are the same as those in the first embodiment. Is omitted. The holding member 60 has a surface on the side opposite to the side corresponding to the waterproof plug 50 bulging like an umbrella, and the surface is a taper inclined from the fitting hole 60 in the center toward the outer peripheral side. It is the surface 62. On the other hand, the fitting protrusion 5 of the waterproof plug 50
1 is longer than the fitting protrusion 14 of the first embodiment according to the thickness of the holding member 60, and the retaining portion 52 is
The stepped portion is inclined according to the inclination of the tapered surface 62 of the holding member 60. When the holding member 60 is pressed against the rear end surface of the waterproof plug 50 so as to be aligned and closely attached, the retaining portion 52
Shrinks and deforms while being fitted into the fitting hole 63 of the holding member 60 and locked to the hole edge, whereby the fitting projection 52 and the fitting hole 63 are fitted in the retaining state, and the waterproof plug 50 and holding member 6
0 and 1 are integrated.

In this embodiment, since the outer surface of the holding member 60 is the tapered surface 62, even if the connector is positioned with the rear end portion of the cavity 2 facing upward, the water will be tapered surface 62. Therefore, the taper surface 62 flows toward the outer peripheral side according to the inclination of the tapered surface 62 and is discharged to the outside of the opening edge of the cavity 2. Therefore, it is possible to prevent the water accumulated on the outer surface of the holding member 60 from entering the inside of the cavity 2 through the gap between the outer peripheral surface of the holding member 60 and the inner peripheral surface of the cavity 2, which prevents the waterproof function. It is being improved. <Fourth Embodiment> Next, a fourth embodiment of the present invention will be described with reference to FIG.
Will be described with reference to. In this embodiment, the shape of the holding member is changed from that of the above-mentioned third embodiment, and the fitting protrusion of the waterproof plug is deformed accordingly.

The holding member 80 is the holding member 50 of the third embodiment.
The thickness is increased as a whole, and the locking flange portion 83 is formed on the outer peripheral surface by extending the outer peripheral edge of the tapered surface 82 so as to project outward from the opening edge of the cavity 2. There is. On the other hand, the fitting protrusion 71 of the waterproof plug 70 is longer than the fitting protrusion 51 of the third embodiment according to the thickness of the holding member 80. When the holding member 80 is pressed against the rear end surface of the waterproof plug 70 so as to be in close contact with the rear end surface of the waterproof plug 70, the retaining portion 72 shrinks and deforms, and the fitting protrusion 84 and the fitting hole 84 fit together. Therefore, the waterproof plug 70 and the holding member 8
0 and 1 are integrated.

In this embodiment, since the retaining brim portion 83 is formed on the outer periphery of the holding member 80 so as to completely cover the opening of the cavity 2, the water flowing toward the outer peripheral side along the tapered surface 82. Is discharged beyond the opening edge of the cavity 2 to the outside thereof. Therefore, water is prevented from entering the gap between the outer periphery of the holding member 70 and the inner periphery of the cavity 2,
Waterproofing can be performed more reliably. In particular, in recent years, a high-pressure car wash machine often sprays high-pressure water onto the vehicle to wash the car. In such a case, the sprayed water can be prevented from entering the outside by being discharged to the outside of the opening edge by the tapered surface. <Other Embodiments> The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments are also included in the present invention.

(1) In the above-described embodiment, the holding member is integrally assembled with the waterproof plug to prevent the holding member from floating with respect to the cavity 2. However, according to the present invention, the holding member is a waterproof plug. It is also possible to prevent floating by engaging with the inner periphery of the cavity or the engaging portion provided on the opening edge portion thereof without assembling.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state in which a waterproof plug and a holding member according to a first embodiment are separated from each other.

FIG. 2 is a perspective view showing a state in which the waterproof plug and the holding member according to the first embodiment are assembled.

FIG. 3 is a cross-sectional view showing a state in which the waterproof plug and the holding member of Example 1 are assembled.

FIG. 4 is a cross-sectional view showing a state in which the waterproof plug and the holding member according to the first embodiment are attached to an electric wire and assembled in a cavity.

FIG. 5 is a cross-sectional view of the electric wire of Example 1 in which a lateral tensile force is applied.

FIG. 6 is a perspective view showing a state in which a waterproof plug and a holding member according to the second embodiment are separated from each other.

FIG. 7 is a perspective view showing a state in which a waterproof plug and a holding member of Example 2 are assembled.

FIG. 8 is a cross-sectional view showing a state in which a waterproof plug and a holding member of Example 3 are attached to an electric wire and assembled in a cavity.

FIG. 9 is a cross-sectional view showing a state where a waterproof plug and a holding member of Example 4 are attached to an electric wire and assembled in a cavity.

FIG. 10 is a cross-sectional view showing a state where a waterproof plug of a conventional example is attached to an electric wire and assembled in a cavity.

FIG. 11 is a cross-sectional view showing a state in which a tensile force in a lateral direction is applied to an electric wire of a conventional example.

[Explanation of symbols]

 2 ... Cavity 4 ... Electric wire 3 ... Terminal metal fitting 10 ... Waterproof plug 20 ... Holding member 21 ... Fitting hole

Claims (3)

[Claims] 1. A terminal fitting to which an electric wire is crimped is inserted into the cavity, and a cylindrical waterproof plug having elasticity is closely fitted to the outer circumference of the electric wire and is also closely fitted to the inner circumference of the cavity. In a waterproof structure of a connector, which is adapted to prevent water from entering the cavity by fitting, a holding member having a fitting hole for fitting the electric wire therein and fitted in the cavity is provided. The waterproof structure of the connector. 2. The waterproof structure for a connector according to claim 1, wherein an outer surface of the holding member facing the outside of the cavity is an umbrella-shaped tapered surface. 3. The waterproof structure for a connector according to claim 1, wherein the holding member is integrally fitted to the waterproof plug.