JPH08222317A - Coming-off preventing method for water proofing rubber plug and coming-off preventing structure - Google Patents

Abstract

PURPOSE: To carrying out caulking without producing cracks in a rubber plug. CONSTITUTION: Before a rubber plug 1 is inserted in a terminal metal fitting 6 having an insulation barrel 9 in the rear end part, the insulation barrel 9 is closed in a circular shape. After that, a locking part 7 formed in the tip of the rubber plug 1 is led to the insulation barrel 9 while compressing the locking part 7. Consequently, the locking part 7 is locked in the rear edge of the insulation barrel 9 and thus the rubber plug 1 is prevented from coming off.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing a rubber plug used in a waterproof connector from coming off and a structure therefor.

[0002]

2. Description of the Related Art Conventionally, in a waterproof connector, when inserting a terminal fitting into a cavity of a connector housing, a waterproof rubber plug is previously fitted to the tip of an electric wire coating to ensure water tightness. ing. The rubber stopper is generally fixed by caulking the tip of the rubber stopper with an insulation barrel of a terminal fitting. In caulking, as shown in FIG. 7, in the terminal fitting 30, the wire barrel 33 for caulking the core wire 32 of the electric wire 31 and the insulation barrel 34 for caulking the electric wire cover are both open. . After setting the electric wire with the rubber plug in the terminal fitting 30, the barrels 33 and 34 are caulked. Particularly, in the insulation barrel 34, the rubber stopper 35 is rounded (caulked) along the outer peripheral surface of the caulked portion 36 formed at the tip thereof.

[0003]

However, the above-mentioned prior art has the following problems. That is, since the terminal fitting 30 is formed by punching out a thin metal plate, the edge portion of the insulation barrel 34 may have a sharp edge.
Therefore, when the wire coating is caulked, the wire coating bulging between the gaps where the edges are opposed to each other may be cut or scratched as shown in FIG. 8. If such damage is added, it is difficult to secure the sealing property. become.

As a countermeasure against this, if the caulking force is reduced, the rubber plug 3 is reduced in accordance with the decrease in the holding force with respect to the rubber plug 35.
5 and the electric wire 31 are misaligned, and it is feared that a proper sealing condition cannot be obtained.

The present invention has been developed and devised in view of the above-mentioned conventional problems, and an object thereof is to increase the holding force for a rubber plug while keeping the sealing force.

[0006]

According to the invention of claim 1 for achieving the above object, a waterproof rubber plug is attached to a terminal fitting insertable into a cavity of a connector housing in a state in which it is not pulled out. Prior to the insertion of the waterproof rubber plug, the end of the metal terminal is bent into a tubular shape to form an insulation barrel, and then the waterproof rubber plug is partially formed. The locking portion is inserted into the insulation barrel while being compressed, and the locking portion and the insulation barrel are engaged with each other to prevent the retaining portion from coming off.

According to the second aspect of the present invention, the waterproof rubber plug is fitted to the covered end of the electric wire, while the rubber plug is fitted to the end of the terminal fitting insertable into the cavity of the connector housing. An insulation barrel for fixing is formed in a tubular shape, and a locking portion for engaging the insulation barrel at the tip of the rubber stopper to prevent the rubber stopper from coming off when inserted into the insulation barrel. Is formed so as to extend along the circumferential direction.

Further, the invention of claim 3 is characterized in that, in the invention of claim 2, an insertion guide surface which is tapered along the insertion direction is formed on the outer peripheral surface of the engaging portion. It is a thing.

Further, the invention of claim 4 is characterized in that, in the invention of claim 2 or 3, the insulation barrel is formed so as to expand like a trumpet toward the entrance side of the rubber stopper. It is a thing.

[0010]

According to the first and second aspects of the invention, since the insulation barrel of the terminal fitting is already formed into a tubular shape prior to the insertion of the rubber stopper, the locking portion of the rubber stopper is elastic with respect to the insulation barrel. If you insert it while deforming, the locking part will elastically return and engage with the insulation barrel,
This holds the rubber plug.

According to the third aspect of the invention, since the insertion guide surface is a tapered surface when the locking portion of the rubber plug is inserted into the insulation barrel, the insertion operation is guided.

In the invention of claim 4, since the inlet side of the insulation barrel is expanded like a trumpet by providing a relief edge, it is possible to avoid rubbing the edge of the insulation barrel against the rubber plug when the rubber plug is inserted. It

[0013]

According to the first and second aspects of the present invention, the insulation barrel is preliminarily rounded into a tubular shape, and the locking portion of the rubber stopper is inserted thereinto to engage the rubber stopper with the insulation barrel. Since the stopper is used to prevent it from coming off, it is possible to avoid a situation in which the rubber stopper is bitten and damaged, unlike the conventional case of caulking.

According to the third aspect of the invention, since the outer peripheral surface of the locking portion is formed in a tapered shape, the insertion work can be smoothly performed.

Further, according to the invention of claim 4, since the inlet side of the insulation barrel is expanded into a trumpet shape, the insertion work is smooth and the insulation barrel of the insulation barrel is inserted at the time of insertion as in the invention of claim 3. Since the interference with the opening side opening edge is avoided, it is possible to prevent the opening edge from damaging the rubber plug.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. First, the rubber plug 1 will be described with reference to FIG. A part of the tip of the electric wire 2 to which the rubber plug 1 is attached is peeled off to expose the core wire 3. A shaft hole 4 penetrates the rubber plug 1 along the shaft center thereof, and the shaft hole 4 can be fitted into the coating tip of the electric wire 2. Also,
The rubber plug 1 is integrally formed of a rubber material having good elasticity, and two lip portions 5 shown in the drawing are continuously arranged in the longitudinal direction on the rear side. Both lip portions 5 are for closely contacting with the inner wall of the cavity (none of which is shown) of the connector housing to ensure watertightness between the two, and each lip portion bulges annularly along the entire circumference.

On the other hand, a locking portion 7 for the terminal fitting 6 is provided at the front end of the rubber stopper 1. The locking portion 7 is formed in a truncated cone shape having a diameter smaller than that of the lip portion 5, and an insertion guide surface 8 forming a tapered surface is formed on the outer peripheral surface thereof. Further, the front end surface of the locking portion 7 is formed orthogonal to the axis of the rubber stopper 1. Further, the locking portion 7 and the lip portion 5
A mounting portion 10 into which the insulation barrel 9 of the terminal fitting 6 described below is fitted is arranged between the and. Mounting part 1
The outer peripheral surface of 0 is formed in the shape of a right cylinder which is parallel to the axis of the rubber stopper 1, and its width is slightly wider than that of the insulation barrel 9. Further, the outer diameter of the mounting portion 10 is set to be smaller than the outer diameter of the rear end edge of the locking portion 7, so that the rear end surface of the locking portion 7 has a ring-shaped locking surface 11 along the entire circumference. Is formed overhang.

Next, the terminal fitting 6 will be described with reference to FIG. FIG. 1 shows the terminal fitting 6 immediately after bending. The terminal fitting 6 is formed integrally by punching out a conductive metal plate, and has a rectangular tube-shaped connecting portion 12 to which a tab of a male terminal fitting (not shown) is fitted in the front portion. There is. In addition, an elastic contact piece (not shown in detail) for obtaining elastic contact with the male tab is formed by folding back inside the connecting portion 12.

On the rear side of the terminal fitting 6 described above, a neck portion 13 is formed.
A wire barrel 14 is provided via the. The wire barrel 14 is composed of a pair of left and right pieces protruding obliquely upward from the substrate 6a portion of the terminal fitting 6, and when the rubber plug 1 is attached, the wire barrel 14 is caulked to the core wire 3 portion of the electric wire 2, whereby the electric wire 2 and the terminal fitting 6 And are electrically connected. An insulation barrel 9 for fixing the rubber stopper 1 is arranged at the rear end of the terminal fitting 6.

Like the wire barrel 14, the insulation barrel 9 is also composed of a pair of left and right pieces protruding from the base plate 6a portion of the terminal fitting 6, and these two pieces are sufficiently longer than those of the wire barrel 14, respectively. Has been formed. Prior to the connection with the rubber plug 1 side, the both pieces are rounded in a ring shape including the substrate 6a so that the edges of the both pieces face each other with a minute gap. Specifically, the insulation barrel 9 is rounded along the outer peripheral surface of the mounting portion 10 of the rubber stopper 1, and in this embodiment, the inner diameter is set so that a slight clearance is held with the mounting portion 10. (Dimensions may be set so that the mounting portion 10 is crimped). The inner diameter of the insulation barrel 9 is set to be slightly larger than the diameter of the front edge of the locking portion 7 and smaller than the rear edge of the locking portion 7. Thus, the insulation barrel 9 has a rubber stopper 1
The locking portion 7 can be passed while being compressed and deformed, and after passing, it can be engaged with the locking surface 11 to prevent the rubber plug 1 from coming off, in other words, to be positioned. The insulation barrel 9 has such rigidity that the edges thereof are not easily expanded and deformed as the locking portion 7 passes.

Next, the procedure for mounting the rubber plug 1 on such a terminal fitting 6 in a retaining state will be described. Prior to the connection with the rubber plug 1, the terminal fitting 6 will be shown in FIG.
As shown in FIG. 2, both pieces of the insulation barrel 9 are rolled and processed into a substantially closed annular shape. On the other hand, the rubber plug 1 is fitted to the electric wire 2 having the core wire 3 stripped by a predetermined width through the shaft hole 4, and is attached with only the core wire 3 portion exposed.

After the above preparation, the locking portion 7 of the rubber stopper 1
To the inlet side (rear end side) of the insulation barrel 9 and push it in. Then, the locking portion 7 is inserted into the insertion guide surface 8
Slides on the trailing edge of the insulation barrel 9 along the gradient thereof, and accordingly, the engaging portion 7 is guided to elastically deform in the direction of reducing the diameter. Then, when the locking portion 7 passes the insulation barrel 9, the locking portion 7 elastically returns, and as a result, the locking surface 11 engages with the front edge of the insulation barrel 9. As a result, the rubber stopper 1 is reliably regulated in the slip-out direction.

The caulking of the wire barrel 14 and the core wire 3 may be performed after the rubber stopper 1 is pushed into the insulation barrel 9, or may be performed prior to fixing the rubber stopper 1. In this case, the rubber plug 1 is displaced rearward from the above case, the core wire 3 is guided through the insulation barrel 9 to the wire barrel 14 portion and caulked, and then the rubber plug 1 is displaced forward while being insulated. It will be pushed to 9. Thus rubber stopper 1
Are fixed by the terminal fittings 6.

As described above, in the first embodiment, the insulation barrel 9 is preliminarily rounded into an annular shape, and the rubber stopper 1 is inserted and engaged there. Therefore, the rubber is caused by the conventional caulking. The plug 1 is not damaged (cracking), and thus the sealing function is reliably retained. At the same time, the displacement of the rubber plug 1 is prevented.

4 and 5 show a second embodiment of the present invention. In the second embodiment, the entire insulation barrel 9A is expanded into a trumpet shape toward the entrance side (the side where the rubber plug 1 is inserted). In this case, the diameter of the inlet side of the insulation barrel 9A is larger than the outer diameter of the rear end of the locking portion 7 of the rubber plug 1, but the diameter of the outlet side is the outer diameter of the front edge of the locking portion 7. It becomes smaller than that, and the locking portion 7 can be engaged there.

In the second embodiment thus constructed, since the insulation barrel 9A is expanded toward the inlet side, when the locking portion 7 is pushed into the insulation barrel 9A, the locking portion 7 is insulated. Barrel 9
Since it is inserted without rubbing against the edges of the mating portions (gap portions) of the edges of A, damage is avoided in advance.

The other structure is the same as that of the first embodiment, so that the same effect can be obtained.

FIG. 6 shows a third embodiment of the present invention. The third embodiment shows another example for avoiding damage due to the mating portion of the insulation barrel 9B. In other words, this is one in which only the edge on the inlet side of the insulation barrel 9B is opened to form the escape edge 15, and by doing so, the rubber stopper 1 is restricted from being cut and has a sealing function. Can be maintained.

The other structure is the same as in the first and second embodiments.
Therefore, the same effect can be exhibited.

Besides, the present invention can be variously modified, and the following, for example, also belong to the technical scope of the present invention. In any of the embodiments, mutual connecting means are provided between the opposite edges of the insulation barrel, for example, a claw piece is projected on one edge and a locking hole engageable with the claw piece is formed on the other edge. You may do it. With such a configuration, even if the terminal fitting is made of a thin material, the insulation barrel is not expanded and deformed by the insertion of the rubber plug 1, and the holding force of the rubber plug 1 is not impaired. The locking portion 7 does not necessarily have to be provided along the entire circumference, and may be a portion that overhangs. The point is that it can be caught on the insulation barrel to prevent it from coming off. In the figure, the one applied to the female terminal fitting is shown, but it goes without saying that it can also be applied to the male terminal fitting.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a terminal fitting and a rubber plug according to a first embodiment.

FIG. 2 is a cutaway view showing an engaged state with an insulation barrel.

FIG. 3 is a perspective view of a rubber plug.

FIG. 4 is a perspective view showing a terminal fitting of the second embodiment.

FIG. 5 is a cutaway view showing a state of engagement with an insulation barrel.

FIG. 6 is a cutaway view showing a retaining structure according to a third embodiment.

FIG. 7 is an exploded perspective view of a conventional terminal fitting and a rubber stopper.

FIG. 8 is a sectional view showing a conventional problem.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Rubber stopper 2 ... Electric wire 6 ... Terminal metal fitting 7 ... Locking portion 8 ... Insertion guide portion 9 ... Insulation barrel 11 ... Locking surface

Claims (4)

[Claims] 1. A method for attaching a waterproof rubber plug to a terminal fitting insertable into a cavity of a connector housing in a state in which the waterproof rubber plug is prevented from coming off, and prior to insertion of the waterproof rubber plug, The end of the terminal fitting is bent into a tubular shape to form an insulation barrel, and then the locking part formed on a part of the waterproof rubber stopper is compressed and inserted into the insulation barrel. A retaining method for a waterproof rubber stopper, characterized in that the retaining stopper is performed by engaging the valve with an insulation barrel. 2. A waterproof rubber stopper is fitted to the covered end of the electric wire, while an insulation for fixing the rubber stopper is attached to the end of the terminal fitting that can be inserted into the cavity of the connector housing. The barrel is formed into a tubular shape,
The rubber stopper is characterized in that a locking portion that engages with the insulation barrel to prevent the rubber stopper from coming off when inserted into the insulation barrel is formed to project along the circumferential direction. Waterproof rubber stopper retaining structure. 3. The waterproof rubber stopper retaining structure according to claim 2, wherein an outer peripheral surface of the engaging portion is formed with an insertion guide surface which is tapered along an insertion direction. . 4. The pull-out of the waterproof rubber plug according to claim 2, wherein the insulation barrel is formed by expanding in a trumpet shape toward the entrance side of the rubber plug. Stop structure.