JPH0850956A - Fixing structure of rubber plug for sealing - Google Patents

Abstract

PURPOSE:To prevent the coming-off of a rubber plag, and to maintain the sealing condition between the rubber plug and a wire securely. CONSTITUTION:A rubber plug 1 is inserted to the front end of a wire 2, and the fixing area of the rubber plug 1 is calked by the insulation barrel 8 of a terminal metal fitting 3. A projecting edge 14 is provided to the insulation barrel 8 along the longitudinal direction, and when a calking is applied to the insulation barrel 8, the corresponding part of the projecting edge 14 compresses the cover of the wire 2, and the part functions as an internal sealing member 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing structure for a rubber plug for sealing.

[0002]

2. Description of the Related Art In a so-called waterproof connector, FIG.
As shown in (1), a rubber plug 31 is fitted to the electric wire 30 inserted into the housing of the connector, and the rubber plug 31 ensures the sealing property with the housing. That is, the rubber plug 31 has the wire insertion hole 3 along the axis.
2 penetrates, and a seal edge 33 is formed on the outer periphery thereof.
Is protruding. The rubber plug 31 has a terminal fitting 3 at the front portion (the left side portion in FIG. 3) of the portion where the seal edge 33 is formed.
It is fixed by crimping the insulation barrel 35 of No. 4.

[0003]

By the way, the rubber stopper 31 is used.
Since the fixing force between the terminal metal fitting 34 and the terminal fitting 34 is exclusively due to the caulking force of the insulation barrel 35, the rubber plug 3
In order to prevent the slip-out of No. 1, simply increase the caulking force. However, when the caulking force is simply increased, the edge of the insulation barrel 35 bites into the peripheral surface of the rubber stopper 31, so that the edge of the insulation barrel 35 is sharply cut off to form a so-called sharp edge. It is expected that the rubber plug 31 will be cut into the groove and the sealing performance will be impaired. Therefore, conventionally, the setting of the caulking force has become delicate, and the variation causes the damage of the rubber plug 31, or the terminal fitting 3
The deviation from 4 would have occurred.

The rubber plug 31 is also required to have the following features. Sealing with the housing side is achieved by the above-mentioned sealing edge 33, and also with respect to sealing with the electric wire, an internal sealing edge 36 is formed. However, even if the inner seal edge 36 is provided, the electric wire 30
When the wire is pulled to the side, the hole wall of the wire insertion hole 32 and the wire 3
There was a tendency for a gap to be formed between the two and 0, and the sealing performance to be impaired.

The present invention has been developed and devised in view of the above-mentioned problems, and an object thereof is to provide a fixing structure for a rubber plug for sealing which can prevent the rubber plug from coming off and can maintain the sealing property with an electric wire. Is to provide.

[0006]

According to a first aspect of the invention for achieving the above object, a rubber plug for sealing having an electric wire insertion hole penetrating along an axis is provided by an insulation barrel of a terminal fitting. A structure for fixing by caulking, wherein a protruding edge is formed in an annular shape on a surface of the insulation barrel facing the rubber plug, and when the insulation barrel is caulked, the protruding edge is an inner peripheral surface of the wire insertion hole. The corresponding edge is bulged to form a seal edge with the electric wire.

[0007]

According to the above construction, when the electric wire is inserted into the electric wire insertion hole of the rubber stopper and caulked by the insulation barrel, the projecting edge locally and annularly compresses the rubber stopper. This prevents the rubber plug from coming off. On the other hand, in the hole wall of the wire insertion hole, the portion corresponding to the portion compressed by the projecting edge bulges annularly to form an inner seal edge for the wire.

[0008]

The effects of the present invention are as follows. According to the first aspect of the present invention, since the caulking is performed by the projecting edge, the sharp edge of the insulation barrel does not have to bite into the rubber stopper, and therefore the rubber stopper can be protected from damage or the like. . Further, since the rubber plug receives the local compressive force by the projecting edge and forms the internal sealing edge for the electric wire, a new sealing portion can be secured and the sealing property with the electric wire can be made more reliable.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, the rubber stopper 1
Is inserted into the electric wire 2 and is located at the coating tip of the electric wire 2. Then, in a state of being caulked and fixed by the terminal fitting 3, it is inserted into the cavity 4 of the connector as shown in FIG. 2 so as to maintain the sealing property between the cavity 4 and the electric wire 2.

First, the rubber stopper 1 will be described in detail. The rubber stopper 1 has a cylindrical shape as a whole and is integrally molded. An electric wire insertion hole 5 into which the covered electric wire 2 can be inserted is formed so as to penetrate along the axis thereof, and the opening edge on one end side (the right end side in FIG. 2A) expands into a trumpet shape. The insertion of the covered electric wire 2 is facilitated.

On the other hand, the outer peripheral surface of the rubber plug 1 is a seal area 7 in which the two outer seal edges 6 shown in the figure are arranged in the right half area in FIG. It is a fixed region 9 of the terminal fitting 3 with the insulation barrel 8. The sealing area 7 is formed thicker than the fixing area 9 and both outer sealing edges 6
Are arranged in parallel at appropriate intervals and formed in an annular shape along the entire circumference. Then, the electric wire 2 and the rubber plug 1 together with the cavity 4
When inserted inside, both outer seal edges 6 can come into contact with the wall surface of the cavity 4 in a compressed state, that is, in a state where watertightness is secured.

Further, an inner seal edge 10 is arranged in a range of the wire insertion hole 5 corresponding to the seal area 7.
The inner seal edge 10 on the side closest to the opening edge is positioned continuously to the above-mentioned expanded portion. Each internal seal edge 1
0 is formed in a ring shape along the entire circumference and can be contacted with the covered electric wire 2 in a state of being compressed and ensuring watertightness.

Unlike the seal region 7, the fixing region 9 has a cylindrical shape without a protrusion, and this portion is caulked by the terminal fitting 3 so as not to cause an inadvertent displacement of the covered electric wire 2. It is a part to do.

On the other hand, as shown in FIG. 1, the terminal fitting 3 is provided at its tip with a connecting portion 11 capable of receiving a mating terminal fitting (a male terminal fitting not shown), and subsequently to the covered electric wire 2.
A wire barrel 13 for crimping the core wire 12 exposed from the wire barrel 13 is further provided with an insulation barrel 8 following the wire barrel 13.
The insulation barrel 8 is formed so as to extend symmetrically in a direction substantially orthogonal to the axis of the terminal fitting 3, and has a length capable of wrapping substantially the entire outer peripheral surface of the fixing region 9 of the rubber stopper 1 without a gap. Have Further, a protrusion 14 is formed on the surface of the insulation barrel 8 facing the rubber plug 1 by stamping so as to project toward the rubber plug 1, and the protrusion 14 is formed at the center of the insulation barrel 8. It is formed over the entire length. The projecting edge 14 thus formed by punching
2 has a semicircular cross section as shown in FIG. 2B, that is, it is formed with a gentle arc surface, so that even if it digs into the peripheral surface of the rubber stopper 1 by caulking, the outer peripheral surface of the rubber stopper 1 is It does not cause damage such as cuts. And
By caulking the rubber plug 1 with the insulation barrel 8, the protruding edge 14 is formed on the inner peripheral surface of the wire insertion hole 5.
Since the portion corresponding to and swells (see the chain double-dashed line in FIG. 2B), this portion is more strongly compressed than the peripheral portion and functions as the internal seal portion 15 for the electric wire 2.

Since this embodiment is constructed as described above, the wire 12 is inserted into the wire insertion hole 5 of the rubber stopper 1, and the core 12 is caulked by the wire barrel 13.
The insulation barrel 8 caulks substantially the entire circumference of the fixed region 9 with a caulking force which is substantially uniform. As a result, the terminal fitting 3 and the rubber plug 1 are fixed to the tip of the electric wire 2. Then, when it is inserted into the cavity 4 of the connector as it is, the outer seal edge 6 secures the seal with the cavity 4 and the inner seal edge 10 secures the seal with the covered electric wire 2.

When the insulation barrel 8 is crimped, the projecting edge 14 bites into the covered portion of the electric wire 2, so that the inner peripheral surface of the electric wire insertion hole 5 corresponding to this portion receives the compressive force to receive the ring. Bulge out. Since this bulging portion is pressed against the covered electric wire 2 more strongly than other portions, the inner sealing portion 15 is formed as described above, and the seal between the electric wire covering is secured. In particular, since the inner seal portion 15 is located relatively inside the cavity 4, there is also an advantage that even if the electric wire 2 is pulled laterally, it is less susceptible to the influence.

Further, since the projecting edge 14 is formed, the caulking force can be enhanced at the same time, and the displacement or slipping out of the rubber plug 1 can be prevented, and the projecting edge 14 exclusively provides the caulking force. Since the sharp edge of the insulation barrel 8 does not dig into the outer peripheral surface of the rubber stopper 1 and the projecting edge 14 is formed with an arc surface, the rubber stopper 1 is not cut. Therefore, also from this point, the sealing property can be secured.

The present invention can be modified in various ways,
The following modifications are also included in the technical scope of the present invention.

The projecting edge does not have to be a continuous annular shape as in the present example, but may be intermittently arranged at a constant pitch.

The one shown in the drawing shows that the inner peripheral surface (corresponding to the fixed region) of the wire insertion hole is in close contact with the outer peripheral surface of the electric wire before caulking the insulation barrel. A slight clearance may be held between the inner peripheral surface of the wire insertion hole and the wire before caulking as long as the edge is formed and a seal with the wire coating is secured. With such a structure, the operation when inserting the rubber plug into the electric wire while ensuring the inner and outer seals is facilitated.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment.

FIG. 2A is a sectional view showing a state of being inserted into a connector, and FIG. 2B is an enlarged sectional view showing a main part.

FIG. 3 is a sectional view showing a conventional fixing structure.

[Explanation of symbols]

 1 ... Rubber plug 3 ... Terminal metal fitting 5 ... Wire insertion hole 8 ... Insulation barrel 14 ... Projection edge 15 ... Internal seal part

Claims (1)

[Claims] 1. A structure in which a sealing rubber plug having an electric wire insertion hole penetrating along an axial center is crimped and fixed by an insulation barrel of a terminal fitting, the surface of the insulation barrel facing the rubber plug. The protruding edge is formed in an annular shape, and when the insulation barrel is crimped, the protruding edge bulges the corresponding portion of the inner peripheral surface of the wire insertion hole to form an internal seal edge with the wire. The fixing structure of the rubber plug for sealing, which is characterized in that