JPH1110751A - Waterproof rubber plug, method and mold for manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly pull out a rubber plug from a mold. SOLUTION: In the case of molding a rubber plug 1 with a flange periphery expansion formed at its one end, slits 9 are cut radially with respect to the flange periphery. In this manner, when the rubber plug 1 is pulled out of the mold, the flange peripheral portion is allowed to deform in the contracted direction by the slits 9, so that it is not hindered from being pulled out from the mold by the expansion of the flange peripheral portion caught in the mold inner face, and the pulling-out from the mold is implemented smoothly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a waterproof rubber stopper,
The present invention relates to a molding method and a mold used therein.

[0002]

2. Description of the Related Art Conventionally, in a connector used in a place where waterproofing is required, a rubber plug is attached to a terminal portion of an electric wire connected to a terminal fitting to prevent water from entering from a cavity insertion side. It was prevented by a rubber stopper. Further, the rubber stopper 32 is caulked by a barrel piece of the terminal fitting so as not to easily cause displacement, but in order to further enhance reliability, a portion (caulked portion) outside the portion caulked by the barrel piece is provided. Flange edge 31 at the end
Has been devised to protrude along the entire circumference integrally. Such a rubber stopper is formed by a mold 33, and the outline at that time is as shown in FIG.

[0003]

The rubber stopper 32 molded in the mold 33 is pulled in the axial direction after molding to be released. However, since the flange edge 31 is formed so as to protrude, this portion is caught and cannot be easily removed. That is, when a pulling force is applied to the rubber plug 32 in the leftward direction in FIG. 6, since the above-described caulked portion 34 is thinner than other places, the pulling force is absorbed here and reaches the flange edge 31. This is because it is difficult to work.

[0004] The above-mentioned problem is caused by pulling the rubber plug in the axial direction to remove the rubber plug, and it seems that the problem can be solved simply by setting the mold opening direction to a direction perpendicular to the axis. However, opening the mold in such a direction may cause burrs on the peripheral surface of the rubber plug. Since the flash generated on the peripheral surface impairs the sealing performance, such a method cannot be adopted.

[0005] After all, the rubber stopper has to be removed along the axial direction, and the smooth removal operation cannot be easily realized due to such circumstances.

The present invention has been devised in view of the above-mentioned conventional problems, and has as its object to provide a molding method and a mold for realizing easy demolding, and a rubber as a finished product. Is to provide a stopper.

[0007]

According to a first aspect of the present invention, there is provided an electric wire insertion hole penetrating along an axis, and a flange edge is formed circumferentially at one end of an outer peripheral surface thereof. A method of removing a waterproof rubber plug formed so as to protrude along the axial direction from a molding die in an axial direction, and removing the deformation. It is characterized by being molded before the mold.

According to a second aspect of the present invention, a waterproof rubber plug is formed in which an electric wire insertion hole penetrates along a shaft core and a flange edge is formed at one end of an outer peripheral surface thereof so as to protrude along a circumferential direction. A mold for molding a side portion of the rubber plug, and a movable mold that is opened and closed in the axial direction from the flange edge side with respect to the main body mold,
In addition, the movable mold is provided with ribs for forming a deformation allowable portion that allows the flange edge portion to be deformed.

A third aspect of the present invention is a waterproof rubber plug in which a wire insertion hole penetrates along a shaft core and a flange edge is formed at one end of an outer peripheral surface thereof so as to protrude along a circumferential direction. The flange edge portion is formed with a deformation permitting portion for permitting the flange edge portion to be deformed.

[0010]

According to the first aspect of the present invention, when the rubber stopper formed in the molding die is removed from the mold, the deformation allowable portion already formed on the flange edge portion is removed from the flange edge portion. To facilitate the removal from the mold.

According to the second aspect of the present invention, the rubber stopper is formed in a molding space surrounded by the main body mold and the movable mold, and the flange formed by the rib formed in the movable mold at this time. A deformation allowing portion is formed in the portion. Therefore, if the rubber stopper is pulled out in the axial direction while the movable mold is opened from the main body mold, the flange edge portion is depressed by the deformation permitting portion and can be easily extracted from the mold.

[0012]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIG. First, the structure of the rubber plug 1 according to the present embodiment will be briefly described. The entire rubber stopper 1 is formed in a substantially cylindrical shape and integrally formed, and an electric wire insertion hole 2 penetrates the inside thereof along the axis. In the outer peripheral surface, the seal protruding edge 3A shown in FIG.
To 3C project annularly at equal pitch intervals. In the illustrated example, each of the seal protruding edges 3A to 3C is configured such that the outer diameter and the thickness in the axial direction increase in order from the leading one 3A. This is mainly due to the ease of insertion into the cavity of the connector housing (not shown) and ease of removal from the mold. In addition, seal protruding edge 3C
A base 4 is formed between the base and one of the edges.

On the other hand, a mounting portion 6 for the terminal fitting 5 described below is formed in the remaining half length range of the rubber plug 1. The mounting portion 6 is smaller than the outer diameters of the valleys of the seal protruding edges 3A to 3C and the outer diameter of the base 4 described above.
Further, a flange edge 7 is formed between the mounting portion 6 and the front edge so as to protrude. Although the flange edge 7 is smaller than the outer diameter of each of the seal protruding edges 3A to 3C and the base 4, the mounting portion 6
Because it is formed with dimensions larger than the outer diameter of
A step is formed at the boundary with the mounting portion 6.

Further, as shown in FIG. 3, four slits 9 (corresponding to the deformable portions of the present invention) are provided at intervals of 90 ° in the flange edge portion 7 as shown in FIG. Each slit 9 is cut along the axial direction over a length range from the chamfered surface 8 to a substantially central portion of the mounting portion 6. As a result, the rubber plug 1 is allowed to undergo the concave deformation on the mounting portion 6 side, and the outer diameter of the flange edge 7 becomes substantially equal to the outer diameter of the mounting portion 6 in the natural state at the time of the concave deformation. It is set as follows.

When the rubber plug 1 thus formed is mounted on the terminal fitting 5, the electric wire is passed through the internal electric wire insertion hole 2, while the electric wire core wire is moved by the wire barrel 10 of the terminal fitting 5. Can be crimped. Also, the insulation barrel 11 of the terminal fitting 5 is crimped to the mounting portion 6, and at this time, the flange edge 7 is
Is formed so as to prevent the rubber plug 1 from coming off.

Next, a mold for molding the rubber plug 1 will be described. In the present embodiment, a so-called multi-cavity molding mold for simultaneously molding a large number of rubber stoppers 1 will be described. In the drawings, only one is shown.

As shown in FIG. 4, the mold in the present embodiment includes an upper mold 12 (corresponding to a movable mold of the present invention) and a middle mold 1.
3 (corresponding to the main body mold of the present invention) and the lower mold 14. Of these, the core 15 protrudes from the lower mold 14 corresponding to the molding location of the electric wire insertion hole 2 of each rubber plug 1. A molding space for molding is formed, and a sheet-shaped gap is held between the lower mold 14 and the middle mold 13 in a closed state. I am trying to do it.

A surface for forming the front end surface of the rubber plug 1 and four ribs 1 for forming slits projecting therefrom at positions corresponding to the slits 9 are provided on the opposing surface of the upper mold 12.
7 are formed. The upper mold 12 moves in the axial direction to open the mold before the molded rubber stopper 1 is released from the middle mold 13.

The procedure for molding and removing the rubber stopper 1 is as follows. Each of the above-mentioned molds is closed and the rubber stopper 1 is molded by an injection molding method or the like. Then, after a certain time, first, the lower mold 14 and the upper mold 12
Are respectively opened along the axial direction. by this,
On the upper mold 12 side, the slits 9 appear when the ribs 17 are removed, and when the lower mold 14 is opened, the core 15 is removed from the wire insertion hole, and as described above, between the lower mold 14 and the middle mold 13. Has the above-mentioned sheet-shaped gap, the burrs 18 remain in a sheet-like shape, and the molded rubber plugs 1 are connected to each other.

Next, the sheet-like burrs 18 are pinched and pulled in the direction of the arrow P shown in FIG. Then, the flange edge 7 is also pulled through the mounting portion 6 by the pulling force acting on the rubber plug 1. At this time, the flange edge 7 portion is depressed and deformed by each slit 9, and its outer diameter becomes almost equal to the outer diameter of the mounting portion 6.
Is smoothly removed from the middle mold 13 without being caught on the molding surface of the middle mold 13. Thus, the plurality of rubber stoppers 1 are collectively taken out of the middle mold 13.

Thereafter, if the burrs 18 are removed from the rear end face of the rubber plug 1 by a deburring step, a desired rubber plug 1 is obtained.

As described above, according to the present embodiment, a plurality of slits 9 are provided in the flange edge portion 7 to allow squeezing deformation, so that the removal at the time of removing the mold can be performed smoothly.

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

In the present embodiment, the slit 9 communicating with the inside is provided as the deformation permitting portion. However, instead of this, a thin portion may be recessed.

The number and arrangement of the deformable portions should not be limited to those of the present embodiment.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a state in which a rubber stopper is attached to a terminal fitting.

FIG. 2 is a side view of a rubber stopper.

FIG. 3 is a front view of the same.

FIG. 4 is a sectional view showing a state during molding.

FIG. 5 is a cross-sectional view showing a state when the mold is removed.

FIG. 6 is a sectional view showing a conventional molding state.

[Description of Signs] 1 ... Rubber stopper 6 ... Mounting part 7 ... Flange rim 9 ... Slit (deformation allowable part) 12-14 ... Mold

Claims (3)

[Claims] 1. A waterproof rubber plug, through which an electric wire insertion hole penetrates along an axis and an outer peripheral surface of which is formed so that a flange edge protrudes along the circumferential direction, is axially moved from a molding die. A method of forming a waterproof rubber plug, characterized in that a deformable portion for deforming the flange edge portion by depressing and deforming at the time of demolding is formed prior to demolding. Method. 2. A mold for forming a rubber plug for waterproofing, in which an electric wire insertion hole penetrates along an axis and one end of an outer peripheral surface thereof has a flange edge formed to protrude along a circumferential direction. A main body mold for molding a side portion of the rubber stopper, and a movable mold that is opened and closed along the axial direction from the flange edge side with respect to the main body mold, and the movable mold includes A mold for molding a rubber plug for waterproofing, characterized in that a rib is formed for molding a deformable portion that allows a flange edge portion to be depressed and deformable. 3. A waterproof rubber plug in which an electric wire insertion hole penetrates along an axis and a flange edge is formed at one end of an outer peripheral surface thereof so as to protrude along a circumferential direction. Is a rubber stopper for waterproofing, characterized in that a deformation permitting portion for permitting dent deformation of the flange edge portion is formed.