JPH1140244A - Waterproof rubber plug - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the ease of insertion and sealing performance of a waterproof rubber plug which is inserted into the cavity of a connector housing and protects the terminal against water and dust. SOLUTION: A waterproof rubber cap is equipped with a plurality of ring- shaped seal lips 3-5 for the cavity of a connector housing and circumferential grooves 6 and 7 formed between the sea lips, wherein the circumferential grooves 6 and 7 are furnished at the bottoms with a plurality of crests 8 and 8' and valleys 9 and 9'. The outside diameter of the crests 8 and 8' is equal to or greater than the inside diameter of the cavity, while the outside diameter of the valleys 9 and 9' is smaller. The positions of the crests 8 and 8' show phase misalignment between the first 6 and second circumferential grooves 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof rubber plug which is inserted into a cavity of a connector housing to protect terminals from water and dust.

[0002]

2. Description of the Related Art FIGS. 4 to 6 show a conventional waterproof rubber stopper. The waterproof rubber plug 14 has a small-diameter portion 15 for terminal crimping in the first half, and a large-diameter portion 17 for sealing in contact with the inner wall surface 11a of the cavity (terminal accommodating chamber) 11 of the connector housing 10 in the second half. A central portion has a wire insertion hole 18 in the longitudinal direction.

At the front end of the small-diameter portion 15, a stopper 16 for preventing a crimping piece (rear foot portion) 19 of the terminal 13 is formed, and at the large-diameter portion 17, a plurality (three in this example) of annular seal lips 20 are provided. (Hereinafter referred to as lips) are formed in parallel. The circumferential groove 21 between each lip 20 is formed concentrically with the lip 20 in an annular shape. The lip 20 prevents water, dust and the like from entering the cavity 11 from the outside.

[0004]

SUMMARY OF THE INVENTION
The conventional waterproof rubber stopper 14 has a vertical cross-section as shown in FIG.
Used for circular (including substantially elliptical) cavities 11
When trying to ensure the sealing performance,
11, the diameter D of the circumferential groove 21 of the rubber stopper 14 is smaller than the short diameter D of the rubber stopper 14. _ThreeIs large
When tightened, the rubber plug insertion force into the cavity 11 increases
However, the terminal insertion workability is deteriorated.

Conversely, when the diameter D ₃ of the circumferential groove 21 is made smaller than the short diameter D of the cavity 11, as shown in FIG.
The lip 20 of FIG. 4 bends (displaces) in the direction opposite to the insertion, the pressing force on the inner wall surface 11a of the cavity 11 becomes weak, and the sealing performance is reduced.

[0006] In view of the above, it is an object of the present invention to provide a waterproof rubber plug that can improve the workability of inserting into a cavity and the sealing property.

[0007]

In order to achieve the above object, the present invention provides a waterproof rubber having a plurality of annular sealing lips for a cavity of a connector housing and a peripheral groove formed between the annular sealing lips. The plug is characterized in that a plurality of peaks and valleys are formed at the bottom of the circumferential groove (claim 1). Compared to the inside diameter of the cavity,
The outer diameters of the ridges are equal or larger, and the outer diameters of the valleys are smaller. It is also effective that the positions of the ridges are out of phase between the first peripheral groove and the second peripheral groove (claim 3).

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. The same parts as those in the related art are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIGS. 1 to 3, a waterproof rubber plug 1 according to the present embodiment has a circumferential groove 6 between a plurality of (three in this embodiment) annular lips 3 to 5 in a large diameter portion 2 in the latter half. 7 is characterized in that the bottom surface is formed in a substantially wave shape.

That is, as shown in FIG. 2 showing a section taken along the line AA in FIG. 1, peaks (thick portions) 8 and valleys (thin portions) 9 are alternately formed in the circumferential direction at the bottom of the circumferential groove 6. ing. In this example, the six peaks 8 project radially equally in the rubber plug radial direction. A valley 9 is located between the peaks 8. Each peak 8 and valley 9 is formed in a curved shape.

The diameter D ₁ formed by the peak 8 (the outer diameter of the peak 8) is
7 is set to be equal to or larger than the minor diameter D of the elliptical (including substantially elliptical) cavity 11 of the connector housing 10 in FIG. Further, D ₂ eggplant diameter (outside diameter of the valley 9) of the valley 9 is set smaller than the minor diameter (inside diameter) D of the cavity 11. That is, the outer diameter D of the peak 8
The inner diameter D of ₁ ≧ cavity 11> an outer diameter D ₂ of the valley 9.

When the rubber plug 1 is inserted into the elliptical cavity 11, the annular seal lip 3, 4 of the rubber plug 1 is connected to the terminal (FIG. 6) by the peak portion 8 in the short diameter portion 11a ₁ (FIG. 7). (Rubber stopper) Deflection (displacement) in the opposite direction to insertion is suppressed.

That is, the peak portion 8 comes into close contact with the inner wall surface 11a of the cavity 11, abuts against the rear surface of the compressed lip 3 (the lip 3 and the peak portion 8 have the same diameter and are integrated),
The lip 3 is prevented from falling down. When a short-diameter portion 11a ₁ falling lip 3 is prevented, tilting lip 3 is suppressed even in the longer diameter section 11a ₂ (Figure 7).

The lip 3 of the rubber plug 1 has a diameter much larger than that of the peak portion 8 and a long diameter portion 11a of the cavity 11 having an elliptical diameter.
₂ (Fig. 7) is fully adhered, and exhibits a reliable seal.

The portion (tightening portion) where the peak portion 8 overlaps the inner wall surface 11a of the cavity 11 escapes to the space 12 (FIG. 2) on the valley portion 9 side. Thereby, the force of the ridge 8 pressing the inner wall surface 11a of the cavity 11 decreases, and the insertion force of the terminal 13 (rubber plug 1) decreases. The terminal 13 (rubber stopper 1) is smoothly inserted with a small force. In other words, the trough 9 enables a low insertion force of the terminal 13 (rubber plug 1).

The relief action of the peak 8 to the valley 9 becomes more remarkable because the shape of the peak 8 is a gentle curved shape. Even if the peaks 8 and the valleys 9 have a saw-tooth shape, the lip 3 can be prevented from being distorted and the valleys 9 can be prevented from being distorted.
The escaping action of the ridges 8 is exerted to some extent.

The number of peaks 8 is not limited to six.
No. Short diameter portion 11a of cavity 11 ₁(Two places) each mountain
In order for parts 8 to touch, the number of peaks 8 must be even
preferable. However, if the number of peaks 8 is too small,
The ability to support 3 so as not to bend is reduced.
If the number is too large, the space 12 formed by the valleys 9 becomes small.
As a result, the relief (bending) action of the peak 8 to the valley 9 becomes weaker.
I will. Therefore, the number of the peaks 8 is preferably about six.
You. Even if the number of peaks 8 is odd, a considerable effect is obtained.
Can be expected.

FIG. 3 shows a cross section taken along line BB of FIG.
In the section A (FIG. 2) and the section BB (FIG. 3),
8 ′ is 30 ° (the adjacent angle of the peak 8 is 60 °,
The phase is shifted by half (30 °). That is, the valley 9 ′ of the second peripheral groove 7 is located behind the peak 8 of the first peripheral groove 6, and the second peripheral groove is located behind the valley 9 of the first peripheral groove 6. The ridges 8 ′ and the valleys 9, 9 ′ are alternately located between the first circumferential groove 6 and the second circumferential groove 7.

With this configuration, even if the first lip 3 on the front side bends (displaces) into the space 12 in the valley 9 of the first circumferential groove 6, the second lip 4 on the rear side is moved to the second lip 4. Abutting against the ridges 8 'of the circumferential groove 7 to prevent bending (shift) and sufficiently secure waterproofness.

The outer diameter D ₁ of the peak 8 ′ of the second peripheral groove 7 is the same as the outer diameter D ₁ of the peak 8 of the first peripheral groove 6,
Outer diameter D ₂ is the outer diameter D ₂ of the troughs 9 'of the crests 9 of the first peripheral groove 6
Is the same as

Incidentally, the rearmost lip 5 is pressed by, for example, a rear holder (not shown) to prevent bending (displacement). The above-mentioned waterproof rubber stopper 1 is an elliptical cavity 1
Needless to say, the present invention is effective not only in the case of 1 but also in a perfectly circular cavity.

[0022]

As described above, according to the first aspect of the present invention, when the waterproof rubber plug is inserted into the cavity, the peak prevents the annular seal lip from bending in the direction opposite to the insertion direction. The pressing force of the seal lip to the seal lip does not decrease so much, and a reliable sealing property is exhibited especially in an elliptical cavity. At the same time, since the peaks bend toward the valleys and escape, the contact pressure between the peaks and the cavity is reduced, and the waterproof rubber plug and the terminal can be smoothly inserted with a small force. According to the second aspect of the present invention, the above effects are more remarkably exhibited. According to the third aspect of the present invention, even if the first annular seal lip is bent at the valley of the first circumferential groove, the second annular seal lip is at the same position on the rear side. Is supported by the ridges of the peripheral groove and is prevented from bending, so that the sealing performance is sufficiently ensured.

[Brief description of the drawings]

FIG. 1 shows a waterproof rubber stopper according to the present invention, wherein (a) is a front view and (b) is a side view.

FIG. 2 is a sectional view taken along line AA of FIG. 1 (b).

FIG. 3 is a sectional view taken along line BB of FIG. 1 (b).

FIG. 4 is a side view showing a conventional waterproof rubber stopper.

FIG. 5 is a sectional view taken along line CC of FIG. 4;

FIG. 6 is a longitudinal sectional view showing a state where a waterproof rubber plug is inserted into a cavity integrally with a terminal.

FIG. 7 is a front view showing a cavity.

[Explanation of symbols]

1 waterproof rubber plug 3-5 annular sealing lip 6,7 circumferential grooves 8, 8 'crest 9,9' valley 10 connector housing 11 cavity D inside diameter D _1, D ₂ the outer diameter

Claims (3)

[Claims] 1. A waterproof rubber plug comprising a plurality of annular sealing lips for a cavity of a connector housing and a circumferential groove formed between the annular sealing lips, wherein a plurality of peaks and valleys are formed at the bottom of the circumferential groove. And a waterproof rubber stopper formed with a waterproof rubber stopper. 2. The waterproof rubber plug according to claim 1, wherein the outer diameter of the ridge is equal to or larger than the inner diameter of the cavity, and the outer diameter of the valley is smaller than the inner diameter of the cavity. 3. The waterproof rubber plug according to claim 1, wherein the positions of the ridges are out of phase between the first peripheral groove and the second peripheral groove.