JPH0822861A - Waterproof rubber plug - Google Patents

Abstract

PURPOSE:To provide a waterproof rubber plug which can exhibit a sufficiently good sealing property even when wire is curved obliquely. CONSTITUTION:A cylindrical main body part 32 has circular rugged parts 40, 42 provided respectively on the inner and outer peripheries thereof. A cover 36 is provided integrally with the wire-insertion-side end of the main body part 32, and an abutment surface 44 that abuts the end face 1a of the open edge of a hole 3 in a housing 1 is provided on the main body part 32 side of the cover 36, and a tapered part 48 whose reduced-diameter end leads to the end face 50 of the cover 36 is provided on the end face 50 side of the cover 36. When the diameter of the hole 3 in the housing 1 is X, the thickness from the abutment surface 44 to the end face 50 of the cover 36 is C, and the distance from the end face 50 of the cover 36 to the increased-diameter end of the tapered part 48 is A, then C and A are set so that the following requirements are met: (C/X)X100=10-30% and (A/C)X100=5-30%.

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 seals a gap between the outer circumference of an electric wire and the inner circumference of an insertion hole of a housing.

[0002]

2. Description of the Related Art As a conventional example of a waterproof rubber stopper, the actual open sho 62
The one disclosed in Japanese Laid-Open Patent Publication No. 163879 is known. FIG. 15 shows the usage state of this waterproof rubber plug.
In the figure, 1 is a housing such as a connector, 3 is an insertion hole for an electric wire formed in the housing, 5 is an electric wire, and 10 is a waterproof rubber plug.

The waterproof rubber plug 10 is fitted into the outer circumference of the electric wire 5 and inserted into the insertion hole 3 to seal the gap between the outer circumference of the electric wire 5 and the inner circumference of the insertion hole 3 of the housing 1.
The waterproof rubber plug 10 has a thick body 1 for sealing a gap between the outer circumference of the electric wire 5 and the inner circumference of the insertion hole 3 of the housing 1.
2 and a thin caulking portion 14 extending to the tip side thereof, and the electric wire insertion hole 15 is penetrated through the center to form a cylindrical shape as a whole.

The caulking portion 14 is a portion for caulking the electric wire 5, and for example, the caulking piece 1 provided at the rear end of the electric wire connecting terminal.
By being tightened from the outside by 9, the electric wire 5
It is fixed to. An annular protrusion 16 is provided on the inner periphery of the main body 12 so as to be in close contact with the outer periphery of the electric wire 5, and an annular protrusion 17 is provided on the outer periphery of the main body 12 so as to be in close contact with the inner periphery of the insertion hole 3. In addition, a taper surface 18 for facilitating the insertion of the electric wire 5 is formed at the hole edge of the electric wire insertion hole 15 on the electric wire insertion side.

[0005]

In the above-mentioned conventional waterproof rubber plug 10, as shown in FIG. 16, when the electric wire 5 extending to the outside of the housing 1 is bent, the electric wire 5 and the waterproof rubber plug 10 have inner circumferences. A gap H is likely to open between the annular protrusion 16 provided, and water may permeate into the housing 1 through the gap H. Further, since there is the tapered surface 18 at the inner peripheral edge on the wire insertion side, water may collect in the recess formed by the tapered surface 18 and the electric wire 5, and the water passes through the gap H to the inside of the housing 1. There was a possibility of soaking.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a waterproof rubber plug capable of more reliable sealing.

[0007]

According to a first aspect of the present invention, the gap between the outer circumference of the wire and the inner circumference of the insertion hole is sealed by fitting the wire into the outer circumference of the wire and inserting the wire into the insertion hole of the housing. A waterproof rubber plug having a tubular main body and annular protrusions provided on the inner and outer peripheries of the main body and in close contact with the outer perimeter of the electric wire and the inner perimeter of the insertion hole of the housing. Integrally at the end of the main body on the wire insertion side,
The inner diameter is formed in a size to be in close contact with the outer peripheral surface of the electric wire,
Further, a cylindrical lid portion having an outer diameter larger than that of the insertion hole of the housing is provided, and an abutting surface that abuts the housing end surface of the opening peripheral edge of the insertion hole is provided on the body portion side of the lid portion. At the same time, a taper portion is provided on the end surface side of the lid portion, the reduced diameter end of which is continuous with the end surface of the lid portion, the insertion hole diameter of the housing is X, and the wall thickness from the contact surface to the end surface of the lid portion is C. ,
When the distance from the end surface of the lid portion to the enlarged diameter end of the tapered portion is A, the dimensions of C and A are (C / X) × 100 = 10 to 30% (A / C) × 100 = 5 It is characterized by setting so as to satisfy the condition of 30%.

The invention according to claim 2 is the waterproof rubber plug according to claim 1, wherein the dimensions of C and A are (C / X) × 100 = 10 to 25% (A / C) × 100 = 10. It is characterized in that it is set to satisfy the condition of ~ 25%.

A third aspect of the present invention is the waterproof rubber plug according to the first or second aspect, wherein an inner peripheral edge of the lid portion on the wire insertion side is provided with a taper surface that spreads outward, and an end surface of the lid portion is provided. It is characterized in that a drainage channel is provided which extends from the tapered surface to the outer periphery of the lid portion.

The invention according to claim 4 is the waterproof rubber plug according to claim 3, wherein a plurality of the drainage channels are radially formed.

A fifth aspect of the present invention is the waterproof rubber plug according to the fourth aspect, characterized in that a drainage groove is provided as the drainage channel.

A sixth aspect of the present invention is the waterproof rubber plug according to the fourth aspect, characterized in that a drain hole is formed inside the lid as the drainage channel.

[0013]

In the invention of claim 1, since the wall thickness C of the lid and the dimension A of the taper are set as described above, the end portion (lid portion) of the waterproof rubber plug has appropriate rigidity and flexibility. At the same time, the local followability to the bending of the electric wire in the inner peripheral portion on the end face side is improved. Therefore, even if the electric wire is pulled obliquely, due to its flexibility, the contact surface does not separate from the housing end surface, and a gap is not formed in that portion. Further, due to the local followability of the portion on the end face side, even if the electric wire is curved, it is possible to prevent a gap from being formed between the electric wire and the inner circumference of the waterproof rubber plug. Also, due to its moderate rigidity,
The lid part does not enter the insertion hole of the housing. Further, since the lid portion has the taper portion, the rigidity of the lid portion in the thickness direction increases, and even if the lid portion is pulled inside the insertion hole, the end surface of the lid portion does not have a recess, and water does not collect.

On the other hand, if the thickness of the lid is larger than the above condition, the rigidity of the lid becomes too high,
When the electric wire is bent, the entire lid portion follows the movement of the electric wire, the contact surface is separated from the end surface of the housing, and there is a strong possibility that a gap is formed in that portion. On the contrary, if the thickness of the lid is smaller than the above conditions, the rigidity of the lid becomes too low, and when the wire is pulled inward of the insertion hole,
There is a strong possibility that the water will sink into the insertion hole, and a useless recess will occur in the recessed portion, making it easier for water to collect. Also, if there is no taper on the end face side of the lid, the possibility of the above-mentioned dent problem increases, and the local flexibility of the end face side inner peripheral part of the lid part disappears, and it follows the curve of the wire. When the electric wire bends, the possibility that a gap will be created between the electric wire and the inner circumference of the waterproof rubber plug increases.

According to the second aspect of the present invention, the rigidity and flexibility of the lid portion are in the optimum state, and the followability of the inner peripheral portion of the end portion of the lid portion to the electric wire is also in a favorable state.

According to the third aspect of the invention, since the taper surface is provided, the electric wire can be easily inserted. On the other hand, water drops tend to collect in the recess formed by the tapered surface and the outer circumference of the electric wire, but since the water drop is discharged to the outside through the drainage channel, water does not actually collect in the recess.

According to the fourth aspect of the present invention, since the drainage channels are radially formed, no matter how the waterproof rubber plug is inclined, the water drops that fall into the recess formed by the tapered surface and the outer circumference of the electric wire It is discharged to the outside through one of the drainage channels.

According to the fifth aspect of the invention, although the rigidity of the lid part is slightly lowered, the drainage channel can be easily formed.

According to the sixth aspect of the invention, the drainage channel can be formed without significantly lowering the rigidity.

[0020]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a waterproof rubber plug 30 according to an embodiment of the present invention.
2 is a sectional view of the waterproof rubber plug 30 showing the dimensional relationship between the waterproof rubber plug 30 and the housing 1 together, and FIG. 3 is a view showing the waterproof rubber plug 30 mounted on the outer periphery of the electric wire 5 and the housing 1 inserted. It is sectional drawing which shows the state inserted in the hole 3.

The waterproof rubber plug 30 has a thick main body portion 32 for sealing a gap between the outer circumference of the electric wire 5 and the inner circumference of the insertion hole 3 of the housing 1, and a thin-walled main body portion 32 extending to the tip side thereof. It is composed of a tightening portion 34 and a lid portion 36 integrally formed on the base end side thereof, and an electric wire insertion hole 38 penetrates through the center thereof to form a cylindrical shape as a whole.

The wire insertion hole 38 has a portion 38a corresponding to the inner circumference of the lid 36 and a portion 3 corresponding to the inner circumference of the main body 32.
8b and a portion 38c corresponding to the crimp portion 34, each of which has a predetermined inner diameter.
The portion 38a corresponding to the inner circumference of the lid portion 36 is set so as to be in close contact with the outer circumference of the electric wire 5, and the hole edge 38d has a taper surface (outwardly spread) of a minimum size as necessary. (Not shown) is formed to improve the insertability of the electric wire 5.

The portion 3 corresponding to the inner circumference of the main body 32
8b is provided with an annular projection 40 whose tip portion closely adheres to the outer periphery of the electric wire 5 at intervals in the electric wire insertion direction so as to form three continuous corrugated waveforms. On the outer circumference of the main body portion 32, annular projections 42 that are in close contact with the inner circumference of the insertion hole 3 are provided at intervals in the wire insertion direction so as to form three continuous corrugations. The positions of the annular protrusion 40 on the inner peripheral side and the annular protrusion 42 on the outer peripheral side correspond to each other. Further, a portion 38c corresponding to the inner circumference of the caulking portion 34
Is formed so as to fit loosely on the outer periphery of the electric wire 5.

The outer diameter of the lid portion 36 is formed to be slightly larger than the insertion hole 3 of the housing 1, and the body portion 3 of the lid portion 36 is formed.
On the second side, a contact surface 44 that contacts the housing end surface 1a at the opening peripheral edge of the insertion hole 3 is provided. In addition, the contact surface 44
The portion from the end surface 50 of the lid portion 36 is configured by the first taper portion 46 and the second taper portion 48. The first taper portion 46 and the second taper portion 48 both have a reduced diameter toward the end face 50 side, and the first taper portion 46 has a gentler gradient than the second taper portion 48. The second taper portion 48 has a gradient of an angle close to the end surface 50 orthogonal to the wire insertion direction, and the reduced diameter end is continuous with the end surface 50. Further, the first taper portion 46 has a diameter-expanded end connected to the outer peripheral end of the contact surface 44, and a diameter-reduced end connected to the diameter-expanded end of the second taper portion 46. Therefore, the outer shape of the lid portion 36 is formed into a substantially arc surface shape by the two tapered portions 46 and 48.

In particular, in this waterproof rubber plug 30, the diameter of the insertion hole 3 of the housing 1 is X, the wall thickness from the contact surface 44 to the end surface 50 of the lid portion C is C, and the end surface 50 of the lid portion 36 is second. When the distance to the expanded end of the tapered portion 48 of A is A, C,
The dimension of A is set so as to satisfy the condition of (C / X) × 100 = 10 to 30% (1) (A / C) × 100 = 5 to 30% (2).

Next, the operation will be described.

When using this waterproof rubber stopper 30, as shown in FIG.
As shown in FIG. 3, the waterproof rubber plug 30 is fixed to the outer periphery of the electric wire 5 by caulking the caulking piece 19 on the outer periphery of the caulking portion 34, and is inserted into the insertion hole 3 of the housing 1 in that state. Then, the annular protrusion 40 on the inner periphery of the main body portion 32 strongly adheres to the outer periphery of the electric wire 5, and the annular protrusion 42 on the outer periphery of the main body portion 32 closely adheres to the inner periphery of the insertion hole 3 of the housing 1. Electric wire 5
And the gap between the insertion hole 3 of the housing 1 is sealed. Also,
The contact surface 44 of the lid portion 36 abuts on the housing end surface 1a to close the inlet of the insertion hole 3, and the inner circumference of the lid portion 36 closely contacts the outer circumference of the electric wire 5 so that the inner portion of the electric wire 5 and the waterproof rubber plug 30 is closed. Close it so that there is no unnecessary gap between it and the circumference.

In the waterproof rubber plug 30 of this embodiment, the lid portion 3
Since the thickness C of 6 and the dimension A of the second taper portion 48 are set as described above, the end portion (lid portion 36) of the waterproof rubber plug 30 on the wire insertion side has appropriate rigidity and flexibility. become.
Further, the inner peripheral portion on the side of the end face 50 has a local followability with respect to the bending of the electric wire 5.

Therefore, even when the electric wire 5 is bent obliquely as shown in FIG. 4, the contact surface 44 does not separate from the housing end surface 1a because the lid portion 36 is deformed flexibly due to its flexibility. There is no gap in the part. Further, due to the local followability of the inner peripheral portion on the end face 50 side, even if the electric wire 5 bends, that portion follows the electric wire 5 well, and a gap is formed between the electric wire 5 and the inner periphery of the waterproof rubber plug 30. Occurrence is suppressed. As a result, useless gaps are created and water is unlikely to enter, and the sealing performance is improved.

Here, for example, the wall thickness dimension C of the lid 36 is
As shown in FIG. 5, consider a waterproof rubber plug 30A having a size larger than the above conditions. In this case, the rigidity of the lid portion 36 becomes too high, and as shown in FIG. 6, when the electric wire 5 is bent at an angle, the entire lid portion 36 deforms following the movement of the electric wire 5, and The contact surface 44 is separated from the housing end surface 1a, and a gap H is likely to occur in that portion.

On the contrary, as shown in FIG. 7, the waterproof rubber plug 30B in which the wall thickness dimension C of the lid 36 is smaller than the above condition will be considered. In this case, the rigidity of the lid portion 36 becomes too low, and when the electric wire 5 is pulled inward of the insertion hole 3, the lid portion 36 may be depressed in the insertion hole 3, and There is a risk that unnecessary recesses will occur in the part and water will easily accumulate. Further, as shown in FIG. 8, considering the waterproof rubber plug 30C without the second taper portion 48 on the end surface 50 side of the lid portion 36, in that case, the rigidity of the lid portion 36 in the thickness direction decreases. Therefore, when the lid portion 36 is pulled inside the insertion hole 3 by the force of the arrow F, a recess 36a may be formed on the end surface of the lid portion 36, and water may accumulate. Further, the local flexibility of the inner peripheral portion of the lid portion 36 on the end face 50 side is reduced,
The ability to follow the electric wire 5 is reduced, and when the electric wire 5 is bent, there is an increased possibility that a gap will be created between the electric wire 5 and the inner circumference of the waterproof rubber plug 30c.

On the other hand, if the conditions are set as in the present embodiment, it is possible to secure appropriate rigidity, flexibility, and followability with respect to the electric wire, so that the lid portion 36 has the housing 1 as shown in FIG. Without getting into the insertion hole 3 of
The end face of the lid portion 36 does not have a recess 36a as shown in FIG.

As a result of investigating the sealing property when the electric wire 5 is bent as shown in FIG. 4 and the possibility of the lid portion 36 entering as shown in FIG. 7 by appropriately changing the value of C / X. Is shown in the table of FIG. From this result, from the viewpoints of both the sealing property and the entry prevention, C /
It can be seen that a certain effect can be expected by setting the value of X.

Further, the table of FIG. 10 shows the results of examining the occurrence of the depression 36a as shown in FIG. 8 by changing A / C. From this result, it is understood that the depression does not occur if the dimension of the second tapered portion 48 is set as in the conditional expression (2).

Further, the dimensions of C and A are set so that the condition of (C / X) × 100 = 10 to 25% (3) (A / C) × 100 = 10 to 25% (4) is satisfied. It can be seen that more desirable effects can be expected with certainty.

The structure of the lid 36 of the above embodiment may be changed to the waterproof rubber plug 70 shown in FIGS. 11 and 12.

The lid 72 of the waterproof rubber stopper 70 is shown in FIG.
As shown in FIG. 1 and FIG. 12, a parallel cylindrical portion 74 is provided between the first tapered portion 46 and the contact surface 44, and a tapered surface that spreads outward at the hole edge of the wire insertion hole 38 on the wire insertion side. 7
6 is provided, and the first taper portion 46 is provided from the end surface 50 of the lid portion 72.
A drain groove 78, which serves as a drainage channel and extends from the tapered surface 76 to the outer periphery of the lid 72, is provided in a cross shape in a range extending to the cross section. The bottom surface of each drain groove 78 inclines slightly downward from the lower end of the tapered surface 76 toward the outer side in the radial direction so that water flows outward.

When this waterproof rubber plug 70 is used, since the taper surface 76 is provided at the hole edge of the wire insertion hole 38, the wire can be easily inserted. Even if the lid 72 of the waterproof rubber stopper 70 faces upward, the water accumulated in the recess formed by the tapered surface 76 and the outer circumference of the electric wire is discharged to the outside through the drain groove 78. Water accumulates in the area of 76. In particular, since the drainage grooves 78 are formed radially, the effect can be expected no matter what direction the waterproof rubber plug 70 is inclined.

Although it is easy to form the drainage groove 78, if it is feared that the rigidity is too low, as shown in FIG.
As shown in FIG. 14, a waterproof rubber plug 80 may be configured. In this case, a drain hole 88 is bored in the meat of the lid portion 82 instead of the drain groove. With this waterproof rubber stopper 80,
It is possible to form a drainage channel without significantly reducing the rigidity.

The waterproof rubber stoppers 70, 80 have a lid 72,
When the drain groove 78 and the drain hole 80 are provided in 82, the lid portion 7
Since the flexibility of Nos. 2 and 82 is increased, the followability to the housing and the electric wire is improved.

[0042]

As described above, according to the invention of claim 1, even when the electric wire is bent outside the housing, the gap between the electric wire and the insertion hole of the housing is surely sealed.
Good sealability can be maintained.

According to the second aspect of the invention, a more reliable sealing property can be exhibited.

According to the invention of claim 3, claim 1 or 2
In addition to the effect of the invention described above, a taper surface is provided on the inner peripheral edge of the lid on the wire insertion side, and a drainage path is provided on the end surface, so it is unnecessary to prevent water from accumulating in the recess formed by the taper surface and the wire. It is possible to improve the insertability of the electric wire while preventing the entry of various water.

According to the fourth aspect of the present invention, it is possible to suppress the accumulation of water regardless of the direction in which the waterproof rubber plug is inclined.

According to the fifth aspect of the invention, the drainage channel can be easily formed, and the increase in cost can be suppressed.

According to the sixth aspect of the invention, it is possible to minimize the decrease in rigidity due to the provision of the drainage channel.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the dimensional relationship of one embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a usage state of an embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a case where an electric wire is pulled obliquely in FIG.

FIG. 5 is a cross-sectional view showing the contrast of an embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a case where the electric wire is pulled obliquely in FIG.

FIG. 7 is a cross-sectional view showing another comparative example for one embodiment of the present invention.

FIG. 8 is a cross-sectional view showing still another contrast with respect to one embodiment of the present invention.

FIG. 9 is a table showing the effectiveness of numerical limitation of one embodiment of the present invention.

FIG. 10 is a table showing the effectiveness of numerical limitation in one embodiment of the present invention.

FIG. 11 is a perspective view showing another embodiment of the present invention.

12 is a sectional view taken along the line XII-XII in FIG.

FIG. 13 is a perspective view showing still another embodiment of the present invention.

14 is a cross-sectional view taken along arrow XIV-XIV in FIG.

FIG. 15 is a cross-sectional view showing a usage state of a conventional waterproof rubber plug.

16 is a cross-sectional view when the electric wire is pulled obliquely in FIG.

[Explanation of symbols]

 1 Housing 1a End face 3 Insertion hole 5 Electric wire 30 Waterproof rubber plug 32 Main body part 36 Lid part 40 Annular protrusion 42 Annular protrusion 44 Contact surface 48 Second taper part (tapered part) 50 End face 70,80 Waterproof rubber plug 72, 82 Lid 76 Tapered surface 78 Drain (drain) 88 Drain (drain)

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[Procedure amendment]

[Submission date] October 13, 1994

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

FIG.

Claims (6)

[Claims] 1. A tubular main body part which is fitted to the outer circumference of an electric wire and is inserted into an insertion hole of a housing to close a gap between the outer circumference of the electric wire and the inner circumference of the insertion hole; A waterproof rubber plug provided on each of an inner circumference and an outer circumference of the electric wire and an annular protrusion that is in close contact with an inner circumference of an insertion hole of the housing, wherein the waterproof rubber plug is integrated with an end of the tubular main body on an electric wire insertion side. A cylindrical lid portion having an inner diameter that is in close contact with the outer peripheral surface of the electric wire and an outer diameter that is larger than the insertion hole of the housing. A contact surface that abuts the housing end surface at the opening periphery of the insertion hole, and a taper portion where the reduced diameter end is continuous with the end surface of the lid portion is provided on the end surface side of the lid portion, The diameter is X, and the thickness from the contact surface to the end surface of the lid is C When the distance from the end surface of the lid portion to the expanded diameter end of the tapered portion is A, the dimensions of C and A are (C / X) × 100 = 10 to 30% (A / C) × 100 = 5 A waterproof rubber stopper characterized by being set to satisfy the condition of -30%. 2. The waterproof rubber stopper according to claim 1, wherein the dimensions of C and A are (C / X) × 100 = 10 to 25% (A / C) × 100 = 10 to 25%. A waterproof rubber stopper that is set to meet the requirements. 3. The waterproof rubber plug according to claim 1 or 2, wherein a taper surface that spreads outward is provided on an inner peripheral edge of the lid portion on a wire insertion side, and an end surface of the lid portion is covered with the taper surface. A waterproof rubber stopper characterized in that a drainage channel is provided on the outer periphery of the part. 4. The waterproof rubber plug according to claim 3, wherein a plurality of the drainage channels are radially formed. 5. The waterproof rubber plug according to claim 4, wherein a drain groove is provided as the drainage channel. 6. The waterproof rubber plug according to claim 4, wherein a drainage hole is formed inside the lid as the drainage channel.