JP2000055203A - Packing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a packing unseparable from an insertion member even applied by tensile strength, and moreover high in productivity. SOLUTION: Annular inside adhesive parts 14 are formed on the inner surface of a main body part 12 over the whole periphery integrally with the main body part 12, and annular outside adhesive parts 16 are formed on the outer surface over the whole periphery integrally with the main body part 12. A diameter- contracted part 18 is formed closer to an another end side than the adhesive parts 14 integrally with the main body part 12. Since when the main body part 12 is inserted into the gap between tubular and insertion members, the diameter-contracted part 18 contacts the outer surface of the insertion member to elastically bend to the outer side to apply strong frictional force between the insertion part and the diameter-contracted part 18, thereby causing the resistance to the movement of a seal packing 10 in its separating direction. Productivity can be increased because of the integral formation of the all of the main body part 12, the inner and outer side adhesive parts 14 and 16 the diameter-contracted part 18, and flange and projection parts 22 and 24 with the same material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a packing,
More specifically, the present invention relates to a packing disposed between a tubular member and an insertion member inserted inside the tubular member to seal between an inner surface of the tubular member and an outer surface of the insertion member.

[0002]

2. Description of the Related Art FIG. 13 shows a state in which a conventional packing (seal packing 110) is mounted on a waterproof connector 120. Waterproof connector 120 is male housing 1
22 and a female housing 124, into which a cord or the like is inserted.

The seal packing 110 includes a main body 112 formed in a substantially cylindrical shape, and a stopper 118 integrally fixed at one end (an end on the female housing 124 side) of the main body 112 by insert molding. The main body 112 includes a cylindrical portion 126 of the male housing 122,
It is arranged between the insertion portion 128 of the female housing 124. The main body 112 is made of rubber, and has tight contact portions 114 and 116 formed on its outer and inner circumferences.
Reference numerals 4 and 116 closely contact the tubular portion 126 and the insertion portion 128, respectively, to seal between the inner periphery of the tubular portion 126 and the outer periphery of the insertion portion 128. Thereby, the seal packing 1
The cord or the like inserted inside 10 is waterproofed from the outside.

The stopper 118 is formed of a resin having a higher rigidity than the main body 112 and has an annular shape.
A protruding portion 119 extending outside the main body 112 is formed. The protrusion 119 is locked by a locking claw 130 formed on the female housing 124. The male housing 122 and the female housing 124 are pulled apart from each other, and a pulling force acts on the seal packing 110. However, the female housing 124 is not detached from the insertion portion 128.

However, since the seal packing 110 is composed of the two parts, the main body 112 and the stopper 118, the productivity is low and the production cost is sometimes high.

[0006]

SUMMARY OF THE INVENTION In view of the above fact, it is an object of the present invention to obtain a highly productive packing which does not separate from the insertion member even when a pulling force is applied.

[0007]

According to the first aspect of the present invention, the inner surface of the tubular member is inserted between the tubular member and an insertion member inserted inside the tubular member. A packing for sealing between an outer surface of the member and a main body formed substantially in a cylindrical shape by an elastic material and disposed between the cylindrical member and the insertion member; and a main body integrated with the main body. An outer contact portion formed on the outer periphery of the cylindrical member and in close contact with the inner surface of the cylindrical member over the entire periphery; and an outer contact portion formed integrally with the main body portion on the inner periphery of the main body portion and in close contact with the outer surface of the insertion member over the entire periphery. An inner contact portion to be formed, and an inner periphery of the main body portion integrally formed with the main body portion is formed by at least partially reducing the diameter of the inner main body portion. And a reduced diameter portion for applying a force.

Accordingly, in a state in which the main body is disposed between the tubular member and the insertion member, the outer contact portion is provided on the inner surface of the tubular member, the inner contact portion is provided on the outer surface of the insert member, and extends over the entire circumference. As a result, the space between the inner surface of the tubular member and the outer surface of the insertion member is sealed.

In this state, the reduced diameter portion is elastically deformed and presses the insertion member, and a frictional force of a predetermined value or more acts between the reduced diameter portion and the insertion member. Therefore, the detachment of the packing from the insertion member can be prevented without providing a conventional stopper.

Further, the inner contact portion, the outer contact portion and the reduced diameter portion are all formed integrally with the main body, and the packing is not constituted by a plurality of parts as in the prior art. For this reason, the productivity is increased and the production cost can be reduced.

According to a second aspect of the present invention, in the first aspect of the invention, the reduced diameter portion is formed at a position separated from the inner contact portion by a predetermined distance in the axial direction of the main body. It is characterized by the following.

Therefore, when the main body is disposed between the tubular member and the insertion member, the reduced diameter portion is pushed outward by the insertion portion, so that the portion of the main body in the vicinity of the reduced diameter portion also extends outward. May be spread out. Even in such a case, since the reduced diameter portion is formed at a position separated from the inner contact portion by a predetermined distance in the axial direction of the main body, the inner contact portion does not spread outward, and the inner contact portion does not extend to the outer surface of the insertion member. Adhesion can be secured.

According to a third aspect of the present invention, in the first or second aspect of the invention, the tapered portion whose inner diameter gradually increases toward the side where the insertion member is inserted is formed in the reduced diameter portion. It is characterized by having been done.

That is, the insertion member is inserted from the side whose inner diameter is gradually increased by the tapered portion. Therefore, the insertion member can be easily inserted.

[0015]

FIG. 1 is a perspective view showing a one-pole seal packing 10 according to a first embodiment of the present invention. 2 (A), FIG. 2 (B), FIG.
(C) and FIG. 2 (D) show the seal packing 10 in a plan view, a front view, a right side view, and a bottom view, respectively. Further, FIGS. 3A and 3B show the seal packing 10 in a sectional view taken along line AA and a sectional view taken along line BB of FIG. 2A, respectively. In addition, seal packing 1
The left side view of 0 appears symmetrically with the right side view. The rear view of the seal packing 10 appears symmetrically with the front view.

As shown in FIG. 5, the seal packing 10
Is used by being attached to the waterproof connector 70. The waterproof connector 70 includes a male housing 72 and a female housing 74. Further, the male housing 72 has a substantially cylindrical tubular portion 76, and the female housing 74 has an insertion portion inserted into the tubular portion 76. Portions 78 are respectively formed. The cylindrical portion 76 is inserted into the insertion portion 78 so that the male housing 72 and the female housing 74 are integrated, and the waterproof connector 70 is configured as a whole. An insertion hole 80 is formed in the male housing 72 and the female housing 74 so that a cord or the like is inserted and connected.

As shown in FIGS. 1 to 3, the seal packing 10 has a main body 12 formed of rubber in a substantially cylindrical shape. As shown in FIG. 5, the main body 12 has a predetermined shape so that the main body 12 can be disposed in a gap formed between the cylindrical portion 76 of the male housing 72 and the insertion portion 78 of the female housing 74. It has been.

The inner surface of the main body 12 has one end in the axial direction (FIG. 3).
In the vicinity of (the upper end in (A)), an annular inner contact portion 14 swelling inward is formed over the entire circumference and integrally with the main body portion 12. In addition, the outer surface of the main body 12 has a position substantially the same as that of the inner contact portion 14 (a position near one end in the axial direction).
In addition, an annular outer contact portion 16 bulging outward is formed over the entire circumference and integrally with the main body portion 12. In the natural state (in a state in which the inner contact portion 14 is not elastically deformed), the inner periphery of the inner contact portion 14 (the ridge line where the inner contact portion 14 swells most inward) is positioned inside the outer surface of the insertion portion 78 so as to be inside. The shape of the contact portion 14 is determined. Similarly, in the natural state,
The shape of the outer contact portion 16 is determined such that the outer periphery of the outer contact portion 16 (the ridge line at which the outer contact portion 16 bulges outward) is located outside the inner surface of the tubular portion 76.

Therefore, with the main body 12 inserted into the gap between the cylindrical portion 76 and the insertion portion 78, the inner contact portion 14
Is in contact with the outer surface of the insertion portion 78 and elastically bends outward, and is brought into close contact with the outer surface of the insertion portion 78 over the entire circumference by this reaction force. Similarly, the outer contact portion 16 comes into contact with the inner surface of the cylindrical portion 76 and elastically bends inward, so that the outer contact portion 16 comes into close contact with the inner surface of the cylindrical portion 76 over the entire circumference by the reaction force. As a result, the flow of fluid (water, oil, or the like) into the waterproof connector 70 is prevented, and the internal cord is waterproofed. The inner contact portion 14 and the outer contact portion 16
The number is not particularly limited, but is two in this embodiment.

On the inner surface of the main body 12, the main body 12 is expanded inward at a position on the other end side (the female housing 74 side, lower side in FIGS. 3A and 3B) than the inner contact portion 14. A reduced diameter portion 18 that is substantially reduced in diameter from the main body portion 12 is formed over the entire circumference and integrally with the main body portion 12.
As can be seen from FIG. 2A, the ridge line of the reduced diameter portion 18 is:
It is located further inside than the ridge line of the inner contact portion 14. When the main body portion 12 is inserted into the gap between the cylindrical portion 76 and the insertion portion 78, the reduced diameter portion 18 comes into contact with the outer surface of the insertion portion 78 and elastically flexes outward. Press 78. For this reason, a large frictional force acts between the insertion portion 78 and the reduced diameter portion 18.

As shown in detail in FIG. 4, a tapered portion 20 whose diameter is gradually increased toward the other end is formed at the other end of the reduced diameter portion 18 from the ridge line. Due to the tapered portion 20, the inner diameter of the reduced diameter portion 18 is gradually increased toward the other end. Accordingly, the opening area inside the main body 12 when the insertion portion 78 is inserted into the main body 12 is increased, and the insertion is facilitated.

The other end of the main body 12 is formed with a flange 22 which extends the main body 12 in a ring shape outward. Further, from both ends of the main body 12 in the width direction (the left-right direction in FIG. 2A), a protrusion 24 is formed by partially projecting outward from the flange 22. As shown in FIG. 5, when the main body 12 is attached to the insertion portion 78, the protrusion 24 is positioned at a predetermined position so as to be accommodated in an accommodation hole 84 formed in the outer cylinder 82 of the female housing 74. It is formed in a shape. Further, as shown in FIG. 5, when the seal packing 10 moves in the detaching direction from this state, the seal packing 10 hits a locking claw 86 formed on the outer cylinder 82, and resistance to this movement is generated.

Next, the mounting method and operation of the seal packing 10 according to the first embodiment will be described.

First, the seal packing 10 is placed in a state where the female housing 74 and the male housing 72 are separated from each other.
It is mounted on the insertion portion 78 of the female housing 74. That is, the insertion portion 78 is attached to the opening on the other end side of the main body portion 12, and the entire seal packing 10 is pushed into the insertion portion 78. At this time, since the tapered portion 20 is formed on the other end side of the reduced diameter portion 18 and the opening is substantially enlarged, the insertion portion 78 can be easily inserted.

During insertion, the projection 24 formed at the other end of the main body 12 contacts the outer cylinder 82 of the female housing 74. Since the main body 12 is entirely formed of rubber, the projection is formed. 24 bends. Therefore, the seal packing 10 can be mounted smoothly without obstruction or large resistance when the seal packing 10 is mounted.

As shown in FIG. 5, the projection 24 is
Then, when the seal packing 10 is accommodated in the accommodation hole 84 and the other end of the seal packing 10 comes into contact with the wall 88 of the female housing 74, the mounting to the female housing 74 is completed.

In the mounted state, the inner contact portion 14 formed on the main body portion 12 is elastically bent outward and comes into close contact with the outer surface of the insertion portion 78 by the reaction force.

Further, the reduced diameter portion 18 is pressed from the outer surface of the insertion portion 78 and elastically bends outward.
Is pressed against the outer surface. As a result, a large frictional force equal to or greater than a predetermined value acts between the outer surface of the insertion portion 78 and the reduced diameter portion 18.

When the reduced diameter portion 18 elastically bends outward as described above, a portion of the inner surface of the main body 12 near the reduced diameter portion 18 also elastically bends outward. Since the reduced diameter portion 18 is formed at a position separated by a predetermined distance in the axial direction from the inner contact portion 14, the inner contact portion 14 does not elastically bend outward and secures the adhesion of the insertion portion 78 to the outer surface. Is done.

Next, the cylindrical portion 76 of the male housing 72 is inserted between the outer cylinder 82 of the female housing 74 and the main body 12 of the seal packing 10. Thereby, as shown in FIG. 5, the male connector 72 is integrated with the female connector 74 to form the waterproof connector 70.

The outer contact portion 16 formed on the main body 12 of the seal packing 10 is pushed by the inner surface of the cylindrical portion 76 and elastically bends inward, and comes into close contact with the inner surface of the cylindrical portion 76 by the reaction force. ing. Therefore, with the seal packing 10 attached to the waterproof connector 70, the inner contact portion 14 contacts the outer surface of the insertion portion 78 of the female housing 74, and the outer contact portion 16 contacts the inner surface of the cylindrical portion 76 of the male housing 72. Then, the space between the outer surface of the insertion portion 78 and the inner surface of the tubular portion 76 is sealed. Therefore, the cord or the like inserted into the waterproof connector 70 is waterproofed.

When the male housing 72 is pulled with respect to the female housing 74 in the mounted state, a pulling force acts on the seal packing 10 via the outer contact portion 16. However, between the reduced diameter portion 18 of the seal packing 10 and the outer surface of the insertion portion 78, a large frictional force greater than a predetermined value acts due to the elastic deformation of the reduced diameter portion 18, so that the female housing of the seal packing 10 It becomes a resistance of the movement in the detaching direction with respect to 74.

A force larger than this frictional force acts on the seal packing 10, and as shown in FIG.
Is slightly moved in the disengagement direction (upward), the projection 24 hits the locking claw 86, which is a resistance to the movement. That is, the frictional force acting between the reduced diameter portion 18 of the seal packing 10 and the outer surface of the insertion portion 78 and the protrusion 24
The separation of the seal packing 10 from the female housing 74 is securely prevented by the movement resistance caused by the contact of the seal packing 10 with the locking claw 86.

In the seal packing 10 according to the first embodiment, the main body portion 12, the inner contact portion 14, the outer contact portion 16, the reduced diameter portion 18, the flange portion 22, and the projection 24 are all made of the same material. Since it is integrally formed and does not constitute a seal packing with a plurality of parts as in the related art, the productivity is increased and the production cost can be reduced.

FIG. 7 is a perspective view showing a two-pole seal packing 40 according to a second embodiment of the present invention. 8A, FIG. 8B, FIG. 8C, FIG.
(D) is a plan view of the seal packing 40,
It is shown in a front view, a right side view, and a bottom view. further,
9A and 9B show the seal packing 40 in a cross-sectional view taken along a line CC and a line DD in FIG. 8A, respectively. The left side view of the seal packing 40 appears symmetrically with the right side view. Also, seal packing 4
The back view of 0 appears symmetrically with the front view.

As shown in FIG. 11, the seal packing 40 is attached to a two-pole waterproof connector 90 (consisting of a male housing 92 and a female housing 94) into which two cords are inserted. The main body 42 is formed wider than the seal packing 10 according to the first embodiment. Hereinafter, the first
The same reference numerals are given to the same components, members, and the like as those of the seal packing 10 and the waterproof connector 90 according to the embodiment, and the description is omitted.

The seal packing 4 according to the second embodiment
0, as can be seen from FIG.
Are not formed over the entire inner periphery of the main body 42 of the seal packing 40, but are formed only at both ends in the width direction. The projecting end of the reduced diameter portion 44 is
(In other words, the interval between the two reduced diameter portions 44 is shorter than the width of the insertion portion 78).

Further, a tapered portion 46 whose diameter is gradually increased toward the other end is formed on the other end side of the ridge line of the reduced diameter portion 44, and the inner diameter of the reduced diameter portion 44 (the opposite reduced diameter portion 44). Width) is gradually increased.

Accordingly, also in the seal packing 40, when the main body 42 is mounted on the insertion portion 78 of the female housing 74, the insertion portion 78 can be easily inserted.
In addition, since the projection 24 hits the outer cylinder 82 and is bent during the insertion, no obstruction occurs when the seal packing 10 is mounted, and no large resistance is generated.

In the mounted state, the inner contact portion 14 is inserted into the insertion portion 78.
And the outer surface of the insertion portion 78 and the reduced diameter portion 1.
8, a large frictional force equal to or greater than a predetermined value acts.
The reduced diameter portion 44 is formed at a position away from the inner contact portion 14 by a predetermined distance, and the adhesion of the inner contact portion 14 to the outer surface of the insertion portion 78 is ensured.

As shown in FIG. 11, between the outer cylinder 82 of the female housing 94 and the main body 12 of the seal packing 10,
When the cylindrical portion 76 of the male housing 92 is inserted, the male housing 92 is integrated with the female housing 94 to form the waterproof connector 90. In this state, the outer contact portion 16 is in close contact with the inner surface of the cylindrical portion 76, and the space between the outer surface of the insertion portion 78 and the inner surface of the cylindrical portion 76 is sealed.

Here, even if the male housing 72 is pulled with respect to the female housing 74, a predetermined value is maintained between the reduced diameter portion 18 of the seal packing 10 and the outer surface of the insertion portion 78 by the elastic deformation of the reduced diameter portion 18. Since the above-mentioned large frictional force acts, the seal packing 10 resists the movement of the seal housing 10 in the detaching direction with respect to the female housing 74. Further, when a force greater than this frictional force acts on the seal packing 10 and the seal packing 10 slightly moves in the detaching direction as shown in FIG. Detachment from the housing 74 is reliably prevented.

Further, the seal packing 40 is also similar to the seal packing 10 according to the first embodiment, and is similar to the seal packing 10 according to the first embodiment.
2. Since the inner contact portion 14, the outer contact portion 16, the reduced diameter portion 18, the flange portion 22, and the protrusion 24 are all integrally formed of the same material, productivity is increased and production cost is reduced. It becomes possible.

In the above description, the seal packings 10 and 2 attached to the one-pole waterproof connector 70 are described.
Seal packing 4 to be attached to pole waterproof connector 90
However, the present invention is not limited to the waterproof connector to which the seal packing of the present invention is attached. Thus, the seal packing of the present invention can be configured. In addition, not only the waterproof connector, the tubular member, the insert member inserted inside the tubular member, in any case to seal between the inner surface of the tubular member and the outer surface of the insert member between, The packing (seal packing 10, 40) of the present invention can be used.

As is clear from the above description,
The reduced diameter portions 18 and 44 do not necessarily need to be formed over the entire inner surface of the main body portion 12, and the position and shape are not particularly limited as long as the above-described frictional force can be applied. In addition, the positional relationship between the reduced diameter portions 18 and 44 and the inner contact portion 14 and the outer contact portion 16 is not limited to the above, and, for example, the inner contact portion 14 and the outer contact portion 16 are formed by the main body portions 12 and 42. And the reduced diameter portions 18, 44 may be formed at one end of the main body portions 12, 44 at a position separated from the inner contact portion 14 by a predetermined distance. That is,
Even with such a configuration, the cylindrical portion 7 of the inner contact portion 14
6, the inner contact portion 14 and the outer contact portion 16 can seal between the inner surface of the cylindrical portion 76 and the outer surface of the insertion portion 78.

Further, the inner contact portion 14 and the outer contact portion 1
6 does not necessarily have to be bulged inward and outward from the main body parts 12 and 42 as described above, and it is sufficient that it is in close contact with the insertion part 78 and the tubular part 76. For example,
The shape of the main body 12 may be determined so that the entire inner and outer surfaces of the main bodies 12 and 42 are in close contact with the insertion portion 78 and the cylindrical portion 76, respectively.

The frictional force acting between the reduced diameter portions 18 and 44 and the insertion portion 78 is sufficiently large, and the seal packings 10 and 40 are provided.
When the pulling force acts on the female housing 74, the protrusion 24 need not necessarily be formed.

The material constituting the seal packings 10 and 40 is not limited to the above-mentioned rubber, but may be the inner contact portion 14 or 40.
Any elastic material can be used as long as the outer contact portion 16 and the reduced diameter portions 18 and 44 can be elastically deformed so as to exert their respective functions. For example, a resin having a predetermined elasticity may be used.

[0049]

According to the first aspect of the present invention, the inner surface of the cylindrical member and the outer surface of the insert member are disposed between the cylindrical member and the insertion member inserted inside the cylindrical member. A packing that seals between the body and is formed in a substantially cylindrical shape by an elastic material and is disposed between the cylindrical member and the insertion member; and is formed on an outer periphery of the body integrally with the main body. An outer contact portion that is formed on the inner surface of the cylindrical member and adheres over the entire circumference; and an inner contact portion that is formed on the inner periphery of the main body portion integrally with the main body portion and adheres over the entire outer surface of the insertion member. And an inner circumference of the main body portion formed integrally with the main body portion at least partially reduced in diameter, and presses the insertion member by elastic deformation to apply a frictional force of a predetermined value or more to the insertion member. Having a reduced diameter portion, so that a seal is provided between the inner surface of the tubular member and the outer surface of the insertion member. Can, Rutotomoni, productivity is high, it is possible to lower the production cost. .

According to a second aspect of the present invention, in the first aspect of the invention, the reduced diameter portion is formed at a position separated from the inner contact portion by a predetermined distance in the axial direction of the main body. Therefore, the inner contact portion does not spread outward, and high adhesion to the outer surface of the insertion member can be secured.

According to a third aspect of the present invention, in the first or second aspect of the invention, the tapered portion whose inner diameter gradually increases toward the side where the insertion member is inserted is formed in the reduced diameter portion. Therefore, the insertion member can be easily inserted.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a seal packing according to a first embodiment of the present invention.

2A is a plan view, FIG. 2B is a front view, FIG. 2C is a right side view, and FIG. 2D is a bottom view showing the seal packing according to the first embodiment of the present invention.

3A shows a seal packing according to the first embodiment of the present invention, FIG. 3A is a cross-sectional view taken along line AA of FIG. 2A, and FIG.
FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 4 is an enlarged sectional view showing the vicinity of a reduced diameter portion of the seal packing according to the first embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a state where the seal packing according to the first embodiment of the present invention is mounted on the waterproof connector.

FIG. 6 is a cross-sectional view showing a state in which the seal packing according to the first embodiment of the present invention is attached to the waterproof connector and has moved in a detaching direction.

FIG. 7 is a perspective view showing a seal packing according to a second embodiment of the present invention.

8A is a plan view, FIG. 8B is a front view, FIG. 8C is a right side view, and FIG. 8D is a bottom view showing a seal packing according to a second embodiment of the present invention.

9A shows a seal packing according to a second embodiment of the present invention, FIG. 9A is a cross-sectional view taken along line CC of FIG. 8A, and FIG.
FIG. 9 is a sectional view taken along line DD of FIG.

FIG. 10 is an enlarged sectional view showing the vicinity of a reduced diameter portion of a seal packing according to a second embodiment of the present invention.

FIG. 11 is a cross-sectional view showing a state in which a seal packing according to a second embodiment of the present invention is mounted on a waterproof connector.

FIG. 12 is a cross-sectional view illustrating a state in which a seal packing according to a second embodiment of the present invention is mounted on a waterproof connector and has moved in a detaching direction.

FIG. 13 is a cross-sectional view showing a state where a conventional seal packing is mounted on a waterproof connector.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 seal packing (packing) 12 main body part 14 inner contact part 16 outer contact part 18 reduced diameter part 20 taper part 40 seal packing (packing) 42 main body part 44 reduced diameter part 46 taper part 70 waterproof connector 76 tubular part (tubular part) Member) 78 insertion part (insertion member) 90 waterproof connector

Claims (3)

[Claims] 1. A packing disposed between a cylindrical member and an insertion member inserted inside the cylindrical member to seal between an inner surface of the cylindrical member and an outer surface of the insertion member. A main body portion formed of an elastic material in a substantially cylindrical shape and disposed between the cylindrical member and the insertion member; and a body formed integrally with the main body portion on an outer periphery of the main body portion and entirely formed on an inner surface of the cylindrical member. An outer contact portion that adheres over the circumference; an inner contact portion that is formed integrally with the main body portion on the inner periphery of the main body portion and adheres over the entire outer surface of the insertion member; and a main body that is integral with the main body portion. A reduced diameter portion formed by at least partially reducing the inner circumference of the portion, and pressing the insertion member by elastic deformation to apply a frictional force of a predetermined value or more to the insertion member. Characteristic packing. 2. The packing according to claim 1, wherein the reduced diameter portion is formed at a position separated from the inner contact portion by a predetermined distance in an axial direction of the main body. 3. The packing according to claim 1, wherein a tapered portion whose inner diameter gradually increases toward a side where the insertion member is inserted is formed in the reduced diameter portion.