JPH11304002A - Seal structure using o-ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure excellent sealed properties by using an extremely narrow diametral O-ring. SOLUTION: The bottom part of a groove part 14 storing an extremely narrow diametral O-ring 13 is formed into a circular arc cross sectional shape so as to be tightly stuck to the whole peripheral surface of the groove part 14 side of the O-ring 13 squeezed, and the opening side thereof is formed into a vertical wall so as to vertically sandwich the O-ring 13 from a radial direction, thus, without using the space of a squeeze margin causing dispersion of adhesion, the extremely narrow diametral O-ring 13 can be tightly stuck to the groove part 14 side and a counterpart side circumferential surfaces within a wide adhesion area so as to seal between an inner circumferential surface and a peripheral surface, therefore excellent sealed properties can be ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an O-ring, and more particularly to an O-ring.
The present invention relates to a seal structure using an O-ring having a very small diameter such as a wire diameter of not more than mm.

[0002]

2. Description of the Related Art A seal structure using an O-ring is often used for a connection portion, particularly a fitting portion, of a device requiring water tightness. The seal structure of such a fitting portion employs a structure in which a groove along the circumferential direction is formed on one of the inner peripheral surface and the outer peripheral surface to be fitted, and an O-ring is housed in the groove.
When the inner peripheral surface and the outer peripheral surface are fitted with each other, the O-ring is crushed and deformed, and the O-ring is brought into close contact with the inner peripheral surface and the outer peripheral surface, thereby sealing between the two.

[0003] Generally, as shown in FIG.
The O-ring 2 is housed in the groove 1 and the inner peripheral surface 3 and the outer peripheral surface 4 are fitted to each other. The O-ring is crushed and deformed so as to secure a close contact area, so that good sealing properties can be obtained.

[0004]

SUMMARY OF THE INVENTION Such a rectangular groove 1 is provided.
The structure in which the O-ring 2 is housed provides good sealing performance when the O-ring 2 has a wire diameter exceeding 1.5 mm. However, if an O-ring 2 having an extremely small diameter such as a wire diameter of 1 mm or less is used, the rectangular groove portion 1 cannot be set in consideration of the crushing margin due to restrictions such as processing tolerance.

[0005] In this case, the adhesion of the O-ring 2 largely varies, and good sealing properties cannot be secured. Therefore, as shown in FIG. 4, a groove portion 5 having a triangular cross section which is hardly restricted by processing tolerance or the like is used to accommodate the ultra-fine O-ring 2 in the groove portion 5.

[0006] However, since the groove 5 is formed with an inclined surface 6 going upward in both sides of the O-ring 2, the inner peripheral surface 3 and the outer peripheral surface 4 are fitted as shown in FIG. At the time of fitting, the O-ring 2 may fall out of the groove 5 or fall out of the groove 5. Particularly, since the groove portion 5 for accommodating the ultra-fine O-ring 2 is shallow, the tendency is high, and it is difficult to secure good sealing performance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a seal structure which can secure good sealing performance by using an ultra-fine O-ring.

[0008]

According to a first aspect of the present invention, there is provided a seal structure in which a groove for accommodating an O-ring is brought into close contact with the entire outer peripheral surface on the groove side of the crushed O-ring. The cross-sectional shape of the arc is as follows.

Thus, when the inner peripheral surface and the outer peripheral surface are fitted, the O-ring is in close contact with the entire arc surface of the groove, and the ring portion is formed between the inner peripheral surface and the outer peripheral surface from the opening of the groove. It causes crushing deformation that spreads, and comes into close contact with the peripheral surface of the other party.

In the case of an O-ring having an extremely small diameter, the amount of crushing deformation is small. Therefore, the close contact depending only on the crushing deformation spreading between the inner peripheral surface and the outer peripheral surface causes a large amount of deformation on both the inner peripheral surface and the outer peripheral surface. The contact area is secured.

[0011] At this time, since there is no space in the groove to cause the O-ring to be crushed, the variation in the adhesion of the O-ring is reduced. Moreover, both sides of the groove sandwiching the O-ring
Since the O-ring is a wall surface that sandwiches the O-ring, the O-ring does not come out of the groove or fall out of the groove at the time of fitting, so that good sealing performance can always be expected. In addition, even if the O-ring does not undergo crushing deformation during assembly, good sealing can be performed because the O-ring fills the gap due to the internal pressure.

According to the second aspect of the present invention, the peripheral surface portion where the groove is formed further absorbs the crushing deformation of the O-ring, so that good sealing performance is ensured regardless of the accuracy tolerance of the groove. As a result, the peripheral surface portion where the groove is formed is formed of an elastic member so that the elastic deformation of the peripheral surface portion absorbs the crushing deformation of the O-ring.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on one embodiment shown in FIGS. The drawings show a sealing structure of a fitting portion to which the present invention is applied. In the drawing, reference numeral 11 denotes a substantially cylindrical mouth of a device requiring water tightness, and reference numeral 12 denotes an outer peripheral surface 11a of the mouth 11. For example, a cylindrical part. The mouth 11 has a main body portion 11b made of a metal member, and a distal end portion 11c into which the cylindrical component 12 fits is made of an elastic member, for example, a synthetic resin. The tip 11c is formed at the same time when the main body 11b is formed. The cylindrical component 12 is made of a metal member, for example, a synthetic resin member.

One of the outer peripheral surface 11a (tip portion 11c) of the mouth body 11 and the inner peripheral surface 12a of the cylindrical part 12 which overlap by fitting, for example, the outer peripheral surface 11a of the mouth body 11
Is provided with an O-ring 13 having an extremely small diameter, for example, a wire diameter of 1 mm or less.

The present invention is adopted in the mounting structure of the O-ring 13. Describing the same structure, reference numeral 14 denotes an annular groove formed on the outer peripheral surface 11a along the circumferential direction. The bottom of the groove portion 14 is formed in an arc shape such that the entire outer peripheral surface on the inner peripheral side of the O-ring 13 (the entire outer peripheral surface on the groove side) is in close contact. Further, the opening side of the groove portion 14 is the arc surface 1.
4a from the semicircular portion to the outer peripheral surface side in a substantially right angle direction (the mouth 11
(In a direction substantially perpendicular to the axis of the vertical axis). 14b indicates a straight wall (vertical wall) of the groove 14. The O-ring 13 is accommodated in the groove 14, and is regulated by a straight wall 14b (vertical wall) vertically sandwiching the O-ring 13 from the radial direction.

The O-ring portion protruding from the groove 14 comes into close contact with the inner peripheral surface 12a of the cylindrical part 12,
The space between the inner peripheral surface / outer peripheral surface of the mouth body 11 and the cylindrical part 12 is sealed.

The sealing mechanism will be described. As the O-ring 13 is fitted with the tip part 11a of the mouth body 11 and the cylindrical part 12, the entire inner circumferential surface of the O-ring 13 is formed by the arc of the groove 14. While being in close contact with the entire surface 14a, the outer peripheral portion of the O-ring 13 undergoes crush deformation such that it expands from the opening of the groove portion 14 between the inner peripheral surface 12a and the outer peripheral surface 11a. 12 inner peripheral surface 12a
And adhere.

Here, since the O-ring 13 having a very small diameter has a small amount of crushing deformation, the O-ring 13 is closely adhered only to the crushing deformation expanding between the inner peripheral surface 12a and the outer peripheral surface 11a.
a and the outer peripheral surface 11a are sealed while securing a large contact area.

At this time, since there is no space in the groove 14 for the allowance for the crushing of the O-ring 13, variations in the adhesion of the O-ring 13 are reduced, and good adhesion is obtained. In addition, even if the O-ring 13 does not undergo crushing deformation during assembly, the O-ring 13 fills the gap due to the internal pressure.
Good sealing is obtained.

In addition, both walls of the groove 14 are O-ring 1
Since the wall 3 sandwiches the O-ring 13, the O-ring 13 does not come out of the groove 14 or fall out of the groove 14 at the time of fitting. In particular, as shown in FIG.
Since the wall surface of the groove portion 14 that sandwiches 3 is formed by the parallel straight wall 14b that is perpendicular to the radial direction, the O-ring 13 can be reliably prevented from coming off.

Therefore, good sealing performance can be ensured by using the O-ring 13 having an extremely small diameter. In addition, the elasticity of the peripheral surface portion where the groove portion 14 is formed (the tip portion 11 made of synthetic resin)
c), the crush deformation of the O-ring 13 is absorbed, so that good sealing performance can always be ensured irrespective of the tolerance of the accuracy of the groove portion 14 and the like.

In the embodiment, the example in which the O-ring is mounted on the outer peripheral surface is described. However, the same applies to the structure in which the O-ring is mounted on the inner peripheral surface. Further, the present invention is applied to a structure for sealing a fitting portion between a mouth body and a cylindrical part, but is not limited to this, and may be applied to a fitting portion requiring another seal.

[0023]

As described above, according to the first aspect of the present invention, an O-ring having a very small diameter can be formed on the peripheral surface on the groove side and on the mating side without using the space of the crushing margin that causes variation in adhesion. Can be brought into close contact with many contact areas. In addition, since the O-ring having an extremely small diameter is restricted by the groove wall surface, the O-ring does not come out of the groove or fall out of the groove at the time of fitting. In addition, even if the O-ring does not collapse during assembly, the O-ring is
A ring seals the gap.

Therefore, good sealing performance can be ensured by using an O-ring having a very small diameter. In particular, if the wall surface of the groove that sandwiches the O-ring is formed in the vertical wall, it is possible to reliably prevent the O-ring from coming off.

According to the second aspect of the present invention, since the crushing deformation of the O-ring can be absorbed by the peripheral surface portion in which the groove is further formed, regardless of the tolerance of the accuracy of the groove, etc. The ring has an effect that good sealing properties can always be ensured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a seal structure according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view for explaining a structure around a 0-ring / groove portion of the seal structure.

FIG. 3 is a sectional view for explaining a seal structure using a conventional O-ring.

FIG. 4 is a cross-sectional view for explaining a seal structure using a different conventional O-ring.

[Explanation of symbols]

 11a: outer peripheral surface 12a: inner peripheral surface 13: O-ring 14: groove portion 14a: circular arc surface.

Claims (2)

[Claims] A groove is formed in one of an inner peripheral surface and an outer peripheral surface overlapping by fitting so as to extend in a circumferential direction, and an O-ring is housed in the groove, and the O-ring is crushed by the fitting and causes deformation. In a sealing structure in which the inner peripheral surface and the outer peripheral surface are in close contact with each other to seal therebetween, an arc in which the groove for accommodating the O-ring is in close contact with the entire outer peripheral surface on the groove side of the crushed O-ring. A seal structure using an O-ring, wherein the seal structure is configured to have a shape of a cross section. 2. The peripheral part where the groove is formed,
The seal structure using an O-ring according to claim 1, wherein the seal structure is formed of a member having elasticity.