JPH0614131Y2 - Seal ring - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a seal ring, which is provided between a piston and a cylinder and satisfies both the sealing property and the sliding property even under a high pressure with a temperature change. It relates to a seal ring.

[Prior Art and its Problems] Conventionally, in the case where a high pressure acts between members that relatively move such as a piston and a cylinder, a seal ring that seals both members is shown in FIG. The one shown is known as a typical one.

That is, the seal ring 30 shown in FIG. 4 has a concave groove 3 formed in the piston 1 which is one member between the piston 1 and the cylinder 2 which are relatively moving members.
It is disposed inside, and is made of synthetic resin as a whole, and has a rectangular cross section and a wide sealing surface 30a.

However, in the seal ring 30 shown in FIG. 4, although the sealing surface 30a is wide, the sealing characteristic is good, but the sliding resistance is large when the piston 1 reciprocates in the cylinder 2. It was too much to be put to practical use.

On the other hand, as shown in FIGS. 5 and 6, it is known that the sliding resistance is reduced, and the seal ring 30 shown in these figures is the same as that shown in FIG. On the other hand, the width of the sealing surface 30a is reduced.

That is, the seal ring 30 shown in FIG. 5 is different from the seal ring shown in FIG. 4 in that both corners of the seal surface 30a are cut into tapered shapes to reduce the width of the seal surface 30a. The seal ring 30 shown in FIG.
In contrast to the one shown in FIG. 4, the seal ring 30 has a narrow overall shape, and the seal surface 30a has a small width. However, in the seal ring 30 shown in FIG. 5 and FIG. 6, the sliding resistance becomes smaller than that shown in FIG. It had a problem that it was not enough.

Further, as means for improving the sealing characteristic, those shown in FIGS. 7 and 8 are known.

That is, in the piston shown in FIG. 7, which has the groove 3 between the cylinder 2 and the seal ring 30, the diameter of the piston 1 is divided by the groove 3. The diameter on the opposite side to the acting pressure side was set to be large. That is, when the gap between the cylinder 2 and the piston 1 with the groove 3 as a boundary is set to the pressure side t and the side t ₁ opposite to the pressure side, t> t ₁ is satisfied. The seal ring 30 provided is
The deformed portion protruding into the narrow gap between the cylinder 2 and the piston 1 on the side opposite to the pressure side is reduced to improve the sealing characteristic.

Further, in the case shown in FIG. 8, the seal ring 30
A metal backup ring 32 is also used as a separate member of the seal ring 30.
It is located on the side opposite to the pressure side in the concave groove 3 with respect to the seal ring 30.
It suppresses excessive deformation of and improves the sealing characteristics.

However, even with the means for improving the seal characteristics shown in FIGS. 7 and 8, the sliding ring heat generation causes the seal ring 30 itself to thermally expand and the tightening margin to increase. Although the sealing characteristics are satisfied,
It is difficult to keep the sliding resistance low, and when these conventional seal rings 30 are used at high temperatures, they are constrained by the cylinder 2 even if the diameter dimension increases, so that creep occurs and they are used at high temperatures. When used again at room temperature after the above, the diameter dimension is reduced due to the creep generated at the high temperature and high pressure, and a gap is formed between the outer periphery of the seal ring 30 and the cylinder 2, resulting in the loss of the sealing characteristics. Had.

The present invention solves the above-mentioned problems of the conventional seal ring, and has both sealing characteristics and sliding characteristics even after being used at high temperature and high pressure, even at normal temperature and high pressure. It is an object of the present invention to provide a seal ring that can satisfy the above.

[Means for solving problems]

In order to solve the above problems, the present invention provides a seal ring, which is disposed in a groove provided in a piston moving in a cylinder and seals between the cylinder and the cylinder, wherein the seal ring is an annular base. And a vertical portion provided on the outer peripheral surface of the annular base portion and an outer peripheral surface provided on the outer peripheral surface of the vertical portion and closely contacting the inner peripheral surface of the cylinder, and an upper annular portion wider than the vertical portion. A first ring made of synthetic resin having a concave portion formed by the annular base portion, the vertical portion and the upper annular portion, and a projecting annular portion fitted into the concave portion on one side are provided, and an outer peripheral surface of the cylinder is formed. It is provided with a second metal ring made of an annular main body that is separated from the inner peripheral surface.

[Action]

According to the present invention, by adopting the above configuration, a metal ring having a linear expansion coefficient significantly smaller than that of a synthetic resin is fitted to the synthetic resin ring, so that the synthetic resin ring is made even under a high pressure with a temperature change. It is possible to suppress the increase of the interference due to the thermal expansion of the ring, suppress the sliding resistance to a small value within the range where the sealing property is satisfied, and simultaneously satisfy both the sealing property and the sliding property.

〔Example〕

 Embodiments of the present invention shown in the drawings will be described below.

1 is a sectional view showing a first embodiment of a seal ring according to the present invention, FIG. 2 is a sectional view showing a second embodiment of a seal ring according to the present invention, and FIG. 3 is a third embodiment according to the present invention. It is sectional drawing which shows an Example.

The seal ring 4 shown in FIG. 1 is arranged in a concave groove 3 provided in a piston 2 moving in the cylinder 1.

The seal ring 4 for sealing between the cylinder 1 and
The annular base portion 5a, the vertical portion 5b provided on the outer peripheral surface of the annular base portion 5a, and the outer peripheral surface provided on the outer peripheral surface of the vertical portion 5b are in close contact with the inner peripheral surface 1a of the cylinder 1. A first ring 5 made of synthetic resin having an upper annular portion 5c wider than the portion 5b, and a concave groove 5d formed by the annular base portion 5a, the vertical portion 5b and the upper annular portion 5c, and the concave portion 5d on one side. A second annular ring 6 made of an annular main body 6b having an outer peripheral surface spaced apart from the inner peripheral surface 1a of the cylinder 1.

In the figure, 4a is a sealing surface formed on the outer peripheral surface of the upper annular portion 5c.

In the seal ring 4 having the above-mentioned configuration, the protruding annular portion 6a of the metal second ring 6 having a remarkably smaller linear expansion coefficient than the synthetic resin has the concave portion 5d of the synthetic resin first ring 5.
Since the most part of the annular base portion 5a is fitted, the thermal expansion of the synthetic resin first ring 5 at a high temperature is suppressed by the metal second ring 6, and the sliding resistance of the seal ring 4 is made constant to some extent. can do.

Therefore, since the width of the upper annular portion 5c is secured as the minimum sealing surface 4a required for the sealing property while preventing the occurrence of creep, the sealing characteristics are excellent even under high temperature and high pressure, and the sliding property is high. Resistance can be kept low.

FIG. 2 shows a second embodiment of the present invention.

The seal ring 14 differs from that shown in FIG. 1 in that an annular base portion 15a, a vertical portion 15b provided on the outer peripheral surface of the annular base portion 15a, and an outer peripheral surface of the vertical portion 15b are provided. The outer peripheral surface has a tapered shape, and a top portion which is in close contact with the inner peripheral surface 1a of the cylinder 1 is formed on the acting pressure side.
A first synthetic resin member having an upper annular portion 15c wider than the vertical portion 15b, and forming a recess 15d with the annular base portion 15a, the vertical portion 15b and the upper annular portion 15c.
A second ring 16 made of metal, which is composed of a ring 15 and a ring-shaped main body 16b which is provided on one side with a projecting annular portion 16a which is fitted into the recess 15d and whose outer peripheral surface is separated from the inner peripheral surface 1a of the cylinder 1. I am.

In the figure, 14a indicates a sealing surface of the seal ring 14.

With this configuration, since the sealing surface 14a is reduced as compared with the seal ring 4 of the first embodiment,
The sliding resistance can be kept low even at higher temperatures and pressures.

Next, FIG. 3 shows a third embodiment of the present invention.

The seal ring 24 includes an annular base portion 25a and a vertical portion 25b provided at the center of the outer peripheral surface of the annular base portion 25a.
And an upper annular portion 2 which is provided on the outer peripheral surface of the vertical portion 25b, the outer peripheral surface of which is in close contact with the inner peripheral surface 1a of the cylinder 1 and which has protrusions on both sides to be wider than the vertical portion 25b.
5c, a first ring 25 made of synthetic resin having a concave portion 25d formed on both sides of the vertical portion 25b by the annular base portion 25a, the vertical portion 25b, and the upper annular portion 25c, and the concave portion on any one of the left and right sides. The second metal member 25d is provided with a projecting annular portion 26a to be fitted into the inner peripheral surface 1a of the cylinder 1 and has an outer peripheral surface separated from the inner peripheral surface 1a.
It comprises rings 26A and 26B.

In the figure, 24a indicates a sealing surface of the seal ring 24.

Therefore, the seal ring 24 having the above-mentioned configuration is different from the first embodiment in that the protruding annular portion 26a formed on one side of the two metal second rings 26A and 26B having a small linear expansion coefficient, 26a are fitted into the recesses 25d, 25d formed on both sides of the synthetic resin first ring 25, and the annular base 25a
Is held from both sides, the thermal expansion of the synthetic resin first ring 25 is surely suppressed by the two second rings 26A and 26B made of metal, and the second ring is provided on one side as shown in the first embodiment. Compared to the one in which the ring 6 is fitted, it does not generate creep even under high temperature and high pressure, has excellent sealing characteristics, and can keep sliding resistance low.

[Effect of device]

According to the present invention, the configuration as described above prevents the occurrence of creep at high temperature and high pressure, can keep the sliding resistance low, and also allows the creep to occur at high temperature even after returning to normal temperature. Therefore, it has an excellent effect that the diameter does not change and the sealing property can be maintained and the sliding resistance can be suppressed even when used at room temperature and high pressure.

[Brief description of drawings]

1 is a sectional view showing a first embodiment of a seal ring according to the present invention, FIG. 2 is a sectional view showing a second embodiment of a seal ring according to the present invention, and FIG. 3 is a third view of a seal ring according to the present invention. A sectional view showing an embodiment and FIGS. 4 to 8 are sectional views showing a conventional seal ring. 1 ... Cylinder 2 ... Piston 3 ... Recessed groove 4, 14, 24, 30 ... Seal ring 5, 15, 25 ... First ring 5a, 15a, 25a ... Annular base 5b, 15b, 25b. Vertical part 5c, 15c, 25c ... Upper annular part 5d, 15d, 25d ... Recessed part 6, 16, 26 ... Second ring 6a, 16a, 26a ... Projected annular part 6b, 16b, 26b ... Annular body

Claims (1)

[Scope of utility model registration request] 1. A seal ring (4) (14) which is disposed in a groove (3) provided in a piston (2) moving in a cylinder (1) and seals with the cylinder (1).
(24), wherein the seal rings (4), (14), (2)
4) is a ring-shaped base portion (5a) (15a) (25a), a vertical portion (5b) (15b) (25b) provided on the outer peripheral surface of the ring-shaped base portion (5a) (15a) (25a), and this vertical The outer peripheral surface is provided on the outer peripheral surfaces of the parts (5b), (15b) and (25b), and the outer peripheral surface is in close contact with the inner peripheral surface (1a) of the cylinder (1), and the vertical parts (5b) (15b) (25b). A wider upper annular portion (5c) (15c) (25c), and the annular base portions (5a) (15a) (25a), the vertical portions (5b) (15b) (25b) and the upper annular portion (5c). ) (15c) (25c) and recess (5d) (15
d) The first ring (5), (15) and (25) made of a synthetic resin on which (25d) is formed, and the recess (5d) on one side.
(15d) (25d) protruding annular portion (6a)
An annular body (6b) provided with (16a) and (26a), the outer peripheral surface of which is separated from the inner peripheral surface (1a) of the cylinder (1).
A seal ring, comprising: a metal second ring (6) (16) (26) made of (16b) and (26b).