JPH11351404A - High pressure seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the manufacturing cost of a high pressure seal and ensure a long lifetime. SOLUTION: A high pressure seal 20 comprises a seal body 21 and a seal ring 22, and a first back-up ring 23 and a second back-up ring 24, so as to seal a high pressure fluid. The lip portion 21a is tapered, and the rubber seal ring 22 having a square cross section can be contacted therewith. The seal body 21 and the seal ring 22 have polygonal cross sections by combining the straight-line portions, which results in the easy processing of a lathe and the reduction in the manufacturing cost. The seal ring 22 can easily judge the twisting condition where it is not fitted with the lip portion 21a, which prevents the lifetime from being shortened. The first back-up ring and the second back-up ring 23, 24 deviate at the inner peripheral side or the outer peripheral side, so as to improve the adhesiveness for sealing the high pressure fluid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-pressure seal for sealing a high-pressure fluid in a device for handling a high-pressure fluid.

[0002]

2. Description of the Related Art Conventionally, a high-pressure water jet system as shown in FIG. 5 has been used for various processes such as cutting. Such a system is disclosed, for example, by Akashi Technical Research Institute of Kawasaki Heavy Industries, Ltd.
"Kawasaki Heavy Industries Technical Report" No. 108 No. 52 issued on March 20
It is published in Figure 1 on the page. The high-pressure water generator 1
For example, ultrahigh-pressure water having a pressure of several 1,000 kgf / cm ² is generated. The generated ultra-high pressure water is supplied to the on-off valve 2
Is supplied to the nozzle 3 through the nozzle and jetted as a high-pressure water jet. The high-pressure water generator 1 includes an accumulator 4, check valves 5a, 5b, 5c, 5d, a directional control valve 6, a hydraulic unit 7, a water supply unit 8, and an intensifier 9. The ultra-high pressure water is obtained by increasing the pressure of the water supplied from the water supply unit 8 by the pressure intensifier 9.

The pressure intensifier 9 is of a backward movement type. A high pressure water plungers 13a and 13b in high pressure water cylinders 12a and 12b on both sides alternately increase water pressure by a hydraulic piston 11 reciprocating in a hydraulic cylinder 10. Increase pressure. The pressure receiving area of the hydraulic piston 11 is equal to the high pressure water plungers 13a, 13a.
The hydraulic oil supplied from the hydraulic unit 7 is switched by the directional control valve 6 to move by several hundred mm in, for example, about 2 seconds per stroke, because the pressure receiving area is considerably larger than the pressure receiving area of the end face b. . Hydraulic piston 11
, The high-pressure water cylinders 12a, 12b are alternately switched between the suction side and the discharge side, and the check valves 5a,
5b; 5c and 5d switch between suction and discharge of water, and store the generated ultra-high pressure water in the accumulator 4.

In the pressure intensifier 9, a high-pressure water cylinder 12a, 1
Since the water is pressurized to an ultra-high pressure in 2b, it is necessary to seal the ultra-high pressure water so as not to leak into the hydraulic cylinder 10 or to leak outside the pressure intensifier 9. The outer peripheral surfaces of the high-pressure water plungers 13a, 13b and the high-pressure water cylinders 12a,
High pressure water plungers 13a, 13a
It is necessary to prevent ultra-high pressure water from entering the hydraulic cylinder 10 while allowing the sliding displacement of 3b, and the sliding side high pressure seals 14a and 14b are provided. In addition, fixed-side high-pressure seals 15a and 15b are provided near the both ends of the high-pressure water cylinders 12a and 12b because members provided with ports for water intake and discharge need to be inserted from the outside. The sliding-side high-pressure seals 14a and 14b and the fixed-side high-pressure seals 15a and 15b are
a and 12b, which are also common because they seal against ultra-high pressure water.

FIG. 6 shows a schematic configuration of the sliding-side high-pressure seal 14a of FIG. Other sliding-side high-pressure seals 14b and fixed-side high-pressure seals 15a and 15b have the same configuration. A seal body 16 made of a synthetic resin such as polyethylene is disposed on the side receiving the pressure from the ultra-high pressure water. An O-ring 17 made of urethane rubber or the like is fitted as a seal in the lip portion 16a of the seal body. Seal body 1
With respect to 6, a resin backup ring 18 made of polyacetal and a metal backup ring 19 made of a copper alloy or the like are arranged adjacent to the hydraulic cylinder 11 side.

[0006]

In a high-pressure seal as shown in FIG. 6, an O-ring 17 is fitted into a lip 16a of a seal body 16, and the lip 16a is pressed by ultra-high pressure water.
So that the inner peripheral surface and the outer peripheral surface of the seal body 16 are in close contact with the outer peripheral surface of the high-pressure water plunger 13a and the inner peripheral surface of the high-pressure water cylinder 12a. However, the contact between the O-ring 17 and the lip portion 16a of the seal body 16 is a point contact, and when the pressure of the ultra-high pressure water acts, a large force is locally applied. The O-ring 17 is easily twisted when fitted into the lip portion of the seal body 16 and has a uniform circular cross section, so that even if twisting occurs, it is difficult to recognize. If twisting occurs, a large force acts, so that the O-ring 17
The life of the device will be shortened. Further, since the lip portion 16a of the seal body 16 has a complicated shape including a curved surface, it is difficult to form the lip portion 16a by lathing or the like, and the processing cost is high. Furthermore, a resin backup ring 18
Is expected to deform with a moderate elasticity so as to seal between the inner peripheral surface of the high-pressure water cylinder 12a and the outer peripheral surface of the high-pressure water plunger 13a. Contact is not made evenly, and the sealability is easily impaired.

An object of the present invention is to provide a high-pressure seal in which the manufacture of the seal body is easy and the life of the seal ring and the backup ring can be extended.

[0008]

The present invention is provided between an inner peripheral surface of a cavity formed in a high-pressure fluid device and an outer peripheral surface of an insertion member inserted into the cavity. A high-pressure seal for sealing a high-pressure fluid acting on an insertion member from the side, having a tapered lip on one side in the insertion direction, and having an end face perpendicular to the insertion direction on the other side in the insertion direction. A seal ring having a polygonal shape that is fitted to the lip portion of the seal body from one side in the insertion direction, and a contact portion with the lip portion is adapted to the lip portion and is capable of surface contact; Is disposed adjacent to the other side in the insertion direction, has an end surface perpendicular to the insertion direction on one side in the insertion direction, and is inclined at a predetermined angle from a direction perpendicular to the insertion direction on the other side in the insertion direction. Backup ring with inclined surface The first backup ring is disposed adjacent to the other side in the insertion direction, has an inclined surface parallel to the inclined surface on one side in the insertion direction, and has an insertion direction on the other side in the insertion direction. And a second backup ring having an end surface perpendicular to the high pressure seal.

According to the present invention, since the tapered lip portion may be formed on the seal body, the outer shape of the cross-sectional shape of the lip portion can be constituted by a straight line, and processing by a lathe or the like is easy. Manufacturing costs can be reduced. Since the seal ring has a cross-sectional shape that makes surface contact with the tapered lip, it is fitted in the seal body,
Whether or not the twist has occurred can be easily determined, and the twist can be mounted on the lip portion of the seal body without twist. Since the contact surfaces of the first and second backup rings are inclined from a plane perpendicular to the insertion direction, when backing up the seal body that receives the force from the high-pressure fluid, one of them comes inward, The other is displaced outward, respectively, to further supplement the sealing of the seal body.

In the present invention, the first backup ring is made of a copper alloy, the second backup ring and the seal body are made of polyacetal or polyethylene, and the seal ring is made of urethane rubber or nitrile rubber. And

According to the present invention, since the seal body and the seal ring are in surface contact with each other at the tapered lip portion, one is displaced inward and the other is displaced outward by the pressure from the high-pressure fluid. The inner peripheral surface of the cavity and the outer peripheral surface of the insertion member can be tightly sealed respectively. Since the first backup ring is made of a copper alloy, even if the first backup ring is brought into close contact with the inner peripheral surface of the cavity or the outer peripheral surface of the insertion member by a force generated on the inclined surface, the cavity or the insertion member is made of a harder material such as stainless steel. In this case, the inner peripheral surface and the outer peripheral surface can be securely adhered and sealed without damaging the inner peripheral surface or the outer peripheral surface.

In the present invention, the high-pressure fluid device is a high-pressure pump, and the insertion member is a plunger.

According to the present invention, the high-pressure pump can be reliably sealed so that the high-pressure fluid does not leak from around the plunger for compressing the fluid.

[0014]

FIG. 1 shows a schematic configuration of a high-pressure seal 20 according to an embodiment of the present invention. The seal body 21 is formed in a ring shape from a synthetic resin such as polyethylene. The lip portion 21a is formed in a tapered shape, and has a cross-sectional shape that is inclined at, for example, about 45 ° with respect to the direction of the axis 20a. The high-pressure seal 20 is provided between the cylindrical cavity and the cylindrical insertion member, the outer peripheral portion 21b of the seal main body 21 is parallel to the inner peripheral surface of the cavity, and the inner peripheral portion 21c of the seal main body 21 is It is parallel to the outer peripheral surface of the insertion member.

A rectangular seal ring 22 is fitted to the lip 21a of the seal body 21. Seal ring 22
Is formed of a rubber material, such as urethane rubber or nitrile rubber, which is durable to high-pressure fluid, and has an inclined surface 22 a parallel to the tapered portion of the lip portion 21 a of the seal body 21, and an outer peripheral surface 2.
2b and an inner peripheral surface 22c. The cross-sectional shape of the seal ring 22 has a pentagonal shape including straight sides corresponding to each of the inclined surface 22a, the outer peripheral surface 22b, and the inner peripheral surface 22c.

The inner peripheral surface 22c of the seal ring 22 is in surface contact with the inner outer peripheral surface 21d connected to the lip 21a on the inner peripheral portion 21c side of the seal body 21. Seal body 21
Has a polygonal sectional shape including a lip portion 21a, an outer peripheral portion 21b, an inner peripheral portion 21c, and an inner outer peripheral surface 21d.
Since each of the seal body 21 and the seal ring 22 has a polygonal cross-sectional shape, operations for manufacturing these by lathing or the like are easy, and manufacturing costs can be reduced. The end surface 21e of the seal body 21 opposite to the lip 21a is perpendicular to the direction of the axis 20a. An end surface 22d connecting the outer peripheral surface 22b and the inner peripheral surface 22c of the seal ring 22 is also perpendicular to the direction of the axis 20a.

The end face 21e of the seal body 21 has an axis 2
End surface 23a of first backup ring 23 perpendicular to 0a
Face-to-face contact. The first backup ring 23 has an end face 2
It has an inclined surface 23b facing 3a. The inclined surface 24b of the second backup ring 24 contacts the inclined surface 23b of the first backup ring 23. The inclined surface 24a is
Since it is parallel to the inclined surface 23b, the contact is made on the surface.
The inclination angle is about 15 ° with respect to a direction perpendicular to the axis 20a. End surface 24b of second backup ring 24
Is mechanically held from the outside. The first backup ring 23 is made of, for example, a copper alloy such as phosphor bronze or beryllium copper, and since the insertion member and the cavity are formed of stainless steel or the like, the first backup ring 23 is hardly damaged even when it comes into contact. The second backup ring 24 is formed of the same material as the seal body 21.

FIG. 2 shows a configuration of a pressure intensifier 29 as a high-pressure fluid device using the high-pressure seal 20 shown in FIG. Such an intensifier 29 can be used as the intensifier 9 in the high-pressure water generator 1 shown in FIG. A hydraulic cylinder 30 is provided in the center of the pressure intensifier 29, and a hydraulic piston 31 can reciprocate in the cavity. High-pressure water cylinders 32a and 32b are provided on both sides of the hydraulic cylinder 30, and high-pressure water plungers 33a and 33b pressurize water in the cavities. Since the pressure receiving area of the end faces of the high-pressure water plungers 33a and 33b is much smaller than the pressure receiving area of the hydraulic piston 31, the water is pressurized to an extremely high pressure.

The high-pressure seal 20 shown in FIG. 1 includes high-pressure water cylinders 32a and 32b and high-pressure water plungers 33a and 33b.
Sliding high pressure seals 34a, 34b for sealing between
And the high pressure water cylinders 32a and 32b are commonly used as fixed high pressure seals 35a and 35b for sealing near both ends of the high pressure water cylinders 32a and 32b. The high-pressure water cylinders 32a and 32b and the high-pressure water plungers 33a and 33b are formed of, for example, stainless steel such as SUS630. High pressure water cylinder 32
The seal rings 36a, 36b and the seal rings 37a, 37a,
37b are respectively attached to hold the end faces 24b of the second backup ring 24 shown in FIG. Therefore, the pressure which the seal body 21 of FIG. 1 receives from the ultra-high pressure water is transmitted from the end face 21e of the seal body 21 to the end face 23a of the first backup ring 23, and from the inclined face 23b to the inclined face 24a of the second backup ring 24. And from the end face 24b to the seal rings 36a, 36 in FIG.
b; 37a, 37b. Further, a force for displacing the first backup ring 24 inward and the second backup ring 25 outward is generated on the inclined surfaces 23b and 24a, and the adhesion is improved.

Suction ports 38a and 38b are provided for sucking water into the high-pressure water cylinders 32a and 32b.
In order to discharge the pressurized water, the discharge port 39a,
39b are provided. Hydraulic ports 40a and 40b are provided for introducing hydraulic oil into the hydraulic cylinder 30. In order to detect the position of the hydraulic piston 31 in the hydraulic cylinder 30, the position detectors 41 a and 41 b
Is provided. Check valve blocks 42a and 42b are inserted into both ends of the high-pressure water cylinders 32a and 32b, respectively. The fixed-side high-pressure seals 35a and 35b seal the outer peripheral surfaces of the check valve blocks 42a and 42b and the inner peripheral surfaces of the high-pressure water cylinders 32a and 32b. Check valve plugs 43a and 43b are further inserted into both ends of each check valve block 42a and 42b, and end caps 44a and 44b are attached outside.

FIG. 3 shows a partial configuration near the sliding-side high-pressure seal 34a in FIG.
The partial configuration around a is shown. Other sliding side high pressure seal 3
4b and the fixed-side high-pressure seal 35b have basically the same configuration. Fixed side high pressure seal 3
The check valves 5b and 5d shown in FIG.
Is provided on the suction side. Normally, the spring is pressed toward the suction valve seat 52 by a poppet spring. Further, a poppet 55 and a discharge valve seat 56 corresponding to the check valves 5a and 5c on the discharge side are provided.

In the embodiment described above, the high-pressure seal 2
Although 0 is used in the backward-type intensifier 29 for generating a high-pressure water jet, the high-pressure seal 20 of the present invention can be suitably used even if the intensifier is a single-acting type. Further, the high-pressure seal 20 of the present invention can be suitably applied to other high-pressure fluid devices such as hydraulic pressure and pneumatic pressure.

[0023]

As described above, according to the present invention, the manufacture of the seal body of the high-pressure seal used in the high-pressure fluid device is facilitated, the manufacturing cost is reduced, and the seal ring is less likely to be twisted, and the life is shortened. Can be prevented from becoming shorter. In addition, the life of the backup ring can be extended.

Further, according to the present invention, it is possible to extend the life of the high-pressure seal by using appropriate materials for the seal body, the seal ring, and the backup ring.

According to the present invention, a high-pressure seal around the plunger, which is displaced while contacting a high-pressure fluid with a high-pressure pump, can be effectively performed.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a sectional view showing a configuration of a pressure intensifier 29 using the high-pressure seal 20 of FIG.

3 is a partial cross-sectional view of the vicinity of a sliding-side high-pressure seal 34a in FIG.

FIG. 4 is a partial cross-sectional view of the vicinity of a fixed-side high-pressure seal 35a in FIG.

FIG. 5 is a piping diagram of a water jet system including the pressure intensifier 9;

FIG. 6 is a partial cross-sectional view showing a configuration of a high-pressure seal conventionally used in the pressure intensifier 9 of FIG.

[Explanation of symbols]

 Reference Signs List 20 high-pressure seal 21 seal body 21a lip portion 22 seal ring 22a, 23b, 24a inclined surface 23 first backup ring 24 second backup ring 29 intensifier 30 hydraulic cylinder 31 hydraulic piston 32a, 32b high-pressure water cylinder 33a, 33b high-pressure water plunger 34a, 34b Sliding-side high-pressure seal 35a, 35b Fixed-side high-pressure seal 42a, 42b Check valve block

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masamichi Yamaguchi 3-1-1, Higashikawasaki-cho, Chuo-ku, Kobe-shi, Hyogo Kawasaki Heavy Industries, Ltd. Kobe Plant (72) Inventor Yoshimitsu Yamamoto Higashi-Kawasaki, Chuo-ku, Kobe-shi, Hyogo 3-1-1 Cho-cho Kawasaki Heavy Industries, Ltd. Kobe Plant

Claims (3)

[Claims] 1. A high-pressure fluid provided between an inner peripheral surface of a cavity formed in a high-pressure fluid device and an outer peripheral surface of an insertion member inserted into the cavity, and acting on the insertion member from one side in an insertion direction. A seal body having a tapered lip on one side in the insertion direction and an end surface perpendicular to the insertion direction on the other side in the insertion direction; and a one side in the insertion direction. And a seal ring having a polygonal shape that is fitted to the lip portion of the seal body and the contact portion with the lip portion is adapted to the lip portion and can make surface contact, and is adjacent to the seal body on the other side in the insertion direction. A first surface having an end surface perpendicular to the insertion direction on one side in the insertion direction, and a slope inclined at a predetermined angle from a direction perpendicular to the insertion direction on the other side in the insertion direction. Backup ring and first backup In the insertion direction, one side in the insertion direction has an inclined surface parallel to the inclined surface, and the other side in the insertion direction has an end surface perpendicular to the insertion direction. And a second backup ring having the high pressure seal. 2. The method according to claim 1, wherein the first backup ring is made of a copper alloy, the second backup ring and the seal body are made of polyacetal or polyethylene, and the seal ring is made of urethane rubber or nitrile rubber. The high pressure seal according to claim 1. 3. The high-pressure seal according to claim 1, wherein the high-pressure fluid device is a high-pressure pump, and the insertion member is a plunger.