JP2008157299A - Ultra-high-pressure sealing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain a sufficient sealing effect to the multiple number of reciprocation of a piston by forming a cylindrical seal of multiple layered ring-like members. <P>SOLUTION: A high-pressure sealing structure of this invention comprises a cylindrical seal presser 5 and a cylindrical seal 2 serially arranged between a piston rod 4 and a cylinder hole 1A of a cylinder 1. The cylindrical seal 2 made of a resin is structured by laminating multiple ring-like members 10, 11, 12 and 13 having a different cross sectional shape in the axial direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ultra-high pressure seal structure, and in particular, a cylindrical seal is formed by a plurality of ring-shaped members stacked on each other, and the cylindrical seal is deformed so as to protrude toward the inside and outside of the cylinder by pressure from the axial direction. Thus, the present invention relates to a novel improvement for maintaining a sufficient sealing effect against a large number of reciprocating motions of the piston.

Examples of this type of ultra-high pressure seal structure that have been conventionally used include the configurations disclosed in Patent Documents 1, 2, 3, and 4 described below.
That is, although not particularly shown in any case, in the case of the configuration of Patent Document 1, a seal in which a rubber packing and a metal packing are combined is employed.
Moreover, in the case of the structure of patent document 2, the seal | sticker which combined the rubber packing and the metal packing is employ | adopted.
Moreover, in the case of patent document 3, the seal | sticker which combined the rubber packing and the metal packing is employ | adopted similarly to the above-mentioned.
Furthermore, in the case of Patent Document 4, a seal in which an O-ring, leather packing, and metal packing are combined is employed.

Japanese Patent Laid-Open No. 2-60909 Utility Model Registration No. 2582019 No. 7-54689 Japanese Utility Model Publication No. 6-18759

Since the conventional ultra-high pressure seal structure is configured as described above, the following problems exist.
That is, the configuration of each sealing member disclosed in each of the above-mentioned documents is a combination of rubber and metal. When the sealing operation is performed, the components such as the cylinder and the piston are damaged and disassembled. Even if it is cared for, it has a short life of about once, and is not suitable for a product that is repeatedly subjected to pressure.
Further, the conventional seal member is a fixed seal that does not apply a load to the side of the seal, and is for only one pressurization, and cannot be sealed against repeated pressure increase / decrease.

  An ultra-high pressure seal structure according to the present invention includes an ultra-high pressure including a piston rod that reciprocates in a cylinder, and a cylindrical seal retainer and a cylindrical seal that are arranged in series between the piston rod and a cylinder hole of the cylinder. In the sealing device, the cylindrical seal is configured by laminating a plurality of annular members having different cross-sectional shapes formed of a resin material in the axial direction of the cylindrical seal, and each annular member is A pressure-receiving member that directly receives the pressure of the cylindrical seal presser and has a V-shaped or U-shaped convex portion in cross section, a ring-shaped groove member that joins the pressure-receiving member and forms a V-shaped or U-shaped cross section, and the ring-shaped groove A ring-shaped inner member having a tapered surface joined to the inner outer slope of the member, a ring-shaped outer member joined to the outer outer slope of the ring-shaped groove member and the tapered surface, and having a triangular cross-section. Is made structure, also, the annular groove member has a configuration consisting of a plurality.

Since the super high pressure seal structure according to the present invention is configured as described above, the following effects can be obtained.
That is, all the cylindrical seals are made of resin and are formed of a laminate of a plurality of ring-shaped members, and each ring-shaped member is deformed so as to project to the cylinder side and the piston side under pressure, Sealing against repeated pressure increase / decrease can be achieved by reciprocating sliding of the piston rod without damaging the piston.
In addition, the cylindrical seal is deformed to cope with sliding under ultrahigh pressure (80 to 700 MPa), and the piston rod can be operated repeatedly.
Furthermore, since the cylindrical seal is entirely made of a resin material, it can be used repeatedly without damaging the cylinder and the piston.

  In the present invention, a plurality of pistons are formed by forming a cylindrical seal with a plurality of ring-shaped members stacked on each other, and deforming the cylindrical seal so as to protrude toward the inside and outside of the cylinder by pressure from the axial direction. It is an object of the present invention to provide an ultra-high pressure seal structure capable of maintaining a sufficient sealing effect with respect to the reciprocating motion of the.

Hereinafter, preferred embodiments of an ultrahigh pressure seal structure according to the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram schematically showing an ultra-high pressure seal structure according to the present invention. In FIG. 1, reference numeral 1 denotes a cylindrical cylinder, and both ends of the cylinder 1 are closed by lids 1a and 1b. It has been.

A pair of cylindrical seals 2 and 2A are located at both ends in the cylinder hole 1A of the cylinder 1, and cylindrical seal pressers 5 are inserted between the cylindrical seals 2 and 2A. In a hole 5A formed by the cylindrical seals 2 and 2A and the seal presser 5, a piston rod 4, a pressure medium 6 and a bush 3 which are reciprocally movable are disposed. Therefore, the cylindrical seal 2 and the cylindrical seal retainer 5 are disposed between the cylinder 1 and the piston rod 4.
A pipe 7 is provided through the lid 1 a and the bush 3, and the pressure medium 6 can be supplied into the cylinder 1 through the pipe 7.

As shown in FIGS. 2 and 3, the cylindrical seal 2 has a ring shape as a whole, and is formed of only resin, and the first to fourth ring members 10, 11, 11, 11, 11, 11, 11, 11, 11 12 and 13 are laminated together along the axial direction.
The first ring-shaped member 10 constitutes a pressure receiving member that is deformed so as to project to both sides by the arrow A when pressure is applied by the seal retainer 5 and a convex portion 10a having a V-shaped or U-shaped cross section. have.

The first ring-shaped member 10 is provided with a plurality of second ring-shaped members 11 as ring-shaped groove members having a V-shaped or U-shaped cross section for joining to the convex portion 10a.
The groove shape of each of the second ring-shaped members 11 is configured so that it can be joined following the shape of the convex portion 10a.

  A ring-shaped outer member 12 having a triangular cross-section is bonded to the outer outer inclined surface 11a facing the cylinder 1 of the second ring-shaped member 11 in the lowermost stage in FIG. Is provided.

  An annular outer member 15 to which a tapered surface 13a is joined is provided on the inner outer slope 11b facing the piston rod 4 side of the second annular member 11, and this tapered surface 13a is joined to the annular outer member 12. Yes.

Therefore, as shown in FIG. 4, when the pressure in the pressure direction indicated by the arrow B is applied as the pressure by the seal presser 5, the second annular members 11 are moved to both sides by the action of the convex portion 10a. And the third ring-shaped member 12 projects in the outer direction indicated by the arrow D, and the fourth ring-shaped member 13 moves toward the inner side indicated by the arrow E by the pressing force from the inner outer slope 11b. By projecting the fourth ring-shaped member 13 in the direction, the seals between the inner surface of the cylinder 1 and the outer surfaces of the piston rod 4 and the bush 3 can be made complete by the respective ring-shaped members 10 to 13.
In addition, the surface roughness of the circumferential surface of the cylinder hole 1A and the piston rod 4 is 0.05 s to 12.5 s.

Next, the operation of the pressure booster to which the ultra high pressure seal structure according to the present invention shown in FIG. 1 is applied will be described.
In the state of FIG. 1, when the inside of the cylinder 1 is pressurized at an initial pressure of about 80 MPa and the piston rod 4 is slid up and down by a hydraulic unit (not shown), the pressure medium 6 of the cylinder 1 is further pressurized.
The pressurized pressure medium 6 can pressurize a specimen not shown through the pipe 7.
In addition, when the above-described sliding movement of the piston rod 4 up and down once (that is, the pressure is increased to 700 MPa and the pressure is reduced to 80 MPa) is counted as one time, a maximum of 1000 or more sealing operations can be achieved.

Next, the configuration shown in FIG. 5 will be described with respect to an embodiment in which the ultrahigh pressure seal structure according to the present invention is applied to the longitudinal cylinder 1 and a seal test is conducted.
In the test apparatus having the configuration shown in FIG. 5, the same parts as those in FIG. 1 are denoted by the same reference numerals, description thereof will be omitted, and only different parts will be described.
A check valve 7A and a pressure sensor 9 are connected to the pipe 7. Fixing screws 32 as stoppers are provided at both ends of the piston rod 4, and the position of the piston rod 4 that is reciprocally moved by the hydraulic unit 30 is a pair. The limit switches 31, 33 are configured to be detected.

  In the above-described configuration, reciprocal switching of the piston rod 4 is performed by detection of the limit switches 31 and 33. As an actual seal test, the inner diameter of the cylinder 1 is 88.9 mm and the outer diameter of the piston rod 4 is 76.2 mm, a pressure medium 6 made of water + solvent is placed in the cylinder 1, and after the pressure is increased from 0 MPa to, for example, 80 MPa with the pressure increasing pump 7a, the pressure is increased to 1000 MPa while sliding the piston rod 4 by hydraulic pressure. An experiment in which the pressure is reduced and then the pressure is reduced to 80 MPa while sliding the piston rod 4 by hydraulic pressure reduction is shown in No. 6 of FIG. 1 to No. An experiment was conducted using a cylindrical seal 2 of No. 5 (No. 1 to No. 4 is a seal prepared as a comparative example, and No. 5 is a seal of the present invention).

As a result of the seal test of the cylindrical seal 2 described above, as shown in FIG. 1 and no. In the case of 2 cylindrical seals 2, the seal was achieved only 3 times.
No. In the case of the cylindrical seal 2 of 3, the cylindrical seal 2 protrudes from the cylinder wall surface and the side surface of the piston when force is applied, and brass was used for the pop-out prevention ring. Stayed a few times.

No. In the case of the cylindrical seal 2 shown in FIG. It was almost the same as the structure of No. 3, and a high-density resin was used for the pop-out prevention ring, so that 650 seals could be achieved.
No. In the cylindrical seal 2 of the present invention of No. 5, it was possible to achieve a maximum of 1000 times or more as a sliding seal under an ultrahigh pressure of 700 MPa.
Note that, under the above-described high pressure of 700 MPa, the expansion and contraction of the member of the cylindrical seal 2 must be taken into consideration, and as the material, an elastic plastic or a high-density resin is optimal.

It is sectional drawing which shows the ultra-high pressure seal structure by this invention. FIG. 2 is a partial cross-sectional view of the cylindrical seal of FIG. 1. It is a perspective view which shows the cylindrical seal | sticker of FIG. It is sectional drawing which shows the principal part of FIG. It is a block diagram of the apparatus which performs the seal test of the cylindrical seal | sticker by this invention. It is explanatory drawing which shows the cylindrical seal | sticker with which it uses for the test by the apparatus of FIG. It is a result graph which shows the frequency | count of a seal test of the various cylindrical seals of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder 2 Cylindrical seal 3 Bush 4 Piston rod 5 Cylindrical seal retainer 6 Pressure medium 7 Piping 10 1st ring member (pressure receiving member)
10a Convex part 11 Second annular member (annular groove member)
11a Outer outer slope 11b Inner outer slope 12 Third annular member (annular outer member)
13 Fourth ring-shaped member (ring-shaped inner member)
13a Tapered surface

Claims (3)

A piston rod (4) that reciprocates in the cylinder (1), a cylindrical seal retainer (5) disposed in series between the piston rod (4) and the cylinder hole (1A) of the cylinder (1), and In the ultra-high pressure sealing device provided with the cylindrical seal (2),
The cylindrical seal (2) is formed by laminating a plurality of annular members (10, 11, 12, 13) formed of a resin material and having different cross-sectional shapes in the axial direction of the cylindrical seal (2). Features an ultra-high pressure seal structure.   Each of the ring-shaped members (10, 11, 12, 13) directly receives the pressure of the cylindrical seal presser (5) and has a pressure receiving member (10) having a V-shaped or U-shaped convex portion (10a) in cross section. A ring-shaped groove member (11) which is joined to the pressure-receiving member (10) and has a V-shaped or U-shaped cross section, and a tapered surface (13a) which is bonded to the inner outer slope (11b) of the ring-shaped groove member (11) A ring-shaped inner member (13) having an annular outer member (12) which is joined to the outer outer slope (11a) and the tapered surface (13a) of the ring-shaped groove member (11) and forms a triangle in cross section. The ultra-high pressure seal structure according to claim 1.   The super high pressure seal structure according to claim 1 or 2, wherein the annular groove member (11) comprises a plurality.

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