JP2017053425A - Seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict damage of a first back-up ring due to its expansion in its diameter at the time of insertion in a seal composed of combination of a seal ring installed in an installing groove having a rectangular cross section, the first back-up ring and a second back-up ring.SOLUTION: A first back-up ring has a flat-shaped end surface perpendicular to an axis contacted with a side surface of an installing groove, a cylindrical surface-shaped peripheral surface contacted with another member and a slant surface part crossing with the end surface part and the peripheral surface and then the first back-up ring is formed into a triangular shape in section. A second back-up ring has a flat-shaped end surface perpendicular to an axis contacted with a seal ring, a cylindrical surface-shaped peripheral surface part contacted with a bottom surface part of the installing groove and a slant surface part arranged in correspondence with the slant surface part of the first back-up ring and formed into a triangular shape in section. The slant surface part of the first back-up ring and the slant surface part of the second back-up ring contacted to each other are provided with non-slip structure of convexoconcave engagement.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sealing device according to a sealing technique. The sealing device of the present invention is particularly suitable for use as a high-pressure seal for sealing a high-pressure sealing fluid.

  Conventionally, a sealing device 1 shown in FIG. 4 is known as a high-pressure seal. This sealing device 1 is disposed between two members 51 and 52 facing each other and seals so that the sealing fluid on the high-pressure side H does not leak to the low-pressure side L, and one of the two members 51 and 52 is sealed. Comparison between the seal ring 11 mounted in the mounting groove 53 provided in the member (for example, the shaft) 51 and in close contact with the other member (for example, the housing) 52, and the anti-sealing fluid side (low pressure side L) of the seal ring 11 The first backup ring 21 is hard and the second backup ring 31 is relatively soft and is disposed between the seal ring 11 and the first backup ring 21.

  The mounting groove 53 is a groove having a rectangular cross section because it is easy to process. The first backup ring 21 has a planar end surface portion 21a perpendicular to the axis that contacts the anti-sealing fluid side surface portion 53b of the mounting groove 53, a cylindrical surface portion 21b that contacts the other member 52, and an end surface portion 21a and a circumferential surface. A slope portion 21c that intersects the surface portion 21b is provided, and is formed in a triangular cross section. The second backup ring 31 includes a planar end surface portion 31 a perpendicular to the axis that the seal ring 11 contacts, a cylindrical circumferential surface portion 31 b that contacts the bottom surface portion 53 a of the mounting groove 53, and a slope portion 21 c of the first backup ring 21. Corresponding slopes 31c are provided, and are also formed in a triangular cross section.

  In the sealing device 1 configured as described above, since the first backup ring 21 is disposed on the anti-sealing fluid side (low pressure side L) of the seal ring 11, the seal ring 11 protrudes into the gap 54 between the two members 51 and 52. And the second backup ring 31 is disposed between the seal ring 11 and the first backup ring 21, so that the seal ring 11 is connected to the first backup ring 21 and the other member. It is possible to prevent damage from protruding into a gap (not shown) between 52.

JP-A-10-68467

  However, in the sealing device 1, the slope portion 21c of the first backup ring 21 and the slope portion 31c of the second backup ring 31 that are in contact with each other are both formed as smooth tapered surfaces (conical surfaces), and both sides 21c, 31c. The following inconvenience is pointed out because no slip stopper is provided in the taper surface inclination direction.

That is, when the sealing device 1 is assembled between the two members 51 and 52, as shown in FIG. 5A, first, the sealing device 1 is mounted in the mounting groove 53 of one member 51, and then the sealing device 1 is mounted. with one of the members 51 inserted into the inner circumferential side of the other member 52 (the shaft hole 52a) (arrow x) is, than the inner diameter _{d 2} towards the outer diameter _{d 1} of the shaft hole 52a before insertion of the seal ring 11 Because it is large, the following events occur.

  That is, as shown in FIG. 5 (B), the seal ring 11 temporarily stops insertion when the seal ring 11 interferes with the opening peripheral edge 52b of the shaft hole 52a at the outer periphery during the insertion. Since the insertion of the one member 51 and the first backup ring 21 and the second backup ring 31 pushed by the member 51 is continued (arrow x), the distance t between the side surface portion 53b of the mounting groove 53 and the seal ring 11 is set at this time. It is gradually narrowed. Accordingly, the first backup ring 21 is strongly compressed in the axial direction between the side surface portion 53 b of the mounting groove 53 and the second backup ring 31, whereby the inclined portion 21 c of the first backup ring 21 is inclined to the inclined portion 31 c of the second backup ring 31. The first backup ring 21 is deformed so as to increase its diameter (arrow y). Further, since the insertion is further continued in the state where the diameter is expanded and deformed in this way, the first backup ring 21 interferes with the opening peripheral edge portion 52b of the shaft hole 52a at the outer peripheral portion, thereby damaging the first backup ring 21. There is.

  In view of the above, the present invention provides a sealing device comprising a combination of a seal ring, a first backup ring, and a second backup ring mounted in a mounting groove having a rectangular cross section. It is an object of the present invention to provide a sealing device that can prevent damage.

  In order to achieve the above object, a sealing device of the present invention is a sealing device that is disposed between two members facing each other and seals a sealing fluid, and is provided in a mounting groove provided in one of the two members. A seal ring mounted and in close contact with the other member; a relatively hard first backup ring disposed on the anti-sealing fluid side of the seal ring; and a comparison disposed between the seal ring and the first backup ring A second soft backup ring, the mounting groove having a rectangular cross section, and the first backup ring has a planar end surface perpendicular to the axis that contacts the side surface of the mounting groove opposite to the sealing fluid. And a cylindrical peripheral surface portion that contacts the other member, and an inclined surface portion that intersects the end surface portion and the peripheral surface portion. And a sloped portion provided corresponding to an axially perpendicular end surface portion in contact with the seal ring, a cylindrical circumferential surface portion in contact with the bottom surface portion of the mounting groove, and a slope portion of the first backup ring. And a non-slip structure is provided on the slope portion of the first backup ring and the slope portion of the second backup ring, which are in contact with each other.

  In the sealing device of the present invention having the above-described configuration, the first backup ring is provided with a non-slip structure by engaging the projections and depressions on the slope portion of the first backup ring and the slope portion of the second backup ring that are in contact with each other. It is difficult for the slope part of this to slip with respect to the slope part of a 2nd backup ring. Therefore, the first backup ring is prevented from being deformed so as to increase its diameter, and thus the first backup ring can be prevented from being damaged by interference with the peripheral edge of the opening of the shaft hole. .

  A cut portion may be provided at a corner portion where the end surface portion and the slope portion intersect in the first backup ring, and a cut portion may be provided also at a corner portion where the peripheral surface portion and the slope portion intersect in the second backup ring ( Details will be described later).

  In the present invention, as described above, in the sealing device comprising a combination of the seal ring, the first backup ring, and the second backup ring mounted in the mounting groove having a rectangular cross section, the diameter of the first backup ring is increased upon insertion. Damage can be suppressed.

(A) is sectional drawing of the sealing device which concerns on 1st Example of this invention, (B) is a partial expanded sectional view of the 1st backup ring and 2nd backup ring with which the sealing device is equipped. Explanatory drawing which shows the mounting | wearing process of the sealing device with (A) and (B) (A) is sectional drawing of the sealing device which concerns on 2nd Example of this invention, (B) is sectional drawing which shows the eccentric state of the sealing device Sectional drawing of the sealing device which concerns on a prior art example Explanatory drawing which shows the mounting | wearing process of the sealing device with (A) and (B)

  Next, embodiments of the present invention will be described with reference to the drawings.

First embodiment ...
FIG. 1A shows a cross section of the sealing device 1 according to the first embodiment of the present invention. The sealing device 1 according to the embodiment is used for a high-pressure seal portion in a hydraulic device such as an injector, and is configured as follows.

  That is, the sealing device 1 is arranged in an annular gap between a shaft (one member) 51 and a housing (other member) 52 as two members facing each other, and is present on the high-pressure side H in the right direction in the figure. The fluid is sealed so as not to leak to the low-pressure side (atmosphere side) B in the left direction in the figure. The fluid is sealed in an annular mounting groove 53 provided on the peripheral surface of the shaft 51 and is fixed to the shaft hole of the housing 52. An O-ring 11 as a seal ring that is in close contact with the inner peripheral surface, a first backup ring 21 that is disposed on the anti-sealing fluid side (low-pressure side L) of the O-ring 11 and is also mounted in the mounting groove 53, and the O-ring 11 And a second backup ring 31 disposed between the first backup rings 21 and mounted in the mounting groove 53. Alternatively, the O-ring 11 may be a seal ring having another cross-sectional shape such as a D-ring or an X-ring.

  The O-ring 11 is formed by a rubber-like elastic body. The first backup ring 21 is formed of, for example, nylon resin that is harder than the second backup ring 31. The second backup ring 31 is formed of, for example, PTFE resin that is softer than the first backup ring 21.

  The mounting groove 53 is formed as a rectangular groove having a rectangular cross section because it is easy to process. Therefore, there is no tapered shape in the groove, and the mounting groove 53 is a combination of only a cylindrical bottom surface portion 53a and two axial side surface portions 53b.

  The first backup ring 21 has an axially perpendicular planar end surface portion 21 a on the anti-sealing fluid side (low pressure side L) that contacts the side surface portion 53 b of the mounting groove 53, and an outer peripheral side that contacts the inner peripheral surface of the shaft hole of the housing 52. The cylindrical surface-shaped peripheral surface portion 21b and the end surface portion 21a and the tapered surface-shaped inclined surface portion 21c intersecting the peripheral surface portion 21b are formed in a triangular cross section (right triangle shape). The inclined surface portion 21c has a linear cross section, and the taper direction is gradually reduced from the sealed fluid side (high pressure side H) to the anti-sealed fluid side (low pressure side L).

  The second backup ring 31 has a cylindrical end surface 31 a that is in contact with the sealing fluid side (high pressure side H) of the sealing fluid side (high-pressure side H) and an axial perpendicular plane end surface portion 31 a and a bottom surface portion 53 a of the mounting groove 53. The peripheral surface portion 31b and the end surface portion 31a and the tapered surface-like inclined surface portion 31c intersecting the peripheral surface portion 31b are provided and formed in a cross-sectional triangle shape (right triangle shape). The inclined surface portion 31c has a linear cross section, and the taper direction is gradually reduced from the sealed fluid side (high pressure side H) to the anti-sealed fluid side (low pressure side L).

  The slope portion 21c of the first backup ring 21 and the slope portion 31c of the second backup ring 31 are provided corresponding to each other, and the slope angle, slope length, maximum outer diameter size, minimum inner diameter size, and the like are equal or substantially equal. Is formed.

  Further, as shown in an enlarged view in FIG. 1 (B), the slope portions 21c of the first backup ring 21 and the slope portion 31c of the second backup ring 31 that are in contact with each other are provided with irregularities 25 and 35, respectively. An anti-slip structure 41 is provided by engaging the projections 25 and 35. The shape, size, etc. of the unevenness 25, 35 are not particularly limited as long as they can prevent / suppress slippage of both slope portions 21c, 31c, in particular, slipping toward the slope directions of the slope portions 21c, 31c. . The irregularities 25 and 35 are provided on the entire surface of the slope portions 21c and 31c, or are provided on a part of the slope portions 21c and 31c. The irregularities 21c and 31c include fine irregularities by so-called surface roughening.

  In the sealing device 1 configured as described above, since the first backup ring 21 is disposed on the anti-sealing fluid side (low pressure side L) of the seal ring 11, the seal ring 11 protrudes into the gap 54 between the shaft 51 and the housing 52. And the second backup ring 31 is disposed between the seal ring 11 and the first backup ring 21, so that the seal ring 11 is between the first backup ring 21 and the housing 52. It is possible to prevent damage from protruding into a gap (not shown).

  Further, the slope portions 21c of the first backup ring 21 and the slope portion 31c of the second backup ring 31 that are in contact with each other are provided with irregularities 25 and 35, respectively, and an anti-slip structure 41 by engagement of these irregularities 25 and 35 is provided. Therefore, when the sealing device 1 is inserted into the shaft hole 52a together with the shaft 51 as shown in FIGS. 2A to 2B, the inclined portion 21c of the first backup ring 21 becomes the second backup ring. It is hard to slip with respect to the slope part 31c of 31. Accordingly, since the first backup ring 21 is prevented from being deformed so as to increase its diameter, it is possible to prevent the first backup ring 21 from being damaged due to interference with the opening peripheral edge 52b of the shaft hole 52a. It is possible.

Second embodiment ...
Next, a second embodiment of the present invention will be described. FIG. 3A shows a cross section of the sealing device 1 according to the second embodiment of the present invention. The sealing device 1 according to the second embodiment has the same configuration as the sealing device 1 according to the first embodiment, and further includes the following configuration.

  That is, the sealing device 1 has the seal ring 11, the first backup ring 21, and the second backup ring 31 as described above, and the corner portion where the end surface portion 21a and the slope portion 21c of the first backup ring 21 intersect is included. The cut part 22 is provided in the. The cut portion 22 is formed in an annular shape and is cut in a direction parallel to the direction of the central axis 0 of the first backup ring 21, and thus the cut portion 22 is formed in a cylindrical surface shape. The cut portion 22 has a diameter larger than that of the bottom surface 53 a of the mounting groove 53.

  Moreover, the cut part 32 is provided in the corner | angular part where the peripheral surface part 31b and the slope part 31c in the 2nd backup ring 31 cross | intersect. The cut portion 32 is formed in an annular shape and is cut in a direction orthogonal to the direction of the central axis 0 of the second backup ring 31. Accordingly, the cut portion 32 is formed in a plane perpendicular to the axis.

  In the sealing device 1 to which the above configuration is added, by having the same configuration as that of the first embodiment, the following operation and effect are exhibited in addition to the same operation and effect as the first embodiment.

  That is, since the cut portion 22 is provided at the corner where the end face portion 21a and the slope portion 21c intersect in the first backup ring 21 having a triangular cross section, the shaft 51 and the housing 52 are mutually connected as shown in FIG. Even if it is decentered, this corner portion does not interfere with the bottom surface portion 53a of the mounting groove 53 and is crushed. Therefore, it is possible to suppress the occurrence of breakage such as cracks due to squashed corners in the relatively hard first backup ring 21.

  Moreover, since the cut part 32 is provided in the corner | angular part where the peripheral surface part 31b and the slope part 31c cross | intersect in the 2nd backup ring 31 of triangular cross section, as shown in FIG.3 (B), the axis | shaft 51 and the housing 52 are shown. Even if they are decentered from each other, the corner portion does not interfere with the side surface portion 53b of the mounting groove 53 to be crushed. Accordingly, the relatively soft second backup ring 31 is greatly inclined due to the crushing of the corners, and a gap is generated between the second backup ring 31 and the bottom surface portion 53a of the mounting groove 53, and the seal ring 11 protrudes from this gap. It is possible to prevent damage.

  Further, since the cut portion 22 provided in the first backup ring 21 is cut in a direction parallel to the direction of the central axis 0 of the first backup ring 21, the first backup ring 21 has a simple shape and can be processed. It is easy and easy to manufacture. Further, since the cut portion 32 provided in the second backup ring 31 is cut in a direction orthogonal to the direction of the central axis 0 of the second backup ring 31, the second backup ring 31 is also simple in shape, It is easy to process and easy to manufacture. Therefore, it is possible to provide a backup ring component that is easy to process and easy to manufacture while having the cut portions 22 and 32.

  In this embodiment, as shown in part E of FIG. 3B, the corner part 31e where the end face part 31a and the slope part 31c intersect in the second backup ring 31 is not provided with a cut part. The portion 31e is pointed and interferes with the inner peripheral surface of the shaft hole of the housing 52 when the shaft 51 and the housing 52 are eccentric from each other. However, the sealed fluid side (high pressure side H) of the corner portion 31e is a space, and a escape place is secured here. Therefore, it is not necessary to provide a cut portion in the corner portion 31e, and the protrusion of the seal ring 11 is more easily suppressed without providing the cut portion.

DESCRIPTION OF SYMBOLS 1 Sealing device 11 Seal ring 21 1st backup ring 21a, 31a End surface part 21b, 31b Peripheral surface part 21c, 31c Slope part 31e Corner part 22, 32 Cut part 25, 35 Concavity and convexity 31 2nd backup ring 41 Anti-slip structure 51 One member)
52 Housing (the other member)
52a Shaft hole 52b Opening peripheral edge 53 Mounting groove 53a Bottom face 53b Side face 54 Projection gap

Claims (2)

A sealing device arranged between two members facing each other for sealing a sealing fluid,
A seal ring mounted in a mounting groove provided in one of the two members and in close contact with the other member; a relatively hard first backup ring disposed on the anti-sealing fluid side of the seal ring; A relatively soft second backup ring disposed between the seal ring and the first backup ring;
The mounting groove is a groove having a rectangular cross section,
The first backup ring has an axially perpendicular planar end surface portion that contacts an anti-sealing fluid side surface portion of the mounting groove, a cylindrical circumferential surface portion that contacts the other member, and the end surface portion and the circumferential surface portion. It is formed in a cross-sectional triangle shape with slopes that intersect
The second backup ring is provided corresponding to an axially perpendicular planar end surface portion that contacts the seal ring, a cylindrical peripheral surface portion that contacts a bottom surface portion of the mounting groove, and a slope portion of the first backup ring. Formed with a triangular section with a sloped portion,
An anti-slip structure is provided on the inclined surface portion of the first backup ring and the inclined surface portion of the second backup ring, which are in contact with each other, by providing an uneven engagement. The sealing device according to claim 1.
A cut portion is provided at a corner portion where the end surface portion and the slope portion of the first backup ring intersect,
The sealing device according to claim 1, wherein a cut portion is provided at a corner portion where the peripheral surface portion and the slope portion of the second backup ring intersect.

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