JP4920211B2 - Sealing method and apparatus - Google Patents

Description

  The present invention relates to a sealing method and an apparatus used for an accumulator or the like.

A piston type accumulator is connected to the hydraulic circuit to absorb pulsation. A ring groove is provided on the outer peripheral surface of the piston of the piston type accumulator, and a rubber O-ring is fitted into the ring groove. When the hydraulic pressure of the hydraulic circuit becomes high, the piston slides, so the O-ring is pushed and deformed in the sliding direction, and a part of it protrudes into the gap between the piston and the cylinder and is locally broken. End up. As a result, liquid leakage occurs, which is a fatal defect as an accumulator.

  In order to solve this problem, as shown in FIG. 8, an O-ring groove 11 is formed on the outer peripheral surface of the piston 30 of the piston type accumulator, and a flat backup ring 12 is fitted into the O-ring groove 11. The O-ring 14 is prevented from sticking out by polymerizing the backup ring 12 and the O-ring 14.

  The backup ring 12 is a flat endless ring made of synthetic resin, and has an inner diameter that is the same as the groove inner diameter of the O-ring groove 11. When the backup ring 12 is fitted into the O-ring groove 11, the diameter of the backup ring is expanded and the outer diameter portion of the O-ring groove 11 is passed through. ) (See, for example, Patent Document 1).

  In FIG. 8, 2 is a cylinder to which the piston 30 is attached, 3 is a side plate for closing the cylinder 2, 5a is a fluid inlet / outlet provided in the side plate 5, 7 is a cover for the supply / discharge valve 6, and 9 is an accumulator. , 10 indicates a gas chamber communicating with the supply / exhaust valve 6, and 20 indicates a liquid chamber communicating with the liquid inlet 5a.

JP2002-3235

The conventional example has the following problems.
(1) At the time of mounting, the expanded backup ring 12 is plastically deformed and cannot safely return to the original state. Therefore, since the inner diameter becomes larger than that before mounting, the inner diameter becomes larger than a dimension defined by a standard such as JIS standard.

  (2) Since the backup ring 12 is loosely fitted in the O-ring groove 11, it is displaced as the O-ring 14 slides. Therefore, since the mounting stability of the backup ring 12 is not good, deformation of the O-ring may not be regulated as designed.

  In view of the above circumstances, an object of the present invention is to prevent the inner diameter of a backup ring mounted in an O-ring groove from becoming larger than a standard standard dimension. Another object is to attach the backup ring stably.

The present invention includes a concave 0-ring groove, an endless fluororesin backup ring mounted in the O-ring groove, and an O-ring mounted in the O-ring groove and polymerized on the backup ring. In the sealing device; the inner diameter of the back application before mounting is smaller than that of the standard dimension and smaller than the inner diameter of the O-ring groove. was inserted into the groove, the O said backup ring that is inserted into the ring groove, the way back to the original state by the restoring force, the inner surface is pressure contact with the bottom wall portion of the O-ring groove, so cling It is characterized by being fixed .

  The inner diameter of the back application before mounting of the present invention is formed smaller than that of the standard, the width and thickness thereof are formed larger than that of the standard, and the inner diameter of the back application after mounting is The inner diameter of the standard is the same as or smaller than that of the standard, and the width and thickness thereof are the same as those of the standard. The 0-ring groove of the present invention includes a pair of left and right side walls sandwiching the bottom wall, and one of the side walls is detachably provided. The inner diameter of the backup ring of the present invention is characterized in that the size is in the range of 50% to less than 100% of the inner diameter of the O-ring groove.

  The present invention is a sealing method in which an endless fluororesin backup ring and an O-ring are fitted into a concave O-ring groove and polymerized; the inner diameter of the backup ring before mounting is the same as that of the O-ring groove. It is formed smaller than the inner diameter of the groove, and when installed, the backup ring is expanded and inserted into the O-ring groove, and then the inner diameter surface is brought into contact with the bottom wall portion by a restoring force. To do.

  The backup ring of the present invention is characterized in that the diameter is expanded by an expansion insertion jig.

Since the present invention is configured as described above, the inner surface of the backup ring mounted in the O-ring groove is in contact with the bottom wall portion. Therefore, the inner diameter of the backup ring does not become larger than the standard standard size.
Further, when the inner diameter of the backup ring after mounting becomes smaller than the standard size, the inner diameter surface of the backup ring comes into pressure contact with the bottom wall portion of the O-ring groove and clings. Therefore, since the displacement of the backup ring is restricted, it can be maintained at the design mounting position.

An embodiment of the present invention will be described.
An O-ring and a backup ring are inserted into the concave O-ring groove.
The ring-shaped base of the backup ring is an endless ring made of a fluororesin and formed flat. The inner diameter of the ring is smaller than the inner diameter of the O-ring groove, and the outer diameter is smaller than the outer diameter of the O-ring groove.

  The inner diameter of the backup ring is smaller than a standard standard dimension such as JIS standard, and the width and thickness are larger than the standard dimension. The size of the inner diameter is appropriately selected as necessary. For example, the inner diameter is selected in a range of 50% to less than 100% of the O-ring groove inner diameter.

  When the backup ring is mounted in the O-ring groove, the diameter is increased, the outer diameter portion of the groove is passed, and the backup ring is dropped into the bottom wall portion. Then, the expanded backup ring tries to return to the original state by the restoring force in the 0-ring groove, but abuts on the bottom wall part in the middle of the deformation and clings to the bottom wall part. Fixed.

  The inner diameter of the backup ring at this time is smaller than that of the standard, but it is not always necessary to make it smaller and may be the same. By adjusting the size of the inner diameter of the backup ring before mounting, the inner diameter of the backup ring after mounting can be made the same as the standard.

An embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 6, a concave O-ring groove 11 is provided on the outer peripheral surface of the piston 30 of the piston type accumulator. An O-ring 14 and a backup ring 100 are inserted into the O-ring groove 11. The O-ring groove 11 includes a bottom wall portion 11a and a pair of left and right side walls 11b and 11c that sandwich the bottom wall portion 11a. Groove inner diameter of the O-ring groove 11 is Do, Mizogai径is formed to D _1.

  The O-ring 14 is made of rubber, and its outer diameter is slightly larger than the groove outer diameter D1 of the 0-ring groove 11 in the natural state shown in FIG. Has been.

The ring-shaped base body 100B of the backup ring 100 is an endless ring made of a fluororesin and formed flat. The inner diameter do of the ring 100 is smaller than the groove inner diameter Do of the O-ring groove 11, for example, do = 72.4 mm, and the outer diameter d ₁ is smaller than the groove outer diameter D ₁ of the O-ring groove 11. For example, D ₁ = 77.5 mm. The backup ring 100 has a width w of, for example, w = 2.55 mm and a thickness of, for example, t = 1.27 mm.

  The inner diameter do is smaller than the JIS standard dimension (75 mm), and the width w and the thickness t are larger than the JIS standard dimension (w = 2.50 mm, t = 1.25 mm). The size of the inner diameter do is appropriately selected as necessary. For example, the inner diameter do is selected in a range of 50% to less than 100% of the groove inner diameter Do of the O-ring groove 11.

  The backup ring 100 is mounted in the O-ring groove 11 using the extension insertion jig 105. The jig 105 includes a tapered cylinder 106 that is locked to one end of the piston 30, and an expansion and contraction pressing ring 108 that is loosely fitted to the tapered cylinder 106.

The diameter of the engaging portion 106 a of the tapered cylinder 106 is larger than the outer diameter D ₁ of the O-ring groove 11, for example, 82 mm, and the diameter of the insertion portion 106 b is the inner diameter d _{1 of the} backup ring 100. It is smaller, for example, 72 mm.

  As shown in FIGS. 2 and 3, the expansion and contraction holding ring 108 is composed of a lower link member 110 and an upper link member 112 that are overlapped with each other and connected by pins 115. Both link members 110 and 112 are provided with a plurality of link pieces 110a and 112a arranged with a predetermined connection gap in the circumferential direction, but the connection gaps of both link members 110 and 112 are shifted from each other. Yes. In addition, the magnitude | size and position of the said connection gap are suitably selected as needed.

  A long hole 109 is provided in the link piece 112 a of the upper link member 112. A pin 115 is inserted into the long hole 109, its leg portion is fixed to the link piece 110 a of the lower link member 110, and its head portion 115 a is in contact with the upper surface of the link piece 112 a of the upper link member 112.

Next, the operation of the present embodiment will be described.
As shown in FIG. 2, the engaging portion 106a of the taper cylinder 106 of the expansion insertion jig 105 is locked to the end of the piston 30, and the first expansion / contraction press ring 108 is inserted into the insertion portion 106b of the taper cylinder 106. The backup ring 100 is inserted into the insertion portion 106b. Further, the second expansion and contraction pressing ring 108 is inserted into the insertion portion 106b, and the backup ring 100 is sandwiched between the pressing rings 108 and 108 (see the backup ring 100A in FIG. 2).

  Next, when a force in the direction of arrow A1 is applied to the expansion / contraction holding ring 108, the expansion / contraction holding link 108 moves on the tapered cylinder 106 while spreading in the circumferential direction and reaches the piston 30. The diameter is expanded by elastic deformation (see the backup ring 100B in FIG. 2). At this time, the backup ring 100 is pushed while being held by the expansion / contraction pressing ring 108 and elastically deforms along the tapered cylinder 106, so that the diameter can be easily expanded.

Further, the expansion / contraction holding ring 108 is moved in the same direction to drop the backup ring 100 into the O-ring groove 11 and remove the expansion insertion jig 105 from the piston 30 (see FIG. 2 backup ring 100c).
The backup ring 100 that has fallen into the O-ring groove 11 tries to return to its original state by a restoring force. However, since the inner diameter do is smaller than the groove inner diameter Do of the O-ring groove 11, the inner diameter surface 100a is In the course of restoration, it is pressed against the bottom wall 11a of the O-ring groove 11 and fixed so as to cling (see FIG. 6).

  Next, the O-ring 14 is inserted into the O-ring groove 11 and superposed with the backup ring 100. The inner diameter do of the backup ring 100 at this time is larger than the inner diameter before fitting, but is smaller than the JIS standard dimension (75 mm), for example, do = 74,5 mm, and 0.5 mm from the standard dimension. It's small. On the other hand, the width w and thickness t of the backup ring 100 are w = 2.50 mm and t = 1.25 mm, which are the same as the JIS standard dimensions.

  Thereafter, the piston 30 is inserted into the cylinder 2. When the piston 30 slides, the O-ring 14 presses the backup ring 100 and presses the backup ring 100 against the side wall portion 100c. At this time, the backup ring 100 is pressed against the bottom wall portion 11a of the O-ring groove 11 and fixed so as to cling. Therefore, the backup ring is less likely to be displaced than the conventional example, so that the mounting stability can be improved.

The embodiment of the present invention is not limited to the above, and may be as follows, for example.
(1) Instead of integrally forming the bottom wall portion and the left and right side wall portions of the O-ring groove, one side wall portion is made detachable, and when the backup ring is mounted, the side wall portion is removed and mounted.

(2) Instead of sandwiching the backup ring between the pair of left and right expansion insertion jigs, one side of the backup ring may be pushed by one expansion insertion jig.

(3) Adjust the inner diameter of the backup ring before mounting so that the inner diameter of the backup ring after mounting is the same as the standard such as JIS standard.

It is a top view which shows embodiment of this invention. 2A is a cross-sectional view taken along the line II-II in FIG. 1, and FIG. 2B is a front view for explaining how to insert the backup ring. It is the III-III sectional view taken on the line of FIG. It is a top view of an expansion-contraction pressing member. It is a front view of an expansion-contraction pressing member. It is an enlarged vertical sectional view of an O-ring groove when a backup ring and an O-ring are inserted. It is an enlarged longitudinal cross-sectional view which shows the state which inserted the piston which inserted the backup ring and O-ring in the cylinder. It is a longitudinal cross-sectional view which shows a prior art example.

Explanation of symbols

2 cylinder 11 O-ring groove 11a bottom wall part 11b side wall part 11c side wall part 12 backup ring 14 O-ring 100 backup ring 100a inner diameter surface 105 extended insertion jig Do groove inner diameter D ₁ groove outer diameter do inner diameter d ₁ outer diameter w width t thickness

Claims (6)

In a sealing device comprising a concave 0-ring groove, an endless fluororesin backup ring mounted in the O-ring groove, and an O-ring mounted in the O-ring groove and polymerized on the backup ring ;
The inner diameter of the back application before mounting is smaller than that of the standard dimension and smaller than the groove inner diameter of the O-ring groove,
When installing, expand the diameter and insert into the O-ring groove,
Said O-ring wherein the backup ring that is inserted into the groove, the way back to the original state by the restoring force, that is pressure contact, is fixed so as to cling to the bottom wall portion of the O-ring groove and the inner surface A sealing device characterized. The inner diameter of the back application before mounting is formed smaller than that of the standard, and the width and thickness thereof are formed larger than that of the standard.
The inner diameter of the back application after mounting is formed to be the same as or smaller than the inner diameter of the standard, and the width and thickness thereof are the same as those of the standard. Sealing device. The sealing device according to claim 1 or 2, wherein the O-ring groove includes a pair of left and right side wall portions sandwiching the bottom wall portion, and one of the side wall portions is detachably provided. The sealing device according to claim 1 or 2, wherein an inner diameter of the backup ring has a size in a range of 50% to less than 100% of a groove inner diameter of the O-ring groove. A sealing method in which an endless fluororesin backup ring and an O-ring are fitted and polymerized in a concave O-ring groove;
The inner diameter of the backup ring before mounting is formed smaller than the groove inner diameter of the O-ring groove,
When installing, expand the backup ring and insert it into the O-ring groove,
Thereafter, the inner diameter surface is brought into contact with the bottom wall portion by a restoring force. The sealing method according to claim 5, wherein the diameter of the backup ring is expanded by an expansion insertion jig.

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