JP2010265954A - Shaft seal structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shaft seal structure best suited for expecting the improved versatility of a hydraulic shock absorber to be mounted on a vehicle by embodying itself as an oil seal to construct the shaft seal part of the hydraulic shock absorber between a cylinder body and a rod body. <P>SOLUTION: The shaft seal structure is provided between one side 3 and the other side 2 opposed to one side 3 in a relatively movable manner. It includes a base part 12 fixedly held on one side 3, and an external side lip part 11 put in slide contact with the other side 2 opposed to the base part 12 while extending therefrom for scraping foreign matters D deposited on the other side 2 through the external. The external side lip part 11 has an oscillation suppressing means 4 for suppressing the axial movement of a pointed end portion 11a of the external side lip part 11 put in slide contact with the other side 2 during relative movement between one side 3 and the other side 2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a shaft seal structure, and more particularly, to an improvement in a shaft seal structure suitable for implementation in a shaft seal portion in devices with repeated relative movement.

  There have been various proposals for a shaft seal structure suitable for implementation in a shaft seal portion in devices with repeated relative movement. Among them, for example, Patent Document 1 is mounted on a vehicle. A shaft seal structure embodied in an oil seal that constitutes a shaft seal portion in a hydraulic shock absorber is disclosed.

  In other words, the oil seal disclosed in Patent Document 1 as a conventional example constitutes a shaft seal portion between a cylinder body and a rod body that is inserted into and retracted into the cylinder body. In addition to having a dust lip portion and an oil lip portion that are in sliding contact with the outer periphery, it has a metal core made of a metal material that integrally holds the dust lip portion and the oil lip portion.

  Incidentally, the cored bar is formed in the shape of a washer and holds a dust lip part and an oil lip part integrally formed in a substantially cylindrical shape at the inner peripheral side end part, and the outer peripheral side part is fixedly held on the cylinder body side. .

  Therefore, in this oil seal, the rod body sticks to the outer periphery of the rod body protruding from the cylinder body when the rod body moves in and out of the cylinder body, that is, during relative movement between the cylinder body and the rod body. The lubricating oil film is scraped off at the oil lip portion and left in the cylinder body, and dust as foreign matter adhering to the outer periphery of the rod body is scraped off at the dust lip portion to prevent entry into the cylinder body.

Japanese Patent Laid-Open No. 2001-165326 (see paragraphs 0002 to 0010 and FIG. 4 in the specification)

  However, in the proposal disclosed in Patent Document 1 described above, there is no problem in the basic operation of the oil seal, but in devices that are often in a dust atmosphere such as a hydraulic shock absorber, It may be pointed out that the adverse effects are not completely eliminated.

  That is, FIG. 6 shows the behavior of the dust strip portion in the oil seal described above. When the stationary state shown in FIG. 6 (A), the oil seal 1 that contacts the outer periphery of the rod body 2 at a height H as set. When the rod body 2 protrudes from a cylinder body (not shown), the tip end portion 11a is extended upward (H + α) following the movement of the rod body 2 as shown in FIG. 6B. ) While deforming to expand in the radial direction.

  Then, the tip portion 11a deformed so as to expand in the radial direction while being stretched upward is the same as shown in FIG. 6C when the rod body 2 is reversed and immersed in the cylinder body. Following the movement of the body 2, the body 2 is crushed downward (H-α) and deformed to a reduced diameter.

  That is, it is confirmed that when the rod body 2 repeatedly appears and disappears with respect to the cylinder body, the tip end portion 11a of the dust lip portion 11 in the oil seal 1 is expanded or contracted in the radial direction to perform a so-called swing motion. It was done.

  From this, as shown in FIG. 6 (B), when dust D, which is a foreign object, enters between the expanded tip portion 11a and the rod body 2, the dust D When immersing into the cylinder body, as shown in FIG. 6 (C), it fits between the tip portion 11a and the rod body 2, and so-called biting into the inner peripheral surface of the dust lip portion 11, therefore, There is a possibility that the inner peripheral surface of the strip portion 11 is damaged, or the outer peripheral surface of the rod body 2 is damaged, resulting in a problem that the predetermined sealing performance at the shaft seal portion is deteriorated.

  Accordingly, the present invention has been made in view of the above-described circumstances, and an object thereof is, for example, a shaft seal portion between a cylinder body and a rod body in a hydraulic shock absorber mounted on a vehicle. The shaft seal structure which is embodied in the oil seal that constitutes and is optimal for expecting the improvement of the versatility of the hydraulic shock absorber.

  In order to achieve the above object, the structure of the shaft seal structure according to the present invention is basically a shaft seal structure provided between one side and the other side facing the one side so as to be relatively movable. A base portion fixedly held on the one side, and an external lip portion that slides on the other side facing the other side while being held by the base and scrapes off foreign matters adhering to the other side from the other side. In the shaft seal structure, the outer side lip portion has a swing suppression means, and the swing suppression means has the outer side at the time of relative movement between the one side and the other side. It is assumed that radial movement at the tip of the lip is suppressed.

  Therefore, in the shaft seal structure of the present invention, the swing suppression means suppresses the radial movement at the tip of the outer lip portion that is in sliding contact with the other side during relative movement between the one side and the other side. Therefore, the tip of the outer lip portion does not unnecessarily expand or contract in the radial direction.

  As a result, foreign matter is less likely to enter between the outer lip portion and the other side, and damage to the outer lip portion and other side damage due to the intrusion of foreign matter are less likely to occur, reducing the predetermined sealing performance. I won't let you.

It is a fragmentary longitudinal cross-section which shows the arrangement | positioning state of the oil seal which embodies the shaft seal structure by this invention. 2A and 2B are half plan views showing the oil seal of FIG. 1, in which FIG. 1A is a plan view and FIG. 2B is a longitudinal sectional view taken along line XX in FIG. It is a figure which shows the oil seal by other embodiment similarly to FIG. 2 (B). Furthermore, other embodiment is shown, (A), (C) is a half-ridge vertical sectional view which shows an oil seal, (B) is a top view which shows an insert plate. FIG. 4 is a view showing an oil seal according to still another embodiment in the same manner as in FIG. 3. It is the fragmentary longitudinal cross-section which expands and shows the dust lip part in the conventional oil seal, Comprising: (A) shows the state at the time of rest, (B) shows the state by which the pointed end part was expanded, (C ) Indicates a state in which the tip portion is reduced in diameter.

  In the following, the present invention will be described based on the illustrated embodiment. In the illustrated embodiment, the shaft seal structure according to the present invention is an oil disposed at the head end of a cylinder body in a hydraulic shock absorber formed into a cylindrical shape. Embodied in a seal.

  That is, first, the hydraulic shock absorber absorbs road surface vibration that is input to a wheel that is disposed at each of the four wheels of the vehicle and is suspended at the lower end, for example, as shown in FIG. Then, the rod body 2 which is an upper end side member and which is the other side referred to in the present invention is inserted into the cylinder body 3 which is one side referred to in the present invention so as to be able to extend and retract.

  And in this hydraulic shock absorber, although not shown, the cylinder body 3 is connected to the axle side of the vehicle that pivotally supports the wheels via a connecting member such as a knuckle bracket, for example. It is connected to the vehicle body side of the vehicle under the presence of an elastic connecting mechanism such as an insulator, and can be moved in and out of the cylinder body 3.

  Further, in this hydraulic shock absorber, when the rod body 2 is projected and retracted with respect to the cylinder body 3, for example, a piston that is housed in the cylinder body 3 and connected to the rod body 2 is not shown. The attenuating means provided in the part produces a predetermined attenuating action to improve the riding comfort in the vehicle.

  Incidentally, in embodying the present invention, the hydraulic shock absorber is formed in a single cylinder type having an air chamber that is formed in a gas-liquid separation structure in the cylinder body 3 and exhibits an air spring force, although not shown in the figure. Alternatively, it may be any one formed in a double cylinder type having a reservoir that forms an air chamber with an oil surface as a boundary by arranging an outer cylinder outside the cylinder body 3.

  On the other hand, as shown in FIG. 1, an oil seal 1 that embodies a shaft seal structure according to the present invention includes a metal core 12 that is a base metal material that is fixedly held by a cylinder body 3 on one side, and the core. Dustrip made of a rubber material that is an external lip portion that slides on the opposite rod body 2 held by the gold 12 and scrapes off dust D (see FIG. 6) adhering to the rod body 2 from the outside. Part 11.

  At this time, the oil seal 1 is accommodated inside the cylinder body 3 made of a cylindrical body and is formed in a substantially annular shape through which the rod body 2 made of a round bar penetrates the shaft core portion. 12 is also formed in the shape of a washer having a hole in the shaft core.

  And the outer peripheral side part of the core metal 12 formed in this washer shape is sandwiched between a bent end part 3a which is the upper end part of the cylinder body 3 and a lower rod guide (not shown) and is fixedly held.

  Further, it has the dust lip portion 11 at the inner peripheral side end portion of the cored bar 12 and an oil lip portion 13 which is also a lower inner side lip portion made of a rubber material. The dust lip portion 11 and the oil lip portion 13 are integrated to form a cylindrical shape, and the rod body 2 is slidably penetrated inside.

  Further, the oil lip portion 13 has a pointed end portion 13 a that is in sliding contact with the outer periphery of the rod body 2 corresponding to the pointed end 11 a in the dust lip portion 11, and the pointed end portion 13 a is pulled out from the cylinder body 3. When protruding in this manner, the lubricating oil film (not shown) adhering to the outer periphery of the rod body 2 is scraped off and left in the cylinder body 3, that is, it does not leak out of the cylinder body 3.

  Incidentally, in many cases, a garter spring S is wound around the outer periphery of the oil lip portion 13, and the tightening margin for the rod body 2 in the oil lip portion 13 is guaranteed. This is also wound around the outer periphery of the dust lip portion 11, and the fastening allowance for the rod body 2 in the dust lip portion 11 may be guaranteed.

  Further, when molding the dust lip portion 11 and the oil lip portion 13, an outer peripheral seal portion 14 is provided at the outer peripheral side end portion of the base portion 12, and a check valve portion is provided on the back surface of the base portion 12 in the figure. 15 are integrally formed.

  The outer peripheral seal portion 14 prevents so-called leakage between the oil seal 1 and the cylinder body 3, and the check valve portion 15 brings the lower end into contact with the upper end of a rod guide (not shown) so as to operate the working fluid from the so-called reservoir. A predetermined check valve function for preventing the flowing hydraulic oil from flowing back into the cylinder body 3 is exhibited.

  On the other hand, the tip 11a of the dust lip 11 is the same as described above, but when the rod 2 is immersed in the cylinder body 3, dust adheres to the outer periphery of the rod body 2 protruding from the cylinder body 3. It functions to prevent D from being scraped off and entering the dust strip 11.

  And in the oil seal 1 in this invention, the dust lip part 11 has the swing suppression means 4 as shown also in FIG. 2, and this swing suppression means 4 is the cylinder body 3 and the rod body 2. In the relative movement between the two, the tip end portion 11a of the dust strip portion 11 that is in sliding contact with the rod body 2 is restrained, that is, so-called swinging motion that moves in the radial direction is suppressed.

  That is, in the conventional case where the dust lip portion 11 does not have this kind of swing suppression means 4, as described above, when the rod body 2 protrudes from the cylinder body 3, it follows the movement of the rod body 2. Then, the tip portion 11a of the dust lip portion 11 is deformed to increase in diameter while being extended upward (see FIG. 6B).

  Then, the tip portion 11a deformed so as to expand in the radial direction while being extended upward follows the movement of the rod body 2 when the rod body 2 is reversed and immersed in the cylinder body 3. Then, it is deformed to have a reduced diameter while being crushed downward (see FIG. 6C).

  That is, when the rod body 2 repeats projecting and retracting with respect to the cylinder body 3, the pointed portion 11a of the dust lip portion 11 in the oil seal 1 is expanded, contracted, or expanded in the radial direction. In addition, since the rod body 2 expands and contracts in the axial direction, which is the direction in which the rod body 2 protrudes and retracts, the head swings.

  And, as long as this swinging motion is caused, there is no problem, but as described above, when the oil seal 1 is in a dust atmosphere, the point D 11a and the rod body where the dust D expands as described above. 2 between the inner periphery of the dust lip portion 11 and the outer periphery of the rod body 2 (see FIG. 6C), damage the inner peripheral surface of the dust lip portion 11, or the rod body 2 Are damaged, and the predetermined sealing performance by the oil seal 1 is reduced.

  Therefore, in the present invention, the tip end portion 11a of the dust lip portion 11 in the oil seal 1 has the swing suppression means 4 for suppressing the swing motion that repeatedly expands and contracts in the radial direction.

  Incidentally, the suppression of the swing motion mentioned here does not mean that the above-described expansion / contraction of the tip end portion 11a of the dust lip portion 11 is completely prevented, and the tip end portion 11a cannot be easily expanded or contracted easily. It means to make it difficult to expand and contract.

  By the way, when the suppression of the swing motion is meant to completely prevent expansion and contraction at the tip portion 11a, the deformation at the tip portion 11a is prevented, so that the rod of the oil seal 1 is eliminated by the amount of so-called margin. The sliding friction with respect to the body 2 becomes very large, which is not preferable.

  From the above viewpoint, the swing suppression means 4 according to the present invention is first shown in FIG. 1 as an example, that is, in a place shown in FIG. 2, that is, a shallow C-shaped section (FIG. 2B). The cap member 41 is formed so as to have a reference).

  The cap member 41 is basically made of a material harder than the rubber material forming the dust lip portion 11, for example, made of a rubber material harder than the rubber material forming the dust lip portion 11, or It is made of a hard resin material and further made of a metal material.

  In addition, when the cap member 41 is made of a rubber material, it becomes easy to assimilate with the dust strip portion 11, and when it is made of a hard resin material, it is easy to reduce the component cost, and when it is made of a metal material, It becomes easy to ensure durability.

  Further, as shown in FIG. 2 (B), the cap member 41 has an end portion as an upper end portion in the drawing having a pointed end portion 11a in the dust strip portion 11, and the dust strip portion 11 continuous to the end portion. In FIG. 2, the outer side inclined portion which is the left side portion is disposed so as to cover in the circumferential direction.

  At this time, the cap member 41 has hook portions 41a and 41b at the upper end portion and the lower end portion in the drawing, and the hook portions 41a and 41b are formed in the dust lip portion 11 so as to correspond thereto. It is inserted into a groove (not shown) to prevent the dust strip 11 from dropping off.

  On the other hand, since this cap member 41 is so-called retrofitted to the dust lip portion 11, as shown in FIG. 2A, it is formed in a C-ring shape having a split 41 c and can be easily attached to the dust lip portion 11. I have to.

  Incidentally, even if the cap member 41 is formed in an annular shape without the split 41c, it is possible to attach the dust lip portion 11 by forcibly deforming the dust lip portion 11, but in this case, It is not preferable because the possibility that the dust strip portion 11 may be deformed by tampering to cause fatigue or damage is increased.

  The cap member 41 has notches 41d formed at appropriate intervals in the circumferential direction at the top end portion covering the upper end of the dust lip portion 11, and the end of the dust lip portion 11 is Care is taken not to unnecessarily increase deformation prevention.

  That is, when the cap member 41 has the notches 41d at appropriate intervals in the circumferential direction, the cap member 41 is allowed to be deformed in the diameter increasing direction. Even in the case where the body 2 appears and inclines in an inclined state, the cap member 41 is preferably deformed in the diameter increasing direction so that a so-called excessive lateral force is not applied to the end portion of the dust lip portion 11.

  In this cap member 41, the split 41c is formed so as to cut the entire range from the so-called upper end to the lower end, but the notch portion 41d cuts only the top end portion leaving the hook portion 41a. Alternatively, it is formed so as to cut off the outer peripheral portion and the hook portion 41b in addition to the top end portion, and in place of this, only the outer peripheral portion is cut off leaving the hook portion 41b, Alternatively, the top end portion and the hook portion 41a are cut off in addition to the outer peripheral portion.

  In other words, in forming the cutout portion 41d, the top end portion and the outer peripheral portion are cut off, but one of the hook portions 41a and 41b is always left.

  Incidentally, in the portion shown in FIG. 2A, the cutout portion 41d has a hook portion 41a, but is formed in a form not having the hook portion 41b.

  The manner of the split 41c and the notch 41d will not be described each time, but is the same in the cap members 42, 43, 44, 45 constituting the swing suppression means 4 of each embodiment shown in FIG. It is embodied in.

  Therefore, in the oil seal 1 formed as described above, that is, in the shaft seal structure according to the present invention, since the dust lip portion 11 has the swing restraining means 4, the tip end portion 11a of the dust lip portion 11 The oscillating motion that moves in the radial direction tends to be suppressed, and the pointed portion 11a does not expand unnecessarily in the radial direction. Makes it difficult for foreign matter dust D to enter

  Further, since it is difficult for the dust D to enter between the dust lip portion 11 and the rod body 2, it is difficult to damage the dust lip portion 11 or damage the rod body 2 due to the penetration of the dust D, and a predetermined sealing property. To ensure.

  3 to 5 show another embodiment of the oil seal 1 that embodies the shaft seal structure according to the present invention, that is, another embodiment of the swing restraining means 4 included in the dust lip portion 11. Will explain this.

  First, FIG. 3 shows an example in which the cap member 41 shown in FIG. 2 that constitutes the swing suppression means 4 is modified, and the cap member 41 covers the upper end portion of the dust lip portion 11. Instead of being arranged as described above, the cap member 42 shown in FIG. 3A is arranged so as to be embedded in the upper end portion of the dust lip portion 11.

  At this time, the hook portions 42 a and 42 b of the cap member 42 are inserted into grooves (not shown) formed in the dust lip portion 11 in the same manner as the cap member 41 described above, and the cap member 42 is inserted. Is prevented from falling off from the dust lip 11.

  As a result, the cap member 42 is not easily peeled off from the dust lip portion 11, but the cap member 42 does not protrude from the upper end portion of the dust lip portion 11 and the appearance is improved.

  Incidentally, even though this cap member 42 is not shown, it is formed in a C-ring shape having a split (see reference numeral 41c in FIG. 2), and in the circumferential direction from the top end or from the top end to the outer periphery. Have notches (see reference numeral 41d in FIG. 2) formed at appropriate intervals.

  The same applies to cap members 43, 44, and 45, which will be described later, with respect to preventing the cap member from falling off the dust lip portion 11 by fitting the hook portion into the groove formed in the dust lip portion 11. It is.

  3 (B), 3 (C) and 3 (D) show a simplified configuration in place of the cap member 42 described above. The cap member 43 shown in FIG. In the drawing of the part 11, the outer side inclined part which is the left side part is provided with a hook part 43 a so as to be embedded, and is difficult to peel off from the upper end part of the dust strip part 11.

  The cap member 43 has a hook portion 43a and has a split (not shown) and a notch (not shown). From an overall point of view, the cap member 42 has In comparison, it is advantageous in that the amount of material is reduced and the number of processes is reduced.

  Both the cap member 44 shown in FIG. 3 (C) and the cap member 45 shown in FIG. 3 (D) have hook portions 44a and 45a at the end portion which is the upper end portion of the dust strip portion 11 in the drawing. Like the cap member 43 described above, it is difficult to peel off from the upper end portion of the dust strip portion 11.

  Even in the cap members 44 and 45, as in the cap member 43 described above, it is advantageous in that the amount of material is reduced and the number of processing is reduced as compared with the cap member 42 described above.

  Incidentally, since the cap members 44 and 45 are disposed at the end portion of the dust strip portion 11 which is the upper end portion in the drawing, it is preferable that the cap members 44 and 45 have a split portion and a notch portion.

  On the other hand, in the cap member 45 shown in FIG. 3D, since the hook portion 45a is provided along the axial direction in the dust lip portion 11, the above-described cap member 44 includes the hook portion 44a. In other words, it is advantageous in that it is less likely to be peeled off from the upper end portion of the dust lip portion 11 as compared with a case where the top end portion is provided at a right angle.

  Incidentally, with respect to a groove (not shown) formed in the end portion of the dust strip portion 11 in which the hook portion 44 a in the cap member 44 is inserted, the dust strip portion 11 in which the hook portion 45 a in the cap member 45 is inserted. Compared to a groove (not shown) formed at the end of the substrate, the formation becomes easier.

  As shown in FIG. 4, the swing restraining means 4 has an insert plate 46 embedded in the dust lip 11, and the insert plate 46 is formed in an annular shape as shown in FIG. It has an end portion 46a and an upper end side portion 46b connected to the base end portion 46a and formed in a comb blade shape.

  Incidentally, the base end portion 46a is supported with the lower end portion being brought into contact with the upper end of the core metal 12 as shown in FIG. As shown to (A), 46b is extended along the axial direction which the dust lip part 11 inclines.

  Therefore, in the insert plate 46, the upper end side portion 46b is deformed so as to raise the upper end in a state where the lower end is supported by the base end portion 46a, and the upper end portion of the dust strip portion 11 is expanded. Is allowed to be deformed.

  The swinging suppression means 4 having the insert plate 46 has an advantage that the same appearance as that of the conventional oil seal 1 can be maintained because the arrangement state is not visible.

  FIG. 5 shows that the swing suppression means 4 can be provided in the oil seal 1 even after the rod body 2 has penetrated the shaft core portion of the oil seal 1. 4 is provided before the rod body 2 is inserted into the shaft core portion of the oil seal 1. Therefore, when the rod body 2 is inserted, the diameter expansion corresponding to the tightening margin is essential. .

  And this swing suppression means 4 has cover members 47, 48 or 49, and each is fixed to the dust strip portion 11 by using an adhesive, and in the cover member 47 shown in FIG. The cover member 48 shown in (B) is formed in a shape that does not have the hook portions 41a and 41b similar to the cap member 41 (see FIG. 2B), compared to the cover member 47 shown in (A). Thus, the structure is simplified only by the top end portion, and in the cover member 49 shown in (C), the material can be extremely reduced, and the improvement in versatility can be greatly expected.

  To explain a little, in any of the embodiments, the above-described split or notch portion is not necessary, but the cover member 47 has a function as the swing suppression means 4 in the dust lip portion 11. From the point of emphasis, the upper end portion of the dust strip portion 11 is formed so as to entirely cover with a gap between the inner peripheral side end and the rod body 2.

  On the other hand, in the cover member 48, in addition to the configuration as the swing suppression means 4 in the dust strip portion 11, the inner peripheral side end is in light contact with the outer periphery of the rod body 2, and the scraper function is exhibited. It is possible to reduce the burden on the dust strip 11 by scraping as much as possible the large amount of dust D adhering to the outer periphery of the rod body 2.

  In contrast to the above, the cover member 49 can reduce the cost as much as possible with respect to the provision of the swing suppression means 4 in the dust lip portion 11. It is disposed on the outer peripheral side of the part 11.

  At this time, it is ideal that the cover member 49 is formed in an annular shape and does not have a split, but has a split so as to allow the diameter expansion of the dust strip portion 11, particularly the upper end portion. It may be configured.

  Incidentally, when the cover member 49 has a split and can be reduced in diameter, the dust strip portion 11 is the same as the garter spring S (see FIG. 1) in appearance.

  However, the garter spring S sets the tightening allowance for the rod body 2 of the dust lip portion 11. Compared with this, the cover member 49 sets the allowance for the rod body 2 in the dust lip portion 11. Instead, the swinging motion of the tip portion 11a in the dust strip portion 11 is suppressed, and there is a clear functional difference.

  Therefore, in the shaft seal structure according to the present invention which is the oil seal 1 formed as described above, the external lip portion held on one side scrapes off foreign matters adhering to the other side. As well as preventing so-called intrusion into the interior, the swing restraining means for restraining the radial movement at the pointed end that slides against the other side when the outer lip portion moves relative to the other side between the one side and the other side. Therefore, the tip end portion of the outer lip portion does not expand or contract in the radial direction, and foreign matter does not enter between the outer lip portion and the other side where the outer lip portion slides.

  As a result, foreign matter does not enter between the outer lip portion and the other side, the outer lip portion is not damaged by the foreign matter, or the other side is not damaged, the predetermined sealing performance is not lowered, For example, it is optimal for improving durability in a hydraulic shock absorber and expecting improvement in its versatility.

  As described above, the shaft seal structure according to the present invention is embodied in the oil seal 1 disposed at the head end portion of the cylinder body 3 in the hydraulic shock absorber. Of course, the shaft seal structure of the present invention may be embodied in a hydraulic cylinder, which is disposed at the head end portion of the cylinder body in the cylinder.

  In the above description, the hydraulic shock absorber that embodies the shaft seal structure according to the present invention is mounted on the vehicle. However, according to the intention of the present invention, the hydraulic shock absorber constitutes the seismic isolation device. It may also be a damper used for other devices with relative movement.

  For example, the present invention is suitable for an oil seal that constitutes a shaft seal portion between a cylinder body and a rod body in a hydraulic shock absorber mounted on a vehicle.

DESCRIPTION OF SYMBOLS 1 Oil seal 2 Rod body which is the other side 3 Cylinder body which is one side 4 Swing suppression means 11 Dustrip part which is the outer side lip part 11a Pointed part 12 Core metal 41, 42, 43, 44, 45 which is the base part Split member 41c 41d Notch portion 46 Insert plate 46a Base end portion 46b Upper end side portion 47, 48, 49 Cover member D Dust as foreign matter

Claims (5)

  A shaft seal structure provided between one side and the other side facing the one side so as to be relatively movable, and a base portion fixedly held on the one side and extending from the base portion In a shaft seal structure having an external lip portion that slides in contact with the opposite other side and scrapes off foreign matter adhering to the outside on the other side, the external lip portion has a swing suppression means. The swing suppression means suppresses the radial movement of the tip of the external lip portion that is in sliding contact with the other side during relative movement between the one side and the other side. A shaft seal structure characterized by   The swing suppression means has a cap member disposed at an end portion having a pointed portion at the outer lip portion and / or an outer inclined portion continuous with the end portion, and the cap member is split. The shaft seal structure according to claim 1, wherein the shaft seal structure is formed in a C ring shape.   The swing suppression means has an insert plate embedded in the outer lip portion, and the insert plate is formed in an annular shape, and is connected to the base end portion and extends outward. The shaft seal structure according to claim 1, wherein the upper end side portion is formed in an annular comb blade shape.   The above-mentioned swing suppression means has a cover member that is extended by using an adhesive material at an end portion having a pointed portion at the above-mentioned outer side lip portion and / or at an outer side inclined portion continuing to this end portion, and this cover The shaft seal structure according to claim 1, wherein the outer lip portion is in sliding contact with the other side when the member is deployed.   An oil in which the one side is a cylinder body side in the hydraulic shock absorber, the other side is a rod body that is removably inserted into the cylinder body, and the outer lip portion is in sliding contact with the rod body It is a dust lip portion in the seal, and the base portion is a core metal that integrally holds the dust lip portion at the inner peripheral side end portion in the oil seal, and the outer peripheral side portion of the core metal is the cylinder The shaft seal structure according to claim 1, 2, 3, or 4, which is fixedly held on the body side.

Images