JP5715348B2 - Seal structure in suspension system - Google Patents

Description

  The present invention relates to a seal structure for a suspension device used in a saddle-ride vehicle, and more particularly to an improvement in a seal structure for a front fork and a rear cushion unit in a motorcycle.

  A suspension device used in a saddle riding vehicle, for example, a front fork functions as a suspension that absorbs road surface vibration by suspending the front wheel of a two-wheeled vehicle, and as a damper that damps road surface vibration by accommodating a shock absorber inside. Is also known to work.

  The front fork includes a vehicle body side tube, a wheel side tube that is inserted into and retracted into the vehicle body side tube, and a cylindrical lubrication formed between the vehicle body side tube inner periphery and the wheel side tube outer periphery. A clearance and a seal member that is provided on the inner periphery of the opening end portion of the vehicle body side tube on the wheel side tube insertion side and holds the lubricating fluid accommodated in the lubrication clearance are set upside down.

  Then, the working fluid for lubrication flows into the lubrication gap through an oil hole opened near the upper end opening of the wheel side tube.

  The seal member includes a dust seal located on the outside and an oil seal provided in series with the dust seal and located on the inside.

  The dust seal scrapes off foreign matters such as dust adhering to the outer periphery of the wheel side tube to prevent foreign matters from entering the front fork, and the oil seal has lubricating oil flowing into the lubrication gap. Prevent leakage outside the front fork.

JP 2008-64180 A (FIG. 1)

  A conventional front fork is provided with the above-described seal structure made of a seal member so that the oil-seal holds the lubricating hydraulic oil flowing into the lubrication gap, so that the wheel-side tube smoothly protrudes and retracts from the vehicle-side tube. Useful in that it is possible.

  However, the conventional front fork described above, for example, replaces a suspension spring that is interposed between the vehicle body side tube and the wheel side tube and urges the front fork in the extending direction, and encloses air in the vehicle body side tube. When the inside of the front fork is maintained at a high pressure tendency, such as when the front fork is an air suspension, the following problems may be pointed out.

  That is, when the pressure inside the front fork becomes high, the pressure acts on the lubrication gap via the oil hole. If this oil seal is damaged by foreign matter or scratches around the inner tube, the oil seal will be damaged. There is a risk that the hydraulic fluid for lubrication will be ejected from the front fork due to the internal pressure of the front fork.

  Therefore, an object of the present invention is to provide a fail-safe second seal member in addition to the oil seal, and even if the oil seal is damaged, the working oil in the lubrication gap is ejected outside the front fork. It is an object of the present invention to provide a seal structure in a suspension device that can prevent the above-described problem.

Means for solving the above problems, and the outer tube, a cylindrical lubrication is formed between the inner tube that is inserted retractably into the outer tube, the inner periphery and the inner tube outer periphery the outer tube A gap, a first seal member that is provided on the inner periphery of the opening end of the outer tube on the inner tube insertion side and holds the lubricating fluid that is accommodated in the lubrication gap, and upward from the oil level of the hydraulic oil in suspension system and a reservoir chamber which is maintained position to the gas is sealed in high pressure trend, the second seal member provided on the first sealing member in series, the second seal member sealing the gas air seal And an oil seal that is provided in series on the first seal member side of the air seal and seals the lubricating fluid. Together to seal between the inner tube, always in sliding contact with the inner circumference of the inner tube outer periphery or the outer tube is positioned inside the first seal member always positioned above the oil surface, the The lubricating gap is characterized in that the lower end is sealed with the first seal member and the upper end is sealed with the second seal member .

According to the present invention, by providing the second seal member, the hydraulic fluid for lubrication is lubricated even when the pressure inside the suspension device does not act on the outside of the second seal member and the first seal member is damaged. It is possible to prevent ejection from the gap.
The second seal member includes an air seal that seals the gas, and an oil seal that is provided in series on the first seal member side of the air seal and seals the lubricating fluid. It is possible to reliably seal the hydraulic oil.

  In addition, the sliding surface of the second seal member is always located inside the first seal member, so that the second seal member is not damaged by an external factor. It can be avoided and function reliably as fail-safe.

It is a half sectional view showing the most extended state of a suspension device concerning a first embodiment of the present invention. It is a half sectional view showing the most contracted state of the suspension device according to the first embodiment of the present invention. It is a partial expanded half sectional view which shows the most extended state of the suspension apparatus which concerns on 1st embodiment of this invention. It is a partial notch sectional view which shows the suspension apparatus which concerns on other embodiment of this invention.

  Hereinafter, the seal structure in the suspension system showing the first embodiment of the present invention will be described with reference to the drawings. The same reference numerals given throughout the several drawings indicate the same or corresponding parts.

  In the present embodiment, the seal structure in the suspension device according to the present invention is embodied in a front fork that accommodates therein damping force generating means for damping road surface vibrations input to the front wheel while suspending the front wheel of the motorcycle. It is.

  The front fork includes a pair of left and right fork members that stand on both sides of the front wheel of the motorcycle. The fork member includes an outer tube 1, an inner tube 2 that is removably inserted into the outer tube 1, and the outer tube. A cylindrical lubrication gap 3a formed between the inner circumference of the tube 1 and the outer circumference of the inner tube 2 and the lubrication gap provided on the inner circumference of the opening end 10 of the outer tube 1 on the inner tube 2 insertion side. And a first seal member 11 that holds the lubricating fluid contained in 3a.

  A second seal member 21 is provided in series with the first seal member 11, and the second seal member 21 is in sliding contact with the inner periphery of the outer tube 1 located on the inner side of the first seal member 11. .

  Below, each component of the front fork in this Embodiment is each demonstrated.

  The front fork is set upside down by placing the outer tube 1 on the vehicle body side of the motorcycle and the inner tube 2 on the wheel side of the motorcycle.

  Although not shown, the upper end side of the outer tube 1 in the drawing is connected to the handle of the two-wheeled vehicle, and the lower end side of the inner tube 2 in the drawing is connected to the axle of the front wheel of the two-wheeled vehicle.

  Further, the front fork shown in the figure functions as an air suspension with gas enclosed in the fork member, and also functions as a damper with a damping force generating means described later.

  The fork member is hermetically sealed by sealing the upper and lower ends with the cap member 12 and the bottom member 22 and sealing the sliding surfaces of the outer tube 1 and the inner tube 2 with the second seal member 21 according to the present invention. Is done.

  The inside of the fork member refers to a space excluding an oil reservoir chamber 3 described later, which is defined by the second seal member 21, among the spaces formed inside the outer tube 1 and the inner tube 2.

  The interior of the fork member is located below and is filled with hydraulic oil, and the reservoir chamber R is located above the oil level O of the hydraulic oil and the reservoir chamber R is filled with gas and maintained in a pressure-increasing tendency. It is divided into.

  The reservoir chamber R comprises an upper air chamber R1 formed in the outer tube 1 and a lower air chamber R2 formed in the inner tube 2, and these air chambers R1 and R2 are always kept in communication. It is.

  The hydraulic fluid chamber filled with the hydraulic fluid includes an extension side hydraulic fluid chamber P2 located in the upper part in the figure and a pressure side hydraulic oil chamber P1 located in the lower part in the figure by the piston 15 slidably contacting the inner circumference of the inner tube 2. It is divided into and.

  The extension side hydraulic oil chamber P2 is pressurized through the oil surface O by the gas accommodated in the reservoir chamber R.

  The piston 15 that divides the hydraulic oil chambers P1 and P2 is held via a distal end member 14 at a distal end portion of a rod 13 whose base end portion is fixed to a cap member 12 that seals the upper end of the outer tube 1 in the figure. Thus, the hydraulic oil moves up and down in the drawing as the fork member expands and contracts.

  Although not shown, the piston 15 includes a port that penetrates the thickness of the piston 15. The port includes a pressure-side port that communicates the hydraulic oil chambers P1 and P2 when the fork member contracts, and an extension of the fork member. It is sometimes composed of an extension port communicating with the hydraulic oil chambers P1, P2.

  Further, the piston 15 is provided with a damping force generating means, and the damping force generating means permits the communication of the pressure side port only when the fork member is contracted and generates a predetermined damping force, and the fork member. The extension side leaf valve V2 generates a predetermined damping force by permitting the communication of the extension side port only during the extension.

  By providing the above configuration, the reservoir chamber R pressurizes the expansion side hydraulic oil chamber P2 together with the piston 15 when the fork member is extended, so that the differential pressure between the expansion side hydraulic oil chamber P2 and the pressure side hydraulic oil chamber P1 is increased. Thus, the opening of the extension side leaf valve V2 can be assisted to prevent the pressure side hydraulic oil chamber P1 from being depressurized and aeration to occur.

  Accordingly, the front fork can exhibit a function as a damper without being provided with a damper cylinder, a rod guide, or the like in the fork member, and can be formed to be lightweight.

  Further, the gas sealed in the reservoir chamber R changes its compression ratio due to the volume change of the reservoir chamber R due to the expansion and contraction of the fork member, and generates a predetermined spring reaction force corresponding to this compression ratio to function as an air spring. To do.

  Therefore, the front fork can exhibit a function as a suspension without using a suspension spring formed of a coil spring, and further weight reduction can be achieved.

  The gas sealed in the reservoir chamber R also compensates for the volume change of the reservoir chamber R that increases or decreases the volume of the rod 13 that appears and disappears into the inner tube 2.

  The configuration of the damping force generating means is not limited to the above, and a known method such as an orifice formed in a port penetrating the piston 15 can be appropriately selected.

  Further, the damping force in the damping force generating means may be adjustable by a known method. As the adjusting method, although not shown, a bypass path that bypasses the damping force generating means and penetrates the piston is provided, and this bypass path A method of changing the opening degree of is known.

  Further, the pressurization of the expansion side hydraulic oil chamber P2 by the reservoir chamber R is realized by setting the internal pressure of the reservoir chamber R to a predetermined internal pressure capable of maintaining a pressure increasing tendency by the gas sealed in the reservoir chamber R. As long as the aeration of the pressure side hydraulic oil chamber P1 can be prevented, it can be set as appropriate.

  However, when the reservoir chamber R is maintained in a pressure-increasing tendency, the fork member is urged in the expansion direction by the gas in the reservoir chamber R when the contraction stroke is started from the vicinity of the maximum expansion of the fork member. For this reason, the contraction stroke is not started quickly, and the ride comfort may be deteriorated.

  Therefore, in the present embodiment, the balance spring 4 that urges the fork member in the contraction direction is provided in order to realize a good riding comfort even at the start of the contraction stroke.

  The balance spring 4 is interposed between an upper spring receiver 4a fixed to the inner tube side and a lower spring receiver 4b fixed to the piston side.

  The upper spring receiver 4a is fixed to the insertion side of the inner tube 2 into the outer tube 1, that is, to the lower end of the partition wall member 5 attached to be overlapped with the one end portion located at the upper side in the figure. The receiver 4 b is fixed to a cylindrical case 16 attached to the outer periphery of the tip end portion of the rod 13.

  By providing the structure, the balance spring 4 is compressed when the fork member is in the extended state, as shown in FIG. 1, and the upper end of the inner tube 2 in the drawing and the tip of the rod 13 are separated from each other. In order to urge 13 to enter the inner tube 2, the fork member is urged in a contracting direction.

  Therefore, even when the fork member is in the vicinity of the maximum extension, the balance spring 4 urges the fork member in the contraction direction against the internal pressure of the reservoir chamber R, so that the contraction stroke is quickly started and the riding comfort is improved. There is no deterioration.

  Further, the case 16 including the lower spring receiver 4b includes a through hole 16a that communicates the upper and lower sides of the case 16, and does not hinder the movement of the hydraulic oil, and the pressure of the reservoir chamber R applied to the oil level O Acts under the case 16 via the through-hole 16a, so that it is possible to pressurize the entire extending hydraulic fluid chamber P2.

  The upper end of the balance spring 4 is preferably fixed to the upper spring receiver 4a. However, the present invention is not limited to this. Even if the lower end of the balance spring 4 is fixed to the lower spring receiver 4b, both ends are fixed. It may be used free of charge.

  The rod 13 for holding the piston 15 includes a pair of upper and lower cushion members 17a and 17b attached to the outer periphery thereof. The upper cushion member 17a is in the vicinity of the base end member of the rod 13 and the lower cushion member 17b is the rod 13. It is attached at the approximate center.

  These cushion members 17a and 17b are made of an elastic material, and when the fork member is fully extended, as shown in FIG. 1, the inner peripheral piece 5a of the partition wall member 5 to which the lower cushion member 17b is fixed to the inner tube 2 is provided. As shown in FIG. 2, the upper cushion member 17 a comes into contact with the upper surface of the inner peripheral piece 5 a of the partition member 5 when the fork member is contracted most.

  Therefore, each cushion member 17a, 17b absorbs an impact when the fork member is most extended and contracted, and prevents further expansion and contraction.

  Even when the cushion member 17b and the partition member 5 are in contact with each other, the upper and lower reservoir chambers R1 and R2 communicate with each other, and the cushion member 17b and the partition member 5 communicate with the upper and lower reservoir chambers R1 and R2. It does not prevent

  By the way, on the lower side of the inner tube 2 in the figure, a cap-like bottom case 23 made of a hard synthetic resin is fixed to the bottom member 22, and although not shown, the outer periphery of the bottom case 23 and the bottom member 22 are liquid-tight. An air chamber A that is sealed and communicates with the outside air is provided inside the bottom case 23.

  The bottom case 23 is formed in such a length that the upper end and the piston 15 do not come into contact with each other when the fork member is most contracted as shown in FIG. It is possible to reduce the amount and reduce the weight of the front fork.

Therefore, as long as the stroke length is ensured, the fork member may be shortened without providing the bottom case 23.

  By providing the above configuration, the front fork in the present embodiment can exhibit basic performance as a front fork such as an air suspension and a function as a damper.

  Moreover, the said front fork is provided with the structure for making the inner tube 2 protrude and retract smoothly in the outer tube 1, and the structure which concerns on this invention is embodied in the said structure.

  As shown in FIG. 3, the fork member forms a cylindrical lubrication gap 3a between the inner circumference of the outer tube 1 and the outer circumference of the inner tube 2, and accommodates lubricating hydraulic oil in the lubrication gap 3a. And a pair of upper and lower annular bearings 6a and 6b.

  An opening end 10 on the inner tube insertion side of the outer tube 1, that is, an inner periphery of a lower end in the figure, is provided with an annular first seal member 11 that is in sliding contact with the outer periphery of the inner tube 2. The hydraulic fluid for lubrication is held in the lubrication gap 3a.

  The first seal member 11 includes an annular dust seal 11a located outside and an annular oil seal 11b provided in series inside the dust seal 11a, and a conventionally known configuration is employed.

  A second seal member 21 is provided in series with the first seal member 11, and the second seal member 21 is in sliding contact with the inner periphery of the outer tube 1 positioned on the inner side of the first seal 11. And the inner tube 2 are sealed.

  Accordingly, the pressure inside the fork member does not act on the lubrication gap 3a outside the second seal member 21, and even when the first seal member 11 is damaged, the working fluid for lubrication is ejected from the lubrication gap 3a. It becomes possible to prevent.

  Further, the inner circumference of the outer tube 1 located on the inner side of the first seal member 11 is always located on the inner side of the first seal member 11 and is not exposed to the outside air. It is kept smooth because it is not damaged by any factors.

  Accordingly, the sliding surface of the second seal member 21 is kept smooth, and it is possible to reliably function as a fail-safe while avoiding the risk of the second seal member 21 being damaged by scratches on the sliding surface.

  In the present embodiment, the lubricating gap 3a is sealed at the lower end side in the figure with the first seal member 11, and the upper end side in the figure is attached to the inner tube 2 via the partition member 5 in the second seal member. 21 and is expanded and contracted as the fork member expands and contracts.

  That is, as shown in FIG. 1, when the fork member is in the extended state, the first seal member 11 and the second seal member 21 approach each other and the volume of the lubrication gap 3a contracts, as shown in FIG. In addition, when the fork member is in the contracted state, the first seal member 11 and the second seal member 21 are separated from each other, and the volume of the lubrication gap 3a is expanded.

  The lubrication gap 3a communicates with the volume compensation chamber 3b via an oil hole 30 provided on the distal end side of the inner tube 2 in the figure, and constitutes an oil reservoir chamber 3 sealed together with the volume compensation chamber 3b.

  The oil reservoir chamber 3 is partitioned from the inside of the fork member by the second seal member 21 and, when the fork member is in an extended state, the inside thereof is located below and filled with hydraulic fluid for lubrication. A lubricating fluid chamber L and an air chamber G located above the oil level O1 of the lubricating fluid chamber L are formed (FIGS. 1 and 3).

  With this configuration, when the fork member extends, the volume of the lubrication gap 3a decreases, so that the hydraulic oil overflowing from the lubrication gap 3a flows into the volume compensation chamber 3b through the oil hole 30. (FIG. 1).

  When the fork member contracts, the volume of the lubrication gap 3a increases, so that the hydraulic oil that is insufficient in the lubrication gap 3a is supplied from the volume compensation chamber 3b into the lubrication gap 3a through the oil hole 30. (FIG. 2).

  And the increase / decrease in the hydraulic oil in the volume compensation chamber 3b is compensated by expansion / contraction of the gas accommodated in the air chamber G.

  By providing the above configuration, the pressure in the reservoir chamber R inside the fork member does not act on the oil reservoir chamber 3 positioned outside the second seal member 21, and the oil reservoir chamber 3 is partitioned from the fork member interior. It is possible to prevent the pressure inside the fork member from acting on the lubrication gap 3a.

  Further, the oil level in the lubrication gap 3a is reduced by forming the lubrication fluid chamber L and the air chamber G in the oil reservoir chamber 3 including the volume compensation chamber 3b and including the lubrication gap 3a and the volume compensation chamber 3b. And the volume change of the lubrication gap 3a can be compensated.

  The volume compensation chamber 3b is formed by a cylindrical partition member 5 provided on the insertion side of the inner tube 2 into the outer tube 1, that is, on the inner side of one end located on the upper side in the drawing.

  As shown in FIG. 3, the partition member 5 protrudes from one end of the inner tube 2 and has an annular protrusion 50 provided with the second seal member 21 on the outer periphery, and extends from the protrusion 50. An annular coupling part 51 whose outer periphery is coupled to the inner circumference of one end of the inner tube 2, an annular reduced diameter part 52 extending from the coupling part 51 and having a reduced outer diameter, and the reduced diameter part 52 The outer periphery of the inner tube 2 is provided with a close contact portion 53 that is in liquid-tight contact with the inner periphery of the inner tube 2 via a seal member 53a.

  A volume compensation chamber 3 b is formed between the outer periphery of the reduced diameter portion 52 and the inner periphery of the inner tube 2, and the volume compensation chamber 3 b has the oil hole 30 in the lap portion with the reduced diameter portion 52 in the inner tube 2. It is opened and communicated with the lubrication gap 3 a through the oil hole 30.

  With the above configuration, when the front fork is assembled, the partition wall member 5 is assembled by filling the hydraulic oil up to the vicinity of the upper end while the fork member is maintained in the most contracted state, and then assembling the partition member 5 to the inner tube 2. Since the air chamber is naturally formed therein, the oil reservoir chamber 3 in the present invention can be easily realized.

  Further, since the second seal member 21 is attached to the partition wall member 5, the second seal member 21 can also be easily assembled.

  The second seal member 21 is disposed in series with the air seal 21a facing the reservoir chamber R and seals the gas sealed in the reservoir chamber R, and operates in the lubrication gap 3a. And an annular oil seal 21b for sealing oil.

  By providing this configuration, the seals 21a and 21b can reliably seal the gas in the reservoir chamber R and the hydraulic oil in the lubrication gap 3a.

  The characteristics of the seal used as the second seal member 21 can be appropriately selected depending on the object to be sealed.

  If the air seal 21a has a function of sealing the hydraulic oil in the lubrication gap 3a to the extent that it does not scrape into the reservoir chamber R, the oil seal 21b is not necessarily provided.

  By the way, in the present embodiment, a pair of upper and lower annular bearings 6a and 6b that facilitate smooth sliding between the outer tube 1 and the inner tube 2 are provided in the lubrication gap 3a, and the outer periphery of the upper end portion of the inner tube 2 in the figure. The upper annular bearing 6a is positioned on the inner periphery of the outer tube 1 and the lower annular bearing 6b is slidable.

  The upper annular bearing 6a is provided above the oil hole 30 that connects the lubrication gap 3a and the volume compensation chamber 3b, is fitted in a groove 24 formed on the outer periphery of the inner tube 2, and does not move. By being brought into sliding contact with the inner periphery of the outer tube 1 and having this configuration, the hydraulic oil that moves between the lubrication gap 3a and the volume compensation chamber 3b is not hindered.

  On the other hand, the lower annular bearing 6b is slidably provided in a groove 10a formed on the inner periphery of the lower tip 10 of the outer tube 1 in the figure, and slides on the inner periphery of the inner tube 2 via an oil film. It contacts and moves up and down as the inner tube 2 moves.

  By providing this configuration, it becomes possible to supply hydraulic oil to the oil seal 11b in the first seal member 11 to ensure the slidability of the oil seal 11b.

  While the preferred embodiment of the present invention has been described above, it should be understood that modifications, variations and changes may be made without departing from the scope of the claims.

  For example, in the above-described embodiment, an inverted front fork is used. However, the present invention is not limited to this. It goes without saying that an upright front walk may be used.

  Further, as shown in FIG. 4, a second seal member 210 provided in series with the first seal member 11 is provided on the inner periphery of the outer tube 1, and the second seal member 210 is always on the inner side of the first seal member 11. It may be in sliding contact with the outer periphery of the inner tube 2 positioned.

  By providing the configuration, the pressure inside the fork member does not act on the annular gap 3a outside the second seal member 210, and the first seal member 11 is damaged as in the first embodiment. In this case, it is possible to prevent the hydraulic fluid for lubrication from being ejected from the lubrication gap 3a.

  The outer periphery of the inner tube 2 that is always located inside the first seal member 11 means the outer periphery of the inner tube 2 that is located inside the outer tube 1 even when the fork member shown in FIG. Is.

  Accordingly, in this case as well, the sliding surface of the second seal member 210 is kept smooth without being damaged by an external factor. Therefore, as in the first embodiment, the second seal member 210 is maintained. However, it is possible to avoid the risk of damage due to scratches on the sliding surface and to function reliably as fail-safe.

  Also in the present embodiment, the second seal member 210 is provided in series with the annular air seal 210a that opposes the reservoir chamber R and seals the gas sealed in the reservoir chamber R, and the air seal 210a. And an annular oil seal 210b for sealing the hydraulic oil in the lubrication gap 3a.

  With this configuration, the seal 210a and 210b can reliably seal the gas in the reservoir chamber R and the hydraulic oil in the lubrication gap 3a.

  In the present embodiment, when the lubricating hydraulic oil is accommodated in the lubrication gap located above the second seal member 210 in the drawing, the second seal member 210 is formed only from the oil seal. It may be.

  Further, the oil seal 210b is not necessarily provided as long as the air seal 210a has a function of sealing the hydraulic oil in the lubrication gap 3a to the extent that it does not scrape into the reservoir chamber R.

  In the figure, the seal structure of the suspension device according to the present invention is embodied in the front fork. However, the present invention is not limited to this, and the seal structure according to the present invention is embodied in the rear cushion unit and other suspension devices. It may be converted.

  In the present embodiment, the working oil is stored in the fork member. However, the present invention is not limited to this, and it is needless to say that an aqueous working fluid may be used.

In addition, although the hydraulic fluid is used as the lubricating fluid, a hydraulic fluid other than the hydraulic fluid stored in the fork member, for example, an aqueous hydraulic fluid or other hydraulic fluid may be used.

A Air chamber G Air chamber L Lubricating fluid chamber O, O1 Oil level P1 Pressure side hydraulic oil chamber P2 Extension side hydraulic oil chamber R Reservoir chamber V1 Pressure side leaf valve V2 Extension side leaf valve 1 Outer tube 2 Inner tube 3 Oil reservoir chamber 3a Lubrication Clearance 3b Volume compensation chamber 4 Balance spring 5 Partition members 6a and 6b Annular bearing 11 First seal member 12 Cap member 13 Rod 14 Tip member 15 Piston 16 Case 17 Cushion members 21 and 210 Second seal member 22 Bottom member 23 Bottom case

Claims (3)

And the outer tube, the the inner tube is inserted retractably into the outer tube, a cylindrical lubrication gap formed between the inner periphery and the inner tube outer periphery the outer tube, said inner tube of said outer tube A first seal member that is provided in the inner periphery of the opening end on the insertion side and holds the lubricating fluid accommodated in the lubrication gap, and is located above the oil surface of the hydraulic oil and is filled with gas and tends to be high pressure A suspension device comprising a reservoir chamber to be maintained;
A second seal member is provided in series with the first seal member,
It said second sealing member has a air seal for sealing the gas, and the outer tube and the inner tube and a oil seal for sealing the lubricating fluid provided in series with the first sealing member side of the air seal with a seal between the, always in sliding contact with the inner circumference of the inner tube outer periphery or the outer tube is positioned inside the first seal member always positioned above the oil surface,
The seal structure for a suspension device , wherein the lubrication gap has a lower end sealed with the first seal member and an upper end sealed with the second seal member . The lubricating gap, the sealing structure in the suspension system according to claim 1, characterized by being in communication with the volume compensation chamber partitioned within the suspension system.   3. The seal in the suspension device according to claim 2, wherein the oil reservoir chamber composed of the annular gap and the volume compensation chamber is formed therein with a lubricating fluid chamber composed of the lubricating fluid and an air chamber. Construction.

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