JP2014167314A - Seal member and front fork equipped therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the followability degradation or warpage of a dust lip without mounting a garter spring.SOLUTION: A seal member 1 for blocking a space between an outer tube 4 and an inner tube 5 is formed by insert metals 2, 7 and an elastic body 3 covering the insert metals 2, 7. It includes: an annular fitted part 10 to be fitted to the inner periphery of the outer tube 4; and an annular dust lip 11 extending from the fitted part 10 to a counter outer tube side while gradually diameter-shrinking its inner periphery, and having a front end slide-contacting the outer peripheral face of the inner tube 5. The insert metals 2, 7 are the one-side insert metal 2 arranged on the fitted part 10, and the other-side insert metal 7 arranged on the dust lip 11.

Description

  The present invention relates to a seal member and an improvement of a front fork provided with the seal member.

  In general, a shock absorber that generates a damping force using a working fluid such as hydraulic oil, a cylinder device that drives an object using the working fluid, and the like are a cylinder member such as a cylinder that contains the working fluid. A shaft member such as a piston rod inserted in the cylinder member so as to be movable in the axial direction is provided, and can be expanded and contracted by relative movement between the cylinder member and the shaft member. A sealing member is provided between the cylindrical member and the shaft member, and the leakage of the working fluid in the cylindrical member is prevented by this sealing member.

  In addition, a front fork shock absorber that suspends a front wheel in a straddle-type vehicle such as a motorcycle is connected to an outer tube (cylinder member) connected to one of the vehicle body side or the wheel side and to the other of the vehicle body side or the wheel side. The shock absorber body is composed of an inner tube (shaft member) that is inserted into the outer tube so as to be movable in the axial direction, the working fluid is accommodated in the shock absorber body, and the overlapping portion of the outer tube and the inner tube The outside air side opening of the cylindrical gap formed between the two is sealed with a seal member.

  Particularly, in the front fork described above, mud, sand, etc. (hereinafter referred to as foreign matter) are likely to adhere to the outer peripheral surface of the inner tube when the vehicle is running, so an oil seal provided with an oil lip that prevents the working fluid from flowing out of the shock absorber body A dust seal seal member with a dust strip that scrapes off foreign matter adhering to the outer peripheral surface of the inner tube is connected in series, and the dust seal seal member reliably scrapes off the foreign matter. In addition to preventing foreign matter from entering the shock absorber body, the sliding surface of the oil lip is wrinkled by foreign matter adhering to the inner tube, thereby preventing the working fluid from leaking (for example, Patent Documents 1 and 2). ).

  In the front fork, the inner tube may bend or tilt with respect to the outer tube due to the input of external force. Therefore, the length of the dust lip is increased to improve the followability to the inner tube. The strip is prevented from opening away from the inner tube.

JP 2013-002622 A JP 2012-180883 A

  Here, the dust lip is made of an elastic body such as rubber and has a tightening margin with respect to the inner tube, so that it is pressed against the outer peripheral surface of the inner tube. There is a possibility that followability to the inner tube may be reduced. In addition, in order to make it easier to scrape off foreign matter and to prevent the tip of the dust lip from being taken into the outer tube side when the inner tube enters the outer tube, Although it is preferable to make the inclination angle of the strip small (near parallel), in this case, there is a possibility that the tip of the dust lip warps in a direction away from the inner tube, and warping occurs. For this reason, in the sealing member disclosed in Japanese Patent Application Laid-Open No. 2012-180883, an urging member called a garter spring is attached to the outer periphery of the front end portion of the dust lip to suppress follow-up deterioration and warping.

  However, when a garter spring is used, the cost increases. In general, a garter spring is formed in an annular shape by connecting both ends of a coil spring formed by winding a wire to form a spiral. When the inside of the garter spring is filled with foreign matter, the tightening force by the garter spring is reduced, and there is a possibility that the effect obtained by providing the garter spring cannot be obtained sufficiently. Furthermore, when attaching a garter spring, it is necessary to increase the thickness of the tip of the dust lip that corresponds to this attachment part. If the tip of the dust lip is arranged so that the tip of the dust lip is facing upward, It becomes easy to accumulate.

  Accordingly, an object of the present invention is to provide a sealing member that can reduce the cost and cost by suppressing a decrease in followability and warping to a shaft member such as an inner tube without attaching the garter spring to the dust lip. An object of the present invention is to provide a front fork provided with this seal member.

  Means for solving the above problem is formed of an insert metal and an elastic body covering the insert metal, and a cylindrical member and a shaft member inserted into the cylindrical member so as to be movable in the axial direction A sealing member for closing a gap between the annular fitting portion fitted to the inner periphery of the cylindrical member, and a distal end portion extending from the fitting portion toward the side opposite to the cylindrical member while the inner circumference is gradually reduced in diameter. In a seal member provided with an annular duster that is in sliding contact with the outer peripheral surface of the shaft member, and a front fork provided with the seal member, the insert metal is disposed on the one-side insert metal, and It is comprised with the other side insert metal arrange | positioned at the said dust lip.

  According to the present invention, even if a garter spring is not attached to a dust lip, it is possible to suppress a decrease in followability to a shaft member such as an inner tube or a warp, and to reduce costs.

It is the front view which notched and showed the principal part of the front fork provided with the sealing member which concerns on one embodiment of this invention. It is the figure which expanded and showed the cutting part end surface of the seal member concerning one embodiment of the present invention.

  A sealing member according to an embodiment of the present invention will be described below with reference to the drawings. The same reference numerals used throughout the several drawings indicate the same parts.

  As shown in FIG. 1, the seal member 1 according to the present embodiment is formed of insert metals 2 and 7 and an elastic body 3 covering the insert metals 2 and 7, and an outer tube (tubular member). 4 and the inner tube (shaft member) 5 inserted in the outer tube 4 so as to be movable in the axial direction are closed. The seal member 1 includes an annular fitting portion 10 fitted to the inner periphery of the outer tube 4 and the outer tube side (anti-cylinder side) while the inner periphery is gradually reduced in diameter from the fitting portion 10. An annular dust strip 11 extending in the member side) and having a tip portion slidably contacting the outer peripheral surface of the inner tube 5 is provided.

  The insert metals 2 and 7 are composed of the one-side insert metal 2 disposed in the fitting portion 10 and the other-side insert metal 7 disposed in the dust lip 11.

  Further, in the present embodiment, the seal member 1 is used in a shock absorber of a suspension device called a front fork that suspends a front wheel in a straddle-type vehicle such as a motorcycle. Since the configuration of the front fork is well known and any configuration may be adopted, it is not specifically illustrated. For example, the front fork includes a suspension spring that elastically supports the vehicle body and a shock absorber that generates a damping force. In parallel, shocks caused by road surface irregularities are absorbed by the suspension springs, and expansion and contraction movements by the suspension springs are suppressed by a shock absorber to suppress the transmission of the impacts to the vehicle body.

  The shock absorber includes an outer tube 4 connected to one of the vehicle body side or the wheel side, and an inner tube 5 connected to the other of the vehicle body side or the wheel side and inserted into the outer tube 4 so as to be movable in the axial direction. Can be telescopically expanded and contracted. Further, the shock absorber main body F composed of the outer tube 4 and the inner tube 5 has a vehicle body side opening that is closed by a cap member (not shown), and the wheel side opening connects the shock absorber to the axle of the front wheel. Of the cylindrical gap T formed between the overlapping portions of the outer tube 4 and the inner tube 5 are sealed with the sealing members 1 and 6, The inside is separated from the outside air. Although not shown, the shock absorber main body F contains hydraulic oil as a working fluid, a damping force generation mechanism for generating a damping force using the hydraulic oil, a suspension spring, and the like. Yes. The working fluid is not limited to working oil, and may be water, an aqueous solution, gas, or the like. Further, the configuration of the damping force generation mechanism is well known, and any configuration may be adopted, and detailed description thereof is omitted here.

  Furthermore, although not shown in the figure, the cylindrical gap T is provided with an annular bearing that supports the inner tube 5 and contains hydraulic oil as a lubricant that lubricates the sliding surface of the bearing. Two sealing members 1 and 6 that close the outside air side opening of the cylindrical gap T are arranged in series, and the sealing member 6 on the outer tube side (the lower side in FIG. 1) prevents the leakage of the hydraulic oil. The anti-outer tube side (upper side in FIG. 1) seal member 1 that is used for preventing oil seal and that is on the outside air side scrapes off the foreign matter adhering to the outer peripheral surface of the inner tube 5, and the foreign matter is put into the shock absorber main body F. It is used for dust sealing which prevents contamination and prevents the oil seal member 6 from sticking out due to foreign matters and preventing hydraulic fluid in the shock absorber main body F from leaking from this portion. Note that a liquid different from hydraulic oil (working fluid), grease, or the like may be used as the lubricant.

  In the present embodiment, the present invention is embodied in a seal member 1 for dust seal, and the configuration of the seal member 1 will be described in detail below.

  As shown in FIG. 2, the seal member 1 is formed by coating a metal one-side insert metal 2 and the other-side insert metal 7 which are formed as separate bodies with an elastic body 3 such as rubber. , 7 corresponds to a core bar that reinforces the elastic body 3 that substantially functions as a seal. Further, since the seal member 1 is formed by insert molding, both the insert metals 2 and 7 and the elastic body 3 are bonded and integrated at the time of molding.

  Further, as described above, the seal member 1 has an annular fitting portion 10 fitted to the inner circumference of the outer tube 4 and the inner circumference is gradually reduced in diameter from the upper end in FIG. However, it has an annular dust strip 11 that extends to the side opposite to the outer tube (upper side in FIG. 2) and has a tip portion that is in sliding contact with the outer peripheral surface of the inner tube 5. And an annular sub dust strip 12 that extends to the side opposite to the outer tube (upper side in FIG. 2) while being reduced in diameter, and has a tip that is in sliding contact with the outer peripheral surface of the inner tube 5. Then, the recess formed between the dust lip 11 and the sub dust lip 12 functions as a foreign matter accumulation portion when the foreign matter moves to the lower side in FIG.

  In the present embodiment, the fitting portion 10 of the seal member 1 includes an annular flange portion 10a that protrudes from the inner side of the outer tube 4 to the outer peripheral side and press-contacts to the tip of the outer tube 4 and has an inverted L-shaped cross section. Since it is formed, the sealing member 1 can be positioned by this flange portion 10 a, and the one-side insert metal 2 is also formed in an inverted L-shaped cross section in accordance with the shape of the fitting portion 10. Further, when the elastic body 3 that covers the one-side insert metal 2 and forms the fitting portion 10 together with the one-side insert metal 2 is an outer peripheral seal portion 30, the outer peripheral side of the outer peripheral seal portion 30 is the one-side insert metal. 2 and the outer tube 4 are compressed and elastically deformed and closely contacted from the inner peripheral surface of the outer tube 4 to the distal end surface, so that the space between the outer tube 4 and the seal member 1 is closed. The shape of the fitting portion 10 and the shape of the one-side insert metal 2 that reinforces the fitting portion 10 can hold the seal member 1 on the inner periphery of the outer tube 4, and the outer tube 4 and the seal member 1. As long as the gap between the two can be closed, it can be changed as appropriate.

  Subsequently, the other-side insert metal 7 formed in a ring shape or a C ring shape is disposed on the outer peripheral portion of the dust strip 11 in the seal member 1. When the elastic body 3 that covers the other side insert metal 7 and forms the dust lip 11 together with the other side insert metal 7 is defined as the inner peripheral seal portion 31, Since the portion 31a that forms the distal end portion is in sliding contact with the outer peripheral surface of the inner tube 5 and has a predetermined allowance for the inner tube 5, the space between the inner tube 5 and the seal member 1 is blocked. At the same time, the foreign matter adhering to the outer peripheral surface of the inner tube 5 can be scraped off by the dust lip 11. Furthermore, the diameter 31a of the elastic body 3 is expanded in accordance with the outer diameter of the inner tube 5. However, since the other-side insert metal 7 is disposed on the outer peripheral portion on the tip end side of the dust lip 11, Can be suppressed by the other-side insert metal 7. The shape and position of the other-side insert metal 7 do not directly contact the inner tube 5 but can follow the inner tube 5 and move with the dust strip 11 (inner seal 31). As long as the relative movement between 5 and the dust strip 11 is not hindered, it can be changed as appropriate.

  Next, the effect by providing the sealing member 1 which concerns on this Embodiment is demonstrated. The seal member 1 according to the present embodiment is formed by insert metals 2 and 7 and an elastic body 3 covering the insert metals 2 and 7, and an outer tube (tubular member) 4 and the outer tube 4. The space between the inner tube (shaft member) 5 that is inserted therein so as to be movable in the axial direction is closed. The seal member 1 includes an annular fitting portion 10 fitted to the inner periphery of the outer tube 4 and the outer tube side (anti-cylinder side) while the inner periphery is gradually reduced in diameter from the fitting portion 10. An annular dust strip 11 extending in the member side) and having a tip portion slidably contacting the outer peripheral surface of the inner tube 5 is provided.

  The insert metals 2 and 7 include the one-side insert metal 2 disposed in the fitting portion 10 and the other-side insert metal 7 disposed in the dust lip 11.

  According to the above configuration, even if the length of the dust lip 11 is sufficiently long and the inclination angle with respect to the inner tube 5 is reduced, the other-side insert metal 7 follows the inner tube 5 while reinforcing the dust lip 11. Therefore, without attaching a garter spring to the dust lip 11 as in the prior art, it is possible to suppress a decrease in followability and warping of the dust lip 11 to the inner tube (shaft member) 5. Moreover, since the other side insert metal 7 is coat | covered with the elastic body 3, there is no malfunction of accumulating a foreign material like a garter spring. Further, since the garter spring can be eliminated, the cost is reduced, and it is not necessary to increase the thickness of the tip of the dust lip 11 as when the garter spring is attached, and the tip of the dust lip 11 faces upward. However, the problem that foreign matter is accumulated at the tip of the dust strip 11 is also eliminated.

  Moreover, in this Embodiment, the said other side insert metal 7 is formed in cyclic | annular form or C cyclic | annular form.

  Therefore, since the dust lip 11 can be reinforced along the circumferential direction by the other-side insert metal 7, it is possible to enhance the effect of suppressing a decrease in followability to the inner tube (shaft member) 5 and warping. Moreover, when forming the sealing member 1 by insert molding, it is easy to shape | mold.

  In the present embodiment, the other-side insert metal 7 is disposed at the outer peripheral portion on the tip end side of the dust lip 7.

  According to the above configuration, since the other-side insert metal 7 is disposed on the tip end side of the dust lip 11, the vicinity of the sliding contact portion between the dust lip 11 and the inner tube (shaft member) 5 is reinforced with the other-side insert metal 7. Thus, it is possible to enhance the effect of suppressing a decrease in followability to the inner tube (shaft member) 5 and warping. Even if the other-side insert metal 7 is disposed on the front end side of the dust lip 11, it is slidably brought into contact with the outer peripheral surface of the inner tube (shaft member) 5 because it is disposed on the outer peripheral portion of the dust lip 11. The thickness of the elastic body 3 (part 31a) can be ensured.

  Moreover, in this Embodiment, the sealing member 1 is utilized for the front fork, and has block | closed between the outer tube 4 which is a cylinder member, and the inner tube 5 which is a shaft member.

  In particular, since the front fork is disposed at the front portion of the vehicle, foreign matter is likely to adhere to the vehicle during travel, and when a garter spring is provided, foreign matter is likely to accumulate inside the garter spring. Therefore, the front fork includes the seal member 1 according to the present invention, and it is extremely effective to suppress a decrease in followability and warping to the inner tube (shaft member) 5 without attaching a garter spring to the dust lip 11. is there.

  Further, in the present embodiment, the seal member 1 extends from the approximate center of the inner periphery of the fitting portion 10 toward the anti-outer tube side (anti-cylinder member side) while the inner periphery is gradually reduced in diameter. Since the annular sub dust strip 12 slidably contacting the outer peripheral surface of the inner tube (shaft member) 5 is provided, the foreign dust attached to the outer peripheral surface of the inner tube 5 is scraped off in addition to the dust strip 11. Can do.

  Although preferred embodiments of the present invention have been described in detail above, it should be understood that modifications, variations and changes may be made without departing from the scope of the claims.

  For example, in each of the above embodiments, the seal member 1 according to the present invention is used for a front fork. However, the seal member 1 may be used for a shock absorber for a vehicle, a cylinder device, or the like.

  Further, in each of the above embodiments, the sealing member 1 according to the present invention includes a dust lip 11 for scraping off foreign matter adhering to the outer periphery of the inner tube 5 that is a shaft member, and a sub lip strip 12 and is a double lip. Although the structure is adopted, the sub dust strip 12 may be eliminated to form a single lip structure. Further, the seal member 1 according to the present invention is replaced with the sub dust strip 12 and the inner circumference is gradually reduced in diameter from the fitting portion 10 while extending in the opposite direction (outer tube side) from the dust strip, and the tip portion is an inner tube (shaft member). ) An oil lip slidably contacting the outer periphery of 5 may be provided, and the configuration of the seal member can be appropriately selected.

DESCRIPTION OF SYMBOLS 1 Seal member 2 One side insert metal 7 The other side insert metal 3 Elastic body 4 Outer tube (cylinder member)
5 Inner tube (shaft member)
10 Fitting part 11 Dustrip

Claims (4)

A seal member that is formed of an insert metal and an elastic body that covers the insert metal, and that seals between the tubular member and the axial member that is movably inserted in the axial direction into the cylindrical member, An annular fitting portion that is fitted to the inner periphery of the cylindrical member, and a distal end portion that is in sliding contact with the outer peripheral surface of the shaft member while the inner periphery is gradually reduced in diameter from the fitting portion and extends toward the non-cylinder member side. In a sealing member comprising an annular dust strip,
The said insert metal is comprised by the one side insert metal arrange | positioned at the said fitting part, and the other side insert metal arrange | positioned at the said dust lip, The sealing member characterized by the above-mentioned.   The said other side insert metal is formed in cyclic | annular form or C cyclic | annular form, The sealing member of Claim 1 characterized by the above-mentioned.   The seal member according to claim 1, wherein the other-side insert metal is disposed on a front end side outer peripheral portion of the dust lip. A front fork comprising an outer tube that is a cylindrical member and an inner tube that is a shaft member that is movably inserted into the outer tube,
A front fork comprising the seal member according to any one of claims 1 to 3, which seals between the outer tube and the inner tube.

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