Title of Invention	DUST COVER MOUNTING STRUCTURE FOR HYDRAULIC SHOCK ABSORBER
Abstract	A dust cover mounting structure of a hydraulic shock absorber (10) comprises. a damper tube (11); a piston rod (12) provided with a spring seat (15); a suspension spring (13) supported to the spring seat (15) via a spring rubber (40); and a mounting portion (51) of a dust cover (50) held between the spring seat (15) and the spring rubber (40), wherein the spring seat (15) has a non-annular outer shape, a standing-up rib (34) is provided in an outer edge thereof, and the mounting portion (51) has a non-annular outer shape profiling an inner periphery of the rib (34) received in the inner periphery of the rib.

Title of Invention

DUST COVER MOUNTING STRUCTURE FOR HYDRAULIC SHOCK ABSORBER

Abstract

A dust cover mounting structure of a hydraulic shock absorber (10) comprises. a damper tube (11); a piston rod (12) provided with a spring seat (15); a suspension spring (13) supported to the spring seat (15) via a spring rubber (40); and a mounting portion (51) of a dust cover (50) held between the spring seat (15) and the spring rubber (40), wherein the spring seat (15) has a non-annular outer shape, a standing-up rib (34) is provided in an outer edge thereof, and the mounting portion (51) has a non-annular outer shape profiling an inner periphery of the rib (34) received in the inner periphery of the rib.

Full Text	-1- DUST COVER MOUNTING STRUCTURE OF HYDRAULIC SHOCK ABSORBER TECHNICAL FIELD The present invention relates to a dust cover mounting structure of a hydraulic shock absorber. BACKGROUND ART Conventionally, there has been a hydraulic shock absorber, as described in Japanese Patent Application Laid-Open Publication (JP-A) No. 57-129942, such that a damper tube and a piston rod are provided, a spring seat is provided in the piston rod, a suspension spring is supported to the spring seat via a spring rubber, and a mounting portion of a dust cover is held between the spring seat and the spring rubber. However, the prior art has the following problems. (1) The spring seat is provided with a standing-up rib on an annular outer edge, and the mounting portion of the dust cover is rotatably received along an inner periphery of the annular rib. Accordingly, a torsion force generated at a time of extension and compression of the suspension spring rotates the dust cover to which the torsion force is applied via the spring rubber while rubbing the dust cover against the spring seat, whereby dusts are generated on the basis of abrasion of the dust cover so as to pollute an environment. This dust generation is significant when the dust cover is made of a resin. (2) Since the mounting portion between the spring rubber and the dust cover is simply laminated on the spring seat, it is quite -2- possible that the spring rubber and the dust cover are dropped off in a step of attaching an assembly obtained by laminating the spring rubber and the dust cover on the spring seat to the piston rod so as to bring into contact and align with the spring seat, so that an assembling 5 property is deteriorated. (3) An outer periphery of the spring rubber is restricted neither by the spring seat nor the dust cover. Accordingly, when the spring rubber repeatedly receives a compression force on the basis of a spring force of the suspension spring, the spring rubber freely protrudes in a 10 direction of the outer periphery so as to be yielded and deformed, so that there is a risk that the spring rubber is broken or dropped off. DISCLOSURE OF THE INVENTION An object of the present invention is to prevent dusts from 15 being generated due to rotation of a dust cover at a time of holding a mounting portion of the dust cover between a spring rubber and a spring seat which receive a suspension spring. Further, another object of the present invention is to improve an assembling property of a spring seat, a dust cover and a spring 2 0 rubber and to prevent the spring rubber from being yielded and deformed. In accordance with the present invention, there is provided a dust cover mounting structure of a-hydraulic-shock- absor-ber comprising- 2 5 a damper tube,' a piston rod; a spring seat provided in the piston rod; -3- a suspension spring supported to the spring seat via a spring rubber; and a mounting portion of a dust cover held between the spring seat and the spring rubber, wherein the spring seat is formed in a non-annular outer shape, a standing-up rib is provided in an outer edge thereof, and the mounting portion of the dust cover is formed in a non-annular outer shape profiling an inner periphery of the rib of the spring seat and is received in the inner periphery of the rib. ^ BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS FIG. 1 is a cross sectional view showing a hydraulic pressure shock absorber." FIG. 2 is a plan view of FIG. 1;, FIG. 3 is a schematic view showing a spring seat; FIG. 4 is a schematic view showing a dust cover; and FIG. 5 is a schematic view showing a spring rubber. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A hydraulic shock absorber 10 has, as shown in FIGS. 1 and 2, a damper tube 11, a piston rod 12 and a suspension spring 13, and is structured such that a lower spring seat 14 is attached to an outer peripheral portion of the damper tube 11. An upper spring seat 15 is attached to the piston rod 12 and the suspension spring 13 is interposed between the spring seats 14 and 15. The hydraulic shock absorber 10 is provided with an axle side mounting portion 16 in a lower portion of the damper tube 11, is -4- provided with a vehicle body side mounting portion 17 in the upper spring seat 15 attached to the piston rod 12, and a mounting bolt 18 attaches to the vehicle - body side mounting portion 17. The hydraulic shock absorbed 10 absorbs an impact applied from a road surface by the suspension spring 13 and damps an expanding and compressing vibration of the suspension spring 13 by a damping device (not shown) installed within the damper tube 11. In this case, the hydraulic shock absorber 10 positions receiving seats 22 and 23 and a cover 24 by a joint collar 21 inserted and attached to an outer end portion of the piston rod 12. Mount rubbers 25A and 25B are provided between the receiving seats 22 and 23, and a mounting nut 26 is engaged with an upper end portion of the piston rod 12 in a state of holding a base end portion 31 of the upper spring seat 15 between the mount rubbers 25A and 25B. Further, a bump rubber 27 is press-fitted around the piston rod 12 surrounded by the cover 24. A bump stopper cap 28 is fixed around an axial seal portion through which the piston rod 12 of the damper tube 11 extends, and a bump rubber contact plate 28A is provided in the bump stopper cap 28. In this case, in the hydraulic shock absorber 10, the circular suspension spring 13 is supported to the upper spring seat 15 via a spring rubber 40, and a mounting portion 51 of a dust cover 50 is held between the upper spring seat 15 and the spring rubber 40. A description will be in detail given below of a mounting structure of the dust cover 50. The spring seat 15 is, as shown in FIG. 3, made of a metal, has the base end portion 31 mentioned above (provided with a cup 31A -5-surrounding the mount rubber 25A), and is provided with a-cylindrical portion 32 extending from an outer peripheral side of the base end portion 31 and a spring receiving portion 33 provided at an extending end of the cylindrical portion 32. The spring receiving portion 33 of 5 the spring seat 15 forms the vehicle body side mounting portion 17 mentioned above at a back surface thereof. It is provided with the mounting bolt 18, is formed in a non-annular shape such as a diamond shape and an oval shape, and is provided with the standing-up rib 34 on an outer edge of a front surface thereof. 10 The dust cover 50 is, as shown in FIG. 4, made of a resin such as PE (polyethylene), TPE (thermoplastic elastomer (santplane)) or the like, has the mounting portion 51 mentioned above and is provided with a cylindrical portion 52 extending from an inner peripheral side of the mounting portion 51. The mounting portion 51 of the dust cover 15 50 has a non-annular outer shape profiling the inner periphery of the rib 34 of the spring seat 15, and the outer shape is received in the inner periphery of the rib 34. The mounting portion 51 of the dust cover 50 is further provided with a thick protruding portion 53 at two positions in both 2 0 sides in a direction of a long diameter of the outer shape of the spring seat 15, and is provided with a circular arc step-shaped groove 54 receiving a part of the outer periphery of the spring rubber 40 in the protruding portion 53. In this case, the mounting portion 51 is provided with a circular recess portion 51A for receiving a head portion 2 5 of the mounting bolt 18 attached to the spring receiving portion 33 of the spring seat 15 in a range extending around the protruding portion 53 in the back surface side brought into contact with the spring seat 15, -6- and is provided with a circular convex portion 51B protruding to an opposite side to the recess portion 51A in correspondence to an existence of the recess portion 51 A, in a front surface side thereof. The spring rubber 40 is, as shown in FIG. 5, made of a rubber (NR), and is structured such that a flat annular inner periphery is formed as a hole portion 41 attached to the cylindrical portion 52 of the dust cover 50. An outer periphery is formed as a standing-up portion 42 standing up in a front surface side, and a circular spring seat surface 43 is formed in an inner peripheral side of the standing-up portion 42. The spring rubber 40 is provided with a circular recess portion 44 corresponding to the circular convex portion 51B of the mounting portion 51 at two positions in a diametrical direction of the back surface brought into contact with the mounting portion 51 of the dust cover 50. The spring rubber 40 is provided with projections 45 at a plurality of positions (for example, six positions) in a peripheral direction on an outer periphery of the standing-up portion 42. It is press-fitted to the inner periphery of the rib 34 of the spring seat 15 via the projection 45 in a direction of a short diameter of the outer shape of the spring seat 15, and is received (or press-fitted) in the groove 54 of the protruding portion 53 of the dust cover 50 via the projection 45 in a direction of a long diameter of the outer shape of the spring seat 15. In this case, each standing-up portion 42 of the spring rubber 40 is constituted by a thin standing-up portion 42A in which the projection 45 is provided, and a thick standing-up portion 42B disposed between the adjacent thin standing-up portions 42A and 42A. Accordingly, the hydraulic shock absorber 10 is assembled in a rj manner mentioned below. (l) The lower end portion of the suspension spring 13 is seated to the lower spring seat 14 attached to the outer peripheral portion of the damper tube 11. 5 (2) The mounting portion 51 of the dust cover 50 is assembled in the spring receiving portion 33 of the upper spring seat 15 and the spring rubber 40 holding the mounting portion 51 is pressure inserted to the inner periphery of the rib 34 of the spring receiving portion 33 of the upper spring seat 15, thereby obtaining the assembled body. 10 (3) The assembled body in the item (2) mentioned above is inserted to the damper tube 11 and the piston rod 12, and the spring rubber 40 which the spring receiving portion 33 of the upper spring seat 15 backs up via the dust cover 50 is brought into contact and aligned with the upper end portion of the suspension spring 13. 15 Thereafter, the mounting nut 26 is engaged with the upper end portion of the piston rod 12, whereby an assembly is completed. Therefore, in accordance with the present embodiment, the following effects can be obtained. (l) The spring seat 15 is provided with the standing-up rib 34 2 0 on the non-annular outer edge, and the mounting portion 51 of the dust cover 50 is received so as to profile the inner periphery of the non-annular rib 34, thereby preventing the dust cover 50 from rotating. Accordingly, even when a torsion force generated at a time of extension and compression of the suspension spring 13 is applied to the dust 2 5 cover 50 via the spring rubber 40, the dust cover 50 does not rotate at all, so that dust is not generated on the basis of the friction between the dust cover 50 and the spring seat 15. -8-(2) The spring rubber 40 is pressure inserted to the inner periphery of the rib 34 of the spring seat 15 via the projection 45 on the outer periphery thereof in a state of holding the mounting portion 51 of the dust cover 50 therebetween, thereby constituting the assembled 5 body. Accordingly, the spring rubber 40 and the dust cover 50 do not drop off from the spring seat 15 in an assembling step of attaching the assembled body to the piston rod 12 so as to bring into contact and align with the suspension spring 13, so that an assembling property can be improved. 10 (3) The spring rubber 40 is structured such that the outer periphery in the direction of the short diameter of the spring seat 15 is pressure inserted to the inner periphery of the rib 34 of the spring seat 15 so as to be restricted, and the outer periphery in the direction of the long diameter of the spring seat 15 is received (may be pressure 15 inserted) to the groove 54 of the protruding portion 53 in the dust cover 50 so as to be restricted. Accordingly, even when the spring rubber 40 repeatedly receives a compression force on the basis of a spring force of the suspension spring 13, the spring rubber 40 does not freely protrude in a direction of the outer periphery so as to be prevented from being 2 0 yielded and deformed. (4) The dust cover 50 is formed by a resin, whereby it is possible to secure a strength sufficient to restrict the deformation of the spring rubber 40 in the dust cover 50. In this case, in the embodiment in accordance with the present 2 5 invention, the structure may be made such that the outer shape of the spring rubber is also formed in a non-annular shape profiling the inner periphery of the rib of the spring seat, and the spring rubber is -9-pressure inserted to all the area of the inner periphery of the rib of the spring seat with holding the non-annular mounting portion of the dust cover between the spring rubber and the spring seat. Further, the dust cover may be provided with a groove formed in series in a peripheral direction so as to receive all the periphery of the spring rubber. At this time, the spring rubber may be structured such that a part in a height direction is received in the groove of the dust cover and another part in the height direction is pressure inserted to the inner periphery of the rubber of the spring seat in an external portion of the groove of the dust cover. As mentioned above, the embodiment in accordance with the present invention is described in detail, however, the particular structure of the present invention is not limited to the embodiment and a design modification within the scope of the present invention will be contained in the present invention. For example, the rib provided in the outer edge of the spring seat is not always required to extend the entire periphery of the spring seat. Further, the cylindrical portion of the dust cover is not limited to the structure extending from the inner peripheral side of the mounting portion, and may extend from the outer peripheral side so as to surround the outer periphery of the suspension spring. INDUSTRIAL APPLICABILITY In accordance with the invention stated in the first aspect, the following effect (l) can be obtained. (l) The spring seat is provided with the standing-up rib on the non-annular outer edge, and the mounting portion of the dust cover is -10- received so as to profile the inner periphery of the non-annular rib, thereby preventing the dust cover from rotating. Accordingly, even when torsion force generated during extension and compression of the suspension-spring is applied to the dust cover via the spring rubber, the dust cover does not rotate at all;so that the dust is not generated due to the friction between the dust cover and the spring seat. In accordance with the invention stated in the second aspect, the following effects (2) and (3) can be obtained. (2) The spring rubber is press-fitted into the inner periphery of the rib of the spring seat to hold the mounting portion of the dust cover therebetween, thereby constituting the assembled body. Accordingly, the spring rubber and the dust cover do not drop off from the spring seat while attaching the assembled body to the piston rod so as to bring into contact and align with the suspension spring, so that assembling can be improved. (3) The outer periphery of the spring rubber is restricted by the rib of the spring seat. Accordingly, even when the spring rubber repeatedly receives a compression force due to the spring force of the suspension spring, the spring rubber does not freely protrude in a direction of the outer periphery so as to be prevented from being yielded and deformed. In accordance with the invention stated in the third aspect, the following effect (4) can be obtained. -1QA- (4) The spring rubber is received in the groove of the dust cover and the outer periphery thereof is restricted by .the groove or, the dust cover. Accordingly, even when the spring rubber repeatedly receives a -11- compression force on the basis of a spring force of the suspension spring, the spring rubber does not freely protrude in a direction of the outer periphery so as to be prevented from being yielded.and deformed. In accordance with the invention stated in the fourth aspect, the following effects (5) and (6) can be obtained. (5) The spring rubber is pressure inserted to the inner periphery of the rib of the spring seat via the projection on the outer periphery thereof in a state of holding the mounting portion of the dust cover therebetween, thereby constituting the assembled body. Accordingly, the spring rubber and the dust cover do not drop off from the spring seat in an assembling step of attaching the assembled body to the piston rod so as to bring into contact and align with the suspension spring, so that an assembling property can be improved. (6) The spring rubber is structured such that the outer periphery in the direction of the short diameter of the spring seat is pressure inserted to the inner periphery of the rib of the spring seat so as to be restricted and the outer periphery in the direction of the long diameter of the spring seat is received (may be pressure inserted) to the groove of the protruding portion in the dust cover so as to be restricted. Accordingly, even when the spring rubber repeatedly receives a compression force on the basis of a spring force of the suspension spring, the spring rubber does not freely protrude in a direction_ of the _outer periphery so as to be prevented from_being_ yielded and deformed. In accordance with the invention stated in the fifth aspect, the following effect (7) can be obtained. (7) The dust cover is formed by a resin, whereby it is possible to -12- secure a strength sufficient to restrict the deformation of the spring rubber in the dust cover. In accordance with the invention stated in the sixth aspect, the following effect (8) can be obtained. 5 (8) The circular convex portions are provided at two positions in the diametrical direction of the surface brought into contact with the spring rubber in the mounting portion of the dust cover. The circular convex portions are engaged with the circular recess portions provided at two positions in the diametrical direction of the surface brought into 10 contact with the mounting portion of the dust cover in the spring rubber in the peripheral direction. Accordingly, even when the torsion force generated at a time of extension and compression of the suspension spring is applied to the spring rubber, it is possible to prevent the spring rubber from rotating in the peripheral direction 15 with respect to the dust cover due to the engagement between the circular convex portion of the dust cover and the circular recess portion of the spring rubber. Therefore, it is possible to prevent the abrasion between the dust cover and the spring rubber. In accordance with the invention stated in the seventh aspect, 2 0 the following effect (9) can be obtained. (9) The standing-up portion of the spring rubber is constituted by the thin standing-up portion in which the projection is provided on the outer periphery, and the thick standing-up portion provided between the adjacent thin standing-up portions. Accordingly, when 2 5 the spring rubber is pressure inserted to the inner periphery of the rib of the spring seat via the projection on the outer periphery thereof or received in the groove of the protruding portion of the dust cover in a -13-state that the spring rubber holds the mounting portion of the dust cover therebetween, the standing-up portion in which the projection is provided is easily elastically deformed in the radial direction of the spring rubber since the standing-up portion in which the projection is provided is thin, so that the pressure inserting (or receiving) work of the spring seat can be made easy. In addition, after the spring seat is pressure inserted (or received), the projection provided in the thin standing-up portion is continuously pressure inserted (or received) by the elastic recovery force to the inner periphery of the rib in the spring seat or in the groove of the protruding portion in the dust cover, so that it is possible to stably form the sub-assembled body obtained by easily attaching the spring rubber and the dust cover to the spring seat. In accordance with the invention stated in the eighth aspect, the following effect (10) can be obtained. (10) In addition to the mounting portion of the dust cover, the outer shape of the spring rubber is also formed in the non-annular shape profiling the inner periphery of the rib in the spring seat, thereby preventing the rotation of the dust cover and the spring rubber. Accordingly, even when the torsion force generated at a time of extension and compression of the suspension spring is applied to dust cover via the spring rubber, both of the dust cover and the spring seat do not rotate at all and dust is not generated on the basis of the friction with respect to the spring seat. As mentioned above, in accordance with the present invention, it is possible to prevent dust from being generated due to the rotation of the dust cover during holding the mounting portion of the dust cover between the spring rubber for receiving the suspension spring and the -14-spring seat. Further, in accordance with the present invention, it is possible to improve an assembling property of the spring seat, the dust cover and the spring rubber, and it is possible to prevent the spring rubber 5 from being yielded and deformed. -15-WE CLAIM: 1. A dust cover mounting structure of a hydraulic shock absorber (10) comprising: a damper tube (11); a piston rod (12); a spring seat (15) provided in the piston rod; a suspension spring (13) supported to the spring seat (15) via a spring rubber (40); and a mounting portion (51) of a dust cover (50) held between the spring seat (15) and the spring rubber (40), wherein the spring seat (15) is formed in a non-annular outer shape, a standing-up rib (34) is provided in an outer edge thereof, and the mounting portion (51) of the dust cover (50) is formed in a non-annular outer shape profiling an inner periphery of the rib of the spring seat and is received in the inner periphery of said rib (34). 2. A dust cover mounting structure of a hydraulic shock absorber as claimed in claim 1, wherein said spring rubber (40) is press-fitted in the inner periphery of the rib (34) in the spring seat (15). 3. A dust cover mounting structure of a hydraulic shock absorber as claimed in claim 1 or 2, wherein said dust cover (50) is provided with a groove (54) for receiving the spring rubber (40). -16- 4. A dust cover mounting structure of a hydraulic shock absorber as claimed in claim 1, wherein said dust cover is provided with a thick protruding portion (53) in a direction of a long diameter of the outer shape of the spring seat (15), a: groove (54) for receiving the spring rubber is provided in the protruding portion, the spring rubber (40) is provided with projections (45) at a plurality of positions in a peripheral direction of the outer periphery, and the spring rubber is press- fitted in the inner periphery of the rib (34) in the spring seat (15) vie said projections in a direction of a short diameter of the outer shape of the spring seat and is received in the groove (54) of the protruding portion (53) in the dust cover (50) via said projections in a direction of a long diameter of the outer shape of the spring seat. 5. A dust cover mounting structure of a hydraulic shock absorber as claimed in claim 1 or 2, wherein said spring rubber is made of a rubber and said dust cover is made of a resin. 6. A dust cover mounting structure of a hydraulic shock absorber as claimed in claim 1, wherein circular convex portions (51B) are provided at two positions in a diametrical direction of a surface brought into contact with said spring rubber in the mounting portion of said dust cover, and circular recess portions (44) are provided at two positions in a diametrical direction of a surface brought into contact with the mounting portion of said dust cover in said spring rubber, said -17- circular recess portions being engaged with the circular convex portions provided in the mounting portion of said dust cover in the peripheral direction. 7. A dust cover mounting structure of a hydraulic shock absorber as claimed in claim 4, wherein said spring rubber (40) is provided with a standing-up portion (42) forming a spring seated surface in an inner peripheral side, and the standing-up portion is constituted by a thin standing-up portion (42A) provided with said projection (45) and a thick standing-up portion (42B) disposed between the adjacent thin standing-up portions (42A). 8. A dust cover mounting structure of a hydraulic shock absorber as claimed in claim 1, wherein an outer shape of said spring rubber (40) is formed in a non- annular shape profiling the inner periphery of the rib (34) in said spring seat (15), and said spring rubber holds the non-annular mounting portion of said dust cover between said spring rubber and said spring seat and is press-fitted to the entire area of the inner periphery of the rib (34) in said spring seat (15). A dust cover mounting structure of a hydraulic shock absorber (10) comprises. a damper tube (11); a piston rod (12) provided with a spring seat (15); a suspension spring (13) supported to the spring seat (15) via a spring rubber (40); and a mounting portion (51) of a dust cover (50) held between the spring seat (15) and the spring rubber (40), wherein the spring seat (15) has a non-annular outer shape, a standing-up rib (34) is provided in an outer edge thereof, and the mounting portion (51) has a non-annular outer shape profiling an inner periphery of the rib (34) received in the inner periphery of the rib.

Full Text

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DUST COVER MOUNTING STRUCTURE OF HYDRAULIC SHOCK ABSORBER
TECHNICAL FIELD
The present invention relates to a dust cover mounting structure of a hydraulic shock absorber.
BACKGROUND ART
Conventionally, there has been a hydraulic shock absorber, as described in Japanese Patent Application Laid-Open Publication (JP-A) No. 57-129942, such that a damper tube and a piston rod are provided, a spring seat is provided in the piston rod, a suspension spring is supported to the spring seat via a spring rubber, and a mounting portion of a dust cover is held between the spring seat and the spring rubber.
However, the prior art has the following problems.
(1) The spring seat is provided with a standing-up rib on an
annular outer edge, and the mounting portion of the dust cover is
rotatably received along an inner periphery of the annular rib.
Accordingly, a torsion force generated at a time of extension and
compression of the suspension spring rotates the dust cover to which
the torsion force is applied via the spring rubber while rubbing the dust
cover against the spring seat, whereby dusts are generated on the basis
of abrasion of the dust cover so as to pollute an environment. This
dust generation is significant when the dust cover is made of a resin.
(2) Since the mounting portion between the spring rubber and
the dust cover is simply laminated on the spring seat, it is quite

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possible that the spring rubber and the dust cover are dropped off in a
step of attaching an assembly obtained by laminating the spring rubber and the dust cover on the spring seat to the piston rod so as to bring into contact and align with the spring seat, so that an assembling 5 property is deteriorated.
(3) An outer periphery of the spring rubber is restricted neither by the spring seat nor the dust cover. Accordingly, when the spring rubber repeatedly receives a compression force on the basis of a spring force of the suspension spring, the spring rubber freely protrudes in a 10 direction of the outer periphery so as to be yielded and deformed, so that there is a risk that the spring rubber is broken or dropped off.
DISCLOSURE OF THE INVENTION
An object of the present invention is to prevent dusts from 15 being generated due to rotation of a dust cover at a time of holding a mounting portion of the dust cover between a spring rubber and a spring seat which receive a suspension spring.
Further, another object of the present invention is to improve an assembling property of a spring seat, a dust cover and a spring 2 0 rubber and to prevent the spring rubber from being yielded and deformed.
In accordance with the present invention, there is provided a
dust cover mounting structure of a-hydraulic-shock- absor-ber
comprising-
2 5 a damper tube,'
a piston rod; a spring seat provided in the piston rod;

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a suspension spring supported to the spring seat via a spring rubber; and
a mounting portion of a dust cover held between the spring seat and the spring rubber,
wherein the spring seat is formed in a non-annular outer shape, a standing-up rib is provided in an outer edge thereof, and the mounting portion of the dust cover is formed in a non-annular outer shape profiling an inner periphery of the rib of the spring seat and is
received in the inner periphery of the rib.

^ BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
FIG. 1 is a cross sectional view showing a hydraulic pressure shock absorber."
FIG. 2 is a plan view of FIG. 1;, FIG. 3 is a schematic view showing a spring seat; FIG. 4 is a schematic view showing a dust cover; and FIG. 5 is a schematic view showing a spring rubber.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A hydraulic shock absorber 10 has, as shown in FIGS. 1 and 2, a damper tube 11, a piston rod 12 and a suspension spring 13, and is structured such that a lower spring seat 14 is attached to an outer peripheral portion of the damper tube 11. An upper spring seat 15 is attached to the piston rod 12 and the suspension spring 13 is interposed between the spring seats 14 and 15.
The hydraulic shock absorber 10 is provided with an axle side mounting portion 16 in a lower portion of the damper tube 11, is

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provided with a vehicle body side mounting portion 17 in the upper spring seat
15 attached to the piston rod 12, and a mounting bolt 18 attaches to the vehicle -
body side mounting portion 17. The hydraulic shock absorbed 10 absorbs an
impact applied from a road surface by the suspension spring 13 and damps an
expanding and compressing vibration of the suspension spring 13 by a damping
device (not shown) installed within the damper tube 11.
In this case, the hydraulic shock absorber 10 positions receiving seats 22 and 23 and a cover 24 by a joint collar 21 inserted and attached to an outer end portion of the piston rod 12. Mount rubbers 25A and 25B are provided between the receiving seats 22 and 23, and a mounting nut 26 is engaged with an upper end portion of the piston rod 12 in a state of holding a base end portion 31 of the upper spring seat 15 between the mount rubbers 25A and 25B. Further, a bump rubber 27 is press-fitted around the piston rod 12 surrounded by the cover 24. A bump stopper cap 28 is fixed around an axial seal portion through which the piston rod 12 of the damper tube 11 extends, and a bump rubber contact plate 28A is provided in the bump stopper cap 28.
In this case, in the hydraulic shock absorber 10, the circular suspension spring 13 is supported to the upper spring seat 15 via a spring rubber 40, and a mounting portion 51 of a dust cover 50 is held between the upper spring seat 15 and the spring rubber 40. A description will be in detail given below of a mounting structure of the dust cover 50.
The spring seat 15 is, as shown in FIG. 3, made of a metal, has the base end portion 31 mentioned above (provided with a cup 31A

-5-surrounding the mount rubber 25A), and is provided with a-cylindrical
portion 32 extending from an outer peripheral side of the base end portion 31 and a spring receiving portion 33 provided at an extending end of the cylindrical portion 32. The spring receiving portion 33 of 5 the spring seat 15 forms the vehicle body side mounting portion 17 mentioned above at a back surface thereof. It is provided with the mounting bolt 18, is formed in a non-annular shape such as a diamond shape and an oval shape, and is provided with the standing-up rib 34 on an outer edge of a front surface thereof.
10 The dust cover 50 is, as shown in FIG. 4, made of a resin such
as PE (polyethylene), TPE (thermoplastic elastomer (santplane)) or the like, has the mounting portion 51 mentioned above and is provided with a cylindrical portion 52 extending from an inner peripheral side of the mounting portion 51. The mounting portion 51 of the dust cover
15 50 has a non-annular outer shape profiling the inner periphery of the rib 34 of the spring seat 15, and the outer shape is received in the inner periphery of the rib 34.
The mounting portion 51 of the dust cover 50 is further provided with a thick protruding portion 53 at two positions in both
2 0 sides in a direction of a long diameter of the outer shape of the spring seat 15, and is provided with a circular arc step-shaped groove 54 receiving a part of the outer periphery of the spring rubber 40 in the protruding portion 53. In this case, the mounting portion 51 is provided with a circular recess portion 51A for receiving a head portion
2 5 of the mounting bolt 18 attached to the spring receiving portion 33 of the spring seat 15 in a range extending around the protruding portion 53 in the back surface side brought into contact with the spring seat 15,

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and is provided with a circular convex portion 51B protruding to an opposite side
to the recess portion 51A in correspondence to an existence of the recess portion 51 A, in a front surface side thereof.
The spring rubber 40 is, as shown in FIG. 5, made of a rubber (NR), and is structured such that a flat annular inner periphery is formed as a hole portion 41 attached to the cylindrical portion 52 of the dust cover 50. An outer periphery is formed as a standing-up portion 42 standing up in a front surface side, and a circular spring seat surface 43 is formed in an inner peripheral side of the standing-up portion 42. The spring rubber 40 is provided with a circular recess portion 44 corresponding to the circular convex portion 51B of the mounting portion 51 at two positions in a diametrical direction of the back surface brought into contact with the mounting portion 51 of the dust cover 50.
The spring rubber 40 is provided with projections 45 at a plurality of positions (for example, six positions) in a peripheral direction on an outer periphery of the standing-up portion 42. It is press-fitted to the inner periphery of the rib 34 of the spring seat 15 via the projection 45 in a direction of a short diameter of the outer shape of the spring seat 15, and is received (or press-fitted) in the groove 54 of the protruding portion 53 of the dust cover 50 via the projection 45 in a direction of a long diameter of the outer shape of the spring seat 15. In this case, each standing-up portion 42 of the spring rubber 40 is constituted by a thin standing-up portion 42A in which the projection 45 is provided, and a thick standing-up portion 42B disposed between the adjacent thin standing-up portions 42A and 42A.
Accordingly, the hydraulic shock absorber 10 is assembled in a

rj
manner mentioned below.
(l) The lower end portion of the suspension spring 13 is seated to the lower spring seat 14 attached to the outer peripheral portion of the damper tube 11.
5 (2) The mounting portion 51 of the dust cover 50 is assembled
in the spring receiving portion 33 of the upper spring seat 15 and the spring rubber 40 holding the mounting portion 51 is pressure inserted to the inner periphery of the rib 34 of the spring receiving portion 33 of the upper spring seat 15, thereby obtaining the assembled body.
10 (3) The assembled body in the item (2) mentioned above is
inserted to the damper tube 11 and the piston rod 12, and the spring rubber 40 which the spring receiving portion 33 of the upper spring seat 15 backs up via the dust cover 50 is brought into contact and aligned with the upper end portion of the suspension spring 13.
15 Thereafter, the mounting nut 26 is engaged with the upper end portion of the piston rod 12, whereby an assembly is completed.
Therefore, in accordance with the present embodiment, the following effects can be obtained.
(l) The spring seat 15 is provided with the standing-up rib 34
2 0 on the non-annular outer edge, and the mounting portion 51 of the dust cover 50 is received so as to profile the inner periphery of the non-annular rib 34, thereby preventing the dust cover 50 from rotating. Accordingly, even when a torsion force generated at a time of extension and compression of the suspension spring 13 is applied to the dust
2 5 cover 50 via the spring rubber 40, the dust cover 50 does not rotate at all, so that dust is not generated on the basis of the friction between the dust cover 50 and the spring seat 15.

-8-(2) The spring rubber 40 is pressure inserted to the inner
periphery of the rib 34 of the spring seat 15 via the projection 45 on the outer periphery thereof in a state of holding the mounting portion 51 of the dust cover 50 therebetween, thereby constituting the assembled 5 body. Accordingly, the spring rubber 40 and the dust cover 50 do not drop off from the spring seat 15 in an assembling step of attaching the assembled body to the piston rod 12 so as to bring into contact and align with the suspension spring 13, so that an assembling property can be improved.
10 (3) The spring rubber 40 is structured such that the outer
periphery in the direction of the short diameter of the spring seat 15 is pressure inserted to the inner periphery of the rib 34 of the spring seat 15 so as to be restricted, and the outer periphery in the direction of the long diameter of the spring seat 15 is received (may be pressure
15 inserted) to the groove 54 of the protruding portion 53 in the dust cover 50 so as to be restricted. Accordingly, even when the spring rubber 40 repeatedly receives a compression force on the basis of a spring force of the suspension spring 13, the spring rubber 40 does not freely protrude in a direction of the outer periphery so as to be prevented from being
2 0 yielded and deformed.
(4) The dust cover 50 is formed by a resin, whereby it is possible to secure a strength sufficient to restrict the deformation of the spring rubber 40 in the dust cover 50.
In this case, in the embodiment in accordance with the present
2 5 invention, the structure may be made such that the outer shape of the spring rubber is also formed in a non-annular shape profiling the inner periphery of the rib of the spring seat, and the spring rubber is

-9-pressure inserted to all the area of the inner periphery of the rib of the
spring seat with holding the non-annular mounting portion of the dust cover between the spring rubber and the spring seat.
Further, the dust cover may be provided with a groove formed in series in a peripheral direction so as to receive all the periphery of the spring rubber. At this time, the spring rubber may be structured such that a part in a height direction is received in the groove of the dust cover and another part in the height direction is pressure inserted to the inner periphery of the rubber of the spring seat in an external portion of the groove of the dust cover.
As mentioned above, the embodiment in accordance with the present invention is described in detail, however, the particular structure of the present invention is not limited to the embodiment and a design modification within the scope of the present invention will be contained in the present invention. For example, the rib provided in the outer edge of the spring seat is not always required to extend the entire periphery of the spring seat. Further, the cylindrical portion of the dust cover is not limited to the structure extending from the inner peripheral side of the mounting portion, and may extend from the outer peripheral side so as to surround the outer periphery of the suspension spring.
INDUSTRIAL APPLICABILITY
In accordance with the invention stated in the first aspect, the following effect (l) can be obtained.
(l) The spring seat is provided with the standing-up rib on the non-annular outer edge, and the mounting portion of the dust cover is

-10-
received so as to profile the inner periphery of the non-annular rib, thereby preventing the dust cover from rotating. Accordingly, even when torsion force generated during extension and compression of the suspension-spring is applied to the dust cover via the spring rubber, the dust cover does not rotate at all;so

that the dust is not generated due to the friction between the dust cover and the

spring seat.
In accordance with the invention stated in the second aspect, the following effects (2) and (3) can be obtained.
(2) The spring rubber is press-fitted into the inner periphery of the rib of
the spring seat to hold the mounting portion of the dust cover therebetween,
thereby constituting the assembled body. Accordingly, the spring rubber and the
dust cover do not drop off from the spring seat while attaching the assembled
body to the piston rod so as to bring into contact and align with the suspension
spring, so that assembling can be improved.
(3) The outer periphery of the spring rubber is restricted by the rib of the
spring seat. Accordingly, even when the spring rubber repeatedly receives a
compression force due to the spring force of the suspension spring, the spring
rubber does not freely protrude in a direction of the outer periphery so as to be
prevented from being yielded and deformed.
In accordance with the invention stated in the third aspect, the following effect (4) can be obtained.

-1QA-
(4) The spring rubber is received in the groove of the dust cover and the outer periphery thereof is restricted by .the groove or, the dust cover. Accordingly, even when the spring rubber repeatedly receives a

-11-
compression force on the basis of a spring force of the suspension spring, the spring rubber does not freely protrude in a direction of the outer periphery so as to be prevented from being yielded.and deformed.
In accordance with the invention stated in the fourth aspect, the following effects (5) and (6) can be obtained.
(5) The spring rubber is pressure inserted to the inner
periphery of the rib of the spring seat via the projection on the outer
periphery thereof in a state of holding the mounting portion of the dust
cover therebetween, thereby constituting the assembled body.
Accordingly, the spring rubber and the dust cover do not drop off from
the spring seat in an assembling step of attaching the assembled body
to the piston rod so as to bring into contact and align with the
suspension spring, so that an assembling property can be improved.
(6) The spring rubber is structured such that the outer
periphery in the direction of the short diameter of the spring seat is
pressure inserted to the inner periphery of the rib of the spring seat so
as to be restricted and the outer periphery in the direction of the long
diameter of the spring seat is received (may be pressure inserted) to
the groove of the protruding portion in the dust cover so as to be
restricted. Accordingly, even when the spring rubber repeatedly
receives a compression force on the basis of a spring force of the
suspension spring, the spring rubber does not freely protrude in a
direction_ of the _outer periphery so as to be prevented from_being_
yielded and deformed.
In accordance with the invention stated in the fifth aspect, the following effect (7) can be obtained.
(7) The dust cover is formed by a resin, whereby it is possible to

-12-
secure a strength sufficient to restrict the deformation of the spring
rubber in the dust cover.
In accordance with the invention stated in the sixth aspect, the following effect (8) can be obtained.
5 (8) The circular convex portions are provided at two positions
in the diametrical direction of the surface brought into contact with the spring rubber in the mounting portion of the dust cover. The circular convex portions are engaged with the circular recess portions provided at two positions in the diametrical direction of the surface brought into
10 contact with the mounting portion of the dust cover in the spring rubber in the peripheral direction. Accordingly, even when the torsion force generated at a time of extension and compression of the suspension spring is applied to the spring rubber, it is possible to prevent the spring rubber from rotating in the peripheral direction
15 with respect to the dust cover due to the engagement between the circular convex portion of the dust cover and the circular recess portion of the spring rubber. Therefore, it is possible to prevent the abrasion between the dust cover and the spring rubber.
In accordance with the invention stated in the seventh aspect,
2 0 the following effect (9) can be obtained.
(9) The standing-up portion of the spring rubber is constituted by the thin standing-up portion in which the projection is provided on the outer periphery, and the thick standing-up portion provided between the adjacent thin standing-up portions. Accordingly, when
2 5 the spring rubber is pressure inserted to the inner periphery of the rib of the spring seat via the projection on the outer periphery thereof or received in the groove of the protruding portion of the dust cover in a

-13-state that the spring rubber holds the mounting portion of the dust
cover therebetween, the standing-up portion in which the projection is provided is easily elastically deformed in the radial direction of the spring rubber since the standing-up portion in which the projection is provided is thin, so that the pressure inserting (or receiving) work of the spring seat can be made easy. In addition, after the spring seat is pressure inserted (or received), the projection provided in the thin standing-up portion is continuously pressure inserted (or received) by the elastic recovery force to the inner periphery of the rib in the spring seat or in the groove of the protruding portion in the dust cover, so that it is possible to stably form the sub-assembled body obtained by easily attaching the spring rubber and the dust cover to the spring seat.
In accordance with the invention stated in the eighth aspect, the following effect (10) can be obtained.
(10) In addition to the mounting portion of the dust cover, the outer shape of the spring rubber is also formed in the non-annular shape profiling the inner periphery of the rib in the spring seat, thereby preventing the rotation of the dust cover and the spring rubber. Accordingly, even when the torsion force generated at a time of extension and compression of the suspension spring is applied to dust cover via the spring rubber, both of the dust cover and the spring seat do not rotate at all and dust is not generated on the basis of the friction with respect to the spring seat.
As mentioned above, in accordance with the present invention, it is possible to prevent dust from being generated due to the rotation of the dust cover during holding the mounting portion of the dust cover between the spring rubber for receiving the suspension spring and the

-14-spring seat.
Further, in accordance with the present invention, it is possible to improve an assembling property of the spring seat, the dust cover and the spring rubber, and it is possible to prevent the spring rubber 5 from being yielded and deformed.

-15-WE CLAIM:
1. A dust cover mounting structure of a hydraulic shock absorber (10)
comprising:
a damper tube (11);
a piston rod (12);
a spring seat (15) provided in the piston rod;
a suspension spring (13) supported to the spring seat (15) via a spring rubber (40); and
a mounting portion (51) of a dust cover (50) held between the spring seat (15) and the spring rubber (40),
wherein the spring seat (15) is formed in a non-annular outer shape, a standing-up rib (34) is provided in an outer edge thereof, and the mounting portion (51) of the dust cover (50) is formed in a non-annular outer shape profiling an inner periphery of the rib of the spring seat and is received in the inner periphery of said rib (34).
2. A dust cover mounting structure of a hydraulic shock absorber as claimed
in claim 1, wherein said spring rubber (40) is press-fitted in the inner periphery of
the rib (34) in the spring seat (15).
3. A dust cover mounting structure of a hydraulic shock absorber as claimed
in claim 1 or 2, wherein said dust cover (50) is provided with a groove (54) for
receiving the spring rubber (40).

-16-
4. A dust cover mounting structure of a hydraulic shock absorber as claimed
in claim 1, wherein said dust cover is provided with a thick protruding portion (53)
in a direction of a long diameter of the outer shape of the spring seat (15), a:
groove (54) for receiving the spring rubber is provided in the protruding portion,
the spring rubber (40) is provided with projections (45) at a plurality of positions
in a peripheral direction of the outer periphery, and the spring rubber is press-
fitted in the inner periphery of the rib (34) in the spring seat (15) vie said
projections in a direction of a short diameter of the outer shape of the spring seat
and is received in the groove (54) of the protruding portion (53) in the dust cover
(50) via said projections in a direction of a long diameter of the outer shape of
the spring seat.
5. A dust cover mounting structure of a hydraulic shock absorber as claimed
in claim 1 or 2, wherein said spring rubber is made of a rubber and said dust
cover is made of a resin.
6. A dust cover mounting structure of a hydraulic shock absorber as claimed
in claim 1, wherein circular convex portions (51B) are provided at two positions in
a diametrical direction of a surface brought into contact with said spring rubber in
the mounting portion of said dust cover, and circular recess portions (44) are
provided at two positions in a diametrical direction of a surface brought into
contact with the mounting portion of said dust cover in said spring rubber, said

-17-
circular recess portions being engaged with the circular convex portions provided in the mounting portion of said dust cover in the peripheral direction.
7. A dust cover mounting structure of a hydraulic shock absorber as claimed
in claim 4, wherein said spring rubber (40) is provided with a standing-up portion
(42) forming a spring seated surface in an inner peripheral side, and the
standing-up portion is constituted by a thin standing-up portion (42A) provided
with said projection (45) and a thick standing-up portion (42B) disposed between
the adjacent thin standing-up portions (42A).
8. A dust cover mounting structure of a hydraulic shock absorber as claimed
in claim 1, wherein an outer shape of said spring rubber (40) is formed in a non-
annular shape profiling the inner periphery of the rib (34) in said spring seat (15),
and said spring rubber holds the non-annular mounting portion of said dust cover
between said spring rubber and said spring seat and is press-fitted to the entire
area of the inner periphery of the rib (34) in said spring seat (15).
A dust cover mounting structure of a hydraulic shock absorber (10) comprises.
a damper tube (11); a piston rod (12) provided with a spring seat (15); a suspension spring (13) supported to the spring seat (15) via a spring rubber (40); and a mounting portion (51) of a dust cover (50) held between the spring seat (15) and the spring rubber (40),
wherein the spring seat (15) has a non-annular outer shape, a standing-up rib (34) is provided in an outer edge thereof, and the mounting portion (51) has a non-annular outer shape profiling an inner periphery of the rib (34) received in the inner periphery of the rib.

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Patent Number

205862

Indian Patent Application Number

IN/PCT/2002/01064/KOL

PG Journal Number

15/2007

Publication Date

13-Apr-2007

Grant Date

13-Apr-2007

Date of Filing

19-Aug-2002

Name of Patentee

SHOWA CORPORATION

Applicant Address

14-1 FUJIWARA-CHO, 1-CHOME, GYODA-SHI, SAITAMA, JAPAN.

Inventors:

#	Inventor's Name	Inventor's Address
1	KOYANO HIDEHIKO	C/O SHOWA CORPORATION, SAITAMA HEAD OFFICE & PLANT, 14-1, FUJIWARA-CHO 1-CHOME, GYODA-SHI, SAITAMA, JAPAN.
2	MURATA TAKESHI	C/O SHOWA CORPORATION, SAITAMA HEAD OFFICE & PLANT, 14-1, FUJIWARA-CHO 1-CHOME, GYODA-SHI, SAITAMA, JAPAN.
3	SEGAWA JIRO	C/O SHOWA CORPORATION, SAITAMA HEAD OFFICE & PLANT, 14-1, FUJIWARA-CHO 1-CHOME, GYODA-SHI, SAITAMA, JAPAN.
4	KATO SHUICHI	C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, 4-1 CHUO 1-CHOME, WAKO-SHI, SAITAMA, JAPAN
5	SUNAMI KEIICHI	C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, 4-1 CHUO 1-CHOME, WAKO-SHI, SAITAMA, JAPAN
6	HASEGAWA TOSHIYA	C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, 4-1 CHUO 1-CHOME, WAKO-SHI, SAITAMA, JAPAN
7	INABA SHIGENORI	C/O SANNO TEC CO. LTD., 3-7 CHUO 2-CHOME, WAKO-SHI, SAITAMA, JAPAN

PCT International Classification Number

F 16 F 9/38

PCT International Application Number

PCT/JP00/09053

PCT International Filing date

2000-12-20

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	2000-044945	2000-02-22	Japan