Dust cover assembly and method of producing the same

#The disclosure of Japanese Patent Application No. 2000-325455 filed on Oct. 25, 2000 including the specification, drawings and abstract is incorporated herein by reference in its entirety.

#1. Field of the Invention

#The present invention relates generally to techniques associated with a dust cover to be attached to a shock absorber used in a suspension mechanism of an automotive vehicle. More particularly, the present invention is concerned with a novel dust cover assembly that permits an easy and firmly attachment thereof to the shock absorber without looseness thereof, a method of producing the dust cover assembly, and a product equipped with the dust cover assembly.

#The forgoing and/or other objects features and advantages of the invention will become more apparent from the following description of a preferred embodiment with reference to the accompanying drawings in which like reference numerals designate like elements and wherein:

#FIG. 1 is an elevational view in axial cross section of a dust cover assembly constructed according to a first embodiment of the invention, which is attached to a shock absorber of a vehicle.

#FIG. 2 is an enlarged view in vertical or axial cross section of a fixing member of the dust cover assembly of FIG. 1, which is assembled with a bound stopper;

#Referring first to FIG. 1, there is shown a dust cover assembly including a tubular dust cover 10 and a fixing member 16 constructed according to a first embodiment of the invention. The dust cover assembly is mounted on a shock absorber 12 of a suspension system of an automotive vehicle. The shock absorber 12 has a known structure in which a cylinder 13 filled with a suitable fluid such as oil and a piston rod 14 are assembled together such that the piston rod 14 is slidably received by the cylinder 13 so as to provide a reciprocatory motion thereof in its axial direction with respect to the cylinder 13. The shock absorber 12 is installed on the vehicle such that the cylinder 13 is attached to a suspension-side member of the vehicle, e.g., a suspension arm (not shown), while the piston rod 14 is attached to a body of the vehicle, so that the piston rod 14 is axially reciprocatory moved with respect to the cylinder 13 according to a swinging motion of the suspension arm. The fixing member 16 and a pressing member 17 are fixed to a protruding end portion of the piston rod 14, and equipped with a rubber mount in the form of a lower cushion rubber 20 and an upper cushion rubber 18. In the presence of the fixing and pressing members 16, 17, the piston rod 14 is elastically connected to the body 15 via the lower and upper cushion rubbers 18, 20. The fixing member 16 also functions to provide a portion on which one axial end portion (i.e., an upper axial end portion as seen in FIG. 1) of the dust cover 10 is radially outwardly disposed and fitted. Thus, the dust cover 10 is attached to the fixing member 16 so as to extend axially downwardly for covering a protruded portion of the piston rod 14 over its substantially entire axial length and the cylinder 13 over its axially upper end portion as seen in FIG. 1.

#Hereinafter, there will be described in detail a method of producing the dust cover assembly. Initially the fixing member 16 is prepared as shown in FIG. 2. The fixing member 16 is made of a rigid metallic material and includes a first metal holder in the form of an upper metal holder 22 and a second metal holder in the form of a lower metal holder 24. The upper metal holder 22 is a cylindrical cup shaped member including a bottom wall portion 26 having a through hole 28 at its central portion and a cylindrical wall portion 30 having an outward flange 32 integrally formed at its open end portion so as to extend radially outwardly. A cylindrical sleeve 33 made of metal and having a small diameter is fixed to the bottom wall portion 26 of the upper metal holder 22 such that one of axially opposite open-end faces of the cylindrical sleeve 33 is superposed on and welded to an peripheral portion of the through hole 28 of the bottom wall portion 26. Thus, the cylindrical sleeve 33 is held in a substantially concentric or coaxial relationship with the upper metal holder 22 and protrudes axially outwardly (upwardly) from the cylindrical wall portion 30. In this condition, a bore of the cylindrical sleeve 33 is held in communication with the through hole 28.

#On the other hand, the lower metal holder 24 is an inverted cylindrical cup shaped member, which has a diameter larger than a diameter of the upper metal holder 22, and which is open to one of vertically opposite sides thereof (a lower side as seen in FIG. 1) that is remote from the upper metal holder 22. The lower metal holder 24 includes a top wall portion 34 (as a bottom wall portion thereof) having a through hole 36 at its central portion and a cylindrical wall portion 38 whose diameter varies in its axial direction. Described in detail, the cylindrical wall portion 38 has a smallest diameter portion at its axially intermediate portion. The diameter of the cylindrical wall portion 38 is gradually increased from the smallest diameter portion in axially upward and downward directions of the cylindrical wall portion 38, so that the cylindrical wall portion 38 has an engaging portion in the form of a shallow annular recess 40 open in its outer circumferential surface and extending in its circumferential direction at its axially intermediate portion. Namely, the annular recess 40 has an undercut shape in the axial direction of the lower metal holder 24. The cylindrical wall portion 38 has a largest diameter at its open-end portion. The thus constructed upper and lower metal holders 22, 24 are superposed on each other at the bottom wall portion 26 and the top wall portion 34, and fixed together by a spot welding, such that the upper and lower metal holders 22, 24 are held in concentric with or coaxial relationship with each other and open to the axially opposite directions. In this condition, the through holes 28, 36 are connected to each other to form a mounting bore of the fixing member 16.