JPH0514690U - Fitting structure of bump cushion for vehicle shock absorber and dust cover - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a fitting structure in which a bump cushion of a vehicle shock absorber and a dust cover can be easily fitted to each other and the fitting is not easily disengaged. In a structure in which a bump cushion 32 mounted on an end portion of a piston rod of a shock absorber and a dust cover 40 surrounding the bump cushion 32 and the piston rod are fitted to each other at one end side surface of the bump cushion end. Angle a between the side outer surface 38 of the section and the bump cushion end surface 36 adjacent thereto and angle b between the corresponding side inner surface 44 of the dust cover end and the adjacent dust cover end surface 42. The angle a on the bump cushion side is set to be the same as or larger than the angle b on the dust cover side within a range of 20 degrees or less.
In addition, the inner side surface 46 of the dust cover, which continues to the fitting portion 45, is bent outwardly with respect to the inner side surface 44 of the fitting portion in a dogleg shape to increase the inner diameter of the dust cover 40.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fitting structure for a bump cushion of a vehicle shock absorber and a dust cover.

[0002]

[Prior Art]

 Conventionally, a shock absorber mainly composed of a shock absorber has been used in a vehicle in order to reduce the impact caused by the unevenness of the road surface and to reduce the impact to improve the running stability. As shown in FIG. 4, the shock absorber is constructed such that the upper spring seat 10 and one end of the piston rod 14 of the shock absorber 12 are fixed to a vehicle body (not shown), and a cylinder is attached to the outer periphery of the end of the piston rod 14. A bump cushion (also referred to as a bound bumper) 18 made of a ball-shaped elastic body and a dust cover 20 made of a hollow cylindrical elastic body that surrounds the outer periphery of the bump cushion 18 and hangs downward are respectively fitted. The upper end of the coil spring 21 is supported on the lower surface of the edge of the upper spring seat 10.

The bump cushion 18 is for preventing the upper end of the cylinder 22 of the shock absorber from directly colliding with the vehicle body through the upper spring seat 10 due to a bad road or the like, and thereby attenuating the impact. On the other hand, the dust cover 20 is for surrounding the bump cushion 18 and the piston rod 14 of the shock absorber to prevent dust from entering from the outside.

Conventionally, the bump cushion 18 and the dust cover 20 are fixed to each other by fitting a concave portion 24 formed on the end side surface of the bump cushion 18 and a convex portion 26 formed on the end side surface of the dust cover 20. It is supposed to be done.

However, in the conventional fitting structure of the bump cushion and the dust cover, the lower end of the convex portion 26 of the dust cover 20 contacts the edge portion of the end face 27 of the bump cushion 18 during fitting as shown in FIG. There were cases where mating could not be done smoothly. In addition, due to variations in molding conditions or shrinkage after molding, the dimensions of the bump cushion 18 or the dust cover 20 may change, and the above fitting may not be possible, or even if the fitting is possible, the fitting may easily come off or rattling. There was something. Further, when the bump cushion 18 and the dust cover 20 are assembled to the piston rod, even if the bump cushion 18 and the dust cover 20 are already fitted from the viewpoint of workability, the fitting will be disengaged during the actual assembly. Work sometimes became difficult.

Further, the bump cushion 18 and the dust cover 20 are usually fixed to the end portion of the piston rod 14 by setting the inner diameters of the rod cushion insertion holes 28 and 30 of the bump cushion 18 and the dust cover 20 into which the piston rod 14 is inserted. This is performed by making the inner diameter of the rod insertion holes 28, 30 smaller than the outer diameter of the rod 14 by a predetermined amount and crimping the inner surface of the rod insertion hole 28, 30 to the outer surface of the piston rod 14. Therefore, if the bump cushion 18 and the dust cover 20 are easily disengaged from the beginning as described above, the bump cushion becomes more likely to be disengaged due to repeated compression and restoration of the bump cushion due to unevenness of the road surface. The loose bump cushion facilitates movement between the cylinder and the end of the piston rod. As a result, the function of dampening and mitigating shocks was sometimes impaired.

[0007]

[Problems to be solved by the device]

 Therefore, in view of the above points, the present invention provides a fitting structure for a bump cushion and a dust cover that allows easy fitting of the bump cushion and the dust cover, and that prevents the fitting from coming off.

[0008]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention provides a bump cushion made of a cylindrical elastic body mounted on the outer periphery of the end portion of a piston rod of a vehicle shock absorber, and a hollow cylindrical elastic body surrounding the bump cushion and the piston rod. In the structure in which the dust cover consisting of the body is fitted on the side surfaces at one end of both sides, the angle between the side outer surface of the bump cushion end that becomes the fitting portion and the bump cushion end surface adjacent to the side outer surface, The angle between the side inner surface of the dust cover end corresponding to that and the dust cover end surface adjacent to the side inner surface is an acute angle, and the angle of that portion on the bump cushion side is set to the angle on the dust cover side. The same as or larger than 20 degrees, and the side inner surface of the dust cover that continues to the fitting part is Outward by bending the shape of "V" is was to expand the inner diameter of the dust cover.

[0009]

[Action]

 The bump cushion is inserted into the dust cover through the opening at one end of the dust cover and is pushed into the fitting portion at the other end so that the side surfaces of the end portion fit together. At that time, the inner surface of the side of the dust cover that continues to the fitting part bends outward in a V shape with respect to the inner surface of the side of the fitting part, and the inner diameter expands. Easy to push.

In addition, since the bump cushion and the dust cover have an acute angle between the side outer surface of the end that becomes the fitting portion and the inner side surface of the end, and the end surface adjacent thereto, respectively. The inner surface of the part and the outer surface of the side part each have a shape that is recessed toward the other end. Therefore, even if the outer diameter of the end of the bump cushion becomes slightly larger than the design value and the side surface of the dust cover end may open outward, the side of the dust cover at the mating part is still in a recessed state. The fitting with the bump cushion does not come off. Even if the outer diameter of the end of the bump cushion is slightly smaller than the design value, the side surface of the end of the dust cover, which is the fitting part, has a shape that is recessed toward the other end as described above. The bump cushion and dust cover are almost never disengaged. The acute angle is preferably 60 to 87 degrees in order to facilitate fitting and to obtain a reliable fitting action.

Further, if the above-mentioned acute angle is set to be larger in the range of 20 degrees or less on the bump cushion side than on the dust cover side, the side surface of the end portion of the dust cover at the time of fitting is the bump cushion side. It can be crimped to the side of the edge to reduce the rattling of the bump cushion and dust cover.

[0012]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view of a vehicle shock absorber showing an embodiment of a fitting structure of a bump cushion and a dust cover according to the present invention, and FIG. 2 is a sectional view of the bump cushion and the dust cover. The same parts as those of the conventional example are indicated by the same reference numerals.

The bump cushion 32 is made of an elastic material such as rubber or urethane elastomer, and has a cylindrical shape. The bump cushion 32 has a rod insertion hole 34 that penetrates the bump cushion 32 in the longitudinal direction. The angle a between the outer surfaces 38 is an acute angle of 70 degrees. The acutely angled side outer surface 38 constitutes a fitting portion 39 with the dust cover 40. The diameter of the rod insertion hole 34 is slightly smaller than the outer diameter of the piston rod 14 of the shock absorber.

On the other hand, the dust cover 40 is made of an elastic material such as rubber and has a hollow cylindrical shape with one end opened. The angle b between the open end surface 42 of the rod insertion hole 41 and the side inner surface 44 at the end is The bump cushion 32 has an acute angle of 70 degrees, which is the same as the angle a. The side inner surface 44 at the acute angled end constitutes a fitting portion 45 with the bump cushion 32. Further, on the side surface of the dust cover 40, the inner side surface 46 continuing to the fitting portion 45 is bent outwardly with respect to the side inner surface 44 of the fitting portion 45 in a dogleg shape so that the inner diameter of the dust cover is reduced. It spreads out, then again becomes almost parallel to the longitudinal direction and forms a bellows shape near the open end. The inner diameter of the fitting portion 45 of the dust cover 40 is substantially equal to the outer diameter of the fitting portion 39 of the bump cushion 32.

The bump cushion 32 and the dust cover 40 thus formed are fitted as follows and mounted on the piston rod of the shock absorber. First, the bump cushion 32 is inserted into the dust cover 40 from the opening end at one end of the dust cover 40 with the fitting portion 39 at the end thereof facing the fitting portion 45 at the end of the dust cover 40. Then, the end portion of the bump cushion 32 is pushed until reaching the end portion of the dust cover 40, and the fitting portion 39 of the bump cushion and the fitting portion 45 of the dust cover are matched to each other, so that the bump cushion 32 and the dust cover 40 are joined. The mating is done. At this time, since the side inner surface 46 of the dust cover 40 that continues to the fitting portion 45 is bent outward in a dogleg shape with respect to the side inner surface 44 of the fitting portion 45, that side is formed. The end portion of the bump cushion 32 is easily pushed into the fitting portion 45 of the dust cover 40 along the inner surface 46 of the portion.

The bump cushion 32 and the dust cover 40, which are fitted to each other, are attached to the ends of the piston rod 14 with the piston rod 14 of the shock absorber being slightly forcibly inserted into the rod insertion holes 34 and 41. .

FIG. 3 is a cross-sectional view of a bump cushion and a dust cover forming a fitting structure according to another embodiment of the present invention. In this embodiment, the angle c between the side outer surface 50 of the end portion which becomes the fitting portion 48 of the bump cushion 46 and the end surface 52 adjacent thereto is 82 degrees, while the end portion which becomes the fitting portion 56 of the dust cover 54. In this example, the angle d between the side inner surface 58 of the section and the end surface 60 adjacent thereto is 70 degrees. In this embodiment, the acute angle c on the bump cushion side in the fitting portion is 12 degrees larger than the acute angle d on the dust cover side, so that the side surface of the dust cover at the fitting portion is more reliable. Since it is crimped to the side of the bump cushion, it provides a secure fit with less rattling.

The acute angle in the above is determined by the material, shape, etc. of the bump cushion and the dust cover, and is not limited to the value in the embodiment.

[0019]

[Effect of the device]

 Since the fitting structure of the bump cushion and the dust cover of the present invention has the above-mentioned structure, the fitting of the bump cushion and the dust cover is easy, and further, there is an effect that it is hard to come off once fitted. Moreover, even if the bump cushion and the dust cover are deformed due to variations in molding conditions or shrinkage after molding, they will not be unable to mate and will have less rattling.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a vehicle shock absorber showing a fitting structure of a bump cushion and a dust cover according to an embodiment of the present invention.

FIG. 2 is a sectional view of a bump cushion and a dust cover used in an embodiment of the present invention.

FIG. 3 is a sectional view of a bump cushion and dust used in another embodiment of the present invention.

FIG. 4 is a schematic sectional view of a vehicle shock absorber showing a conventional bump cushion and dust cover fitting structure.

FIG. 5 is a cross-sectional view of a bump cushion and a dust cover during conventional fitting.

[Explanation of symbols]

 10 Upper Spring Seat 12 Shock Absorber 14 Shock Absorber Piston Rod 32 Bump Cushion 36 Bump Cushion End Surface 38 Bump Cushion End Side Surface 39 Bump Cushion Fitting Area 40 Dust Cover 42 Dust Cover End Surface 44 Dust Cover End Inner side surface of 45 Dust cover fitting part 46 Inner side surface of dust cover fitting part

Claims (1)

[Scope of utility model registration request] 1. A bump cover made of a tubular elastic body mounted on the outer periphery of a piston rod of a shock absorber for a vehicle, and a dust cover made of a hollow tubular elastic body having an opening at one end surrounding the bump cushion and the piston rod. In a structure in which the side surfaces of both ends are fitted to each other, an angle between a side outer surface of a bump cushion end portion which is a fitting portion and a bump cushion end surface adjacent to the side outer surface, and a dust cover corresponding thereto. The angle between the side inner surface of the end portion and the end surface adjacent to the side inner surface is set to an acute angle, and the angle of the bump cushion side of that portion is equal to or less than 20 degrees compared with the dust cover side angle. Make the dust cover large by bending the inner side surface of the dust cover that continues to the mating part outwards with respect to the inner side surface of the mating part in a V shape. The fitting structure of the bump cushion of the vehicle shock absorber and the dust cover, characterized in that the inner diameter of the bar is enlarged.