JP4525783B2 - Dust cover - Google Patents

Description

  The present invention relates to a dust cover used for a shock absorber of a vehicle, and more particularly to a dust cover provided with an insulator.

  In the strut type suspension device, an upper end portion of a shock absorber is attached to a vehicle body, and a lower end portion is coupled to a wheel, and is interposed between the wheel and the vehicle body. A coil spring is extrapolated around the shock absorber, and the coil spring is disposed between a spring seat fixed to the top of the piston rod of the shock absorber and a lower seat fixed to the middle portion of the outer shell of the shock absorber. Is done. Generally, an insulator that insulates vibration is provided between a spring seat and a coil spring.

  In the above-described strut suspension device, a dust cover having a bellows-cylindrical main body cylinder portion is provided between the shock absorber and the coil spring in order to protect the oil seal of the shock absorber from foreign matters such as sand. Some dust covers are integrally formed with a main body cylinder portion and an insulator. The spring seat is provided with a drain hole for discharging foreign matter such as muddy water that falls on the spring seat. The insulator of the dust cover is also provided with a drain hole for discharging foreign matters such as muddy water.

Patent Document 1 discloses a dust cover 100 including an insulator portion 102 shown in FIG. In the dust cover 100, a circumferential groove 110 that receives intrusion water from the drain hole 108 of the spring seat 106 is provided on the inner peripheral side of the insulator portion 102. A path 112 is provided continuously to the circumferential groove 110. In Japanese Patent Application No. 2007-074011, in a dust cover having an insulator portion, a seal lip that seals between the contact surface of the spring seat and the spring seat is provided in the circumferential direction of the opening on one end side in the axial direction of the main body cylindrical portion. And a dust cover that is integrally projected in a state in which the plurality of portions are divided by the dividing portions provided at a plurality of locations in the circumferential direction and the plurality are arranged in the circumferential direction independently of each other. ing.
JP 2005-16641 A

  As shown in FIG. 3, according to the dust cover 100 disclosed in Patent Document 1, a gap 114 exists between the spring seat 106 and the insulator portion 102. Therefore, when the foreign matter is discharged from the drain hole 108, the foreign matter can enter the dust cover from the gap 114.

  This invention is made | formed in view of such a condition, The objective is to provide the dust cover which can prevent suitably the penetration | invasion of the foreign material to an inside.

In order to solve the above problems, a dust cover according to an aspect of the present invention is a dust cover used in a shock absorber, and is a main body cylinder portion inserted in a coil spring and a spring seat provided at an upper end portion of the shock absorber. And an insulator part clamped between the coil spring and a connecting part for connecting the main body cylinder part and the insulator part. The connecting portion has a protrusion that protrudes toward the spring seat and has a through hole. The annular upper end of the protrusion is in close contact with the lower opening of the drain hole provided in the spring seat. The protrusion is formed so that the thickness of the upper part is thinner than that of the lower part. According to this aspect, the annular upper end portion of the protrusion is closely attached to the periphery of the lower opening of the drain hole provided in the spring seat, so that the foreign matter from the drain hole of the spring sheet is dusted by the through hole of the protrusion. It can be discharged outside the cover. By making the thickness of the upper part of the protrusion part thinner than the lower part, the flexibility of the upper part of the protrusion part can be improved.

  The annular upper end of the protrusion has flexibility. Since the annular upper end portion of the protrusion has flexibility, the adhesion of the annular upper end portion to the spring seat can be enhanced.

  The protrusion may be formed with a tapered through hole in which the inner diameter of the annular upper end is larger than the inner diameter of the annular lower end. This makes it difficult for foreign matter to enter from the annular lower end.

  ADVANTAGE OF THE INVENTION According to this invention, the dust cover which can prevent suitably the penetration | invasion of the foreign material to an inside can be provided.

  The dust cover according to the present embodiment includes a bellows-cylindrical main body cylinder part, an insulator part sandwiched between a spring seat and a coil spring, and a connecting part that connects the main body cylinder part and the insulator part. The protrusion part which provided the through-hole connected with the exterior of a dust cover is arrange | positioned in the position facing each of the drainage hole of the spring seat at the time of an assembly | attachment.

  FIG. 1 is a cross-sectional view showing a state in which the dust cover 10 according to the embodiment of the present invention is assembled to the spring seat 38. As shown in FIG. 1, the dust cover 10 used for the shock absorber 42 includes a bellows-cylindrical main body cylinder part 16, an insulator part 24, and a connecting part 20 that connects the main body cylinder part 16 and the insulator part 24. Prepare.

  The shock absorber 42 functioning as a shock absorber is provided with a cylindrical outer shell 44 connected to the wheel side, a piston rod 12 connected to the vehicle body side, and a piston rod 12 connected to the vehicle body side. And a cap 46 closing the one end side opening. Hydraulic oil is enclosed in the outer shell 44. An oil seal is provided between the cap 46 and the piston rod 12 to prevent the hydraulic oil from leaking outside the outer shell 44. The oil seal is formed of a flexible material such as rubber.

  A lower seat that supports the lower end of the coil spring 18 is attached to the outer periphery of the outer shell 44. The lower sheet is a dish-shaped member formed by press-molding a metal material. A hole for inserting the outer shell 44 is provided in the center of the lower sheet. The lower sheet is welded and fixed to an intermediate portion of the outer shell 44 with the outer shell 44 inserted in the central hole.

  The piston rod 12 is attached to the vehicle body by inserting a male screw into an attachment hole provided at a predetermined position of the vehicle body via an upper support and screwing and tightening. Further, the lower end of the outer shell 44 is attached to the wheel by a predetermined attachment member.

  A bound stopper 14 that restricts excessive displacement of the piston rod 12 downward and a spring seat 38 that supports the upper end of the coil spring 18 are attached to the upper portion of the piston rod 12.

  The bound stopper 14 is a thick-walled cylindrical rubber elastic body, and is attached to the upper portion of the piston rod 12 so as to be fixed. When the shock absorber 42 contracts greatly, the bound stopper 14 is elastically deformed by being narrowed in the axial direction between the spring seat 38 and the cap 46. Thereby, the contraction amount of the shock absorber 42 can be limited in a buffering manner.

  The spring seat 38 has an attachment portion having a hole for inserting and attaching the piston rod 12 at the center, a ring-shaped spring upper end support portion 48 extending in the radial direction from the peripheral portion of the attachment portion, muddy water, etc. The peripheral groove part 50 in which the drainage hole 40 for discharging | emitting is formed is provided.

  The coil spring 18 is disposed between the spring seat 38 and the lower seat in a state of being radially separated from the outer peripheral surface of the shock absorber 42. The upper end portion of the coil spring 18 is supported by the spring seat 38 via the insulator portion 24. On the other hand, the lower end portion of the coil spring 18 is supported by the lower seat via a rubber lower insulator.

  In the assembly process of the dust cover 10, the coil spring 18 is extrapolated to the shock absorber 42, the dust cover 10 is inserted from above between the shock absorber 42 and the coil spring 18, and the spring seat 38 is disposed from above the dust cover 10. To do. At this time, the spring seat 38 is positioned so that the drain hole 40 is disposed at the position of the protrusion 22 of the dust cover 10.

  Hereinafter, description will be given with reference to FIG. 2 together with FIG. FIG. 2 is a perspective view showing a part of the dust cover 10 according to the embodiment of the present invention. The main body cylinder portion 16 of the dust cover 10 according to the present embodiment is a bellows-like cylindrical elastic body formed by injection molding, for example, urethane resin. An inner diameter of the main body cylinder portion 16 is formed larger than an outer diameter of the shock absorber 42, and the main body cylinder portion 16 is inserted between the shock absorber 42 and the coil spring 18.

  The main body cylinder portion 16 prevents foreign matter from adhering to the oil seal of the shock absorber 42. The main body cylinder portion 16 is open at the lower end and may be unfixed to the outer shell 44 of the shock absorber 42. By making the lower end of the main body cylinder portion 16 unfixed, the rigidity of the dust cover 10 does not affect the forward / backward movement of the shock absorber 42. Moreover, the lower end of the main body cylinder part 16 may be an annular rib shape that is thick on the outer peripheral side and has improved strength. The main body cylinder portion 16 is assembled so that the central axis of the main body cylinder portion 16 coincides with the central axis of the shock absorber 42. The main body cylinder part 16 is integrally formed with the insulator part 24 and the connecting part 20 that connects the main body cylinder part 16 and the insulator part 24.

  The annular insulator portion 24 is provided as a flange extending from the upper end of the connecting portion 20 in the outer diameter direction. The insulator portion 24 may be formed of a rubber material. The insulator portion 24 is sandwiched between the lower surface of the spring upper end support portion 48 of the spring seat 38 and the upper end of the coil spring 18 and insulates vibration therebetween. In order to restrict the upper end of the coil spring 18 from moving in the radial direction, a semicircular concave groove portion is formed on the lower surface of the insulator portion 24. The insulator portion 24 is supported by the annular connecting portion 20.

  The connecting part 20 includes an enlarged diameter part 28 that expands the diameter of the main body cylinder part 16, a cylindrical wall part 26, and a protruding part 22 formed on the enlarged diameter part 28. The cylindrical wall portion 26 extends substantially vertically downward with respect to the insulator portion 24. The wall portion 26 is connected to the annular upper portion of the enlarged diameter portion 28, and the lower portion of the enlarged diameter portion 28 is connected to the main body cylinder portion 16. The wall part 26 may be provided with a larger diameter than the main body cylinder part 16, and the diameter expansion part 28 may be increased in diameter while being inclined from the main body cylinder part 16 toward the wall part 26. That is, the diameter-expanded portion 28 may be formed in a funnel shape whose diameter increases toward the top. In the example shown in FIG. 1, since the insulator portion 24 is formed in an elliptical shape, the enlarged diameter portion 28 is also configured to have a slope according to it.

  The protrusion 22 protrudes toward the spring seat 38 on the inner side of the connecting portion 20, that is, on the upper surface of the enlarged diameter portion 28. The protrusion 22 is provided with a through hole 36 that allows the inside and outside of the dust cover 10 to communicate with each other and muddy water or the like from the drain hole 40 can be discharged to the outside of the dust cover 10. An annular lower end 32 of the through hole 36 is directed to the outside of the dust cover 10. Further, the through hole 36 may be formed in a tapered shape in which the inner diameter of the annular upper end portion 30 is larger than the inner diameter of the annular lower end portion 32. By forming the through hole 36 in a tapered shape, muddy water or the like can be prevented from entering from the annular lower end 32.

  When the dust cover 10 is assembled, the annular upper end 30 of the protrusion 22 is pressed and brought into close contact with the periphery of the lower opening of the drain hole 40 of the spring seat 38. Thus, the protrusion 22 can discharge foreign matter such as muddy water discharged from the drain hole 40 to the outside of the dust cover 10. The protrusion 22 has a height that reaches the lower opening of the drain hole 40 when the dust cover 10 is assembled, and the annular upper end 30 of the protrusion 22 is formed to have a larger diameter than the diameter of the drain hole 40.

  The protrusion 22 may be formed so that the thickness of the upper part gradually becomes smaller than the thickness of the lower part as it goes from the annular lower end part 32 toward the annular upper end part 30. Accordingly, the protrusion 22 can be in close contact with the periphery of the drain hole 40 of the spring seat 38 to improve the adhesion.

  Further, the annular upper end portion 30 may be formed of a highly adhesive rubber material and may have flexibility. An annular valve may be formed on the annular upper end 30 in the outer diameter direction. At the time of assembly, the insulator portion 24 is pressed by the elastic force of the coil spring 18, and the protrusion 22 is also pressed against the spring seat 38. At this time, the annular upper end 30 functions as a seal and can cover the periphery of the lower opening of the drain hole 40 in close contact. Further, the annular upper end portion 30 can function as a slip stopper that prevents displacement. Accordingly, it is possible to suppress the positional relationship between the drain hole 40 and the protrusion 22 from being shifted due to vehicle vibration at the time of assembly, and appropriately prevent foreign matter from entering the dust cover 10. In FIG. 2, only one protrusion 22 is shown, but a plurality of protrusions 22 may be provided according to the number of drain holes 40 of the spring seat 38.

  Further, the protrusion 22 also functions as a support member for the dust cover 10. The circumferential groove portion 50 of the spring seat 38 is provided at a position lower than the spring upper end support portion 48 in order to promote drainage to the drain hole 40. Therefore, the protruding portion 22 fixes the dust cover 10 to the lower portion of the circumferential groove portion 50 at a position lower than the height of the insulator portion 24. Further, the protrusion 22 supports the dust cover 10 inside the insulator portion 24. In addition to the support by the insulator portion 24, the protrusion 22 supports the dust cover 10 at a plurality of positions, so that the rigidity against the displacement and twist when the main body cylinder portion 16 is folded can be increased. The dust cover 10 that can be stably folded along the central axis 16 can be realized.

  The present invention has been described above based on the embodiment. It should be understood by those skilled in the art that these embodiments are exemplifications, and that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention. For example, the protrusion 22 may be provided on the wall 26 and protrude toward the drain hole 40 of the spring seat 38.

It is sectional drawing which shows the state which assembled | attached the dust cover which concerns on embodiment of this invention to the spring seat. It is a perspective view which shows a part of dust cover which concerns on embodiment of this invention. It is sectional drawing which shows the conventional dust cover.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Dust cover, 12 Piston rod, 14 Bound stopper, 16 Body cylinder part, 18 Coil spring, 20 Connection part, 22 Protrusion part, 24 Insulator part, 26 Wall part, 28 Diameter expansion part, 30 Annular upper end part, 32 Annular lower end Part, 36 through-hole, 38 spring seat, 40 drainage hole, 42 shock absorber, 48 spring upper end support part.

Claims (3)

A dust cover used for a shock absorber,
A main body cylinder portion inserted in the coil spring;
An insulator portion sandwiched between a spring seat provided at an upper end portion of the shock absorber and the coil spring;
A connecting part for connecting the main body cylinder part and the insulator part;
With
The connecting portion has a protrusion that protrudes toward the spring seat and is formed with a through hole;
The annular upper end of the protrusion is in close contact with the lower opening of the drain hole provided in the spring seat ,
The protrusion is formed such that the upper portion is thinner than the lower portion .   The dust cover according to claim 1, wherein an annular upper end portion of the protrusion has flexibility. 3. The dust cover according to claim 1, wherein the protrusion is formed with a tapered through hole in which an inner diameter of the annular upper end is larger than an inner diameter of the annular lower end.

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