Patent Publication Number: US-2022235844-A1

Title: Cover cap and insulator for shock absorber including the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit and priority to Korean Patent Application No. 10-2021-0012325, filed on Jan. 28, 2021, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a cover cap and an insulator for a shock absorber including the same, and more particularly, to an insulator used for a shock absorber capable of improving ride quality of a vehicle, and a cover cap included in the insulator. 
     BACKGROUND 
     In general, a shock absorber serves to inhibit or attenuate vibration transmitted from a road surface and absorbs vibrational energy in an upward/downward direction of a vehicle body in a state in which the shock absorber is mounted between a wheel and the vehicle body or the frame. 
     The shock absorber increases durability life by reducing dynamic stress of each component of the vehicle body, ensures grounding properties of tires by inhibiting unsprung mass motions, and improves motional performance of the vehicle by inhibiting a posture change caused by an inertial force. 
     The shock absorber typically includes a piston rod having one end fixed to the vehicle body, and a cylinder having one end fixed to the vehicle wheel. Further, an insulator is disposed at one end of the piston rod. 
     The insulator in the related art has a hollow portion formed at a center thereof so that one end of the piston rod may be penetratively coupled to the insulator. A body of the insulator is fastened to the vehicle body by bolting or the like. A bushing coupled to one end of the piston rod is movably installed in the insulator. Further, an impact absorbing member for absorbing impact is interposed between the bushing and the body of the insulator. In addition, a cover cap is coupled to the body in a direction opposite to a direction of the piston rod and covers the hollow portion. 
     However, the impact absorbing member disposed in the body of the insulator is deformed by the motion of the bushing. When a pushing force applied by the piston rod in a direction toward the vehicle body is high, the amount of deformation of the impact absorbing member increases, such that the impact absorbing member comes into contact with the cover cap. Further, as the pushing force applied by the piston rod in the direction toward the vehicle body becomes higher, a degree to which the impact absorbing member is pushed by the cover cap is increased, and the impact absorbing member loses vibration insulation properties. 
     When the vehicle travels in the state in which the impact absorbing member loses the vibration insulation properties as described above, the impact absorbing member cannot effectively inhibit vibration transmitted from the road surface, which causes noise. 
     SUMMARY 
     The present disclosure has been made in an effort to provide a cover cap and an insulator for a shock absorber including the same, which are capable of stably reducing transmitted vibration. 
     An exemplary embodiment of the present disclosure provides a cover cap including: a cap main body having a circular plate shape; and a cap hollow portion penetrating a center of the cap main body. Further, a part or the entirety of the cap hollow portion is formed such that a diameter thereof increases toward one surface of the cap main body and the diameter maximally increases at one surface of the cap main body. 
     One surface of the cap main body may be flat, and the other surface of the cap main body, which is opposite to one surface of the cap main body, may protrude toward a center of the circular plate shape. 
     A plurality of cap grooves may be formed in the other surface of the cap main body and radially disposed with respect to the cap hollow portion. 
     Another exemplary embodiment of the present disclosure provides an insulator for a shock absorber, the insulator including: a body having an installation hole penetratively formed in a longitudinal direction; a bushing installed in the installation hole of the body so as to be movable in the longitudinal direction and having a coupling hole formed such that one end of a piston rod extending from a cylinder is coupled to the coupling hole; an impact absorbing member configured to surround the bushing in the installation hole of the body; and a cover cap configured to cover the installation hole in a direction opposite to a direction in which one end of the piston rod is coupled. Further, the cover cap includes a cap main body having a circular plate shape, and a cap hollow portion penetrating a center of the cap main body, and a part or the entirety of the cap hollow portion is formed such that a diameter thereof increases toward one surface of the cap main body and the diameter maximally increases at one surface of the cap main body. 
     The impact absorbing member may be interposed between the bushing and the cover cap. 
     The impact absorbing member may be spaced apart from the cover cap even when the bushing moves in the longitudinal direction. 
     The impact absorbing member may be made of any one of rubber and urethane. 
     The body may further include a body hollow portion configured to communicate with the installation hole and formed such that one end of the piston rod is inserted into the body hollow portion. 
     The bushing may include a bushing protruding portion protruding in a cylindrical shape from one surface of the bushing facing the cover cap. 
     An outer diameter of the bushing protruding portion may be smaller than a minimum inner diameter of the cap hollow portion of the cover cap. 
     One surface of the cap main body may be flat, and the other surface of the cap main body, which is opposite to one surface of the cap main body, may protrude toward a center of the circular plate shape. 
     A plurality of cap grooves may be formed in the other surface of the cap main body and radially disposed with respect to the cap hollow portion. 
     According to the embodiment of the present disclosure, the cover cap and the insulator for a shock absorber including the same may stably reduce the transmitted vibration. 
     The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front perspective view illustrating a cover cap according to an embodiment of the present disclosure. 
         FIG. 2  is a rear perspective view illustrating the cover cap illustrated in FIG.  1 . 
         FIG. 3  is a cross-sectional view illustrating an insulator for a shock absorber including the cover cap illustrated in  FIG. 1 . 
         FIG. 4  is a cross-sectional view illustrating an operating state of the insulator for a shock absorber illustrated in  FIG. 3 . 
         FIG. 5  is a graph illustrating a vibration reducing effect implemented by the insulator for a shock absorber including the cover cap according to the embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawing, which forms a part hereof. The illustrative embodiments described in the detailed description, drawing, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. 
     Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those with ordinary skill in the art to which the present disclosure pertains may easily carry out the embodiments. The present disclosure may be implemented in various different ways, and is not limited to the embodiments described herein. 
     It is noted that the drawings are schematic, and are not illustrated based on actual scales. Relative dimensions and proportions of parts illustrated in the drawings are exaggerated or reduced in size for the purpose of clarity and convenience in the drawings, and any dimension is just illustrative but not restrictive. The same reference numerals designate the same structures, elements or components illustrated in two or more drawings in order to exhibit similar characteristics. 
     Embodiments of the present disclosure illustrate ideal embodiments of the present disclosure in detail. As a result, various modifications of the drawings are expected. Therefore, the embodiments are not limited to specific forms in regions illustrated in the drawings, and for example, include modifications of forms by the manufacture thereof. 
     Hereinafter, a cover cap  201  according to an embodiment of the present disclosure will be described with reference to  FIGS. 1 and 2 . 
     The cover cap  201  according to the embodiment of the present disclosure may be used for an insulator  101  for a shock absorber. 
     As illustrated in  FIGS. 1 and 2 , the cover cap  201  according to the embodiment of the present disclosure may include a cap main body  210  having a circular plate shape, and a cap hollow portion  290  penetrating a center of the cap main body  210 . In this case, a part or the entirety of the cap hollow portion  290  may be shaped such that a diameter thereof increases toward one surface of the cap main body  210  and the diameter maximally increases at one surface of the cap main body  210 . In this case, as illustrated in  FIG. 3 , one surface of the cap main body  210  faces a bushing  400  and an impact absorbing member  500  of the insulator  101  for a shock absorber to be described below. 
     One surface of the cap main body  210  is flat, and the other surface of the cap main body  210 , which is opposite to one surface of the cap main body  210 , may have a shape that protrudes toward a center of the circular plate shape. Further, a plurality of cap grooves  217  may be formed in the other surface of the cap main body  210  and radially disposed with respect to the cap hollow portion  290 . The plurality of cap grooves  217 , which is formed as described above, may improve strength of the cover cap  210  and reduce a weight of the cover cap  210 . 
     With the above-mentioned configuration, the cover cap  201  according to the embodiment of the present disclosure may be formed to enable the insulator  101  for a shock absorber to stably reduce transmitted vibration. 
     Hereinafter, the insulator  101  for a shock absorber including the cover cap  201  according to the embodiment of the present disclosure will be described with reference to  FIGS. 3 and 4 . 
     The shock absorber serves to inhibit or attenuate vibration transmitted from a road surface and absorbs vibrational energy in an upward/downward direction of a vehicle body in a state in which the shock absorber is mounted between a wheel and the vehicle body or the frame. The shock absorber includes a piston rod (not illustrated) fixed to a vehicle body, and a cylinder (not illustrated) fixed to a vehicle wheel. Further, the insulator  101  is installed at one end of the piston rod. 
     As illustrated in  FIG. 3 , the insulator  101  for a shock absorber may include a body  300 , the bushing  400 , the impact absorbing member  500 , and the cover cap  201  described above. 
     The body  300  may include an installation hole  350  penetratively formed in a longitudinal direction, and a body hollow portion  360  communicating with the installation hole  350  and formed such that one end of the piston rod (not illustrated) is inserted into the body hollow portion  360 . In the present specification, the longitudinal direction may be identical to the longitudinal direction of the piston rod. 
     The bushing  400  may be inserted into the installation hole  350  of the body  300  to be described below. That is, the installation hole  350  may have a cylindrical shape so that the bushing  400  may be inserted into the installation hole  350 . 
     The body  300  may further include a rubber coupling groove  370  formed to communicate with the body hollow portion  360 . A bumper rubber (not illustrated) coupled to one end of the piston rod (not illustrated) may be inserted into the rubber coupling groove  370 . A lower end of the bumper rubber is in close contact with an upper end of the cylinder (not illustrated), such that the bumper rubber may elastically support a portion between the body  300  and the cylinder. Further, the piston rod may be penetratively coupled in the upward/downward direction in the bumper rubber. 
     A rim portion of the body  300  may extend to have a predetermined length and define a predetermined area. Further, a fastening member such as a bolt may be installed on the rim portion of the upper end of the body  300  and coupled to the vehicle body. 
     The bushing  400  is installed in the installation hole  350  of the body  300  so as to be movable in the longitudinal direction. To this end, intervals, in which the bushing  400  may move, may be defined above and below the installation hole  350  of the body  300 . 
     The bushing  400  may include a coupling hole  460  formed to be coupled to one end of the piston rod extending from the cylinder. 
     A stepped portion formed at an outer periphery of the piston rod is caught by a lower end of the bushing  400 , and an end of the piston rod may be inserted into the coupling hole  460  of the bushing. 
     The bushing  400  may include a bushing protruding portion protruding in a cylindrical shape from one surface of the bushing  400  facing the cover cap  201 . In this case, an outer diameter of the bushing protruding portion may be smaller than a minimum inner diameter of the cap hollow portion  290  of the cover cap  201 . 
     The impact absorbing member  500  may be formed to surround the bushing  400  in the installation hole  350  of the body  300 . In particular, the impact absorbing member  500  is also interposed between the bushing  400  and the cover cap  201 . Specifically, the impact absorbing member  500  may surround all edges of the lateral surface and the upper and lower surfaces of the bushing  400 . Further, the impact absorbing member  500  may be spaced apart from the cover cap  201  even though the bushing  400  moves in the longitudinal direction in the installation hole  350  of the body  300 . 
     The impact absorbing member  500  may be made of any one of rubber and urethane. The impact absorbing member  500  may effectively absorb impact by using non-linear properties even when high-frequency waves with low amplitude occurs. 
     The cover cap  201  may cover the installation hole  350  of the body  300  in a direction opposite to the direction in which one end of the piston rod is coupled. That is, the cover cap  201  may be coupled to an opened upper side of the installation hole  120  of the body  300 . 
     The cover cap  201  may include the cap main body  210  having a circular plate shape, and the cap hollow portion  290  penetrating the center of the cap main body  210 . Further, a part or the entirety of cap hollow portion  290  may be formed such that a diameter thereof increases toward one surface of the cap main body  210  and the diameter maximally increases at one surface of the cap main body  210 . In this case, one surface of the cap main body  210  is a surface facing the bushing  400  and the impact absorbing member  500 . 
     Since the cover cap  201  has the above-mentioned shape, the pushing force applied by the piston rod in the direction toward the vehicle body is strongly applied, such that the bushing  400  moves, as illustrated in  FIG. 4 . Therefore, the impact absorbing member  500  may be kept spaced apart from the cover cap  201  without coming into contact with the cover cap  201  even though the impact absorbing member  500  disposed in the installation hole  350  of the body  300  is deformed. 
     Therefore, since the impact absorbing member  500  is pushed by the cover cap  201 , it is possible to prevent the impact absorbing member  500  from losing vibration insulation properties. That is, it is possible to prevent the occurrence of noise by effectively inhibiting vibration transmitted from the road surface. 
     With the above-mentioned configuration, the cover cap  201  and the insulator  101  for a shock absorber including the same according to the embodiment of the present disclosure may stably reduce transmitted vibration. 
     Hereinafter, the comparison between vibration properties of the embodiment and the comparative example will be described with reference to  FIG. 5 . 
     The embodiment is the cover cap  201  and the insulator  101  for a shock absorber including the same according to the embodiment of the present disclosure, and the comparative example is an insulator in the related art. Specifically, in the case of the comparative example, when the bushing moves as the pushing force applied by the piston rod in the direction toward the vehicle body is strongly applied, the impact absorbing member comes into contact with the cover cap while being deformed. 
     As illustrated in  FIG. 5 , it can be ascertained that vibration is reduced on average by 2.6 dB in a section of 100 to 400 Hz in the embodiment compared to the comparative example. 
     While the embodiments of the present disclosure have been described with reference to the accompanying drawings, those skilled in the art will understand that the present disclosure may be carried out in any other specific form without changing the technical spirit or an essential feature thereof. 
     Accordingly, it should be understood that the aforementioned embodiments are described for illustration in all aspects and are not limited, and the scope of the present disclosure shall be represented by the claims to be described below, and it should be construed that all of the changes or modified forms induced from the meaning and the scope of the claims, and an equivalent concept thereto are included in the scope of the present disclosure. 
     From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.