JP2014185755A - Dust cover assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dust cover assembly of a new structure capable of realizing superior durability while effectively preventing intrusion of foreign matters by easily assembling a resin dust cover and a rubber upper insulator to each other with sufficient strength.SOLUTION: An upper insulator 16 is provided with a cylindrical portion 40, locking projections 44, 46 are formed in a state of projecting from the cylindrical portion 40 to an outer peripheral side, and extended in the circumferential direction, and a bellows cylindrical portion 18 of a dust cover 14 is formed by blow molding. An engagement cylindrical portion 30 formed by pressing a parison 68 disposed on an outer peripheral face of the cylindrical portion 40 in the upper insulator 16, to an outer peripheral face of the cylindrical portion 40 with a blow molding die, is disposed at an upper side of the bellows cylindrical portion 18, and the engagement cylindrical portion 30 is axially locked to the locking projections 44, 46.

Description

  The present invention relates to a dust cover assembly including a dust cover attached to a suspension mechanism and an upper insulator.

  2. Description of the Related Art Conventionally, there is known a dust cover assembly that includes a dust cover that is externally attached to a shock absorber and covers a periphery of a protruding portion of a piston rod, and an upper insulator that supports an upper end portion of a coil spring. As this dust cover assembly, as disclosed in Japanese Patent Application Laid-Open No. 2003-72338 (Patent Document 1), for example, there is one in which a dust cover and an upper insulator are integrally formed of a rubber elastic body.

  By the way, the dust cover is connected to the upper insulator integrally with the upper insulator and supported by the piston rod, thereby preventing foreign matter from entering from above. On the other hand, the lower end portion is loosely inserted in a state in which free relative displacement with respect to the cylinder is allowed, and the action of a tensile force on the dust cover is avoided when the shock absorber is extended.

  However, if the gap set between the lower end portion of the dust cover and the cylinder is large, foreign matter such as dust and water may enter from the lower end opening of the dust cover and adhere to the piston rod. Furthermore, the bellows tube portion of the dust cover may be caught in a contracted state, and the dust cover may not be able to follow the expansion and contraction of the shock absorber.

  In view of this, Japanese Patent Application Laid-Open No. 10-331897 (Patent Document 2) and the like have proposed a structure in which the lower end portion of the dust cover is supported by a cylinder, for example, by being engaged with an engaging claw protruding from the cylinder. In such a structure, the dust cover is forced to expand and contract following the expansion and contraction of the shock absorber, and an axial tensile force can be exerted on the dust cover. It is also being considered to plan.

  However, if the dust cover is made of resin, it cannot be integrally formed with the upper insulator formed of a rubber elastic body in order to obtain a buffering action. In addition, it is difficult to obtain a sufficient fixing strength by post-fixing a resin dust cover to the rubber upper insulator. Although it is conceivable to provide a metal fitting for supporting the upper end portion of the dust cover in the upper insulator, there is a possibility that the number of parts, an increase in weight, or the like may become a problem.

JP 2003-72338 A Japanese Patent Laid-Open No. 10-331897

  The present invention has been made in the background of the above-mentioned circumstances, and the problem to be solved is that a resin dust cover and a rubber upper insulator are attached to each other easily and with sufficient strength to allow entry of foreign matter. It is an object of the present invention to provide a dust cover assembly having a novel structure capable of realizing excellent durability while effectively preventing the above.

  Hereinafter, the aspect of this invention made | formed in order to solve such a subject is described. In addition, the component employ | adopted in each aspect as described below is employable by arbitrary combinations as much as possible.

  According to a first aspect of the present invention, a resin dust cover that is externally attached to a shock absorber of a suspension mechanism includes a bellows cylinder portion in which a peak portion and a valley portion are continuously provided, and both upper and lower sides of the bellows cylinder portion. Is supported by one of the piston rod and cylinder of the shock absorber, and a rubber upper insulator for supporting the upper end of the coil spring in the suspension mechanism is provided at the upper end of the dust cover. In the attached dust cover assembly, a cylindrical portion is formed in the upper insulator, and a locking projection that protrudes from the cylindrical portion toward the outer peripheral side and extends in the circumferential direction is formed. The bellows tube portion of the dust cover is formed by blow molding, and the upper insulator is disposed above the bellows tube portion. An engaging cylinder formed by pressing a parison disposed on the outer peripheral surface of the cylindrical portion in the blow molding die against the outer peripheral surface of the cylindrical portion. It is characterized by being locked in the axial direction with respect to the stop protrusion.

  According to the dust cover assembly having the structure according to the first aspect, since the resin dust cover can be easily attached to the rubber upper insulator, the resin cover having excellent durability is used. A dust cover can be employed. Therefore, a dust cover with a large axial dimension can be used to prevent intrusion of foreign matter from the opening at the lower end, and the dust cover can be extrapolated to the shock absorber by supporting the upper and lower sides of the dust cover on the shock absorber. Can be kept in a state.

  In addition, a locking projection that protrudes to the outer peripheral side is formed on the cylindrical portion of the upper insulator to which the engaging cylindrical portion of the dust cover is attached, and the engaging cylindrical portion corresponding to the outer peripheral surface of the cylindrical portion is formed. It is locked in the axial direction with respect to the locking projection. As a result, a sufficient axial pull-out resistance is ensured between the dust cover and the upper insulator, and the assembled state of the dust cover and the upper insulator is stably maintained.

  Further, by closing the blow molding die, the engaging cylinder part is molded in close contact with the outer peripheral surface of the upper insulator, and is formed with a dust cover attached to the upper insulator in advance. The Therefore, the process of assembling the dust cover with respect to the upper insulator becomes unnecessary, and the number of manufacturing processes of the dust cover assembly is reduced, so that the dust cover assembly can be easily obtained.

  According to a second aspect of the present invention, in the dust cover assembly described in the first aspect, the cylindrical protrusions of the upper insulator are formed with a plurality of rows of the locking protrusions separated vertically in the axial direction. It is what has been.

  According to the second aspect, a larger axial drag force acting between the upper insulator and the dust cover is obtained, and the assembled state of the dust cover assembly is stably maintained.

  According to a third aspect of the present invention, in the dust cover assembly described in the first or second aspect, at least a part of the circumference of the locking projection is divided in the circumferential direction. And an anti-rotation means for restricting relative rotation of the dust cover and the upper insulator in the circumferential direction by the engagement cylinder portion entering the division groove and being locked in the circumferential direction. Is configured.

  According to the third aspect, the relative orientation of the dust cover in the circumferential direction with respect to the upper insulator is easily set, and the relative orientation of the upper insulator and the dust cover is stably maintained.

  According to a fourth aspect of the present invention, in the dust cover assembly according to any one of the first to third aspects, the protrusion dimension (t) of the locking protrusion includes the locking protrusion. However, t ≧ T / 4 with respect to the thickness dimension (T) of the cylindrical portion.

  According to the fourth aspect, the locking area in the axial direction of the locking protrusion with respect to the engaging cylinder portion can be set sufficiently large, and the axial locking between the dust cover and the upper insulator. An acting axial pull-out drag can be advantageously obtained.

  According to a fifth aspect of the present invention, in the dust cover assembly according to any one of the first to fourth aspects, a cylindrical metal fitting attached to the shock absorber is attached to the cylindrical portion of the upper insulator. Is inserted and arranged.

  According to the fifth aspect, since the amount of deformation of the tubular portion toward the inner peripheral side is limited by the tubular fitting, the dust cover is prevented from being detached from the upper insulator due to the deformation of the tubular portion.

  According to the present invention, since the resin dust cover can be easily attached to the rubber upper insulator, the resin dust cover having excellent durability can be adopted, and the intrusion of dust and the like can be achieved. It can be advantageously prevented. In addition, a locking protrusion is formed on the cylindrical portion of the upper insulator, and the dust cover is removed from the upper insulator by locking the locking protrusion and the engaging cylinder of the dust cover in the axial direction. It can be advantageously prevented from coming off.

  Further, the engaging cylinder portion of the dust cover and the cylindrical portion of the upper insulator are fitted by being pressed by a blow molding die during blow molding of the dust cover. Therefore, the process of assembling the dust cover and the upper insulator becomes unnecessary, and the dust cover assembly can be easily manufactured.

The longitudinal cross-sectional view which shows the dust cover assembly as one Embodiment of this invention in the mounting state to a suspension mechanism. The longitudinal cross-sectional view of the dust cover assembly shown by FIG. The longitudinal cross-sectional view which expands and shows the principal part of the dust cover assembly shown by FIG. It is a longitudinal cross-sectional view explaining the manufacturing process of the dust cover assembly shown by FIG. 2, Comprising: The figure which shows the state before mold closing. It is a longitudinal cross-sectional view explaining the manufacturing process of the dust cover assembly shown by FIG. 2, Comprising: The figure which shows the state after mold closing and before blow molding. It is a longitudinal cross-sectional view explaining the manufacturing process of the dust cover assembly shown by FIG. 2, Comprising: The figure which shows the state after blow molding and before a mold opening.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a dust cover assembly 10 according to an embodiment of the present invention in a mounted state with respect to a suspension mechanism 12 of a vehicle. The dust cover assembly 10 includes a dust cover 14 and an upper insulator 16. In the following description, the vertical direction means the vertical direction in FIG. 1 in principle.

  More specifically, as shown in FIG. 2, the dust cover 14 has a substantially cylindrical shape as a whole and is made of synthetic resin. The synthetic resin forming the dust cover 14 is not particularly limited. In this embodiment, for example, polypropylene (PP) as a thermoplastic resin is mixed with ethylene / propylene rubber (EPDM) and dispersed. Has been adopted because of its excellent weather resistance and moldability. However, in the case of forming with a thermoplastic resin, for example, polyolefin resins such as polypropylene and polyethylene, polyamide resins, polyvinyl chloride resins, polyester resins, urethane resins, styrene resins, olefin resins, etc. Any of these thermoplastic elastomers can be employed.

  In addition, a bellows cylinder portion 18 is provided at an axially intermediate portion of the dust cover 14. The bellows cylinder portion 18 includes a crest 20 extending in a circumferential annular shape with a substantially roll-over V-shaped section convex on the outer peripheral side, and trough portions 22, 24 extending in a circumferential annular shape with a substantially roll-over V-shaped cross section recessed on the outer peripheral side. , And have a structure in which they are arranged alternately in the axial direction. Further, the valleys formed on both the upper and lower sides sandwiching the peak 20 are one having a large valley 22 having a large depth and the other having a small valley 24 having a small depth. The end portion and the inner peripheral end portion of the small valley portion 24 are positioned so as to be shifted from each other in the radial direction.

  Furthermore, a fitting cylinder portion 26 is integrally formed below the bellows cylinder portion 18. The fitting cylinder portion 26 has a substantially cylindrical shape and includes a circumferential groove 28 that opens to the inner circumferential surface.

  Further, on the upper side of the bellows cylinder portion 18, an engagement cylinder portion 30 is integrally formed. The engagement cylinder portion 30 has a substantially cylindrical shape and includes a first engagement groove 32 and a second engagement groove 34. The first engagement groove 32 and the second engagement groove 34 are concave grooves that open to the inner peripheral surface and extend in the circumferential direction, respectively, and the first engagement groove 32 is an axis with respect to the second engagement groove 34. It is arranged at a predetermined distance above the direction.

  Furthermore, the first engagement groove 32 and the second engagement groove 34 are formed with contact portions 36 at a plurality of locations in the circumferential direction. The contact portion 36 protrudes from the engagement cylinder portion 30 toward the outer peripheral side in the first engagement groove 32 and the second engagement groove 34. Thereby, the 1st engagement groove | channel 32 and the 2nd engagement groove | channel 34 of this embodiment are divided | segmented into the circumferential direction by the contact part 36, and in this embodiment, on the circumference of each engagement groove | channel 32,34. The six abutting portions 36 are formed in each, and the engaging grooves 32 and 34 are each divided into six in the circumferential direction. In the present embodiment, the contact portion 36 of the first engagement groove 32 and the contact portion 36 of the second engagement groove 34 are formed at substantially the same position in the circumferential direction.

  Further, the engaging cylinder portion 30 constituting the upper end portion of the dust cover 14 is attached to the upper insulator 16. The upper insulator 16 is a generally annular rubber elastic body as a whole, and integrally includes a spring receiving portion 38 and a cylindrical portion 40. The spring receiving portion 38 is annular and includes a cylindrical inner peripheral portion that extends vertically and an outer peripheral portion that protrudes from the upper end portion of the inner peripheral portion toward the outer peripheral side.

  Further, the spring receiving portion 38 is integrally formed with a cylindrical portion 40 protruding downward. The tubular portion 40 protrudes from the inner peripheral end of the spring receiving portion 38, and a first locking projection 44 and a second locking projection 46 are provided on the outer peripheral surface thereof. Both the first locking projection 44 and the second locking projection 46 protrude from the cylindrical portion 40 toward the outer peripheral side and extend in the circumferential direction. The protrusions 44 are arranged at a predetermined distance above the axial direction. Further, both the first locking protrusion 44 and the second locking protrusion 46 are gradually narrower in the axial direction toward the protruding tip side.

  Furthermore, as shown in FIG. 3, the first locking protrusion 44 and the second locking protrusion 46 protrude on the outer peripheral side with substantially the same dimension: t, and the first and second locking protrusions. Projection dimension of 44, 46: t is in the range of t ≧ T / 4 with respect to the maximum thickness dimension: T of the tubular part 40 where the first and second locking projections 44, 46 are formed. Is set to If the projection dimension: t of the first and second locking projections 44, 46 is too small with respect to the maximum thickness dimension: T of the tubular portion 40, first and second engagement grooves 32 described later will be described. , 34, the locking margin in the axial direction of the first and second locking projections 44, 46 becomes too small, and a sufficient fixing force between the dust cover 14 and the upper insulator 16 cannot be obtained. More preferably, the projecting dimension: t of the first and second locking projections 44, 46 is set in a range of t ≧ T / 3 with respect to the maximum thickness dimension: T of the tubular part 40. In this embodiment, approximately t = T / 2 is set.

  Furthermore, a dividing groove 48 is formed on the circumference of the first locking projection 44 and the second locking projection 46. The dividing groove 48 is a concave groove that opens in the outer peripheral surface and extends in the axial direction, and the first locking protrusion 44 and the second locking protrusion 46 are divided in the circumferential direction by the dividing groove 48. In the first locking projection 44 and the second locking projection 46, division grooves 48 are formed at a plurality of positions on the circumference, and the first and second locking projections 44, 46 are sandwiched between the division grooves 48. Are divided in the circumferential direction, and in the present embodiment, each of the locking protrusions 44 and 46 is divided into six in the circumferential direction by six dividing grooves 48. Further, the dividing groove 48 of the first locking protrusion 44 and the dividing groove 48 of the second locking protrusion 46 are formed at substantially the same position in the circumferential direction. The dividing grooves 48 are formed with a circumferential width substantially corresponding to the contact portion 36 of the upper insulator 16 and are distributed at positions corresponding to the contact portion 36 on the circumference.

  The dust cover 14 and the upper insulator 16 having such a structure are attached to each other with the engaging cylinder portion 30 fitted into the cylindrical portion 40. That is, the engaging cylinder portion 30 of the dust cover 14 is externally inserted into the cylindrical portion 40 of the upper insulator 16 and, as shown in FIG. 3, the first engagement is opened on the inner peripheral surface of the engaging cylinder portion 30. A first locking projection 44 and a second locking projection 46 of the tubular portion 40 are fitted into the joint groove 32 and the second engagement groove 34. As a result, the first and second locking protrusions 44 and 46 and the first and second engaging grooves 32 and 34 are locked in the axial direction, and the engaging cylinder 30 is fitted into the cylindrical portion 40. Therefore, the dust cover assembly 10 is configured.

  According to the dust cover assembly 10 having such a structure, the resin dust cover 14 can be easily assembled to the rubber upper insulator 16.

  Further, the first and second engaging protrusions provided in the cylindrical portion 40 of the upper insulator 16 with respect to the first and second engaging grooves 32 and 34 provided in the engaging cylindrical portion 30 of the dust cover 14. Since the parts 44 and 46 are fitted and locked in the axial direction, the dust cover 14 and the upper insulator 16 can be firmly assembled without bonding.

  In addition, in the present embodiment, the first and second engagement grooves 32 and 34 and the first and second locking projections 44 and 46 are provided so as to be vertically separated in the axial direction. Therefore, the pulling-out drag force due to the engagement of the first and second engagement grooves 32 and 34 and the first and second engagement protrusions 44 and 46 between the dust cover 14 and the upper insulator 16 is exerted more greatly. The dust cover 14 can be more effectively prevented from coming off from the upper insulator 16.

  Further, in the present embodiment, a plurality of contact portions 36 that divide the first and second engagement grooves 32 and 34 are provided, and the first and second locking projections 44 and 46 are arranged in the circumferential direction. A plurality of dividing grooves 48 to be divided are formed, and the contact portion 36 is fitted into the dividing groove 48 and locked in the circumferential direction. As a result, the moving ends of the first and second locking projections 44 and 46 in the first and second engagement grooves 32 and 34 are brought into contact with each other by the contact between the contact portion 36 and the dividing groove 48 in the circumferential direction. Anti-rotation means is defined that limits the relative rotation of the dust cover 14 with respect to the upper insulator 16. Therefore, the relative direction in the circumferential direction of the dust cover 14 with respect to the upper insulator 16 can be easily set, and the dust cover 14 and the upper insulator 16 can be held in the set direction.

  Incidentally, in the dust cover assembly 10, the dust cover 14 is formed by blow molding, and the assembly of the dust cover 14 and the upper insulator 16 is realized at the time of blow molding of the dust cover 14. Hereinafter, an example of a method for manufacturing the dust cover assembly 10 will be described.

  First, as shown in FIG. 4, a pair of left and right blow molding dies 50, 50 are prepared, a molding jig 52 is prepared, and the vulcanized upper insulator 16 is set in the molding jig 52.

  The blow molding die 50 includes a half molding surface 54 having a shape corresponding to the outer peripheral surface of the dust cover 14. When the pair of blow molding dies 50, 50 are combined face to face, these blow molding dies 50 are arranged. , 50, and an inner surface of the cavity 56 is formed as a cavity forming surface 58 constituted by the half-molded surfaces 54, 54.

  The forming jig 52 includes an inner peripheral restraining portion 60 having a substantially cylindrical shape. The inner peripheral restraining portion 60 is formed with an outer diameter substantially corresponding to the inner diameter of the upper insulator 16, and the upper insulator 16 is extrapolated upside down. Further, a blow pipe 62 projecting upward is provided at substantially the center in the radial direction of the inner peripheral restraining portion 60, and the blow pipe 62 is connected to an external air pipe (not shown) so that the blow pipe 62 Compressed air is sent out.

  In addition, a flange-shaped outer periphery mounting portion 64 that protrudes to the outer peripheral side is integrally formed at the lower end portion of the inner peripheral restraint portion 60. The outer periphery mounting portion 64 has a shape in which the upper surface of the inner peripheral portion thereof substantially corresponds to the upper surface of the upper insulator 16. Can be placed upside down.

  Then, as shown in FIG. 4, a pair of blow molds 50 in which the parison 68 formed by heating and softening the forming material of the dust cover 14 and formed into a cylindrical shape by extruding from the die 66 and the like are arranged apart from each other. , 50. Further, the lower end portion of the parison 68 is expanded by means such as mold forming so as to have a larger diameter than the cylindrical portion 40 of the upper insulator 16, and the lower end portion of the expanded parison 68 is the upper insulator 16. It is extrapolated to the cylindrical part 40.

  Next, as shown in FIG. 5, the blow molds 50, 50 are closed, and a cavity 56 is formed between the blow molds 50, 50 and the molding jig 52.

  Therefore, the inner peripheral restraint portion 60 of the forming jig 52 is sandwiched between the lower end portions of the blow molds 50 and 50 at the upper end portion where the tubular portion 40 is extrapolated. Thereby, the lower end portion of the parison 68 disposed on the outer peripheral surface of the tubular portion 40 is pressed against the outer peripheral surface of the tubular portion 40 by the blow molding dies 50, 50, so that the outer peripheral surface of the tubular portion 40 is pressed. Shaped along the shape. As a result, the engagement cylinder portion 30 is formed by the lower end portion of the parison 68, and the first and second engagement grooves 32 and 34 that open to the inner peripheral side of the engagement cylinder portion 30 are formed. In this manner, the parison 68 is fitted to the tubular portion 40 of the upper insulator 16 by closing the blow molds 50 and 50.

  In the present embodiment, the inner peripheral surface of the cylindrical portion 40 is spaced apart from the outer peripheral surface of the inner peripheral restraining portion 60 of the forming jig 52 to the outer peripheral side with a gap. Elastic deformation to the circumferential side is allowed in a state where the deformation amount is limited by the inner circumferential restraint portion 60. As a result, when the blow molding dies 50 and 50 are closed, the engagement cylinder 30 is formed in a reduced diameter state in which the cylinder 40 is elastically deformed to the inner peripheral side. The tubular portion 40 is brought into close contact with the engaging tubular portion 30 by being elastically biased toward the engaging tubular portion 30. As shown in FIG. 5, in order to cause sufficient elastic deformation of the cylindrical portion 40 toward the inner peripheral side, a gap between the overlapping surfaces of the cylindrical portion 40 and the inner peripheral restraining portion 60 is defined as a blow mold 50. , 50 is formed so as to enter below the lower end of 50.

  Next, in a state where the blow molds 50 and 50 and the forming jig 52 are closed, compressed air is sent from the blow pipe 62 to the inner peripheral side of the parison 68, so that the parison 68 is bulged and deformed to the outer peripheral side by air pressure. And pressed against the cavity forming surface 58. Thereby, as shown in FIG. 6, the parison 68 is formed into a thin cylindrical shape having an outer surface shape corresponding to the cavity forming surface 58, and is a blow molded product 70 including the bellows cylindrical portion 18 and the fitting cylindrical portion 26. Is formed.

  In addition, since unnecessary portions are formed at both ends in the axial direction of the blow molded product 70, the blow molded product 70 is cut by the two-dot chain line in FIG. 6 after being removed from the blow molding dies 50, 50, The dust cover assembly 10 is formed by removing unnecessary portions at both ends in the axial direction.

  As described above, when the dust cover 14 is molded, the engaging cylinder portion 30 of the dust cover 14 is inserted into the upper insulator 16 and the first and second engaging grooves 32 and 34 are engaged with the first and second engaging grooves 32 and 34. The protrusions 44 and 46 are inserted, and the dust cover 14 is formed in a state assembled to the upper insulator 16. According to such a manufacturing method, the process of assembling the dust cover 14 to the upper insulator 16 can be omitted, and the dust cover assembly 10 can be obtained more easily.

  The dust cover assembly 10 formed in this manner is attached to a suspension mechanism 12 of an automobile as shown in FIG. The suspension mechanism 12 includes a piston rod 74 and a cylinder 76 that constitute a shock absorber 72, and an upper support 78 is attached to the upper end portion of the piston rod 74. The upper support 78 has a structure in which an inner member 80 and an outer member 82 are elastically connected by a main rubber elastic body 84. The inner member 80 is fixed to the upper end portion of the piston rod 74, and the outer member 82 projects. The plurality of planting bolts 86 are attached to the vehicle body side (not shown). Further, a bound stopper 88 is fitted on the piston rod 74. The bound stopper 88 is a cylindrical elastic body made of foamed urethane or the like, and has an upper end fitted into a cylindrical fitting 90 fixed to the outer member 82 of the upper support 78 and a lower end. Protrudes downward from the cylindrical fitting 90. Furthermore, a coil spring 92 is extrapolated to the shock absorber 72, an upper end is supported by the outer member 82 of the upper support 78, and a lower end is fixed to the cylinder 76 and a lower spring seat (not shown). It is supported by.

  A cylinder cap 94 is attached to the upper end portion of the cylinder 76. The cylinder cap 94 has a substantially bottomed cylindrical shape in the opposite direction, and is placed on the upper end portion of the cylinder 76, and a locking claw 96 protruding to the outer peripheral side is integrally formed at the lower end portion.

  The dust cover assembly 10 is disposed so that the dust cover 14 is externally inserted into the shock absorber 72 of the suspension mechanism 12 and covers the protruding portion of the piston rod 74 from the cylinder 76 in the shock absorber 72.

  Further, the upper insulator 16 is attached to the outer member 82 of the upper support 78 attached to the upper end portion of the piston rod 74 so that the upper side of the dust cover 14 above the bellows cylinder portion 18 is moved by the piston rod 74. Supported. On the other hand, the latching claw 96 of the cylinder cap 94 is inserted into the circumferential groove 28 provided in the fitting cylinder part 26 of the dust cover 14 and is locked in the axial direction, whereby the bellows cylinder part in the dust cover 14. A lower side than 18 is attached to the cylinder 76.

  Furthermore, in this embodiment, the outer member 82 of the upper support 78 also serves as an upper spring seat, and the spring receiving portion 38 of the upper insulator 16 is superimposed on the outer member 82 from below, so that the upper end portion of the coil spring 92 is Is supported by the outer member 82 via the spring receiving portion 38. Further, the spring receiving portion 38 is pressed against the outer member 82 by the elasticity of the coil spring 92, and the upper insulator 16 is attached to the outer member 82.

  Further, a cylindrical metal fitting 90 that supports the bound stopper 88 is inserted and arranged in an inserted state with respect to the cylindrical portion 40 of the upper insulator 16, and the first and second locking projections 44, 46 of the cylindrical portion 40. Protrudes toward the cylindrical fitting 90, and the fitting portion between the tubular portion 40 and the engaging tubular portion 30 is located on the outer peripheral side of the cylindrical fitting 90. Thereby, the deformation amount to the inner peripheral side of the cylindrical part 40 and the engaging cylinder part 30 is limited by the cylindrical metal fitting 90, and the cylindrical part 40 and the engaging cylinder part 30 are stably held in the fitted state. Is done. In the present embodiment, the cylindrical metal fitting 90 is arranged on the inner peripheral side away from the cylindrical portion 40, but the cylindrical metal fitting 90 and the cylindrical portion 40 are overlapped in a contact state. Also good.

  When the dust cover assembly 10 is mounted on the suspension mechanism 12, the dust cover 14 is supported by the piston rod 74 at the upper end and supported by the cylinder 76 at the lower end. The dust cover 14 always extends below the protruding portion of the piston rod 74 from the cylinder 76. Therefore, it is possible to effectively prevent dust and the like from entering from the lower end opening of the dust cover 14 and adhering to the protruding portion of the piston rod 74. In addition, the opening at the lower end of the dust cover 14 has a substantial opening area reduced by the locking claws 96 of the cylinder cap 94, so that the entry of foreign matter is more effectively prevented.

  Furthermore, the dust cover 14 whose upper and lower ends are supported by the shock absorber 72 is made of resin, and sufficient durability against the tensile force is ensured. Moreover, even if the length of the bellows cylinder portion 18 is sufficiently thin by blow molding, even if the length of the bellows cylinder portion 18 is long enough to prevent the entry of foreign matter from the lower end opening, the shock absorber 72 Since it is possible to follow the expansion and contraction to a high degree, it is possible to avoid the bellows tube portion 18 from being damaged by the compressive force in the axial direction. In addition, since the dust cover 14 is elastically supported by the rubber upper insulator 16, the force acting on the dust cover 14 due to the elastic deformation of the upper insulator 16 is reduced, and the durability of the dust cover 14 is improved. Figured.

  In addition, since the fitting portion between the dust cover 14 and the upper insulator 16 is located on the outer peripheral side of the cylindrical metal fitting 90 that supports the bound stopper 88, the shock absorber 72 contracts greatly due to a shocking large input. In addition, the fitting portion between the dust cover 14 and the upper insulator 16 is protected by a cylindrical metal fitting 90. Therefore, the force acting on the fitting portion between the dust cover 14 and the upper insulator 16 is reduced, and the dust cover 14 can be prevented from falling off the upper insulator 16.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited by the specific description. For example, in the above-described embodiment, the engagement groove is configured by the first engagement groove 32 and the second engagement groove 34 that are spaced apart in the vertical direction in the engagement cylinder portion 30 of the dust cover 14, and the upper and lower rows. However, only one row of the engaging grooves may be provided, or three or more rows that are separated from each other in the vertical direction may be provided. Similarly, the locking protrusions provided on the upper insulator do not necessarily need to be constituted by the first locking protrusions 44 and the second locking protrusions 46, but are arranged in one row or three rows spaced apart from each other in the vertical direction. The above locking protrusions may be provided.

  Furthermore, the engagement groove does not necessarily have to be divided in the circumferential direction by the contact portion 36, and may be, for example, an annular concave groove that is continuous over the entire circumference. Similarly, the locking protrusion does not necessarily have to be divided in the circumferential direction by the dividing groove 48, and may be, for example, an annular protrusion that extends over the entire circumference.

  Moreover, although the upper insulator 16 of the said embodiment is formed with the rubber elastic body single-piece | unit, the cylindrical part 40 is embedded by burying the cylindrical restraint member formed with the hard material in the cylindrical part 40, for example. It is also possible to limit the amount of deformation. According to this, the fixing force of the dust cover 14 and the upper insulator 16 can be increased, and the dust cover 14 is blow-molded without restraining the outer peripheral surface of the tubular portion 40 with the blow-molding dies 50, 50. You can also.

10: Dust cover assembly, 12: Suspension mechanism, 14: Dust cover, 16: Upper insulator, 18: Bellows cylinder part, 20: Mountain part, 22: Otani part (valley part), 24: Otani part (valley part) 30: engagement cylinder part, 32: first engagement groove, 34: second engagement groove, 36: contact part, 40: cylindrical part, 44: first locking projection, 46: second engagement Stop projection, 48: Split groove, 50: Blow mold, 68: Parison, 72: Shock absorber, 74: Piston rod, 76: Cylinder, 90: Cylindrical metal fitting, 92: Coil spring

Claims (5)

The resin dust cover that is externally attached to the shock absorber of the suspension mechanism has a bellows cylinder portion in which a peak portion and a valley portion are continuously provided, and the piston rod and the cylinder of the shock absorber are arranged on both upper and lower sides of the bellows cylinder portion. In the dust cover assembly, a rubber upper insulator that supports the upper end of the coil spring in the suspension mechanism is attached to the upper end of the dust cover. ,
While the upper insulator is formed with a cylindrical portion, a locking projection that protrudes from the cylindrical portion to the outer peripheral side and extends in the circumferential direction is formed,
The bellows tube portion of the dust cover is formed by blow molding, and a parison disposed on the outer peripheral surface of the tube portion of the upper insulator is formed above the bellows tube portion with a blow mold. A dust cover characterized in that an engagement cylinder portion formed by pressing against the outer peripheral surface of the shape portion is provided, and the engagement cylinder portion is axially locked to the engagement protrusion. Assembly.   2. The dust cover assembly according to claim 1, wherein the cylindrical portion of the upper insulator is formed with a plurality of rows of the locking protrusions separated vertically in the axial direction.   A split groove that divides the locking protrusion in the circumferential direction is formed on at least a part of the circumference of the locking protrusion, and the engaging cylinder portion enters the dividing groove to lock in the circumferential direction. 3. The dust cover assembly according to claim 1, wherein the dust cover assembly includes a detent means for restricting relative rotation of the dust cover and the upper insulator in the circumferential direction.   The projecting dimension (t) of the locking protrusion is t ≧ T / 4 with respect to the thickness dimension (T) of the cylindrical part including the locking protrusion. The dust cover assembly according to any one of claims.   The dust cover assembly according to any one of claims 1 to 4, wherein a cylindrical fitting attached to the shock absorber is inserted and disposed in the cylindrical portion of the upper insulator.

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