JP2014185657A - Dust cover assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dust cover assembly of a new structure capable of improving durability by preventing damage of the dust cover with the light-weight and compact structure.SOLUTION: An engagement cylindrical portion 28 is disposed on an axial upper part of a bellows cylindrical portion 18 of a resin dust cover 14, an engagement groove 32 extended in the circumferential direction, is formed in a state of being opened on an outer peripheral face of the engagement cylindrical portion 28, and a plurality of insertion grooves 40 extended upward from the engagement groove 32 are formed. An upper insulator 16 is provided with a locking projection 68 made of a material harder than the upper insulator 16, and projecting to an inner peripheral side, the engagement cylindrical portion 28 of the dust cover 14 is inserted to the upper insulator 16, and the locking projection 68 inserted to the engagement groove 32 through the insertion grooves 40, is axially locked in the engagement groove 32 by relative rotation of the dust cover 14 to the upper insulator 16, thus an upper end portion of the dust cover 14 is assembled and supported in the upper insulator 16.

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, in an automobile suspension mechanism, a dust cover that is externally attached so as to cover a piston rod of a shock absorber is known, and an upper insulator that supports a coil spring of the suspension mechanism at an upper end is known. For example, Japanese Patent Laid-Open No. 2003-72338 (Patent Document 1) proposes a dust cover assembly in which a dust cover and an upper insulator are integrally formed of a rubber elastic body.

  Incidentally, in addition to the structure in which only the upper end portion shown in Patent Document 1 is attached to the piston rod, the dust cover is attached to the piston rod at the upper end portion and the lower end portion to prevent foreign matter from entering from below. A structure attached to the cylinder may also be adopted. In this case, since a tensile load in the axial direction can be input to the dust cover, the dust cover formed of a rubber elastic body may have insufficient durability. Therefore, adoption of a dust cover made of synthetic resin disclosed in Japanese Patent Application Laid-Open No. 2007-32732 (Patent Document 2) and the like is also under consideration. Since such a synthetic resin dust cover is separated from the rubber upper insulator, the upper end portion of the dust cover is fixed to an upper support metal fitting, a bump stopper holding metal fitting, or the like.

  However, when trying to fix the dust cover to these metal fittings, if the metal fittings are arranged above the upper insulator, it is necessary to extend to the lower side of the upper insulator. The increase of the problem becomes a problem. Furthermore, if the shock absorber is greatly contracted in the axial direction due to the input of a large load, the dust cover may be sandwiched between the metal fitting and the cylinder and damaged.

JP 2003-72338 A JP 2007-32732 A

  The present invention has been made in the background of the above-mentioned circumstances, and its solution is a light-weight and compact structure that can prevent the dust cover from being damaged and can improve durability. An object of the present invention is to provide a dust cover assembly.

  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.

  That is, the first aspect of the present invention provides a cylindrical dust cover that is supported on both ends of each of the piston rod and cylinder of the shock absorber constituting the suspension mechanism and is externally inserted into the piston rod, and the suspension mechanism. A dust cover assembly comprising a rubber upper insulator that supports one end of a coil spring constituting the bellows tube portion in which the dust cover is made of a resin and a peak portion and a valley portion are continuously provided in the axial direction. And an engaging cylinder portion is provided in the dust cover above the bellows cylinder portion in the axial direction, and the engaging cylinder portion is open to the outer peripheral surface and extends in the circumferential direction. A groove is formed, and a plurality of insertion grooves extending upward from the engagement groove are partially formed on the circumference, while the upper insulator projects to the inner circumference side. A plurality of locking projections made of a harder material than the upper insulator, and the engaging cylinder portion of the dust cover is inserted into the upper insulator so that the insertion of the engaging cylinder portion is performed. The upper end of the dust cover is secured by the locking projection inserted into the engaging groove through the groove being axially locked to the engaging groove by the relative rotation of the dust cover with respect to the upper insulator. The part is assembled and supported by the upper insulator.

  According to the dust cover assembly having the structure according to the first aspect, the upper end of the dust cover is inserted into the upper insulator, and then the dust cover is rotated relative to the upper insulator in the circumferential direction. The locking protrusions protruding from the upper insulator are inserted into the engaging grooves formed in the dust cover and locked in the axial direction. As a result, the dust cover assembly can be formed by simply assembling the resin dust cover and the rubber upper insulator, which are separately formed, without adhesion.

  Furthermore, since the locking projection is made of a harder material than the upper insulator, it is prevented from coming off from the engagement groove due to deformation of the locking projection itself, and the assembled state of the dust cover and the upper insulator is stable. Maintained.

  In addition, since the dust cover is not attached to a metal fitting such as an upper support but is attached by being inserted into the upper insulator, an increase in size in the axial direction, an increase in weight, and the like are avoided.

  Furthermore, the upper end of the dust cover is elastically supported by the rubber upper insulator, so that it is possible to avoid an excessive force acting on the dust cover due to the deformation of the upper insulator when the shock absorber is greatly contracted by the input. Therefore, the durability is improved. In addition, abnormal noise caused by expansion / contraction deformation of the dust cover or contact of the dust cover such as stone is reduced by the vibration isolation effect of the upper insulator.

  According to a second aspect of the present invention, in the dust cover assembly described in the first aspect, an inner peripheral portion of the upper insulator is formed of a harder material than the upper insulator and is disposed on the entire circumference in the circumferential direction. An annular restraining portion that extends over is provided integrally, and the locking projections are formed at a plurality of locations on the circumference of the annular restraining portion.

  According to the second aspect, since the inner peripheral portion of the upper insulator is reinforced over the entire circumference by the annular restraining portion, the dust cover is prevented from falling off due to the deformation of the inner peripheral portion of the upper insulator. As a result, the assembled state of the upper insulator can be more advantageously maintained. Moreover, by forming the locking projection on the circumference of the annular restraining portion, the locking projection can be easily provided at a predetermined position on the circumference of the inner peripheral portion of the upper insulator. Note that the annular restraining portion is integrally provided with respect to the inner peripheral portion of the upper insulator, in addition to being integrally formed by two-color molding or the like, the upper insulator and the annular restraining portion are formed separately, and they are The case where it integrates by insert molding or post-adhesion is also included.

  According to a third aspect of the present invention, in the dust cover assembly according to the first or second aspect, the engagement protrusion is brought into contact with the engagement groove, so that the engagement protrusion A contact portion for defining a moving end of the locking projection in the engagement groove in the relative rotation direction of the dust cover with respect to the upper insulator when locked to the engagement groove is provided. is there.

  According to the third aspect, since the moving end of the locking protrusion in the engagement groove is defined by the contact with the contact portion, when the dust cover is assembled by rotating relative to the upper insulator. Further, the locking protrusion is positioned in the engagement groove without passing through the engagement groove. Therefore, the assembly state of the dust cover and the upper insulator by the locking protrusions and the locking grooves in the axial direction can be easily realized.

  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 upper insulator for locking the locking protrusion to the engagement groove is provided. In the relative rotation of the dust cover, an overhanging protrusion is provided in the engagement groove that can be overcome while the engaging protrusion receives resistance.

  According to the fourth aspect, after the dust cover and the upper insulator are assembled, the movement of the locking projection in the engagement groove is limited by the resistance force when the overpass projection is overcome. Relative rotation in the opposite direction to that when assembling the dust cover with respect to is restricted, and the dust cover can be prevented from falling off the upper insulator.

  In addition, it is possible to grasp by hand that the locking projection has been inserted to a predetermined position in the engagement groove due to the resistance force received by the locking projection when getting over the overpass projection. It is possible to prevent the dust cover from being assembled incorrectly.

  According to a fifth aspect of the present invention, in the dust cover assembly according to any one of the first to fourth aspects, the engagement groove is formed in a plurality of divided states on the periphery of the dust cover. The insertion grooves are formed in the vicinity of one end in the circumferential direction of each of the divided engagement grooves, and the locking protrusions in the upper insulator are positioned at circumferential positions corresponding to the insertion grooves. A plurality are provided.

  According to the fifth aspect, since the locking protrusions are dispersed on the circumference with respect to the engagement groove and are axially locked at a plurality of locations, the dust cover and the upper insulator are assembled in a balanced manner on the circumference. be able to.

  According to the present invention, the engaging projection of the upper insulator is engaged with the dust cover by inserting the engaging cylinder portion of the dust cover into the upper insulator and rotating the dust cover relative to the upper insulator. It is inserted into the groove and locked in the axial direction. As a result, the resin dust cover can be easily assembled to the rubber upper insulator, and the upper end of the dust cover is assembled to the upper insulator in an inserted state. Is also avoided.

  In addition, since the dust cover is attached to the rubber upper insulator, the axial compressive force acting on the dust cover when the shock absorber contracts significantly is mitigated by the elastic deformation of the upper insulator, improving durability. Figured. In addition, abnormal noise or the like generated when the dust cover expands or contracts or a stone or the like abuts is absorbed or reduced by the buffer action of the upper insulator.

The longitudinal cross-sectional view which shows the dust cover assembly as one aspect | mode of this invention in the mounting state to a suspension mechanism. The perspective view which shows the dust cover assembly of FIG. FIG. 3 is a longitudinal sectional view of the dust cover assembly shown in FIG. 2. FIG. 3 is a plan view of the dust cover assembly shown in FIG. 2. The perspective view of the dust cover which comprises the dust cover assembly shown by FIG. The top view of the dust cover shown by FIG. VII-VII sectional drawing of FIG. VIII-VIII sectional drawing of FIG. The top view of the upper insulator which comprises the dust cover assembly shown by FIG. XX sectional drawing of FIG. The longitudinal cross-sectional view which expands and shows the principal part of the upper insulator shown by FIG. The longitudinal cross-sectional view which expands and shows another principal part of the upper insulator shown by FIG. FIG. 15 is a longitudinal sectional view showing a disassembled state before assembly of the dust cover shown in FIG. 7 and the upper insulator shown in FIG. 10, and is a sectional view taken along line XIII-XIII in FIG. 14. The top view of the decomposition | disassembly state shown by FIG.

  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 mounted on a suspension mechanism 12 of an automobile. As shown in FIGS. 2 to 4, the dust cover assembly 10 includes a dust cover 14 and an upper insulator 16. In the following description, the vertical direction refers to the vertical direction in FIG.

  More specifically, the dust cover 14 has a thin cylindrical shape as a whole, and is formed of a 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. Moreover, as a molding method of the dust cover 14, blow molding is preferably employed, but injection molding can also be employed.

  In addition, the dust cover 14 includes a bellows cylinder portion 18 at an intermediate portion in the axial direction. The bellows tube portion 18 has a crest 20 that is continuous on the entire circumference with a substantially roll-over V-shaped cross section that is convex on the outer peripheral side, and a trough portions 22, 24 that are continuous on the entire circumference with a substantially roll-over V-shaped cross section that is concave on the outer peripheral side. In this structure, a plurality of parts are provided alternately in the axial direction. Moreover, the Otani part 22 and the Nakatani part 24 whose depth dimension is smaller than the Otani part 22 are formed in each one side on both sides of the peak part 20, and the inner peripheral end and Nakatani part 24 of these Otani parts 22 are formed. The inner peripheral end of the is displaced in the radial direction.

  Furthermore, a small valley portion 26 that opens to the outer peripheral side is formed at the outer peripheral end portion of the peak portion 20. The small valley portion 26 has a substantially roll-over V-shaped cross section that is concave on the outer peripheral side, and is continuous over the entire circumference.

  And the bellows cylinder part 18 can be expanded and contracted in the axial direction by changing the angle of the outer peripheral end of the peak part 20 and the angle of the inner peripheral end of the valley parts 22 and 24, respectively. Furthermore, in this embodiment, the small valley part 26 is formed in the outer peripheral part of the peak part 20, and the range of the length which can be expanded-contracted in an axial direction is ensured more largely. In addition, since the large valley portion 22, the middle valley portion 24, and the small valley portion 26 are formed at different depths, and the inner peripheral ends thereof are shifted from each other in the radial direction, the valley portions 22, 24, 26 are formed. The inner peripheral ends of the accordion cylinders are prevented from overlapping in the axial direction, and the axial dimension of the bellows cylinder portion 18 in the most contracted state is reduced.

  Further, an engaging cylinder portion 28 is provided in the dust cover 14 above the bellows cylinder portion 18 in the axial direction. The engaging cylinder portion 28 has a substantially cylindrical shape as a whole, and a flange portion 30 that protrudes to the outer peripheral side is integrally formed at the lower end portion, and is connected to the upper end of the bellows cylinder portion 18.

  Further, an engagement groove 32 is formed in the engagement cylinder portion 28. The engagement grooves 32 are concave grooves that open to the outer peripheral surface and extend in the circumferential direction by a predetermined length, and are divided into three separate engagement grooves in the divided state at three locations on the circumference of the engagement cylinder portion 28. Is provided. In the present embodiment, the three engagement grooves 32, 32, 32 are formed in substantially the same shape and the same size, and are provided at substantially equal intervals in the circumferential direction on the circumference of the engagement cylinder portion 28. . The engaging groove 32 includes an upper wall portion 34 whose upper wall portion projects in the axial direction at the upper end portion of the engaging cylinder portion 28, and the lower wall portion in the axial direction is a flange portion. 30.

  Furthermore, a contact portion 36 is formed at one end in the circumferential direction of the engagement groove 32. The abutting portion 36 projects to the outer peripheral side with substantially the same dimensions as the upper wall portion 34, extends in the axial direction and is connected to the upper wall portion 34 and the flange portion 30 at both axial ends. As a result, the engagement groove 32 has a bag path shape in which one end portion in the circumferential direction is surrounded by the upper wall portion 34, the flange portion 30, and the contact portion 36.

  Further, an overpass projection 38 is formed in the engagement groove 32. The overpass projection 38 protrudes from the bottom wall portion of the engagement groove 32 to the outer peripheral side in the vicinity of the other circumferential end portion of the engagement groove 32, and moves up and down between the upper wall portion 34 and the flange portion 30. It extends. Further, as shown in FIG. 8, the overpass projection 38 has a projecting dimension to the outer peripheral side smaller than the contact portion 36, and the engagement groove 32 is partially formed at the formation portion of the overpass projection 38. In addition to the shallow bottom, the other end in the circumferential direction of the engagement groove 32 is open in the circumferential direction without being blocked by the overpass projection 38. In FIG. 8, a virtual circle indicating the position of the protruding tip of the contact portion 36 is indicated by a two-dot chain line.

  Further, the other end opening in the circumferential direction of each engagement groove 32 is communicated with the insertion groove 40. The insertion groove 40 is opened on the outer peripheral surface of the engaging cylinder portion 28 and extends upward from the other circumferential end of the engaging groove 32. Furthermore, the insertion groove 40 is formed between the circumferentially adjacent engagement grooves 32 and 32 on the circumference of the engagement cylinder portion 28, and each insertion groove 40 is an engagement cylinder portion. It is partially formed on the circumference of 28.

  Further, a fitting cylinder part 42 is formed below the bellows cylinder part 18. The fitting cylinder portion 42 has a substantially cylindrical shape, and a circumferential groove 44 that opens to the inner circumferential surface is formed at an intermediate portion in the axial direction. Furthermore, the lower end part of the fitting cylinder part 42 is made into the taper cylinder part 46 which becomes a large diameter gradually below.

  Furthermore, a plurality of bent portions 48 are formed on the circumference of the fitting cylinder portion 42. The bent portion 48 has a mountain-shaped cross section that protrudes toward the outer peripheral side and opens toward the inner peripheral side, extends substantially linearly in the axial direction, and has four main deformation portions 50, 50, 50 provided substantially evenly on the periphery. , 50 and four sub-deformation parts 52, 52, 52, 52 provided substantially evenly on the circumference between the circumferential directions of the main deformation parts 50. In addition, the main deformation portion 50 has a projecting dimension toward the outer peripheral side larger than that of the sub deformation portion 52, and an angle of the projecting tip portion is smaller than that of the sub deformation portion 52.

  On the other hand, as shown in FIGS. 9 and 10, the upper insulator 16 is an annular rubber elastic body, and has a cylindrical shape that protrudes downward from the inner peripheral end portion of the spring receiving portion 54 having a substantially annular plate shape. The part 56 is integrally formed. Further, the cylindrical portion 56 includes an inner flange-like fitting portion 58 at the lower end portion, and a cylindrical seal lip 60 protruding upward is integrally formed at the inner peripheral end portion of the fitting portion 58. Has been. Furthermore, the fitting portion 58 is formed with three drain holes 62, 62, 62 penetrating vertically, and each drain hole 62 is integrally formed with the seal lip 60 around the drain hole 62. Surrounded by a wall 64.

  Furthermore, as shown in FIGS. 11 and 12, an annular restraining portion 66 is provided on the fitting portion 58 of the upper insulator 16. The annular restraint portion 66 is formed of a material harder than a portion including the fitting portion 58 integrally formed of a rubber elastic body. In the present embodiment, the annular restraint portion 66 is formed of metal, hard synthetic resin, hard rubber, or the like. It is comprised by the made ring-shaped member. In addition, locking protrusions 68 that protrude inward in the radial direction are partially formed integrally at three locations on the circumference of the annular restraining portion 66. Each locking projection 68 has a thickness dimension that can be inserted into the engagement groove 32, and an axial view shape and a circumferential dimension that can be inserted into the insertion groove 40. Above, it is arrange | positioned in the circumferential direction position corresponding to the insertion groove 40 of the cylinder part 28 for engagement. And the annular restraint part 66 is being fixed to the lower end part of the inner peripheral end of the fitting part 58 over the perimeter, and the latching protrusion 68 protrudes to the inner peripheral side from the fitting part 58 ( (See FIGS. 9 and 10). The annular restraining portion 66 is formed separately from the fitting portion 58 and may be provided integrally by being inserted at the time of molding or by being fixed later, for example, by two-color molding or the like. It may be formed integrally in advance.

  The dust cover 14 is attached to the upper insulator 16 having such a structure. That is, as shown in FIGS. 13 and 14, the engagement of the dust cover 14 with the upper insulator 16 in a state where the locking protrusion 68 of the upper insulator 16 is positioned in the circumferential direction with respect to the insertion groove 40 of the dust cover 14. The fitting tube portion 28 is inserted, and the locking projection 68 is inserted into the insertion groove 40 in the axial direction. Thereafter, the dust cover 14 is rotated relative to the upper insulator 16 in the circumferential direction, and the locking projection 68 is inserted into the engagement groove 32 from the insertion groove 40, whereby the locking projection 68 is engaged with the engagement groove. 32 is locked in the axial direction. 3 and 4, the upper end portion of the dust cover 14 is assembled and supported on the inner peripheral side of the upper insulator 16, and thus the dust cover assembly 10 of the present embodiment is configured. ing.

  In this way, the engaging cylinder portion 28 that is the upper end portion of the dust cover 14 is inserted into the fitting portion 58 of the upper insulator 16, and the dust cover 14 is rotated relative to the upper insulator 16, whereby Since the portion 68 is inserted into the engagement groove 32 and locked in the axial direction, the resin dust cover 14 can be easily assembled to the rubber upper insulator 16.

  In addition, since the locking protrusion 68 provided on the upper insulator 16 is hard, the locking protrusion 68 itself is prevented from coming off from the engaging groove 32 due to deformation, and the upper insulator 16 of the dust cover 14 is prevented. The assembled state with respect to is stably maintained.

  In addition, since the engagement grooves 32 are formed in a plurality of divided states and distributed on the circumference of the engagement cylinder portion 28 of the dust cover 14, the dust cover 14 and the upper insulator 16 are provided over the entire circumference. Is well-balanced. In particular, the engagement grooves 32 are provided in a distributed manner over an area of a half or more on the circumference, so that the dust cover 14 is prevented from being inclined with respect to the upper insulator 16 and a stable support state is realized. Further, in the present embodiment, since the plurality of engaging grooves 32 having substantially the same shape are arranged substantially uniformly on the circumference, the dust cover 14 and the upper insulator 16 are more balanced on the entire circumference. While being assembled well, the orientation at the time of assembling the dust cover 14 and the upper insulator 16 is not specified, and the assembling work is easy.

  Furthermore, in the present embodiment, the engagement protrusions 68 abut on the contact portions 36 in the circumferential direction, so that the engagement grooves 32 of the engagement protrusions 68 in the relative rotation direction of the dust cover 14 with respect to the upper insulator 16. The moving end in the inside is defined. As a result, the locking projection 68 is easily positioned between the upper wall portion 34 and the flange portion 30, and the locking projection 68 and the upper wall portion 34 and the flange portion 30 are locked in the axial direction. The dust cover 14 and the upper insulator 16 are assembled.

  Furthermore, when the dust cover 14 is rotated relative to the upper insulator 16, the locking projection 68 passes over the riding projection 38 in the circumferential direction while receiving resistance and is inserted into the engagement groove 32. It is supposed to be. Therefore, it is possible to grasp with ease the fact that the locking projection 68 has been inserted between the contact portion 36 and the overpass projection 38 due to the resistance force when getting over the overpass projection 38, and assured assembly. Work is realized.

  The dust cover assembly 10 having such a structure is attached to a suspension mechanism 12 of an automobile, for example, as shown in FIG. That is, the bellows tube portion 18 of the dust cover 14 is extrapolated so as to surround the piston rod 72 of the shock absorber 70 constituting the suspension mechanism 12, and the upper insulator 16 is attached to the piston rod 72 and the spring seat bracket (not shown). Is superimposed. Further, the upper end portion of the coil spring 74 constituting the suspension mechanism 12 is pressed against the spring receiving portion 54 of the upper insulator 16 from below, and the upper end portion of the coil spring 74 is supported by the upper insulator 16. The upper insulator 16 is pressed against the spring seat fitting by the elasticity of the coil spring 74. Note that the lower end portion of the coil spring 74 is supported by a spring bracket 78 fixed to the cylinder 76 of the shock absorber 70.

  Further, the locking claw 82 provided on the cylinder cap 80 attached to the upper end portion of the cylinder 76 opens the fitting cylinder portion 42 with respect to the circumferential groove 44 formed in the fitting cylinder portion 42 of the dust cover 14. It is inserted from the part. Thereby, the dust cover 14 is attached to the piston rod 72 through the upper insulator 16 at the upper end portion and attached to the cylinder 76 at the lower end portion.

  When the shock absorber 70 contracts greatly in such a state of being mounted on the suspension mechanism 12, the axial compression force may be further applied from the state in which the dust cover 14 contracts vertically. In this case, since the upper end portion of the dust cover 14 is attached to the upper insulator 16 formed of a rubber elastic body, the compressive force acting on the dust cover 14 is reduced by the elastic deformation of the upper insulator 16 upward. Thus, the durability of the dust cover 14 is improved.

  Moreover, since the hard annular restraint portion 66 is provided over the entire circumference of the inner peripheral end portion of the upper insulator 16, the shape of the inner peripheral end portion is maintained even during elastic deformation of the upper insulator 16, The locking of the locking protrusion 68 and the engaging groove 32 in the axial direction is maintained. Therefore, the dust cover 14 is prevented from falling off due to the deformation of the upper insulator 16, and the dust cover 14 and the upper insulator 16 are held in the assembled state.

  Similarly, when an axial tensile force acts on the dust cover 14, the tensile force exerted on the dust cover 14 is reduced by the elastic deformation of the upper insulator 16, and the locking by the elastic deformation of the upper insulator 16 is performed. The protrusion 68 is prevented from coming off from the engaging groove 32, and the dust cover 14 and the upper insulator 16 are held in the assembled state.

  In addition, it can be expected that transmission due to vibration of the upper cover 16 such as vibration accompanying expansion and contraction of the dust cover 14 and impact force due to contact of foreign matters such as stones is reduced or avoided by the vibration isolating action of the upper insulator 16. .

  Further, since the relative rotational force exerted on the dust cover 14 with respect to the upper insulator 16 in the mounted state on the suspension mechanism 12 is smaller than the relative rotational force exerted on the dust cover 14 during assembly, Due to the resistance force, the locking projection 68 is restricted from moving in the engagement groove 32 in the direction opposite to that during assembly. As a result, the dust cover 14 and the upper insulator 16 are held in a mutually assembled state, and the dust cover 14 is prevented from falling off.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited by the specific description. For example, the number of engagement grooves is not particularly limited, the contact portion 36 may be omitted, and one engagement groove may extend over the entire circumference, or may be divided into two or more. May be. When a plurality of engaging grooves are provided, the shapes of the engaging grooves can be different from each other. Further, the circumferential length of the engagement groove is not limited, and an engagement groove having an extremely short circumferential length can be adopted as long as a sufficient locking force in the axial direction can be obtained. Furthermore, a plurality of rows of engaging grooves extending in the circumferential direction are formed at different positions vertically in the axial direction, and locking protrusions are respectively inserted into the plurality of rows of engaging grooves. By locking the engaging groove in the axial direction, the dust cover and the upper insulator can be more firmly assembled.

  Further, the abutting portion 36 does not necessarily have to protrude to the outer peripheral side with the same dimension as the upper wall portion 34, and may protrude to the outer peripheral side with a size larger than that of the upper wall portion 34. Further, when the abutting portion protrudes to the outer peripheral side with a size smaller than that of the upper wall portion 34, for example, the dust cover 14 is formed by forming the abutting portion with a projecting dimension similar to that of the overpass projection 38. The dust cover 14 and the upper insulator 16 can be assembled regardless of the direction of rotation relative to the upper insulator 16.

  Further, the overpass projection 38 provided in the engagement groove 32 is not essential and can be omitted.

  Moreover, in the said embodiment, although the structure where the some latching protrusion 68 was integrally provided in the cyclic | annular restraint part 66 was illustrated, these latching protrusions 68 are fitted by the structure independent from each other. You may provide in the part 58. FIG. Further, the plurality of locking protrusions 68 may have different shapes.

  Further, the specific shape of the upper insulator is not limitedly interpreted. For example, the fitting portion 58 is omitted, and the locking protrusion 68 is provided on the cylindrical portion 56 and protrudes to the inner peripheral side. It is also possible to change the shape and the presence or absence of the seal lip 60.

  The specific shape of the bellows tube portion 18 is not limited to the one having the large valley portion 22, the middle valley portion 24, and the small valley portion 26, and is a general bellows formed by alternately connecting peaks and valleys. It may be a shape. Furthermore, the specific shape of the fitting cylinder part 42 is not limited, for example, the bending part 48 can be abbreviate | omitted.

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: Nakatani part (valley part) 28: engagement cylinder portion, 32: engagement groove, 36: abutment portion, 38: overpass projection, 40: insertion groove, 66: annular restraint portion, 68: locking projection, 70: shock absorber, 72: Piston rod, 74: Coil spring, 76: Cylinder

Claims (5)

A cylindrical dust cover that is supported on both ends of the piston rod and cylinder of the shock absorber that constitutes the suspension mechanism and is externally inserted into the piston rod, and a rubber that supports the upper end of the coil spring that constitutes the suspension mechanism In a dust cover assembly provided with an upper insulator made of
The dust cover is made of resin and has a bellows tube portion in which a peak portion and a valley portion are continuously provided in the axial direction, and an engagement tube portion is axially above the bellows tube portion of the dust cover. The engaging cylinder portion is formed with an engaging groove that opens to the outer peripheral surface and extends in the circumferential direction, and an insertion groove that extends upward from the engaging groove is partially on the periphery. While several are formed
The upper insulator is provided with a plurality of locking projections that are harder than the upper insulator and projecting to the inner peripheral side, and the engaging cylinder portion of the dust cover is inserted into the upper insulator. The locking projection inserted into the engagement groove through the insertion groove of the engagement cylinder portion is locked in the axial direction with respect to the engagement groove by relative rotation of the dust cover with respect to the upper insulator. Thus, the dust cover assembly is characterized in that the upper end portion of the dust cover is assembled and supported by the upper insulator.   An annular restraining portion that is formed of a harder material than the upper insulator and extends over the entire circumference in the circumferential direction is integrally provided on the inner peripheral portion of the upper insulator. The dust cover assembly according to claim 1, wherein the locking projections are formed at a plurality of locations.   When the engaging protrusion comes into contact with the engaging groove, the engaging protrusion protrudes in the direction of relative rotation of the dust cover with respect to the upper insulator when the engaging protrusion is engaged with the engaging groove. The dust cover assembly according to claim 1, wherein a contact portion that defines a moving end of the portion in the engagement groove is provided.   In the relative rotation of the dust cover with respect to the upper insulator for locking the locking protrusion to the engagement groove, the overpass protrusion that can get over while receiving the resistance force is the engagement protrusion. The dust cover assembly of any one of Claims 1-3 provided in the inside.   The engagement groove is formed in a plurality of divided states on the periphery of the dust cover, the insertion groove is formed near one end in the circumferential direction of each of the divided engagement grooves, and the upper The dust cover assembly according to any one of claims 1 to 4, wherein a plurality of the locking protrusions in the insulator are provided with circumferential positions corresponding to the insertion grooves.

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