JP2013204761A - Cylindrical vibration control device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylindrical vibration control device and a method of manufacturing the same, capable of firmly fixing a synthetic resin stopper member to an outer peripheral surface of an inner shaft member, with a simple structure.SOLUTION: A cylindrical vibration control device 10 includes a synthetic resin stopper member 50 projecting toward an outer cylinder member 14 from an inner shaft member 12, while connecting the inner shaft member 12 and the outer cylinder member 14 by a body rubber elastic body 16. A swelling part 64 is arranged on an outer peripheral surface of an axial intermediate part of the inner shaft member 12. Serration grooves 72 are formed for extending in the axial direction in the swelling part 64. One axial end part 76 of the serration groove is formed as an open end for opening toward the axial direction, and the other axial end part 78 is formed as a closed end closed in the axial direction by a wall part. The stopper member 50 is inserted into the serration grooves 72, and is fixed to an outer peripheral surface 74 of the swelling part 64.

Description

  The present invention relates to a cylindrical vibration isolator having a structure in which an inner shaft member and an outer cylinder member, which are spaced apart from each other in the radial direction, are connected by a rubber elastic body of a main body, for example, a suspension bush for automobiles, a subframe mount, The present invention relates to a cylindrical vibration isolator that can be used as a mount or the like and a method for manufacturing the same.

  2. Description of the Related Art Conventionally, a cylindrical vibration isolator is known in which an inner shaft metal member and an outer tube metal member which are spaced apart from each other in a radial direction are connected by a rubber elastic body, and is used, for example, in an automobile suspension mount or body mount. .

  In such a cylindrical vibration isolator, an input load from the outside is exerted in the direction perpendicular to the axis between the inner shaft fitting and the outer cylinder fitting. Then, in order to limit the amount of elastic deformation of the main rubber elastic body and the relative displacement between the inner shaft bracket and the outer tube bracket when an excessive load in the direction perpendicular to the axis is input, the inner shaft bracket is directed toward the outer tube bracket. A stopper portion protruding at a predetermined height is employed.

  By the way, such a stopper part can be integrally formed on the outer peripheral surface of the metal inner shaft bracket, but for reasons of processing, ensuring the design freedom of the protruding height, and reducing the weight. A structure has been proposed in which a stopper member formed of a synthetic resin material is fixed to the outer peripheral surface of the inner shaft fitting. For example, it is as described in JP 2004-144150 A (Patent Document 1).

  However, the synthetic resin stopper member has a problem that it is difficult to secure the fixing force to the inner shaft fitting. In addition, Patent Document 1 proposes to increase the fixing force of the stopper member by knurling the outer peripheral surface of the inner shaft member. There is a problem that the processing step is troublesome.

JP 2004-144150 A

  The present invention has been made in the background of the above-mentioned circumstances, and the problem to be solved is that a stopper member made of synthetic resin is firmly fixed to the outer peripheral surface of the inner shaft member with a simple structure. An object of the present invention is to provide a cylindrical vibration isolator and a method for manufacturing the same.

  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. In addition, aspects or technical features of the present invention are not limited to those described below, but are described in the entire specification and drawings, or can be understood by those skilled in the art from those descriptions. It should be understood that it is recognized on the basis of.

  According to the first aspect of the present invention, the outer cylinder member is arranged separately from the outer peripheral side of the inner shaft member, and the inner shaft member and the outer cylinder member are connected by the main rubber elastic body. In the cylindrical vibration damping device provided with the synthetic resin stopper member protruding toward the outer cylindrical member, a bulging portion is provided on the outer peripheral surface of the axially intermediate portion of the inner shaft member. A serration groove extending in the axial direction is formed, one end of the serration groove in the axial direction is an open end that opens in the axial direction, and the other end in the axial direction of the serration groove is axially formed by the wall. While the closed end is closed, the stopper member is inserted into the serration groove and fixed to the outer peripheral surface of the bulging portion.

  In the cylindrical vibration isolator of this aspect, the bulging portion is provided on the outer peripheral surface of the axial intermediate portion of the inner shaft member, and the serration groove extending in the axial direction is formed in the bulging portion. The serration groove can be formed without reducing the thickness in the direction perpendicular to the axis of the inner shaft member, that is, without impairing the strength of the inner shaft member.

  In addition, since the stopper member made of synthetic resin is inserted into the serration groove provided in the bulging portion and fixed to the outer peripheral surface of the bulging portion, a large deposition area can be secured with unevenness, and the adhesion force Can be improved. Moreover, a large positioning force in the circumferential direction can be ensured by the engaging action of the irregularities.

  In addition, since the other end of the serration groove in the axial direction is a closed end closed in the axial direction by the wall, the axial engagement surface is more advantageously secured, and the axial positioning force is more effective. To be demonstrated. Also, since one end of the serration groove in the axial direction is an open end that opens in the axial direction, it is easy to enter the resin, and defects such as voids and poor resin filling can be effectively avoided. is there.

  According to a second aspect of the present invention, in the cylindrical vibration isolator described in the first aspect, the bulging portion includes a stepped surface at both axial end portions and a large-diameter cylindrical surface at the axially central portion. The open end of the serration groove is open to one step surface in the axial direction of the bulging portion.

  According to the second aspect, since the bulging portion is formed with a step surface at both axial end portions and a large-diameter cylindrical surface at the axial center portion, both side steps of the stopper member made of synthetic resin. Due to the engaging action on the surface, a large axial positioning force can be secured. In addition, the engagement area on both side step surfaces can ensure a large deposition area, and an improvement in fixing force can be realized. In addition, since the open end of the serration groove is open to one step surface in the axial direction of the bulging portion, it is easy to enter the resin, and defects such as voids and poor resin filling can be effectively avoided. It is.

  According to a third aspect of the present invention, in the cylindrical vibration isolator described in the first or second aspect, the serration groove extends straight with a constant cross-sectional shape in the axial direction of the inner shaft member. It is.

  According to the third aspect, since the serration groove extends straight with a constant cross-sectional shape in the axial direction of the inner shaft member, it is easy for the resin to enter, and defects such as voids and poor resin filling are also effective. Can be avoided. Further, the manufacturing is easy, the occurrence of defects such as burrs can be suppressed, and the cost can be reduced.

  According to a fourth aspect of the present invention, there is provided a method of manufacturing a cylindrical prevention device according to any one of the first to third aspects, wherein the molding metal fitting is punched with respect to the die molding hole. When the inner shaft member is forged and formed by forming the outer peripheral surface of the forming metal fitting with the die forming hole by pushing in the direction, the large die corresponding to the bulging portion is formed in the die forming hole. A groove-forming projection is formed to protrude on the inner peripheral surface of the diameter portion, and the serration groove is forged by the groove-forming projection.

  According to such a manufacturing method, the intended cylindrical vibration isolator according to the present invention can be manufactured stably and easily. That is, the product quality can be stabilized and the manufacturing process can be simplified. In addition, according to this aspect, the formation of the bulging portion on the inner shaft member and the formation of the serration groove, particularly the formation of the serration groove having a special structure having an open end and a closed end, can be extremely efficiently performed by forging. It is possible to do this.

  According to the present invention, the bulging portion is provided on the outer circumferential surface of the axially intermediate portion of the inner shaft member, the serration groove extending in the axial direction is formed on the bulging portion, and one axial end portion of the serration groove is The other end in the axial direction of the serration groove is a closed end that is closed in the axial direction by the wall, and the stopper member is inserted into the serration groove to bulge out. It was made to adhere to the outer peripheral surface of the part. As a result, serration grooves can be formed without damaging the strength of the inner shaft member, and a large positioning force in the circumferential direction and axial direction of the stopper member can be ensured. Thus, it was possible to form a serration groove having a simple structure extremely efficiently.

The side view of the differential mount as 1st embodiment of this invention. II-II longitudinal cross-sectional view of FIG. III-III longitudinal cross-sectional view of FIG. The A section enlarged view of FIG. The side surface enlarged view of the inner shaft member of the differential mount shown in FIG. The front enlarged view of the bulging part of the inner shaft member shown in FIG. The side view which shows the serration groove | channel formation process of the inner shaft member shown in FIG.

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

  First, the cylindrical vibration isolator 10 which is 1st embodiment of this invention is shown by FIGS. The cylindrical vibration isolator 10 is formed by connecting an inner shaft member 12 and an outer cylinder member 14 spaced apart on the outer peripheral side thereof by a main rubber elastic body 16. For example, the cylindrical vibration isolator 10 is configured such that an inner shaft member 12 is attached to a body member of an automobile, and an outer cylinder member 14 is attached by being press-fitted and fixed in a mounting hole provided in a differential housing of the automobile. The housing is used as a differential mount that supports the body member in a vibration-proof manner. The differential mount is adapted to be subjected to external forces mainly due to vibration from the road surface and torque reaction force during traveling of the vehicle in the direction perpendicular to the axis. In the following description, the axial direction and the radial direction refer to the axial direction and the radial direction of the inner shaft member 12 or the outer cylindrical member 14 in principle.

  More specifically, the inner shaft member 12 is a metal fitting having a solid or hollow rod shape, and is formed of a metal material such as steel. In the present embodiment, the inner shaft member 12 includes a cylindrical outer peripheral surface 18 that extends straight in the axial direction, and a center hole 20 that extends in the oval cross section and extends on the central axis. On the other hand, the outer cylinder member 14 is a metal fitting having a cylindrical shape having a larger diameter than the inner shaft member 12 by a predetermined amount, and is formed of an appropriate metal material in the same manner as the inner shaft member 12. In the present embodiment, the outer cylindrical member 14 has a cylindrical shape that extends straight in the axial direction, is externally attached to the inner shaft member 12, and is spaced apart from the outer peripheral surface 18 of the inner shaft member 12. In addition, the inner shaft member 12 and the outer cylinder member 14 are disposed on the same central axis.

  A main rubber elastic body 16 is disposed between the radially opposed surfaces of the inner shaft member 12 and the outer cylinder member 14. The main rubber elastic body 16 has a thick, generally cylindrical block shape as a whole, and the inner peripheral surface 22 of the main rubber elastic body 16 is fixed to the outer peripheral surface 18 of the inner shaft member 12. The outer peripheral surface 24 of the main rubber elastic body 16 is fixed to the inner peripheral surface 26 of the outer cylinder member 14. In the present embodiment, the main rubber elastic body 16 is formed of an integrally vulcanized molded product that is vulcanized and bonded to the inner shaft member 12 and the outer cylindrical member 14.

  In the present embodiment, the outer cylindrical member 14 is shorter in the axial direction than the inner shaft member 12, and both axial ends of the inner shaft member 12 extend from both axial sides of the outer cylindrical member 14. It is projected at a predetermined length. The length of the main rubber elastic body 16 in the axial direction is smaller on the outer peripheral surface 24 than on the inner peripheral surface 22, so that stress is dispersed when an external load is input.

  Further, slits 30 and 32 extending in the axial direction are formed through the main rubber elastic body 16 between the radially opposed surfaces of the inner shaft member 12 and the outer cylindrical member 14. The spring ratio in the perpendicular direction is set. In the present embodiment, a pair of first slits 30 and 30 are formed on both sides of the inner shaft member 12 in the direction perpendicular to the axis that is the vertical direction in FIG. Further, a pair of second slits 32 and 32 are formed on both sides of the inner shaft member 12 in a direction perpendicular to the axis perpendicular to this (left and right direction in FIG. 2).

  In the present embodiment, both the first slit 30 and the second slit 32 are formed to have a shape that extends in the circumferential direction by a predetermined length along the inner circumferential surface 26 of the outer cylindrical member 14 and penetrates in the axial direction. Has been. The first slit 30 is formed with a larger cross-sectional shape in the circumferential direction and the radial direction than the second slit 32. Thereby, the spring characteristic in the vertical direction in FIG. 2 that is the opposing direction of the first slit 30 is set softer than the spring characteristic in the horizontal direction in FIG. 2 that is the opposing direction of the second slit 32. .

  Further, in each of the first slit 30 and the second slit 32, either one of the outer peripheral surface 18 of the inner shaft member 12 and the inner peripheral surface 26 of the outer cylinder member 14 is directed to the other surface. Protruding stopper rubbers 34 and 36 are formed. Particularly in the present embodiment, the first stopper rubber 34 and the second stopper rubber 36 are both integrally formed of the main rubber elastic body 16. The first stopper rubber 34 is formed in the first slit 30 so as to protrude at a predetermined height radially outward from the outer peripheral surface 18 on the inner shaft member 12 side toward the outer cylinder member 14 side. . On the other hand, the second stopper rubber 36 is formed in the second slit 32 so as to protrude radially inward from the inner peripheral surface 26 side of the outer cylindrical member 14 toward the inner shaft member 12 side at a predetermined height. Yes.

  The projecting tip end surfaces 38 and 40 of the first stopper rubber 34 and the second stopper rubber 36 abut against the radially opposing surfaces 42 and 44 of the slits 30 and 32, whereby the inner shaft member 12 and the outer cylinder member A stopper mechanism for limiting the relative displacement in the direction perpendicular to the 14 axis in a buffering manner is configured. In the present embodiment, the first stopper rubber 34 and the second stopper rubber 36 are both provided continuously over the entire length in the axial direction of the slits 30, 32. For example, the stopper rubbers 34 and 36 may be formed only in the central portion in the axial direction.

  Here, in the first stopper rubber 34, a stopper member 50 fixed to the outer peripheral surface 18 of the inner shaft member 12 is disposed in an embedded state. The stopper member 50 has a cylindrical center fitting portion 52 and a pair of stopper projections 54 protruding outward from the center fitting portion 52 on both sides in the direction perpendicular to the axis. ing. And it is integrally molded by the synthetic resin material, such as polyamide, polypropylene, and polyethylene, in a shape integrally including the center fitting portions 52, 52 and the pair of stopper projections 54, 54.

  The stopper member 50 is fixedly attached to the outer peripheral surface 18 of the central portion in the axial direction of the inner shaft member 12 in an outer fitting state on the inner peripheral surface 56 of the center fitting portion 52. The main body rubber elastic body 16 and the first stopper rubber 34 are covered and covered on the outer peripheral surface 58 of the stopper member 50 over substantially the entire surface. In particular, the first stopper rubber 34 is attached to the protruding front end surfaces of the pair of stopper protrusions 54 and 54 to form a buffer layer 60 having a predetermined thickness. Further, the buffer layer 60 is thin at the center portion of the protruding front end surface of the stopper projection 54 and thick at both sides in the circumferential direction, and when the first stopper rubber 34 contacts the outer cylinder member 14 side. The buffering action by the buffer layer 60 is more effectively exhibited with non-linear spring characteristics. Furthermore, in the present embodiment, the protruding front end surface of the stopper projection 54 covered with the first stopper rubber 34 is opposed to the first slit 30 in the radial direction and is brought into contact with the outer cylindrical member 14 side. A shock absorbing rubber 62 that covers the inner peripheral surface 26 of the outer cylindrical member 14 is provided on the radially opposing surface 42.

  Further, the outer peripheral surface 18 of the axially central portion of the inner shaft member 12 to which the stopper member 50 is fixed is projected on the outer peripheral side of the cylindrical outer peripheral surface 18 of the inner shaft member 12 and has a large diameter. 64 is formed. The axial length of the bulging portion 64 is larger than the axial length of the central fitting portion 52 of the stopper member 50, and the central fitting portion 52 extends from the bulging portion 64 to both sides in the axial direction. In the extended region, it is fixed to the outer peripheral surface 18 of the inner shaft member 12.

  In particular, the bulging portion 64 of this embodiment is formed with step surfaces 66 and 68 projecting from the cylindrical outer peripheral surface 18 of the inner shaft member 12 in a step shape at both axial ends, and the axial center portion is an inner shaft. The member 12 is formed with a large-diameter cylindrical surface 70 having a substantially constant outer diameter larger than the cylindrical outer peripheral surface 18 of the member 12 and extending in the axial direction on the same central axis as the cylindrical outer peripheral surface 18 of the inner shaft member 12.

  Further, as shown in FIGS. 4 to 6, the bulging portion 64 is formed with a serration groove 72 extending in the axial direction. 5 to 6, members other than the inner shaft member 12 are not shown for easy understanding. In the present embodiment, the serration groove 72 has a shape that extends linearly in the axial direction, and is formed with a plurality of grooves that extend substantially parallel to each other at a predetermined distance in the circumferential direction. The depth of the serration groove 72 is configured to be equal to or smaller than the protruding height of the bulging portion 64. The specific depth dimension is determined in consideration of the input load and the like. It is determined appropriately, and can be formed with a depth dimension of, for example, 0.5 mm or more. The cross-sectional shape is formed to have a substantially V-shaped cross-section that expands toward the outer peripheral surface 74 of the bulging portion 64, and is configured to extend with a substantially constant cross-sectional shape.

  In particular, in the present embodiment, all of the serration grooves 72 are formed so as to extend linearly in parallel with the central axis of the inner shaft member 12. Further, one end 76 in the axial direction of the serration groove 72 is opened in the stepped surface 66 of the bulging portion 64 and constitutes an open end opened in the axial direction from the bulging portion 64. On the other hand, the other end 78 in the axial direction of the serration groove 72 is terminated. That is, an end wall is formed to form a closed end structure, and the other end portion 78 in the axial direction is not open.

  And with respect to the bulging part 64 in which such a serration groove 72 is formed, the inner peripheral surface 56 of the center fitting part 52 of the stopper member 50 is formed on the entire surface of the bulging part 64 including the inside of the serration groove 72. On the other hand, it is firmly fixed. In short, the stopper member 50 is inserted into the serration groove 72, and a protrusion corresponding to the serration groove 72 is formed in the center fitting portion 52 and assembled in a fitted state.

  In the cylindrical vibration isolator 10 having such a structure, a large area of the stopper member 50 to be attached to the inner shaft member 12 can be secured due to the uneven shape of the bulging portion 64 in which the serration groove 72 is formed. , Thereby improving the fixing force. Moreover, it becomes possible to ensure a large positioning force in the circumferential direction by the engaging action of the uneven shape. In addition, due to the engaging action of the bulging portion 64 on both side step surfaces 66 and 68, a large axial positioning force can be secured.

  Further, the other end portion 78 in the axial direction of the serration groove 72 is terminated, and an end wall is formed to form a closed end structure, so that the stopper member 50 is axially oriented with respect to the inner shaft member 12. The engaging surface is more advantageously secured, and the axial positioning force is more effectively exhibited. In addition, since one end 76 in the axial direction is an open end instead of a hole shape that opens at the center of the bulging portion 64, it is easy for the resin to enter, and there are defects such as voids and poor resin filling. Can also be effectively avoided. Further, since the groove depth becomes shallower toward the other end 78 in the axial direction of the serration groove 72, the burr hardly occurs.

  The embodiment of the present invention has been described in detail above, but this is merely an example, and the present invention is not construed as being limited by the specific description in the embodiment. The present invention can be implemented in various modifications, corrections, and the like based on knowledge, and is not enumerated one by one, so long as such embodiments do not depart from the spirit of the present invention. Needless to say, it is included in the range.

  For example, the protruding height and size of the bulging portion 64 are not limited, and should be set in consideration of the characteristics required for the required stopper member 50 and the magnitude of the input load. . In the above embodiment, the cross-sectional shape of the bulging portion 64 has been described by taking a trapezoidal shape in which the outer peripheral surface 74 of the bulging portion 64 is flat. Needless to say, the present invention can also be applied to the case where 66 and 68 have a multi-stage configuration and the outer peripheral surface 74 having a spherical shape. In the present embodiment, the bulging portion 64 is formed in the central portion in the axial direction, but it is not necessary to be in the central portion in the axial direction. The position may be biased in one axial direction depending on the shape of the inner shaft member 12 or the mounting member, the load input state, or the like.

  In addition, the second slit 32 is employed according to the required anti-vibration characteristics and is not essential in the present invention. Further, the shape and size of the first slit 30 can be appropriately changed according to required characteristics.

  Further, the number, shape, size, and the like of the serration grooves 72 formed in the bulging portion 64 are appropriately determined in consideration of the required fixing force (positioning force) of the stopper member 50 to the inner shaft member 12, resin strength, and the like. Can be changed. The serration groove 72 may be inclined with respect to the central axis of the inner shaft member 12 and extend in the axial direction. Further, it is not necessarily straight, and may be curved and extend in the axial direction. Of course, the serration grooves 72 are not necessarily provided at equal intervals.

  In addition, the scope of application of the present invention is not limited to the differential mount of the embodiment. For example, the suspension bush mounted on the vehicle body side or the wheel side of the suspension member or the sub member vehicle body. The present invention can be similarly applied to a member mount that is mounted on the mounting portion, a cylindrical engine mount that is mounted on the mounting portion of the power unit to the vehicle body, and the like. The external force input in the mounted state may include an axial load input in addition to a direction perpendicular to the axis, or an input in the twisting direction or torsional direction. Application to a device is also possible.

  Further, the inner shaft member 12 and the outer cylinder member 14 may be eccentrically arranged according to the characteristics required for the vibration isolator, and the spring characteristics of the main rubber elastic body 16 are also anisotropic (diameter). The directional spring characteristics may be different on the circumference).

  Moreover, the stopper member 50 does not need to protrude in a pair (both sides) in a position opposed to each other in the radial direction, and the protruding heights may be different from each other even when protruding to both sides. Furthermore, the shape of the stopper member 50 can be, for example, a projecting tip end surface having a spherical outer peripheral surface or the like, and thereby, for example, the spring characteristics in the twisting direction can be tuned softly.

  By the way, the cylindrical vibration isolator 10 having the structure as described above is advantageously manufactured according to the following steps. First, the inner shaft member 12 and the outer cylinder member 14 are prepared and prepared in separate processes. Here, the outer cylinder member 14 is formed by cutting a metal pipe material at a predetermined length. On the other hand, the inner shaft member 12 is a bulged portion provided with serration grooves 72 by, for example, cutting the outer peripheral surface 18 of the inner shaft member 12 with respect to the raw pipe obtained by cutting a metal pipe material at a predetermined length. 64 may be formed, but preferably, the bulging portion 64 and the serration groove 72 are formed by forging.

  For example, a block-shaped molding metal fitting obtained by cutting a solid metal rod having a circular cross section with a diameter slightly smaller than the outer diameter of the inner shaft member 12 to an appropriate length is prepared. And the forge die provided with the die | dye provided with the hole for shaping | molding which gives the outer peripheral surface shape of the target inner shaft member 12, and the outer diameter punch which gives the inner peripheral surface shape of the target inner shaft member 12 is used. The inner shaft member 12 having the outer peripheral surface 18 including the center hole 20 and the bulging portion 64 as described above is formed by forging the metal fitting for molding.

  In the next step, as shown in FIG. 7, serration grooves 72 are formed in the bulging portion 64 of the molding fitting 80 obtained in this way. More specifically, the length of the forming hole 84 of the die 82 in this step is formed slightly longer than the length of the forming metal fitting 80, and the mouth portion 84a of the forming hole 84 is expanded in a step shape. Is formed. A plurality of serration groove forming projections 86 project from the molding hole 84. The serration groove forming projection 86 is substantially the axial length of the bulging portion 64 of the molding fitting 80 at the inner peripheral surface 84b of the large diameter portion corresponding to the bulging portion 64, that is, at the substantially central portion of the molding hole 84. It is extended by. The serration groove forming protrusion 86 has a shape extending linearly in the axial direction, and is formed with a plurality of protrusions extending substantially parallel to each other at a predetermined distance in the circumferential direction.

  The punch 88 in this step has a cylindrical shape having a diameter substantially the same as the diameter of the outer peripheral surface 18 of the molding fitting 80, and its axis is positioned so as to coincide with the axis of the molding hole 84 of the die 82, The punch 88 can move close to the die 82 side on the axis. In this step, as shown in FIG. 7 (a), the molding fitting 80 is aligned with the molding hole 84 of the die 82 before the molding hole 84 of the die 82 with a chuck (not shown). Gripped in position. In this state, as shown in FIG. 7B, the punch 88 is moved to the die 82 side with a considerable acceleration. Thereby, the serration groove 72 is formed in the bulging part 64 of the metal fitting 80 for molding, and the metal fitting 80 for molding becomes the inner shaft member 12 (FIG. 7C).

  Furthermore, the inner shaft member 12 obtained in this way is positioned and set in a molding cavity of an injection mold for resin-molding the stopper member 50. Thereafter, an insert resin molded product in which the stopper member 50 is fixed to the outer peripheral surface 18 of the inner shaft member 12 can be obtained by injecting and filling a resin material into the molding cavity and cooling and hardening.

  Subsequently, the obtained insert resin molded product and the outer cylindrical member 14 are respectively positioned and set at predetermined positions in the molding cavity of the vulcanization molding die of the main rubber elastic body 16. After that, by filling the molding cavity with a rubber material and subjecting it to vulcanization treatment, the target cylindrical vibration isolator 10 can be obtained as an integrally vulcanized molded product of the main rubber elastic body 16.

  When the main rubber elastic body 16 is vulcanized, pretreatment such as a chemical conversion film can be applied to the outer peripheral surface 18 of the inner shaft member 12 and the inner peripheral surface 26 of the outer cylindrical member 14 in advance. In addition, after the vulcanization molding of the main rubber elastic body 16, the outer cylindrical member 14 is subjected to a drawing process to reduce the diameter so that the tensile stress of the main rubber elastic body 16 can be eliminated or pre-compression can be applied. .

  According to such a manufacturing method, it is possible to stably and easily manufacture the cylindrical vibration isolator 10 according to the target invention, and to realize stabilization of product quality and simplification of the manufacturing process. I can do it. In particular, the formation of the bulging portion 64 on the inner shaft member 12 and the formation of the serration groove 72, particularly the serration groove 72 having a special structure having an open end and a closed end can be formed extremely efficiently. It is.

  Further, when the resin forming the stopper member 50 is performed, the serration groove 72 is an open end at one end portion 76, so that the stopper is formed as compared with a case where both have a closed end structure. When the member 50 is molded, the resin material can be smoothly circulated into the serration groove 72 and the flow of the resin material is promoted, thereby suppressing the occurrence of defective products due to poor filling of the resin material into the serration groove 72. You can expect the effect that it is.

10: cylindrical vibration isolator, 12: inner shaft member, 14: outer cylinder member, 16: rubber elastic body of the main body, 18: outer peripheral surface, 50: stopper member, 52: center fitting portion, 54: stopper protrusion, 56: inner peripheral surface, 64: bulged portion, 66, 68: stepped surface, 70: large-diameter cylindrical surface, 72: serration groove, 76: one end, 78: other end, 80: for molding Metal fitting, 82: Die, 84: Hole for molding, 86: Projection, 88: Punch

Claims (4)

The outer cylinder member is arranged apart from the outer peripheral side of the inner shaft member, and the inner shaft member and the outer cylinder member are connected by a main rubber elastic body, while projecting from the inner shaft member toward the outer cylinder member. In the cylindrical vibration isolator provided with a stopper member made of synthetic resin,
A bulging portion is provided on the outer peripheral surface of the axially intermediate portion of the inner shaft member to form a serration groove extending in the axial direction of the bulging portion, and one axial end portion of the serration groove is directed in the axial direction. And an open end that opens and the other end in the axial direction of the serration groove as a closed end closed in the axial direction by the wall,
A cylindrical vibration isolator comprising the stopper member inserted into the serration groove and fixed to the outer peripheral surface of the bulging portion. The bulging portion is formed with a step surface at both axial end portions and a large-diameter cylindrical surface at the axial central portion,
The cylindrical vibration isolator according to claim 1, wherein the open end of the serration groove is open to the stepped surface on one side in the axial direction of the bulging portion.   The cylindrical vibration isolator according to claim 1 or 2, wherein the serration groove extends straight with a constant cross-sectional shape in the axial direction of the inner shaft member. It is a manufacturing method of the cylindrical prevention device according to any one of claims 1 to 3,
When the inner shaft member is forged by pressing the forming metal fitting into the die forming hole with a punch in the axial direction and forming the outer peripheral surface of the forming metal fitting with the die forming hole,
A groove forming projection is formed on the inner peripheral surface of the large diameter portion corresponding to the bulging portion in the die forming hole, and the serration groove is forged by the groove forming projection. Manufacturing method of cylindrical vibration isolator.

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