JP2006242289A - Vibration-proofing bush - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration-proofing bush capable of responding to a request for a large twisting angle by allowing a spring constant in the twisting direction to be set further low while increasing a spring constant in a direction perpendicular to an axis, in relation to a press-in type vibration-proofing bush; to provide its manufacturing method. <P>SOLUTION: This vibration-proofing bush comprises: an outer tube fitting 1; a rubber elastic body 2 nearly cylindrically formed by being vulcanized and stuck to the inside surface of the outer tube fitting 1 and having projection parts 21, 21 at both axial ends of its inside surface; and an inner tube fitting 3 having, on its circumferential surface, recessed grooves 31, 31 engaging with the projection parts 21, 21 of the rubber elastic body 2 and pressed in the inner peripheral side of the rubber elastic body 2. A sliding treatment is applied to at least either of contact surfaces of the rubber elastic body 2 and the inner tube fitting 3. By reducing the diameter of the outer tube fitting 1 throughout the whole axial part from the peripheral side of the outer tube fitting 1 after pressing the inner tube fitting 3 in the inner peripheral side of the rubber elastic body 2, radial pre-compression is applied to the rubber elastic body 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an anti-vibration bush that is suitably employed, for example, in a connection part of a vehicle suspension.

  Conventionally, in a vehicle suspension, for example, in order to suppress vibration transmitted to the vehicle body, a vibration isolating bush has been employed in a connecting portion such as a rod or an arm. A press-fitting type as disclosed in 1-4 is known. These anti-vibration bushes are integrally connected to the inner cylinder fitting, the outer cylinder fitting coaxially disposed on the outer peripheral side of the inner cylinder fitting, and the inner cylinder fitting and the outer cylinder fitting interposed therebetween. And is assembled by press-fitting at least one of the inner cylinder fitting and the outer cylinder fitting into the rubber elastic body. In these anti-vibration bushes, if the outer cylinder fitting and the rubber elastic body are not bonded, there is a risk that they will come off when a large force is applied in the axial direction. A diameter-reduced portion or a bent portion is formed so as to prevent the omission.

  Further, as disclosed in, for example, Patent Document 5, a spherical sliding bush having a built-in spherical sliding mechanism that absorbs a force in a twisting direction around the bush axis and a twisting direction inclined with respect to the bush axis. Assemblies are known. The vibration isolating bush includes an inner cylindrical fitting having a spherical convex surface on the outer peripheral surface of the axially intermediate portion, a sliding member having a spherical concave surface slidably in contact with the spherical convex surface of the inner cylindrical fitting, and a distance to the outside of the inner cylindrical fitting. And a presser sleeve, a lace fitting, an elastic member, an outer cylinder fitting, and the like that are arranged concentrically with each other.

  By the way, the anti-vibration bush used for the suspension generally has a high spring constant in the direction perpendicular to the bush axis in order to ensure good steering stability of the vehicle, and in the twist direction in order to obtain a good riding comfort. It is required as an important requirement to lower the spring constant. Therefore, in the case of a press-fit type anti-vibration bush, the rubber elastic body interposed between the inner cylinder fitting and the outer cylinder fitting is in a pre-compressed state by press fitting, so that the spring constant in the bush axis direction Further, since the rubber elastic body is not bonded to the inner cylinder fitting or the outer cylinder fitting, the spring constant in the torsion direction is lowered. Therefore, when a large torsion angle is required, a press-fit type or a spherical sliding type vibration-proof bushing is preferably employed.

However, in the case of a press-fitting type vibration-proof bushing, in order to meet the demand for a large torsion angle, the rubber elastic body needs to be pre-compressed according to the torsion angle. However, if the pre-compression of the rubber elastic body is increased, a large pressing force is required at the time of press-fitting, so that the press-fitting work becomes difficult and the rubber elastic body is damaged. Therefore, there is a limit to increasing the precompression. On the other hand, in the case of a spherical sliding bush assembly, since a large number of parts are combined, the structure becomes complicated and an increase in cost is inevitable. In addition, since a slight backlash is likely to occur, this adversely affects the initial steering stability.
Japanese Patent Laid-Open No. 9-19975 JP-A-8-233008 JP-A-8-270698 Japanese Patent No. 3051004 Japanese Utility Model Publication No. 5-29561

  The present invention has been made in view of the above circumstances, and in a press-fitting type vibration-proof bushing, the spring constant in the direction perpendicular to the axis can be increased while the spring constant in the torsion direction can be set lower, so that It is a problem to be solved to provide a vibration-proof bushing capable of meeting corner requirements and a method for manufacturing the same.

  An anti-vibration bush according to the present invention that solves the above-described problems is an outer cylinder fitting and a vulcanization-bonded inner circumferential surface of the outer cylinder fitting that is formed into a cylindrical shape and has a recess or a recess in at least one place on its inner circumferential surface. A rubber elastic body having a convex portion, and an inner cylinder fitting that has a convex portion or a concave portion that engages with the concave portion or the convex portion of the rubber elastic body on the outer peripheral surface and is press-fitted to the inner peripheral side of the rubber elastic body. And at least one of the contact surfaces of the rubber elastic body and the inner cylinder fitting has been subjected to a sliding treatment, and the rubber elastic body is, after the inner cylinder fitting has been press-fitted to the inner peripheral side, The outer cylinder fitting is pre-compressed in the radial direction by reducing the diameter of the outer cylinder fitting from the outer peripheral side to the entire axial direction.

  In the anti-vibration bush of the present invention, when a large force acts in the torsional direction around the bush axis, the rubber elastic body and the inner cylindrical fitting are subjected to a sliding process on at least one of the contact surfaces. Slip occurs between the elastic body and the inner cylinder fitting. Therefore, the spring constant in the torsion direction can be set to be significantly low, and a large torsion angle can be handled without limit. Further, since the rubber elastic body is always sufficiently precompressed by the press-fitting of the inner cylinder fitting and the reduced diameter of the outer cylinder fitting, the spring constant in the direction perpendicular to the axis can be set high. At the same time, no play is generated between the rubber elastic body and the inner cylindrical metal fitting, unlike the above-described spherical sliding vibration-proof bushing. Further, since the rubber elastic body and the inner cylindrical metal fitting are engaged by the concave or convex portions respectively provided on the inner peripheral surface of the rubber elastic body and the outer peripheral surface of the inner cylindrical metal fitting, the relative movement in the axial direction is restricted. This prevents the inner cylinder fitting from coming off.

  In the present invention, the sliding treatment applied to at least one of the contact surfaces of the rubber elastic body and the inner cylindrical metal fitting can be performed, for example, by baking a sliding agent such as molybdenum disulfide on the contact surface. . Further, as the sliding treatment applied to the contact surface of the rubber elastic body, for example, the rubber elastic body may be formed of a self-lubricating rubber material in which a lubricant is kneaded into natural rubber. The rubber elastic body formed of a self-lubricating rubber material can reduce the friction coefficient of the contact surface by blooming the lubricant on the contact surface.

  In the present invention, it is preferable that the press-fit rate of the rubber elastic body when the inner cylinder fitting is press-fitted into the inner peripheral side of the rubber elastic body is 5 to 15%. The press-fit rate here refers to the reduction rate of the thickness of the rubber elastic body after press-fit after press-fit, [(thickness dimension of the rubber elastic body before press-fit) − (thickness of the rubber elastic body after press-fit) Dimension)] / (thickness dimension of rubber elastic body before press fit) × 100. Moreover, it is preferable that the precompression rate of the rubber elastic body after the diameter reduction processing of the outer cylinder fitting is 20 to 25%. Here, the pre-compression rate means a reduction rate of the thickness of the rubber elastic body from before the press-fitting after the diameter reduction processing of the outer cylinder fitting, [(thickness dimension of the rubber elastic body before the press-fitting) − (reduction diameter) Thickness dimension of rubber elastic body after processing)] / (thickness dimension of rubber elastic body before press fitting) × 100.

  In the present invention, the concave portion or the convex portion provided on the inner peripheral surface of the rubber elastic body and the outer peripheral surface of the inner cylindrical metal fitting are provided with concave portions at both axial ends of the outer peripheral surface of the inner cylindrical metal fitting, It is preferable to provide convex portions at both ends in the axial direction of the surface. In this way, since the concavo-convex engagement state between the rubber elastic body and the inner cylindrical metal fitting is obtained at both axial end portions, it is possible to effectively prevent disconnection. Moreover, it is preferable to provide the taper part which becomes a small diameter as it approaches an edge at least at one end part of an outer cylinder metal fitting. In this way, since the end of the rubber elastic body is pressed inward in the radial direction by the tapered portion, it is possible to more reliably prevent the inner cylinder fitting from coming off. Furthermore, if it has a stopper part provided at one end of the outer cylinder fitting so as to face a bracket disposed on the outer side of one end of the outer cylinder fitting, the axial direction of the outer cylinder fitting and the inner cylinder fitting can be reduced. By restricting the relative displacement, it is possible to more reliably prevent the inner cylinder fitting from coming off.

  The manufacturing method of the vibration-proof bushing according to the present invention that solves the above-described problem is a cylindrical rubber elastic body having a concave portion or a convex portion in at least one place on its inner peripheral surface with respect to the inner peripheral surface of the outer cylindrical fitting. Rubber elastic body forming step of forming the outer peripheral surface of the rubber elastic body by vulcanization and bonding, the outer peripheral surface of the inner tube fitting having the convex portion or the concave portion engaged with the concave portion or the convex portion of the rubber elastic body on the outer peripheral surface, and the rubber elasticity A sliding treatment step for subjecting at least one surface of the inner peripheral surface of the body to a sliding treatment, an assembling step for press-fitting and assembling the inner cylinder fitting on the inner circumferential side of the rubber elastic body, and an after-assembling step And a pre-compression applying step of applying a radial pre-compression to the rubber elastic body by performing a diameter reducing process on the outer cylinder fitting from an outer peripheral side.

  In the present invention, the sliding treatment step is performed, for example, by applying a sliding agent such as molybdenum disulfide on the inner peripheral surface of the rubber elastic body or baking it on the outer peripheral surface of the inner cylindrical metal fitting. Further, for example, by forming a rubber elastic body with a self-lubricating rubber material in which a lubricant is kneaded with natural rubber, it is possible to subject the inner peripheral surface of the rubber elastic body to a sliding treatment. When the rubber elastic body is formed of the self-lubricating rubber material and the sliding treatment is performed only on the inner peripheral surface of the rubber elastic body, the sliding treatment step is included in the rubber elastic body forming step.

  In this invention, it is preferable that the press-fit rate of the rubber elastic body in an assembly | attachment process shall be 5-15%. Moreover, it is preferable that the pre-compression rate of the rubber elastic body after the pre-compression applying step is 20 to 25%. The press-fit rate and pre-compression rate of the rubber elastic body here are the same as described above. Moreover, in this invention, it is preferable to perform the taper part formation process which forms the taper part which becomes a small diameter as it approaches an end edge in the at least one end part of an outer cylinder metal fitting after completion | finish of an assembly | attachment process. By performing the taper portion forming step, the end portion of the rubber elastic body is pressed inward in the radial direction, so that the inner cylindrical fitting can be more reliably prevented from coming off. In addition, this taper part formation process can be performed before or after a precompression provision process, or simultaneously with a precompression provision process.

  According to the vibration-proof bushing of the present invention, at least one of the contact surfaces of the rubber elastic body and the inner cylinder fitting is subjected to a sliding treatment, and the rubber elastic body has the inner cylinder fitting on the inner peripheral side. After being press-fitted, since the outer cylinder fitting is subjected to diameter reduction processing from the outer peripheral side of the outer cylinder fitting to the whole in the axial direction, the spring constant in the direction perpendicular to the axis is increased. However, the spring constant in the torsion direction can be set to be lower, so that the demand for a large torsion angle can be met. Further, the rubber elastic body and the inner cylinder fitting are engaged by the concavo-convex portions provided on the contact surfaces thereof, so that the inner cylinder fitting can be prevented from coming off.

  Moreover, according to the manufacturing method of the vibration-proof bushing of the present invention, the rubber elastic body forming step, the sliding treatment step, the assembling step, and the precompression applying step are sequentially performed. Therefore, the spring constant in the direction perpendicular to the axis can be increased while the spring constant in the torsional direction can be set lower so that the demand for a large torsion angle can be met, and the inner cylindrical fitting can be prevented from coming off. An anti-vibration bush can be easily obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view taken along the axial direction of the vibration isolating bushing according to the present embodiment, and FIG. 2 is a cross-sectional view taken along the axial direction in a state where the rubber elastic body and the outer tube fitting are integrated. FIG. 3 is a cross-sectional view along the axial direction of the inner cylinder fitting relating to the vibration-proof bushing.

  As shown in FIG. 1, the vibration-proof bushing of the present embodiment is formed in a substantially cylindrical shape by being vulcanized and bonded to the outer cylinder fitting 1 and the inner circumference surface of the outer cylinder fitting 1. The rubber elastic body 2 having the ridges 21 and 21 at both ends in the direction, and the concave grooves 31 and 31 engaging with the ridges 21 and 21 of the rubber elastic body 2 are provided on the outer peripheral surface. The inner cylindrical metal fitting 3 is press-fitted to the peripheral side, and the rubber elastic body 2 and the inner cylindrical metal fitting 3 are slidable in the torsional direction, and radial pre-compression is imparted to the rubber elastic body 2. Has been.

  The outer cylinder fitting 1 is formed in a cylindrical shape having a substantially constant diameter with an iron-based metal, and is formed at one end thereof in an annular flange shape that is bent at a substantially right angle and extends outward in the radial direction. A stopper 11 is provided. Moreover, the other end part of the outer cylinder metal fitting 1 is provided with the taper part 12 which becomes a small diameter as it approaches an end edge. The outer cylinder fitting 1 shown in FIG. 1 is formed with a tapered portion 12 and a diameter reducing process with respect to the outer cylinder fitting 1 shown in FIG. Yes.

  The rubber elastic body 2 is integrated with the outer cylinder fitting 1 as shown in FIG. 2 by inserting the outer cylinder fitting 1 into the vulcanization mold forming the rubber elastic body 2 and performing vulcanization molding. The outer peripheral surface is vulcanized and bonded to the inner peripheral surface of the outer tube fitting 1. This rubber elastic body 2 is formed of a self-lubricating rubber material in which a lubricant is kneaded into natural rubber. At both ends in the axial direction of the inner peripheral surface of the rubber elastic body 2, protrusions 21, 21 projecting inward in the radial direction so as to engage with concave grooves provided on the outer peripheral surface of the inner cylindrical metal fitting 3. It is formed so as to make one round in the circumferential direction with a predetermined width.

  Further, a central ridge 22 projecting radially inward is provided at the axially central portion of the inner peripheral surface of the rubber elastic body 2 in order to average the precompression applied to the rubber elastic body 2 in the axial direction. Is formed so as to make one round in the circumferential direction. On one end side of the rubber elastic body 2, a rubber buffer portion 23 that extends to the outer surface of the stopper portion 11 of the outer tube fitting 1 and is vulcanized and bonded is provided so as to have a predetermined thickness. The rubber elastic body 2 is pre-compressed in a range of 20 to 25% in the radial direction by reducing the diameter of the outer cylinder fitting 1 after the inner cylinder fitting 1 is press-fitted to the inner peripheral side thereof. ing.

  As shown in FIGS. 1 and 3, the inner cylinder fitting 3 is formed in a thick cylindrical shape from an iron-based metal. Grooves recessed inward in the radial direction so as to engage with protrusions 21, 21 provided on the inner peripheral surface of the rubber elastic body 2 at both axial ends of the outer peripheral surface of the inner cylindrical metal fitting 3 31 and 31 are formed with a predetermined width so as to make a round in the circumferential direction. A sliding treatment is performed on the outer peripheral surface of the inner cylindrical metal fitting 3 by baking molybdenum disulfide as a sliding agent over the entire outer peripheral surface. The inner cylinder fitting 3 is assembled by being press-fitted into the inner peripheral side of the rubber elastic body 2 in a range where the press-fit rate of the rubber elastic body 2 is 5 to 15%. Thereby, the inner cylinder fitting 3 and the rubber elastic body 2 are set to be slidable in the torsion direction, and the spring constant in the torsion direction is set to be sufficiently low.

  The anti-vibration bush according to the present embodiment is manufactured by sequentially performing a rubber elastic body forming step, a sliding treatment step, an assembly step, a precompression applying step, and a tapered portion forming step. First, in the rubber elastic body forming step, an outer cylinder fitting 1 having an annular flange-shaped stopper 11 at one end is prepared, and the outer cylinder fitting 1 is inserted into a vulcanization mold for forming the rubber elastic body 2. Then, vulcanization molding is performed using a self-lubricating rubber material. As a result, as shown in FIG. 2, the rubber elastic body 2 is formed by vulcanizing and bonding the outer peripheral surface thereof to the inner peripheral surface of the outer tube fitting 1. At this time, ridges 21 and 21 are formed at both axial ends of the inner peripheral surface of the rubber elastic body 2, and a central ridge 22 is formed at the axial central portion of the inner peripheral surface. A rubber buffer portion 23 is formed on the side.

  In the next sliding treatment step, the inner cylindrical metal fitting 1 formed in a predetermined shape having the concave grooves 31 and 31 at both axial ends of the outer peripheral surface is prepared, and sliding is performed over the entire outer peripheral surface of the inner cylindrical metal fitting 1. A sliding treatment is performed by fixing molybdenum disulfide as an agent by baking. Thereafter, as shown in FIG. 4A, the inner cylinder fitting 3 subjected to the sliding treatment is press-fitted and assembled to the inner peripheral side of the rubber elastic body 2 integrated with the outer cylinder fitting 1. An assembling process is performed to obtain an anti-vibration bush in an assembled state as shown in FIG. At this time, the press-fit rate of the rubber elastic body 2 is lowered to a range of 5 to 15%, the outer peripheral surface of the inner cylindrical metal fitting 3 is subjected to a sliding treatment, and the rubber elastic body 2 is a self-lubricating rubber material. Therefore, the press-fitting work can be easily performed.

  In the next pre-compression applying step, as shown in FIG. 4 (c), the outer cylinder fitting 1 after the assembly step is subjected to diameter reduction processing from the outer peripheral side using a drawing device such as an eight-way drawing, and rubber A radial pre-compression is applied to the elastic body 2. At this time, pre-compression is applied to the rubber elastic body 2 in a range where the pre-compression ratio is 20 to 25%. Then, in the next taper portion forming step, a taper portion 12 having a smaller diameter as the end edge is approached is formed at the end portion of the outer tube fitting 1 opposite to the stopper portion 11 using a caulking device or the like. Thereafter, shaping processing, finishing processing, and the like are performed as necessary to complete the vibration isolating bush as shown in FIG.

  The anti-vibration bushing of the present embodiment configured as described above is used by being attached to a connecting portion such as a rod or an arm in a vehicle suspension, for example, as shown in FIG. In this case, the outer cylinder fitting 1 of the vibration isolating bush is press-fitted and installed in a cylindrical mounting hole 51 provided at one end of the arm member 50. And the inner cylinder metal fitting 3 is arrange | positioned between the opposing wall parts 61 and 62 of the U-shaped bracket 60 fixedly provided by the vehicle body side, The insertion hole (not shown) of both wall parts 61 and 61 is carried out. ) And the bolts 63 and nuts 64 inserted into the inner holes of the inner cylindrical metal fitting 3, so that both ends in the axial direction of the inner cylindrical metal fitting 3 are attached to the wall portions 61 and 62. . As a result, the stopper portion 11 provided at one end of the outer cylindrical metal fitting 1 is in a state of facing the one wall portion 61 with a predetermined distance through the rubber buffer portion 23 therebetween, and the stopper portion 11 and the rubber buffer portion. A stopper mechanism that restricts excessive relative displacement in the axial direction between the outer cylinder fitting 1 and the inner cylinder fitting 3 is configured by the portion 23 and the one wall portion 61 opposed to them.

  When a large force acts on the vibration isolating bush attached in this state in the torsional direction around the bush axis, a sliding process is performed on the outer peripheral surface of the inner cylindrical metal fitting 3 in contact with the rubber elastic body 2, and Since the rubber elastic body 2 is formed of a self-lubricating rubber material, a slip occurs between the rubber elastic body 2 and the inner tube fitting 3. Therefore, the spring constant in the torsion direction can be set to be significantly low, and a large torsion angle can be handled without limit. In addition, since the rubber elastic body 2 is always sufficiently pre-compressed by the press-fitting of the inner cylindrical fitting 3 and the reduced diameter of the outer cylindrical fitting 1, the spring constant in the direction perpendicular to the axis is set high. In addition, backlash does not occur between the rubber elastic body 2 and the inner cylinder fitting 3.

  The rubber elastic body 2 and the inner cylindrical metal fitting 3 are engaged by the protrusions 21, 21 provided on the inner peripheral surface of the rubber elastic body 2 and the concave grooves 31, 31 provided on the outer peripheral surface of the inner cylindrical metal fitting 3. Accordingly, the inner cylinder fitting 3 is prevented from coming off by restricting the relative movement in the axial direction. Further, the inner cylinder is also formed by the end of the rubber elastic body 2 being pressed into the groove 31 of the inner cylinder fitting 3 by the tapered portion 12 provided at the other end of the outer cylinder fitting 1. Removal of the metal fitting 3 is prevented. Furthermore, an excessive relative displacement in the axial direction between the outer cylinder fitting 1 and the inner cylinder fitting 3 is achieved by a stopper mechanism constituted by the stopper portion 11 and the rubber cushioning portion 23 of the outer cylinder fitting 1 and the wall portion 61 of the bracket 60. Is restricted, so that the inner cylinder fitting 3 is prevented from coming off.

  As described above, the anti-vibration bushing of the present embodiment is such that the outer peripheral surface of the inner cylindrical fitting 3 that contacts the rubber elastic body 2 is subjected to a sliding process, and the rubber elastic body 2 is formed of a self-lubricating rubber material. In addition, the rubber elastic body 2 is formed by reducing the diameter of the outer cylinder fitting 1 from the outer circumference side of the outer cylinder fitting 1 to the whole in the axial direction after the inner cylinder fitting 3 is press-fitted to the inner circumference side. Since it is pre-compressed in the radial direction, the spring constant in the direction perpendicular to the axis can be increased while the spring constant in the torsion direction can be set lower to meet the demand for a large torsion angle. Moreover, since the rubber elastic body 2 and the inner cylinder metal fitting 3 are engaged by the protrusions 21 and 21 and the concave grooves 31 and 31 provided on their contact surfaces, the inner cylinder metal fitting 3 is prevented from coming off. be able to. Furthermore, a tapered portion 12 is provided at the other end of the outer tube fitting 1, and a stopper mechanism constituted by the stopper portion 11 and the rubber cushioning portion 23 of the outer tube fitting 1 and the wall portion 61 of the bracket 60. Therefore, it is possible to more reliably prevent the inner cylinder fitting 3 from coming off.

  Moreover, according to the manufacturing method of the vibration-proof bushing of the present embodiment, the rubber elastic body forming step, the sliding treatment step, the assembling step, the precompression applying step, and the tapered portion forming step are sequentially performed. Therefore, the spring constant in the direction perpendicular to the axis can be increased while the spring constant in the torsion direction can be set lower, so that the demand for a large torsion angle can be met, and the inner cylindrical fitting can be more easily removed. An anti-vibration bush that can be reliably prevented can be easily obtained.

It is sectional drawing which follows the axial direction of the anti-vibration bush which concerns on embodiment of this invention. It is sectional drawing in alignment with the axial direction of the state in which the rubber elastic body and outer cylinder metal fitting which concern on embodiment of this invention were integrated. It is sectional drawing which follows the axial direction of the inner cylinder metal fitting which concerns on embodiment of this invention. It is explanatory drawing of the manufacturing process of the anti-vibration bush in embodiment of this invention. It is sectional drawing which shows the attachment state of the vibration proof bush which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Outer cylinder metal fitting 11 ... Stopper part 12 ... Tapered part 2 ... Rubber elastic body 21 ... Projection part 22 ... Center projection part 23 ... Rubber buffer part 3 ... Inner cylinder metal fitting 31 ... Groove 50 ... Arm member 51 ... Installation Hole 60 ... Bracket 61, 62 ... Wall 63 ... Mounting bolt 64 ... Nut

Claims (12)

An outer cylinder fitting, a rubber elastic body that is vulcanized and bonded to the inner circumferential surface of the outer cylinder fitting and is formed into a cylindrical shape, and has a concave portion or a convex portion in at least one place on its own inner circumferential surface; An inner cylinder fitting that has a convex portion or a concave portion that engages with the concave portion or the convex portion on the outer peripheral surface and is press-fitted to the inner peripheral side of the rubber elastic body,
A sliding process is applied to at least one of the contact surfaces of the rubber elastic body and the inner cylinder fitting, and the rubber elastic body is inserted into the outer circumference after the inner cylinder fitting is press-fitted on the inner peripheral side. An anti-vibration bush characterized by being pre-compressed in the radial direction by reducing the diameter of the outer cylindrical fitting from the outer peripheral side of the cylindrical fitting to the entire axial direction.   The inner cylinder fitting has recesses provided at both axial ends of the outer peripheral surface, and the inner peripheral surface of the rubber elastic body is provided with a projection that engages with the recess of the inner cylinder fitting. The anti-vibration bush according to claim 1.   The vibration isolation according to claim 1 or 2, wherein the sliding treatment is performed by fixing a sliding agent on at least one of an outer peripheral surface of the inner cylindrical metal fitting and an inner peripheral surface of the rubber elastic body. bush.   The anti-vibration bush according to claim 1 or 2, wherein the rubber elastic body is formed of a self-lubricating rubber material.   The anti-vibration bush according to any one of claims 1 to 4, wherein a press-fit rate of the rubber elastic body when the inner cylinder fitting is press-fitted into an inner peripheral side of the rubber elastic body is 5 to 15%.   The anti-vibration bushing according to claim 1, wherein a pre-compression rate of the rubber elastic body after the diameter reduction processing of the outer cylinder fitting is 20 to 25%.   The anti-vibration bush according to any one of claims 1 to 6, wherein the outer cylinder fitting has a tapered portion having a diameter that decreases toward an end edge at least at one end portion.   The said outer cylinder metal fitting has a stopper part provided so that it might extend in the radial direction outward from the other end, and might be opposed to the bracket arrange | positioned on the other end side outer side of the said outer cylinder metal fitting. Anti-vibration bush described. A rubber elastic body forming step of forming an outer peripheral surface of a cylindrical rubber elastic body having a concave portion or a convex portion in at least one place on the inner peripheral surface of the outer cylindrical metal member by vulcanization bonding; ,
Sliding that applies a sliding process to at least one of the outer peripheral surface of the inner cylindrical metal fitting having the convex or concave portion engaged with the concave or convex portion of the rubber elastic body on the outer peripheral surface and the inner peripheral surface of the rubber elastic body Processing steps;
An assembling step for press-fitting and assembling the inner cylinder fitting to the inner peripheral side of the rubber elastic body;
A pre-compression applying step of applying a radial pre-compression to the rubber elastic body by reducing the diameter of the outer tube fitting after the assembly step from the outer peripheral side;
A method for manufacturing an anti-vibration bush, comprising:   The method for manufacturing a vibration-proof bushing according to claim 9, wherein a press-fit rate of the rubber elastic body in the assembling step is 5 to 15%.   The method for manufacturing a vibration-isolating bush according to claim 9 or 10, wherein a pre-compression rate of the rubber elastic body after completion of the pre-compression applying step is 20 to 25%.   The vibration-proof bushing according to any one of claims 9 to 11, further comprising a taper portion forming step of forming a taper portion having a smaller diameter as approaching an end edge at least one end portion of the outer cylinder fitting after the assembly step. Method.

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