WO2007097070A1

WO2007097070A1 - Process for producing antivibration bush

Info

Publication number: WO2007097070A1
Application number: PCT/JP2006/321774
Authority: WO
Inventors: Ken Suzuki
Original assignee: Toyo Tire & Rubber Co., Ltd.
Priority date: 2006-02-20
Filing date: 2006-10-31
Publication date: 2007-08-30
Also published as: JP2007218412A; JP3951274B1

Abstract

A process for producing an antivibration bush, in which even when the thickness of the outer tube is large, draw forming thereof is easy and a durability enhancement can be attained. There is provided a process for producing antivibration bush (10) having inner tube (12) and outer tube (14) and, interposed therebetween, rubbery elastic matter (16), which process, to facilitate draw forming even when the thickness of the outer tube is large, comprises making axially extending multiple incised grooves (24) on internal circumferential surface (15) of the outer tube (14), the incised grooves (24) distributed at equal intervals along the circumference; conducting vulcanization forming of the rubbery elastic matter (16) between the outer tube (14) furnished with the incised grooves (24) and the inner tube (12); and performing draw forming of the outer tube (14) after the vulcanization forming. In a preferred mode, with respect to the outer tube (14) wherein the external circumferential surface (19) thereof is in the form of straight tube and wherein the internal circumferential surface (15) is furnished with concave spherical surface (22) corresponding to convex spherical surface (20) of the inner tube (12), the incised grooves (24) are made on the internal circumferential surface (15).

Description

Specification

Anti-vibration bushing manufacturing method

Technical field

[0001] The present invention relates to a vibration isolating bush used by being incorporated in an automobile suspension device or the like.

Background art

Conventionally, in an automobile suspension device, an anti-vibration bush is used at a connection portion between a vehicle body and a suspension for the purpose of vibration damping, buffering, and the like. Such an anti-vibration bush is generally provided between a shaft member such as an inner cylinder, an outer cylinder arranged at an interval on the outer side of the shaft member, and the shaft member and the outer cylinder. (For example, refer to Patent Document 1 below).

As such an anti-vibration bush, in order to increase the panel constant in the direction perpendicular to the axis and to decrease the panel constant in the twisting direction, a bulge portion that bulges in the axis perpendicular direction at the axial center of the inner cylinder A so-called bulge-type anti-vibration bush is known (see Patent Documents 2 to 6 below).

[0004] By the way, as a suspension apparatus provided with this type of vibration isolating bushing, the following Patent Document 7 discloses a multi-link type rear suspension apparatus shown in FIGS. In this suspension device, an axle 62 that rotatably supports a wheel 60, one end portions 64a and 66a are swingably connected to the axle 62, and the other end portions 64b and 66b swing to a suspension member 68 that is a vehicle body side member. A pair of front and rear upper links 64, 66, which are movably connected, and one end portions 70a, 72a are swingably connected to the axle 62, and the other end portions 70b, 72b are swingably connected to the suspension member _68. The pair of front and rear lower links 70, 72 and a toe control link 74 having one end 74a swingably connected to the axle 62 and the other end 74b swingably connected to the suspension member 68. Here, symbol F indicates the front side of the vehicle body, and symbol H indicates the vehicle body width direction.

[0005] The other end portions 64b, 66b, 70b, 72b, 74b of the links 64, 66, 70, 72, 74 and the suspension member 68 are connected to the vibration isolating bushes 76, 78, 80, 82, 84, respectively. Connected through The axial center of each anti-vibration bush pi, p2, p3, p4, p5 force In the plan view, the longitudinal direction of each link rl, r2, r3, r4, r5 Arranged

In the multilink suspension device, as shown in FIG. 12, each link 64, 66, 70, 72, 74 is set in an inclined posture in plan view. Specifically, the front lower link 70 force is set to an inclined posture located in the vehicle front side F toward the inner side in the vehicle body width direction H in plan view, and the rear lower link 72 is set in the vehicle width direction in plan view. The toe control link 74 is set to the leaning posture located on the front side F of the vehicle body in the plan view in H as the outward side is set to H, and is set to the inclined posture located on the front side F of the vehicle side in the vehicle width direction H. It has been done.

[0007] Therefore, during traveling of the vehicle, forces in various directions are input to the vibration isolating bushes 80, 82, 84 coupled mainly to the lower links 70, 72 and the toe control link 74. For example, when the suspension device is displaced in the vertical direction with respect to the vehicle body, the anti-vibration bushings 80, 82, 84 not only have a force in the twisting direction N (see Fig. 3) but also a force in the twisting direction Z (see Fig. 1). Join. In addition, when the suspension device is displaced in the left-right direction with respect to the vehicle body, the anti-vibration bushes 80, 82, 84 have not only the force in the direction perpendicular to the axis Y (see Fig. 1) but also in the axial direction X (see Fig. 1). Power is also added.

[0008] With respect to such an input, in the conventional general anti-vibration bushing, both the inner cylinder and the outer cylinder are straight cylinders having a constant diameter, so that the panel constant in the twisting direction is large. Since the panel constant in the vertical direction of the pen- sion device is large, it is difficult to improve the ride comfort. In addition, with this conventional anti-vibration bushing, the panel constant in the axial direction is not so large, so the panel constant in the left-right direction of the suspension device cannot be increased! Difficult to improve,

[0009] On the other hand, the panel type constant in the twisting direction can be reduced with the noisy type anti-vibration bush described in Patent Document 2. However, even in this bulge type, the inner peripheral surface of the outer cylinder is straight, so that when it is displaced in the twisting direction, the rubber-like rigid body has rubber between the inner cylinder and the outer cylinder at both ends in the axial direction. The elastic body was compressed, and the panel constant in the twisting direction was not always sufficiently reduced. That Therefore, the effect of reducing the panel constant in the vertical direction of the suspension device is insufficient, and further improvement is required to improve riding comfort. Also, with the bulge-type vibration isolating bushes described in this document, the panel constant in the axial direction cannot be increased, so the panel constant in the left-right direction of the suspension device is increased to improve vehicle handling stability. It was difficult to do.

[0010] On the other hand, in the bulge type vibration-proof bush described in Patent Documents 3 and 4, the central portion in the axial direction of the outer cylinder is expanded outwardly in correspondence with the bulging portion forming the spherical shape of the inner cylinder. As a result, the panel constant in the twisting direction can be further reduced. However, these anti-vibration bushes have a large diameter part with a constant diameter at the center in the axial direction of the outer cylinder in order to press fit and hold the outer cylinder in the cylindrical holder of the link. In some cases, the dimensions are not always sufficient, and further improvement in the removal force is required. Further, in order to provide the large-diameter portion, the inner peripheral surface of the outer cylinder is formed in a substantially trapezoidal cross section. Therefore, it is said that the shape sufficiently follows the shape of the bulging portion on the inner cylinder side that forms a spherical shape. It is also difficult, and the rubber-like elastic body interposed between them has a large change in the axial thickness, which affects the performance.

[0011] By the way, in an anti-vibration bush equipped with an outer cylinder, the outer cylinder is squeezed in the direction of diameter reduction after vulcanization molding in order to improve the durability by removing the shrinkage of the rubber-like elastic body after vulcanization molding. Processing is usually performed (for example, see Patent Documents 4 and 8 below).

Patent Document 1: Japanese Patent Laid-Open No. 2002-81479

Patent Document 2: Japanese Unexamined Patent Publication No. 2004-144150

Patent Document 3: Japanese Patent Laid-Open No. 9-100859

Patent Document 4: Japanese Patent Laid-Open No. 9-203428

Patent Document 5: Japanese Unexamined Patent Publication No. 2005-344764

Patent Document 6: Japanese Unexamined Patent Publication No. 9-100861

Patent Document 7: Japanese Unexamined Patent Publication No. 2005-112258

Patent Document 8: Japanese Patent Application Laid-Open No. 11-230224

Disclosure of the invention

Problems to be solved by the invention

[0012] When the outer cylinder is drawn after the vulcanization molding of the vibration-proof bushing as described above, There is a problem that the wall thickness of the outer cylinder is large, and it is difficult to draw.

[0013] The present invention has been made in view of these points, and is a vibration-proof bushing that can be easily drawn and improved in durability even when the thickness of the outer cylinder is large. The purpose is to provide a manufacturing method.

Means for solving the problem

[0014] The manufacturing method according to the present invention includes a shaft member, an outer cylinder disposed on the outer side of the shaft member, and a rubber-like elastic member interposed between the shaft member and the outer cylinder. A vibration isolating bush comprising a body, a step of producing an outer cylinder in which a plurality of grooves extending in the axial direction are distributed in the circumferential direction on an inner circumferential surface, and an outer periphery of the shaft member Forming a rubber-like elastic body between the shaft member and the outer cylinder provided with the concave groove so that a rubber-like elastic body is integrally bonded to a surface and an inner peripheral surface of the outer cylinder; And drawing the outer cylinder after forming the rubber-like elastic body.

[0015] According to this method, since the plurality of concave grooves are provided in the circumferential direction on the inner peripheral surface of the outer cylinder, even when the thickness of the outer cylinder is large, the rubber-like elastic body is molded. The outer cylinder can be drawn and the durability can be improved immediately.

[0016] In this way, when the outer cylinder is drawn after the rubber-like elastic body is molded, the plurality of concave grooves are formed so that distortion due to the drawing does not occur as much as possible at the interface between the rubber-like elastic body and the inner peripheral surface of the outer cylinder. Are preferably arranged at equal intervals in the circumferential direction on the inner peripheral surface of the outer cylinder. Furthermore, it is preferable that the plurality of concave grooves are arranged on the inner peripheral surface of the outer cylinder at intervals of 6 to 90 ° in the circumferential direction and wider than the groove width. If the arrangement of the concave grooves is set to be sparser than every 90 °, the number of the concave grooves is too small, and the distortion of the rubber-like elastic body is concentrated at the interface with the outer cylinder. Thus, by appropriately arranging a predetermined number or more of the grooves, the strain at the adhesive interface of the rubber-like elastic body is dispersed, and a preferable drawing process is performed within a range where the adhesive surface is not destroyed. Therefore, it is possible to prevent peeling at the bonding surface between the rubber-like elastic body and the outer cylinder.

In the present invention, the shaft member and the outer cylinder may be configured as follows. That is, it is preferable that the shaft member has a bulging portion that bulges in a direction perpendicular to the axis at the central portion in the axial direction, and the outer peripheral surface of the bulging portion forms a convex spherical surface. The outer cylinder has a constant outer peripheral diameter in the axial direction. The inner peripheral surface portion of the central portion in the axial direction surrounding the convex spherical surface is recessed in the concave spherical surface corresponding to the convex spherical surface, and is formed in the central portion in the axial direction of the outer cylinder. It is preferable that the wall thickness is thinner than the wall thickness at both ends in the axial direction.

As described above, the inner peripheral surface of the outer cylinder is formed as a concave spherical surface corresponding to the convex spherical surface of the bulging portion of the shaft member. The interposed rubber elastic body is substantially only subjected to shear deformation, and it is possible to avoid compression of the rubber elastic body between the shaft member and the outer cylinder as much as possible. The spring constant can be effectively reduced. In addition, since the rubber-like elastic body is subjected not only to shear deformation but also to compression deformation between the convex spherical surface and the concave spherical surface at the time of displacement in the axial direction, the panel constant in the axial direction can be increased. In addition, since the rubber-like elastic body interposed between the convex spherical surface and the concave spherical surface has a constant thickness in the axial direction, it is not only when displaced in the twisting direction but also when displaced in the direction perpendicular to the axial direction. Vibration suppression performance and durability can be improved by suppressing the application of uniform stress.

[0019] Further, the outer cylinder is provided with a concave portion that forms a concave spherical surface in the central portion in the axial direction, and the diameter of the outer peripheral surface is a straight cylindrical shape that is constant in the axial direction. A sufficient axial dimension for press-fitting with the cylindrical holder can be ensured, and the pulling force of the cylindrical holder can be improved. If the inner peripheral surface of the central portion of the outer cylinder is made concave spherical in this way, the thickness increases at both ends of the outer cylinder. However, as described above, in the present invention, the inner peripheral surface of the outer cylinder is applied to the inner peripheral surface of the outer cylinder. Even in this case, there is an advantage that the depth of the concave spherical surface can be set deeply because of the plurality of concave grooves provided, even in this case, the outer cylinder can be drawn.

[0020] In the above case, the convex spherical surface and the concave spherical body are not filled between the shaft member and the outer cylinder on the outer side in the axial direction of the virtual spherical surface defined by the concave spherical surface. It is preferable to interpose between the spherical surfaces. Further, both end surfaces in the axial direction of the rubber-like elastic body are formed in a curved surface shape that swells inward in the axial direction, and a virtual spherical surface defined by the concave spherical surface is a cross-section along the axial direction of the shaft member. A curved surface-like axial end surface intersects, and the intersection ω between the phantom spherical surface and the axial end surface is located on the outer cylinder side from the innermost point (Κ) in the axial end surface. Thus, it is preferable to mold the rubber-like elastic body. This makes it rubbery when displaced in the prying direction. It is possible to reliably avoid the compression panel from being applied at the axial end of the elastic body, and to further reduce the spring constant in the twisting direction.

The invention's effect

[0021] According to the method for manufacturing a vibration isolating bush of the present invention, even when the outer cylinder is thick, the outer cylinder is drawn after the rubber-like elastic body is formed, and the durability of the vibration isolating bush is improved immediately. Can be improved.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The anti-vibration bush 10 according to the embodiment is used for the multi-link suspension device shown in FIGS. 11 and 12, and more specifically, the other end portion 70b of the front lower link 70 and Anti-vibration bush 80 connecting suspension member 68, anti-vibration bush 82 connecting other end 72b of rear lower link 72 and suspension member 68, and other end 74b of suspension control link 74 and suspension Used as anti-vibration bushing 84 connecting member 68. The overall configuration of the suspension device is as described above, and a description thereof is omitted. The anti-vibration bushing 76 connecting the other end portion 64b of the front upper link 64 and the suspension member 68, and the anti-vibration bushing 78 connecting the other end portion 66b of the rear upper link 66 and the suspension member 68. In this example, the conventional anti-vibration bush is used. However, the anti-vibration bush 10 according to this embodiment may be used.

As shown in FIG. 1, the anti-vibration bush 10 includes an inner cylinder 12 as a shaft member, an outer cylinder 14 that is coaxially disposed so as to surround the outer cylinder 14, and an inner cylinder 12. And a cylindrical rubber-like elastic body 16 interposed between the outer cylinder 14 and the outer cylinder 14. Then, as shown in FIG. 10, the inner cylinder 12 is fixed to the bracket 1 by tightening with a fastening member (not shown) such as a bolt with both end faces sandwiched between the brackets 1 of the suspension member. The outer cylinder 14 is fixed by being press-fitted into a cylindrical holder 3 such as the lower link 70, so that the vibration isolating bush 10 connects the lower link 70 and the bracket 1 on the suspension member side in an anti-vibration manner. To do.

[0025] The inner cylinder 12 is a cylindrical member made of metal such as iron, steel or aluminum, and is shown in FIGS. Thus, a bulging portion 18 that bulges over the entire circumference in the direction perpendicular to the axis Y is provided at the center in the axial direction X. The outer peripheral surface of the bulging portion 18 forms a convex spherical surface 20. The convex spherical surface 20 is formed in the shape of a sphere that forms the axial center of a spherical surface having a center Α on the axis Α, and is a general cylindrical portion (with a constant outer diameter) at both axial ends of the inner cylinder 12. The outer peripheral surface of the straight cylindrical part) is formed in a gentle continuous manner.

[0026] The outer cylinder 14 is a cylindrical member made of metal such as iron, steel, or aluminum. As shown in FIGS. 7 and 8, the outer shape is circular in cross section and the diameter of the outer peripheral surface 19 is in the axial direction X. It is formed in a certain straight cylinder shape.

As shown in FIG. 1, the inner peripheral surface 15 of the outer cylinder 14 has a central portion in the axial direction X surrounding the convex spherical surface 20 concentric with the convex spherical surface 20 (that is, a common center P A concave spherical surface 22). In other words, the inner peripheral surface partial force of the outer cylinder 14 surrounding the bulging portion 18 is recessed on the concave spherical surface 22 corresponding to the convex spherical surface 20. More specifically, the inner peripheral surface 15 at the center of the outer cylinder 14 is axially aligned with the convex spherical surface 20 of the inner cylinder 12 at a certain interval in the shape after drawing described later. It is formed as a concave spherical surface 22 that is recessed outward in the right-angle direction Y. The concave spherical surface 22 has a spherical shape that forms the central portion of the spherical surface, and is gently continuous from the inner peripheral surface 15a of the general cylindrical portion (straight cylindrical portion having a constant inner diameter) at both axial ends of the outer cylinder 12. Is formed.

[0028] And, by providing the concave concave spherical surface 22, the outer cylinder 14 is formed such that the thickness T1 at the central portion in the axial direction X is thinner than the thickness T2 at both end portions in the axial direction X. (See Figure 8). In addition, as shown in FIG. 8, in the state before drawing, the central portion of the inner peripheral surface 15 of the outer cylinder 14 in the axial direction is not the exact concave spherical surface 22 and the center P is the axis of the outer cylinder 14. The center P is formed in the shape of a sphere with the center P located on the axis A as shown in Fig. 1 by drawing in the reduced diameter direction.

As shown in FIGS. 7 and 8, a plurality of concave grooves 24 extending in the axial direction X are provided at equal intervals in the circumferential direction C on the inner peripheral surface 15 of the outer cylinder 14. The cylinder 14 is formed thin at the circumferential position where the concave groove 24 is provided. Specifically, the concave grooves 24 are arranged on the inner peripheral surface 15 of the outer cylinder 14 at intervals of 6 to 90 ° in the circumferential direction and with a gap D wider than the groove width W. In the example, a total of 12 concave grooves 24 are provided every 30 °, and the interval between adjacent concave grooves 24 is D is set to more than twice the groove width W (specifically, about 3 times). In addition, it is more preferable that the concave groove 24 is provided every 15 to 45 °.

[0030] As shown in FIG. 7, the concave groove 24 is formed to be depressed into a circular arc shape as a shape before drawing. Further, in this example, since the concave spherical surface 22 is provided on the inner peripheral surface 15 in the central portion in the axial direction X as described above, the concave groove 24 is the other axial direction excluding the portion where the concave spherical surface 22 is provided. It is formed over the entire part.

[0031] The rubber-like elastic body 16 is integrally vulcanized and bonded to the inner peripheral surface 15 of the outer cylinder 14 and the outer peripheral surface 13 of the inner cylinder 12, and is connected to the convex spherical surface 20 of the inner cylinder 12. As shown in Fig. 1, it is formed in a spherical band shape with a substantially constant thickness in the shape after drawing, as shown in Fig. 1. The

Further, as shown in FIG. 2, on the axially outer side XI of the phantom spherical surface 26 defined by the concave spherical surface 22 on the outer cylinder 14 side, a rubber-like elastic body is provided between the inner cylinder 12 and the outer cylinder 14. It is provided with an annular straight part that dents in the axially inward direction X2, such as V, which is not filled with 16.

[0033] More specifically, the rubber-like elastic body 16 has a pair of left and right axial end faces 17 of the rubber-like elastic body 16 exposed between the axial ends of the inner cylinder 12 and the outer cylinder 14. It is formed in a curved surface shape that swells in the axially inward side X2, and here, it is formed in a circular shape in a cross section along the axial direction X shown in FIG. In the cross section along the axial direction, the phantom spherical surface 26 defined by the concave spherical surface 22 intersects the curved axial end surface 17 at the intersection J, and this intersection J is in the axial end surface 17. The innermost point in the axial direction (that is, the point corresponding to the deepest part (bottom) of the end face 17 in the axial direction) is located closer to the outer cylinder 14 than K. In this example, the innermost point K on the axial end face 17 is on a line 27 that bisects the gap between the inner cylinder 12 and the outer cylinder 14 in the radial direction, and is radially outside the line 27. The intersection point J is located on the opposite side.

In addition, as shown in FIG. 2, the outermost diameter of the bulging portion 18 on the inner cylinder 12 side (the outer diameter at the apex of the bulging portion 18) dl is the inner diameter of the general cylindrical portion of the outer cylinder 14. It is set to be smaller than d2, and the thickness of the rubber elastic body 16 between the convex spherical surface 20 and the concave spherical surface 22 E force is set to be larger than the maximum bulging height G of the bulging portion 18 of the inner cylinder 12 Has been. As a result, while avoiding an excessive panel constant in the axial direction X, a preferred panel in the direction perpendicular to the axis Y, the twisting direction Ζ and the twisting direction 方向 is obtained. It is configured to obtain a constant.

Note that a rubber film 28 connected to the rubber-like elastic body 16 is formed on the outer peripheral surface 13 of the inner cylinder 12 and the inner peripheral surface 15 of the outer cylinder 14 on the axially outer side XI.

A method for manufacturing the vibration isolating bush 10 will be described. In manufacturing, first, as shown in FIGS. 5 and 6, the inner cylinder 12 having the bulging portion 18 constituting the convex spherical surface 20 and the straight cylindrical outer peripheral surface 19 as shown in FIGS. At the same time, outer cylinders 14 each having a concave spherical surface 22 corresponding to the convex spherical surface 20 and a concave groove 24 extending in the axial direction on the inner peripheral surface 15 are produced.

[0037] Next, the inner cylinder 12 and the outer cylinder 14 are placed in a molding die (not shown), and a rubber material is injected into the molding die, so that a rubber-like material is formed between the inner cylinder 12 and the outer cylinder 14. The elastic body 16 is vulcanized and molded, and the rubber-like elastic body 16 is integrally vulcanized and bonded to the outer peripheral surface 13 of the inner cylinder 12 and the inner peripheral surface 15 of the outer cylinder 14. As a result, the vulcanized molded body before drawing shown in FIGS. In the vulcanized molded body, a rubber-like elastic body 16 enters into the concave groove 24 of the outer cylinder 14, and the rubber-like elastic body 16 vulcanizes to the inner peripheral surface 15 of the outer cylinder 14 even in the concave groove 24. Adhesive strength is increased.

[0038] Thereafter, the outer cylinder 14 of the vulcanized molded body is drawn. Drawing is performed using a die 52 having dice pieces 50 radially divided into a plurality of pieces as shown in FIG. In this example, the die 52 is divided into twelve, which is the same number as the concave groove 24 of the outer cylinder 14, and is set so that the concave groove 24 is positioned at the center in the circumferential direction of each die piece 50. By moving the piece 50 inward in the diameter, the outer cylinder 14 is drawn in the direction of diameter reduction. Thereby, the vibration isolating bush 10 shown in FIGS. 1 and 2 is obtained. The concave groove 24 remains in a state in which the rubber-like elastic body 16 enters the concave groove 24 that does not completely sag after drawing.

[0039] In the present embodiment configured as described above, the inner peripheral surface of the outer cylinder 14 is provided even though the thickness of the outer cylinder 14 is large by providing the concave spherical surface 22 at the center of the outer cylinder 14. By uniformly arranging the plurality of concave grooves 24 in 15, the outer cylinder 14 can be easily drawn after vulcanization molding. In addition, by properly arranging the required number of the concave grooves 24, it is possible to disperse the distortion due to the restriction at the adhesive interface between the rubber-like elastic body 16 and the outer cylinder 14, and to avoid the destruction of the adhesive interface. Further, peeling between the rubber-like elastic body 16 and the outer cylinder 14 can be prevented.

[0040] The obtained anti-vibration bushing 10 has an inner peripheral surface 15 of the outer cylinder 14 and a convex spherical surface 20 of the inner cylinder 12. The concentric concave spherical surface 22 makes it possible to effectively reduce the panel constant in the twisting direction Z because the force received by the rubber-like elastic body 16 is only shear deformation when displaced in the twisting direction Z. . As a result, the panel constant in the vertical direction of the suspension device can be reduced, so that ride comfort can be improved.

[0041] Further, when displaced in the axial direction X, as shown in FIG. 2, the rubber-like elastic body 16 receives not only shear deformation but also compression deformation between the convex spherical surface 20 and the concave spherical surface 22. The panel constant in the axial direction X can be increased. When the displacement is in the direction perpendicular to the axis Y, the concave spherical surface 22 on the outer cylinder 14 side restricts the escape of rubber in the axial direction X, and the panel constant in the axial perpendicular direction Y can be increased. As a result, the panel constant in the left-right direction of the suspension device is increased, and the steering stability can be improved. Therefore, both ride comfort and handling stability can be achieved.

In particular, the intersection J between the virtual spherical surface 26 and the axial end surfaces 17 of the rubber-like elastic body 16 is positioned closer to the outer cylinder 14 than the innermost point K of the axial end surface 17. As a result, it is possible to reliably avoid the compression panel from being applied at the axial end portion of the rubber-like elastic body 16 during displacement in the twisting direction Z, and to further reduce the panel constant in the twisting direction Z. For this reason, the panel constant in the vertical direction of the suspension device can be further reduced, and the suspension can be supple. Therefore, the vertical movement is absorbed by the suspension so as not to change the height of the occupant's eyes. A flat feeling can be obtained.

[0043] Further, since the thickness of the rubber-like elastic body 16 interposed between the convex spherical surface 20 and the concave spherical surface 22 in the axial direction X is constant, it is not particularly effective when displaced in the direction perpendicular to the axis Y. By suppressing the application of uniform stress, the vibration isolation performance and durability can be improved.

[0044] Further, the outer cylinder 14 is provided with a concave portion constituting the concave spherical surface 22 in the central portion in the axial direction, but the diameter of the outer peripheral surface 19 is a straight cylindrical shape constant in the axial direction. A sufficient axial dimension for press-fitting with the cylindrical holder 3 can be secured, and the removal force from the cylindrical holder 3 can be improved.

[0045] In the above embodiment, the force described with reference to the bush of a no-restriction type can be applied to a vibration isolating bush that is not a bulge type. In this case, the inner peripheral surface of the outer cylinder The groove may be formed so as to extend in the entire axial direction. In the above embodiment, In order to form a bulge-type bush, the bulging portion 18 provided on the inner cylinder 12 is integrally formed of a metal material. However, the bulge is formed by providing an annular covering made of resin on the outer peripheral surface of the inner cylinder. An outlet may be formed.

Industrial applicability

The present invention can be used for various anti-vibration bushes such as an anti-vibration bush used in an automobile suspension device and a cylindrical anti-vibration bush as an engine mount.

Brief Description of Drawings

FIG. 1 is a cross-sectional view of an anti-vibration bush according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of the vibration isolating bush.

FIG. 3 is a side view of the vibration isolating bush before drawing.

4 is a cross-sectional view taken along the line IV-IV in FIG.

FIG. 5 is a side view of the inner cylinder.

FIG. 6 is a cross-sectional view taken along line VI—VI in FIG.

FIG. 7 is a side view of the outer cylinder.

8 is a cross-sectional view taken along line VIII-VIII in FIG.

FIG. 9 is a view showing a drawing process of the vibration isolating bush.

FIG. 10 is a cross-sectional view showing an assembled state of the vibration isolating bush.

FIG. 11 is a perspective view of a suspension device.

FIG. 12 is a plan view of the suspension device.

Explanation of symbols

[0048] 10 ··· Anti-vibration bush, 12 ··· Inner tube (shaft member), 13 ··· Outer surface of inner tube, 14 · · · Outer tube, 15 ··· Inner surface of outer tube, 16 ··· ··· Rubber elastic body, 17 ··· Axial end face of rubber elastic body, 18 ··· bulge portion, ··· Outer peripheral surface of outer cylinder, 20 ··· convex spherical surface, 22 ··· concave spherical surface, 24 ··················································································· J. Τ2 ··· Thickness at both ends of the outer cylinder in the axial direction, X ... axial direction, XI · · · axially outward side, Χ2 · · · axially inward side, Y ... axis perpendicular direction, Ζ · Picking direction

Claims

The scope of the claims

[1] An anti-vibration bushing comprising: a shaft member; an outer cylinder disposed at an interval outside the shaft member; and a rubber-like elastic body interposed between the shaft member and the outer cylinder. A method of manufacturing an outer cylinder in which a plurality of concave grooves extending in the axial direction are distributed in the circumferential direction on the inner circumferential surface;

A rubber-like elastic body is formed between the shaft member and the outer cylinder provided with the concave groove so that the rubber-like elastic body is integrally bonded to the outer peripheral surface of the shaft member and the inner peripheral surface of the outer cylinder. And a step of drawing the outer cylinder after molding the rubber-like elastic body,

A method for manufacturing a vibration-proof bushing.

[2] The method for manufacturing a vibration-proof bushing according to claim 1, wherein the plurality of concave grooves are arranged at equal intervals in the circumferential direction on the inner peripheral surface of the outer cylinder.

[3] The plurality of concave groove forces are arranged on the inner circumferential surface of the outer cylinder at intervals of 6 ° to 90 ° in the circumferential direction with a gap larger than the groove width.

A method for manufacturing the vibration-proof bushing according to claim 3.

[4] The shaft member has a bulging portion that bulges in a direction perpendicular to the axis at a central portion in the axial direction, and an outer peripheral surface of the bulging portion forms a convex spherical surface.

The outer cylinder is formed in a straight cylinder shape having a constant outer peripheral surface diameter in the axial direction, and an inner peripheral surface portion of an axially central portion surrounding the convex spherical surface is a concave spherical surface corresponding to the convex spherical surface. The thickness of the outer cylinder in the axially central portion is thinner than the thickness at both axial ends.

The method for manufacturing the vibration-proof bushing according to claim 1.

[5] The convex spherical surface and the concave spherical surface are arranged so that the rubber-like elastic body is not filled between the shaft member and the outer cylinder on the axially outer side of the virtual spherical surface defined by the concave spherical surface. Between

A method for manufacturing the vibration-proof bushing according to claim 4.

[6] Both end surfaces in the axial direction of the rubber-like elastic body are formed into curved surfaces that swell inward in the axial direction. In addition, in a cross section along the axial direction of the shaft member, a virtual spherical surface defined by the concave spherical surface intersects with the curved axial end surface, and an intersection ω between the virtual spherical surface and the axial end surface is The rubber-like elastic body is molded so as to be located on the outer cylinder side from the innermost point (κ) in the axial end face.

6. A method for manufacturing a vibration-proof bush according to claim 5.