JP3924729B1 - Anti-vibration bush - Google Patents

Abstract

An anti-vibration bush capable of sufficiently reducing the spring constant in the twisting direction and increasing the spring constant in the axial direction is provided.
In an anti-vibration bushing 10 in which a rubber-like elastic body 16 is interposed between an inner cylinder 12 and an outer cylinder 14, the inner cylinder 12 bulges in a central portion in the axial direction X in a direction perpendicular to the axis Y. The outer peripheral surface of the bulging portion forms a convex spherical surface 20. The outer cylinder 14 is formed in a straight cylinder shape in which the diameter of the outer peripheral surface 19 is constant in the axial direction, and an inner peripheral surface portion surrounding the convex spherical surface 20 forms a concave spherical surface 22 concentric with the convex spherical surface 20. The rubber-like elastic body 16 is disposed between the convex spherical surface 20 and the concave spherical surface 22 so as not to be filled between the inner cylinder 12 and the outer cylinder 14 on the axially outer side X1 of the virtual spherical surface 26 defined by the concave spherical surface 20. Is interposed.
[Selection] Figure 1

Description

  The present invention relates to an anti-vibration bush used by being incorporated in an automobile suspension device or the like.

  2. Description of the Related Art Conventionally, in an automobile suspension device, a vibration isolating bush is used at a connection portion between a vehicle body and a suspension for the purpose of vibration damping and buffering. Such an anti-vibration bush is generally provided between a shaft member such as an inner cylinder, an outer cylinder arranged on the outer side of the shaft member, and between the shaft member and the outer cylinder so as to elastically support both. And a rubber-like elastic body to be bonded together.

  As such an anti-vibration bush, in order to reduce the spring constant in the twisting direction while increasing the spring constant in the direction perpendicular to the axis, a bulging part that bulges in the direction perpendicular to the axis is provided in the axial center part of the inner cylinder. So-called bulge-type vibration-proof bushes are known (see Patent Documents 1 to 5 below).

  By the way, as a suspension device provided with this type of vibration isolating bushing, the following Patent Document 6 discloses a multi-link type rear suspension device shown in FIGS. In this suspension apparatus, 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 are pivoted to a suspension member 68 that is a vehicle body side member. A pair of front and rear upper links 64 and 66, which are movably connected, and one end portions 70a and 72a are swingably connected to the axle 62, and the other end portions 70b and 72b are swingably connected to the suspension member 68. A pair of front and rear lower links 70, 72, and a toe control link 74 having one end 74 a pivotably connected to the axle 62 and the other end 74 b pivotably connected to the suspension member 68. Here, the symbol F indicates the front side of the vehicle body, and the symbol H indicates the vehicle body width direction.

The other ends 64b, 66b, 70b, 72b, 74b of the links 64, 66, 70, 72, 74 and the suspension member 68 are connected to each other through vibration-proof bushings 76, 78, 80, 82, 84, respectively. The shaft centers p1, p2, p3, p4, and p5 of each anti-vibration bushing are arranged so as to be along a direction orthogonal to the longitudinal directions r1, r2, r3, r4, and r5 of each link in plan view. Has been.
JP 2004-144150 A JP-A-9-1000085 JP-A-9-203428 JP 2005-344664 A Japanese Patent Laid-Open No. 9-1000085 Japanese Patent Laying-Open No. 2005-112258

  In the multi-link suspension device, as shown in FIG. 12, each link 64, 66, 70, 72, 74 is set in an inclined posture in plan view. More specifically, the front lower link 70 is set to an inclined posture positioned on 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 to the vehicle body width in plan view. The toe control link 74 is set to an inclined posture that is positioned on the front side F of the vehicle body in the vehicle width direction H in a plan view. Yes.

  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, not only the force in the twisting direction N (see FIG. 3) but also the force in the twisting direction Z (see FIG. 1) is applied to the vibration isolating bushes 80, 82, 84. . Further, when the suspension device is displaced in the left-right direction with respect to the vehicle body, not only the force in the direction perpendicular to the axis Y (see FIG. 1) but also the force in the axis direction X (see FIG. 1) is applied to the vibration isolating bushes 80, 82, 84. Join.

  In response 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 spring constant in the twisting direction is large. Since the spring constant in the direction becomes large, it is difficult to improve riding comfort. Also, with this conventional vibration-proof bushing, the spring constant in the axial direction is not so large, and therefore the spring constant in the left-right direction of the suspension device cannot be increased, so it is difficult to improve the steering stability of the vehicle. .

  On the other hand, in the case of the bulge type vibration isolating bush described in Patent Document 1, the spring constant in the twisting direction can be reduced. However, even in this bulge type, since the inner peripheral surface of the outer cylinder is straight, at the both ends in the axial direction of the rubber-like elastic body at the time of displacement in the twisting direction, a rubber-like shape is formed between the inner cylinder and the outer cylinder. The elastic body is compressed, and the spring constant in the twisting direction is not necessarily sufficiently reduced. Therefore, the effect of reducing the spring constant in the vertical direction of the suspension device is also insufficient, and further improvement is required to improve riding comfort. Further, in the bulge type vibration isolating bush described in the same document, the spring constant in the axial direction cannot be increased. Therefore, the spring constant in the left-right direction of the suspension device is increased to improve the steering stability of the vehicle. It was difficult.

  On the other hand, in the bulge type anti-vibration bushes described in Patent Documents 2 and 3, the axially central portion of the outer cylinder is expanded outwardly in correspondence with the bulging portion forming the spherical shape of the inner cylinder. Thus, the spring constant in the twisting direction can be further reduced. However, in these anti-vibration bushes, in order to press fit and hold the outer cylinder in the cylindrical holder of the link, a large-diameter portion having a constant diameter is provided at the axial central portion of the outer cylinder. In some cases, it is not 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 difficult, and the rubber-like elastic body interposed therebetween also has a large thickness change in the axial direction, which affects the performance.

  On the other hand, in the thing of the said patent document 4, by using the cylindrical holder of a link also with an outer cylinder, the inner peripheral surface of an outer cylinder respond | corresponds to the shape of the bulging part on the inner cylinder side which makes | forms a spherical shape. The concave spherical surface is formed, thereby eliminating the disadvantages caused by the large diameter portion having the constant diameter. However, when the rubber elastic body is integrally vulcanized and molded into the cylindrical holder of the link in this way, the mold becomes excessive and the processability is poor.

  On the other hand, in the thing of the said patent document 5, an intermediate cylinder is provided between an inner cylinder and an outer cylinder, and the bulging part corresponding to the shape of the bulging part by the side of the inner cylinder which makes | forms a spherical shape is provided in this intermediate cylinder. By providing, the outer cylinder is formed in a straight cylinder shape having a constant outer peripheral diameter. In this case, between the bulging portion forming the spherical shape of the intermediate cylinder and the inner peripheral surface of the outer cylinder, it is the same as that of the conventional bulge type as in the above-mentioned Patent Document 1, and therefore sufficient performance is not necessarily obtained. It may not be demonstrated.

  The present invention has been made in view of the above points, and can sufficiently reduce the spring constant in the twisting direction without impairing the press-fitting retention of the link with respect to the cylindrical holder, and the spring in the axial direction. An object of the present invention is to provide an anti-vibration bush capable of increasing the constant.

An anti-vibration bush according to the present invention includes a shaft member, an outer cylinder that concentrically surrounds the shaft member, and an outer peripheral surface of the shaft member and an inner peripheral surface of the outer cylinder that are vulcanized and bonded to each other. A rubber-like elastic body interposed between the cylinder and a vibration-proof bush,
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 the outer peripheral surface of the bulging portion forms a convex spherical surface,
The outer cylinder is formed in a straight cylindrical shape having a constant outer peripheral 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 that is concentric with the convex spherical surface. The thickness at the axially central portion of the outer cylinder is formed thinner than the thickness at the axially opposite ends,
The rubber-like elastic body is interposed between the convex spherical surface and the concave spherical surface so as not to be 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. Established ,
On the inner peripheral surface of the outer cylinder, a plurality of concave grooves extending in the axial direction are provided in the axial direction at both end portions in the axial direction formed thick, and the inner peripheral surface of the outer cylinder and the The outer peripheral surface of the shaft member is integrally vulcanized and bonded by vulcanization molding of the rubber-like elastic body, and the rubber-like elastic body enters the concave groove so that the inner peripheral surface of the outer cylinder in the concave groove. And the outer cylinder is drawn after the vulcanization adhesion .

  According to this configuration, the inner peripheral surface of the outer cylinder is a concave spherical surface that is concentric with the convex spherical surface of the bulging portion of the shaft member, so that the displacement between the convex spherical surface and the concave spherical surface when displaced in the twisting direction. The interposed rubber-like elastic body is substantially only subjected to shear deformation, and it is possible to avoid compression of the rubber-like elastic body between the shaft member and the outer cylinder as much as possible. The 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 spring 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. It is possible to improve the anti-vibration performance and durability by suppressing the application of uniform stress.

  In addition, the outer cylinder is provided with a concave portion constituting a concave spherical surface in the central portion in the axial direction, but the outer peripheral surface has a constant cylindrical shape in the axial direction. A sufficient axial dimension for press-fitting can be ensured, and the removal force from the cylindrical holder can be improved.

  In the anti-vibration bush of the present invention, both end surfaces in the axial direction of the rubber-like elastic body are formed in curved surfaces that swell inward in the axial direction, and are defined by the concave spherical surface in a cross section along the axial direction of the shaft member. A virtual spherical surface intersects with the curved axial end surface, and an intersection (J) between the virtual spherical surface and the axial end surface is more than the innermost point (K) on the axial end surface. It is preferable to be located on the outer cylinder side. This reliably prevents the compression spring from being applied at the axial end of the rubber-like elastic body when displaced in the twisting direction, and the spring constant in the twisting direction can be further reduced.

The anti-vibration bush of the present invention is also provided with a plurality of concave grooves extending in the axial direction at the both ends in the axial direction formed thick on the inner peripheral surface of the outer cylinder , since the inner circumferential surface of the outer cylinder and the outer peripheral surface of the shaft member is bonded by vulcanization integrally by vulcanization molding of the rubber-like elastic body, the outer cylinder is drawn after the pressurized vulcanization wearing, following The effect of is produced .

  As described above, since the outer cylinder is thick at both axial ends, it is difficult to draw the outer cylinder after vulcanization, but in this way, a plurality of recesses are formed on the inner peripheral surface of the outer cylinder. By providing the grooves in the circumferential direction, the outer cylinder can be easily drawn even in this case. Further, by providing the concave groove in this way, there is also an advantage that the depth of the concave spherical surface can be set deep.

  When the outer cylinder is drawn after vulcanization and bonding as described above, the plurality of concave grooves are formed on the outer cylinder so that distortion due to drawing does not occur as much as possible at the interface between the rubber-like elastic body and the outer peripheral surface of the outer cylinder. It is preferable that they are arranged at equal intervals in the circumferential direction on the inner peripheral surface. 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 at an interval 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. Therefore, by appropriately arranging a predetermined number or more of the concave grooves as described above, it is possible to disperse the strain at the adhesive interface of the rubber-like elastic body and perform a preferable drawing process within a range where the adhesive surface is not destroyed. Accordingly, it is possible to prevent peeling at the bonding surface between the rubber-like elastic body and the outer cylinder.

  With the anti-vibration bush of the present invention, the spring constant in the twisting direction can be sufficiently reduced and the spring constant in the axial direction can be increased without impairing the press-fitting retention of the link to the cylindrical holder. .

  Hereinafter, an anti-vibration bush 10 according to an embodiment of the present invention will be described with reference to the drawings.

  The anti-vibration bush 10 according to the present embodiment is used in the above-described 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 the suspension member. 68, a vibration isolating bush 82 that connects the other end 72b of the lower link 72 and the suspension member 68, and a second end 74b of the toe control link 74 and the suspension member 68. It is used as an anti-vibration bush 84 that connects the two. The overall configuration of the suspension device is as described above, and a description thereof will be omitted. Note that the vibration isolating bush 76 that connects the other end portion 64 b of the front upper link 64 and the suspension member 68, and the vibration isolating bush 78 that connects the other end portion 66 b of the rear upper link 66 and the suspension member 68. In this example, the conventional anti-vibration bush is used, but the anti-vibration bush 10 according to the present embodiment may also be used for these.

  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 inner cylinder 12, and an inner cylinder 12 and an outer cylinder 14. And a cylindrical rubber elastic body 16 interposed therebetween. 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 in a state in which both end surfaces are 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, whereby 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.

  The inner cylinder 12 is a cylindrical member made of metal such as iron, steel, or aluminum, and as shown in FIGS. A bulging portion 18 is provided. 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 central portion of a spherical surface having a center P on the axis A, and is a general cylindrical portion (with a constant outer diameter) at both axial end portions of the inner cylinder 12. The straight cylindrical part) is formed smoothly and continuously from the outer peripheral surface 13.

  The outer cylinder 14 is a cylindrical member made of metal such as iron, steel, and aluminum. As shown in FIGS. 7 and 8, the outer shape has a circular cross section, and the diameter of the outer peripheral surface 19 is constant in the axial direction X. It is formed in a straight cylindrical 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 that is concentric with the convex spherical surface 20 (that is, has a common center P). The concave spherical surface 22 is formed. That is, the inner peripheral surface portion of the outer cylinder 14 surrounding the bulging portion 18 is recessed in a concave spherical surface 22 concentric with the convex spherical surface 20. More specifically, the inner peripheral surface 15 at the central portion of the outer cylinder 14 is in the direction perpendicular to the axis Y so as to follow the convex spherical surface 20 of the inner cylinder 12 with a certain distance in the shape after drawing described later. It is formed as a concave spherical surface 22 that is recessed outward. The concave spherical surface 22 forms a spherical band that forms the central portion of the spherical surface, and continues smoothly 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.

  Since the concave spherical surface 22 is provided, 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 ends in the axial direction X (FIG. 8). reference). As shown in FIG. 8, in the state before drawing, the central portion in the axial direction of the inner peripheral surface 15 of the outer cylinder 14 is not a strict concave spherical surface 22, and the center P is from above the axis A of the outer cylinder 14. The center P is formed in a spherical shape with the center P positioned on the axis A as shown in FIG.

  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. It 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. A total of 12 concave grooves 24 are provided every 30 °, and the interval D between adjacent concave grooves 24 is set to be twice or more (specifically, about three times) the groove width W. In addition, it is more preferable to provide the concave groove 24 every 15 to 45 °.

  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 has other axial directions except for the portion where the concave spherical surface 22 is provided. It is formed over the entire part.

  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 formed between the convex spherical surface 20 of the inner cylinder 12 and the outer cylinder 14. It is interposed so as to fill a space between the concave spherical surface 22, and as shown in FIG. 1, it is formed in a spherical band shape having a substantially constant thickness in the shape after drawing.

  Further, as shown in FIG. 2, the rubber-like elastic body 16 is filled between the inner cylinder 12 and the outer cylinder 14 on the axially outer side X1 of the virtual spherical surface 26 defined by the concave spherical surface 22 on the outer cylinder 14 side. In order to prevent this, an annular straight portion that is depressed toward the axially inner side X2 is provided.

  More specifically, the rubber-like elastic body 16 has a pair of left and right axial end surfaces 17 of the rubber-like elastic body 16 exposed between the axial ends of the inner cylinder 12 and the outer cylinder 14 in the axially inward direction. It is formed in a curved surface shape that swells to the side X2, and here, it is curved and formed in an arc 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 the most in the axial end surface 17. An axially inner point (that is, a point corresponding to the deepest part (bottom) of the axial end face 17) K is located on the outer cylinder 14 side. 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 J is located on the side.

  2, the outermost diameter (outer diameter at the apex of the bulging portion 18) d1 of the bulging portion 18 on the inner cylinder 12 side is smaller than the inner diameter d2 of the general cylindrical portion of the outer cylinder 14. Further, the thickness E of the rubber-like elastic body 16 between the convex spherical surface 20 and the concave spherical surface 22 is set to be larger than the maximum bulging height G of the bulging portion 18 of the inner cylinder 12. . Thereby, while avoiding an excessive spring constant in the axial direction X, preferable spring constants in the direction perpendicular to the axis Y, the twisting direction Z, and the torsional direction N are obtained.

  A rubber film 28 that is continuous with 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 X1.

  When manufacturing the anti-vibration bushing 10, the inner cylinder 12 shown in FIGS. 5 and 6 and the outer cylinder 14 shown in FIGS. 7 and 8 are formed, and both are placed in a molding die (not shown). The rubber-like elastic body 16 is vulcanized and molded by injecting a rubber material into the mold, and the rubber-like elastic body 16 is vulcanized integrally with the outer peripheral surface 13 of the inner cylinder 12 and the inner peripheral surface 15 of the outer cylinder 14. Adhere. As a result, the vulcanized molded body before drawing shown in FIGS. In the vulcanized molded body, the rubber-like elastic body 16 enters the concave groove 24 of the outer cylinder 14, and the rubber-like elastic body 16 is vulcanized on the inner peripheral surface 15 of the outer cylinder 14 also in the concave groove 24. Adhesive strength is increased.

  Next, the vulcanized product is subjected to drawing. Drawing is performed using a die 52 having dice pieces 50 that are radially divided into a plurality of pieces as shown in FIG. In this example, the dice 52 are divided into twelve, which is the same number as the concave grooves 24 of the outer cylinder 14. The dice 52 are set so that the concave grooves 24 are positioned in the circumferential center of each die piece 50. By moving 50 radially inward, the outer cylinder 14 is drawn in the direction of diameter reduction. Thereby, the anti-vibration bush 10 shown in FIGS. The concave groove 24 is not completely crushed after the drawing process, and remains in a state where the rubber-like elastic body 16 enters the concave groove 24.

  In the present embodiment configured as described above, when the inner peripheral surface 15 of the outer cylinder 14 is a concave spherical surface 22 concentric with the convex spherical surface 20 of the bulging portion 18 of the inner cylinder 12, the displacement in the twisting direction Z is achieved. Since the force received by the rubber-like elastic body 16 interposed between the convex spherical surface 20 and the concave spherical surface 22 is only shear deformation, the spring constant in the twisting direction Z can be effectively reduced. As a result, the spring constant in the vertical direction of the suspension device can be reduced, so that riding comfort can be improved.

  In addition, at the time of displacement in the axial direction X, as shown in FIG. 2, since the rubber-like elastic body 16 is subjected not only to shear deformation but also to compression deformation between the convex spherical surface 20 and the concave spherical surface 22, The spring constant at X can be increased. Further, at the time of displacement in the direction perpendicular to the axis Y, the escape of the rubber in the axial direction X is restricted by the concave spherical surface 22 on the outer cylinder 14 side, and the spring constant in the direction perpendicular to the axis Y can be increased. Thereby, the spring 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, on the axially outer side X1 of the phantom spherical surface 26, the rubber-like elastic body 16 is not filled between the inner cylinder 12 and the outer cylinder 14, and further, the phantom spherical face 26 and the rubber-like surface are not filled. Since the intersection J with the axial end surfaces 17 of the elastic body 16 is positioned closer to the outer cylinder 14 than the innermost point K of the axial end face 17, the rubber-like elastic body is displaced in the twisting direction Z. It is possible to reliably avoid the compression spring from being applied at the 16 axial ends, and to further reduce the spring constant in the twisting direction Z. Therefore, the spring constant in the vertical direction of the suspension device can be further reduced and the suspension can be made flexible, so that the vertical movement is absorbed by the suspension so as not to change the height of the occupant's eyes. A feeling can be obtained.

  Further, since the thickness in the axial direction X of the rubber-like elastic body 16 interposed between the convex spherical surface 20 and the concave spherical surface 22 is constant, non-uniform stress particularly when displaced in the direction perpendicular to the axis Y. It is possible to improve the anti-vibration performance and durability by suppressing the action of.

  Further, since the outer cylinder 14 is provided with a concave portion constituting the concave spherical surface 22 at the central portion in the axial direction, the diameter of the outer peripheral surface 19 is a constant cylindrical shape in the axial direction. A sufficient axial dimension for press-fitting can be ensured, and the removal force from the cylindrical holder 3 can be improved. Moreover, since the rubber-like elastic body is not integrally vulcanized and molded in the cylindrical holder of the link as in the above-mentioned Patent Document 4, but is vulcanized and molded by the vibration isolating bush 10 alone, the molding die is excessively large. It is excellent in processability.

  In this embodiment, the inner peripheral surface 15 of the outer cylinder 14 and the outer peripheral surface 13 of the inner cylinder 12 are integrally vulcanized and bonded by vulcanization molding of the rubber-like elastic body 16, and the outer cylinder 14 is bonded after the vulcanization bonding. However, since the plurality of concave grooves 24 are provided in the circumferential direction on the inner peripheral surface 15 of the outer cylinder 14, the following effects can be obtained. That is, by providing the concave spherical surface 22 at the center of the outer cylinder 14, the outer cylinder 14 can be easily drawn after vulcanization molding even though the thickness of the outer cylinder 14 is large.

  In the above embodiment, the bulging portion 18 provided in the inner cylinder 12 is integrally formed of a metal material in order to obtain a bulge-type bush. However, a resin-made annular covering is provided on the outer peripheral surface of the inner cylinder. Thus, the bulging portion may be formed.

  INDUSTRIAL APPLICABILITY The present invention can be used for various types of 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.

It is sectional drawing of the anti-vibration bush which concerns on one Embodiment of this invention. It is a principal part expanded sectional view of the vibration proof bush. It is a side view before the drawing process of the vibration isolating bush. It is the IV-IV sectional view taken on the line of FIG. It is a side view of an inner cylinder. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. It is a side view of an outer cylinder. It is the VIII-VIII sectional view taken on the line of FIG. It is a figure which shows the drawing process of the vibration isolating bush. It is sectional drawing which shows the assembly | attachment state of the vibration isolating bush. It is a perspective view of a suspension device. It is a top view of a suspension apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Anti-vibration bush, 12 ... Inner cylinder (shaft member), 13 ... Outer peripheral surface of inner cylinder, 14 ... Outer cylinder, 15 ... Inner peripheral surface of outer cylinder, 16 ... Rubber-like elastic body, 17 ... Rubber-like elastic body 18 ... bulging portion, 19 ... outer peripheral surface of outer cylinder, 20 ... convex spherical surface, 22 ... concave spherical surface, 24 ... concave groove, 26 ... virtual spherical surface, J ... intersection of virtual spherical surface and axial end surface , K: innermost point on the axial end face, T1: thickness at the axial center of the outer cylinder, T2: thickness at both axial ends of the outer cylinder, X: axial direction, X1: axially outer Side, X2: axially inward side, Y: axially perpendicular direction, Z: twisting direction

Claims (4)

A shaft member, an outer cylinder that concentrically surrounds the shaft member, an outer peripheral surface of the shaft member, and an inner peripheral surface of the outer cylinder are vulcanized and bonded to each other and are interposed between the shaft member and the outer cylinder. An anti-vibration bush comprising a rubber-like elastic body,
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 the outer peripheral surface of the bulging portion forms a convex spherical surface,
The outer cylinder is formed in a straight cylindrical shape having a constant outer peripheral 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 that is concentric with the convex spherical surface. The thickness at the axially central portion of the outer cylinder is formed thinner than the thickness at the axially opposite ends,
The rubber-like elastic body is interposed between the convex spherical surface and the concave spherical surface so as not to be 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. Established ,
On the inner peripheral surface of the outer cylinder, a plurality of concave grooves extending in the axial direction are provided in the axial direction at both end portions in the axial direction formed thick, and the inner peripheral surface of the outer cylinder and the The outer peripheral surface of the shaft member is integrally vulcanized and bonded by vulcanization molding of the rubber-like elastic body, and the rubber-like elastic body enters the concave groove so that the inner peripheral surface of the outer cylinder in the concave groove. An anti-vibration bush that is vulcanized and bonded, and the outer cylinder is drawn after the vulcanized bond . The concave groove is provided over the entire thick axial portion on both sides except the thin axial portion corresponding to the top of the concave spherical surface,
The anti-vibration bush according to claim 1. The concave groove was formed to be depressed into a circular arc shape as a shape before drawing,
The anti-vibration bush according to claim 1. The plurality of concave grooves are arranged on the inner peripheral surface of the outer cylinder at regular intervals at intervals of 6 ° to 90 ° in the circumferential direction and at intervals wider than the groove width.
The anti-vibration bush according to claim 1 .

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