Stabilizer bush

Abstract

To provide a stabilizer bush having a new structure which adopts a pedestal member and can stably position and hold a stabilizer bar, and can improve durability while avoiding excessive hardening of a spring property in a twisting direction.SOLUTION: There is provided a stabilizer bush 10, wherein a bush body 12 composed of a cylindrical elastic body has linear parts 22 and 34 brought into close contact with the outer peripheral surface of a stabilizer bar 62 on inner peripheral surfaces 20 and 32, in the bush body 12, a hard pedestal member 48 is arranged in a mounting side part 19 mounted on the side of a vehicle body 66, an inside surface 50 brought into close contact with the bush body 12 in the pedestal member 48 is determined as an axial direction convex surface 52 gradually projecting inward from both ends in the axial direction to the center over the full length in the axial direction in a part positioned on the outer peripheral sides of the linear parts 22 and 34, and the inside surface 50 of the pedestal member 48 is determined as a circumferential direction recessed surface 54 bent in a circumferential direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a stabilizer bush for use in automobiles and the like. [Background technology]

[0002] Conventionally, stabilizer bushings have been used to support a stabilizer bar on the vehicle body side. As shown in, for example, Japanese Patent No. 6339544 (Patent Document 1), such stabilizer bushings include a bushing body made of an elastic body having a generally cylindrical shape, and are fitted onto the stabilizer bar in an externally inserted state, while a band-shaped bracket overlapping the outer peripheral surface is attached to the vehicle body, thereby elastically positioning and holding the stabilizer bar relative to the vehicle body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6339544 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in a stabilizer bushing, for example, when improved durability is required, it is generally considered to deal with this by increasing the hardness of the rubber.

[0005] However, increasing the rubber hardness increases the spring characteristics in the prying direction and other directions input when the vehicle is traveling, which may have a negative effect on, for example, ride comfort, etc. In particular, in some cases, a mounting base member is attached to the vehicle body side of the bush main body for the purpose of adjusting the support position of the stabilizer bar and improving the stability of the support position, but in this case, the presence of the base member tends to make the spring characteristics in the prying direction and other directions even harder, and there is also the problem that concentration of elastic strain makes it even more difficult to ensure durability.

[0006] The problem to be solved by the present invention is to provide a stabilizer bush of a novel structure that can stably position and hold the stabilizer bar by using a base member, and that can improve durability while avoiding the spring characteristics in the prying direction becoming excessively stiff. [Means for solving the problem]

[0007] The following describes preferred embodiments for understanding the present invention, but the embodiments described below are merely illustrative and may be combined with one another as appropriate, and the multiple components described in each embodiment may be recognized and used independently as far as possible, and may also be combined with any of the components described in another embodiment as appropriate. As a result, the present invention is not limited to the embodiments described below, and various other embodiments may be realized.

[0008] The first aspect is a stabilizer bushing that elastically positions and holds a stabilizer bar in a vehicle, wherein a bushing body made of a cylindrical elastic body has a straight portion on its inner surface that is in intimate contact with the outer peripheral surface of the stabilizer bar, and a hard base member is provided on the mounting portion of the bushing body that is attached to the vehicle body, and the inner surface of the base member that is in intimate contact with the bushing body is an axially convex surface that gradually protrudes inward from both axial ends toward the center over the entire axial length of the portion located on the outer periphery of the straight portion, and the inner surface of the base member that is in intimate contact with the bushing body is a circumferentially concave surface that is curved in the circumferential direction.

[0009] With a stabilizer bushing constructed according to this embodiment, the spring characteristics in each direction can be adjusted by the base member, and the required performance can be achieved to a higher degree. That is, by providing an axially convex surface on the inner surface of the base member, the thickness dimension of the bushing body between the stabilizer bar and the base member is set small in the axial center portion, and a hard spring characteristic is achieved by the protrusion of the axially convex surface in the direction in which the base member and the stabilizer bar are aligned. This enables the stabilizer bar to be stably positioned and maintained, and excessive deformation of the bushing body is prevented, thereby improving durability.

[0010] Furthermore, the thickness dimension between the stabilizer bar and the base member at both axial ends of the bush body is largely ensured by the change in the inward protruding dimension of the axially convex surface, which provides soft spring characteristics against the deformation of the stabilizer bar in the twisting direction, thereby providing a good ride comfort of the vehicle.

[0011] In addition, by providing a circumferentially concave surface on the inner surface of the base member, both end portions of the circumferentially concave surface contribute to hard spring characteristics in the direction in which the stabilizer bar and the base member are aligned. Furthermore, by providing the circumferentially concave surface, it is possible to prevent the bush body located between the stabilizer bar and the base member from becoming locally thin, thereby realizing a good ride comfort due to soft spring characteristics against the torsional displacement of the stabilizer bar.

[0012] In the second aspect, in the stabilizer bushing described in the first aspect, the axially convex surface protrudes in a shape that gradually curves inward from portions located on the outer periphery of both axial ends of the straight portion of the bushing body toward the axial center, and a straight portion extending axially at a constant protruding height is provided in the axial center portion.

[0013] With the stabilizer bushing constructed according to this embodiment, the straight portion provided in the axial center portion of the base portion stabilizes the mounting state of the stabilizer bar. Also, the bushing body between the stabilizer bar and the base member is thin-walled within a predetermined axial length range where the straight portion is provided, so that it is easy to set the axial spring to be hard in the direction in which the stabilizer bar and the base member are aligned while realizing soft spring characteristics against input in the prying direction.

[0014] A third aspect is the stabilizer bushing according to the second aspect, wherein the axial length of the straight portion is set within a range of 1 / 10 to 1 / 2 of the linear portion.

[0015] A stabilizer bushing constructed according to this embodiment can achieve a good balance between a hard spring characteristic in the axial direction and a soft spring characteristic in the prying direction by providing a straight portion.

[0016] A fourth aspect is a stabilizer bushing described in any one of the first to third aspects, wherein the bushing body has a two-part structure consisting of an attachment side portion that is attached to the vehicle body and an opposing side portion that is arranged opposite and overlapped with the attachment side portion in a direction perpendicular to the axis.

[0017] With a stabilizer bushing constructed in accordance with this embodiment, the mounting side portion, which is attached to the vehicle body via a base member, and the opposing side portion, which is positioned opposite the mounting side portion, are each formed independently, thereby improving the formability of the bushing body and facilitating attachment to the stabilizer bar.

[0018] A fifth aspect is a stabilizer bushing described in any one of the first to fourth aspects, wherein the linear portion of the inner surface of the bushing body is a fastening surface that is fastened to the stabilizer bar.

[0019] According to the stabilizer bushing constructed according to this aspect, the linear portion of the inner peripheral surface of the bushing body is fixed to the stabilizer bar, thereby realizing stable attachment of the stabilizer bushing to the stabilizer bar.

[0020] A sixth aspect is a stabilizer bushing according to any one of the first to fifth aspects, wherein the inner surface of the bushing body is provided with enlarged diameter portions on both axial sides of the straight portion that expand axially outward and away from the stabilizer bar.

[0021] With a stabilizer bushing constructed in accordance with this embodiment, for example, when the inner surface of the bushing body is pressed against the stabilizer bar, causing the inner end of the bushing body to bulge outward in the axial direction, the bulging portion is contained within the inner circumference of the enlarged diameter portion, preventing the axial end face from protruding excessively.

[0022] In this embodiment, the axially convex surface of the base member is desirably formed to have an axial length extending from the linear portion of the bush body to both axial sides and reaching the enlarged diameter portions on both sides. Also, it is desirably that the entire axial length of the inner surface of the base member is made into an axially convex surface, so that the inner surface of the base member is furthest radially outward from the stabilizer bar at both axial ends. Effect of the Invention

[0023] According to the present invention, by employing a base member, it is possible to stably position and hold the stabilizer bar, and it is possible to improve durability while avoiding the spring characteristics in the prying direction from becoming excessively hard. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a perspective view showing a stabilizer bush according to a first embodiment of the present invention; [Diagram 2] FIG. 2 is a cross-sectional view of the stabilizer bush shown in FIG. 1, which corresponds to the cross-section II-II of FIG. 3. [Diagram 3] III-III cross section of Figure 2 [Figure 4] FIG. 2 is a perspective view of a first member constituting the stabilizer bush shown in FIG. [Diagram 5] FIG. 2 is a perspective view of a second member constituting the stabilizer bush shown in FIG. [Figure 6] 6 is a cross-sectional view of the second member shown in FIG. 5, which corresponds to the cross-section VI-VI of FIG. [Figure 7] Cross-sectional view of FIG. 6 taken along the line VII-VII [Figure 8] FIG. 6 is a perspective view of a base member constituting the second member shown in FIG. [Figure 9] FIG. 9 is a plan view of the base member shown in FIG. [Figure 10] 12 is a cross-sectional view of the base member shown in FIG. 8, which corresponds to the cross section XX in FIG. 11. [Figure 11] XI-XI cross section of Figure 10 [Figure 12] A perspective view of the stabilizer bush shown in Figure 1 with a stabilizer bar and a bracket attached. [Figure 13] FIG. 2 is a cross-sectional view showing the stabilizer bush of FIG. 1 mounted on a vehicle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0026] 1 to 3 show a stabilizer bushing 10 as a first embodiment of the present invention. The stabilizer bushing 10 includes a bushing body 12 formed of a rubber elastic body. In the following description, in principle, the up-down direction refers to the up-down direction in Fig. 2, the front-rear direction refers to the left-right direction in Fig. 2, and the left-right direction refers to the left-right direction in Fig. 3.

[0027] The bushing body 12 is made of a rubber elastic body, is cylindrical as a whole, and has an inner hole 14 that penetrates in the front-rear direction. The bushing body 12 has a two-part structure composed of a first member 16 as a mutually independent opposing side portion, and an elastic body 19 of a second member 18 as an attachment side portion.

[0028] As shown in FIG. 4, the first member 16 is generally semi-cylindrical and is formed entirely of a rubber elastic body. More specifically, a first inner peripheral surface 20, which is the inner peripheral surface of the first member 16, is a curved surface with a generally arc-shaped cross section that is less than half the circumference, and as shown in FIG. 2, a middle portion in the front-rear direction is a first straight portion 22 that extends in the front-rear direction with a generally constant cross section, and both front and rear sides of the first straight portion 22 are first enlarged diameter portions 24, 24 that are tapered and expand outward in the front-rear direction. The axial length dimension (La) of the first straight portion 22 is preferably half or more of the axial length of the first member 16, and more preferably 2 / 3 or more. In addition, a first outer peripheral surface 26, which is the outer peripheral surface of the first member 16, is a middle portion in the circumferential direction that is an arc-shaped cross section, and both ends are flat surfaces that expand approximately perpendicular to the left-right direction. First end faces 28, 28 which are circumferential end faces of the first member 16 are flat surfaces which extend approximately perpendicular to the up-down direction and are positioned on approximately the same plane.

[0029] Both axial ends of the first member 16 are provided with first ridges 30 that protrude outward. As shown in Fig. 2, the front and rear inner surfaces of the base end portion of the first ridges 30 are inclined upward and outward, and the front and rear outer surfaces of the base end portion widen substantially perpendicular to the front and rear direction, narrowing in the front and rear direction toward the protruding tip. The tip portion of the first ridges 30 narrows in the front and rear direction toward the protruding tip, and both the front and rear surfaces are curved surfaces.

[0030] As shown in Figs. 5 to 7, the second member 18 is generally semi-cylindrical. More specifically, the second inner peripheral surface 32, which is the inner peripheral surface of the second member 18, has a substantially arcuate cross section that is less than half the circumference, and as shown in Figs. 2 and 6, the intermediate portion in the front-rear direction is a second linear portion 34 that extends in the front-rear direction with a substantially constant cross-sectional shape, and the front and rear sides of the second linear portion 34 are second enlarged diameter portions 36, 36 that are tapered and expand outward in the front-rear direction. The axial length dimension La of the second linear portion 34 is preferably equal to or greater than half the axial length of the second member 18, and more preferably equal to or greater than 2 / 3. The second outer peripheral surface 38, which is the outer peripheral surface of the second member 18, is generally rectangular when viewed in the front-rear direction, and includes a pair of left and right side surfaces 40, 40 and a lower surface 42. The side surfaces 40, 40 and the lower surface 42 are all generally rectangular surfaces, with the side surfaces 40, 40 extending generally perpendicular to the left-right direction, and the lower surface 42 extending generally perpendicular to the up-down direction. The second end surfaces 44, 44, which are circumferential end surfaces of the second member 18, are flat surfaces extending generally perpendicular to the up-down direction, and are located on generally the same plane.

[0031] Second ridges 46 protruding outward to the left and right are provided on the side surfaces 40, 40 of the second member 18. The second ridges 46 are provided on both front and rear end portions of each side surface 40, and extend linearly and continuously in the up-down direction with substantially the same cross-sectional shape as the first ridges 30.

[0032] The second member 18 has a structure in which a seat member 48 is fixed in an embedded state to an elastic body 19 serving as an attachment side portion constituting the bush body 12. The seat member 48 is a hard member formed of metal, synthetic resin or the like, and has a generally rectangular plate or rectangular block shape as a whole, as shown in Figures 8 to 11. More specifically, the seat member 48 has a generally flat lower surface, and an inner seat upper surface 50 has an axial convex surface 52 and a circumferential concave surface 54.

[0033] As shown in FIG. 10, the axially convex surface 52 has a convex vertical cross-sectional shape that protrudes more inwardly, i.e., upward, from both ends in the front-rear direction toward the center. In the axially convex surface 52 of this embodiment, the relative inclination angle with respect to the axial direction decreases from both axial ends toward the center. In the axially convex surface 52 of this embodiment, a straight portion 56 is provided in the axial center portion, which extends in the axial direction with a substantially constant protruding height. The straight portion 56 extends without inclining with respect to the axial direction, and preferably has an axial length dimension Lb of 1 / 4 or less of the entire axial length of the axially convex surface 52. The axial length Lb of the straight portion 56 is preferably set within a range of 1 / 10 to 1 / 2 of the axial length La of the first and second linear portions 22, 34 of the bush body 12 (see FIG. 6). In addition, in this embodiment, the axially convex surface 52 has a substantially constant inclination angle with respect to the axial direction in the middle axial portion, and the inclination angle gradually increases toward both axially outward ends at both axial end portions, giving the surface an overall curved shape.

[0034] 11, the circumferential concave surface 54 is a curved surface having an arc-shaped cross section that curves in the circumferential direction. The circumferential concave surface 54 is provided in the middle part in the left-right direction of the base upper surface 50, and both end parts in the left-right direction are flat and extend approximately perpendicular to the up-down direction.

[0035] In the top view of the base member 48 shown in Fig. 9, the four corners are provided with protrusions 58 that protrude outward to the left and right. The front and rear outer surfaces of the protrusions 58 extend substantially perpendicular to the front and rear direction, and the front and rear inner surfaces are inclined outwardly to the front and rear toward the protruding tip, forming a tapered shape that narrows in the front and rear direction toward the protruding tip. In addition, as shown in Fig. 8, the corners of the base member 48 including the protrusions 58 have cutout portions 60 at their upper ends, and the position of the upper surface is set lower than the other parts of the base upper surface 50.

[0036] The pedestal member 48 thus structured is disposed in close contact with the elastic body 19, as shown in Figures 6 and 7. That is, the pedestal member 48 is fixed in an embedded state in the elastic body 19, and almost the entire surface is covered by the elastic body 19. In particular, the upper surface (pedestal upper surface 50) of the pedestal member 48 is an inner surface that is in close contact with the elastic body 19 over its entirety, and is covered by the elastic body 19 and not exposed to the outside. Note that the pedestal member 48 is inserted, for example, during vulcanization molding of the elastic body 19, and is vulcanization-bonded to the elastic body 19.

[0037] The pedestal member 48 is disposed at a position biased downward with respect to the elastic body 19, and preferably disposed at a portion of the elastic body 19 that is lower than the second inner circumferential surface 32. This makes the thickness dimension of the portion of the elastic body 19 that covers the pedestal upper surface 50 larger than the thickness dimension of the portion that covers the lower surface of the pedestal member 48. The pedestal member 48 is located approximately in the center with respect to the elastic body 19 in the front-rear and left-right directions.

[0038] As shown in FIG. 6, the axial convex surface 52 of the base member 48 reaches further outward in the axial direction than the second linear portion 34 of the second inner peripheral surface 32, and reaches halfway into the second enlarged diameter portion 36. In this embodiment, the axial convex surface 52 is provided so as to extend outward in the axial direction from the axial center of the second enlarged diameter portion 36. The axial convex surface 52 protrudes from the portion located on the outer circumferential side of both axial ends from the second linear portion 34 toward the axial center in a shape that gradually curves inward (upward), and the distance from the second linear portion 34 gradually increases outward in the axial direction. In addition, both ends of the axial convex surface 52 with a large inclination angle are located below the second enlarged diameter portion 36, so that the distance between the axial convex surface 52 and the second enlarged diameter portion 36 is secured at both axial ends. Therefore, the thickness dimension of the elastic body 19 covering the axial convex surface 52 is secured to be large at both axial ends in the axial direction.

[0039] The protruding tip portions of each protrusion 58 of the base member 48 are fixedly attached to the inside of each second protrusion 46, and the protrusions 58 suppress downward deformation of the second protrusion 46 due to the attachment of a bracket 64 described later.

[0040] 7, the circumferential concave surface 54 of the base member 48 is provided outwardly to the left and right beyond both left and right ends of the second inner circumferential surface 32. This ensures that the thickness dimension of the second member 18 covering the circumferential concave surface 54 is large.

[0041] 1 to 3, the stabilizer bushing 10 is formed by stacking the first member 16 and the second member 18 on top of each other in the up-down direction. The first end faces 28, 28 of the first member 16 and the second end faces 44, 44 of the second member 18 are stacked on top of each other in the up-down direction. Both circumferential ends of the first ridges 30, 30 of the first member 16 and upper ends of the second ridges 46, 46 of the second member 18 are stacked on top of each other to form ridges that are continuously provided on the top surface and both side surfaces of the stabilizer bushing 10.

[0042] An inner hole 14 penetrating in the front-rear direction is formed between the first member 16 and the second member 18. The inner circumferential surface of the inner hole 14 is composed of a first inner circumferential surface 20 and a second inner circumferential surface 32, and is a flattened circular hole whose maximum inner diameter dimension in the up-down direction is smaller than its maximum inner diameter dimension in the left-right direction.

[0043] As shown in Fig. 12 and Fig. 13, the stabilizer bush 10 is mounted on a vehicle by inserting a stabilizer bar 62 into the inner hole 14 and attaching a bracket 64 overlapping the outer circumferential surface to a vehicle body 66, thereby elastically positioning and holding the stabilizer bar 62 with respect to the vehicle body 66. The stabilizer bush 10 of this embodiment is configured in a mounted state to the stabilizer bar 62 by arranging a first member 16 and a second member 18 which are independent of each other so as to sandwich the stabilizer bar 62 from both above and below, and by fixing a first inner circumferential surface 20 of the first member 16 and a second inner circumferential surface 32 of the second member 18 to the outer circumferential surface of the stabilizer bar 62. Since the stabilizer bush 10 is configured by the first member 16 and the second member 18 which are independent of each other in this way, it becomes easy to manufacture the first member 16 and the second member 18 and to mount the stabilizer bush 10 on the stabilizer bar 62. In addition, the stabilizer bushing 10 is attached to the stabilizer bar 62 with the first end faces 28, 28 of the first member 16 and the second end faces 44, 44 of the second member 18 overlapping each other, and the first end faces 28, 28 and the second end faces 44, 44 may be adhered to each other.

[0044] The outer diameter dimension of the stabilizer bar 62 is larger than the maximum inner diameter dimension of the inner hole 14 in the vertical direction, and the inner hole 14 of the bush body 12 is expanded in the vertical direction by inserting the stabilizer bar 62 into the inner hole 14. As a result, both upper and lower portions of the inner hole 14 of the bush body 12 are compressed in the vertical direction, and the inner peripheral surfaces 20, 32 of the bush body 12 are in close contact with the outer peripheral surface of the stabilizer bar 62. In this embodiment, the outer peripheral surface of the stabilizer bar 62 is fixed in close contact with the first and second straight portions 22, 34 of the bush body 12, and the first and second straight portions 22, 34 serve as fixing surfaces for the stabilizer bar 62. In this way, the bush body 12 is fixed to the stabilizer bar 62 at the first and second straight portions 22, 34, thereby achieving stable attachment of the stabilizer bush 10 to the stabilizer bar 62. When the first member 16 and the second member 18 are combined with each other, the stabilizer bar 62 is disposed between the first inner circumferential surface 20 and the second inner circumferential surface 32, so that the stabilizer bar 62 is inserted into the inner hole 14 of the stabilizer bushing 10. In this embodiment, the stabilizer bar 62 is bonded to the inner circumferential surface of the inner hole 14 (the first and second linear portions 22, 34).

[0045] When the first and second straight portions 22, 34 of the bushing body 12 are fixed to the outer circumferential surface of the stabilizer bar 62, the inner peripheral end of the bushing body 12 is pressed against the stabilizer bar 62 and deformed so as to bulge outward in the axial direction. Therefore, the first and second enlarged diameter portions 24, 36 are provided on both axial sides of the first and second straight portions 22, 34 of the bushing body 12, respectively, so that the inner peripheral end of the bushing body 12 bulging outward in the axial direction is accommodated in the first and second enlarged diameter portions 24, 36 and can be prevented from protruding outward in the axial direction. Note that the inner peripheral end of the bushing body 12 overlaps the stabilizer bar 62 even in the bulging portion bulging outward in the axial direction, so that a large mounting area of ​​the bushing body 12 to the stabilizer bar 62 is ensured.

[0046] The bracket 64 is a band-shaped member made of metal or the like, and integrally includes a groove-shaped bush mounting portion 68 that opens downward, and mounting pieces 70, 70 that extend outward to the left and right from both ends of the bush mounting portion 68. Both front and rear ends of the bush mounting portion 68 are groove-shaped portions 72 that correspond to the first ridges 30, 30 and the second ridges 46, 46 of the bush body 12, and have a concave cross section that opens toward the inner circumference and protrudes toward the outer circumference. In addition, both front and rear ends of the mounting piece 70 are provided with reinforcing ribs 74 that protrude upward and are continuous with the groove-shaped portion 72 in the circumferential direction. The provision of the groove-shaped portions 72, 72 and the reinforcing ribs 74, 74 increases the deformation rigidity of the band-shaped bracket 64.

[0047] As shown in Fig. 13, the bracket 64 is fixed to the vehicle body 66 by overlapping the mounting pieces 70, 70 on the vehicle body 66 and screwing the bolts 78 inserted into the bolt holes 76 penetrating the mounting pieces 70 into the vehicle body 66. The stabilizer bush 10 attached to the stabilizer bar 62 in an externally inserted state is sandwiched between the bush attachment portion 68 of the bracket 64 and the vehicle body 66 in the vertical direction, and is attached to the vehicle body 66. As a result, the stabilizer bar 62 is supported relative to the vehicle body 66 via the stabilizer bush 10 and elastically positioned and held. In the vehicle-attached state of the stabilizer bush 10, the first member 16 is interposed between the stabilizer bar 62 and the bracket 64, and the second member 18 is interposed between the stabilizer bar 62 and the vehicle body 66, and is attached to the vehicle body 66 side.

[0048] With the stabilizer bushing 10 thus mounted on the vehicle, the base member 48 is disposed vertically between the stabilizer bar 62 and the vehicle body 66. This makes it possible to adjust the volume (thickness dimension in the vertical direction) of the bushing main body 12 interposed between the stabilizer bar 62 and the vehicle body 66 while appropriately setting the vertical position of the inner hole 14 through which the stabilizer bar 62 is inserted with respect to the vehicle body 66. Therefore, by appropriately setting the shape and size of the base member 48, the spring characteristics in the vertical direction of the stabilizer bushing 10 can be tuned with a large degree of freedom.

[0049] That is, the base upper surface 50 of the base member 48 is provided with an axially convex surface 52 whose upward protruding height dimension increases toward the axial center. As a result, the vertical thickness dimension of the bush main body 12 interposed between the stabilizer bar 62 and the vehicle body 66 is made smaller at the axial center portion, and the vertical spring of the stabilizer bush 10 can be set to be stiff. Therefore, the stabilizer bar 62 can be stably positioned relative to the vehicle body 66, and the deformation of the bush main body 12 is restricted, thereby improving durability.

[0050] The thickness dimension of the portion of the bush body 12 covering the axially convex surface 52 is set to be large at both ends in the front-rear direction. As a result, when the stabilizer bar 62 is twisted and displaced in the up-down direction relative to the vehicle body 66, the spring of the bush body 12 caused by compression / tension between the stabilizer bar 62 and the base member 48 at both ends in the front-rear direction is reduced, and soft spring characteristics against input in the twisting direction are realized, thereby improving the ride comfort of the vehicle.

[0051] In addition, the base upper surface 50 of the base member 48 is provided with a circumferentially concave surface 54, and the thickness dimension of the bush body 12 is secured over the entire circumference without being locally reduced around the stabilizer bar 62. This reduces the spring constant of the bush body 12 when the stabilizer bar 62 is twisted in the circumferential direction, and realizes soft spring characteristics against the torsion of the stabilizer bar 62, thereby realizing a good ride comfort of the vehicle.

[0052] As described above, by using a base member 48 having an axially convex surface 52 and a circumferentially concave surface 54 on the base upper surface 50, the stabilizer bushing 10 is able to achieve low spring characteristics in the twisting and torsional directions while increasing the spring rigidity in the vertical direction.

[0053] In this embodiment, a straight portion 56 extending in the axial direction with a substantially constant protruding height is provided in the axial center portion of the axially convex surface 52. This allows the stabilizer bushing 10 to be stably attached to the stabilizer bar 62 at the straight portion 56. In addition, the bushing body 12 located between the upper and lower opposing surfaces of the stabilizer bar 62 and the base member 48 is thin-walled over the entire length of the straight portion 56, which more advantageously achieves stiff spring characteristics in the vertical direction. In addition, since the straight portion 56 is provided in the axial center portion, adverse effects on the low spring characteristics in the prying direction are suppressed.

[0054] In particular, the axial length of the straight portion 56 in this embodiment is set within the range of 1 / 10 to 1 / 2 of the first and second straight portions 22, 34 of the bush body 12, thereby achieving a good balance between stiff spring characteristics in the vertical direction and soft spring characteristics in the vertical prying direction.

[0055] Although the embodiment of the present invention has been described in detail above, the present invention is not limited to the specific description. For example, the axially convex surface 52 does not necessarily have to be provided over the entire axial length of the base member 48, but may be provided over the entire length of the portion of the base member 48 located on the outer circumferential side of the first and second straight portions 22, 34 of the bush body 12. In short, in the above embodiment, the portion of the base member 48 that is outwardly spaced from the first and second straight portions 22, 34 in the axial direction, in other words, the portion of the base member 48 located on the outer circumferential side of the first and second enlarged diameter portions 24, 36 of the bush body 12 does not have to be the axially convex surface 52.

[0056] The first and second enlarged diameter portions 24, 36 are not essential to the first and second inner circumferential surfaces 20, 32 of the bushing body 12, and the first and second straight portions 22, 34 may be provided over the entire axial length of the first and second inner circumferential surfaces 20, 32. In this case, since the seat upper surface 50 is located on the outer circumferential side of the first and second straight portions 22, 34 over the entire axial length, the axially convex surface 52 is provided over the entire axial length of the seat upper surface 50.

[0057] The straight portion 56 may not be present in the axially central portion of the axially convex surface 52, and for example, the inward protruding height of the axially convex surface 52 may vary over the entire axial length.

[0058] The axially convex surface 52 may be a smoothly convexly curved surface, or may be configured by a surface presenting a broken line-like vertical cross-sectional shape.

[0059] The size, shape, arrangement, etc. of the base member 48 shown in the above embodiment, such as the relative size of the base member 48 with respect to the mounting portion (elastic body 19) of the bush body 12, the outer peripheral shape of the base member 48, the distance from the inner hole 14 of the base member 48, the axial inclination angle of the axially convex surface 52, and the circumferential curvature of the circumferentially concave surface 54, are merely examples and may be modified as appropriate.

[0060] The mounting side portion (elastic body 19 of second member 18) and the opposing side portion (first member 16) of the bushing body 12 may be integrally formed without being independent from each other. In this case, for example, by forming a slit in a part of the peripheral wall portion of the inner hole 14, it is possible to make it possible to insert the stabilizer bar 62 into the inner hole 14 through the slit.

[0061] The bush body 12 does not have to be adhered to the outer peripheral surface of the stabilizer bar 62, and may be attached to the stabilizer bar 62 by being in close contact with the outer peripheral surface of the stabilizer bar 62 without being adhered. [Explanation of symbols]

[0062] 10 Stabilizer bush (first embodiment) 12 Bush body 14 Inner hole 16 First member (opposite side portion) 18 Second member 19 Elastic body (mounting part) 20 First inner peripheral surface (inner peripheral surface) 22 First straight part (straight part) 24 First expanded diameter section (expanded diameter section) 26 First outer peripheral surface 28 First end face 30 First protrusion 32 Second inner peripheral surface (inner peripheral surface) 34 Second straight part (straight part) 36 Second expanded diameter section (expanded diameter section) 38 Second outer peripheral surface 40 Side 42 Bottom surface 44 Second end face 46 Second protrusion 48 Pedestal member 50 Pedestal top surface (inner surface) 52 Axial convex surface 54 Circumferential concave surface 56 Straight section 58 Protrusion 60 Notched part 62 Stabilizer bar 64 Bracket 66 Vehicle body 68 Bush mounting part 70 Mounting piece 72 Groove 74 Reinforcing rib 76 Bolt holes 78 Volts

Claims

1. A stabilizer bush for elastically positioning and retaining a stabilizer bar in a vehicle, comprising: a bushing body made of a cylindrical elastic body has a linear portion on an inner peripheral surface thereof which is brought into close contact with an outer peripheral surface of the stabilizer bar, A hard base member is provided on a mounting portion of the bush body that is attached to a vehicle body, an inner surface of the base member that is in intimate contact with the bush body is an axially convex surface that gradually protrudes inward from both axial ends toward the center over the entire axial length of a portion that is located on the outer circumferential side of the linear portion, The inner surface of the base member that is in intimate contact with the bush body is a circumferentially concave surface that is curved in the circumferential direction.

2. 2. A stabilizer bush as described in claim 1, wherein the axially convex surface protrudes in a shape that gradually curves inward from portions located on the outer periphery of both axial ends of the straight portion of the bush body toward the axial center, and a straight portion extending in the axial direction to a constant protruding height is provided in the axially central portion.

3. 3. The stabilizer bushing according to claim 2, wherein the axial length of the straight portion is set within a range of 1 / 10 to 1 / 2 of the linear portion.

4. A stabilizer bush as described in any one of claims 1 to 3, wherein the bush body has a two-part structure consisting of an attachment side portion that is attached to the vehicle body side and an opposing side portion that is arranged opposite and overlapped with the attachment side portion in a direction perpendicular to the axis.

5. 3. The stabilizer bushing according to claim 1, wherein the linear portion of the inner peripheral surface of the bushing body serves as a fixing surface that is fixed to the stabilizer bar.

6. 3. The stabilizer bushing according to claim 1, wherein an inner peripheral surface of the bushing body is provided with enlarged diameter portions on both axial sides of the linear portion, the enlarged diameter portions expanding axially outwardly and spaced apart from the stabilizer bar.

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