JP2006347370A - Suspension bush - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suspension bush with a novel structure capable of facilitating installing work to an automobile and stably obtaining predetermined operation stability and vibration-proofing property. <P>SOLUTION: An inner side fixing member 42 provided with an outward flange part 50 at an axial end of a cylindrical part 48 and an outer side fixing member 44 provided with an inward flange part at an axial end of a cylindrical part 58 are arranged with a gap and the cylindrical part 48 of the inner side fixing member 42 is externally fitted/fixed to an axial end of an inner shaft member 12 by connecting axial opposed surfaces of both flange parts 50, 60 by a connection rubber elastic body 46. Axial pre-compression is applied to the connection rubber elastic body 46 by fitting/fixing the cylindrical part 58 of the outer side fixing member 44 to an axial end of an outer cylinder member 14. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a suspension bush interposed in a pivot joint of a suspension arm to a vehicle body in an automobile, and in particular, a suspension bush having a novel structure that can advantageously achieve desired spring characteristics and good assembly properties. It is about.

  2. Description of the Related Art Conventionally, a suspension bush is known as a type of vibration-proof connection body that is interposed in a pivot connection portion of a suspension arm to a vehicle body in an automobile. The suspension bushing has a structure in which an outer cylinder fitting is disposed at a predetermined distance radially outward of the inner cylinder fitting, and the inner cylinder fitting and the outer cylinder fitting are elastically connected by a main rubber elastic body. The outer cylinder fitting is fitted and fixed to the cylindrical arm eye formed at the end of the suspension arm by press-fitting etc., and the body side mounting bracket is overlaid on the inner cylinder fitting and fixed with bolts etc. Thus, the bushing connects the suspension arm and the vehicle body in an anti-vibration manner.

  By the way, the suspension bush may be required to have a large spring rigidity in the bush axis direction, which is the central axis direction of the arm eye, for the purpose of improving the steering stability of the vehicle. For this purpose, in Patent Document 1 (Japanese Patent Laid-Open No. 2000-249180), an outward flange portion is provided at the end edge portion of the outer cylinder fitting, and a stopper rubber is projected axially outward from the flange portion. In addition, a washer is placed at the end of the inner cylinder fitting, and a stopper rubber is interposed between the flange and the washer's axially facing surface to tighten the fixing bolt inserted in the inner cylinder fitting and washer. Based on this, a structure has been proposed in which axial compression is applied to the stopper rubber to increase the spring stiffness in the axial direction of the bush.

  However, with such a bush, it is time-consuming to assemble the bushing because it is pre-compressed to the stopper rubber by placing a washer at each axial end of the inner tube fitting at the site when mounting to a car. It was troublesome. Moreover, for example, as shown in Patent Document 2 (Japanese Patent Laid-Open No. 10-274268), assembling between a pair of mounting plate portions opposed to each other with a predetermined distance in a channel-shaped mounting bracket or the like having a conventional structure is performed. Considering this, it is difficult to adopt the bush.

  That is, as a measure for interposing a bush between a pair of mounting plate portions and pre-compressing the stopper rubber in the axial direction, for example, (i) the axial dimension of the bush provided with the stopper rubber is set to a pair of mounting plate portions. The bushing is fitted between the mounting plate portions in a state where the axial direction of the bush extends in the opposing direction of both plate portions, and the stopper rubber is compressed and deformed by contact of each mounting plate portion. Axial pre-compression is applied to the rubber, or (ii) the axial dimension of the bush provided with the stopper rubber is made smaller than the opposing distance between the pair of mounting plate parts, and the axial direction is in the opposing direction of the two plate parts. Insert the bushing between the opposing surfaces in the extended state, insert the fixing bolts into the pair of mounting plate parts and bushes, and tighten the fixing bolts to displace the pair of mounting plate parts toward each other in the opposing direction. Or transform , It is conceivable to or exerts an axial precompression to the rubber stopper via the mounting plate portion.

  However, in the former method (i), the bush cannot be easily fitted between the pair of mounting plate portions, and there is a possibility that the stopper rubber may be damaged if the bush is forcibly fitted. In the latter method (ii), depending on the strength of the mounting plate portion and the elasticity of the stopper rubber, a large amount of labor may be required for fastening the fixing bolt, or the durability of the mounting plate portion may be reduced. there were. For this reason, the suspension bush having the conventional structure as shown in Patent Document 1 cannot be satisfactorily assembled to the pair of mounting plate portions opposed to each other with a predetermined distance therebetween.

  Therefore, in Patent Document 3 (Japanese Patent Application Laid-Open No. 11-63058), a mounting bracket is configured including a cylindrical portion and an outward flange portion, and a mounting bracket having a stopper rubber fixed to the flange portion is provided as an inner cylindrical bracket. A structure has been proposed in which a pre-compression in the axial direction is applied to the rubber by affixing and fixing to the end in the axial direction and abutting a stopper rubber against an end edge around the opening of the arm eye. Thereby, the bush can be fitted between the pair of mounting plate portions in a state in which the stopper rubber is pre-compressed in the axial direction.

  However, in such a bush, since the stopper rubber is in contact with the end edge around the opening of the arm eye, it is difficult to ensure a sufficient contact area. As a result, when a large load is input, there is a problem that the stress of the contact portion of the stopper rubber with the arm eye becomes excessive, and the durability of the stopper rubber is lowered. In addition, when a large load such as a twisting direction is input and the inner cylinder fitting and the outer cylinder fitting are greatly displaced, the contact state between the arm eye and the rubber may be easily released, and the axial spring stiffness may be reduced. Reliability was not enough.

  Patent Document 4 (Japanese Patent Laid-Open No. 11-182599) discloses an inner cylinder side fixing bracket and an outer cylinder side fixing bracket each having a cylindrical portion and an outward flange portion formed at one axial end portion thereof. The inner cylinder side fixing bracket is provided with a rubber elastic body interposed between the radial facing surfaces of the cylindrical portions and between the axial facing surfaces of the flange portions. And the outer cylinder side fixing bracket is fitted and fixed to the inner cylinder bracket and the outer cylinder bracket, respectively, so that the rubber elastic body arranged between both flange portions is subjected to axial pre-compression and the axial spring stiffness is increased. A larger structure has been proposed.

  However, in such a suspension bush, since the arm eye is a large part and it is difficult to achieve high dimensional accuracy, it is possible to stably obtain the fixing strength of the outer cylinder side fixing bracket that is directly fitted and fixed to the arm eye. It was difficult. As a result, there is a risk that rattling or displacement may occur in the outer cylinder side fixing bracket during load input.

  In addition, when assembling the above-mentioned bush to the automobile, in addition to press-fitting the main rubber elastic body having the inner and outer cylindrical metal fittings from one end in the axial direction of the arm eye using a predetermined press-fitting device or the like at the work site. It was necessary to press-fit the outer cylinder side fixing bracket from the other axial end of the arm eye and press the inner cylinder side fixing bracket into the inner cylinder bracket. In short, only axial pre-compression is applied after assembly. For this reason, it is necessary to perform both press-fit assembly to the arm eye and axial precompression work at the assembly site for the arm eye of the bush. Therefore, the problem that the work on the production line in the automobile factory was troublesome and inefficient was inherent.

JP 2000-249180 A Japanese Patent Laid-Open No. 10-274268 JP-A-11-63058 Japanese Patent Laid-Open No. 11-182599

Here, the present invention has been made in the background as described above, and the problem to be solved is that the assembly work to the automobile is facilitated, and the expected steering stability and vibration-proof performance. Is to provide a suspension bush having a novel structure that can be stably obtained.

  Hereinafter, the aspect of this invention made | formed in order to solve such a subject is described. In addition, the component employ | adopted in each aspect as described below is employable by arbitrary combinations as much as possible. Further, aspects or technical features of the present invention are not limited to those described below, but are described in the entire specification and drawings, or an invention that can be understood by those skilled in the art from those descriptions. It should be understood that it is recognized based on thought.

(Aspect 1 of the present invention)
A feature of the first aspect of the present invention is that an outer cylinder member attached to the suspension arm is spaced apart from the inner shaft member attached to the vehicle body on the outer peripheral side, and the inner shaft member and the outer cylinder member are arranged. In the suspension bush connected to each other by a rubber elastic body, an inner side fixing member having an outward flange portion at one opening end edge in the axial direction of the cylindrical portion, and a cylindrical portion of the inner side fixing member An outer side fixing member provided with an inward flange portion at one opening end edge in the axial direction of the cylindrical portion having a large diameter is spaced apart from the flange portion of the inner side fixing member and the outer side fixing member. Adopting a pre-compression member in which the axially opposed surface of the outer side fixing member and the flange portion are connected by a connecting rubber elastic body, the cylindrical portion of the inner side fixing member is connected to the shaft of the inner shaft member. While the outer end fixing member is fitted and fixed to the opposite end portion, the axial length of the connecting rubber elastic body is fixed by fitting and fixing the cylindrical portion of the outer side fixing member to the axial end portion of the outer cylindrical member. Is a suspension bush to which the pre-compression member is mounted in a state in which the pre-compression is exerted by making it smaller than the free length.

  In the suspension bush having the structure according to this aspect, since the outer side fixing member is fixed to the outer cylinder member, the press fitting fixing portion is compared with the conventional structure that press fits to a large part such as an arm eye. It is possible to manage the dimensional accuracy of parts at high level. Therefore, the fixing force of the bush to the suspension arm, the deformation amount of the connecting rubber elastic body at the time of pre-compression, and the axial spring rigidity are set stably, and the desired vibration-proof effect and vehicle Steering stability can be advantageously achieved.

  Further, when the pre-compression member is mounted on the bush while pre-compressing the connected rubber elastic body, axial pre-compression is exerted on the main rubber elastic body by the bush alone. Therefore, it is easy to handle at the time of product shipment or assembling work on an automobile. In addition, when attaching the bush to the automobile, the step of pre-compressing the connecting rubber elastic body can be simplified or omitted, and the operation becomes easy.

  In particular, in this embodiment, the flange portion of the outer side fixing member is inward. Therefore, the axial pre-compression can be realized by making good use of the space of the inner peripheral portion of the outer side fixing member. Moreover, when mounting to the automobile, it is possible to insert and assemble the arm eye from one side in the axial direction where the flange portion of the outer side fixing member in the bush is fixed. That is, since the flange portion of the outer side fixing member does not hinder the insertion of the bush into the arm eye, the pre-compressed bush is attached to the suspension arm by the insertion assembly from one side of the arm eye in the axial direction. As a result, the workability can be greatly improved as compared with the bush of the conventional structure in which the arm eye is inserted and assembled from both sides in the axial direction and pre-compresses.

(Aspect 2 of the present invention)
A feature of aspect 2 of the present invention is the suspension bush according to aspect 1 of the present invention, wherein in the precompression member, the connecting rubber elastic body is perpendicular to the inner shaft member and the outer cylinder member. One set is formed so as to face each other in one direction.

  In this aspect, the spring ratio in the axial direction and the direction perpendicular to the axis and the spring ratio in the two perpendicular directions to the axis can be advantageously set. Further, for example, the steering stability can be further improved by attaching the bushing to the automobile so that the axial direction is the lateral direction of the vehicle and the one direction perpendicular to the axial direction is the longitudinal direction of the vehicle.

(Aspect 3 of the present invention)
A feature of aspect 3 of the present invention is a suspension bush according to aspect 1 or 2 of the present invention, wherein a pair of the pre-compression members is used, and both end portions in the axial direction of the inner shaft member and the outer cylinder member In other words, the pre-compression member is attached to each.

  In this aspect, since the connecting rubber elastic body is disposed at both axial end portions of the inner shaft member and the outer cylindrical member, axial spring rigidity can be obtained more advantageously. In addition, since the pair of connected rubber elastic bodies are formed separately from the main rubber elastic body, the rubber material and the like are considered in consideration of the difference in characteristics required between the connected rubber elastic body and the main rubber elastic body. This makes it possible to increase the degree of freedom in design such as spring characteristics. In addition, it is possible to easily provide a suspension bush having different spring characteristics and the like by making the main rubber elastic body common and appropriately changing one or both of the pair of connected rubber elastic bodies.

(Aspect 4 of the present invention)
A feature of the fourth aspect of the present invention is that in the suspension bush according to any one of the first to third aspects of the present invention, the pre-compression is applied to one axial end portion of the inner shaft member and the outer cylinder member. While the member is mounted, a stopper rubber projecting outward in the axial direction from the axial end surface of the outer cylindrical member is provided at the other axial end of the outer cylindrical member.

  In this aspect, on one side in the axial direction, it is possible to configure a stopper mechanism or to apply axial pre-compression by the stopper rubber integrally formed simultaneously with the main rubber elastic body. In particular, when axial pre-compression is applied with a stopper rubber, a large shaft can be obtained by simply assembling the pre-compression member only on one side in the axial direction with respect to the inner shaft member and the outer cylinder member. A directional precompression load can be applied.

(Aspect 5 of the present invention)
A feature of the fifth aspect of the present invention is that in the suspension bush according to any one of the first to fourth aspects of the present invention, a pair of attachments facing each other in parallel at a predetermined distance on the vehicle body side. A bracket having a plate portion is provided, and is fitted between the pair of mounting plate portions of the bracket so that an axial direction of the inner shaft member extends in a direction opposite to the pair of mounting plate portions. The inner shaft member is mounted by being fixed to the bracket.

  In this aspect, since the bush in a state in which the axial pre-compression is exerted is mounted between the pair of mounting plate portions, when the bush is mounted on the bracket, the operation of pre-compressing the bush is specially performed. There is no need to consider. Therefore, a device necessary for mounting is simplified and mounting work is facilitated.

(Aspect 6 of the present invention)
A feature of aspect 6 of the present invention is that, in the suspension bush according to any one of aspects 1 to 5 of the present invention, a stepped portion is formed at an axially intermediate portion of the outer cylinder member, and this stepped According to the present invention, an axial fixing position of the outer side fixing member relative to the outer cylinder member is defined by the portion.

In this aspect, it is possible to accurately define the distance between the facing surfaces of the flange portion of the outer side fixing member and the flange portion of the inner side fixing member. Therefore, the amount of compressive deformation of the connecting rubber elastic body disposed between both flange portions, and hence the axial precompression with respect to the bush can be set with higher accuracy.

As is clear from the above description, the suspension bush having the structure according to the present invention can be shipped with the rubber elastic body subjected to axial pre-compression, and is easy to handle. Further, when the outer side fixing member is mounted on the automobile, the flange portion of the outer side fixing member is directed inward, so that the outer side fixing member can be inserted and assembled into the arm eye from one axial side of the bush to which the outer side fixing member is fixed. . Therefore, workability is dramatically improved as compared with a bush having a conventional structure in which pre-compression is applied during assembly by inserting and assembling from both axial sides of the arm eye.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described. 1 and 2 show a suspension bush 10 as one embodiment of the present invention. The suspension bush 10 has a structure in which an inner cylinder fitting 12 as an inner shaft member and an outer cylinder fitting 14 as an outer cylinder member are elastically connected by a main rubber elastic body 16. For example, in the torsion beam type suspension mechanism 18 of an automobile, the bush 10 is fixed to an arm eye 22 formed at an end portion in the axial direction of a trailing arm 20 as a suspension arm, and the inner cylinder 12 is a vehicle. By being fixed to a channel 24 as a bracket provided on the body side, the arm eye 22 is swingable about one axis with respect to the channel 24 by being interposed in a pivotal connecting portion with respect to the vehicle body of the trailing arm 20. Anti-vibration connection is made (see FIG. 3). In the following description, unless otherwise specified, the vertical direction refers to the vertical direction in FIG. 1 which is the bush axis direction.

  More specifically, the inner cylinder fitting 12 and the outer cylinder fitting 14 each have a substantially cylindrical shape. The axial length of the inner cylinder fitting 12 is made larger than that of the outer cylinder fitting 14. Further, the inner diameter dimension of the outer cylinder fitting 14 is made larger than the outer diameter dimension of the inner cylinder fitting 12.

  In addition, a stepped portion 26 is formed in an intermediate portion in the axial direction of the outer cylinder fitting 14. The stepped portion 26 has a tapered shape in which the diameter dimension gradually decreases from one axial direction (upper in FIG. 1) to the other (lower in FIG. 1). One side in the axial direction of the outer tube fitting 14 is a large diameter portion 28 with the stepped portion 26 interposed therebetween, and the other side is a small diameter portion 30 having a smaller diameter than the large diameter portion 28. Yes. A flange portion 32 that extends outward in the direction perpendicular to the axis is integrally formed at the opening edge of the large diameter portion 28.

  Such an outer cylinder fitting 14 is positioned opposite to the inner cylinder fitting 12 in the radial direction (left and right in FIG. 1) with a predetermined distance therebetween, so that each central axis of the inner cylinder fitting 12 and the outer cylinder fitting 14 is arranged. Are positioned on substantially the same line. Further, both end portions in the axial direction of the inner cylindrical metal fitting 12 protrude from the axial end portion of the outer cylindrical metal fitting 14 in the axially outward direction. A main rubber elastic body 16 is disposed between the radially opposed surfaces of the inner cylinder fitting 12 and the outer cylinder fitting 14.

  The main rubber elastic body 16 has a thick, substantially cylindrical shape. The inner peripheral surface of the main rubber elastic body 16 is vulcanized and bonded to the outer peripheral surface from the upper end in the axial direction of the inner cylindrical metal fitting 12 to the middle portion in the axial direction, and the outer peripheral surface of the main rubber elastic body 16 is the outer cylindrical metal fitting 14. The inner cylinder fitting 12 and the outer cylinder fitting 14 are elastically connected to each other by the main rubber elastic body 16 by being vulcanized and bonded over substantially the entire inner peripheral surface. In short, the main rubber elastic body 16 is formed as an integrally vulcanized molded product 34 including the inner cylinder fitting 12 and the outer cylinder fitting 14. Further, at both end portions in the axial direction of the main rubber elastic body 16, there are formed hollow portions 36 that open in a concave shape outward in the axial direction and extend in the circumferential direction by a predetermined length (for example, one round). Thereby, the stress at the axial end of the main rubber elastic body 16 due to the tensile deformation of the main rubber elastic body 16 is reduced.

  Further, a stopper rubber 38 that protrudes outward in the axial direction from the axial end surface of the outer cylinder fitting 14 is provided at the other axial end (upper in FIG. 1) of the outer cylinder fitting 14. The stopper rubber 38 has a substantially constant trapezoidal or semicircular cross section and extends in a circumferential direction with a predetermined length (for example, one round), and is integrally formed with the main rubber elastic body 16 so as to be axial in the outer cylinder fitting 14. It is vulcanized and bonded to a flange portion 32 provided at the other end. Further, the protruding tip end portion of the stopper rubber 38 is positioned at substantially the same height as the end portion of the inner cylinder fitting 12 in the axial direction. In short, the protruding tip of the stopper rubber 38 is positioned at the same height as the end of the inner tube fitting 12 according to the required anti-vibration characteristics, manufacturability, or the like, or slightly more axial than the end. It can be positioned outward or inward.

  A pre-compression member 40 is attached to one end (downward in FIG. 1) of the inner cylinder fitting 12 and the outer cylinder fitting 14 in the axial direction. The pre-compression member 40 has a structure in which an inner cylinder side fixing bracket 42 as an inner side fixing member and an outer cylinder side fixing bracket 44 as an outer side fixing member are connected by a connecting rubber elastic body 46.

  The inner cylinder side fixing bracket 42 includes a cylindrical portion 48 having a substantially cylindrical shape with a small diameter. The inner diameter dimension of the cylindrical portion 48 is slightly larger than the outer diameter dimension of the inner cylinder fitting 12. A flange portion 50 that extends outward in the direction perpendicular to the axis is integrally formed at one opening end edge of the cylindrical portion 48 in the axial direction (downward in FIG. 1). The outward flange portion 50 has an annular shape in a plan view, and the outer diameter dimension thereof is smaller than the outer diameter dimension of the large diameter portion 28 of the outer cylinder fitting 14. Further, a pair of notch portions 52 extending in one direction perpendicular to the axis (left and right in FIG. 2) and reaching the outer peripheral edge of the flange portion 50 are formed in the radially intermediate portion of the flange portion 50. These notched portions 52 and 52 are opposed to each other in a direction (up and down in FIG. 2) perpendicular to one direction perpendicular to the axis. As a result, the flange portion 50 has a pair of narrow rectangular portions 56, 56 in which the outer peripheral edge portion has a substantially arc shape and a wide pair of arc-shaped portions 54, 54 and the outer peripheral edge portion is a notch-shaped portion 52. The pair of arc-shaped portions 54 and 54 and the rectangular portions 56 and 56 are opposed to each other in the direction perpendicular to the axis. That is, the pair of arcuate portions 54 and 54 are opposed to each other in a direction (left and right in FIG. 2) orthogonal to the facing direction of the pair of rectangular portions 56 and 56.

  On the other hand, the outer cylinder side fixing bracket 44 includes a substantially cylindrical tubular portion 58 having a larger diameter than the cylindrical portion 48 of the inner cylinder side fixing bracket 42. The outer diameter dimension of the cylindrical part 58 is made larger than the outer diameter dimension of the small diameter part 30 of the outer cylinder fitting 14. An inward flange portion 60 having an annular shape in a plan view is formed integrally with an opening edge of one of the cylindrical portions 58 in the axial direction (downward in FIG. 1). ing. The inner diameter dimension of the flange portion 60 is larger than the outer diameter dimension of the inner cylinder fitting 12 or the outer diameter dimension of the cylindrical portion 48 of the inner cylinder side fixing bracket 42, and the flange portion of the inner cylinder side fixing bracket 42. The outer diameter of the 50 arcuate portions 54 is made smaller. A reinforcing rib 62 extending upward by a predetermined length is integrally formed at the inner peripheral edge of the flange portion 60.

  The central axes of the cylindrical portions 48 and 58 of the inner cylinder side fixing bracket 42 and the outer cylinder side fixing bracket 44 are positioned substantially on the same line, and the inner cylinder side fixing bracket 42 has one axial direction (FIG. 1). The outer cylinder side fixing metal fitting 44 is positioned on the other side in the axial direction (upper in FIG. 1) on the side of the middle and the lower side, and the metal fittings 42 and 44 are spaced apart from each other. Further, both the outward flange portion 50 of the inner cylinder side fixing bracket 42 and the inward flange portion 60 of the outer cylinder side fixing bracket 44 are positioned on the other side in the axial direction (downward in FIG. 1). The flange portions 50 and 60 are opposed to each other at a predetermined distance in the axial direction. Further, a connecting rubber elastic body 46 is disposed between the arcuate portion 54 of the outward flange portion 50 and the inward flange portion 60.

  The connecting rubber elastic bodies 46 have a substantially constant arc-shaped cross section and have a shape extending in the axial direction, and are provided in a pair in the present embodiment. The upper end surface of each connecting rubber elastic body 46 is vulcanized and bonded to the lower end surface of the inward flange portion 60, and the lower end surface of each connecting rubber elastic body 46 is the upper end surface of the arcuate portion 54 of the outward flange portion 50. Is vulcanized and bonded. In other words, the pair of connected rubber elastic bodies 46, 46 is an integrally vulcanized molded product including the inner cylinder side fixing bracket 42 and the outer cylinder side fixing bracket 44, and the flange portion 50 ( The arcuate portion 54) and the axially opposed surfaces of the flange portion 60 of the outer cylinder side fixing bracket 44 are connected. The pre-compression member 40 includes the inner cylinder side fixing bracket 42, the outer cylinder side fixing bracket 44, and the connecting rubber elastic bodies 46, 46. Further, since each of the connecting rubber elastic bodies 46 is disposed between the flange portions 50 and 60, the connecting rubber elastic body 46 is in a direction perpendicular to the axis of the inner cylinder side fixing bracket 42 and the outer cylinder side fixing bracket 44. One set is formed so as to face each other in one direction (left and right in FIG. 2). A part of the connecting rubber elastic body 46 is also turned to the upper end surface of the inward flange portion 60 and the outer peripheral surface of the reinforcing rib 62 so that the inward flange portion 60 and the reinforcing rib 62 are substantially embedded and arranged. Thus, a large fixing force of the connecting rubber elastic body 46 to the outer cylinder side fixing bracket 44 is ensured.

  The cylindrical portion 48 of the inner cylinder side fixing bracket 42 in the pre-compression member 40 is press-fitted into one end (downward in FIG. 1) of the inner cylinder bracket 12 in the axial direction, so that the inner cylinder side fixing bracket 42 is pressed. The flange portion 50 and the end of the inner cylinder fitting 12 are substantially flush with each other, and are fitted and fixed to the inner cylinder fitting 12.

  Further, the cylindrical portion 58 of the outer cylinder side fixing bracket 44 in the precompression member 40 is extrapolated to the small diameter portion 30 of the outer cylinder bracket 14. In particular, in this embodiment, when the cylindrical portion 58 is extrapolated to the small-diameter portion 30, the axial end of the cylindrical portion 58 is brought into contact with the stepped portion 26 of the outer cylindrical bracket 14, so that the outer cylindrical bracket is 14, the fitting and fixing position of the outer cylinder side fixing bracket 44 with respect to 14 is defined. In addition, since the cylindrical portion 58 extrapolated to the small-diameter portion 30 is subjected to diameter reduction processing such as drawing processing, the cylindrical portion 58 of the outer cylinder-side fixing bracket 44 is connected to the axial end of the outer cylindrical bracket 14. It is fitted and fixed to the portion (small diameter portion 30). The outer peripheral surface of the large-diameter portion 28 of the outer cylinder fitting 14 and the outer peripheral surface of the cylindrical portion 58 are substantially flush with each other in the axial direction.

  In this way, the suspension bush 10 is configured by assembling the pre-compression member 40 to the integrally vulcanized molded product 34 of the main rubber elastic body 16 provided with the inner and outer cylindrical fittings 12 and 14. The opposing direction of the flange portion 50 of the inner cylinder side fixing bracket 42 and the flange portion 60 of the outer cylinder side fixing bracket 44 extends in parallel with the bush axis direction. Further, the distal end portion of the arc-shaped portion 54 of the flange portion 50 of the inner cylinder side fixing bracket 42 is located at the same position as the large diameter portion 28 of the outer cylinder bracket 14 in the radial direction or radially inward from the large diameter portion 28. It is positioned. That is, the portion of the bush 10 having the maximum outer diameter dimension is the flange portion 32 of the outer cylinder fitting 14.

  In addition, since the inner and outer cylinder side fixing brackets 42 and 44 are fixed at predetermined positions of the inner and outer cylinder brackets 12 and 14, respectively, the opposing distance between both flange portions 50 and 60 of the precompression member 40 is increased. It is smaller than that. As a result, the axial length of each connecting rubber elastic body 46 is made smaller than the free length, so that each connecting rubber elastic body 46 is pre-compressed in the axial direction. The pre-compression member 40 is mounted on the bush 10 in such a state that the connecting rubber elastic body 46 is pre-compressed, whereby the spring rigidity in the axial direction of the bush 10 is increased.

  The suspension bush 10 having such a structure is conveyed to an appropriate place such as an automobile assembly factory, a parts factory, a repair factory, etc., and as shown in FIG. A pair is assembled to the torsion beam suspension mechanism 18 in which a pair of trailing arms 20 and 20 that support each other are coupled and fixed to each other by a torsion beam 64 extending in the vehicle width direction (left and right in FIG. 3).

  An arm eye 22 having a substantially cylindrical shape is formed at the end of the trailing arm 20. In addition, the outer diameters of the large-diameter portion 28 of the outer cylinder fitting 14, the cylindrical portion 58 of the outer cylinder-side fixing fitting 44, and the flange portion 50 of the inner cylinder-side fixing fitting 42 are made smaller than the inner diameter dimension of the arm eye 22. In addition, the axial dimension of the large-diameter portion 28 of the outer cylinder fitting 14 and the cylindrical portion 58 of the outer cylinder side fixing fitting 44 is substantially the same as the length of the hole of the arm eye 22.

  The bush 10 is fitted into the arm eye 22 from the axial end of the inner cylinder metal 12 on the side where the inner cylinder side metal fitting 42 is fixed, and the large diameter portion 28 of the outer cylinder metal 14 and the outer cylinder side metal fitting 44 are fixed. The cylindrical portion 58 is press-fitted into the arm eye 22, and the flange portion 32 of the outer cylindrical metal fitting 14 is superimposed on the opening edge of the arm eye 22. Thereby, the bush 10 is fitted and fixed to the arm eye 22. Further, a stopper rubber 38 projecting from the flange portion 32 of the outer cylinder fitting 14 on one side in the axial direction of the bush 10 and one axial end portion of the inner cylinder fitting 12 and a precompression member on the other axial side of the bush 10 are provided. The connecting rubber elastic body 46 and the other end portion in the axial direction of the inner cylindrical metal member 12 protrude from the arm eye 22 outward in the axial direction.

  A channel 24 is fixed on the vehicle body side. The channel 24 has a known structure with a U-shaped cross section, and includes a pair of substantially flat plate-shaped mounting plate portions 66 and 66 that face each other at a predetermined distance in parallel. An insertion hole 68 is formed through substantially the center of each mounting plate portion 66. Further, the axial length of the inner cylindrical metal fitting 12 is made smaller than the distance between the opposing surfaces of the pair of mounting plate portions 66, 66. Further, the stopper rubber 38 provided at both ends in the axial direction of the bush 10 and protruding outward in the axial direction from the arm eye 22 and the flange portion 50 of the inner cylinder side fixing bracket 42 are the same as the axial end of the inner cylinder bracket 12. It is positioned at a height and does not protrude outward in the axial direction from the inner cylinder fitting 12.

  The bush 10 fixed to the arm eye 22 is fitted between the facing surfaces of the pair of mounting plate portions 66 and 66, and the axial direction of the inner cylinder fitting 12 (bush 10) is the facing direction of the pair of mounting plate portions 66 and 66. It is arranged in a state extending in the left and right direction in FIG. The distal end portion of the stopper rubber 38 and one end portion in the axial direction of the inner cylinder fitting 12 are in contact with one mounting plate portion 66, and the flange portion 50 of the inner cylinder side fixing fitting 42 and the axial direction of the inner cylinder fitting 12. The other end is in contact with the other mounting plate 66. In particular, in the present embodiment, the stopper rubber 38 has an axial length substantially the same as the free length, and its protruding tip is brought into contact with the mounting plate portion 66, whereby the stopper rubber 38 is axially moved. There is no special pre-compression.

  In addition, the inner hole of the inner cylinder fitting 12 is aligned with the insertion hole 68 of each attachment plate portion 66, and the support bolt 70 extends from one attachment plate portion 66 to the inner hole and both attachment plates of the inner cylinder fitting 12. It is inserted into the insertion holes 68 and 68 of the portions 66 and 66 and screwed to the fixing nut 72 disposed on the other mounting plate portion 66. In particular, in the present embodiment, the inner cylinder fitting 12 is a channel in a state where the opposing direction of the pair of arcuate portions 54, 54 in the flange portion 50 of the inner cylinder side fixing fitting 42 extends in the vehicle front-rear direction (up and down in FIG. 3). 24 is fixed. As a result, the pair of connected rubber elastic bodies 46 are opposed to each other in the vehicle front-rear direction.

  As a result, the suspension bush 10 is pivotally supported by the channel 24 via the support bolt 70, and the trailing arm 20 is connected to the vehicle body so as to be swingable around the center axis of the support bolt 70. Yes. Accordingly, the axial direction of the bush 10 extends in the vehicle left-right direction (left and right in FIG. 3), and the opposing direction of the pair of connecting rubber elastic bodies 46 extends in the vehicle front-rear direction (up and down in FIG. 3). In this state, the pair of bushes 10 and 10 are attached to the automobile and constitute a part of the suspension mechanism 18. Further, the pair of bushes 10 and 10 are arranged so that each stopper rubber 38 is positioned inward in the vehicle width direction and each pair of connected rubber elastic bodies 46 and 46 is positioned outward in the vehicle width direction. Axis of symmetry (center line) extending in the front-rear direction at the center of the vehicle: they are mounted symmetrically with respect to XX.

  Further, the support bolt 70 is further tightened to deform the pair of mounting plate portions 66, 66 of the channel 24 in a direction approaching each other, so that the stopper rubber 38 abutted on one mounting plate portion 66 is brought into contact with the stopper rubber 38. A pre-compression in the axial direction is exerted, or a pre-compression in the axial direction is further exerted on the connecting rubber elastic body 46 via the flange portion 50 of the inner cylinder side fixing bracket 42 superimposed on the other mounting plate portion 66. It is also possible.

  In the suspension bush 10 having the above-described structure, the outer cylinder side fixing bracket 44 is fitted and fixed to the outer cylinder bracket 14, and the inner cylinder side fixing bracket 42 is fitted and fixed to the inner cylinder bracket 12. Thus, the connecting rubber elastic body 46 is pre-compressed in the axial direction, and the pre-compression member 40 including the connecting rubber elastic body 46 is disposed. Therefore, since the bushing is pre-compressed in the axial direction before mounting on the vehicle, in addition to simplifying the mounting operation, each member constituting the vehicle is assembled when mounting to the vehicle. A significant deviation in the amount of compressive deformation of the desired connected rubber elastic body 46 due to a dimensional error or the like is suppressed, and the spring rigidity in the axial direction is advantageously exerted to achieve the desired vibration-proof performance and control. Stability is obtained stably.

  Further, the large-diameter portion 28 of the outer cylinder fitting 14 and the cylindrical portion 58 of the outer cylinder side fixing fitting 44 cooperate to form a substantially cylindrical shape, and the flange portion 60 of the outer cylinder side fixing fitting 44 is provided. Since the portion extends radially inward, only the flange portion 32 formed at one end portion in the axial direction of the large-diameter portion 28 is the only portion protruding radially outward from the large-diameter portion 28 and the cylindrical portion 58. It is said that.

  Accordingly, the pre-compressed bush 10 is press-fitted into the arm eye 22 from one axial side (downward in FIG. 1) where the inward flange portion 60 of the outer cylinder side fixing bracket 44 in the bush 10 is provided. Can be fixed by fitting.

  Further, when the channel 24 is mounted between the pair of mounting plate portions 66, 66, the axial length of the bush 10 including the precompression member 40 is easily made smaller than the facing distance of the mounting plate portion 66. In addition, since the bush 10 in a state of being pre-compressed is mounted, it is necessary to perform a special pre-compression operation on the bush 10 in the mounted state of the mounting plate 66. Disappear.

  Therefore, in the suspension bush 10 according to the present embodiment, as well known in the art, a pair of cylindrical portions provided with a flange portion are respectively fitted and fixed from one axial direction of the arm eye, and the flange portion. Rubber is applied via the mounting plate portion based on the fact that the rubber elastic body fixed to the base plate is pre-compressed in the axial direction or the bush is fitted between the pair of mounting plate portions to deform the mounting plate portion. Compared with a conventional bushing or the like that pre-compresses the elastic body, the efficiency of the mounting operation can be dramatically improved.

  In the present embodiment, a pair of connecting rubber elastic bodies 46 are provided, and the pair of connecting rubber elastic bodies 46, 46 are opposed to each other in the vehicle front-rear direction. The spring ratio and the vehicle front-rear direction and the spring ratio in the vehicle up-down direction orthogonal to the direction are suitably adjusted, and the steering stability of the vehicle can be exhibited more advantageously. In particular, the connecting rubber elastic bodies 46, 46 are fixed to the pair of arc-shaped portions 54, 54 in the flange portion 50 of the inner cylinder side fixing bracket 42, so that the connecting rubber elastic bodies 46, 46 are opposed to each other. It can be easily set in the longitudinal direction of the vehicle, and the mounting work is further simplified.

  Furthermore, in this embodiment, the axial end of the cylindrical portion 58 of the outer cylinder side fixing bracket 44 is brought into contact with the stepped portion 26 of the outer cylinder bracket 14, so that the outer cylinder bracket 14 of the outer cylinder side fixing bracket 44 is contacted. By defining the fitting and fixing position with respect to, the facing distance between the flange portion 60 of the outer cylinder side fixing bracket 44 and the flange portion 50 of the inner cylinder side fixing bracket 42 is defined with high accuracy. Therefore, the amount of precompression applied to the connecting rubber elastic body 46 is adjusted with high accuracy, and a desired spring rigidity is obtained.

  In the present embodiment, the flange portion 50 of the inner cylinder side fixing bracket 42 is superposed on the mounting plate portion 66, so that the strength of the mounting plate portion 66 is utilized to further improve the axial spring rigidity. Can be demonstrated.

  As mentioned above, although one embodiment of the present invention has been described in detail, this is merely an example, and the present invention is not limited to any specific description by this embodiment, and is based on the knowledge of those skilled in the art. The present invention can be implemented with various changes, modifications, improvements, etc., and all such embodiments are within the scope of the present invention without departing from the spirit of the present invention. Needless to say, there is.

  For example, in the said embodiment, the step part 26 was formed in the outer cylinder metal fitting 14, However, This step part 26 is not an essential structural requirement. Hereinafter, a suspension bush according to the present invention in a form different from that of the above-described embodiment will be described with reference to FIG. 4, and members and parts having substantially the same structure as the above-described embodiment are illustrated in FIG. 4. The same reference numerals as those in the embodiment are attached to the components, and detailed description thereof is omitted.

  That is, in the suspension bush shown in FIG. 4, a thin rubber layer 74 integrally formed with the main rubber elastic body 16 is attached and formed on the inner peripheral surface of the outer cylindrical fitting 14 ′ having a substantially cylindrical shape. At the same time, the outer diameter dimension of the cylindrical portion 58 ′ of the outer cylinder side fixing bracket 44 is made smaller than the inner diameter dimension of the outer cylinder bracket 14 ′ having the rubber layer 74, so that the cylindrical portion 58 ′ is replaced with the outer cylinder bracket 14 ′. Is inserted into the outer cylindrical fitting 14 'and subjected to diameter reduction processing such as drawing, so that the outer peripheral surface of the cylindrical portion 58' is in close contact with the inner peripheral surface of the outer cylindrical fitting 14 'via the rubber layer 74. The outer cylinder side fixing metal fitting 44 is fitted and fixed to the outer cylinder metal fitting 14 '. In such a structure, the outer cylinder side fixing bracket 44 is easily and stably fixed to the outer cylinder bracket 14 '.

  Further, in the embodiment, a pair of connecting rubber elastic bodies 46 are provided between the flange portion 60 of the outer cylinder side fixing bracket 44 and the flange portion 50 of the inner cylinder side fixing bracket 42 so as to be perpendicular to the vehicle longitudinal direction. However, the shape, size, structure, number, arrangement, and the like of the connecting rubber elastic body 46 are not limited to those illustrated. For example, the connecting rubber elastic body has an annular shape extending continuously in the circumferential direction between the flange portions 50, 60, or the connecting rubber elastic body extending by a predetermined length in the circumferential direction is the flange portions 50, 60. One or two or more may be provided at an appropriate location in between.

  Moreover, in the said embodiment, although the stopper rubber 38 was made into the annular | circular shape extended continuously in the perimeter of the circumferential direction, you may be made into the circular arc shape etc. which extend in the circumferential direction by predetermined length.

  Furthermore, in the above embodiment, when the protruding end portion of the stopper rubber 38 is positioned at the same height as the axial end portion of the inner cylindrical metal member 12 and the bush 10 is fitted into the channel 24, the stopper rubber 38 Although the axial length is substantially the same as the free length, it is in contact with the mounting plate portion 66. For example, the height of the stopper rubber is changed, and the protruding tip is set in the axial direction of the inner cylinder fitting. Based on the fact that it is positioned axially outward from the end, and the tip end of the stopper rubber is brought into contact with the mounting plate and is compressed and deformed with the axial length of the stopper rubber being smaller than the free length. Apply pre-compression to the stopper rubber, or position the protruding tip of the stopper rubber axially inward from the axial end of the inner cylinder fitting, and face the protruding tip and the mounting plate with a predetermined distance You can also squeeze A. In particular, when pre-compression is applied to the stopper rubber, the connecting rubber elastic body of the stopper rubber and the pre-compression member cooperates to increase the spring stiffness in the axial direction of the bush.

  In the above embodiment, the stopper rubber 38 and the flange portion 32 are provided at one axial end of the outer cylindrical metal member 14, and a large vibration load such as an axial direction or a twisting direction is input to the bush 10. The flange portion 32 of the outer tube fitting 14 and the mounting plate portion 66 of the channel 24 are brought into contact with each other via the stopper rubber 38, so that the relative displacement between the inner tube fitting 12 and the outer tube fitting 14 is buffered. Although the limiting stopper mechanism includes the flange portion 32, the stopper rubber 38, and the mounting plate portion 66, it is not necessary to provide such a stopper mechanism.

  Further, instead of the stopper mechanism described above, a precompression member may be mounted on one end in the axial direction opposite to the other end in the axial direction where the precompression member of the outer cylinder fitting and the inner cylinder fitting is arranged. Is possible. In other words, using a pair of precompression members, it is also possible to attach the precompression members to the axial ends of the inner cylinder fitting and the outer cylinder fitting, respectively.

Moreover, in the said embodiment, although the inner cylinder metal fitting 12 in the bush 10 was fixed to the channel 24 provided with a pair of attachment board parts 66 and 66, it is not necessary to fix to this channel 24. For example, as disclosed in JP-A-7-83259, JP-A-2002-295560, etc., a plate member such as a washer is bolted to the end of the inner cylinder fitting, and the vehicle is connected via the plate member. It may be attached to the body side.

It is a longitudinal cross-sectional explanatory drawing which shows the suspension bush as one Embodiment of this invention, Comprising: It is a figure equivalent to the II cross section of FIG. It is bottom explanatory drawing which shows the suspension bush in FIG. FIG. 2 is an explanatory schematic view showing a state in which the suspension bush in FIG. 1 is mounted between a trailing arm and a channel in the suspension mechanism. It is a longitudinal cross-sectional explanatory drawing which shows the suspension bush as another specific example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Suspension bush 12 Inner cylinder metal fitting 14 Outer cylinder metal fitting 16 Main body rubber elastic body 20 Trailing arm 40 Precompression member 42 Inner cylinder side fixing metal fitting 44 Outer cylinder side fixing metal fitting 46 Connection rubber elastic body 48 Cylindrical part 50 Flange part 58 Cylinder Shaped part 60 flange part

Claims (6)

In the suspension bush in which the outer cylinder member attached to the suspension arm is arranged apart from the outer shaft side with respect to the inner shaft member attached to the vehicle body, and the inner shaft member and the outer cylinder member are connected by the main rubber elastic body. ,
An inner side fixing member having an outward flange portion at one opening edge of the cylindrical portion in the axial direction, and one axial direction of the cylindrical portion having a larger diameter than the cylindrical portion of the inner side fixing member An outer side fixing member having an inward flange portion at the opening edge is arranged away from each other so that the flange portion of the inner side fixing member and the flange portion of the outer side fixing member face each other in the axial direction. While adopting a pre-compression member in which the surfaces are connected by a connecting rubber elastic body, the tubular portion of the inner side fixing member is externally fixed to the axial end portion of the inner shaft member, while the outer side fixing member By fitting and fixing the cylindrical portion to the axial end portion of the outer cylindrical member, the axial length of the connecting rubber elastic body is made smaller than the free length and pre-compression is applied. The suspension bush, wherein the precompression member is mounted. Interview.   The suspension bush according to claim 1, wherein in the pre-compression member, the coupling rubber elastic body is formed as a pair so as to oppose each other in one direction perpendicular to the axis of the inner shaft member and the outer cylinder member.   The suspension bush according to claim 1 or 2, wherein a pair of the pre-compression members are used, and the pre-compression members are respectively attached to both axial ends of the inner shaft member and the outer cylinder member.   The pre-compression member is attached to one axial end of the inner shaft member and the outer cylindrical member, while the other axial end of the outer cylindrical member is pivoted from the axial end surface of the outer cylindrical member. The suspension bush according to any one of claims 1 to 3, further comprising a stopper rubber protruding outward in the direction.   On the vehicle body side, a bracket having a pair of mounting plate portions facing each other in parallel at a predetermined distance is provided, and the inner shaft member is disposed between the pair of mounting plate portions of the bracket. 5. The inner shaft member is attached by being fitted in a state in which the axial direction of the inner shaft member extends in the opposing direction of the pair of mounting plate portions, and the inner shaft member is fixed to the bracket. Suspension bushing.   2. A stepped portion is formed at an axially intermediate portion of the outer cylindrical member, and the axially fixed fixing position of the outer side fixing member with respect to the outer cylindrical member is defined by the stepped portion. The suspension bush as described in any one of thru | or 5.

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