JP2010013037A - Vibration isolation mechanism of steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration isolation mechanism capable of securing a good feeling of a steering by preventing hysteresis in operation while reducing the number of parts and simplifying a structure. <P>SOLUTION: This mechanism comprises an outer tube 12 fixed into a through-hole 10a of a mounting part 10 by press-fitting, and an inner tube 13 arranged on an inner peripheral side of the outer tube. A first elastic body 14 is vulcanized and adhered between the inner tube and the outer tube, a second annular elastic body 15 is fixed to a top end of the inner tube by press-fitting, and a third elastic body 16 contacting a lower bracket piece 8b is provided on a lower face of a flange part 12a of the outer tube. A clearance part C2 is formed between an upper face of the second elastic body 15 and an upper bracket piece 8a, and an annular protrusion part 21 elastically contacting the lower face of the upper bracket piece 8a is integrally provided on the upper face of the second elastic body 15, so as to restrain hysteresis between shearing-deformation and its restoration. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an improvement in an anti-vibration mechanism that is applied to a steering device for a vehicle, for example, and is provided between a steering housing and a vehicle body and absorbs vibrations input from the steering housing to the vehicle body.

  As a conventional anti-vibration mechanism applied to a vehicle steering apparatus, one described in Patent Document 1 below is known.

  In this vibration isolation mechanism, a metallic inner cylinder and an outer cylinder, which are spaced apart from each other in the radial direction, are connected by a rubber elastic body, the inner cylinder is fixed to the vehicle body, and the outer cylinder is fixed to the steering housing. It is installed. Two substantially annular metal stopper plates are arranged at the upper and lower ends in the axial direction of the inner cylinder, and both the stopper plates are fastened together by bolts and nuts and fixed to the vehicle body. Yes.

In addition, a pair of straight portions are formed on the outer periphery of the rubber elastic body, and a buffer protrusion that protrudes from the inner cylinder side toward the outer cylinder side is integrally provided at a central position of the two straight portions. With the straight portion, the spring constant in the lateral direction of the vehicle body can be set smaller than the spring constant in the longitudinal direction of the vehicle body, thereby realizing a weak under steering performance. In addition, when the large load acting in the lateral direction of the vehicle is applied, the buffer protrusion can alleviate a sudden change in the rise of the load-deflection characteristic.
JP 2002-160647 A

  However, in the conventional vibration isolating mechanism, an inner cylinder is provided on the inner side of the rubber elastic body, and an outer cylinder is provided on the outer side. Since each of the two stopper plates is provided, the number of parts is inevitably increased as a whole, and a technical problem such as a complicated structure is caused.

  The present invention has been devised by paying attention to such a technical problem, and provides a vibration isolation mechanism capable of simplifying the structure while suppressing an increase in the number of components.

  According to the first aspect of the present invention, in particular, the steering device side bracket includes a bracket main body attached to the steering device and a through hole formed in the bracket main body, and the vehicle body side bracket is the steering device side bracket. A first bracket having a first bolt insertion hole which is disposed on one end side of the through hole and through which the mounting bolt is inserted, and a second bolt which is disposed on the other end side of the through hole and through which the mounting bolt is inserted. A second bracket having an insertion hole.

  An outer cylinder is fixed inside the through-hole, and an inner cylinder is disposed at a position spaced apart at a predetermined interval in the radial direction inside the outer cylinder, and the outer cylinder and the inner cylinder A first elastic body is interposed between the bracket main body and the first bracket, and a substantially flange-shaped second elastic body is interposed between the bracket main body and the second bracket. Is provided with a substantially annular third elastic body.

  According to the present invention, for example, the third elastic body is provided integrally with the first elastic body made of hard rubber or synthetic resin without using a metal stopper plate as in the prior art, and the second elastic body is provided. Since the body and the third elastic body are arranged to be sandwiched between the vehicle body side bracket and the steering device side bracket, an increase in the number of parts of the vibration isolating mechanism can be suppressed and the structure can be simplified.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a vibration isolation mechanism in a vehicle steering apparatus according to the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 5, this steering device has a substantially cylindrical steering housing 1 arranged in the width direction of the vehicle body, one end of which is linked to a steering wheel (not shown), and a pinion formed at the lower end. A rack shaft that is linked to the steering shaft 2 via a steering shaft 2 and a rack formed in a predetermined range in the axial direction and that is movable in the vehicle body width direction by the rack and pinion mechanism as the steering wheel rotates. 3 are accommodated.

  Further, tie rods 5 and 5 are coupled to both ends of the rack shaft 3 via ball joints 4 and 4, and via unillustrated knuckles connected to axially outer ends of the tie rods 5 and 5. It is linked to the left and right wheels. As a result, the rack shaft 3 moves in the axial direction according to the rotation angle of the steering wheel, and the direction of both wheels is changed by pulling the knuckle left and right via the tie rods 5, 5. Is supposed to change.

  Further, as shown in FIG. 5, two steering device side brackets 6 are provided at both axial ends of the steering housing 1, and the steering device is provided via each bracket 6 and the inside of each bracket 6. The whole is fixed to the two brackets 8 on the vehicle body member 7 side.

  Each of the vehicle body side brackets 8 is formed in a substantially U-shaped cross section by an upper bracket piece 8a that is a first bracket protruding from the vehicle body member 7 and a lower bracket piece 8b that is a second bracket. The brackets 6 and 6 on the steering device side are connected between 8a and 8b via an anti-vibration mechanism described later. Bolt insertion holes 8c and 8d are vertically formed at substantially the center positions of the upper and lower bracket pieces 8a and 8b, respectively.

  Each of the brackets 6 of the steering device is formed in the same shape, one end is fixed to the outer periphery of the steering housing 1 and the other end protrudes forward of the vehicle body, and the connection And a cylindrical mounting portion 10 which is a bracket body integrally formed on the other end side of the portion 9. Each mounting portion 10 has a length L in the axial direction set to be shorter than a length between the bracket pieces 8a and 8b, and a holding hole 10a which is a through hole in the inner axial direction is formed through vertically. Has been.

  And the vibration-proof mechanism 11 which absorbs the vibration input from the road surface through the steering housing 1 during driving | running | working is accommodated and arrange | positioned inside the attaching part 10 of each said bracket 6, respectively. In addition, since these vibration-proof mechanisms 11 are all the same, the bracket 6 and the vibration-proof mechanism 11 will be described below for convenience.

  As shown in FIGS. 1 to 3, the vibration isolation mechanism 11 includes an outer cylinder 12 press-fitted and fixed to the inner peripheral surface of the mounting portion 10, and a diameter from the inner peripheral surface to the inner peripheral side of the outer cylinder 12. An inner cylinder 13 spaced apart in the direction, and a first elastic body 14 interposed between the outer cylinder 12 and the inner cylinder 13 and elastically connecting the outer cylinder 12 and the inner cylinder 13 to each other. 1, the second elastic body 15 press-fitted and fixed to the upper end portion 13 a in the axial direction in FIG. 1, and the lower bracket piece 8 b and the mounting portion 10 on the lower end side in the axial direction of the inner cylinder 13. A third elastic body 16 disposed between the lower surface of the first elastic body 16 and the second elastic body 16.

  The outer cylinder 12 is formed of a metal material in a substantially cylindrical shape of a thin plate, and the outer diameter is set to a size having a press-fitting allowance for the mounting portion 10, and the axial length thereof is the mounting portion. 10 in the axial length. Further, a flange portion 12a extending horizontally in the radial direction is integrally provided at the lower end edge of the outer cylinder 12, and the upper end surface of the flange portion 12a is in contact with the lower end surface of the mounting portion 10. Yes.

  The inner cylinder 13 is formed in a substantially thick cylindrical shape with a metal material, and its axial length L1 is longer than that of the outer cylinder 12, and an upper end portion 13a and a lower end portion 13b are formed. The upper end 13 a protrudes upward and downward from the upper and lower edges of the first elastic body 14, and the upper end 13 a slightly protrudes from the wall thickness W of the second elastic body 15. Further, the shaft portion 17a of the mounting bolt 17 is inserted into the bolt insertion hole 13c provided in the inner cylinder 13 through the bolt insertion holes 8c, 8d of the bracket pieces 8a, 8b. Each bracket 6 is attached to each bracket 8 of the member 7 of the vehicle body by bolts 17 and nuts 18, and at the time of such assembly, the upper and lower edges of the inner cylinder 13 are the bolt insertion holes of the bracket pieces 8 a and 8 b. The upper and lower surfaces near the hole edges of 8c and 8d are in pressure contact with the bolt axial force.

  As shown in FIGS. 1 and 3, the first elastic body 14 is formed in a substantially cylindrical shape made of a hard rubber material, and a pair of arc-shaped recesses that are hollowed out by a predetermined size on the outer peripheral wall. The part 19 is formed in axial symmetry. A solid portion 20 is formed in pressure contact with the inner peripheral surface of the outer cylinder 14 at a position approximately 90 ° in the circumferential direction from the straight portion 19. The first elastic body 14 is configured such that the two straight portions 19 are in the axial direction (vehicle body width direction X) and the two solid portions 20 are in the direction perpendicular to the axis (vehicle body longitudinal direction Y) with respect to the steering housing 1. Is arranged.

  As shown in FIGS. 1 and 2, the first elastic body 14 has an inner peripheral surface fixed to the outer peripheral surface of the inner cylinder 13 by vulcanization adhesion, while the outer peripheral surface of the solid portion 20 is It is similarly fixed to the inner peripheral surface of the outer cylinder 12 by vulcanization adhesion. Thus, the first elastic body 14 is formed integrally with the outer cylinder 12 and the inner cylinder 13. The outer peripheral surface of each of the straight portions 19 is not in contact with the outer cylinder 12.

  Further, the first elastic body 14 is set to have an axial length shorter than the inner cylinder 13, and an upper end portion 14 a is disposed on the same plane as the upper end portion of the outer cylinder 12. Thus, when the vibration isolating mechanism 11 is assembled to the bracket pieces 8a and 8b via the mounting bolts 17, the step-shaped annular first gap is formed between the step-like lower end portion 14b and the upper surface of the lower bracket piece 8b. One gap C1 is formed.

  As shown in FIGS. 1 and 2, the second elastic body 15 is made of a hard rubber material separate from the first elastic body 14, and the inner cylinder is inserted through an insertion hole 15a formed penetratingly formed in the center. 13 is press-fitted and fixed to the upper end portion 13a with an appropriate margin, and the outer diameter thereof is set to be substantially the same as the outer diameter of the third elastic body 16, and the lower surface of the outer peripheral portion 15b is the outer cylinder 12 or It is in contact with each upper surface of the mounting portion 10. Further, as shown in FIG. 1, the second elastic body 15 has an annular second shape with a predetermined width between the upper surface and the lower surface of the upper bracket piece 8a when the vibration isolation mechanism 11 is assembled. A gap C2 is formed. In addition, an annular protrusion 21 whose tip is elastically in contact with the lower surface of the upper bracket piece 8a is integrally provided at a substantially central position in the radial direction of the upper surface.

  Then, during vibration in the vertical direction Z of the steering device, the vertical vibration of the vibration isolation mechanism 11 is allowed through the second gap C2, and the sudden vertical vibration of the vibration isolation mechanism 11 is suppressed by the protrusion 21. It is like that. That is, as will be described later, the low-elasticity portion is suppressed by the protrusion 21 while the hysteresis is suppressed by the second gap portion C2.

  The third elastic body 16 is integrally formed of a hard rubber material made of the same material as the first elastic body 14 at the time of molding, so that the outer cylinder 12 of the first elastic body 14 is formed as shown in FIG. When vulcanized and bonded to the inner peripheral surface, the upper surface is simultaneously vulcanized and bonded to the lower surface of the flange portion 12a of the outer cylinder 12, and when the vibration isolator 11 is assembled, the lower surface is the lower bracket piece. It is designed to elastically contact the upper surface of 8b.

  Hereinafter, the operation of the present embodiment will be described.

  First, the assembly procedure of the vibration isolation mechanism 11 will be briefly described. The outer cylinder 12 of the vibration isolation mechanism 11 in which the inner cylinder 13, the outer cylinder 12, and the first and third elastic bodies 14 and 16 are unitized in advance as a unit. Is inserted into the holding hole 10a of each mounting portion 10 from below and inserted until the flange portion 12a hits the lower surface of the mounting portion 10.

  Next, the second elastic body 15 is press-fitted into the upper end portion 13a of the inner cylinder 13 from above through the insertion hole 15a, and the lower surface is brought into contact with the upper surfaces of the first elastic body 14, the outer cylinder 12 and the mounting portion 10. Let

  Thereafter, as shown in FIG. 1, with the vibration isolation mechanisms 11 attached, the mounting portions 10 are arranged in a sandwiched state while being positioned between the upper and lower two bracket pieces 8a and 8b of the vehicle body. At the same time, the shaft portion 17a of each mounting bolt 17 is inserted into the upper bolt insertion hole 8c and the inner cylinder 13 and the lower bolt insertion hole 8c, and a nut 18 is screwed in with a predetermined jig. tighten. Thereby, the vibration isolation mechanism 11 can be easily attached between the vehicle body side bracket 8 and the steering device side bracket 11.

  The anti-vibration mechanism 11 attached between the brackets 8 and 11 is such that the tip of the annular protrusion 21 of the second elastic body 15 elastically contacts the lower surface of the upper bracket piece 8a via the second gap C2. The lower surface of the third elastic body 16 is in elastic contact with the upper surface of the lower bracket piece 8b.

  According to the vibration isolation mechanism 11, the spring ratio in the vehicle lateral direction (X direction) and the front-rear direction (Y direction) can be set to be large by the two straight portions 19 and the two solid parts 20. It is possible to set the static spring constant in the vehicle left-right direction small while securing the static spring constant in the front-rear direction.

  Moreover, in the case of the special structure of the first, second, and third elastic bodies 14, 15, and 16 such as the vibration isolating mechanism 11 of the present embodiment, the second elastic body 15, the vehicle body side bracket 8, and the steering side A relatively large sliding resistance is generated between the mounting portion 10 and the displacement characteristic with respect to the load (N) as indicated by a thin line (P) with respect to the required characteristic indicated by the thick line (Q) in FIG. It becomes a characteristic and the hysteresis tends to increase.

  Therefore, in the present embodiment, since the second gap C2 is formed between the second elastic body 15 and the upper bracket 8a, the presence of the second gap C2 causes the thick solid line (Q) in FIG. As shown, it is possible to reduce the hysteresis generated during the shear deformation and the restoration deformation.

  As a result, the steering feeling does not change according to the steering situation, and a stable steering feeling can be obtained at all times.

  However, although the hysteresis can be reduced by the second gap portion C2, the presence of the second gap portion C2 causes the vehicle vertical direction (Z direction) characteristics to be sheared as shown by the thick solid line (Q) in FIG. And a low elastic part will become easy to generate | occur | produce in a restoring direction.

  Therefore, in this vibration isolating mechanism 11, by providing the above-described annular protrusion 21 on the upper surface of the second elastic body 15, the characteristic in the Z direction is an ideal characteristic indicated by a thin line (S) in FIG. That is, the low elastic portion can be made close to a small S characteristic.

  Therefore, the vibration control mechanism 11 can provide excellent vibration suppression effects in all the X, Y, and Z directions.

  In the present embodiment, the third elastic body 16 is provided integrally with the first elastic body 14 made of hard rubber without using the conventional metal stopper plate, and the second elastic body. 15 and the third elastic body 16 are sandwiched between the upper and lower bracket pieces 8a, 8b of the vehicle body side bracket 8 and the mounting portion 10 of the steering device side bracket 6, thereby suppressing an increase in the number of parts of the vibration isolation mechanism 11. In addition, the structure can be simplified.

  Further, since the first elastic body 14 is integrally fixed to both the inner cylinder 13 and the outer cylinder 12 by vulcanization bonding, the bonding work using an adhesive is not necessary, and the third elastic body 16 is attached to the first elastic body 16. Since it can form simultaneously with the elastic body 14 and the said vulcanization | cure adhesion | attachment, the efficiency of these shaping | molding and adhesion | attachment operations improves.

  Since the second elastic body 15 is formed separately from the first elastic body 14, the degree of freedom in designing the second elastic body 15 is improved. For example, the hardness of the second elastic body 15 is adjusted. By doing so, it becomes possible to adjust the Z direction characteristic.

[Second Embodiment]
FIG. 7 shows a second embodiment in which the flange portion 12 a of the outer cylinder 12 is eliminated and the third elastic body 26 has the same structure as the second elastic body 15.

  That is, the third elastic body 26 is formed in a disk shape by a hard rubber material separately from the first elastic body 13, and the lower end of the inner cylinder 13 is inserted through an insertion hole 26a formed through the center. The outer diameter of the second elastic body 15 is set to be approximately the same as the outer diameter of the second elastic body 15, and the upper surface of the outer peripheral portion 26b is fixed to the first elastic body 13 or the outer surface. The cylinder 12 is in contact with the lower surfaces of the mounting portion 10.

  The third elastic body 26 is formed with an annular third gap C3 having a predetermined width between the lower surface of the third elastic body 26 and the lower surface of the lower bracket piece 8b when the vibration isolation mechanism 11 is assembled. In addition, an annular second protrusion 27 is integrally provided at a substantially central position in the radial direction of the lower surface, with a tip portion elastically contacting the lower surface of the lower bracket piece 8b. When the steering device vibrates in the Z direction, which is the vertical direction, the first and second projecting portions 21 allow the vertical vibration of the vibration isolation mechanism 11 through the third gap C3 together with the first gap C2. , 27 suppresses sudden vertical vibration of the vibration isolation mechanism 11. That is, by providing the third gap C3 in addition to the second gap C2, it is possible to further suppress the occurrence of hysteresis described above.

  In addition, by providing the second protrusion 27, the Z-direction characteristic can be made closer to the ideal S characteristic.

Moreover, by further adjusting, for example, the hardness of the third elastic body 26, the vibration isolation mechanism 11 can be further tuned up. Since the other configuration is the same as that of the first embodiment, the same operation and effect can be obtained.
[Third Embodiment]
FIG. 8 shows the third embodiment, and the flange portion 12a of the outer cylinder 12 is the same as that of the first embodiment, but the flange portion 13c is formed integrally with the lower end portion 13b of the inner cylinder 13, A lower end portion 14c of the first elastic body 14 formed in an enlarged flange shape is disposed between the flange portion 13c and the flange portion 12a.

  When the flange portion 13c of the inner cylinder 13 is assembled between the steering device side bracket 6 and the vehicle body side bracket 8 of the vibration isolation mechanism 11, the lower surface thereof is in contact with the upper surface of the lower bracket piece 8b. .

  The lower end portion 14c of the first elastic body 14 is formed to be gradually thinner toward the outside, and is vulcanized and bonded to the inner cylinder 13 and the outer cylinder 12 at the same time as the first elastic body 14 is vulcanized and bonded. .

  Therefore, according to this embodiment, in addition to the effects such as the reduction in the number of parts and the simplification of the structure, the third enlarged portion of the first embodiment is provided by the lower end portion 14c of the first elastic body 14 in the form of the enlarged flange. Similar to the elastic body 16, the effect of reducing the hysteresis in the Z direction can be obtained, and the presence of the flange 13 c makes it possible to stably support the vibration isolation mechanism 11 between the brackets 6 and 8.

It is a longitudinal cross-sectional view in 1st Embodiment of the vibration isolator which concerns on this invention. It is a side view of the vibration isolating mechanism of this Embodiment. It is the sectional view on the AA line of FIG. 2 of the vibration isolating mechanism. It is a characteristic view which shows the load and displacement in the vibration isolating mechanism. It is a characteristic view which shows the load and bending in the vibration isolating mechanism. It is a perspective view which shows the steering device and vehicle body member to which the vibration isolating mechanism of this Embodiment is applied. It is a longitudinal cross-sectional view in 2nd Embodiment of an anti-vibration mechanism. It is a longitudinal cross-sectional view in 3rd Embodiment of an anti-vibration mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Steering housing 6 ... Steering apparatus side bracket 7 ... Car body member 8 ... Car body side bracket 8a ... Upper bracket piece 8b ... Lower bracket piece 11 ... Anti-vibration mechanism 10 ... Mounting part 12 ... Outer cylinder 12a ... Flange part 13 ... Inside Cylinder 14 ... first elastic body 15 ... second elastic body 16 ... third elastic body 17 ... mounting bolt 21 ... projection C2 ... second gap

Claims (6)

In the vibration isolator provided between the steering device side bracket and the vehicle body side bracket,
The bracket on the steering device side includes a bracket main body attached to the steering device, and a through hole formed in the bracket main body,
The vehicle body side bracket is disposed on one end side of the through hole of the steering device side bracket, and is disposed on the other end side of the through hole and a first bracket having a first bolt insertion hole through which a mounting bolt is inserted. A second bracket having a second bolt insertion hole through which the mounting bolt is inserted,
An outer cylinder is fixed to the inner peripheral side of the through-hole, and the inner cylinder is arranged at a position spaced apart at a predetermined interval in the radial direction inside the outer cylinder,
In addition, a first elastic body is interposed between the outer cylinder and the inner cylinder, and a substantially flange-shaped second elastic body is interposed between the bracket body and the first bracket, An anti-vibration mechanism for a steering device, wherein a substantially annular third elastic body is provided between the bracket body and the second bracket. In the vibration isolating mechanism of the steering device according to claim 1,
The inner cylinder is extended so as to protrude from both end sides in the axial direction of the through hole, and the axial length of the protruding one end side is longer than at least the axial thickness of the second elastic body. An anti-vibration mechanism for a steering device. In the vibration isolating mechanism of the steering device according to claim 1,
The vibration isolating mechanism for a steering device, wherein the first elastic body is joined to the outer peripheral surface of the inner cylinder and the inner peripheral surface of the outer cylinder by vulcanization adhesion. In the vibration isolating mechanism of the steering device according to claim 1,
The anti-vibration mechanism for a steering device, wherein the second elastic body is formed separately from the first elastic body. In the vibration isolating mechanism of the steering device according to claim 1,
The outer cylinder integrally has a flange portion extending radially outward at an end portion on the second bracket side,
The vibration isolation mechanism for a steering apparatus, wherein the third elastic body is provided integrally with the first elastic body on an outer surface of the flange portion. In the vibration isolating mechanism of the steering device according to claim 1,
A gap is formed between the upper surface of the second elastic body and the opposed surface of the first bracket facing the upper surface, and the upper surface of the second elastic body is arranged on the opposed surface of the first bracket. An anti-vibration mechanism for a steering device, characterized in that a projecting portion that comes into contact with the elastic member is integrally provided.

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