JP2005048914A - Vibration proofing fixation structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration proofing fixation structure having an elastic body such as a vibration proofing bush and capable of increasing the rigidity in the direction FA of prying. <P>SOLUTION: The elastic body 16 is provided between an outer cylindrical part 14 and an inner cylindrical part 12 arranged concentrically on an inner side of the outer cylindrical part 14. A fixed part 18 is tightened and fixed on an end face in the axial direction of the inner cylindrical part 12 by a bolt 22. A predetermined clearance D1 in the axial direction is ensured between an end face 31 in the axial direction of the outer cylindrical part 14 and an opposing side face 32 of the fixed part 18 opposing to the end face 31 in the axial direction. A projecting part 41 protruding in the axial direction in the clearance D1 in the axial direction toward the opposing side face 32 is provided on the end face 31 in the axial direction of the outer cylindrical part 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an anti-vibration fixing structure having an elastic body such as an anti-vibration bush, and more particularly to an anti-vibration fixing structure suitably used for a mount part of a steering gear housing of a vehicle.

In vehicles, a vibration-proof fixing structure having an elastic body is applied to many mount parts such as a steering gear housing and struts. For example, in Patent Document 1, an anti-vibration bush having an elastic body that attenuates and cuts off transmission of vibrations at a portion where a knuckle and a lateral link are fixed is applied.
JP 2000-291708 A

  In such an anti-vibration fixing structure, the use of an elastic body provides the original advantage of damping and blocking the transmission of vibration, but on the other hand, the input in a specific direction, specifically the axis orthogonal direction of the inner and outer cylinders The strength / rigidity against the input in the twisting direction, which is the surrounding direction, is lowered, and there is a possibility that undesirable bending or the like may be caused. For example, when an anti-vibration fixing structure is applied to a part where a rack housing of a power steering device is mounted on a vehicle body member, vibrations from the steering wheel can be reduced or blocked by the elasticity of the elastic body. On the other hand, because the universal joint is mainly provided on the steering shaft that links the rack in the rack housing and the steering wheel, it is not preferable on the rack housing side due to the rotation input from the steering wheel. There is a risk that the steering input will act, and as a result, the steering feel will be reduced.

  The present invention has been made in view of such a problem, and has as its main object to effectively improve the rigidity against twisting input with a simple structure.

  According to a first aspect of the present invention, an elastic body is interposed between the outer tube portion and the inner tube portion disposed concentrically on the inner side of the outer tube portion, and on the axial end surface of the inner tube portion. In the anti-vibration fixing structure in which the fixed part is fastened and fixed together by fixing means, the outer cylinder part has a shorter axial dimension than the inner cylinder part, and faces the axial end face of the outer cylinder part and the axial end face. And a projecting portion protruding in the axial direction in the axial gap on at least one of the axial end face or the opposing side surface of the outer cylinder portions facing each other. Is provided.

  According to the first aspect of the present invention, when the input in the twisting direction acts on the fixed portion or the outer cylinder, the convex portion comes into contact with the opposite side surface, so that the rigidity and strength in the twisting direction are increased, and the further twisting is performed. Directional displacement can be substantially prevented. Thus, the rigidity in the twisting direction can be effectively increased with a simple structure in which the convex portion is provided.

  According to a second aspect of the present invention, an elastic body is interposed between an outer cylinder provided in the steering gear housing and an inner cylinder arranged concentrically inside the outer cylinder, and the inner cylinder A vibration-proof fixing structure in which a fixed part provided on a vehicle body member is fastened and fixed to an axial end surface of the inner cylinder part by a bolt that penetrates the part, and the outer cylinder part has an axial dimension larger than that of the inner cylinder part A predetermined axis between the axial end surface of the outer cylindrical portion and the opposing side surface of a member such as a washer or a bolt head fixed to the fixed portion or the inner cylindrical portion facing the axial end surface. A gap is secured in the direction, and the elastic body has a flange portion interposed in a compressed state in the gap in the axial direction, and a shaft is provided on at least one of the axial end face or the opposite side surface of the outer cylinder portions facing each other. A convex portion protruding in the direction is provided, and this convex portion is radially outside of the flange portion. Te, and is characterized by being located within the axial gap.

  The steering gear housing is generally subjected to unfavorable twisting input due to rotational input from the steering wheel, and if the steering gear housing is excessively displaced in the twisting direction due to this, the steering feel is lowered. There is a risk of inviting. According to the second invention, similar to the first invention, the rigidity in the twisting direction can be effectively improved while having a simple structure, so that excessive displacement in the twisting direction can be sufficiently reduced and prevented. Therefore, it is possible to sufficiently suppress the deterioration of the steering feel.

  Referring to FIG. 12, the rack-and-pinion type power steering apparatus includes a steering gear housing (rack housing) 1 that movably accommodates and supports a rack associated with a pair of steering wheels. The steering gear housing 1 is supported and fixed to a suspension member 7 (see FIG. 3) as a vehicle body member at two locations, a cylinder side fixing portion 2 and a housing side fixing portion 3. The cylinder side fixed part 2 in the steering gear housing 1 is provided at the position of the power cylinder 1a of the power steering which is a pipe part, and the housing side fixed part 3 is provided at the position of the steering gear housing main body 1b which is a casting. Yes. As is well known, a universal joint 6 is provided on the steering shaft 5 that links the rack and the steering wheel 4 that is rotated by the driver.

  Hereinafter, several embodiments in which the vibration-proof fixing structure according to the present invention is applied to the housing-side fixing portion 3 will be described in detail with reference to the drawings. In addition, the same referential mark is attached | subjected to the component which is common in a some Example, and description of the overlapping structure and effect is abbreviate | omitted suitably.

  A first embodiment of the present invention will be described with reference to FIGS. An elastic body 16 made of an elastic material such as rubber is interposed between the metal outer cylinder portion 14 and the metal inner cylinder portion 12 disposed concentrically inside the outer cylinder portion 14. It is disguised.

  As shown also in FIG. 2, the outer cylinder part 14 is integrally cast with the housing main body 1b. Here, the two outer cylinder parts 14 are juxtaposed along the axial direction L2 of the housing body 1b. The axial direction L1 of each outer cylinder part 14 is substantially orthogonal to the housing axial direction L2. As will be described later, an elastic body 16 bonded to the inner cylinder portion 12 is fixed to each outer cylinder portion 14 by press fitting or the like. As shown in FIG. 3, the suspension member 7 has two fixed parts 18 to which the inner cylinder part 12 is fixed together. As shown in FIG. 1, the fixed portion 18 is opposed substantially parallel to one axial side surface of the outer cylinder portion 14 except for the fitting recess 19 in which one axial end portion of the inner cylinder portion 12 is fitted. It has a flat thin plate shape.

  As shown in FIGS. 1 and 4, at the time of assembly, one axial end portion of the inner cylinder portion 12 is fitted into the fitting recess portion 19 of the fixed portion 18 so that one shaft of the inner cylinder portion 12 is fitted. In the state where the fixed portion 18 is overlaid on the end surface in the direction and the annular washer 20 is overlaid on the other end surface in the axial direction of the inner cylinder portion 12, the head 12, the nut 23, and the nut 24, the fixed portion 18 and the inner cylindrical portion 12 are firmly fastened and fixed, and the fixed portion 18 and the outer cylindrical portion 14 are elastically connected via the elastic body 16. Connected. That is, the bolt 22, the nut 24, and the washer 20 constitute fixing means for fastening and fixing the fixed portion 18 and the inner cylinder portion 12 together. The inner cylinder portion 12, the fixed portion 18 and the washer 20 are respectively formed with bolt holes through which the bolts 22 pass.

  Thus, by fitting the inner cylinder part 12 in the fitting recessed part 19, the inner cylinder part 12 can be easily positioned and aligned with the fixed part 18, and the workability is excellent. In addition, the elastic body 16 that is vulcanized and bonded to the inner cylinder part 12 can be assembled in advance by press fitting or the like to the outer cylinder part 14 that is formed integrally with the housing body 1b. Advantages such as reduction and simplification of assembly work can be obtained.

  The outer cylinder portion 14 is set to have a shorter axial dimension than the inner cylinder portion 12. Accordingly, a predetermined first axial gap D1 is ensured between the first axial end surface 31 of the outer cylinder portion 14 facing each other and the first opposing side surface 32 of the fixed portion 18, and the outer cylinder. A predetermined second axial gap D <b> 2 is secured between the other second axial end face 33 of the portion 14 and the second opposing side face 34 of the washer 20.

  The elastic body 16 includes a cylindrical cylindrical portion 26 interposed in a compressed state between the outer peripheral surface of the inner cylindrical portion 12 and the inner peripheral surface of the outer cylindrical portion 14, and both axial ends of the cylindrical portion 26. A pair of substantially disk-shaped flanges 28 projecting outward in the radial direction. The axial dimension of the flange 28 in the natural length state is longer than the corresponding axial gap D1, D2 so that each flange 28 is interposed in the axial gap D1, D2 in a compressed state. Is set. Typically, the pair of flanges 28 are set to have the same axial length, and the axial gaps D1 and D2 are also set to the same dimensions.

  The inner cylinder part 12, the fixed part 18 and the washer 20 fixed by the bolts 22 and the like are not in direct contact with the outer cylinder part 14 so that vibrations in all directions can be effectively absorbed and reduced. They are connected only via the elastic body 16. Specifically, the axial direction of the inner cylinder part 12 is connected only through the cylinder part 26 of the elastic body 16, and the axial direction L1 of the inner cylinder part 12 is connected only through the flange part 28.

  As a characteristic configuration of the present embodiment, it protrudes in the axial direction on the first axial end face 31 of the outer cylindrical portion 14 facing the first opposing side surface 32 of the fixed portion 18 with the first axial gap D1 interposed therebetween. The convex part 41 is integrally formed. The convex portion 41 is positioned in the axial gap D1 radially outside the flange portion 28 so as not to interfere with the flange portion 28, and is formed in an annular shape over the entire circumference. The height of the convex portion 41 is such that a slight gap is secured between the tip of the convex portion 41 and the first opposing side surface 32 of the fixed portion 18 in the steady state after the bolt fastening as shown in FIG. Is set. That is, the height of the convex portion 41 is set to be shorter than the axial gap D1 so that the tip of the convex portion 41 does not contact the opposite side surface 32 in a steady state.

  By such a convex portion 41, a moment in a twist direction FA that is a direction around the axis orthogonal direction (a direction around the center O in FIG. 1) acts on the outer cylinder portion 14 (or the fixed portion 18), and the outer cylinder portion 14 (or the fixed portion 18) starts to be displaced in the twisting direction FA, immediately, the convex portion 41 comes into contact with the opposite side surface, and the rigidity with respect to the twisting direction FA is rapidly increased. Displacement is substantially prevented. In this way, with the simple structure of providing the convex portion 41, the rigidity with respect to the twisting direction FA can be effectively increased, and the excessive deformation of the twisting direction FA can be eliminated.

  In particular, in a rack and pinion type steering apparatus provided with the universal joint 6, due to the rotational input from the steering wheel 4, an input of the twisting direction FA acts on the steering gear housing 1, and the displacement of the twisting direction FA is reduced. When it becomes larger, there is a specific problem that the steering feeling is lowered, which is extremely effective for such a problem.

  As shown in FIG. 2C, the front end surface 41a of the convex portion 41 is rounded into a substantially semicircular cross section. Thereby, the impact of the convex part 41 and its opposing side surface is relieved, and the impact sound is reduced.

  If the convex portion 41 abuts against the opposite side surface of the fixed portion 18 during bolt fastening due to an assembly error or the like, the bolt fastening axial force increases rapidly, and the desired bolt axial force can be obtained. This may not be possible and may cause variations in bolt axial force and insufficient axial force. Therefore, in the state before the bolt fastening shown in FIG. 4, the inner cylinder portion 12 is convex 41 with respect to the elastic body 16 and the outer cylinder portion 14 as compared to the intended steady state after the bolt fastening shown in FIG. 1. A large approach and overhang to the side where there is. That is, in the state before the bolt fastening, the inner cylinder part 12 is protruded excessively to the side where the convex part 41 exists with respect to the outer cylinder part 14. As a result, the axial dimension D1 on the side where the convex portion 41 exists is secured relatively large during bolt fastening, and it is possible to effectively avoid the situation where the convex portion 41 contacts the opposite side surface during the bolt fastening operation. it can.

  FIG. 5 shows a second embodiment of the present invention. In the second embodiment, the convex portion 42 is formed as a separate body from a metal material or a resin material, and faces the first axial end surface 31 of the outer cylinder portion 14 with a first axial gap D1 therebetween. Only the point which is being fixed to the 1st opposing side surface 32 of the to-be-fixed part 18 differs from said 1st Example. For example, as shown in FIG. 10, an O-ring that is a general-purpose part or a well-known C-ring can be used for the convex portion 42. Accordingly, there is an advantage that the diameter and the axial dimension of the convex portion 42 can be easily changed by exchanging the convex portion 42.

  In the third embodiment shown in FIG. 6, the convex portion 43 is integrated with the first opposing side surface 32 of the fixed portion 18 that faces the first axial end surface 31 of the outer cylinder portion 14 with the first axial gap D1 therebetween. The second embodiment is different from the second embodiment only in that it is bent. According to the third embodiment, the convex portion 43 can be easily formed on the fixed portion 18 by press molding, and the convex portion is a separate member as in the second embodiment. The number of parts is reduced.

  The fourth embodiment shown in FIG. 7 differs from the first embodiment only in that convex portions 44a and 44b are formed on both axial end faces 31, 33 of the outer cylinder portion 14, respectively. That is, the first convex portion 44a is formed on the first axial end surface 31 of the outer cylinder portion 14, and the first convex portion 44a is axially moved in the first axial gap D1 toward the first opposing surface 32 of the opposed fixed portion 18. The second projecting portion 44b is formed on the second axial end surface 33 of the outer cylinder portion 14, and extends axially in the second axial gap D2 toward the second opposing side surface 34 of the opposing washer 20. It protrudes.

According to the fourth embodiment, since the convex portions 44a and 44b are provided in both the axial gaps D1 and D2, respectively, the rigidity in the twisting direction FA can be further ensured, and the excessive twisting direction FA is excessive. Deformation can be more reliably suppressed and avoided. In addition, since both axial gaps D1 and D2 are secured, the axial position of the fixed portion 18 with respect to the bolt 22 will not be excessively shifted due to use over time and for a long time.
Furthermore, since the convex portions 44a and 44b are integrally formed with the outer cylinder portion 14, the number of parts is reduced as compared with the case where the convex portions are separated.

  In the fifth embodiment shown in FIG. 8, the convex portions 45 a and 45 b provided in the axial gaps D <b> 1 and D <b> 2 are separate from the outer cylinder portion 14, and are formed on the axial end surfaces 31 and 33 of the outer cylinder portion 14. It differs from the fourth embodiment only in that it is a C-ring or O-ring that is fixed later. According to the fifth embodiment, there is an advantage that the diameter and axial dimension of the convex portion can be easily changed.

  The sixth embodiment shown in FIG. 9 differs from the fourth embodiment only in that the convex portions 46a and 46b provided in the axial gaps D1 and D2 are integrally formed on the opposing side surfaces 32 and 34, respectively. Is different. That is, the first convex portion 46 a is bent at the first opposing side surface 32 of the fixed portion 18 and protrudes in the axial direction toward the first axial end surface 31 of the opposing outer cylinder portion 14. As shown in FIG. 11, the second convex portion 46 b is bent at the outer peripheral edge portion of the ring-shaped washer 20, and extends in the axial direction toward the second axial end surface 33 of the opposed outer cylinder portion 14. It protrudes. According to such a 6th Example, convex part 46a, 46b can be easily formed in the thin-plate-shaped to-be-fixed part 18 and the washer 20, for example by press work, and a convex part is a different body. Compared to, the number of parts can be reduced.

  As described above, the present invention has been described based on the specific embodiments. However, the present invention is not limited to the above-described embodiments, and includes various modifications and changes without departing from the spirit of the present invention. . For example, the inner cylinder part and the outer cylinder part according to the present invention are not limited to a cylindrical shape having a uniform annular cross section, and may be any one that can be arranged concentrically with an elastic body interposed therebetween. Moreover, it is good also as a structure which abbreviate | omits a washer and the head part of a volt | bolt contacts the axial direction end surface of an inner cylinder directly. In this case, the seating surface of the bolt head constitutes an opposing side surface facing the axial end surface of the outer cylinder. Further, in the above-described embodiments, the convex portion is a ridge extending over the entire circumference or substantially the entire circumference, but the convex portion may be constituted by a plurality of protrusions provided intermittently in the circumferential direction. The fixing structure of the present invention may be applied to a strut mounting site or the like.

  Technical ideas other than the invention described in the claims that can be grasped from the above-described contents are listed.

  (1) A first axial gap is ensured between one first axial end surface of the outer cylindrical portion and a first opposing side surface opposed to the first axial end surface, and the outer cylindrical portion A second axial gap is secured between the other second axial end face of the second axial face and a second opposing side face facing the second axial end face, and the convex portion is provided in the first axial gap. The first convex portion and the second convex portion provided in the first axial gap are configured.

  Since the convex portions are provided in the first and second axial gaps in this way, the above-described displacement in the twisting direction can be more reliably prevented, and even if the elastic body is deteriorated with time, 1 and 2nd axial direction clearance can be ensured stably. Therefore, it is possible to prevent the axial displacement of the outer tube portion and the fixed portion over a long period of time.

  (2) A first axial gap is ensured between one first axial end surface of the outer cylindrical portion and a first opposing side surface facing the first axial end surface, and the outer cylindrical portion A second axial gap is secured between the other second axial end face of the second axial face and a second opposing side face facing the second axial end face, and the convex portion is connected to the first axial gap and the second axial face. It is provided only in one of the axial gaps.

  And in the state before fixation by fixing means, such as a volt | bolt, compared with the state after fixation, the inner cylinder part is largely projected beforehand on the side in which a convex part exists with respect to an outer cylinder part. That is, the inner cylinder part is offset with respect to the outer cylinder part to the side where the convex part exists. As a result, in the state immediately after fixing, the axial gap on the side where the convex portion exists is relatively large, and it is effective that the convex portion abuts against the opposite side surface during fixing work due to an assembly error or the like. Can be avoided. If the convex part comes into contact with the opposite side surface during the fixing operation, the desired bolt fastening force cannot be obtained, and the bolt may be loosened.

  (3) The opposing side surface is formed on a washer that is fastened and fixed to the axial end surface of the inner cylinder. In this case, even if the convex portion is relatively large away from the axial center of the inner / outer cylinder in the radially outward direction, it can be easily handled by changing the dimensions of the washer.

  (4) The inner cylinder portion is fixed by being sandwiched between the head portion or washer of the bolt and the fixed portion. That is, it is not necessary to fix the bolt and the inner cylinder part by welding or the like.

  (5) The convex portion is integrally bent to the fixed portion or washer by press working. In this case, the convex portion can be easily press-molded, and the number of parts can be reduced as compared with the case where the convex portion is a separate body.

  (6) The convex portion is a C ring or an O ring. In this case, the dimension of the convex portion can be easily changed by exchanging the C ring or the O ring.

Sectional drawing which shows the fixing | fixed part which concerns on 1st Example of this invention. The outer cylinder part formed in the steering gear housing is shown, (A) is a side view, (B) is sectional drawing which follows the 4B-4B line, (C) is an enlarged view of 4C part. The side view which shows the to-be-fixed part formed in the suspension member. Sectional drawing which shows the state just before bolt fixation of the fixing | fixed part which concerns on the said 1st Example. Sectional drawing which shows the fixing | fixed part which concerns on 2nd Example of this invention. Sectional drawing which shows the fixing | fixed site | part which concerns on 3rd Example of this invention. Sectional drawing which shows the fixing | fixed site | part which concerns on 4th Example of this invention. Sectional drawing which shows the fixing | fixed part which concerns on 5th Example of this invention. Sectional drawing which shows the fixing | fixed site | part which concerns on 6th Example of this invention. The front view (A) which shows the O-ring as a convex part, sectional drawing (B), and a rear view (C). The front view (A), side view (B), and back view (C) which show the washer in which the convex part was formed. The side view which shows the steering gear housing to which the said Example is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 ... Inner cylinder part 14 ... Outer cylinder part 16 ... Elastic body 18 ... Fixed part 20 ... Washer 22 ... Bolt (fixing means)
28 ... collar 31 ... first axial end surface 32 ... first opposing side surface 33 ... second axial end surface 34 ... second opposing side surface 41-44 ... convex portion

Claims (2)

An elastic body is interposed between the outer cylindrical portion and the inner cylindrical portion disposed concentrically inside the outer cylindrical portion, and the fixed portion is fixed to the axial end surface of the inner cylindrical portion. In the anti-vibration fixing structure that is fixed together by
The outer cylinder part has a shorter axial dimension than the inner cylinder part, and a predetermined axial gap is secured between the axial end surface of the outer cylinder part and the opposite side surface facing the axial end face,
And the vibration-proof fixing structure characterized by providing the convex part which protrudes in the said axial gap in an axial direction in at least one of the axial direction end surface or opposing side surface of the outer cylinder part which mutually opposes. An elastic body is interposed between an outer cylinder part provided in the steering gear housing and an inner cylinder part arranged concentrically on the inner side of the outer cylinder part, and by a bolt penetrating the inner cylinder part The fixed portion provided on the vehicle body member is a vibration-proof fixing structure in which the fixed portion is fastened to the axial end surface of the inner cylinder portion,
The outer cylinder part has a shorter axial dimension than the inner cylinder part, the axial end surface of the outer cylinder part, and the opposite side surface of the fixed part or the member fixed to the inner cylinder part facing the axial end face, A predetermined axial gap is secured between
The elastic body has a collar portion interposed in a compressed state in the axial gap,
And at least one of the axial end face or the opposite side surfaces of the outer cylinder portions facing each other is provided with a convex portion protruding in the axial direction, the convex portion being radially outward from the flange portion, and An anti-vibration fixing structure that is located in an axial gap.

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