JP2006193064A - Lower arm mounting structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lower arm mounting structure which enables the rear end of a lower arm body to be connected easily to a rear side bush and has the lower arm body that is composed of a single pipe material to be highly rigid and lighter in weight, thus improves attachability and reduces costs. <P>SOLUTION: The lower arm mounting structure 4 comprises the lower arm body 10 which has a bent part 11 extending inwardly of a vehicle width direction from a wheel support member 5 and bending backward and is composed of the pipe member, a front side bracket 12 which extends inwardly of the vehicle width direction from the bent part 11 of the lower arm body 10, a front side bush 13 which is fixed to the front side bracket 12, and the rear side bush 14 which is inserted by press fitting into the rear end of the lower arm body 10 to be fixed there. The rear end of the lower arm body 10 is connected to a vehicle body 1 via the rear side bush 14. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a lower arm mounting structure for mounting a lower arm of a suspension for swingably supporting a wheel with respect to a vehicle body.

  2. Description of the Related Art Conventionally, an A-type lower arm of a suspension of an automobile or the like includes a lower arm body that has a curved portion that extends inward in the vehicle width direction and curves backward from a wheel support member that rotatably supports a wheel, and the curved portion of the lower arm body. The front bracket that extends inward in the vehicle width direction and the rear end of the lower arm main body are connected to the vehicle body. In particular, the rear end of the lower arm main body is A lower arm mounting structure that is connected to a vehicle body via a hub is well known.

Here, in the lower arm mounting structure of Patent Document 1, the rear bushing is fixed to the rear end portion of the lower arm main body and protrudes to the rear side, the inner cylinder into which the support shaft is inserted, and the inner cylinder And a cylindrical rubber member fixedly provided between the inner cylinder and the outer cylinder, and a nut is screwed onto the tip of the support shaft inserted into the inner cylinder, The lower arm main body and the rear bush are connected, and the outer cylinder of the rear bush is connected to the vehicle body via a bracket.
Japanese Patent Laid-Open No. 10-309917

  In the conventional lower arm mounting structure, when the rear end of the lower arm body is connected to the vehicle body via the rear bush, the connection between the lower arm body and the rear bush is performed through welding, bolt fastening, etc. It is difficult to easily perform this connection, resulting in a complicated structure and disadvantageous in terms of cost. In the lower arm mounting structure of Patent Document 1, the support shaft of the rear bush is fixed to the lower arm body by welding or the like, and further, the outer cylinder of the rear bush is connected to the vehicle body via the bracket. The problem becomes significant.

Here, when the lower arm body is made of a single pipe material, the structure of the lower arm body can be simplified and the rigidity and weight can be reduced, but the rear end portion of the lower arm body is connected to the vehicle body via the rear bushing. In addition, some complicated connection structure is required at the rear end portion of the lower arm body, and it is difficult to configure the lower arm body with a single pipe material.
It is an object of the present invention to easily connect the rear end portion of the lower arm body and the rear bushing, and to form the lower arm body with a single pipe material, to reduce the rigidity and weight, and to improve the assembling property. It is to provide a lower arm mounting structure that can be cost-effective.

  The lower arm mounting structure according to claim 1 is a lower arm mounting structure for mounting a lower arm of a suspension for swingably supporting a wheel with respect to a vehicle body, and extends inward in the vehicle width direction from a wheel support member that rotatably supports the wheel. A lower arm body having a curved portion that curves rearward and made of a pipe material, a front bracket that extends inward in the vehicle width direction from the curved portion of the lower arm main body, a front bush that is fixed to the front bracket, and the lower arm And a rear bushing that is press-fitted and fixed to the rear end portion of the main body in an internally fitted manner, and the rear end portion of the lower arm main body is connected to the vehicle body via the rear bushing.

  In this lower arm mounting structure, the lower arm main body is formed of a single pipe member, and the lower arm main body has a curved portion that extends inward in the vehicle width direction and curves backward from a wheel support member that rotatably supports the wheel. Here, the lower arm body can be manufactured at low cost by bending a pipe base material by roll molding, but can also be molded by various molding methods such as so-called hydroform molding. A front bracket extends inward in the vehicle width direction from the curved portion of the lower arm body, a front bush is fixed to the front bracket, and the front bracket is connected to the vehicle body via the front bush.

  A rear bush is press-fitted and fixed to the rear end portion of the lower arm main body, and the rear end portion of the lower arm main body is coupled to the vehicle body via the rear bush. In other words, it is not necessary to connect the lower arm body and the rear bushing via welding, bolt fastening, or the like, and it can be easily performed by press-fitting and fixing the rear bushing into the rear end portion of the lower arm body. Further, by such connection, the lower arm body can be made of a single pipe material, and can be highly rigid and lightweight. That is, the assemblability of the lower arm can be improved and the cost can be reduced.

In the lower arm mounting structure of the first aspect, the following configuration can be adopted.
The rear bush includes an outer cylinder, an inner cylinder, a cylindrical elastic member provided between the outer cylinder and the inner cylinder, a rod-shaped support shaft that is inserted into the inner cylinder and fixed to the vehicle body, And a cylindrical rubber member interposed between the inner cylinder and the support shaft and fixed integrally to the inner cylinder or the support shaft in advance (Claim 2). The rear bush includes a cylindrical member, a cylindrical elastic member provided inside the cylindrical member, and a rod-like support shaft that is integrally fixed to the elastic member in an insertion manner and fixed to the vehicle body. (Claim 3). The support shaft is fixed in advance to the lower arm body side, and fastening means for fixing the support shaft to a member on the vehicle body side is provided.

  According to the lower arm mounting structure of claim 1, in particular, the lower arm main body having a curved portion that extends inward in the vehicle width direction and curves backward from a wheel support member that rotatably supports the wheel and that is configured of a pipe material. And a rear bushing that is press-fitted and fixed in an internally fitted manner is provided at the rear end portion of the lower arm main body, and the rear arm end portion of the lower arm main body is connected to the vehicle body via the rear bushing. There is no need to perform connection with welding or bolt fastening, etc., and it can be easily performed by press-fitting and fixing the rear bushing to the rear end portion of the lower arm main body, and by such connection, The lower arm body can be made of a single pipe material, can be made highly rigid and lightweight, and the assemblability of the lower arm can be improved and the cost can be reduced.

  According to the lower arm mounting structure of claim 2, the rear bush is inserted into the outer cylinder, the inner cylinder, a cylindrical elastic member provided between the outer cylinder and the inner cylinder, and the inner cylinder. And a cylindrical rubber member that is interposed between the inner cylinder and the support shaft and is integrally fixed to the inner cylinder or the support shaft in advance. The cylinder, the inner cylinder, and the elastic member can be easily and integrally configured. The outer cylinder is press-fitted and fixed to the rear end of the lower arm main body in an inner fitting shape, and the support shaft is easily attached to the inner cylinder via the rubber member. Thus, the rear bushing can be easily provided in the rear end portion of the lower arm main body so as to be fitted inside, and the support shaft is fixed to the vehicle body and the lower arm is interposed via the rear bushing. Since the rear end of the main unit can be connected to the vehicle body, the assembly of the lower arm can be further improved. It can be a low cost.

  According to the lower arm mounting structure of the third aspect, the rear bush is integrally fixed to the cylindrical member, the cylindrical elastic member provided on the inner side of the cylindrical member, and the elastic member so as to be inserted. And a rod-like support shaft fixed to the vehicle body, the cylindrical member, the elastic member, and the support shaft can be easily and integrally configured by molding, and the cylindrical member is disposed at the rear end of the lower arm body. By press-fitting in a fitting manner and fixing the support shaft to the vehicle body, the rear end of the lower arm body can be connected to the vehicle body via the rear bushing, so that the assembly of the lower arm can be further improved and the cost can be reduced. Can do.

  According to the lower arm mounting structure of the fourth aspect, the support shaft is fixed to the lower arm main body side in advance, and the fastening means for fixing the support shaft to the vehicle body side member is provided. And the rear end of the lower arm body can be connected to the vehicle body via the rear bush.

  The lower arm mounting structure of the present invention is a structure for mounting an A-type lower arm of a front suspension that rotatably supports a wheel with respect to a vehicle body, and extends inward in the vehicle width direction from a wheel support member that rotatably supports the wheel. And a lower arm main body having a curved portion that curves backward and configured by a pipe material, a front bracket that extends inward in the vehicle width direction from the curved portion of the lower arm main body, a front bush that is fixed to the front bracket, and a lower arm main body And a rear bush that is press-fitted and fixed in an inner fitting manner at the rear end, and the rear end of the lower arm main body is connected to the vehicle body via the rear bush.

  As shown in FIG. 1, a lower arm mounting structure 4 for mounting a front suspension A-type lower arm 3 for swingably supporting a wheel 2 with respect to a vehicle body 1 such as an automobile has a wheel support for rotatably supporting the wheel 2. A lower arm body 10 that has a curved portion 11 that extends inward in the vehicle width direction from the member 5 (wheel support 5) and that curves backward, and is formed of a single pipe material, and a vehicle width from the curved portion 11 of the lower arm body 10 A front bracket 12 that extends inward in the direction, a front bush 13 that is fixed to the front bracket 12, and a rear bush 14 that is press-fitted and fixed to the rear end portion of the lower arm body 10 through the front bush 13. The front bracket 12 is connected to the vehicle body 1, and the rear end portion of the lower arm body 10 is connected to the vehicle body 1 via the rear bush 14.

  Here, the end of the lower arm body 10 on the outer side in the vehicle width direction (wheel 2 side) is connected to the wheel support member 5 via a ball joint 6. A knuckle arm 7 is connected to the wheel support member 5 and protrudes forward. The tip of the tie rod 8 is pin-coupled to the tip of the knuckle arm 7, and when the steering is operated, the tie rod 8 is moved in the longitudinal direction via the steering device. The wheel support member 5 is rotated about the vertical axis, and the wheel 2 is steered.

  As shown in FIGS. 2 and 3, the rear bush 14 includes an outer cylinder 20 that is press-fitted and fixed to the rear end of the lower arm body 10 in an inner fitting manner, and an inner cylinder 21 that is disposed inside the outer cylinder 20. A cylindrical rubber elastic member 22 provided between the outer cylinder 20 and the inner cylinder 21, a rod-shaped support shaft 23 inserted into the inner cylinder 21 and fixed to the vehicle body 1, and the inner cylinder 21 And a cylindrical rubber member 24 which is interposed between the inner cylinder 21 and the support shaft 23 and fixed integrally with the inner cylinder 21 or the support shaft 23 (in the present embodiment, the inner cylinder 21). The outer cylinder 20, the inner cylinder 21, and the elastic member 22 are integrally formed by molding.

  As shown in FIG. 4, members 20 to 22 and 24 other than the support shaft 23 of the rear bush 14 are fixedly provided in advance on the lower arm body 10, and the rear end portion of the support shaft 23 of the rear bush 14 is a vehicle body. From this state, the support shaft 23 is press-fitted and fixed to the inner cylinder 21 and the rubber member 24, and the rear bush 14 shown in FIGS. 2 and 3 is configured.

  For example, a flange 20a is formed at the rear end of the outer cylinder 20, the flange 20a abuts on the rear end surface of the lower arm body 10, and a flange 22a is formed at the rear end of the elastic member 22. 22a abuts on the rear end surface of the outer cylinder 20, a recess 22b is formed at the rear end of the elastic member 22, and a flange 21a is formed at the rear end of the inner cylinder 21, and the flange 21a is formed in the recess 22a. It is mated.

  For example, the rear end portion of the inner cylinder 21 is located on the rear side of the rear end portion of the outer cylinder 20, and the support shaft 23 is not press-fitted into the inner cylinder 21 and the rubber member 24 as shown in FIG. The rear end portion of the elastic member 22 is located rearward of the rear end portion of the inner cylinder 21, and a tapered portion 23a is formed at the front end portion of the support shaft 23. As shown in FIG. The lower arm main body is pressed into the inner cylinder 21 and the rubber member 24, and the member 1a on the vehicle body 1 side compresses the rear end portion including the flange 22a of the elastic member 22 and abuts against the rear end surface of the inner cylinder 21. 10 is connected to the vehicle body 1.

The lower arm mounting structure 4 has the following effects.
A lower arm body 10 is provided that has a curved portion 11 that extends inward in the vehicle width direction and that curves rearward from a wheel support member 3 that rotatably supports the wheel 2 and is configured of a pipe material. A rear bush 14 that is press-fitted and fixed in an internally fitted manner is provided in the portion, and the rear end portion of the lower arm main body 10 is connected to the vehicle body 1 via the rear bush 14 so that the lower arm main body 10 and the rear bush 14 are The connection does not need to be performed through welding, bolt fastening, or the like, and can be easily performed by press-fitting and fixing the rear bush 14 to the rear end portion of the lower arm body 10. The lower arm main body 10 is made of a single pipe material, can be made highly rigid and lightweight, can improve the assemblability of the lower arm 3, and can be manufactured at low cost.

  The rear bush 14 is inserted into the outer cylinder 20, the inner cylinder 21, a cylindrical elastic member 22 provided between the outer cylinder 20 and the inner cylinder 21, and the inner cylinder 21 and is fixed to the vehicle body 1. Rod-shaped support shaft 23 and a cylindrical rubber member 24 that is interposed between the inner cylinder 21 and the support shaft 23 and is integrally fixed to the inner cylinder 21 in advance. 20, the inner cylinder 21, and the elastic member 22 can be easily configured integrally, and the outer cylinder 20 is press-fitted and fixed to the rear end portion of the lower arm body 10 in an inner fitting manner, and the support shaft 23 is attached to the rubber member 24. The rear bush 14 can be easily fitted in the rear end portion of the lower arm body 10 so that the support shaft 23 is fixed to the vehicle body 1. The rear end of the lower arm body 10 is connected to the vehicle body 1 via the rear bush 14 Since wear, it can be a low cost can further improve the assembly of the lower arm 3.

  Since the support shaft 23 is fixed to the member 1a on the vehicle body 1 side in advance and the support shaft 23 is press-fitted into the inner cylinder 21 and the rubber member 24, the support shaft 23 can be easily press-fitted and fixed to the inner cylinder 21 and the rubber member 24. Thus, the rear bush 14 can be easily configured, and the rear end portion of the lower arm body 10 can be easily connected to the member 1a on the vehicle body 1 via the rear bush 14.

  As shown in FIG. 5, in the lower arm mounting structure 4A, the support shaft 23A is fixed to the lower arm body 10 side in advance, and a bolt member 30 and a nut member are used as fastening means for fixing the support shaft 23A to the member 1a on the vehicle body 1 side. 31 is provided, and the configuration regarding this point is different from the lower arm mounting structure 4 of the first embodiment.

  That is, the rear bush 14A includes an outer cylinder 20, an inner cylinder 21, an elastic member 22, a support shaft 23A, and a rubber member 24, and the bolt member 30 is integrated with the support shaft 23A so as to extend rearward from the support shaft 23A. A screw portion 30 a is formed at the rear end portion of the bolt member 30. A bolt hole 1b through which the bolt member 30 is inserted is formed in the member 1a on the vehicle body 1, and the nut member 31 is screwed into the screw portion 30a in a state where the bolt member 30 is inserted into the bolt hole 1b. The rear end portion of the lower arm body 10 is connected to the vehicle body 1 through the side bush 14A.

  As shown in FIG. 6, in this lower arm mounting structure 4B, the rear bush 14B is fitted into the rear end portion of the lower arm main body 10 so as to be press-fitted and fixed. It has a cylindrical rubber elastic member 41 provided in a fitting shape, and a rod-like support shaft 42 that is fixed to the elastic member 41 in an inserted manner and fixed to the vehicle body 1. The cylindrical member 40, the elastic member 41, and the support shaft 42 are integrally configured by molding.

  The support shaft 42 is fixed in advance to the lower arm body 10 side, and a bolt member 50 and a nut member 51 are provided as fastening means for fixing the support shaft 42 to the member 1a on the vehicle body 1 side. A bolt member 50 is formed integrally with the support shaft 42 so as to extend rearward from the support shaft 42, and a screw portion 50 a is formed at the rear end portion of the bolt member 50. A bolt hole 1b through which the bolt member 50 is inserted is formed in the member 1a on the vehicle body 1, and the nut member 51 is screwed into the screw portion 50a in a state where the bolt member 50 is inserted into the bolt hole 1b. The rear end portion of the lower arm body 10 is connected to the vehicle body 1 via the side bush 14B.

  According to the lower arm mounting structure 4B, the rear bush 14B is integrally formed in a cylindrical member 40, a cylindrical elastic member 41 provided on the inner side of the cylindrical member 40, and the elastic member 41 so as to be inserted. Since it has the rod-shaped support shaft 42 that is fixed to the vehicle body 1, the cylindrical member 40, the elastic member 41, and the support shaft 42 can be easily configured integrally by molding, and the cylindrical member 40. The lower arm main body 10 is press-fitted and fixed to the rear end portion of the lower arm body 10 in an internally fitted manner, and the support shaft 42 is fixed to the vehicle body 1 so that the rear end portion of the lower arm main body 10 is connected to the vehicle body 1 via the rear bush 14B. As a result, the assembly of the lower arm 3 can be further improved and the cost can be reduced.

  The support shaft 42 is fixed to the lower arm main body 10 side in advance, and fastening means for fixing the support shaft 42 to the member 1a on the vehicle body 1 side (the bolt member 50 and the nut member 51 are provided. The rear end portion of the lower arm main body 10 can be connected to the vehicle body 1 through the rear bush 14B while being securely fixed to the member 1a on the vehicle body 1 side.

  As shown in FIG. 7, in the lower arm mounting structure 4C, the support shaft 42C is fixed in advance to the member 1a on the vehicle body 1, and the support shaft 42a is press-fitted and fixed to the elastic member 40 in the form of an inner cylinder. However, it is different from the lower arm mounting structure 4B of the third embodiment.

  As shown in FIG. 8, in this lower arm mounting structure 4D, the lower arm main body 10 is changed in the lower arm mounting structure 4 of the first embodiment. That is, in this lower arm mounting structure 4D, most of the lower arm main body 10D is formed in the small diameter pipe portion 10Da, and a large diameter pipe portion 10Db having a larger diameter than the small diameter pipe portion 10Da is formed in the rear end portion of the lower arm main body 10D. A rear bush 14 is press-fitted and fixed to the large-diameter pipe portion 10Db.

  The lower arm main body 10D may be integrally formed by adopting hydroforming, or may be configured by connecting a small-diameter pipe portion 10Da and a large-diameter pipe portion 10Db that are previously formed by welding or the like. This lower arm mounting structure 4D can be applied to a small vehicle in which it is not desirable to make the lower arm main body 10 large. In addition, you may change the lower arm main body 10 in the lower arm attachment structures 4A-4C of Examples 2-4 into the lower arm main body 10D.

  In addition, various modifications other than the matters disclosed in the first to fifth embodiments can be added, and in various automobiles or vehicles other than automobiles, lower arms that support the wheels to be swingable with respect to the vehicle body are attached. The present invention can be applied to the lower arm mounting structure.

1 is a plan view of a main part of a vehicle including a lower arm mounting structure according to Embodiment 1. FIG. It is sectional drawing of the rear-end part of a lower arm main body, and a rear side bush. It is the III-III sectional view taken on the line of FIG. It is sectional drawing (before connection) of the rear-end part of a lower arm main body, and a rear side bush. It is sectional drawing of the rear-end part of a lower arm main body which concerns on Example 2, and a rear side bush. FIG. 6 is a cross-sectional view of a rear end portion and a rear bushing of a lower arm body according to a third embodiment. FIG. 10 is a cross-sectional view of a rear end portion and a rear bushing of a lower arm body according to a fourth embodiment. FIG. 10 is a cross-sectional view of a rear end portion and a rear bushing of a lower arm body according to a fifth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Car body 2 Wheel 3 Lower arm 4, 4A-4D Lower arm attachment structure 5 Wheel support member 10, 10D Lower arm main body 11 Curved part 12 Front bracket 13 Front bush 14, 14A-14C Rear bush 20 Outer cylinder 21 Inner cylinder 22, 41 Elasticity Member 23, 23A, 42, 42C Support shaft 24 Rubber member 40 Cylindrical member

Claims (4)

In the lower arm mounting structure for mounting the lower arm of the suspension for swingably supporting the wheel with respect to the vehicle body,
A lower arm body that has a curved portion that extends inward in the vehicle width direction and curves backward from a wheel support member that rotatably supports the wheel, and is configured of a pipe material;
A front bracket extending inward in the vehicle width direction from the curved portion of the lower arm body;
A front bush fixed to the front bracket;
A rear bushing that is press-fitted and fixed to the rear end of the lower arm main body,
A lower arm mounting structure, wherein a rear end portion of a lower arm main body is connected to a vehicle body via the rear bush.   The rear bush includes an outer cylinder, an inner cylinder, a cylindrical elastic member provided between the outer cylinder and the inner cylinder, a rod-shaped support shaft that is inserted into the inner cylinder and fixed to the vehicle body, 2. The lower arm mounting structure according to claim 1, further comprising a cylindrical rubber member interposed between the inner cylinder and the support shaft and fixed integrally with the inner cylinder or the support shaft in advance.   The rear bush includes a cylindrical member, a cylindrical elastic member provided inside the cylindrical member, and a rod-like support shaft that is integrally fixed to the elastic member in an insertion manner and fixed to the vehicle body. The lower arm mounting structure according to claim 1, wherein:   4. The lower arm mounting structure according to claim 2, wherein the support shaft is fixed to the lower arm body side in advance, and fastening means for fixing the support shaft to a member on the vehicle body side is provided.