JP3518381B2 - Automotive suspension mounting structure - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension mounting structure provided in a lower portion of an engine room of an automobile or the like. 2. Description of the Related Art As shown in FIG. 8, a subframe 3 called a so-called girder frame is mounted below an engine room 2 of a vehicle body 1 of an automobile. 2. Description of the Related Art A suspension mounting structure for rotatably supporting base ends 4a and 5a of suspension arms 4 and 5 represented by a compression arm is known. The sub-frame 3 includes a pair of left and right side frame portions 6, a front frame portion (front cross member) 7 provided on the front end side of the side frame portions 6,
It has also been proposed to use a rear frame (rear cross member) 8 provided on the rear end side of the side frame 6 and the like, and to use an extruded aluminum alloy material in order to reduce the weight of each of the frames 6, 7, and 8. ing. The side frame 6 has a bracket 9 for mounting the suspension arm 4. The bracket 9 is a separate component formed separately from the side frame portion 6 and is fixed to the side frame portion 6 by welding. A base end (a bush) 4a of the suspension arm 4 is housed inside the bracket 9,
The suspension arm 4 is supported by the shaft member 10 extending in the front-rear direction so as to be rotatable vertically. [0005] In the prior art, the number of components is increased because the bracket 9 separate from the side frame portion 6 is used. Moreover, since it is necessary to secure a mounting surface for mounting the bracket 9 on the side frame portion 6, a part of the side frame portion 6 needs to be cut off, and the rigidity of the suspension mounting portion decreases due to a decrease in the main cross section. Cause you to Moreover, when the bracket 9 is welded to the side frame portion 6, the strength of the welded portion may be reduced, and special consideration is required to obtain a predetermined welding quality. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a lightweight, simple structure and high rigidity suspension mounting structure without using a bracket. According to the first aspect of the present invention, there is provided a frame material for a suspension mounting portion according to the present invention, which comprises, for example, an upper wall, a lower wall, and front and rear vertical ribs. And the like, and is formed of an extruded material such as an aluminum alloy which is extruded so as to form a closed cross section and extend along the direction in which the suspension arm extends. The base end of the suspension arm is accommodated inside the closed cross section of the frame member, and a shaft member for pivotally supporting the base end is fixed to the partition wall of the closed cross section. In the present invention, an upper inclined wall extending obliquely downward from an upper portion of a front vertical rib as a partition wall and a diagonally upward extending from a lower end portion of the vertical rib at a front portion of the frame member. The lower inclined wall is integrally formed, and a highly rigid triangular second closed section surrounded by the upper and lower inclined walls and the vertical ribs is formed. A nut member for fixing the member is housed. In this configuration, a large main cross section is ensured by being able to accommodate the base end portion of the suspension arm and all components (such as a shaft member and a nut member) necessary for mounting the suspension arm inside the main cross section of the frame material, and In combination with the high rigidity of the second closed cross-section portion, a suspension arm mounting portion with higher rigidity can be realized. Also, the frame material side
On the surface, with a fastening tool for rotating the shaft member
A recess having a shape that avoids interference is formed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A suspension mounting structure according to an embodiment of the present invention will be described below with reference to the drawings. The sub-frame 20 shown in FIG. 2 and the like constitutes a suspension mounting portion referred to in the present invention. The sub-frame 20 includes a pair of left and right side frame portions 21,
22 and front frame part (front cross member) 23
And a rear frame portion (rear cross member) 24 in a cross-girder shape. This subframe 20
Is fixed from below the lower structure 1a of the engine room 2 by a fastening member such as a bolt (not shown), similarly to the conventional example shown in FIG. The side frame portions 21 and 22 are bilaterally symmetrical and have the same basic configuration. Therefore, one side frame portion 21 will be described below as a representative. As shown in FIGS. 1 to 3, the side frame portion 21 includes a front frame member 30 located on the front side, an intermediate frame member 31 located at a middle portion in the front-rear direction, and a rear frame member 32 located at the rear side. Are welded at their joints. These frame members 30, 31, 32
Each is made of an extruded material such as an aluminum alloy.
Also, the front cross member 23 and the rear cross member 2
4 is also made of an extruded material such as an aluminum alloy. The pushing direction of the front cross member 23 and the rear cross member 24 is the width direction of the vehicle body (the direction indicated by arrow A in FIG. 2).
It is. The front frame member 30 constituting the front portion of the side frame portion 21 is made of an extruded material such as an aluminum alloy extruded in a direction indicated by an arrow B in FIG. By cutting off, a shape as shown in FIG. 1 and the like is formed. The cylindrical member 36 is welded to the vertical hole 35 formed in the front frame member 30 with the cylindrical member 36 inserted. The front frame member 30 is fastened to the lower structure 1a of the vehicle body (shown in FIG. 8) by bolts (not shown) inserted from below the cylindrical member 36. An intermediate frame member 31 constituting an intermediate portion in the front-rear direction of the side frame portion 21 is provided in the front-rear direction of the vehicle body (FIG. 2).
In the direction indicated by the arrow C in FIG. 1), and has an almost rectangular closed cross section. As shown in FIGS. 1 and 4, the rear end surface 31 a of the intermediate frame member 31 is cut at an angle corresponding to a slope wall 46 of the rear frame member 32 described later, and the rear end surface 31 a and the slope wall 46 are welded to each other. It has become so. A rear frame member 32 constituting a rear portion of the side frame portion 21 is provided with a suspension arm 5 described later.
5 is made of an extruded material such as an aluminum alloy that is extruded along the direction in which it extends 5 (the direction indicated by arrow D in FIG. 2). The rear frame member 32 includes an upper wall 40 and a lower wall 41 extending in the front-rear direction of the vehicle body, an intermediate rib 42 integrally formed between the upper wall 40 and the lower wall 41, and a frame member 32. , A front vertical rib 43 provided at a position near the front end and a vertical rib 44 positioned at the rear side, an upper inclined wall 45 extending obliquely downward from the upper end of the front vertical rib 43, and a front vertical rib. A lower inclined wall 46 extending obliquely upward from the lower end of the bottom 43 is integrally formed. On the front side of the front vertical rib 43, a dovetail groove rail 47 for accommodating a nut member 58 described below is integrally formed.
The vertical ribs 43 and 44 are an example of the partition wall according to the present invention. Inside the frame member 32 for attaching the following shaft member (bolt 57), the upper wall 40 and the lower wall 41 are provided.
And a first closed cross-section 51 surrounded by the front vertical ribs 43 and the rear vertical ribs 44, and is formed by the front vertical ribs 43, the upper inclined wall 45, and the lower inclined wall 46. An enclosed second closed section 52 is formed. As shown in FIG. 4, the first closed cross section 51 is a quadrangle (trapezoid) when viewed from the side of the frame member 32, while the second closed cross section 52 is a substantially triangular shape having a tapered front end. It has become. In the first closed section 51, a proximal end 56 of a lateral arm as an example of a suspension arm 55 is accommodated. One example of the base end portion 56 is as shown in FIG.
A bolt 57 that takes the form of a bush in which a rubber bush 56b is housed inside the outer cylinder 56a and functions as a shaft member
And a nut member 58 screwed to the bolt 57 so as to be attached to the vertical rib 43 as the front partition and the vertical rib 44 as the rear partition. The bolt 57 functioning as a shaft member extends in a direction perpendicular to the direction in which the frame member 32 is pushed out, and is bridged between the front vertical rib 43 and the rear vertical rib 44. And this bolt 57
Through the hole 56c of the bush inner cylinder of the base end portion 56, the suspension arm 55 is supported rotatably in the vertical direction. The longitudinal ribs 43 and 44 are formed with holes 60 and 61 along the front and rear direction for passing the bolt 57. As shown in FIG. 5, the nut member 58 has a washer 65 also serving as a washer, and a nut body 66 fixed to the washer 65. As shown in FIG. 4, the washer portion 65 is provided with the dovetail groove rail 4 formed on the front vertical rib 43.
7, the front vertical rib 43 is held in a predetermined position at a predetermined position. The washer 65 is provided with a stopper 67 for regulating the insertion depth of the washer groove rail 47. That is, when the nut member 58 is inserted into the dovetail groove rail 47 and the screw hole 66a of the nut main body 66 is inserted to a position matching the holes 60 and 61 of the vertical ribs 43 and 44, the stopper 67 is moved to the frame member 32. The nut member 58 is positioned by contacting the side surface of the nut member 58. A hole 70 is formed at a position near the rear end of the frame member 32 along the vertical direction. A shaft member 71 (shown in FIG. 3) extending in the up-down direction is inserted into the hole 70, and the base member (bush) 7 of a compression arm 72, which is an example of a suspension arm, is inserted by the shaft member 71.
3 is attached so as to be rotatable in the front-rear direction. Further, a cylindrical member 76 is welded to an arc-shaped notch 75 formed at the rear end of the frame member 32, and a bolt (not shown) inserted from below the cylindrical member 76 allows the rear frame member 32 to be attached to the vehicle body. Is fastened to the lower structure 1a (shown in FIG. 8). As shown in FIG. 6, the bolt 57 is fastened to the nut member 58 by rotating a socket portion 80a of a fastening tool 80 such as an impact wrench. For this reason, the fastening tool 80
A concave portion 81 having a shape capable of avoiding interference with the recess 81 is formed. The concave portion 81 is formed by shaving the intermediate portion in the front-rear direction of the extruded shape 32a made of an aluminum alloy as shown in FIG. 7 by machining, as shown by a two-dot chain line. By forming such a concave portion 81, the operation of assembling the bolt 57 by the fastening tool 80 can be performed without any problem. The subframe 20 configured as described above
Is made of an aluminum alloy extruded shape 32a, so that it is sufficiently lightweight, and in addition to the first closed cross-section 51 formed on the frame member 32 for attaching the shaft member, the base end of the suspension arm 55 56, and the front and rear partitions, that is, the vertical ribs 43 and 44 that are a part of the frame member 32.
Since the bolts 57 are supported, the number of parts is smaller than in the case of using the bracket 9 as in the conventional example shown in FIG. 8, and since welding is unnecessary, the strength depends on the welding quality. Nor. In addition, there is no need to reduce the main cross-sectional area as in the case of using a bracket, and it is possible to exhibit a stable and high strength particularly at a portion where the suspension arm is attached. Further, since the second closed section 52 forms a highly rigid triangular closed section by the vertical ribs 43 and the inclined walls 45 and 46, the rigidity of the joint with the intermediate frame member 31 can be increased. In addition, since the nut member 58 can be accommodated by utilizing the internal space of the closed cross section 52, it is possible to prevent the fastening parts such as nuts from being exposed to the outside. Since all the fastening parts such as the bolts 57 and the nut members 58 are accommodated inside the closed cross section of the frame member 32, the main cross section of the frame member 32 can be enlarged, and higher rigidity can be exhibited. Now you can. In practicing the present invention, each component of the present invention including the side frame portion and the suspension arm constituting the present invention, an extruded material, a shaft member, a closed cross section and the like constituting the frame material will be described. It goes without saying that the present invention can be implemented by being modified appropriately. According to the first aspect of the present invention, the front portion of the frame member made of the extruded shape constituting the subframe disposed in the lower part of the engine room of the vehicle body has the front side as the partition wall. An upper inclined wall extending diagonally downward from the upper portion of the vertical rib and a lower inclined wall extending diagonally upward from the lower end of the vertical rib are integrally formed, and the upper and lower inclined walls and the vertical rib are formed integrally. By forming a high-rigidity triangular second closed cross-section surrounded by the above, the nut member for fixing the shaft member is housed in the second closed cross-section, so that the inside of the main cross-section of the frame member is formed. A large main cross section is secured by accommodating the base end portion of the suspension arm and all components (such as a shaft member and a nut member) necessary for mounting the suspension arm, and the rigidity of the second closed cross section itself is high. Koto and Aima Thus, a suspension arm mounting portion with higher rigidity can be realized. Therefore, a lightweight, simple structure and high rigidity suspension mounting structure can be obtained. Ma
The shaft member is rotated on the side surface of the frame member.
A concave shape is formed to avoid interference with the fastening tool
Assembly work for shaft members such as bolts
It can be carried out.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of a part of a sub-frame showing one embodiment of the present invention. FIG. 2 is an overall plan view of the subframe shown in FIG. 1; FIG. 3 is a perspective view showing a state where the sub-frame shown in FIG. 1 is assembled. FIG. 4 is a cross-sectional view of a part of the sub-frame taken along line IV-IV in FIG. 3; FIG. 5 is a perspective view of a nut member used for the subframe shown in FIG. 1; FIG. 6 is a plan view showing a rear frame member and a suspension arm of the sub-frame shown in FIG. 1; FIG. 7 is a plan view of an extrusion used for the rear frame member shown in FIG. 6; FIG. 8 is a perspective view of a part of a vehicle body and a subframe showing a conventional suspension mounting structure. DESCRIPTION OF SYMBOLS 20 ... sub-frames 21 and 22 ... side frame portions 32 ... frame members 32a ... extrusion members 40 ... upper walls 41 ... lower walls 43 ... front vertical ribs (partitions) 44 ... rear vertical ribs (partitions) 51: first closed section 52: second closed section 55: suspension arm 56: base end 57: bolt (shaft member) 58: nut member

Claims (1)

(57) Claims 1. A sub-frame disposed in a lower portion of an engine room of a vehicle body, and each of a pair of left and right side frame portions constituting the sub-frame is disposed in a width direction of the vehicle body. In a suspension mounting portion structure for mounting an extending suspension arm so as to be vertically rotatable by a shaft member, the frame member for mounting the shaft member of the side frame portion forms a closed cross section and extends along a direction in which the suspension arm extends. The frame member accommodates a base end of the suspension arm inside the closed cross section of the frame material, and fixes the shaft member to a partition wall of the closed cross section. An upper inclined wall extending obliquely downward from an upper part of the front vertical rib as the partition wall, and a lower end of the vertical rib at a front portion of the material; And a lower inclined wall extending obliquely upward from the upper surface, and integrally form a rigid, triangular second closed section surrounded by the upper and lower inclined walls and the vertical ribs. 2, the nut member for fixing the shaft member is housed in the closed cross section, and the shaft member is rotated on the side surface of the frame member.
Is formed to avoid interference with the fastening tool
Suspension mounting portion structure of an automobile, characterized by being.