JP6042231B2 - Front body structure of automobile - Google Patents

Description

  The present invention relates to a front body structure of a vehicle in which front and rear bushes of a lower arm are fastened in an opening at a vehicle width direction side end portion of a suspension member, and a stabilizer is disposed on an upper surface.

  As a conventional front body structure of an automobile, a suspension member is formed such that an upper member and a lower member are coupled so as to form a hollow shape, and are provided at openings on both sides in the vehicle width direction, and the front of the lower arm is provided in the opening. , The rear bushing is inserted and fastened in the vertical direction of the vehicle, and a stabilizer is disposed on the upper surface of the suspension member. In such a front body structure, in order to avoid interference with the lower arm that swings up and down and the stabilizer that moves up and down, the portion between the left and right end portions of the suspension member between the front and rear bushing mounting portions is provided. A shape curved inward in the vehicle width direction is employed (see, for example, Patent Document 1).

Japanese Patent No. 3419221

  In the conventional structure, since the portions between the left and right end portions of the suspension member and the mounting portions of the rear bush are curved toward the inside of the vehicle, stress is concentrated on the curved portion by the vehicle longitudinal direction input from the lower arm, There is a problem that the strength and rigidity are likely to be insufficient.

On the other hand, it is conceivable to reduce the stress concentration by making the curved shape as shallow as possible by lowering the vehicle width direction side end portion to which the bush of the upper member is fastened. However, in this case, the offset amount between the vehicle width direction side end portion and the suspension member center portion in the vehicle width direction is increased, and the bending moment acting on the offset portion is increased, so that the strength and rigidity are likely to be insufficient. Occurs.

  The present invention has been made in view of the above-described conventional situation, and can relieve stress concentration at the left and right side end portions of the suspension member, and while avoiding interference with the lower arm and the stabilizer, An object of the present invention is to provide a front body structure of an automobile that can reduce the offset amount of the vehicle.

The present invention is formed by connecting the upper member and the lower member so as to form a hollow shape, and has a vehicle width direction central portion and a side portion that is positioned lower than the central portion and serves as a mounting portion of the lower arm, An opening is formed at the end of the side in the vehicle width direction, a suspension member having a seating surface for attachment to the vehicle body is formed at the rear end corner, and the front and rear bushes are vertically arranged in the opening. In a front vehicle body structure of an automobile having a lower arm that is inserted and fastened to the side portion, and a stabilizer that is disposed so as to pass above the end portion and that is displaced vertically as the lower arm swings up and down,
A step portion having a paragraph surface lower than the side portion is formed on the side portion of the upper member, and the paragraph surface is positioned at a low position where interference with the stabilizer displaced at the lowest position can be avoided. The step portion overlaps at least a part in the vertical direction, and the step portion is substantially parallel to a straight line connecting the attachment portion of the front bush and the attachment seat surface to the vehicle body.

According to a second aspect of the present invention, in the front body structure of the automobile according to the first aspect,
A bulk member having a substantially concave cross section having an upper horizontal side portion, a lower horizontal side portion and a vertical side portion is disposed in the vicinity of the opening, and the front end of the stepped portion has the upper horizontal side of the bulk member in plan view. It is arranged to be continuous with the flange for mounting the front bush formed on the side,
The rear end of the stepped portion is arranged to be continuous with a mounting seat surface of the upper member to the vehicle body.

  According to invention of Claim 1, the level | step-difference part which has a paragraph surface lower than this side part is formed in the side part of an upper member, and this paragraph surface is made into the low position which can avoid interference with the stabilizer displaced to the lowest. Since it is positioned, the side part of the upper member that serves as the bush mounting part of the lower arm can be positioned at a relatively high position, so that the amount of offset from the center part of the side part can be reduced and acts on the offset part. The bending moment can be reduced, and the problem of insufficient strength and rigidity can be avoided or suppressed.

Further, since the paragraph surface is positioned at a low place, the paragraph surface can be positioned on the outside in the vehicle width direction so as to overlap with at least a part of the stabilizer in the vertical direction, and the stepped portion is It can be made substantially parallel to the straight line connecting the mounting portion of the front bushing and the mounting seating surface of the suspension member to the vehicle body, thereby making it possible to shallowly curve the portion between the front and rear bushing mounting portions of the suspension member. The stress concentration on the curved portion can be alleviated without adding parts, and the problem of insufficient strength and rigidity can be avoided or suppressed from this point. As a result, steering stability can be improved and the occurrence of road noise can be suppressed.

As described above, stress concentration in the curved portion can be reduced without adding a reinforcing component, so that the weight can be reduced and, as a result, the cost can be suppressed.

According to the invention of claim 2, since the flange portion for attaching the front bush of the bulk member and the mounting surface of the upper member to the vehicle body are connected by the step portion, the rigidity with respect to the longitudinal input from the lower arm can be further increased. As a result, the steering stability can be further improved, and the generation of road noise can be suppressed.

1 is a plan view of a front body structure of an automobile according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional side view (a cross-sectional view taken along line II-II in FIG. 1) of a lower arm attachment portion in the structure. It is a section front view (III-III line sectional view of Drawing 1) of an attachment leg part in the above-mentioned structure. It is the perspective view seen from the vehicle width direction inner side of the bulk member in the above-mentioned structure. It is a top view of the said bulk member. It is a top view of the lower arm in the said structure. It is a side view which shows typically the attachment state to the vehicle body frame of the suspension member in the said structure. It is a cross-sectional front view (cross-sectional view taken along line VIII-VIII in FIG. 1) showing the behavior of the stabilizer and the lower arm in the structure.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 8 are views for explaining a front body structure of an automobile according to Embodiment 1 of the present invention. In this embodiment, front, rear, left, and right are states when the vehicle front is viewed. Means before, after, left and right.

In the figure, reference numeral 12 denotes left and right side members constituting a vehicle body skeleton member. The side members 12 are obliquely extended from the main body portion 12a to the vehicle width direction outside while extending from the main body portion 12a to the vehicle width direction. And a front portion 12b extending upward and horizontally forward therefrom.

A suspension member 14 is disposed so as to extend from the lower surface of the front end portion of the main body portion 12a of the side member 12 to below the front portion 12b. The suspension member 14 connects the upper member 2 and the lower member 3 so as to form a hollow shape, and is provided in the vicinity of the front portion of the suspension member main body 1 having openings 1d on both sides in the vehicle width direction. The suspension member main body 1 is provided with mounting legs 9 that support the side member (vehicle body frame member) 12.

The suspension member main body 1 has the left and right mounting legs 9, 9 fastened to the front portion 12b of the side member 12 with bolts 12c, and the mounting portion 1g to the vehicle body formed at the rear corner portion described later is bolted. The side member 12 is fixedly supported by being fastened to the main body 12a of the side member 12 by 12d.

The suspension member main body 1 is arranged so as to be stepped at a center portion 1a located in the center in the vehicle width direction and at the left and right sides in the vehicle width direction and at a lower position than the center portion 1a when viewed in the vehicle longitudinal direction. The left and right side portions (side portions) 1b and 1b are arranged so as to connect the left and right side portions 1b and 1b and the central portion 1a. It has left and right inclined portions 1c and 1c that form an inclination.

Further, a recess 1e for securing an arrangement space for the engine unit or the like is formed in the front portion of the suspension member body 1 so as to be recessed toward the rear of the vehicle. An attachment portion 1g for attaching the suspension member main body 1 to the main body portion 12a of the side member 12 is formed at the rear corner portion of the suspension member main body 1. Reference numeral 1f denotes a reinforcing bead that is recessed so as to extend from the left and right inclined portions 1c to the central portion 1a.

The left and right side portions 1b and 1b are formed with the opening 1d for inserting a lower arm 4 to be described later.

The suspension member body 1 is made of sheet metal and has a hollow shape with the upper member 2 having a substantially hat-shaped cross section and the lower member 3 that is also made of sheet metal and has a substantially hat-shaped cross section. It is combined so as to be formed.

The upper member 2 has an upper wall portion 2a, a front wall portion 2b, a rear wall portion 2c, and front and rear flange portions 2d and 2e, and has a substantially hat shape as described above. The lower member 3 has a lower wall portion 3a, a front wall portion 3b, a rear wall portion 3c, and front and rear flange portions 3d and 3e, and has a substantially hat shape as described above. The front and rear flange portions 3d and 3e of the lower member 3 and the front and rear flange portions 2d and 2e of the upper member 2 are joined by spot welding.

The mounting portion 1g has a structure in which a collar 13b is disposed between mounting seat surfaces 2h and 3h formed on the upper wall portion 2a of the upper member 2 and the lower wall portion 3a of the lower member 3, and is fixed by welding.

A bulk member 6 made of sheet metal is disposed in the left and right sides of the suspension member main body 1. The bulk member 6 is formed by welding and joining two front and rear parts of a bulk front portion 6 ′ and a bulk rear portion 6 ″, and has substantially the same length as the longitudinal direction of the suspension member body 1. The member body 1 is disposed slightly obliquely so as to extend from the front portion of the opening 1d to the inclined portion 1c.

The bulk front portion 6 'of the bulk member 6 has an upper horizontal side portion 6a having substantially the same width as the side portion 1b, a lower horizontal side portion 6b, and a vertical side portion 6c having substantially the same height as the side portion 1b. The cross section has a concave shape. An upper flange portion 6d is formed on the bulk rear portion 6 ''. The upper horizontal side portion 6a and the upper flange portion 6d, the lower horizontal side portion 6b and the lower edge portion 6e are welded and fixed to the upper wall portion 2a of the upper member 2 and the lower wall portion 3a of the lower member 3, respectively. The bulk member 6 bridges the upper wall 2a of the upper member 2 and the lower wall 3a of the lower member 3 and substantially closes the opening 1d.

A concave upper front bead 2f and an upper rear bead for attaching the front end of the lower arm 4 and the upper ends of the rear bushes 4a and 4b to the front and rear of the side portion 1b of the upper wall 2a of the upper member 2 2g protrudes into the opening 1d and is recessed so as to extend in the vehicle width direction from the opening 1d to the inclined portion 1c. Similarly, the lower front bead 3f for attaching the lower end portions of the front and rear bushes 4a and 4b of the lower arm 4 to the portion of the lower wall portion 3a of the lower member 3 facing the upper front bead 2f and the upper rear bead 2g. The lower bead 3g is formed so as to protrude into the opening 1d and to extend in the vehicle width direction from the opening 1d to the rising inclined portion 1c.

Further, an upper reinforcing bead 6f and a lower reinforcing bead 6g for reinforcing the upper front bead 2f and the lower front bead 3f are provided on the upper horizontal side 6a and the lower horizontal side 6b of the bulk front part 6 'of the bulk member 6, respectively. Is formed so as to protrude into the opening 1d and to contact the upper front bead 2f and the lower front bead 3f from the inside. The upper reinforcing bead 6f and the lower reinforcing bead 6g are welded and fixed to the upper front bead 2f and the lower front bead 3f, and serve as upper and lower flange portions for attaching the front bush 4a.

A front bolt hole a is formed so as to vertically penetrate the lower front bead 3f and the lower reinforcing bead 6g from the upper front bead 2f and the upper reinforcing bead 6f, and vertically penetrates the lower rear bead 3g from the upper rear bead 2g. A rear bolt hole b is formed as shown.

Here, the upper wall 2a of the upper member 2 and the upper lateral side 6a of the bulk member 6 are formed so that the closed section A extends from the front bolt hole a to the rear of the vehicle as follows. That is, the lower reinforcing bead 6g is formed to have substantially the same shape and size as the lower front bead 3f, whereas the upper reinforcing bead 6f is extended so as to extend rearward of the vehicle from the upper front bead 2f. Yes. The closed section A is formed by the extension 6f 'of the upper reinforcing bead 6f and the portion 2f' corresponding to the extension 6f 'of the upper wall 2a.

The lower arm 4 has a substantially L shape having a base portion 4g extending in the vehicle front-rear direction and an arm body 4e extending outward in the vehicle width direction from the front portion of the base portion 4g. The front and rear bushes 4a and 4b are fixed to the end portions with their axes directed in the vertical direction. The front bush 4a and the rear bush 4b are obtained by baking and fixing a rubber member 4f between an inner cylinder 4c and an outer cylinder 4d.

The lower arm 4 aligns the front bush 4a with the front bolt hole a with its axis line up and down, and the rear bush 4b with the rear bolt hole b with its axis line up and down. In this state, the bolt 5 is inserted into the inner cylinder 4c from below and the nut member 5a is tightened to support the suspension member body 1.

Here, most of the base portion 4g of the lower arm 4 is located between the upper wall portion 2a and the lower wall portion 3a constituting the side portion 1b of the upper member 2 and the lower member 3, and the vertical strokes of the left and right wheels. Along with this, it swings up and down as shown in FIG.

The left and right mounting legs 9, 9 made of sheet metal are formed so as to protrude upward slightly behind the mounting bolts 5 of the left and right front bushes 4 a of the suspension member body 1. . Each of the attachment legs 9 is a cylindrical body in which a main body portion 10 located on the inner side in the vehicle width direction and a reinforcing portion 11 located on the outer side in the vehicle width direction are welded.

Flange portions 11c and 11d are formed outwardly at the lower ends of the base portion 11a and the protruding portion 11b of the reinforcing portion 11. The flange portion 11d is welded and fixed to a portion 2f ′ constituting the closed section A of the upper wall portion 2a of the upper member 2. Further, the flange portion 11c is fixed by welding in the vicinity of the boundary portion between the upper front bead 2f and the closed section A.

Further, the lower end portion 10e of the main body portion 10 penetrates downward from the upper wall portion 2a of the upper member 2 to the lower wall portion 3a of the lower member 3, and the lower end portion 10e includes the upper wall portion 2a and the lower wall portion 3a. Further, the outer end portion 10 a ′ of the front and rear wall portions 10 a is welded and fixed to the vertical wall portion 6 c of the bulk member 6.

An opening toward the outside is formed at the upper end of the mounting leg 9, and a collar 13a is disposed in the opening. A bolt 12c for fixing the mounting leg 9 to the front portion 12b of the side member 12 passes through the collar 13a.

A stabilizer 15 is disposed on the upper surface of the suspension member main body 1. This stabilizer 15 has a generally U-shaped plan view made of a spring steel round bar, and has a lateral side portion 15a extending in the vehicle width direction, and a longitudinal side portion 15c bent forward at both ends of the lateral side portion 15a. , 15c. Both end portions of the lateral side portion 15a are rotatably supported by both end portions of the central portion 1a of the suspension member body 1 by support brackets 15b and 15b, and the vertical side portion 15c is connected to the lower arm via a connecting rod (not shown). It is connected to the 4 side.

The stabilizer 15 is twisted according to the vertical stroke difference between the left and right wheels, and the vertical side portion 15c is displaced up and down as shown in FIG.

Here, at the outer end in the vehicle width direction of the upper wall portion 2a constituting the side portion 1b of the upper member 2, a stepped portion 16 having a paragraph surface 16a positioned lower than the upper wall portion 2a is formed. ing. The paragraph surface 16a is located at a low position where it can avoid interference with the stabilizer 15 'displaced to the bottom, and is out of the vehicle width direction to a position overlapping with a part of the stabilizer 15' in the vertical direction in plan view. It extends toward.

The step portion 16 is a straight line B connecting the mounting portion of the front bush 4a, more specifically, the bolt 5, and the mounting seat surface 2h to the vehicle body, more specifically, the bolt 12d in plan view. And approximately parallel. More precisely, the paragraph surface 16a is formed wider at the center in the front-rear direction, and the outer end surface 16a 'of the paragraph surface 16a is closer to the straight line B in parallel.

Furthermore, the front end 16b of the stepped portion 16a is disposed so as to be continuous with the outer edge of the front bushing flange portion 6a of the bulk member 6 in a plan view,
The rear end 16c of the stepped portion 16a is disposed so as to be continuous with the mounting seat surface 2h of the upper member 2 to the vehicle body.

According to this embodiment, as shown in FIG. 8, a stepped portion having a paragraph surface 16a lower than the upper wall portion 2a at the outer end in the vehicle width direction of the upper wall portion 2a constituting the side portion 1b of the upper member 2. 16 and the paragraph surface 16a is positioned at a low position where interference with the lowest displaced stabilizer 15 'can be avoided, so that the upper member serving as a mounting portion for the front and rear bushes 4a and 4b of the lower arm 4 is formed. 2 can be positioned at a relatively high position by h1, so that the offset amount h2 with respect to the central portion 1a of the upper wall 2a can be reduced. As a result, the bending moment generated in the inclined portion 1c having the offset amount h2 can be reduced by the vertical input from the lower arm 4, and the problem of insufficient strength and rigidity can be avoided or suppressed.

Further, since the paragraph surface 16a is positioned at a low place, the paragraph surface 16a can be positioned on the outer side in the vehicle width direction so as to overlap a part of the stabilizer 15 in the vertical direction. Can be made substantially parallel to a straight line B connecting the mounting portion of the front bush 4a and the mounting seat surface 2h of the suspension member main body 1 to the vehicle body in plan view. As a result, the curve between the front and rear bush mounting portions of the suspension member main body 1 can be made shallow, and stress concentration on the curved portion can be alleviated. From this point, the problem of insufficient strength and rigidity can be avoided or suppressed. it can. As a result, steering stability can be improved and the occurrence of road noise can be suppressed.

In addition, stress concentration at the curved portion can be alleviated without adding a reinforcing component, so that the weight can be reduced and, as a result, the cost can be suppressed.

Further, since the flange portion 6a for attaching the front bush of the bulk member 6 and the mounting seat surface 2h of the upper member 2 to the vehicle body are connected by the stepped portion 16, the rigidity with respect to the longitudinal input from the lower arm 4 can be further increased. As a result, the steering stability can be further improved, and the generation of road noise can be suppressed.

Further, a bulk member 6 is disposed in the vicinity of the opening 1d of the suspension member main body 1, and the upper lateral side 6a and the lower lateral side 6b of the bulk member 6 are connected to the upper wall 2a and the lower member 3 of the upper member 2, respectively. Since the lower wall 3a is welded and fixed, the vicinity of the opening 1d of the suspension member body 1 can be bridged up and down, and the rigidity around the opening 1d can be increased.

1 Suspension member main body 1a Central part 1b Side part (side part)
1d Opening 2 Upper member 2h Mounting seat 3 Lower member 4 Lower arms 4a, 4b Front and rear bush 6 Bulk member 6a Upper horizontal side 6b Lower horizontal side 6c Vertical side 6f Upper reinforcing bead (bushing mounting flange)
15 Stabilizer 16 Stepped portion 16a Paragraph 16b Stepped portion front end 16c Stepped portion rear end B Straight line

Claims (2)

The upper member and the lower member are coupled so as to form a hollow shape, and have a vehicle width direction center portion and a side portion that is positioned lower than the center portion and serves as a mounting portion of the lower arm, An opening is formed at the end in the vehicle width direction, a suspension member having a seating surface for attachment to the vehicle body is formed at the rear end corner, and front and rear bushes are inserted into the opening in the vertical direction. In a front vehicle body structure of a vehicle having a lower arm fastened to a side portion and a stabilizer that is disposed so as to pass above the vehicle width direction end portion and that is displaced up and down as the lower arm swings up and down,
Forming a stepped portion having a paragraph surface lower than the side portion on the side portion of the upper member;
The paragraph surface is located at a low position where interference with the stabilizer displaced at the lowest position can be avoided, and is formed so as to overlap with at least a part of the stabilizer in the vertical direction,
The front vehicle body structure of an automobile, wherein the stepped portion is substantially parallel to a straight line connecting a mounting portion of the front bush and a mounting seat surface to the vehicle body. The front body structure of an automobile according to claim 1,
A bulk member having a substantially concave cross section having an upper lateral side, a lower lateral side and a vertical side in the vicinity of the opening is disposed.
The front end of the stepped portion is arranged so as to be continuous with a flange portion for mounting a front bush formed on the upper horizontal side portion of the bulk member in plan view,
A front body structure of an automobile, wherein a rear end of the stepped portion is arranged so as to be continuous with a mounting seat surface of the upper member to the vehicle body.

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