JP2012171483A - Vehicle body structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure strength corresponding to the direction of the moment different by a part, while preventing an increase in mass.SOLUTION: A side frame 200 for constituting a vehicle body frame 100 secures the strength by arranging a front end 202 with the vehicle longitudinal direction as a strong axis K. The strong axis K gradually rotates by twisting around the axial center G toward the vehicle longitudinal direction side. The vehicle width direction becomes the strong axis K in the vicinity of a central part in the vehicle longitudinal direction, so that the strength is secured.

Description

  The present invention relates to a vehicle body structure.

  In Patent Document 1, in an industrial vehicle in which a front pillar that supports a head guard is inclined in a rearward direction, both front pillars are formed in a shape that curves convexly forward and are located outside. An industrial vehicle is described that is formed of a pillar material having an asymmetrical cross-sectional shape in which a surface is a curved surface and a surface located inside is a flat surface (see Patent Document 1).

  In such a front pillar, the strength is ensured by increasing the cross section in the direction of the moment. However, when the direction of the moment differs depending on the part, to ensure the strength of all the parts, a uniformly large cross section is required, and as a result, the mass of the front pillar increases.

JP-A-9-124288

  In view of the above, an object of the present invention is to provide a vehicle body skeleton member capable of ensuring strength corresponding to the direction of moment that varies depending on a part while suppressing an increase in mass.

  The vehicle body structure according to claim 1 is arranged along the vehicle front-rear direction and is curved so as to protrude upward from the front end portion in the vehicle front-rear direction toward the center portion, and the strong axis of the cross-sectional main axis is the front end The vehicle body skeleton members arranged along the vehicle longitudinal direction at the portion and arranged along the vehicle width direction at the central portion are arranged on both sides of the vehicle.

In the vehicle body structure according to the first aspect, the strong axis of the cross-sectional main shaft disposed along the vehicle front-rear direction at the front end portion is disposed along the vehicle width direction at the center portion. In the case of a frontal collision, the strength is determined by the moment around the axis in the vehicle width direction that acts on the front end of the vehicle body frame member. Therefore, the strength is ensured by setting the strong axis at the front end of the vehicle body frame member as the vehicle longitudinal direction. Is done. In the case of a side collision, the strength is determined by the moment about the vehicle longitudinal axis acting on the center part of the vehicle body frame member, so the strength is ensured by setting the strong axis at the center part of the vehicle body frame member to the vehicle longitudinal direction. Is done.
Therefore, strength corresponding to the directions of moments different between the front end portion and the central portion in the vehicle front-rear direction is ensured while suppressing an increase in the mass of the vehicle body skeleton member.

  The vehicle body structure according to claim 2 is configured such that the vehicle body skeleton member is twisted about the axis from the front end portion toward the center portion.

  In the vehicle body structure according to claim 2, the vehicle body skeleton member is twisted about the axis as it goes from the front end portion toward the center portion, so that the strong axis of the cross-sectional main shaft is rotated, and the strong shaft is The direction is easily changed.

  The vehicle body structure according to claim 3 is configured so that the line of sight and the strong axis coincide or substantially coincide with each other in the vicinity of the height of the driver's field of view.

  The vehicle body structure according to claim 3 is configured so that the strong axis of the vehicle body skeleton member coincides with or substantially coincides with the line of sight in the vicinity of the height of the driver's field of view. Therefore, the field of view blocked by the vehicle body skeleton member is reduced.

  In the vehicle body structure according to a fourth aspect, the vehicle body skeleton member has a uniform cross section from the front end portion to the central portion.

  In the vehicle body structure according to the fourth aspect, since the vehicle body skeleton member has a uniform cross section from the front end portion to the center portion, an increase in mass is reliably suppressed.

  According to the first aspect of the present invention, as compared with the structure to which the present invention is not applied, the moment that is different between the front end portion and the center portion in the vehicle front-rear direction while suppressing an increase in the mass of the vehicle body skeleton member. The strength corresponding to the direction can be ensured.

  According to the second aspect of the present invention, the direction of the strong axis of the main axis of the cross section of the vehicle body skeleton member can be easily changed between the front end portion and the rear end portion.

  According to the third aspect of the present invention, as compared with a structure in which the strong axis of the vehicle body skeleton member does not coincide with the line of sight, the field of view blocked by the vehicle body skeleton member can be reduced.

  According to the fourth aspect of the present invention, an increase in mass can be reliably suppressed as compared with a structure in which the vehicle body skeleton member does not have a uniform cross section.

It is the side view seen from the vehicle width direction left outside which shows typically a vehicle provided with a vehicle frame member concerning an embodiment of the present invention. It is a perspective view showing typically a body frame which constitutes vehicles provided with a vehicle frame member concerning an embodiment of the present invention. 1 shows a cross section orthogonal to the axis of the left side frame constituting the vehicle body frame, (A) is a cross-sectional view perpendicular to the axis of the front end portion (A-A line in FIG. 1), and (B) is the central portion (FIG. 1 is a cross-sectional view perpendicular to the axis of line BB in FIG. 1, and FIG. 5C is a cross-sectional view perpendicular to the axis of the rear end portion (line CC in FIG. 1). FIG. 2 is a horizontal sectional view taken along line DD in FIG. 1. (A) is a diagram schematically showing the distribution of moments about the axis in the vehicle width direction acting on the vehicle body frame at the time of a frontal collision, and (B) is a vehicle vertical direction acting on the vehicle body frame at the time of a side collision. It is a figure which shows typically distribution of an axial periphery moment. (A) which shows the side frame of the modification of embodiment of this invention is an axis perpendicular sectional view corresponding to Drawing 3 (A), and (B) is an axis perpendicular sectional view corresponding to Drawing 3 (B). , (C) is a cross-sectional view perpendicular to the axis corresponding to FIG. It is a horizontal sectional view corresponding to Drawing 4 of a side frame of a modification of an embodiment of the present invention.

  A vehicle body skeleton member according to an embodiment of the present invention will be described with reference to FIGS. The front side in the vehicle front-rear direction is indicated by an arrow FR, the outer side in the vehicle width direction is indicated by an arrow OUT, and the upper side in the vehicle vertical direction is indicated by an arrow UP. Further, a member on the left side in the vehicle width direction toward the vehicle front side is denoted by L after the reference numeral, and a member on the right side in the vehicle width direction toward the vehicle front side is denoted by R after the reference numeral. However, when there is no need to distinguish between left and right, L and R are omitted.

<Overall configuration>
First, the overall configuration of the vehicle 10 including the vehicle body skeleton member according to the embodiment of the present invention will be described.

  As shown in FIG. 1 and FIG. 2, the vehicle 10 is a small-sized (lightweight body structure) commuter with one or two persons (in this embodiment, it is assumed to be a single person as an example). The vehicle body frame 100 constituting the vehicle 10 includes side frames 110L and 110R arranged along the vehicle front-rear direction on left and right sides in the vehicle width direction, and side frames 200L and 200R as an example of a vehicle body skeleton member. is doing.

  The side frames 110L and 110R are disposed at the bottom of the vehicle. On the other hand, the side frames 200L and 200R are arranged on the upper side of the side frames 110L and 110R and have a semicircular curved shape. The front end portion 202 of the side frame 200 is joined to the vicinity of the front end portion 112 of the side frame 110, and the rear end portion 204 of the side frame 200 is joined to the rear end portion 114 of the side frame 110. Details of the upper side frame 200 will be described later.

  The lower side frames 110L and 110R and the upper side frames 200L and 200R are joined by center frames 120L and 120R disposed along the vehicle vertical direction at a substantially central portion in the vehicle longitudinal direction.

  A cross frame 130 (see FIG. 2) arranged along the vehicle width direction is joined between the central portions 206L and 206R where the upper portions 122 of the center frame 120 of the upper left and right side frames 200L and 200R are joined. Yes. Further, a cross frame 140 (see FIG. 5) disposed along the vehicle width direction between the central portions 116L and 116R where the lower portions 124L and 124R of the center frames 120L and 120R of the left and right side frames 110L and 110R on the lower side are joined. 2) are joined.

  Further, a cross frame 150 disposed along the vehicle width direction is joined between portions where the rear end portion 114 of the lower side frame 110 and the rear end portion 204 of the side frame 200 are joined. Further, a bumper reinforcement 160 disposed along the vehicle width direction is joined between the front end portions 112L and 112R of the side frames 110L and 110R in the vehicle front-rear direction.

  As shown in FIG. 1, a space surrounded by the vehicle body frame 100 is a driver space 30 for the driver 20 to drive.

  A seat 40 on which the driver 20 sits is provided above the concave portion at the center in the vehicle front-rear direction of the side frame 110 in the driver space 30. In front of the seat 40, devices and mechanisms necessary for driving operation such as a handle 42, an accelerator pedal (not shown), and a brake pedal (not shown) are arranged.

  In the present embodiment, a front panel (not shown) is provided on the front surface of the driver space 30, a roof panel (not shown) is provided on the upper surface of the driver space 30, and a rear panel is further provided on the rear side. (Not shown) are provided. In addition, in order for the driver | operator 20 to visually recognize the front and back, the windshield (not shown) comprised by transparent resin, glass, etc. is provided in a part of front panel and rear panel.

  In the present embodiment, both side surfaces of the driver space 30 are open so that the driver 20 can get on and off from both the left and right sides. In addition, the door for boarding / alighting etc. may be provided in the right-and-left both sides | surfaces of the driver's space 30.

  The vehicle 10 is mounted with a power source (drive source) (for example, an electric motor or an engine), a power transmission mechanism, or the like. A pair of left and right front wheels 16 and a rear wheel 18 are provided in the vicinity of the front end and the vicinity of the rear end, respectively, and are configured to be rotationally driven by the power source and the power transmission mechanism described above.

<Details of side frame structure>
Next, details of the upper side frames 200L and 200R as an example of the vehicle body skeleton member will be described.

  As shown in FIGS. 1 and 2, the side frame 200 is arranged on the upper side of the side frame 110, and the shape in the side view is a shape curved in a substantially semicircular shape protruding upward. More specifically, after the side frame 200 is inclined obliquely upward from the front end portion 202 toward the vehicle rear side, the side frame 200 extends in a substantially horizontal direction (vehicle front-rear direction) in the vicinity of the center portion 206, and then the rear end portion. It inclines diagonally downward toward 204 (vehicle rear side).

  As shown in FIGS. 3 and 4, the side frame 200 is a hollow pipe whose cross section (axial cross section perpendicular to the axis G) is elliptical. The major axis of the ellipse is the strong axis K, and the minor axis of the ellipse is the weak axis J. The length of the ellipse in the major axis direction is defined as a vertical width A1, and the length in the minor axis direction is defined as a lateral width A2.

  Note that the strong axis K is the cross-sectional principal axis that maximizes the cross-sectional secondary moment in the cross-section orthogonal to the axis G (axis-perpendicular cross-section), and the weak axis J is the cross-sectional main axis that minimizes the cross-sectional secondary moment. The In addition, the cross-section main axis is a set of axes having a maximum (strong axis) and minimum (weak axis) cross-sectional secondary moment with respect to the axis among two orthogonal axes passing through the centroid of the cross section.

  As shown in FIG. 3A, in the front end portion 202L of the left side frame 200, the strong axis K is arranged along the vehicle longitudinal direction, and the weak axis J is arranged along the vehicle width direction.

  As shown in FIG. 3B, the side frame 200L is twisted counterclockwise around the axis G as it goes toward the vehicle rear side, and the strong axis K gradually rotates. As shown in FIG. 3C, the strong axis K is arranged along the vehicle width direction and the weak axis J is arranged along the vehicle vertical direction in the center portion 206L in the vehicle longitudinal direction.

  Furthermore, as it goes to the vehicle rear side, it is twisted counterclockwise around the axis G, and at the rear end portion 204L (see FIGS. 1 and 2), the strong axis K is arranged along the vehicle longitudinal direction, and the weak axis J is The arrangement is along the vehicle width direction (the same arrangement as in FIG. 3A).

  Similarly, in the right side frame 200R, the front end portion 202R (see FIG. 2) is arranged such that the strong axis K is arranged along the vehicle longitudinal direction and the weak axis J is arranged along the vehicle width direction. Then, as it goes toward the rear side of the vehicle, it is twisted clockwise around the axis G to gradually rotate the strong axis K (see FIG. 4), and in the central part 206R (see FIG. 2) in the vehicle front-rear direction, the strong axis K is In the rear direction 204R (see FIG. 2), the strong axis K is arranged in the vehicle longitudinal direction and the weak axis J is in the vehicle width direction. It becomes arrangement along. That is, FIG. 3B is the same as FIG. 3 except for left-right symmetry.

  Further, as shown in FIG. 4, the line of sight S and the strong axis K are set so as to coincide or substantially coincide with each other in the vicinity of the height of the eyes (view) 24 of the driver 20.

  As described above, the side frame 200 of the present embodiment has a uniform cross section perpendicular to the axis G (axial right angle cross section), but twists around the axis G toward the vehicle rear side and the strong axis K rotates. The pipe has a twisted structure whose direction changes. Moreover, the side frame 200 having such a twisted structure can be molded by, for example, hydroforming.

<Action and effect>
Next, the operation and effect of this embodiment will be described.

  Here, FIG. 5A schematically illustrates a distribution of moments about an axis in the vehicle width direction that acts on the body frame 100 at the time of a frontal collision of the vehicle 10. FIG. 5B schematically illustrates the distribution of the moment about the axis in the vehicle vertical direction acting on the vehicle body frame 100 when the vehicle 10 undergoes a side collision (in this figure, the collision on the left side of the vehicle). In the figure, the longer the line M, the greater the moment.

  As shown in FIG. 5A, during a frontal collision of the vehicle 10, a load F is input to the bumper reinforcement 160 at the front end of the vehicle. Therefore, a moment about an axis in the vehicle width direction is generated at the front end portion 202 of the side frame 200. Moreover, this moment becomes small as it goes to the vehicle rear side.

  As shown in FIG. 5 (B), during a side collision of the vehicle 10, a load F is input to the center frame 120 on the side of the vehicle. Therefore, a moment about an axis in the vehicle front-rear direction is generated at the central portion 206 of the side frame 200. Moreover, this moment becomes small as it goes to the vehicle front side and the rear side.

  As shown in FIGS. 3 and 4, in the side frame 200 of the vehicle 10 of the present embodiment, the front end portion 202 is disposed with the vehicle longitudinal direction as a strong axis K (see FIG. 3A). Since the strength of the front end portion 202 of the side frame 200 is determined by the moment about the axis in the vehicle width direction, the strength is increased by setting the strong axis K (direction in which the section modulus increases) of the front end portion 202 to the vehicle longitudinal direction. It is secured.

  The side frame 200 is twisted about the axis G as it goes to the rear rear side of the vehicle, and the strong axis K gradually rotates. The vehicle width direction is the strong axis K in the vicinity of the center in the vehicle front-rear direction. Since the strength of the central portion 206 of the side frame 200 is determined by the moment about the axis in the vehicle longitudinal direction, the strength is obtained by setting the strong axis K (direction in which the section modulus increases) of the central portion 206 as the vehicle longitudinal direction. It is secured.

  Although illustration is omitted, at the time of rear-front collision of the vehicle 10, the load F is input to the cross frame 150 at the front end of the vehicle in the rear end portion 204 of the side frame 200 in the same manner as at the time of front collision. A moment about an axis in the vehicle width direction is generated at the rear end portion 204 of the frame 200. Therefore, since the strength of the rear end portion 204 of the side frame 200 is determined by the moment about the axis in the vehicle width direction, the strong axis K (direction in which the section modulus increases) of the rear end portion 204 is defined as the vehicle longitudinal direction. This ensures the strength.

  Thus, the side frame 200 has a uniform cross section perpendicular to the axis G (see FIGS. 3 and 4). However, the side frame 200 is twisted about the axis G toward the rear side of the vehicle and has a twisted structure in which the strong shaft K rotates and changes its direction, so that the mass of the side frame 200 (area and thickness of the cross section perpendicular to the axis). It is possible to ensure the strength corresponding to the directions of different moments at the front end portion 202 and the central portion 206 and further at the rear end portion 204 while suppressing the increase in the pressure.

  Further, as shown in FIG. 4, the line of sight S and the strong axis K are set to coincide with each other or substantially coincide with each other in the vicinity of the height of the eyes (view) 24 of the driver 20 (see also FIG. 3). Therefore, for example, as compared with the case where the line of sight S and the strong axis K do not coincide or substantially coincide with each other, the area that blocks the field of view of the driver 20 becomes narrower.

<Modification>
Next, a modification of the side frame of the present embodiment will be described with reference to FIGS. In the modification, the upper side frames 200L and 200R (see FIG. 2) in the above embodiment are the side frames 300L and 300R. Further, as will be described later, the modified side frames 300L and 300R differ from the side frames 200L and 200R only in cross-sectional shape, and the overall shape and the like in a side view are the same as those of the side frames 200L and 200R. Yes.

  The side frames 300L and 300R as an example of the vehicle body skeleton member are hollow pipes having a substantially trapezoidal cross section perpendicular to the axis G (a cross section perpendicular to the axis). Further, the vertical width A1 which is the height of the trapezoid is longer than the horizontal width A2 of the trapezoid (substantially coincides with the lower base 303). Therefore, the strong axis K coincides with the height direction of the trapezoid, and the weak axis J coincides with the direction along the lower base 303 and the upper base 305.

  As shown in FIG. 6A, in the front end portion 302L of the left side frame 300L, the lower bottom 303L side faces the vehicle front side, the strong axis K is the vehicle front-rear direction, and the weak axis J is the vehicle width direction. Yes. As shown in FIG. 6B, the side frame 300L is twisted counterclockwise around the axis G as it goes toward the vehicle rear side, and the strong axis K gradually rotates.

  As shown in FIG. 6C, in the center portion 306L in the vehicle front-rear direction, the lower bottom 303L side faces the left outer side in the vehicle width direction, the strong axis K is the vehicle width direction, and the weak axis J is the vehicle vertical direction. Further, as it goes toward the vehicle rear side, it is twisted counterclockwise around the axis G, and at the rear end, the lower bottom 303 side faces the vehicle rear side, the strong axis K becomes the vehicle front-rear direction, and the weak axis J becomes the vehicle width direction. (Arrangement in the upside down direction with FIG. 6A).

  Similarly, in the right side frame 300R (see FIG. 7), at the front end, the lower bottom 303 side faces the vehicle front side, the strong axis K is the vehicle front-rear direction, and the weak axis J is the vehicle width direction. Then, as it goes toward the rear side of the vehicle, it is twisted clockwise around the axis G, and the strong shaft K gradually rotates (see FIG. 4), and the lower bottom 303 side is directed outwardly in the vehicle width direction at the center in the vehicle front-rear direction. The strong axis K is the vehicle width direction and the weak axis J is the vehicle vertical direction (FIG. 6B is the same as FIG. 6 except for left-right symmetry). Further, as it goes toward the vehicle rear side, it is twisted clockwise around the axis G, and at the rear end, the lower bottom 303 side faces the vehicle rear side, the strong axis K becomes the vehicle front-rear direction, and the weak axis J becomes the vehicle width direction.

  Further, as shown in FIG. 7, the line of sight S and the strong axis K are set so as to coincide or substantially coincide with each other in the vicinity of the height of the eye (view) 24 of the driver 20. Further, the lower base 303 side of the trapezoid is arranged outward (a side far from the driver 20).

  As described above, the side frame 300 has a uniform cross section perpendicular to the axis G. However, the side frame 300 is twisted around the axis G toward the rear side of the vehicle, and the strong axis K rotates to change the direction. It is a pipe of structure. Similarly, the side frame 300 having such a twisted structure can be formed by hydroforming or the like.

<Action and effect>
Next, operations and effects of the modified side frame 300 will be described.

  The side frame 300 has a uniform cross section (cross section perpendicular to the axis) perpendicular to the axis G (see FIGS. 6 and 7). However, the side frame 300 has a torsional structure in which the strong axis K rotates and the direction changes as the vehicle moves toward the rear of the vehicle, so that the mass of the side frame 300 (area and thickness of the cross section perpendicular to the axis) is increased. While suppressing the increase, it is possible to secure the strength corresponding to the directions of moments different at the front end portion 302 and the central portion 306 and further at the rear end portion.

  Further, as shown in FIG. 7, the line of sight S and the strong axis K are set so as to coincide or substantially coincide with each other in the vicinity of the height of the eyes (view) 24 of the driver 20 (see also FIG. 3). At this time, the width of the upper base 305 is set so that the maximum width that blocks the field of view of the driver 20 is the horizontal width A2 (lower base 303). Thus, when the width A2 in the weak axis J direction that blocks the line of sight is located at a position far from the driver 20, for example, the view of the driver 20 is blocked as compared with the configuration in which the lower bottom 303 is on the near side. The area becomes narrower.

<Others>
The present invention is not limited to the above embodiment.

  For example, in the above embodiment and the modification, the side frame as an example of the vehicle body skeleton member is a hollow pipe having a substantially elliptical or substantially trapezoidal cross section at right angles to the axis, but is not limited thereto. A solid rod-like frame may be used. Further, the cross section perpendicular to the axis may be a substantially rectangular shape or a substantially triangular shape. Alternatively, it may have a cross-sectional H shape or a cross-sectional C shape. In short, any body frame member having a uniform cross section in which the cross section perpendicular to the axis has a strong axis and a weak axis may be used.

  Further, for example, in the above embodiment and the modification, the left and right side frames are connected via the cross frame, but the present invention is not limited to this. For example, the rear end or front end of the side frame may be throttled inward in the vehicle width direction, and the ends may be joined together.

  Further, for example, in the above-described embodiment and the modification, the vehicle 10 is a small commuter with one person or two persons (in this embodiment, one person), but is not limited thereto. The present invention can also be applied to personal mobility, microcars (minicars), passenger carts for golf, bicycles with motors with roofs, light vehicles, and the like.

  Furthermore, it cannot be overemphasized that it can implement with a various aspect in the range which does not deviate from the summary of this invention.

10 vehicle 100 body frame 200L side frame (body frame member)
200R Side frame (body skeleton member)
202L front end portion 202R front end portion 204L rear end portion 204R rear end portion 206L center portion 206R center portion 300L side frame (vehicle body frame member)
300R side frame (body frame)
302L front end 306L center
G axis
K strong axis
J Weak axis

Claims (4)

  It is arranged along the vehicle front-rear direction and curved so as to protrude upward as it goes from the front end part in the vehicle front-rear direction to the center part, and the strong axis of the cross-sectional main axis is along the vehicle front-rear direction at the front end part A vehicle body structure in which the vehicle body skeleton members arranged at the center portion along the vehicle width direction are arranged on both side portions of the vehicle.   2. The vehicle body structure according to claim 1, wherein the vehicle body skeleton member is configured to be twisted around an axial center from the front end portion toward the central portion.   3. The vehicle body structure according to claim 1, wherein the vehicle body skeleton member is configured such that the line of sight and the strong axis coincide with each other or substantially coincide with each other in a vicinity of a height of a driver's field of view.   The vehicle body structure according to any one of claims 1 to 3, wherein the vehicle body skeleton member has a uniform cross section from the front end portion to the central portion.

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