JP4259473B2 - Body structure - Google Patents

Description

  The present invention relates to a vehicle body structure represented by, for example, a structure for fixing a dash cross member and a front pillar of an automobile.

  As a shock absorbing structure at the time of a collision, an automobile has a crushable zone in the front part of the side member extending in the front-rear direction. The crashable zone collapses when an impact is input during a collision. As described above, the crushable zone is crushed to absorb an impact at the time of a vehicle collision.

  However, there is an increase in cabin as a demand for automobiles. Therefore, automobiles have been made deck forward. As a result, in the automobile, the front part of the side member tends to be shorter than the cabin. That is, the crushable zone tends to be shorter.

  It is conceivable that the impact at the time of collision is transmitted to the cabin without being sufficiently absorbed due to the shortened crashable zone.

  For this reason, a vehicle body front structure has been proposed in which the impact caused by the collision is released to the side wall of the vehicle body so that the impact due to the collision is absorbed by the side wall of the vehicle in addition to the side member (see, for example, Patent Document 1). .)

  This type of vehicle body front structure includes a dash cross member that is connected to a side member and a front pillar as a side wall of the vehicle body.

  The dash cross member includes an intermediate portion that is passed between a pair of side members that are arranged in the vehicle width direction, and left and right end portions that are bent upward from the end portion of the intermediate portion. The intermediate portion is constructed between the side members via a welding bracket. The left and right end portions are fixed by welding to the corresponding front pillars. The dash cross member is formed in the shape described above by bending one pipe member.

The dash cross member is arranged as described above, and transmits an impact applied to the side member to the front pillar.
JP 2004-74868 A

  In the case of the automobile body structure disclosed in Patent Document 1, as a vehicle body assembly procedure, first, a dash cross member is installed between both side members. Next, the side wall portion of the vehicle body represented by the front pillar is attached. At this time, in the front pillar, portions to be fixed to the left and right end portions of the dash cross member in the front pillar are fixed to the left and right end portions of the dash cross member.

  On the other hand, the dash cross member is formed by bending one pipe material. When the pipe material is bent, it tends to return to its original shape by elasticity. Therefore, the shape of the dash cross member is deformed by the elasticity of the pipe material after being bent into the designed shape.

  Thus, the position of the front pillar fixed to the left and right ends of the dash cross member is also designed by deforming the dash cross member into a shape different from the shape designed for the elasticity of the pipe material. There is a tendency to deviate from the arrangement. A deviation in the arrangement of the front pillars is not preferable because it causes a deviation in the vehicle width.

  Accordingly, an object of the present invention is to provide a vehicle body structure capable of preventing a vehicle width shift while maintaining an impact absorbing structure.

  The vehicle body structure of the present invention includes a side member, a vehicle body side wall, a dash cross member, and a bracket. The side member extends in the longitudinal direction of the vehicle body. The dash cross member has a base fixed to the side member, and an end connected to the base and fixed to the side wall of the vehicle body. The bracket is provided at the end of the dash cross member. The bracket fixes the dash cross member to the side wall of the vehicle body. The end of the dash cross member is formed by bending a member forming the dash cross member. The bracket has a return margin on the side opposite to the direction in which the member forming the dash cross member is bent with respect to the end of the dash cross member.

  In the vehicle body structure configured as described above, the dash cross member is fixed to the side member and the vehicle body side wall. Therefore, the impact applied to the vehicle body in the front-rear direction is absorbed by the side member and also transmitted to the side wall of the vehicle body through the dash cross member. Therefore, the shock absorbing structure of the vehicle body is maintained.

  The bracket has a return allowance. Therefore, the error in the position of the end of the dash cross member caused by the member that forms the dash cross member being bent and then returning in the opposite direction to the direction bent by elasticity is absorbed by the return allowance. Is done.

  That is, even if an error occurs in the shape of the dash cross member, only the fixing position of the bracket and the end changes, and the position of the bracket with respect to the base does not change.

In addition , the bracket has an accommodating portion that accommodates a portion to be fixed to the bracket at the end of the dash cross member. The return allowance is provided in the accommodating portion.

The bracket has an opening toward the vehicle body side wall. The bracket is fixed by contacting the opening with the side wall of the vehicle body.

  In the vehicle body structure of the present invention, even if an error occurs in the shape of the dash cross member, the position of the bracket relative to the base does not change. Therefore, even if the dash cross member is fixed to the side member and then the vehicle body side wall is fixed to the bracket, the position of the vehicle body side wall does not change due to an error in the shape of the dash cross member. That is, the deviation of the vehicle width is suppressed.

  As described above, in the vehicle body structure of the present invention, the shift of the vehicle width is suppressed while maintaining the shock absorbing structure.

  A vehicle body structure according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a front portion of a frame 11 of a vehicle body 10 of an automobile. The front structure of the frame 11 of the vehicle body 10 includes a pair of side members 20, a skeleton member 100 as a vehicle body side wall, a dash cross member 40, and a pair of brackets 50.

  The side members 20 are separated from each other in the vehicle width direction A and extend in the front-rear direction of the vehicle body 10. Each side member 20 is bent obliquely rearward and downward from the front side portion 21 to the rear side. Each side member 20 is bent so as to extend from the front side portion 21 obliquely rearward and downward to a predetermined length and then to extend substantially horizontally again.

  The skeleton member 100 includes a pair of front pillars 30. One front pillar 30 is disposed outside the one side member 20 in the vehicle width direction. The other front pillar is disposed outside the other side member 20 in the vehicle width direction. Each front pillar 30 includes an inner panel 31 and an outer panel 32 (indicated by a two-dot chain line in the figure). The inner panel 31 is disposed on the inner side in the vehicle width direction with respect to the outer panel 32.

  The dash cross member 40 is constructed on one side member 20 and the other side member 20. The dash cross member 40 includes an intermediate portion 41 as a base portion, and an end portion 42 formed from both ends of the intermediate portion 41 toward the outer side in the vehicle width direction. The intermediate part 41 and each end part 42 are connected continuously.

  The intermediate portion 41 has a substantially bar shape extending in the vehicle width direction A from one side member 20 to the other side member 20. The intermediate portion 41 is fixed on the one side member 20 and the other side member 20 by the bracket 12.

  One end portion 42 is bent at a predetermined angle from one end of the intermediate portion 41 toward obliquely rearward. One end portion 42 extends obliquely rearward for a predetermined length, and then bends by a predetermined angle toward the inner side in the vehicle width direction through the rear at the bent portion 41b.

  The other end portion 42 is bent at a predetermined angle from the other end of the intermediate portion 41 toward obliquely rearward. The other end 42 extends a predetermined length obliquely rearward, and then bends by a predetermined angle inward in the vehicle width direction through the rear at the bent portion 41d.

  FIG. 2 shows the dash cross member 40 as viewed from above. As shown in FIG. 2, the dash cross member 40 has a substantially trapezoidal shape when viewed from above. That is, each end portion 42 has a shape that intersects the intermediate portion 41 that is the base portion.

  The dash cross member 40 is formed by bending a single rod-shaped pipe member 43 so as to have the above shape. The pipe material 43 is an example of a member that forms the dash cross member 40. However, the member forming the dash cross member 40 is not limited to the pipe material 43.

  A direction A1 of bending of the pipe member 43 indicated by a two-dot chain line in FIG. 2 is a direction toward the inside of the vehicle body through the rear with respect to the intermediate portion 41 when the dash cross member 40 is fixed to the side member 20. It becomes.

  In the present embodiment, the one end portion 42 and the other end portion 42 have, for example, a substantially symmetric shape in the vehicle width direction A.

  As shown in FIG. 1, one bracket 50 is fixed to one end 42 of the dash cross member 40. The other bracket 50 is fixed to the other end 42 of the dash cross member 40.

  FIG. 3 shows an enlarged range surrounded by F3 in FIG. Note that the bracket 50 provided at one end 42 and the bracket 50 provided at the other end 42 may be symmetrical to each other in the vehicle width direction. Therefore, the bracket 50 will be described as a representative of the bracket 50 provided at one end portion 42.

  As shown in FIG. 3, the bracket 50 includes an upper wall 51, a lower wall 52, and a side wall 53. The upper wall 51 and the lower wall 52 are substantially parallel to each other. The side wall 53 is connected to the inner end in the vehicle width direction of the upper wall 51 and the inner end in the vehicle width direction of the lower wall 52.

  On the inner panel 31 side of the bracket 50, an opening 54 is defined by the outer end in the vehicle width direction of the upper wall 51 and the lower wall 52. Therefore, the cross section of the bracket 50 has a substantially concave shape that opens toward the inner panel 31.

  Of the one end portion 42, for example, a distal end portion 44 positioned at the distal end relative to the bent portion 41 b (the bent portion 41 d in the other end portion 42) is accommodated in the internal space B of the bracket 50. The tip portion 44 is an example of a fixing portion referred to in the present invention. The internal space B is defined by the inner surface 51a of the upper wall 51, the inner surface 52a of the lower wall 52, and the inner surface 53a of the side wall 53, and is an example of an accommodation portion referred to in the present invention.

  FIG. 4 shows a cross section of the bracket 50 and the dash cross member 40 along the vehicle width direction A. As shown in FIG. 4, the height of the internal space B of the bracket 50, that is, the length from the inner surface 52 a of the lower wall 52 to the inner surface 51 a of the upper wall 51 is substantially the same as the outer diameter of the pipe material 43. Yes. The internal space B of the bracket 50 has a predetermined interval L1 in the vehicle width direction A. The size in the width direction including the predetermined interval L1 will be described in detail later.

  As shown in FIG. 3, a long hole 55 is formed in the upper wall 51 of the bracket 50. The long hole 55 extends substantially along the direction in which the distal end portion 44 extends, for example. As shown in FIG. 4, the long hole 55 penetrates the upper wall 51 in the vertical direction. The long hole 55 has a predetermined interval L2 in the vehicle width direction A. The interval L2 of the width along the vehicle width direction A of the long hole 55 will be described later in detail.

  The bracket 50 is fixed to the dash cross member 40 by welding the peripheral edge 55 a of the elongated hole 55 to the tip end portion 44 of one end portion 42 of the dash cross member 40.

  As shown in FIG. 3, the opening 54 of the bracket 50 is abutted against the front surface 34 of the convex portion 33 of the inner panel 31 and the surfaces 35 and 36 connected to the front surface 34. As shown in FIG. 1, the convex portion 33 of the inner panel 31 protrudes inward in the vehicle width direction. The front surface 34 is a surface facing the front of the vehicle body 10 in the convex portion 33. A surface 35 connected to the front surface 34 is disposed in front of the front surface 34. The surface 36 connected to the front surface 34 is disposed behind the front surface 34.

  Therefore, the edge of the opening 54 of the bracket 50 is formed along the front surface 34 and the surfaces 35 and 36 connected to the front surface 34.

  A flange 56 is formed along the convex portion 33 at the edge of the opening 54. The bracket 50 is fixed to the front pillar 30 by welding the flange 56 to the convex portion 33.

  On the other hand, as described above, the dash cross member 40 is formed from a single pipe member 43. Both end portions 42 are formed by bending the pipe material 43. Therefore, after the pipe member 43 is bent, it slightly returns to the opposite side to the bent direction due to elasticity. This phenomenon is called springback.

  The springback generated in the dash cross member 40 will be specifically described. FIG. 5 shows the relationship between the dash cross member 40 before the spring back occurs and the dash cross member 40 after the spring back occurs, and is a plan view of the relationship seen from above.

  In FIG. 5, the solid line indicates the actual shape of the dash cross member 40. In FIG. 5, a two-dot chain line indicates a shape in which the dash cross member 40 is to be formed. In the dash cross member 40, the pipe member 43 is once bent along the direction A1 into a shape to be formed (indicated by a two-dot chain line), and then a springback is generated, and an actual shape (indicated by a solid line) Become).

  As shown by a solid line in FIG. 5, both end portions 42 of the dash cross member 40 are slightly expanded from a shape to be formed (shown by a two-dot chain line). That is, the distance L3 between the one end 42 and the other end 42 in the shape of the dash cross member 40 to be formed is equal to the one end 42 and the other end in the actual shape of the dash cross member 40. It becomes smaller than the space | interval L4 between the parts 42.

  A direction A2 indicated by an arrow in FIG. 5 is a direction in which the pipe member 43 attempts to return to the original shape by the spring back. The direction A2 is opposite to the direction A1.

  Further, in FIG. 5, an error between the shape to be formed of the dash cross member 40 indicated by the two-dot chain line and the actual shape of the dash cross member 40 indicated by the solid line is exaggerated.

  Actually, the dash cross member 40 is formed in anticipation of the spring back described above. However, some errors occur depending on the pipe material 43. The shape including this error is the actual shape of the dash cross member 40. Therefore, the error between the actual shape of the dash cross member 40 and the shape to be formed is small.

  Here, the width L2 along the vehicle width direction A of the long hole 55 of the bracket 50 and the size in the width direction including the width L1 along the vehicle width direction A of the internal space B are specifically described. explain.

  A tip 44 shown by a solid line in FIG. 4 indicates the position of the tip 44 of the actually formed dash cross member 40 in the internal space B. 4 is a state before the springback occurs in the dash cross member 40, that is, in the inner space B of the front end portion 44 when the dash cross member 40 is in a shape to be formed. The position at is shown.

  In FIG. 4, the relative positional relationship between each bracket 50 and the intermediate portion 41 is a predetermined relative positional relationship set based on the design value of the vehicle width. Similarly, the postures of the brackets 50 and the intermediate portion 41 are also predetermined predetermined postures.

  As shown in FIG. 4, the relative distance relationship between the brackets 50 and the intermediate portion 41 of the dash cross member 40 is set to a predetermined relative positional relationship in the interval L2 of the width along the vehicle width direction A of the long hole 55. The top of the actual tip 44 (indicated by the solid line) and the length of the top of the tip 44 in the shape to be formed (indicated by the two-dot chain line). .

  The interval L1 of the internal space B is such that when the relative positional relationship between each bracket 50 and the intermediate portion 41 is a predetermined relative positional relationship, the end portion 42 when it is in the shape to be formed, It has a length that can accommodate the end portion 42 of the shape.

  That is, the internal space B has a size capable of absorbing an error between the end portion 42 when it is in the shape to be formed and the end portion 42 of the actual shape.

  In the internal space B, the space on the side A3 opposite to the direction A1 with respect to the front end portion 44 before the springback occurs is a return allowance B1.

  Therefore, the position of the bracket 50 does not depend on the shape of each end portion 42 of the dash cross member 40. That is, even if a springback occurs in each end portion 42, the position and posture of each bracket 50 with respect to the intermediate portion 41 are maintained at a predetermined position and posture.

  Also, the degree of springback is fully expected. Therefore, as shown in FIG. 5, the error between the distance L3 between the two end portions 42 before the spring back occurs and the distance L4 between the end portions 42 after the spring back occurs is sufficiently predicted. Occur within the range Therefore, the interval L2 of the width of the long hole 55 and the interval L1 of the width of the internal space B in the vehicle width direction A are sufficiently predicted.

  Next, an example of the procedure for assembling the vehicle body 10 will be described. 6 and 7 show a part of the assembly procedure of the vehicle body 10.

  First, the dash cross member 40 is formed. The dash cross member 40 is formed from a pipe material 43. As shown in FIG. 2, each end portion 42 of the dash cross member 40 is formed by bending the pipe member 43 along the bending direction A1 at both ends of the intermediate portion 41 and the bent portions 41b and 41d. The

  Next, the bracket 50 is fixed to each end portion 42 of the dash cross member 40. As shown in FIG. 6, each bracket 50 is fixed to the corresponding end portion 42 using, for example, a jig 60.

  The jig 60 includes a base 61, a dash cross member fixing portion 62, and a pair of bracket fixing portions 63. The dash cross member fixing portion 62 fixes the intermediate portion 41 of the dash cross member 40. One bracket 50 is fixed to one bracket fixing portion 63. The other bracket 50 is fixed to the other bracket fixing portion 63.

  The dash cross member fixing portion 62 and each bracket fixing portion 63 are fixed to the base 61. The arrangement relationship between the dash cross member fixing portion 62 and each bracket fixing portion 63 on the base 61 and the posture of the bracket 50 at the portion 63a where the bracket 50 is fixed in the bracket fixing portion 63 are as follows. When the intermediate portion 41 is fixed to the bracket, the relative positional relationship and posture between the intermediate portion 41 and each bracket 50 are set to be the predetermined relative positional relationship and the predetermined posture.

  First, one bracket 50 is fixed in a predetermined posture at a portion 63a to which the bracket 50 is to be fixed in one bracket fixing portion 63. Similarly, the other bracket 50 is fixed to the other bracket fixing portion 63.

  Next, the intermediate portion 41 is fixed to the dash cross member fixing portion 62. Each end 42 is accommodated in the internal space B of the corresponding bracket 50. And as shown in FIG. 4, the front-end | tip part 44 and the bracket 50 are mutually fixed by welding each other.

  At this time, even if a springback occurs in the dash cross member 40, the position of each end portion 42 only changes in the internal space B of the bracket 50.

  Therefore, even if a springback occurs in the dash cross member 40, the relative positional relationship and posture between the intermediate portion 41 and each bracket 50 are maintained in the predetermined relative positional relationship and the predetermined posture described above. When each bracket 50 is fixed to the dash cross member 40, the dash cross member 40 is removed from the jig 60.

  Next, as shown in FIG. 7, the side members 20 are arranged. Next, an intermediate portion 41 of the dash cross member 40 is installed between the one side member 20 and the other side member 20 along the vehicle width direction A. The intermediate portion 41 is fixed to the upper portion of the side member 20 via the bracket 12.

  Next, the inner panel 31 of each front pillar 30 is assembled to the corresponding bracket 50 from the outside in the vehicle width direction toward the inside.

  At this time, the relative positional relationship and posture between each bracket 50 and the intermediate portion 41 are set to a predetermined relative positional relationship and a predetermined posture. Therefore, the distance between the front pillar 30 fixed to one bracket 50 and the inner panel 31 fixed to the other bracket 50 corresponds to the design value of the vehicle width of the vehicle body 10.

  When each inner panel 31 is assembled to the corresponding bracket 50, the flange 56 of the bracket 50 is welded to the convex portion 33 of the inner panel 31. Therefore, the dash cross member 40 is fixed to the front pillar 30.

  By arranging the dash cross member 40 as described above, even when an impact is input from the front of the vehicle body 10 such as when an automobile collides, the impact is absorbed by the side member 20 and the dash cross member. 40 is also transmitted to the front pillar 30. Therefore, the impact is absorbed by the front pillar 30 in addition to the side member 20.

  In the vehicle body structure configured in this way, the width interval L1 of the internal space B of the bracket 50 in the vehicle width direction A includes the return allowance B1, so that the length of the springback of the dash cross member 40 is absorbed. Have.

  Therefore, even if a springback occurs in the dash cross member 40, the relative positional relationship and posture between the intermediate portion 41 of the dash cross member 40 and each bracket 50 can always be maintained at the predetermined relative positional relationship and the predetermined posture. it can. As a result, the vehicle width of the vehicle body 10 is maintained at the design value without being influenced by the springback of the dash cross member 40.

  The bracket 50 has an internal space B. The tip end portion 44 of the dash cross member 40 is accommodated in the internal space B. Therefore, the distal end portion 44 is supported in the internal space B when the distal end portion 44 and the bracket 50 are fixed. That is, since the internal space B has a support function for supporting the distal end portion 44, the distal end portion 44 is stably fixed to the bracket 50. Furthermore, it is not necessary to prepare a separate support means.

  Further, the bracket 50 has an opening 54 toward the front pillar 30 and has a substantially concave cross section. Therefore, each bracket 50 is easily formed. Further, the opening 54 of the bracket 50 is closed by the convex portion 33 of the inner panel 31. That is, the bracket 50 uses the convex portion 33 to make the internal space B a closed space. Therefore, the bracket 50 does not require a member to cover the opening 54. For this reason, since the material which forms the bracket 50 is reduced, the cost of the bracket 50 is reduced.

  Next, a vehicle body structure according to a second embodiment of the present invention will be described with reference to FIG. In addition, the structure which has a function similar to 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits description. In the present embodiment, the fixing structure between the bracket 50 and the tip end portion 44 of the dash cross member 40 is different from that of the first embodiment.

  This point will be specifically described. FIG. 8 shows a fixing structure between one bracket 50 and one tip portion 44 of the dash cross member 40. The fixing structure between the other bracket 50 and the other tip 44 may be the same. Therefore, a fixing structure between one bracket 50 and one tip 44 will be described as a representative.

  As shown in FIG. 8, a first through hole 71 through which the bolt 70 penetrates in the vertical direction is formed at the distal end portion 44 of the dash cross member 40. The diameter of the first through hole 71 is substantially the same as the outer diameter of the bolt 70. And the 2nd through-hole 72 penetrated in the up-down direction is formed in the upper wall 51 and the lower wall 52 of the bracket 50. As shown in FIG.

  The bracket 50 and the distal end portion 44 are fixed by bolts 70 and nuts 73. The bolt 70 penetrates the second through hole 72 and the first through hole 71 from above the upper wall 51, for example. A washer 75 is interposed between the bolt 70 and the upper wall 51. The bolt 70 is screwed with the nut 73 below the lower wall 52. A washer 75 is interposed between the nut 73 and the lower wall 52.

  By tightening the bolt 70, the distal end portion 44 is firmly sandwiched between the upper wall 51 and the lower wall 52. Therefore, the distal end portion 44 is fixed to the bracket 50.

  Note that the second through-hole 72 is inserted into the first through-hole 71 even if the second through-hole 72 is in a state before the springback occurs in the dash cross member 40 as indicated by a two-dot chain line in FIG. As shown, the vehicle width direction A is widened.

  Even in the fixing structure using the bolt 70 and the nut 73 as in the present embodiment, the same effect as in the first embodiment can be obtained.

  In the first and second embodiments, the shape of each end portion 42 of the dash cross member 40 is substantially the same. Therefore, the shape of each bracket 50 is also symmetric in the vehicle width direction A. However, it is not limited to this.

  For example, the end portions 42 may be formed different from each other. And each bracket 50 may be formed so as to be different from each other corresponding to the corresponding end portion 42.

  In short, each bracket 50 only needs to have a return allowance for absorbing the springback of the dash cross member 40.

  The dash cross member 40 may be formed by bending the pipe member 43 three-dimensionally. Even in this case, the bracket 50 only needs to have a return margin on the side opposite to the direction in which the pipe material 43 is bent at the bending point where the pipe material 43 is bent.

  Further, the assembly procedure of the vehicle body 10 is not limited to using the jig 60 as described above. For example, the bracket 50 may be fixed to the dash cross member 40 by measuring the position of the bracket 50 with respect to the intermediate portion 41 without using the jig 60.

The perspective view which shows the vehicle body structure which concerns on the 1st Embodiment of this invention. The top view which looked at the dash cross member shown by FIG. 1 from upper direction. The perspective view which expands and shows F3 shown by FIG. Sectional drawing which follows the vehicle width direction of the bracket and dash cross member which were shown by FIG. The top view which shows the relationship between the shape in which a dash cross member should be formed, and the actual shape of a dash cross member. The perspective view which shows the state which fixes a bracket to the dash cross member shown by FIG. 1 using a jig. The perspective view which shows the state which fixes an inner panel to the dash cross member fixed to the side member. Sectional drawing which shows the fixation structure of the bracket and dash cross member based on the 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Vehicle body, 20 ... Side member, 30 ... Front pillar (vehicle body side wall), 40 ... Dash cross member, 41 ... Middle part (base part) 42 ... End part, 43 ... Pipe material (member which forms a dash cross member), 44 ... tip part (part to be fixed to the bracket at the end part), 50 ... bracket, 54 ... opening, A1 ... direction (direction in which the dash cross member is bent), A3 ... opposite side, B ... internal space (accommodating) Part), B1 ... return allowance.

Claims (1)

A side member extending in the longitudinal direction of the vehicle body,
A vehicle body side wall,
A dash cross member having a base fixed to the side member, and an end continuous to the base and fixed to the vehicle body side wall;
A bracket provided at the end and fixing the dash cross member to the vehicle body side wall;
Comprising
The end is formed by bending a member forming the dash cross member,
Said bracket, said the previous SL direction member is folded to form the dash cross member with respect to end have a margin back to the opposite side, to accommodate the site to be secured to the bracket at the end Having an accommodating portion, having an opening toward the vehicle body side wall and being fixed in contact with the vehicle body side wall,
The vehicle body structure is characterized in that the return allowance is provided in the housing portion .

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