JP4413650B2 - Bonding structure for automotive frame materials - Google Patents

Description

  The present invention relates to an automobile frame material coupling structure that absorbs impact energy at the time of collision by compressive deformation.

2. Description of the Related Art Conventionally, a body frame of an automobile is known in which impact energy at the time of collision is absorbed by axial compression deformation of a front side frame provided at a front portion of the body. As such an impact-absorbing frame material, the same applicant as the present application uses an aluminum alloy extrusion to form a plurality of cross-sectional outlines perpendicular to the extrusion direction that form a substantially regular polygonal shape corresponding to the sides of the polygon. Has already proposed a polygonal frame material having a plurality of inner plate portions extending radially from a central portion toward a plurality of apex portions corresponding to the apexes of the polygon ( (See Patent Documents 1, 2, and 3.)
Japanese Patent Laid-Open No. 11-208519 JP 2003-72587 A Japanese Patent Laid-Open No. 2003-72588

  However, in the case of the polygon frame material as described above, it is possible to adopt a configuration in which the frame material is coupled in a plug-in manner with a seal fitting when coupled with other frame components. In such a configuration, the polygon frame material is coupled. Since the polygonal frame material is constrained by the frame component material in the region where it mates with the other frame component material, the buckling deformation in the out-of-plane direction of the polygonal frame material is prevented. As a result, the inconvenience of not functioning occurs. On the other hand, in order to suppress the influence on the energy absorption stroke due to the fitting with other frame components, a configuration in which the fitting dimension is shortened is also conceivable. However, in this case, the horizontal direction is different from the axial direction of the polygon frame material. As a result, the strength of the frame member is reduced with respect to the external force, so that inconveniences are imposed on the design items such as the cross-sectional dimension and length of the frame material in order to achieve the required strength.

  The present invention has been devised on the basis of such inventor's knowledge, and the main purpose thereof is a polygonal frame material that absorbs shock at the time of collision by plastic deformation in the axial direction. Provided is an automotive frame material coupling structure configured such that a region fitted with a frame component of a coupling partner can function as an effective energy absorbing stroke without causing a decrease in strength against different lateral external forces. There is.

In order to solve such a problem, in the present invention, the outer contour of the cross section has a substantially regular polygonal shape, and a plurality of outer plate portions (21) corresponding to the sides of the polygon, and the apex of the polygon. A polygonal frame member (2) having a plurality of inner plate portions (24) radially extending from the central portion (23) toward a plurality of corresponding apex angle portions (22), and a coupling partner thereof In the joining structure of an automobile frame material that joins another frame constituent material (3, 4), the frame constituent material that is the joining partner is a cylindrical fitting portion (33 · 41) has a projecting portion (34, 44) projecting radially inward from the inner surface thereof and coming into contact with the apex portion of the polygonal frame material from the radially outer side, Allow the outer plate portion to deform radially outward during compression deformation Approximately between (A · B) is, as defined between the inner surface and the outer plate portion of the fitting portion, the projecting portion of the frame structure material, an abutment surface for said polygonal frame member A concave portion (25) that is formed in an arcuate cross section and that is concave inward in the radial direction is formed in the apex portion of the polygonal frame member, and the protrusion is brought into contact with the concave portion to thereby form the protrusion. The part was held at a position aligned with the inner plate part . In particular, the frame component is a bumper extension (3) connected to the bumper beam (1), and the fitting is performed on the bumper extension in a manner protruding forward from a main body (32) connected to the bumper beam. A portion (33) may be formed, and the front end portion of the polygonal frame material may be fitted into the fitting portion. The frame component is a bracket (4) attached to the front end of the side frame (5), and the fitting is performed on the bracket in a manner protruding rearward from a flange portion (42) connected to the side frame. A joining portion (41) is formed, and the rear end portion of the polygonal frame material is preferably fitted into the fitting portion.

  According to this, since the polygonal frame material can be smoothly buckled and deformed in the region where the polygonal frame material is inserted into the fitting portion of the frame component material to be joined, the polygonal frame material fitting region is effective. It can be made to function as an energy absorption stroke, thereby ensuring a large energy absorption stroke and increasing the amount of energy absorption. In addition, for lateral force different from the axial direction of the polygonal frame material, the stress generated in the surface direction of the inner plate part acts on the protruding portion at a position aligned with the inner plate portion, so that it has a large proof stress. Can be ensured, and deformation of the polygonal frame material due to lateral external force can be suppressed.

In this case, the fitting portion is provided with a restricting portion with which an end face in the axial direction of the polygonal frame material is abutted at one end, and the polygonal frame material is welded to the restricting portion with the axial end portion of the outer plate portion. It is good to set it as the structure fixed with respect to the frame structural material which joins and becomes a connection partner. According to this, since the outer plate portion has a relatively high degree of freedom of deformation, the burden of the collision load is small, so by welding here, it is possible to suppress a decrease in load resistance due to the heat affected zone of welding. .

  Thus, according to the present invention, since the polygonal frame material smoothly buckles and deforms even in the fitting region inserted into the fitting part of the frame constituent material to be joined, the fitting region has effective energy. It functions as an absorption stroke, and has a great effect in securing a large energy absorption stroke and increasing the amount of energy absorption.

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

  FIG. 1 is a perspective view showing a bumper beam assembly to which the present invention is applied. FIG. 2 is a top view of the bumper beam assembly shown in FIG. In this bumper beam assembly, a bumper beam 1 provided along the front bumper face at the front of the vehicle body is supported on both the left and right sides by a polygonal frame 2 that absorbs impact energy at the time of collision by crushing deformation in the axial direction. The front end of the polygon frame 2 is coupled to the bumper beam 1 via the left and right bumper extensions 3, and the rear end of the polygon frame 2 is coupled to the side frame 5 via the bracket 4.

  The polygon frame 2 and the bumper beam 1 are extruded by an aluminum alloy, and the bumper extension 3 and the bracket 4 are cast by an aluminum alloy. The polygon frame 2 is integrated with the bumper extension 3 and the bracket 4 by welding, and the bumper extension 3 is integrated with the bumper beam 1 by bolt fastening.

  The bumper beam assembly including the bumper beam 1, the polygonal frame 2, the bumper extension 3, and the bracket 4 is attached to the side frame 5 by fastening the bracket 4 to the side frame 5 with bolts 7.

  FIG. 3 is a perspective view showing the polygonal frame and the bumper extension shown in FIG. FIG. 4 is a cross-sectional view of the polygon frame and the bumper extension shown in FIG. 1 cut along a plane orthogonal to the axis of the polygon frame. The polygonal frame 2 has a substantially regular polygonal shape in cross-sectional outline, and a plurality of outer plate portions 21 corresponding to the sides of the polygon and a plurality of vertex portions 22 corresponding to the apexes of the polygon. It consists of a plurality of inner plate portions 24 extending radially from the central portion 23. In particular, here, the polygonal frame 2 has a regular hexagonal shape having six outer plate portions 21 and six inner plate portions 24 each.

  The bumper extension 3 includes a body portion 32 that extends in the vehicle body width direction and includes a connection portion 31 for the bumper beam 1 at one end, and a cylindrical fitting that protrudes forward from the body portion 32 in a manner that surrounds the polygonal frame 2. A plurality of projecting portions 34 projecting radially inward from the inner surface of the fitting portion 33 and coming into contact with the apex portion 22 of the polygon frame 2 from the radially outer side. A space A is defined between the fitting portion 33 and the outer plate portion 21 to allow the outer plate portion 21 to be deformed outward in the radial direction when the polygonal frame 2 is buckled and deformed. It has become so.

  When the polygonal frame 2 is buckled and deformed by an axial collision load, the apex angle portion 22 can be deformed in the circumferential direction although the deformation in the radial direction is restricted by the inner plate portion 24, and the outer plate can be deformed. Since the portion 21 can be deformed inward and outward in the radial direction, the polygonal frame 2 smoothly buckles and deforms, but the fitting region where the polygonal frame 2 is inserted into the fitting portion 33 of the bumper extension 3 Inside, the protruding portion 34 provided in the fitting portion 33 does not restrain the circumferential deformation of the apex corner portion 22 and the outer plate portion 21 is allowed to deform radially outward by the space A. The polygonal frame 2 can be smoothly buckled and deformed in substantially the same manner as outside the fitting region.

  Further, in this polygonal frame 2, when a lateral external force different from the axial direction is applied, the component force generates a stress in the surface direction on the inner plate portion 24. A large load does not act on the outer plate portion 21 which acts on the fitting portion 33 via the protruding portion 34 located at a position aligned with the plate portion 24 and has a high degree of freedom of deformation. For this reason, the polygon frame 2 has a large proof strength against a lateral external force different from the axial direction, and deformation of the polygon frame 2 due to the lateral external force can be suppressed.

  The protrusion 34 provided on the fitting portion 33 of the bumper extension 3 has a contact surface with the polygonal frame 2 having a substantially arc-shaped cross section. Further, the apex angle portion 22 of the polygonal frame 2 is slightly concave inward in the radial direction in a form in which the apex angle of the regular hexagon is cut out, and the recess 25 has its center at the center of the inner plate portion 24. The protrusion 34 abutting against the recess 25 moderately restrains the deformation in the circumferential direction of the apex corner 22 and holds the protrusion 34 at a position aligned with the inner plate 24. It has become.

  FIG. 5 is a cross-sectional view of the polygonal frame and bracket shown in FIG. 1 cut along a plane perpendicular to the axis of the polygonal frame. The bracket 4 includes a bottomed cylindrical fitting portion 41 into which an end of the polygonal frame 2 is inserted, and a flange portion 42 extending outward from the outer periphery of the fitting portion 41. The bolt 7 that penetrates the portion 42 is fastened and fixed to the side frame 5.

  Similar to the fitting portion 33 of the bumper extension 3, a plurality of inner surfaces of the fitting portion 41 of the bracket 4 protrude inward in the radial direction and abut against the apex portion 22 of the polygonal frame 2 from the radially outer side. Is provided between the fitting portion 41 and the outer plate portion 21. A space B that allows the outer plate portion 21 to deform radially outward when the polygonal frame 2 is buckled and deformed. It is to be defined. The protrusion 44 has a substantially arc-shaped cross section at the contact surface with the polygonal frame 2.

  FIG. 6 is a cross-sectional view taken along line VI-VI shown in FIG. In the fitting portion 33 of the bumper extension 3, a projecting portion 34 extends in the axial direction over substantially the entire length, and abuts on the apex portion 22 of the polygonal frame 2. The fitting portion 41 of the bracket 4 is formed in a bottomed cylindrical shape, and a protruding portion 44 extends in the axial direction over the substantially entire length of the side wall 41b, so that the apex corner portion 22 of the polygonal frame 2 is formed. Abut.

  FIG. 7 is a cross-sectional view taken along line VII-VII shown in FIG. Between the fitting portion 33 of the bumper extension 3 and the outer plate portion 21 of the polygonal frame 2, a space A that allows the outer plate portion 21 to deform outward in the radial direction is defined. Similarly, a space B allowing the radially outward deformation of the outer plate portion 21 is defined between the fitting portion 41 and the outer plate portion 21 of the polygon frame 2. Is smoothly buckled and deformed in a region where the bumper extension 3 and the bracket 4 are fitted, and functions as an effective energy absorption stroke over the entire length thereof. It should be noted that the spaces A and B that allow deformation of the outer plate portion 21 during buckling deformation are preferably set to a gap size that is half or more of the buckling amplitude.

  The fitting portion 33 of the bumper extension 3 is provided with an inward flange portion 35 against which the end surface of the polygonal frame 2 in the axial direction is abutted. The polygonal frame 2 is an end portion of the outer plate portion 21 in the axial direction. Are welded and joined to the inward flange portion 35 and fixed to the bumper extension 3 by, for example, a weld bead 36 by butt welding. Further, the fitting portion 41 of the bracket 4 is formed in a bottomed cylindrical shape, and the end surface in the axial direction of the polygon frame 2 is abutted against the bottom wall 41 a, and the polygon frame 2 is in the axial direction of the outer plate portion 21. Is fixed to the bracket 4 by a weld bead 46 by fillet welding, for example. For this reason, since the thermal influence of welding is limited to the outer plate part 21 where the burden of the collision load is small, it is possible to suppress a decrease in load resistance due to welding.

  FIG. 8 is a cross-sectional view showing another example of the frame material coupling structure shown in FIG. In this polygonal frame 81, in order to increase the load resistance, the concave portion 25 of the apex portion 22 in the example shown in FIG. 5 is eliminated, and the apex portion 82 is convex outward in the radial direction. A protruding portion 92 provided on the fitting portion 91 of the bracket is in contact with the convex portion.

  FIG. 9 shows the correlation between the axial load and the stroke in the frame material coupling structure shown in FIGS. In the configuration (comparative example) in which the outer plate portion 21 is surface-constrained without constraining the apex corner portion 22 of the polygonal frame 2, the deformation amount (stroke) generated by the input of the axial load is the fitting portion. When the region extends into the region (restraint portion) inserted into 33 and 41, a sudden increase in the force (force) occurs, whereas as shown in FIGS. In the configuration in which the portion 22 is constrained (Example), since the buckling deformation proceeds in the fitting region (constraint portion), the amount of deformation until a sudden load increase, that is, the energy absorption stroke is large. The effectiveness of the present invention regarding the collision load in the axial direction can be confirmed.

  FIG. 10 is a load characteristic diagram when a lateral external force is input in the frame material coupling structure shown in FIGS. 4 and 5. As shown in FIGS. 4 and 5, in the configuration (example) in which the apex angle portion 22 of the polygonal frame 2 is constrained by the protrusions 34 and 44 on the inner surfaces of the fitting portions 33 and 41, the apex angle portion 22 is not constrained. Compared to the configuration (comparative example), the generated load (Load) against the amount of deformation (Stroke) when an external force in the horizontal direction (direction perpendicular to the axis of the frame) is input is larger. It is recognized that the rigidity and strength against the external force in the direction are greatly improved, and the effectiveness of the present invention regarding the external force in the lateral direction can be confirmed.

  In the present embodiment, the example of the bumper beam system has been described. However, the present invention is not limited to this, and is widely applied to a configuration in which a polygonal frame material is combined with other various frame components. be able to.

  The combined structure of the automobile frame material according to the present invention has an effect of increasing the energy absorption amount by ensuring a large energy absorption stroke at the time of collision, and in order to absorb impact energy at the time of collision by compressive deformation. This is useful as a coupling structure for automobile frame materials provided on the side frames of the parts.

It is a perspective view showing a bumper beam assembly to which the present invention is applied. FIG. 2 is a top view of the bumper beam assembly shown in FIG. 1. FIG. 2 is a perspective view showing a polygon frame and a bumper extension shown in FIG. 1. It is sectional drawing which cut | disconnected the polygon frame and bumper extension shown in FIG. 1 by the plane orthogonal to the axis line of a polygon frame. It is sectional drawing which cut | disconnected the polygon frame and bracket shown in FIG. 1 by the plane orthogonal to the axis line of a polygon frame. It is sectional drawing cut | disconnected by the VI-VI line shown in FIG. It is sectional drawing cut | disconnected by the VII-VII line shown in FIG. It is sectional drawing which shows another example of the coupling | bonding structure of the frame material shown in FIG. FIG. 6 is a diagram showing a correlation between an axial load and a stroke in the frame material coupling structure shown in FIGS. 4 and 5. FIG. 6 is a load characteristic diagram when a lateral external force is input in the frame material coupling structure shown in FIGS. 4 and 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bumper beam 2 * 81 Polygon frame 3 Bumper extension 4 Bracket 5 Side frame 21 Outer plate part 22 * 82 Vertical corner part 23 Center part 24 Inner plate part 25 Recess 33 * 41 * 91 Fitting part 34 * 44 * 92 Protrusion part

Claims (3)

The outer contour of the cross section has a substantially regular polygonal shape, and extends radially from the center toward a plurality of outer plate portions corresponding to the sides of the polygon and a plurality of apex portions corresponding to the apexes of the polygon. A frame structure for an automobile that combines a polygonal frame material having a plurality of inner plate portions and a frame component material to be combined therewith,
The frame constituent material that is the mating partner protrudes radially inward from the inner surface of the cylindrical fitting portion into which the polygon frame material is fitted, and has a diameter with respect to the apex angle portion of the polygon frame material. A space that has a protruding portion that abuts from the outside in the direction, and allows a radially outward deformation of the outer plate portion when the polygonal frame material is compressed and deformed, and an inner surface of the fitting portion and the outer plate portion so as to be defined between the,
The projecting portion of the frame constituent material is formed in a substantially arc-shaped cross section with respect to the polygonal frame material, and a concave portion that is recessed radially inward at the apex angle portion of the polygonal frame material. An automobile frame material coupling structure, characterized in that the projecting portion is formed in contact with the concave portion and the projecting portion is held at a position aligned with the inner plate portion .   The frame component material is a bumper extension connected to a bumper beam, and the fitting portion is formed on the bumper extension in a manner protruding forward from a main body portion connected to the bumper beam. 2. The automobile frame material coupling structure according to claim 1, wherein a front end portion of the polygonal frame material is fitted.   The frame constituent material is a bracket attached to a front end of a side frame, and the fitting portion is formed on the bracket in a manner protruding rearward from a flange portion connected to the side frame, and the fitting portion The connecting structure for an automobile frame material according to claim 1 or 2, wherein a rear end portion of the polygon frame material is fitted into the frame material.

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