JP2013216288A - Structure of vehicle body front part of automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure of a vehicle body front part of an automobile, in which the performance of a connection structure between a front side frame and a lower member is not affected by welding performance and collision performance is further improved so that even in full-lap collision of vertical offset and narrow offset collision, the transmission of a collision load and the generation of a reaction force are exactly performed on both of the front side frame and the lower member.SOLUTION: A first connecting protrusion part 34 which is protruded to the side of a lower member 16 is integrally molded on a lateral surface part of a front side frame 18, and a second connecting protrusion part 36 which is protruded to the side of the front side frame 18 is integrally molded on a lateral surface part of the lower member, wherein the first connecting protrusion part 34 and the second connecting protrusion part 36 are fitted and connected to each other.

Description

  The present invention relates to a vehicle body front structure of an automobile, and more particularly to a type of vehicle body front structure in which a front side frame and a lower member are connected by a connection structure.

  As a front body structure of an automobile, left and right front side frames that extend in the longitudinal direction of the vehicle body, and an outer end in the vehicle width direction from the front side frame that is connected to the front pillar and extends downward from the connection portion to the front of the vehicle body. There are known left and right lower members, in which left and right front side frames and a lower member are connected to each other by a connecting member (for example, Patent Documents 1 to 3).

  The connecting member transmits a collision load input to one of the front side frame and the lower member by a full wrap collision or an offset collision to the other, and the transmission of the collision load and generation of reaction force are performed by both the front side frame and the lower member. Thus, the collision performance is improved.

  There are various types of connecting members such as plate-shaped, groove-shaped cross-sections, round pipes, etc., all of which are composed of separate parts from the front side frame and lower member, and are welded to the front side frame and lower member by welding. It is joined.

Japanese Patent No. 3599327 Japanese Patent No. 4091499 JP 2010-18082 A

  In the conventional front structure of the vehicle body, the connecting member is constituted by a separate part from the front side frame and the lower member, and the joining of the connecting member, the front side frame and the lower member is welding, so the number of parts for the vehicle body configuration is increased. The performance (mechanical strength) of the connection structure between the front side frame and the lower member by the connecting member is affected by the welding performance, and the tensile direction and shearing of the joint between the connecting member, the front side frame and the lower member There is a limit to increasing the bond strength in the direction.

  For this reason, the collision performance is further improved against the full-wrap collision with the vertical offset of the front bumper beam mounted on the front side frame of the front side frame and the narrow offset collision that collides outward from the front side frame in the vehicle width direction. It is difficult to plan.

  The problem to be solved by the present invention is that the performance of the connecting structure between the front side frame and the lower member by the connecting member is not affected by the welding performance, and the transfer of the collision load is also performed in the full-wrap collision or the narrow offset collision of the vertical offset. In other words, the collision performance is further improved by generating the reaction force accurately in both the front side frame and the lower member.

  The vehicle body front structure according to the present invention includes a left and right front side frame (18) extending in the longitudinal direction of the vehicle body, and a front pillar (10) whose upper end is located outside the front side frame (18) in the vehicle width direction. The left and right lower members (16) that are joined to each other and extend forward and downward from the joint, and the connecting structure that connects the left and right front side frames (18) and the lower members (16) to each other. In the front structure, the lower member (16) extends vertically across the front side frame (18) when viewed from the side of the vehicle body. The front side frame (18) and the lower member (16) A side portion opposite to each other in the vehicle width direction at the crossing portion, and the side portion of the front side frame (18) is on the lower member side. The first connecting protrusion (34) is integrally formed, and the side member of the lower member (16) protrudes toward the front side frame (18) to protrude to the first connecting protrusion (34). ) And the second connecting protrusion (36) are integrally formed, and the first connecting protrusion (34) and the second connecting protrusion (36) are joined at the overlapping portion. Yes.

  According to this configuration, the first connecting protrusion (34) is integrally formed with the front side frame (18), and the second connecting protrusion (36) is integrally formed with the lower member (16), and integrated by welding. Therefore, the connecting portion between the first connecting protrusion (34) and the front side frame (18) and the connecting portion between the second connecting protrusion (36) and the lower member (16) have welding performance. Without being affected, the bond strength in the tensile direction and the shear direction is high.

  In the vehicle body front structure according to the present invention, preferably, the first connecting protrusion and the second connecting protrusion have a cylindrical shape, more preferably a cylindrical shape, and are mutually cylindrical. It is mated.

  According to this structure, both the 1st connection protrusion part (34) and the 2nd connection protrusion part (36) comprise closed cross-sectional shape, and can obtain high bending rigidity. In particular, it is preferable for drawing workability that the first connecting protrusion (34) and the second connecting protrusion (36) are cylindrical.

  The vehicle body front part structure according to the present invention is preferably located on the outer side of the first connecting protrusion (34) and the second connecting protrusion (36). A welding opening (38) is formed through the workpiece, and the first connecting protrusion (36) and the second connecting protrusion (38) are joined by welding in the welding opening (38). Has been.

  According to this structure, a rigid double structure is obtained by the welded first connecting protrusion (34) and the second connecting protrusion (36).

  The vehicle body front part structure according to the present invention is preferably located on the outer side of the first connecting protrusion (34) and the second connecting protrusion (36). However, the projecting tip side is formed in a semi-cylindrical shape having only a half of the cylindrical cross section.

  According to this configuration, the second connecting protrusion (36) on the other side can be placed and set on the semi-cylindrical portion (40), so that the assembly workability is improved.

  According to the vehicle body front structure according to the present invention, the first connecting protrusion is integrally formed with the front side frame, and the second connecting protrusion is integrally formed with the lower member. The connecting portion between the first connecting protrusion and the front side frame and the connecting portion between the second connecting protrusion and the lower member are not affected by the welding performance and have high strength in the tensile and shear directions. Become a thing.

The perspective view of the vehicle body front part which shows one Embodiment of the vehicle body front part structure of the motor vehicle by this invention. The disassembled perspective view of the principal part of the vehicle body front part structure by this embodiment. The perspective view of the principal part of the vehicle body front part structure by this embodiment. The top view of the principal part of the vehicle body front part structure by this embodiment. Sectional drawing along line VV of FIG. The top view which shows the transmission path | route of the collision load at the time of a collision. The top view which shows the transmission path | route of the collision load at the time of a collision. The top view which shows the transmission path | route of the collision load at the time of a collision. The perspective view which shows the principal part of other embodiment of the vehicle body front part structure of the motor vehicle by this invention.

  Embodiments of a vehicle body front structure according to the present invention will be described below with reference to FIGS. The vehicle body front part structure is generally bilaterally symmetric, and other vehicle body structural members excluding the cross member and the like exist in a pair of left and right unless otherwise specified.

  As shown in FIG. 1, the front part of the vehicle body includes left and right front pillar parts 10, and right and left roof side rail parts 12 that are joined to the upper ends of the front pillar parts 10 and extend in the longitudinal direction of the car body. The left and right side sill portions 14 joined to the lower end of the front pillar portion 10 and extending in the longitudinal direction of the vehicle body, and the left and right side sill portions 14 joined to the upper and lower intermediate portions of the front pillar portion 10 It has a lower member 16 and left and right front side frames 18 extending in the longitudinal direction of the vehicle body. These are all configured in a box-shaped closed cross-sectional shape.

  The left and right roof side rail portions 12 are joined to the left and right end portions of the front roof member 20 extending in the vehicle width direction. The left and right end portions of the dashboard upper member 22 extending in the vehicle width direction are joined to the upper and lower intermediate portions of the left and right front pillar portions 10. The front roof member 20, the left and right roof side rail portions 12, and the dashboard upper member 22 define a front window opening.

  The front side frame 18 is a lower body member, and is dive under the dashboard lower member 24 provided at the lower part of the dashboard upper member 22, and the rear end is joined to the front ends of left and right floor frames (not shown). Left and right bumper beam extension members 26 are attached to the front end. Left and right end portions of a bumper beam 28 extending in the vehicle width direction are joined to the left and right bumper beam extension members 26.

  The bumper beam extension member 26 is a crash member at the time of a frontal collision, has a lower rigidity and lower strength than the front side frame 18 and the bumper beam 28, and compresses and deforms (crushes) when receiving a frontal collision load exceeding a predetermined value. is there.

  The lower member 16 is located outside the front side frame 18 in the vehicle width direction and forms a skeleton of a front tie house or a side fender. The lower member 16 may be constituted by a joined body that is joined to the front pillar portion 10 and a member that extends forward and downward from the vehicle body. The former is sometimes called an upper member and the latter is called a lower member. However, in this specification, the whole is collectively referred to as a lower member. The left and right front damper housings 30 are joined to the inner side of the lower member 16 in the vehicle width direction.

  The lower member 16 extends vertically across the vicinity of the front end of the front side frame 18 when viewed from the side of the vehicle body. As a result, the lower end (tip) of the lower member 16 is positioned below the arrangement position on the front end side of the front side frame 18. The left and right ends of the front bulkhead lower cross member 32 extending in the vehicle width direction are joined to the lower ends of the left and right lower members 16.

  The main part of the vehicle body front structure according to the present embodiment will be described with reference to FIGS.

  The lower member 16 and the front side frame 18 are each a substantially U-shaped channel member (groove-shaped cross section) channel members 16A and 18A, and flat plates joined to the channel members 16A and 18A so as to close the groove openings of the channel members 16A and 18A. The plate members 16B and 18B have a closed cross-sectional shape.

  The plate member 16B of the lower member 16 is located on the inner side in the vehicle width direction, the plate member 18B of the front side frame 18 is located on the outer side in the vehicle width direction, and these plate members 16B are disposed at a transverse section where the lower member 16 crosses the front side frame 18 up and down. , 18B form side portions facing each other in parallel at a predetermined interval in the vehicle width direction.

  A cylindrical first connecting projection 34 protruding toward the plate member 16B is integrally formed by drawing at a portion where the plate member 18B faces the plate member 16B. A cylindrical second connecting protrusion 36 protruding toward the plate member 18B is integrally formed by drawing at a portion where the plate member 16B faces the plate member 18B. The outer diameter of the second connecting protrusion 36 is equal to or slightly smaller than the outer diameter of the first connecting protrusion 34. The axial lengths of the first connecting protrusion 34 and the second connecting protrusion 36 are the distance between the lower member 16 and the front side frame 18 in the vehicle width direction, that is, between the plate member 16B and the plate member 18B. Equal to vehicle width direction dimension. With this dimension setting, the second connecting protrusion 36 is inserted into the first connecting protrusion 34 over the entire axial length of the first connecting protrusion 34 and is fitted in a cylindrical shape. This fitting is a fitting in which the first connecting protrusion 34 and the second connecting protrusion 36 are in close contact with each other in the radial direction, and preferably has no radial gap.

  As a result, the first connecting protrusion 34 and the second connecting protrusion 36 extend in the radial direction to the entire length of the separation distance in the vehicle width direction between the lower member 16 and the front side frame 18 over the entire circumference. Are overlapping.

  A plurality of long-hole-like welding openings 38 extending in the axial direction are formed through the first connecting projection 34. The lower member 16 and the front side frame 18 are fillet welded by MIG welding or the like at the opening end surface of the welding opening 38 and the outer peripheral surface of the second connecting projection 36, and this fillet weld W (see FIG. 5), the first connecting protrusion 34 and the second connecting protrusion 36 are coupled. The number of the welding openings 38 may be set to an appropriate value according to the required coupling strength between the first connecting protrusion 34 and the second connecting protrusion 36. As described above, the first connecting protrusion 34 and the second connecting protrusion 36 are welded to obtain a rigid double structure.

  According to the above-described connection structure, the front side frame 18 and the lower member 16 are firmly fixed by the first connection protrusion 34 and the second connection protrusion 36 without separately requiring separate connection members. Connected to The first connecting protrusion 34 is formed integrally with the front side frame 18, and the second connecting protrusion 36 is formed integrally with the lower member 16, and is not integrated by welding. The connecting portion between the side frame 18 and the connecting portion between the second connecting protrusion 36 and the lower member 16 are not affected by the welding performance, that is, without causing individual differences, the tensile direction (bending direction) and the shearing direction. The bond strength is high.

  Thereby, the transmission of the collision load between the front side frame 18 and the lower member 16 by the fitting structure of the first connection protrusion 34 and the second connection protrusion 36 is favorably performed, and the vertical offset is reduced. Even in a full lap collision or a narrow offset collision, transmission of a collision load to the rear of the vehicle body and generation of a reaction force are accurately performed by both the front side frame 18 and the lower member 16. This improves the front collision performance.

  FIG. 6 shows a state in which a collision load F1 is input to the bumper beam 28 due to a collision with a counterpart vehicle having the same ground height as the own vehicle. When the collision load F <b> 1 is input to the bumper beam 28, the bumper beam extension member 26 is crushed, and the collision load input to the front end of the front side frame 18 causes the front side frame 18 to be deformed and retracted backward in the vehicle body.

  At this time, since the first connecting protrusion 34 and the second connecting protrusion 36 are integrally formed with the front side frame 18 and the lower member 16, the first connecting protrusion 34 and the second connecting protrusion 36 are formed. The projecting portion 36 does not peel from the front side frame 18 or the lower member 16, and the first connecting projecting portion 34 and the second connecting projecting portion 36 receive a tensile load according to the deformation of the front side frame 18. The lower member 16 follows the first connecting protrusion 34 and the second connecting protrusion 36 as load transmission paths. Accordingly, a sufficient reaction force can be generated as a whole by the both members of the front side frame 18 and the lower member 16 against the collision load F1.

  FIG. 7 shows a state in which a collision load F2 is input to the lower member 16 due to a collision with an opponent vehicle in which the bumper beam has a height above the own vehicle. When the collision load F <b> 2 is input to the lower member 16, a tensile load acts on the first connecting protrusion 34 and the second connecting protrusion 36.

  At this time, since the first connecting protrusion 34 and the second connecting protrusion 36 are integrally formed with the front side frame 18 and the lower member 16, the first connecting protrusion 34 and the second connecting protrusion 36 are formed. The projecting portion 36 does not peel off from the front side frame 18 or the lower member 16, and the connected state between the front side frame 18 and the lower member 16 is maintained, and the front side frame 18 follows the deformation of the lower member 16. Accordingly, a sufficient reaction force can be generated as a whole against both the collision load F <b> 2 by both the front side frame 18 and the lower member 16. This operation is the same when a narrow offset collision occurs.

  FIG. 8 shows that a connecting portion between the front side frame 18 and the lower member 16 formed by the first connecting protrusion 34 and the second connecting protrusion 36 of the own vehicle collides with a pole on the road and the like. The state input to the collision load F3 is shown. At this time, since the first connecting protrusion 34 and the second connecting protrusion 36 are integrally formed with the front side frame 18 and the lower member 16, the first connecting protrusion 34 and the second connecting protrusion 36 are formed. The front projecting portion 36 does not peel off from the front side frame 18 or the lower member 16, and the front side frame 18 and the lower member 16 follow the deformation of the first connecting projecting portion 34 and the second connecting projecting portion 36. . As a result, a sufficient reaction force can be generated as a whole against both the collision load F3 and the front side frame 18 and the lower member 16. This operation is the same when a narrow offset collision occurs.

  In the present embodiment, since the first connecting protrusion 34 and the second connecting protrusion 36 are cylindrical, the connection between the first connecting protrusion 34 and the second connecting protrusion 36. Both have a closed cross-sectional shape, and high bending rigidity (strength) can be obtained. Thereby, the thickness of the first connecting protrusion 34 and the second connecting protrusion 36 can be reduced, and the weight can be reduced. Moreover, it is preferable in terms of drawing workability that the first connecting protrusion 34 and the second connecting protrusion 36 are cylindrical bodies and are integrally formed with the plate members 18B and 16B.

  As shown in FIG. 5, the axial length of the second connecting projection 36 is longer than the axial length of the first connecting projection 34 by the plate thickness of the plate member 16B. The protrusion 36 penetrates through the plate thickness portion of the plate member 16B, which means that the lower member 16 and the front side frame 18 are connected by the first connecting protrusion 34 and the second connecting protrusion 36. It is more preferable for increasing the shear strength.

  Another embodiment of a vehicle body front structure according to the present invention will be described with reference to FIG. 9, parts corresponding to those in FIG. 3 are denoted by the same reference numerals as those in FIG. 3, and description thereof is omitted.

  In the present embodiment, the protruding front end side of the first connecting protrusion 34 is formed in a semi-cylindrical shape having only a half of the cylindrical cross section. The half cylinder portion 40 is in the lower half, and the upper half is the open portion 42. The opening 42 may be formed by notching after the drawing of the first connecting protrusion 34 or by drawing of the first connecting protrusion 34.

  In this embodiment, at the time of assembly, the distal end side of the second connecting protrusion 36 is placed on the semi-cylindrical portion 40 from the opening 42, and in this state, the second connecting protrusion 36 is moved to a predetermined position. Since it can be inserted into the connecting protrusion 34, the assembly workability is improved. Further, in this case, the edge portion of the half cylinder portion 40 can also be fillet welded to the second connecting protrusion 36.

  Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to such embodiments so that those skilled in the art can easily understand, and departs from the spirit of the present invention. It is possible to change appropriately within the range not to be. For example, the first connecting protrusion 34 and the second connecting protrusion 36 may be formed of an elliptic cylinder or a polygonal cylinder. The connection between the first connecting protrusion 34 and the second connecting protrusion 36 may be performed by a fastener such as a bolt without welding. In addition, the inner diameter of the second connecting protrusion 36 is slightly larger than that equal to the outer diameter of the first connecting protrusion 34, and the first connecting protrusion 34 is located in the second connecting protrusion 36. A fitting structure may be used. The first connecting protrusion 34 and the second connecting protrusion 36 may be integrally formed with the channel members 18A and 16A.

  In addition, all the components shown in the above embodiment are not necessarily essential, and can be appropriately selected without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 Front pillar part 16 Lower member 18 Front side frame 26 Bumper beam extension member 28 Bumper beam 30 Front damper housing 34 1st connection protrusion part 36 2nd connection protrusion part 38 Welding opening 40 Half cylinder part 42 Opening part

Claims (5)

Left and right front side frames extending in the front-rear direction of the vehicle body, left and right lower members extending from the front side frame to the front pillar with the upper end being joined to the front pillar, A vehicle body front structure including a connection structure that connects the front side frame and the lower member between each other,
The lower member extends vertically across the front side frame when viewed from the side of the vehicle body, and the front side frame and the lower member have side portions facing each other in the vehicle width direction at the crossing portion,
A first connecting protrusion that protrudes toward the lower member is integrally formed on the side surface of the front side frame, and the side surface of the lower member protrudes toward the front side frame and protrudes toward the first side frame. A second connecting protrusion overlapping the connecting protrusion is integrally formed;
A vehicle body front structure in which the first connecting protrusion and the second connecting protrusion are joined at an overlapping portion.   The vehicle body front part structure according to claim 1, wherein the first connecting protrusion and the second connecting protrusion have a cylindrical shape and are fitted into each other in a cylindrical shape.   The vehicle body front part structure according to claim 1, wherein the first connecting protrusion and the second connecting protrusion have a cylindrical shape and are fitted into each other in a cylindrical manner.   A welding opening is formed through the first coupling protrusion and the second coupling protrusion which are located outside of each other in the fitting portion, and the first opening is formed in the welding opening. The vehicle body front part structure according to claim 2 or 3, wherein the connecting protrusion and the second connecting protrusion are joined by welding.   Of the first connecting protrusion and the second connecting protrusion, the protrusion tip side of the one that is located on the outer side of the fitting portion is formed in a semi-cylindrical shape having only a half of the cylinder cross section. The vehicle body front part structure according to any one of claims 2 to 4.

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