JP2010023799A - Vehicle body front part structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle body front part structure, capable of effectively reinforcing a connecting part between a rear end part of a front side member and a dash panel, while suppressing increase in the weight of a vehicle body. <P>SOLUTION: A front-side member extension 34, having an L-shape in plane view, is interposed between a flange part (inner-side upper-part flange 28D and inner-side side-part flange 28E) at the rear-end part of the front-side member inner 28 and a dash panel 14. The front-side member extension 34 is constituted of a base part 34A, which extends in the vehicle width direction along the dash panel 14 and an extension part 34B, which is extended perpendicularly, from an inside lower end part of the base part 34A to a vehicle front side. The base part 34A is spot-welded to both of the flanges 28D and 28E, and is also spot-welded to the dash panel 14. The extension part 34B is spot-welded to a sidewall part 28B of the front-side member inner 28. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle body front part structure including a front side member and a dash panel.

Patent Document 1 below discloses a vehicle body front structure in which a plate-like descent prevention means is disposed at a connecting portion between a rear end portion of a front side member and a dash panel on the vehicle interior side of the dash panel. . This prevents the rear end of the front side member from descending to the vehicle lower side at the time of a frontal collision, and as a result, the energy absorption effect can be enhanced by causing the front side member to undergo axial compression plastic deformation as intended. Is.
JP 2001-30954 A

  However, in the case of the above prior art, the front side member has a size that can cover the rear end portion of the front side member when viewed from the rear of the vehicle and is configured to set the fall prevention means with a large plate thickness. Even if the connecting portion between the rear end portion and the dash panel can be reinforced, the weight of the vehicle body increases. For this reason, there has been a demand for a vehicle body front structure that effectively reinforces the joint between the rear end portion of the front side member and the dash panel while suppressing an increase in the weight of the vehicle body.

  In view of the above facts, the present invention has an object to obtain a vehicle body front structure that can effectively reinforce a joint portion between a rear end portion of a front side member and a dash panel while suppressing an increase in vehicle body weight. It is.

  According to a first aspect of the present invention, a vehicle body front portion structure includes a dash panel that separates a vehicle body front portion and a cabin, and a dash panel that is disposed on both sides of the vehicle body front portion along the vehicle front-rear direction and at the rear end portion. A pair of left and right front side members having a flange portion for coupling to the base portion, a base portion interposed between the flange portion and the dash panel of the front side member and welded to the flange portion and the dash panel, and the base portion A reinforcing member including an extending portion that extends from the vehicle to the vehicle front side and is welded to the inner wall surface of the front side member.

  According to a second aspect of the present invention, in the vehicle body front portion structure according to the first aspect, the front side member has a substantially rectangular cross-sectional shape, and the base portion includes at least a flange portion on the side wall side of the front side member and a dash panel. The extension portion is welded to the side wall of the front side member.

  According to a third aspect of the present invention, in the vehicle body front part structure according to the first aspect, the front side member has a substantially rectangular cross-sectional shape, and the base portion includes at least a flange portion on the upper wall side of the front side member and a dash panel. And the extension portion is welded to the upper wall of the front side member.

  According to a fourth aspect of the present invention, in the vehicle body front portion structure according to the first aspect, the front side member has a substantially rectangular cross-sectional shape, and the base portion has a flange portion on the side wall side of the front side member and an upper wall side. A first leg portion and a front side member which are shaped to straddle both flange portions and are interposed between the flange portions and the dash panel, and the extension portion is welded to the inner surface of the side wall of the front side member. And a second leg portion welded to the inner surface of the upper wall.

  According to a fifth aspect of the present invention, in the vehicle body front portion structure according to any one of the first to fourth aspects, the flange portion is provided on the rear end side of the front side member when viewed in the longitudinal direction of the front side member. It has a flange portion on the side wall side and a flange portion on the upper wall side that are arranged apart from each other around the ridge line portion, and the base portion has a shape straddling both the flange portion on the side wall side and the flange portion on the upper wall side. And the flange portion on the side wall side and the flange portion on the upper wall side are connected by welding to both the flange portion on the side wall side and the flange portion on the upper wall side.

  According to the first aspect of the present invention, the flange portion is provided at the rear end portion of the front side member, and the front side member and the dash panel are connected by connecting the flange portion to the dash panel. Is done.

  Here, when traveling on a rough road, the front side member is displaced in the vehicle vertical direction and the vehicle longitudinal direction. Specifically, the front side member is displaced to the vehicle lower side and the vehicle front side, and is displaced to the vehicle upper side and the vehicle rear side by the road surface input when traveling on a rough road. At this time, due to the displacement of the front side member in the vertical direction of the vehicle, a load in the peeling direction is input to the connecting portion between the front side member and the dash panel (that is, the flange portion of the front side member).

  However, in the present invention, a reinforcing member is interposed between the flange portion of the front side member and the dash panel, the base portion of the reinforcing member is welded to the flange portion and the dash panel, and extends from the base portion to the vehicle front side. Since the extended part is welded to the inner wall surface of the front side member, the load in the peeling direction acting on the welded part of the flange part is applied to the side wall of the front side member via the extension part in the shearing direction. As well as being distributed to the welded part to the dash panel. For this reason, since the load burden concerning the welding site | part of the flange part of a front side member and a dash panel is reduced, an excessive stress does not concentrate on the said welding site.

  Further, since the reinforcing member only needs to have a base portion and an extending portion, it does not have to be large so as to cover the rear end portion of the front side member as in the prior art. Therefore, according to this invention, a reinforcement member can be reduced in size and weight compared with a prior art.

  According to the second aspect of the present invention, the front side member has a substantially rectangular cross-sectional shape, and the base portion of the reinforcing member is interposed between the flange portion at least on the side wall side of the front side member and the dash panel. At the same time, since the extension part of the reinforcing member is welded to the side wall of the front side member, it is particularly necessary to reduce the load in the peeling direction that acts on the connecting part between the flange part on the side wall side of the front side member and the dash panel. It is valid.

  According to the third aspect of the present invention, the front side member has a substantially rectangular cross-sectional shape, and the base portion of the reinforcing member is interposed between at least the flange portion on the upper wall side of the front side member and the dash panel. In addition, the extension part of the reinforcing member is welded to the upper wall of the front side member, so the load in the peeling direction that acts on the connecting part between the flange part on the upper wall side of the front side member and the dash panel is particularly reduced. It is effective when you want to.

  According to the fourth aspect of the present invention, the front side member has a substantially rectangular cross-sectional shape, and the base portion of the reinforcing member straddles both the flange portion on the side wall side and the flange portion on the upper wall side of the front side member. And is interposed between the flange portion and the dash panel. Further, the first leg provided in the extending portion of the reinforcing member is welded to the inner surface of the side wall of the front side member, and the second leg provided in the extending portion of the reinforcing member is welded to the inner surface of the upper wall of the front side member. The Therefore, the vehicle body front part structure according to the present invention is a structure having both the invention according to claim 2 and the invention according to claim 3, and the coupling part between the flange part on the side wall side and the dash panel, and the upper wall side structure. It is effective when it is desired to reduce the load in the peeling direction acting on both the flange portion and the dash panel connection portion in a balanced manner.

  According to the fifth aspect of the present invention, the following effects can be obtained.

  When traveling on a rough road, as described above, the front side member is displaced in the vehicle vertical direction and the vehicle longitudinal direction. Due to the displacement of the front side member in the vehicle longitudinal direction at this time, the ridge line portion on the rear end side of the front side member Stress concentrates on That is, in the present invention, the side wall side flange portion and the upper wall side flange portion formed at the rear end portion of the front side member are arranged apart from each other around the ridge line portion, so the side wall side flange portion and This is the same as a large notch between the flange portion on the upper wall side (that is, there is no flesh of the plate forming the flange portion). Therefore, when the front side member is displaced in the vehicle front-rear direction, the notch between the flange portion on the side wall side and the flange portion on the upper wall side widens or narrows. For this reason, stress becomes easy to concentrate on the rear end of the ridge line part which faces a notch part.

  However, in the present invention, the base portion of the reinforcing member is shaped so as to straddle both the flange portion on the side wall side and the flange portion on the upper wall side, and the base portion is used as the flange portion on the side wall side and the flange portion on the upper wall side. Since the flange portion on the side wall side and the flange portion on the upper wall side are connected by welding to both of the two, the rear end of the ridge line portion is reinforced. As a result, excessive stress does not concentrate on the rear end of the ridge line portion.

  As described above, the vehicle body front structure according to the first aspect of the present invention effectively reinforces the connecting portion between the rear end portion of the front side member and the dash panel while suppressing an increase in the vehicle body weight. It has an excellent effect of being able to.

  The vehicle body front structure according to the second aspect of the present invention is necessary for a vehicle type that particularly requires a load countermeasure in the peeling direction that acts on a coupling portion between the flange portion on the side wall side of the front side member and the dash panel. It has an excellent effect that a load in the peeling direction can be converted into a load in the shearing direction with a minimum number of members (amount).

  The vehicle body front part structure according to the present invention described in claim 3 is for a vehicle type that particularly requires a load countermeasure in the peeling direction that acts on the connecting portion between the flange portion on the upper wall side of the front side member and the dash panel. It has an excellent effect that the load in the peeling direction can be converted into the load in the shearing direction with the minimum necessary member (amount).

  According to a fourth aspect of the present invention, there is provided a vehicle body front portion structure including a coupling portion between the flange portion on the side wall side of the front side member and the dash panel, and a coupling portion between the flange portion on the upper wall side of the front side member and the dash panel. It has an excellent effect that the load in the peeling direction can be converted into the load in the shearing direction in a balanced manner with the minimum necessary number of members (quantity) for all types of vehicles that require load countermeasures in the peeling direction to act. .

  According to the fifth aspect of the present invention, the vehicle body front portion structure has an excellent effect that the joint portion between the rear end portion of the front side member and the dash panel can be more effectively reinforced.

  Hereinafter, some embodiments of the vehicle body front structure according to the present invention will be described with reference to FIGS. In these drawings, an arrow FR appropriately shown indicates the vehicle front side, an arrow UP indicates the vehicle upper side, and an arrow IN indicates the vehicle width direction inner side.

  FIG. 4 is an overall perspective view of a vehicle including the vehicle body front part structure according to the present embodiment. As shown in this figure, a dash panel 14 extending in the vehicle width direction and the vehicle vertical direction is provided upright at a position separating the engine room 10 and the cabin 12 of the vehicle. A pair of left and right front side members 18 are disposed along the vehicle front-rear direction at the lower portions on both sides of the vehicle body front portion 16 separated by the dash panel 14. The front side member 18 is configured as a vehicle body skeleton member having a rectangular closed cross-sectional structure as will be described later. Note that the front end portions of the pair of left and right front side members 18 are bolted directly or via a crash box to the front bumper reinforcement 20 having a rectangular closed cross-sectional structure as an example in which the vehicle width direction is disposed at the vehicle front end portion as a longitudinal direction. And so on.

  FIG. 1 shows an enlarged state of the connecting portion (the portion indicated by the arrow 1 in FIG. 4) between the rear end portion 18A of the front side member 18 and the dash panel 14 described above. FIG. 3 is an exploded perspective view of a connecting portion between the rear end portion 18A of the front side member 18 and the dash panel 14. Further, FIG. 2 shows a perspective view of an intermediate process before the front side member 18 is assembled to the dash panel 14.

  As shown in these drawings, the front side member 18 includes, as a whole, a main body 22 that extends linearly along the longitudinal direction of the vehicle, and a lower portion of the dash panel 14 from the rear end of the main body 22. And a bent portion 24 that is bent diagonally rearward and downward along the shape. Further, structurally, the front side member 18 includes a front side member outer 26 disposed on the outer side in the vehicle width direction, and a front side member inner disposed adjacent to the inner side of the front side member outer 26 in the vehicle width direction. 28. The front side member outer 26 is configured as a flat panel extending along the vehicle vertical direction and the vehicle front-rear direction. On the other hand, the front side member inner 28 is configured as a long panel having a vertical cross-sectional shape of a hat.

  The front side member inner 28 is disposed such that the open side faces outward in the vehicle width direction, and includes an upper wall portion 28A that forms a substantially horizontal plane, a side wall portion 28B that is disposed in parallel with the front side member outer 26, and an upper wall portion 28A. And a lower wall portion 28 </ b> C arranged in parallel with the main body. An end of the upper wall portion 28A on the outer side in the vehicle width direction is bent to the upper side of the vehicle to form an upper flange portion 30. Similarly, the end of the lower wall portion 28C on the outer side in the vehicle width direction is bent to the vehicle lower side to form a lower flange portion 32. The upper flange portion 30 and the lower flange portion 32 are spot welded to the front side member outer 26, whereby the front side member outer 26 and the front side member inner 28 are integrated to form a cylindrical shape having a rectangular closed cross-section structure. The vehicle skeleton member is formed. In addition, in FIG. 1 etc., the spot of spot welding is shown by the white circle.

  At the rear end of the upper wall portion 28A of the front side member inner 28 described above, an inner side upper flange 28D is formed as a flange portion on the upper wall side that is bent toward the vehicle upper side. Further, an inner side side flange 28E as a side wall side flange portion bent toward the inner side in the vehicle width direction is formed at the rear end of the side wall portion 28B of the front side member inner 28. Although illustration is omitted, an inner side lower flange bent toward the vehicle lower side is formed at the rear end of the lower wall portion 28C of the front side member inner 28. Further, an outer side side flange 28A that is bent outward in the vehicle width direction is formed at the rear end of the front side member outer 26.

  Here, as shown in FIG. 3, between the rear end portion 18A of the front side member 18 and the dash panel 14, the front side member as a reinforcing member formed in a substantially L shape in a plan view. An extension 34 is interposed. The front side member extension 34 is formed in a substantially bowl shape when viewed from the front side of the vehicle and extends in the vehicle width direction along the dash panel 14 and an inner side in the vehicle width direction of the base portion 34A. And an extending portion 34B extending from the vicinity of the end portion toward the vehicle front side.

  Specifically, the front side member extension 34 is manufactured as follows. That is, when a flat developed shape including the base portion 34A and the extension portion 34B is punched from the base material by pressing, a notch 40 having a predetermined length is made at a position that becomes a boundary between the base portion 34A and the extension portion 34B. Then, the extending part 34B separated from the base part 34A by the notch 40 is raised vertically with a line extending in the vehicle vertical direction passing through the terminal end of the notch 40 as a broken line. As a result, the extended portion 34B can be disposed in surface contact with the inner wall surface (the surface on the outer side in the vehicle width direction) of the side wall portion 28B of the front side member inner 28, and the extended portion 34B is spot welded to the side wall portion 28B. Joined by one spot weld 42). As shown in FIG. 2, when assembling, the front side member extension 34 is spot welded to the rear end portion of the front side member inner 28 by spot welding and then spot welded to the dash panel 14.

  The base 34A and the front side member inner 28 formed in a substantially bowl shape are spot-welded at positions where they overlap with the inner side upper flange 28D and the inner side side flange 28E of the front side member inner 28 (the first side). 2 spot weld 44). Further, the base 34A has a vertical dimension that exceeds the welding allowance of the second spot weld 44, and is spot welded at a position overlapping the dash panel 14 (third spot weld 46). In other words, the vertical dimension of the base portion 34A is set to a vertical dimension obtained by adding the welding allowance to the dash panel 14 to the flange width of the inner side upper flange 28D and the inner side side flange 28E.

  The front side member extension 34, the front side member inner 28, the front side member outer 26, and the dash panel 14 are made of a metal material. Further, the plate thickness of the front side member extension 34 is set to be greater than the plate thickness of the dash panel 14 and the same as or equal to the plate thickness of the front side member 18.

  (Operation and effect of this embodiment)

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

  First, the phenomenon that occurs in the joint portion between the front side member and the dash panel when traveling on a rough road will be described using the comparative example shown in FIG. 5 that does not include the vehicle body front structure according to the present embodiment as an example.

  5A, the front side member extension 34 described above is not provided, and the rear end portion 50A of the front side member 50 is directly spot welded to the dash panel 52. When a vehicle having this vehicle body front structure travels on a rough road, as shown in FIG. 5B, the front side member 50 is displaced to the vehicle lower side and the vehicle front side by the road surface input, and the vehicle upper side And it is displaced to the vehicle rear side. FIG. 5B depicts the former state at the time of displacement.

  Due to the displacement of the front side member 50 in the longitudinal direction of the vehicle and the displacement in the vertical direction of the vehicle at this time, a connecting portion between the rear end portion 50A of the front side member 50 and the dash panel 52 will be described below. Two types of stress concentration occur.

  First, as shown in FIG. 5B, the front side member 50 is displaced in the vehicle vertical direction (displacement in the direction of arrow A in FIG. 5B and displacement in the direction opposite to the direction of arrow A). The load in the peeling direction is input to the inner side upper flange 50B (see FIG. 6A) of the front side member 50 and the spot welded portion 54 of the inner side side flange 50C. Therefore, the spot-welded portion 54 of the inner side upper flange 50B and the inner-side side flange 50C of the front side member 50 and the dash panel 52 (particularly, the spot welded portion 54 marked with X adjacent to the notch 58). High stress is generated (stress concentration occurs).

  Next, the front side member 50 is displaced in the vehicle front-rear direction (displacement in the direction of arrow B in FIG. 5B and displacement in the direction opposite to the direction of arrow B), whereby the ridge line portion 56 ( Stress is concentrated in FIG. 6 (A). That is, when traveling on a rough road, as described above, the front side member 50 is displaced in the vehicle vertical direction and the vehicle front-rear direction. Due to the displacement of the front side member 50 in the vehicle front-rear direction at this time, the inner side upper flange 50B The notch 58 between the inner side flange 50C and the inner side flange 50C is deformed in the direction in which it opens or closes (the direction of arrow C in FIG. 6B indicates the direction of opening). For this reason, the root of the notch 58 (that is, the rear end of the ridge line part 56 of the rear end part 50A of the front side member 50) becomes a deformation starting point, and stress concentration first occurs in this part, and then the ridge line part 56 The stress concentration part propagates along the line.

  On the other hand, as shown in FIGS. 1 to 3, in the vehicle body front structure according to the present embodiment, with respect to peeling at the spot welded portion due to the displacement of the front side member 18 in the vehicle vertical direction. The front side member extension 34 is interposed between the rear end portion 18A of the front side member 18 and the dash panel 14, and the base portion 34A of the front side member extension 34 is connected to the inner upper flange 28D and the inner side of the front side member 18. Spot welded by the flange 28E and the second spot weld 44, and the base 34A of the front side member extension 34 is spot welded by the dash panel 14 and the third spot weld 46, and extends from the base 34A to the front side of the vehicle. The extended portion 34B that is made to move is connected to the front side member inner 28. Since the side spot 28B is spot-welded to the side wall 28B by the first spot welding portion 42, the separation acting on the connecting portion between the rear end portion 18A of the front side member 18 and the dash panel 14 when the front side member 18 is displaced in the vehicle vertical direction. The load in the direction can be transmitted to the extending portion 34B and received as a load in the shear direction, and can be distributed to the third spot weld 46, which is a newly set hitting point, and transmitted to the dash panel 14. From the above, it is possible to avoid excessive stress from being concentrated on the connecting portion between the flange portion (the inner side upper flange 28D and the inner side side flange 28E) of the rear end portion 18A of the front side member 18 and the dash panel 14. it can.

  Further, with respect to stress concentration at the spot welded portion caused by the displacement of the front side member 18 in the vehicle longitudinal direction, the opposing corner portion between the inner side upper flange 28D and the inner side side flange 28E (FIG. 6A). ) Of the spot welded portions 54) are connected by the base 34 </ b> A of the front side member extension 34, so that the notch 58 is reinforced. For this reason, it is suppressed that the notch part 58 deform | transforms in the direction which closes or opens. Therefore, excessive stress can be avoided from concentrating on the rear end of the ridge line portion 56.

  Furthermore, since the front side member extension 34 is functionally required to include the base portion 34A and the extension portion 34B, the large reinforcement that covers the rear end portion of the front side member as in the prior art described above. It need not be a member. Therefore, according to this embodiment, a reinforcement member can be reduced in size and weight compared with the said prior art.

  As described above, according to the vehicle body front structure according to the present embodiment, it is possible to effectively reinforce the coupling portion between the rear end portion 18A of the front side member 18 and the dash panel 14 while suppressing an increase in vehicle body weight. it can.

  Since the front side member extension 34 is provided, a patch is set on the front surface of the dash panel 14, so that the dash panel 14 can be reinforced. This also contributes to an improvement in the durability of the joint between the rear end portion 18A of the front side member 18 and the dash panel 14.

  In the vehicle body front structure according to the present embodiment, the base 34A of the front side member extension 34 is interposed between the inner side upper flange 28D and the inner side side flange 28E of the front side member inner 28 and the dash panel 14. In addition, since the extending portion 34B of the front side member extension 34 is welded to the side wall portion 28B of the front side member inner 28, the flange portion (inner side) of the front side member inner 28 on the side wall portion 28B side is adopted. This is effective in the case where it is particularly desired to reduce the load in the peeling direction that acts on the connecting portion between the side flange 28E) and the dash panel 14. Therefore, it is the minimum necessary for a vehicle type that requires a load countermeasure in the peeling direction that acts on the connecting portion between the flange portion (inner side side flange 28E) on the side wall 28B side of the front side member 18 and the dash panel 14. The load in the peeling direction can be converted into the load in the shearing direction by the member (amount).

  [Supplementary explanation of this embodiment]

  Other embodiments will be described below. In addition, about the same component as embodiment mentioned above, the same number is attached | subjected and the description is abbreviate | omitted suitably.

  A front side member extension 60 shown in FIG. 7 includes a base portion 60A having the same shape as the base portion 34A shown in FIG. 3, and an extended portion 60B that is bent horizontally at the vehicle front side by bending the lower edge of the base portion 60A. And is composed of. When assembling, the extended portion 60B of the front side member extension 60 is attached to the lower surface of the upper wall portion 28A of the front side member inner 28 and joined by spot welding.

  According to the above configuration, since the extending portion 60B extends from the lower edge of the front side member extension 60 to the vehicle front side, the flange portion (the inner side upper flange 28D) on the upper wall portion 28A side of the front side member 18 is provided. ) And the dash panel 14 is effective when it is particularly desired to reduce the load in the peeling direction that acts on the bonding site. In other words, according to the above configuration, it is necessary to take measures against the load in the peeling direction that acts on the connecting portion between the flange portion (inner side upper flange 28D) on the upper wall portion 28A side of the front side member 18 and the dash panel 14. The load in the peeling direction can be converted into the load in the shearing direction with the minimum necessary members (amount) for the vehicle type.

  The front side member extension 62 shown in FIG. 8 is a composite of the front side member extension 34 shown in FIG. 3 and the front side member extension 60 shown in FIG. That is, the front side member extension 62 includes a base portion 62A having the same shape as the base portion 34A shown in FIG. 3, and a first leg extending vertically from the vicinity of the inner end portion of the base portion 62A to the vehicle front side. It is comprised by the part 62B and the 2nd leg part 62C extended horizontally from the lower edge of the base 62A to the vehicle front side. The first leg portion 62B is spot welded to the inner wall surface of the side wall portion 28B of the front side member inner 28, and the second leg portion 62C is spot welded to the lower surface of the upper wall portion 28A of the front side member inner 28. .

  According to the above configuration, both the function of the front side member extension 34 shown in FIG. 3 and the function of the front side member extension 60 shown in FIG. 7 can be exhibited. Therefore, the connecting portion of the rear end portion 18A of the front side member 18 on the side wall portion 28B side (inner side side flange 28E) and the dash panel 14 and the upper wall portion 28A side flange portion (inner side upper flange 28D). ) And the dash panel 14 are effective when the load in the peeling direction acting on both of the bonding sites is desired to be reduced in a balanced manner. In other words, the connecting portion between the flange portion (inner side side flange 28E) on the side wall portion 28B side of the front side member 18 and the dash panel 14, and the flange portion (inner side upper portion) on the upper wall portion 28A side of the front side member 18 The load in the peeling direction is converted into the load in the shearing direction with the minimum number of members (quantity) for all types of vehicles that require measures against the load in the peeling direction that acts on the connecting part of the flange 28D) and the dash panel 14. can do.

  The front side member extension 64 shown in FIG. 9 is obtained by dividing the front side member extension 62 shown in FIG. 8 into two in the vehicle width direction. That is, the front side member extension 64 includes a first front side member extension member 66 including a first base portion 66A and a first leg portion 66B, and a second front side member extension member including a second base portion 68A and a second leg portion 68B. 68. In this case, since the opposing corners of the inner side upper flange 28D and the inner side flange 28E are not connected to each other, the ridge line portion 56 is caused by the displacement of the front side member 18 in the vehicle front-rear direction. It does not have a function to suppress stress concentration.

FIG. 5 is an enlarged perspective view of a portion taken along line 1 of FIG. 4 showing an enlarged main part of the vehicle body front structure according to the present embodiment. FIG. 2 is an enlarged perspective view showing a state in which a front side member extension shown in FIG. 1 is attached to a rear end portion of a front side member. It is an expansion perspective view which isolate | separates and shows the front side member, front side member extension, and dash panel which are shown by FIG. 1 is an overall perspective view of a vehicle including a vehicle body front structure according to an embodiment. (A) is a side view which shows the state before the displacement of the vehicle body front part structure which is proportional, (B) is a side view which shows the state which the front side member displaced by the road surface input at the time of rough road driving | running | working. (A) is an enlarged perspective view of the connecting portion between the front side member and the dash panel before the front side member is displaced in the vehicle front-rear direction, and (B) is the front side member in the vehicle front-rear direction. It is an expansion perspective view of the same joint part showing the state where this displacement occurred. It is an expansion perspective view which shows another embodiment of a front side member extension in relation to a front side member inner. It is an expansion perspective view which shows another embodiment of a front side member extension in relation to a front side member inner. It is an expansion perspective view which shows another embodiment of a front side member extension in relation to a front side member inner.

Explanation of symbols

14 Dash panel 16 Car body front part 18 Front side member 18A Rear end part 28A Upper wall part 28B Side wall part 28D Inner side upper flange (flange part on the upper wall side)
28E Inner side flange (side wall flange)
34 Front Side Member Extension 34A Base 34B Extension 42 First Spot Weld 44 44 First Spot Weld 46 First Spot Weld 60 Front Side Member Extension (Reinforcement Member)
60A Base 60B Extension 62 Front side member extension (reinforcement member)
62A Base 62B First leg 62C Second leg 64 Front side member extension (reinforcing member)
66 First front side member extension member 66A First base 66B First leg 68 Second front side member extension member 68A Second base 68B Second leg

Claims (5)

A dash panel that separates the front of the vehicle body and the cabin;
A pair of left and right front side members arranged along the vehicle longitudinal direction on both sides of the front part of the vehicle body and provided with flange portions for coupling to the dash panel at the rear end part;
A base portion that is interposed between the flange portion of the front side member and the dash panel and is welded to the flange portion and the dash panel, and extends from the base portion to the vehicle front side and is welded to the inner wall surface of the front side member. A reinforcing member configured to include an extending portion,
A vehicle body front structure. The front side member has a substantially rectangular cross-sectional shape,
The base portion is interposed between the flange portion on at least the side wall side of the front side member and the dash panel, and the extension portion is welded to the side wall of the front side member.
The vehicle body front part structure according to claim 1. The front side member has a substantially rectangular cross-sectional shape,
The base portion is interposed between at least the upper wall flange portion of the front side member and the dash panel, and the extension portion is welded to the upper wall of the front side member.
The vehicle body front part structure according to claim 1. The front side member has a substantially rectangular cross-sectional shape,
The base portion has a shape straddling both the flange portion on the side wall side and the flange portion on the upper wall side of the front side member, and is interposed between the flange portion and the dash panel, and the extension portion is a front portion. A first leg welded to the inner surface of the side wall of the side member and a second leg welded to the inner surface of the upper wall of the front side member;
The vehicle body front part structure according to claim 1. The flange portion has a flange portion on the side wall side and a flange portion on the upper wall side that are arranged around the ridge line portion on the rear end side of the front side member when viewed in the longitudinal direction of the front side member,
The base portion has a shape straddling both of the flange portion on the side wall side and the flange portion on the upper wall side, and is welded to both the flange portion on the side wall side and the flange portion on the upper wall side to thereby form the flange portion on the side wall side. And the flange on the upper wall side
The vehicle body front part structure according to any one of claims 1 to 4, wherein the vehicle body front part structure is provided.

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