JP2017170954A - Front structure of car body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a front structure of a car body, which can restrain a front bulkhead from being brought down forward by a ground load and improve assemblability.SOLUTION: A front structure of a car body comprises a front fastening part A1 in which a vertical frame part 50 of a front bulk head and a front side frame are fastened together, and a rear fastening part A2 in which the vertical frame part 50 and a front side frame are fastened together in the rear of the front fastening part A1. At least a lower part of the vertical frame part 50 presents a closed section structure, and the front and rear fastening parts A1 and A2 are arranged in a vertically offset manner.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a vehicle body front structure.

  Conventionally, a front bulkhead having a rectangular frame shape in front view is bolted to the front end portions of a pair of left and right front side frames of a vehicle (see Patent Document 1). In the structure described in Patent Document 1, the rear surface of the front bulkhead is bolted to the flange portion of the front side frame.

Japanese Patent No. 4945324

  When a vehicle having such a structure travels on a curved road surface between a horizontal surface and an inclined surface, the front bulkhead of the vehicle may be grounded. In this case, the ground load applied to the lower end portion of the front bulkhead acts as a moment for tilting the front bulkhead forward. Therefore, a structure capable of suitably suppressing the front bulkhead from falling forward due to a ground load is desired.

  Moreover, in the structure described in Patent Document 1, since the bolt fastening is performed from the rear of the front bulkhead, the assembly work is difficult.

  The present invention has been made in view of the above points, and provides a vehicle body front structure that can prevent the front bulkhead from tipping forward due to a grounding load and improve assembly. Let it be an issue.

  In order to solve the above-described problems, a vehicle body front structure according to the present invention includes a front side frame that extends in the front-rear direction of a vehicle, and a vertical frame portion of a front bulkhead that is attached to a front end portion of the front side frame. A front fastening part to which the vertical frame part and the front side frame are fastened, and the vertical frame part and the front side frame at the rear of the front fastening part. A rear fastening portion to be fastened, and at least a lower portion of the vertical frame portion has a closed cross-sectional structure, and the front fastening portion and the rear fastening portion are arranged to be offset in the vertical direction. It is characterized by being.

According to this configuration, since the rear fastening portion is disposed at a position offset in the vertical direction with respect to the front fastening portion, the assembling property of the front fastening portion and the rear fastening portion from the front can be improved.
In addition, since at least the lower part of the vertical frame portion of the front bulkhead has a closed cross-sectional structure, the vehicle travels on a curved road surface between a horizontal surface and an inclined surface, and the lower end portion of the front bulkhead contacts the road surface. While securing rigidity, the upper part of the vertical frame portion can be reduced in weight as an open cross-sectional structure.
Further, since the front bulkhead and the front side frame are bolted by the rear fastening portion and the front fastening portion, when the vehicle travels on a curved road surface between the horizontal surface and the inclined surface, the lower end portion of the front bulkhead is Even if it contacts the road surface, the front bulkhead can be prevented from falling forward.

  The front fastening portion and the rear fastening portion may be arranged to wrap in the vehicle width direction.

  According to such a configuration, since the front fastening portion and the rear fastening portion are arranged at a position where the front fastening portion wraps in the vehicle width direction, the vertical frame portion is prevented from being twisted by a ground load, and the front bulkhead is further It can suppress more suitably that it falls forward.

  The vertical frame portion includes at least an inner wall portion, a front wall portion, and a rear wall portion, and has an outer wall portion below the front side frame to form a closed cross-sectional structure, and the front wall A front extension portion extending outward in the vehicle width direction and constituting a part of the front fastening portion, and a part of the rear fastening portion extending outward in the vehicle width direction from the rear wall portion. And a rear extension portion to be configured.

According to this configuration, since the vertical frame portion includes the inner wall portion, the front wall portion, and the rear wall portion, the storage space for the cooling device such as the radiator can be configured inward in the vehicle width direction of the front end portion of the front side frame. .
Further, since the front extension portion and the rear extension portion are provided, the ground load can be suitably transmitted from the front wall portion and the rear wall portion of the vertical frame portion to the front side frame.

  The front fastening portion includes the front extension portion and a front flange portion that extends in a vertical direction from a front end portion of the front side frame and is fastened to the front extension portion, and the rear The fastening portion includes the rear extension portion and a rear bracket portion that extends downward from a lower wall portion of the front side frame and is fastened to the rear extension portion, and the rear bracket portion is A base attached to the lower wall, an attachment extending downward from the front end of the base, and extending in the front-rear direction from the base and the attachment across the bent portion between the base and the attachment And a side wall portion to be provided.

  According to this configuration, since the side wall portion of the bracket with the lower nut supports the bending moment that the front bulkhead falls forward due to the grounding load, the front bulkhead is prevented from falling forward and the grounding load is reduced to the side wall. It can transmit suitably to a front side frame via a part.

  The outer wall portion may have a bead shape extending in the vertical direction.

  According to this configuration, the rigidity of the vertical frame portion below the front side frame can be improved while suppressing an increase in weight.

  The vehicle body front portion structure may include a weakened portion attached to a lower end portion of the vertical frame portion and more fragile than the vertical frame portion.

  According to such a configuration, the front bulkhead can be suitably prevented from falling forward by being crushed so that the fragile portion is crushed by the ground load in the early stage of ground contact.

  The front bulkhead has a rectangular frame shape when viewed from the front, and the vertical frame portion constitutes an inner wall portion, a front wall portion, and a rear wall portion and has an opening on the outer side in the vehicle width direction, and the front side And a lid member that constitutes the outer wall portion below the frame.

  According to this configuration, the U-shaped main body member improves the rigidity of the rectangular frame shape of the front bulkhead, and the lid member further improves the rigidity below the front side frame of the vertical frame portion. Further, since the lid member is not provided on the upper side, the weight can be reduced.

  A bumper beam is fastened to the front fastening portion, and the bumper beam may be fixed to the vertical frame portion at a portion different from the front fastening portion.

  According to such a configuration, the bumper beam can be fastened to the front fastening portion in a state where the bumper beam is pre-assembled to the vertical frame portion of the front bulkhead, so that the assembling property can be improved.

  According to the present invention, in the front structure of the vehicle body, the front bulkhead can be prevented from falling forward due to a grounding load, and the assemblability can be improved.

It is a perspective view which shows the vehicle body front part structure which concerns on embodiment of this invention. It is a front view which shows the vehicle body front part structure which concerns on embodiment of this invention. It is a top view which shows the vehicle body front part structure which concerns on embodiment of this invention. It is the perspective view which looked at the vertical frame part of the front side frame and the front bulkhead from the vehicle width direction inner side. It is the side view which looked at the vertical frame part of the front side frame and the front bulkhead from the vehicle width direction outside. It is the disassembled perspective view which looked at the vertical frame part of the front side frame and the front bulkhead from the vehicle width direction outer side. (A) is the perspective view which looked at the front-end part of the front side frame from the slightly front inside the vehicle width direction, (b) is the perspective view which looked at the front end part of the front side frame from the slightly rear inside the vehicle width direction. is there. It is the VIII-VIII sectional view taken on the line of FIG. It is the IX-IX sectional view taken on the line of FIG. It is the elements on larger scale of a vehicle body front part structure, (a) is a front view which shows a front fastening part, (b) is a front view which shows a rear fastening part.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the description, the same elements are denoted by the same reference numerals, and redundant description is omitted. Note that “front and rear” indicated by arrows in each figure indicates the longitudinal direction of the vehicle body, “up and down” indicates the vertical direction of the vehicle body, and “left and right” indicates the left and right direction (vehicle width direction) viewed from the driver's seat. Show. Moreover, in each figure, description of the volt | bolt B and the nut N is abbreviate | omitted suitably.

<Car body front structure>
As shown in FIGS. 1 to 3, a vehicle body front structure 1 according to an embodiment of the present invention includes a pair of left and right front side frames 2 and 2 and a front end portion of a pair of left and right front side frames 2 and 2. The front bulkhead 3 is attached, the bumper beam 4 is installed between the front end portions of the pair of left and right front side frames 2, 2, and the impact absorbing member 5 is attached to the front surface of the bumper beam 4.

<Front side frame>
The pair of left and right front side frames (also referred to as front side members) 2 and 2 are metal structural members that extend in the front-rear direction. The front side frames 2 and 2 are formed in a hollow structure by combining, for example, rolled steel plates having a U-shaped cross section.

  As shown in FIG. 4 to FIG. 6, the front side frame 2 includes an axial crushing allowable portion 10, a bending deformation allowable portion 20, a flange member 30, and a pair of upper and lower rear bracket members 40, 40. Prepare.

≪Axial crushing tolerance part≫
The shaft crushing allowable portion 10 is a member that constitutes the front portion of the front side frame 2 and is configured to be more fragile than the bending deformation allowable portion 20 by selection of material, thickness, and the like.
At the time of front collision of the vehicle, the shaft crushing allowable portion 10 is crushed in the axial direction of the shaft crushing allowable portion 10 by the front collision load F1.

  A plurality of concave portions 10a arranged in the front-rear direction are formed as weak portions in the inner wall portion, the outer wall portion, and the lower wall portion of the axial crushing allowable portion 10. The plurality of recesses 10a have a vertically long shape (a shape that is long in the vertical direction in the inner wall portion and the outer wall portion and a shape that is long in the vehicle width direction in the lower wall portion), and is recessed toward the inside of the axial crushing allowable portion 10. It is out. Due to the plurality of concave portions 10a, the axial crushing allowable portion 10 is easily crushed in the axial direction at the time of frontal collision of the vehicle.

≪Bending deformation allowable part≫
The bending deformation allowable portion 20 is a member that constitutes the center portion and the rear portion of the front side frame 2 and is configured to have higher rigidity than the axial crush allowable portion 10 by selection of material, thickness, and the like.
The damper housing 6 is joined to the outer wall portion at the rear portion of the bending deformation allowing portion 20 by welding or the like (see FIG. 3).
The damper housing 6 has a substantially U shape having an opening on the outer side in the vehicle width direction in a plan view, and a damper on which a front wheel of the vehicle is suspended is accommodated therein.
At the time of the frontal collision of the vehicle, the bending deformation allowing portion 20 is seen in plan view by the front collision load F1 due to the bent shape of the bending deformation allowing portion 20 and the influence of assembly with other members such as the damper housing 6. It is accordion-shaped, that is, bent and deformed so that peaks and valleys appear alternately (see the thick dotted line in FIG. 3).

≪Flange member≫
The flange member 30 is a metal member attached to the front end portion of the shaft crushing allowable portion 10.
The flange member 30 includes a base portion 31 that has a U-shape when viewed from the front by the outer wall portion, the upper wall portion, and the lower wall portion, and the outside of the rectangular cylindrical portion 31 from the front end portion of the base portion 31 (upward, outward in the vehicle width direction, And a flange portion 32 extending downward). The base portion 31 is joined to the front end portion of the axial crushing allowable portion 10 by welding or the like via another member.

≪Front flange with nut≫
The upper part of the flange part 32 constitutes an upper front flange part 33 with a nut. The upper flange portion 33 with nut is formed with a hole 33a for inserting a bolt B, and a nut N is attached to the rear side of the hole 33a.
The lower portion of the flange portion 32 constitutes a lower front flange portion 34 with a nut. The lower flange portion 34 with a nut has a hole 34a for inserting a bolt B, and a nut N is attached to the rear side of the hole portion 34a.
Further, a hole 32a for inserting the bolt B is formed in the intermediate portion of the flange portion 32, and a nut N is attached to the rear side of the hole 32a.

≪Rack bracket member with nut≫
The rear bracket member 40 with a nut is a metal member that is attached to a portion that is behind the flange portion 32 of the flange member 30 of the shaft crushing allowable portion 10.
As shown in FIGS. 6 and 7, the rear bracket member 41 with nut includes a base end portion 41 attached to the upper wall portion or the lower wall portion of the axial crushing allowable portion 10, and a vertical direction from the front end portion of the base end portion 41. And a side wall 43 extending rearward from one end in the vehicle width direction of the base end portion 41 and the mounting portion 42 is a metal member that is integrally provided. .
A hole 42a for inserting the bolt B is formed in the mounting portion 42, and a nut N is attached to the rear side of the hole 42a.
The side wall part 43 is provided straddling the bending part between the base end part 41 and the attaching part 42, and exhibits L shape by side view.

<Front bulkhead>
As shown in FIG. 2, the front bulkhead 3 is a metal structural member that has a rectangular frame shape when viewed from the front.
The front bulkhead 3 includes a pair of left and right vertical frame portions 50 and 50 and a pair of upper and lower horizontal frame portions 60 and 60 provided between the pair of left and right vertical frame portions 50 and 50.
The upper horizontal frame portion 60 is constructed between the upper end portions of the vertical frame portions 50 and 50, and the lower horizontal frame portion 60 is constructed between the lower end portions of the vertical frame portions 50 and 50. In the present embodiment, the upper horizontal frame portion 60 has a closed cross-sectional structure, and the lower horizontal frame portion 60 has an open cross-sectional shape.

≪Vertical frame part≫
As shown in FIG. 4, the vertical frame portion 50 includes an inner wall portion 51, a front wall portion 52, a rear wall portion 53, and an outer wall portion 54.
The inner wall portion 51, the front wall portion 52, and the rear wall portion 53 are provided over the entire vertical frame portion 50, and the outer wall portion 54 is provided below the front side frame 2 in the vertical frame portion 50. It has been.
That is, the vertical frame portion 50 has a closed cross-sectional shape below the front side frame 2 due to the inner wall portion 51, the front wall portion 52, the rear wall portion 53, and the outer wall portion 54.
Further, the vertical frame portion 50 has an open cross-sectional shape by the inner wall portion 51, the front wall portion 52, and the outer wall portion 54 at the same height as the front side frame 2 and above it.

The vertical frame portion 50 includes a pair of upper and lower front extension portions 55 and 55 extending outward from the front wall portion 52 in the vehicle width direction, and a pair of upper and lower portions extending from the rear wall portion 53 outward in the vehicle width direction. And rear extension portions 56, 56.
The front extension 55 is formed integrally with the front wall 52, and the rear extension 56 is formed by another member joined to the rear wall 53 or the outer wall 54 by welding or the like.
The upper front extension 55 is provided with a hole 55a for inserting a bolt B at a position corresponding to the hole 33a. The lower front extension 55 is formed with a hole 55a for inserting a bolt B at a position corresponding to the hole 34a.
The upper rear extension 56 is formed with a bolt B insertion hole 56a at a position corresponding to the hole 42a of the upper rear bracket member 40 with a nut. The lower rear extension 56 is formed with a hole 56a for inserting a bolt B at a position corresponding to the hole 42a of the lower bracket member 40 with a nut.

As shown in FIG. 3, the inner wall portion 51 is formed with a pair of front and rear bead portions 51a and 51a extending in the vertical direction. The bead portions 51 a and 51 a are formed from the vicinity of the lower end portion of the inner wall portion 51 to the upper side of the upper end portion of the shaft collapse allowing portion 10.
In the inner wall portion 51, the space between the pair of front and rear bead portions 51a and 51a is located more outward in the vehicle width direction than the outside of the pair of front and rear bead portions 51a and 51a.
Between the pair of front and rear bead portions 51a and 51a of the inner wall portion 51, a plurality of holes (openings) 51b and 51b having a vertically long shape are formed.
One hole 51 b is formed at the same height as the axial crushing allowable portion 10 of the front side frame 2.

In the present embodiment, the plurality of hole portions 51b are formed in a recessed portion 51c having a vertically long shape formed between a pair of front and rear bead portions 51a and 51a. The recess 51c is located outward in the vehicle width direction from the outside of the recess 51c.
In other words, the front bead portion 51a is configured between the front wall portion 52 and a ridge line extending in the vertical direction on the front side of the concave portion 51c, and the rear bead portion 51a is formed between the rear wall portion 53 and the concave portion 51c. It is comprised between the ridgeline extended in the up-down direction of a rear side.

Further, a plurality of hole portions (openings) 51d arranged alternately with the above-described hole portions 51b are formed between the pair of front and rear bead portions 51a and 51a of the inner wall portion 41.
The hole 51d is a round hole for positioning, and is deformed so as to be crushed in the front-rear direction in the same manner as the hole 51b at the time of front collision of the vehicle.

  The pair of front and rear bead parts 51a and 51a are for improving the rigidity of the vertical frame part 50 with respect to the ground load F2, and the holes 51b and 51d are provided in the front and rear direction of the vertical frame part 50 with respect to the front collision load F1. This is to improve the ease of deformation.

The outer wall portion 54 is formed with a pair of front and rear bead portions 54a, 54a extending in the vertical direction. The bead portions 54 a and 54 a are formed from the lower end portion to the upper end portion of the outer wall portion 54.
In the outer wall portion 54, the recess between the pair of front and rear bead portions 54 a and 54 a is positioned more inward in the vehicle width direction than the pair of front and rear bead portions 54 a and 54 a.
In other words, the front bead portion 54a is configured between a front flange portion 57 (described later) and a ridge line extending in the vertical direction on the front side of the concave portion, and the rear bead portion 54a is formed on the rear flange. It is comprised between the part 57 and the ridgeline extended in the up-down direction of the back side of a recessed part.

  The pair of front and rear bead portions 54a, 54a is for improving the rigidity of the vertical frame portion 50 with respect to the ground load F2.

≪Main body member and lid member≫
The inner wall portion 51, the front wall portion 52, the rear wall portion 53, and the front extension portion 55 are configured by a main body member 50A having an opening on the outer side in the vehicle width direction, and the outer wall portion 54 is configured by a lid member 50B. .
As shown in FIG. 8, the lid member 50 </ b> B includes flange portions 57 and 57 extending outward from the front and rear end portions of the outer wall portion 54 in the vehicle width direction.
The front flange portion 57 is disposed on the rear side of the front wall portion 52 and joined to the front wall portion 52 by welding or the like.
The rear flange portion 57 is disposed on the front side of the rear wall portion 53 and joined to the rear wall portion 53 by welding or the like.

≪Vulnerable part≫
As shown in FIG. 1, the vehicle body front structure 1 includes a pair of left and right fragile portions 70, 70.
The fragile portion 70 is a metal member attached to the lower end portion of the vertical frame portion 50.
The fragile portion 70 is a member configured to be more fragile than the vertical frame portion 50 by selecting a material, a thickness, and the like.
In the present embodiment, the fragile portion 70 is formed into a substantially housing shape by bending a metal thin plate, and a member exhibiting the substantially housing shape is welded or the like to the lower end portion (front wall portion 52) of the vertical frame portion 50. , The rear wall portion 53 and the like).
When the vehicle is in contact with the front bulkhead 3 of the vehicle, the fragile portion 70 is crushed so as to be crushed by the contact load F2.

<Bumper beam and shock absorbing member>
As shown in FIG. 1, the bumper beam 4 is a metal member laid between a pair of left and right vertical frame portions 50 and 50 at the same height as the pair of left and right front side frames 2 and 2. The shock absorbing member 5 is attached to the front surface of the bumper beam 4 and is a metal or resin member that protects a collision object by positively deforming and absorbing the shock when the vehicle collides. .

The left end portion of the bumper beam 4 is fixed (bolt fastened) to the vertical frame portion 50 of the front bulkhead 3 via a metal fixing member 80.
The fixing member 80 includes a base portion 81 that is joined to the front wall portion 52 of the vertical frame portion 50 by welding or the like, and a flat plate portion 82 that is bolted to the base portion 81.
The left end portion of the bumper beam 4 is bolted to the flat plate portion 82 of the fixing member 80.
In the bumper beam 4, holes 4a and 4a for inserting bolts B are formed at positions corresponding to the holes 55a and 33a and positions corresponding to the holes 55a and 34a, respectively.
The bumper beam 4 is formed with a hole 4b for inserting a bolt B at a position corresponding to the hole 32a.

As shown in FIG. 9, the right end portion of the bumper beam 4 is fixed (bolt fastened) to the vertical frame portion 50 of the front bulkhead 3 via a metal plate 90.
The plate 90 is a thin plate provided between the front wall portion 52 of the right vertical frame portion 50 and the right end portion of the bumper beam 4, and is used for attaching a tow hook (so-called eyebolt) at the front portion of the vehicle. Is. Bolt B insertion holes 52a and 90a are respectively formed in the front wall 52 and the plate 90 of the right vertical frame 50, and the front wall 52 and the plate 90 are formed in the holes 52a and 90a. Bolts are fastened from the front. The bumper beam 4 and the plate 90 are joined by welding or the like. Further, the bumper beam 4 and the shock absorbing member 5 are formed with openings 4c and 5a at portions located in front of the holes 52a and 90a, respectively.

<Fastening structure>
As shown in FIG. 10, the vehicle body front structure 1 includes a pair of upper and lower front fastening portions A1 and A1, a pair of upper and lower rear fastening portions A2 and A2, and a fastening portion A3.

≪Front fastening part≫
As shown in FIG. 10A, the upper front fastening portion A1 includes a bumper beam 4, a front extension 55 on the upper side of the vertical frame portion 50 of the front bulkhead 3, and a front nut with an upper side of the front side frame 2. The flange portion 33 and the flange portion 33 are overlapped in order from the front side, and are bolted from the front in these hole portions 4a, 55a, and 33a.
The lower front fastening part A1 includes the bumper beam 4, the front extension part 55 on the lower side of the vertical frame part 50 of the front bulkhead 3, and the front flange part 34 with a nut on the lower side of the front side frame 2 on the front side. The holes 4a, 55a and 34a are overlapped in order from the front and bolted from the front.
In the present embodiment, the front fastening portion A1 refers to a region where all of the bolt-fastened bumper beam 4, the front extension portion 55, and the front flange portion 33 with a nut are in contact with each other.
When the front fastening portion A1 is a fastening portion between the front side frame 2 and the vertical frame portion 50, the front extension portion 55 and the front flange portions 33 and 34 with nuts are overlapped with each other so as to contact each other. It can be said that the area | region which is in contact is front fastening part A1.
In particular, with respect to the upper front fastening part A1, two bolts B are used, and the front extension part 55 and the front part with a nut fastened with bolts are provided on the outer side in the vehicle width direction of the front fastening part A1 corresponding to the above-described definition. It can be said that the region where the flange portions 33 overlap and contact each other is also the front fastening portion A1.

≪Rear fastening part≫
As shown in FIG. 10B, the upper rear fastening portion A2 includes an upper rear extension 56 on the vertical frame portion 50 of the front bulkhead 3, and a rear bracket member 40 with a nut on the upper side of the front side frame 2. Are overlapped on the front and back, and bolts are fastened from the front in these holes 56a and 42a.
The lower rear fastening portion A2 is formed by overlapping the lower rear extension 56 of the vertical frame portion 50 of the front bulkhead 3 and the rear bracket member 40 with a nut on the lower side of the front side frame 2 in the front-rear direction. These holes 56a and 42a are configured by bolting from the front.
In the present embodiment, the rear fastening portion A2 refers to a region in which the bolt-fastened rear extension 56 and the nut-attached rear bracket member 40 are in contact with each other.

≪Fastening part≫
As shown in FIG. 10A, the fastening portion A3 is provided between the pair of upper and lower front fastening portions A1 and A1, and the bumper beam 4 and the flange portion 32 of the front side frame 2 are overlapped in the front-rear direction. These are configured by fastening bolts from the front.
In addition, the impact absorbing member 5 has an opening 5b at a site in front of the fastening portion A3.

As shown in FIG. 10B, the pair of upper and lower rear fastening portions A2 and A2 are provided at positions offset vertically relative to the front side frame 2 with respect to the front side frame 2 from the pair of upper and lower front fastening portions A1 and A1. It has been.
That is, the upper rear fastening portion A2 is provided above the upper front fastening portion A1, and the lower rear fastening portion A2 is provided below the lower front fastening portion A1. All the fastening portions A1 and A2 are visible in front view.
In the present invention, the pair of upper and lower front fastening portions A1 and A1 and the pair of upper and lower rear fastening portions A2 and A2 have holes for inserting the bolts B of the fastening portions A1 and A2 visible in front view. What is necessary is just to be offset up and down so that a bolt fastening operation | work is possible.

  Further, the pair of upper and lower rear fastening portions A2 and A2 are provided at a position overlapping (wrapping) with the pair of upper and lower front fastening portions A1 and A1 in the vehicle width direction when viewed from the front.

<At the time of front collision>
At the time of frontal collision of the vehicle, as shown in FIG. 5, a rearward frontal collision load F <b> 1 acts on the vehicle body front structure 1. The axial crushing allowable portion 10 is axially crushed by the front collision load F1 and decreases to the width of the remaining region B1.
On the other hand, the vertical frame portion 50 of the front bulkhead 3 has a hole 51b in a region B2 larger than the remaining region B1. The vertical frame portion 50 is deformed so that the holes 51b and 51d are crushed in the front-rear direction at the same time as the axial crushing of the axial crushing allowable portion 10 by the front collision load F1, or is deformed to be bent at the holes 51b and 51d. At the same time as or after the deformation, the mounting portion 42 of the rear flange portion 40 with the nut is deformed so as to fall backward (see the two-dot chain line in FIG. 5), so that the region B3 in the remaining region B1 is reduced. .

In other words, at the same height as the axial crushing allowable portion 10, the width in the front-rear direction of the vertical frame portion 50 is larger than the width B1 in the front-rear direction when the axial crushing allowable portion 10 is completely crushed by the front impact load F1.
Further, holes 51b and 51d are formed in such a wide portion of the vertical frame portion 50.
The vertical frame portion 50 is deformed so that the holes 51b and 51d are crushed by the front impact load F1, or is deformed so as to be bent at the holes 51b and 51d, so that the remaining region B3 having a front-rear width of the remaining region B1 or less. Deforms to become smaller.
At the same height as the axial crushing allowable portion 10, the difference between the width in the front-rear direction of the vertical frame portion 50 and the width in the front-rear direction of the hole 51b may be equal to or less than the front-rear width of the remaining region B1 of the axial crushing allowable portion. desirable.

<At grounding>
When the vehicle travels on a curved road surface between a horizontal surface and an inclined surface, the front bulkhead 3 of the vehicle may be grounded. At the time of grounding of the front bulkhead 3 of the vehicle, a grounding load F2 that is obliquely upward rearward acts on the lower end portion of the front bulkhead 3 as shown in FIG. The fragile portion 70 is crushed so as to be crushed by the ground load F2. Moreover, since the grounding load F2 is smaller than the front collision load F1, the bending deformation of the side wall 43 of the rear flange portion 40 with the nut due to the grounding load F2 is suppressed. Accordingly, the ground load F2 is transmitted to the front side frame 2 through the vertical frame portion 50 and the side wall portion 43 of the lower flange portion 40 with a nut.

  In the present embodiment, the side wall portion 43 of the lower flange portion with nut 40 is formed wider than the side wall portion 43 of the upper flange portion with nut 40 in order to suitably transmit the ground load F2.

In the vehicle body front structure 1 according to the embodiment of the present invention, the pair of upper and lower rear fastening portions A2 and A2 are disposed at positions that are vertically offset from the pair of upper and lower front fastening portions A1 and A1. The assembling property of the front fastening part A1 and the rear fastening part A2 can be improved.
Further, in the vehicle body front structure 1, at least the lower part of the vertical frame portion 50 of the front bulkhead 3 exhibits a closed cross-sectional structure, so that the vehicle travels on a curved road surface between a horizontal plane and an inclined plane and the front bulkhead 3 It is possible to reduce the weight of the upper portion of the vertical frame portion 50 as an open cross-sectional structure while ensuring rigidity when the lower end portion contacts the road surface.
In the vehicle body front structure 1, the front bulkhead 3 and the front side frame 2 are bolted by the pair of upper and lower rear fastening portions A2 and A2 and the pair of upper and lower front fastening portions A1 and A1, so that the vehicle is level. Even when the lower end portion of the front bulkhead 3 contacts the road surface when traveling on a curved road surface between the front and the inclined surfaces, the front bulkhead 3 can be prevented from falling forward.

  The vehicle body front structure 1 is disposed at a position where the pair of upper and lower front fastening portions A1 and A1 and the pair of upper and lower rear fastening portions A2 and A2 wrap in the vehicle width direction. It is possible to prevent the portion 50 from being twisted and to more suitably suppress the front bulkhead 3 from falling forward.

Further, in the vehicle body front structure 1, the vertical frame portion 50 includes an inner wall portion 51, a front wall portion 52, and a rear wall portion 53, so that a storage space for a cooling device such as a radiator is used as a vehicle width at the front end portion of the front side frame 2. Can be configured inwardly in the direction.
Further, since the vehicle body front part structure 1 has a closed cross-sectional structure below the front side frame 2 of the vertical frame part 50, the front bulkhead 2 is grounded without inhibiting the axial crushing of the axial crushing allowable part 10. The rigidity with respect to the ground contact load F2 can be improved.
Further, since the vehicle body front structure 1 includes the front extension 55 and the rear extension 56, the ground load F2 is suitably transmitted from the front wall 52 and the rear wall 53 of the vertical frame 50 to the front side frame 2. be able to.

  Further, the vehicle body front structure 1 supports the bending moment at which the front bulkhead 3 is tilted forward by the ground load F2 because the side wall portion 43 of the bracket 40 with the lower nut supports the front bulkhead 3 to be tilted forward. In addition, the ground load F2 can be suitably transmitted to the front side frame 2 through the side wall portion 43.

  Moreover, since the vehicle body front structure 1 includes the bead portion 54a formed on the outer wall portion 54 of the vertical frame portion 50, the rigidity of the vertical frame portion 50 below the front side frame 2 is suppressed while suppressing an increase in weight. Can be improved.

  Moreover, since the vehicle body front part structure 1 includes the fragile portion 70, the front bulkhead 3 is preferably prevented from falling forward by being crushed so that the fragile portion 70 is crushed by the grounding load F2 in the initial stage of ground contact. Can do.

  Further, in the vehicle body front structure 1, since the vertical frame portion 50 is constituted by the main body member 50 </ b> A and the lid member 50 </ b> B, the main body member 50 </ b> A having a U-shape improves the rigidity of the rectangular frame shape of the front bulkhead 3. At the same time, the lid member 50B further improves the rigidity below the front side frame 3 of the vertical frame portion 50, and the lid member 50B is not provided above the front side frame 3, so that weight reduction can be realized. it can.

  Moreover, since the vehicle body front part structure 1 can be fastened to the front fastening part A1 in a state where the bumper beam 4 is attached to the vertical frame part 50 of the front bulkhead 3 in advance, the assembling property can be improved.

Moreover, since the hole 51b is formed in the vertical frame portion 50 of the front bulkhead 3 in the vehicle body front structure 1, the vertical frame portion 50 is crushed in the front-rear direction by the front collision load F1 when the vehicle collides. The front bulkhead 3 is not deformed and does not hinder the deformation of the shaft collapse allowing portion 10.
Moreover, since the front bulkhead 3 is provided on the inner side in the vehicle width direction of the shaft collapse allowing portion 10 in the vehicle body front structure 1, it is possible to reduce the size of the vehicle body in the front-rear direction.

  Further, the vehicle body front structure 1 has the bead portions 51a formed before and after the hole portion 51b of the vertical frame portion 50, so that the rigidity with respect to the ground load F2 is improved and the vertical frame portion 50 is provided at the time of a frontal collision of the vehicle. The front bulkhead 3 is not deformed so as to be crushed in the front-rear direction by the front collision load F <b> 1, and the deformation of the shaft collapse allowing portion 10 is not hindered.

  Moreover, since the recessed part 10a as a weak part is formed in the vehicle body front part structure 1 between the front fastening part A1 and the rear fastening part A2 of the axial crushing allowable part 10, the axial crushing allowable part is caused by the front collision load F1. 10 can be suitably axially crushed.

  In the vehicle body front structure 1, the rear bracket member 40 with a nut has an L-shape when viewed from the side, so that the rear bracket member 40 with a nut bends at the bent portion due to the front collision load F <b> 1 and the front bulkhead 3 is retracted. The impact energy can be absorbed appropriately.

  Further, in the vehicle body front portion structure 1, the vertical frame portion 50 has the holes 51b and 51d in the region B2 larger than the remaining region B1 after the axial crushing of the axial crushing allowable portion 10, and therefore the vertical frame portion is caused by the front collision load F1. 50 can be deformed into the remaining area B1 to suitably absorb the impact energy.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably. For example, the front fastening portion A1 and the rear fastening portion A2 may be provided on only one of the upper and lower sides with respect to the front side frame 2, and the front fastening portion A1 is provided on one of the upper and lower sides of the front side frame 2. The rear fastening portion A <b> 2 may be provided on the other upper and lower sides of the front side frame 2. Moreover, it is desirable that the bolts B (that is, each hole) of the front fastening portions A1 and A1 and the rear fastening portions A2 and A2 are arranged on a straight line extending in the vertical direction.

DESCRIPTION OF SYMBOLS 1 Vehicle body front part structure 2 Front side frame 3 Front bulkhead 4 Bumper beam 10 Shaft crushing tolerance part 10a Recessed part (fragile part)
20 Bending deformation allowable portion 30 Flange member 40 Rear bracket member with nut (rear bracket portion)
41 Base part 42 Attachment part 43 Side wall part 50 Vertical frame part 50A Main body member 50B Lid member 51 Inner wall part 51a Bead part 51b Hole part 52 Front wall part 53 Rear wall part 54 Outer wall part 54a Bead part 55 Front extension part 56 Rear extension part 57 Flange part 60 Horizontal frame part 70 Fragile part 80 Fixing member 90 Plate B Bolt F1 Front impact load F2 Ground load N Nut

Claims (8)

A front side frame extending in the longitudinal direction of the vehicle;
A vertical frame portion of a front bulkhead attached to a front end portion of the front side frame;
A vehicle body front structure comprising:
A front fastening portion to which the vertical frame portion and the front side frame are fastened;
A rear fastening part to which the vertical frame part and the front side frame are fastened behind the front fastening part,
With
At least the lower part of the vertical frame part has a closed cross-sectional structure,
The vehicle body front part structure, wherein the front fastening part and the rear fastening part are arranged so as to be offset in a vertical direction. The vehicle body front part structure according to claim 1, wherein the front fastening part and the rear fastening part are arranged to wrap in the vehicle width direction. The vertical frame portion is
While having at least an inner wall portion, a front wall portion and a rear wall portion,
Below the front side frame, it has an outer wall portion and has a closed cross-sectional structure,
A front extension that extends outward from the front wall in the vehicle width direction and forms part of the front fastening portion;
A rear extension portion extending outward in the vehicle width direction from the rear wall portion and constituting a part of the rear fastening portion;
The vehicle body front part structure according to claim 1, comprising: The front fastening portion is
The front extension;
A front flange extending from the front end of the front side frame in either of the vertical directions, and a front flange portion fastened to the front extension;
With
The rear fastening portion is
The rear extension;
A rear bracket portion extending downward from a lower wall portion of the front side frame and fastened to the rear extension portion;
With
The rear bracket portion includes a base portion attached to the lower wall portion, an attachment portion extending downward from a front end portion of the base portion, and a bent portion between the base portion and the attachment portion from the base portion and the attachment portion. The vehicle body front part structure according to claim 3, further comprising: a side wall portion extending in the front-rear direction across the vehicle. The vehicle body front part structure according to claim 3, wherein the outer wall portion has a bead shape extending in the vertical direction. The vehicle body front part structure according to claim 1, further comprising a fragile portion attached to a lower end portion of the vertical frame portion and more fragile than the vertical frame portion. The front bulkhead has a rectangular frame shape in front view,
The vertical frame portion is
A main body member that forms an inner wall portion, a front wall portion, and a rear wall portion and has an opening on the outer side in the vehicle width direction;
A lid member constituting an outer wall portion below the front side frame;
The vehicle body front part structure according to claim 1, comprising: A bumper beam is fastened to the front fastening portion,
The vehicle body front part structure according to claim 1, wherein the bumper beam is fixed to the vertical frame part at a part different from the front fastening part.

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