Vehicle body front structure

Abstract

A vehicle body front structure is provided with: a front side frame extending in the front-rear direction on the front side of a vehicle; a load transmission block, which is a cast member for connecting the rear part of a front side frame and another skeleton member, is provided with: a frame insertion part which is open to the front side and through which a rear region of the front side frame is inserted; and a load support wall which is erected from the edge of the opening in a direction orthogonal to the front-back direction, and which is provided with a bracket which protrudes in a direction intersecting the front-back direction and abuts against the front surface of the load support wall at a position further forward than the position where the front side frame is inserted into the frame insertion part. In a state in which the rear region is inserted into the frame insertion portion of the load transmission block, the front side frame is fastened and fixed to the peripheral wall of the frame insertion portion in the vertical direction by a first fastening member and fastened and fixed to the peripheral wall in the vehicle width direction by a second fastening member. The bracket is fastened and fixed to the load support wall of the load transmission block from the front-rear direction by a third fastening member.

Description

Technical Field

[0001] The invention relates to a vehicle body front structure.

[0002] This application claims priority based on Special Application No. 2023-180520 filed in Japan on October 19, 2023, and the contents are incorporated herein by reference. Background Art

[0003] In recent years, efforts to provide access to sustainable transportation systems have become increasingly active. To achieve this goal, efforts are being made to further improve traffic safety and convenience through research related to the improvement of vehicle body rigidity.

[0004] As a front structure of a vehicle body, there is known a structure in which a pair of front side frames are arranged on the left and right sides of the front of the vehicle, and the rear portions of the front side frames are connected to another frame member via load transfer blocks (for example, see Japanese Patent Application Laid-Open No. 2002-166853).

[0005] In the vehicle body front structure described in Japanese Patent Application Laid-Open No. 2002-166853, the load transfer block is composed of an upper block serving as a strut housing and a lower block connected to the lower end of the upper block, and a fitting hole extending in the front-rear direction is formed between the upper block and the lower block. The upper block and the lower block are formed integrally by casting. The rear region of the front side frame is embedded in the fitting hole formed by the upper block and the lower block.

[0006] In the case of the vehicle body front structure, a plate-like portion that abuts against the side surface of the rear region of the front side frame is provided at a portion constituting a part of the fitting hole on the upper block side, and the plate-like portion is fixed to the side surface of the front side frame by welding. After the rear region of the front side frame is fixed by welding to the upper block, the lower block is connected to the front side frame. At this time, the rear region of the front side frame is arranged in a fitting state inside the fitting hole formed between the upper block and the lower block.

[0007] In the vehicle body front structure, the load transfer block is composed of the upper block and the lower block which are cast parts, so the number of components of the load transfer block can be reduced. In addition, since the side surface of the rear region of the front side frame is welded to the plate-shaped portion of the upper block, the area of ​​the welded portion can be ensured to be large, and the support rigidity of the rear region of the front side frame can be improved. Therefore, when the impact load is input from the front of the vehicle, the front side frame can be smoothly crushed. Summary of the invention

[0008] However, in the vehicle body front structure described in Japanese Patent Application Laid-Open No. 2002-166853, the load transfer block is composed of an upper block and a lower block, and a plate-shaped portion for welding and fixing the front side frame must be formed on the upper block. Therefore, the structure of the load transfer block becomes complicated, and the work for fixing the front side frame also becomes complicated. In addition, when the load transfer block is formed by a cast component, it may be difficult to perform a firm welding depending on the shape of the abutting portion abutting the front side frame and the characteristics of the raw material of the cast component.

[0009] Therefore, currently, studies are being conducted to simplify the structure of the load transfer block and to fix the rear region of the front side frame to the load transfer block by a fastening member.

[0010] However, when the discrete multiple locations of the peripheral area of ​​the rear area of ​​the front side frame are fixed by the fastening member, when the impact load is input from the front of the vehicle, stress biased to a part of the peripheral area of ​​the front side frame is likely to act. And when stress biased to a part of the peripheral area of ​​the front side frame acts, the stress may cause the tilt or bending of the front side frame, and may hinder the smooth crushing (energy absorption) of the front side frame.

[0011] The present invention aims to provide a vehicle body front structure in which the rear region of the front side frame is fixed to the load transfer block by a fastening member and the front side frame can be smoothly crushed when an impact load is input from the front. Furthermore, the present invention further aims to contribute to the development of a sustainable transport system.

[0012] In order to achieve the above-mentioned object, the vehicle body front structure according to the solution of the present invention adopts the following structure.

[0013] (1) The scheme of the present invention comprises: a front side frame (for example, the front side frame 10 of the embodiment) extending substantially in the front-to-back direction on the side of the front portion of the vehicle; and a load transfer block (for example, the load transfer block 11 of the embodiment) which is a cast component connecting the rear portion of the front side frame to other frame members, the load transfer block having: a frame insertion portion (for example, the frame insertion portion 30 of the embodiment) opening to the front side and allowing the rear region of the front side frame to be inserted through the opening; and a load bearing wall (for example, the load bearing wall 32 of the embodiment) rising from the edge of the opening in a direction substantially orthogonal to the front-to-back direction and extending toward the frame insertion portion at a position closer to the front side frame. A bracket (for example, the bracket 33 of the embodiment) is provided at a front position of the insertion portion of the load transfer block, which protrudes in a direction intersecting the front-to-back direction and abuts against the front surface of the load-bearing wall. When the rear area of ​​the front side frame is inserted into the frame insertion portion of the load transfer block, it is fastened and fixed to the peripheral wall of the frame insertion portion from the top and bottom directions by a first fastening member (for example, the bolt 35A of the embodiment), and is fastened and fixed to the peripheral wall from the vehicle width direction by a second fastening member (for example, the bolt 35B of the embodiment). The bracket is fastened and fixed to the load-bearing wall of the load transfer block from the front-to-back direction by a third fastening member (for example, the bolt 34 of the embodiment).

[0014] According to the scheme (1) above, when an impact load is input from the front of the front side frame, the load is supported by the peripheral wall of the frame insertion portion of the load transfer block through the first fastening member and the second fastening member. At this time, the input load is supported in a distributed manner by the wall of the frame insertion portion facing the up-down direction and the wall facing the vehicle width direction through the first fastening member and the second fastening member. Moreover, the impact load input to the front side frame is also supported by the load supporting wall of the load transfer block through the third fastening member that fastens the bracket to the load supporting wall of the load transfer block. Thus, the input load is also supported in a distributed manner by the load supporting wall of the load transfer block facing the front-rear direction. Therefore, when an impact load is input from the front, it is difficult for a stress biased toward a portion of the peripheral area of ​​the front side frame to act, and it is difficult for the front side frame to tilt or bend.

[0015] (2) In the above aspect (1), the load supporting wall of the load transmission block may stand upward from an edge of the opening, and the bracket may stand upward from an upper surface of the front side frame.

[0016] According to the above-mentioned configuration (2), when the bracket is fastened to the load bearing wall of the load transfer block by the third fastening member, the rear region of the front side frame is fixed to the load transfer block via the bracket in a suspended manner from above. Therefore, the rear region of the front side frame is stably supported by the load transfer block. Furthermore, when an impact load is input from the front, the rear region of the front side frame is less likely to tilt or bend.

[0017] (3) In the above-mentioned scheme (1), the load transfer block may also have a surrounding wall (for example, the surrounding wall 50 of the embodiment), which protrudes forward from the periphery of the opening of the frame insertion portion and surrounds the outer peripheral surface of the front side frame, and a flattening storage space (for example, the flattening storage space 55 of the embodiment) for storing the flattened portion when the front side frame is flattened in the front-to-back direction is provided between the surrounding wall and the front side frame.

[0018] According to the above (3) configuration, when the front side frame is crushed and deformed from the front side toward the rear end side due to an impact load input from the front, the crushed portion is accommodated in the crushed accommodation space between the surrounding wall and the front side frame as the crushing progresses. Therefore, the rear region of the front side frame is less likely to bend and deform when the impact load is input. Therefore, when this structure is adopted, the front side frame can be crushed and deformed more smoothly.

[0019] In addition, a part of the crushed portion stored in the crushed storage space is wound around the front surface side of the load bearing wall. As a result, the rearward displacement of the rear region of the front side frame can be restricted by the contact between the crushed portion and the load bearing wall. Therefore, when an impact load is input, the front side frame can be crushed and deformed more smoothly.

[0020] (4) In the above aspect (1), at least one of the first fastening member and the second fastening member may be provided in plurality and arranged in the front-rear direction so as to be staggered in a direction intersecting the front-rear direction.

[0021] According to the above (4) solution, when the impact load is input from the front, if the front side frame is crushed to the rear region, the peripheral region of each fastening member is also deformed from the front to the rear. At this time, in this structure, since the plurality of fastening members are arranged in a zigzag shape, the deformed parts of the rear region of the front side frame are dispersed at a plurality of positions in the vehicle width direction and the vertical direction. Therefore, when this structure is adopted, it is possible to effectively suppress the front side frame from falling down or breaking at the later stage of the impact load input.

[0022] (5) In the above-mentioned aspect (1), a reinforcing wall (for example, the reinforcing wall 37 of the embodiment) extending across the internal space of the front side frame may be connected to the left and right side walls of the front side frame, and the reinforcing wall may extend in a manner that at least spans the fastening portion of the second fastening member in the front-rear direction.

[0023] According to the above-mentioned solution (5), when an impact load is input from the front, the load transmitted to the left and right side walls of the front side frame can be made substantially equal by the function of the reinforcing wall. Therefore, when this structure is adopted, it is possible to effectively suppress the left-right tilting and breaking of the front side frame at the later stage of the input of the impact load.

[0024] (6) In the above aspect (1), the first fastening member and the second fastening member may fasten and fix the front side frame and the frame insertion portion at positions offset from each other in the front-rear direction.

[0025] According to the above-mentioned (6) solution, when the impact load is input from the front, if the front side frame is crushed to the rear area, the peripheral area of ​​each fastening member is also deformed from the front to the rear. At this time, in this structure, since the first fastening member and the second fastening member are arranged offset from each other in the front-to-back direction, it is easy to alternately deform the peripheral area of ​​the first fastening member and the peripheral area of ​​the second fastening member. Therefore, when this structure is adopted, it is possible to effectively suppress the front side frame from falling down or breaking at the later stage of the impact load input.

[0026] According to the scheme of the present invention, the input impact load is supported in a dispersed manner on the peripheral wall of the frame insertion portion of the load transfer block in mutually intersecting directions by the first fastening member and the second fastening member, and can be supported on the load support wall of the load transfer block in the front-rear direction by the third fastening member. Therefore, when the impact load is input from the front, it is difficult for a stress biased toward a part of the peripheral area of ​​the front side frame to act, and it is difficult for the front side frame to tilt or bend. Therefore, when the vehicle body front structure of the present invention is adopted, the rear area of ​​the front side frame can be fixed to the load transfer block by the fastening member, and the front side frame can be smoothly crushed when the impact load is input from the front. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a perspective view of the front part of the vehicle according to the embodiment.

[0028] Figure 2 It is a side view of the front part of the vehicle of embodiment.

[0029] Figure 3 This is a perspective view of the load transmission block according to the embodiment as viewed from the upper rear side.

[0030] Figure 4 is with Figure 3 Section IV-IV corresponds to a sectional view of the front of the vehicle.

[0031] Figure 5 It is a perspective view showing a fixing portion of a front side frame and a load transfer block according to an embodiment.

[0032] Figure 6 Yes Figure 4 An enlarged cross-sectional view of a portion of the

[0033] Figure 7 The front side frame of the embodiment is along Figure 4A front view of the fixing portion of the front side frame and the load transfer block cut along line VII-VII.

[0034] Figure 8 The front side frame of the embodiment is along Figure 7 A top view taken along line VIII-VIII.

[0035] Explanation of symbols:

[0036] 10: front side frame; 11: load transfer block; 30: frame insertion portion; 32: load bearing wall; 33: bracket; 34: bolt (third fastening member); 35A: bolt (first fastening member); 35B: bolt (second fastening member); 37: reinforcement wall; 50: surrounding wall; 55: flattened storage space. DETAILED DESCRIPTION

[0037] Hereinafter, an embodiment of the present invention will be described based on the drawings. Note that arrows FR indicating the front of the vehicle, arrows UP indicating the upper direction of the vehicle, and arrows LH indicating the left side of the vehicle (left side facing forward) are indicated at appropriate positions in the drawings.

[0038] Figure 1 is a perspective view of the front portion of the vehicle 1 according to the present embodiment. Figure 2 This is a side view of the front portion of the vehicle 1 as viewed from the left side.

[0039] Figure 1 , Figure 2 Reference numeral 2 in the figure denotes a passenger compartment, and reference numeral 3 denotes a front compartment in front of the compartment 2 for storing a drive motor and an engine. Front side frames 10 extending substantially in the front-rear direction of the vehicle body are arranged on both sides in the vehicle width direction of the front compartment 3. The rear ends of the left and right front side frames 10 are connected to the frame member of the front part of the compartment 2 via a load transfer block 11 described in detail later.

[0040] The left and right side members 4 extending substantially along the front-rear direction of the vehicle body are arranged on the lower side of the vehicle room 2. The floor 5 arranged below the vehicle room 2 is bridged on the left and right side members 4. The floor 5 is reinforced by a plurality of reinforcement frames (not shown) extending along the front-rear direction and the width direction of the vehicle body.

[0041] In the present embodiment, the floor panel 5 and these reinforcing frames are collectively referred to as a floor member 12. It should be noted that the left and right front side frames 10 extend forward from a position above the floor member 12.

[0042] The front part of the vehicle interior 2 is separated from the front cabin 3 by a lower instrument panel 13. The lower instrument panel 13 is connected at its lower end to the front edge of the floor member 12 and rises obliquely forward and upward from the front of the floor member 12. The upper part of the lower instrument panel 13 is connected to a cowl top cover 14 and other frame members.

[0043] The front pillar 6 constituting the front edge of the door opening on the front side is connected to the front end of the left and right side rails 4. An upper beam 7 extending substantially along the front-rear direction of the vehicle body is connected to the front side of the upper portion of each front pillar 6, at the outer position in the vehicle width direction of the front cabin 3. The upper beam 7 is bent from the left and right front pillars 6 toward the lower front portion of the vehicle body, and the front end portion extends to the outer side of the front end portion of the front side frame 10. The front end portion of each upper beam 7 is connected to the front end portion of the corresponding left and right front side frame 10 via a connecting member not shown.

[0044] Shock absorber housings 15 of left and right upper portions of load transmission blocks 11, which will be described in detail later, are connected to bases (rear regions) of the left and right upper beams 7. The shock absorber housings 15 support upper portions of shock absorbers of a front suspension (not shown).

[0045] Figure 3 This is a perspective view of the load transfer block 11 viewed from the upper rear side. Figure 4 is with Figure 3 Section IV-IV corresponds to a sectional view of the front of the vehicle.

[0046] like Figure 1 , Figure 4 As shown in the figure, each of the left and right front side frames 10 fixed to the load transfer block 11 is formed into a square tube (square tube) frame shape. The rear end of the front side frame 10 is inserted into a frame fixing portion 17 of the load transfer block 11 described later, and in this state, it is fixed to the frame fixing portion 17 by a plurality of bolts 35A, 35B (fastening members). The front side frame 10 is formed of, for example, aluminum, iron-based metal, or the like.

[0047] Figure 5 It is a perspective view showing a fixing portion of the front side frame 10 and the load transfer block 11 .

[0048] The front side frame 10 is a frame member that supports the drive components and suspension components arranged in the front cabin 3. When an impact load is input from the front of the vehicle, the front side frame 10 is compressed in the front-rear direction to absorb the energy of the impact load. Figure 2 , Figure 5 As shown, a plurality of reinforcing ribs 21 extending in the up-down direction are provided on the left and right side walls of the front side frame 10. The plurality of reinforcing ribs 21 are separately arranged in the front-back direction on the side walls of the front side frame 10. The front side frame 10 is facilitated to be flattened and deformed in a corrugated manner when an impact load is inputted by the plurality of reinforcing ribs 21.

[0049] The reinforcing ribs 21 extending in the up-down direction are provided only in the middle region to the front region in the front-back direction of the side wall of the front side frame 10. A plurality of reinforcing ribs 22 extending in the front-back direction are provided in the rear region of the side wall of the front side frame 10. The front side frame 10 restricts deformation of the rear region at the initial stage of crushing when an impact load is input, by means of the reinforcing ribs 22 extending in the front-back direction.

[0050] like Figure 3 As shown, the load transfer block 11 is formed into a bilaterally symmetrical shape. The load transfer block 11 is provided with a shock absorber housing portion 15, a frame fixing portion 17, a connecting wall 19, and a floor fixing portion 18 in the left and right regions, respectively. The load transfer block 11 having these elements is integrally cast, for example, by aluminum or the like. That is, the load transfer block 11 is an integrally cast component having the above-mentioned components.

[0051] As described above, the shock absorber housing 15 is a portion that supports the upper portion of the shock absorber of the front suspension. Figure 1 As shown in FIG. 1 , the shock absorber housing 15 is arranged above the front side frame 10 and outside the front side frame 10 in the vehicle width direction. The shock absorber housing 15 is formed into a downward bowl shape (a downward bottomed cylindrical shape), and the shock absorber is arranged on the lower side (inner side) of the bowl shape. The shock absorber housing 15 supports the upper part of the shock absorber of the front suspension at its top.

[0052] As described above, the damper housing portion 15 is connected to the base of the corresponding left and right upper beams 7 by bolt fastening or the like. Furthermore, the cowl top cover 14 is mounted on the left and right damper housing portions 15 connected to the upper beams 7. The left and right ends of the cowl top cover 14 are connected to the corresponding left and right damper housing portions 15 by bolt fastening or the like.

[0053] The frame fixing portion 17 is provided continuously below the side wall 15s on the inner side in the vehicle width direction of the shock absorber housing portion 15. The frame fixing portion 17 is a portion for fixing the rear portion of the front side frame 10, and is formed in a substantially rectangular block shape extending in the front-rear direction of the vehicle body. Figure 4 As shown, a frame insertion portion 30 having a quadrilateral shape in a front view into which the rear region of the front side frame 10 is inserted is provided in the block portion of the frame fixing portion 17. The frame insertion portion 30 is open toward the front side of the vehicle, and a load-bearing rib 31 is protrudingly provided at the bottom opposite to the open side. The rib 31 is a load-bearing wall protruding toward the front side of the vehicle from the bottom wall 30a of the frame insertion portion 30, and two ribs cross each other in an X-shape in a front view. The entire area of ​​the front end surface of the rib 31 is formed flat. When the front side frame 10 is inserted into the frame insertion portion 30, the front end surface of the rib 31 faces the rear end surface of the front side frame 10 with a small gap therebetween.

[0054] When the rear portion of the front side frame 10 attempts to move backward when an impact load is input from the front, the rear end surface of the front side frame 10 abuts against the front surface of the rib 31. The front side frame 10 is thereby restricted from excessively moving backward.

[0055] Figure 6 Yes Figure 4 An enlarged cross-sectional view of a portion of the Figure 7 The front side frame 10 is Figure 4 A front view of the fixing portion of the front side frame 10 and the load transfer block 11 cut along the line VII-VII. Figure 8 The front side frame 10 is Figure 7 A top view taken along line VIII-VIII.

[0056] A load bearing wall 32 connected to the upper opening edge of the frame insertion portion 30 is provided on the front side of the block portion of the frame fixing portion 17. The load bearing wall 32 is a flat wall perpendicular to the front-rear direction of the vehicle body and rises vertically upward from the upper opening edge of the frame insertion portion 30.

[0057] In addition, if Figure 5 , Figure 7 As shown in FIG. 1 , a surrounding wall 50 is provided on the front surface of the block portion of the frame fixing portion 17 so as to protrude forward from the periphery of the region where the opening of the frame insertion portion 30 and the front surface of the load bearing wall 32 are combined. The surrounding wall 50 is a cylindrical wall having a rectangular shape when viewed from the front, and surrounds the outer side of the front side frame 10 protruding forward from the opening of the frame insertion portion 30. The surrounding wall 50 includes an upper wall 50u, a lower wall 50l, and left and right side walls 50s, and a gap is formed between at least the upper wall 50u and the left and right side walls 50s and the outer peripheral surface of the front side frame 10. The gap constitutes a crushed storage space 55 for storing the crushed portion when the front side frame 10 is crushed in the front-rear direction by an impact load from the front.

[0058] A bracket 33 having a substantially L-shaped shape is fixed to the upper surface of the front side frame 10 near the rear by welding or the like in a side view. The bracket 33 is fixed to a position on the upper surface of the front side frame 10 that is forward of the portion inserted into the frame insertion portion 30. The bracket 33 has a raised piece 33a that abuts against the front surface of the load bearing wall 32 of the frame fixing portion 17, and in this state is fixed to the load bearing wall 32 by a bolt 34 (third fastening member). The bolt 34 has a shaft portion extending in the front-rear direction of the vehicle body, and is screwed into the load bearing wall 32 to restrict displacement of the front side frame 10 in the front-rear direction of the vehicle body. The bracket 33 is fastened and fixed to the load bearing wall 32 of the load transmission block 11 from the front-rear direction by the bolt 34 (third fastening member).

[0059] The rear region of the front side frame 10 inserted (fitted) into the frame insertion portion 30 of the frame fixing portion 17 is fastened and fixed to the lower wall and one side wall of the frame insertion portion 30 by a plurality of bolts 35A and 35B (first fastening members and second fastening members).

[0060] The bolt 35A (first fastening member) passes through the lower wall of the frame insertion portion 30 from top to bottom and is screwed into a cylindrical nut 36 made of an iron-based metal protruding from the upper surface of the lower wall. Similarly, the bolt 35B (second fastening member) passes through one side wall of the frame insertion portion 30 and is screwed into a cylindrical nut 36 made of an iron-based metal protruding from the inner surface of the side wall. The front side frame 10 is fastened and fixed to the peripheral wall (lower wall) of the frame insertion portion 30 from the top to bottom by the bolt 35A, and is fastened and fixed to the peripheral wall (one side wall) of the frame insertion portion 30 from the vehicle width direction by the bolt 35B.

[0061] like Figure 6 to Figure 8 As shown in the figure, three bolts 35A are provided for fastening the front side frame 10 to the lower wall of the frame insertion portion 30. The plurality of bolts 35A are arranged in a staggered manner in the vehicle width direction toward the front-rear direction of the front side frame 10. That is, the plurality of bolts 35A are alternately arranged at left and right positions sandwiching the center of the lower wall of the front side frame 10 in the width direction.

[0062] In addition, bolts 35B for fastening the front side frame 10 to the side wall of the frame insertion portion 30 are arranged at two locations on the upper side and two locations on the lower side of the side wall of the front side frame 10. The upper and lower corresponding bolts 35B are arranged at the same position in the front-rear direction. Figure 6 As shown, the two bolts 35B on the rear side are arranged at a substantially middle position between the rearmost bolt 35A and the central bolt 35A among the three bolts 35A for fixing the lower wall in the front-to-back direction. Similarly, the two bolts 35B on the front side are arranged at a substantially middle position between the central bolt 35A and the frontmost bolt 35A among the three bolts 35A for fixing the lower wall in the front-to-back direction. Therefore, the bolts 35A for fixing the lower wall (first fastening member) and the bolts 35B for fixing the side wall (second fastening member) fasten and fix the front side frame 10 and the frame insertion portion 30 at positions offset from each other in the front-to-back direction.

[0063] like Figure 6 , Figure 7As shown in FIG. 1 , a reinforcing wall 37 (partition wall) is provided inside the rear region of the front side frame 10, extending in the horizontal direction and connecting the left and right side walls of the front side frame 10. The reinforcing wall 37 extends from the rear end of the front side frame 10 to a position on the front side of the connection portion between the front side frame 10 and the frame fixing portion 17 by the bracket 33 and the bolt 34. The reinforcing wall 37 extends in the front-to-back direction so as to straddle the connection portion between the front side frame 10 and the frame fixing portion 17 by the bolts 35A and 35B and the connection portion by the bracket 33 and the bolt 34.

[0064] However, the reinforcing wall 37 only needs to extend in the front-rear direction so as to straddle at least the fastening portion of the bolts 35B for fixing the side wall.

[0065] In addition, if Figure 2 , Figure 3 As shown, the floor fixing portion 18 of the load transfer block 11 extends in the vehicle width direction along the front edge of the floor member 12. The floor fixing portion 18 is formed in a long plate shape with sufficient wall thickness in the upper and lower parts. The floor fixing portion 18 overlaps the front edge of the floor member 12 and is fixed to the floor member 12 by a plurality of bolts.

[0066] The left and right symmetrical regions of the load transfer block 11 are connected to each other at the floor fixing portion 18 of the left region and the floor fixing portion 18 of the right region. Figure 3 As shown, the floor fixing portion 18 in the left region and the floor fixing portion 18 in the right region are connected to each other by a connecting block portion 40 at a substantially central position in the vehicle width direction.

[0067] The connecting wall 19 of the load transfer block 11 extends substantially along the front surface of the instrument panel lower panel 13 disposed at the front portion of the vehicle interior 2, and connects the frame fixing portion 17 to the floor fixing portion 18 below it. The connecting wall 19 is formed in a plate shape having a sufficient wall thickness, similarly to the above-mentioned floor fixing portion 18. The connecting wall 19 is smoothly connected to the floor fixing portion 18 below in a continuous plate shape.

[0068] The upper end of the connecting wall 19 is connected to the rear lower end of the block portion of the frame fixing portion 17. The width of the connecting wall 19 in the vehicle width direction gradually expands downward with the connecting portion connected to the frame fixing portion 17 as the vertex. That is, the connecting wall 19 is formed in a substantially isosceles triangle shape when viewed from the front. The lower end region of the connecting wall 19, where the width gradually expands, is continuous (connected) to the floor fixing portion 18.

[0069] A plurality of upper reinforcing ribs 20 protrude upward and extend in the front-rear direction (diagonally in the front-rear direction) on the upper surface of the connecting wall 19. The plurality of upper reinforcing ribs 20 are formed on the upper surface of the connecting wall 19 so as to be spaced apart in the vehicle width direction and parallel to each other.

[0070] In addition, if Figure 3 As shown, a panel fixing portion 23 having a flat upper surface and partially recessed in a step-like manner is formed on the upper surface of the narrowed upper region of the connecting wall 19 in the vehicle width direction. The instrument panel lower panel 13 is fastened and fixed to the panel fixing portion 23 .

[0071] <Effects of Implementation Methods>

[0072] As described above, in the vehicle body front structure of the present embodiment, the front side frame 10 is inserted (fitted) into the frame insertion portion 30 of the load transfer block 11, and in this state, the peripheral walls of the front side frame 10 and the frame insertion portion 30 are fastened and fixed from the up-down direction by the bolts 35A (first fastening member), and fastened from the vehicle width direction by the bolts 35B (second fastening member). In addition, the bracket 33 protruding from the front side frame 10 is fastened and fixed to the load support wall 32 of the load transfer block 11 from the front-back direction by the bolts 34 (third fastening member). Therefore, when an impact load is input from the front, the input load can be distributed and supported by the peripheral walls of the frame insertion portion 30 in mutually intersecting directions by the bolts 35A and 35B, and supported by the load support wall 32 of the load transfer block 11 in the front-back direction by the bolts 34. As a result, when an impact load is input from the front, stress biased to a part of the peripheral area of ​​the front side frame 10 is unlikely to act, and the front side frame 10 is unlikely to tilt or bend.

[0073] Therefore, when the vehicle body front structure of this embodiment is adopted, the rear region of the front side frame 10 is fixed to the load transfer block 11 by the fastening member (bolts 35A, 35B, 34), and the front side frame 10 can be smoothly crushed when an impact load is input from the front.

[0074] In particular, in the vehicle body front structure of the present embodiment, a structure is adopted in which the bolts 35A (first fastening member) and the bolts 35B (second fastening member) penetrate the peripheral wall of the frame insertion portion 30 and are fastened and fixed from the outside of the peripheral wall of the frame insertion portion 30. Therefore, the fastening operation of the bolts 35A and 35B can be easily performed.

[0075] In addition, in the vehicle body front structure of the present embodiment, a structure is adopted in which a bracket 33 is protruded from the front side frame 10, the bracket 33 is overlapped on the front surface of the load supporting wall 32 of the load transmission block 11, and the bracket 33 is fastened and fixed from the front side of the load transmission block 11 by the bolt 34. Therefore, the fastening operation of the bolt 34 can be easily performed.

[0076] A method of fastening and fixing the frame insertion portion 30 to the rear end portion of the front side frame 10 by bolts (fastening members) from the bottom side can also be considered, but in this case, if the thickness (protruding height) of the load-bearing portion such as the rib 31 is to be ensured, the axial length of the bolt becomes long, and the fastening work becomes difficult. In contrast, when this structure is adopted, the axial length of the bolt 34 can be shortened, and the fastening work of the bolt 34 can also be easily performed from the front side.

[0077] In addition, in the vehicle body front structure of the present embodiment, the load bearing wall 32 of the load transmission block 11 stands upward from the edge of the opening of the frame insertion portion 30, and the bracket 33 protrudes upward from the upper surface of the front side frame 10. Therefore, when the bracket 33 is fastened and fixed to the load bearing wall 32 by the bolt 34 (third fastening member), the rear area of ​​the front side frame 10 is fixed to the load transmission block 11 in a suspended manner from above via the bracket 33. As a result, the rear area of ​​the front side frame 10 is stably supported by the load transmission block 11. Moreover, when an impact load is input from the front, it is more difficult for the rear area of ​​the front side frame 10 to tilt or bend.

[0078] In the vehicle body front structure of the present embodiment, a surrounding wall 50 is provided on the load transfer block 11, which protrudes forward from the periphery of the opening of the frame insertion portion 30 and surrounds the outer peripheral surface of the front side frame 10. In addition, a crushing storage space 55 is provided between the surrounding wall 50 and the front side frame 10, which stores the crushed portion when the front side frame 10 is crushed in the front-rear direction. Therefore, if the front side frame 10 is crushed and deformed from the front side to the rear end side due to the input of an impact load from the front, the crushed portion is stored in the crushing storage space 55 between the surrounding wall 50 and the front side frame 10 as the crushing progresses. As a result, the rear area of ​​the front side frame 10 is supported by the surrounding wall 50 via the stored crushed portion, and the rear area of ​​the front side frame 10 is less likely to bend and deform. Therefore, when this structure is adopted, the front side frame can be crushed and deformed more smoothly.

[0079] Furthermore, when this structure is adopted, a part of the crushed portion stored in the crushed storage space 55 also goes around the front side of the load supporting wall 32. Therefore, the rearward displacement of the rear region of the front side frame 10 can be restricted by the contact between the crushed portion and the load supporting wall 32. Therefore, when the impact load is input, the front side frame 10 can be crushed and deformed more smoothly.

[0080] In addition, in the vehicle body front structure of the present embodiment, a plurality of bolts 35A are provided for fixing the front side frame 10 to the lower wall of the frame insertion portion 30, and the bolts 35A are arranged in a staggered manner in the vehicle width direction in the front-rear direction. Therefore, when an impact load is input from the front, if the front side frame 10 is crushed to the rear region, the peripheral region of each bolt 35A is also deformed from the front to the rear. At this time, since the plurality of bolts 35A are arranged in a zigzag manner, the deformation site of the rear region of the front side frame 10 is dispersed to two positions in the vehicle width direction, and the deformation is easily performed alternately at the two positions. Therefore, when this structure is adopted, it is possible to effectively suppress the front side frame 10 from falling down or breaking at the later stage of the input of the impact load.

[0081] In addition, in the vehicle body front structure of the present embodiment, the left and right side walls of the front side frame 10 are connected to the reinforcing wall 37 extending across the internal space of the front side frame 10. And the reinforcing wall 37 extends in a manner that straddles the fastening portion of the bolt 35B (second fastening member) at least in the front-rear direction. Therefore, when an impact load is input from the front, the load transmitted to the left and right side walls of the front side frame 10 can be dispersed approximately equally by the reinforcing wall 37. In particular, in the case of a structure in which only one of the left and right side walls of the front side frame 10 is fastened and fixed to the frame insertion portion 30 by the bolt 35B as in the present embodiment, it is possible to avoid stress concentration only on the left and right side walls of the front side frame 10.

[0082] Therefore, when this structure is adopted, it is possible to effectively suppress the left-right direction tilting and breaking of the front side frame 10 at the late stage of input of the impact load.

[0083] In addition, in the vehicle body front structure of the present embodiment, the bolts 35A (first fastening members) for fixing the lower wall of the front side frame 10 and the bolts 35B (second fastening members) for fixing the side wall fasten and fix the front side frame 10 and the frame insertion portion 30 at positions offset from each other in the front-rear direction. Therefore, when an impact load is input from the front, when the front side frame 10 is crushed to the rear area, the deformation of the surrounding area of ​​the bolts 35A for fixing the lower wall and the deformation of the surrounding area of ​​the bolts 35B for fixing the side wall are likely to alternately occur. Therefore, when this structure is adopted, it is possible to effectively suppress the front side frame 10 from falling down or breaking at the later stage of the input of the impact load.

[0084] The present invention is not limited to the above-mentioned embodiment, and various design changes can be made without departing from the scope of the present invention. For example, in the above-mentioned embodiment, only one side wall of the left and right side frame 10 is fixed to the frame insertion portion 30 by the bolt 35B, but the left and right side walls of the front side frame 10 may also be fixed to the frame insertion portion 30 by the bolt 35B.

[0085] In the above-described embodiment, the bolts 35A that fasten the lower wall of the front side frame 10 to the frame insertion portion 30 from the vertical direction are arranged in a serrated shape. However, the bolts 35B that fasten the side wall of the front side frame 10 to the frame insertion portion 30 from the vehicle width direction may also be arranged in a serrated shape. It should be noted that only the bolts 35B that fasten the side wall of the front side frame 10 to the frame insertion portion 30 from the vehicle width direction may be arranged in a serrated shape.

[0086] Furthermore, in the above-described embodiment, the load bearing wall 32 of the load transmission block 11 stands upward from the edge of the opening of the frame insertion portion 30, and the bracket 33 protrudes upward from the upper surface of the front side frame 10. However, the load bearing wall 32 may be made to stand sideways or downward from the edge of the opening of the frame insertion portion 30, and the bracket 33 superimposed on the load bearing wall 32 may also protrude sideways or downward in the same manner. In this case, the bracket 33 may also be fastened to the load bearing wall 32 from the front-rear direction by the bolt 34.

[0087] In the above embodiment, the load transfer block 11 is formed integrally with a block in the left region for fixing the left front side frame 10 and a block in the right region for fixing the right front side frame 10. However, the load transfer block may be formed with the block in the left region and the block in the right region as separate components.

Claims

1. A vehicle body front structure, characterized in that: It has: a front side frame extending generally in the front-rear direction laterally of the front portion of the vehicle; and A load transfer block is a casting component that connects the rear portion of the front side frame to other frame members. The load transfer block has: a frame insertion portion which is open to the front side and through which the rear region of the front side frame is inserted; and a load bearing wall rising from the edge of the opening in a direction substantially perpendicular to the front-rear direction, A bracket is provided at a position of the front side frame forward of a portion inserted into the frame insertion portion, the bracket protruding in a direction intersecting the front-rear direction and abutting against a front surface of the load bearing wall. The front side frame is fastened and fixed to the peripheral wall of the frame insertion portion from the top to the bottom by a first fastening member when the rear region is inserted into the frame insertion portion of the load transfer block, and is fastened and fixed to the peripheral wall from the vehicle width direction by a second fastening member. The bracket is fastened and fixed to the load supporting wall of the load transfer block from the front-rear direction by a third fastening member.

2. The vehicle body front structure according to claim 1, characterized in that: The load bearing wall of the load transfer block rises upward from the edge of the opening. The bracket stands upward from the upper surface of the front side frame.

3. The vehicle body front structure according to claim 1, characterized in that: The load transfer block further includes a surrounding wall that protrudes forward from the periphery of the opening of the frame insertion portion and surrounds the outer peripheral surface of the front side frame. A flattened storage space for storing the flattened portion when the front side frame is flattened in the front-rear direction is provided between the surrounding wall and the front side frame.

4. The vehicle body front structure according to claim 1, characterized in that: A plurality of at least one of the first fastening members and the second fastening members are provided, and are arranged in the front-rear direction so as to be staggered in a direction intersecting the front-rear direction.

5. The vehicle body front structure according to claim 1, characterized in that: The left and right side walls of the front side frame are connected to a reinforcement wall extending across the inner space of the front side frame. The reinforcing wall extends in the front-rear direction so as to straddle at least the fastening portion of the second fastening member.

6. The vehicle body front structure according to claim 1, characterized in that: The first fastening member and the second fastening member fasten and fix the front side frame and the frame insertion portion at positions offset from each other in the front-rear direction.

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