Frame structure of the vehicle body

Abstract

This vehicle chassis frame structure comprises: a pair of right and left side members (11); a bumper frame (17); a first crossmember (13a); and a second crossmember (19) which is disposed below the side members and between the first crossmember and the bumper frame so as to extend in the vehicle width direction; columnar members (31) which extend downward from the respective side members so as to support the right and left ends of the second crossmember; and extension members (33) which extend toward the outer side of the vehicle width direction from the columnar members at the right and left ends of the second crossmember and which extend to the position facing the inner side, in the vehicle front-back direction, of an extension part of the bumper frame.

Description

Technical Field

[0001] The present invention relates to a frame structure of a vehicle body, and particularly to a technique for improving collision safety.

Background Art

[0002] A bumper frame extending in the vehicle width direction for absorbing the impact during a frontal collision is disposed at the front part of the vehicle. Further, the buffer portion of the side member that supports the bumper frame can absorb the impact by deforming during a frontal collision, and can mitigate the impact on the passenger compartment and the like. And, there are multiple cases for a frontal collision of a vehicle, such as a so-called full overlap where the vehicles face each other directly and collide on the entire surface, and a so-called offset collision where the collision occurs only on one side, left or right. In particular, in the case of an offset collision, a local load is generated at one end of the bumper frame in the left-right direction. Therefore, it is conceivable that the buffer portions of the bumper frame and the side member may deform more than expected and cannot sufficiently absorb the impact.

[0003] Therefore, a technique has been developed to suppress the buffer portions of the bumper frame and the side member from deforming more than expected even when a local load occurs at one end of the bumper frame in the left-right direction by disposing side stays that extend from a cross member disposed on the side member and support the left and right end portions of the bumper frame (Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the technique disclosed in the above Patent Document 1, considering the load applied to the other vehicle during an offset collision, the load at the position corresponding to the side member or the side stay may locally increase, which is not preferable. On the other hand, if the buffer portion of the side member or the rigidity of the side stay is reduced, there is a risk of reducing the shock absorption performance, so there is room for further improvement.

[0006] The present invention has been made in view of such problems, and an object thereof is to provide a frame structure of a vehicle body that can reduce the generation of local loads applied to the other vehicle (the collided object) while maintaining the shock absorption performance during a vehicle collision.

Means for Solving the Problems

[0007] To achieve the above object, the frame structure of the vehicle body of the present invention is a frame structure of a vehicle body that supports the vehicle body, and includes a pair of left and right side members extending in the vehicle front-rear direction, a bumper frame provided at an end portion outside the vehicle front-rear direction of the side member and extending in the vehicle width direction, having an extension portion extending outward in the vehicle width direction from the side member, a first cross member provided between the pair of left and right side members and extending in the vehicle width direction, a second cross member located below the side member and between the first cross member and the bumper frame and extending in the vehicle width direction, a column member extending downward from the side member and supporting the left and right end portions of the second cross member, and an extension member extending outward in the vehicle width direction from the column member at the left and right end portions of the second cross member and extending to a position facing inside the vehicle front-rear direction of the extension portion of the bumper frame.

[0008] As a result, a second cross member extending in the vehicle width direction is positioned below the side member between the first cross member and the bumper frame, and the left and right ends of the second cross member are supported by column members extending downward from the buffer portion of the side member. Extension members extending outward in the vehicle width direction and positioned inside the vehicle in the longitudinal direction outside the side member of the bumper frame are disposed at the left and right ends of the second cross member. By supporting the left and right ends of the second cross member with the column members, it is possible to swing the second cross member outward of the vehicle about the upper end of the column member and press it to bring it into contact with the object to be collided with earlier.

[0009] As another aspect, it is preferable that a buffer portion that buckles and absorbs impact when a load of a predetermined value or more is applied in the vehicle longitudinal direction is provided between the bumper frame and the first cross member of the side member. As a result, by providing a buffer portion that buckles and absorbs impact when a load of a predetermined value or more is applied in the vehicle longitudinal direction between the bumper frame and the first cross member of the side member, for example, when the entire bumper frame receives an impact such as a full overlap collision, the buffer portion can be crushed without being hindered by the extension member or the second cross member. When receiving an impact with a bias in one direction in the vehicle width direction of the bumper frame such as an offset collision, the extension member and the second cross member support the bumper frame, and it is possible to reduce an increase in local rigidity at a position corresponding to the buffer portion.

[0010] As another aspect, a mount bracket for supporting the body is provided at a location where the column member of the side member is provided. The mount bracket has a mount support portion to which a mount member connected to the body is attached, and a front wall portion and a rear wall portion that extend downward at intervals from the front and rear of the mount support portion and are joined to the outer side surface in the vehicle width direction of the side member. The column member is preferably joined to the side surface of the side member between the front wall portion and the rear wall portion of the mount bracket.

[0011] Thereby, a mounting bracket for supporting the body is provided at a location where the pillar member of the side member is provided, and by providing a pillar member so as to extend downward from between a front wall portion and a rear wall portion joined to the outer side surface in the vehicle width direction of the side member, it is possible to increase the strength of the portion of the side member where the pillar member is attached. As another aspect, the extending member has an inner protruding portion that protrudes toward the center from the inner end portion on the inner side in the vehicle longitudinal direction of the second cross member, and the inner protruding portion is provided at a position that contacts the first cross member when either one of the portions between the bumper frame and the first cross member of the left and right side members is crushed.

[0012] Thereby, when either one of the portions between the bumper frame and the first cross member of the left and right side members is crushed, the inner protruding portion that protrudes toward the center from the inner end portion on the inner side in the vehicle longitudinal direction of the second cross member contacts the first cross member. During an offset collision, the inner protruding portion contacts the first cross member, and the inner side in the vehicle width direction of the second cross member is swung toward the center in the vehicle longitudinal direction with the inner protruding portion as an axis, and the extending member located outside the inner protruding portion in the vehicle width direction can be pressed outward in the vehicle longitudinal direction, that is, toward the other vehicle side.

[0013] As another aspect, it is preferable that the extending member has a fixing portion with one end fixed to the end portion on the outer side in the vehicle width direction of the extending member and the other end fixed to the extending portion of the bumper frame. Thereby, by providing a fixing portion that extends from the end portion on the outer side in the vehicle width direction of the extending member to the end portion on the outer side in the vehicle width direction of the bumper frame with respect to the side member, it is possible to suppress the bumper frame from swinging in the vehicle longitudinal direction during a vehicle collision.

[0014] As another aspect, it is preferable that the extending member has a first member having an opening that opens toward the center in the vehicle longitudinal direction and a second member that closes at least a part of the opening of the first member. Thereby, it is possible to ensure the rigidity of the extending member.

[0015] As another aspect, it is preferable that a rigidity reducing portion for reducing the rigidity against the force bending in the vehicle longitudinal direction is formed at the center in the vehicle width direction of the second cross member. By forming a rigidity reducing portion for reducing the rigidity against the force bending in the vehicle longitudinal direction at the center in the vehicle width direction of the second cross member, when a collision occurs, the rigidity reducing portion of the second cross member is pressed toward the center side in the vehicle longitudinal direction, and it is possible to press the bumper frame outward by the reinforcing portion using the force.

[0016] As another aspect, the extending member is connected to the column member and has a connecting portion extending in the vehicle longitudinal direction, left and right extending portions extending outward in the vehicle width direction from the end portions outside the vehicle longitudinal direction of the connecting portion, and the fixing portion fixed by a fixing member extending in the vehicle vertical direction at the end portions outside the vehicle width direction of the left and right extending portions. Thereby, during a full overlap collision, since the fixing portion rotates about a fixing member extending in the vehicle vertical direction, it is possible to absorb an impact while reducing the increase in the rigidity of the buffer portion by the extending member and the fixing portion.

Effect of the Invention

[0017] According to the frame structure of the vehicle body of the present invention, a second cross member extending in the vehicle width direction is positioned between the first cross member and the bumper frame below the side member, and the left and right end portions of the second cross member are supported by column members extending downward from the buffer portion of the side member. An extending member extending outward in the vehicle width direction and positioned inside the vehicle longitudinal direction outside the side member of the bumper frame is disposed at the left and right end portions of the second cross member. Since the left and right end portions of the second cross member are supported by the column members, the second cross member can be swung and pressed outward of the vehicle about the upper end of the column member to contact the object to be collided with earlier. Thereby, while maintaining the impact absorption performance at the time of collision of the vehicle, it is possible to reduce the generation of a local load applied to the object to be collided with.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

BEST MODE FOR CARRYING OUT THE INVENTION

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Referring to FIG. 1, a rear perspective view of the front part of the chassis 3 of the vehicle 1 is shown. The vehicle 1 is an automobile having a frame-structured chassis 3. That is, the vehicle 1 is composed of mounting a body including a cabin 2, an upper body (not shown), an engine, etc. on the chassis 3.

[0020] The vehicle body 3 is the framework of the vehicle 1 formed by combining a plurality of frame members. Specifically, the vehicle body 3 includes side members 11, a suspension frame 13, a mount bracket 15, a bumper frame 17, and a lower cross member (second cross member) 19.

[0021] The side members 11 are a pair of left and right arranged columnar members made of, for example, iron that extend in the longitudinal direction of the vehicle. These side members 11 are located below the center in the vertical direction of the vehicle 1. Also, the pair of left and right side members 11 are fixed to each other by a plurality of cross member members that extend in the vehicle width direction such as the suspension frame 13 and the lower cross member 19, and relative rocking is suppressed.

[0022] The suspension frame 13 is a frame provided between the pair of left and right side members 11 and includes a front cross member member (first cross member) 13a and a rear cross member member 13b that extend in the vehicle width direction. This suspension frame 13 can relieve vibrations and impacts transmitted from the ground to the vehicle 1 while supporting the drive shaft by providing a lower arm (not shown).

[0023] Referring to FIG. 2, a side view of the front portion of the vehicle body 3 is shown. Also, referring to FIG. 3, a bottom view of the front portion of the vehicle body 3 is shown. An extension (buffer portion) 12 is formed at the front portion of the side member 11. This extension 12 is formed in the range from the front end (end portion) 11a of the side member 11 to the front end of the front cross member member 13a of the suspension frame 13, and is formed to buckle and absorb impact when a load of a predetermined amount or more is applied in the longitudinal direction of the vehicle.

[0024] Referring to FIG. 4, an enlarged view of the range A in FIG. 1 is shown. The mount bracket 15 is a frame on which the cabin (body) 2 of the vehicle 1 is placed via a mounting member 16 on the upper side. Further, the mount bracket 15 is disposed outside the vehicle width direction of the pair of left and right side members 11, between the front end 11a of the side member 11 and the front end of the front cross member member 13a, that is, it is disposed on the extension 12.

[0025] On this mount bracket 15, by bending a flat plate member, a mount support portion 15a to which a mount member 16 connected to the cabin 2 is attached, and front end portions and rear end portions of the mount support portion 15a extend downward at intervals from each other, and a front wall portion 15b and a rear wall portion 15c joined to the outer side surface in the vehicle width direction of the side member 11 are formed. Thereby, the mount bracket 15 is formed in a box shape that is open to the outside in the vehicle width direction and downward.

[0026] The bumper frame 17 has a lower buffer member 21, an upper buffer member 23, and a fixing bracket 25, and is located at the front end of the vehicle body 3. The front side of this bumper frame 17 is covered by a resin bumper (not shown) provided at the front end of the vehicle 1. The lower buffer member 21 is a buffer member that extends in the vehicle width direction and is fixed to the front end 11a of the side member 11 by, for example, bolts. This lower buffer member 21 is bent so that an end portion (extension portion) 21a extending outward in the vehicle width direction from the position fixed to the front end 11a of the side member 11 inclines backward. The upper buffer member 23 is a buffer member that extends in the vehicle width direction and is located above the lower buffer member 21. This upper buffer member 23 is bent so that the end portion on the outer side in the vehicle width direction inclines backward. Further, the upper buffer member 23 is fixed to the lower buffer member 21 by a plurality of fixing brackets 35 extending in the vehicle up and down direction.

[0027] Therefore, when a load is applied from the front to the rear of the vehicle, such as a frontal collision accident of the vehicle 1, the bumper frame 17 can receive the load applied from the front and above the side member 11 to the rear as a whole. The lower cross member 19 is a frame member that is located below the side member 11 and between the suspension frame 13 and the bumper frame 17, and extends in the vehicle width direction. By providing this lower cross member 19, the vehicle body 3 can suppress the relative swing of the pair of left and right side members 11 and enhance the vehicle body rigidity, similar to a plurality of cross member members (not shown) provided on the side members 11. A deformation hole (rigidity reduction portion) 19a that extends in the vertical direction is provided at the center in the vehicle width direction of this lower cross member 19. Further, column members 31 and extension members 33 are provided at the left and right end portions of the lower cross member 19, and the column members 31 are fixed to the side members 11.

[0028] The column member 31 is a skeletal member that extends downward from the inner side in the vehicle longitudinal direction between the front wall portion 15b and the rear wall portion 15c of the mount bracket 15 in each of the left and right side members 11. The lower end of this column member 31 is welded to the left and right ends of the lower cross member 19, for example. Therefore, the lower cross member 19 is supported below the mount bracket 15 so as to be suspended at the left and right ends by the column members 31.

[0029] Thereby, the mount bracket 15 can firmly support the column member 31, and the mount bracket 15 can also enhance its rigidity by the column member 31 being provided on the mount bracket 15. Further, since the mount bracket 15 is disposed on the extension 12, it can moderately allow the movement of the extension member 33 due to the deformation of the extension 12.

[0030] Referring to FIG. 5, a top view of the extension member 33 is shown. According to FIGS. 4 and 5, the extension member 33 is a pair of left and right members that are joined to the left and right ends of the lower cross member 19 via the lower ends of the column members 31 and extend outward in the left-right direction. Further, the extension member 33 is formed in an arc shape when viewed from the vehicle vertical direction, the rear side (one end) in the vehicle longitudinal direction extends in the vehicle longitudinal direction and is welded to the outer end portion of the lower cross member 19 in the vehicle width direction, and the front side (the other end) extends in the vehicle width direction.

[0031] Specifically, the extended member 33 is formed with a connection portion 33a, left and right extended portions 33b, a rear protruding portion (inner protruding portion) 33c, and a fixing portion 33d. The connection portion 33a is formed to extend in the vehicle front-rear direction and is connected to the outer surface of a pillar member 31 connected to the left and right end portions of the lower cross member 19. The left and right extended portions 33b extend in an arc shape outward in the vehicle width direction from the front end portion of the connection portion 33a in the vehicle front-rear direction. The rear protruding portion 33c extends rearward from the rear end portion of the connection portion 33a in the vehicle front-rear direction and also extends inward in the vehicle width direction, protruding rearward from the rear end 19b of the lower cross member 19 and being formed to be located outward from the outer end portion in the vehicle width direction of the suspension frame 13.

[0032] The fixing portion 33d is a member formed by bending a flat plate member. This fixing portion 33d is welded to the upper surface of the left end (outer end in the vehicle width direction) of the left and right extended portions 33b of the extended member 33 and extends toward the rear surface of the end portion 21a of the lower buffer member 21. Therefore, when a load in the vehicle front-rear direction is applied to the end portion 21a of the lower buffer member 21, the fixing portion 33d can transmit the load to the left end (outer end in the vehicle width direction) of the left and right extended portions 33b of the extended member 33. Also, when a load in the vehicle front-rear direction from the front is applied from the lower cross member 19 to the extended member 33 as in the case where an offset collision described later occurs, the fixing portion 33d can transmit the load to the left end (outer end in the vehicle width direction) of the lower buffer member 21.

[0033] The extension member 33 includes a first member 41 (outer member) having an opening that opens rearward (toward the center in the vehicle longitudinal direction), and a second member 43 (inner member) that closes at least a part of the opening of the first member 41. Since the second member 43 of the present embodiment is disposed inside the first member 41, for convenience, the first member 41 is also referred to as the outer member 41, and the second member 43 is also referred to as the inner member 43. The outer member 41 is a member formed by bending a flat plate member into an arc shape so as to extend forward and leftward (toward the outer side in the vehicle width direction) from the end on the outer side in the vehicle width direction of the lower cross member 19. Further, the rear end of the outer member 41 on the side of the lower cross member 19 extends rearward from the rear end surface of the lower cross member 19 to form a part of the rear protruding portion 33c. The outer member 41 has an upper end surface and a lower end surface formed by bending the upper end and the lower end rearward and leftward. In other words, an opening that opens rearward and leftward (toward the outer side in the vehicle width direction) is formed.

[0034] The inner member 43 is formed by bending a flat plate member into an arc shape along the outer member 41. The inner member 43 extends from the end 41a of the upper end surface of the outer member 41 toward the end 41b of the lower end surface. Further, the inner member 43 has a protruding portion 43a formed to extend downward from the end 41b of the lower end surface of the outer member 41. The inner member 43 is located inside the outer member 41 and has a shape that opens forward (toward the outer side in the vehicle longitudinal direction). Thereby, the inner member 43 closes at least a part of the opening of the outer member 41.

[0035] Thereby, even when a load in the vehicle longitudinal direction is applied to the left end portion (the end portion on the outer side in the vehicle width direction), the extension member 33 can transmit the load to the lower cross member 19 without being deformed. On the other hand, since the extension member 33 is thinner and has lower rigidity than the lower cross member 19, when another vehicle 100 collides with the vehicle 1 from the front as described later, the extension member 33 deforms relatively more than the lower cross member 19.

[0036] Next, the deformation and the effect of the front part of the vehicle body 3 when another vehicle (the collided object) 100 collides from the front of the vehicle 1 will be described. Hereinafter, as shown in FIG. 6, the case where the other vehicle 100 collides with the entire width direction of the bumper frame 17 is referred to as a "full overlap collision", and as shown in FIGS. 7 to 9, the case where the other vehicle 100 collides from the center to the left side in the width direction of the bumper frame 17 is referred to as an "offset collision".

[0037] Referring to FIG. 6, an explanatory diagram for explaining the deformation of the front part of the vehicle body 3 when the other vehicle 100 makes a full overlap collision from the front of the vehicle 1 is shown. When the other vehicle 100 makes a full overlap collision in front of the vehicle 1 and a load is uniformly applied in the vehicle width direction of the bumper frame 17, the buffer portion C collapses so as to shrink in the vehicle longitudinal direction. Here, the buffer portion C corresponds to the portion from the front end 11a of the side member 11 in the vehicle body 3 to the front cross member member 13a of the suspension frame 13. That is, the extension 12 is included in the buffer portion C.

[0038] When the other vehicle 100 collides with the front part of the bumper frame 17 and a predetermined load is applied to the left and right extensions 12, the left and right extensions 12 are crushed rearward. At this time, since the rear protruding portion 33c of the extension member 33 is located outside the left and right outer ends of the front cross member member 13a, even if the rear shrinkage portion 12a is crushed and the lower cross member 19 and the front cross member member 13a come close to each other, the front cross member member 13a is not contacted. Therefore, in the case where the other vehicle 100 makes a full overlap collision with the vehicle 1, since the rear protruding portion 33c of the extension member 33 does not contact the front cross member member 13a, it is possible to maintain the crushing allowance of the rear shrinkage portion 12a.

[0039] Further, in the full overlap collision, since the vehicle 1 collides with the other vehicle 100 over the entire width direction by the bumper frame 17, it is possible to suppress the local increase in the rigidity on the vehicle 1 side, and thus to suppress the local application of a high load to the other vehicle 100. In particular, since the lower cross member 19 is supported by the column member 31, it can swing so as to move backward about the upper end of the column member 31. Thus, while reducing the increase in the rigidity of the buffer portion C by the extension member 33 and the fixing portion 33d, it is possible to absorb an impact.

[0040] Furthermore, since the fixing portion 33d is not directly attached to the lower cross member 19 but is attached to the extension member 33 having a lower rigidity than the lower cross member 19, when the front cross member member 13a is crushed, while satisfactorily reducing the increase in the rigidity of the buffer portion C by the extension member 33 and the fixing portion 33d, it is possible to absorb an impact. Referring to FIGS. 7 to 9, there is shown an explanatory diagram for explaining the deformation of the front portion of the vehicle body 3 when another vehicle 100 makes an offset collision from the front of the vehicle 1. When another vehicle 100 makes an offset collision from the front of the vehicle 1 and applies a load rearward from the center in the vehicle width direction of the bumper frame 17 to the left side, the left side of the buffer portion C from the center in the left - right direction is crushed so as to shrink in the vehicle front - rear direction in the order shown in FIGS. 7 to 9.

[0041] Specifically, first, the rear - side contraction portion 12a is crushed (see FIG. 7). Thereby, not only the impact is absorbed by the extension 12, but also the impact can be absorbed by absorbing the impact when bending the lower cross member 19. Also, when another vehicle 100 makes an offset collision from the front of the vehicle 1, the lower cross member 19 bends in the vicinity of the deformation hole 19a. Thus, the lower cross member 19 can contact the other vehicle 100 earlier as compared with the case where a lower cross member without the deformation hole 19a is used. Furthermore, since the deformation hole 19a is formed in the lower cross member 19, the lower cross member 19 can bend in the vicinity of the deformation hole 19a. Thus, the extension member 33 can swing about the deformation hole 19a and bring the rear - protruding portion 33c into contact with the front - left side of the front cross member member 13a. In particular, since the extension member 33 swings toward the rear side of the vehicle about the upper end of the column member 31, the rear - protruding portion 33c can be brought into contact with the other vehicle 100 earlier.

[0042] After that, if the other vehicle 100 continues to move toward the vehicle 1, the lower cross member 19 bends at the deformation hole 19a (see FIGS. 8 and 9). The lower cross member 19 bent at the deformation hole 19a in this way has the portion near the deformation hole 19a pressed rearward by the other vehicle 100. At this time, a rotational force that presses the left end forward about the column member 31 is generated in the extension member 33. As a result, as the portion near the deformation hole 19a of the left lower cross member 19 is pressed rearward by the other vehicle 100, the left and right extension portions 33b of the extension member 33 can be pressed toward the front of the vehicle like a lever principle, and the left side of the bumper frame 17 can be pressed against the other vehicle 100 via the fixing portion 33d. In particular, when the extension member 33 is pressed rearward via the fixing portion 33d, the lower cross member 19 can be swung so that the vicinity of the deformation hole 19a faces the front side (outside the vehicle) of the vehicle about the column member 31 in the vertical direction, and the lower cross member 19 can be brought into contact with the other vehicle 100 earlier. Therefore, by bringing the lower cross member 19 into contact with the other vehicle 100 earlier, the left side of the bumper frame 17 can be pressed against the other vehicle 100 via the fixing portion 33d earlier.

[0043] Therefore, even in a case where the right extension 12 is not crushed by an offset collision and the left extension 12 alone is insufficient to absorb the impact and the buffering performance becomes lower compared to a full overlap collision, the lower cross member 19 is deformed to bend and the extension member 33 presses the left side of the bumper frame 17 against the other vehicle 100 via the fixing portion 33d, thereby increasing the rigidity of the left side of the buffer portion C and ensuring buffering performance equivalent to that of a full overlap collision (see FIG. 9).

[0044] Further, as described above, the bumper frame 17 is formed by fixing the upper buffer member 23 with the fixing bracket 25 above the lower buffer member 21 attached to the front end 11a of the side member 11. Here, considering the case where the fixing portion 33d is not provided, when a collision occurs such that the upper buffer member 23 is positively pressed rearward in the vehicle longitudinal direction, the bumper frame 17 swings so that the upper end tilts rearward about the front end 11a of the side member 11.

[0045] Therefore, by providing the fixing portion 33d and pulling the lower end of the lower buffer member 21 downward and rearward, it is possible to surely absorb the impact by the extension 12 while suppressing the swinging of the bumper frame 17 as described above.

[0046] Next, with reference to FIGS. 10 to 12, a modified example of the present invention will be described. FIG. 10 is a top view of the front part of the vehicle body 3 in the modified example. FIG. 11 is a perspective view showing the periphery of the extending member 33 in the modified example. FIG. 12 is a perspective view of the extending member 33 in the modified example. In FIG. 12, the fixing portion 33d of the extending member 33 is not shown.

[0047] The extending member 33 of this modified example has a different shape compared to the above-described embodiment. More specifically, the left and right extending portions 33b of the extending member 33 in the above-described embodiment were formed in an arc shape when viewed from the vehicle vertical direction (see FIG. 5), but the left and right extending portions 33b of the extending member 33 in this modified example are formed in a substantially straight line shape when viewed from the vehicle vertical direction.

[0048] The extending member 33 of this modified example includes a connecting portion 33a, left and right extending portions 33b, a rear protruding portion (inner protruding portion) 33c, and a fixing portion 33d, similar to the above-described embodiment.

[0049] The connecting portion 33a is formed to extend in the vehicle longitudinal direction and is connected to the outer surface of the column member 31 that is connected to the left and right end portions of the lower cross member 19. The left and right extending portions 33b extend substantially linearly outward in the vehicle width direction from the front end portion in the vehicle longitudinal direction of the connecting portion 33a. The rear protruding portion 33c extends rearward from the rear end portion in the vehicle longitudinal direction of the connecting portion 33a and also extends inward in the vehicle width direction and protrudes rearward of the rear end 19b of the lower cross member 19.

[0050] The rear end portion of the fixing portion 33d is fixed by a bolt 40 as a fixing member to the upper surface of the left end (outer end in the vehicle width direction) of the left and right extending portion 33b and extends toward the rear side surface of the end portion 21a (see FIG. 1) of the lower buffer member 21 of the bumper frame 17. Through holes (not shown) for fixing the bolt 40 are formed in the fixing portion 33d and the left and right extending portion 33b in the vehicle vertical direction. Therefore, the bolt 40 screwed and fixed to the through hole is arranged to extend in the vehicle vertical direction.

[0051] The front end portion of the fixing portion 33d is fixed to the rear side surface of the end portion 21a (see FIG. 1) of the lower buffer member 21 of the bumper frame 17 by a bolt 42 extending in the vehicle longitudinal direction. The fixing portion 33d is arranged to be inclined so as to extend outward in the vehicle width direction toward the front. That is, the line connecting the connection portion by the bolt 40 between the rear end portion of the fixing portion 33d and the left and right extending portion 33b and the connection portion by the bolt 42 between the front end portion of the fixing portion 33d and the bumper frame 17 extends outward in the vehicle width direction toward the front.

[0052] The extension member 33 includes a first member 41 having an opening that opens rearward (toward the center in the vehicle longitudinal direction), and a second member 43 that closes at least a part of the opening of the first member 41. The first member 41 is a substantially L-shaped member that extends forward and leftward (toward the outside in the vehicle width direction) from the outer end of the lower cross member 19 in the vehicle width direction, as viewed from the vehicle vertical direction. Further, the outer member 41 has a rear end on the side of the lower cross member 19 extending rearward from the rear end surface of the lower cross member 19 to form a part of the rear protruding portion 33c. By bending the upper end and the lower end of this outer member 41 rearward and leftward, an upper end surface and a lower end surface are formed. In other words, an opening 41c that opens rearward and leftward (toward the outside in the vehicle width direction) is formed.

[0053] The inner member 43 is formed by bending a flat plate member so as to follow the outer member 41. That is, the inner member 43 has a first portion 43c that extends in the front-rear direction and constitutes the connecting portion 33a, a second portion 43d that extends outward in the vehicle width direction from the front end of the first portion 43c and constitutes the left and right extending portions 33b, and a third portion 43e that extends inward in the vehicle width direction from the rear end of the first portion 43c and constitutes the rear protruding portion 33c.

[0054] The inner member 43 extends from the end portion 41a of the upper end surface of the outer member 41 toward the end portion 41b of the lower end surface. Further, the inner member 43 is formed with a protruding portion 43a that extends below the end portion 41b of the lower end surface of the outer member 41 and another protruding portion 43b that extends above the end portion 41a of the upper end surface of the outer member 41. Thereby, the inner member 43 closes at least a part of the opening 41c of the outer member 41.

[0055] In this modification, since the fixing portion 33d and the left and right extending portions 33b are fixed by a bolt 40 as a fixing member that extends in the vehicle vertical direction, as will be described later, the shock absorption effect when a full overlap collision (see FIG. 6) occurs can be improved.

[0056] As described above with reference to FIG. 6, when another vehicle 100 makes a full-overlap collision with the front of the vehicle 1 and a predetermined load is applied to the left and right extensions 12, as shown in FIG. 10, a load Fa is applied rearward to the connection portion between the front end portion of the fixing portion 33d and the bumper frame 17 by the bolt 42. Here, since the connection portion between the rear end portion of the fixing portion 33d and the left and right extending portions 33b by the bolt 40 is located closer to the inner side in the vehicle width direction than the connection portion between the front end portion of the fixing portion 33d and the bumper frame 17 by the bolt 42, a moment load Fb is generated to rotate the fixing portion 33d about the bolt 40 as the central axis. When this moment load Fb exceeds the fastening force between the fixing portion 33d and the left and right extending portions 33b by the bolt 40, the fixing portion 33d rotates in the direction of the moment load Fb. Therefore, while reducing the increase in the rigidity of the buffer portion C by the extending member 33 and the fixing portion 33d, the impact can be absorbed. Note that the fixing member for fixing the left and right extending portions 33b and the fixing portion 33d is not limited to the bolt 40, and for example, a pin or the like may be adopted.

[0057] As described above, in the frame structure of the vehicle body according to the present invention, it is a frame structure of the vehicle body that supports the cabin 2 which is a part of the vehicle body of the vehicle 1, and includes a pair of left and right side members 11 extending in the vehicle longitudinal direction, and a bumper frame 17 provided to extend in the vehicle width direction outside the vehicle longitudinal direction of the side member 11, that is, at the front end 11a on the front side of the side member 11, and having an end portion 21a extended outside the vehicle width direction from the side member 11, and a front cross member member 13a of the suspension frame 13 provided between the side members 11 and extending in the vehicle width direction.

[0058] Further, in the end portion structure of the vehicle 1 according to the present invention, a lower cross member 19 located below the side member 11, between the front cross member member 13a and the bumper frame 17, and extending in the vehicle width direction, a pillar member 31 extending downward from the side member 11 and supporting the left and right end portions of the lower cross member 19, and an extending member 33 disposed at the left and right end portions of the lower cross member 19 via the pillar member 31 and extending outward in the vehicle width direction to extend to a position facing the inner side in the vehicle longitudinal direction of the end portion 21a of the bumper frame 17 are provided.

[0059] Therefore, a lower cross member 19 extending in the vehicle width direction is positioned below the side member 11 and between the front cross member member 13a and the bumper frame 17. The left and right end portions of the lower cross member 19 are supported by a pillar member 31 extending downward from the extension 12 of the side member 11. Extension members 33 extending outward in the vehicle width direction and positioned on the rear side in the vehicle longitudinal direction outside the side member 11 of the bumper frame 17 are disposed at the left and right end portions of the lower cross member 19. The extension members 33 support the bumper frame 17. Since the lower cross member 19 is positioned below the side member 11, the swing of the lower cross member 19 and the extension members 33 can be promoted during a collision as compared with the case where the lower cross member 19 is attached to the side member 11. That is, since the left and right end portions of the lower cross member 19 are supported by the pillar member 31, the lower cross member 19 can be swung forward in the vehicle and pressed to contact the other vehicle 100 earlier with the upper end of the pillar member 31 as an axis.

[0060] And, between the bumper frame 17 of the side member 11 and the front cross member member 13a of the suspension frame 13, an extension 12 is provided which buckles and absorbs an impact when a load of a predetermined value or more is applied in the vehicle longitudinal direction. Therefore, when the entire bumper frame 17 receives an impact, such as in a full overlap collision, the bumper frame 17 is supported so that the load is evenly applied to the left and right extensions 12, and the extensions 12 can be crushed equally on the left and right. When the bumper frame 17 receives an impact biased in one direction in the vehicle width direction, such as in an offset collision, the extension members 33 support the bumper frame 17, and an increase in local rigidity at a position corresponding to the extension 12 can be reduced.

[0061] An extension 12 of the side member 11 in the longitudinal direction of the vehicle, that is, a position where the mount bracket 15 is provided, is provided with a mount bracket 15 that supports the cabin 2 which is a part of the body of the vehicle 1. The mount bracket 15 has a mount support portion 15a to which a mount member 16 connected to the cabin 2 is attached, and a front wall portion 15b and a rear wall portion 15c that extend downward at intervals from the front and rear of the mount support portion 15a and are joined to the outer side surface of the side member 11 in the vehicle width direction. Since the extension member 33 extends from the side member 11 between the front wall portion 15b and the rear wall portion 15c, the strength of the portion of the side member 11 where the column member 31 is attached can be increased.

[0062] And the extension member 33 has a rear protruding portion 33c that protrudes toward the center side from the rear end (inner end portion) 19b of the lower cross member 19. The rear protruding portion 33c is provided at a position that contacts the front side cross member member 13a when either one of the portions between the bumper frame 17 of the side member 11 and the front side cross member member 13a is crushed. Thereby, at the time of an offset collision, the rear protruding portion 33c contacts the front side cross member member 13a, and the inner side of the lower cross member 19 in the vehicle width direction is swung toward the center in the vehicle longitudinal direction about the rear protruding portion 33c, and the extension member 33 located outside the vehicle width direction from the rear protruding portion 33c can be pressed outward in the vehicle longitudinal direction, that is, toward the other vehicle side.

[0063] In particular, since the rear protruding portion 33c is located outside the end portion of the front side cross member member 13a in the vehicle width direction, it is possible to suppress the rear protruding portion 33c from contacting the front side cross member member 13a during a full overlap collision while allowing the rear protruding portion 33c to contact the front side cross member member 13a during an offset collision.

[0064] And since it has a fixing portion 33d with one end fixed to the outer end portion of the extension member 33 in the vehicle width direction and the other end fixed to the end portion 21a of the bumper frame 17, it is possible to suppress the bumper frame 17 from swinging in the vehicle longitudinal direction during a collision of the vehicle 1.

[0065] And, since the lower cross member 19 is formed with a deformation hole 19a at the center in the vehicle width direction to reduce the rigidity against the force that bends in the vehicle longitudinal direction, the deformation hole 19a of the lower cross member 19 can be used to press the bumper frame 17 outward by the reinforcing portion using the force that presses the deformation hole 19a of the lower cross member 19 toward the center side in the vehicle longitudinal direction during a collision.

[0066] And, since the left and right extending portions 33b of the extending member 33 have a first member 41 having an opening that opens toward the center side in the vehicle longitudinal direction and a second member 43 that closes at least a part of the opening of the first member 41, the rigidity of the extending member 33 can be ensured.

[0067] And, the extending member 33 in the modification is connected to the column member 31 and has a connecting portion 33a that extends in the vehicle longitudinal direction, left and right extending portions 33b that extend outward in the vehicle width direction from the end portions on the outer side in the vehicle longitudinal direction of the connecting portion 33a, and a fixing portion 33d that is fixed by a bolt 40 as a fixing member at the end portions on the outer side in the vehicle width direction of the left and right extending portions 33b. Therefore, during a full overlap collision, since the fixing portion 33d rotates about the fastening portion by the bolt 40, it is possible to absorb an impact while reducing the increase in the rigidity of the buffer portion C by the extending member 33 and the fixing portion 33d.

[0068] This concludes the description of the frame structure of the vehicle body according to the present invention. However, the present invention is not limited to the above-described embodiment and can be modified without departing from the gist of the invention.

[0069] For example, in the present embodiment, the extension 12, the bumper frame 17, the lower cross member 19, etc. are disposed at the front portion of the vehicle 1, and the case where another vehicle 100 collides with the vehicle 1 from the front has been described. However, the rear portion of the vehicle 1 may be configured in the same manner to prepare for the case where another vehicle 100 collides with the vehicle 1 from the rear.

[0070] In addition, in this embodiment, the extension member 33 is formed with the rear protruding portion 33c, but it may be formed on the lower cross member 19, or a portion protruding forward may be formed at a position corresponding to the rear protruding portion 33c from the front side cross member member 13a of the suspension frame 13.

[0071] In addition, in this embodiment, the fixing portion 33d is used, but the lower end of the lower buffer member 21 of the bumper frame 17 may be extended so that the extension member 33 directly contacts the bumper frame 17 when the vehicle 1 collides with another vehicle 100.

[0072] This application is based on Japanese Patent Application No. 2021-002080 filed on January 8, 2021 and PCT International Application No. PCT / JP2021 / 037404 filed on October 8, 2021, the contents of which are incorporated herein by reference.

Explanation of Reference Numerals

[0073] 1 Vehicle 2 Cabin (Body) 3 Chassis 11 Side Member 11a Front End (End Portion) 12 Extension (Buffer Portion) 13a Front Side Cross Member Member (First Cross Member) 15 Mounting Bracket 15a Mounting Support Portion 15b Front Wall Portion 15c Rear Wall Portion 16 Mounting Member 17 Bumper Frame 19 Lower Cross Member (Second Cross Member) 19a Deformation Hole (Rigidity Reduction Portion) 19b Rear End (Inner End Portion) 21a End Portion (Extension Portion) 31 Column Member 33 Extension Member 33a Connection Portion 33b Left and Right Extension Portions 33c Rear Protruding Portion (Inner Protruding Portion) 33d fixing part 40 bolts (fixing members) 41 outer member (first member) 43 inner member (second member) 100 other vehicle (collided object)

Claims

1. A frame structure of a chassis that supports a vehicle body, comprising: a pair of left and right side members extending in the longitudinal direction of the vehicle; a bumper frame provided at an end of the side member outside the vehicle in the longitudinal direction and extending in the vehicle width direction, having an extension portion extending outward in the vehicle width direction from the side member; a first cross member provided between the pair of left and right side members and extending in the vehicle width direction; a second cross member located below the side member and between the first cross member and the bumper frame and extending in the vehicle width direction; a pillar member extending downward from the side member and supporting the left and right ends of the second cross member; an extension member extending outward in the vehicle width direction from the pillar member at the left and right ends of the second cross member and along substantially the same direction as the extension direction of the second cross member, and extending to a position facing the inner side in the longitudinal direction of the extension portion of the bumper frame; the extension member has an inner protruding portion protruding inward in the longitudinal direction of the vehicle from the inner end portion on the inner side in the longitudinal direction of the second cross member; the inner protruding portion is provided at a position in contact with the first cross member when either one of the portions between the bumper frame and the first cross member of the left and right side members is crushed; a frame structure of a chassis.

2. Between the bumper frame and the first cross member of the side member, there is a buffer portion that buckles and absorbs impact when a load of a predetermined value or more is applied in the longitudinal direction of the vehicle. The frame structure of the chassis according to claim 1, characterized in that.

3. A mount bracket for supporting the vehicle body is provided at a position where the pillar member of the side member is provided, the mount bracket has a mount support portion to which a mount member connected to the vehicle body is attached, and a front wall portion and a rear wall portion that extend downward at intervals from the front and rear of the mount support portion and are joined to the outer side surface of the side member in the vehicle width direction; the pillar member is joined to the side surface of the side member between the front wall portion and the rear wall portion of the mount bracket. The frame structure of the chassis according to claim 1 or 2, characterized in that.

4. A fixing portion is provided, one end of which is fixed to the outer end portion of the extension member in the vehicle width direction, and the other end of which is fixed to the extension portion of the bumper frame. The frame structure of the chassis according to any one of claims 1 to 3, characterized in that.

5. The extension member includes a first member having an opening that opens inward in the vehicle longitudinal direction, and a second member that closes at least a part of the opening of the first member. The frame structure of the vehicle chassis according to any one of claims 1 to 4, characterized in that.

6. A rigidity reduction portion for reducing the rigidity against a force that bends in the vehicle longitudinal direction is formed in the center in the vehicle width direction of the second cross member. The frame structure of the vehicle chassis according to any one of claims 1 to 5, characterized in that.

7. The extension member is a connecting portion connected to the column member and extending in the vehicle longitudinal direction, and left and right extension portions extending outward in the vehicle width direction from the end portion outside the vehicle longitudinal direction of the connecting portion. It has The frame structure according to claim 4, wherein the fixing portion is fixed to the end portion outside the vehicle width direction of the left and right extension portions by a fixing member extending in the vehicle vertical direction.

8. A frame structure of a vehicle chassis that supports a vehicle body, a pair of left and right side members extending in the vehicle longitudinal direction, a bumper frame provided to extend in the vehicle width direction at the end portion outside the vehicle longitudinal direction of the side member and having an extension portion extending outward in the vehicle width direction from the side member, a first cross member provided between the pair of left and right side members and extending in the vehicle width direction, a second cross member located below the side member and between the first cross member and the bumper frame and extending in the vehicle width direction, a column member extending downward from the side member and supporting the left and right end portions of the second cross member, and an extension member extending outward in the vehicle width direction from the column members at the left and right end portions of the second cross member and extending to a position facing inside the vehicle longitudinal direction of the extension portion of the bumper frame. The extension member has an inner protruding portion that protrudes inward in the vehicle longitudinal direction from the inner end portion inside the vehicle longitudinal direction of the second cross member. The inner protruding portion is provided at a position that contacts the first cross member when either one of the portions between the bumper frame and the first cross member of the left and right side members is crushed. A fixing portion is provided, one end of which is fixed to the end portion outside the vehicle width direction of the extension member, and the other end of which is fixed to the extension portion of the bumper frame. The frame structure of the vehicle chassis.

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