JP6597731B2 - Front body structure of the vehicle - Google Patents

Description

  The present invention includes a front portion of a vehicle having a front side frame having a closed cross section extending in the vehicle front-rear direction and provided with a mount bracket mounting portion for mounting a mount bracket provided in a power train mount that supports the power train. It relates to the body structure.

As illustrated in Patent Documents 1 and 2, there is known one in which a front side frame is provided with a node member as a reinforcing member.
Patent Document 1 discloses that a front side frame (1), a lower member (3) disposed on the outer side in the vehicle width direction of the front side frame (1), and between these (1) and (3), A gusset (2) extending in the vehicle front-rear direction from the front end of the side frame (1) to the first break point (P1), and a collision load at the time of an offset collision is transmitted via the lower member (3) and the gusset (2). In this way, it can be reliably transmitted to the front side frame (1).

  Furthermore, the thing of patent document 1 is equipped with the bulkhead (13) as a node member which receives and supports the collision load transmitted from a gusset (2) at the time of an offset collision inside the front side frame (1).

  On the other hand, in Patent Document 2, the engine mount (30) is supported on the front side frame (11) in the front-rear direction in order to reduce engine vibration transmitted to the passenger compartment via the engine mount (30). The coupling portions (18) and (19) are provided. Each of the coupling portions (18) and (19) includes partition walls (82) and (92) as node members, and the engine mount (30). The support strength is improved.

  By the way, it is known to absorb the front collision load by compressing and deforming the crash can at the frontal collision (hereinafter referred to as “front collision”) or by bending and deforming the front side frame at a predetermined folding start point. Yes.

  Further, the inventors can compress the front part of the front side frame positively and deform it so that the front part can also have a load absorbing function, which is effective in improving the load absorbing performance at the time of the front collision. Inspired to be.

  Here, the front side frame (1) of Patent Document 1 described above is provided with a plurality of folding points (P1 to P3) so as to be bent and deformed by receiving a front impact load in the vehicle longitudinal direction. The bulkhead (13) is arranged inside so as not to hinder the folding of the vehicle. As described above, the front part of the front side frame (1) is gusseted on the outer side surface along the vehicle longitudinal direction. (2) is provided to provide high strength.

  However, as is apparent from such a configuration, Patent Document 1 is based on the idea of compressing and deforming the front portion of the front side frame at the time of a front collision so that the shock load absorbing function is also actively carried on the front portion. There is no description about the deformation mode and the configuration that the front part is formed with low strength so that compression deformation of the front part is not hindered at the time of front collision, and it is improved from the viewpoint of enhancing load absorption performance by the front side frame There was room for.

  Further, in the configuration of Patent Document 2, the front portion of the front side frame (11) of the engine mount (30) with respect to the connecting portions (18) and (19) is configured with low strength so as to be compressed and deformed at the time of the front collision. In this case, when gear noise transmitted from the power train to the vehicle body side via the engine mount (30) is transmitted to the front side portion of the front side frame (11), the front side portion is an orthogonal cross section in the vehicle longitudinal direction. There is concern that the NVH performance may be adversely affected by causing the passenger to feel uncomfortable by transmitting the amplified vibration to the passenger compartment side.

  Furthermore, if the front side portion of the front side frame (11) is configured with low strength so as to be compressed and deformed at the time of the front collision, the difference in strength between the low strength front portion and the high strength connecting portions (18), (19). Smooth load transmission from the front part of the front side frame (11) to the part where the joints (18) and (19) are provided, such as when the front impact load concentrates on these boundary parts at the time of the front impact There is also a possibility of being inhibited.

  In short, both the front side frames of Patent Documents 1 and 2 are provided with a node member as a reinforcing member, but the load absorption performance and NVH performance by the front side frame at the time of the front collision are not compatible.

JP 2013-193571 A International Publication No. 2012/017747

  Therefore, the present invention can improve the load absorption performance without impeding the deformation of the front side frame at the time of a front collision, while reducing the gear noise and engine noise transmitted from the power train to the front side frame via the power train mount, thereby reducing NVH. An object of the present invention is to provide a vehicle front body structure capable of enhancing performance.

The present invention includes a front portion of a vehicle having a front side frame having a closed cross section extending in the vehicle front-rear direction and provided with a mount bracket mounting portion for mounting a mount bracket provided in a power train mount that supports the power train. The front side frame has a low-strength region, a medium-strength region, and a high-strength region in this order from the front end toward the rear of the vehicle, and the high-strength region includes the mount bracket mounting portion. The low-strength region is configured to have a strength capable of compressive deformation with respect to a front impact load, and a reinforcing member that prevents shear deformation of the closed cross section of the front side frame is provided in the medium-strength region, In the vehicle longitudinal direction of the strength region, the region excluding the mounting bracket mounting portion, and the medium strength region In the vehicle longitudinal direction, in a region other than the reinforcing member is by pre-collision load that provided the bending deformation promoting portion that promotes bending deformation in the vehicle width direction of the front side frame.

  According to the above configuration, the load absorption performance of the front side frame can be improved during a front collision, and the NVH performance is improved by reducing gear noise and engine noise transmitted from the power train to the front side frame via the power train mount. Can do.

Further, as described above, in the vehicle longitudinal direction of the high intensity region, a region excluding the mounting bracket mounting portion, and in the vehicle longitudinal direction in said intensity region, a region except for the reinforcing member, the bending piece deformation promoting portion By providing these, the reinforcing member and the mounting bracket attaching portion can be bent and deformed without being hindered from being bent and deformed by the deformation promoting portion at the time of a front collision, and load absorption performance can be improved. Can be increased.

The present invention also includes a front side frame having a front side frame having a closed cross section extending in the vehicle front-rear direction and provided with a mount bracket mounting portion for mounting a mount bracket provided on a power train mount that supports the power train. The front side frame has a low-strength region, a medium-strength region, and a high-strength region in this order from the front end toward the rear of the vehicle, and the high-strength region includes the mount bracket mounting portion. And the low-strength region is configured with a strength capable of compressive deformation with respect to a front impact load, and the medium-strength region is provided with a reinforcing member for preventing shear deformation of the closed cross section of the front side frame, Of the panels constituting the front side frame, the panel in the low strength region is the medium strength. And it is formed at least one of the material of the thin plate thickness and lower strength than the panel in the region.

Thus, among the panel constituting the front side frame, wherein the panel in the low intensity region, by forming at least one of the material of the thin plate thickness and lower strength than the panel in said in intensity region The front side frame can be formed to be compressible and deformable against the front impact load in the low strength region, and the strength of the low strength region and the high strength region is increased by increasing the strength of the medium strength region as compared with the low strength region. The difference can be mitigated.

  As an aspect of the present invention, a crash can is attached to the front end of the front side frame, and the low-strength region is substantially the same as an orthogonal cross-sectional shape of the crash can in the vehicle longitudinal direction and is straight in the vehicle longitudinal direction. Can be extended.

  According to the above configuration, the crash can is compressed and deformed rearward of the vehicle at the time of a front collision, and the low-strength region of the front side frame can be compressed and deformed. Can be increased.

  As an aspect of the present invention, both the crash can and the low-strength region can be formed in a substantially cross shape in a cross section orthogonal to the vehicle longitudinal direction.

  According to the above configuration, both the low-strength region of the crash can and the front side frame are substantially cross-shaped in cross section, so that the cross-section coefficient can be increased in the vertical direction and the vehicle width direction, Even if a front impact load is input from a position offset vertically or horizontally with respect to the front side frame and the crash can extending in the longitudinal direction of the vehicle, the convex protruding upward and downward and left and right forms a substantially cross-shaped cross section. By supporting the part, the crash can and the front side frame can be prevented from falling and deforming in the low-strength region, and these can be firmly compressed and deformed to absorb the collision load.

  As an aspect of the present invention, the high-strength region has a substantially rectangular cross section in the vehicle front-rear direction, and the medium-strength region has a substantially rectangular shape as the vehicle cross-section in the vehicle front-rear direction progresses backward from a substantially cross shape. It can be configured to change in shape.

  According to the above configuration, the intermediate strength region has a cross-sectional shape between the low-strength region having a substantially cross-shaped cross section and the high-strength region having a substantially rectangular cross section in the vehicle front-rear direction of the front side frame. Since the shape is such that the vehicle changes smoothly in the longitudinal direction of the vehicle, the front impact load can be smoothly transmitted from the low strength region to the high strength region through the medium strength region.

  As an aspect of the present invention, a mount reinforcing member that reinforces the mount bracket mounting portion can be disposed on the mount bracket mounting portion.

  According to the above configuration, the rigidity of the mount bracket mounting portion can be increased by the mount reinforcing member disposed in the mount bracket mounting portion, and the gear noise transmitted from the power train to the front side frame via the power train mount, the engine Noise can be reduced and NVH performance can be enhanced.

  Further, by disposing a mount reinforcing member in the mount bracket mounting portion included in the high strength region, a portion corresponding to the mount bracket mounting portion in the high strength region is prevented from being bent and deformed during a front collision. be able to.

  According to the present invention, the load absorption performance can be improved without impeding the deformation of the front side frame at the time of a front collision, and the gear noise and engine noise transmitted from the power train to the front side frame via the power train mount can be reduced. NVH performance can be increased.

The top view which shows the principal part of the front part vehicle body structure of the vehicle of this embodiment. Sectional drawing which looked at the principal part of the front part vehicle body structure of the vehicle of this embodiment from the vehicle width direction inner side. Sectional drawing which shows the state which removed the inner panel of the front side frame in FIG. The left view which shows the principal part of the front vehicle body structure of the vehicle of this embodiment. The perspective sectional view which looked at the principal part of the front part body structure of the vehicle of this embodiment of a state where the inner panel of the front side frame was removed from the vehicle width direction inner front. The arrow line view seen from the arrow D direction in FIG. The arrow view seen from the arrow A direction and upper direction in FIG. The CC sectional view taken on the line of FIG. The front view (a), plan view (b), left side view (c), and right side view (d) of the node member. The BB expanded sectional view of FIG. Sectional drawing which showed the principal part of the front part vehicle body structure of the vehicle of this embodiment after deformation | transformation by the front collision corresponding to FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the figure, arrow F indicates the front of the vehicle, arrow OUT indicates the vehicle width direction outer side (the vehicle left side), arrow IN indicates the vehicle width direction inner side (the vehicle right side), and arrow U indicates the vehicle upper side.

  Since the front vehicle body structure V of the vehicle according to the present embodiment has a substantially left-right symmetrical shape, it will be described based on the configuration on the left side of the vehicle, except when specifically noted.

  As shown in FIGS. 1 to 4, the front vehicle body structure V of the vehicle includes a bumper beam 1 installed at its front end so as to extend in the vehicle width direction, and a passenger compartment C (see FIGS. 2 and 3). A dash panel 2 that forms a partition wall with the engine room E, and a pair of left and right front side frames that extend from the lower side of the dash panel 2 to the front of the dash panel 2 via a kick-up portion 3 (see FIGS. 2 to 4). 4 (only the left side is shown), and a pair of left and right crash cans 5 (only the left side is shown) disposed between the left and right end portions of the bumper beam 1 and the front side frame 4.

  The crash can 5 is formed of a metal cylindrical body extending in the vehicle front-rear direction, and a cross section perpendicular to the vehicle front-rear direction is formed in a substantially cross shape projecting up, down, left, and right (see FIGS. 5 and 7). Since the crash can 5 is formed in a substantially cross shape in front view as described above, the section modulus in the vertical direction and the horizontal direction is set to a large value. As a result, even when a front collision load is input at a position offset in the vertical direction or the horizontal direction with respect to the crash can 5 at the time of an offset collision, the crash can 5 is hardly bent and deformed, and is compressed and deformed in a bellows shape. (Ie, axial compression) to effectively absorb the front impact load.

  As shown in FIGS. 1 to 4, a mounting plate 52 attached to the front end portion of the front side frame 4 is fixed to the rear end portion of the crash can 5. Both ends of the bumper beam 1 in the vehicle width direction are joined to the front end portion of the crash can 5 via the bracket 7.

  The front side frame 4 is disposed on the inner side in the vehicle width direction and is opened toward the outer side in the vehicle width direction, and the outer panel 1A (see FIG. 5) formed of a flat steel plate material constituting the outer wall surface portion 41. It consists of an inner panel 1B (see FIG. 7) formed of a cross-sectional (front view) hat-shaped steel plate material having an opening 1Bd (see FIG. 10).

  As shown in FIGS. 1, 4 to 6, 8, and 10, in particular, FIG. 10, the outer panel 1 </ b> A includes a flat outer panel body 1 </ b> Aa and an upper edge from the upper edge of the outer panel body 1 </ b> Aa. The outer upper flange portion 1Ab that protrudes and the outer lower flange portion 1Ac that protrudes downward from the lower edge of the opening 1Bd are integrally formed.

  The inner panel 1B is formed in a cross-sectional (front view) U-shape and has an inner wall surface 42 of the front side frame 4 as shown in FIG. 1, FIG. 2, FIG. 7, FIG. The inner panel main body 1Ba to be formed, the inner upper flange 1Bb that protrudes upward from the upper edge of the opening 1Bd in the inner panel main body 1Ba, and the inner lower flange that protrudes downward from the lower edge of the opening 1Bd It is integrally formed with 1Bc.

As shown in FIG. 10, the outer panel 1A is disposed so as to close the opening 1Bd that opens toward the vehicle width direction outer side of the inner panel 1B, the outer upper flange portion 1Ab, the inner upper flange portion 1Bb, and the outer lower flange. The portion 1Ac and the inner lower flange portion 1Bc are joined by being fixed by spot welding or the like over a plurality of locations along the vehicle longitudinal direction.
Thus, as shown in FIGS. 8 and 10, the front side frame 4 extends in the vehicle front-rear direction and has a closed cross section 1C (space) inside.

  1 to 4, a set plate 6 is fixed to the front end portion of the front side frame 4, and the mounting plate 52 of the crash can 5 is attached to the set plate 6 by bolting or the like.

  As shown in FIGS. 2 to 8, the front side frame 4 supports the power train 10 (PT) via a power train mount 18 (hereinafter referred to as “PT mount 18”), and the front side frame 4. A powertrain mount bracket 19 (hereinafter referred to as “PT mount”) provided in the PT mount 18 at a substantially intermediate position between the joint portion 48 (see FIGS. 1 and 8) to the dash panel 2 in the vehicle longitudinal direction and the set plate 6. A mount bracket attaching portion 49 for attaching the bracket 19 ") is provided.

  In this example, the power train 10 is configured such that a horizontal engine is disposed on the right side of the engine room E, and a transmission including gears and the like is disposed on the left side of the engine room E. Therefore, the PT mount 18 on the left side of the vehicle shown in FIG. 1 and the like is configured as a mission mount, and the PT mount (not shown) on the right side of the vehicle is configured as an engine mount.

  As shown in FIGS. 3 to 5, the mount bracket attaching portion 49 is provided with a mount reinforcing member 20. The mount reinforcing member 20 includes a reinforcing member main body 21 (see FIGS. 3, 5, and 6) that bulges inward in the vehicle width direction, and an outer edge of the vehicle width of the reinforcing member main body 21 and the upper edge to the upper side. Reinforcing reinforcing member upper flange portion 22 (see FIGS. 5 and 6) and reinforcing member lower flange portion 23 (see FIGS. 3, 5, and 5) projecting downward from the vehicle width outer edge and lower edge of the reinforcing member main body portion 21. 6)).

  The reinforcing member main body 21 connects an inner wall surface portion 21b (see FIGS. 3, 5, and 6) that extends in the vertical direction on the outer side in the vehicle width direction, and an upper end of the inner wall surface portion 21b and a lower end of the reinforcing member upper flange portion 22. An upper wall surface portion 21a (see FIGS. 5 and 7), and a lower wall surface portion 21c (see FIGS. 3, 5, and 6) connecting the lower end of the inner wall surface portion 21b and the upper end of the reinforcing member lower flange portion 23. It is formed with.

  As shown in FIG. 5, the mount reinforcing member 20 includes an upper member 24 that mainly forms an upper wall surface portion 21a and a reinforcing member upper flange portion 22, and mainly an inner wall surface portion 21b, a lower wall surface portion 21c, and a lower reinforcing member. It is integrally formed by joining the lower member 25 constituting the flange portion 23.

  The reinforcing member upper flange portion 22 is interposed between the outer upper flange portion 1Ab and the inner upper flange portion 1Bb of the front side frame 4 so as to be sandwiched between the outer upper flange portion 1Ab and the inner upper flange portion 1Bb. The flange portions 1Ab, 22, 1Bb of the sheets are joined by spot welding (see FIG. 7).

  Similarly, the reinforcing member lower flange portion 23 is interposed between the outer lower flange portion 1Ac and the inner lower flange portion 1Bc, and the three flanges 1Ac, 23, 1Bc are joined by spot welding (see FIG. 3, see FIGS. 5 and 7).

  3, FIG. 5, and FIG. 7, the mark “X” indicates the welding location of the outer lower flange portion 1Ac, the reinforcing member lower flange portion 23, and the inner lower flange portion 1Bc. On the other hand, although not shown, the outer upper flange portion 1Ab, the reinforcing member upper flange portion 22 and the inner upper flange portion 1Bb are also welded so as to correspond to the welding location.

  Although not shown, the upper wall surface portion 21a and the inner wall surface portion 21b of the reinforcing member main body portion 21 are respectively connected to the upper wall surface portion 43 and the outer wall surface portion 41 of the mount bracket mounting portion 49 of the front side frame 4 from the closed cross section 1C side. It arrange | positions so that it may contact | abut (refer FIG.5, FIG.7, FIG.8), and each contact location is joined by spot welding.

  As shown in FIGS. 1 and 5, the upper wall surface portion 21 a of the reinforcing member main body portion 21 and the upper wall surface portion 21 a of the mount bracket mounting portion 49 are each provided with two mounting holes 26 a and 26 b. As shown in FIGS. 3, 5 to 7, and 8, the reinforcing member main body 21 has a lower side from the lower surface of the upper wall surface portion 21 a so as to correspond to the two mounting holes 26 a and 26 b in the plan view. A pipe-shaped weld nut 27 is provided.

  The weld nut 27 is fixed to the lower surface of the upper wall surface portion 21a of the reinforcing member main body portion 21 and is also fixed to the inner wall surface portion 42 of the reinforcing member main body portion 21 via the support member 28 as shown in FIG. Thus, the reinforcing member body 21 is supported.

  As shown in FIGS. 1, 5, and 7, the PT mount bracket 19 provided in the PT mount 18 is on the weld nut 27 side together with the upper wall surface portions 21 a and 43 of the reinforcing member main body portion 21 and the mount bracket mounting portion 49. It is attached to the mount bracket attaching portion 49 of the front side frame 4 by fastening with the heavy bolt B.

  As shown in FIGS. 4, 5, and 8, the outer wall surface portion 41 of the front side frame 4 is provided with a recessed groove portion 50 that is recessed toward the closed section 1 </ b> C side (inner side in the vehicle width direction).

  The concave groove 50 is formed such that the rear edge 50r is located between the front mounting hole 26a and the rear mounting hole 26b (see FIG. 8), and the front edge 50f of the concave groove 50 is It is formed at a position rearward from a node member 30 (see FIGS. 3, 4, and 8) described later and in front of the front end of the mount bracket mounting portion 49 (see the same figure). The recessed groove part 50 is provided in the area | region except the upper part in the outer wall surface part 41 (refer FIG. 3, FIG. 4).

  As shown in FIGS. 1 to 4, 7, and 8, the front portion of the front side frame 4 has a cross shape that is substantially the same as the cross shape of the crash can 5 from the front end of the front side frame 4 to the rear. It has the compression deformation part 11 extended in a vehicle front-back direction.

  Specifically, at least the compression deformation portion 11 of the front side frame 4 in the vehicle front-rear direction is formed with an inner bulging portion 12B that protrudes inward in the vehicle width direction from an intermediate portion in the vertical direction of the inner wall surface portion 42 of the compression deformation portion 11. (See FIGS. 1, 2, 7, 8, and 10), an outer raised portion 12A that protrudes outward in the vehicle width direction from an intermediate portion in the vertical direction of the outer wall surface 41 of the compression deformable portion 11 (FIG. 1). 3, 4, 6, and 8). The inner raised portion 12B constitutes the right protruding piece of the compression deforming portion 11 having a cross-shaped cross section, and the outer raised portion 12A constitutes the left protruding piece of the compressive deforming portion 11 having a cross sectional shape.

  As shown in FIGS. 1 to 4, 7, and 8, both the outer raised portion 12 </ b> A and the inner raised portion 12 </ b> B extend from the front end of the front side frame 4 toward the rear of the vehicle relative to the compression deformable portion 11, and are compressed. In the rearward extension portion of the deformable portion 11, the length of each bulge is formed so as to decrease toward the rear of the vehicle (see FIGS. 1, 7, and 8).

The outer protruding portion 12A has a rear end 12Ar extending rearward of the vehicle to a position on the front side with respect to the front edge 50f of the recessed groove portion 50, more specifically, to a position where the node member 30 described later is disposed (FIG. 4, FIG. 8), the rear end 12Br of the inner raised portion 12B extends to the rear of the vehicle up to the mount bracket mounting portion 49, that is, the position corresponding to the front edge of the mount reinforcing member 20 (see FIGS. 2, 7, and 8).
That is, the inner raised portion 12B is formed to the rear of the vehicle so that the length in the vehicle front-rear direction is longer than the outer raised portion 12A (see FIG. 8).

  On the other hand, an orthogonal cross section in the vehicle front-rear direction is formed in a substantially rectangular shape at the front end of the mount bracket mounting portion 49 of the front side frame 4, that is, behind the front end of the mount reinforcing member 20 (see FIGS. 1 and 8). ).

  As described above, the outer bulging portion 12A and the inner bulging portion 12B are formed so that the respective bulging lengths become smaller toward the rear of the vehicle than the compression deforming portion 11 (see FIGS. 1 and 7). (See FIG. 8). Accordingly, the portion of the front side frame 4 between the compression deformable portion 11 and the mount bracket mounting portion 49 in the vehicle front-rear direction has a substantially cross-sectional shape to a substantially rectangular shape as the cross-section orthogonal to the vehicle front-rear direction advances toward the rear of the vehicle. It is formed so as to gradually change in shape (see FIGS. 1 to 4, 7, and 8).

  As shown in each enlarged portion of the X1 portion and the X2 portion in FIG. 8, the compression deformation portion 11 of the front side frame 4 is configured so that the outer panel 1A and the inner panel 1B corresponding to the compression deformation portion 11 are crushed. 5 is formed as a thin portion Tn having substantially the same thickness as 5.

  On the other hand, the rear part of the front side frame 4 with respect to the compressive deformation part 11 is formed such that the outer panel 1A and the inner panel 1B corresponding to the rear part are thicker than the compressive deformation part 11 (low-strength region R1 described later). The thick part Tc is formed.

  As shown in FIGS. 1 to 4, 6, 7, and 8, the rear end portion of the compression deformable portion 11 of the front side frame 4, that is, the surface corresponding to the boundary portion between the thin portion Tn and the thick portion Tc. A plate thickness change line L in which the plate thickness changes in a stepped shape is formed along the circumferential direction of the front side frame 4.

  The front side frame 4 having the thin wall portion Tn and the thick wall portion Tc adjusts the gap between the rolls during rolling, and the tailored weld blank method in which the steel plates having different thicknesses are joined by laser welding or plasma welding and then press-formed. It can be formed by a tailored rolled blank method that creates different thicknesses.

  As shown in FIGS. 1 to 8, the front side frame 4 has a low-strength region R <b> 1, a medium-strength region R <b> 2, and a high-strength region R <b> 3 in this order according to the strength against the front impact load from the front end toward the rear of the vehicle. It is divided.

  As shown in FIGS. 1 to 4 and FIGS. 6 to 8, the low-strength region R <b> 1 corresponds to the compression deformation portion 11 that compresses and deforms with respect to the front collision load in the vehicle front-rear direction of the front side frame 4. It is an area. As described above, the low-strength region R1 (compression deforming portion 11) is formed substantially in the same shape as the cross-sectional shape of the crash can 5 from the crash can 5 in the vehicle front-rear direction, that is, in a substantially cross shape in front view. By forming the panel surface with the thin portion Tn, the panel surface is configured to have a low strength so as to be compressively deformable with respect to the front impact load.

  The middle strength region R2 is between the rear end (position of the plate thickness change line L) of the low strength region R1 (compression deforming portion 11) and the front end of the mount bracket mounting portion 49 in the vehicle front-rear direction of the front side frame 4. This is a corresponding region, and as described above, it is formed by the thick portion Tc having a thick plate thickness, so that it has a higher strength than the low strength region R1, and the cross section in the vehicle longitudinal direction is substantially cross-shaped. It is formed so as to change from a shape to a substantially rectangular shape as it advances backward.

Specifically, in the middle strength region R2, the projecting lengths of the outer raised portion 12A and the inner raised portion 12B gradually decrease from the rear end of the low strength region R1 toward the rear of the vehicle. When the portion 12A disappears (that is, reaches the rear end 12Ar of the outer raised portion 12A) (see FIGS. 1, 4 and 8) and then reaches the high strength region R3, the inner raised portion 12B in the inner wall surface portion 42 disappears (that is, By reaching the rear end 12Br of the inner raised portion 12B (see FIGS. 1, 2, 7, and 8), the orthogonal cross section in the vehicle front-rear direction becomes a substantially rectangular shape.
A node member 30 to be described later is provided in the medium strength region R2.

  The high-strength region R3 is a region including at least the mount bracket attachment portion 49 in the vehicle front-rear direction of the front side frame 4, and specifically, as shown in FIGS. This is a region from the front end to the joint 48 with the dash panel 2. As described above, the high-strength region R3 has a substantially rectangular cross section in the vehicle front-rear direction, and the outer panel 1A and the inner panel 1B of the front side frame 4 in the high-strength region R3 have a plate thickness. It is formed by a thick portion Tc that is thicker than the low-strength region R1. Further, as shown in FIGS. 3 and 5 to 8, the high strength region R <b> 3 is higher than the medium strength region R <b> 2 by providing the mount reinforcing member 20 in the mount bracket mounting portion 49 included in the high strength region R <b> 3. It consists of strength.

  As shown in FIGS. 3 to 5 and 8 in FIG. 1 to FIG. 8, in the vehicle longitudinal direction of the front side frame 4, the position near the front side of the front edge 50 f of the groove 50 formed in the outer wall surface portion 41. That is, a node member 30 as a reinforcing member for preventing shear deformation of the closed cross section 1C of the front side frame 4 is provided at the rear position of the medium strength region R2.

  9 (a), 9 (b), 9 (c), and 9 (d), the node member 30 is a flat plate configured as a partition wall that partitions the front side frame 4 in the front-rear direction of a closed cross section 1C that extends in the vehicle front-rear direction. A node member main body portion 31 (see FIGS. 5 to 7), an inner side joint flange portion 32 protruding from the inner end of the node member main body portion 31 in the vehicle width direction (see the same figure), and the node An outer side joining flange portion 33 projecting from the outer end in the vehicle width direction of the member main body portion 31 to the rear of the vehicle (see the same figure), and an upper joint flange portion 34 projecting forward from the upper end of the node member main body portion 31 (see FIG. 5). (See FIG. 7).

  Similarly, as shown in FIGS. 9A, 9 </ b> B, 9 </ b> C, and 9 </ b> D, the inner-side joining flange portion 32 includes an upper rear extending portion 32 u that extends rearward from the upper portion of the rear end side. And a lower rear extending portion 32d extending rearward from the lower portion of the rear end side of the inner side joining flange portion 32. The outer side joining flange portion 33 includes an upper extending portion 33u extending upward from its upper end and a lower extending portion 33d extending downward from the lower end of the outer side joining flange portion 33.

  Here, as described above, the inner-side joining flange portion 32 and the outer-side joining flange portion 33 both extend toward the rear of the vehicle with respect to the node member main body portion 31, but FIG. ), (C), (d), the inner-side joining flange portion 32 has an upper rear extension portion 32u and a lower rear extension portion 32d extending rearward of the outer side joining flange portion 33 than the outer side joining flange portion 33. It is formed to be put out. That is, the inner side joining flange portion 32 is arranged such that the upper rear extending portion 32u and the lower rear extending portion 32d are offset from the outer side joining flange portion 33 toward the rear of the vehicle in a side view of the vehicle. .

  In FIG. 3, FIG. 5, and FIG. 7, x marks attached to the node member 30 indicate spot welding locations of the front side frame 4 and the node member 30. The upper joint flange 34 of the node member 30 is joined by spot welding to the upper wall surface 43 of the front side frame 4 (see FIGS. 5 and 7). Further, the upper rear extension 32u provided on the inner side joining flange portion 32 of the node member 30 is spot-welded to the upper portion of the inner raised portion 12B in the inner wall surface portion 42 of the front side frame 4, and the inner side of the node member 30 The lower rear extending portion 32d provided in the joining flange portion 32 is joined to the lower portion of the inner raised portion 12B on the inner wall surface portion 42 of the front side frame 4 by spot welding (see FIGS. 5 to 7).

  Furthermore, as shown in FIGS. 3, 6, 7, and 10, the upper extending portion 33 u provided in the outer side joint flange portion 33 of the node member 30 is formed with the outer upper flange portion 1 </ b> Ab of the front side frame 4. The upper upper flange portion 1Bb is interposed between the outer upper flange portion 1Ab and the inner upper flange portion 1Bb so as to sandwich the upper extension portion 33u provided in the outer joint flange portion 33 of the node member 30. The flange portions 1Ab, 33u, and 1Bb of the sheets are joined by spot welding (particularly, refer to SW1 in FIG. 10).

  Similarly, a downward extending portion 33d provided in the outer side joining flange portion 33 of the node member 30 is interposed between the outer lower flange portion 1Ac and the inner lower flange portion 1Bc, and these three flange portions 1Ac, 33d. , 1Bc are spot-welded (particularly, refer to SW2 in FIG. 10).

  By the way, as shown in FIGS. 2 to 4, the sub-frame 100 is disposed below the front side frame 4, and the front portion of the sub-frame 100 is the compression deformation portion 11 of the front side frame 4. As shown in FIGS. 2 to 7, the lower part of the front portion 11 f (see FIG. 2) is joined via a box-shaped subframe connection bracket 101 extending in the vertical direction.

  As shown in FIG. 1 to FIG. 4 and FIG. 6 to FIG. 8, the outer wall surface 41 and the inner wall surface of the compression deformation portion 11 are located in the vicinity of the joining portion (front portion 11 f) of the subframe connecting bracket 101 and at the rear side. In 42, a compression deformation promoting portion 15 is formed. The compression deformation promoting portion 15 is formed by a concave groove that extends in the vertical direction so as to promote the compressive deformation of the rear portion of the compression deformation portion 11 relative to the joint portion with the subframe connection bracket 101 at the time of a front collision.

  The compressive deformation promoting portion 15 is a concave groove that mainly functions as a starting point for compressive deformation of the rear portion 11r of the compressive deforming portion 11. However, depending on the aspect of the front impact load, the compressive deformation promoting portion 11 can be appropriately bent. It also functions as a starting point.

  As shown in FIGS. 1 to 4, 7, and 8, a compression deformation promoting portion 51 is provided in the vicinity of the front end of the crash can 5 and on the rear side, and also on the outer wall surface portion 41 and the inner wall surface portion 42 thereof. It has been. The compression deformation promoting portion 51 is formed by a concave groove extending in the vertical direction so as to promote the compression deformation of the crash can 5.

  At the time of the front collision, particularly in the initial stage, the crash can 5 is compressed and deformed rearward of the vehicle with the compression deformation promoting portion 51 as a compression starting point, and the front side frame 4 is appropriately applied in accordance with the front collision load acting at the time of the front collision. The compression deformation portion 11 (low strength region R1) also compresses and deforms toward the rear of the vehicle to absorb the energy of the front impact load.

  The front portion 11f (see FIG. 2) of the compression deformation portion 11 in the vehicle front-rear direction with respect to the compression deformation acceleration portion 15 is compressed and deformed with respect to the front collision load, but as described above, the subframe is connected to the lower portion thereof. Since the bracket 101 is joined, the strength against the front impact load may be higher than that of the rear portion 11r (see FIG. 2). However, since the compression deformation promoting portion 15 is provided at the rear edge 50r of the connection portion of the subframe connecting bracket 101 in the low strength region R1, the compression deformation promoting portion 15 acts as a compression starting point at the time of the front collision, so that the low strength region In R1, the rear portion 11r is more firmly compressed and deformed than the front portion 11f to absorb the collision load.

  As shown in FIGS. 3, 4, and 8, the outer front side bending deformation promoting portion 45 that promotes bending deformation of the front edge 50 f of the concave groove portion 50 inward in the vehicle width direction by the front impact load. It is formed as.

  As shown in FIGS. 2 and 8, the vehicle is located on the rear side of the mounting bracket mounting portion 49 of the front side frame 4 and on the front side of the outer rear bending deformation promoting portion 47 (see FIG. 3) described later. An inner side bending deformation promoting portion 46 formed of a groove extending in the vertical direction is formed. The inner side bending deformation promoting portion 46 is formed in the inner wall surface portion 42 by a concave groove extending in the vertical direction so as to promote the bending deformation of the front side frame 4 to the outside in the vehicle width direction due to the front collision load.

  As shown in FIGS. 3 to 5, 8, the position of the base side of the portion of the front side frame 4 that extends substantially horizontally from the dash panel 2 to the front of the vehicle, that is, the joint 48 with the dash panel 2. In the vicinity of the front side, an outer rear side bending deformation promoting portion 47 is formed on the outer wall surface portion 41 thereof.

  Out of these three bending deformation promoting portions 45, 46 and 47, the outer front bending deformation promoting portion 45 is the front edge 50f of the concave groove portion 50 extending in the vertical direction as described above, and the outer rear bending deformation promoting portion 47 is Both of the concave grooves extending in the vertical direction are formed in the outer wall surface portion 41 so as to promote bending deformation of the front side frame 4 inward in the vehicle width direction due to the front impact load. Further, the outer front side bending deformation promoting portion 45 is formed in the medium strength region R2, and the inner side bending deformation promoting portion 46 and the outer rear side bending deformation promoting portion 47 are formed in the high strength region R3.

  If the energy of the front impact load cannot be absorbed by only the compression deformation of the low-strength region R1 (compression deformation portion 11) of the crash can 5 and the front side frame 4 described above during the front impact, the front side frame 4 is bent and deformed (bending deformation) at least at three points of the outer front bending deformation promoting portion 45, the inner side bending deformation promoting portion 46, and the outer rear bending deformation promoting portion 47.

  Specifically, as shown in FIG. 11, when a front impact load (see a thick arrow in FIG. 11) acts, the front side frame 4 protrudes inward in the vehicle width direction at the outer front bending deformation promoting portion 45. The outer rear portion located on the base side of the front side frame 4 is bent and deformed so as to protrude outward in the vehicle width direction at the inner side bending deformation promoting portion 46 located immediately behind the mount bracket mounting portion 49. The side bending deformation promoting portion 47 is bent and deformed so as to protrude inward in the vehicle width direction.

  Note that the crash can 5 and the compression deformation portion 11 (low strength region R1) of the front side frame 4 are both linearly deformed (axially compressed) rearward of the vehicle with respect to the front impact load. For example, as shown in FIG. 11, the compression deformation portion 11 of the front side frame 4 is bent and deformed outward in the vehicle width direction in the compression deformation promoting portion 15 in addition to the axial compression linearly rearward. That is, depending on the mode of the front impact load, the front side frame 4 is in a bending deformation mode in which it is bent and deformed at four points by adding the compression deformation promoting part 15 to the three points of the bending deformation promoting parts 45, 46 and 47 described above. Although it obtains (refer FIG. 11), even in that case, the front side frame 4 can absorb energy by compression and bending.

  A front body structure V of a vehicle according to the present embodiment has a closed cross section 1C extending in the vehicle front-rear direction, and a mount bracket mounting portion for attaching a PT mount bracket 19 provided in the PT mount 18 that supports the power train 10. 49 is a front body structure of a vehicle including a front side frame 4 provided with 49, and the front side frame 4 has a low strength region R1, depending on the strength against a front impact load from the front end toward the rear of the vehicle. It has a medium strength region R2 and a high strength region R3 in this order (see FIGS. 1 to 4, 7, and 8). The high strength region R3 includes a mount bracket mounting portion 49, and the low strength region R1 is Reinforcing portion that is configured to be compressible and deformable against the front impact load and prevents shear deformation of the closed cross section 1C of the front side frame 4 in the middle strength region R2. In which the section member 30 is provided as a (1, 3, see FIGS. 5 to 11).

  According to the above configuration, the gear noise generated from the transmission provided in the power train 10 is transmitted between the mount bracket mounting portion 49 of the front side frame 4 and the set plate 6 via the PT mount 18. The deformation of the orthogonal cross section (the above-mentioned closed cross section 1C) in the front-rear direction of the front side frame 4 is suppressed by the node member 30, that is, vibration amplification is suppressed, and vibration transmitted to the vehicle rear (vehicle interior) is reduced. NVH performance can be improved.

  On the other hand, by providing the middle strength region R2 between the low strength region R1 and the high strength region R3 in the front-rear direction of the front side frame 4, the strength difference from the low strength region R1 to the high strength region R3 is alleviated. Smooth load transmission at the time of a collision. Furthermore, since the node member 30 is located behind the low-strength region R1 of the front side frame 4, it does not hinder the compressive deformation of the low-strength region R1 to the rear of the vehicle at the time of the front collision, and at the time of the front collision Load absorption performance can be enhanced.

  Therefore, both NVH performance and load absorption performance at the time of collision can be achieved.

  As an aspect of the present invention, the front side of the high-strength region R3 in the vehicle front-rear direction and the region excluding the mounting bracket mounting portion 49 and the medium-strength region R2 in the vehicle front-rear direction excluding the node member 30 are affected by the front impact load. The outer front side bending deformation promoting part 45, the inner side bending deformation promoting part 46, and the outer rear side bending deformation promoting part 47 are provided as bending deformation promoting parts for promoting the bending deformation of the frame 4 in the vehicle width direction. (See FIGS. 3, 4 and 8).

  According to the above configuration, the bending deformation promoting portions 45, 46, 47 are provided in the region excluding the mounting bracket mounting portion 49 and the node member 30 in the vehicle front-rear direction of the front side frame 4. It is possible to improve the load absorption performance of the front side frame 4 without being hindered by the joint members 30 and the mount bracket mounting portions 49 from bending and deforming at the bending deformation promoting portions 45, 46 and 47. .

  As an aspect of the present invention, among the panels 1A and 1B constituting the front side frame 4, the panels 1A and 1B in the low strength region R1 are formed with thin portions Tn thinner than the panels 1A and 1B in the medium strength region R2. (See FIG. 8).

  According to the above configuration, the low-strength region R1 of the front side frame 4 can be formed so as to be compressively deformable with respect to the front impact load, and the medium-strength region R2 has a lower strength and higher strength than the low-strength region R1. It can be interposed between these regions R1 and R3 so as to alleviate the intensity difference between the strength region R1 and the high strength region R3.

  As an aspect of the present invention, a crash can 5 is provided at the front end of the front side frame 4, and the low-strength region R1 is substantially the same as the orthogonal cross-sectional shape of the crash can 5 in the vehicle longitudinal direction and straight in the vehicle longitudinal direction. (Refer to FIGS. 1 to 4, 7, and 8).

  According to the above configuration, the crash can 5 can be compressed and deformed rearward of the vehicle at the time of a front collision, and the low-strength region R1 of the front side frame 4 can be compressed and deformed. Performance can be increased.

  As an aspect of the present invention, the crash can 5 and the low-strength region R1 are both formed in a cross shape with a cross section orthogonal to the vehicle longitudinal direction (see FIGS. 1 to 5, 7, and 8).

  According to the above configuration, the crash can 5 and the low-strength region R1 of the front side frame are both substantially cross-shaped in the cross-section in the vehicle front-rear direction. Even when a front collision load is input from a position offset vertically or horizontally with respect to the front side frame 4 and the crash can 5 that extend in the vehicle longitudinal direction, a substantially cross-shaped cross section is formed. The protrusions (outer bulging portion 12A and inner bulging portion 12B) projecting up and down and left and right are supported to make the crash can 5 and the low-strength region R1 of the front side frame difficult to bend and deform. It can be compressed and deformed to absorb the collision load.

  As an aspect of the present invention, the high-strength region R3 has a substantially rectangular cross section in the vehicle front-rear direction, and the medium-strength region R2 has a substantially rectangular shape as the vehicle cross-section in the vehicle front-rear direction progresses backward from a substantially cross shape. It is comprised so that it may change into a shape (refer FIGS. 1-4, FIG. 7, FIG. 8).

  According to the above configuration, the medium-strength region R2 has a cross-sectional shape between the low-strength region R1 having a substantially cross-shaped cross section and the high-strength region R3 having a substantially rectangular cross-section in the vehicle front-rear direction of the front side frame 4. Since the shape is such that the vehicle changes smoothly in the longitudinal direction of the vehicle, the front impact load is smoothly transferred from the low strength region R1 to the high strength region R3 through the medium strength region R2 between the R1 and R3. Can be communicated to.

  As an aspect of the present invention, the mount bracket attaching portion 49 is provided with a mount reinforcing member 20 that reinforces the mount bracket attaching portion 49 (see FIGS. 3 and 5 to 8).

  According to the above configuration, the rigidity of the mount bracket mounting portion 49 can be increased by the mount reinforcing member 20 disposed in the mount bracket mounting portion 49, and the gear noise transmitted from the engine to the front side frame 4 via the engine mount, the engine Noise can be reduced and NVH performance can be enhanced.

  In addition, by disposing the mount reinforcing member 20 in the mount bracket mounting portion 49 included in the high strength region R3, a portion corresponding to the mount bracket mounting portion 49 in the high strength region R3 is bent and deformed at the time of a front collision. Can be prevented.

The present invention is not limited to the configuration of the above-described embodiment, and can be formed in various embodiments.
The node member 30 is not limited to the above-described configuration as long as it can prevent the shear deformation of the closed cross section 1C. For example, although not illustrated, a member that ties the closed cross section 1C diagonally or a corner of the closed cross section 1C is omitted. It can be formed of a member connecting two sides (two surfaces) constituting the part.

  The above-described compression deformation promoting portion 15, outer outer side bending deformation promoting portion 45, inner side bending deformation promoting portion 46, and outer rear side bending deformation promoting portion 47 are concave (or convex) toward at least one of the inner side and the outer side in the vehicle width direction. If it is a shape which can be bent and deformed by a front impact load, such as a bead and a fragile part (thin wall part, hole part) formed in, it will not specifically limit.

V ... Vehicle front body structure 1A ... Outer panel (panel constituting the front side frame)
1B ... Inner panel (panel constituting the front side frame)
1C ... Closed section 4 ... Front side frame 5 ... Crash can 10 ... Power train 18 ... Power train mount 19 ... PT mount bracket (mount bracket)
20 ... Mount reinforcing member 30 ... Node member (reinforcing member)
49 ... Mount bracket mounting portion 45 ... Outer front side bending deformation promoting portion (bending deformation promoting portion)
46 ... Inner side bending deformation promotion part (bending deformation promotion part)
47 ... Outer rear side bending deformation promotion part (bending deformation promotion part)
R1 ... Low strength region R2 ... Medium strength region R3 ... High strength region Tn ... Thin wall portion (panel in the low strength region)
Tc: Thick part (panel in medium strength region)

Claims (6)

A front body structure of a vehicle having a front side frame provided with a mounting bracket mounting portion for mounting a mounting bracket provided on a power train mount for supporting a power train, and having a closed cross section extending in a vehicle longitudinal direction. And
The front side frame has a low-strength region, a medium-strength region, and a high-strength region in this order from the front end toward the rear of the vehicle.
The high-strength region includes the mount bracket mounting portion, and the low-strength region is configured with a strength capable of compressive deformation with respect to a front impact load,
In the medium strength region, a reinforcing member for preventing shear deformation of the closed cross section of the front side frame is provided ,
A vehicle width direction of the front side frame due to a front impact load in a region excluding the mount bracket mounting portion in the vehicle longitudinal direction of the high strength region and a region excluding the reinforcing member in the vehicle longitudinal direction of the medium strength region. A vehicle body structure for a front portion of a vehicle provided with a bending deformation promoting portion that promotes bending deformation to the vehicle. A front body structure of a vehicle having a front side frame provided with a mounting bracket mounting portion for mounting a mounting bracket provided on a power train mount for supporting a power train, and having a closed cross section extending in a vehicle longitudinal direction. And
The front side frame has a low-strength region, a medium-strength region, and a high-strength region in this order from the front end toward the rear of the vehicle.
The high-strength region includes the mount bracket mounting portion, and the low-strength region is configured with a strength capable of compressive deformation with respect to a front impact load,
In the medium strength region, a reinforcing member for preventing shear deformation of the closed cross section of the front side frame is provided ,
Of the panels constituting the front side frame, the panel in the low-strength region is formed of at least one of a plate thickness and a low-strength material that are thinner than the panel in the medium-strength region. Front car body structure. A crash can attached to the front end of the front side frame,
The vehicle front body structure according to claim 1 or 2 , wherein the low-strength region is substantially the same as an orthogonal cross-sectional shape of the crash can in the vehicle longitudinal direction and extends straight in the vehicle longitudinal direction. The vehicle front body structure according to claim 3 , wherein the crash can and the low-strength region are both formed in a substantially cross-shaped cross section in the vehicle front-rear direction. The high-strength region has a substantially rectangular cross section in the vehicle front-rear direction,
5. The vehicle front body structure according to claim 4 , wherein the medium-strength region is configured such that an orthogonal cross section in a vehicle front-rear direction changes from a substantially cross shape to a substantially rectangular shape as it advances rearward. The front body structure of a vehicle according to any one of claims 1 to 5 , wherein a mount reinforcing member that reinforces the mount bracket mounting portion is disposed in the mount bracket mounting portion.

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