CN109204512B

CN109204512B - Reinforcing structure at rear part of front longitudinal beam

Info

Publication number: CN109204512B
Application number: CN201710515800.0A
Authority: CN
Inventors: 小山贤司
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2017-06-29
Filing date: 2017-06-29
Publication date: 2020-03-27
Anticipated expiration: 2037-06-29
Also published as: CN109204512A

Abstract

The invention provides a reinforcing structure for a rear part of a front longitudinal beam, which can reliably prevent the rear part of the front longitudinal beam from being damaged by impact. The reinforcing structure of the front side member rear portion comprises a front side member (16) and an outer reinforcing plate (30) fixedly connected with the front side member rear portion (28), the cross section of the front side member rear portion along the vehicle width direction is U-shaped, the front side member rear portion is composed of a bottom wall (28a), an inner side wall (28c) extending upwards from the inner side end of the bottom wall, an outer side wall (28b) extending upwards from the outer side end of the bottom wall, an inner side flange (28e) formed by bending the edge from the upper end of the inner side wall, and an outer side flange (28d) formed by bending the edge from the upper end of the outer side wall, and the outer reinforcing plate is arranged on the inner side flange and the outer side flange in a mode of approximately straight line at least from one end of the outer reinforcing plate in the vehicle width direction to the position of the.

Description

Reinforcing structure at rear part of front longitudinal beam

Technical Field

The invention relates to an automobile body structure, in particular to a reinforcing structure of a rear part of a front longitudinal beam.

Background

It is known that front side members on the left and right sides of a front portion of a vehicle body are mainly responsible for energy absorption in a frontal collision or the like, and are also a main structure of a cab for preventing deformation. Generally, the front portion of the front side member takes on an energy absorbing function, while the rear portion of the front side member is close to the cab, and therefore, it is necessary to protect the personal safety of the driver and the passengers by reducing the amount of intrusion into the cab during a collision by resisting deformation in the event of a frontal collision, an offset collision, or the like.

Patent document 1 discloses a front-cabin longitudinal beam rear-section structure, which includes a longitudinal beam rear section 11, a first reinforcing plate 12 and a second reinforcing plate 13, the cross section of which is U-shaped, and the yield strength of which is gradually decreased, the longitudinal beam rear section 11 is located below a front panel 21, a bending region 16 is provided at a position corresponding to the foot of a passenger on the longitudinal beam rear section 11 and the front panel 21, a first cavity 15 is formed between the longitudinal beam rear section 11 and the front panel 21, the first reinforcing plate 12 and the second reinforcing plate 13 are arranged in the bending region 16 along the length direction of the longitudinal beam rear section 11 and are overlapped in the first cavity 15 from bottom to top, and the part of the first cavity 15 corresponding to the bending region 16 is divided into a second cavity 152, a third cavity 153 and a fourth cavity 154 from bottom to top. Through reasonable matching between the transition of material grade and the transition of the deformation-resistant cavity, the absorption and the transmission of the collision energy of the rear section structure of the longitudinal beam of the front cabin can be effectively and continuously completed.

Further, patent document 2 discloses a reinforcing structure for a side member of an automobile, the reinforcing structure including: the longitudinal beam inner plate 22 is fixedly connected onto the longitudinal beam outer plate 21, the strip-shaped reinforcing plate 3 is arranged in a cavity of the longitudinal beam inner plate 22, the reinforcing plate 3 is arranged in a U shape and is fixedly connected with the longitudinal beam inner plate 22 in a welding mode, two sides of the reinforcing plate are bent upwards, the longitudinal beam inner plate 22 is welded, the reinforcing plate divides the longitudinal beam into a plurality of closed areas, the bending resistance of the longitudinal beam is improved, the reinforcing plate and the longitudinal beam inner plate are both in a U shape, the welding point is located on the upper portion of the supporting surface of the reinforcing plate.

Documents of the prior art

Patent document

Patent document 1: CN204415518U

Patent document 2: CN201882151U

Disclosure of Invention

However, the inventors of the present application have found that in the front side member rear-end structure of patent document 1, since the second reinforcement plate 13 is U-shaped, and the U-shaped flange is welded to the flange of the front side member, the front side member is opened by an impact force applied thereto when a vehicle collides, and is deformed, and such deformation is propagated to the cab, which endangers the personal safety of the driver and the passengers.

In the reinforcing structure for the side member of the automobile of patent document 2, the reinforcing plate 3 is fitted into the front side member in a U-shape and is welded and fixed to the inner wall of the front side member, and therefore, when a vehicle collides, the front side member is deformed by opening the front side member opening by the impact force received. This is because the direction of the opening force (left and right) coincides with the welding direction (left and right), the reinforcing plate is easily separated from the inner wall of the front side member, and the opening of the front side member cannot be restricted.

The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a reinforcement structure for a rear portion of a front side member, which can reliably prevent the rear portion of the front side member from being damaged by an impact.

In order to achieve the above object, a first aspect of the present invention provides a reinforcing structure for a rear portion of a front side member, comprising a front side member and an outer reinforcement panel fixed to a rear portion of the front side member, wherein a section of the rear portion of the front side member in a vehicle width direction is U-shaped, which comprises a bottom wall, an inner side wall extending upwards from the inner side end of the bottom wall, an outer side wall extending upwards from the outer side end of the bottom wall, an inner side flange formed by bending the edge from the upper end of the inner side wall, and an outer side flange formed by bending the edge from the upper end of the outer side wall, the outer reinforcement panel is provided so as to straddle the inner flange and the outer flange in a substantially straight line at least from one end of the outer reinforcement panel in the vehicle width direction to a position of the outer reinforcement panel corresponding to the other end of the bottom wall in the vehicle width direction in a cross section along the vehicle width direction.

According to a second aspect of the present invention, in the front-side-frame rear reinforcement structure of the first aspect, the outer gusset spans the inner flange and the outer flange in a substantially straight line from one end of the outer gusset in the vehicle width direction to the other end of the outer gusset in the vehicle width direction in a cross section along the vehicle width direction.

According to a third aspect of the present invention, in the front-side-member-rear-portion reinforcing structure according to the first or second aspect, the outer reinforcement plate includes: the outer flange is provided with a first joint part jointed with the outer flange, a second joint part jointed with the inner flange, and a flat plate positioned between the first joint part and the second joint part, and the layer difference between the first joint part and/or the second joint part and the flat plate is only 0-3 mm.

According to a fourth aspect of the present invention, in the front-side-member rear reinforcement structure according to any one of the first to third aspects, a strength of the outer gusset is higher than a strength of the front side member.

According to a fifth aspect of the present invention, in the front side member rear reinforcement structure according to any one of the first to fourth aspects, a plate thickness of the outer reinforcement plate is not higher than a plate thickness of the front side member.

According to a sixth aspect of the present invention, in the front-side-member rear reinforcement structure according to any one of the first to fifth aspects, an inner reinforcement plate is provided in the U-shaped cross section of the front-side-member rear portion, and the inner reinforcement plate divides a space between the outer reinforcement plate and the front-side-member rear portion into two spaces.

According to a seventh aspect of the present invention, in the front-side-member rear reinforcement structure according to the sixth aspect, the strength of the inner gusset is higher than the strength of the front side member.

According to a reinforcement structure of a front side member rear part of an eighth aspect of the present invention, in the reinforcement structure of a front side member rear part of the sixth or seventh aspect, a plate thickness of the inner reinforcement plate is not higher than a plate thickness of the front side member.

Effects of the invention

According to the first aspect of the present invention, since the outer gusset spans the inner flange and the outer flange of the front side member rear portion so as to be substantially linear at least from one end of the outer gusset in the vehicle width direction to a position of the outer gusset corresponding to the other end of the bottom wall in the vehicle width direction in the cross section along the vehicle width direction, the strength of the front side member rear portion can be improved by the outer gusset, specifically, when the front side member rear portion receives a collision impact, although the front side member rear portion receives an impact force that urges the front side member rear portion opening (i.e., the U-shaped cross section) to open to both sides, the outer gusset is welded to the both side flanges of the front side member rear portion, the welding direction (vertical direction) is perpendicular to the opening direction (i.e., the force receiving direction, the horizontal direction), the outer gusset and the front side member rear portion constitute a closed cross section, and therefore, the deformation direction (i.e., the extending direction, the outer reinforcing plate is stretched into a straight line from an approximate straight line and can not be stretched (slightly deformed), and then the opening at the rear part of the front longitudinal beam is limited to be opened, so that the opening at the rear part of the front longitudinal beam is limited to be opened, namely the rear part of the front longitudinal beam is deformed, the strength of the rear part of the front longitudinal beam is improved, and therefore the rear part of the front longitudinal beam can be kept to be a U-shaped section through the outer reinforcing plate, the rear part of the front longitudinal beam is prevented from being opened to two sides of the U-shaped section when being collided.

According to the second aspect of the present invention, since the outer gusset is substantially linear in the entire cross section in the vehicle width direction, the U-shaped opening in the cross section of the front side member rear portion can be more reliably prevented from being opened to both sides, and the front side member rear portion can be more reliably prevented from being damaged by impact.

According to the third aspect of the present invention, when the layer differences between the flat plate and the first joint portion and the second joint portion of the outer gusset are both 0mm (that is, the outer gusset is entirely linear), the outer gusset does not deform (that is, the outer gusset remains linear) when the rear portion of the front side member receives a collision impact, and is disposed astride the rear portion of the front side member, so that the U-shaped opening in the cross section of the rear portion of the front side member can be prevented from opening to both sides to the maximum extent, and the rear portion of the front side member can be more reliably prevented from being damaged by the impact. In the case where the difference in level between the first joint portion and/or the second joint portion of the outer gusset and the flat plate is greater than 0mm and less than 1.5mm, the coating can be ensured; when the thickness is 1.5mm or more and 3mm or less, not only the coating can be ensured but also the generation of collision noise can be prevented.

According to the fourth aspect of the present invention, since the strength of the outer gusset is higher than that of the front side member, the rear portion of the front side member can be further reliably prevented from spreading to both sides of the U-shaped cross section thereof upon collision, and the rear portion of the front side member can be prevented from being damaged by impact.

According to the fifth aspect of the present invention, since the plate thickness of the outer gusset is not higher than the plate thickness of the front side frame, the strength of the rear portion of the front side frame can be ensured without increasing the plate thickness of the outer gusset, thereby achieving weight reduction of the vehicle and cost reduction.

According to the sixth technical scheme, the inner reinforcing plate is arranged between the rear part of the front longitudinal beam and the outer reinforcing plate, so that a multi-layer cavity structure is formed, the rear part of the front longitudinal beam can be further prevented from opening towards two sides, the strength of the rear part of the front longitudinal beam is ensured, and the rear part of the front longitudinal beam is prevented from being damaged by impact.

According to the seventh aspect of the present invention, since the strength of the inner gusset is higher than that of the front side member, the rear portion of the front side member can be further prevented from being opened to both sides by using the inner gusset having high strength, and impact damage can be prevented.

According to the eighth aspect of the present invention, since the plate thickness of the inner gusset is not higher than the plate thickness of the front side member, the requirement for weight reduction can be satisfied without increasing the plate thickness of the inner gusset.

According to the present invention, it is possible to provide a reinforcing structure for a rear portion of a front side member that reliably prevents an impact damage to the rear portion of the front side member.

Drawings

Fig. 1 is a perspective view of a front portion of a vehicle body as viewed from above and to the left.

Fig. 2 is a side view of the rear periphery of the front side member on the right side in fig. 1 as viewed from the outside in the vehicle width direction.

Fig. 3 is a perspective view of the right front side frame of fig. 1 as viewed from the outside in the vehicle width direction.

Fig. 4 is a perspective view of the right front side member rear portion of the first embodiment.

Fig. 5 is a perspective view of the right front side member rear portion of the present embodiment, with the second reinforcement plate removed.

Fig. 6 is a perspective view of the right front side member rear portion of the present embodiment, excluding the first reinforcement plate and the second reinforcement plate.

Fig. 7 is a perspective view of section a-a in fig. 4.

Fig. 8 is an enlarged sectional view B-B in fig. 4, and is a view with only a sectional portion enlarged.

Fig. 9 is a longitudinal cross-sectional view of the right front side member rear portion in fig. 4, showing only cross sections of the front side member rear portion, the first reinforcement panel, and the second reinforcement panel.

Fig. 10 is a view corresponding to fig. 8 of the right front side member rear portion according to the second embodiment of the present invention.

Description of the reference numerals

10 … vehicle; 11 … vehicle body; 12 … vehicle cabin; 13 … power unit housing chamber; 15 … front baffle; 16 … front longitudinal beam; 18 … subframe; 21 … a dash panel; 25 … load path member; 27 … front longitudinal front beam; 28. 128 … front longitudinal beam rear part; 28a, 128a …; 28b, 128b …; 28c, 128c … rear inner side walls of the front longitudinal beams; 28d, 128d … outboard flanges on the rear of the front rail; 28e, 128e … rear inboard flange of front rail; 28f, 128f … through holes in the rear part of the front side member; 29. 129 … first stiffener (inner stiffener); 29a, 129a … bottom wall of the first reinforcing panel; 29b, 129b …; 29c, 129c … an inner side wall of the first reinforcing plate; 29d, 129d … through holes of the first reinforcing plate; 30. 130 … second stiffener plate (outer stiffener plate); 30a, 130a … a second stiffener plate; 30b, 130b … a first joint of a second reinforcement panel; 30c … bent portion of second reinforcing plate; 30d, 130d … a second joint of a second reinforcing panel; 45 … side sill side extensions; 46 … channel side extensions; 47 … outriggers; 58 … front end support; 61. 161 … subframe mounting brackets; 62 … fastening means; 63. 163 … knurled nuts; CL … vehicle width center line.

Detailed Description

The following describes a mode for carrying out the present invention based on the drawings. The present invention is not limited to the embodiments described below at all, and various modifications can be made as long as the present invention has substantially the same configuration and can achieve the same operational effects as the present invention.

In the following description of the orientation, the direction viewed by the driver seated in the driver's seat is used as a reference. "front" refers to the direction in which a driver sitting in the driver's seat faces, and is also the direction of travel of the vehicle; "rearward" refers to the direction the driver faces away from, and is also the opposite direction to the direction of travel of the vehicle; "left" refers to the left hand side of the driver; "right" refers to the right hand side of the driver. In the following drawings, for convenience, only necessary portions related to the present invention are illustrated.

First, a vehicle front frame structure is briefly explained. As shown in fig. 1 and 2, the vehicle 10 is, for example, a passenger vehicle, and a power unit accommodating chamber 13 at a front portion and a vehicle compartment 12 located right behind the power unit accommodating chamber 13 are formed inside a vehicle body 11. The vehicle body 11 is a monocoque body, and is formed in a left-right symmetrical shape with respect to a vehicle width center line CL that passes through the center in the vehicle width direction of the vehicle 10 and extends in the vehicle front-rear direction. The front half of the vehicle body 11 includes: a front bulkhead 15 joined to front ends of the left and right

front side members

16, 16; left and right

front side members

16, 16 located on left and right sides of the front portion of the vehicle body 11 and extending in the front-rear direction of the vehicle body; a dash panel 21 which is a partition wall positioned behind the left and right

front side members

16, 16 and which partitions the vehicle body 11 into a front and a rear, i.e., a power unit accommodating chamber 13 which partitions the front side and a vehicle cabin 12 which partitions the rear side; and a sub-frame 18 which is superposed from below and mounted to the lower end portions of the left and right

front side members

16, 16. Since the front portion of the subframe 18 is connected to the lower portion of the front bulkhead 15 by the left and right load path members 25, a front collision force can be smoothly transmitted from the front bulkhead 15 to the subframe 18 via the left and right load path members 25 at the time of a frontal collision of the vehicle 10. Further, the lower end portions of the left and right front side frames 16, 16 are provided with left and right front end support portions 58 for attaching left and right front end portions of the subframe 18 via left and right fastening members 62.

The left and right

front side members

16, 16 include: front side

member front portions

27, 27 extending straight in the vehicle body front-rear direction, and then extending rearward while curving from the vehicle width direction outer side to the vehicle width direction inner side; and front side member

rear portions

28, 28 each having a bent structure in which the front side member

rear portions

28, 28 are bent downward once rearward so as to pass under the dash panel 21 and the rear lower ends are bent rearward so that the rear lower ends are inclined downward rearward along the lower end of the dash panel 21 toward the rear of the vehicle body and the rear lower ends extend horizontally rearward.

The rear ends of the front side member

rear portions

28, 28 are branched into left and right side

sill side extensions

45, 45 and left and right

tunnel side extensions

46, 46. That is, the entire combination of the rear ends of the left and right front side member rear portions 28, the left and right side sill side extension portions 45, and the left and right tunnel

side extension portions

46, 46 is formed in a substantially Y-shape in plan view. The front end portions of the left and right side sill-

side projecting portions

45, 45 are connected to left and right side sills (i.e., body side members, not shown) via left and

right outriggers

47, 47.

The reinforcement structure for the front side member rear portion of the present invention will be described in detail below with reference to fig. 3 to 9, centering on the front side member rear portion on the right side. The reinforcing structure of the left front side member rear portion is bilaterally symmetrical to the right side, and therefore, the explanation thereof is omitted.

As shown in fig. 6, 7, and 8, the front side member rear portion 28 has a U-shape that opens upward in cross section and includes: a bottom wall 28a, an outer side wall 28b extending upward from an outer end of the bottom wall 28a in the vehicle width direction, an inner side wall 28c extending upward from an inner end of the bottom wall 28a in the vehicle width direction, an outer flange 28d formed by bending an edge from an upper end of the outer side wall 28b, and an inner flange 28e formed by bending an edge from an upper end of the inner side wall 28 c. As shown in fig. 5, 7, and 8, a first reinforcing plate 29 is provided in the front side member rear portion 28, specifically, in the U-shaped cross section of the front side member rear portion 28. The first reinforcing plate 29 is formed in a U-shaped cross section, and thus may also be referred to as an "inner reinforcing plate". The first reinforcing plate 29 is also U-shaped with an upward opening in cross section, and includes: a bottom wall 29a provided along the longitudinal direction of the bottom wall 28a of the front side member rear portion 28; an outer wall 29b extending upward from an outer end of the bottom wall 29a and located on the outer side in the vehicle width direction; and an inner wall 29c extending upward from an inner end of the bottom wall 29a in the vehicle width direction. The first reinforcing plate 29 is provided on the front-side member rear portion 28 by being engaged with the outer side wall 28b and the inner side wall 28c of the front-side member rear portion 28. Specifically, the first reinforcement plate 29 is provided on the front side member rear portion 28 by joining the outer side wall 29b and the inner side wall 29c of the first reinforcement plate 29 to the outer side wall 28b and the inner side wall 28c of the front side member rear portion 28 by welding (e.g., spot welding), respectively.

As shown in fig. 3, 4, 7, and 8, a second reinforcing plate 30 is provided on the front side member rear portion 28. The second gusset 30 is provided in the front-side member rear portion 28 by joining the outer flange 28d and the inner flange 28e of the front-side member rear portion 28, that is, the second gusset 30 covers the front-side member rear portion 28 approximately linearly in the cross section in the vehicle width direction. More specifically, the second reinforcement panel covers the front side member rear portion 28 approximately linearly in a cross section in the vehicle width direction from a joining position with the outer flange 28d to a joining position with the inner flange 28 e. The second gusset 30 covers the front side member rear portion 28, i.e., the U-shaped cross section, and thus may be referred to as an "outer gusset". The second reinforcement plate 30 includes: a first engaging portion 30b that engages with the outer side flange 28d of the front side member rear portion 28; a second engagement portion 30d that engages with the inside flange 28e of the front side member rear portion 28; a flat plate 30a located between the first joint portion 30b and the second joint portion 30d and provided along the longitudinal direction of the bottom wall 28a of the front side member rear portion 28 and the bottom wall 29a of the first reinforcing plate 29; and a bent portion 30c extending upward from the vehicle width direction inner end of the flat plate 30 a. The first joint portion 30b and the second joint portion 30d are joined to the outer flange 28d and the inner flange 28e of the front side member rear portion 28 by welding (e.g., spot welding), respectively.

The description will be made about "approximately straight line". As shown in the enlarged cross-sectional view of fig. 8, the first joint portion 30b of the second reinforcing plate 30 is connected to the flat plate 30a by a very small bent portion, that is, there is a very small level difference (exaggeratedly shown in fig. 8) between the first joint portion 30b and the flat plate 30 a. In the present embodiment, the dimension of the bent portion in the vertical direction, that is, the height (which may also be referred to as a step or a height difference between the first joint portion 30b and the flat plate 30 a) is 2 mm. Such a level difference is designed to ensure coating and prevent the occurrence of collision noise. The term "approximately straight line" as used herein includes a case where the difference in level is 2mm, more specifically, a case where the difference in level is 0 to 3 mm. On the other hand, the dimension in the vertical direction, that is, the height of the bent portion 30c between the second joint portion 30d and the flat plate 30a (which may also be referred to as a level difference or a height difference between the second joint portion 30d and the flat plate 30 a) is large and larger than 3 mm. That is, the second gusset 30 is substantially linear from one end in the vehicle width direction (the vehicle width direction outer end of the first joining portion 30b in the present embodiment) to a position where the second gusset 30 corresponds to the other end in the vehicle width direction of the bottom wall 28a (the vehicle width direction inner end of the bottom wall 28a in the present embodiment). In other words, the second reinforcement panel 30 is provided across the inner flange 28e and the outer flange 28d of the front-side member rear portion 28 so as to be substantially linear from a position corresponding to one end in the vehicle width direction of one side flange (i.e., one of the inner flange 28e and the outer flange 28d) of the front-side member rear portion 28 to a position corresponding to one end in the vehicle width direction of the other side flange (the other of the inner flange 28e and the outer flange 28d) in the vehicle width direction in cross section along the vehicle width direction. In other words, the second reinforcement panel 30 is disposed across the inner flange 28e and the outer flange 28d of the front side member rear portion 28 so as to form a substantially straight line from one vehicle width direction end of one of the first joining portion 30b and the second joining portion 30d (the vehicle width direction outer end of the first joining portion 30 b) to one vehicle width direction end of the other joining portion (the vehicle width direction outer end of the second joining portion 30d, more specifically, the vehicle width direction outer end of the bent portion 30c in the present embodiment) in a cross section in the vehicle width direction.

Thus, when the vehicle front portion is collided, specifically, when the front side frame rear portion 28 is collided, although the impact force applied to the front side frame rear portion 28 drives the opening (i.e. the U-shaped cross section) of the front side frame rear portion to open towards both sides, the second reinforcing plate 30 is welded to both side flanges of the front side frame rear portion 28 in a welding direction (vertical direction) perpendicular to the opening direction (i.e. the force receiving direction, the left-right direction), and the second reinforcing plate 30 forms a closed cross section with the front side frame rear portion 28, so that the deformation direction (i.e. the extending direction) of the second reinforcing plate 30 when being impacted coincides with the force receiving direction, and the opening of the front side frame rear portion 28 is restricted after the second reinforcing plate 30 is extended from a nearly straight line to a straight line and then cannot be extended (after being slightly deformed), and the opening of the front side frame rear portion 28 is restricted, and the strength of the front, the front-side-member rear portion 28 can thereby be held in the U-shaped cross section by the second gusset 30, thereby preventing the front-side-member rear portion 28 from spreading to both sides of the U-shaped cross section thereof upon a collision, and preventing the front-side-member rear portion 28 from being damaged by an impact.

As is apparent from fig. 3 and 4, the second reinforcement panel 30 is provided across the front side member rear portion 28 so that a cross section along the vehicle width direction of the first joint portion 30b is substantially linear from the vehicle width direction outer end of the first joint portion 30b to the vehicle width direction outer end of the second joint portion 30d in the entire longitudinal direction of the first joint portion 30 b.

In the above embodiment, the difference in level between the first joint portion 30b of the second gusset 30 and the flat plate 30a is 2mm, but it is preferable that there is no difference in level therebetween because, when the front-side-frame rear portion 28 receives a collision impact without a difference in level, the second gusset 30 straddles the front-side-frame rear portion 28 in an original straight form (without an expansion process of converting an approximate straight line into a straight form), and therefore the front-side-frame rear portion 28 fitted thereto will not deform at all, and the effect of preventing the front-side-frame rear portion from being damaged by the impact can be exerted more.

Further, the steel material used for the front side member 16 (front side member rear portion 28) is JSC780Y, and the steel material used for the first reinforcement plate 29 and the second reinforcement plate 30 is HQAS1500H, so that the yield strength of the first reinforcement plate 29 and the second reinforcement plate 30 is greater than the yield strength of the front side member 16, and therefore the front side member rear portion 28 can be more reliably prevented from being opened to both sides of the U-shaped cross section thereof at the time of a collision, and the front side member rear portion 28 can be prevented from being damaged by an impact. Here, the specific steel material of the front side member 16, the first reinforcement plate 29, and the second reinforcement plate 30 is only an example, and any other steel material may be used as long as the strength of the first reinforcement plate 29 and the second reinforcement plate 30 can be ensured to be larger than the strength of the front side member 16. Further, since the plate thicknesses of the first reinforcement plate 29 and the second reinforcement plate 30 are not higher than the front side frame 16, the strength of the front side frame rear portion can be ensured without increasing the plate thicknesses of the first reinforcement plate and the second reinforcement plate, and the vehicle can be made lightweight and the cost can be reduced.

Further, as shown in fig. 7 and 8, since the first reinforcing plate 29 divides the space between the second reinforcing plate 30 and the front side member rear portion 28 into two spaces, that is, a multi-layer cavity structure is formed, the front side member rear portion 28 can be further prevented from being opened to both sides while ensuring the strength of the front side member rear portion 28.

As shown in fig. 7 and 8, a subframe attachment bracket 61 is provided below the front-side frame rear portion 28, and the subframe attachment bracket 61 is joined to the front-side frame rear portion 28 with a predetermined distance downward from the bottom wall 28 a. A lug nut 63 is joined to the subframe attachment bracket 61, and the lug nut 63 is a cylindrical member having a female screw penetrating in the vertical direction, and is joined at its upper end portion to the through hole 28f formed in the bottom wall 28a of the front side member rear portion 28 and the through hole 29d formed in the bottom wall 29a of the first reinforcing plate 29, and at its lower end portion to the subframe attachment bracket 61. In this way, the upper and lower ends of the lug nut 63 are joined to the sub frame attachment bracket 61, the front side member rear portion 28, and the first reinforcing plate 29. The collar nut 63 is screwed with a fastening member 62 (see fig. 1).

As shown in fig. 3, 4, and 9, the second reinforcement plate 30 extends from the front end of the front-side-member rear portion 28 (i.e., the end corresponding to the front-side-member front portion 27) to the rear end of the front-side-member rear portion 28 (i.e., the end corresponding to the vehicle-body side member), in other words, the second reinforcement plate 30 is provided astride the front-side-member rear portion 28 so as to extend between the front end and the rear end of the front-side-member rear portion 28. The first reinforcing plate 29 also extends from the front end of the front-side-member rear portion 28 to the rear end of the front-side-member rear portion 28, that is, the first reinforcing plate 29 is provided so as to straddle the front-side-member rear portion 28 so as to extend between the front end and the rear end of the front-side-member rear portion 28. Since the first reinforcement plate 29 and the second reinforcement plate 30 are both provided so as to straddle between the front end and the rear end of the front-side-member rear portion 28 in the longitudinal direction, i.e., the vehicle front-rear direction, the strength of the front-side-member rear portion 28 can be ensured over the entire length of the front-side-member rear portion 28, and the front-side-member rear portion 28 can be more reliably prevented from spreading to both sides.

As can be seen from the enlarged sectional view of fig. 8, the length of the inner side wall 28c of the front-side-member rear portion 28 in the up-down direction, i.e., the depth thereof, is larger than the length of the outer side wall 28b in the up-down direction, i.e., the depth thereof. This is for the front-side-member rear portion 28 to engage with the bottom surface of the dash panel 21. Specifically, since the dash panel 21 is provided on the front side member rear portion 28 as described above, it is necessary to match the shapes of both, and in the actual vehicle design, the dash panel is designed first, and then the front side member rear portion is designed according to the shape of the bottom surface of the dash panel, and in the present embodiment, the depth of the outer wall 28b and the depth of the inner wall 28c are designed to be different so that the front side member rear portion 28 fits the bottom surface (not shown) of the dash panel 21 that is higher on one side in the vehicle width direction. In such an arrangement in which the front side member rear portion 28 is higher on the one side and lower on the other side, the lower side of the front side member rear portion 28 contributes to an increase in the foot space for the passenger. In addition, in order to fit the difference in depth between the outer side wall 28b and the inner side wall 28c of the front side member rear portion 28, the bent portion 30c between the second joint portion 30d and the flat plate 30a is larger than 3 mm.

Of course, depending on the vehicle type, there is a case where there is no significant height variation in the vehicle width direction of the dash panel corresponding to the installation position of the front side member rear portion, and the structure in this case is shown in fig. 10. Fig. 10 is a view corresponding to fig. 8 of the right front side member rear 128 of the second embodiment of the present invention. The difference from the first embodiment is only that in the second embodiment, since the same reference numerals are given to the same or equivalent members as those of the first embodiment, and the description is omitted, except that the depth of the outer wall 128b and the inner wall 128c of the front side member rear portion 128 is substantially the same, and the bent portion 30c is not provided, as in the first embodiment, only the difference from the first embodiment will be mainly described.

As shown in fig. 10, the length in the vertical direction, i.e., the depth, of the inner side wall 128c of the front side member rear portion 128 is substantially the same as the length in the vertical direction, i.e., the depth, of the outer side wall 128 b. The second gusset 130 does not have a member corresponding to the bent portion 30c of the first embodiment, and is formed to have a substantially linear cross section as a whole, that is, the second gusset 130 is formed to have a substantially linear shape from one end to the other end in the vehicle width direction. In this case, the U-shaped cross-sectional opening of the front side member rear portion 128 can be more reliably prevented from being opened to both sides, and the front side member rear portion can be more reliably prevented from being damaged by impact. In this case, the second reinforcing plate 130 is provided so as to be substantially linear from one end to the other end in the vehicle width direction over the entire length of the first joint portion 130b and the second joint portion 130 d.

The embodiments and effects of the present invention have been described above, but the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention.

In the above-described embodiment, the reinforcing structure of the front side member rear portion has been described by taking a passenger car as an example, but the present invention is not limited to this, and the present invention can be applied to any structure as long as it prevents one of the open cross sections from expanding during a force application.

Claims

1. The utility model provides a reinforcing structure at front longitudinal rear portion, including front longitudinal and with the outer reinforcing plate of front longitudinal's rear portion rigid coupling, its characterized in that:

the rear portion of the front side member is U-shaped in cross section in the vehicle width direction and is composed of a bottom wall, an inner side wall extending upward from an inner end of the bottom wall, an outer side wall extending upward from an outer end of the bottom wall, an inner side flange formed by bending an edge from an upper end of the inner side wall, and an outer side flange formed by bending an edge from an upper end of the outer side wall,

the outer reinforcement panel is provided so as to straddle the inner flange and the outer flange in a substantially straight line at least from one end of the outer reinforcement panel in the vehicle width direction to a position of the outer reinforcement panel corresponding to the other end of the bottom wall in the vehicle width direction in a cross section along the vehicle width direction.

2. The front side member rear reinforcement structure according to claim 1, characterized in that:

the outer reinforcement panel is disposed across the inner flange and the outer flange so as to be substantially linear from one end of the outer reinforcement panel in the vehicle width direction to the other end of the outer reinforcement panel in the vehicle width direction in a cross section along the vehicle width direction.

3. The front side member rear reinforcement structure according to claim 1 or 2, characterized in that:

the outer reinforcing plate includes: a first engaging portion engaged with the outer flange, a second engaging portion engaged with the inner flange, and a flat plate located between the first engaging portion and the second engaging portion,

the difference in level between the first joint and/or the second joint and the flat plate is only 0-3 mm.

4. The front side member rear reinforcement structure according to claim 1 or 2, characterized in that:

the strength of the outer reinforcing plate is higher than that of the front longitudinal beam.

5. The front side member rear reinforcement structure according to claim 4, characterized in that:

the plate thickness of the outer reinforcing plate is not higher than the plate thickness of the front side member.

6. The front side member rear reinforcement structure according to claim 1 or 2, characterized in that:

an inner reinforcing plate is arranged in the U-shaped cross section of the rear part of the front longitudinal beam, and the inner reinforcing plate divides the space between the outer reinforcing plate and the rear part of the front longitudinal beam into two spaces.

7. The front side member rear reinforcement structure according to claim 6, wherein:

the strength of the inner reinforcing plate is higher than that of the front longitudinal beam.

8. The front side member rear reinforcement structure according to claim 7, wherein:

the plate thickness of the inner reinforcing plate is not higher than the plate thickness of the front side member.