WO2021117805A1

WO2021117805A1 - Center pillar reinforcement

Info

Publication number: WO2021117805A1
Application number: PCT/JP2020/046030
Authority: WO
Inventors: 洋康小坂
Original assignee: 豊田鉄工株式会社
Priority date: 2019-12-11
Filing date: 2020-12-10
Publication date: 2021-06-17
Also published as: JP2021091311A; JP7163270B2

Abstract

This center pillar reinforcement is obtained by press-molding a tailored blank and comprises a lower member and an upper member. The center pillar reinforcement is provided with: the lower member having a lower-end edge part joined to a side sill of a vehicle; and the upper member that is joined by welding to the upper side of the lower member and that has an upper-end edge part joined to a roof side rail of the vehicle. The upper member has a tensile strength greater than the tensile strength of the lower member. The upper member and the lower member are each provided with a pair of vertical wall parts and a ceiling part that connects therebetween. The ceiling part of the lower member has a projection-like plane part that projects, in an external direction of the vehicle, below a joint part with respect to the upper member. The vertical wall parts of the upper member each have a door striker mounting part above the joint part. The ceiling part is provided with a bead that extends beyond the joint part, in the longitudinal direction of the center pillar reinforcement, from an upper-side edge section of the projection-like plane part to a position on the lower side of the door striker mounting part or a position corresponding to the door striker mounting part, so as to project in the external direction of the vehicle.

Description

Center Pillar Reinforcement

The present invention relates to center pillar reinforcement.

Conventionally, various technologies related to center pillar reinforcement have been proposed. For example, in the vehicle body structure described in Japanese Patent Application Laid-Open No. 2019-93814, the center pillar reinforcements arranged on the closed cross section of the center pillars are manufactured from tailored blanks by press molding, and plasmas are formed on the end faces of each other. It has an upper panel joined by welding and a lower panel thinner than the upper panel. The boundary between the upper panel and the lower panel, that is, the welded joint, is set lower than the waist of the occupant sitting in the seat.

In addition, a bead formed convex toward the outside of the vehicle is arranged on the upper panel (the part above the joint). As a result, it is possible to realize a deformation mode in which the load applied to the portion between the joint portion and the bead at the time of a side collision is transmitted to the joint portion and the vicinity of the joint portion between the upper panel and the lower panel is bent.

However, since the bead of the center pillar reinforcement of the above publication is arranged in the upper panel, when the blank for the upper panel and the blank for the lower panel are joined by plasma welding and then molded by cold pressing. If the difference in tensile strength between the upper panel and the lower panel is large, wrinkles are generated on the outer surface of the welded portion along the longitudinal direction of the center pillar reinforcement, and the press formability is deteriorated. Even if the design is such that the bending starting point at the time of a side collision is inside the lower panel (below the joint), if the difference in tensile strength between the upper panel and the lower panel is large, the bending starting point at the time of an actual side collision is designed. There is a risk of bending from a joint located above. It is desired to provide a means capable of improving press moldability in press molding of a tailored blank in which a plurality of members having a large difference in tensile strength are joined.

One aspect of the present invention is a center pillar reinforcement press-molded from a tailored blank composed of a lower member and an upper member, wherein the lower member whose lower end edge is joined to a side sill of a vehicle and the lower member. The upper member is provided with the upper member to be joined to the upper side by welding and the upper end edge is to be joined to the roof side rail of the vehicle, and the upper member has a tensile strength larger than the tensile strength of the lower member. Each of the upper member and the lower member includes a pair of vertical wall portions and a ceiling portion connecting the vertical wall portions thereof, and the ceiling portion of the lower member is below the joint portion with the upper member. The vertical wall portion of the upper member has a door striker mounting portion formed above the joint portion, and the ceiling portion has a convex flat portion protruding outward of the vehicle. Is a joint portion along the longitudinal direction of the center pillar reinforcement from the upper edge portion of the convex flat surface portion to a position below the door striker mounting portion or a position corresponding to the door striker mounting portion. It is provided with a bead formed so as to project outward of the vehicle so as to straddle the vehicle.

Depending on the embodiment, the upper member is made of a high-tensile steel plate having a tensile strength of 980 MPa or more, the lower member is made of a high-tensile steel plate having a tensile strength of 440 MPa or more, and the upper member is composed of a high-tensile steel plate having a tensile strength of 440 MPa or more. It has a tensile strength of 1.5 times or more the tensile strength of the lower member.

Depending on the embodiment, the bead is formed so that the protruding height gradually decreases from the upper edge portion of the convex flat surface portion to the upper side.

Depending on the embodiment, the bead is formed so as to have the same protruding height from the upper edge portion of the convex flat surface portion to the upper side.

In some embodiments, the bead is located at the center of the ceiling in the width direction, and the ceiling is a welded portion that welds reinforcing members arranged on the inner surface of the ceiling on both sides of the bead. Has.

Depending on the embodiment, the convex flat surface portion includes a door hinge mounting flat surface portion protruding outward of the vehicle.

It is a front view which shows an example of the center pillar reinforcement which concerns on one Embodiment. It is a side view of the center pillar reinforcement shown in FIG. It is a figure which shows an example of the blank of the center pillar reinforcement shown in FIG. It is an enlarged front view of the main part which shows the joint part of the lower member and the upper member shown in FIG. It is an enlarged side view of the main part which shows the joint part of the lower member and the upper member shown in FIG. FIG. 5 is a cross-sectional view taken along the line VI-VI of the joint of FIGS. 4 and 5. It is a VII-VII arrow cross-sectional view of the joint of FIG. 4 and FIG. FIG. 6 is a cross-sectional view taken along the line VIII-VIII of the joint portion of FIG. It is a figure which shows an example of the molding analysis result in the case of having a bead. It is a figure which shows an example of the molding analysis result in the case which does not have a bead. It is an enlarged front view of the main part which shows the joint part of the lower member and the upper member of the center pillar reinforcement which concerns on another embodiment. FIG. 11 is a cross-sectional view taken along the line XII-XII of the joint portion of FIG. FIG. 5 is an enlarged front view of a main part showing a joint portion between a lower member and an upper member of the center pillar reinforcement according to still another embodiment. FIG. 3 is a cross-sectional view taken along the line XIV-XIV of the joint portion of FIG.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the drawings. The same reference numerals used in the following description and drawings for a plurality of embodiments indicate the same or similar parts. The arrow FR appropriately shown in each figure indicates the front side of the vehicle, and the arrow UP indicates the upper side of the vehicle. Further, the arrow IN indicates the inside in the vehicle width direction. In the following description, the description regarding the direction shall be made with reference to this direction.

[Center Pillar Reinforcement]
1 to 3 show a schematic configuration of a center pillar reinforcement 1 according to a first embodiment of the present invention. As shown in FIGS. 1 and 2, the elongated center pillar reinforcement 1 is spot-welded to the inside of the center pillar having a closed cross section with the center pillar outer (not shown) and the center pillar inner (not shown). It is integrally fixed by fastening rivets.

The center pillar reinforcement 1 is formed in a predetermined shape having a cross-sectional hat shape that opens inward in the vehicle width direction, and flange portions 14 that are bent outward at substantially right angles to both end edges on the opening side having a groove-like cross section. Is provided. In the center pillar reinforcement 1, the upper end member 11 having a substantially T-shaped front view in which the upper end edge portion is connected to the roof side rail 3 via the mounting portion 15 and the lower end edge portion being side sill 5 via the mounting portion 16. It is composed of a lower member 12 having a substantially inverted T-shape in front view, which is connected to the lower member 12, and extends in the vertical direction.

The upper member 11 and the lower member 12 are integrally welded to each other by a joining line 18 extending over the entire width so as to intersect in the longitudinal direction of the center pillar reinforcement 1. The range of the lower member 12 is appropriately set so that a predetermined reinforcing strength can be obtained in consideration of the cross-sectional shape, size, and the like of the center pillar reinforcement 1. As shown in FIG. 2, the range of the lower member 12 is within a range of about 1/5 to 1/3 of the total height H of the center pillar reinforcement 1, for example, a range of about 1/3 from the lower end. Is set to. Specifically, the upper end edge of the lower member 12 is set to be lower than, for example, the waist of a seated occupant.

[Tailored blank]
Here, as shown in FIG. 3, the center pillar reinforcement 1 is a steel plate member obtained by forming a tailored blank 21 by cold pressing. The center pillar reinforcement 1 can also be formed by hot-pressing or warm-pressing the tailored blank 21.

In this tailored blank (tailored weld blank) 21, the lower end edge of the upper member 11 and the upper end edge of the lower member 12 are joined by welding along a joining line 18 extending over the entire width so as to intersect in the longitudinal direction thereof. There is. As the welding method of the upper member 11 and the lower member 12, any appropriate welding method such as laser welding, plasma welding, and (mash) seam welding can be used. The upper member 11 and the lower member 12 can be welded with their end faces abutting each other.

The upper member 11 and the lower member 12 are made of high-tensile steel plates having substantially the same plate thickness (for example, a thickness of about 1.4 to 2.0 mm), and the upper member 11 has a tension greater than the tensile strength of the lower member 12. It has strength, and is preferably set to have a tensile strength of about 1.5 times or more. Specifically, the tensile strength of the upper member 11 is 980 MPa or more, for example, 980 MPa, 1180 MPa, 1470 MPa and the like. The tensile strength of the lower member 12 is 440 MPa or more, for example, 590 MPa, 780 MPa, or the like.

The upper member 11 and the lower member 12 do not necessarily have to have the same plate thickness, and can be individually set in consideration of the required strength and press formability. For example, the plate thickness of the lower member 12 may be set to be thinner than the plate thickness of the upper member 11 so that the material strength of the lower member 12 is smaller than the material strength of the upper member 11. Further, the upper member 11 and the lower member 12 do not necessarily have to be abutted and welded, and the ends may be overlapped and welded by spot welding or the like to be joined.

[Structure near the joint of the center pillar reinforcement]
Next, the configuration of the center pillar reinforcement 1 formed from the tailored blank 21 in the vicinity of the joint will be described with reference to FIGS. 4 to 8. As shown in FIGS. 4 to 6, the upper member 11 is formed in a substantially hat-shaped cross section that opens inward in the vehicle width direction, and has a front flange portion 11A and a front vertical wall portion from the front side to the rear side in the vehicle front-rear direction. It has 11B, a vertically long bead portion 11C formed in the vertical direction, a ceiling portion 11D formed substantially flat, a rear vertical wall portion 11E, and a rear flange portion 11F in this order. The front vertical wall portion 11B and the rear vertical wall portion 11E rise outward from the front flange portion 11A and the rear flange portion 11F, which are formed substantially flat, respectively, and the vertically long bead portion 11C and the ceiling at the ends in the vehicle outer direction. They are connected to each other by part 11D.

Further, as shown in FIGS. 4 and 5, the ceiling portion 11D of the upper member 11 projects at a predetermined height (for example, about 3 mm to 10 mm in height) toward the outside of the vehicle over the entire width of the ceiling portion 11D. The upper door hinge mounting flat surface portion 11G is formed. A pair of through holes 11H to which a hinge for a rear door (not shown) is attached is vertically arranged on the upper door hinge mounting flat surface portion 11G. Further, the front vertical wall portion 11B is provided with a door striker mounting portion at a substantially central position in the vertical direction of the ceiling portion 11D, and a pair of door striker mounting holes 25 are provided through the upper and lower two positions.

As shown in FIGS. 4, 5 and 6, the lower end member 12 is formed so that the upper end side is continuously formed with the upper member 11 and the joint line 18 interposed therebetween, and has a substantially hat-shaped cross section that opens inward in the vehicle width direction. ing. Like the upper member 11, the lower member 12 has a front flange portion 12A, a front vertical wall portion 12B, a vertically elongated bead portion 12C formed in the vertical direction, and a ceiling portion formed substantially flat from the front side to the rear side in the vehicle front-rear direction. It has 12D, a rear vertical wall portion 12E, and a rear flange portion 12F in this order. The front vertical wall portion 12B and the rear vertical wall portion 12E rise from the front flange portion 12A and the rear flange portion 12F, which are formed substantially flat, toward the outside of the vehicle, respectively, and the vertically long bead portion 12C and the ceiling at the outer end of the vehicle. They are connected to each other by part 12D.

Further, a lower door hinge mounting flat surface portion 12G is formed at a position slightly below the joint line 18 of the ceiling portion 12D. The door hinge mounting flat surface portion 12G is formed as a convex flat surface portion that projects at a predetermined height (for example, a height of about 3 mm to 10 mm) toward the outside of the vehicle in a horizontally long rectangular shape in front view over the entire width of the ceiling portion 12D. There is.

A pair of through holes 12H to which a hinge for a rear door (not shown) is attached is arranged along the vehicle front-rear direction on the door hinge mounting flat surface portion 12G. Further, the vertically long bead portion 12C is provided up to a position facing the lower end of the front end edge of the door hinge mounting flat surface portion 12G. Below the lower end edge of the door hinge mounting flat surface portion 12G, the ceiling portion 12D is formed substantially flat and is connected to the horizontally long rectangular mounting portion 16 at the lower end.

[bead]
Further, as shown in FIGS. 4 and 5, the bead 27 is formed from a pair of door striker mounting holes 25 in the ceiling portion 11D of the upper member 11 from the substantially central portion of the upper end edge of the door hinge mounting flat portion 12G of the lower member 12. Is provided along the longitudinal direction of the center pillar reinforcement 1 across the joint line 18 toward the lower position.

As shown in FIGS. 4, 7 and 8, the bead 27 has a convex shape of a cross-sectional arc protruding toward the outside of the vehicle, and is formed in a convex shape extending in the longitudinal direction of the center pillar reinforcement 1. Specifically, the bead 27 passes from the upper end of the door hinge mounting flat surface portion 12G of the lower member 12 to substantially the center of the ceiling portion 12D in the vehicle width direction, further straddles the joint line 18, and further straddles the joint line 18, and the ceiling portion 11D of the upper member 11 It is formed into an elongated ridge extending downward from the door striker mounting hole 25 of the above.

The width of the bead 27 is set to about 1/4 to 1/5 of the width of each of the

ceiling portions

11D and 12D, and is formed into a substantially elongated rectangular shape with a long vertical direction. The height of the lower end of the bead 27 protruding from the ceiling 12D is formed to be substantially equal to the height of the door hinge mounting flat surface 12G protruding from the ceiling 12D. The bead 27 is formed so that the protruding height gradually decreases upward, and the bead 27 is formed with substantially the same width until the protruding height from the ceiling portion 11D at the upper end portion becomes about 1/2 of the lower end portion. However, above that, it is molded in a tapered shape in the front view.

As a result, the bending strength of the

ceiling portions

12D and 11D sandwiching the joint line 18 including the upper end of the door hinge mounting flat surface portion 12G of the lower member 12 to the upper end portion of the bead 27 of the ceiling portion 11D of the upper member 11 is increased. According to 27, the bending strength on the lower side of the lower end of the door hinge mounting flat surface portion 12G can be increased. Further, since the bead 27 is formed so that the protruding height gradually decreases from the upper end edge portion of the door hinge mounting flat surface portion 12G to the upper side, stress concentration can be avoided.

As a result, even if the tensile strength of the upper member 11 is set to about 1.5 times or more the tensile strength of the lower member 12, it is possible to prevent the joint line 18 from becoming a fracture starting point at the time of a side collision. Therefore, at the time of a side collision, the lower member 12 is surely bent from the bending starting point set on the side sill 5 side (lower side) of the lower end of the door hinge mounting flat surface portion 12G, and the amount of the collision object entering the vehicle interior side is reduced. Can be planned.

[Reinforcing member]
As shown in FIGS. 4, 5 and 7, the width of the bead 27 is set to about 1/4 to 1/5 of the width of each of the

ceiling portions

11D and 12D, so that the width of the bead 27 is set on both sides of the bead 27. , 28A to 28D of each welded portion for performing spot welding or the like may be set. Then, for example, a reinforcing member 31 represented by a two-dot chain line formed in a shallow cross-sectional substantially groove shape that opens inward in the vehicle width direction is arranged on the inner side surface in the vehicle width direction facing the beads 27 of the

ceiling portions

11D and 12D. It may be welded by spot welding or the like.

In FIGS. 4 and 7, the welded portion is indicated by a cross. As a result, by welding the reinforcing member 31 by spot welding or the like, the joining line 18 including the upper end of the door hinge mounting flat surface portion 12G of the lower member 12 to the upper end portion of the bead 27 of the ceiling portion 11D of the upper member 11 is formed. The bending strength of the sandwiched

ceiling portions

12D and 11D can be further increased.

[Analysis result]
Next, the analysis results by CAE (Computer Aided Engineering) of the portion including the junction line 18 in the case where the center pillar reinforcement 1 has the bead 27 and the case where the bead 27 is not configured as described above are shown in FIGS. 9 and 9. It will be described based on 10. In the model used for this analysis, the upper member 11 was set to a high-strength steel plate having a tensile strength of 1470 MPa and a plate thickness of 1.6 mm. The lower member 12 was set to a high-strength steel plate having a tensile strength of 590 MPa and a plate thickness of 1.4 mm. Further, the center pillar reinforcement 1 was set to be molded by cold pressing of the tailored blank 21.

As shown in FIG. 9, when the bead 27 is provided, each of the joint lines 18 including the upper end of the door hinge mounting flat surface portion 12G of the lower member 12 to the upper end portion of the bead 27 of the ceiling portion 11D of the upper member 11 is sandwiched. No wrinkles are generated on the

ceiling portions

12D and 11D. This is because the bead 27 is deformed so as to match the cross-sectional line length during press molding by a cold press, so that the occurrence of wrinkles can be suppressed and the press moldability can be improved.

On the other hand, as shown in FIG. 10, when the bead 27 is not provided, the joint line 18 including the upper end of the door hinge mounting flat surface portion 12G of the lower member 12 to the upper end portion of the bead 27 of the ceiling portion 11D of the upper member 11 Large wrinkles 29 are generated on the

ceiling portions

12D and 11D sandwiching the above. This is because the upper member 11 is a high-tensile steel plate having a tensile strength of 1470 MPa and the lower member 12 is a high-tensile steel plate having a tensile strength of 590 MPa, so that the ductility of the upper member 11 is smaller than the ductility of the lower member 12. During press molding by a cold press, each large wrinkle 29 is generated along the longitudinal direction of the center pillar reinforcement 1.

[effect]
In the center pillar reinforcement 1 described above, the bead 27 formed across the joint line 18 extends from the upper end edge of the door hinge mounting flat surface portion 12G to a position below the pair of door striker mounting holes 25. During press molding such as cold pressing, the cross-sectional line length can be made uniform, wrinkles can be effectively suppressed, and press moldability can be improved.

Further, the bead 27 can increase the bending strength of the portion sandwiching the joint line 18 from the upper end edge portion of the door hinge mounting flat surface portion 12G to the position below the pair of door striker mounting holes 25. As a result, in the event of a side collision, the vehicle is surely bent from the bending starting point set below the lower end of the door hinge mounting flat surface portion 12G set on the lower member 12, and the amount of collision objects entering the vehicle interior side is reduced. Can be planned.

Further, the upper member 11 is made of a high-tensile steel plate having a tensile strength of 980 MPa or more, the lower member 12 is made of a high-tensile steel plate having a tensile strength of 440 MPa or more, and the upper member 11 is made of a lower member 12 It has a tensile strength of about 1.5 times or more of the tensile strength of. As a result, it is possible to improve the press moldability in press molding such as cold pressing, secure the required material strength, and reduce the weight of the upper member 11. Further, since the bead 27 is formed so that the protruding height gradually decreases from the upper end edge portion of the door hinge mounting flat surface portion 12G to the upper side, stress concentration is avoided and it becomes a fracture starting point at the time of a side collision. Can be prevented.

[Deformation example of bead shape]
As shown in FIGS. 11 and 12, as another embodiment, a bead 43 having a different shape can be used instead of the bead 27. Specifically, the bead 43 extends from the substantially central portion of the upper end edge of the door hinge mounting flat surface portion 12G of the lower member 12 to a position below the pair of door striker mounting holes 25 in the ceiling portion 11D of the upper member 11. It is provided along the longitudinal direction of the center pillar reinforcement 41 across the joint line 18.

The bead 43 has a convex shape with a cross-sectional arc protruding toward the outside of the vehicle, and is formed in a convex shape extending in the longitudinal direction of the center pillar reinforcement 41. Specifically, the bead 43 passes from the upper end of the door hinge mounting flat surface portion 12G of the lower member 12 to substantially the center of the ceiling portion 12D in the vehicle width direction, and further straddles the joint line 18 to form the ceiling portion 11D of the upper member 11. It is formed into a ridge that extends elongated toward a position below the door striker mounting hole 25. The width of the bead 43 is set to about 1/4 to 1/5 of the width of each of the

ceiling portions

11D and 12D, and is formed into a substantially elongated rectangular shape in the front view, which is long in the vertical direction.

Further, the height of the lower end of the bead 43 protruding from the ceiling 12D is slightly lower than the height of the door hinge mounting flat surface 12G protruding from the ceiling 12D (for example, a height of about 70 to 90%). It is molded. The bead 43 is formed upward so as to have substantially the same width and the protrusion heights from the

ceiling portions

12D and 11D are substantially the same height, and the bead 43 is formed in a tapered shape in the front view at the upper end portion. ..

As a result, the bead 43 is formed so as to have the same protruding height from the upper end edge portion of the door hinge mounting flat surface portion 12G to the upper side, so that the bead 43 is joined from the upper end edge portion of the door hinge mounting flat surface portion 12G. It is possible to improve the bending strength up to the portion where the bead 43 is formed across the 18. As a result, even if the tensile strength of the upper member 11 is set to about 1.5 times or more the tensile strength of the lower member 12, the portion sandwiching the joint line 18 becomes the fracture starting point at the time of a side collision. Can be prevented. Therefore, at the time of a side collision, the lower member 12 is surely bent from the bending starting point set on the side sill 5 side (lower side) of the lower end of the door hinge mounting flat surface portion 12G, and the amount of the collision object entering the vehicle interior side is reduced. Can be planned.

Further, in the center pillar reinforcement 41 described above, similarly to the center pillar reinforcement 1 of FIGS. 4 and 5, the upper edge of the door hinge mounting flat surface portion 12G is formed by the bead 43 formed across the joint line 18. During press molding such as cold pressing from the part to the position below the pair of door striker mounting holes 25, the cross-sectional line length can be made uniform, and the occurrence of wrinkles can be effectively suppressed and press molding. It is possible to improve the sex.

As shown in FIGS. 13 and 14, as another embodiment, a bead 53 having a different shape can be used instead of the

beads

27 and 43. Specifically, as shown in FIGS. 13 and 14, the bead 53 mounts a pair of door strikers on the ceiling portion 11D of the upper member 11 from the substantially central portion of the upper end edge of the door hinge mounting flat portion 12G of the lower member 12. It is provided along the longitudinal direction of the center pillar reinforcement 51 across the joint line 18 up to a position of the hole 25 facing the door striker mounting hole 25 on the upper side.

The bead 53 has a convex shape with a cross-sectional arc protruding toward the outside of the vehicle, and is formed in a convex shape extending in the longitudinal direction of the center pillar reinforcement 51. Specifically, the bead 53 passes from the upper end of the door hinge mounting flat surface portion 12G of the lower member 12 to substantially the center of the ceiling portion 12D in the vehicle width direction, further straddles the joint line 18, and further straddles the joint line 18, and the ceiling portion 11D of the upper member 11 It is formed into an elongated ridge extending toward a position corresponding to the door striker mounting hole 25 on the upper side of the above. The width at the lower end of the bead 53 is set to about 1/4 to 1/5 of the dimension of the door hinge mounting flat surface portion 12G in the vehicle front-rear direction, and becomes a substantially elongated triangular shape in the front view that gradually tapers upward. It is molded.

Further, the height of the lower end of the bead 53 protruding from the ceiling 12D is formed to be substantially equal to the height of the door hinge mounting flat surface 12G protruding from the ceiling 12D. The bead 53 is formed so that the protruding height gradually decreases upward and reaches the outer surface of the ceiling portion 11D of the upper member 11 at the upper end portion.

As a result, the bending strength of the

ceiling portions

12D and 11D sandwiching the joint line 18 including the upper end of the door hinge mounting flat surface portion 12G of the lower member 12 to the upper end portion of the bead 53 of the ceiling portion 11D of the upper member 11 is increased. According to 53, the bending strength on the lower side of the lower end of the door hinge mounting flat surface portion 12G can be made larger than the bending strength. Further, since the bead 53 is formed so that the protruding height gradually decreases from the upper end edge portion of the door hinge mounting flat surface portion 12G to the upper side, stress concentration can be avoided.

Further, in the center pillar reinforcement 51 described above, similarly to the center pillar reinforcement 1 of FIGS. 4 and 5, the upper edge of the door hinge mounting flat surface portion 12G is formed by the bead 53 formed across the joint line 18. During press molding such as cold pressing from the portion to the position facing the door striker mounting hole 25 on the upper side of the pair of door striker mounting holes 25, the cross-sectional line length can be made uniform and wrinkles occur. Can be effectively suppressed to improve press formability.

[Other Embodiments]
Further embodiments will be described below.

In the center pillar reinforcement 1 of FIGS. 4 and 5, from the upper end edge of the door hinge mounting flat portion 12G of the lower member 12 to a position below the pair of door striker mounting holes 25 in the ceiling portion 11D of the upper member 11 2 The beads 27 may be arranged along the longitudinal direction of the center pillar reinforcement 1 at a predetermined distance in the front-rear direction of the vehicle.

In the center pillar reinforcement 41 of FIGS. 11 and 12, from the upper end edge of the door hinge mounting flat portion 12G of the lower member 12 to a position lower than the pair of door striker mounting holes 25 in the ceiling portion 11D of the upper member 11, 2 The beads 43 may be arranged along the longitudinal direction of the center pillar reinforcement 41 at a predetermined distance in the front-rear direction of the vehicle.

In the center pillar reinforcement 51 of FIGS. 13 and 14, from the upper end edge of the door hinge mounting flat portion 12G of the lower member 12, the door striker mounting hole on the upper side of the pair of door striker mounting holes 25 in the ceiling portion 11D of the upper member 11 The two beads 53 may be arranged along the longitudinal direction of the center pillar reinforcement 51 with a predetermined distance in the front-rear direction of the vehicle toward the position facing the 25.

With these configurations, each ceiling sandwiching the joint line 18 including the upper end of the door hinge mounting flat surface portion 12G of the lower member 12 to the upper end portions of the

beads

27, 43, 53 of the ceiling portion 11D of the upper member 11 is interposed. The bending strength of the

portions

12D and 11D can be further increased by the two

beads

27, 43 and 53, respectively, to be higher than the bending strength on the lower side of the lower end of the door hinge mounting flat surface portion 12G.

[Effect of Embodiment]
The embodiment described above has the following effects.

In some embodiments, a bead formed across the joint is used to make the cross-sectional line length uniform by press molding from the upper edge of the convex flat surface to the position below the door striker mounting portion. It is possible to effectively suppress the occurrence of wrinkles and improve the press formability. Further, the bead can increase the bending strength of the portion sandwiching the joint portion from the upper end edge portion of the convex flat surface portion to the position below the door striker mounting portion. As a result, at the time of a side collision, the vehicle can be reliably bent from the bending starting point set in the lower member, and the amount of the colliding object entering the vehicle interior can be reduced.

Depending on the embodiment, the upper member is made of a high-tensile steel plate having a tensile strength of 980 MPa or more, the lower member is made of a high-tensile steel plate having a tensile strength of 440 MPa or more, and the upper member is a lower member. It has a tensile strength of 1.5 times or more of the tensile strength. As a result, it is possible to improve the press moldability in press molding, secure the required material strength, and reduce the weight of the upper member.

In some embodiments, the bead is formed so that the protruding height gradually decreases from the upper edge portion of the convex flat surface portion to the upper side, so that stress concentration is avoided and the bead is used as a fracture starting point at the time of a side collision. It can be prevented from becoming.

In some embodiments, the beads are formed so as to have the same protrusion height from the upper edge portion of the convex flat surface portion to the upper side, so that the joint portion is formed from the upper end edge portion of the convex flat surface portion. It is possible to improve the bending strength up to the portion where the bead is formed by sandwiching it. As a result, even if the tensile strength of the upper member is set to be larger than the tensile strength of the lower member, it is possible to effectively prevent the portion sandwiching the joint portion from becoming the starting point of fracture at the time of a side collision. ..

Depending on the embodiment, since the bead is arranged at the center position in the width direction of the ceiling portion, the welded portion for welding the reinforcing member arranged on the inner side surface of the ceiling portion can be widened to improve workability. Can be planned.

Depending on the embodiment, a bead formed across the joint portion is used to make the cross-sectional line length uniform by press molding from the upper end edge portion of the door hinge mounting flat portion to the position below the door striker mounting portion. It is possible to effectively suppress the occurrence of wrinkles and improve the press formability. Further, the bead can increase the bending strength of the portion sandwiching the joint portion from the upper end edge portion of the door hinge mounting flat surface portion to the position below the door striker mounting portion. As a result, at the time of a side collision, the vehicle can be reliably bent from the bending starting point set in the lower member, and the amount of the colliding object entering the vehicle interior can be reduced.

Although various embodiments have been described above, the present invention is not limited to these embodiments, and various improvements, modifications, additions, and deletions can be made without departing from the gist of the present invention. I want to be understood.

Claims

A center pillar reinforcement press-molded from a tailored blank consisting of a lower member and an upper member.
With the lower member whose lower end edge is joined to the side sill of the vehicle,
It is provided with the upper member which is joined to the upper side of the lower member by welding and whose upper end edge is joined to the roof side rail of the vehicle.
The upper member has a tensile strength larger than the tensile strength of the lower member.
The upper member and the lower member each include a pair of vertical wall portions and a ceiling portion connecting the vertical wall portions.
The ceiling portion of the lower member has a convex flat portion that protrudes outward from the vehicle below the joint portion with the upper member.
The vertical wall portion of the upper member has a door striker mounting portion formed above the joint portion.
The ceiling portion is provided along the longitudinal direction of the center pillar reinforcement from the upper edge portion of the convex flat surface portion to a position below the door striker mounting portion or a position corresponding to the door striker mounting portion. A bead formed so as to project outward of the vehicle across the joint.
Center pillar reinforcement.
The center pillar reinforcement according to claim 1.
The upper member is made of a high-strength steel plate having a tensile strength of 980 MPa or more.
The lower member is made of a high-strength steel plate having a tensile strength of 440 MPa or more.
The upper member has a tensile strength of 1.5 times or more the tensile strength of the lower member.
Center pillar reinforcement.
The center pillar reinforcement according to claim 1 or 2.
The bead is formed so that the protruding height gradually decreases from the upper edge portion of the convex flat surface portion to the upper side.
Center pillar reinforcement.
The center pillar reinforcement according to claim 1 or 2.
The bead is formed so as to have the same protrusion height from the upper edge portion of the convex flat surface portion to the upper side.
Center pillar reinforcement.
The center pillar reinforcement according to any one of claims 1 to 4.
The bead is arranged at a central position in the width direction of the ceiling portion.
The ceiling portion has welded portions on both sides of the bead for welding reinforcing members arranged on the inner side surface of the ceiling portion.
Center pillar reinforcement.
The center pillar reinforcement according to any one of claims 1 to 5.
The convex flat surface portion includes a door hinge mounting flat surface portion projecting outward of the vehicle.
Center pillar reinforcement.