Twelve-cornered strengthening member, assemblies including a twelve-cornered strengthening member, and methods of manufacturing and joining the same

A strengthening member for an automotive vehicle comprises a twelve-cornered cross section including sides and corners creating internal angles and external angles. To facilitate a connection between the strengthening member and the automotive component, one of the strengthening member and the automotive component may transition from the twelve-cornered cross section at a first end of the strengthening member to a four-cornered cross section at a second end of the strengthening member. An automotive assembly may include a strengthening member connected to an automotive component via a separate bridge connection member.

TECHNICAL FIELD

The present teachings relate generally to a strengthening assembly for a vehicle body or other structures. The present teachings relate more specifically to a strengthening member, motor vehicle assemblies including a strengthening member, connected to another automotive component, and methods of making and joining the strengthening member and assemblies.

BACKGROUND

It is desirable, for vehicle strengthening members, to maximize impact energy absorption and bending resistance while minimizing mass per unit length of the strengthening member. Impact energy absorption may be maximized, for example, by assuring that the strengthening member compacts substantially along a longitudinal axis of the strengthening member upon experiencing an impact along this axis. Such longitudinal compaction may be referred to as a stable axial crush of the strengthening member.

When a compressive force is exerted on a strengthening member, for example a force due to a front impact load on a vehicle's front rail or other strengthening member in the engine compartment, the strengthening member can crush in a longitudinal direction to absorb the energy of the collision. In addition, when a bending force is exerted on a strengthening member, for example a force due to a side impact load on a vehicle's front side sill, B-pillar or other strengthening member, the strengthening member can bend to absorb the energy of the collision.

Conventional strengthening members rely on increasing the thickness and hardness of corner portions to improve crush strength. However, such increased thickness and hardness increases weight and decreases manufacturing feasibility. It may be desirable to provide a strengthening assembly configured to achieve the same or similar strength increase as provided by the thickened corners, while minimizing mass per unit length of the member, and maintaining a high manufacturing feasibility.

It also may be desirable to provide a strengthening member that can achieve increased energy absorption and a more stable axial collapse when forces such as front and side impact forces are exerted on the strengthening member. Additionally, it may be desirable to provide a strengthening member that possesses improved noise-vibration-harshness performance due to work hardening on its corners.

It also may be desirable to provide structures to connect the strengthening member to another automotive component to promote a stable axial crush. When the other automotive component has a different shape than the strengthening member, it may be difficult to apply welding techniques to connect the strengthening member and the other component due to the variation in shape. This difficulty may result in a connection that is not secure and which causes an unstable axial crush.

SUMMARY

In accordance with the various exemplary embodiments, the present disclosure provides a strengthening member for an automotive vehicle, the strengthening member including a first end and a second end. The first end has a twelve-cornered cross section including sides and corners creating internal angles and external angles. The second end is configured to connect to a four-cornered cross section of another automotive component. The cross section of the strengthening member transitions along a length of the strengthening member from the twelve-cornered cross section at the first end to a four-cornered cross-section at the second end.

In accordance with the various exemplary embodiments, the present disclosure further provides a motor vehicle assembly including a strengthening member and an automotive component. The strengthening member has a twelve-cornered cross section at a first end of the strengthening member and a four-cornered cross section at a second end of the strengthening member. The cross section of the strengthening member transitions along a length of the strengthening member from the twelve-cornered cross section at the first end to the four-cornered cross-section at the second end. The automotive component has a four-cornered cross section at an end of the automotive component connected to the second end of the strengthening member.

In accordance with the various exemplary embodiments, the present disclosure further provides a motor vehicle assembly including a strengthening member and an automotive component. The strengthening member has a twelve-cornered cross section along a length of the strengthening member from a first end of the strengthening member to a second end of the strengthening member. The automotive component has a twelve-cornered cross section at an end of the automotive component connected to the second end of the strengthening member. The cross section of the automotive component transitions from the twelve-cornered cross section to a four-cornered cross section along a longitudinal axis of the automotive component.

In accordance with the various exemplary embodiments, the present disclosure further provides a method of manufacturing a strengthening member of a motor vehicle, the method including forming a strengthening member from at least one piece. The forming includes forming the strengthening member to have a twelve-cornered cross section at a first end of the strengthening member and a four-cornered cross section at a second end of the strengthening member. The cross section of the strengthening member transitions along a length of the strengthening member from the twelve-cornered cross section at the first end to the four-cornered cross-section at the second end.

In accordance with the various exemplary embodiments, the present disclosure further provides a method of manufacturing a motor vehicle assembly, the method including providing a strengthening member having a twelve-cornered cross section in at least a portion of the strengthening member. The method further includes providing an automotive component forming a structural portion of the assembly. The automotive component has a four-cornered cross section along at least a portion of a length of the automotive component. The method further includes providing a transition between twelve corners and four corners at an end of at least one of the strengthening member and the automotive component where the strengthening member and the automotive component are connected to one another. Further, the method includes connecting the strengthening member to the automotive component.

Additional objects and advantages will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present teachings. The objects and advantages of the teachings will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. The accompanying drawings, which are incorporated in and constitute part of this specification, illustrate exemplary embodiments of the invention and together with the description, serve to explain principles of the disclosure.

Although the following detailed description makes reference to illustrative embodiments, many alternatives, modifications, and variations thereof will be apparent to those skilled in the art. Accordingly, it is intended that the claimed subject matter be viewed broadly.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Reference will now be made in detail to various embodiments, examples of which are illustrated in the accompanying drawings. The various exemplary embodiments are not intended to limit the disclosure. To the contrary, the disclosure is intended to cover alternatives, modifications, and equivalents.

The present teachings contemplate providing a strengthening member with a twelve-cornered cross section having a substantially increased stiffness throughout the sides and corners without increasing thickness within the corners. The strengthening member can achieve increased energy absorption and a more stable axial collapse when forces such as front and side impact forces are exerted on the strengthening member. The strengthening member can also possess improved durability and noise-vibration-harshness (NVH) performance due to work hardening on the twelve corners. The degrees of the internal and external angles of the present teachings can achieve the same strength increase as thickened corners, while minimizing mass per unit length of the member and maintaining a high manufacturing feasibility because the member can be formed by bending, rolling, stamping, pressing, hydro-forming, molding, extrusion, cutting, casting, and forging.

An exemplary embodiment of a twelve-cornered cross section for a strengthening member in accordance with the present teachings is illustrated inFIG. 1. As illustrated, the cross section comprises twelve sides having lengths S1-S12and thicknesses T1-T12, eight internal corners with angles θi1-θi8and four external corners with angles θe1-θe4. The internal and external angular degrees can be varied to achieve improved strength and other performance features (e.g., stability of folding pattern) compared to existing 90°-angled cross sections. This improved strength obviates the need for increased corner thickness, which is an unexpected and unpredicted benefit of fine-tuning the internal and external angular degrees of a strengthening member having a twelve-sided cross section. In accordance with various embodiments of the present teachings, each internal angle can range from about 100° to about 110°, and each external angle can range from about 105° to about 130°. The lengths S1-S12and thicknesses T1-T12of the sides can be varied to a certain degree, as would be understood by one skilled in the art, for example in accordance with available packaging space within a vehicle. Each internal angle and each external angle of the strengthening member may have an angular degree selected to promote the stable axial crush in accordance with the disclosed range of degrees, while accommodating package constraints of an environment in which the assembly is to be used.

In certain embodiments of the present teachings a thickness of the sides and corners can range from about 0.7 mm to about 6.0 mm. In certain embodiments, the thickness of the sides is substantially the same as the thickness of the corners.

Conventional strengthening members having square or rectangular cross sections are widely used due to their high manufacturing feasibility. Because a strengthening member with a twelve-cornered cross section in accordance with the present teachings has substantially increased strength and stiffness without requiring thicker corner portions, it has a higher manufacturing feasibility than previously-contemplated twelve-cornered members that have thickened 90° corners. While still providing a desired strength, a strengthening member in accordance with the present teachings can be formed in one or multiple sections by, for example, bending, rolling, stamping, pressing, drawing, hydro-forming, molding, extrusion, cutting, casting, and forging. Thus-formed sections can be joined via welding, adhesive, fastening, or other known joining technologies.

In accordance with certain exemplary embodiments of the present teachings, the thickness of the strengthening member may vary, for example, within one side or from side to side to optimize the overall axial crush and bending performance. Examples of such varied thickness embodiments are illustrated inFIGS. 5D and 6D, which are described in detail below.

In comparing crash energy absorption of strengthening members of varying shapes having the same thickness and perimeter, as illustrated inFIG. 2, for example for an impact with a rigid wall at 35 mph, a twelve-cornered cross section in accordance with the present teachings demonstrated the shortest crush distance and smallest folding length. The twelve-cornered cross section in accordance with the present teachings also demonstrated the most stable axial collapse and the highest crash energy absorption. In fact, a twelve-cornered cross section in accordance with the present teachings can achieve about a 100% increase in crash energy absorption over a square cross section and a 20-30% increase in crash energy absorption over hexagonal and octagonal cross sections.FIG. 3illustrates an exemplary axial collapse of the strengthening members shown inFIG. 2. As can be seen, the strengthening member having a twelve-cornered cross section in accordance with the present teachings exhibits the shortest crush distance and most stable folding pattern.

FIG. 4illustrates a graph of mean crush force for an impact with a rigid wall at 35 mph, in kN, exerted axially on exemplary strengthening members having the cross sections shown inFIG. 2. As can be seen, a strengthening member having a twelve-cornered cross section in accordance with the present teachings can sustain a much higher crushing force for a given resulting crushing distance. This allows improved impact energy management while minimizing mass per unit length.

A twelve-cornered cross section in accordance with the present teachings is contemplated for use with a number of structural members such as a front rail, a side rail, a cross member, roof structures, and other components that can benefit from increased crash energy absorption. In addition, the present teachings can be applied to both body-on-frame and unitized vehicles or other type of structures.

FIGS. 5A-5Dillustrate exemplary embodiments of a vehicle front rail having a cross section in accordance with the present teachings. The front rail is of a type without convolutions.FIG. 5Aillustrates a front rail having a known, substantially rectangular cross section with four corners510,512,514,516of about ninety degrees, and four sides520,522,524,526.FIGS. 5B through 5Dillustrate front rails having twelve-cornered cross sections in accordance with the present teachings, the corner indentations11inFIG. 5Cbeing greater than the indentations12inFIG. 5B. In these illustrated exemplary embodiments, the rails have a two-part construction comprising pieces A and B. The present teachings contemplate rails of other construction such as one-piece or even 3-or-more piece construction, the number of pieces inFIGS. 5A through 5Dbeing exemplary only.

The embodiments ofFIGS. 5B and 5Cinclude top and bottom sides SBand SThaving substantially the same length as each other, and left and right sides SLand SRalso having substantially the same length as each other. Piece A includes side SRand part of sides SBand ST. Piece B includes side SLand part of sides SBand ST. To simplifyFIGS. 5B-5D, all of the sides S1through S12, as illustrated inFIG. 1, are not labeled but are of course present. Similarly, the eight internal corners (angles: θi1-θi8) and four external corners (angles: θe1-θe4), as illustrated inFIG. 1, are not labeled but are present.

FIG. 5Dillustrates a front rail having a twelve-cornered cross section, the rail being formed with different depths of indentations, for example to accommodate packaging constraints of a vehicle's engine compartment. In accordance with such an embodiment needing to have a varied shape to accommodate engine compartment constraints, to achieve optimized axial crush performance, the thicknesses of the sides, angles of the corners, and indentation depths can all be adjusted to provide optimal strength, size and shape. In the example ofFIG. 5D, corner indentations13and14have the different depths, corner indentation14being shallower than corner indentation13. Corner indentations15and16have substantially the same depth as each other, that depth differing from the depths of corner indentations13and14. The top and bottom sides SBand SThave different lengths, with STbeing longer than SB, and the left and right sides SLand SRhave differing lengths, with SRbeing longer than SL. The internal and external angles θ may also differ as a result of the differing side lengths and corner indentation depths. The present teachings also contemplate a twelve-cornered cross section where each of the corner indentations has a different depth and a different angle, and each of the sides has a different length, or where some of the sides have the same length and some of the corner indentations have the same depth and perhaps the same internal and external angles θ.

For a front rail comprising SAE1010 material, a front rail as illustrated inFIG. 5B(with shallower indentations) can save, for example, about 17% weight compared to a square or rectangular cross section, and a front rail as illustrated inFIG. 5C(with deeper indentations) can save, for example, about 35% weight. For a front rail comprising DP600 material, a front rail as illustrated inFIG. 5B(with shallower indentations) can save, for example, about 23% weight and a front rail as illustrated inFIG. 5C(with deeper indentations) can save, for example, about 47% weight. Such weight savings are realized because the increased strength of the twelve-cornered cross section allows the use of a thinner gauge material to provide the same strength.

FIGS. 6A-6Dillustrate exemplary embodiments of a vehicle front rail having a cross section in accordance with the present teachings. The front rail is of a type with convolutions.FIG. 6Aillustrates a convoluted front rail having a known, substantially rectangular cross section with four corners610,612,614,616of about ninety degrees, and four sides620,622,624, and626.FIGS. 6B through 6Dillustrate convoluted front rails having twelve-cornered cross sections in accordance with the present teachings, the corner indentations I8 inFIG. 6Cbeing greater than the indentations I7 inFIG. 6B. In these illustrated exemplary embodiments, the rails have a two-part construction with pieces C and D. As stated above, the two-piece constructions shown inFIGS. 6B through 6Dare exemplary only and the present teachings contemplate rails of other construction such as one-piece or even 3-or-more piece construction.

The embodiments ofFIGS. 6B and 6Cinclude top and bottom sides SBand SThaving substantially the same length as each other, and left and right sides SLand SRalso having substantially the same length as each other. Piece C includes side SRand part of sides SBand ST. Piece D includes side SLand part of sides SBand ST. To simplifyFIGS. 6B-6D, all of the sides S1through S12, as illustrated inFIG. 1, are not labeled but are present. Similarly, the eight internal corners (angles: θi1-θi8) and four external corners (angles: θe1-θe4), as illustrated inFIG. 1, are not labeled but are present.

FIG. 6Dillustrates a convoluted front rail having twelve-cornered cross section, the rail being formed with different depths of indentations, for example to accommodate packaging constraints of a vehicle's engine compartment. In accordance with such an embodiment needing to have a varied shape to accommodate engine compartment constraints, to achieve optimized axial crush performance, the thicknesses of the sides, angles of the corners, and indentation depths can all be adjusted to provide optimal strength, size and shape. In the example ofFIG. 6D, corner indentations I9 and I10 have the different depths, with corner indentation I10 being shallower than corner indentation I9. Corner indentations I11 and I12 have substantially the same depth as each other, that depth differing from the depths of corner indentations I9 and I10. The top and bottom sides SBand SThave different lengths, with STbeing longer than SB, and the left and right sides SLand SRhave differing lengths, with SRbeing longer than SL. The internal and external angles θ may also differ as a result of the differing side lengths and corner indentation depths. The present teachings also contemplate a twelve-cornered cross section where each of the corner indentations has a different depth and a different angle, and each of the sides has a different length, or where some of the sides have the same length and some of the corner indentations have the same depth and perhaps the same internal and external angles θ.

For a convoluted front rail comprising SAE1010 material, a front rail as illustrated inFIG. 6B(with shallower indentations) can save, for example, about 20% weight compared to a square or rectangular cross section, and a front rail as illustrated inFIG. 6C(with deeper indentations) can save, for example, about 32% weight. For a convoluted front rail comprising DP600 material, a front rail as illustrated inFIG. 6B(with shallower indentations) can save, for example, about 30% weight and a front rail as illustrated inFIG. 6C(with deeper indentations) can save, for example, about 41% weight.

Strengthening members having a variety of cross sections are illustrated inFIG. 7. As can be seen, CAE006 has a twelve-cornered cross section with external angles of 90°. CAE007 has a twelve-cornered cross section with external angles of 108° in accordance with the present teachings. CAE008 has a twelve-cornered cross section with external angles of 124° in accordance with the present teachings. CAE009 has a twelve-cornered cross section with external angles of 140°. CAE010 has a twelve-cornered cross section with external angles of 154°. Finally, CAE011 has a square cross section. A comparison of the axial crush strength of the illustrated square and twelve-cornered cross sections having differing external angles is illustrated inFIG. 8. As can be seen, the overall axial crush strength of the strengthening member having a twelve-cornered cross section is far greater than that of the strengthening member having a square cross section.

As can further be seen, the exemplary strengthening members with twelve-cornered cross sections having external angles of 108° and 124° show an overall increase in axial crush strength over twelve-cornered cross sections having external angles of 90°. In fact, deviation of the angles from 90° such that each internal angle is about the same as other internal angles and ranges from about 100° to about 110°, and each external angle is about the same as other external angles and ranges from about 105° to about 130°, increases strength without negatively affecting the stability of a crush mode of the strengthening member. Such an increase in strength obviates the need for reinforcing (e.g., thickening) the concave portions at the four corners of the strengthening member, decreasing weight and cost and increasing manufacturing feasibility.

Strengthening members in accordance with the present teachings can comprise, for example, steel, aluminum, magnesium, fiberglass, nylon, plastic, a composite or any other suitable materials.

In addition to the structure of the strengthening member, the manner of connection of the strengthening member also plays a role in the ability of the strengthening member to provide a stable axial collapse and high energy absorption under crash conditions. Further, the various exemplary embodiments described herein contemplate strengthening members having a shape to facilitate a stable axial collapse. A strengthening member connected in accordance with the present teachings may provide approximately a 20% increase in amount of energy absorbed versus a direct connection between a twelve-cornered strengthening member and a four-cornered automotive component.

In accordance with certain embodiments, the present teachings contemplate joints between a strengthening member having a twelve-cornered cross section in at least a portion of the strengthening member and an automotive component having a four-cornered cross section in at least a portion of the automotive component. For example, a bridge connection member can be used to join a strengthening member and automotive component to promote a stable axial crush by ensuring a secure connection between the different shapes of the strengthening member and the other automotive component.

In one embodiment, the connection member comprises a transition on one end of the strengthening member from twelve corners to four corners to allow this end to be securely welded to the automotive component. In another embodiment, the bridge connection member comprises a backing plate interposed between the strengthening member and the automotive component. In another embodiment, the bridge connection member comprises at least one bracket connecting the strengthening member and the automotive component.

In further embodiments, slot welds or fish-mouth welds connect the strengthening member and the automotive component. In yet another embodiment, an automotive component transitions at one of its ends from four corners to twelve corners to allow the end to be securely welded to the strengthening member. It is also within the scope of the present teachings to combine any of the embodiments set forth above.

Strengthening members of the various exemplary embodiments described herein may be used a structural member in various locations of a vehicle. For example, the strengthening members may be used as a front rail of a vehicle frame, a side rail of a vehicle frame, a rear rail of a vehicle frame, a cross member of a vehicle frame, a cross member of a vehicle frame outside of the vehicle engine compartment, a door beam, roof structures, or any other structural component of a vehicle that uses a beam structure or strengthening member.

FIG. 9Aillustrates a strengthening member900having a twelve-cornered cross section, in accordance with the present disclosure, connected to an automotive component950having a four-cornered cross section. Automotive component950may be, for example, a portion of a vehicle frame to which strengthening member900is joined. Connections between automotive parts generally include welding each of the corners of the parts to be connected. However, when a strengthening member900in accordance with the present disclosure is connected with an automotive component950in this manner, it is not possible to apply welds at all corners of the strengthening member, which decreases the stability of the connection. Because the connection is not stable, there is a tendency for the connection itself to be distorted upon application of an impact load. This distortion rotates the strengthening member900and prevents the strengthening member900from compacting along a longitudinal direction, which results in an unstable axial crush, as shown inFIG. 9B.

Strengthening member900may be shaped to facilitate a stable axial crush. According to an exemplary embodiment, strengthening member900may include a tapered section910that facilitates a stable collapse of strengthening member900along an axial direction (e.g., along a longitudinal axis920) of strengthening member900. Tapered section910may taper so that a cross-sectional area of strengthening member changes along the axial direction (e.g., along longitudinal axis920) of the strengthening member900. For example, tapered section910may taper so that the cross-sectional area increases in a direction along longitudinal axis920from the front to the rear of strengthening member900, such as when strengthening member900is joined to automotive component950in the configuration shown inFIG. 9A. According to an exemplary embodiment, tapered section910may taper so that the cross-sectional area of tapered section changes in a range of, for example, about 30% to about 70% along the length of tapered section910(e.g., along longitudinal axis920).

According to an exemplary embodiment, a cross-section of a strengthening member is a twelve-cornered cross-section throughout the length of the tapered section.

As depicted inFIG. 9A, tapered section910may be shaped so that a top surface916of strengthening member900is sloped while bottom surface918is substantially straight. Further, lateral surfaces914of strengthening member may be sloped to form tapered section910. Other configurations of surfaces914,916,918are envisioned by the exemplary embodiments described herein in order to provide tapered section910. For example, top surface916may be substantially straight while bottom surface918tapers, both top surface916and bottom surface918may taper, and other configurations may be utilized to form tapered section910. As shown inFIG. 9A, the portions of surfaces914,916,918rearward of tapered section910may be substantially straight to facilitate joining of strengthening member900to automotive component950

As depicted in the exemplary embodiment ofFIG. 9A, tapered section910may be located at a front portion912of strengthening member900, with respect to a front-rear direction of a motor vehicle in which strengthening member900is installed, such as when automotive component950is a front portion of a frame of the motor vehicle. Other configurations of strengthening member900relative to automotive component950are envisioned by the various exemplary embodiments described herein. For example, strengthening member900may be reversed with respect to the front-rear direction of a motor vehicle and located behind automotive component950so that tapered section910faces the rear of a motor vehicle, such as when automotive component950is a rear portion of the frame of the motor vehicle.

FIGS. 9C,9D, and9E are exemplary embodiments of cross-sectional shapes that may be used for the twelve-cornered cross section of the strengthening member900and the four-cornered cross section of the automotive component950. As depicted inFIG. 9C, strengthening member900may have a two-part construction comprising pieces902and904. The present teachings contemplate strengthening members of other constructions, such as one-piece constructions or even 3-or-more piece constructions, the number of pieces inFIGS. 9C through 9Ebeing exemplary only.FIG. 9Cresembles the structures illustrated in at leastFIGS. 1 and 7and may have internal angles and external angles according to the various exemplary embodiments described herein. For example, the internal angles of the strengthening member may range from about 100° to about 110°, and the external angles may range from about 105° to about 130°. In this example, the internal angles of corner indentations of the strengthening member900are generally depicted as being similar, but it is possible to have different internal angles at each of the corner indentations, as shown inFIGS. 5D and 6D.

FIG. 9Dis an exemplary embodiment of an overlapping portion where the strengthening member900is inserted into the automotive component950. As depicted inFIG. 9D, automotive component950may have a two-part construction comprising pieces952and954. As shown in the exemplary embodiment ofFIG. 9D, the twelve-cornered cross-sectional profile of the strengthening member900does not align with the corners of the four-cornered cross-sectional profile of the automotive component950. While planar edges of the distinct cross sections formed by pieces902,904and952,954are in proximity, the lack of corner alignment prevents welding of the connection between the cross sections at all corners, and thereby leads to instability during crash conditions, as illustrated inFIG. 9B.

FIG. 9Eis an exemplary embodiment of a four-cornered automotive component950, comprising pieces952and954, along the longitudinal axis920inFIG. 9Aand rearward of the overlapping portion depicted inFIG. 9D. While the corners are shown as having a rounded shape, this particular shape is not intended to limit the claimed subject matter in any way.

In accordance with the present disclosure, a stable connection between a twelve cornered strengthening member and an automotive component having less than twelve corners may be facilitated by a bridge or transitional part or portion of a part such that corners and/or edges of strengthening member and automotive component parts to be connected are aligned in a manner that permits sufficient connection by welding or other means, such as mechanical fasteners like brackets, bolts, and/or nuts. It should be understood that a desired connection can be formed by, for example, modifying one end of the strengthening member to correspond with one end of the automotive component, modifying one end of the automotive component to correspond with one end of the strengthening member, or an intermediate piece such as a bridge plate or bracket may be provided.

In accordance with one aspect of the present disclosure and as illustrated inFIG. 10A, an exemplary embodiment of a connection between a twelve-cornered strengthening member1000and a four-cornered automotive component1050has a transition1020at one end of the strengthening member1000from twelve corners to four corners. This configuration allows the strengthening member1000to be connected directly to the automotive component by an overlapping portion1030and welding1040at aligned corners or other means of attachment between complementary shapes.

Strengthening member1000may include a tapered section1010to facilitate a stable axial collapse, as described above with regard to the exemplary embodiment ofFIG. 9A. Strengthening member1000may include other shapes or structure in addition to, or alternative to, tapered section1010to facilitate a stable axial collapse of strengthening member1000. According to an exemplary embodiment, strengthening member1000may include protrusions1012to facilitate a stable axial collapse, as will be described below. A strengthening member1000may include various numbers of protrusions1012, such as, for example, one, two, three, four, five, six, seven, eight, or more protrusions1012. The protrusions1012may be located on a lateral surface1014of strengthening member and on a surface (not shown) that is an opposite side of strengthening member1000to lateral surface1014. Top1016and bottom1018surface of strengthening member1000may lack protrusions1012, as depicted in the exemplary embodiment ofFIG. 10A, or may include protrusions1012to facilitate a stable axial collapse of strengthening member1000. The protrusions1012may be located and spaced relative to one another to promote an axial crush beginning at a portion of the strengthening member1000located away from the connection between the twelve-cornered strengthening member1000and the four-cornered automotive component1050, such within tapered section1010.

Protrusions may be configured to have a predetermined shape that facilitates a stable axial collapse of strengthening member. For example, protrusions1012may be provided with an undulating or wave-like shape that is more likely to compress along an axial direction, such as in a manner similar to the compression of an accordion. Disposing protrusions1012and tapered section1010at locations away from the connection between the strengthening member1000and automotive component1050enables a single strengthening member1000to be used in various motor vehicles of differing weights. By way of example, if a strengthening member1000provides too much resistance to compression, a vehicle having a lower weight may not be able to axially crush the strengthening member1000in a stable manner, and so impact energy may be more likely to be transmitted into the automotive component1050, and thereby into the rest of the vehicle.

Protrusions1012may have various configurations to facilitate a stable axial collapse of a strengthening member. According to an exemplary embodiment, a protrusion1012may extend along only a portion of a surface of a strengthening member1010, such as along the front-rear and top-bottom directions depicted inFIG. 10A. For example, protrusions1012may extend along a portion of lateral surface1014along the top-bottom direction inFIG. 10Aso that flat portions1060of lateral surface1014are present between protrusions1012and corners1062forming top and bottom edges of lateral surface1014. According to an exemplary embodiment, protrusions1012may extend along a top-bottom direction of a surface over an extent of, for example, about 30% to about 60% of the length of the surface along the top-bottom direction. Further, a protrusion1012may extend from lateral surface1014to increase the width of strengthening member1000(in a direction transverse to the front-rear direction) by an amount of, for example, about 5% to about 10%, such as at a center of a protrusion1012.

Protrusions of the various exemplary embodiments described herein may have an increased strength in comparison to other portions of a strengthening member (e.g., portions of a strengthening member where a protrusion is not present). The increased strength of a protrusion may be due to the material strength and/or the structural geometry of the protrusion. For example, the material of a protrusion may be work hardened during the manufacturing operation that forms the protrusion in a strengthening member, resulting in the protrusion having a higher strength than other portions of the strengthening member. As a result, the protrusion a stable axial collapse of a strengthening member.

The protrusions1012and the tapered section1010may help ensure that an axial crush begins away from the connection between the strengthening member1000and the automotive component1050and the crush continues as the cross section, and corresponding impact energy absorption, of the strengthening member1000increases, such as towards a rear portion of the strengthening member1000. Because vehicles may vary in configurations and differ in weight, it may be desirable to provide a strengthening member1000that is configured to promote a stable axial crush along the strengthening member1000from an area having smaller resistance (e.g., a front portion of tapered section1010) to compression to an area having a larger resistance to compression (e.g., a rear portion of strengthening member1000, such as where strengthening member1000connects to automotive component1050).

By configuring a strengthening member according to the various exemplary embodiments described herein, a strengthening member is provided that absorbs energy during a crash and can be efficiently used in various motor vehicles. According to an exemplary embodiment, the strengthening members may be designed to accommodate varying amounts of crush force, such as less crush force for smaller vehicles and greater crush force for larger vehicles. For example, the strengthening members of the embodiments described with respect toFIGS. 9A-19have a mean crush force, exerted axially, for an impact with a rigid wall at 35 mph of about 100 kN to about 300 kN at a crush distance of about 400 mm. In another example, a strengthening member has a mean crush force, exerted axially, for an impact with a rigid wall at 35 mph of about 100 kN to about 200 kN at a crush distance of about 150 mm. In another example, a strengthening member has a mean crush force for an impact with a rigid wall at 35 mph, exerted axially, of about 200 kN to about 300 kN at a crush distance of about 400 mm.

The shape of the portion of the strengthening member that connects to an automotive component may be designed to facilitate connection between the strengthening member and the automotive component, such as when the strengthening member and automotive component differ in cross-sectional shapes. For example, the shape at the end of transition1020, which transitions the cross-section of strengthening member1000from twelve corners to four corners, may be substantially complementary to the shape of the automotive component1050. In this manner, the strengthening member1000may be inserted into the automotive component1050, or vice versa, at overlapping portion1030, and all of the corners and sides of strengthening member1000and automotive component1050may align for welding (e.g., at weld locations1040) in order to securely connect the strengthening member1000to the automotive component1050. This secure connection facilitates a stable axial collapse, as shown inFIG. 10B. A stable axial collapse (e.g.,FIG. 10B) provides additional energy absorption in comparison to an unstable axial collapse (e.g.,FIG. 9B). For example, the exemplary embodiment ofFIG. 19depicts energy absorption test results for a stable axial collapse and an unstable axial collapse, with the stable axial collapse exhibiting a 20% greater amount of energy absorption. Further, the connection between strengthening member900and automotive component950reduces the need for additional intermediate connection structures, thereby reducing the overall weight and cost of the system. In addition, the use of fewer parts may provide a stable connection and a resulting stable axial crush while optimizing manufacturing feasibility.

FIGS. 10C,10D, and10E are exemplary embodiments of cross-sectional shapes that may be used for the twelve-cornered cross section of the strengthening member1000, the overlapping portion1030, and the four-cornered cross section of the automotive component1050inFIG. 10A. InFIG. 10C, the portion of the strengthening member1000before the transition1020(e.g., forward of transition1020along the front-rear direction shown inFIG. 10A) has a cross section similar to the cross section which is illustrated inFIG. 9C. As depicted inFIG. 10C, strengthening member1000and automotive component1050may have two-part constructions respectively comprising pieces1002,1004and1052,1054, or may have other constructions, as described above with regard toFIG. 9C. Further,FIG. 10Cresembles the structures illustrated in at leastFIGS. 1 and 7and may have internal angles and external angles according to the various exemplary embodiments described herein.

FIG. 10Dis an exemplary embodiment of an overlapping portion where the strengthening member1000is inserted into the automotive component1050. As shown in the exemplary embodiment ofFIG. 10D, the shape of the strengthening member1000after the transition1020(e.g., rearward of transition1020along the front-rear direction inFIG. 10A) is substantially complementary to the four-cornered shape of the automotive component1050. In other words, the cross-sectional shape of strengthening member1000transitions from the shape shown inFIG. 10Cto the shape depicted inFIG. 10in order to be complementary to the cross-sectional shape of automotive component1050. The particular shapes and angles are not intended to limit the scope of the disclosure, and merely represent an exemplary embodiment for transitional cross-sections between a twelve-cornered cross section and a four-cornered cross section.

An amount of overlap1030between the strengthening member1000and the automotive component1050may depend on various factors, such as, for example, dimensions of the strengthening member1000and automotive component1050, the type of weld used, or if the strengthening member1000is inserted within the automotive component1050or vice versa. For the exemplary embodiment ofFIG. 10A, there may be an overlap1030of, for example, approximately 15 mm to approximately 25 mm for flat weld joint. A transition1020of the strengthening member1000from twelve corners to four corners may be located forward of (e.g., adjacent to) the overlapping portion1030along the front-rear direction depicted inFIG. 10A.

FIG. 10Eis an exemplary embodiment of a four-cornered automotive component1050rearward of the overlapping portion1030. While the corners are shown as having a rounded shape, this particular shape is not intended to limit the claimed subject matter in any way.

FIG. 11Ais a view of another exemplary embodiment of a connection between a twelve-cornered strengthening member1100and a four-cornered automotive component1150. As withFIG. 10A, the strengthening member1100may include a tapered section1110and/or protrusions1112, as described above. Protrusions1112may be configured as described above with regard toFIG. 10Aor may have different shapes. For example, protrusions1112may extend from a top to bottom of lateral side1114(e.g., from corner115to corner1116on lateral side1114), as depicted in the exemplary embodiment ofFIG. 11A.

InFIG. 11A, the connection between the strengthening member1100and the automotive component1150comprises a backing plate1130interposed between the strengthening member1100and the automotive component1150. Backing plate1130may therefore serve as a transition or bridge between strengthening member1100and automotive component1150. This configuration facilitates connection of the strengthening member1100to the automotive component1150via the backing plate1130. For example, backing plate1130may be respectively connected to strengthening member1100and automotive component1150, such as via welds1140at the respective ends of the strengthening member1100and automotive component1150, such as along the corners and sides of each connected element. In another example, the backing plate1130is bolted to the automotive component1150(e.g., bolted to a flange (not shown) of the automotive component1150) or attached by any other known means, such as via other fastening means. This secure connection between the strengthening member1100, backing plate1130, and automotive component1150facilitates a stable axial crush, as shown inFIG. 11B. The backing plate1130can be formed as one plate or two plates respectively joined to strengthening member1100and automotive component1150and connected to one another. In an exemplary embodiment where the backing plate1130is formed as one plate, both strengthening member1100and automotive component1150may be welded to the same backing plate1130. In an exemplary embodiment where the backing plate1130is formed as two plates, strengthening member1100and automotive component1150may be welded to separate plates, and the separate plates may be bolted together or joined via other means known in the art.

As depicted in the exemplary embodiment ofFIG. 11A, strengthening member1100may have a twelve-cornered cross-section from the front to the rear of the strengthening member1100. Therefore, backing plate1130may facilitate joining strengthening member1100to automotive component1150, such as when automotive component1150has a four-cornered cross-section. Other configurations may be utilized for strengthening member1100, such as a cross-section that transitions from a twelve-cornered cross-section to a four-cornered cross-section, as described above in regard toFIG. 10A.

FIG. 12Ais another exemplary embodiment of a connection between a twelve-cornered strengthening member1200and a four-cornered automotive component1250. Strengthening member1200may include a tapered section1210, as described above with regard to the exemplary embodiment ofFIG. 9A. The strengthening member1200may include protrusions1212as described above. For example, protrusions1212may extend along a portion of a surface, such as lateral surface1214, along a top-bottom direction inFIG. 12A. For instance, flat portions1260may be provided between protrusions1212and top and bottom edges of surface1214that are formed by corners1260of strengthening member1200. Further, although protrusions1212may be formed by curved surfaces, as depicted inFIGS. 9A and 10A, protrusions1212may be formed by various angled surfaces that form corners1264, as depicted inFIG. 12A.

According to an exemplary embodiment, at least one of the strengthening member and the automotive component may include one or more cutouts to facilitate welding the strengthening member and automotive component to one another. For example, inFIG. 12A, the connection comprises slot welds in the sides of the automotive component1250within the overlapping portion1230between strengthening member1200and automotive component1250. Cutouts can be provided in at least one of the strengthening member1200and the automotive component1250to facilitate the welding, such as by providing one or more slots1220around a circumference of the automotive component1250. As a result, when the strengthening member1200is inserted into the automotive component1250, additional surface area of the strengthening member1200may be welded at location(s)1240at the slot(s)1220and portions of the strengthening member1200and automotive component1250to be joined may be more accessible during welding. This configuration may also be reversed such that the slots are formed in the strengthening member1200and the automotive component1250is inserted into the strengthening member1200. This secure connection facilitates a stable axial crush, as shown inFIG. 12B.

According to an exemplary embodiment, slots1220and welds1240may be discrete and extend along portions of surfaces of strengthening member1200and automotive component1250. For example, slots1220and welds1240may extend along a portion of surfaces of strengthening member1200and automotive component1250between corners1260of strengthening member1200because corresponding surfaces of strengthening member1200and automotive component1250are in contact or close proximity to one another at those locations, in comparison to corners1260because of the difference in cross-sectional shapes of strengthening member1200and automotive component1250. As a result, slots1220and welds1240facilitate joining strengthening member1200and automotive component1250when they have differing cross-sections, such as when strengthening member1200has a twelve-cornered cross-section and automotive component1250has a four-cornered cross-section, as depicted in the exemplary embodiment ofFIG. 12A. Other configurations are envisioned for strengthening member1200and automotive component, such as a cross-section for strengthening member1200that transitions from a twelve-cornered cross-section to a four-cornered cross-section, as described above in regard toFIG. 10A.

FIG. 13Ais a view of another exemplary embodiment of a connection between a twelve-cornered strengthening member1300and a four-cornered automotive component1350. Strengthening member1300may include a tapered section1310and/or protrusions1312, as discussed in the exemplary embodiments herein. InFIG. 13A, the connection includes one or more fish-mouth weld joints, which may include removal of material at a connected end of the automotive component1350to form cutouts1320having a fish-mouth shape, insertion of the strengthening member1300into the fish-mouth shaped cutouts1320to create an overlapping portion1330, and welding at locations1340along the increased surface area of the strengthening member1300exposed by the fish-mouth shape.

According to an exemplary embodiment, fish-mouth shaped cutouts1320and welds1340may be discrete and extend along portions of strengthening member1300and automotive component1350. As a result, fish-mouth shaped cutouts1320and welds1340facilitate joining strengthening member1300and automotive component1350when they have differing cross-sections, as discussed above with regard to the exemplary embodiment ofFIG. 12A. Other configurations are envisioned for strengthening member1300and automotive component, such as a cross-section for strengthening member1300that transitions from a twelve-cornered cross-section to a four-cornered cross-section, as described above in regard toFIG. 10A.

WhileFIG. 13Ashows the strengthening member1300inserted into the automotive component1350, this configuration may also be reversed such that the material is removed from an end of the strengthening member and the automotive component is inserted into the strengthening member. This secure connection facilitates a stable axial crush, as shown inFIG. 13B. In the exemplary embodiment ofFIG. 13A, it may be desirable to provide an overlapping portion1330with an approximately 10 mm inner overlap (e.g., a distance1370between a rear edge1360of strengthening member1300, depicted via a dashed line inFIG. 13A, and a rear edge1322of fish-mouth shaped cutout1320) and 10 mm outer overlap (e.g., a distance1372between a front edge1324of fish-mouth shaped cutout1320and the rear edge1322of the fish-mouth shaped cutout1320) to secure the fish-mouth weld joint. Thus, a total overlap between strengthening member1300and automotive component1350may include both the inner overlap (e.g., distance1370) and the outer overlap (e.g., distance1372).

FIGS. 14A and 15Aare views of further exemplary embodiments of a connection between a twelve-cornered strengthening member1400or1500and a four-cornered automotive component1450or1550. Strengthening members1400,1500may respectively include tapered sections1410,1510and/or protrusions1412,1512, as discussed in the exemplary embodiments herein. Further, the strengthening members may include bridge connection members. In the embodiments ofFIGS. 14A and 15A, one or more bridging brackets1420or1520extend between the strengthening member1400or1500and the automotive component1450or1550at overlapping portions1430or1530, respectively. For example,FIG. 14Adepicts a strengthening member1400joined to an automotive component1450via a single bracket1420whileFIG. 15Adepicts a strengthening member1500joined to an automotive component1550via a plurality of brackets1520. The brackets1420or1520may be secured by welding, such as at locations1440or1540, or any other known means of attachment. This secure connection facilitates a stable axial crush, as shown inFIGS. 14B and 15B.

Brackets1420,1520facilitate joining strengthening members1400,1500and automotive components1450,1450when they have differing cross-sections, as discussed above with regard to the exemplary embodiment ofFIG. 12A. Other configurations are envisioned for the strengthening members and automotive components, such as a cross-section for strengthening members1400,1500that transitions from a twelve-cornered cross-section to a four-cornered cross-section, as described above in regard toFIG. 10A.

FIG. 16Ais a view of another exemplary embodiment of a connection between a twelve-cornered strengthening member1600and a four-cornered automotive component1650. Strengthening member1600may include a tapered section1610and/or protrusions1612, as discussed in the exemplary embodiments herein. InFIG. 16A, the connection between strengthening member1600and automotive component1650comprises a transition1620at one end of the automotive component1650in which the cross-section of automotive component1650transitions from a twelve-cornered cross-section to a four-cornered cross section along at least a portion of automotive component1650, such as along a longitudinal axis1614of automotive component1650. As a result, the cross-section of the end of the automotive component1650at the connection may correspond to the cross-section of strengthening member1600, which may have a twelve-cornered cross-sectional shape, as depicted in the exemplary embodiment ofFIG. 16A. This configuration allows the strengthening member1600to be connected directly to the automotive component1650at overlapping portion1630by welding, such as at locations1640, or other known means of attachment. The shape at the end of the transition will be substantially complementary to the shape of the strengthening member, so all of the corners and/or sides may be welded together to securely connect the strengthening member to the automotive component. This secure connection facilitates a stable axial crush, as shown inFIG. 16B.

FIGS. 16C-16Eillustrate a transition from a four-cornered cross section to a twelve-cornered cross section of automotive component1650. As depicted inFIGS. 16C-16E, strengthening member1600and automotive component1650may have two-part constructions respectively comprising pieces1602,1604and1652,1654, or may have other constructions, as described above with regard toFIG. 9C. Further,FIG. 16Cresembles the structures illustrated in at leastFIGS. 1 and 7and may have internal angles and external angles according to the various exemplary embodiments described herein. For example, the internal angles of the strengthening member may range from about 100° to about 110°, and the external angles may range from about 105° to about 130°.

FIG. 16Cillustrates the strengthening member1600, which is provided with a twelve-cornered cross section as previously discussed. In this exemplary embodiment, strengthening member1600does not include a transition to any other cross-sectional shape. Instead, the transitional structure is included in the automotive component1650.

FIG. 16Dis an exemplary embodiment of an overlapping portion in which the strengthening member1600is inserted into the automotive component1650. As shown in the exemplary embodiment ofFIG. 16D, the shape of the automotive component1650after the transition1620is substantially complementary to the twelve-cornered shape of the strengthening member1600. The particular shapes and angles are not intended to limit the scope of the disclosure, and merely represent an exemplary embodiment for transitional cross-sections between a twelve-cornered cross section and a four-cornered cross section.

An amount of overlap1630between the strengthening member1600and the automotive component1650may depend on other dimensions, type of weld used, or which element is overlapping. For the exemplary embodiment ofFIG. 16A, there may be an overlap1630of approximately 15 mm for flat weld joint. A transition1620of the automotive component1650from four corners to twelve corners may be located just after the overlapping portion1630.

FIG. 16Eis an exemplary embodiment of a four-cornered automotive component1650after the overlapping portion1630. While the corners are shown as having a rounded shape, this particular shape is not intended to limit the claimed subject matter in any way.

FIG. 17Ais a view of another exemplary embodiment of a connection between a twelve-cornered strengthening member1700and a four-cornered automotive component1750. Strengthening member1700may include a tapered section1710and/or protrusions1712, as discussed in the exemplary embodiments herein. InFIG. 17A, the connection comprises a transition1720along at least a portion of the length of the strengthening member1700(e.g., along longitudinal axis1760) from twelve corners to four corners, as well as a fish-mouth shaped cutouts1725, and a mating component1735. Mating component1735may be, for example, a bracket connected to outer or inner surfaces of the strengthening member1700and the automotive component1750. The connection also comprises a fish-mouth weld joint as described above and illustrated by the fish-mouth shaped cutouts1725of the strengthening member1700at the overlapping portion1730, along with welds, such as at locations1740, or other known connections formed by other means of attachment as previously discussed. This secure connection facilitates a stable axial crush, as shown inFIG. 17B.

FIGS. 17C-17Gillustrate cross sections of the exemplary embodiment ofFIG. 17A, in which the connection comprises the mating component1735and the fish-mouth weld joint including fish-mouth shaped cutouts1725and welds.FIG. 17Cillustrates the strengthening member1700, which is provided with a twelve-cornered cross section as previously discussed. In this exemplary embodiment, strengthening member1700includes a transition1720as discussed above. As depicted inFIGS. 17C-17G, strengthening member1700and automotive component1750may have two-part constructions respectively comprising pieces1702,1704and1752,1754, or may have other constructions, as described above with regard toFIG. 9C. Further,FIG. 17Cresembles the structures illustrated in at leastFIGS. 1 and 7and may have internal angles and external angles according to the various exemplary embodiments described herein. For example, the internal angles of the strengthening member may range from about 100° to about 110°, and the external angles may range from about 105° to about 130°.

FIG. 17Dshows the strengthening member1700after the transition1720to four corners, with the mating component1735connected to an outer surface of the strengthening member1700. It is also possible to connect the mating component1735to an inner surface of the strengthening member1700.

FIG. 17Eshows an exemplary embodiment of an overlapping portion1730where the automotive component1750is inserted into the strengthening member1700, with the mating component1735still connected. As shown in the cross sections of the exemplary embodiment illustrated inFIGS. 17D-17E, the shape of the strengthening member1700may include the transition1720from a twelve-cornered cross section to a four-cornered cross section, as discussed in detail with respect to other embodiments.

FIG. 17Fshows an exemplary embodiment of a four-cornered automotive component1750connected to the mating component1735.FIG. 17Gshows an exemplary embodiment of a four-cornered automotive component1750at a portion where the mating component1735is no longer connected. While the corners of the automotive component1750are shown as having a rounded shape, this particular shape is not intended to limit the claimed subject matter in any way.

As previously noted, it is also within the scope of the present invention to combine any of the embodiments disclosed above. For example, a connection may comprise a transition from twelve corners to four corners, or vice versa, a fish-mouth weld, and one or more mating components, as shown inFIGS. 9A-17B, or any other combination of the exemplary embodiments according to the present disclosure.

As discussed in the exemplary embodiments above, a bridge connecting member may be used to connect a strengthening member and an automotive component. The present disclosure contemplates bridge connecting members that include a transition from a twelve-cornered cross section to a four-cornered cross section to facilitate a connection between the strengthening member and the automotive component. Turning toFIG. 18, exemplary embodiments of a strengthening member1800, automotive component1850, and bridge connecting member1810to connect strengthening member1800and automotive component1850are shown. Strengthening member1800and automotive component1850may be configured according to the various exemplary embodiments described herein. For example, strengthening member1800may have a twelve-cornered cross-section (e.g., along an entire length of strengthening member1800) and automotive component1850may have a four-cornered cross-section, as depicted inFIG. 18. To facilitate a connection between member1800and component1850, bridge connecting member1810may transition from a twelve-cornered cross section, such as at a first end1812that connects to strengthening member1800, to a four-cornered cross section, such as at a second end1814that connects to automotive component1850. As a result, a strong connection between strengthening member1800and automotive component1850is facilitated, as a well as a stable axial collapse of strengthening member1800.

While the present teachings have been disclosed in terms of exemplary embodiments in order to facilitate a better understanding, it should be appreciated that the present teachings can be embodied in various ways without departing from the scope thereof. Therefore, the invention should be understood to include all possible embodiments which can be embodied without departing from the scope of the invention set out in the appended claims.

It will be apparent to those skilled in the art that various modifications and variations can be made to the devices and methods of the present disclosure without departing from the scope of its teachings. Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the teachings disclosed herein. It is intended that the specification and embodiment described herein be considered as exemplary only.