Programmed-deformation structural assembly for a motor vehicle structure
Patent Information
- Application Number
- EP2023783480
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-10-12
- Filing Date
- 2023-09-11
- Publication Date
- 2025-08-20
AI Technical Summary
Current motor vehicle structural assemblies fail to effectively absorb energy from lateral impacts, leading to excessive intrusion into the passenger compartment and potential damage to rechargeable batteries, while attempts to enhance stiffness through increased thickness or section lead to weight and cost increases, and require varying assembly lengths for different vehicles, resulting in increased costs.
A structural assembly with programmed deformation, comprising lateral parts that can be fixedly attached to side rails and designed to deform during impacts, absorbing energy and reducing deceleration, with customizable materials and thickness based on vehicle type, allowing for reduced vehicle height and common parts across different vehicle platforms.
The structural assembly effectively absorbs lateral impact energy, reduces the probability of collapse, enhances passenger and battery protection, and allows for reduced vehicle height and common parts across different vehicle variations, thereby improving passive protection and reducing costs.
Smart Images
Figure 1.1
Abstract
Description
DESCRIPTION TITLE: PROGRAMMED DEFORMATION STRUCTURAL ASSEMBLY FOR A MOTOR VEHICLE STRUCTURE Technical field of the invention
[0001] The present invention claims priority from French application 2210469 filed on October 12, 2022, the content of which (text, drawings, and claims) is incorporated herein by reference. The invention relates to motor vehicles comprising a structure including a floor on which a structural assembly known as a heel board is transversely mounted, and more specifically such a structural assembly. State of the art
[0002] Some motor vehicles include a structure with a floor attached to two side members (right and left) and an area above which at least one seat is intended to be installed (for example, a rear bench seat in the case of a car). A structural assembly, consisting of a component, sometimes referred to in the trade as a "heelboard," and a crossmember attached to this component, is generally mounted transversely across this area. This structural assembly, which forms part of the vehicle's structure, has two opposing ends attached to the side members (right and left) respectively.
[0003] The vehicles (automobiles) described above must be capable of protecting their passengers when they experience a side impact on one of their side members. A "side impact" is defined here as an impact along a direction with a non-zero transverse component. This requires that their structure have very high rigidity, which must be even greater the heavier the vehicle and the more the side impact results from a collision with an object. small longitudinal extension, such as a post. It should be noted that when the vehicle has a purely electric or hybrid (thermal and electric) powertrain, it includes a rechargeable battery pack which can be installed between its side members, under the floor area on which the structural assembly is installed transversely, and must also be protected in the event of a side impact.
[0004] Since the side members and the entire structural assembly contribute to the aforementioned rigidity, they must absorb as much of the energy as possible from a side impact. However, in most vehicles, the aim is to minimize drag and therefore height, which necessitates limiting the height of the side members. It should be noted that when a rechargeable battery pack is present, the aforementioned constraint also imposes a height limitation on the battery pack itself. Consequently, if the driving range is to remain unchanged, the width of the rechargeable battery pack must be increased, thus reducing the width of the side members, even though these same side members must also protect the rechargeable battery pack.
[0005] Current structural assemblies are derived from purely internal combustion engine vehicles and therefore do contribute to rigidity, but they absorb little to no energy from a side impact. Consequently, they tend to collapse in a side impact, leading to excessive intrusion into the vehicle's passenger compartment and potential damage to the rechargeable battery pack.
[0006] It has therefore been proposed to reinforce the entire structure by increasing its thickness and / or cross-section, but this leads to an increase in the vehicle's weight and cost. Furthermore, this reduces the structure's ability to deform, resulting in an excessive dynamic stress peak that could cause the floor to collapse and / or induce excessive vehicle deceleration (harmful to passengers and the rechargeable battery).
[0007] Furthermore, reducing the width of the side members necessitates the use of a longer structural assembly (in the transverse direction). Consequently, depending on the powertrain type and the transverse dimensions of the rechargeable battery pack, structural assemblies of varying lengths must be used for vehicles sharing the same structure (or platform). These structural assemblies of different lengths do not share common components, thus increasing vehicle costs.
[0008] The invention therefore aims in particular to improve the situation, in particular to increase the passive protection of passengers, as well as of a possible rechargeable battery assembly, in the event of a side impact. Presentation of the invention
[0009] In particular, it proposes for this purpose a structural assembly, on the one hand, intended to be part of a structure of a motor vehicle comprising a floor attached to two right and left longitudinal members and including an area above which at least one seat is intended to be installed, and, on the other hand, comprising a first piece defining a heeled board and associated with a cross member and being suitable for being installed transversely on this area by being attached to the longitudinal members.
[0010] This structural assembly is characterized by the fact that it comprises two lateral parts, each designed to be fixedly attached to one of the longerons, and each arranged to deform in a programmed manner in the event of a stress received during an impact by the associated longeron, in order to absorb part of this stress.
[0011] This programmed deformation of a lateral part during a side impact allows the structural assembly to effectively absorb part of the energy of this lateral impact and limit the deceleration of the vehicle, and therefore reduce the probability of collapse of the structural assembly.
[0012] The structural assembly according to the invention may include other features which may be taken separately or in combination, and in particular:
[0013] - each of the first pieces and cross members can include two opposing first lateral sub-parts, each contributing to the definition of one of the lateral parts;
[0014] - in the presence of the first option, it may include two second pieces attached and fixedly joined respectively to two opposite ends of the cross member, defining respectively the first lateral sub-parts of this cross member, and suitable for being fixedly joined respectively to the longitudinal members;
[0015] - in the presence of the last sub-option, each of the second parts can have a shape and / or thickness and / or material varying according to a type of vehicle powertrain, this type being chosen from purely electric, hybrid and purely thermal;
[0016] - also in the presence of the last sub-option, it may include two third pieces added and fixedly attached respectively to the second pieces, and suitable for being fixedly attached respectively to the longitudinal members;
[0017] - in the presence of the last sub-sub-option, each of the third parts can have a shape and / or thickness and / or material varying according to a type of vehicle powertrain, this type being chosen from purely electric, hybrid and purely thermal;
[0018] - it may include a reinforcing piece fixedly attached to a front face of the cross member, comprising two opposing lateral sub-parts, each contributing to the definition of one of the lateral parts, and arranged to reinforce a transverse stiffness of the structural assembly in a main part located between the lateral parts;
[0019] - in the presence of the last option, the reinforcement piece may have a shape and / or thickness and / or material varying according to a type of vehicle powertrain, this type being chosen from purely electric, hybrid and purely thermal.
[0020] The invention also proposes a motor vehicle comprising a structure having, on the one hand, a floor attached to two right and left longitudinal members and including an area above which at least one seat is intended to be installed, and, on the other hand, a structural assembly of the type presented above and installed transversely on this area by being attached to the longitudinal members.
[0021] For example, this motor vehicle may also include a rechargeable battery pack installed under the floor between the frame rails. Brief description of the figures
[0022] Other features and advantages of the invention will become apparent upon examination of the detailed description below, and the accompanying drawings (obtained using CAD / CAM (“Computer-Aided Design / Computer-Aided Manufacturing”)), in which:
[0023] [Fig. 1] schematically illustrates, in a perspective view, part of an example of a motor vehicle structure comprising an example of an embodiment of a structural assembly according to the invention,
[0024] [Fig. 2] schematically illustrates, in a perspective view from the front, a left-hand part of a first example of an embodiment of a structural assembly according to the invention,
[0025] [Fig. 3] schematically illustrates, in a perspective view from the front, a left-hand part of the first piece of the structural assembly of figure 2,
[0026] [Fig. 4] schematically illustrates, in a perspective view from the front side, a left part of a cross member of the structural assembly of figure 2, equipped with a second piece, itself equipped with a third piece,
[0027] [Fig. 5] schematically illustrates, in a perspective view from the front, a reinforcing piece of the structural assembly of figure 2,
[0028] [Fig. 6] schematically illustrates, in a perspective view from the front, a left-hand part of a second example of an embodiment of a structural assembly according to the invention,
[0029] [Fig. 7] schematically illustrates, in a perspective view from the front, a left-hand part of the first piece of the structural assembly of figure 6,
[0030] [Fig. 8] schematically illustrates, in a perspective view from the front, a left-hand part of a cross member of the structural assembly of Figure 6, fitted with a second piece, itself fitted with a third piece, and
[0031] [Fig. 9] schematically illustrates, in a perspective view from the front side, a reinforcing piece of the structural assembly of figure 6. Detailed description of the invention
[0032] The invention aims in particular to provide a structural assembly ES with programmed deformation intended to be part of a structure SV of a motor vehicle VA.
[0033] In what follows, the motor vehicle VA is considered, by way of non-limiting example, to be a car. However, the invention is not limited to this type of motor vehicle. It relates to any motor vehicle comprising a structure including a floor having an area on which a structural assembly can be transversely installed and fixedly attached to two lateral longitudinal members.
[0034] In figures 1 to 9, the X direction is the longitudinal direction of the vehicle (automobile) VA, which is substantially parallel to the lateral (or longitudinal) sides including the side doors, the Y direction is the transverse direction of the vehicle VA, which is perpendicular to the longitudinal direction X, and the Z direction is the vertical direction of the vehicle VA, which is perpendicular to the longitudinal direction X and the transverse direction Y.
[0035] Furthermore, in the preceding and following text, the term "front" is defined in relation to the front end of vehicle VA, and the term "rear" is defined in relation to the rear end of vehicle VA (opposite the front end). Therefore, the front portion of a component is (intended to be) oriented towards the front end of vehicle VA, while the rear portion of that component is (intended to be) oriented towards the rear end of vehicle VA.
[0036] Figure 1 schematically illustrates part of an example of a vehicle (automobile) structure SV, including an example of an embodiment of a structural assembly ES according to the invention. Although only partially shown in Figure 1, the structure SV includes, in particular, a floor PV having right and left longitudinal sides attached respectively to two lateral longitudinal members LV, right and left, and comprising a zone ZP on which a structural assembly ES is installed transversely (along the transverse direction Y), above which at least one seat (for example, a rear bench seat in the case of a car) is intended to be installed.
[0037] It should be noted that in the example illustrated (though not exhaustively) in Figure 1, the vehicle VA also includes a rechargeable battery pack EB installed under the floor area ZP (and therefore under the structural assembly ES) between the side members LV (right and left). However, this is not mandatory, as the invention also applies when the vehicle VA does not have a rechargeable battery pack EB.
[0038] As illustrated at least partially in Figure 1, a structural assembly ES, according to the invention, is suitable for forming part of the structure SV of a vehicle VA, and more specifically for being installed transversely on the area ZP of the floor PV by being attached to the side rails LV.
[0039] As partially illustrated in Figures 2 and 6, a structural assembly ES, according to the invention, comprises at least a first part P1 associated with a cross member TP, and two lateral parts PL suitable for being fixedly attached respectively to the two lateral longitudinal members LV.
[0040] The first part P1 defines a heeled board. For example, and as illustrated non-limitingly in figures 3 and 7, it may have a main part PP1 having a cross-section in a plane XZ in the general shape of S (with substantially horizontal lower and upper parts, and a substantially vertical intermediate part, defining the heeled board and connecting the lower and upper parts).
[0041] The first part P1 comprises a rear face FR1 which is oriented towards a front face FV2 of the cross member TP. The first part P1 is fixedly attached to the cross member TP, for example by welding, and together they define a hollow body having a substantially rectangular cross-section in a plane XZ.
[0042] Each of the two lateral parts PL is designed to be fixedly attached to one of the lateral longitudinal members LV, and is arranged so as to deform in a programmed manner in the event of a force absorbed during a lateral impact by the associated lateral longitudinal member LV (arrow F1 in Figure 1), in order to absorb part of this force.
[0043] It is recalled that here we mean "lateral impact" an impact following a direction having a non-zero transverse component (along the transverse direction Y).
[0044] Thanks to this programmed deformation of a lateral part PL during a lateral impact, the structural assembly ES can now to effectively absorb part of the energy of this side impact and limit the deceleration of the vehicle VA, which reduces the probability of collapse of the entire structural assembly ES and thus increases the passive protection of the passengers and the possible rechargeable battery.
[0045] For example, and as illustrated non-limitingly in figures 3 and 4 and 7 and 8, the first part P1 and the cross member TP can each comprise two first lateral sub-parts SPL1j (j = 1 or 2) opposed to each other and each participating in the definition of one of the lateral parts PL. Thus, in the event of a lateral impact, the first part P1 and the cross member TP together undergo programmed deformation (and therefore participate in absorbing part of the energy of the lateral impact).
[0046] The index j designates the first piece P1 when it is equal to one (1) and the cross member TP when it is equal to two (2).
[0047] It should be noted that a first lateral sub-section SPL1j can extend to the associated lateral longitudinal member LV in order to be fixedly attached (for example by welding) to the latter (LV). However, this is not mandatory. Thus, this is the case for each first lateral sub-section SPL1i of the first part P1 (see figures 2, 3, 6, and 7), but it is not the case for each first lateral sub-section SPL12 of the cross member TP (see figures 2, 4, 6, and 8; the reasons for this will be explained later).
[0048] It should be noted that in the example illustrated (but not limited to) in Figures 2, 3, 6, and 7, the first side sub-parts SPL11 are an integral part of the first part P1 (and therefore are not attached). In this case, the first part P1 is advantageously common to all vehicle variants using the same structure (or platform). However, in an alternative embodiment not shown, the first side sub-parts SPLI 1 could be attached by welding to opposite ends of a main part of the first part P1.
[0049] Also, for example, and as illustrated (but not limited to) in Figures 4 and 8, the structural assembly ES may also include two second parts which are attached and fixedly connected to two opposite ends ET of the cross member TP. These second parts define the first lateral sub-parts SPLI2 of the cross member TP, and are designed to be fixedly connected to the lateral longitudinal members LV.
[0050] It will be understood that in this optional embodiment the TP crossmember consists of a main part PP2, which can advantageously be common to all vehicle variants using the same structure (or platform), and two second parts SPLI2 attached respectively to the two ends ET of the main part PP2. This attachment is preferably achieved by welding.
[0051] The main part PP2 can, for example and as illustrated without limitation in figures 4 and 8, have a section in an XZ plane in the general shape of S (with lower and upper parts substantially horizontal, and an intermediate part substantially vertical and connecting the lower and upper parts).
[0052] It should be noted that each of the secondary SPH2 parts can have a shape, thickness, and / or material that varies depending on the type of powertrain (or GMP) of the vehicle VA. In this case, this type can be chosen from purely electric, hybrid, and purely internal combustion. It is understood that this allows, when the main PP2 part is common to all vehicle variants using the same structure (or platform), for variations of the secondary SPH2 parts that are adapted to the different vehicle variants. In other words, each TP crossmember is adapted to the specific needs of its vehicle by attaching two secondary SPL12 parts, defined for that vehicle, to its common main PP2 part.
[0053] Also, for example, and as illustrated, but not limited to, and at least partially, in Figures 2, 4, 6, and 8, the structural assembly ES may also include two third parts P3 which are attached and fixedly connected respectively to the second parts SPLI2. These third parts P3 are designed to be fixedly connected respectively to the lateral stringers LV.
[0054] It should be noted that each of the third parts P3 can have a shape, thickness, and / or material that varies depending on the type of powertrain (or GMP) of the vehicle VA. In this case, this type can be chosen from purely electric, hybrid, and purely internal combustion. It is understood that this allows, when the main part PP2 is common to all vehicle variants using the same structure (or platform), for variations of third parts P3 that are adapted respectively to the different vehicle variants (and more specifically to the different shapes of the LV side members equipping these different vehicle variants). In other words, each crossmember TP is adapted to the specific needs of its vehicle thanks to the attachment of each of its second parts SPLI2 to a third part P3 defined for that vehicle.
[0055] For example, and as illustrated, but not limited to, Figures 5 and 9, the structural assembly ES may also include a reinforcement piece PR that is fixedly attached to the front face FV2 of the cross member TP. This reinforcement piece PR comprises a main part PP3 extended on the right and left by two opposing lateral sub-parts SPL2, each contributing to the definition of one of the lateral parts PL. Thus, in the event of a lateral impact, the second lateral sub-part SPL2 undergoes the programmed deformation (and therefore contributes to absorbing part of the lateral impact energy). Furthermore, this reinforcement piece PR is arranged to increase the transverse stiffness of the structural assembly ES in its main part PP, which is located between its lateral parts PL. Consequently, the piece The PR reinforcement not only has an energy absorption function, but also a stiffening function which allows the structural assembly ES to stop deformation and transfer the remaining force after energy absorption to its opposite lateral part PL, and thus define a kind of survival space for the rechargeable battery.
[0056] It should be noted that the PR reinforcement part can have a shape, thickness, and / or material that varies depending on the type of powertrain (or GMP) of the vehicle VA. In this case, the type can be chosen from purely electric, hybrid, and purely internal combustion. This allows for variations of the PR reinforcement part that are adapted to different vehicle variants. In other words, each PR reinforcement part is tailored to the specific needs of its vehicle.
[0057] For example, and as illustrated non-limitingly in figures 5 and 9, the reinforcement piece PR may have a cross-section in an XZ plane in the general shape of an L or a U. Preferably, it forms a hollow body with the cross member TP (to which it is attached).
[0058] When the structural assembly ES includes second pieces SPL12 (right and left) and third pieces P3 (right and left), the ends (right and left) of the reinforcement piece PR are preferably fixedly joined (for example by welding) to these second SPL12 and third P3 pieces respectively.
[0059] It should also be noted that the structural assembly ES preferably has a cross-section in the XZ plane with a smaller surface area in its lateral parts PL than in its main part (comprising the main parts PP1, PP2, and PP3). This allows for lower stiffness in each lateral part PL dedicated to absorption. For example, the cross-section in the XZ plane of each lateral part PL can vary (increase) monotonically as one approaches the main parts PP1, PP2, and PP3. This variation may also be linear.
[0060] Also, for example, in the first implementation example illustrated in figures 2 to 5 and adapted to a purely electric powertrain vehicle:
[0061] - the first part P1 can be made of DP type steel (or "dual phase" - double phase), with a thickness between 1.2 mm and 1.4 mm,
[0062] - the main part PP2 of the TP cross member can be made of DP type steel, with a thickness between 1.2 mm and 1.4 mm,
[0063] - Each second SPH2 part can be made from DP type steel, with a thickness between 1.8 mm and 2 mm,
[0064] - each third P3 part can be made of DP type steel, with a thickness between 1.7 mm and 1.9 mm, and
[0065] - the PR reinforcement piece can be made of THLE type steel (“Very High Elastic Limit”), with a thickness between 1.9 mm and 2.1 mm.
[0066] Also, for example, in the second implementation example illustrated in figures 6 to 9 and adapted to a hybrid-type powertrain vehicle:
[0067] - the first part P1 can be made of DP type steel, with a thickness between 1.2 mm and 1.4 mm,
[0068] - the main part PP2 of the TP cross member can be made of DP type steel, with a thickness between 1.2 mm and 1.4 mm,
[0069] - Each second SPH2 part can be made from type E steel (for mechanical construction), with a thickness between 1.6 mm and 1.8 mm,
[0070] - each third P3 part can be made of type E steel, with a thickness between 1.6 mm and 1.8 mm, and
[0071] - the PR reinforcement piece can be made of DP type steel, with a thickness between 1.6 mm and 1.8 mm.
[0072] The invention offers several advantages, including:
[0073] - the ability to independently adjust the programmed deformation setting of the PL side parts for each type of GMP, and possibly also every type of vehicle silhouette,
[0074] - the possibility of limiting the stresses borne by the main "undeformable" PP section and therefore minimizing the cross-section of the hollow body of the structural element ES in order to free up maximum space for the rechargeable battery assembly EB. The programmed deformation allows for a reduced PV floor height and therefore an extension of the rechargeable battery assembly EB towards the rear of the vehicle VA,
[0075] - increased protection for passengers and the possible EB rechargeable battery pack.
Claims
CLAIMS
1. Structural assembly (ES) suitable for forming part of a structure (SV) of a motor vehicle (VA) comprising a floor (PV) secured to two side members (LV) right and left and comprising a zone (ZP) above which at least one seat is intended to be installed, said structural assembly (ES) comprising a first part (P1) defining a heel board and associated with a cross member (TP) and being suitable for being installed transversely on said zone (ZP) while being secured to said side members (LV), characterized in that it comprises two lateral parts (PL) each suitable for being fixedly secured to one of said side members (LV) and each arranged so as to deform in a programmed manner in the event of a force absorbed during an impact by said associated side member (LV), to absorb part of said force.
2. Structural assembly according to claim 1, characterized in that each of said first part (P1) and crosspiece (TP) comprises two first lateral sub-parts (SPL1j) opposite each other and each participating in the definition of one of said lateral parts (PL).
3. Structural assembly according to claim 2, characterized in that it comprises two second pieces added and fixedly secured and respectively to two opposite ends (ET) of said crosspiece (TP), respectively defining said first lateral sub-parts (SPLI2) of this crosspiece (TP), and suitable for being fixedly secured and respectively to said side members (LV).
4. Structural assembly according to claim 3, characterized in that each of said second parts (SPLI2) has a shape and / or a thickness and / or a material varying according to a type of a powertrain of said vehicle, said type being chosen from purely electric, hybrid and purely thermal.
5. Structural assembly according to claim 3 or 4, characterized in that it comprises two third parts (P3) added and fixedly secured respectively to said second parts (SPLI2), and suitable for being fixedly secured respectively to said side members (LV).
6. Structural assembly according to claim 5, characterized in that each of said third parts (P3) has a shape and / or a thickness and / or a material varying according to a type of a powertrain of said vehicle, said type being chosen from purely electric, hybrid and purely thermal.
7. Structural assembly according to one of claims 1 to 6, characterized in that it comprises a reinforcing piece (PR) fixedly secured to a front face (FV2) of said crosspiece (TP), comprising two second lateral sub-parts (SPL2) opposite and each participating in the definition of one of said lateral parts (PL), and arranged so as to reinforce a transverse stiffness of said structural assembly (ES) in a main part (PP) located between said lateral parts (PL).
8. Structural assembly according to claim 7, characterized in that said reinforcing part (PR) has a shape and / or a thickness and / or a material varying according to a type of a powertrain of said vehicle, said type being chosen from purely electric, hybrid and purely thermal.
9. Motor vehicle (VA) comprising a structure (SV) comprising a floor (PV) secured to two side members (LV) right and left and comprising a zone (ZP) above which at least one seat is intended to be installed, characterized in that said structure (SV) further comprises a structural assembly (ES) according to one of the preceding claims, installed transversely on said zone (ZP) while being secured to said side members (LV).
10. Vehicle according to claim 9, characterized in that it comprises a rechargeable battery assembly (EB) installed under said floor (PV) between said side members (LV).