Subframe for the front axle of a vehicle and vehicle with such a subframe

Abstract

The invention relates to a subframe (1) for the front axle of a vehicle, which subframe has a crash structure (13) projecting laterally outwards in the vehicle transverse direction (y) at each of its two front subframe corners in the vehicle longitudinal direction (x), which crash structure dissects the load into the subframe (1) in the event of a frontal crash with slight lateral overlap. The subframe (1) has a vertical bracket (17) projecting upwards from a lower subframe plane (H) at each of its two front subframe corners, which vertical bracket can be connected to a body longitudinal member (18) of the vehicle via body connection points (23) in an upper joining plane (F). According to the invention, the vertical bracket (17) is extended outwards from the vehicle in the vehicle transverse direction (y) in the upper joining plane (F), forming the crash structure (13).

Description

[0001] The invention relates to a subframe for the front axle of a two-track vehicle according to the preamble of claim 1 and to a vehicle with such a subframe according to claim 10.

[0002] In a small-overlap crash test, a collision occurs with a collision obstacle with a small lateral overlap. In this case, the impact force in the vehicle's longitudinal direction can be transmitted at least partially laterally outside a front body longitudinal member into a crash structure located on the side of the subframe. The crash structure can be attached as an add-on component, such as a welded assembly, to each of the vehicle's front subframe corners and project outward laterally in the vehicle's transverse direction. The crash force transmitted in the small-overlap crash test causes the vehicle to move laterally out of the obstacle area.

[0003] The subframe also has a wheel suspension, with at least one control arm connected to a control arm mounting point on the subframe. Due to the limited connection options available on the subframe, the provision of both the control arm bracket and the crash structure can lead to a space conflict in the current state of the art.

[0004] DE 10 2018 205 085 A1 discloses a body structure for a vehicle in whose front end a subframe is arranged, which supports a drive component and is connected to lateral body longitudinal members at body connection points. The subframe is constructed from two subframe longitudinal members and at least one front cross member, which is connected to the subframe longitudinal members at front corner nodes. The front subframe cross member has a cross member center section running in the vehicle's transverse direction, which is extended upwards on both sides of the vehicle outwardly, made of the same material and in one piece with a vertical cross member support arm. The cross member support arm is connected at the front to a front end of the respective body longitudinal member, forming a front body connection point.

[0005] DE 10 2018 104 583 A1 discloses a front chassis structure with a set plate to which an impact absorber is connected. The front chassis structure comprises: a pillar element with an inner support plate portion for supporting the impact absorber, an outer support plate portion for supporting the impact absorber in cooperation with the inner support plate portion, and a pillar portion with a horizontal cross-section that curves rearward from the inner and outer support plate portions; a connecting element for connecting the pillar portion to the vehicle body; a front longitudinal member that extends rearward from the pillar element; and a projecting element that projects outward from the pillar element. FR 3 124 117 A1 discloses a vehicle with a subframe with height stop.

[0006] The object of the invention is to provide a subframe for the front axle of a two-track vehicle in which the crash structure can be connected to the subframe in a space-saving manner compared to the prior art, in particular while avoiding a space conflict with a wheel guide bearing point on the subframe side.

[0007] The object is solved by the features of claim 1 or 10. Preferred developments of the invention are disclosed in the subclaims.

[0008] The invention relates to a subframe for the front axle of a two-track vehicle. At each of its two front subframe corners in the longitudinal direction of the vehicle, the subframe has a crash structure that projects laterally outward in the transverse direction of the vehicle. In a frontal crash with slight lateral overlap, the crash structure dissipates loads into the subframe. The crash force is introduced into the subframe in a load path via the crash structure. Furthermore, at each of its two front subframe corners, the subframe has a vertical bracket that projects upwards from a lower subframe level. This bracket can be connected to a longitudinal body member of the vehicle via connection points in an upper joining level. The characterizing part of claim 1 claims measures to provide a space-efficient arrangement of the crash structure and stable crash load dissipation via the crash structure into the body structure of the vehicle.Accordingly, the vertical console is extended outward in the upper joining plane, forming the crash structure in the transverse direction of the vehicle. In the event of a crash with a small lateral overlap, the crash force is therefore transmitted in a crash load path from the crash structure via the force-transmitting body connection points directly into the body longitudinal member.

[0009] The subframe is equipped with a wheel suspension with at least one check rail. This check rail is connected to a check rail bearing point on the subframe side. A core of the invention is to avoid a space conflict between the crash structure and the check rail bearing point on the subframe side, and to essentially decouple the check rail bearing point from the crash load path. Against this background, the check rail bearing point on the subframe side is positioned in the lower subframe level, i.e., essentially outside the crash load path, and is connected in particular to the front subframe cross member.

[0010] The crash structure therefore projects laterally outwards beyond the body longitudinal member or the connection points to the body longitudinal member in the vehicle's transverse direction with a transverse offset.

[0011] In one technical implementation, the subframe has two subframe longitudinal members extending in the vehicle's longitudinal direction and at least one front subframe cross member. This connects the two subframe longitudinal members to each other. According to the invention, the front subframe cross member can be divided into a central cross bridge and the vertical brackets projecting laterally from it for connection to the respective body longitudinal member. The central cross bridge of the subframe cross member, together with the two subframe longitudinal members, spans the lower subframe level.

[0012] To ensure proper force absorption in the event of a crash with minimal lateral overlap, it is preferable for the center crossbar to be made of the same material and / or integrally connected to the respective vertical brackets on both sides of the vehicle's transverse direction. Such a combination of the crossbar and the two vertical brackets forms an extremely stable subframe cross member, which is advantageous for crash load absorption.

[0013] In a specific embodiment, the center crossbar is extended in the vehicle's transverse direction into a side flank of the vertical console that is raised diagonally outward. A height stop of the vertical console is located at the upper end of the side flank. The connection points for the body longitudinal members are formed in the upper side of the height stop. Furthermore, the height stop is extended laterally outward in the vehicle's transverse direction, forming the crash structure.

[0014] An inner corner area is formed between the height stop and the side flank of the vertical console. The control arm bearing point can be positioned in this inner corner area, saving space and decoupled from a crash load path. The check arm bearing point is preferably located in the lower subframe level at the transition between the crossbar and the side flank of the vertical console.

[0015] With regard to a further decoupling of the wheel guide bearing point from a crash load path, it is preferred if the body connection points formed on the vertical console are arranged outside the wheel guide bearing point by a transverse offset in the vehicle transverse direction.

[0016] Viewed in the longitudinal direction of the vehicle, the front subframe cross member according to the invention has a curved profile, with the center crossbar arranged in the lower subframe plane and merging in the transverse direction of the vehicle into a side flank of the vertical console that is raised diagonally outwards. The center crossbar arranged in the lower subframe plane defines a free space at the bottom of the vehicle in which components of a front-side radiator module can be arranged in a space-efficient manner.

[0017] In a specific design variant, the subframe can be an axle support for a tension strut axle. This has a separate two-link assembly for each vehicle wheel, in which the check rail acts as a front tension strut and a rear check rail acts as a compression strut or support link.

[0018] An embodiment of the invention is described below with reference to the accompanying figures. They show: Fig. 1 and Fig. 2 different views illustrating the structure and function of the subframe according to the invention.

[0019] In the Fig. 1 shows a subframe 1 of a two-track vehicle in a bottom view, which has subframe longitudinal members 3 extending in the vehicle's longitudinal direction x. These are connected to a subframe cross member 5, 7 at the front and rear of the vehicle, respectively.

[0020] The subframe 1 is an axle support for a tension strut axle. The tension strut axle has a Fig. 1, in which a front wheel control arm 9 acts as a tension strut and a rear wheel control arm 11 acts as a compression strut or support arm. In addition, the subframe 1 has a crash structure 13 at each of its two front subframe corners, which protrudes laterally outward from the subframe 1 in the vehicle transverse direction y.

[0021] When assembled, the vehicle features a crash management system, which is connected as a front-end structure to the subframe 1 and to the two body longitudinal members 18. Furthermore, the crash management system is covered by a vehicle outer skin. The crash management system, the vehicle outer skin, and various other add-on components have been omitted from the figures for clarity.

[0022] A core of the invention lies in the component geometry of the front subframe cross member 5. This is constructed from a central cross bridge 15, which, made of the same material and in one piece, merges on both sides in the vehicle transverse direction y outwards into a vertical console 17, which can be connected to a body longitudinal member 18 of the vehicle. The two subframe longitudinal members 13 are connected to the central cross bridge 15. In addition, the central cross bridge 15, together with the two subframe longitudinal members 3, spans a Fig. 2 indicated lower subframe level H. In the Fig. 2, only one half of the subframe 1 is shown; the other subframe half, not shown, is mirror-symmetrical with respect to the vehicle center longitudinal plane M.

[0023] The middle cross bridge 15 goes in the Fig. 2 on each side of the vehicle into a side flank 19 of the vertical console 17, which is raised diagonally outwards. Further on, towards the outside of the vehicle, a height stop 21 is connected. Body connection points 23 are formed on its upper side, specifically for connection to the body longitudinal member 18 in an upper joining plane F ( Fig. 2), which is offset upwards by a height offset Δz with respect to the lower subframe plane H.

[0024] As from the Fig. 1 or Fig. 2, the height stop 21 is extended laterally outwards in the vehicle transverse direction y, forming the crash structure 13; this means that the crash structure 13 formed on the height stop 21 extends the respective body longitudinal member 18 outwards in the vehicle transverse direction y with the transverse offset Δy1 ( Fig. 1) surpasses.

[0025] In the Fig. 2, an inner corner region 26 is spanned between the height stop 21 and the side flank 19 of the vertical console 17. A check rail bearing point 27 is positioned in the inner corner region 26, specifically in the lower subframe plane H at the transition between the center cross bridge 15 and the side flank 19 of the vertical console 17. The check rail bearing point 27 is also offset inwardly of the vehicle by a transverse offset Δy2 in the vehicle transverse direction y with respect to the body longitudinal member 18.

[0026] According to the Fig. 2, the central cross bridge 15 of the front subframe cross member 5 delimits a free space towards the bottom of the vehicle in which components of a front-side radiator module 29 are arranged in a space-efficient manner.

[0027] In one of the Fig.In the small-overlap crash test indicated in Figure 1, in which a collision with a collision obstacle 31 with a small lateral overlap occurs, the crash force Fc is introduced into the crash-facing crash structure 13 and, via a crash load path L, is transmitted directly into the body longitudinal member 18 at the force-transmitting body connection points 23. In contrast, the subframe-side wheel guide bearing point 27, positioned in the lower subframe plane H, remains essentially decoupled from the crash load path L. LIST OF REFERENCE SYMBOLS: 1 subframe 3 subframe longitudinal members 5 front subframe cross member 7 rear subframe cross member 9 front wheel control arm 11 rear wheel guide 13 Crash structure 15 middle cross bridge 17 Vertical console 18 body longitudinal members 19 side flank 21 Height stop 23 connection points 26 inner corner area 27 Check rail bearing point 29 Cooler module 31 Collision obstacle FC Crashkraft L Crash load path FR direction of travel H lower subframe level F upper joining level M Vehicle center longitudinal plane Δy1 transverse offset Δy2 transverse offset Δz height offset QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2018 205 085 A1

[0004] DE 10 2018 104 583 A1

[0005] FR 3 124 117 A1

[0005]

Claims

[1] Subframe (1) for the front axle of a vehicle, which has at each of its two front subframe corners in the longitudinal direction (x) of the vehicle a crash structure (13) projecting laterally outwards in the transverse direction (y) of the vehicle, which in a frontal crash with low lateral overlap causes a load transfer into the subframe (1), wherein the subframe (1) has at each of its two front subframe corners a vertical console (17) projecting upwards from a lower subframe plane (H) which can be connected in an upper joining plane (F) to a body longitudinal member (18) of the vehicle via body attachment points (23), characterized by, that the vertical console (17) is extended outwards in the vehicle transverse direction (y) in the upper joining plane (F) forming the crash structure (13), and that in particular in the event of a crash the crash force (Fc) can be introduced in a crash load path (L) from the crash structure (13) via the force-transmitting body attachment points (23) directly into the body longitudinal member (18). [2] Auxiliary frame (1) according to claim 1, characterized by , that the subframe (1) has a wheel suspension with at least one wheel control arm (9) which is articulated to a subframe-side wheel control arm bearing point (25), and that in particular the subframe-side wheel control arm bearing point (25) is positioned in the lower subframe plane (H), and that in particular in the event of a crash the wheel control arm bearing point (25) is substantially decoupled from the crash load path (L). [3] Auxiliary frame (1) according to claim 1 or 2, characterized by, that the crash structure (13) projects laterally outwards beyond the body longitudinal member (18) or the body attachment points (23) in the vehicle transverse direction (y) with a transverse offset (Δy1). [4] Auxiliary frame (1) according to any of the preceding claims, characterized by , that the subframe (1) has two subframe longitudinal members (3) extending in the longitudinal direction (x) of the vehicle and at least one front subframe cross member (5) connecting the two subframe longitudinal members (3) together, and that in particular the front subframe cross member (5) is subdivided into a central cross member (15) and into the lateral vertical brackets (17). [5] Auxiliary frame (1) according to claim 4, characterized by, that the central cross member (15) of the subframe cross member (5) and the two subframe longitudinal members (3) span the lower subframe plane (H), and / or that in particular the central cross member (15) transitions in a single material and / or in one piece on both sides in the transverse direction (y) of the vehicle to the outside into the respective vertical console (17). [6] Auxiliary frame (1) according to claim 5, characterized by, that the front subframe crossmember (5) has a curved profile in which the lower central crossmember (15) of the vehicle transitions in the transverse direction (y) into a side flank (19) of the vertical console (17) that is obliquely raised outwards, and that in particular a height stop (21) of the vertical console (17) is formed at the upper end of the side flank (19), and that in particular the height stop (21) has the attachment points (23) for the body longitudinal members (18) on its upper side, and / or that in particular the height stop (21) is extended laterally outwards in the transverse direction (y) of the vehicle, forming the crash structure (13). [7] Auxiliary frame (1) according to claim 6, characterized by, that the wheel guide bearing point (27) is positioned in an inside corner area (26) between the height stop (21) and the side flank (19) of the vertical console (17), and that in particular the wheel guide bearing point (27) is positioned in the lower subframe plane (H) at the transition between the cross bridge (15) and the side flank (19) of the vertical console (17). [8] Auxiliary frame (1) according to any of the preceding claims, characterized by , that the body attachment points (23) formed on the vertical console (17) are arranged by a lateral offset (Δy2) in the vehicle transverse direction (y) outside the wheel control bearing point (25), and / or that in particular the central cross member (15) of the front subframe cross member (5) limits a clearance space to the bottom of the vehicle, and that components of a vehicle front-side radiator module (29) are arranged in the clearance space. [9] Auxiliary frame (1) according to any of the preceding claims, characterized by, that the subframe (1) is an axle carrier for a tension strut axle which has a dissolved double-link assembly for each vehicle wheel, in which the wheel link (9) acts as a front tension strut and a rear wheel link (11) acts as a compression strut. [10] Vehicle comprising in its front section two longitudinal body members (18) extending in the longitudinal direction (x) of the vehicle and an auxiliary frame according to one of the preceding claims.

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