Supporting structure for a vehicle

Abstract

The invention relates to a supporting structure, in particular a subframe, for the front-end region of a vehicle, having an assembly mounting in which a drive assembly (1) is supported on a cross beam (7) of the supporting structure via an assembly bearing (17), wherein the cross beam (7) is formed with a reduced cross-section with a mounting recess (21) which is open at the top in the vertical direction (z) of the vehicle and in which the assembly bearing (17) is arranged, and having a steering gear (35) that is connected to the supporting structure via steering gear fastening points (43, 45). According to the invention, in order to compensate for the reduction in cross-section, the cross beam (7) has at least one of the steering gear fastening points (43, 45) on each side of the mounting recess (21) in the vehicle transverse direction (y), with the result that the steering gear (35) bridges the mounting recess (21) so as to form a force-transmitting transverse load path.

Description

[0001] Support structure for a vehicle

[0002] DESCRIPTION:

[0003] The invention relates to a support structure, in particular an auxiliary frame, for the front section of a vehicle according to the preamble of claim 1.

[0004] The drive unit of an electric vehicle consists of an electric motor, a downstream transmission, and an oil module for cooling and lubricating the drive unit components. Such a drive unit can be supported by a three-point mounting on a subframe at the front of the vehicle. This three-point mounting can include a front mounting point positioned centrally on a front subframe crossmember, and two rear mounting points attached laterally to subframe longitudinal members.

[0005] For packaging reasons, a particularly low mounting position of the front three-point engine mount may be necessary in the vehicle's vertical direction. In a generally applicable prior art design, the subframe crossmember is therefore formed with a reduced cross-section and a mounting recess open upwards in the vehicle's vertical direction, in which the front engine mount is located. Due to the reduced cross-section, the load-bearing capacity of the front subframe crossmember is weakened.

[0006] From EP 2 415 654 A2, a subframe for motor vehicles is known which is attached to longitudinal members of the motor vehicle body and has two longitudinal members and at least one cross member, on which mounting points for wheel suspension elements and / or for engine mounts are also provided. According to the invention, the subframe is approximately U-shaped, with two lateral longitudinal members (as U-legs) and a cross member detachably connected thereto as U-base, wherein the cross member and / or the longitudinal members are stiffened with a steering gear housing.

[0007] From DE 10 2005 061 417 B4, a subframe for a motor vehicle is known, comprising two longitudinal members and a cross member as well as a planar stiffening element. The longitudinal members are each connected at a first end to the cross member via a node element. These node elements each form a connection for a wheel guide member.

[0008] From DE 10 2011 106 619 A1, a front axle system for a vehicle for absorbing a total load is known, comprising: a front axle frame element and a steering gear device which is connected to the front axle frame element, wherein the front axle frame element is designed to absorb a first part of the total load, and the steering gear device is designed to absorb a second, remaining part of the total load.

[0009] The object of the invention is to provide a supporting structure, in particular an auxiliary frame, for the front section of a vehicle, in which the load-bearing capacity of the supporting structure can be increased compared to the prior art without additional component effort.

[0010] The problem is solved by the features of claim 1. Preferred embodiments of the invention are disclosed in the dependent claims.

[0011] The invention relates to a support structure, in particular a subframe, for the front end of a vehicle. The support structure includes a powertrain mount, in which a drive unit of the vehicle is supported on a crossmember of the support structure via a powertrain mount. The crossmember has a reduced cross-section with a mounting recess that opens upwards in the vehicle's vertical direction, in which the powertrain mount is arranged. The support structure also includes a steering gear, which is connected to the support structure (i.e., to the subframe) via steering gear mounting points.According to the characterizing part of claim 1, the following measures are taken to compensate for the reduction in the load-bearing capacity of the cross member due to the mounting recess formed therein: To compensate for the reduction in cross-section in the transverse direction of the vehicle, the cross member has at least one steering gear mounting point on each side of the mounting recess. This stiffens the cross member in the area of ​​the mounting recess. The steering gear bridges the mounting recess, forming a force-transmitting transverse load path.

[0012] The steering gear can be designed for parallel steering and feature a rack and pinion housing. Furthermore, the steering gear includes a control unit that drives an electric actuator via a ball screw, which in turn drives the pinion or pushrod. For particularly effective stiffening, it is preferred that the steering gear, especially its pushrod / rack housing, is arranged vertically aligned with the mounting recess in the vehicle's vertical direction.

[0013] In a technical implementation, the engine mount can have a bearing core that defines an engine mount pivot axis aligned in the transverse direction of the vehicle, a radially outer outer sleeve that is pressed into a mounting eye of an engine mount of the drive unit, and a damping element that is positioned between the radially inner bearing core and the radially outer outer sleeve.

[0014] To further stiffen the crossmember in the area of ​​its mounting recess, the following design of the component mount is of great importance: The bearing core can be designed as a double journal made of solid material. The double journal can project beyond the component mount on both sides with a bearing core journal. The two bearing core journals can be bolted to the crossmember on both sides of the mounting recess in the transverse direction of the vehicle. In this case, the bearing core bridges the mounting recess, forming a second force-transmitting transverse load path that runs parallel to the transverse load path provided by the steering gear.

[0015] In the area of ​​the mounting recess, the crossbeam has only one bottom-side cross web, which has a significantly reduced web cross-section compared to the adjacent crossbeam sections.

[0016] In such a design, the bottom-side crossbar of the mounting recess provides a first transverse load path, the bearing core a second transverse load path, and the steering gear a transverse load path, which bridge the mounting recess in a component-rigid manner.

[0017] For further stiffening, the crossmember can have one vehicle-inside steering gear mounting point and one vehicle-outside steering gear mounting point on each side of its mounting recess. These can be spaced apart from each other by a lateral offset.

[0018] In a technical implementation, the crossmember can be part of a subframe crossmember that can be mounted to the vehicle's body structure in the front section. The subframe crossmember connects two longitudinal subframe longitudinal members. The subframe crossmember can be extended on both sides in the transverse direction of the vehicle by a crossmember node element that extends upwards beyond the subframe longitudinal member. The crossmember node element can have a body longitudinal member attachment point on its upper surface, allowing the subframe to be connected to the vehicle body.

[0019] With this type of crossmember geometry, the respective outer and / or inner steering gear mounting point can be positioned on the raised crossmember node. The outer steering gear mounting points are offset vertically from the inner steering gear mounting points, which further increases the overall component stiffness of the subframe crossmember.

[0020] In one specific embodiment, the steering gear is bolted to the steering gear mounting points of the subframe crossmember, with the bolting direction preferably oriented in the longitudinal direction of the vehicle. To further increase component stiffness, it is preferred that the bolting direction in the connection between the bearing core and the subframe crossmember is not oriented in the longitudinal direction of the vehicle, but rather in the vertical direction of the vehicle.

[0021] An embodiment of the invention is described below with reference to the accompanying figures. These show:

[0022] Figures 1 and 2 show different views illustrating the structure of the support structure according to the invention.

[0023] Figure 1 shows a top view of a subframe for the front section of an electrically powered vehicle. A drive unit 1, indicated by dashed lines, is supported on the subframe via a three-point mounting. The drive unit 1 consists of an electric motor, a downstream transmission, and an oil module for cooling the components of the drive unit 1.

[0024] In Figure 1, the subframe has two lateral subframe longitudinal members 3, which extend in the longitudinal direction x of the vehicle and are connected to each other via a front subframe crossmember 5 and a rear subframe crossmember 7. The rear subframe crossmember 7 is extended on both sides in the transverse direction y of the vehicle by a crossmember node element 9, which extends upwards in the vertical direction z of the vehicle beyond the subframe longitudinal member 3. Each of the crossmember node elements 9 has a body longitudinal member attachment point 11 on its upper surface. Similarly, crossmember node elements 13 are also formed on the front subframe crossmember 5, each having body longitudinal member attachment points 11 on its upper surface.

[0025] On the outside of the two subframe longitudinal members 3, bearing brackets for wheel guides (not shown) are formed, of which only two bearing brackets 15 are indicated in Figure 1 in the outer corner area between the vehicle rear subframe cross member 7 and the respective subframe longitudinal member 3.

[0026] The three-point mounting of the drive unit 1 consists of a front unit mount 17, which is mounted centrally on the rear subframe cross member 7, and two rear lateral unit mounts 19, which are each mounted on the inside of the subframe longitudinal members 3.

[0027] The front-mounted engine mount 17, as shown in Figure 2, has a radially inner bearing core 27 that defines an engine mount pivot axis aligned in the transverse direction y of the vehicle. The front-mounted engine mount 17 also has a radially outer sleeve 29, which is pressed into a mounting eye 31 of an engine support 33 of the drive unit 1. A damping element 30 (for example, an elastomer body), indicated in Figure 2, is located between the radially inner bearing core 27 and the outer sleeve 29.

[0028] For packaging reasons, the front engine mount 17 is positioned particularly low in the vehicle's vertical direction z, as shown in Figures 1 and 2. Therefore, the rear subframe crossmember 7 is designed with a reduced cross-section and a mounting recess 21 open upwards in the vehicle's vertical direction z. As shown in Figures 1 and 2, the front engine mount 17 is partially located in the mounting recess 21 of the rear subframe crossmember 7. The mounting recess 21 is bounded downwards by a bottom-side transverse web 23 of the subframe crossmember 7, which has a significantly reduced web cross-section compared to the adjacent crossmember sections 25 on both sides.

[0029] To compensate for the reduction in cross-section due to the mounting recess 21 in the vehicle's rear subframe cross member 7, the following measures are taken according to the invention:

[0030] The bearing core 27 of the front vehicle engine mount 17 is designed as a double pin made of solid material. This pin projects beyond the front vehicle engine mount 17 on both sides with a bearing core pin. The bearing core pins are connected in the transverse direction y of the vehicle on both sides of the mounting recess 21 by bolted connections 22 to the cross-sectional cross member sections 25 of the rear vehicle subframe cross member 7. In the bolted connections 22, the bolting direction is oriented in the vehicle's vertical direction z. The bearing core 27 of the front vehicle engine mount 17 bridges the mounting recess 21, forming a force-transmitting transverse load path, thereby stiffening the rear vehicle subframe cross member 7.

[0031] Furthermore, a steering gear 35, indicated only by dashed lines in Figure 1, is attached to the rear subframe crossmember 7 of the vehicle. The steering gear 35 consists of a cylindrical rack and pinion housing 37 elongated in the transverse direction y of the vehicle, an electric actuator 39 for driving the rack or pinion, and an electronic control unit 41.

[0032] The rear subframe crossmember 7 has, on both sides of the central mounting recess 21, an inner steering gear mounting point 43 and an outer steering gear mounting point 45. The two steering gear mounting points 43 and 45 are each formed on the crossmember node element 9 of the rear subframe crossmember 7. The outer steering gear mounting point 45 is arranged by a vertical offset Az above the inner mounting point 43 and spaced a lateral offset Ax from the inner steering gear mounting point 43.

[0033] As shown in Figure 2, mounting brackets 38 are formed on the cylindrical rack / pushrod housing 37. These brackets are screwed to the crossmember node elements 9 at the vehicle's inner and outer mounting points 43, 45, in a screw direction aligned with the vehicle's longitudinal direction x. As shown in Figure 1, the elongated rack / pushrod housing 37 of the steering gear 35 is arranged vertically aligned with the mounting recess 21 when viewed in the vehicle's vertical direction z. In this way, the rack / pushrod housing 37 of the steering gear 35 bridges the mounting recess 21, forming an additional force-transmitting transverse load path.

[0034] REFERENCE MARK LIST

[0035] I Drive unit

[0036] 3 Subframe longitudinal members

[0037] 5 front subframe crossmembers

[0038] 7 rear vehicle subframe crossmember

[0039] 9 Crossbeam node element

[0040] II Body longitudinal member attachment point

[0041] 13 further node element

[0042] 15 bearing bracket

[0043] 17 vehicle front engine mount

[0044] 19 rear vehicle engine mount

[0045] 21 Mounting recess

[0046] 22 Screw connection

[0047] 23 bottom-side crossbeam

[0048] 25 Crossbeam section

[0049] 27 Bearing core

[0050] 29 Outer sleeve

[0051] 30 damping element

[0052] 31 Mounting eye

[0053] 33 Aggregate support

[0054] 35 Steering gear

[0055] 37 Rack and pinion / pushrod housings

[0056] 38 Mounting bracket

[0057] 39 Actuator

[0058] 41 Control unit

[0059] 43 vehicle interior steering gear mounting point

[0060] 45 Vehicle outer steering gear mounting point

[0061] Ay cross offset

[0062] Az Height offset

Claims

PATENT CLAIMS:

1. Support structure, in particular subframe, for the front section of a vehicle, with an engine mounting, in which a drive unit (1) is supported on a cross member (7) of the support structure via an engine mount (17), wherein the cross member (7) is formed with a cross-sectional reduction in the direction of the vehicle height (z) with a mounting recess (21) open upwards in which the engine mount (17) is arranged, and with a steering gear (35) which is connected to the support structure via steering gear mounting points (43, 45), characterized in that the cross member (7) has at least one of the steering gear mounting points (43, 45) on both sides of the mounting recess (21) to compensate for the cross-sectional reduction in the transverse direction (y) of the vehicle, so that the steering gear (35) bridges the mounting recess (21) by forming a force-transmitting transverse load path.

2. Support structure according to claim 1, characterized in that the steering gear (35) has a rack / pushrod housing (37) that is elongated in the transverse direction (y) of the vehicle, and in particular that the steering gear (35), especially its rack / pushrod housing (37), is arranged in the vertical direction (z) of the vehicle in line with the mounting recess (21).

3. Support structure according to claim 1 or 2, characterized in that the aggregate bearing (17) has a bearing core (27) which defines an aggregate bearing pivot axis aligned in the transverse direction (y) of the vehicle, a radially outer outer sleeve (29) which is pressed into a mounting eye (31) of an aggregate support (33) of the drive unit (1), and an intermediate damping element (30).

4. Supporting structure according to claim 3, characterized in that the bearing core (27) is designed as a double pin made of solid material, which projects over the aggregate bearing (17) on both sides with a bearing core pin.

5. Support structure according to claim 4, characterized in that the bearing core pins are screwed (22) to the cross member (7) on both sides of the mounting recess (21) in the transverse direction (y) of the vehicle, so that the bearing core (27) bridges the mounting recess (21) by forming a second force-transmitting transverse load path.

6. Support structure according to one of the preceding claims, characterized in that the cross member (7) has on both sides of the mounting recess (21) a vehicle-inside steering gear mounting point (43) and a vehicle-outside steering gear mounting point (45) which are spaced apart from each other by a transverse offset (Ay).

7. Support structure according to one of the preceding claims, characterized in that the cross member (7) is a subframe cross member which connects two subframe longitudinal members (3) extending in the longitudinal direction (x) of the vehicle, and / or that in particular the subframe cross member (7) is extended on both sides in the transverse direction (y) of the vehicle by a cross member node element (9) which is raised in the vertical direction (z) of the vehicle beyond the subframe longitudinal member (3), and that in particular the cross member node element (9) has a body longitudinal member attachment point (11) on its upper side.

8. Support structure according to claim 6 or 7, characterized in that the vehicle interior steering gear mounting point (43) and the vehicle exterior steering gear mounting point (45) are separated by a height offset (Az) are offset from each other, and in particular the vehicle outer steering gear mounting point (45) and / or the vehicle inner steering gear mounting point (43) is positioned on the raised cross member node element (9) of the subframe cross member (7).

9. Support structure according to one of the preceding claims, characterized in that the steering gear (35) is connected to the fastening points (43, 45) of the subframe cross member (7) in a screw connection in which the screw direction is aligned in the longitudinal direction (x) of the vehicle, and in particular in the screw connection (22) between the bearing core (27) and the subframe cross member (7) the screw direction is aligned in the vertical direction (z) of the vehicle.

Images