Motor vehicle auxiliary frame

Abstract

Subframe (10) of a motor vehicle, comprising two front functional nodes (18-1, 18-2) viewed in the longitudinal direction (FL) of the vehicle, and two rear functional nodes (20-1, 20-2), wherein at least two functional nodes (18-1, 18-2, 20-1, 20-2) are connected by means of at least one cross member (24), and the front functional nodes (18-1, 18-2) are connected to the rear functional nodes (20-1, 20-2) by means of two longitudinal members (22-1, 22-2), wherein the functional nodes (18-1, 18-2, 20-1, 20-2) are formed with bearing receptacles into which rubber-metal bearings (14) are pressed for connection to the body, and wherein stop discs (12) are arranged on the rubber-metal bearings (14) by means of screw connections, wherein at least one stop disc (12) is for at least one the rubber-metal bearing (14) is designed as an aggregate support (16), and wherein the aggregate support (16) is designed with a bearing eye (36) in which a bearing is pressed in,which is connected to a unit via its bearing core (38).

Description

[0001] The invention relates to a subframe for a motor vehicle.

[0002] Subframes for motor vehicles are known in a variety of forms from the prior art. For example, DE 10 2005 045 295 B4 discloses an open subframe for a motor vehicle comprising two front and two rear functional nodes. The front functional nodes are connected by a cross member element, and two longitudinal member elements connect the front and rear functional nodes.

[0003] Subframes are used to pre-assemble parts of a motor vehicle and then insert and connect the pre-assembled unit to the vehicle body. Not only are vehicle components such as wheel suspension or hydraulic units for the vehicle's steering system attached to the subframe, but the engine is also supported on the subframe. Furthermore, the body is directly connected to the subframe. The subframe thus contributes to stability and crash safety.

[0004] The functional nodes of a subframe serve, among other things, to connect it to the body. The connection is made by means of rubber-metal bearings through which a fastening screw passes. The rubber-metal bearings are pressed into corresponding recesses in the subframe and have an inner sleeve and an outer sleeve, with an elastic intermediate layer arranged between the inner and outer sleeves. A fixed stop disc is provided on the circumference of the elastic part of the bearing. It is arranged between the subframe and the head of the fastening screw and extends radially outward from the inner sleeve (see DE 199 01 299 C1). The stop disc limits the axial spring travel of the rubber-metal bearing and enables soft support of the subframe in its main vertical load direction.

[0005] EP 1 188 643 A1 describes a triangular stop plate designed as a connecting structure between the subframe and the body. DE 10 2006 036 852 A1 discloses a truncated cone-shaped stop plate designed as an adapter, which is designed as the end piece of a stiffening element and serves as a connection between the subframe and the stiffening element.

[0006] The subsequently published DE 10 2017 214 955 A1 discloses a subframe of a motor vehicle, comprising two front functional nodes viewed in the vehicle longitudinal direction and two rear functional nodes, wherein at least two functional nodes are connected by means of at least one cross member, and the front functional nodes are connected to the rear functional nodes by means of two longitudinal members, wherein the functional nodes are designed with bearing receptacles into which rubber-metal bearings are pressed for connection to the body, and wherein stop disks are arranged on the rubber-metal bearings by means of screw connections, wherein at least one stop disk for at least one of the rubber-metal bearings is designed as an assembly support.

[0007] A corresponding subframe is also disclosed in the subsequently published DE 10 2016 214 344 A1.

[0008] The invention is based on the object of developing a subframe according to the closest DE 10 2017 214 955 A1 in such a way that the geometry of the subframe is simplified.

[0009] This problem is solved by the features of patent claim 1.

[0010] The subclaims form advantageous developments of the invention.

[0011] In a known manner, the subframe for a motor vehicle comprises four functional nodes, whereby - viewed in the longitudinal direction of the vehicle - the two front functional nodes are connected by means of a cross member and two longitudinal members connect the front to the rear functional nodes. The functional nodes form mounting points for the subframe bearings. The outer sleeve of such a rubber-metal bearing is connected to the subframe, and the core is connected to the body. Between the core and the outer sleeve is a coupling layer in the form of an elastomer. The core is attached to the body by means of a screw, with a stop washer clamped between the core and the screw.

[0012] According to the invention, at least one stop plate of a rubber-metal mount is designed such that it simultaneously serves as an assembly support. Compared to the conventional connection of the assembly support, this functionally integrated connection reduces the number of connection points in the body. The connection of the stop plate designed as an assembly support according to the invention is achieved by means of an existing connection point at the functional node, which has a high degree of rigidity outside the support geometry of the subframe. This advantageously makes it possible to use a lighter and therefore more cost-effective subframe that still meets the functional requirements.

[0013] The stop plate preferably has a through-hole configured to connect to the core of the bearing by means of a screw connection. The screw connection extends through the stop plate configured as the engine support, the rubber-metal bearing of the subframe, and the body. The stop plate thus serves to limit the travel of the subframe, which vibrates due to the elastic coupling. The integrated connection of the engine support, which also serves as a stop plate, advantageously reduces the complexity of the subframe.

[0014] According to a preferred embodiment of the stop disc according to the invention, it can also have additional connection points. It is conceivable that connection points to the body and / or the traction battery are formed. These connection points can further develop the stop disc in such a way that, in the event of an accident-related load introduction, an additional load path opens up particularly early. A head-on collision with an obstacle while the vehicle is moving forward can, for example, cause the stop disc according to the invention to be displaced rearward in the vehicle's longitudinal direction, whereby the check arm is impacted and deformed in the area of ​​the connection. The check arm is displaced backward, whereby the center of rotation of the front wheel is displaced rearward in the vehicle's longitudinal direction before the front wheel is displaced and turned in due to the accident.This can prevent serious intrusions in the bulkhead area behind the front wheel (see DE 10 2012 024 145 A1). Thus, a force path is formed via the stop plate, which serves as a support for the engine, which assists in distributing the energy in the event of a crash.

[0015] It is conceivable that the aggregate support according to the invention is arranged at one or more functional nodes. It is also possible for the aggregate support to be mounted using the connection according to the invention in a hybrid construction with a conventional connection.

[0016] Further advantages and possible applications of the present invention will become apparent from the following description in conjunction with the embodiments shown in the drawing.

[0017] In the drawing: Fig. 1 a side view of a subframe of a motor vehicle with mounted stop disc; Fig. 2 a view of the subframe according to Fig. 1 from below; and Fig. 3 a detailed view of the mounted stop disc.

[0018] Fig. 1 to 3 show a schematic representation of a subframe for a motor vehicle, designated overall by the reference number 10, in which a stop disc 12 for a rubber-metal bearing 14 is designed as an aggregate support 16.

[0019] According to the Fig. 1 and Fig. In the embodiment illustrated in Figure 2, the subframe 10 of a motor vehicle comprises, viewed in the vehicle's longitudinal direction FL, two front functional nodes 18-1, 18-2 and two rear functional nodes 20-1, 20-2, which are connected by means of two longitudinal members 22-1, 22-2, wherein the front functional nodes 18-1, 18-2 are connected by means of a cross member 24. The functional nodes 18-1, 18-2, 20-1, 20-2 have recesses 26 into which rubber-metal bearings 14 are pressed, which serve to connect to the body by means of screw connections 28.

[0020] As in Fig. As shown in Figure 3, the rubber-metal bearings 14 have an inner sleeve 30 and an outer sleeve 32, with an elastic intermediate layer 34 arranged between them. The outer sleeve 32 is connected to the subframe (not shown here), with the inner sleeve 30 being connected to the body. A stop disc 12 is arranged between the head of the screw connection 28 and the underside of the subframe 10 and extends radially outward from the inner sleeve 30. The stop disc 12 limits the spring travel of the rubber-metal bearing 14 on the underside of the elastic intermediate layer 34, in particular the path from the subframe to the body.

[0021] In Fig. 1 to Fig.3, the stop disc 12 of the rubber-metal bearing 14 is functionally integrated as a unit support 16, which in this case is designed as a console-like support part that has at least one bearing eye 36 for receiving a bearing core 38 that can be connected to the unit. The local dynamic strength of the functional nodes 18-1, 18-2, 20-1, 20-2 enables the connection of the functionally integrated unit support 16. It can be connected to any functional node 18-1, 18-2, 20-1, 20-2. The unit support 16 is connected by means of a screw connection 28, which mounts the subframe 10 to the body via the functional nodes 18-1, 18-2, 20-1, 20-2. The screw connection 28 passes through the stop plate 12 / unit support 16, the rubber-metal bearing 14 of the subframe 10 and the body.

[0022] The engine support 16 can also have additional connection points, which are designed, for example, as connection points to the body and / or the traction battery. These connection points can further develop the stop plate 12 in such a way that an additional load path is opened up in the event of an impact. Thus, the inventive embodiment of the stop plate 12 designed as the engine support 16 supports the transmission of forces in the event of a crash.

Claims

[1] Subframe (10) of a motor vehicle, comprising two front functional nodes (18-1, 18-2) viewed in the vehicle longitudinal direction (FL) and two rear functional nodes (20-1, 20-2), wherein at least two functional nodes (18-1, 18-2, 20-1, 20-2) are connected by means of at least one cross member (24), and the front functional nodes (18-1, 18-2) are connected to the rear functional nodes (20-1, 20-2) by means of two longitudinal members (22-1, 22-2), wherein the functional nodes (18-1, 18-2, 20-1, 20-2) are formed with bearing receptacles into which rubber-metal bearings (14) are pressed for connection to the body, and wherein stop discs (12) are arranged on the rubber-metal bearings (14) by means of screw connections, wherein at least one stop disc (12) is designed as an aggregate support (16) for at least one of the rubber-metal bearings (14), and wherein the aggregate support (16) is designed with a bearing eye (36) in which a bearing is pressed,which is connected to an aggregate via its bearing core (38). [2] Subframe (10) according to claim 1, characterized by that the connection of the unit support (16) to the functional node (18-1, 18-2, 20-1, 20-2) is effected by means of a common screw connection (28) passing through the through-hole and the rubber-metal bearings (14). [3] Subframe (10) according to one of the preceding claims, characterized by that the unit support (16) is designed as a console-shaped support part. [4] Subframe (10) according to one of the preceding claims, characterized by that the unit support (16) has at least one further support point. [5] Subframe (10) according to claim 4, characterized by that the additional mounting point is designed as a connection point to the body and / or the traction battery.

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