Subframe for accommodating an electrical energy storage device in a motor vehicle

Abstract

Subframe (1) in a body of a motor vehicle for connecting longitudinal and transverse members for wheels (12) of an axle of the motor vehicle, wherein a region (2) of the subframe (1) is designed as a supporting ring (3) for receiving an electrical energy store (4), characterized in that the subframe (1) has a branching or doubling (7) for receiving at least one power electronics unit (8) for an electrical machine (9).

Description

[0001] The invention relates to a subframe in a body of a motor vehicle for connecting longitudinal and transverse members for wheels of an axle of the motor vehicle.

[0002] Motor vehicles having such subframes are known from the prior art.

[0003] Furthermore, a wide variety of modifications to electrically powered vehicles are known. These involve the use of electric machines that can be operated as motors and / or generators. The vehicles are equipped with an electrical energy storage device, such as a high-voltage battery.

[0004] DE 10 2010 018 729 A1 describes a subframe in a motor vehicle body that forms part of an additional structure for a crumple zone of the vehicle. This additional structure has two support levels arranged one above the other in the vertical direction of the vehicle. A deformation-resistant zone of the upper support level serves to accommodate a battery box, thus forming a type of safety cell for the battery box, preventing accident-related damage to the batteries housed in the battery box. Another battery box is arranged below the upper support level in the vertical direction of the vehicle and is also protected by a deformation-resistant zone.

[0005] An arrangement of an energy storage device on a body shell of a motor vehicle is described in DE 10 2010 033 123 A1. The energy storage device is arranged in an underbody area of ​​the body shell.

[0006] US 2008 / 0 283 317 A1 describes a protective housing for a vehicle battery in a motor vehicle. The protective housing is arranged between two longitudinal members of the vehicle body and connected to them and a vehicle cross member. DE 10 2012 010 897 B3 discloses a subframe in a body of a motor vehicle according to the preamble of claim 1. DE 10 2013 210 575 A1, DE 10 2011 081 836 A1, WO 2012 / 028 956 A1, DE 10 2010 043 901 A1 and US 2011 / 0 132 676 A1 disclose further prior art.

[0007] The object of the invention is to further develop a subframe of the type mentioned at the outset so that a structurally simple, stable mounting of an electrical energy storage device in the motor vehicle is ensured.

[0008] This object is achieved by the subframe having a branch or doubling section for accommodating at least one power electronics unit for an electric motor. The power electronics unit is preferably arranged directly adjacent to the supporting ring. Furthermore, the subframe can have an area with fastening elements for at least one electric motor and the longitudinal and transverse control arms for the axle wheels. Thus, the subframe is provided with additional functions. A portion of the subframe is designed as a load-bearing ring to accommodate the electrical energy storage device. A subframe is also understood here to mean an auxiliary structure designed to meet the corresponding load requirements, e.g., a complex cast structure with struts, shells, and ribs.

[0009] The body is designed in the area of ​​the subframe in such a way that it is designed as a ring that has a load-bearing function and is therefore ideally suited to accommodate the electrical energy storage unit.

[0010] The supporting ring is designed in particular to have upper and lower support structures for the electrical energy storage device. These support structures are preferably made of fiber-reinforced plastic as a particularly lightweight solution; or of die-cast aluminum as a cost-effective solution with good thermal conductivity.

[0011] Preferably, the supporting structures are formed by two half-shells to accommodate the energy storage device. This energy storage device is, in particular, a high-voltage battery.

[0012] At least one electric machine is provided, which can preferably be operated in motor and generator mode.

[0013] The subframe may also have crash elements.

[0014] Preferably, the subframe is provided with fastening areas for screwing to the body.

[0015] The supporting ring of the subframe, which serves to accommodate the electrical energy storage device, is arranged in particular in a region of the subframe that faces away from the rear in the case of a rear-wheel drive motor vehicle, or away from the front in the case of a front-wheel drive motor vehicle. In the case of a rear-wheel drive motor vehicle, the branching or doubling for accommodating the at least one power electronics unit for the electric motor is preferably located behind the supporting ring, adjacent to the supporting ring. Furthermore, behind this branching or doubling is the area with the fastening elements for the electric motor and the longitudinal and transverse control arms. The crash elements are arranged behind this region of the subframe.In the case of a front-wheel drive, however, the arrangement of the above-mentioned elements is reversed, so that the crash elements are located in the front area of ​​the subframe, thus in the front area of ​​the vehicle, and the other elements are located behind it, starting with the area of ​​the fastening elements, then the branching or doubling and finally the load-bearing ring.

[0016] The crash elements are therefore designed for the front and rear ends of the vehicle to absorb energy in the event of a crash.

[0017] Further features of the invention emerge from the subclaims, the accompanying drawings and the description of the preferred embodiment shown in the drawings, without being limited thereto.

[0018] It shows: Fig. 1: In a schematic representation, illustrated in a side view, the subframe in the body of the motor vehicle designed as a passenger car, with the components of the motor vehicle assigned to the subframe, Fig. 2: The arrangement according to Fig. 1 in a plan view, Fig. 3: An enlarged view of the area of ​​the subframe that has the branching / doubling.

[0019] The figures illustrate, with regard to the subframe 1 and elements interacting with it, a region 2 of the subframe 1, which is designed as a supporting ring 3 for accommodating an electrical energy storage device 4, which is a high-voltage battery. The ring 3 accommodates an upper support structure 5 and a lower support structure 6 made of fiber-reinforced plastic in the form of two half-shells for the energy storage device 4. The ring 3 has a rectangular shape with a rectangular ring opening, based on the plan view.

[0020] Adjacent to the ring 3, the subframe 1 has a branching or doubling section 7 for accommodating at least one power electronics unit 8 for an electric motor 9. Two electric motors 9 and a power electronics unit 8 assigned to the respective electric motor 9 are illustrated. Adjacent to the branched or doubled section 10, the subframe 1 has a further section 11 with fastening elements (not shown) for the two electric motors 9, as well as longitudinal and transverse control arms (not shown) for wheels 12 of an axle of the passenger car. Finally, the subframe 1, adjacent to this section 11, has a section 13 that is located in the area of ​​the front or rear end of the passenger car and in the area of ​​which crash elements 14 are provided for energy absorption in the event of a crash.Accordingly, point 15 defines neither the front end of the passenger car nor the rear end of the passenger car, in the longitudinal extension of the vehicle in the longitudinal extension of the illustrated subframe 1. On the side of the subframe 1 facing away from the front end or rear end of the subframe 1, the subframe is provided with an additional fastening area 16 for screwing the subframe 1 to the rest of the body. In this respect, fastening tabs 17 are illustrated for this area 16. This is where the screw connection to the rest of the body takes place. Of course, further connection points for screwing the subframe 1 to the rest of the body can also be provided in areas 2, 10 and / or 11.

[0021] The invention thus discloses a special design of a subframe for representing an integrated electric drive module. List of reference symbols 1 subframe 2 Area 3 rings 4 energy storage 5 Supporting structure 6 Supporting structure 7 Branching / doubling 8 Power electronics 9 Electric motor 10 Area 11 Area 12 edges 13 Area 14 Crash element 15 points 16 Area 17 Mounting tab

Claims

[1] Subframe (1) in a body of a motor vehicle for connecting longitudinal and transverse members for wheels (12) of an axle of the motor vehicle, wherein a region (2) of the subframe (1) is designed as a supporting ring (3) for receiving an electrical energy storage device (4), characterized by that the subframe (1) has a branching or doubling (7) for accommodating at least one power electronics unit (8) for an electrical machine (9). [2] Subframe (1) according to claim 1, characterized by that the supporting ring (3) has upper and lower supporting structures (5, 6) for the electrical energy storage device (4). [3] Subframe (1) according to claim 2, characterized by that the supporting structures (5, 6) are made of fiber-reinforced plastic. [4] Auxiliary frame (1) according to claim 2 or 3, characterized by that the supporting structures (5, 6) are formed by two half-shells. [5] Subframe (1) according to one of claims 1 to 4, characterized bythat the subframe (1) has an area (11) with fastening elements for at least one electric machine (9) and the longitudinal and transverse control arms for the wheels (12) of the axle. [6] Subframe (1) according to claim 5, characterized by that the electric machine (9) can be operated in motor mode or in motor mode and generator mode. [7] Subframe (1) according to one of claims 1 to 6, characterized by that the subframe (1) has crash elements (14). [8] Subframe (1) according to one of claims 1 to 7, characterized by that the subframe (1) has fastening areas (16) for connecting, in particular screwing, to the body. [9] Subframe (1) according to claim 7 or 8, characterized by that the crash elements (14) are arranged in the region of the front or rear end of the vehicle. [10] Subframe (1) according to claim 9, characterized bythat the region (11) with the fastening elements for the at least one electric machine (9) and the longitudinal and transverse control arms for the wheels (12) of the axle are arranged adjacent to the crash elements, this region (11) is arranged between the crash elements (14) and the region (10) of the branching or doubling (7), and the region (10) of the branching or doubling (7) is arranged between the region (11) with the fastening elements and the region (2) which has the ring (3). [11] Subframe (1) according to one of claims 1 to 10, characterized by that the area (2) having the ring (3) is arranged directly next to the area (10) of the subframe (1) which accommodates power electronics (8).

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