SUBFRAME STRUCTURE

• US 20130249250A1
• Filed: 12/06/2011
• Published: 09/26/2013
• Est. Priority Date: 12/06/2010
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Miyahara, Tetsuya, Ohhama, Shosuke
• Granted Patent: US 9,067,621 B2
• Time in Patent Office: Days
• US Class Current: 296/204
• CPC Class Codes: B23K 20/122 using a non-consumable tool, e.g. friction stir welding
• CPC Class Codes: B23K 20/125 Rotary tool drive mechanism
• CPC Class Codes: B23K 20/1265 Non-butt welded joints, e.g. overlap-joints, T-joints or spot welds
• CPC Class Codes: B62D 21/00 Understructures, i.e. chassis frame on which a vehicle body may be mounted combined frame and vehicle body B62D23/00 ; characterised by the material thereof B62D29/00
• CPC Class Codes: B62D 21/11 with resilient means for suspension , e.g. of wheels or engine; sub-frames for mounting engine or suspensions
• CPC Class Codes: B62D 21/155 Sub-frames or underguards
• CPC Class Codes: B62D 27/02 rigid
• CPC Class Codes: B62D 27/023 Assembly of structural joints
• CPC Class Codes: B62D 27/026 Connections by glue bonding in general F16B11/00; processes C09J5/00
• CPC Class Codes: B62D 29/00 Superstructures, understructures, or sub-units thereof, characterised by the material thereof B62D33/044, B62D33/048 take precedence
• CPC Class Codes: B62D 29/008 predominantly of light alloys, e.g. extruded
• CPC Class Codes: C25D 7/00 Electroplating characterised by the article coated

Abstract

The present invention comprises: a front subframe consisting of steel and divided in the front-rear direction of the vehicle; and a rear subframe consisting of light metal such as an aluminum alloy. The front subframe comprises a press-formed body formed by pressing. The rear subframe comprises a die-cast body formed by die-casting. The front subframe and the rear subframe are joined together by friction stir welding while the left and right rear side sections of the rear subframe are superposed on the upper surfaces of the thin plate sections of the front subframe.

Claims

1. A subframe structure for a vehicle, the subframe structure being arranged at a front of the vehicle and fixed to or floatably supported by a vehicle-body member, comprising:

a front subframe made of steel; and

a rear subframe made of light metal, wherein

the rear subframe and the front subframe are divided in a front-rear direction of the vehicle, and

the front subframe and the rear subframe are joined together by friction stir welding in a state in which the rear subframe is superposed on the front subframe.

2. The subframe structure according to claim 1, wherein

the front subframe comprises a press-formed body formed by pressing,

the rear subframe comprises a die-cast body formed by die-casting, and

the front subframe and the rear subframe are joined together by the friction stir welding in the state in which the rear subframe is superposed on the front subframe.

3. The subframe structure according to claim 1, wherein

the front subframe comprises a front cross member extending along a width direction of the vehicle and a pair of left and right side members extending from the front cross member toward a rear of the vehicle so as to be substantially parallel to each other,

the rear subframe comprises a pair of left and right rear side sections and a rear cross section connecting the pair of left and right rear side sections to each other,

the left and right side members of the front subframe are provided with respective extending sections extending to a side of the rear of the vehicle,

the extending sections of the front subframe and the left and right rear side sections of the rear subframe are provided with respective flange sections, and

the left and right rear side sections of the rear subframe are superposed on upper surfaces of the extending sections of the front subframe to join the flange sections together.

4. The subframe structure according to claim 3, wherein

closed cross sections are formed by the left and right side members of the front subframe and the left and right rear side sections of the rear subframe,

bolt insertion holes are formed on sides of the left and right side members of the front subframe, and the left and right side members of the front subframe and the left and right rear side sections of the rear subframe are fastened by bolts penetrating the closed cross sections.

5. The subframe structure according to claim 3, wherein

the extending sections of the front subframe comprise respective thin-plate-shaped steel members,

electrodeposition coating is applied to the extending sections of the front subframe before being joined to a thin-plate-shaped aluminum member, thereby forming respective electrodeposition coating films on joining surfaces joined to the aluminum member, laminating surfaces between the thin plates, and rear surfaces of the thin plate on a side opposite to the joining surfaces joined to the aluminum member,

the steel member and the aluminum member are superposed one on the other, and a rotation tool for the friction stir welding is rotated to penetrate in a direction perpendicular to the superposed surface and from a side of the aluminum member toward a side of the steel member to join the flange sections together.

6. The subframe structure according to claim 3, wherein

the left and right side members of the front subframe have two or more steel thin plates joined together, and closed cross sections are formed between the joined steel thin plates.