Vehicle body frame for motorcycle and its fabrication method

• US 20020059728A1
• Filed: 12/07/2001
• Published: 05/23/2002
• Est. Priority Date: 08/10/1998
• Status: Active Grant

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Mochizuki, Shinsuke, Nakagawa, Masahiko, Koya, Eitarou
• Granted Patent: US 6,796,030 B2
• Time in Patent Office: Days
• US Class Current: 29/897.2
• CPC Class Codes: B21D 53/86 other parts for bicycles or motorcycles
• CPC Class Codes: B62K 11/04 characterised by the engine being between front and rear wheels
• CPC Class Codes: B62K 19/12 having cast members
• CPC Class Codes: Y10T 29/49616 Structural member making
• CPC Class Codes: Y10T 29/49622 Vehicular structural member making
• CPC Class Codes: Y10T 29/49885 with coating before or during assembling
• CPC Class Codes: Y10T 29/49888 Subsequently coating
• CPC Class Codes: Y10T 29/49984 and casting
• CPC Class Codes: Y10T 29/49988 Metal casting

Abstract

To adopt die cast products as parts of a vehicle body frame. A vehicle body frame is provided with an alumite treating, showing that brightness and appearance of pivot plates which are die cast products differ from those of non-die cast products, head pipes, longitudinal pipes and cross pipe. By carrying out a local coating treatment on the pivot plates, the pivot plates are provided with a color the same as that of the head pipe, the longitudinal pipes and the cross pipe. By making die cast products portions of constituent parts, the fabrication cost of the vehicle body frame can be reduced.

Claims

1. A method of fabricating a vehicle body frame for a motorcycle comprising the following steps:

integrating aluminum series die cast products and aluminum series non-die cast products fabricated by a method other than die casting;

subjecting an integrated article to an alumite treating; and

coating only die cast portions.

2. The method of fabricating the vehicle body frame for a motorcycle according to claim 1, and further including the step of fabricating said die cast products with molten aluminum injected into a cavity under high pressure.

3. The method of fabricating the vehicle body frame for a motorcycle according to claim 2, and further including the stops of die casting pivot plates for the vehicle body frame and projecting shot grain onto the pivot plates for finishing the surface.

4. The method of fabricating the vehicle body frame for a motorcycle according to claim 1, where in a gate speed for the die casting is 5-15 m/s for the molten metal.