| 摘要 |
1426640 Making pistons; soldering; welding by fusion AUDI NSU AUTO UNION AG and WANKEL GmbH 21 Dec 1973 [21 Dec 1972 8 Nov 1973] 59448/73 Headings B3A and B3R [Also in Division F1] A piston for a rotary I.C. engine of the trochoidal-type is formed from a plurality of sheet steel components welded or brazed together. The components comprise three flank members 1 with seal-receiving members 5 at their apices, two side members 2, 3, the latter having an internally toothed gear ring 12, a pair of abutting hub members 4 which are secured to the inner faces of the side members 2, 3 and are located with respect to the flank members 1 by elements 6. The members 4 have apertures 8, 10 for the circulation of cooling fluid. Pressure equalizing tubes 13 extend through the piston adjacent each apex. In another construction in which the flank members 1<SP>1</SP> are connected by apex elements 14 and are sandwiched between side members 2<SP>1</SP>, 3<SP>1</SP>, a reinforcing web 15 is located between the hub members 4<SP>1</SP>. Studs 17 locate the side members 2<SP>1</SP>, 3<SP>1</SP> on the hub members 4<SP>1</SP>. To assemble the piston all the components except one side member are tack-welded together and the joints covered with brazing paste (preferably Cu with Ni additions), the side member is located and the piston is placed in a brazing furnace. The piston flanks may be welded to the side members by electron beam or laser beam welding. Instead of applying brazing paste the components may be electrolytically copper-coated before assembly so that in the brazing furnace the copper will fill the brazing gaps. After assembly, the gear teeth, bearing bore and apex seal slots are machine finished. |
