Internal combustion engine, especially reciprocating piston internal combustion engine, with compression space adjustable in operation

摘要

For an internal combustion engine, especially a reciprocating piston internal combustion engine 1 with compression space 10 adjustable in operation by means of a device 13, it is proposed that the device 13 be a wall section of a shape memory alloy, which, owing to its temperature-dependent deformation, automatically adjusts the compression space 10. For reversible deformation of the wall section 13 a reversing temperature is selected through the composition of the alloy in such a way that at low temperature when the internal combustion engine is at partial load a high compression ratio is set and at high temperature at full load a low compression ratio corresponding to the deformation. With the wall section 13 arranged opposite a recess 12 in the head 11 of a piston 9, both load-dependent, automatic control of the compression ratio and load-dependent, automatic adjustment of the combustion space geometry are achieved as a result of which an overall improvement of the engine efficiency and a reduction of the fuel consumption at partial load are obtained.