초록 ▼

A method wherein a number of cylinders (2, 3; 1, 4) are grouped on a same exhaust gas manifold (8, 10) such that the pressure in the exhaust pipe (1e . . . 4e) undergoes time-dependent fluctuations of substantial amplitudes, and the exhaust valve (6) of a cylinder (1) is opened during induction or f

A method wherein a number of cylinders (2, 3; 1, 4) are grouped on a same exhaust gas manifold (8, 10) such that the pressure in the exhaust pipe (1e . . . 4e) undergoes time-dependent fluctuations of substantial amplitudes, and the exhaust valve (6) of a cylinder (1) is opened during induction or filling thereof (i.e. adjacent to the bottom dead center) so that, in a given engine speed range, a phase (28) of low instantaneous exhaust pressure prevailing in the exhaust pipe enables the inlet pipe (1a)/cylinder (1)/exhaust pipe (1e) to be scavenged while the inlet valve (5) and the exhaust valve (6) are simultaneously open. The phase (29) of high instantaneous exhaust pressure, caused by another cylinder, after the inlet valve (5) has closed and while the exhaust valve (6) is still open, is used for post-charging the cylinder (1) with air (A) previously stored in the exhaust pipe (1e). The size of the turbine (T) is selected so that there is virtually no post-charging of the cylinder (1) with exhaust gases at engine speeds above said given engine speed range.

대표청구항 ▼

[ I claim:] [1.] A method for improving the operation of an internal combustion engine of the type having a plurality of cylinders each having an inlet valve and an exhaust valve and an inlet and exhaust pipe, at least an exhaust manifold, at least some of said cylinders being connected to said exha

[ I claim:] [1.] A method for improving the operation of an internal combustion engine of the type having a plurality of cylinders each having an inlet valve and an exhaust valve and an inlet and exhaust pipe, at least an exhaust manifold, at least some of said cylinders being connected to said exhaust manifold and conduits for supplying scavenging air from a turbocharger to said cylinders so that the exhaust gas pressure in said exhaust manifold will undergo time-dependent fluctuations of substantial amplitude, comprising the steps of causing, sequentially in said cylinders, the exhaust valve to open while the inlet valve of that cylinder is open to permit scavenging air from the inlet pipe to scavenge the exhaust pipe through that cylinder during a phase of low exhaust pressure while the inlet and exhaust valves are simultaneously open, causing the inlet valve to close while maintaining the exhaust valve open, post-charging the one cylinder with air from the exhaust pipe during a phase of high pressure from another of said cylinders while providing a sufficient turbine flow area in the turbocharger to avoid post-charging of said one cylinder with exhaust gases at engine speeds above a selected engine speed.