GB1354099A - Method and device for supercharging four-stroke internal combustion engines - Google Patents

Abstract

1354099 Super charging I C engines R J POUIT 5 July 1971 31322/71 Heading F1B Four-stroke multi-cylinder I. C. engines are super-charged by using the depression which exists at the exhaust port of a first cylinder after the initial discharge of exhaust gas, the depression being caused to act on the intake port of a second cylinder which is a half-cycle out of phase with the first cylinder. A device for carrying out the method consists of a duct 7 which connects the exhaust port of a cylinder 1 2 to the inlet port of a cylinder 1 1 . The engine has a flat twin layout, the connecting rods of the pistons being connected to crank-pins arranged at 180 degrees spacing, so that the piston of cylinder 1 1 is nearing the end of an induction stroke as the piston of cylinder 1 2 nears the end of a power stroke. As the exhaust valve of cylinder 1 2 opens, the exhaust gas initially discharges rapidly, and as the rate of discharge decreases, the gases moving rapidly down the exhaust pipe leave behind them at the exhaust port a region of low pressure. This low pressure is communicated, through the pipe 7 to the space 6 1 and accelerates the air in the inlet pipe 5 1 and increases the amount of air which enters the cylinder 1 1 . Reverse flow of the exhaust gases in the exhaust pipe, the pipe 7 and the space 6 1 is prevented by non-return devices such as 4 2 and 14. Additional control over the reverse flow of the gases can be provided by using an inlet valve as shown in Fig. 4a. This valve has two enlargements formed on its stem which slide in a cylindrical chamber formed under the valve guide and shut-off the exit from the passage 7 except when the valve is moving towards the closed position. The non-return devices consist of a mushroom-shaped element 21 which is adjustable along a threaded rod 21 and has spiral vanes 21 formed on it. A radically inwardly projecting flange 26 has spiral vanes of opposite hand to those on the element 21, with which it co-operates to form rotating vortices which obturate the flow of fluid in the direction of arrow 27. Gas flowing along the wall 30 of the duct, as shown by the arrow 28 is deflected inwardly by a projecting lip 31, to cause their rotation in the same direction as the jets 27.