Patent GB-298160-A (GB)
Title: Improvements in the charging of internal combustion engines
IPC: F02F1/24
Filed: 1928-10-03
Abstract: 298,160. Schimanek, E. Oct. 4, 1927, [Convention date]. Two, four, and six or more stroke cycle engines. -Engines working with four or more strokes per cycle are supercharged by introducing air to the working cylinder during each out-stroke or at the end of each outstroke. By means of adjustable valve-gear the engine may start on a two-stroke Diesel cycle and then change to four and subsequently to a six or more stroke Diesel cycle. With an engine, as shown in Fig. 1, starting on a two-stroke cycle the pump 4 supplies air to terminal admission ports 11 in the power cylinder 1, the exhaust being controlled by the valve 7. An air suction valve on the power cylinder, not shown in the Figure, remains closed during this period. When the engine is to work on a six-stroke cycle, a cam shaft, is adjusted to work the power cylinder valves to give the following sequence of operation in one cycle. During the power stroke a charge of air is compressed in the pump 4 and is delivered through the valve 6, pipe 12, and terminal ports 11 at the end of the outstroke of power piston 2. During the instroke of the power piston a part of this air charge may. be compressed into the reservoir 9; at the same time a charge is drawn into the pump. On the 3rd stroke a charge of air is drawn through the suction valve into the cylinder, and to this is added at the end of the stroke an air charge from the pump. On the 4th stroke the charge in the power cylinder is delivered to the reservoir 9, and the pump draws in an air charge. During the 5th stroke air is again drawn into the power cylinder from the atmosphere and the charge from the pump is added thereto. On the 6th stroke after the ports 11 are closed by the piston, the valve 8-controlling the connection to the reservoir-is opened and air from the reservoir flows back into the cylinder; the whole air charge is now compressed to ignition temperature and fuel is injected through the valve 10. When working on a four-stroke-cycle, the 3rd and 4th strokes described above are omitted; when working on more than a six-stroke-cycle these two strokes are repeated. The engine may work without the reservoir, but in this case there is no suction of air into the power cylinder on the outstrokes of the power piston. In a modification shown in Fig. 2, two cylinders are used, each of two diameters, the large diameter chambers acting as air pumps; the cylinders are cross-connected as shown, and the exhaust valves 14 are arranged at the outer ends of the power cylinders 13. The two reservoirs 16 may be connected together by a, pipe 19. This engine may work on the two, four or more stroke cycle set out above. In another arrangement, a reservoir 21, Fig. 3, is placed between the delivery valve 24 of the pump and the admission ports 25 to the power cylinder; a valve 27 controls the flow from this reservoir. In this arrangement, an air charge is admitted to the power cylinder from the reservoir 21 at the end of the power stroke, but subsequent charges of air from the pump are stored in the reservoir until the end of the stroke before the final compression) stroke, when the air is admitted to the power cylinder. The air which is drawn into the power cylinder through a valve (not shown) during the suction stroke is delivered to a second rservoir 20 and is re-admitted at the same time as the charge air from the reservoir 21.