Patent GB-272185-A (GB)
Title: Improvements in internal combustion engines having liquid fuel injection
IPC: F01L13/08
Filed: 1927-05-11
Abstract: 272,185. Acro Akt.-Ges., (Assignees of Bosch Akt.-Ges., R.). June 4. 1926, [Convention date]. Void [Published under Sect. 91 of the Acts]. Cylinders receiving liquid fuel.-For starting two-stroke or four-stroke engines having liquidfuel injection, the admission and exhaust valves. are so controlled during a part of the starting operation that air is only admitted towards theends of an outstrole, of the piston, the temperature of the air being raised by its sudden admission into a vacuum in the cylinder. In a fourstroke engine, Fig. 1, the cvlinder head 12 is provided with an air admission valve 19, an exhaust valve 20, and a fuel injection nozzle 18, and the piston 17 may be provided with an auxiliary combustion chamber 39 with a narrow' neck 40 opposite to the fuel nozzle 18. The valve 19 is actuated, through a lever 26 and rod 25, by a cam 27 mounted on the axially displaceable cam shaft 24 and having graduated cam swells. 28, 29, 30, Figs. 6 and 7. The exhaust valve. 20 is actuated, through a lever 23 and rod 22, by a cam 21, and may be opened for the relief of compression by a cam 32 on a shaft 34 actuated by a hand lever 33 and engaging a flange 31 on the rod 22. The shaft 34 carries a pin 36 engaging in a slot 35, Fig. 4, in the cam 32, and the cam has a notch 37 engaged by the flange 31 in its raised position; the lever 33 can thus be returned to its normal position, the cam 32 being retained by the flange 31 until the rod 22 is lifted by the cam 21 sufficiently to allow a spring to return the cam 32. At starting, the valve rod 25 is over the part A, Fig. 6, of the cam 27, so that the inlet valve 19 is not opened, and the exhaust valve is opened by the cam 32. The engine is then cranked without any compression, until the release of the cam 32 allows the exhaust valve to be actuated normally. A vacuum is caused on each outstroke, and on the opening of the exhaust valve, cold air rushes into the cylinder and is thus heated, the greater portion of the air being expelled during the exhaust stroke. The shaft 24 is displaced to bring the cam swells 28, 29' successively under the valve rod 25, opening the valve 19 during the latter part only of the admission stroke, when air rushes into the cylinder and is thus heated. Fuel is admitted while the cam swell 28 is in use, and when the explosions are occurring normally, the cam swell 30 is brought into position to actuate the admission valve for normal running. In a modification, instead of shifting the cam shaft axially, the cam lever 26 is mounted on an eccentric adjusted by means of a hand lever. In a two-stroke engine, Fig. 9, having piston-controlled transfer and exhaust ports 48, 47, a compression-relief valve 42 in the cylinder head is actuated at starting by an axially movable cam 46. At starting, the engine, is turned over and the cam 46 opens the valve 42 on each instroke; on each outstroke, the valve 42 is closed and a vacuum is created in the cylinder until the port 48 opens and air rushes in from the .crank-case 14. When sufficient speed is attained, the cam 46 is thrown out of action by shifting the cam-shaft and the fuel is turned on.