Two-stroke, multicylinder, spark ignition, pumpless injection internal combustion engine

Claim 1

A two-stroke, spark ignition, internal combustion engine with fuel injection by means of combustion gases having a crank-shaft with cranks spaced at 120° intervals comprising: ignition means of 1-3-2 sequence, means for supplying fuel at a predetermined rate, means for delivering fuel with three gas ducts, three cylinders each having two ports in the cylinder wall, said ports being an upper inlet port between the piston midstroke and the piston top dead center and a lower outlet port below the piston midstroke and the bottom dead center, in said engine the upper port of the first cylinder communicating through said gas duct with the lower port of the second cylinder, and the lower port of the first cylinder communicating through said gas ducts with the upper port of a third cylinder, the upper port of the second cylinder communicating through said gas ducts with the lower port of the third cylinder, said means for delivering fuel being connected to each of said gas ducts so that combustion gases in the cylinder flow through the gas duct to the cylinder in which the piston is near the bottom dead center and entrain fuel being delivered to this respective duct by said fuel delivering means, said flow being completed when the lower outlet port is covered by the piston, the injection having occurred in the cylinder after opening of the upper inlet port by the piston, the upper port of the first cylinder communicating through the gas duct with the lower port of the third cylinder and the lower port of the first cylinder communicates through the gas duct with the upper port of the second cylinder, and the lower port of the second cylinder communicates through the gas duct with the upper port of the third cylinder, said means for delivering fuel being connected to each of said gas ducts, said gas ducts communicating in said sequence with working spaces of said cylinders, the fuel being delivered at a predeterminated rate, three fuel proportioners having open valveless means, a metering space of cubic capacity greater than the maximum dose of fuel per one working cycle, a necked-down inlet passage and a necked-down outlet passage, each proportioner communicating by the outlet passage with one gas duct and by the inlet passage with means for delivering fuel at a predetermined rate, fuel through the inlet passage flowing into the metering space, the combustion gases passing the gas duct to the metering space through the outlet passage for displacing the fuel dose enclosed in it and extruding said dose through the same outlet passage to the gas duct, precombustion chambers, in said engine said lower outlet ports of gas ducts in cylinder walls being directed towards the inlet of precombustion chambers, the injection stream injected from said ports forming a substantially rich mixture in the precombustion chamber, an exhaust manifold, in said engine said gas ducts communicating with said cylinders being on a predetermined part of its length in said exhaust manifold, said ducts being preheated by combustion gases, said upper inlet ports in cylinders walls being located higher than the height of piston seal rings, oil collecting on edges of said ports lubricating the cylinder at the instant when the port is uncovered by the piston ring and is forced by gas pressure above the ring between the cylinders bearing surface and the piston.