| 摘要 |
1359794 Fuel-injection I C engines DEERE & CO 17 July 1972 [16 July 1971] 33299/72 Heading F1B A combustion chamber 40 in the piston 34 has a substantially cylindrical side wall 44 and the ratio between the square of the cylinder diameter D 1 and the square of the chamber diameter D 2 is between 2 and 3À5, preferably between 2À3 and 3À2. The clearance F between the annular top face 38 of the piston 34 and the opposed wall 28 of the cylinder head 26 is less than 0À02 in., preferably less than 0À01 in., at top dead centre under full load operating conditions. Air is introduced into the cylinder 32 swirling about the cylinder axis and fuel is injected towards the wall 44 in a plurality of jets from the nozzle tip 68. The air swirl rate in the cylinder may be between 3000 and 6000 r.p.m. calculated in a manner described in the Specification. The surface 38 may have a portion 50 which tapers when the engine is cold but which at full load is parallel to the wall 28. The nozzle 64 is inclined to the cylinder axis and the nozzle orifices 74 to 77 are arranged to provide jets which strike the wall 44 at the same distance from the surface 38. The dimensions of the orifices 74 to 77 and their inclination to the cylinder axis are given in the Specification. The air may be supplied to the cylinder by an exhaust gas driven supercharger (16), Fig. 1, (not shown), via an intercooler (22). The fuel may be injected over approximately 24 degrees of crank angle, Fig. 11, (not shown), beginning 10 to 15 degrees before top dead centre on the compression stroke.
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