Compression-ignition internal combustion engines

Claim 1

In combination, a cylinder for a compression-ignition internal combustion engine having fuel injection transversely to airflow about the cylinder axis, a cylinder head of said cylinder, first portions of said cylinder head defining an outwardly facing lateral surface thereof, first and second inlet valve means in said cylinder head and spaced-apart about the axis of said cylinder, the first inlet valve means being nearer to said lateral surface than is the second inlet valve means, second portions of said cylinder head defining a bounding surface thereof bounding an end of the working space of said cylinder, third portions of said cylinder head defining first and second inlet valve seats for said first and second inlet valve means, fourth portions of said cylinder head defining an inlet duct having a single inlet in said lateral surface and first and second outlets encircled by the respective valve seats, said inlet duct extending to the first outlet and thence immediately to the second outlet, having an outer lateral surface which is radially outer with respect to the cylinder axis, and having an inner lateral surface which is radially inner with respect to the cylinder axis, and a single covering shield for said cylinder head in the form of a segment of a circle disposed at the commencement of the first outlet and having inner and outer edges of which the inner edge is nearer to the axis of said first inlet valve means than is the outer edge, the arrangement being such that: a. as viewed in an axial direction of said cylinder, said inner lateral surface is substantially tangential to the inner peripheries of said seats and said outer lateral surface extends past the first inlet valve seat in the region of the periphery of said working space and is substantially tangential to the inner periphery of the second inlet valve seat, b. as viewed substantially perpendicularly to the cylinder axis and the longitudinal axis of said inlet duct, said inlet duct curves arcuately towards said seats and meanwhile narrows, c. that commencement region of said first outlet nearest to said lateral surface is nearer to said bounding surface than is that commencement region of said second outlet nearest to said lateral surface, d. said inner edge extends, at an oblique inclination with respect to said axis of said first inlet valve means, from said commencement region of said first outlet to said commencement region of said second outlet, and, at its closest approach to said axis of said first inlet valve means, is spaced a distance from this axis of between 0.25 and 0.45 times the inner diameter of said first inlet valve seat, and, as viewed in said axial direction, the two ends of said inner edge are disposed on a straight line which extends approximately radially of said cylinder axis.