Overhead camshaft internal combustion engine with high-pressure fuel injection system

摘要

An overhead-camshaft internal combustion engine is disclosed, in which the fuel pumps are arranged to use efficiently the space within a cylinder head assembly of the engine. The cylinder head assembly includes a cylinder head block, and the engine comprises a camshaft rotatable about a camshaft axis and having a plurality of inlet and exhaust cams for actuating associated inlet and exhaust valves of the engine, and at least one fuel pump comprising a unit pump assembly driven directly by a respective pump cam provided on the camshaft. The engine further comprises a plurality of rocker arms driven by the inlet and exhaust cams and arranged to actuate the inlet and exhaust valves. Each rocker arm is pivotable about a rocker arm axis which is substantially parallel to the camshaft axis. The or each pump assembly is mounted between the rocker arm axis and the cylinder head block.

主权项

1. An overhead-camshaft internal combustion engine having a cylinder head assembly including a cylinder head block; the engine comprising:
a camshaft mounted longitudinally with respect to the cylinder head assembly, the camshaft being rotatable about a camshaft axis and having a plurality of inlet and exhaust cams for actuating associated inlet and exhaust valves of the engine; at least one fuel pump comprising a unit pump assembly driven directly by a respective pump cam provided on the camshaft, the unit pump assembly being elongate to define a pump axis; and a plurality of rocker arms driven by the inlet and exhaust cams and arranged to actuate the inlet and exhaust valves, wherein each rocker arm is pivotable about a rocker arm axis which is substantially parallel to the camshaft axis; characterised in that the cylinder head block defines a mounting surface and, the or each unit pump assembly is mounted in a sleeve fixed onto said mounting surface, and wherein the or each rocker arm is mounted on a rocker shaft mounted on the sleeve so that the or each unit pump assembly is mounted between the rocker arm axis and the cylinder head block.