Crankshaft supporting structure for horizontal opposed type internal combustion engine

摘要

In a horizontally opposed type internal combustion engine, to enable rigid support of a middle journal of a crankshaft through rational utilization of first and second case halves constituting a crankcase, and to thereby contribute to a simplification in structure and a reduction in weight. In a horizontally opposed type internal combustion engine, a crankcase is split at a plane containing the axis line of a crankshaft into first and second case halves connected with first and second cylinder blocks. The first and second case halves are integrally provided with first and second journal supporting walls for supporting a middle journal of the crankshaft. The first and second journal supporting walls front cylinder bores of the first and second cylinder blocks. The first and second journal supporting walls are coupled by a plurality of first bolts inserted from the side of the cylinder bores of the first cylinder block and disposed on opposite sides of and in proximity to the middle journal.