Valve gear of internal combustion engine

A valve-operating system for an internal combustion engine, comprising a main valve lifter (11) moved in unison with a valve (3, 3′, 4) mounted in an engine body (1), a subsidiary valve lifter (12, 12′) adjoining said main valve lifter (11) and slidable relative to said main valve lifter (11), a main cam (15, 15′) for providing a first operational mode to the valve (3, 3′, 4) through said main valve lifter (11), a subsidiary cam (16, 16′) capable of operating said subsidiary valve lifter (12, 12′) with a lift amount larger than said main cam (15, 15′) in a direction to open the valve (3, 3′, 4), main and subsidiary guide bores (24;

• 25, 25′) provided in said main and subsidiary valve lifters (11, 12, 12′) to extend in a direction perpendicular to a direction of operation of said main and subsidiary valve lifters (11, 12, 12′), and a connecting means (33, 33′) having a connecting member (30, 30′) for moving between a non-connecting position where said connecting member (30, 30′) is received in only one of said main and subsidiary guide bores (24;
• 25, 25′) and a connecting position where said connecting member (30, 30′) is received in both of said guide bores (24;
• 25, 25′), so that when said main and subsidiary valve lifters (11, 12) are connected to each other by the connecting state of said connecting means (33), said subsidiary cam (16, 16′) provides a second operational mode to the valve (3, 3′, 4), in which said valve is opened more largely than in said first operational mode,
• characterized in that said main and subsidiary valve lifters (11;
• 12, 12′) have flat faces (11c;
• 12c, 12c′) relatively slidably superposed on each other, and are formed so as to be slidably received in a common lifter guide bore (8) in the engine body (1), said flat faces (11c;
• 12c, 12c′) being formed to extend in parallel to an axis of said lifter guide bore (8), and said main and subsidiary guide bores (24;
• 25, 25) are provided in said main and subsidiary valve lifters (11;
• 12, 12′) so as to open into said corresponding flat faces (11c;
• 12c, 12c′), respectively.

A valve-operating system for an internal combustion engine, comprising a main valve lifter (11) moved in unison with a valve (3, 3′, 4) mounted in an engine body (1), a subsidiary valve lifter (12, 12′) adjoining said main valve lifter (11) and slidable relative to said main valve lifter (11), a main cam (15, 15′) for providing a first operational mode to the valve (3, 3′, 4) through said main valve lifter (11), a subsidiary cam (16, 16′) capable of operating said subsidiary valve lifter (12, 12′) with a lift amount larger than said main cam (15, 15′) in a direction to open the valve (3, 3′, 4), main and subsidiary guide bores (24;

• 25, 25′) provided in said main and subsidiary valve lifters (11, 12, 12′) to extend in a direction perpendicular to a direction of operation of said main and subsidiary valve lifters (11, 12, 12′), and a connecting means (33, 33′)having a connecting member (30, 30′) for moving between a non-connecting position where said connecting member (30, 30′) is received in only one of said main and subsidiary guide bores (24;
• 25, 0.25′) and a connecting position where said connecting member (30, 30′) is received in both of said guide bores (24;
• 25, 25′), so that when said main and subsidiary valve lifters (11, 12) are connected to each other by the connecting state of the connecting means (33), said subsidiary cam (16, 16′) provides a second operational mode to the valve (3, 3′, 4), in which the valve is opened more largely than in the first operational mode,
• characterized in that a roller (19, 20, 20′) is carried on at least one of said main and subsidiary valve lifters (11, 12, 12′) to come into contact with the corresponding cam (15, 15′, 16, 16′).