| 摘要 |
<p>PURPOSE:To flatten characteristics of torque as an increase in torque is ensured, by a method wherein two suction valves are amounted to each cylinder, and the set number or revolutions of the one suction valve, at which switching between a cam for a high speed and a cam for a low speed is effected, is differed with that of the other suction valve. CONSTITUTION:Each of cylinders formed to a cylinder head 1 is provided with two suction valves 2a and 2b, and the suction valves 2a and 2b are respectively driven by means of a cam shaft 3. Two cams 8 for a low speed are secured on the cam shaft 3, and two cams 10 for a high speed are slidably engaged externally of a spline shaft 9 formed outside the cylinder of the cam shaft 3. In a low rotation area where the number of revolutions of an engine is lower than, for example, the number of switching revolutions on the low speed side, first and second valves 16 and 17 are both closed by means of a control unit 18 to switch the cam of each of the suction valves 2a and 2b to the cam 8 for a low speed. This constitution reduces the root of torque of a torque characteristics line.</p> |
