| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an operating characteristics variable device for an engine to realize further flatness of output torque throughout a whole operation area. SOLUTION: The operation characteristics variable device for an engine comprises a valve operating characteristics variable means (VT) to change the operating characteristics of a suction valve, and a suction characteristics variable device (SA) to steppedly change the suction characteristics of a suction passage. The phase of a cam shaft on the suction side with the rotation angle of a crank shaft is variable, and a rotary valve (26) capable of effecting intercommunication in a short-circuit-form manner or cutting off between a suction collection chamber 21 on the side situated upper stream of a suction passage and the suction passage through rotation according to the rotation speed of an engine is situated at the intermediate parts of a plurality of suction passages (22a, 22b, 22c, and 22d) arranged in juxtaposition and independently. In a low rotation speed area, the opening and closing timing of the suction valve is delayed, and an intake air is fed through a long pipe suction passage. In a high rotation speed area, the opening and closing timing of the suction valve is advanced, intake air is fed through a short pipe intake passage, and at least in a middle rotation speed area, the suction passages of a cylinder group where a suction stroke is not continued are brought into intercommunication with and interconnection to each other.</p> |
