| 摘要 |
PURPOSE:To enable to restrict the mixture flow by way of vacuum control, by attaching a second throttle valve to a ready-made engine, and obtaining a negative pressure in an intake pipe corresponding to a required torque. CONSTITUTION:A rod 15 of a diaphragm mechanism 13 is connected to a lever 20 fixed to one end of a shaft 12 of a second throttle valve 11, in the manner that the second throttle valve 11 is opened with retraction of the rod 15 and closed with projection of the rod 15. In case that the negative pressure in an intake pipe tends to become higher than a set value, the opening of the second throttle valve 11 is increased. On the other hand, in case that the negative pressure in the intake pipe tends to become lower than the set value, the opening of the second throttle valve 11 is decreased and the negative pressure at the time is set at a value substantially equal to the set value. Thus, the relationship between the negative pressure Pb and torque Te as shown in the drawing is obtained. With such an arrangement, it is enabled to keep the negative pressure in the intake pipe substantially at a constant value through opening and closing of the second throttle valve 11 and to determine the maximum torque according to the set value of the negative pressure. |
