Patent ID: 6029624
Filing Date: 2000-02-29
Classification: F02D,Y02T

Abstract:
A method for reducing powertrain vibration in a motor vehicle having an internal combustion engine, wherein the vibration is caused by a transition from an open throttle condition to a closed throttle condition, by controlling the airflow flowing through a throttle body to an intake manifold of said engine during said transition, said method comprising:disposing an air bypass valve to communicate with an upstream side and a downstream side of said throttle body so as to be capable of diverting at least a portion of said airflow entering said throttle body into said intake manifold;determining said airflow flowing through said throttle body when a throttle valve of said throttle body is in said open throttle condition;allowing a portion of said airflow through said throttle body to be bypassed through said air bypass valve when said throttle body is in said open throttle condition;detecting when said engine decelerates, thereby indicating a decelerating condition;determining a percentage of said airflow required to prevent said engine from experiencing said powertrain vibration during said condition of deceleration; andopening said air bypass valve to a greater degree for a predetermined time sufficient to enable an additional quantity of said airflow in accordance with said percentage to flow through said air bypass valve to prevent said powertrain vibration.