Mechanical kickdown for electronic throttle control pedal assembly

Abstract

An accelerator pedal assembly (,) for electronically controlling a vehicle engine throttle includes a housing (,), a pedal arm (,) pivotally supported with respect to the housing (,), and a pedal pad (,) connected to a lower end (,) of the pedal arm (,). The pedal arm (,) is pivotable between an idle position and a maximum applied position as a pedal force is applied to the pedal pad (,). Under certain conditions, the accelerator pedal arm (,) can be pivoted to a position that causes the automatic transmission (,) to kickdown by changing to a next lower gear. Under these conditions a feel is imparted to the driver's foot indicating that a downshift has occurred. To simulate this feel in a drive-by-wire application, the pedal arm (,) presents a cam surface (,) for interacting with a spring (,) that has a first end (,) seated within the housing (,) and a movable second end (,) for bias engagement with the pedal arm (,). The spring (,) includes a roller (,) mounted on the second end (,) that is forced into contact with a lobe (,) on the cam surface (,) when the pedal arm (,) is pivoted from a first operable position to a pre-determined kickdown position. As the roller (,) engages the lobe (,), the pedal force required to further pivot the pedal arm (,) is increased imparting a kickdown feel to the driver via the pedal pad (,).