System and method for preventing start pinion/gear ring engagement during selected engine start conditions
AssigneeInternational Truck and Engine Corporation
InventorsBrian P. Marshall, Brent A. Barnhart
Life of this patent
Estimating the term…
Abstract
The invention provides a cranking inhibition control system for an electric starter to an internal combustion engine. Engine rotational speed is developed from the signal produced by a cam shaft position sensor, which drives the logic of the system. Responsive to changes in engine rotation speed which result in engine speed falling below idle speed, the control logic generates a temporary cranking inhibit signal. Once engine speed falls low enough to clearly indicate cranking has ceased, a timer is triggered which resets the inhibit signal to permit cranking after a suitable delay.
Claims13
A control system for an electric starter to an internal combustion engine, the control system comprising:
- a starter switch;
- an engine crank shaft ring gear;
- a cranking motor;
- a pinion rotatably driven by the cranking motor;
- a pinion positioner for selectively engaging and disengaging the pinion and engine crank shaft ring gear;
- a tachometer for generating an engine rotational speed signal;
- and
- control logic responsive to the engine rotational speed signal for determining deceleration of the engine indicative of resetting the start switch to off and further responsive to deceleration of the engine for generating an engine crank inhibit signal of one of two states.
An engine controller for generating a command signal for application to an engine cranking system, comprising:
- a source of an engine rotational velocity signal;
- a delay line connected to the source of the engine rotational velocity signal for generating a delayed engine rotational velocity signal;
- a subtracting circuit connected to the source of the engine rotational velocity signal and the delay line to produce a rotational velocity change signal;
- a source of an engine rotational velocity change threshold level;
- a comparator taking the engine rotational velocity change threshold level and the rotational velocity change signal as inputs and generating a first indication signal;
- a source of an engine rotational velocity threshold level;
- a comparator taking the engine rotational velocity threshold level and the engine rotational velocity signal as inputs and producing a second indication signal;
- and
- an AND gate taking the first and second indication signals as inputs for setting an engine rate change status signal to inhibit engine cranking when both the first and second indication signals assume a first of two states.
Dependencies are inferred from the claim text.