Method and system for controlling engine speed, engine torque and output from a torque converter
View Patent ↗The present invention broadly comprises a method for controlling engine speed, engine torque, and torque converter output including the steps of applying engine torque to a torque converter and modulating the transferring of the torque to a pump for the torque converter. In some aspects, the torque converter further comprises a pump clutch and the method applies torque to the pump clutch and controllably slips the pump clutch. In some aspects, the method supplies engine torque from an engine with a turbocharger and controllably slips the pump clutch to increase speed and torque for the engine during a launch event for the vehicle or determines a parameter regarding operation of the vehicle and controllably slips the pump clutch responsive to the parameter. The present invention also comprises a method for controlling torque converter output by connecting a clutch between an engine and a torque converter and controllably slipping the clutch.
1. A method for increasing engine speed and engine torque during a launch event in a vehicle equipped with a turbocharged engine, comprising:
opening a pump clutch for a torque converter;
applying, to initiate said launch event, engine torque to a damper for the torque converter, wherein the engine is rotating at a first speed when the engine torque is applied to the damper;
for a first time period beginning at the initiation of the launch event, maintaining the pump clutch in the torque converter in an open position such that a pump for the torque converter is not receiving torque from the damper;
during the first time period, increasing the first speed for the engine;
after the expiration of the first time period, controllably slipping said pump clutch to transfer said torque to the pump;
reducing slippage in said pump clutch at a predetermined rate; and,
fully closing said pump clutch.
2. A system for controlling engine speed, engine torque, and torque converter output in a vehicle, comprising:
a damper connected to an output for an engine in said vehicle and for receiving torque from the engine;
a pump clutch with an input connected to the damper and with an output connected to an input for a torque converter; and,
a control element configured to controllably slip said pump clutch at a predetermined rate, wherein:
said engine is turbocharged and said control element is configured to controllably slip said pump clutch during a launch event for said vehicle;
at an initiation of the launch event, the engine is for transferring torque to the damper;
the control element is for opening the pump clutch prior to the initiation of the launch event and keeping the pump clutch open for a first time period beginning at the initiation of the launch event such that a speed of rotation for the engine increases during the first time period and such that a pump for the torque converter does not receive torque from the damper during the first time period;
said control element is configured to reduce slippage in said pump clutch at a predetermined rate after expiration of the first time period; and,
said control element is configured to close said clutch after said clutch is controllably slipped.
3. The system of claim 2 further comprising:
a sensing element configured to determine a parameter associated with operation of said vehicle and to provide a signal regarding said parameter to said control element; and, wherein said control element is configured to controllably slip said clutch responsive to said signal.
4. The system of claim 3 wherein said parameter is regarding traction for said vehicle.
5. The system of claim 3 wherein said control element is configured to limit said torque output.