Gm Global Technolgoy Operations, Inc.

Phillip F Mc Cauley

Charles Francis Long

Jeffrey Kurt Runde

Andrew L Mitchell

Shushan Bai

Darren J Weber

John P Kresse

Brett Caldwell

Timothy Alan Robinson

Scott E Mundy

Scott T Kluemper

Jeffrey J Cole

Steven Franklin James

Scott Mc Thompson

A method is provided for determining variance of actual engine torque from reported engine torque, including configuring a controller with an algorithm to calculate the ratios of current and maximum engine torque to reported torque upon the initiation of high-throttle 1-2 shift, high-throttle 2-3 shift, high-throttle torque converter lockup, and at maximum Engine Rating Torque Function for each high-throttle torque converter drive cycle. An apparatus is also provided for detecting engine torque variance in a vehicle having an engine, a throttle, and a torque converter, the apparatus comprising a controller with memory and an algorithm for calculating the maximum and current engine torque variance upon the occurrence a predetermined throttle condition, and storing the values in accessible memory, wherein the controller is configured to initiate the algorithm upon the occurrence of one of the throttle conditions, and wherein the throttle and torque converter each communicate speed signals to the controller.

Engine overrate detection method and apparatus

Provided is an apparatus to enable a torque transmitting mechanism within an automatically shiftable power transmission to disengage at vehicle stop such that the slip within a fluid drive device is reduced. When vehicle movement is required a main pressure regulator trims the torque transmitting mechanism into engagement. A method of reducing engine load at vehicle stop by employing the apparatus of the present invention is also provided.

Reduced engine load at stop apparatus and method

According to a preferred embodiment of the present invention, a clutch is applied when the vehicle comes to a stop. The application of this clutch locks the output shaft with energy stored therein. When the shift selector is then moved to the park position, the clutch releases the stored energy in a controlled manner by slipping the clutch plates. The controlled slipping reduces the noise as the park pawl tooth contracts an output gear tooth.

Method for improving a drive-to-park shift

An electro-hydraulic control mechanism for use with a multi-speed transmission includes a pair of logic valves, which are manipulated during the ratio interchanges and the ratio establishment by aiding in the distribution of fluid pressure from a plurality of trim valves. The logic valves are retained in specific drive ranges in the event of electrical discontinuance.

Fly-by-wire limp home and multi-plex system

The present invention provides a method and apparatus for a self-cleaning valve assembly. The valve is adapted to cycle and thereby clean the valve assembly in response to one or more predefined parameters which are programmed into a programmable controller. The valve is additionally configured to cycle according to one or more of several different methods which have been shown to efficiently clean the valve assembly. In this manner, the valve assembly is automatically cleaned improving the efficiency thereof and eliminating stuck valve warranty returns.

Self-cleaning valve assembly

A power transmission includes a plurality of torque transmitting mechanisms controlled by an electro-hydraulic control system to provide a reverse drive ratio, a neutral condition and a plurality of forward drive ratios. The electro-hydraulic control has three shift valves, two variable pressure control valves, and a manual control valve. Each of the shift valves have a hydraulically on position, established by a respective solenoid valve, and a hydraulically off position, established by a spring. The manual control valve is moveable to a neutral condition, a reverse drive condition and a forward drive condition. In each of the positions during a neutral to reverse, neutral to forward, or forward/reverse interchange, the shift valves are conditioned to be hydraulically on thereby permitting the manual control valve to be the controlling valve member for completing the interchange. When the reverse ratio is established, the manual control valve directs fluid pressure from one of the variable pressure control valves to one of the shift valves to assist the respective spring and urge the shift valve to the hydraulically off position. During the reverse ratio, neutral condition and the first forward ratio one of the torque transmitting mechanisms is continually engaged.

Electro-hydraulic control with a manual selection valve

Transmission output speed and engine throttle position are inputs to a control which determines acceleration and input speed. Fuzzy logic has acceleration and throttle membership functions and a set of upshift and downshift values, and rules for weighting each of the values in accordance with the degree of membership of acceleration and throttle position in certain of the functions to determine a downshift point and an upshift point. The input speed is compared to the shift points to decide whether to order a shift. Two or more sets of shift values are stored and are selectable for different performance options. The shift values are stated in terms of a percentage of engine governed speed to allow different engines to be coupled to the transmission. Lockup clutch apply and release logic controls converter lockup to maintain converter mode when significant torque multiplication is occurring and generally to maintain lockup mode when the transmission range is at or above the lowest allowable lockup range.

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Zionsville, IN, United States of America

Phillip F Mc Cauley