EP0435375A2
Expired / Lapsed
EP
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Method and apparatus for determining transmission clutch and brake fill time
Assignee: Motors Liquidation Co
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Filing: 1990-12-13
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Granted: —
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Expires: 2010-12-13
Abstract
Abstract The fill time of a clutch C1-C5 in an automatic transmission 10 is determined from empirical data embodied in look-up tables which relate the effects of pump speed and fluid temperature on the fill time. Calculations are made for a baseline clutch and are multiplied by a volume ratio for a particular clutch. The effect of fluid temperature on leakage is tabulated and used with the pump speed to determine the effective pumping speed. The effects of fluid temperature on viscosity and oil flow rate are determined and used to adjust the base fill time for high pumping speeds. The fluid retained in a clutch cavity from a recent application and not fully exhausted is also taken into account.
Inventors
- 👤 Carl Albert Lentz
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 11:10
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/04; F16H61/06; F16H61/061; F16H59/00; F16H59/68; F16H2059/6807; F16H2061/0075; F16H2061/0087; F16H2061/062; F16H59/72
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
195 words
A method of determining the fill time required substantially to fill with fluid a torque transmitting device of an automatic transmission (14) for a vehicle, which automatic transmission (14) comprises a plurality of fluid pressure operated torque transmitting devices (C1-C5) having different internal sizes and which can transmit torque when substantially filled with fluid; a pump (82) for supplying fluid to the torque transmitting devices; a controller (42) for sensing the rate at which fluid is supplied to a torque transmitting device by the pump, and the fluid temperature, and for storing a set of values related to fluid temperature and pumping rate, and to a base fill time representative of the time required substantially to fill with fluid a torque transmitting device of predetermined size; the method comprising the steps of determining an effective pumping rate as a function of the sensed pumping rate and fluid temperature; determining the base fill time as a function of the effective pumping rate from the set of stored values; and determining the fill time for the torque transmitting device as a function of the base fill time and a volume ratio factor for the torque transmitting device.
Claim 2
Dependent Claim
56 words
A method according to claim 1, wherein the step of determing the effective pumping rate comprises the steps of compensating for temperature dependent fluid leakages by determining the amount of fluid leakage as a function of the sensed fluid temperature; and adjusting the effective pumping rate as a function of the determined amount of fluid leakage.
Claim 3
Dependent Claim
79 words
A method according to claim 1 or 2, wherein for effective pumping rates above a preset rate, the step of determining the base fill time comprises the steps of determining the base fill time at the preset rate, determining a fluid viscosity correction factor as a function of the sensed fluid temperature, and calculating the base fill time at the effective pumping rate by multiplying the base fill time at the preset rate by the fluid viscosity correction factor.
Claim 4
Independent Claim
29 words
A method according to any preceding claim, wherein the step of determining the fill time comprises the step of multiplying the base fill time by the volume ratio factor.
Claim 5
Independent Claim
87 words
A method according to any preceding claim, wherein the step of determining the fill time includes the steps of determining the time elapsed between the most recent discharge of fluid from the torque transmitting device and the commencement of pumping of fluid thereinto, determining the amount of residual fluid contained in the torque transmitting device as a function of the determined elapsed time; and determining the fill time as a function of the base fill time, the volume ratio factor, and the determined amount of residual fluid.
Claim 6
Dependent Claim
201 words
Apparatus for determining the fill time required substantially to fill with fluid a torque transmitting device of an automatic transmission (14) for a vehicle, which automatic transmission (14) comprises a plurality of fluid pressure operated torque transmitting devices (C1-C5) having different internal sizes and which can transmit torque when substantially filled with fluid; and a pump (82) for supplying fluid to the torque transmitting devices; the apparatus comprising a controller (42) for sensing the rate at which fluid is supplied to a torque transmitting device by the pump, and the fluid temperature, and means for storing a set of values related to fluid temperature and pumping rate and to a base fill time representative of the time required substantially to fill with fluid a torque transmitting device of predetermined size, the controller (42) being adapted to determine an effective pumping rate as a function of the sensed pumping rate and fluid temperature, to determine the base fill time as a function of the effective pumping rate from the set of stored values, and to determine the fill time for the torque transmitting device as a function of the base fill time and a volume ratio factor for the torque transmitting device.
Claim 7
Dependent Claim
50 words
Apparatus according to claim 6, wherein the controller (42) is adapted to compensate for temperature dependent fluid leakages by determining the amount of fluid leakage as a function of the sensed fluid temperature and by adjusting the effective pumping rate as a function of the determined amount of fluid leakage.
Claim 8
Dependent Claim
74 words
Apparatus according to claim 6 or 7, wherein for effective pumping rates above a preset rate, the controller (42) is adapted to determine the base fill time at the preset rate, to determine a fluid viscosity correction factor as a function of the sensed fluid temperature, and to calculate the base fill time at the effective pumping rate by multiplying the base fill time at the preset rate by the fluid viscosity correction factor.
Claim 9
Dependent Claim
87 words
Apparatus according to any one of claims 6 to 8, wherein the controller (42) is adapted to determine the time elapsed between the most recent discharge of fluid from the torque transmitting device and the commencement of pumping of fluid thereinto, to determine the amount of residual fluid contained in the torque transmitting device as a function of the determined elapsed time; and to determine the fill time as a function of the base fill time, the volume ratio factor, and the determined amount of residual fluid.
References Cited (Backward Citations)
No citation records indexed.
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