US 5,265,018 AGranted

Transmission speed matching control

AssigneeFord New Holland, Inc.

InventorsDavid G. Sokol, Richard P. Strosser, James W. Macqueene

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Abstract

A vehicle transmission system having shift levers mechanically linked to couplers for selection of ranges of gear speed ratios and electro-hydraulic powershift clutches for selection of a gear speed ratio within the selected range is provided with controls for avoiding unexpected speeds or speed changes under certain conditions. If the vehicle is moving at start-up as a result of a stall or accidental reset of the microprocessor, and the shift levers have not been moved since the stall or reset, the microprocessor retrieves from a nonvolatile memory an indication of the last selected powershift gear prior to the reset and uses it for the initial powershift gear selection. When an operator depresses a clutch, shifts a shift lever and then changes his mind and shifts the shift lever back to its original position before releasing the clutch above a threshold point, the microprocessor selects the powershift gear in effect at the time the clutch pedal was depressed.

Claims12

Dependent claims

In a vehicle having a transmission system driven by a vehicle engine and including at least one range shift lever mechanically linked to a respective coupler and movable between first and second positions to select a range of gears, a plurality of electro-hydraulic powershift clutches selectively operable in response to electrical signals for selecting one powershift gear within a selected range, and microprocessor means responsive to actuation of powershift gear selection means or movement of a range shift lever between its first and second positions for applying electrical signals to said powershift clutches, apparatus for selecting an initial powershift gear at engine start-up comprising:

first means for repeatedly sensing present positions of all range shift levers;
memory means for retaining data even though power to said microprocessor means may be interrupted;
said microprocessor means including means for storing in said memory means an indication of the last selected powershift gear and further means responsive to said first means for storing in said memory means indications of the last sensed positions of the range shift levers;
and,
second means for sensing when said vehicle is moving;
said microprocessor means including means responsive to said first and second means and said memory means for applying electrical signals to said powershift clutches in accordance with said stored indication of said last selected powershift gear when said vehicle is moving at engine start-up and said present positions of said range shift levers are the same as the last sensed positions of said range select levers as indicated by said stored indications of the last sensed positions of said range select levers.

3 more elements

In a transmission system driven by a vehicle engine and including a range shift lever mechanically linked to a coupler and movable between first and second positions to select a first or a second range of gears, a plurality of powershift clutches selectively energizable to select one powershift gears within a selected range, powershift switch means for manually selecting a powershift gear, sensor means for sensing the position of said range shift lever, first circuit means responsive to said powershift switch means and said sensor means for setting into a first register a powershift gear value representing a powershift gear to be selected, and second circuit means responsive to a clutch pedal movable between a depressed position and a released position for energizing said powershift clutches according to said powershift gear value in said first register as said clutch pedal is released, the improvement comprising:

a second register;
first means for transferring said powershift gear value from said first register to said second register and entering a new powershift gear value in said first register the first time said range shift lever is shifted from one of said first and second positions to the other during a given depression of said clutch pedal;
and,
second means for transferring said powershift gear value in said second register back to said first register if said range shift lever is also shifted from said other to said one of said first and second positions during said given depression of said clutch pedal;
whereby, upon release of said clutch pedal the powershift gear selected is determined by said powershift gear value if the range shift lever is shifted twice such that said range shift lever returns to its original position during said given depression of said clutch pedal but is determined by said new powershift gear value if the range shift lever is shifted only one time.

2 more elements

In a transmission system driven by a vehicle engine and including range shift levers mechanically linked to couplers and each movable between first and second positions to select ranges of gears, a plurality of powershift clutches selectively energizable to select one powershift gear within a selected range, powershift switch means for manually selecting a powershift gear, sensor means for sensing the position of the range shift levers, first circuit means responsive to said powershift switch means and said sensor means for setting into a first register a powershift gear value representing a powershift gear to be selected, and second circuit means responsive to a clutch pedal movable between a depressed position and a released position for energizing said powershift clutches according to the value in said first register as the clutch pedal is released, the improvement comprising:

a second register;
first means for transferring said powershift gear value from said first register to said second register and entering a new powershift gear value in said first register the first time a range shift lever is shifted from one of said first and second positions to the other during a given depression of said clutch pedal;
and,
second means for transferring the value in said second register back to said first register if a shifted range shift lever is also shifted from said other to said one of said first and second positions during said given depression of said clutch pedal;
whereby, upon release of said clutch pedal the powershift gear selected is determined by said powershift gear value if a range shift lever is shifted twice such that said range shift lever returns to its original position during said given depression of said clutch pedal but is determined by said new powershift gear value if a range shift lever is shifted only one time.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/710,360Filed 3 Jun 1991
Granted: 23 Nov 1993
Term ends: Not estimatedThe source records don’t support an estimate.

Classification27 codes

F16H 61/702
Specially adapted for change-speed gearing in group arrangement, i.e. with separate change-speed gear trains arranged in series, e.g. range or…:…
B60W 10/02
Conjoint control of vehicle sub-units of different type or different function: including control of driveline clutches
B60W 10/10
Conjoint control of vehicle sub-units of different type or different function: including control of change-speed gearings
B60W 30/1819
Propelling the vehicle: propulsion control with control means using analogue circuits, relays or mechanical links