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US 8,301,347 B2Granted
Control for managing actuator output pressure applied to a torque transmitting mechanism of a multi-speed transmission
AssigneeAllison Transmission, Inc.
InventorsJeff Shultz, Peter Swingler
Life of this patent
Estimating the term…
Abstract
A method for managing torque transmitting mechanism actuator output pressure under low supply pressure conditions is provided. The method is executable to control engagement of a torque transmitting mechanism during such conditions.
Claims21
A control for a torque transmitting mechanism of a vehicle transmission, comprising:
- a supply of hydraulic transmission fluid,
- an electro-hydraulic actuator in fluid communication with the fluid supply, the electro-hydraulic actuator being configured to provide an output pressure to a torque transmitting mechanism of a vehicle transmission, and
- an electronic control configured to detect a trim phase of the torque transmitting mechanism, and during the trim phase, send a first pressure command to the electro-hydraulic actuator when the fluid supply supplies fluid to the electro-hydraulic actuator at a first pressure, send a second pressure command less than the first pressure command to the electro-hydraulic actuator when the fluid supply supplies fluid to the electro-hydraulic actuator at a second pressure less than the first pressure, and send a third pressure command to the electro-hydraulic actuator greater than the second pressure command when the fluid supply supplies fluid to the electro-hydraulic actuator at a third pressure less than the first pressure.
A control for a torque transmitting mechanism of a vehicle transmission, comprising:
- a supply of hydraulic transmission fluid,
- an electro-hydraulic actuator in fluid communication with the fluid supply, the electro-hydraulic actuator being configured to provide an output pressure to a torque transmitting mechanism of a vehicle transmission, and
- an electronic control configured to detect a trim phase of the torque transmitting mechanism, and during the trim phase, send a first pressure command to the electro-hydraulic actuator when the fluid supply supplies fluid to the electro-hydraulic actuator at a first pressure, send a second pressure command to the electro-hydraulic actuator when the fluid supply supplies fluid to the electro-hydraulic actuator at a second pressure, and send a third pressure command to the electro-hydraulic actuator when the fluid supply supplies fluid to the electro-hydraulic actuator at a third pressure,
- wherein the electro-hydraulic actuator is a closed-end, variable bleed solenoid valve,
- wherein second and third pressures supplied by the fluid supply to the electro-hydraulic actuator are less than the first pressure supplied by the fluid supply to the electro-hydraulic actuator,
- wherein the first pressure command commands a trim pressure, the second pressure command is a “pressure off” command, the third pressure command is a “pressure on” command, and
- wherein the pressure off command commands zero pressure and the pressure on command commands a pressure equal to the trim pressure modified by an offset.
4 more elements
A method of controlling torque transmitting mechanism actuator output pressure at an electro-hydraulic actuator, comprising:
- receiving an indicator of a transmission input speed of a vehicle at an electrical control,
- receiving an indicator of a temperature of a hydraulic fluid of an electro-hydraulic control operably coupled to the vehicle transmission at the electrical control,
- issuing a first pressure command from the electrical control to the electro-hydraulic actuator if the transmission input speed indicator is greater than a threshold transmission input speed, and
- issuing repeating second and third pressure commands from the electrical control to the electro-hydraulic actuator while the transmission input speed indicator is less then the threshold transmission input speed and the temperature indicator is greater than a threshold temperature, wherein at least the second pressure command is less than the first pressure command and the third pressure command is greater than the second pressure command.
1 more element
A control for a torque transmitting mechanism of a vehicle transmission, comprising:
- a supply of hydraulic transmission fluid,
- an electro-hydraulic actuator in fluid communication with the fluid supply, the electro-hydraulic actuator being configured to provide an output pressure to a torque transmitting mechanism of a vehicle transmission, and
- an electronic control configured to detect a trim phase of the torque transmitting mechanism, and during the trim phase, send a trim pressure command to the electro-hydraulic actuator when the fluid supply supplies fluid to the electro-hydraulic actuator at a first pressure, send a “pressure off” command to the electro-hydraulic actuator when the fluid supply supplies fluid to the electro-hydraulic actuator at a second pressure less than the first pressure, and send a “pressure on” command to the electro-hydraulic actuator when the fluid supply supplies fluid to the electro-hydraulic actuator at a third pressure less than the first pressure, wherein the “pressure on” command commands a pressure equal to the trim pressure command modified by an offset.
Dependencies are inferred from the claim text.