Method and system of controlling shift of transmission speed ratio for gas turbine engine vehicle

• US 5,233,888 A
• Filed: 06/04/1991
• Issued: 08/10/1993
• Est. Priority Date: 06/06/1990
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Fukuda, Daiki
• Primary Examiner(s): Lorence, Richard M.
• Assistant Examiner(s): Levi, Benjamin
• Application Number:
  US07/710,073
• Time in Patent Office: 798 Days
• Field of Search: 74/866, 364/424.1
• US Class Current: 477/30
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/11 Stepped gearings
• CPC Class Codes: B60W 30/18 Propelling the vehicle
• CPC Class Codes: B60W 30/1819 Propulsion control with control means using analogue circuits, relays or mechanical links
• CPC Class Codes: F16H 2061/0232 Selecting ratios for bringing engine into a particular state, e.g. for fast warming up or for reducing exhaust emissions
• CPC Class Codes: F16H 59/48 Inputs being a function of acceleration
• CPC Class Codes: F16H 59/74 Inputs being a function of engine parameters F16H59/14 takes precedence
• CPC Class Codes: F16H 61/0213 characterised by the method for generating shift signals

Abstract

In a gas turbine engine vehicle having a two-shaft type gas turbine engine including a gas generator constituted by a compressor and a compressor turbine arranged coaxially with the compressor, a combustion chamber, a variable nozzle, and a power turbine rotatable about a turbine shaft independently of a shaft of the compressor and the compressor turbine, a transmission speed ratio is shifted to a higher stage than the current transmission speed ratio when an engine acceleration requirement is greater than a predetermined value. As a result, a lowering of a vehicular acceleration characteristics due to a response lag in a variation of revolution speed at the compressor turbine can be prevented, and thus an enhanced acceleration and deceleration of the automotive vehicle is provided.

Claims

1. A method for controlling a shift of a transmission speed ratio in an automatic power transmission employed in a gas turbine engine vehicle having a two-shaft type gas turbine engine including a gas generator constituted by a compressor and a compressor turbine arranged coaxially with said compressor, a combustion chamber, a variable nozzle, and a power turbine rotatable about a turbine shaft independently of a shaft of said compressor and said compressor turbine, wherein the method comprises the steps of:

detecting a steady state of said engine;

detecting an acceleration of the engine;

determining whether an engine accelerating condition satisfies a predetermined condition, wherein said predetermined condition is a requirement for a degree of acceleration from the steady state at more than a predetermined value;

shifting a transmission speed ratio to a stage higher than a current transmission speed ratio when an acceleration condition satisfying said predetermined condition is detected; and

selecting shift characteristics of said automatic power transmission so that as high a rotational range of said power turbine as possible is used when the requirement for a degree of acceleration from the steady state is less than said predetermined value.

2. A method as set forth in claim 1, which further comprises a step of selecting shift characteristics of said automatic power transmission for performing a shift down operation to maintain the engine speed at as high a speed as possible within a range in which the rotation speed of said power turbine is maintained at a speed lower than or equal to an acceptable maximum rotation speed, when the engine is decelerated.

3. A system of controlling a shift of a transmission speed ratio in an automatic power transmission employed in a gas turbine engine vehicle having a two-shaft type gas turbine engine including a gas generator constituted by a compressor and a compressor turbine arranged coaxially with said compressor, a combustion chamber, a variable nozzle, and a power turbine rotatable about a turbine shaft independently of a shaft of said compressor and said compressor turbine, wherein the system comprises:

means for detecting a steady state of said engine, said means for detecting a steady state being coupled to said engine;

means for directly detecting an acceleration of the engine, said means for detecting an acceleration being coupled to said engine;

means for determining whether the engine accelerating condition satisfies a predetermined condition, said means for determining being coupled to said means for detecting an acceleration, wherein said predetermined condition is a requirement for a degree of acceleration from the steady state at more than a predetermined value;

means for shifting up the transmission when a condition of said engine changes from a decelerating condition, said decelerating condition including a steady state, to an accelerating condition, said means for shifting up being coupled to said transmission; and

means for selecting shift characteristics of said automatic power transmission so that as high a rotational range of said power turbine as possible is used when the requirement for a degree of acceleration from the steady state is less than a predetermined value; and

means for shifting a transmission speed ratio to a stage higher than a current transmission speed ratio when an engine accelerating condition satisfying said predetermined condition is detected, said means for shifting a transmission speed ratio being coupled to said transmission.

4. A system of controlling a shift of a transmission speed ratio in an automatic power transmission employed in a gas turbine engine vehicle having a two-shaft type gas turbine engine including a gas generator constituted by a compressor and a compressor turbine arranged coaxially with said compressor, a combustion chamber, a variable nozzle, and aa power turbine rotatable about a turbine shaft independently of a shaft of said compressor and said compressor turbine, wherein the system comprises:

means for detecting a steady state of said engine, said means for detecting a steady state being coupled to said engine;

means for directly detecting an acceleration of the engine, said means for detecting an acceleration being coupled to said engine;

means for determining whether the engine accelerating condition satisfies a predetermined condition, said means for determining being coupled to said means for detecting an acceleration, wherein said predetermined condition is a requirement for a degree of acceleration from the steady state at more than a predetermined value;

means for shifting up the transmission when a condition of said engine changes from a decelerating condition, said decelerating condition including a steady state, to an accelerating condition, said means for shifting up being coupled to said transmission;

means for selecting shift characteristics of said automatic power transmission for performing a shift down operation to maintain the engine speed at as high a speed as possible within a range in which the rotation speed of said power turbine is maintained at a speed lower than or equal to an acceptable maximum rotation speed, when the engine is decelerated, said means for selecting shift characteristics being coupled to said automatic power transmission;

means for shifting a transmission speed ratio to a stage higher than a current transmission speed ratio when an engine accelerating condition satisfying said predetermined condition is detected, said means for shifting a transmission speed ratio being coupled to said transmission.

5. A system of controlling a shift of a transmission speed ratio in an automatic power transmission employed in a gas turbine engine vehicle having a two-shaft type gas turbine engine including a gas generator constituted by a compressor and a compressor turbine arranged coaxially with said compressor, a combustion chamber, a variable nozzle, and aa power turbine rotatable about a turbine shaft independently of a shaft of said compressor and said compressor turbine, wherein the system comprises:

means for detecting a steady state of said engine, said means for detecting a steady state being coupled to said engine;

means for directly detecting an acceleration of the engine, said means for detecting an acceleration being coupled to said engine;

means for determining whether the engine accelerating condition satisfies a predetermined condition, said means for determining being coupled to said means for detecting an acceleration, wherein said predetermined condition is a requirement for a degree of acceleration from the steady state at more than a predetermined value;

means for shifting up the transmission when a condition of said engine changes from a decelerating condition, said decelerating conditions including a steady state, to an accelerating condition, said means for shifting up being coupled to said transmission; and

means for shifting a transmission speed ratio to a stage higher than a current transmission speed ratio when an engine accelerating condition satisfying said predetermined condition is detected, said means for shifting a transmission speed ratio being coupled to said transmission;

means for selecting shift characteristics of said automatic power transmission by which as high a rotational range of said power turbine as possible is used when the requirement for a degree of acceleration from the steady state is less than a predetermined value;

means for selecting shift characteristics of said automatic power transmission for performing a shift down operation to maintain the engine speed at as high a speed of said power turbine is maintained at a speed lower than or equal to an acceptable maximum rotation speed, when the engine acceleration is negative.