CONTROL APPARATUS FOR HYBRID VEHICLE

• US 20120202646A1
• Filed: 01/30/2012
• Published: 08/09/2012
• Est. Priority Date: 02/03/2011
• Status: Active Grant

• Current Assignee: Jatco Limited (Nissan Motor Co., Ltd.)
• Original Assignee: Jatco Limited (Nissan Motor Co., Ltd.)
• Inventors: Suzuki, Masami, Yamanaka, Fumihiro
• Granted Patent: US 8,812,208 B2
• Time in Patent Office: Days
• US Class Current: 477/5
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/115 with planetary gears
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/30 Control strategies involving selection of transmission gear ratio control of change speed gearings, together with other vehicle sub-units B60W10/10; HEV transmission gearing B60K6/36; gearings and control thereof F16H
• CPC Class Codes: B60W 2710/023 Clutch engagement rate
• CPC Class Codes: B60W 2710/025 Clutch slip, i.e. difference between input and output speeds
• CPC Class Codes: B60W 2710/1005 Transmission ratio engaged
• CPC Class Codes: B60W 2710/1011 Input shaft speed, e.g. turbine speed
• CPC Class Codes: B60W 2710/1022 Input torque
• CPC Class Codes: B60W 30/19 Improvement of gear change, e.g. by synchronisation or smoothing gear shift
• CPC Class Codes: F16H 2061/0444 during fast shifting over two gearsteps, e.g. jumping from fourth to second gear
• CPC Class Codes: F16H 2061/0462 by controlling slip rate during gear shift transition
• CPC Class Codes: F16H 61/061 using electric control means
• CPC Class Codes: F16H 61/686 with orbital gears

Abstract

A control apparatus of a hybrid vehicle provided with an engine, a motor, an automatic transmission performing a shift by engaging/disengaging a plurality of engagement elements, a first clutch arranged between the engine and the motor for transmitting/cutting a driving force between the engine and the motor and a second clutch arranged between the motor and driving wheels for transmitting/cutting a driving force from the motor to the driving wheels, has a slip control section that controls the second clutch to a slip state during the shift of the automatic transmission. In a case of a successive shift in which a current shift and a succeeding shift are successively performed, the slip control section gradually increases an engagement pressure of the second clutch when changing the slip state of the second clutch to a fully engaged state after the current shift is completed and before the succeeding shift is completed.

Claims

1. A control apparatus of a hybrid vehicle, the hybrid vehicle having an engine, a motor, an automatic transmission performing a shift by engaging or disengaging a plurality of engagement elements, a first clutch arranged between the engine and the motor for transmitting/cutting a driving force between the engine and the motor and a second clutch arranged between the motor and driving wheels for transmitting/cutting a driving force from the motor to the driving wheels, the control apparatus comprising:

a slip control section that controls the second clutch to a slip state during the shift of the automatic transmission, and

in a case of a successive shift in which a current shift and a succeeding shift are successively performed, the slip control section gradually increasing an engagement pressure of the second clutch when changing the slip state of the second clutch to a fully engaged state after the current shift is completed and before the succeeding shift is completed.

2. The control apparatus of the hybrid vehicle as claimed in claim 1, wherein:

in a case where an engagement element that is disengaged in the current shift, an engagement element that is disengaged in the succeeding shift and an engagement element that works as the second clutch are different from each other, the slip control section gradually increases the engagement pressure of the second clutch and changes the slip state of the second clutch to the fully engaged state, and

in a case where the engagement element that is disengaged in the current shift and the second clutch are the same, or in a case where the engagement element that is disengaged in the succeeding shift and the second clutch are the same, a control for disengaging the engagement element has priority over the slip state.

3. The control apparatus of the hybrid vehicle as claimed in claim 1, wherein:

in a case of a single shift in which only the current shift is carried out, when changing the slip state of the second clutch to the fully engaged state after the single shift is completed, the slip control section increases the engagement pressure of the second clutch at a greater pressure increase rate of the engagement pressure of the second clutch than a rate of the pressure increase of the second clutch performed during the successive shift.

4. A method for controlling a hybrid vehicle, the hybrid vehicle provided with an engine, a motor, an automatic transmission performing a shift by engaging or disengaging a plurality of engagement elements, a first clutch arranged between the engine and the motor for transmitting/cutting a driving force between the engine and the motor and a second clutch arranged between the motor and driving wheels for transmitting/cutting a driving force from the motor to the driving wheels, the method comprising:

controlling the second clutch to a slip state during the shift of the automatic transmission; and

in a case of a successive shift in which a current shift and a succeeding shift are successively performed, gradually increasing an engagement pressure of the second clutch when changing the slip state of the second clutch to a fully engaged state after the current shift is completed and before the succeeding shift is completed.