Clutch control device for hybrid vehicle

• US 9,623,867 B2
• Filed: 04/03/2014
• Issued: 04/18/2017
• Est. Priority Date: 04/26/2013
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Ashizawa, Hiroyuki, Takamura, Yutaka
• Primary Examiner(s): Hilgendorf, Dale W
• Application Number:
  US14/778,547
• Publication Number:
  US 20160272192A1
• Time in Patent Office: 1,111 Days
• CPC Class Codes: B60K 6/387 Actuated clutches, i.e. clutches engaged or disengaged by electric, hydraulic or mechanical actuating means
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/11 Stepped gearings
• 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 20/19 for achieving enhanced acceleration
• CPC Class Codes: B60W 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/103 Accelerator thresholds, e.g. kickdown
• CPC Class Codes: B60W 2540/106 Rate of change
• CPC Class Codes: B60W 2710/027 Clutch torque
• CPC Class Codes: B60Y 2200/92 Hybrid vehicles
• CPC Class Codes: B60Y 2300/182 Selecting between different operative modes, e.g. comfort and performance modes
• CPC Class Codes: B60Y 2300/192 Power-up or power-down of the driveline, e.g. start up of a cold engine
• CPC Class Codes: B60Y 2300/42 Control of clutches
• CPC Class Codes: B60Y 2300/429 Control of secondary clutches in drivelines
• CPC Class Codes: B60Y 2300/43 Control of engines
• CPC Class Codes: B60Y 2300/63 : Starter motor mode
• CPC Class Codes: B60Y 2400/42 : Clutches or brakes
• CPC Class Codes: F16D 48/06 : Control by electric or electronic means, e.g. of fluid pressure
• CPC Class Codes: Y02T 10/40 : Engine management systems
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y10S 903/914 : Actuated, e.g. engaged or disengaged by electrical, hydraulic or mechanical means
• CPC Class Codes: Y10S 903/93 : Conjoint control of different elements

Abstract

A hybrid vehicle clutch control device includes an engine, a motor generator, a first clutch, a second clutch and at least one controller. The first clutch interrupts a torque transmission between the engine and the motor generator. The second clutch interrupts the torque transmission between the motor generator and driving wheels. The controller starts the engine using torque from the motor generator, when switching from an electric vehicle mode to a hybrid mode. When starting the engine accompanying an accelerator depression, the allocation of the transmission torque capacity of the second clutch is increased when the accelerator position opening amount is equal to or less than a predetermined accelerator position opening amount, as compared to when exceeding the predetermined accelerator position opening amount.

Claims

1. A clutch control device for a hybrid vehicle comprising:

an engine;

a motor generator;

a first clutch for interrupting a torque transmission between the engine and the motor generator;

a second clutch for interrupting the torque transmission between the motor generator and driving wheels; and

at least one controller programmed to

start the engine by utilizing torque from the motor generator, when switching from an electric vehicle mode that cuts off the first clutch and travels via the torque of the motor generator to a hybrid mode that connects the first clutch and travels via the torque of the engine and the motor generator;

calculate a motor upper limit torque,

allocate a first clutch transmission torque capacity command value and a second clutch transmission torque capacity command value within the range of the motor upper limit torque when starting the engine accompanying an accelerator depression, the allocating including controlling both the first clutch and the second clutch to be in a power transmission state, and increasing the allocation of the second clutch transmission torque capacity command value when an accelerator position opening amount is equal to or less than a predetermined accelerator position opening amount, as compared to when exceeding the predetermined accelerator position opening amount,

increase the allocation of the first clutch transmission torque capacity command value as an accelerator depression speed increases when the accelerator position opening amount exceeds the predetermined accelerator position opening amount,

calculate a drive torque command value based on the accelerator position opening amount,

calculate a change rate of the drive torque command value,

calculate a second clutch torque capacity maximum value, which is the maximum value of the torque that can be allocated to the second clutch when starting the engine by subtracting an engine start lower limit torque minimum value, which is the minimum value of an engine start torque that is required for cranking from the motor upper limit torque, and

allocate the second clutch transmission torque capacity command value when the drive torque command value is equal to or less than the second clutch torque capacity maximum value, and increase the allocation of the first clutch transmission torque capacity command value as the drive torque command value change rate increases when the drive torque command value exceeds the second clutch torque capacity maximum value.

2. The clutch control device according to claim 1, wherein

the at least one controller is further programmed to

calculate the engine start lower limit torque that is minimally required for cranking at a current engine rotational speed based on the engine rotational speed and whether or not an initial explosion has already occurred in the engine,

calculate a second clutch torque capacity upper limit value that can be allocated to the second clutch by subtracting the engine start lower limit torque from the motor upper limit torque,

set a first value restricting the upper limit of the drive torque command value with the second clutch torque capacity upper limit value as the second clutch transmission torque capacity command value,

set a second value obtained by subtracting the second clutch transmission torque capacity command value from the motor upper limit torque as the first clutch transmission torque capacity command value when the drive torque command value is equal to or less than the second clutch torque capacity maximum value,

set a third value obtained by reducing this to correct the first value restricting the upper limit of the drive torque command value with the second clutch torque capacity upper limit value as the accelerator depression speed increases, as the second clutch transmission torque capacity command value, and

set a fourth value subtracting the second clutch transmission torque capacity command value from the motor upper limit torque as the first clutch transmission torque capacity command value when the drive torque command value is greater than the second clutch torque capacity maximum value.