Hybrid drive system wherein clutch is engaged when engine speed has exceeded motor speed upon switching from motor drive mode to engine drive mode

• US 7,165,638 B2
• Filed: 12/07/2005
• Issued: 01/23/2007
• Est. Priority Date: 10/08/1999
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Endo, Hiroatsu, Oba, Hidehiro, Ito, Masatoshi, Hoshiya, Kazumi
• Primary Examiner(s): Bottorff; Christopher
• Application Number:
  US11/295,557
• Publication Number:
  US 20060086545A1
• Time in Patent Office: 412 Days
• Field of Search: None
• US Class Current: 180/65.23
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• 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 6/543 the transmission being a continuously variable transmission
• CPC Class Codes: B60L 2260/26 Transition between different drive modes
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• 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 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 10/107 with endless flexible members
• 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 20/40 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 2510/0638 Engine speed
• CPC Class Codes: B60W 2710/025 Clutch slip, i.e. difference between input and output speeds
• CPC Class Codes: F16D 2500/1066 Hybrid
• CPC Class Codes: F16H 3/725 with means to change ratio in the mechanical gearing
• CPC Class Codes: F16H 61/66 specially adapted for continuously variable gearings control of exclusively fluid gearing F16H61/38
• CPC Class Codes: F16H 9/18 : only one flange of each pulley being adjustable
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y10S 903/903 : having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/905 : Combustion engine
• CPC Class Codes: Y10S 903/91 : Orbital, e.g. planetary gears
• CPC Class Codes: Y10S 903/918 : Continuously variable
• CPC Class Codes: Y10S 903/946 : Characterized by control of driveline clutch

Abstract

A hybrid vehicle drive system including (a) an engine, (b) an electric motor, (c) a planetary gear device having a first rotary element connected to the engine, a second rotary element connected to the electric motor and connected through a first clutch to an output member connected to vehicle drive wheel, and a third rotary element connected through a second clutch to the output member, (d) a forward-motor-drive control device for engaging the first clutch and releasing the second clutch to thereby establish a forward motor drive mode in which the vehicle is driven in a forward direction by the electric motor, (e) a forward-engine-drive control device for engaging at least the second clutch to establish an engine-drive mode in which the vehicle is driven in the forward direction by the engine, and (f) a second-clutch control device operable upon switching of a vehicle drive mode from the forward motor drive mode to the forward engine drive mode, for engaging the second clutch only after the engine speed has exceeded the motor speed.

Claims

1. A hybrid drive system for an automotive vehicle comprising:

(a) a vehicle drive power source including an engine operable by combustion of a fuel to generate a drive force, and an electric motor;

(b) a transmission;

(c) a clutch of a frictional coupling type disposed between said engine and said transmission, said clutch being engaged to switch a vehicle drive mode from a motor drive mode in which the automotive vehicle is driven by operation of said electric motor only, to an engine drive mode in which the automotive vehicle is driven by operation of said engine;

(d) clutch-slip control means for effecting a slipping engagement of said clutch upon switching of the vehicle drive mode from said motor drive to said engine drive mode; and

(e) transition-input-torque estimating means for estimating an input torque of said transmission on the basis of an engaging torque of said clutch during said slipping engagement of said clutch while the vehicle drive mode is switched from said motor drive mode to said engine drive mode.

2. The hybrid drive system according to claim 1, further comprising a motor control device operable to gradually reduce a torque of said electric motor according to an increase of said engaging torque of said clutch during said slipping engagement of said clutch.

3. The hybrid system according to claim 1, further comprising a transmission control device operable to control a hydraulic pressure to be applied to said transmission, on the basis of the input torque of the transmission estimated by said transition-input-torque estimating means.

4. A method of estimating an input torque of a transmission of a hybrid drive system for an automotive vehicle comprising (a) a vehicle drive power source including an engine operable by combustion of a fuel to generate a drive force, and an electric motor, (b) a clutch of a frictional coupling type disposed between said engine and said transmission, and (c) a transmission control device operable to control a hydraulic pressure to be applied to said transmission, on the basis of the estimated input torque of the transmission, said method comprising:

determining whether the automotive vehicle is in the process of a transition of a vehicle drive mode, with an engaging action of said clutch, from a motor drive mode in which the automotive vehicle is driven by operation of said electric motor only, to an engine drive mode in which the automotive vehicle is driven by operation of said engine;

determining whether a hydraulic pressure applied to said clutch is in the process of being gradually increased to effect a slipping engagement of said clutch, in the process of said transition of the vehicle drive mode; and

estimating an input torque of said transmission on the basis of an engaging torque of said clutch during said slipping engagement of said clutch.