VEHICLE AND CONTROL METHOD THEREOF

• US 20120215392A1
• Filed: 12/11/2009
• Published: 08/23/2012
• Est. Priority Date: 12/11/2009
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Hashimoto, Toshiya
• Granted Patent: US 8,682,544 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• 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 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 2030/203 related or induced by the clutch
• CPC Class Codes: B60W 2510/0208 Clutch engagement state, e.g. engaged or disengaged
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

In the case that operation stop of the engine is requested while the clutch is engaged and the engine is driven at a higher rotation speed than the resonance rotation speed band, the clutch is disengaged and the engine is driven in the self-sustaining operation at the self-sustaining rotation speed higher than the resonance rotation speed band, the rotation speed Ne of the engine is lowered less than or equal to the second rotation speed Nref2 lower than the resonance rotation speed band with stop of fuel injection into the engine and the partially-engaged clutch after the rotation speed Nm of the motor MG becomes less than or equal to the first rotation speed Nref1 predetermined as a rotation speed lower than the resonance rotation speed after the clutch is disengaged. The rotation speed of the engine is therefore enabled to pass more rapidly through the resonance rotation speed band.

Claims

1. A vehicle, comprising:

an internal combustion engine configured to output power via a clutch to a driveshaft linked to driving wheels;

a motor configured to input and output power from and to the driveshaft;

a transmission that has an input shaft connected via the clutch to an output shaft of the internal combustion engine and connected with a rotating shaft of the motor and transmits power between the input shaft and the driveshaft with a speed change between different speeds;

an accumulator configured to transmit electric power to and from the motor; and

a controller configured to, in a case of a predetermined stop request time that is when operation stop of the internal combustion engine is requested while the internal combustion engine is in operation with the clutch engaged at a higher rotation speed than a resonance rotation speed band that is a rotation speed range of the internal combustion engine where resonance occurs in the vehicle, control the internal combustion engine, the motor, and the clutch so that the clutch is disengaged and the vehicle is driven with a driving force demand required for driving the vehicle while keeping a rotation speed higher than the resonance rotation speed band in the internal combustion engine, and subsequently control the internal combustion engine, the motor, and the clutch so that the rotation speed of the internal combustion engine is lowered below the rotation speed band by partially engaging the clutch and stopping fuel injection into the internal combustion engine and the vehicle is driven with the driving force demand after a rotation speed of the motor reaches less than or equal to a predetermined rotation speed as a rotation speed lower than the resonance rotation speed band,

wherein the controller controls the transmission, in a case that the rotation speed of the motor becomes less than or equal to the predetermined rotation speed if the speed in the transmission is changed to a higher speed level that is a higher speed than a present speed in the transmission in the case of the predetermined stop request time, so that the speed in the transmission is changed to the higher speed level after the clutch is disengaged.

3. The vehicle in accordance with claim 1, wherein the controller controls the transmission, in a case that the rotation speed of the motor does not become less than or equal to the predetermined rotation speed even if the speed in the transmission is changed in the case of the predetermined stop request time, so that the speed in the transmission is changed to a highest speed level of the transmission after the clutch is disengaged.

4. The vehicle in accordance with claim 1, the vehicle further having:

a braking force applying unit configured to apply braking force to the vehicle,

wherein the controller controls the motor and the braking force applying unit, in a case that the driving force demand as a braking force is not satisfied with a nominal torque output from the motor according to the rotation speed of the motor if the speed in the transmission is changed to the higher speed level on condition that the rotation speed of the motor becomes less than or equal to the predetermined rotation speed if the speed in the transmission is changed to the higher speed level in the case of the predetermined stop request time, so that the vehicle is driven with the driving force demand satisfied with the nominal torque output from the motor and the braking force applied from the braking force applying unit to the vehicle.

5. The vehicle in accordance with claim 1, wherein the controller performs control regarding when operation stop of the internal combustion engine is requested upon accelerator-off as the predetermined stop request time.

6. The vehicle in accordance with claim 1, wherein the controller controls the clutch so that the partially engaged clutch is disengaged in a case that the rotation speed of the internal combustion engine becomes less than or equal to a second predetermined rotation speed as a rotation speed lower than the resonance rotation speed band.

2. (canceled)

7. (canceled)