Control method for carrying out a gear shift in a transmission provided with a dual-clutch gearbox

Patent metadata

Field	Value
Publication number	US-9896110-B2
Application number	US-201615255260-A
Country	US
Kind code	B2
Filing date	Sep 2, 2016
Priority date	Sep 3, 2015
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

A control method for carrying out a gear shift in a transmission provided with a dual-clutch gearbox, so as to shift from a current gear to a following gear; the control method comprises the steps of: receiving a gear shift command; opening a first clutch associated with the current gear; closing a second clutch associated with the following gear; determining whether a driving style is a comfort driving style, an energy efficiency driving style, a sports driving style or a racing driving style; and in case of upshifting, controlling the second clutch after the complete closing of the second clutch, so as to allow said second clutch to temporarily transmit a torque that is greater than the torque to be transmitted by the second clutch immediately after the gear shift and than the torque transmitted by the first clutch immediately before the gear shift, only in case of energy efficiency or racing driving style.

First claim

The invention claimed is:

1. A control method for carrying out a gear shift in a transmission provided with a dual-clutch gearbox, so as to shift from a current gear to a following gear;
the transmission comprises the dual-clutch gearbox having two primary shafts, at least one secondary shaft connected to drive wheels, and two clutches, each of which is interposed between a drive shaft of an engine and a corresponding primary shaft;
the control method comprises the steps of:
receiving a gear-shift command;
opening a first clutch associated with the current gear;
closing a second clutch associated with the following gear;
in case of downshifting, controlling the second clutch after the complete closing of the second clutch so as to allow said second clutch to temporarily transmit a torque that is greater than the torque to be transmitted by the second clutch immediately after the gear shift and greater than the torque transmitted by the first clutch immediately before the gear shift;
determining whether a driving style is a comfort driving style, an energy efficiency driving style, a sports driving style or a racing driving style; and
in case of downshifting, activating the engine to generate a torque after the complete opening of the first clutch and so as to synchronize the speed (ω E ) of rotation of the drive shaft with the speed (ω B ) of rotation imposed by the gear ratio of the following gear only in case of sports or racing driving style.

2. The control method according to claim 1 and comprising the additional step of controlling, in case of upshifting, the second clutch after the complete closing of the second clutch so as to allow the second clutch to temporarily transmit a torque that is greater than the torque to be transmitted by the second clutch immediately after the gear shift and than the torque transmitted by the first clutch immediately before the gear shift, only in case of energy efficiency or racing driving style.

3. The control method according to claim 1 , wherein, in case of sports or racing driving style, the engine is activated so as to enhance the noise of the exhaust.

4. The control method according to claim 1 and, in case of upshifting, comprising the further steps of:
determining whether a driving style is a comfort driving style, an energy efficiency driving style, a sports driving style or a racing driving style;
adjusting the torque (T E ) generated by the engine after the complete opening of the first clutch, so as to synchronize the speed (ω E ) of rotation of the drive shaft with the speed (ω B ) of rotation imposed by the gear ratio of the following gear; and
causing the engine to operate in cut-off during the synchronization between the speed (ω E ) of rotation of the drive shaft and the speed (ω B ) of rotation imposed by the gear ratio of the following gear, only in case of sports or racing driving style.

5. The control method according to claim 4 , wherein the engine is caused to operate in cut-off by reducing to zero and subsequently restoring a target of torque (T E ) generated by the engine by means of a step variation.

6. The control method according to claim 1 and comprising the further step of, in case of upshifting, opening the first clutch as the second clutch is closed, only in case of comfort or energy efficiency driving style.

7. The control method according to claim 1 and comprising the further step of, in case of upshifting, partially opening the first clutch in advance of the closing of the second clutch, only in case of a sports or racing driving style.

8. The control method according to claim 1 , wherein:
the clutches are in an oil bath and are pressure-controlled, namely the degree of opening/closing of each clutch is determined by the pressure of the oil on the inside of said clutch;
the second clutch is filled with oil after receiving the gear shift command, by always supplying the greatest possible oil flow rate;
the second clutch is completely closed at the maximum possible speed as soon as the oil filling in said second clutch ends; and
the first clutch is completely opened at the maximum possible speed as soon as the oil filling in the second clutch ends.

9. The control method according to claim 8 and comprising the additional steps of:
determining the oil pressure on the inside of the second clutch; and
establishing that the oil filling in the second clutch has ended when the oil pressure on the inside of the second clutch exceeds a threshold.

10. A control method for carrying out a gear shift in a transmission provided with a dual-clutch gearbox, so as to shift from a current gear to a following gear;
the transmission comprises the dual-clutch gearbox having two primary shafts, at least one secondary shaft connected to drive wheels, and two clutches, each of which is interposed between a drive shaft of an engine and a corresponding primary shaft;
the control method comprises the steps of:
receiving a gear-shift command;
opening a first clutch associated with the current gear;
closing a second clutch associated with the following gear;
in case of downshifting, controlling the second clutch after the complete closing of the second clutch so as to allow said second clutch to temporarily transmit a torque that is greater than the torque to be transmitted by the second clutch immediately after the gear shift and greater than the torque transmitted by the first clutch immediately before the gear shift; and
in case of downshifting, not activating the engine to generate a torque after the complete opening of the first clutch and before the complete closing of the second clutch.

11. A control method for carrying out a gear shift in a transmission provided with a dual-clutch gearbox, so as to shift from a current gear to a following gear;
the transmission comprises the dual-clutch gearbox having two primary shafts, at least one secondary shaft connected to drive wheels, and two clutches, each of which is interposed between a drive shaft of an engine and a corresponding primary shaft;
the control method comprises the steps of:
receiving a gear-shift command;
opening a first clutch associated with the current gear;
closing a second clutch associated with the following gear;
in case of downshifting, controlling the second clutch after the complete closing of the second clutch so as to allow said second clutch to temporarily transmit a torque that is greater than the torque to be transmitted by the second clutch immediately after the gear shift and greater than the torque transmitted by the first clutch immediately before the gear shift;
determining whether a driving style is a comfort driving style, an energy efficiency driving style, a sports driving style or a racing driving style;
in case of upshifting, adjusting the torque (T E ) generated by the engine after the complete opening of the first clutch, so as to synchronize the speed (ω E ) of rotation of the drive shaft with the speed (ω B ) of rotation imposed by the gear ratio of the following gear; and
in case of upshifting, causing the engine to operate in cut-off during the synchronization between the speed (ω E ) of rotation of the drive shaft and the speed (ω B ) of rotation imposed by the gear ratio of the following gear, only in case of sports or racing driving style.

12. The control method according to claim 11 , wherein the engine is caused to operate in cut-off by reducing to zero and subsequently restoring a target of torque (T E ) generated by the engine by means of a step variation.

13. A control method for carrying out a gear shift in a transmission provided with a dual-clutch gearbox, so as to

Assignees

• Ferrari Spa

Inventors

• Barone Alessandro
• Prina Barbara
• Marcigliano Francesco

Classifications

• B60W2540/30

  Driving style · CPC title

• B60W10/06

  including control of combustion engines · CPC title

• B60W10/02

  including control of driveline clutches · CPC title

• F16D2500/31486

  Recognition of user style of driving, e.g. sportive, calm, nervous · CPC title

• B60W2710/021

  Clutch engagement state · CPC title