Device and method for automatic transmission control

A control device for an automatic transmission having a friction clutch to which a torque from an engine is transmitted;

• drive gears, connected to the friction clutch, having their respective speed changing stages;
• driven gears corresponding to the drive gears, respectively;
• a claw clutch provided between the driven gears;
• and an assist clutch having gears for transmitting the torque during speed changing;
• the automatic transmission being configured so that,
• after releasing of the claw clutch, a rotational speed of the output shaft is changed in a positive direction by at least a predetermined value and then changed in a negative direction during the speed changing, a timing for releasing the claw clutch at next speed changing is increased, and when a rotational speed of the same is changed in a negative direction by at least a determined value and then changed in a positive direction, a timing for releasing the claw clutch at next speed changing is slowed.

A control device for an automatic transmission having a friction clutch to which a torque from an engine is transmitted;

• drive gears, connected to the friction clutch, having their respective speed changing stages;
• driven gears corresponding to the drive gears, respectively;
• a claw clutch provided between the driven gears;
• and an assist clutch having gears for transmitting the torque during speed changing;
• the automatic transmission control device being configured such that,
• after releasing of the claw clutch, a torque of the output shaft is changed in an increasing direction by at least a predetermined value, a timing for releasing the claw clutch at next speed changing is increased, and when the torque of the same is changed in a reducing direction by at least a predetermined value, a timing for releasing the claw clutch is slowed.

A control method of an automatic transmission having a friction clutch to which a torque from an engine is transmitted;

• drive gears, connected to the friction clutch, having their respective speed changing stages;
• driven gears corresponding to the drive gears, respectively;
• a claw clutch provided between the driven gears;
• and an assist clutch having gears for transmitting the torque during speed changing;
• said method comprising:
• determining a state of the claw clutch released during the speed changing;
• and
• adjusting a starting time of releasing the claw clutch based on the results of the determination.

A control method of an automatic transmission having a friction clutch to which a torque from an engine is transmitted;

• drive gears, connected to the friction clutch, having their respective speed changing stages;
• driven gears corresponding to the drive gears, respectively;
• a claw clutch provided between the driven gears;
• and an assist clutch having gears for transmitting the torque during speed changing;
• said method comprising at least one of:
• increasing a timing for releasing the claw clutch at a next speed changing when, during the speed changing and after releasing of the claw clutch, a rotational speed of the output shaft is changed in a positive direction by at least a predetermined value, and then changed in a negative direction;
• and
• slowing a timing for releasing the claw clutch at a next speed changing when a rotational speed of the output shaft is changed in a negative direction by at least a predetermined value, and then changed in a positive direction.

A control method of an automatic transmission having a friction clutch to which a torque from an engine is transmitted;

• drive gears, connected to the friction clutch, having their respective speed changing stages;
• driven gears corresponding to the drive gears, respectively;
• a claw clutch provided between the driven gears;
• and an assist clutch having gears for transmitting the torque during speed changing;
• said method comprising at least one of:
• increasing a timing for releasing the claw clutch at a next speed changing when, during the speed changing and after releasing of the claw clutch, a torque of the output shaft is changed in an increasing direction by at least a predetermined value;
• and
• slowing a timing for releasing the claw clutch at a next speed changing when a torque of the output shaft is changed in a reducing direction by at least a predetermined value.

A transmission system comprising

• an automatic transmission having a friction clutch to which a torque from an engine is transmitted;
• drive gears, connected to the friction clutch, having their respective speed changing stages;
• driven gears corresponding to the drive gears, respectively;
• a claw clutch provided between the driven gears;
• and an assist clutch having gears for transmitting the torque during speed changing;
• and a control device having learning determination unit to determine a state of the claw clutch released during the speed changing;
• and
• learning operation unit to adjust the starting time of releasing the claw clutch based on the results of the determination made by the learning determination unit.