Electric brake device
An electric brake mechanism includes a piston ( 6 D) propelled by a rotation-linear motion mechanism ( 8 ) driven by an electric motor ( 7 A). The piston ( 6 D) is configured to press brake pads ( 6 C) against a disc rotor ( 4 ), and to hold the brake pads ( 6 C) at a pressing position by stopping the electric motor ( 7 A). A parking brake control device ( 24 ) is configured to determine, when a request (application command) to hold the brake pads ( 6 C) is made, a judgment timing for judging whether to stop the electric motor ( 7 A) based on a change trend of a current value of the electric motor ( 7 A). When the judgment timing is reached, the parking brake control device ( 24 ) judges whether or not to stop the electric motor ( 7 A).
1 . An electric brake device, comprising:
an electric brake mechanism in which a piston propelled by a rotation-linear motion mechanism driven by an electric motor is configured to press a braking member against a braked member, and to hold the braking member at a pressing position by stopping the electric motor; and
a control unit configured to control the electric motor,
wherein the control unit is configured to, when a request to hold the braking member is made,
calculate a current change of a current value of the electric motor over a predetermined first period of time,
calculate a second period of time based on the calculated current change of the current value over the predetermined first period of time, the second period of time beginning after an end of the predetermined first period of time and ending at a judgment timing at which the holding of the braking member is complete, for judging whether to stop the electric motor, and
to judge, only after the second period of time has elapsed, whether to stop the electric motor.
2 . The electric brake device according to claim 1 , wherein the control unit is configured to judge, when the judgment timing is reached, that the electric motor is allowed to be stopped when the current value of the electric motor is equal to or more than a predetermined value.
3 . The electric brake device according to claim 1 , wherein the control unit is configured to determine, when the current value is increased after a predetermined third period of time has elapsed since a start of driving of the electric motor, the judgment timing for judging whether to stop the electric motor based on the calculated current change of the current value over the predetermined first period of time.
4 . An electric brake device, comprising:
an electric brake mechanism in which a piston propelled by a rotation-linear motion mechanism driven by an electric motor is configured to press a braking member against a braked member, and to hold the braking member at a pressing position by stopping the electric motor; and
a control unit configured to control the electric motor,
wherein the control unit is configured
to determine, when a request to hold the braking member is made, a judgment threshold value for judging whether a rotational position of the electric motor has arrived at a position at which holding of the braking member is complete, the judgment threshold value being determined based on a current change over time of a current value of the electric motor and based on a difference between a motor rotation amount in a normal state and a predicted value of a motor rotation amount, the normal state being a state in which the current value of the electric motor increases linearly, and
to judge, when the judgment threshold value is reached, whether the holding of the braking member is complete.
5 . The electric brake device according to claim 2 , wherein the control unit is configured to determine, when the current value is increased after a predetermined third period of time has elapsed since a start of driving of the electric motor, the judgment timing for judging whether to stop the electric motor based on the calculated current change of the current value over the predetermined first period of time.
6 . The electric brake device according to claim 4 , wherein the predicted value of the motor rotation amount is a motor rotation amount estimated from a current change from an immediately preceding predetermined motor rotation amount when the current value of the electric motor reaches a predetermined value.