Door opening and closing device

A door opening and closing device, comprising:

• a motor configured to generate drive power for a door in an opening direction and a closing direction of the door;
• a door position sensor configured to detect an opening and closing position of the door;
• and
• a controller configured to control the motor based on the opening and closing position detected by the door position sensor,
• wherein:
• the motor comprises a stator comprising at least three-phase coils and a rotor configured to rotate with respect to the stator, and generates the drive power when the rotor rotates with respect to the stator;
• the controller is configured to enter a door holding control mode when the door position sensor detects that the opening and closing position of the door lies within a predetermined range, wherein in the door holding control mode, the controller energizes at least two phases of the motor to brake rotation of the rotor and generate a holding force, thereby inhibiting opening and closing of the door;
• in the door holding control mode, the controller changes a magnitude of the holding force depending on the opening and closing position of the door;
• the predetermined range is a range from a first position to a second position, and includes a predetermined position between the first position and the second position;
• and
• the controller increases the holding force as the opening and closing position of the door lies closer to the predetermined position, and decreases the holding force as the opening and closing position of the door lies apart away from the predetermined position.

A door opening and closing device, comprising:

• a motor configured to generate drive power for a door in an opening direction and a closing direction of the door;
• a door position sensor configured to detect an opening and closing position of the door;
• and
• a controller configured to control the motor based on the opening and closing position detected by the door position sensor,
• wherein:
• the motor comprises a stator comprising at least three-phase coils and a rotor configured to rotate with respect to the stator, and generates the drive power when the rotor rotates with respect to the stator;
• the controller is configured to enter a door holding control mode when the door position sensor detects that the opening and closing position of the door lies within a predetermined range, wherein in the door holding control mode, the controller energizes at least two phases of the motor to brake rotation of the rotor and generate a holding force, thereby inhibiting opening and closing of the door;
• in the door holding control mode, the controller changes a magnitude of the holding force depending on the opening and closing position of the door;
• the predetermined range is a range from a first position to a second position, and includes a predetermined position between the first position and the second position, and
• the controller decreases the magnitude of the holding force in a case where the opening and closing position is the predetermined position to be smaller than a maximum value of the holding force in a case where the opening and closing position of the door lies within a range from the first position to the predetermined position, and a maximum value of the holding force in a case where the opening and closing position of the door lies within a range from the predetermined position to the second position.