Electric lock device

An electric lock device comprising:

• a movable member;
• a cam member rotated in an unlocking direction and a locking direction by driving of a drive source;
• and
• a lock member including a cam contact surface in contact with a sliding surface of the cam member, the lock member following the sliding surface to move between a locking position for inhibiting movement of the movable member and an unlocking position for allowing the movement of the movable member,
• wherein a cam profile of the sliding surface is set so that
• a rotary torque of the cam member for moving the lock member from the locking position to the unlocking position is calculated by the equation
• T=W·R·(Tan α+μ)/(1−μ·Tan α),
• with
• T=the rotary torque of the cam member,
• R=a radial length from a rotation center of the cam member,
• W=a constant load on the cam member,
• α=an angle of inclination between load W and the cam, and
• μ=a constant coefficient of kinetic friction;
• the rotary torque of the cam member is maintained at a constant value over a certain range of rotation angles of the cam member, and
• the lock member is moved in the certain range of rotation angles,
• wherein
• the cam profile comprises a high-load region and a low-load region within a range of movement of the lock member from the locking position to the unlocking position, a load on the drive source in the low-load region being lower than a load on the drive source in the high-load region,
• the high-load region corresponds to the certain range of rotation angles, and
• in the low-load region, the cam profile is set so that a shift stroke amount of the lock member per rotation angle of the cam member is larger than that in the high-load region.