Lock mechanism

A lock mechanism, comprising:

• a rotor including a rotor rotation axis, a pair of rod connecting portions located radially outside of the rotor rotation axis, and a pressure receiving surface located radially outside of the rotor rotation axis, the rotor configured to rotate between a lock input position and a release input position around the rotor rotation axis;
• a knob including a knob rotation axis and a pressing portion located radially outside of the knob rotation axis, the knob configured to rotate between a normal position and a release operation position around the knob rotation axis;
• a locking portion including a pair of rods respectively connected to one and the other of the pair of rod connecting portions, the locking portion configured to change its state between a locked state and a released state with rotation of the rotor between the lock input position and the release input position;
• a rotor urging member configured to urge the rotor to the lock input position;
• and
• a knob urging member configured to urge the knob to the normal position, wherein
• during an opening operation in which the knob rotates from the normal position to the release operation position,
• the pressing portion of the knob pushes the pressure receiving surface while sliding on the pressure receiving surface of the rotor to rotate the rotor from the lock input position to the release input position, and
• a length, obtained by projecting a sliding locus of the pressing portion on the pressure receiving surface on a cross-section in an axial perpendicular direction of the rotor, is not less than 0.8 times a length, by which the position of the pressing portion has been actually changed.