Multi-hardness cushion for automobile and multi-hardness cushion having ventilation structure

A seat cushion, comprising:

• a support cushion having an insert recess with stepped portions, wherein the stepped portions include regions that are elevated relative to other portions of the insert recess, and are formed on laterally opposing sides of the insert recess;
• a friction cushion configured to be detachably inserted into the insert recess, and having a locking part configured to be locked to each of the stepped portions in an assembled state;
• a first ventilation unit having a first air flow channel provided in the insert recess, a plurality of first side flow channels provided in each of the stepped portions, and an air inlet opening provided in the first air flow channel;
• and
• a second ventilation unit having a second air flow channel formed in the friction cushion and facing the first air flow channel in the assembled state, a plurality of second air flow holes leading out of the second air flow channel, and a plurality of second side flow holes formed in each of the locking parts and aligned with the first side flow channels in the assembled state,
• wherein in the assembled state, the support cushion and the friction cushion comprise the first and second ventilation units and make up the seat cushion, air is enabled to flow from the air inlet opening into the first and second air flow channels, the first side flow channels, and the second side flow holes, and air is enabled to flow from the second air flow channel into the second air flow holes.