Cushion of airbag apparatus

1. A cushion of an airbag apparatus, comprising:

a rear panel having a gas inlet formed at a rear thereof, and a first connecting end formed along an edge thereof and deployed forward when gas is introduced into a primary filling room open to a front;

a front panel having a second connecting end formed along an edge thereof at a front of the rear panel and coupled to the first connecting end, a passenger support region which is formed at a front thereof and deployed forward when gas is introduced into a secondary filling room open to a rear;

an upper protruding region that protrudes upward while having a curvature in a side-to-side direction during the forward deployment of the passenger support region; and

a pair of lower protruding regions that protrude with downward curvatures during the forward deployment of the passenger support region.

2. The cushion of claim 1 , wherein both ends of the rear panel in the side-to-side direction are divided into upper and lower parts by a pair of sewing lines based on a connection region,

wherein the sewing lines are sewed to each other in a widthwise direction thereof, and vertically connect both ends of the rear panel in the side-to-side direction.

3. The cushion of claim 2 , wherein the pair of sewing lines is formed to correspond to left and right sides of the connection region.

4. The cushion of claim 2 , wherein the pair of sewing lines is connected to both ends of the connection region in the side-to-side direction, respectively, while a gap between the pair of sewing lines gradually decreases toward the rear.

5. The cushion of claim 2 , wherein the gas inlet is formed at a center position of the connection region.

6. The cushion of claim 2 , wherein the first connecting end comprises a rear-side upper connection section formed at a top of the sewing lines and a rear-side lower connection section formed at a bottom of the sewing lines, and

the second connecting end comprises a front-side upper connection section sewed to the rear-side upper connection section and a front-side lower connection section sewed to the rear-side lower connection section.

7. The cushion of claim 6 , wherein the rear-side upper connection section and the front-side upper connection section have the same length.

8. The cushion of claim 6 , wherein the rear-side lower connection section and the front-side lower connection section have the same length.

9. The cushion of claim 6 , wherein the upper protruding region is at least partially on the rear-side upper connection section, and

the front-side upper connection section comprises a first front-side coupling part having a length in the side-to-side direction such that a center thereof coincides with a center of the rear-side upper connection section, and a pair of second front-side coupling parts bent and extended downward from both ends of the first front-side coupling part in a longitudinal direction.

10. The cushion of claim 9 , wherein the rear-side lower connection section comprises a pair of first rear-side coupling parts formed on left and right sides thereof, respectively, and having a length in the side-to-side direction, and a second rear-side coupling part connected to corresponding ends of the first rear-side coupling parts forming at least a portion of the pair of lower protruding regions, and

the front-side lower connection section comprises a pair of third front-side coupling parts formed on left and right sides thereof, respectively, and protruding while having a curvature in directions facing each other, and a fourth front-side coupling part having a length in the side-to-side direction and both longitudinal ends connected to lower ends of the third front-side coupling parts, respectively.

11. The cushion of claim 10 , wherein the pair of third front-side coupling parts have a side-to-side width larger than the pair of second front-side coupling parts.