Gas spring is a kind of labor-saving lifting spring, which is divided into self-locking gas springs (such as the lifting of the seat bottom and the back of the boss chair, etc.). ) and non-locking gas springs (such as the lifting support of car trunk and wardrobe door). The structure of gas spring is mainly composed of sleeve, piston and piston rod. When high-pressure air or high-pressure nitrogen is added to the sleeve, the pressure difference is generated due to the unequal areas at both ends of the piston, which pushes the piston and piston rod to move and supports people or heavy objects.

For passenger car seats with high frequency of use, it needs a long life, so gas springs can be used.