The invention provides a
rocker arm device which comprises a base, a
rocker arm and a tray. One end of the
rocker arm is hinged to the base through a first installation shaft, and the other end of therocker arm is hinged to the tray through a second installation shaft. The rocker arm device further comprises a
reciprocating motion assembly and an
air spring. The
reciprocating motion assembly is arranged on the side, close to the tray, of the rocker arm through a rotating shaft and conducts
reciprocating motion along with rotation of the rotating shaft. The
air spring comprises a fixed part, atelescopic part and an ejector pin which are sequentially connected, the fixed part is hinged to the base through a third installation shaft, and the telescopic part supports the rocker arm. The reciprocating motion
assembly acts on the ejector pin and is used for locking or unlocking the
air spring. A third rotating shaft is located beyond the area which the rocker arm passes when the rocker armrotates to the
extreme position, and the position of the third installation shaft is adjustable. Due to locking and unlocking operation of the rocker arm device, accurate control can be achieved by referring to the long distance end and the
short distance end of the reciprocating motion assembly, operation is convenient, in addition, the supporting force of the air spring is stable and reliable,the bearing capability can be adjusted, and the application range is wider.