Vehicle height adjusting device

A vehicle height adjusting device, comprising:

• an automatic vehicle height adjusting circuit connecting a pneumatic source to air springs through a leveling valve;
• an air switch-over valve unit provided between said leveling valve and said air springs;
• a kneeling circuit connected to said air springs through said air switch-over valve unit;
• a hydraulic source coupled to said air springs;
• and
• control means for storing the air from said air springs in said kneeling circuit by switching over said air switch-over valve unit when kneeling, and for returning said air to said air springs under hydraulic pressure from said hydraulic source in the return of the vehicle height, said kneeling circuit including an air reservoir device which has a volume variable air chamber and a hydraulic mechanism that varies the volume of said air chamber based on the hydraulic pressure, a first shut-off valve, an air pipe which connects said air chamber to said air switch-over valve unit via said first shut-off valve, a hydraulic switch-over valve, and a hydraulic pipe that connects said hydraulic mechanism to said hydraulic switch-over valve and said hydraulic source.