Non-contract monitoring device for automobile tyre pressure

The utility model relates to an automobile tyre pressure contactless monitoring device. The tooth ring is installed on a rotating wheel hub or a transmission half axle of the rear axle, and a steel ring connected with the tyre into a whole body is tightly fixed on the wheel hub through a bolt; rotating speed sensors are installed on a non-rotational front axle steering knuckle, a rear wheel hub bearing bridge or on a rear axle casing body; the rotating speed sensors are positioned at one side of the tooth ring, the clearance between the rotating speed sensors and the tooth ring can be adjusted; the signal output ends of the rotating speed sensors installed on the front axle and the rear axle are connected with a microcomputer in the cab through an conducting wire, and the microcomputer has an acoustic warning device and a warning lamp. When the automobile drives along the straight line and the certain tyre pressure is insufficient, the rolling radius is less than the rolling radius of the coaxial tyre, the ri