Mechanical, hydraulic and pneumatic linkage steering axle locking device

The utility model discloses a mechanical, hydraulic and pneumatic linkage steering axle locking device, which comprises a steering axle. A left installation plate and a right installation plate are respectively arranged on two sides of the lower end of the steering axle; an upper positioning plate is connected with the upper part of the front end of the left installation plate; the upper end of the upper positioning plate is connected with a locking oil gas cylinder; a locking pin shaft is arranged in the locking oil gas cylinder; a mechanical switch valve is arranged at the upper end of the locking oil gas cylinder; a left adjoint air cylinder is connected with the lower part of the rear end of the left installation plate; a left adjoint pin shaft is arranged in the left adjoint air cylinder; a right adjoint air cylinder is connected with the lower part of the rear end of the right installation plate; a right adjoint pin shaft is arranged in the right adjoint air cylinder; and a mechanical steering valve is arranged at the lower part of the front end of the right installation plate. The utility model can not only meet the operation characteristic of interchanging between two-wheeled steering and four-wheeled steering of low-speed engineering machinery, but also achieve high-speed safe drive under the condition that the front axle of an automobile adopts two-wheeled steering and the rear axle adopts straight bridge.