A Construction Machinery Brake Steering System

Abstract

The invention discloses a construction machinery braking and steering system capable of performing front-wheel priority steering and rear-wheel braking at the same time when the construction machinery is descending with a heavy load and four wheels are locked. In the present invention, the first priority valve is connected to the brake oil circuit of the front axle (steering axle): when not turning, the function of the first priority valve is equivalent to the connected rubber hose, and the brake oil circuit of the front axle remains connected. After braking, normal front and rear axles can be braked at the same time; when the front axle needs to turn, under the action of the control oil pressure, the first priority valve quickly cuts off the brake oil circuit of the front axle, so that the pressure oil of the front axle can be directly returned to the oil tank , that is, the braking pressure of the front axle is reduced to 0. At this time, the front axle can smoothly realize normal steering, while the rear wheels are always in the braking state. After the steering is completed, the spool of the first priority valve is returned to the original position under the action of the return spring, and the pressure oil of the front axle is restored to the connection instantaneously. After that, the front and rear axles are braked simultaneously.

Description

technical field [0001] The invention relates to a construction machine with full hydraulic steering and four-wheel drive, in particular to a construction machine capable of performing front wheel priority steering and rear wheel braking at the same time when the construction machine is descending with a heavy load and the four wheels are locked. Mechanical brake steering system. Background technique [0002] When the construction machinery is under heavy load, when driving on a flat road, the driver steps on the brake pedal, and the four tires of the whole machine are often completely locked. It is a heavy load, and the strong inertia of the whole machine makes the driver need to step on the brake all the time to completely lock the wheels to control the speed of the whole machine. Since the driving speed of construction machinery is much lower than that of cars, the maximum no-load speed generally does not exceed 40km / h, and the heavier the machine, the lower the maximum n...

AI Technical Summary

Problems solved by technology

[0005] 1. The mass of the car body is large, and it is much larger than that of a family car. The whole machine has a strong inertia when driving, and it is not easy to be braked. Therefore, it has high requirements on the braking system.

[0006] 2. The speed of the vehicle is low. Generally, the maximum speed of no-load does not exceed 40km / h, which is far lower than the maximum speed of a car. It is not mainly used for road transportation, but mainly for earth and stone construction operations.

[0007] 3. The braking distance is short. Once the driver steps on the brake, the braking force will reach the maximum, so that the tires will be locked and the slip distance will be the shortest

However, the working conditions used by each customer are very complicated. For the heavy load downhill working condition of the whole machine, that is, when braking, the problem of turning but not being able to turn has become a defect of the traditional design concept.

Images