Engineering machine mechanical braking and steering system with preferentially steering front wheels

Abstract

The invention discloses an engineering machine mechanical braking and steering system which simultaneously performs preferential steering of front wheels and braking of back wheels when the engineering machine under heavy load is in downhill and four wheels are locked. The engineering machine mechanical braking and steering system comprises a left steering cylinder, a right steering cylinder, a steering valve, a foot brake valve, a rear drive axle, a front drive axle, a rear drive axle and an oil tank, wherein a first priority valve is arranged in an oil-way from the K1 port of the foot brake valve to the front drive axle; when not in steering, the first priority valve functions as a rubber pipe for connecting, thus enabling the brake oil-way of the front drive axles to be connected; after braking, the normal simultaneous braking of front and rear drive axles can be achieved; when the front drive axle needs steering, the first priority valve under the effect of controlling the pressure of oil rapidly cuts off the brake oil-way of the front drive axle, so that the pressure oil of the front drive axle directly returns the oil tank, namely, the braking pressure of the front drive axle is reduced to be zero, and now the front drive axle can smoothly achieve normal steering and back wheels are always in braking states.

Description

technical field [0001] The invention relates to a braking and steering system for engineering machinery with front wheel priority steering, in particular to a 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 the four wheels are locked. Active 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 speed of construction machinery is much lower than that of automobiles, the maximum no-load speed generally does not exceed 40km / h, and the heavier the machine, t...

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.

However, for the special working conditions of the above-mentioned construction machinery, there is no specific solution at present. Therefore, a construction machinery braking and steering system that allows the front wheels to steer preferentially has become a better solution.

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