Sliding misoperation prevention parking braking hydraulic system and control method thereof

Abstract

The invention discloses a sliding misoperation prevention parking braking hydraulic system and a control method thereof, and belongs to the technical field of engineering machinery and industrial vehicle. A hydraulic pump oil outlet is connected with an electromagnetic directional valve I and a pilot valve; the electromagnetic directional valve I is connected to brakes in a hydraulic motor I and ahydraulic motor II; the pilot valve is connected to a plunger pump; an electromagnetic directional valve II is installed in an oil circuit between a hydraulic pump and the pilot valve; and a pressureswitch and a shuttle valve group are installed in an oil circuit between the pilot valve and the plunger pump, the shuttle valve group screens and transfers the highest pressure from the pilot valveto the pressure switch, and the pressure switch controls whether the electromagnetic directional valve I gets electricity or not. When a safety device is not ready, even if the pilot valve is operatedby mistakes, any pressure is not output, the whole vehicle keeps the original state, and misoperation prevention is realized; and when the safety device is ready, whether the pilot valve is operatedby mistakes before or not, as long as the pilot valve operation is stopped, the vehicle can keep braking, until a driver operates the pilot valve again, and parking braking is realized.

Description

technical field [0001] The invention relates to a parking brake hydraulic system, in particular to a sliding anti-misoperation parking brake hydraulic system and a control method thereof, belonging to the technical field of construction machinery and industrial vehicles. Background technique [0002] A skid steer loader is a special wheeled chassis equipment that utilizes the difference in the linear velocity of the wheels on both sides to achieve vehicle steering. It is mainly used in situations where the work site is narrow, the ground is uneven, and the work content changes frequently. [0003] Skid-steer loader travel mostly adopts pilot-controlled closed hydraulic system, such as figure 1 As shown, its hydraulic system includes a plunger pump, a hydraulic motor and a pilot valve. The parking brake is applied by means of a brake in the hydraulic motor. Its control logic is: [0004] When the vehicle is started and the safety measures are not ready, the electromagneti...

AI Technical Summary

Problems solved by technology

[0007] First, if the skid steer loader is parked on a sloped road, once the insurance measures are ready, the brake of the hydraulic motor will be opened, and the vehicle will be in danger of rolling and sliding;

[0008] Second, no matter whether the safety measures are ready or not, the gear pump 1 will supply oil to the oil inlet port of the pilot valve 7. At this time, if the pilot valve 7 is accidentally touched, the hydraulic oil will reach the plunger pump 2 through the working port of the pilot valve 7 for control port, thereby changing the output displacement of the plunger pump 2, the plunger pump 2 will supply oil to the hydraulic motor 5 and the hydraulic motor 10 at the same time, the travel hydraulic system builds up pressure, and the hydraulic motor has a tendency to move. The reason is that the braking torque is not enough, and the whole vehicle will appear to walk, which will seriously affect the safe operation of the equipment and even cause personal safety accidents.

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