The core hint: the hydraulic system of the full hydraulic flat ground braking system is introduced in detail: the driving system of the Sany all hydraulic leveling machine is the first to create the hydrostatic drive, and its transmission line is the engine, variable pump, variable motor, balance box and driving wheel, and the variable pump and the variable MDA closed hydraulic system replace the mechanical flat. The transmission line of the ground torque converter, gearbox, transmission shaft and drive axle is greatly simplified.
The driving system of Sany's all hydraulic leveling machine first creates hydrostatic drive. Its transmission line is engine, variable pump, variable motor, balance box and driving wheel. Variable pump and variable motor closed hydraulic system have been used instead of hydraulic torque converter, gearbox, drive shaft and driving bridge. It is greatly simplified. The brake is also used for shoe brake, and the brake is mounted on the driving wheel.
The original design of the brake hydraulic system for the full liquid leveling machine is the same as that of a mechanical leveler. When the brake pedal is loosened on the brake pedal when the brake is brake, the engine speed falls to the idle speed very quickly. At the same time, the swing angle of the variable pump is reduced or returned to the middle, and the variable motor decelerates or stops turning. The whole process variable motor becomes the operating condition of the pump, preventing the driving of the ground machine. This is the brake function of the closed type driving hydraulic system, which is called the hydraulic auxiliary brake. The braking system has a strong braking ability and the maximum braking torque is equal to the maximum driving torque of the motor. Because of the existence of the hydraulic auxiliary brake, the braking effect of the driving is greatly improved. But the impact of the braking process is larger, especially when the leveler is downhill. The brake is only used to limit the speed. If the accelerator pedal is too long to step on the brake pedal, the engine speed drops to the brake pedal after the idle speed, and the hydraulic auxiliary braking ability is larger than the brake capacity, which will make the ground flat. It is not desirable to stop driving.
In order to solve the problem of brake impact, the hydraulic system of vehicle brake is re designed, as shown in Figure 1. The redesigned hydraulic brake hydraulic system of the full hydraulic flat ground machine is connected by brake valve 2 and brake connecting rod 5 to brake brake and hydraulic auxiliary brake, which consists of brake oil cylinder 1, brake pedal 3, brake valve 4, oil tank 6 and brake oil source 7. The same. The brake torque is proportional to the 3 stroke of the brake pedal, and the brake valve 2 is controlled by the brake pedal 3 through the brake connecting rod 5. The brake valve 2 is connected to the oil port of the 10 end of the oil cylinder with the driving variable pump, and when the brake pedal 3 is stepped on the brake pedal 3, the inclined disc controls the high and low pressure of the 10 ends of the cylinder (when the ground machine runs, the 9 side of the valve control valve is electromagnets), the variable pump 12 slanting angle is reduced or returned to the middle, the variable horse reaches 11 decelerates or stops turning, and at the same time the whole pass is over. The hydraulic auxiliary brake plays a role. The greater the 3 stroke on the brake pedal, the better the hydraulic auxiliary braking effect.
The installation test proves that the newly designed hydraulic brake system of the full hydraulic grader solves the problem of brake impact, and the brake is gentle and stable. Compared with the hydraulic braking system of mechanical grader, the braking effect is better because of the superposition of the hydraulic auxiliary brake of the closed driving hydraulic system.
