Electronic control hydraulic driving system used for industrial vehicles

Abstract

The invention discloses an electronic control hydraulic driving system used for industrial vehicles. Functions such as walking, slope sliding, speed limiting, oil adding, steering, lifting and inclining of the vehicles are achieved by using a motor, a controller and a variable hydraulic system only, and meanwhile kinetic energy recycling, potential energy heavy load recycling and light load unloading are achieved. The system has the advantages that by means of a walking speed limiting device, the speed of the vehicles is limited, walking of the vehicles is stable, and automatic oil supplying can be conducted by the hydraulic system in the process of the slope sliding and braking; by adopting a combination type oil tank, oil cooling type installation of mechanical and electrical integration can be achieved, electric elements are not in contact with air, noise of the hydraulic system is reduced, and functions of water proofing, explosion proofing and cooling are achieved; interlocking is carried out on a walking device, a lifting device and an inclining device by the hydraulic system, so that the walking, the lifting and the inclining cannot be conducted at the same time, superposed large currents do not exist, and the discharge capacity efficiency of a storage battery is improved; startup from zero to load currents is completed in 600 millimeters by starting currents of the motor, large starting currents do not exist, and the energy can be saved by more than 15%.

Description

technical field [0001] The invention belongs to the technical field of industrial vehicles, and in particular relates to an electronically controlled hydraulic drive system for industrial vehicles. Background technique [0002] Most of the non-highway mobile equipment and electric engineering vehicles sold and used in the market, including counterbalanced electric forklifts, forward-moving electric forklifts, multi-directional electric forklifts and stacking electric vehicles, mostly adopt international The popular three-phase AC asynchronous induction motor (referred to as AC motor), but these equipment and vehicles have the following defects: [0003] 1) Large starting current; [0004] 2) Large climbing current (requires 2 to 3 times the rated current); [0005] 3) AC motors have defects such as low power factor, low efficiency at low speed, and narrow high-efficiency zone of the motor; [0006] 4) The cost of imported control drives is high; [0007] 5) Potential-fre...

AI Technical Summary

Problems solved by technology

[0003]1) Large starting current;

[0004]2) The climbing current is large (requires 2 to 3 times the rated current);

[0005]3) AC motors have defects such as low power factor, low efficiency at low speed, and narrow high-efficiency zone of the motor;

[0006]4) High cost of imported control drives;

[0008]6) Multiple motors start and run repeatedly at the same time, resulting in superimposed starting and running high currents, which reduces the discharge current capacity of lead-acid batteries by 40%, resulting in increased operating costs, The charging time is extended, and the loading and unloading efficiency of the vehicle is reduced;

[0009]7) Ordinary electric forklifts control the descending speed of the goods through the throttling of the valve when the goods are forked and lowered. During this process, the potential energy of the goods falling is converted into hydraulic pressure The thermal energy of the system will cause the temperature of the oil to rise. Long-term operation in this way will cause the oil to deteriorate, affecting the reliability and working efficiency of the hydraulic components. At the same time, due to the need to replace the hydraulic oil, the cost of use will increase;

[0012]1) When the traveling device is running at full speed, the mechanical efficiency drops by 18%;

[0013]2) The operation is complicated, which affects the loading and unloading efficiency;

[0014]3) The lifting device cannot be electronically controlled for speed regulation, and there is throttling loss;

[0016]5) Brake device and hydraulic motor back pressure loss is serious

[0019]2) Setting two hydraulically controlled one-way valves in the walking system makes the system complex and increases cost and energy consumption;

[0020]3) Since there is no speed limit on slopes in the walking device, it will cause speeding and bring mental burden and danger to the operator;

[0021]4) Lack of oil replenishment device when the vehicle brakes and slopes, which will cause damage to components;

[0022]5) When the lifting device is descending and regenerating, it needs to be operated when the lifting distribution valve is in the middle position, and the operator is easy to misoperate, which affects the loading and unloading efficiency

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