A load-sensing-based excavator swing energy-saving hydraulic system and control method

Abstract

The invention discloses a load sensitivity-based excavator rotary energy-saving hydraulic system and a control method. The load sensitivity-based excavator rotary energy-saving hydraulic system includes a first energy conversion element and a second energy conversion element mounted on the input end and the output end of a rotary hydraulic motor, the drive shaft of the first energy conversion element is connected with a first motor / generator through a first torque tester, the drive shaft of the second energy conversion element is connected with the second motor / generator through a second torque tester, and the first motor / generator and the second motor / generator are electrically connected with an electric energy storage device respectively. According to the load sensitivity-based excavatorrotary energy-saving hydraulic system, mutual conversion of hydraulic energy and mechanical energy can be realized by controlling different work states of a motor or generator of the first motor / generator or the second motor / generator according to a load power state fed back by the first torque tester or the second torque tester by respective controllers, and thus, the kinetic energy during braking is recovered and reused during the rotary start-up.

Description

technical field [0001] The invention relates to an excavator hydraulic system and a control method, in particular to a load-sensitive excavator rotary energy-saving hydraulic system and control method suitable for energy-saving control of the excavator's rotary motion, and belongs to the technical field of excavators. Background technique [0002] An excavator is an earth-moving machine that uses a bucket to excavate materials such as soil, coal, sediment, or pre-loosened soil and rocks that are higher or lower than the bearing surface, and is loaded into a transport vehicle or unloaded to a stockyard. It has become one of the most important construction machinery in engineering construction. Hydraulic excavators have high working efficiency and a wide range of applications. However, the problems of high energy consumption and poor emissions have become more and more necessary to improve in the context of social development with higher and higher requirements for energy cons...

AI Technical Summary

Problems solved by technology

[0004] Frequent slewing actions make the slewing device start and brake frequently, and the slewing device needs a lot of power when starting, and the moment of inertia is large during the full-bucket slewing process, and the energy required is also large, and the acceleration of the full-bucket braking is greater than that of the full-bucket startup. Therefore, hydraulic excavators currently widely use load-sensitive variable pumps. The flow rate of the load-sensitive variable pumps automatically adapts to the flow rate of the motor during the slewing start process, and the overflow loss is reduced. However, due to the high pressure at the moment of starting, the pressure will still cause the overflow Flow valve opens to overflow part of hydraulic oil

The braking of the slewing device usually adopts the form of hydraulic braking. During the braking process, the slewing motor becomes a pump, and the pumped oil flows out through the load valve, and the braking energy is completely converted into heat energy. According to statistics, the calorific value of the slewing hydraulic oil circuit It accounts for about 30% to 40% of the total calorific value of the hydraulic system, which not only causes the temperature of the hydraulic oil to rise, but also usually requires an additional cooling device to cool down, which increases fuel consumption.

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