Energy optimization system for hydraulic excavator

Abstract

The invention discloses an energy optimization system for a hydraulic excavator. A third electromagnetic directional valve is respectively communicated with a rodless cavity of an operating cylinder of the hydraulic excavator, a control valve of the hydraulic excavator and a second electromagnetic directional valve, the second electromagnetic directional valve is respectively communicated with an energy accumulator and a first electromagnetic directional valve, the first electromagnetic directional valve is respectively communicated with an oil tank of the hydraulic excavator and an oil incoming port of a hydraulic motor, a fourth electromagnetic directional valve is respectively communicated with an oil outgaining port of the hydraulic motor, the energy accumulator and the oil tank of the hydraulic excavator, an oil inlet of an overflow valve is communicated with the energy accumulator, and an oil outlet of the overflow valve is communicated with the oil tank of the hydraulic excavator. A signal input port of an engine of the hydraulic excavator, a displacement signal port of the hydraulic motor, a signal input port of the first electromagnetic directional valve, a signal input port of the second electromagnetic directional valve, a signal input port of the fourth electromagnetic directional valve, a signal input port of the control valve of the hydraulic excavator, and a signal input port of the third electromagnetic directional valve are respectively communicated with a controller.

Description

technical field [0001] The invention is suitable for engineering machinery with complex working conditions and frequent load mutations, especially for hydraulic excavators that transmit power through a hydraulic system. Background technique [0002] Hydraulic excavators are used in many places, with high fuel consumption and large exhaust emissions. Research on energy saving and emission reduction of excavators has high economic value and environmental protection value. The energy loss on the excavator is mainly reflected in the following three aspects: 1. There is a large energy loss on the power source. When the traditional hydraulic excavator is working, the load changes drastically, which often causes the power source engine with a fixed throttle position to fluctuate on the speed regulation curve, and cannot work stably on the load curve, and the fuel economy is very low; 2. There is energy loss in the hydraulic system . Various throttle valves and relief valves that ...

AI Technical Summary

Problems solved by technology

When the traditional hydraulic excavator is working, the load changes drastically, which often causes the power source engine with a fixed throttle position to fluctuate on the speed regulation curve, and cannot work stably on the load curve, and the fuel economy is very low; 2. There is energy loss in the hydraulic system

Various throttle valves and relief valves that play a controlling role inevitably lose part of the pressure energy of the hydraulic oil during work; 3. Energy loss when the actuator brakes

Hydraulic excavator buckets, sticks, and booms often rely on the reverse pressure of the hydraulic system to provide braking force when they stop moving. The kinetic energy of the actuator is converted into heat energy of the hydraulic system and is lost. At the same time, it has an adverse effect on the hydraulic system and increases failures. probability

[0003] Aiming at the above-mentioned aspect 1 in the current technology, a gasoline-electric hybrid power system composed of an engine, an electric motor and a battery has appeared, which has a certain effect on stabilizing the operating point of the engine, but due to the mechanical characteristics of the electric motor itself, it has the ability to output large torque instantaneously. Insufficient, so there are certain limitations on hydraulic excavators and other construction machinery with sudden load changes. At the same time, the complex monitoring technology and high cost of battery packs have greatly restricted the application of oil-electric hybrid technology on hydraulic excavators; at the same time There is also an oil-hydraulic hybrid power system composed of an engine, a hydraulic pump / motor integrated secondary element, and an accumulator, but the cost of the secondary element is relatively expensive, and the control is more complicated, which limits the application of the oil-hydraulic hybrid power technology. more

For the third aspect, booms, sticks, rotary tables, etc. have corresponding energy recovery patents, but these patents are often limited to the optimization of energy recovery of a single component, the movement state of the working device, and the inflation pressure of the accumulator. There are strict requirements, and the ability to reuse energy is weak, and there are few opportunities for reuse

There are few studies on the second aspect, mainly because it is difficult for hydraulic excavators to bypass the valve control system, and the loss on the valve body is difficult to fundamentally eliminate, and the improvement of the valve body itself is only studied within the valve manufacturer.

In short, the scheme of combining the three to improve energy-saving measures is still blank.

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