Hydraulic Sensing Advance-Retreat Control for Digger Overload Relief
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Solution Overview
Problem
Reciprocated impact diggers and excavators face frequent motor and oil cylinder damage due to overload when digging hard materials, leading to reduced production efficiency, energy consumption, and unnecessary hydraulic system damage, as well as limitations in coal conveying efficiency and increased manufacturing costs.
Innovation Solution
An advance and retreat automatic control method based on hydraulic sensing conversion, utilizing a system with a hydraulic operated directional valve, sequence valve, pressure reducing valve, and energy accumulator to manage pressure and prevent overload, ensuring the digging motor and oil cylinder operate within safe pressure limits, and adjust mechanisms for precise retreat and advance movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If motor power is used to drive the cutting roller to rotate and mill blanks through gear transmission, then the cutting roller can effectively cut hard coal and gangue above F4, but the rotation cutting motor is frequently burned due to overload
Solution Approach 1:
The patent replaces the motor-gear transmission system with a hydraulic motor drive system. The hydraulic motor directly drives the reciprocating impact mechanism without requiring gear reduction, eliminating the motor burning problem caused by overload while maintaining the ability to cut hard materials above F4.
Solution Approach 2:
The patent introduces a hydraulic system with oil cylinders to replace the mechanical motor drive. The hydraulic system provides inherent overload protection through pressure relief valves and can deliver high force for impact mining without the risk of motor burnout, solving the reliability issue while preserving productivity.
2Strength
If the rotation speed of the cutting roller is reduced to protect cutting teeth, then the cutting teeth are protected from damage, but the motor must operate in overload to maintain cutting effectiveness
Solution Approach 1:
The patent replaces the motor-gear system with a hydraulic motor system that can vary force output independently of speed. The hydraulic system maintains cutting tooth protection through controlled reciprocating motion while providing sufficient force for hard material cutting, eliminating the need for motor overload operation.
3Volume of moving object
If a rocker arm is used as a gear transmission box to transmit power to the rotation roller, then space is saved, but the rocker arm becomes huge and blocks conveying space of the coal
Solution Approach 1:
The patent replaces the rocker arm gear transmission with a hydraulic motor system that eliminates the need for complex mechanical transmission components. This substitution removes the space-blocking rocker arm structure while maintaining compact design, thereby restoring coal conveying space and improving conveying efficiency.
4Power
If the rocker arm transmits power through gear, then power transmission is achieved, but the connecting part size becomes overlarge and manufacturing cost increases
Solution Approach 1:
The patent replaces the gear transmission system with a hydraulic motor drive system. This substitution eliminates the need for large connecting parts and complex gear mechanisms, simplifying the structure, reducing manufacturing complexity, and lowering production costs while maintaining full power transmission capability for impact mining.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively prevents motor and oil cylinder damage by managing pressure, enhances production efficiency, reduces energy consumption, improves coal conveying efficiency, and lowers manufacturing costs while ensuring safe and reliable operation.
Implementation Method 1
a pressure value of the digging motor is instantly increased to exceed a setting pressure value, hydraulic oil enters the hydraulic operated directional valve, a valve rod is pushed so that the walking motor is reversely rotated
Implementation Method 2
the sequence valve is cooperated with the hydraulic operated directional valve to ensure precision of retreat and advance restoration of the walking motor
Implementation Method 3
a pressure value of the advance and retreat automatic device based on the hydraulic sensing conversion is less than a pressure value of an overpressure state of the digging motor
Implementation Method 4
an energy accumulator, a sequence valve and a hydraulic operated directional valve and the like; or the advance and retreat automatic device based on the hydraulic sensing conversion is enabled to be formed by an energy accumulator, a sequence valve, a pressure reducing valve and a hydraulic operated directional valve and the like
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
Some embodiments of the present disclosure provide an advance and retreat automatic control method based on hydraulic sensing conversion and an advance and retreat automatic control system based on hydraulic sensing conversion. The advance and retreat automatic control system based on hydraulic sensing conversion is provided with an automatic advance and retreat device (3) based on hydraulic sensing conversion. The advance and retreat automatic control system based on hydraulic sensing conversion also includes a motor (14), an oil cylinder (9), and/or an electric generator (20). The automatic advance and retreat device (3) based on hydraulic sensing conversion cooperates with a digging motor (6) and a walking motor (1) to form a motor automatic advance and retreat mechanism based on hydraulic sensing conversion. When the digging motor (6) encountered an overlarge resistance force, a pressure on the digging motor (6) is instantaneously increased and exceeds a setting pressure value, hydraulic oil enters a hydraulic operated directional valve (2) and pushes a valve rod to make the walking motor (1) reverse and retreat, an ultrahigh pressure state of the digging motor (6) is released to restore to a normal pressure value to make reciprocated impact, the valve rod of the hydraulic operated directional valve (2) is reset, and the walking motor (1) is forwards rotated for advancing. The continuous and stable operation of the advance and retreat automatic control system based on hydraulic sensing conversion is ensured, and the continuous work of automatic advance and retreat is implemented, thereby improving the working efficiency.