Hydraulic Relief Pressure Control for Implement Tracking
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Solution Overview
Problem
Existing hydraulically operated lifting gears for mobile machines face challenges in maintaining optimal attachment tracking on uneven ground while minimizing driving resistance, as high relief forces can cause attachments to lift off, leading to issues like increased cutting height when driving over depressions or crests.
Innovation Solution
A method for controlling a hydraulically operated lifting mechanism with a relief pressure control system that adjusts relief pressure based on soil profile gradient rates, using sensors to detect positive or negative slope rates and electronically controlling a proportional relief pressure valve to minimize driving resistance and ensure improved attachment tracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If high relief force is applied to minimize driving resistance, then driving resistance is reduced, but the attachment lifts off the ground causing poor tracking on uneven terrain
Solution Approach 1:
The relief pressure is made dynamically adjustable through electronic control of the proportional pressure relief valve, allowing the system to adapt the relief force in real-time based on terrain conditions rather than using a fixed mechanical setting
Solution Approach 2:
A sensor arrangement detects the actual ground contact status or terrain conditions and feeds this information back to the control unit, which then adjusts the relief pressure accordingly to maintain optimal attachment tracking while minimizing driving resistance
2Use of energy by moving object
If fixed relief pressure is set for normal operation to save fuel, then fuel consumption is reduced, but the attachment cannot respond to abrupt terrain changes
Solution Approach 1:
The system automatically adjusts the relief pressure in response to terrain changes detected by the sensor arrangement, eliminating the need for manual operator intervention while maintaining optimal performance across varying conditions
Solution Approach 2:
The electronic control system continuously monitors terrain conditions and periodically adjusts the relief pressure as needed, allowing the system to maintain low fuel consumption during normal operation while rapidly responding to terrain changes when detected
3Force
If relief pressure is increased to compensate for implement weight, then driving resistance is minimized, but cutting height becomes too high on sloping terrain
Solution Approach 1:
The system changes the relief pressure parameter dynamically based on detected terrain gradients and slope conditions, reducing relief pressure when sloping terrain is detected to maintain consistent cutting height while still providing weight compensation on level ground
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
This approach allows for reduced driving resistance and improved attachment tracking on uneven ground, preventing brief sagging or swinging, while also saving fuel through optimized relief pressure regulation.
Implementation Method 1
When an attached implement is lowered to the ground, the lifting mechanism provides a relief force
Implementation Method 2
a sensor arrangement which detects a positive or negative gradient of a ground profile traversed by the mobile work machine
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The gear has a relieving pressure limitation valve (43) controllable per unit time depending on a height change of a ground profile, where the height change is detected by a sensor arrangement. The limitation valve is designed as a proportional pressure limitation valve electronically activated by a control unit (48) i.e. electronic control unit (ECU). The sensor arrangement comprises an angle sensor (5) connected to the control unit, so that angular speed between a steering wheel and a mobile working machine is measurable via the angle sensor and the control unit. An independent claim is also included for a method for controlling relieving pressure of a hydraulically operated lifting gear of a mobile working machine.