Tractor Draft Control via Hydraulic Pressure Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing tractor control systems face challenges in safely managing draft control modes, particularly due to reliance on draft force sensing pins, which can be difficult to install and maintain, leading to potential collisions or damage when the drag mode is not properly deactivated in various operational scenarios.
Innovation Solution
A control system that deactivates the draft mode based on predetermined parameter values associated with tractor and implement modes, using pressure sensing within the hydraulic circuit to adjust the position of the implement attachment linkage, eliminating the need for additional draft force sensors and preventing undesired movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If draft force sensing pins are used to control the three-point linkage, then draft control and position control can be achieved, but the system becomes complex and the sensing pins become difficult to install and maintain
Solution Approach 1:
The patent extracts the draft force sensing function from the traditional sensing pin and relocates it to the hydraulic circuit. The hydraulic pump and motor already present in the CVT system are used to sense draft force through pressure measurements, eliminating the need for separate mechanical sensing pins on the linkage.
Solution Approach 2:
The hydraulic components of the CVT system (pump and motor) are made multi-functional. They not only perform their primary function of transmitting mechanical power but also serve as draft force sensing elements. The pressure in the hydraulic circuit naturally reflects the draft force, allowing a single component to serve multiple purposes.
2Manufacturing precision
If the draft mode is activated to adjust implement position based on drag force, then work quality improves, but the implement may collide with ground or tractor components when drag force changes unexpectedly
Solution Approach 1:
The system continuously monitors hydraulic pressure to detect draft force changes before they result in harmful implement movement. By using the hydraulic circuit pressure as a leading indicator of draft force, the control system can anticipate and prevent collisions by adjusting linkage position in advance.
Solution Approach 2:
The hydraulic pressure in the CVT circuit provides continuous feedback about draft force conditions. This feedback loop allows the control system to respond dynamically to changing soil resistance, preventing the implement from moving into harmful positions while maintaining precise depth control during normal operation.
3Measurement precision
If a draft force sensing pin is installed to measure horizontal load, then draft control can be implemented, but the sensing pin may become dirty or damaged and fail to function properly
Solution Approach 1:
The hydraulic fluid acts as an intermediary that transmits draft force information from the implement to the control system without requiring direct mechanical contact between sensing components and the external environment. The pressure in the closed hydraulic circuit reflects draft force while being isolated from dirt and debris.
Solution Approach 2:
The patent replaces the mechanical sensing pin system with a hydraulic pressure-based sensing system. Instead of using a mechanical pin that physically contacts the linkage and is exposed to the environment, the system uses hydraulic pressure measurements within the sealed CVT circuit to determine draft force, eliminating the mechanical sensing pin entirely.
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 solution ensures safer operation by automatically deactivating the draft mode when specific conditions are met, preventing unnecessary and dangerous movements of the linkage and attached implements, thereby enhancing safety and reducing the risk of collisions or damage.
Implementation Method 1
a hydraulic pump supplies pressurised fluid to a hydraulic motor
Implementation Method 2
a pressure sensing means within the hydraulic circuit of a transmission/drive system providing a force signal which is indicative of the current pull force
Data Source
AI summary
A tractor control system, which controls an operating condition of an implement attached to the tractor. The control system includes a sensing means providing a force signal which indicates the pull force necessary to pull an implement in a desired position; a control which receives the force signal; and means for measuring at least one parameter associated with the tractor mode and/or the implement mode and the implement position is adjusted to a new position when the force signal varies. The control system includes pre-determined values associated with certain tractor and/or implement modes. A measured parameter is compared with a pre-determined parameter value and if the measured parameter would result in an undesired movement of the implement, the force signal is deactivated, or the response to the force signal is deactivated to prevent undesired movement of the attachment.