Pilot Neutralizer for Articulated Work Vehicle Steering Cushioning
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Solution Overview
Problem
Existing pilot neutralizing systems in articulated work vehicles do not effectively manage the transition from steering to cushioning, leading to potential frame-to-frame contact and increased operational risks.
Innovation Solution
A pilot neutralizing system that includes a controller and a pilot neutralizer, which are electrically and hydraulically coupled to the steering valve and operator control member. The system detects the articulation position and adjusts the pilot signal by energizing or de-energizing the pilot neutralizer to resist the actuating assembly's movement, thereby preventing frame contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pilot neutralizer is not used, then the steering operation is simple and direct, but the frame-to-frame contact cannot be prevented and operational safety is compromised
Solution Approach 1:
The patent introduces a pilot neutralizer as an intermediary component between the steering valve and the actuating assembly. This neutralizer selectively blocks the pilot signal to the steering valve when the articulation angle approaches the cushion region, thereby preventing frame-to-frame contact without requiring complex mechanical stops or additional actuators. The intermediary successfully resolves the contradiction by adding minimal complexity to achieve enhanced safety.
Solution Approach 2:
The patent replaces traditional mechanical steering stops with a hydraulic control mechanism. Instead of using physical mechanical limits to prevent frame contact, the system uses a pilot neutralizer that electrically/hydraulically blocks the pilot signal to the steering valve, achieving the same protective function through substitution of mechanical system with hydraulic control, thereby improving reliability while maintaining acceptable complexity.
2Reliability
If the pilot signal is blocked abruptly, then the frame contact is prevented immediately, but the steering motion cannot be smoothed and operator comfort is reduced
Solution Approach 1:
The patent implements a dynamic pilot blocking mechanism where the neutralizer is activated progressively as the articulation angle approaches the cushion region. Rather than abrupt blocking, the system dynamically adjusts the pilot signal based on the real-time articulation angle, smoothing the transition and maintaining operator comfort while ensuring frame contact prevention.
Solution Approach 2:
The system performs preliminary action by activating the pilot neutralizer before actual frame contact occurs. The controller detects when the articulation angle enters the cushion region and proactively blocks the pilot signal in advance, allowing the steering motion to be smoothed and controlled rather than reacted to abruptly after contact begins.
3Speed
If the pilot neutralizer remains de-energized, then the steering response is fast and responsive, but the cushioning effect is lost and frame contact risk increases
Solution Approach 1:
The patent employs a dynamic control strategy where the pilot neutralizer transitions between de-energized and energized states based on the articulation angle. The system maintains fast steering response when the articulation angle is within the normal steering range (neutralizer de-energized) and automatically transitions to cushioning mode (neutralizer energized) when approaching the cushion region, thus dynamically balancing speed and reliability.
Solution Approach 2:
The system changes the operational parameter of the pilot neutralizer based on the articulation angle parameter. When the articulation angle is below the cushion region threshold, the neutralizer is de-energized for fast response. When the angle exceeds the threshold, the neutralizer is energized to provide cushioning. This parameter-based control resolves the contradiction by adapting the system behavior to current operating conditions.
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 frame-to-frame contact by smoothly transitioning from steering to cushioning, enhancing operational safety and reducing the risk of damage.
Implementation Method 1
The pilot neutralizer is electrically coupled to the controller and hydraulically coupled between the operator control member and the steering valve to selectively change the pilot signal at the steering valve
Implementation Method 2
the pilot neutralizer is one of de-energized and energized by the controller to change the pilot signal at the steering valve
Implementation Method 3
The steering valve is hydraulically coupled to the fluid pump and the actuating assembly and is configured to change a direction of the hydraulic fluid to operate the actuating assembly based on positions of the steering valve
Implementation Method 4
The fluid pump is configured to provide a hydraulic fluid to actuate the actuating assembly
Data Source
AI summary
A pilot neutralizing system of a work vehicle may include a pilot neutralizer and a flow control apparatus. The work vehicle may include a frame assembly and an actuating assembly to pivot the frame assembly. The pilot neutralizer is hydraulically coupled between an operator control member and a steering valve to selectively direct a pilot signal to the steering valve and is hydraulically coupled to a reservoir via a reservoir line. The pilot signal is used to switch the steering valve to change a direction of a hydraulic fluid flowing from the steering valve to the actuating assembly. The flow control apparatus is hydraulically coupled to the reservoir line and used to change a draining rate of the pilot signal to the reservoir. When the articulation position reaches a cushion region during steering, the pilot signal drains back through the flow control apparatus to the reservoir.