Wheel Loader Engine Speed Control for Vibration Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wheel loaders face challenges in consistently controlling engine rotation speed to inhibit vibrations, as the maximum resonance point and specific rotation speed range vary with component actuation and load conditions, leading to uncomfortable vibrations for operators without affecting workability.
Innovation Solution
A wheel loader system with sensors to detect operating conditions, such as the boom operation angle and vehicle speed, and an engine control unit that limits the maximum engine rotation speed to a predetermined value in specific situations, like when the boom is elevated or the vehicle is stopped, to mitigate vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the engine rotation speed is limited to inhibit vibrations, then operator comfort is improved, but workability deteriorates due to reduced pump discharge amount and lubricating oil supply
Solution Approach 1:
The patent applies dynamics by making the engine rotation speed limit variable rather than fixed. The control unit dynamically adjusts the maximum rotation speed based on real-time detection of working unit operations (boom, arm, bucket). When operations are detected, the engine speed limit is raised to maintain workability; when operations are not detected, the limit is lowered to reduce vibrations and improve operator comfort. This dynamic adjustment resolves the contradiction between vibration reduction and workability maintenance.
Solution Approach 2:
The patent changes the parameter of engine rotation speed limit based on operational conditions. By detecting whether the working unit is being operated and adjusting the maximum rotation speed parameter accordingly (higher during operation, lower during idle), the system optimizes both vibration control and workability. This parameter change approach allows the engine to operate at appropriate speeds for different working conditions, preventing the trade-off between comfort and productivity.
2Object-affected harmful factors
If the engine rotation speed is controlled to be lower than the maximum resonance point, then vibrations are reduced, but it becomes difficult to constantly maintain this control because the resonance point varies with component actuation and load conditions
Solution Approach 1:
The patent implements feedback control by using operation detection means to continuously monitor the state of the working unit (boom, arm, bucket operations). Based on this feedback, the control unit automatically adjusts the engine rotation speed limit. When operations are detected, the system raises the speed limit; when not detected, it lowers the limit. This feedback mechanism ensures the engine operates appropriately under varying conditions without requiring manual intervention, solving the adaptability problem.
Solution Approach 2:
The system performs self-service by automatically detecting working unit operations and autonomously adjusting the engine rotation speed limit without operator intervention. The operation detection means and control unit work together to self-regulate the engine speed based on actual working conditions, eliminating the need for manual control adjustments and ensuring consistent vibration reduction across varying operational states.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
In a wheel loader, through a simple engine control, vibrations attributed to engine rotation are inhibited and uncomfortable vibrations felt by an operator are accordingly inhibited. The present wheel loader includes: a position sensor (34) detecting that a forward/rearward travelling switching lever (33) is located in a neutral position; a boom operation detecting sensor (32) detecting that a boom (6) has been operated; and a control unit (19) . The control unit (19) is configured to limit the maximum rotation speed of an engine to a predetermined rotation speed when the forward/rearward travelling switching lever (33) is located in the neutral position and a boom operating lever (31) has been operated.