Work Vehicle Engine Control Apparatus for Torque Limiting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Bulldozers face challenges in operating efficiently due to excessive traveling horsepower, which can deteriorate the durability of the traveling power train and hinder the ability to achieve desired work modes or fuel economy, especially when the coolant temperature varies.
Innovation Solution
An engine control apparatus that includes work mode selection, fan load detection, and power curve management to limit input torque to the traveling body and work machine, ensuring the engine operates within predetermined limits regardless of coolant temperature, thereby prioritizing work mode or fuel economy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the cooling fan speed is increased to maintain optimal coolant temperature, then the coolant temperature control is improved, but the fan horsepower increases and the traveling horsepower decreases
Solution Approach 1:
The patent applies dynamics by making the power curve selectable and adjustable based on operating conditions. The control device switches between multiple power curves (first power curve for high traveling horsepower, second power curve for high cooling performance) depending on the coolant temperature and work mode, allowing the system to adaptively optimize the trade-off between traveling power and cooling efficiency rather than being fixed
Solution Approach 2:
The patent changes the engine's power output parameters by selecting different power curves. The control device modifies the engine's torque and speed characteristics by switching between predetermined power curves, which changes the available horsepower for traveling and the horsepower available for the cooling fan, thereby resolving the contradiction between cooling performance and traveling power
2Power
If the engine output is increased to provide more traveling horsepower, then the tractive force is improved, but the fan horsepower increases and the coolant temperature control becomes difficult
Solution Approach 1:
The system dynamically switches between different power curves based on real-time coolant temperature monitoring. When coolant temperature is low, the control device selects the first power curve that prioritizes traveling horsepower. When coolant temperature rises, it switches to the second power curve that prioritizes cooling performance, creating a dynamic adaptation that resolves the contradiction
Solution Approach 2:
The control device uses feedback from the coolant temperature sensor to determine which power curve to select. The feedback loop continuously monitors coolant temperature and adjusts the engine power output accordingly by switching between power curves, ensuring that the system responds to temperature changes and maintains optimal thermal management while maximizing traveling power when needed
3Device complexity
If a single power curve is used to simplify engine control, then the control system is simplified, but the ability to optimize for different work modes and temperature conditions is reduced
Solution Approach 1:
The patent segments the power curve into multiple predetermined curves (first power curve, second power curve, etc.), each optimized for specific work modes or temperature conditions. The control device selects the appropriate segment (power curve) based on the current operating conditions, allowing the system to maintain simplicity in execution while achieving complexity in optimization strategy
Solution Approach 2:
The patent prepares multiple power curves in advance before actual operation. These predetermined power curves are pre-calculated and stored in the control device, allowing the system to quickly switch between them based on work mode or temperature conditions without requiring complex real-time calculations, thus maintaining control simplicity while achieving high adaptability
Data Source
AI summary
An engine control apparatus for a work vehicle having a cooling fan or an auxiliary device driven by an engine. The engine control apparatus is capable of operating the work vehicle with the importance placed either on amount of work or fuel economy depending on the situation, and preventing the input of excessive traveling horsepower (or working horsepower), regardless of a selected work mode, to ensure durability of the traveling power train (or work machine drive equipment). Upon selection of a work mode by the work mode selection switch, a controller controls the engine to obtain a power curve selected from those selectable for the selected work mode can be obtained, based on the coolant temperature range and the selected work mode, so that the input torque transmitted to the traveling power train does not surpass the upper limit for the input torque (rated output).