Work Vehicle Engine Speed Control for Brake Cooling
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Solution Overview
Problem
Existing work vehicle systems fail to effectively control the increase in brake cooling oil temperature during high-speed braking, leading to compromised engine performance and potential damage to brake components.
Innovation Solution
A prime mover control device that limits the maximum engine rotation speed based on cooling oil temperature, preventing excessive vehicle speed and thereby reducing heat generation and maintaining optimal engine performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the drive force is reduced by imposing limits on pedal operation quantity and target engine rotation speed to lower maximum engine torque, then the brake cooling oil temperature increase is controlled, but the traveling performance is significantly compromised
Solution Approach 1:
The patent applies dynamics by making the engine rotation speed limit variable rather than fixed. The control device dynamically adjusts the maximum engine rotation speed limit based on the detected brake cooling oil temperature. When the temperature is low, the engine can operate at higher speeds for better traveling performance. When the temperature rises above the threshold, the engine speed limit is reduced to control brake heating. This dynamic adjustment resolves the contradiction by adapting the speed limitation to actual thermal conditions.
Solution Approach 2:
The patent changes the parameter of engine rotation speed limit based on brake cooling oil temperature. The control device detects the temperature and modifies the maximum allowable engine rotation speed accordingly. This parameter change approach allows the system to maintain optimal traveling performance when temperatures are acceptable while effectively controlling brake temperature rise when needed, avoiding permanent performance degradation.
2Temperature
If the engine rotation speed is reduced to a level lower than the rated torque output point to lower maximum engine torque, then the brake cooling oil temperature is controlled, but the engine performance is significantly compromised
Solution Approach 1:
The system dynamically adjusts the engine rotation speed limit based on real-time brake cooling oil temperature detection. When the temperature is within acceptable range, the engine can operate at or near its rated torque output point for optimal power delivery. When the temperature exceeds the threshold, the system temporarily reduces the speed limit to control brake heating. This dynamic approach prevents permanent engine performance degradation while achieving temperature control when necessary.
Solution Approach 2:
The control device changes the engine operation parameters (rotation speed limit) based on the detected brake temperature. Rather than permanently operating below the rated torque point, the system adjusts parameters adaptively - maintaining high performance when temperatures are low and reducing power output only when temperature control is required. This preserves engine performance potential while enabling temperature management.
3Temperature
If the maximum vehicle speed is limited to control brake cooling oil temperature increase, then the brake temperature is controlled, but the vehicle efficiency is reduced
Solution Approach 1:
The patent implements dynamic speed limitation based on brake temperature conditions. The control device allows the vehicle to operate at maximum speed when brake cooling oil temperature is below the threshold, maintaining high productivity. When the temperature rises above the threshold during operation, the system dynamically reduces the maximum allowable speed to control further temperature increase. This approach minimizes impact on vehicle efficiency by limiting speed reduction only when thermally necessary.
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
Effectively suppresses the increase in brake cooling oil temperature, preventing component damage and maintaining vehicle efficiency by limiting engine speed in response to elevated cooling oil temperatures.
Implementation Method 1
the temperature of the brake cooling oil reaches a level equal to or higher than a predetermined value
Data Source
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AI summary
A prime mover control device for a work vehicle, includes: a rotation speed control unit that controls a rotation speed of a prime mover in correspondence to an operation quantity of an accelerator operation member; a temperature detection unit that detects a temperature of cooling oil used to cool a brake; and a speed limiting unit that limits a maximum rotation speed of the prime mover by setting a lower limit for the maximum rotation speed when the temperature of the cooling oil detected by the temperature detection unit is higher than a predetermined temperature, compared to a limit set when the temperature of the cooling oil detected by the temperature detection unit is lower than the predetermined temperature, wherein: a maximum vehicle speed is limited by limiting the maximum rotation speed of the prime mover by the speed limiting unit.