Clutch Control Device for Work Machine Fan Speed
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Solution Overview
Problem
Existing clutch control systems for work machines face challenges in accurately controlling fan rotational speed due to changes in clutch characteristics caused by oil temperature and engine speed, leading to delayed response and difficulty in achieving the desired rotational speed.
Innovation Solution
A clutch control device that includes an engine rotational speed sensor, oil temperature sensor, fan rotational speed sensor, and a controller with modules for calculating target fan rotational speed, selecting appropriate clutch characteristic curves, and generating control signals to adjust clutch operation, accounting for oil temperature and engine speed variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional clutch control system is used without considering clutch characteristic changes, then the control system is simple, but the fan rotational speed cannot be controlled accurately and response is delayed
Solution Approach 1:
The control system dynamically adapts to changing clutch characteristics by storing multiple clutch characteristic curves corresponding to different oil temperatures and engine speeds, and selectively switching between them based on current operating conditions. This allows the system to maintain accurate fan rotational speed control without requiring complex real-time calculation of varying clutch parameters.
Solution Approach 2:
The system changes the control parameter by selecting different clutch characteristic curves based on oil temperature and engine speed conditions. Each curve represents a different operating state of the clutch, allowing the controller to compensate for characteristic changes without increasing overall system complexity.
2Speed
If clutch characteristic changes due to oil temperature and engine speed are not considered, then the control signal calculation is simple, but the response time is delayed and desired rotational speed cannot be achieved
Solution Approach 1:
The system performs preliminary action by pre-storing multiple clutch characteristic curves that correspond to different operating conditions (oil temperatures and engine speeds). When operation begins, the controller simply selects the appropriate pre-stored curve based on current conditions, avoiding the need for complex real-time calculations and achieving fast response.
3Measurement precision
If multiple clutch characteristic curves are stored and selected based on operating conditions, then fan rotational speed control accuracy is improved, but memory requirements and processing complexity increase
Solution Approach 1:
The clutch characteristic data is segmented into multiple discrete curves, each corresponding to a specific oil temperature range and engine speed range. This segmentation allows the controller to store data in a structured manner and select only the relevant curve for current operating conditions, optimizing memory usage while maintaining control precision.
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
Enables precise control of fan rotational speed, reducing delays and improving responsiveness by considering clutch characteristics, thereby optimizing fan operation and reducing fuel consumption.
Implementation Method 1
wet friction clutches are of the configuration that lubrication is performed with oil (engine oil) between friction discs. Thus, in the wet friction clutches, a torque loss, a so-called drag torque attributed to the viscosity of the oil is generated
Data Source
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AI summary
Provided is a clutch control device for a work machine capable of controlling a fan 12 to an appropriate rotational speed. In the clutch control device for the work machine, a controller 50 includes a target fan rotational speed calculation module 60 that calculates a target fan rotational speed for the fan 12, a clutch characteristic curve storage module 62a that stores a plurality of clutch characteristic curves, a clutch command calculation module 62 that outputs with reference to a clutch characteristic curve a first clutch control signal corresponding to the target fan rotational speed, a feedback control module 61 that output a second clutch control signal based on the difference between the target fan rotational speed and an actual fan rotational speed, and an adder that adds the first clutch control signal and the second clutch control signal to output a third clutch control signal.