Cooling Fan Control Device for Construction Machine Warm-Up
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Solution Overview
Problem
In construction machines like hydraulic excavators, the existing cooling fan control devices limit the cooling fan's rotational speed in cold environments to prevent overcooling, leading to reduced cooling capacity and potential sticking of the main spool in the control valve during warm-up operations, which can cause operational issues.
Innovation Solution
The cooling fan control device adjusts its rotational speed based on main pump discharge pressure, engine cooling water temperature, hydraulic oil temperature, and engine rotational speed to ensure effective heat diffusion and prevent sticking of the main spool in the control valve, even in cold environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cooling fan's rotational speed is limited in cold environments to prevent overcooling, then the risk of overcooling is reduced, but the cooling capacity is reduced and heat diffusion in the control valve becomes insufficient
Solution Approach 1:
The control device dynamically adjusts the cooling fan's rotational speed based on multiple parameters including main pump discharge pressure, engine cooling water temperature, hydraulic oil temperature, and engine rotational speed. This multi-parameter-based dynamic adjustment allows the system to maintain appropriate cooling capacity while preventing overcooling in cold environments, resolving the contradiction between reliability and temperature control.
2Reliability
If the cooling fan's rotational speed is limited to low speed in cold environments, then overcooling is avoided, but the main spool in the control valve may stick due to insufficient heat diffusion
Solution Approach 1:
The control device uses multiple parameters (main pump discharge pressure, engine cooling water temperature, hydraulic oil temperature, engine rotational speed) to dynamically determine the cooling fan's rotational speed. This allows the system to maintain higher fan speeds when needed for heat diffusion during warm-up operations, preventing main spool sticking while avoiding overcooling, thus maintaining operational performance.
Solution Approach 2:
The control device continuously monitors multiple system parameters and adjusts the cooling fan's rotational speed based on feedback from these parameters. This closed-loop control ensures that the fan speed is optimized in real-time to prevent both overcooling and heat-related operational issues, resolving the contradiction between preventing overcooling and maintaining ease of operation.
3Device complexity
If the cooling fan operates at fixed rotational speed based on engine cooling temperature and hydraulic oil temperature, then the control is simplified, but insufficient cooling or overcooling occurs during work operations
Solution Approach 1:
The control device transitions from fixed rotational speed control to dynamic rotational speed adjustment based on multiple parameters including main pump discharge pressure, engine cooling water temperature, hydraulic oil temperature, and engine rotational speed. This multi-parameter-based control strategy optimizes cooling efficiency for various work conditions while avoiding overcooling, resolving the contradiction between device complexity and reliability.
Solution Approach 2:
The control device makes the cooling fan's rotational speed dynamic rather than fixed, allowing it to adapt to changing work conditions and environmental factors. This dynamic adjustment based on multiple real-time parameters ensures optimal cooling efficiency while preventing overcooling, resolving the contradiction between control simplicity and cooling reliability.
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
This solution effectively diffuses heat in the control valve, preventing sticking and maintaining higher operational performance of the front working mechanism by ensuring sufficient cooling capacity during warm-up operations.
Implementation Method 1
a cooling fan 21 for cooling with cooling air generated by its rotation the engine cooling water and hydraulic oil circulating in the radiator and the oil cooler
Data Source
Figure 1
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AI summary
The purpose of the present invention is to provide a cooling fan control device for a construction machine, whereby the effects of heat caused by warm-up operation can be suppressed. This cooling fan control device is equipped with a control unit (10a) that controls the rotational speed of a cooling fan (21) in accordance with a main pump discharge pressure (P) detected by a main pump discharge pressure sensor (25), an engine cooling water temperature (Tw) detected by an engine cooling water temperature sensor (26), a hydraulic oil temperature (To) detected by a hydraulic oil temperature sensor (27), and an engine rotational speed (E) detected by an engine rotational speed sensor (28). The cooling fan (21) is rotated at the rotational speed controlled by the control unit (10a), thereby sending the generated cooling air to an oil cooler (19) and a control valve (13).