【作者】 尹静；

【导师】 郭新民；

【作者基本信息】 山东农业大学 ， 农业机械化工程， 2004， 硕士

【摘要】 当前筑路机械的冷却系统主要是采用了传统曲轴定传动比驱动，这种驱动方式使筑路机械的发动机起动转矩大、预热时间长、冷却不合理，风扇耗能较大(在发动机额定工况下功耗约占发动机有效输出功率的5％-12％)，降低了发动机的动力输出，且风扇安装位置受到限制，工作噪声大。 本课题设计了一种新型的冷却系统。本冷却系统可以解决筑路机械在施工中常出现的发动机过热和液压传动系统冷却不足的问题 本论文对该冷却系统的工作原理、硬件组成、软件设计作了详细论述。系统的特点及其实现的功能为：不同于以往单一式的冷却系统，本系统将整个冷却系统分成了两个主要部分：发动机冷却系统和液压油冷却系统，这两个系统分别对发动机和液压油冷却，并由一片单片机进行统一控制。发动机冷却系统采用了电液比例技术控制风扇转速：单片机可以根据冷却液温度、冷却液温度变化率和目标冷却液温度调节液压驱动系统中比例阀的控制电流，进而控制风扇转速。液压油冷却系统采用了电机驱动，然后由单片机根据液压油的温度控制电机的起停。两种风扇驱动方式分别根据不同的冷却要求，独立工作。 该设计方案是经过大量的科学调研及现场考察后制定的。课题研究内容主要是包括：设计方案的确定、主要液压元件和驱动电机的选型计算、实现控制系统中软硬件的合理设计及匹配、系统抗干扰的设计。系统的硬件采用了模块结构设计，主要是包括采样模块、CUP主控制模块、A/D转换模块、D/A转换模块、电液比例驱动模块和电机驱动模块等几个部分组成。在软件设计中力求程序设计简洁，大量运用了子程序的设计与调用，使程序具有易扩展、可修改移植的优点。 总之本系统不仅可以有效解决筑路机械发动机过热和液压油冷却不足及冷启动困难的问题，而且系统还具有安装灵活、节省燃油、降低噪声、体积小、功率大等优点，将之推广运用到筑路机械中，将会获得良好的社会经济效益。更多还原

【Abstract】 The cooling system driving type of domestic construction machinery mainly adopted traditional crankshaft fixed transmission ratio type driving. This type of driving method caused the engine of construction machinery has high start torque, long preheating time, unreasonable cooling, and too much power consumption by the fan (At rated operating condition of engine, the fan power consumption occupies nearly 5% - 12% of effective power output of the engine), which decreased the power output, and the fix location of the fan is limited, and the operation noise is high.In the project we designed a cooling system of new style. It can settle the over heat problem of engine and hydraulic oil system which often happens in the construction machinery engineering construct process.Being different to the structure collation method of traditional cooling system, this system divided the whole system into two parts: cooling system for engine and cooling system for hydraulic oil system, and both of them are controlled by one singlechip. The cooling system for engine adopted hydraulic drive and control technology to control the speed of the fan: the chip adjust the control-current of the proportional value, which used in the engine cooling system , to control the speed of the fan .And the size of the control-current is according to the coolant temperature , coolant temperature change rate and target temperature . As for as the hydraulic cooling system we used a motor to drive and control the fan’s work or stop according to the temperature of the hydraulic oil.The testing result indicate that this cooling system can resolve the overheat problem of engine system and hydraulic system effectively, at the same time it also is easy to fix, source saving and with high power than the traditional cooling system.更多还原