摘 要随着我国医疗事业的发展和计算机的普及与提高，计算机控制技术越来越多地应用于各行各业中，传统的医疗器械已经不能满足患者的需求了。在此推动下，医疗护理器械的开发势头迅猛，但由于各地经济发展的不平衡性以及诸多人为因素的影响，致使许多先进的医护设备得不到应用，给患者带来了许多不便。为了克服这种困难，研制一套功能齐全、造价低廉的护理器械尤为重要，在这种背景下，计算机控制多功能病理床应运而生了。结合病人的需求，设计了一种能自动实现抬头、屈腿、左右侧翻以及同时实现抬头和屈腿等功能的医用多功能病理床。考虑到该病理床要实现各项功能，特将床板分割成八个部分。驱动方式上采用液压驱动方式，之所以选用液压系统，是因为其运动速度平稳，实用性强。每个动作实现都是由两个液压缸同时直接驱动，上升和下降则通过改变换向阀方向来实现。整个设计分为三步进行：首先设计出能实现动作要求的液压系统原理图，根据要求选择各标准件；其次，进行液压缸体的结构设计及材料的选择；最后，做液压站的总体设计。关键词：液压系统；液压驱动；病理床 AbstractWith the development of medical treatment and the improvement of computers, computer control technique is more and more applied to all kinds of industries, which results the sufferers dont satisfy traditional medical instruments. Under the impulse of this, the research of medical instruments greatly engages peoples attention. But because of the unbalance of regional economic progress and a great deal of factitious factor, many advanced medical instrument are not suitably used, which brings a lot of inconveniences. In order to overcome difficulties, it is more important to study a suit of medical instrument that is multifunctional and cheap, so multifunctional pathological bed controlled by computer comes into being.A kind of multifunction turn-over bed for patients is introduced in this paper, which has the functions of raising head, curling legs, side turning over from left to right separately, or raising head and curling legs at the same time according to patients requirement. The bed is composed of 8 parts and hydraulic drive is adopted. We make use of the hydraulic system because hydraulic systems velocity is stable. Each movement is directly driven by both hydraulic cylinders. Raising and falling of the bed is realized by means of diverting valves. The design is making up of three steps .The first; we design the hydraulic system principle picture and choose the hydraulic stand components. The second, we design the hydraulic cylinders construction and their materials. The last, we design the hydraulic station and its arrangement.Keywords Hydraulic System ;The Hydraulic Pressure; The Pathologic Bed;目 录摘要IAbstractII第1章 绪论11.1 液压系统综述11.2 病理床国内外研究现状21.3 课题研究的意义和目的2第2章 病理床液压伺服系统的设计42.1 设计要求42.2 病理床液压执行元件载荷力计算42.2.1 进行工作情况分析42.2.2 头部运动时的负载情况52.2.3 膝部弯曲时的负载情况62.2.4 躯干运动时的负载情况72.3 系统方案制定82.3.1 执行机构的选择82.3.2 调速回路的选择82.3.3 换向回路的选择82.3.4 液压源的选择82.4 动作顺序82.5 病理床液压系统主要参数计算102.5.1 各液压缸的载荷力计算102.5.2 初选液压缸工作压力及液压缸回油腔背压力112.5.3 液压缸主要参数的确定112.5.4 液压缸实际工作压力的确定152.5.5 液压缸实际所需的流量152.5.6 液压缸的输出功率152.6 液压元件的选择162.6.1 液压泵的选择162.6.2 电动机功率的确定172.6.3 液压阀的选择182.6.4 管道尺寸的确定192.6.5 油箱有效容积的确定192.6.6 液压油的选定202.7 病理床液压系统性能验算202.7.1 液压系统压力损失202.7.2 系统温升验算222.8 本章小结23第3章 病理床所用液压缸基本尺寸的设计243.1 液压缸主要尺寸的确定243.1.1 液压缸内径及活塞杆直径的确定243.1.2 缸筒壁厚的计算243.1.3 缸体外径的计算243.1.4 液压缸工作行程的确定243.1.5 最小导向长度的确定253.1.6 缸体长度的确定263.2 液压缸的结构设计273.2.1 缸体与缸盖的连接结构273.2.2 活塞杆与活塞的连接结构273.2.3 密封装置273.2.4 液压缸的缓冲装置283.2.5 液压缸主要零件的材料283.2.6 液压缸的安装方法283.3 本章小结28第4章 病理床液压站的设计294.1 油箱的设计294.1.1 液压油箱容积的确定294.1.2 油箱的结构设计304.2 液压泵组的结构设计314.2.1 布置方式314.2.2 连接和安装方式314.2.3 防振降噪措施324.3 本章小结32结 论33致 谢34参考文献35附录A36CONTENTSAbstractIIChapter 1 Introduction11.1 Summary of the Hydrauliic System11.2 The Research of Pathological Bed 21.3 The Meaning and Purpose of the Research2Chapter 2 The Design of Pathological Bed Hydraulic Servo System42.1 Design Requirements42.2 Pathological Bed Hydraulic Actuator Load Force Calculation42.2.1 Analysis of the Work42.2.2 Load of the Head Movement52.2.3 Load of the Knees Bent62.2.4 Load of the Trunk Movement72.3 System Programming82.3.1 The Choice of Implementing Ageny82.3.2 The Choice of Speed Control Loop82.3.3 The Choice of Trading to the Looop82.3.4 The Choice of Hydraulic Source82.4 Sequence of Movement82.5 The Main Calculation of Pathological Bed Hydraulic System102.5.1 Load Force of the Hydraulic Cylinder Calculation102.5.2Primary Hydraulic Cylinder Pressure and Back Presssure of Hydraulic Cylinder Back to the Oil Chamber112.5.3 The Main Parameters of Hydraulic Cylinder112.5.4 The Determination of Hydraulic Cylinder of the Actual Working152.5.5 Hydraulic Cylinder of the Actual Traffic152.5.6 The Output Power of the Hydraulic Cylinder152.6 Choice of Hydraulic Components162.6.1 The Choice of Hydraulic Pump162.6.2 The Determination of the Motor Power172.6.3 The Choice of Hydraulic Valves182.6.4 The Determination of Pipe Sizes192.6.5 The Determination of the Effective Tank Volume192.6.6 The Selection of the Hydraulic Oil202.7 Pathological Bed Hydraulic System Performance Calculation202.7.1 Hydraulic System Pressure Loss202.7.2 System Temperature Rise Checking222.8 Chapter Summary23Chapter 3