机械专业毕业设计论文

摘要

本毕业设计的课题来源于现场工程实际，主要任务是在现场实习调研的基础上拟定出整个疏煤系统的设计方案，设计出液压系统、电控系统及各组成部分，并选择液压元件及电控元件，最终完成整个系统的设计。

本文设计的液压疏煤系统主要包括两大部分：液压系统和电控系统。其中液压部分是由液压系统控制十个液压缸伸缩，液压缸带动埋在煤中的蒺藜棍运动，进而实现煤仓的疏煤。电控部分采用PLC可编程控制器控制：对电动机的启闭、加热器的开关、电磁换向阀的换向、液压系统的卸荷等实现了手动与自动控制。

本设计包括液压缸设计和电控系统设计两个专题部分。设计的液压缸采用活塞缸——连杆传动方案；活塞采用组合式活塞；前端盖为法兰联接；后端盖采用焊接结构；活塞与连杆用螺母固定。设计中对缸筒，活塞杆，端盖等重要零件进行了结构分析和力学计算。

设计的电控系统，采用PLC可编程控制器作为主要控制元件，压力继电器作为PLC的一个输入端。这样系统可以根据现场实际的需要来控制液压缸的伸缩，即实现了每个液压缸均可独立自动连续运行，又实现每两个液压缸自动连续运行和手动控制。

此外，还对系统中的各类液压元件和电控元件进行了选择，选出合适的型号，并对电控操作台作了初步设计。

关键词：疏煤系统；液压缸；电控系统.

Abstract

The design of the graduate engineering topics from the scene, the main task is to research internship at the scene on the basis of drawing up the dredging of coal system design, design a hydraulic system, electronic control systems and components and hydraulic choice components and electronic control components, the final completion of the entire system design.

In this paper, the design of the hydraulic dredging coal system, including the two main parts: the hydraulic system and electronic control system. Which is part of the hydraulic control system of hydraulic telescopic eight hydraulic cylinders, hydraulic cylinders buried in the coal driven in a few words stick movement, leading to the reduced coal bunker coal. Electronic parts used PLC control: on the hoist motor, heater switch, the change to the electromagnetic valve, the hydraulic system of unloading, and so achieve the manual and automatic control.

In this paper, the design of the hydraulic cylinders and electric control system of this design is part of the topic. In this paper, the design of a hydraulic cylinder piston-cylinder - link transmission programmer; Detroit Pistons used modular; front cover for the flange connection; cover after a welded structure; Pistons and the fixed link with nuts. The design of the cylinder, piston rod, cover, and other important parts of the structure and mechanical calculations.

In this paper, the design of the electric control system, using today's more advanced PLC programmable logic controller as the main control devices, pressure relay as a PLC input. This system can transform the hydraulic oil-hydraulic cylinders to control the expansion, not only to achieve the

independence of each cylinder can be automatically continuous operation, but also to achieve every two hydraulic cylinder automatic and manual control of continuous operation.

In addition, the system in all types of hydraulic components and electronic control components of the relevant terms, elect a suitable model, and electronic control console made a preliminary design.

Key words: reduced coal system; hydraulic cylinder; electronic control system.