《管件内高压成型系统设计》.docVIP

大连交通大学 毕 业 设 计（论 文） 题 目： 院 （系）： 专 业： 班 级： 学生姓名： 导师姓名： 职称： 起止时间： ABSTRACT Hydraulic and pneumatic transmissions and a discipline that is based on fluid medium energy of compressive fluid (pressure oil or compressive air) to accomplish mechanical transmission and automatic control. Recently hydraulic and pneumatic pressure transmission technology has been developed with a large scale petrolic industry in the 19th,and the barbette displace was the first one successful using hydraulic equipment, and then hydraulic machine tool. The great automotive industry introduced hydraulic brakes in the early thirties and hydraulic transmissions in the late thirties. The tractor industry began using hydraulic in 1940 to increase the flexibility and utility of farm equipment. After the World War Ⅱ ,the hydraulic development turned into civil industry, such as machine tool ,engineering, metallurgy, plastic machine, farm machine, vehicle and watercraft. In more recent years , the role of leadership in hydraulic power application has been taken over larger by some of the large earthmoving and construction equipment manufactures. The total power involved is often greater than that required in even the largest aircraft With the development of higher automation of hydraulic machine and increasing use of hydraulic and pneumatic elements, the scaled elements and integrated system with miniaturization is inevitable. Especially in recent years hydraulic and pneumatic transmission is combined closely with the sensor and micro-electronics technology. It has been emerging amounts of new valves such as hydraulic-electricity proportional valves, digital valve, hydraulic and plectra-hydraulic servo cylinders and the integrative elements, which will lead the hydraulic and pneumatic technology to the development of higher pressure, higher speed, lager power, lower energy wastage and noise, longevity and high integration. Nowadays