The Vibration Analysis And Improvement Design Of Beam In Computerized Embroidery Machine

The computerized embroidery machine is developed on the base of the computerized sartorius, which connects the traditional brede with the electric and mechanical technology,and presents some characteristics such as simple structure, steady performance, various functions,advanced automatism, easy operation and low voice. So it's used widely in the accessorial field of Clothes Industry——Embroidery Industry . Embroidery machines made in our country mostly are imitated from the type of other countries, and the technique level of making the accessory is also lower in our country, so the maximum working rev of the homemade computerized embroidery machine is limited. For example, the homemade 20-headed computerized embroidery machine can hardly get the speed of 900rpm. When the principal axis turns over 750rpm, the embroidery machine will vibrate severely, and the thread-broken rate will rise rapidly.The research takes the GY920A 20-headed computerized embroidery machine as a subject, which will improve the performance of the machine by means of theoretic calculation, vibration analysis and finite element analysis.In the part of the vibration experiments and analysis, firstly, used the simple-beam theory to estimate the natural frequency of the beam of the 20-headed computerized embroidery machine.secondly, measured the beam of its low rank natural frequency, the beam's horizontal vibrating acceleration amplitude, speed amplitude and the displacement amplitude in different rev and different turn parts. Found that it is sympathetic vibration, which bring on the thread-broken rate rise rapidly. On this base, established the finite element analysis modle of the vibrating beam, and took on hamonic analysis and modal analysis with the mold. The rusult of test and analysis offer the basis for farther improvement of the computerized embroidery machine.In the design and improvement section, took the three methods as follow: changed the section form of the beam, amended the fixing method of both side of the beam and design the dynamic vibration absorber according to the vibration theory to raise the working speed of the computerized embroidery machine. The most inportant part of this section is the design of dynamic vibration absorber. Firstly, decided the parameters of dynamic vibration absorber according to the vibration theory, then calculated the amplitude of the beam which installed the dynamic vibration absorber according to the theory of elastic mechanics and simulated the effect of the dynamic vibration absorber by finite element analysis to make sure that the dynamic vibration absorber is effection.