Cai Yujun

A new double-face online dynamic balance device and its control system for high speed machine tool spindle

Dynamic balance technology is one of the basic questions that must be considered during the high speed, high-precision machine tool’s design and production course, and its function has a great impact on the working performance, efficiency and life of the machine tool. A new double-face online dynamic balance device with a pneumatic driving system is designed in the paper. Compared with similar balance devices, the dynamic balance device has many advantages: the mechanism structure is simple, the body dimension (the axial dimension in particular) is small, the practical application in the machine tool is easy to realize etc. In order to accurately separate the unbalance vibration component from the vibration measuring signal, the least square algorithm is adopted to fit the fundamental frequency signal. The method has a theoretical advantage compared with the traditional fast Fourier transform algorithm. Based on the influence coefficient principle, the implementation steps of the double-face online dynamic balance are designed. Based on these steps, the location experiments are done to test the position correcting error of the balance discs, the test weight experiments are done to estimate the influence coefficient, and the balance correction experiments are done to examine the online dynamic balance effect. The experimental results indicate that the online dynamic balance device and its control system have the advantage that the system is stable and reliable, the location of the balance disc is accurate and the dynamic balance precision is high.

Research on Numerical Simulation for Automotive Panel Forming and Spring-back Based on Dynaform

The spring-back in automotive panel forming is one of the main problems, and the measure of controlling spring-back needs to predict the spring-back mount accurately. Taking the simulation method of the sheet stamping forming and spring-back as foundation, the simulation of stamping forming and spring-back for roof of automotive is carried out in Dynaform, and the result of simulation also is analyzed. The result shows that no crackle and wrinkle happen during the course of sheet metal forming, there are some regions sinking on the panel, other rising, and sinking tendency greater than rising. In order to control the spring-back, the inverted compensation method is adopted to optimization design die surface according the result of simulation. The rationality of spring-back controlling measure and the veracity of die surface modified are proved by the actual panel and detection result. The qualified product is obtained.

TRIZ in mold of innovative design

TRIZ is a powerful tool for conceptual design, which has the clear definition of innovation and the systemic methodology for contradiction-resolving in the product design. By applying TRIZ theory and technology and aiming at the low productivity of fixed molded honeycomb paperboard mold to carrying out analysis of technology contradiction, applying technology contradiction solve matrix, through the innovation principles of the Spheroidality and combined with the characteristics of the mold, innovative design of the rotary molded honeycomb mold has been made. Shown by the practical application, the rotary molded mold can improve the productivity significantly.