Time filter

Source Type

Li X.-T.,Yanshan University | Wang M.-T.,Yanshan University | Du F.-S.,Yanshan University | Zhang G.-L.,Dalian Design and Research Institute Co.
Journal of Central South University | Year: 2014

Aiming at accuracy control of the thermal crown of work rolls in cold rolling, new parameters such as regulation domain and control-efficiency factors were proposed and a numerical analysis model of the thermal crown of work rolls was established using finite difference method to study roll's thermal deformation. Based on simulation results, the influences of control-efficiency factors on thermal crown are presented and the thermal crown of work rolls is analyzed after taking sub-cooling of sprinkling beam into consideration. It has been found that the control-efficiency factor of any position on the roll's surface is linear function of the temperature and the control ability of water temperature is stronger than other control parameters. In addition, the verification of the model has been carried out based on the producing technology data in some factories and the numerical simulation results coincide well with the experimental data. Therefore, this work has important value for on-line control of roll's crown in cold rolling. © 2014 Central South University Press and Springer-Verlag Berlin Heidelberg.


Song Q.,Yanshan University | Song Q.,Dalian Design and Research Institute Co. | Li J.,Dalian Design and Research Institute Co. | Yin W.,Dalian Design and Research Institute Co.
Nongye Jixie Xuebao/Transactions of the Chinese Society of Agricultural Machinery | Year: 2012

Six-link transmission mechanism optimization design was proposed with the multi-objective demand of path, velocity and acceleration. A brief uniform mathematical description of the slide motion path was established using Fourier series theory. Then the formulas of the slide velocity and acceleration were obtained. According to the constraint conditions of mechanism engineering design, taking the minimum deviation error of slide kinematics data and the minimum mechanism height as the optimization object, the optimization model of transmission mechanism design was established. It was performed by the composite optimization algorithms based on penalty function and complex algorithm. The validity and effectiveness of the proposed method were verified by a practical instance.


Li J.,Yanshan University | Li J.,Dalian Design and Research Institute Co. | Zhao J.,Yanshan University | Ma R.,Yanshan University
Guangxue Jingmi Gongcheng/Optics and Precision Engineering | Year: 2010

To reduce the ellipticity of the steel pipes processed by JCO forming, a precise bending technology was presented based on plastic bending engineering theory and machine vision technology. In the first bending step, the prescribing two-bend was used to obtain the springback law, then using the springback law and considering the aimed bend angle, the exact punch displacement to determine the forming angle in each bending step was predicted. In the succedent bending steps, the bending process was carried out with the exact punch displacement predicted above. The angle error in each bending step was calculated bycomparing the actual forming angle with the aimed bend angle, and each precise bending process was realized bycompensating for the last angle error in the next bending step. Furthermore, the image processing and line detecting algorithms suitable for the image of the steel pipe end plane were proposed by a machine vision system. A calibration method was presented to calculate the exterior parameters of the CCD camera, which employed a equilateral triangle as the calibration board and only needs to capture one image. A mathematical model was derived to convert the angle in the image into the actual forming angle. Experimental results show that the measuring error of the forming angle is less than 0.2° and the ellipticity of the formed pipe is less than 1.5%. Employing the precise bending technology, the high-quality pipes can be manufactured without depending on worker's operating experiences.


Song Q.,Yanshan University | Song Q.,Dalian Design and Research Institute Co. | Guo B.,Yanshan University | Li J.,Dalian Design and Research Institute Co. | Yin W.,Dalian Design and Research Institute Co.
Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery | Year: 2013

A flexible acceleration and deceleration control algorithm of the servo motor was proposed, in which the two trigonometric functions of different cycles were used to construct the acceleration and deceleration function. This algorithm could better match with the servo motor's characteristics, and reduce the requirement of servo motor power. The calculation formulas of displacement, velocity, acceleration and jerk of the servo motor were derived. The performance of this algorithm was compared with the trigonometric function acceleration and deceleration control algorithm. The experimental results showed that this algorithm could be applied to plan the drawing profiles for the servo press.

Loading Dalian Design and Research Institute Co. collaborators
Loading Dalian Design and Research Institute Co. collaborators