Papers by Keyword: Clearance

Abstract: This paper introduces working principle of screw oscillating hydraulic cylinder. Structure parameters and process parameters influence on mechanical efficiency is analyzed, simultaneously, structure parameters and process parameters influence on volumetric efficiency is also analyzed. the maximum mechanical efficiency and optimal spiral angle are acquired. Total transmission efficiency model is established. Transmission efficiency experimental test is carried out, experiment test efficiency is basically in accordance with calculated efficiency.

Abstract: Fine blanking is a press-working process that permits the production of precise finished components which are cleanly sheared through the whole cutting surface. It can be eliminated secondary operations, such as milling, grinding, etc. Recently, many studies on the weight reduction of automobile for fuel saving were underway. Especially, there are many examples in which light metal like Al were applied for automotive parts. The clearance between the punch and die of a fine blanking tool is an important design factor that affects the sheared surface of a product. In a fine blanking process, the clearance is typically assigned a 0.5% material thickness. If the clearance is too big, a fractured surface would occur in the product while if it is too small, bulging would occur. In this study, a setting for optimum clearance was proposed for inner corner shapes by checking shear characteristics and bulging effects according to various clearances. After designing a special part with various corner shapes possessing Al5052 (thickness: 4 mm), a fine blanking tool was constructed and fine blanking experiments were conducted. The result could be usefully applied in fine blanking processes for Al automobile parts with corner shapes in the future.

Abstract: To demonstrate the importance of abrasion and clearance to machinery, this paper studied abrasion of Cam mechanism contact surface, illustrated how abrasion and clearance relate to each other and investigated how they influence kinematic accuracy of the mechanism. In the case of Cam mechanism with flat-bottomed translation follower, it elaborated abrasion styles and bad points and depicted heart-shaped abrasion rate curve. It proposed a mathematical model and optimized design for cam profile, taking abrasion design as an objective function. Aided by Matlab and its optimization toolbox, it also proposed a optimized solution to the objective function mathematical model. And powered by computing capabilities of Matlab, it determined the coefficients in a high-order five-term function and found the optimal value of the objective function quickly in need. By optimization, mechanism abrasion improves and its kinematic accuracy and reliability increase, prolong its life.

Abstract: An automotive drive shaft is used in a front drive transmission vehicle for transmitting rotary movement from the gearbox output shaft to the wheels with a constant velocity. The kinematics model of ball joint and tripod joint has been studied without consideration of clearance. This paper will propose a new model with consideration of the clearances on ball joint and tripod joint. The simulation results are given by using this model. The conclusions are made as well as the future work.

Abstract: Using the traditional control method is difficult to obtain the ideal control result, because the linkage mechanism with clearance is a strongly nonlinear system, and it is difficult to establish the accurate mathematical model. In response to these problems, take the linkage mechanism with clearance for example and establish BP neural network offline modeling, on the basis of the experimental sample data. We separately applied the neural network internal model control and the parameters self-adjusting fuzzy control to reduce the nonlinear error caused by the clearance. The experimental results show that using intelligent control technology, the system stability has been significantly improved, and the system error has been reduced effectively.

Abstract: Fine blanking is a press-working process that permits the production of precise finished components which are cleanly sheared through the whole cutting surface. It can be eliminated secondary operations, such as milling, grinding, etc. Recently, many studies on the weight reduction of automobile for fuel saving were underway. Especially, there are many examples in which light metal like Al were applied for automotive parts. Eco-Al is the new material which is replaced Mg of aluminum alloy with Mg+Al2Ca, therefore Eco-Al material has improved mechanical properties and formability. The clearance between the punch and die of a fine blanking tool is an important design factor that affects the sheared surface of a product. In a fine blanking process, the clearance is typically assigned a 0.5% material thickness. If the clearance is too big, a fractured surface would occur in the product while if it is too small, bulging would occur. In this study, a setting for optimum clearance was proposed for inner corner shapes by checking shear characteristics and bulging effects according to various clearances. After designing a special part with various corner shapes possessing Eco-Al5052 (thickness: 4 mm), a fine blanking tool was constructed and fine blanking experiments were conducted. The result could be usefully applied in fine blanking processes for Eco-Al automobile parts with corner shapes in the future.

Abstract: With the rotating machinery system developing toward high speed, high precision, and high reliability direction, ball bearing dynamic performance have a critical impact to dynamics characteristics of support system. Based on multibody dynamics theory and contact dynamics method,and considering the ball and ring raceway 3 d dynamic contact relationship, using ADAMS dynamics analysis software to establish the multibody dynamics model of crank slider mechanism containing ball bearing dynamic contact relationship.The simulation analysis of the dynamic performance of the ball bearing and the crank slider mechanism dynamics response, and the influence of dynamic performance for considering ball bearing rotating mechanical system dynamics analysis provides a reference method.The simulation analysts the influence of dynamic performance of the ball bearing to the crank slider mechanism dynamics response. It provides a reference method for rotating mechanical system dynamics analysis considering the dynamic performance of the ball bearing.

Abstract: When scroll compressors are operated, the heat and force loads acting on scroll plates result in the deformation of them. The temperature distribution and deformations of scroll plates were researched in this paper. The simulation results show that the maximum temperatures of scroll plates are at the center of scroll profiles. And there are the maximum axial deformation values at the center of scroll profiles. The maximum radial and axial fit clearances of compressor are 59.5μm and 38.8μm respectively.

Abstract: The clearance between the punch and die of a fine blanking tool is an important design factor that affects the sheared surface of a product. In a fine blanking process, the clearance is typically assigned a 0.5% material thickness. If the clearance is too big, a fractured surface would occur in the product while if it is too small, bulging would occur.In this study, a setting for optimum clearance was proposed for inner corner shapes by checking shear characteristics and bulging effects according to various clearances. After designing a special part with various corner shapes possessing SPFH590 (thickness: 4 mm), a high-strength steel material, a fine blanking tool was constructed and fine blanking experiments were conducted. The result could be usefully applied in fine blanking processes for high-strength steel automobile parts with corner shapes in the future.

Abstract: Present work describes a piercing process in order to investigate the clearance of mold parameters and to obtain optimal clearance values for a given sheet material and thickness to be pierced, using the finite element method. The clearance was studied by simulating the piercing operation of a Q235-B sheet. The results of the present paper showed that clearance was the most influential factor for piercing, and numerical experiments was an effectiveness method to get optimal parameters of mold parameters, and the numerical experiment results showed that the best clearance could be got when the ratio of clearance and thickness of material was 0.11.