High-speed Press Research Articles

エンジニアリングセラミックス複合新材料の研究開発と量産，実用化

New composite ceramic materials enable to improve mechanical properties and various performances more than monolithic ceramic materials. Generally, composite ceramic materials include more than two different materials, in addition, more than two crystal structures in case of α and β crystal phase composite Si3N4 material in this research. Composite ceramic materials enable to get various different characteristics that show excellent properties, not only mechanical properties but electrical properties, resistance to oxidation and wear. Properties improvement develops many new applications with superior performance more than conventional materials. In this research, we have developed various ceramic reinforced composite, based on Al2O3 and ZrO2 ceramics with carbide and nitride particles or whisker addition. Farther more we have developed α and β crystal phase composite Si3N4 material by researching the sintering additives stoichiometric ratio and sintering condition. Finally we succeeded in applying ceramic composite materials to various industrial parts, for example, Al2O3-TiC thin magnetic slider substrate, Al2O3-SiC whisker based cutting tool, Si3N4 squeezing roll and wear parts, ZrO2-WC ceramics punch and die for high speed pressing.

Investigations on the dynamic characteristics of a planar slider-crank mechanism for a high-speed press system that considers joint clearance

Clearances in the joints of mechanisms are unavoidable because of numerous uncertainties, such as manufacturing tolerances, assembly processes, and progressing wear. The dynamic characteristics of a planar slider-crank mechanism, including clearance joint and balancing mechanism, are investigated in this study using a computational method. A suitable model is built using the simulation software ADAMS, in which actual features, such as contact and friction, are considered. A contact-impact model that incorporates the IMPACT function and that considers energy loss in the contact process, is also built. The experimental platform is established and acceleration experiments on the mechanical system at different driving speeds are conducted. Obtained tests results demonstrate that the dynamic response of a multibody mechanical system can be effectively predicted using the proposed method. Furthermore, the effects of the driving speed of the crank shaft, the size of the joint clearance, and the balancing mechanism on the dynamic characteristics of the mechanism are studied.

Influences of the Air in Metal Powder High Velocity Compaction

During the process of metal powder high velocity impact compaction, the air is compressed sharply and portion remains in the compacts. In order to study the Influences, a discrete density volleyball accumulation model for aluminium powder was established with the use of ABAQUS. Study found that the powder porosity air obstruct the pressing process because remaining air reduced strength and density of the compacts in the current high-speed pressing (V≤100m/s). When speed further increased (V≥100m/s), the temperature of the air increased sharply, and was even much higher than the melting point of the material. When aluminium powder was compressed at a speed of 200m/s, temperatures of air could reach 2033 K, far higher than the melting point of 877 K. Increased density of powders was a result of local softening and even melt adhesive while air between particles with high temperature and pressure flowed past.

Investigation on the design of hydraulic high-speed punching press with a large press force and a long press stroke

High-speed punching presses are widely applied in modern manufacture industry, especially in occasions of automatic production with a large or a super large quality. To obtain a better production efficiency and a wilder application in industries, it is meaningful to develop the high-speed punching presses with a large press force and a long press stroke. Considering the limitations of mechanical and servo high-speed punching presses, hydraulic technology is the most possible way to develop the high-speed punching press with a large press force and a long press stroke so far. This article has proposed a hydraulic operating principle based on the hydraulic vibration technology for the development of the high-speed punching press with a press force of 1250 kN, a press stroke of 50 mm, and a press velocity of 1000 hpm. With a simulation model built under the AMESim environment, performances of the system are obtained and analyzed. Then, parameter optimization is also carried out and discussed. Finally, the operating principle and the parameters are refined. The obtained results have proved that the design meets the aimed performances of the high-speed punching press.

Dynamic precision analysis and experimental verification of high-speed precision punch press

In order to investigate the impact factors and their affection on high-speed precision multilink punch press (MPP), the dynamic model with different joint clearance was established, and the influence of different clearance and speed on the dynamic positional repeatability of bottom dead center (BDC) was analyzed. The elastic dynamic model of high-speed MPP was established, the affection of the elastic deformation and elastic wave on the positional repeatability of the BDC were presented by using modal superposition method to solve dynamic equation. Meanwhile, experiments on the dynamic repeatability of the BDC of the punch during working were completed. At last, the comparison of the experimental results with the analyzed results was given, and based on which, it can be concluded that the clearance, elastic wave and deformation are the key factors of the dynamic repeatability precision of the BDC.

Dynamic modeling of a high-speed over-constrained press machine

This paper presents a study on the dynamic modeling of a high-speed over-constrained press machine. The main contribution of the paper is the development of an efficient approach to perform the dynamic analysis of a planner over-constrained mechanism. The key idea is the establishment of a more general methodology, which is to gain a deformation compatibility equation for the over-constrained mechanism on the basis of the deformation compatibility analysis at each position of the mechanisms. And this equation is then used together with the force/moment equilibrium equations obtained by the D’Alembert principle to form a total equation for the dynamics of the over-constrained mechanism. The approach is applied to a particular press machine to validate the effectiveness of the approach, and in the meantime to provide some useful information for the improvement of the design of this press machine.

Static and dynamic characteristic analysis of high-speed press bed based on virtual simulation

This paper establishes a three-dimensional solid model of J76-125 Straight Side High-speed Double-crack Precision Press using CATIA, and then the model is imported into an ANSYS environment to form the static and dynamic finite element simulation model. Based on the finite element analysis method, the static stress, deformation, vibration mode and transient response of the press bed are developed under preload conditions, as well as under the combination of the preload and nominal pressure conditions. Besides, the static loading experiment, the mode experiment and the pile-driving experiment are conducted to revise the simulation model. Finally, the simulation model and analysis procedure are verified through the comparison of the experiment results and the simulation ones.

Development of High Speed Precision Press and its Development Trends

High speed press is precision mechanical presses, with automatic feeding device, which has automatic, high-speed, precision three basic elements. This paper first describes the characteristics of the different definitions of high-speed presses and the characteristics of the object suitable for processing parts. Then the research status of high speed precision press at home and abroad was analyzed, and the development trend of high-speed precision presses was investigated.

고속프레스의 다이나믹 시스템 및 방진시스템 설계에 관한 연구

In a high-speed press, numerous moving links are interconnected and each link executes a constrained motion at high speed. As a consequence, high-level dynamic unbalance force and unbalance moment are transmitted to the main frame of the press, which results in unwanted vibration and significantly degrades manufacturing accuracy. Dynamic unbalance force and unbalance moment inevitably transmits high-level vibrational force to the foundation on which the press is installed. Minimizing the vibrational force transmitted to the foundation is critical for the protection of both the operators and the surrounding structures. The whole task should be carried out in two steps. The first step is to reduce dynamic unbalance based upon kinematic and dynamic analyses. The second step is to design and build an optimal vibration isolation system minimizing the vibrational force transmitted to the foundation. Firstly, the dynamic design method is presented to reduce dynamic unbalance force and moment. For this a 3D CAD software was utilized and a computer program was written to compute dynamic unbalance force and moment. Secondly, the design method for vibration isolation system is presented. The method for designing coil springs and viscous dampers are explained in detail.

Designing a High-Speed Press with a Six-Bar Linkage Mechanism

This paper describes the design process of a high-speed cutting press with a linkage mechanism in its drive train. The whole process is carried out for a virtual prototype. The kinematic and dynamic properties of the six-bar linkage mechanism are optimised regarding boundary conditions coming from the production process and kinematic requirements. Using a rigid body model, the geometric dimensions and inertia parameters of the links of the mechanism can be determined. A finite-element (FE) model is build up to check the parts’ durability during work load. A verification of main results is realised on an experimental prototype made from rapid prototyping material.

COMBINED VIBRATION ISOLATOR OF DISC SPRINGS FOR CLOSED HIGH-SPEED PRECISION PRESS: DESIGN AND EXPERIMENTS

The structure, strength, and stiffness of disc springs are analyzed or investigated. Based on the previous studies, two finite element models of combined disc springs are established and their loading and unloading deformation patterns are analyzed to determine the optimal combination of disc springs for a desirable vibration isolator of high-speed press. The structural parameters and loading data of JF75G-200 high-speed press are used for simulation and other experiments. The dynamic working points of disc springs in different combinations are drawn, and complete test data are collected. Results show that combined vibration isolator, an isolator with nonlinearly combined disc springs functioning as a whole for vibration isolation, is the best choice. Results from both simulation and tests confirm the feasibility and validity of the proposed isolator. The isolator can efficiently minimize the vibration of the high-speed press.

Thermal modelling and characteristics analysis of high speed press system

The traditional thermal model of presses neglects the effect of roughness between two contact surfaces on the contact conduction coefficient, which causes the analysis to have a low accuracy. The primary objective of this work is to propose an improved thermal model of the high speed press system with the thermal contact resistance between solid joints and the change of the heat generation power with the temperature of bearings considered to analyze its thermal characteristics. Based on the fractal model and the change of the heat generation power, a complete thermal model for the high speed press system is developed. The temperature histories and the time for reaching thermal equilibrium condition of the high speed press system are explored by the finite element (FE) method. The experimental results demonstrate that the complete model is more accurate than the model without considering the thermal contact resistance and the change of the heat generation power. The thermal expansion of the high speed press system is also investigated, which can provide a theoretical basis for design of structure and intelligent lubrication system to improve its precision.

Rotating Self-locked Condition Research of the Pushing High-speed Forging Hydraulic Press’ Movable Beam

Aiming at the pushing high-speed forging hydraulic press, the frictional resisting torque and friction radius of supporting spherical hinge in the working cylinder is analyzed, the supporting spherical hinge's side thrust to the working cylinder's plunger with single and double spherical hinges structures is studied and influencing factor of hydraulic press' structure parameter to the plunger's side thrust is determined. By synthesizing the structure influences of working cylinder, supporting spherical hinges and movable beam, the conditions the forging eccentricity should meet when the movable beam is in rotating self-locked condition and the internal relations between hydraulic press' structure parameter and movable beam's self-locked condition can be determined. Base on the structure parameter of domestic pushing high-speed forging hydraulic press and some import devices, the forging eccentricity that meets the movable beam's self-locked conditions is calculated and the working conditions of movable beam in eccentric forging and the effect of working cylinder's supporting spherical hinge in the hydraulic press' operation is analyzed. By simulated analysis, the movable beam's rotating self-locked condition in eccentric forging is further verified to provide theoretical basis to the research of large scale double column free forging hydraulic press and the optimization design of medium and small scale hydraulic press.

Load Spectrum Testing and Analysis for Transmission System of Closed High-speed Press

Load spectrum is important for accelerated reliability test and fatigue life prediction of mechanical structure. To study the load spectrum, load signals of transmission system of closed high-speed press were collected under 20 working conditions. The real load signals that reflect dynamic characteristics of the inertial force and the impact load were obtained after signals pretreatment and characteristics analysis. In addition, the load spectrum was obtained after the load time histories had been processed by means of rain-flow counting method. The testing load spectrum provides the first-hand data for fatigue life prediction, studying fatigue damage and accelerated reliability test of the transmission system.

Dynamic analysis of closed high-speed precision press: Modeling, simulation and experiments

To forecast the dynamic responses of closed high-speed precision press accurately, a 3-degree-of-freedom (DOF) dynamic model of mass-spring damping is proposed in this work. This model operates by using the centralized parameter method. Considering the instantaneity of impact load, we employ impulse simulation to simulate the periodic impact working conditions of a JF75G-200 high-speed press using both 2-DOF and 3-DOF models. Simulation data on the dynamic responses of the press are acquired and compared with the results from on-site measuring. The proposed 3-DOF dynamic model of mass-spring damping has been proven by our simulation and test to be reliable as well as effective for detecting the dynamic responses of the press.

Modeling and simulation of flexible slider-crank mechanism with clearance for a closed high speed press system

The traditional model of a slider-crank mechanism for a closed high speed press system always neglects the flexibility of the crank shaft and considers only one revolute clearance joint between the linkage and the slider. This causes any analysis to have a low accuracy. In this work, a rigid–flexible coupling model of the slider-crank mechanism is described, using the software ADAMS, in which the crank shaft and linkage are treated as flexible bodies, and the effect of the clearance of the joints between the crank shaft and the main linkage, and between the main linkage and the main slider are taken into account. The dynamic response of the mechanism with clearance under no-load and piling conditions is explored for the case of a mechanism with a rigid crank shaft and linkage, and the case with a flexible crank shaft and linkage. The simulation results showed that the dynamic response of the mechanism was greatly influenced by the clearance and the motion of the crank shaft center was characterized by three phases: free flight motion, contact motion and impact motion. The influence of the clearance size, input crank shaft speed, and number of clearance joints on the dynamic response of the mechanism was also investigated.

Kinematic Optimization of a New High-Speed Press Using a GA-DE Algorithm

The objective of this paper is to implement the optimal design of a high-speed press with a new transmission mechanism for punching. Firstly, the novel mechanism is shown and its merits are discussed. Then kinematic analysis is carried out by using the vector loop method. Additionally, the kinematic dimensions of the mechanism are derived by using a GA-DE algorithm. Finally, a comparative study for kinematics is made between original and optimized dimensions. The results indicate that proposed novel mechanism with optimized kinematic dimensions is of better output motion for high-speed punching.

Research on Balancing of a Multi-Link High-Speed Precision Press

Balancing mechanism for a multi-link high-speed precision press has been proposed and kinetic equations for the press with balancing mechanism have been derived also. The corresponding computer program has been developed on the basis of Matlab software environment. Take the press developed in the research as an example to calculate for studying balancing effect of this mechanism. Calculation results show that the balancing mechanism can significantly reduce vertical inertial force acted on the bed on the one hand; on the other hand the horizontal inertial forces of some parts and torque need will be increased. Results of the research mentioned above can be used for development of the multi-link high-speed precision press.

J022024 腹部ベルト位置による傷害発生の差異に関する研究([J022-02]傷害防止工学(2))

In recent years, abdominal injury investigation PMHS and experimental animal reported that rapid compression by seat belt to occupant abdomen trigger abdominal trauma. In addition, injury tolerance investigation still not understand generation limit of this abdominal injury. The purpose of our investigation is to find generation limit of this injury. In order to find this tolerance, we developed animal experiment model for abdominal injury. In this animal experiment model, injury device that land high speed press by seat belt make abdominal injury in living swine. As a result, rupture of bowel and mesentery (AIS5) occurred in under abdomen. In addition, rupture of liver and spleen (AIS3) occur in upper abdomen. Hence, injury tolerance of under abdomen is lower than upper abdomen.

Bottom Dead Center Repeat Precision of High-Speed Press Measurement

Bottom dead center repeat precision is the key evaluation standard of high-speed press, it’s an important index to judge production level and technical level. Use model RM-7201 testing apparatus to measure bottom dead center of high-speed press at different conditions, find out laws according to the test result. These findings may helpful in proving correctness of bottom dead center precision analysis and to control the B.D.C precision of the high-speed press. Provide practical guidance basis to improve the press structure and bottom dead center precision.