工艺尺寸链三种应用的探讨

工艺尺寸链主要用于基准不重合时工序尺寸及其偏差的确定,主要探讨工艺尺寸链在精度分析、粗基准选择和定位方案判定这三个方面的应用.     

A power supply for a technological installation

A voltage changer for the power supply of an ultrasonic piezoelectric transducer is designed on the basis of a resonance inverter. The output filter designed on the basis of a series-resonant circuit with parallel and series compensation ensures matching of the changer to the load. The changer ensures a load current of 0.5A±10% within a wide range of the load resistance (from 50 to 400 Ω) at an input voltage of 220 V±15% with automatic tuning to the frequency of the load mechanical resonance. The changer output power is 100 W, and the output current is a sinusoid with a frequency of 22±2 kHz.     

A modified setup for gas-dynamic research and technological development

A modified variant of the LEMPUS-1 experimental setup is described, which was designed in order to extend the possibilities of performing investigations of plasma-chemical reactions and cluster-formation processes in gas jets in a pulse outflow regime, as well as technological processes during cluster-ion surface treatment. This setup provides the mass spectroscopy of molecular beams that are formed from supersonic gas jets and gas mixtures, studying of the plasma-chemical reactions that are initiated in jets by self-sustained and nonself-sustained discharges, studying of the cluster formation processes in gas mixtures, simulation of the supersonic-outflow processes with high flow rates from sonic and supersonic nozzles. Installing high-performance oil-free vacuum pumps makes it possible to investigate the processes in gas jets in the presence of hydrocarbon contaminants. Equipping the setup with ionization and flow-acceleration systems provides studying of the interaction processes of clusters and ions with a solid surface during gas-jet treatment of coatings.     

三段式炭化装置及炭化工艺参数研究

应用新型三段式碳化装置进行甘蔗渣炭化,对原材料含水量、炉内温度、能耗、设定温度等因子对炭化效果的影响进行了研究,优化了炭化装置的工艺参数,为农业生产废弃物的循环利用提供技术支撑.结果表明:下段炭化炉设定温度为600℃、甘蔗渣含水量低于20%时,不能稳定工作;甘蔗渣含水量大于20%时,炉内温度接近设定温度并能保持稳定工作状态;甘蔗渣含水量为40%左右时,炭化分解生成的可燃气体能满足自燃的炭化要求,能耗较低;炭化炉温度700℃时,甘蔗渣碳素率较高,炭化收成率为20%左右.     

A graphics environment for CIM applications

Programmers in graphics applications have come to expect a standard of pre-written software to provide the basic building blocks for their specific needs. Computer-aided engineering (CAE) now requires a similar standard of software to provide an integrated platform with higher levels of graphics functions, solid modelling facilities and user interfaces. PANACEA is a research tool which has provided this base for^oa number of CAE applications programs.     

抑制磨削颤振的实用方法--工艺条件适配法

在一系列磨削试验的基础上 ,提出抑制磨削颤振的实用方法———工艺条件适配法。并由实验验证了该方法的有效性。     

A piezoelectric motor for precision positioning applications

This study presents a novel precise piezoelectric motor capable of operating in either an AC drive mode or DC drive mode. In the AC drive mode, the motor acts as an ultrasonic motor which is driven by two orthogonal mechanical vibration modes to generate elliptical motion at the stator to push the slider into motion. In the DC drive mode, stick-slip friction between the stator and slider is used to drive the motor step-by-step. The experimental results show that the AC drive mode can drive the motor at a high moving speed, while the DC drive mode can simply drive the motor with a nanoscale resolution. In our experiments, a prototype motor is fabricated and its actions are measured. The results demonstrate that in the AC drive mode, the piezoelectric motor can achieve a 106 mm/s speed without a mechanical load and a 34 mm/s speed with 340 g of mechanical load when applying two sine waves with a drive of 11.3 V at 38.5 kHz. Meanwhile, in a DC driving mode, the motor is capable of performing precision positioning with a displacement resolution of 6 nm when driving at 100 Hz.     

A patchboard-based expert-systems model for manufacturing applications

Expert systems have proved to be effective for many problems in manufacturing. Blackboard models are perhaps one of the most widely used paradigms for building expert systems. However, there are situations in which the blackboard model is not applicable because of the dynamic nature of a problem. In this paper, the authors present a patchboard expert-system model in an effort to capture the dynamics of this class of problems. The difference between these two models is discussed, and the theoretical foundation of the patchboard model is detailed.     

A coaxial thermocouple for shock tunnel applications

A chromel-constantan coaxial surface junction thermocouple has been designed, fabricated, calibrated, and tested to measure the temperature-time history on the surface of a body in a hypersonic freestream of Mach 8 in a shock tunnel. The coaxial thermocouple with a diameter of 3.25 mm was flush mounted in the surface of a hemisphere of 25 mm diameter. The hypersonic freestream was of a very low temperature and density, and had a flow time of about a millisecond. Preliminary test results indicate that the thermocouple is quite sensitive to low temperature-rarefied freestreams, and also has a response time of a few microseconds (≈5?μs) to meet the requirements of short duration transient measurements. The sensor developed is accurate, robust, reproducible, and is highly inexpensive.     

A PACVD duplex coating for hot-forging applications

The tribological loading of forging tools is caused by the relative motion between the plastically deformed work piece and the die. In comparison to many other forming processes, hot forging has an especially disadvantageous tribological system, combining thermal, mechanical and chemical loadings. The advantages of hard coatings, which are well known for cutting tools, are to a much lesser extent explored for casting, extrusion, moulding and forging tools. Increasing the lifetime of these tools is an important task in surface engineering because of the complex loading conditions and the often complicated tool geometry, with the plasma-assisted chemical vapour deposition (PACVD) technique being well suited to the depositing of hard coatings onto large dies and moulds.The aim of this paper is to present and discuss possible improvements to industrial applications (i.e., the hot forging of automotive parts) obtained by the duplex PACVD coating of forging dies. The experimental results indicate that the deposition of a proper duplex PACVD coating and the use of a proper substrate treatment lead to improved tribological properties and a longer lifetime for the hot-forging die.     

一种机器装配工艺新方法

通过分析分组修配法的特点，提出了先通过设计计算将修配件进行更合理分组，再利用分组修配法进行装配的一种机器装配工艺新方法。此装配方法可将修配量控制在理想的范围内，既保证了精度，又提高了效率。     

Optimal technological base for long workpieces

A method is proposed for calculating the technological base in the case of long stepped workpieces, each step of which is a solid of revolution. The method is based on contactless measurement of the cross sections of the cylindrical segments. Optimization of the axial base ensures the most uniform distribution of the margin over the cylindrical surface.     

压缩机冷却器的工艺计算

以一典型管壳式冷却器的工艺计算为例,介绍了应用国际通用传热软件进行压缩机冷却器工艺计算的方法及推广价值。     

A combined pulse modulation-processing method for ADCP applications

Acoustic Doppler Current Profiler (ADCP) based on the Doppler principle is the sonar for velocity measurements, which is mainly applied in the large-scale measurements of the oceanic current velocity. In order to satisfy the increasing requirement of high measurement resolution and accuracy compared with the traditional ADCP, this paper investigates the ambiguous functions of different signals and indicates that the pulse combined by several sinusoidal signals will improve the time resolution when keeping good frequency resolution. Then the present research proposes the modulation of a combined pulse as the ADCP׳s emitted signal, as well as the corresponding signal processing method. Two examples are demonstrated to show the effectiveness of the combined pulse modulation-processing method, and it is seen that: 1. the combined pulse has the same spatial resolution as one subpulse, while achieves better frequency resolution and better signal–noise ratio than the latter; 2. although the combined pulse results in a little worse signal–noise ratio than the long sinusoidal signal, the former has much higher spatial resolution; 3. the measurement accuracy of the combined pulse is better than the broadband coded-pulse when they have the same pulse width.     

A magnetically driven piston pump for ultra-clean applications

A magnetically driven piston pump for xenon gas recirculation is presented. The pump is designed to satisfy extreme purity and containment requirements, as is appropriate for the recirculation of isotopically enriched xenon through the purification system and large liquid xenon time projection chamber of EXO-200. The pump, using sprung polymer gaskets, is capable of pumping more than 16 standard liters per minute of xenon gas with 750 Torr differential pressure.     

Improving the technological preparations for manufacturing production

Means of faster and better technological preparation for multiproduct manufacturing are considered. The possibility of technological preparation in parallel with design and organizational preparation is demonstrated. An approach to organizational and technological design in the development of manufacturing processes is proposed. In this approach, the dynamics and goals of production systems are taken into account. A timeline for the introduction of the proposed approach is outlined, and the conditions for its successful implementation are specified.     

A 24 keV liquid-metal-jet x-ray source for biomedical applications

We present a high-brightness 24-keV electron-impact microfocus x-ray source based on continuous operation of a heated liquid-indium/gallium-jet anode. The 30-70 W electron beam is magnetically focused onto the jet, producing a circular 7-13 μm full width half maximum x-ray spot. The measured spectral brightness at the 24.2 keV In K(α) line is 3 × 10(9) photons∕(s × mm(2) × mrad(2) × 0.1% BW) at 30 W electron-beam power. The high photon energy compared to existing liquid-metal-jet sources increases the penetration depth and allows imaging of thicker samples. The applicability of the source in the biomedical field is demonstrated by high-resolution imaging of a mammography phantom and a phase-contrast angiography phantom.     

A convolved multi-Gaussian probability distribution for surface topography applications

A convolved, multi-normal probability distribution model has been developed corresponding to the usual case of successively finer-scale Gaussian structure residing atop the worn upper extremities of the coarser texture immediately below—i.e. secondary structure existing on the worn summits and ridges of rougher primary structure, tertiary structure atop the secondary, etc. Quantification, involving nonlinear regression inside an iterative loop, begins with the global data mean and standard deviation as initial estimates, and yields means, standard deviations, and percent area coverage for all statistically significant structural components. The solution train stops automatically whenever one or more of several termination criteria is met. The method is illustrated graphically with examples of several typical engineered surfaces.     

A PID-type fuzzy controller model for machine control applications

This paper introduces a PID-like fuzzy controller model, which consists of only five fuzzy rules. Each fuzzy rule is designed to carry out a single control task. A self-learning procedure is used to determine the input scale factor for auto-tuning the system. A new performance criterion is suggested as an object function for the auto-tuning procedure. The features of this fuzzy controller, used in position control applications, are demonstrated by the simulation results of two different types of plants — a d.c. motor and an inverted pendulum.Nomenclature adjusting parameter of AIAE - C _I integral control constant in ruleR _I - C _L leading control constant in ruleR _zn andR _zp - C _P proportional control constant in ruleR _P andR _N - D _ZE domain of membership function _ZE - K _a adaptive adjusting constant ofC _L - K _H adjusting parameter for high-border of dynamic domain space - K _L adjusting parameter for low-border of dynamic domain space - P _R ramp input command - P _S step input command - S _de scaling factor for input variable de(change of error) - S _e scaling factor for input variablee(error) - S _o controller output scaling factor - U _max maximum output limit of fuzzy controller