Design of precision measurement system for metallic hole

For most of the high-speed hole diameter measuring process, a contact measuring method is undesirable due to its slow and destructive touching process. Thus, an optical method is usually chosen for non-contact measurement. Unfortunately, for most holes in precise manufacturing, especially those with a high aspect ratio, the optical method cannot be used. In our study, we developed a simple and low-cost precision capacitive hole measuring system. By using a simple alignment mechanism, we prove that a high-resolution hole diameter can be achieved. Comparing a traditional measuring method like coordinate measuring machine with our system, over 99% correlation is easily obtained. The paper also presents a multilayer hole measuring probe and sensor probe for non-through-hole measurement.     

Fiber deflection probe for small hole metrology

This paper presents the development of a new probing method for coordinate measuring machines (CMM) to inspect the diameter and form of small holes. The technique, referred to as fiber deflection probing (FDP), can be used for holes of approximately 100 μm nominal diameter. The expanded uncertainty obtained using this method is 0.07 μm (k = 2) on diameter. The probing system consists of a transversely illuminated fiber (with a ball mounted on the end) whose shadows are imaged using a camera. We can infer the deflection of the probe from the motion of the image seen by the camera, and we infer the position of the measured surface by adding the fiber deflection along x- and y-directions to the machine scale readings. The advantage of this technique is the large aspect ratio attainable (5 mm deep for a 100 μm diameter hole). Also, by utilizing the fiber as a cylindrical lens, we obtain sharp crisp images of the fiber position, thus enabling high resolution for measured probe deflection. Another potential advantage of the probe is that it exerts an exceptionally low force (ranging from a few micronewtons down to hundreds of nanonewtons). Furthermore, the probe is relatively robust, capable of surviving more than 1 mm over-travel, and the probe should be inexpensive to replace if it is broken. In this paper, we describe the measurement principle and provide an analysis of the imaging process. Subsequently, we discuss data obtained from characterization and validation experiments. Finally, we demonstrate the utility of this technique for small hole metrology by measuring the internal geometry of a 129 μm diameter fiber ferrule and conclude with an uncertainty budget.     

Development of a laser-guiding-type deep small-sized hole-measurement system: Measurement accuracy

In this study, a system for measuring small-sized holes with a 17–21 mm diameter and 1000 mm length was constructed. The system comprises a laser interferometer to detect hole accuracy, a probe connected to a measurement bar, and an optical apparatus for detecting the probe attitude (position and inclination). The probe was supported by supporting pads. A steel workpiece with 18 -mm diameter and 800 mm length was used for the performance test. During the experiment, errors were found in terms of hole deviation and roundness profile. Further experiments, using new experimental apparatus and analysis, revealed the causes of errors: electrical noise that increased with time, two periodic stylus swings in the longitudinal direction of the hole per rotation of the measurement unit, and the excessive spring force pushing the tip of the stylus, causing a large frictional force with the hole wall, etc. If these errors are corrected, high accuracy in the measurement of hole deviation and roundness can be achieved.     

基于机器视觉的光纤连接插芯内径测量系统

为了实现针对光纤连接插芯内径参数的精密和快速测量,首先采用了机器视觉方案,通过显微镜把内孔图像成像在高分辨率的CCD上,并获取图像,然后通过图像处理方法,计算出了光纤连接插芯的内径大小和真圆度,最后通过合理设计相应的硬件和软件,实现了光纤连接插芯内径参数的快速非接触式自动测量;同时提出了一种确定图像边缘的新方法,消除了光强变化对阈值设定产生的干扰,并对所采用的参数检测算法进行了阐述。实验结果表明,整个自动测量系统的测量精度达到了亚微米级,且具备抗光强变化干扰的性能。     

Micro-scale hole profile measurement using rotating wire probe and acoustic emission contact detection

The development of a new probing method to inspect the inner diameter of micro-scale holes is presented in this paper. This was accomplished by contact detection using acoustic emission with a Ø170 μm rotating wire probe tip. Contact is detected when the rotating probe approaches and impacts the hole’s inner surface. The effective diameter of the rotating probe is calibrated by using a high precision grade 0 Mitutoyo gauge block. The wire rotating probe used was fabricated with micro stainless steel wire and micro tubes. The probe’s effective diameter was compensated for in the measurement of the hole. The probe was used to measure the diameter and the roundness of micro-scale holes. Probes used in previous publications have different geometry than the probe in this paper and are used almost exclusively for external dimensions. Micro-scale holes of less than 1.0 mm in diameter and 10 mm in depth are successfully measured and the 3D profile is created accordingly. Also, the out-of-roundness values of each level spacing, 50 μm apart in height, are calculated.     

激光三角法内孔测量传感器的光学成像分析

为了实现对孔类零件特别是深孔零件的孔深测量,设计了一套激光内孔测量传感器.该传感器基于激光三角测量的方法,利用梯形棱镜的全反射特性将光路限制在狭窄的空间内,从而实现对深孔或盲孔的测量.针对该传感器的光学成像规律做出了深入的分析,并结合目前存在的问题提出了几种改进方案.实验结果表明:梯形棱镜能够较好地解决测量内孔时物理空...     

自定心深孔参数测量装置及测量方法

深孔内径尺寸测量是大型精密仪器零件加工、制造、装配以及测量过程中的一项重要技术。在研究现有深孔测量方法的基础上,设计了一种具有自定心功能的深孔参数测量装置,背向设置的双锥体自平衡结构来实现测量主轴在被测深孔内的径向定心,对称布置的激光测距传感器进行孔径参数的实时测量,数据记录装置完成测量数据的记录与处理。与现有测量系统比较,该设计优于光杠式行走测量装置,可用于中大型精密仪器轴孔内径的高精度自动化在线测量。     

Curved drilling via inner hole laser reflection

In this paper, we describe curved hole drilling via the reflection of a laser beam off the sidewall of the drilled hole. A slightly offset laser beam forms a tilted surface at the bottom of the hole, controlling the angle of curvature. An ultraviolet laser beam operating at a wavelength of 266 nm was used. To visualize the hole formation process, borosilicate glass was used as the laser workpiece. This method was able to drill a curved hole with an average angle of ∼3° with curvature beginning at a depth of 400–600 μm. A curved hole with a diameter of <50 μm was achieved. A branched hole was also demonstrated by using the reflection of the tilted sidewall. The curved hole formation process was recorded with a high speed camera. Once the ablated sidewall reached a certain depth, drilling ceased as the laser energy fell below the ablation threshold. Ultimately, judicious selection of an appropriate laser fluence and sidewall angle allow the formation of curved holes.     

制孔机器人在制孔过程中的振动抑制研究

Aiming at tlie problem of vibration suppression of tlie hole making robot in the process of making holes,a typical example of a two-joint hole drilling robot to study the control algoritlim was took. The effect of tlie feed direction drilling force on the system of tlie hole making robot was only considered. The mechanism of vibration in the process of making holes was analyzed. Finally the fuzzy compensation inhibit vibration control algorithm was put forwarded. According to the Lagrange equation,the dynamic model of the hole robot was established,and the drilling force model was established according to the theory of oblique cutting model. Then the simulation was carried out by the Matlab/ Simulink platform under a particular position. After a fuzzy controller was used to compensate the dynamic change of the end effector of the hole making robot in the process of the axial drilling force to each joint in advance,the defection of each joint in the hole making process was obviously weakened. The results indicate that the stiffness of the system can be enhanced by adding the vibration suppression algorithm with fuzzy compensation,which further ensures the quality of the hole. [ABSTRACT FROM AUTHOR]     

一种汽车制动缸补偿孔形位尺寸检测方法的研究

为实现汽车制动主缸补偿孔的形位尺寸检测,提出一种光机复合高精度非接触光电成像检测方法.该方法采用高精度的传动机构带动内窥光学系统在有限的主缸内孔中运动,利用高分辨率CCD摄像系统获取补偿孔图像,通过图像处理完成制动主缸补偿孔形位尺寸测量.它实现了小尺寸盲孔的非接触测量,精度高于10μm.     

弯曲孔加工技术及新方法

简析弯曲孔加工中的一些关键技术,介绍几种弯曲孔加工方法及其特点,着重说明基于线框电极的弯曲孔加工新工艺的原理、装置、影响因素和加工结果。     

Control strategy of developed mechanical actuator in measuring hole surface parameter

This paper presents the control strategy of a new type of mechanical actuator used to help in measuring hole surface parameter. The actuator can carry up to a load of 26 kg during measurement. Often, the measurement unit’s attitude is misaligned due to the force acting on it. Actuator is used in order to control the misalignment of such system during measurement. In this research, the complete measurement system consists of a servo motor, a laser diode, a laser interferometer, an optical system, as well as an integrated computer system. The main purpose of this research is to develop the new type of actuator which can control the attitude (position and inclination) of a measurement probe. The experimental results show that it is possible to carry mechanically the loads up to 26 kg of the measurement probe during measurement of deep surface. In this paper, the developed actuator’s control strategy has been discussed widely in order to measure the surface parameter successfully.     

基于环形电极的曲孔加工方法

探讨利用直柄和弧柄环形电极电火花加工曲孔的方法,可加工任意横截面的曲孔,通过加工实例,讨论其加工原理,分析了特别影响环形电极曲孔加工的工艺因素,包括电极形式、环形部分制作、芯料支撑方式、工作液方式和加工状态等,并就其加工特点进行了总结。     

深孔综合参数测试装置设计及测试方法研究

针对目前深孔测试技术的不足,设计了一种基于激光测距的深孔综合参数测量装置,给出了测试方法,并基于最小二乘原理建立了测试数学模型。与现有测量系统比较,该装置可以实现精密仪器中深孔、盲孔的任意截面直径和直线度等孔径参数的测量。     

采用过电铸工艺制造金属微细阵列网板

针对制作尺度10μm的超小微细阵列网板非常困难的问题,提出了采用过电铸工艺制造超小尺寸微细阵列网板的方法。建立了过电铸工艺过程的电场模型,利用有限元分析技术对过电铸工艺过程进行模拟仿真。选取优化的工艺参数(烘胶120℃/60min,曝光3000mJ/cm2,显影2min等)利用光刻制作了高度为50μm、直径为50μm的AZEXP125nXT-10A光刻胶群柱结构,以此胶膜结构作为模具进行了过电铸工艺实验,并与仿真结果进行对比,结果证明了有限元仿真的正确性。最后,通过过电铸缩孔2h获得了厚度达70μm,孔径为4μm的微细阵列网板结构。实验表明,过电铸工艺是一种低廉、安全、可批量生产的制作超小阵列网板的方法。     

斜孔钻模测量工艺孔的稳健位置

应用稳健设计原理,对斜孔钻模测量工艺孔的位置设计进行了分析,理论分析表明其位置尺寸对夹具精度和夹具设计的稳健性有重要影响,进而提出了确定工艺孔位置尺寸的具体方法。     

基于孔补偿的三坐标测量臂误差研究及应用

研究FARO三坐标测量臂测量方程的建立方法和系统误差组成,并根据该误差模型采用简单快捷的孔补偿原理对三坐标测量臂进行多组数据的标定校准。利用校准好的三坐标测量臂对变速箱端盖进行孔直径和定位中心距的高精度测量,为实现变速箱端盖逆向设计制造和保证定位孔定位的可靠性提供科学数据。     

基于孔洞分割的点云孔洞填充算法

逆向设计过程中,由于物体曲面形状复杂和扫描设备的原因,扫描得到的点云中难免有孔洞出现。为了产生封闭的实体曲面,需要对孔洞进行填充。国内外许多学者提出了许多关于孔洞填充的算法,不过这些算法主要针对曲率较小区域的孔洞。基于此,提出了一种新的改进算法,解决了高曲率区域的复杂孔洞填充问题。通过孔洞在投影面上的投影,判断是否存在交叉点,将孔洞分为简单的孔洞和复杂的孔洞。当遇到复杂孔洞时,采用分割的方法把复杂的孔洞分割成简单的孔洞,再对其进行修补。     

Fabrication of stepped hole on zirconia bioceramics by ultrasonic machining

Zirconia (ZrO₂) is a highly biocompatible ceramic material providing fracture strength properties that allow application as dental implants in biomedical engineering. In this present research, experimental analysis has been made for generating stepped hole on zirconia bioceramics with desired quality using ultrasonic machining (USM) process. Four independent controllable input process parameters are abrasive grain diameter, power rating, concentration of abrasive slurry, and tool feed rate. Material removal rate (MRR), overcut of larger diameter (OLD) hole, and overcut of smaller diameter (OSD) hole of stepped hole are considered as the responses. Response surface methodology (RSM) is used for modeling the performance of USM process. Multiobjective optimization has been performed to maximize the MRR and minimize the OLD hole and OSD hole of stepped holes. All the responses are improved at the optimal parametric condition and verified by confirmation test. The present research opens up the application feasibility of USM process for stepped hole generation on bioceramics and its utilization in biomedical field.     

壁冷叶片冲击射流孔的流动特性实验研究

用实验的方法对涡轮叶片壁面冲击冷却的流动特性进行了研究，并用直头五孔探针对冲击射流孔内的流场进行了详细的测量，着重研究了不同雷诺数和不同的通道高度比（通道高度与射流孔直径之比z／d）对射流孔内流动结构和流量系数的影响。实验结果表明：通道高度的变化会明显改变孔内的流场结构和孔的流量系数；而在同一通道高度下，雷诺数的改变对孔内流场影响相对较小。在射流孔内存在着漩涡结构，这有助于深入了解气膜冷却的内在机理。