Recent Patents on Detection Device of Surface Defects on Bearing Balls

2021 ◽  
Vol 14 ◽  
Author(s):  
Chengyi Pan ◽  
Junhong Tang ◽  
Guanqun Cao ◽  
Bingtao Hu
Keyword(s):  
Surface Defects ◽  
Detection Efficiency ◽  
High Surface ◽  
Detection Accuracy ◽  
High Quality ◽  
High Surface Quality ◽  
Existing Problems ◽  
Advantages And Disadvantages ◽  
Surface Detection ◽  
Scope Of Application

Background: With the continuous pursuit of high-quality and high-precision bearings in industrial production, the processing accuracy of bearing balls is increasing, and high surface quality has become the most basic requirement for high-quality bearing balls. Studying the working principle of detection device of surface defects on bearing balls is beneficial to improve the surface accuracy of bearing balls and the quality of bearings. Objective: To meet the increasing requirements for measurement accuracy and efficiency of surface detection on bearing balls, the devices and methods of surface detection on bearing balls have been improved constantly. Methods: This paper reviews various representative patents related to the detection device of surface defects on bearing balls. The advantages and disadvantages of the patents are analyzed. Results: Through tracing the characteristics of different types of the detection device of surface defects on bearing balls, the main existing problems in the current are concluded and analyzed, such as low detection accuracy, low detection efficiency, and limited scope of application, etc. The future development of patents on detection device of surface defects on bearing balls is discussed. Conclusion: The optimization and development of detection device of surface defects on bearing balls are beneficial to improve the detection accuracy and efficiency of surface defects on bearing balls, and are conducive to expand the scope of application of the detection devices. More related patents on detection device of surface defects on bearing balls will be invented.

Variothermal Foam Injection Molding - Dimensional Stability with High Surface Quality

2017 ◽  
Vol 36 (3) ◽  
pp. 151-166 ◽  
Author(s):  
Christian Hopmann ◽  
Nicolai Lammert ◽  
Yuxiao Zhang
Keyword(s):  
Surface Quality ◽  
Surface Defects ◽  
Control Strategies ◽  
High Surface ◽  
Skin Layer ◽  
High Surface Quality ◽  
Major Disadvantage ◽  
Scope Of Application ◽  
Specific Material ◽  
Foam Injection Molding

Thermoplastic foam injection moulding offers various advantages for both processing and product design. Despite its many benefits, the moderate surface quality still constitutes a major disadvantage of this process. The mould temperature can be controlled dynamically to improve the surface quality. Different dynamic temperature control strategies are employed and analysed regarding their effectiveness and scope of application. Mould temperatures above the specific material transition temperatures allow the surface defects to be cured and enable the production of foamed thermoplastic parts with surface qualities comparable to those of the compact reference samples. The high mould temperatures during the injection phase alter the foam structure and the skin layer thicknesses, which impacts the mechanical properties.

Furnace Technologies in Hot Stamping Concepts and Experience from Production

2014 ◽  
Vol 1063 ◽  
pp. 354-357
Author(s):  
Thomas Fuchs ◽  
Fritz Josef Ebner
Keyword(s):  
Cost Efficiency ◽  
Surface Defects ◽  
Hot Stamping ◽  
Black Box ◽  
Single Type ◽  
High Quality ◽  
Advantages And Disadvantages ◽  
Multi Level ◽  
Upper Level ◽  
Process Atmosphere

Nowadays, a furnace designer has to meet the demands of the customer precisely to allow economical production at site. Repeatable high quality throughout millions of produced parts combined with high cost efficiency is needed to stay competitive. Thus the facility has to be changed from a black-box to a glassy furnace which records and controls all important process values that define the properties of the produced parts and the consumption of the facility. Current furnace designs offer a wide variety of layouts with unique advantages and disadvantages. Single type furnace designs are well known and need the lowest investments but they also take up a lot of space and do not offer a back-up solution during maintenance or in the event of malfunctions occurring. Twin type furnaces have a higher degree of flexibility as they still allow 50% production during downtime caused by maintenance or malfunctions, so availability is higher than with single type furnaces. Double layer furnaces, which are stacked versions of the twin type furnaces, only need half of the floor space but maintenance is more complicated on the upper level. An oxygen-free furnace atmosphere is essential for the production of components in process atmosphere in order to ensure high quality results with the minimum of scale and other surface defects. This is not possible in a multi-level furnace.

scholarly journals Surface Detection of Solid Wood Defects Based on SSD Improved with ResNet

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1419
Author(s):  
Yutu Yang ◽  
Honghong Wang ◽  
Dong Jiang ◽  
Zhongkang Hu
Keyword(s):  
Wood Surface ◽  
Feature Detection ◽  
Surface Defects ◽  
Detection Efficiency ◽  
Solid Wood ◽  
Detection Accuracy ◽  
Single Shot ◽  
Wood Panel ◽  
Data Set ◽  
Wood Panels

Due to the lack of forest resources in China and the low detection efficiency of wood surface defects, the output of solid wood panels is not high. Therefore, this paper proposes a method for detecting surface defects of solid wood panels based on a Single Shot MultiBox Detector algorithm (SSD) to detect typical wood surface defects. The wood panel images are acquired by an independently designed image acquisition system. The SSD model included the first five layers of the VGG16 network, the SSD feature mapping layer, the feature detection layer, and the Non-Maximum Suppression (NMS) module. We used TensorFlow to train the network and further improved it on the basis of the SSD network structure. As the basic network part of the improved SSD model, the deep residual network (ResNet) replaced the VGG network part of the original SSD network to optimize the input features of the regression and classification tasks of the predicted bounding box. The solid wood panels selected in this paper are Chinese fir and pine. The defects include live knots, dead knots, decay, mildew, cracks, and pinholes. A total of more than 5000 samples were collected, and the data set was expanded to 100,000 through data enhancement methods. After using the improved SSD model, the average detection accuracy of the defects we obtained was 89.7%, and the average detection time was 90 ms. Both the detection accuracy and the detection speed were improved.

Machining Characteristics of Electrochemical Polishing Using Ultrasonic Vibration for Nanoscale High Surface Quality

2021 ◽  
Vol 21 (9) ◽  
pp. 4891-4896
Author(s):  
Uk Su Kim ◽  
Seung-Yub Baek ◽  
Tae-Wan Kim ◽  
Jeong Woo Park
Keyword(s):  
Surface Quality ◽  
Ultrasonic Vibration ◽  
Surface Defects ◽  
High Current Density ◽  
Removal Rate ◽  
High Surface ◽  
Electrochemical Polishing ◽  
High Surface Quality ◽  
Surface Polishing ◽  
Work Material

This study demonstrates a method to improve the surface quality by adding artificial vibration to the electrolyte in electrochemical polishing (ECP, electropolishing). ECP is a typical non-contact surface polishing process that has been used to improve surface quality without leaving any of the mechanical scratch marks that can arise when applying mechanical processes. ECP can polish work material via electrochemical dissolution between the surfaces of an anode and a cathode, and irregular defects are generated on the surface by impurities and bubbles generated during machining. This study confirms that our novel ECP method yields improved results over conventional ECP based on experiments using vibration electrochemical polishing (VECP) with ultrasonic vibrations. VECP minimizes nanoscale surface defects, improves surface roughness, makes it possible to quickly remove materials at nanoscale by increasing the material removal rate (MRR). Under high current density, where the electrochemical relatively reaction is active, value of the current is increased when ultrasonic vibration is added. The localized roughness of the work material was measured by atomic force microscopy (AFM) according to various electrical conditions. In addition, we also compared the overall surface quality and productivity to those obtained by conventional ECP.

scholarly journals EVALUATION OF THE CONTACT SURFACE PARAMETERS AT KNURLING FINNED HEAT-EXCHANGING SURFACE BY KNURLS AT RING BLANKS

2020 ◽  
Vol 17 (36) ◽  
pp. 372-389
Author(s):  
Aslan Adal bievich TATARKANOV ◽  
Islam Alexandrovich ALEXANDROV ◽  
Andrej Vladimirovich OLEJNIK
Keyword(s):  
Contact Surface ◽  
High Performance ◽  
Quantitative Assessment ◽  
Surface Defects ◽  
High Surface ◽  
Accurate Calculation ◽  
High Surface Quality ◽  
Transverse Strains ◽  
Ring Blank ◽  
Laborious Method

Tubular parts with an external finned heat-exchanging surface are usually produced by the laborious method of cutting on lathes. Besides, there is a method for the high-performance manufacturing of fins by cold knurling with ring-cut knurls, which, compared with cutting, reduces labor intensity by two to six times with a significant increase in the operational properties of the product. The disadvantage of the cold knurling method with ring-cut knurls can be unwanted surface defects and deformations of the entire product. Obtaining finned surfaces on ring blanks with high surface quality during knurling requires accurate calculation of the ratio of longitudinal and transverse strains. The most important factors determining the ratio of longitudinal and transverse strains (rolling-out and rolling-off) are the length and width of the contact surface. The need for a quantitative assessment of the parameters of longitudinal and transverse strains determined the purpose of this manuscript. This study aimed to develop a methodology for calculating the contact surface of a knurl with a ring blank (pipe) when knurling with ring-cut knurls. The proposed method for calculating the knurl's contact surface with a tube when knurling with ring-cut knurls allows for estimating the recommended range of pipe sizes for knurling. Based on the dependencies mentioned in the manuscript, the limiting sizes for blank pipes were calculated to ensure high-quality finning. Experiments on cold rolling of ribbing on pipes with different lengths and diameter ratios were carried out, confirming the possibility of using the proposed methodology for calculating the knurl's contact surface with a pipe when knurling heat-exchanging finning with ring-cut knurls.

scholarly journals A Systematic Approach for Developing 3D High-Quality PDMS Microfluidic Chips Based on Micromilling Technology

Micromachines ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 6
Author(s):  
Amin Javidanbardan ◽  
Ana M. Azevedo ◽  
Virginia Chu ◽  
João P. Conde
Keyword(s):  
Systematic Approach ◽  
High Surface ◽  
Cost Effective ◽  
Average Surface Roughness ◽  
Microfluidic Chips ◽  
High Quality ◽  
High Surface Quality ◽  
Design Flexibility ◽  
New Strategies

In recent years, there has been an increased interest in exploring the potential of micro-and mesoscale milling technologies for developing cost-effective microfluidic systems with high design flexibility and a rapid microfabrication process that does not require a cleanroom. Nevertheless, the number of current studies aiming to fully understand and establish the benefits of this technique in developing high-quality microsystems with simple integrability is still limited. In the first part of this study, we define a systematic and adaptable strategy for developing high-quality poly(methyl methacrylate) (PMMA)-based micromilled structures. A case study of the average surface roughness (Ra) minimization of a cuboid column is presented to better illustrate some of the developed strategies. In this example, the Ra of a cuboid column was reduced from 1.68 μm to 0.223 μm by implementing milling optimization and postprocessing steps. In the second part of this paper, new strategies for developing a 3D microsystem were introduced by using a specifically designed negative PMMA master mold for polydimethylsiloxane (PDMS) double-casting prototyping. The reported results in this study demonstrate the robustness of the proposed approach for developing microfluidic structures with high surface quality and structural integrability in a reasonable amount of time.

scholarly journals Experimental investigation of the machining characteristics in diamond wire sawing of unidirectional CFRP

2021 ◽  
Author(s):  
Lukas Seeholzer ◽  
Stefan Süssmaier ◽  
Fabian Kneubühler ◽  
Konrad Wegener
Keyword(s):  
Surface Quality ◽  
Influencing Factors ◽  
Material Properties ◽  
High Surface ◽  
Workpiece Surface ◽  
High Surface Quality ◽  
High Productivity ◽  
Surface Temperatures ◽  
Process Forces ◽  
The Wire

AbstractEspecially for slicing hard and brittle materials, wire sawing with electroplated diamond wires is widely used since it combines a high surface quality with a minimum kerf loss. Furthermore, it allows a high productivity by machining multiple workpieces simultaneously. During the machining operation, the wire/workpiece interaction and thus the material removal conditions with the resulting workpiece quality are determined by the material properties and the process and tool parameters. However, applied to machining of carbon fibre reinforced polymers (CFRP), the process complexity potentially increases due to the anisotropic material properties, the elastic spring back potential of the material, and the distinct mechanical wear due to the highly abrasive carbon fibres. Therefore, this experimental study analyses different combinations of influencing factors with respect to process forces, workpiece surface temperatures at the wire entrance, and the surface quality in wire sawing unidirectional CFRP material. As main influencing factors, the cutting and feed speeds, the density of diamond grains on the wire, the workpiece thickness, and the fibre orientation of the CFRP material are analysed and discussed. For the tested parameter settings, it is found that while the influence of the grain density is negligible, workpiece thickness, cutting and feed speeds affect the process substantially. In addition, higher process forces and workpiece surface temperatures do not necessarily deteriorate the surface quality.

scholarly journals High-quality net shape geometries from additively manufactured parts using closed-loop controlled ablation with ultrashort laser pulses

2020 ◽  
Vol 9 (1-2) ◽  
pp. 101-110 ◽  
Author(s):  
Daniel Holder ◽  
Artur Leis ◽  
Matthias Buser ◽  
Rudolf Weber ◽  
Thomas Graf
Keyword(s):  
Surface Roughness ◽  
Closed Loop ◽  
High Surface ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Minimum Thickness ◽  
High Quality ◽  
Surface Optical ◽  
The Individual ◽  
Ultrashort Laser

AbstractAdditively manufactured parts typically deviate to some extent from the targeted net shape and exhibit high surface roughness due to the size of the powder grains that determines the minimum thickness of the individual slices and due to partially molten powder grains adhering on the surface. Optical coherence tomography (OCT)-based measurements and closed-loop controlled ablation with ultrashort laser pulses were utilized for the precise positioning of the LPBF-generated aluminum parts and for post-processing by selective laser ablation of the excessive material. As a result, high-quality net shape geometries were achieved with surface roughness, and deviation from the targeted net shape geometry reduced by 67% and 63%, respectively.

scholarly journals Low-Roughness-Surface Additive Manufacturing of Metal-Wire Feeding with Small Power

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4265
Author(s):  
Bobo Li ◽  
Bowen Wang ◽  
Greg Zhu ◽  
Lijuan Zhang ◽  
Bingheng Lu
Keyword(s):  
Additive Manufacturing ◽  
High Surface ◽  
Deposition Process ◽  
High Energy ◽  
Width Ratio ◽  
Thin Wall ◽  
Small Power ◽  
High Surface Quality ◽  
Wall Structures ◽  
Wire Feed

Aiming at handling the contradiction between power constraint of on-orbit manufacturing and the high energy input requirement of metal additive manufacturing (AM), this paper presents an AM process based on small-power metal fine wire feed, which produces thin-wall structures of height-to-width ratio up to 40 with core-forming power only about 50 W. In this process, thermal resistance was introduced to optimize the gradient parameters which greatly reduces the step effect of the typical AM process, succeeded in the surface roughness (Ra) less than 5 μm, comparable with that obtained by selective laser melting (SLM). After a 10 min electrolyte-plasma process, the roughness of the fabricated specimen was further reduced to 0.4 μm, without defects such as pores and cracks observed. The ultimate tensile strength of the specimens measured about 500 MPa, the relative density was 99.37, and the Vickers hardness was homogeneous. The results show that the proposed laser-Joule wire feed-direct metal deposition process (LJWF-DMD) is a very attractive solution for metal AM of high surface quality parts, particularly suitable for rapid prototyping for on-orbit AM in space.

scholarly journals Investigation on the Surface Quality Obtained during Trochoidal Milling of 6082 Aluminum Alloy

Machines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 75
Author(s):  
Nikolaos E. Karkalos ◽  
Panagiotis Karmiris-Obratański ◽  
Szymon Kurpiel ◽  
Krzysztof Zagórski ◽  
Angelos P. Markopoulos
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Process Parameters ◽  
Manufacturing Industry ◽  
High Surface ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
High Surface Quality ◽  
Trochoidal Milling

Surface quality has always been an important goal in the manufacturing industry, as it is not only related to the achievement of appropriate geometrical tolerances but also plays an important role in the tribological behavior of the surface as well as its resistance to fatigue and corrosion. Usually, in order to achieve sufficiently high surface quality, process parameters, such as cutting speed and feed, are regulated or special types of cutting tools are used. In the present work, an alternative strategy for slot milling is adopted, namely, trochoidal milling, which employs a more complex trajectory for the cutting tool. Two series of experiments were initially conducted with traditional and trochoidal milling under various feed and cutting speed values in order to evaluate the capabilities of trochoidal milling. The findings showed a clear difference between the two milling strategies, and it was shown that the trochoidal milling strategy is able to provide superior surface quality when the appropriate process parameters are also chosen. Finally, the effect of the depth of cut, coolant and trochoidal stepover on surface roughness during trochoidal milling was also investigated, and it was found that lower depths of cut, the use of coolant and low values of trochoidal stepover can lead to a considerable decrease in surface roughness.

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