High-speed Vibration Research Articles

Study and Test Analysis of Engine 1/4 Vibration Model

Through the bench test, the vibration characteristics of the front right support of the inline four-cylinder diesel engine is analyzed, and the MATLAB simulations and verifications are performed to the differential equation of 1 / 4 vibration model established by using the front right support as the research object. Experimental and simulation results show that the exciting force performs as basic frequency and second frequency and, the acceleration performs as basic frequency and low-frequency at low speed engine vibration; when it is in the high speed vibration, the exciting force is mainly manifested in the second frequency and the acceleration in high-frequency. The motion equation of 1/4 vibration model can reflect the status of the engine vibration well in the second frequency.

Study of High-Speed Ball Screw Vibration and Noise

Ball screw feeding system is a very important part of the machine tool. The ball screw of High-speed at the same time bring the vibration, noise, temperature rise due to friction and many problems. Noise and temperature rise are the key factors constrain the ball screw in the High-speed. The article summarized the ball screw causes of the vibration, noise, comprehensive both at home and abroad research results to the ball screw vibration and noise generating mechanism .Then pointed out that the ball screw noise generation is the main reason of the screw groove waveness arouses nut forced vibration.Introduced the latest progress of the ball screw drive system modeling and the vibration model analysis,specific introduces several methods of reducing vibration and noise reduction. And talk about the development trend of ball screw vibration and noise to the future.

Preparation of acetylated wood meal and polypropylene composites II: mechanical properties and dimensional stability of the composites

Acetylated wood meals of Sugi (Cryptomeria japonica D.Don) wood were prepared by mechanochemical processing using a high-speed vibration rod mill. Weight percent gain (WPG) of the acetylated wood meals ranged from 7.0 to 35.5 %. Wood–plastic composites (WPCs) containing 50 % acetylated woods were produced by an injection molding technique. The polymer matrix used was polypropylene homopolymer. Maleic anhydride-grafted polypropylene (MAPP) was also used as a compatibilizing agent. The mechanical properties of WPCs in bending and tensile tests were independent of WPG of acetylated wood meals, and the test values for WPCs containing acetylated wood meals were lower than that of unmodified wood meal. The use of MAPP increased bending and tensile strength, but no effect on bending modulus was found. An increase in WPG significantly decreased water absorbability and thickness swelling of WPCs as measured by dimensional stability tests. These results demonstrated that mechanochemical processing is a promising technique for preparing WPC material with improved dimensional stability. The future challenge is to inhibit the decreases in mechanical properties of WPCs containing acetylated wood meals.

Preparation of acetylated wood meal and polypropylene composites I: acetylation of wood meal by mechanochemical processing and its characteristics

Wood meals of Sugi (Cryptomeria japonica D.Don) passing 2.0 mm and retained on 1.0 mm mesh screens were milled along with acetic anhydride (AA) and pyridine as a catalyst in a high-speed vibration rod mill at ambient temperature. The weight percent gain (WPG) of the chemically modified wood was calculated based on the yield after washing with deionized water. The effects of amounts of AA and catalyst added, pulverization time, and saponification of the acetylated wood on WPG were examined. In addition, FT-IR analysis, and water vapor adsorption and desorption tests were performed as functions of the WPG. Increases in WPG, the acetyl contents of the acetylated wood after saponification, changes in the FT-IR spectra after pulverization, and the water vapor sorption isotherms showed that the one-step acetylation systematically modified the hydroxyl groups of the wood into acetyl groups. Up to 38 % WPG was obtained at 100 phr AA and 15 phr catalyst, and 120 min pulverization. Pulverization time and the amounts of AA and catalyst added to the wood meals could be adjusted to obtain acetylated wood meal with the desired WPG. These demonstrated that the mechanochemical acetylation is a method to prepare acetylated wood meals with high WPG at less reaction time and required AA addition.

Three-component access to pyrroles promoted by the CAN–silver nitrate system under high-speed vibration milling conditions: a generalization of the Hantzsch pyrrole synthesis

A sequential multicomponent process involving the high-speed vibration milling of ketones with N-iodosuccinimide and p-toluenesulfonic acid, followed by addition of a mixture of primary amines, β-dicarbonyl compounds, cerium(IV) ammonium nitrate and silver nitrate afforded polysubstituted, functionalized pyrroles. This one-pot, solid-state process can be considered as the coupling of an α-iodoketone preparation with a general version of the classical Hantzsch pyrrole synthesis.

Effect of different substituents on the water-solubility and stability properties of 1 : 2 [60]fullerene derivative·gamma-cyclodextrin complexes

We have demonstrated that C60 derivatives bearing a pyrrolidine moiety as well as a variety of other substituents can form 1 : 2 complexes with γ-cyclodextrin (γ-CDx) using a mechanochemical high-speed vibration milling apparatus. When the influence of the steric hindrance of the substituents on the formation of the complexes was negligible, the water-solubilities of the complexes were shown experimentally to be completely dependent on the hydrophobic properties of the substituent. Furthermore, the stabilities of the γ-CDx-complexes of several different C60 derivatives were found to be similar to or slightly higher than that of the C60·γ-CDx complex, with the solubilities of the complexes showing no correlation to the stabilities. Based on the results of a series of theoretical investigations, we have shown that the stabilities of the γ-CDx-complexes can be affected not only by steric effects but also by the polarities of the substituent groups, which exist in the vicinity of the upper rim of γ-CDx, because the water bound to the polar group can assist in the stabilisation of the complexes.

Efficient ZnBr2-catalyzed reactions of allylic alcohols with indoles, sulfamides and anilines under high-speed vibration milling conditions

Solvent-free reactions of allylic alcohols with various nucleophiles including indoles, sulfamides and anilines were efficiently achieved in the presence of 20% ZnBr2 under high-speed vibration milling conditions, and the products were obtained in good to excellent yields with the formation of water as the only byproduct.

Solvent and catalyst free azo-Michael addition under high-speed vibration milling

Under the high-speed vibration milling conditions, the solvent and catalyst-free azo-Michael addition of chalcone derivatives and amines was found to proceed efficiently in excellent yields at ambient temperature in short reaction time. In most cases, conventional side reactions were avoided and thus quantitative yields were achieved. The influences of the vibration frequency and reaction time on the azo-Michael addition were investigated.

1A1-J04 高速ロボットハンドの指先高速振動を用いたカード飛ばし(ロボットハンドの機構と把持戦略(1))

1A1-J04 高速ロボットハンドの指先高速振動を用いたカード飛ばし(ロボットハンドの機構と把持戦略(1))

The Accuracy Analysis on the External Circular of Zirconia Ceramic Spindle by Precision Machining

The high-speed ceramic electric spindle is applied in high-speed NC machine tools. Now the technology of ceramic spindle with its excellent performance applied to electric spindle is becoming a kind of important development trend. Each surface processing accuracy requirement of high-speed ceramic electric spindle is high. The performance of the electric spindle in largely determines machining precision and production efficiency of the high-speed machine tool. In order to meet the requirements of high speed, high accuracy, high reliability and small vibration in the rapid processing of machine tool, it is necessary to make a rigorous precision testing for the precision-processed spindle and obtain reliable data to meet the design standards and performance requirements of all ceramic high-speed spindle. This paper focuses on the research of surface roughness, roundness and cylindricity analysis of spindle external circular, which can make the precision-processed zirconia ceramic spindle pore to meet the design requirements and provide reliability safeguard to promote the using life and high-speed dynamic balance stability of the whole electric spindle.

The External Circular Precision Detection of Precision Machining Zirconia Ceramics Spindle

The electric spindle is the main form of high-speed NC machine spindle. Now the technology of ceramic spindle with its excellent performance applied to electric spindle is becoming a kind of important development trend. The performance of the electric spindle in largely determines machining precision and production efficiency of the high-speed machine tool. In order to meet the requirements of high speed, high accuracy, high reliability and small vibration in the rapid processing of machine tool, it is necessary to make a rigorous precision testing for the precision-processed spindle and obtain reliable data to meet the design standards and performance requirements of all ceramic high-speed spindle. In this paper, contact Surtronic25 type roughness measuring instrument is used for surface roughness analysis, and Leitz ultra PMM-C12.10.7 type tri-ordinate measuring machine is used for the roundness and cylindricity testing analysis of spindle external circular, which can make the surface roughness, roundness and cylindricity of the precision-processed zirconia ceramic spindle pore ​​to meet the design requirements and provide reliability safeguard to promote the using life and high-speed dynamic balance stability of the whole electric spindle.

Three-Dimensional Dynamic Response Analysis of Shield Tunnel under Train Loads

The vibration loads will be produced between wheel and rail on the running of the high-speed Train. The vibration energy will be transferred to the ground formation through the rail, guiding bed and tunnel lining structure, thereby causing vibration between the formation and surface and environmental interference effect problems. Thus the research of related issues caused by the high-speed train vibration has the vital great significance. The train design speed of the Shiziyang shield tunnel for Guangzhou-Shenzhen-Hong Kong passenger dedicated line is up to 350km/h. In this paper the research object is located in the segment of the homogeneous formation of the Shiziyang shield tunnel. The analysis of this paper includes the dynamic response rules of the shield tunnel and formation under the single high-speed train loads and the law of the pore water pressure accumulation and dispersion under train cyclic loading.

Fabrication of Carbon Nanotube/Zinc Oxide Composite Films by Electrodeposition

Carbon nanotube/zinc oxide (CNT/ZnO) composite films were fabricated by electrodeposition with aqueous solution of ZnCl2 and water-soluble CNTs prepared using a high-speed vibration milling technique. The experimental results of secondary ion mass spectroscopy and Raman scattering spectroscopy clearly showed that the CNTs were embedded in the ZnO films. The field electron emission was observed from selectively-etched CNT/ZnO composite films.

Hierarchical Structure Model of High Speed Milling Hardened Steel

In high speed milling hardened steel, cutting performance of cutter is uncertainty because hardness distribution and machining elements change. Based on the experiments of high speed milling hardened steel, the interaction among cutting force, cutting temperature, cutting vibration, processing surface quality and machining efficiency is investigated by means of interpretative structural modeling method, hierarchical structure model in high speed milling hardened steel is founded, optimization design method of high speed milling performance is proposed. Results show that uneven distribution of hardness swells the interaction of machining elements, and causes cutting vibration and processing surface quality mutations. Hierarchical structure model reveals the relationship between control variables and performance index in high speed milling hardened steel, it helps optimization of process parameters, restrains cutting vibration in high speed milling automobile mould, and improves processing surface quality and machining efficiency.

Hoarseness

Hoarseness is the colloquial expression for dysphonia ; these terms are often used interchangeably in medicine to refer to altered voice quality. Hoarseness may be both a symptom and a sign of dysfunction of the phonatory apparatus. It is never a diagnosis, despite having a corresponding International Classification of Diseases code and sometimes serving as such for purposes of administrative convenience. The same anatomical and physiological features that make the vocal folds uniquely suited for the high-speed vibration necessary for sound production render them exquisitely sensitive to a wide range of abnormalities. The breadth of pathologic conditions that can cause hoarseness makes a unified overview a challenge; hoarseness is simply not a homogeneous category after the initial laryngoscopy. Moreover, the available literature predominantly focuses on specific diagnoses rather than on hoarseness as a whole, so scant published data exist to support an evidence-based approach. Nevertheless, certain unifying principles exist.

비접촉 진동 검출을 위한 유도성 근접센서모듈 개발

금속물체의 피로도를 측정하기 위하여 고속으로 진동시키면서 비접촉으로 정밀하게 변위를 측정하는 방법에 대한 연구가 많이 이루어지고 있다. 비접촉 고속 진동 검출센서들은 와류 센서나 레이저 센서들을 주로 사용하고있지만 매우 고가이다. 최근 저가의 유도성 센서를 고속 진동검출에 적용하려는 연구가 이루어지고 있으나 아직은 초보단계이다. 본 연구에서는 저가의 유도성 센서를 이용하여 비접촉으로 고속 진동을 검출하는 새로운 근접 센서모듈 설계방법을 제안하였다. 기존의 유도성 센서모듈들은 검파, 적분, 및 증폭과정을 통하여 변위를 검출하기 때문에 아날로그회로 특성상 잡음에 약하고 적분과정에서 변위 검출속도 저하의 요인이 된다. 제안된 방법은 AD변환기(Analog to Digital converter)를 사용하지 않고 진동 주파수신호를 직접 디지털 신호로 변환하는 새로운 방법으로 아날로그 잡음의 영향을 적게 받으며 고속으로 신호를 처리할 수 있는 장점이 있다. 성능 평가를 위하여 셰이커로 진동 주파수를 30Hz부터 1,100Hz 까지 일정간격으로 금속편을 진동시키면서 제안된 센서 모듈을 이용하여 비접촉으로 진동 신호를 검출하였다. 실험결과 비접촉 근접 거리 5mm 이내에서 진동 주파수 검출범위는 DC에서 1,100Hz까지 측정할 수 있었으며 진동 폭의 해상도는 <TEX>$20{\mu}m$</TEX>로 나타났다. 따라서 제안된 유도성 센서모듈은 정밀 비접촉 고속 진동검출 센서로서 충분한 성능을 가지고 있다고 평가된다. To measure the fatigue of metallic objects at high speed vibration while non-contact precision displacement measurement on how to have a lot of research conducted. Noncontact high-speed vibration detection sensor of the eddy current sensors and laser sensors are used, but it is very expensive. Recently, High-speed vibrations detection using an inexpensive inductive sensor to have been studied, but is still a beginner. In this paper, a new design of an inexpensive inductive proximity sensor has been suggested in order to measure high frequency dynamic displacements of metallic specimens in a noncontact manner. Detection of the existing inductive sensors, detection, integral, and amplified through a process to detect the displacement noise due to weak nature of analog circuits and integral factor in the process of displacement detection is slow. The proposed method could be less affected by noise, the analog receive and high-speed signal processing is a new way, because AD converter (Analog to Digital converter) without using the vibration frequency signals directly into digital signals are converted. In order to evaluate the sensing performance, The proposed sensor module using non-contact vibration signals were detected while shaker vibration frequencies from 30Hz to 1,100 Hz at intervals of vibrating metallic specimens. Experimental results, Vibration frequency detection range of the metallic specimins within close proximity to contactless 5mm could be measured from DC to 1,100Hz and vibration amplitude of the resolution was <TEX>$20{\mu}m$</TEX>. Therefore, the proposed non-contact inductive sensor module for precision vibration detection sensor is estimated to have sufficient performance.

Biological activity of water-soluble inclusion complexes of 1′-acetoxychavicol acetate with cyclodextrins

1′-Acetoxychavicol acetate (ACA), isolated from the rhizomes and the seeds of the Zingiberaceae plant, has a variety of biological activities such as antitumor, antiallergic and repellent effects. However, ACA seems to have some disadvantages which may limit for future possible clinical applications, for example, its poor water solubility. Furthermore, ACA is not stable in aqueous solutions and undergoes hydrolysis and/or isomerization. To improve the solubility and stability of ACA in water, we prepared the inclusion complexes with various β-cyclodextrins (β-CDs).In aqueous solution, the association constants of ACA with various CDs were estimated at 662 ± 95 (β-CD), 336 ± 70 (methyl-β-CD, Meβ-CD), and 322 ± 44 M −1 (hydroxypropyl-β-CD, HPβ-CD), respectively, by a spectrofluorometric displacement method based on competition between a guest and a fluorescent probe for CDs. It was revealed that almost all ACAs existed as a free molecule in the CD-containing aqueous solution. However, in the case of preparing the inclusion complexes of CDs with ACA by a solid phase ‘high-speed vibration milling’ technique, the average inclusion rates of the obtained water-soluble complexes were calculated as 88 ± 13% (β-CD), 70 ± 1% (Meβ-CD), and 63 ± 2% (HPβ-CD), respectively, by 1H NMR analysis. To characterize the structures of the CD·ACA complexes, 2,3,6-trimethyl-β-CD (TMeβ-CD)·ACA complex was prepared as a model compound (inclusion rate: 40%). As a result of 2D ROESY experiments, it was considered that the aromatic ring of ACA is located in the narrow side of the hydrophobic cavity of the TMeβ-CD and both 1′- and 4-acetoxy groups of ACA positioned in the vicinity of the secondary and primary methoxy groups of TMeβ-CD, respectively. Furthermore, we examined the apoptogenic activity of CD·ACA complexes to evaluate whether or not the bioactivities of ACA were affected by their inclusion. Although the cytotoxicity of all CD·ACA complexes in human epithelial carcinoma HeLa cells and murine adenocarcinoma colon26 cells were diminished as compared with the ACA alone, only HPβ-CD·ACA maintained high levels of activity. In addition, HPβ-CD·ACA, and Meβ-CD·ACA showed suppressive effect for the transcription factor NF-κB activation on LPS-activated murine macrophage RAW264.7 cells and the former was more active complex. Furthermore, HPβ-CD·ACA inhibited the in vivo tumor growth of tumor-bearing mice, although the activity was slightly weak compared with that of free ACA. These results indicate that HPβ-CD is the best host molecule for ACA to form a water-soluble complex with the similar biological activity of free ACA.

Nanopumpkins and a sunscreen agent: the inclusion complex of cucurbituril and Tinosorb S

The commercial sunscreen agent Tinosorb S (TS) is a promising oil-soluble broad spectrum UV filter. Here, we report for the first time a water-dispersible inclusion complex of TS using cucurbituril. The synthesis was carried out via a supramolecular approach in the solid state by using the high-speed vibration milling technique. The formation and the photophysical properties of the solid inclusion complex were investigated by spectroscopic techniques such as UV–vis spectrophotometry, Fourier-transform infrared and solid-state proton nuclear magnetic resonance spectroscopy as well as by thermal gravimetric analysis and X-ray diffractometry. An increase in the absorbance and a shift of the maximum absorption from 380 nm to 345 nm for the inclusion complex were observed in comparison to the precursor complex TS. The stochiometric ratio of cucurbituril and TS in the inclusion complex was found to be 2:1

Influence on Cutting Forces and Vibration in High Speed Machining Pocket Corner

High speed milling hardened mould steel (above HRC50) at pocket corner generates the cutting forces increase and vibration gets fiercely because of the sudden change of cutting direction. It will cause serious wear and possible breakage of cutting tool, and poor quality of parts. Hence, the need to select reasonable cutting parameters and adopt appropriate cutting strategies will help them to achieve their goal. In this paper, the effects cutting parameters including cutting speed, pocket corner angle, feed rate per tooth and radial depth of cut on cutting force and vibration are studied. The results show that sharper pocket corner results in the increase of cutting force and makes vibration strong. Cutting force increase with the increase of cutting speeding, feed per tooth and radial depth of cut. The optimum of cutting speed leads to the decrease of vibration. It is proposed that cutting parameters should be optimized to improve tool life and processing efficiency.

Fiber-Optic Heterodyne Imaging Vibrometer

A method and system for performing two-dimensional laser Doppler vibrometry (LDV) are disclosed. A high speed fiber optic heterodyne imaging vibrometer can be used for the imaging of high speed surface deformation and/or vibration. Images provided by the high speed fiber optic heterodyne imaging vibrometer can be representative of movement, e.g., displacement or vibration, of the surface being imaged.