Vertical Machining Research Articles

Compensation for CNC Machine Tools Comprehensive Error Based on Interpolation Algorithm

In order to reduce the in∞uence of comprehensive error on CNC machine’s precision, the modeling method of comprehensive error was presented in this work based on linear interpolation and Newton interpolation. By using the CNC external machine zero point ofiset function, real-time error compensation was realized online. The experimental results on a vertical milling machine show that the model is convenient in calculation and performs excellent in accuracy prediction. Therefore it is suitable for the compensation for comprehensive error of CNC machine tools.

Research on the Inner Wall of the Blind Hole Drilling Device

This article describes the structure and working principle of the blind hole drilling device through application in the production practice proving its feasibility. At present, electrical discharge machining and welding method are commonly used to solve the problem. However, these methods have low processing efficiency, low manufacturing precision and high cost defect. This paper developed an inner wall of the blind hole drilling device, similar to stand-alone machine accessories and adopted the bevel gear transmission which can directly be mounted on vertical or horizontal milling machine, completing the processing operations in few minutes. This device not only has high processing efficiency and accuracy, but it also greatly reduces the production cost.

Experimental Research on Circular Milling of Bi-Layer Composite Materials Consisting of CFRP Laminates and Titanium Alloys

Recently, to construct an airframe 2-layer composite materials consisting of carbon fiber reinforced plastic (CFRP) laminates and TiAl6V4 still need to be machined, whereby drill holes are frequently machined. Special attention has to be paid to the machining quality, which implies hole dimensional accuracy, defect free peripheral zone, edge quality at inlet and outlet of hole and so on. Machining defects often occur as a consequence of excessive mechanical and thermal loads, which are often caused by wrong process conditions or by the wrong choice of machining process itself. With respect to widely used state-of-the-art machine tools providing high performance and equipped with potent control unit, for the comparatively large drill hole, circular milling gains interest as an alternative to the drilling operation [1, 2]. In this research, in order to select suitable machining conditions for 2-layer composite materials consisting of CFRP laminates and TiAl6V4 a large number of circular milling tests of 6 mm diameter are executed by using a high performance vertical milling machine. Hole diameter deviation from 6 mm and inner surface roughness in relation to number of hole machined are measured and evaluated for CFRP laminates and TiAl6V4. Moreover, from observations of cutting edges in relation to number of hole machined it is confirmed that under wrong machining conditions the difference of heat conductivity between CFRP laminates and TiAl6V4 induces for chips of TiAl6V4 to be deposited on the end cutting edges of endmill used. In this case tool life shortens extremely.

Study on Tribological Performance of Al<sub>2</sub>O<sub>3</sub> Particle Reinforced the Al-Sn Bearing Alloy

In order to improve performance of Al-Sn bearing alloys, a new Al2O3/Al-Sn composite was fabricated through in-situ reaction between Al and SiO2. A study has been conducted to investigate tribological performance of the composite on MMW-1 Computer controlled vertical universal friction and wear testing machine. The results show that Al2O3 and Si particles are mainly distributed in the grain boundary and particles are often coated by a thin Sn layer. Friction coefficient of Al2O3/Al-Sn composites is decreased with Sn additions up to 21wt. %.

Design and Analysis of a Sawing-Milling Compound Machining Center for Special-Shaped Stone Products

Nowadays, the equipment for processing special-shaped stone products is developing towards high efficiency, intelligent and multifunction. Based on the features of stone processing technology, a sawing-milling compound machining center with eight axes and double five-axis simultaneous control for special-shaped stone products was designed. The dynamic performance and processing capacity were tested. Research shows that the sawing and milling compound machining in the same horizontal slide saddle is practicable. This machine can realize both vertical and horizontal machining under five-axis simultaneous control, and its machining accuracy is better than the normal industrial standard.

Influence of Sensor Positioning in Tool Condition Monitoring of Drilling Process through Vibration Analysis

In this study, the relationship between vibration and tool wear and also influence of sensor positioning in tool codition monitoring were investigated during drilling. For this purpose, a series of experiment were conducted in a CNC vertical milling machine using drilling cycle. A 6 mm diameter HSS drill and EN24 as workpiece material were used in these experiments. The vibration was measured in the transverse direction of sensor which is positioned on the workpiece with constant distance from the holes to be drilled for monitoring tool wear as in previous studies. But, positioning of sensor in a constant place with equal distance from all holes to be drilled is not possible for all the workpiece profiles in actual practice. Experiments show that the distance of sensor from the holes in drilling affects the vibration signals for the same state of wear.It shows that the tool wear models presented in previous studies using acceleration signals are sensor location dependent. This work presents a Variance-amplitude of the vibration signals received for tool condition monitoring which is the most sensitive statistical parameter than other statistical parameters such as Root Mean Square (RMS), Exponential, Peak, max-min, mean and standard deviation. Results showed that there was no considerable increase in the vibration amplitude of variance until flank wear value of 0.30 mm was reached, above which the vibration amplitude increased significantly.

A Novel Vertical Lift Machine and its Precise Pose Control

This paper deals with the design and theoretical analysis on a novel vertical lift machine which can vertically lift above 700 kg load up to 3.2 meters above the floor and located the load with high accuracy of position and orientation. Firstly the design model based on the installment demands of line-replaceable units (LRUs) is constructed. Then theoretical analysis including the number of degree of freedom of the lift machine, the inverse kinematic, the control principle, the lift platform pose error and the precise pose control method are conducted in the article. The validity of the design model and the effectiveness of the precise pose control system are confirmed by experiments using a prototype lift machine.

Path Planning for Circular Cutter Envelop Milling of Steam Turbine Blade

In order to solve the problem of poor steam turbine blade processing efficiency, and on the basis of analyzing the turbine blade surface and the existing processing methods, a model of circular cutter turbine blade machining is built. By comparing the tool paths of horizontal and vertical section envelope machining, choosing quasi-vertical cross section envelope machining method and utilizing the original datum and NURBS surface matching mathematic methods, this paper provides an algorithm of residual height calculating, and based on this, the tool path can be planned. Datum show that, the tool path of circular cutter machining blades is much longer than the tool path of ball-end cutter envelop milling machining blades, and the machining efficiency is also highly enhanced.

The Preparation and Tribological Properties of Graphite Fluoride

Solid phase method was adopted to prepare the graphite fluoride solid lubricant. The friction and wear properties of graphite fluoride were tested with MMW-1 vertical universal friction and wear testing machine. The phase of graphite fluoride was analyzed with infrared spectrometer. The morphology of friction surface was analyzed with the scanning electron microscope. The results show that graphite fluoride has an excellent antifriction wear-resisting property, to compare with molybdenum sulfide, the anti-friction property increased by 35%, wear resistance increased by 49%. The main wear mechanism of the test specimens are fatigue wear and adhesive wear. The solid lubrication film for graphite fluoride was formed in the friction surface.

Mineral Oil Barrier Testing of Cellulose-Based and Polypropylene-Based Films

Recycled cardboard has been identified as a major source of mineral oil hydrocarbon (MOH) contamination of foods. Identifying and using appropriate functional barriers is a mechanism through which this problem can be addressed. A number of cellulose-based and biaxially oriented polypropylene (BOPP) films were evaluated as potential functional MOH barriers. The films were tested using a donor material, a paper containing MOH placed on one side of the film barrier and a paper which acted as the receptor on the other. Testing was performed at accelerated conditions of 60°C, the receptor analysed periodically for MOH. The results demonstrated that the cellulose-based film types provided an MOH barrier of >3.5 years. This contrasted with the BOPP selected films, for which only the proprietary acrylic-coated BOPP film provided an effective barrier to MOH migration. Further investigation of the MOH barrier properties of the proprietary acrylic-coated BOPP film was undertaken. Various coating strategies were employed including increasing the coating application weight, increasing the number of coating lay downs and coating one or both surfaces of the film. It was found that an MOH barrier of 1.5 years when tested at 40°C could be achieved for the proprietary acrylic-coated BOPP film; however, barrier effectiveness was dependent on the coating integrity of the film. Further work with a vertical form filler packaging machine and the use of a staining technique with transmission microscopy proved effective at highlighting and assessing the coating integrity of packets during a typical packaging operation. Copyright © 2014 John Wiley & Sons, Ltd.

Preliminary Tribological Study and Tool Life of Four Commercial Drills

The mechanical and tribological properties of drill bits have a strong influence on the characteristics and performance of such tools. Today there are many different types and makes of drills available and their various characteristics influence their efficiency and, of course, their cost. In this preliminary project, four commercial drills were studied; multiple examples of two of the drills were tested. These were selected because of their price and characteristics from those available in the Mexican national market. The tools were submitted to a variety of characterization tests in order to determine their mechanical and tribological behaviors. The tests included hardness by indentation (both micro- and nanotesting), microabrasion by ball cratering, and scratch testing to determine the coating adherence and surface scratch resistance by novel scratch testing procedure. Additionally, the drills were analyzed by energy-dispersive X-ray spectroscopy (EDX), Rutherford backscattering (RBS), and scanning electron microscopy to determine the surface characteristics and composition. The tracks resulting from the tribological tests were studied by profilometry and optical microscopy. The performance of the drill bits was then tested using a vertical drilling machine under controlled conditions of fixed cutting speed, constant load, and drilling depth. The quality of the drilled holes was determined by measuring the difference between the upper and lower diameters of the holes. We found that the wear rate, measured by ball cratering, and the bulk hardness rather than the surface hardness of the drill bits correlated best with the drill performance and lifetime.

Impact-induced explosion-like reactions in vinyl halide polymers

External manifestations and the mechanism of the previously unknown phenomenon of explosion impact-induced reactions in thin-layer polymer samples of vinyl halide polymers are studied by performing experiments on a vertical impact-testing machine. The critical parameters of initiation are determined and the physicochemical limitations on their manifestation are identified. The inability of such reactions to propagate throughout massive samples of material is emphasized.

Reliability Analysis and Experimental Research on Cutting Tool of Vertical Shearing Machine

The failure cause and failure mode of cutting tool is analyzed based on the reliability analysis on cutting tool of vertical shearing machine. Reliability calculation model is established, and experimental research on cutting tool is operated. The results show that the critical failure mode of cutting tool is electric die grinder .The crucial failure cause is that in the shearing process, the UO2 ceramic in the fuel components is crushed into particles with high hardness, these hard material will lead to tool wear. The reliability of cutting tool is 0.892, which cant achieve the spent fuel reprocessing working shearing machine reliability requirements. The structure and materials of cutting tool must be improved. The parallel distance between the upper surface of cutting tool and the lower surface of the pressing block has to be adjusted.

Investigation of Biomechanical and Biosafety of Injection Moulded Implant Materials

This paper presents the attempt to manufacture metallic implant using medical grade 316L stainless steel alloy powder by MIM process. The powder with the median particle size of 15 μm and a binder consisting of palm stearin and poly ethylene were mixed at 160°C using a sigma-blade mixer for one hour to prepare the feedstock of the test bar. The rheological properties of the feedstock was tested using capillary rheometer. The test bar was injection moulded using vertical injection moulding machine with the nozzle temperature of 200°C. Prior to sintering, the specimens were debound using a combination of solvent extraction and thermal pyrolysis method. The specimens were then sintered under vacuum at the temperature between 1300oC to 1360oC. The properties of the sintered bar such as physical appearance and densities were presented and discussed. The biocompatibility including toxicity properties of the implant also been presented. The results showed that physical and mechanical properties of the sintered sample complied with the international standard

Study on Thermal Deformation of Machine Tool under Different Environment Temperature

Taking XK5034 vertical milling machine as the research object, its thermal characteristic's finite element analysis has been carried out through the ANSYS. The front-end of the spindle mainly affects the machining accuracy of machine tool, so on the basis of the temperature field analysis, its thermal deformation was analyzed under different environment temperature, and the change rules between environment temperature and thermal deformation of the front of the spindle was also acquired. The results show that the influence of machine tool thermal deformation under different temperature is obvious.

Influence Parameters Analysis of Forming Quality and System Dynamics Simulation of Vertical Steel Bar Benting

The vertical steel bar bending forming is a kind of new process of bending method. The bending speed, bending radius and clamping length H which is the parameters of vertical steel bar bending machine , is directly affect the quality of bending forming parts. This paper calculated the length of reinforcement before being incised and the springback angle of bending steel bar which obtained the reasonable cutting length and bending Angle; Then based on rigid-flexible virtual prototype technology to build the dynamics model of vertical steel bar bending system. Through simulation analysis ,it obtained the relationship between bending speed, bending radius , clamping length H and forming quality of bending steel bar. In this paper, the analysis method have reference value to the design of similar steel bar bending machines.

The Particle Motion and Power Theory Analysis of Centrifugal Field

This paper discusses accelerated stress conditions of ore particles in the vertical impact test machine rotor passage through numerical analysis method, and to determine the relationship between the movement of particles and the power and the machine parameters.The results show that:In the test machine rotor, motion law of ore particles is determined, and by expression for the particle displacement, speed and power of the numerical analysis method.If the test machine, gravity effects are negligible;Speed is the main factor affecting the characteristics of particle movement, but should not exclude the influence of particle volume and surface quality;Chasing is never occur in the process of particles;With calculated by the theoretical formula of reasonable size of rotor.

Research on Modeling and Simulation of the Trafficability of Vertical Screw Conveyors Intermediate Support Based on EDEM

Vertical screw conveyor is a kind of main equipments of bulk handing and delivery, and the intermediate support structure is one of the key parts of this equipment. It is necessary to make a research on it for improving the design and optimization to improve bulk delivery efficiency. Degree of freedom theory, analysis software of EDEM with discrete element and setting periodic boundary model are applied in this paper to simulate the vertical screw conveyors grain (rice) delivery process under different intermediate support structure. The results show that traditional intermediate support structure is three times statically indeterminate structure, while the degrees of freedom of new intermediate support is 1; The vertical screw transmission capacity of new type of vertical screw axis machine which uses intermediate spokes structure is slightly decreased, and the driving power required to drive screw axis increases slightly at the same time. The materials axial transport speed is not affected, but the requirement is greatly reduced for the manufacture and installation accuracy.

Spindle System Dynamic Characteristics Analysis of Vertical Gantry Machining Center

With the spindle system of a vertical gantry machining center as the research object, based on the vibration theory and finite element method, the modal analysis of spindle system is studied. Firstly, the finite element models of the mandrel box body and motorized spindle frame of spindle system are established by ANSYS. And then do the modal analysis of singleton in the boundary of free constraint. Lastly, based on the analysis results to establish the finite element model of the whole spindle system and do the modal analysis of the whole system which under constraint condition. The result shows that the swing of motorized spindle frame and motorized spindle sleeve of spindle system are more obvious.

Feed Rate Influence on Motion Error Characteristics of CNC Vertical Milling Machine

The increasing number of the Computer Numerical Control (CNC) machines usage in the manufacturing field appears to suggest that they are expected to be in good running condition. Machine tools such as CNC vertical milling machines are meant to produce precise work parts. Motion errors are factors which can directly affect the accuracy of the machine. This study presents an opportunity for interested parties to understand the characteristics of motion errors that exist in the CNC vertical milling machines with different feed rate settings. The purpose of this project is to find out any abnormalities apparent to the machine performance as the feed rate setting is increased. The motion errors of the CNC machines were examined by using a measuring device, namely Double Ball Bar (DBB). This equipment is designed to examine machine performance by measuring the accuracy of its movements. This device, which has two balls of identical size at the end of the bar, was mounted on a spindle and onto a special holder which is mounted on the working table. The machine is programmed to move in a circular motion, clockwise and anti-clockwise in three planes, XY, YZ and ZX. Any deviation from the standard data will represent the imperfection of the machines condition, especially mechanical components such as the slide bearing, spindle bearing or servo motor responses. By knowing the most significant error origin, the corrective countermeasures can then be carried out.