In the 1st part of this investigation, the analysis of tool deflection and locus of tool axis during ball end milling along a contour line was presented. In the paper, cutting force data predicted by using the cutting model proposed in a previous paper and the Finite Element Method were used for analyzing the deformation of a tool. In this paper, tool deflection in the milling of an inclined surface is measured under various slopes of the surface and compared with the predicted results. The predicted results agree with the measured results well enough. Geometrical configurations of the machined surface and the machining errors obtained from the analysis are shown for various slopes of the inclined surface. It is found that machining errors disagree with the magnitudes of deflection of the tool axis in a plane normal to the feed direction, so the errors can't be evaluated by neglecting the condition of cutting edge engaged with the workpiece such as rotational angle and tool geometry. The machining error caused by tool deflection becomes small for milling of an inclined surface where the left side of the feed direction is higher.
High Pressure Micro Jet (HPMJ), a kind of spray cleaning which makes liquid particles impinge to object with high speed, is widely employed in cleaning process for flat panel displays, semiconductors, etc. The purpose of this study is to improve the cleaning efficiency of HPMJ. First, noticing the spray nozzle that has vital function in all components of HPMJ for the cleaning liquid atomization, we have tried to improve shape design of the nozzle to get directional flow of the liquid which lead us to succeed in improvement of flying speed of liquid particles by 20% under the same pressure. Furthermore, it is found, through cleaning test with PSL particles, that this design improvement of the nozzle also improves the cleaning efficiency. From mutual relation between behaviors of liquid particles and results of cleaning test got in this study, it is found that the cleaning efficiency of HPMJ is in proportion to the flying speed of cleaning liquid particles and such speed improvement highly depends on shape design of the nozzle. Thus, it is confirmed that, in High Pressure Micro Jet system, improvement of nozzle design leads to better cleaning efficiency. Further, the improved nozzle can get same cleaning efficiency under lower pressure, which is expected to give environment favorable effects such as fewer consumption of cleaning liquid, reduced energy cost, etc.
This study describes the programming of cutter location based on a constant feed-speed vector at the cutting point with a ball nose end-mill tool by a Five-axis Machining Center. In the present paper, we proposed a new programming method to maintain both feed-speed amplitude and direction at the cutting point using rotational and linear axes controlling. First of all, we focused on generating a hemispherical surface with a ball nose end-mill, and investigated its surface roughness and its profile error. As a result, it can be seen that this method is effective to obtain a fine machined surface roughness and to avoid the influence of linear motion errors on the machined profile at the normal direction to the feed-speed vector.
This paper investigates the influence of kinds of cemented carbide hob materials coated with fully TiN and (Ti, Al)N coatings, in hobbing with minimal quantity lubrication (MQL) system compared with dry cutting in cutting performance, in terms of flank wear (tool life), crater wear and finished surface roughness. Experiments were carried out by simulating hobbing by fly tool cutting on a milling machine. The results obtained are summarized as follows. (1) When changing the kinds of hob materials, P10, P20 and P30, as a substrate, the P30 hob material showed a longest tool life, even if the kinds of coating films were changed. The tool life obtained with the Fully (Ti, Al)N-coated tools is longer than that obtained with TiN-coated tools. The flank wear reduction effect by MQL system, which prolongs the tool life compared with the dry cutting, was recognized. (2) Although the reduction effect was recognized in the crater wear, the thermal cracks occur on the rake face of both fully TiN-and (Ti, Al)N-coated P30 tools. (3) The MQL system decreases the surface roughness with all of the cemented carbide hob materials and the coating films tested. (4) From the viewpoints of the tool life, the crater wear and the surface roughness, the use of MQL system for the fully (Ti, Al)N-coated P30 tool is effective.
A new method for evaluation of adhesion in cutting is proposed. Adhesion of chip induces fluctuation in chip flow or stick-slip movement of chip, so that dynamic component of cutting forces depends on the cutting conditions and properties of the work materials. Continuous turning of a medium carbon steel, a titanium alloy and a nickel-based super heat resistant alloy were carried out. Dynamic components of cutting force were measured by piezoelectric dynamometer. In cutting of a medium carbon steel, the dynamic components below 500Hz increased under the condition of build-up edge (BUE) formation, and gradually decreased with increase of cutting speed. Deposits of work piece on tool face were also observed under conditions in which the power spectrum of cutting force showed peaks. Authors defined friction-coefficient vector on rake face of cutting tool. Fluctuation in the friction-coefficient vector was calculated as for a range of cutting speeds under dry condition and emulsion supply in order to investigate the relationship between adhesion and fluctuation of the dynamic components. Tendency to adhesion was evaluated with newly defined index among a carbon steel S45C, a titanium alloy Ti-6Al-4V and a nickel-based super heat resistant alloy Inconel718, yielded good agreement with empirical rules.
We studied on the implantations of various metals into glass with a continuous-wave (CW) laser beam. Platinum, nickel, SUS304, tantalum, tin, silver and copper were examined to implant into borosilicate glass. Platinum, tantalum, tin and silver were deposited with a thickness of 1 μm and nickel, SUS304 and copper foils with a thickness of 10 μm were placed on the backside of the glass. A CW laser beam oscillating at a wavelength of 514 nm was used to illuminate the film through the glass. The laser beam was focused on the films by a convex lens. As a result, platinum, nickel and SUS304 were implanted in the same manner. However, tantalum, tin, silver and copper were not implanted. The thermal conductivities and melting points of the implanted metals were below 100 W/m·K and ranged from 1500 to 2200 K, respectively. We supposed that the temperature at the laser spot governed the difference. Hence, numerical calculations were performed to estimate the temperature. As a result, the temperature of platinum, nickel, SUS304, tantalum and tin exceeded their melting points within 0.01 s after the laser illumination, whereas those of silver and copper did not exceed their melting points even after 1s. The diameter of the particles was controlled by changing the film thickness. The diameters of the particles were ∼3 μm and ∼50 μm when the thicknesses of the deposited films were 0.1 μm and 5 μm, respectively.
Human feels reaction force when she/he touches environments. Such sensation is necessary for the human especially in accurate operations. A bilateral control system is one of remote control systems and makes it possible to transmit force sensation between operators and environments. A robot hand is a candidate of interfaces for the bilateral control system because it is applicable to variety of fields. Generally, the robot hands have different structures in master-slave robots and tend to be bigger and heavier due to their actuators. These problems deteriorate performance and operationality of the robot hands. In this paper, two types of novel master-slave robot hands were proposed to achieve transmission of clear force sensation in grasping and manipulation. It is easy to design the control system for proposed robot hands because they have the same structures both in the master and the slave robots. Moreover, thrust wires are utilized to solve the over weight problem by placing the motors away from the end-effectors. Thus, it makes the robot hands lighter and placed away from the motors. The performance of the proposed robot hands are evaluated by experiments.
A calibration method is proposed to compensate the measurement error in in-situ measurement using non-contact probes. In the measurement with a measurement-fused machining system, a displacement for calibration is measured with the probes for reference and profile measurement to calibrate the profile probe according to the reference probe. In this paper, the proposed method is used to compensate the measurement error of a triangular surveying type laser displacement sensor caused by tilting of the measuring surface. The experimental result shows that the error is decreased from ±0.9 μm to ±0.5 μm with the method.
This paper presents a micro hole measuring system using an optical fiber probe. The system is composed of a fiber probe, two floodlighting fibers and two double-light reception fibers in the X and Y directions. The fiber probe has an optical fiber of 30μm in diameter with a ball of 50μm in diameter on the end. The probe is deflected when it comes into contact with a hole surface, and this deflection is measured optically. In this research, the accuracy and repeatability of such measurement are examined by measuring a roughness standard specimen and a micro hole. The results clarified that the accuracy of the roughness standard specimen measured by the measuring system corresponds well to that of the surface roughness tester in both shape and value and that the maximum repeatability errors for 10 measurements of a roughness standard specimen is within ±0.03 μm in scanning mode and ±0.1 μm in touch trigger mode.
Quality of products and reduction of products inspection burden are required in production. This paper describes development of automatic inspection system for cylindrical products by image processing. Since a cylindrical product is an axisymmetric object, the scratch can be detected by image processing on the difference image of the captured images. Based on this idea, we have developed the scratch detection algorithm. It has the threshold setting method where the threshold adjustment is able to be done easily by considering the threshold as image data. The availability of the developed inspection system is shown in the experimental result where actual inspection was carried out on a large quantity of cylindrical products.
Calculating volume of defects in casting objects is important for high quality manufacturing. It can be estimated by using X-ray CT scanner that is a non-destructive measurement device. However, conventional methods cannot detect tiny defects based on simple thresholding method. This is because not only their CT values do not fall down to the value of background but also they appear like one set in CT images. As a result, we do not take into account such tiny defects and their calculation accuracy is comparatively low. In this paper, we propose a more accurate method to calculate casting defects' volume. We define two types of defect by their size and apply different calculation models to each defect. We propose a method to separate each defect from the set of defect based on assumption that a tiny defect is approximation of sphere. Our contribution is to detect tiny defects which are not detected or calculated correctly in conventional method and to calculate their volume. This paper also demonstrates more accurate estimation of defects' volume using measured CT data.
This paper proposes a new integrated optimization for comprehensively supporting two main tasks of a conceptual design : functional design and component layout design. The proposed method consists of two optimizations : functional optimization and layout optimization, and derives the optimal solutions by cooperatively executing them. The functional optimization is based on the HGA (hierarchical genetic algorithm) in order to consider a hierarchy of functional structure, whereas the layout optimization is based on the sequence-pair and can also support a hierarchy of parts assembly. Using the proposed method, both the functional structure and the components layout that satisfies performance, cost and area at a high level can be simultaneously obtained. To demonstrate the flow of the proposed method and confirm its effectiveness, this paper describes the case study, where internal devices of a personal computer are designed using the proposed method.
Minimizing brake squeal is one of the most important issues in the development of high performance braking systems. Recent advances in numerical analysis such as finite element analysis have enabled sophisticated analysis of brake squeal phenomena, but current design methods based on such numerical analysis still fall short in terms of providing performance measures for minimizing brake squeal, of high performance design drafts at the conceptual design phase. This paper proposes a conceptual design method for disc brake systems that aims to reduce brake squeal by tailoring the shapes of the brake system components based on the concept of First Order Analysis (FOA). First, the relationships between brake squeal performance and the geometry and characteristics of various components is clarified using a simplified analysis model. Next, a design performance measure is proposed for evaluating brake squeal, and a method for deploying component designs based on this measure is discussed. Finally, a practical design example is provided to confirm that the proposed method can yield useful designs for high performance braking systems.