Design of a Flexible Centering Tooling System

Precise machining of bearing rings is integral to the quality of assembled bearings. The output accuracy of center-based machining systems such as lathes or magnetic chuck grinders can relate directly to the accuracy of part centering before machining. Traditionally, such machines achieve centering by either hard tooling to which the ring is pressed, or through manual centering by a skilled operator using a brass hammer. Hard tooling has the problems of being subject to wear, dimensional inaccuracy, and additional setup time at part type changeover. Manual centering methods are subject to human error, both in accuracy and repeatability. Whether through setup time or manual centering time, either method requires skilled labour a nd is relatively expensive

Cutting Force Investigation of Trochoidal Milling in Nickel-based Superalloy

The gas turbine, aerospace and nuclear industries are dependent upon nickel-based superalloys to enable these industries to continue to innovate. Without these materials the industries would fail to achieve new heights of efficiency as the strength and operating temperature requirements continue to climb. Nickel-based superalloys thrive in these elevated temperature applications, where their great resistance to creep and corrosion is coupled with remarkably high strength values. These same characteristics that are invaluable to the final operating environment severely degrade their machinability with high cutting forces and aggressive rate of tool wear

Energy Consumption Modeling and Analyses in Automotive Manufacturing Plant

Manufacturing plants energy consumption accounts for a large share in world energy usage. Energy consumption modeling and analyses are widely studied to understand how and where the energy is used inside of the plants. However, a systematic energy modeling approach is seldom studied to describe the holistic energy in the plants. Especially using layers of models to share information and guide the next step modeling is rarely studied. In this paper, a manufacturing system temporal and organizational framework was used to guide the systematic energy modeling approach. Various levels of models were established and tested in an automotive manufacturing plant to illustrate how the approach can be implemented. A detail paint spray booth air unit was described to demonstrate how to investigate the most sensitive variables in affecting energy consumption. While considering the current plant metering status, the proposed approach is advanced in information sharing and improvement suggestion determination

Real-Time System Identification for Impact-Based Part Positioning

Simplified part positioning in manufacturing has been achieved using pushing or tapping actuation in place of more complex pick-and-place systems. However, positioning by impact introduces a new source of uncertainty: interfacial frictional effects of sliding, which can result in an uncontrollable and often poorlypredictable actuation distance. The described work provides a friction-based dynamic model of the sliding distance after impact that is used to predict static friction characteristics. A prototype system is simulated and validation data used to improve the model. A control algorithm is also described, tested and validated over a range of actuated masses

Design of a Flexible and Agile Centering Preprocessing System

Precise machining of bearing rings is integral to finished bearing assembly quality. The output accuracy of center-based machining systems such as lathes and magnetic chuck grinders relates directly to the accuracy of part centering before machining. Traditional tooling for centering on such machines is subject to wear, dimensional inaccuracy, setup time (hard tooling) and human error (manual centering). A flexible system for initial part centering is proposed based on a single measurement system and actuator. In this system, the part is placed by hand onto the machine table, automatically rotated and measured to identify center of geometry offset from center of rotation, then moved by a series of controlled manipulations to align the centers. Such a system eliminates the need for part-specific tooling or the inconsistency of manual centering by a skilled operator, reduces the lifetime cost, and creates agility for varied part acceptance with minimal setup effort. Results in both time and accuracy are currently equivalent to the manual process

Application of a Linear Center Identification Scheme to Deterministic Polar Positioning

In a number of manufacturing applications, parts of circular cross-section must be centered for optimal processing or measurement. However, part form is never perfect, making accurate determination of the “centered” state of a part difficult. Imperfect inputs to the manufacturing process such as rough-processed parts, deformation due to heat treatment, or raw formed materials present difficulty in centering by the traditional manual method. This paper presents a filtering and quantification technique for identifying the true center of an imperfect round part through isolation of the lowest polar frequency component. A low-cost device is presented that centers parts based on this frequency domain identification of center

Microstructure Enhanced Sinter Bonding of Metal Injection Molded Part to a Support Substrate

Composites that include a metal injection molded component bonded to a support substrate and methods for forming the composites are described. Methods include forming a metal injection molded green part that includes microstructures on a surface of the green part. The metal injection molded component is located adjacent to a support substrate with the microstructure ends contacting the support substrate at a contact surface. During sintering the metal injection molded component is bonded to the support substrate at the ends of the microstructures. The presence of the microstructures can allow for relative motion between the metal injection molded component and the support substrate during sintering. The large bonding surface area provided by the multiple points of contact between the ends of the microstructures and the support substrate can provide excellent bonding force between the metal injection molded component and the support substrate

Energy Demand Forecasting in an Automotive Manufacturing Plant

Energy analysis is an essential topic within a sustainable manufacturing strategy. To better understand the energy demand in a manufacturing plant, consideration of trends and patterns of energy consumption, and making predictions based on historical data is a promising approach. Time series analysis is a favorable method to be used; because of the rapid development in metering/sensor technology and computational systems, time series analysis can now be deployed on larger-scale systems. However, the application of time series models to manufacturing plant energy modeling is rare due to complexity. This paper augments traditional time series forecasting for manufacturing energy study, with the consideration of data trend and patterns, exogenous influential inputs, and potential overfitting issues. Automotive manufacturing plant electricity demand was used as a study case for the proposed modeling approach validation. In this research, time series analysis is shown to effectively capture the increasing trend and seasonal patterns in the energy demand of a vehicle manufacturing plant. Models with exogenous inputs show a better accuracy as measured by Mean Square Error, and are more robust to sudden deviations

An Investigation of Alternative Path Planning Strategies for Machining of Nickel-Based Superalloys

Nickel-based superalloys play a crucial role in elevated temperature applications where high strength and high resistance to corrosion and creep resistance are required. These environments are largely found in the aerospace, nuclear power and gas turbine industries. Due to the properties that make them suitable for their end use they remain a challenge to manufacture. In the machining of nickel-based superalloys high cutting forces and tool wear occur greatly reducing their machinability. Although there have been multiple recent studies on the machining of such alloys, the field remains vastly unexplored. A limited amount of research has been done in tool path methods, as most previous research focuses on finding optimal machining parameters to curtail the difficulties in machining while keeping the tool path constant. An alternative tool path, trochoidal milling, has been identified to combat the difficulties in machining superalloys and combines linear motion with uniform circular motion, reducing chip load in exchange for increased machining time. Although this method has been shown to reduce flank wear on tools it suffers from notch wear at the depth of cut line

Investigation of Chip Thickness and Force Modelling of Trochoidal Milling

With the ever increasing pressure to reduce processing time and cost, researchers in machining have begun to develop a body of work centered around increasing the throughput of machining operations. While standard toolpaths exist, such as raster and zig-zag, alternative toolpaths have been developed to achieve beneficial kinematics and dynamics for the cutting tool to better achieve high-speed machining conditions. One such toolpath, trochoidal milling, has been identified to decrease machining process time and increase overall tool life. Understanding the undeformed chip thickness produced utilizing trochoidal milling is critical to developing advances in the field. This paper presents a novel approach to modelling the chip thickness of the process for low to medium range cutting speeds. It has been found that the tool path cannot be described as a purely circular path, instead requiring the model of a true trochoid, which is presented in this work. Utilizing efficient, numerical method, the instantaneous chip thickness is solved for and validated experimentally with cutting force measurement, using a semi-mechanistic force model, where the experimental cutting forces find good agreement with the simulated results