Machining Processes PDF

Machining Processes Sawing, Broaching, Shaping, and Filing Machining Processes Dr.-Ing. Amr Nounou Introduction to Sawing Sawing is a basic machining process in which chips are produced by a succession of small cutting edges, or teeth, arranged in a narrow line...

Machining Processes Sawing, Broaching, Shaping, and Filing Machining Processes Dr.-Ing. Amr Nounou Introduction to Sawing Sawing is a basic machining process in which chips are produced by a succession of small cutting edges, or teeth, arranged in a narrow line on a saw “blade.” Each tooth forms a chip progressively as it passes through the workpiece. Progressive formation of chips in sawing The chips are contained within the spaces between successive teeth until the teeth pass from the work. Sawing, Broaching, Shaping, and Filing Machining Processes Source: DeGarmo's Materials and Processes in Manufacturing, 13th Edition, Wiley, 2019. 2 Dr.-Ing. Amr Nounou - Winter 2024-2025 Introduction to Sawing Saw Blades Saw blades are made in three basic configurations; - Hacksaw blade, is straight, relatively rigid, and of limited length, with teeth on one edge. - Bandsaw, is sufficiently flexible that a long length can be formed into a continuous band with teeth on one edge. - Circular saws (or cold saws) a rigid disk having teeth on the periphery. Sawing, Broaching, Shaping, and Filing Machining Processes Source: DeGarmo's Materials and Processes in Manufacturing, 13th Edition, Wiley, 2019. 3 Dr.-Ing. Amr Nounou - Winter 2024-2025 Types of Sawing Machines Power Hacksaws Power hacksaws are machines that mechanically reciprocate a large hacksaw blade. These machines consist of a bed, a workholding frame, a power mechanism for reciprocating the saw frame, and some type of feeding mechanism. Because of the inherent inefficiency of cutting in only one stroke direction, they have often been The power hacksaw blade reciprocates and replaced by more efficient, horizontal uses gravity or hydraulic pressure to feed the saw bandsawing machines. through the workpiece. (Courtesy J. T. Black.) Sawing, Broaching, Shaping, and Filing Machining Processes Source: DeGarmo's Materials and Processes in Manufacturing, 13th Edition, Wiley, 2019. 4 Dr.-Ing. Amr Nounou - Winter 2022-2023 Types of Sawing Machines Bandsawing Machines To a large degree they were made possible by the development of vastly better and more flexible bandsaw blades and simple flashwelding equipment, which can weld the two ends of a strip of bandsaw blade together to form a band of any desired length. Contour bandsawing on vertical bandsawing machine, shown in inset. (Courtesy J. T. Black.) Sawing, Broaching, Shaping, and Filing Machining Processes Source: DeGarmo's Materials and Processes in Manufacturing, 13th Edition, Wiley, 2019. 5 Dr.-Ing. Amr Nounou - Winter 2024-2025 Types of Sawing Machines Circular-Blade Sawing Machines Machines employing rotating circular or cold saw blades are used exclusively for cutoff work. These range from small, simple types, in which the saw is fed manually, to very large saws having power feed and built-in coolant Circular sawing a structural shape on the left. Examples systems, commonly used for cutting off hot- of circular saws (left to right): an insert tooth, a rolled shapes as they come from a rolling mill. segmental tooth, and an integral-tooth circular saw blades on the right. (Courtesy J. T. Black.) Sawing, Broaching, Shaping, and Filing Machining Processes Source: DeGarmo's Materials and Processes in Manufacturing, 13th Edition, Wiley, 2019. 6 Dr.-Ing. Amr Nounou - Winter 2024-2025 Introduction to Broaching The process of broaching is one of the most productive of the basic machining processes. The machine tool is called a broaching machine or a broach, and the cutting tool is also called the broach. Broaching competes economically with milling and boring and is capable of producing precision-machined surfaces. The broach finishes an entire surface in a single pass. Broaches are used in production to finish holes, splines, and flat surfaces. Typical workpieces include small to medium-sized castings and forgings. Sawing, Broaching, Shaping, and Filing Machining Processes Source: DeGarmo's Materials and Processes in Manufacturing, 13th Edition, Wiley, 2019. 7 Dr.-Ing. Amr Nounou - Winter 2024-2025 Introduction to Broaching The pull end of the broach is passed through the part, and a key mates to the slot. The broach is pulled through the part. The broach is retracted (pulled up) out of the part. The part is transferred from the left fixture to the right fixture. One finished part is completed in every manufacturing cycle. Vertical pull-down broaching machine shown with parts in position ready for the two broaches to be inserted. An extra part is shown lying at the front of the machine. (Courtesy J. T. Black.) Sawing, Broaching, Shaping, and Filing Machining Processes Source: DeGarmo's Materials and Processes in Manufacturing, 13th Edition, Wiley, 2019. 8 Dr.-Ing. Amr Nounou - Winter 2024-2025 Introduction to Broaching (a) Photo of pull broach. (b) Basic shape and nomenclature for a conventional pull (hole) broach. Section A–A′ shows the cross section of a tooth. P = pitch; nr = number of roughing teeth; ns = number of semifinishing teeth; nf = number of finishing teeth. (Courtesy J. T. Black.) Sawing, Broaching, Shaping, and Filing Machining Processes Source: DeGarmo's Materials and Processes in Manufacturing, 13th Edition, Wiley, 2019. 9 Dr.-Ing. Amr Nounou - Winter 2024-2025 Introduction to Shaping and Planing From a consideration of the relative motions between the tool and the workpiece, shaping and planing both use a straight- line cutting motion with a single-point cutting tool to generate a flat surface. In shaping, the workpiece is fed at right angles to the Basic geometry for shaping and planing cutting motion between successive strokes of the tool where fc is the feed per stroke, V is the cutting speed, and d is the depth of cut (DOC). In planning the workpiece is reciprocated and the tool is fed at right angles to the cutting motion. Sawing, Broaching, Shaping, and Filing Machining Processes Adapted from the source: DeGarmo's Materials and Processes in Manufacturing, 13th Edition, 10 Wiley, 2019. Dr.-Ing. Amr Nounou - Winter 2024-2025 Introduction to Shaping and Planing The most widely used shaper is the Shaper machine tool horizontal push-cut machine tool, shown here with no tool in the tool post. (Courtesy J. T. Black.) Sawing, Broaching, Shaping, and Filing Machining Processes Adapted from the source: DeGarmo's Materials and Processes in Manufacturing, 13th Edition, 11 Wiley, 2019. Dr.-Ing. Amr Nounou - Winter 2024-2025 Introduction to Shaping and Planing Schematic of planers: (a) double-housing planer with multiple tool heads (4) and a large reciprocating table; (b) singlehousing or open-sided planer; (c) interchangeable multiple tool holder for use in planers. (Courtesy J. T. Black.) Sawing, Broaching, Shaping, and Filing Machining Processes Source: DeGarmo's Materials and Processes in Manufacturing, 13th Edition, Wiley, 2019. 12 Dr.-Ing. Amr Nounou - Winter 2024-2025 Introduction to Shaping and Planing Shaping has largely been replaced by milling and broaching as a production process. Planing can be used to produce horizontal, vertical, or inclined flat surfaces on large workpieces (too large for shapers). Consequently, planing and planers have largely been replaced by planer milling machines or machines that can do both milling and planing. Sawing, Broaching, Shaping, and Filing Machining Processes Source: DeGarmo's Materials and Processes in Manufacturing, 13th Edition, Wiley, 2019. 13 Dr.-Ing. Amr Nounou - Winter 2024-2025 Filing Basically, the metal-removing action in filing is the same as in sawing, in that chips are removed by cutting teeth that are arranged in succession along the same plane on the surface of a tool, called a file. There are two differences: (1) the chips are very small, and therefore the cutting action is slow and easily controlled and (2) the cutting teeth are much wider. Consequently, fine and accurate work can be done. An experienced operator can do very accurate work by hand Four types of teeth (cuts) used in files. filing, but it can be a difficult task. Left to right: single, double, rasp, and curved (vixen). (Courtesy of Nicholson File Company.) Therefore, filing machines have been developed that permit quite accurate results to be obtained rapidly and with much less effort. Sawing, Broaching, Shaping, and Filing Machining Processes Source: DeGarmo's Materials and Processes in Manufacturing, 13th Edition, Wiley, 2019. 14 Dr.-Ing. Amr Nounou - Winter 2024-2025 Filing Machines Band-filing machines provide continuous cutting action. Most band filing is done on contour bandsawing machines by means of a special band file that is substituted for the usual bandsaw blade. Rigid, straight file segments, about 3 in. long, are riveted to a flexible steel band near their leading ends. One end of the steel band contains a slot that can be hooked over a pin in the other end to form a continuous band. A band-filing machine (a) uses segments (b) that are rivited to a steel band (c) to provide a continuous file for finishing wack. (Courtesy of DoAll Co.) Sawing, Broaching, Shaping, and Filing Machining Processes Source: DeGarmo's Materials and Processes in Manufacturing, 13th Edition, Wiley, 2019. 15 Dr.-Ing. Amr Nounou - Winter 2024-2025 Enhance your German terminology … English term German term Sawing Sägen Blade Klinge Tooth Zahn Sawing, Broaching, Shaping, and Filing Machining Processes 16 Dr.-Ing. Amr Nounou - Winter 2024-2025  Thank you for your attention... Sawing, Broaching, Shaping, and Filing Machining Processes 17 Dr.-Ing. Amr Nounou - Winter 2024-2025