Production Engineering Lecture 6 PDF

FACULTY OF APPLIED ARTS PRODUCT DESIGN DEP. LEVEL : 1 COURSE TITLE : PRODUCTION ENGINEERING ASSISTANT PROF. : M.MOHAMED RYEAD LECTURE : 6  2- chip forming cutting ❑ chip forming cutting refers to the separation or reduction of a material by the...

FACULTY OF APPLIED ARTS PRODUCT DESIGN DEP. LEVEL : 1 COURSE TITLE : PRODUCTION ENGINEERING ASSISTANT PROF. : M.MOHAMED RYEAD LECTURE : 6  2- chip forming cutting ❑ chip forming cutting refers to the separation or reduction of a material by the removal of chips. ❑ the cutting tool is harder than the work piece or material to be cut. ❑When cutting achieves tolerances of at least ±0.005" it is called machining. ❑In machining, the workpiece and cutting tool are held in a precise relationship to achieve the desired cut within the required tolerance. ❑The speed, feed, and rate of cutting along with the proper coolants and lubricants are important economical and tool-life considerations in machining cut materials. ❑ Machining is usually a secondary process following a forming process but usually precedes finishing and joining processes.  2-1- Machining and Turning Centers ❑ A machining center is designed to bring numerous cutters to the workpiece rather than bringing the workpiece to each machine. ❑ The major advantage is that a machining center eliminates the extensive set-up repositioning, each time a part is moved. ❑ The old method increased the possibility of error and delayed the actual cutting time while the part was moved. ❑ These computer-controlled machining centers, with fully automated tool changing capability, are designed to perform a variety of cutting operations on up to five surfaces without moving or repositioning. ❑ Turning centers are computer controlled lathes that can have dual turrets with twin turret changers. ❑ A part-turning program can equip and exchange complete sets of tooling in fewer than 30 seconds, a job that formerly required one or more hours to ❑ Some turning centers provide immediate on- machine access to as many as 48 turning tools, which can perform all operations for most parts. ❑ The largest machines are designed for maximum productivity on both spindles, whether turning both ends of a single part or machining two dissimilar parts simultaneously. 2-1-1 - Lathe / Turning ❑A lathe is used to turn cylindrical solid and hollow shapes, as well as threads and similar forms, along the axis. ❑In this process, the workpiece, held in a chuck, rotates as a cutter, held in a tool assembly called a compound tool rest, controlled by an operator. ❑Today, turning centers are automated and fitted with turret heads with up to eight cutting tools each. ❑There are also special-purpose lathes for spinning and large-diameter parts. Operations 3-1-2 - Mill (Bridgeport) ❑ A vertical mill looks like a drill, and in principle it works a bit like one except that it has much more flexibility in its axis of cutting and workpiece movement. ❑The head can be tilted in a number of positions and the cutting table can be finely adjusted in the XYZ axes to tolerances of plus or minus five thousandths (±0.005) of an inch. ❑ A horizontal mill is somewhat similar to a vertical mill except that is designed for extended horizontal milling. ❑Traditional mills are still being used for limited jobs such as design and repair of tooling, as well as in small model shops. A horizontal mill Producing a Prototype with a Milling Machine 2-1-3- Grinding Grinding disc examples Grinding processing examples 2-1-5- Drill Drilling, one of the most common machining processes, employs the twist drill bit as a cutting tool. The twist drill is used to cut holes in a workpiece in one axis.  Common Types of Manufacturing Drill Bits ❖Wood Drill Bits These types of drill bits can be used on any wood including; softwood, hardwood, veneer and plywood because they have one central point that has a high cutting capacity for any wood material. ❖Metal Drill Bits These types of drill bits are used to drill any metal, and they have a benefit since they can also be used to drill holes in wood materials. ❖Concrete Drill Bits These drill bits are made up of a steel shaft and an embedded carbide spear joint that is brazed into them. Their tips are made up of carbide and designed to be much thicker so as to withstand high resistance from concrete walls. ❖Tile and Glass Drill Bits In shape, these drill bits look like small spears. When using these types of drill bits, the glass size and material is a factor of consideration but low speed of drilling is a common aspect of these types of drill bits. 2-1-6- Saw Sawing is often used to cut stock to length for other cutting operations. Most industrial machines are capable of cutting to ±0.005 inch and are essential manufacturing tools. The two basic types of sawing are reciprocating and circular. Circular sawing is divided into a continuous band and the disc blade. The appropriate machine and cutting blade are chosen for their type and thickness or the shape of the material to be cut. Circular sawing disc blade sawing reciprocating Circular sawing continuous band 2-1-7- Bore A boring machine is used to finish-cut circular internal profiles in hollow workpieces or on a hole made by casting or other processes. It is somewhat similar to the turning process. Boring bars are made with vibration-dampening capabilities. Boring machines were originally designed for the internal finish of a cannon barrel. The term bore refers to the process that gives a gun barrel internal spiral configuration and sets the internal diameter and finish on the gun barrel.