devices for data conversion

... Incorrect force diagram The bending moment due to the parallel shift of the resultant cutting force is missed in the force diagram As was shown [14], this missed moment is the prime cause for chip formation ... underwent dramatic changes Unfortunately, the validity of the formula has never been verified for these new conditions Nobody proved so far that it is still valid for any other cutting tool materials ... the cutting force is eliminated, inserts are self-locked in the pockets of the holder for an efficient process where the cutting force does not cause excessive bending, buckling and deformations...

Ngày tải lên: 08/04/2014, 11:17

... should be made before selecting the tool for the job The optimum tool is not necessarily the least expensive or the most expensive, and it is not always the same tool that was used for the job last ... elements for either series of high speed tool steels is in abundant supply and the cost of these elements is skyrocketing In addition, U.S manufacturers must rely on foreign countries for supply ... usually cobalt (Co) is added to the tungsten (WC) in powder form and these two are ball milled together for a period of several days, to form a very intimate mixture Careful control of conditions,...

Ngày tải lên: 17/12/2013, 11:15

... operation, tangential force is the highest of the three forces and accounts for about 98 percent of the total power required by the operation Longitudinal Force: Longitudinal force acts in the direction ... direction is negligible Tangential force Longitudinal force Radial force FIGURE 2.3Typical turning operation showing the forces acting on the cutting tool 2.3 Chip Formation and Tool Wear Regardless ... Force: Radial force acts in a radial direction from the center line of the workpiece The radial force is generally the smallest of the three, often about 50 percent as large as longitudinal force...

Ngày tải lên: 17/12/2013, 11:15

... to forces and power consumption, and the overhead cost of a machine of proper capacity When using tool forces as a machinability rating, either the cutting force or the thrust force (feeding force) ... For example, aluminum is a very lightweight metal (1/3 the density when compared to steel), yet it possesses great strength for its weight Therefore, aluminum has been an excellent material for ... exponent n has values ranging from 0.125 for high speed steel (HSS) tools, to 0.70 for ceramic tools Tool Forces and Power Consumption: The use of tool forces or power consumption as a criterion...

Ngày tải lên: 17/12/2013, 11:15

... the need for material handling and setting the part in the grinder However, work holding devices for large and slender workpieces for hard turning can present problems, since the cutting forces ... revolutions per minute, some means must then be available for converting surface speeds into revolutions per minute (RPM) The common formula for conversion is: SFPM = D× × (RPM) 12 where D is the diameter ... distortion It is therefore, very important to take the necessary time and effort to ensure that the set-up is as rigid as possible for (a) the type of operation to be performed This is especially...

Ngày tải lên: 17/12/2013, 11:15

... machine Single-spindle autorequired for the next part to be run matic lathes perform turning, facing, DeVlieg tooling for a single- or mul- chamfering, grooving, and forming opertiple-spindle automatic ... before adjustments are stops Ram necessary These machines are normally used for small to medium sized production runs where the engine lathe is too slow but the additional production rate Forward ... feed Compound Rest: The compound rest, or compound for short, is mounted on the carriage It can be moved in and out by its handwheel for facing or for setting the depth of cut It can also be rotated...

Ngày tải lên: 17/12/2013, 11:15

... Emeritus Engineering Technology Lawrence Technological University Former Chairman Detroit Chapter ONE Society of Manufacturing Engineers Former President International Excutive Board Society of Carbide ... shaper is a relatively simple machine It is used fairly often in the toolroom or for machining one or two pieces for prototype work Tooling is simple, and shapers not always require operator attention ... the ram on a circular plate so that it can be rotated for making angular cuts The toolhead can also be moved up or down by its hand crank for precise depth adjustments Attached to the toolhead...

Ngày tải lên: 17/12/2013, 11:15

... mounted sensitive drill used for drilling small holes (Courtesy Clausing Industries, Inc.) made of gray cast iron or ductile iron for larger machines, or steel tubing for smaller bench drill presses ... uniform and extremely long workpieces and for hole diameters greater than 7.875 inches The Ejector System requires no seal between the workpiece and the drill bushing The system can therefore ... pressure needed for efficient cutting A table mounted sensitive drill press is shown in Figure 9.3 The drill press has the same motions as the previous one plus a telescoping screw for raising and...

Ngày tải lên: 25/12/2013, 23:17

... tan- wear Edge wear means that the geomgential force will try to etry of the insert is changed, force the resulting in a reduction in the Therefore, with tool down- clearance angle wards and ... cutting force will be standing how cutting forces are tool and workpiece and the friction virtually double that of the cutting affected by the tool geometry and can give rise to vibration In those force ... kept to a minimum and edge angle is small, a 10.3 Cutting Forces On engagement, the tangential force s h a r p e r and the radial cutting force will at- c u t t i n g FIGURE 10.3: Typical indexable...

Ngày tải lên: 25/12/2013, 23:17

... except that it is through it for a bolt to secure it to the milling cutters are usually indexable used for higher rates of metal removal spindle (Fig 12.3) Form Mill: A form mill is a periphand will ... cutting flutes, or of the extra long type for reaching into deep cavities On end mills designed for effective cutting of aluminum, the helix angle is increased for improved shearing action and chip ... cutter body wear, and secondly, high clamping forces causing clamping element and cutter body deformation can and often will result The excessive clamping forces can cause enough cutter body distortion...

Ngày tải lên: 25/12/2013, 23:17

... Vertical machining centers are often preferred for flat parts that must have through holes Fixtures for these parts are more easily designed and built for a vertical spindle Also, the thrust of the ... possibility of chatter Because of the time and effort involved in setting up the milling machine for gang milling, the process is used mainly for production work Since all or almost all of the ... Special Purpose circular slide above it is graduated in Milling Machines degrees for a small portion of its pe- can be used for both vertical and hoririphery The upper portion of the zontal milling...

Ngày tải lên: 25/12/2013, 23:17

... machine for the job The type of drive, hydraulic or electromechanical, is another important factor in machine selection So are convertibility and automation Some machine designs allow for conversion ... narrow the field For internal broaching, the length of a broach in relation to its diameter may determine whether it must be pulled rather than pushed through the workpiece, for a broach tool ... pull types, to simple presses Figure 14.8 shows a variety of forms that can be produced by internal broaches FIGURE 14.8: A variety of forms that can be produced with an internal broach Keyway Square...

Ngày tải lên: 25/12/2013, 23:17

... screens used for sizing Very fine grits are used for polishing and lapping operations, fine FIGURE 16.6: ANSI standard marking system for abrasive grinding wheels (United abrasives manugrains for fine ... and manufactured Natural diamond is a crystalline form of carbon and very expensive In the form of bonded wheels, natural diamonds are used for grinding very hard materials such as cemented carbides, ... mounted on a machine To test for damage, suspend the wheel with a finger and gently tap the side with a screwdriver handle for small wheels, and a wooden mallet for larger wheels An undamaged...

Ngày tải lên: 25/12/2013, 23:17

... separate definitions for an external thread (screw or bolt) and an internal thread (nut) An external thread is a cylindrical piece of material that has a uniform helical groove cut or formed around ... Reaming is performed using the same types of machines as drilling A reamer is a rotary cutting tool with one or more cutting elements used for enlarging to size and contour a previously formed hole ... usually on finish, and a coolant is normally chosen for this purpose rather than for cooling 11.2.4 Reaming Operations Reaming operations can be performed on lathes, drills, and machining centers...

Ngày tải lên: 25/12/2013, 23:17

... chip clearance, plus the drill point Toolholders: Toolholders for hand tapping are called ‘tap wrenches’ They are the same for taps and for reamers (see Fig 11.7 and Fig 11.13), because most taps ... spiral-fluted bottoming tap ‘cold form’ the metal (Courtesy: Morse Cutting Tools) out of the wall of the steel They are made in all sizes up to hole into the thread form with no 1-1/2 inches and ... as other styles, however, the size of the hole drilled before tapping must be no larger than the pitch diameter of the thread The cold-formed thread often has a better finish and is stronger than...

Ngày tải lên: 25/12/2013, 23:17

... can potentially be used for the examination of phenotypic data available from hepatitis C virus (HCV) experiments [19, 21] For example, RNAMute was able to single out a conformational rearranging ... pJ697 RNA [22] Subdomain (boxed) is the region of interest for investigating conformation rearrangements that are thought to be responsible for the inactivation of spectinomycin resistance in E coli ... RNAfold) for each of the N × single-point mutants, since for each nucleotide there are possible mutations Extract the tree T corresponding to the secondary structure of each mutant in the form of...

Ngày tải lên: 22/06/2014, 23:20

... plastic deformation Sometimes, the HSS tool edge is loaded beyond its yield strength and deforms by large-scale plastic deformation, see Fig 8, resulting in edge blunting a) Fig 6.4 b) Plastic deformation ... a high temperature during chip formation High temperatures reduce the strength of the HSS tool, but will also facilitate chemical reactions and possibility to form intermetallic phases between ... Generally, the over all cutting force F is related to cutting speed and feed as indicated in Fig It is indicated that a low friction coating can lower the cutting force and thereby giving a lower...

Ngày tải lên: 07/07/2014, 21:21

... Emeritus Engineering Technology Lawrence Technological University Former Chairman Detroit Chapter ONE Society of Manufacturing Engineers Former President International Excutive Board Society of Carbide ... base These vehicles hold the abrasive in suspension before and during use The paste abrasives are generally used in handlapping operations For machine lapping, light oil is mixed with dry abrasive ... as shown in Fig 18.4 This rotation performs two jobs First it ‘conditions’ the plate, that is, it distributes the wear so that the lapping plate stays flat for a longer time Secondly, it holds...

Ngày tải lên: 21/07/2014, 15:20

... Thus near-net shape castings and forgings are suitable parts for creep-feed grinding Although generally one pass is sufficient, a second pass may be necessary for improved surface finish 17.4 ... castings, forgings, and welded fabricaCrossfeed tions These grinding machines are Crossfeed Infeed Infeed available in various sizes and have up to 225-HP motors to drive the spindle Work Holding Devices: ... adjusted for depth of cut An internal grinding operation with a steady rest is shown in Figure 17.14 17.2.5 Special Grinding Processes Special types of grinders are grinding machines made for specific...

Ngày tải lên: 21/07/2014, 15:20