Aperture treatment is one of the most important working procedure in metallic cutting treatment, 33% what occupy all metal cutting to machine working procedure about. In automation product line, aperture treatment often is deciding to produce periodic accident. But the structure of itself of common twist drill is put in a lot of unreasonable place, block up of its cutting function rise further. In the meantime, the wide application of all sorts of new-style material gives auger cut treatment to increase a lot of difficulty. Solve the main avenue of these problems, divide outside using new cutting tool data, the geometrical parameter that optimizes cutting tool, method that improving cutting condition is a kind of effective. France " Reynolds " and " beautiful " the 3 obliquitous broach that two big Motor Corporation invent repair face of the knife after grinding to form new horizontal stroke namely blade and advocate cutting blade will improve cutting condition. Broach of hard alloy of the SE that Hertel company puts forward whole, grind special horizontal blade and cutting blade appearance to improve cutting efficiency through repairing. Industry of our country automobile uses more extensive X efficient bit, through grinding short horizontal blade, make horizontal blade point is formed it is certain to have before of horn inside blade, improved cutting position, reduced axial feed force. The broach of these 3 kinds of types rose to get on certain level cut efficiency, but their collective defect is to did not undertake dividing bits effectively. Although axial force is reduced somewhat, but auger cut torque to reduce not apparent, auger there still is more energy in cutting a course waste is cutting bits to be out of shape, produce bigger heat in metal cutting. Graph 1 basic structures of group of the shape that plunge knife group auger integrated a variety of broach are repaired grind a method, have centering good, cut precision of fast, bore force of tall, axial and torque are small wait for an advantage. The graph is shown 1 times for 5 ～ 15mm basic model group the blade shape structure that get. Divide outside repairing the blade that grind a horizontal stroke, this broach is in advocate the slot of circular arc of crescent moon form that gave semmetry is ground on cutting blade, form new horizontal stroke blade and the horn before increasing horizontal sword, improved cutting condition; Form in straight blade and boundary of circular arc blade turn bit of implementation cent bits, straight blade will cut next big pitch when bore banding cut bits, circular arc blade will be cut cut bits curlily. Cent bits is reduced cut bits between pull pull torque, so group auger rose to get greatly cut efficiency. But group auger still put in certain defect: (1) accomplishs blade of left, right cutting very hard when blade is ground complete semmetry, produce bigger radial load in bore process lieutenant general so, broach wears away accelerate and produce Kong Kuo; (2) divides bits completely to come true, two outside blade should grind a certain height to differ H(h ≥ F/2) , such, from theoretic tell complete cent bit group get existence radial load; (3) group get cut bits to be on width one divides into two, but cut bits outside end and inside the rate cutting bits of end is poor still bigger, add when reason cutting be out of shape still very big integrated the advantage of afore-mentioned broach, improve their inadequacy, we offerred a kind of new-style bit. The horizontal blade of new-style broach is repaired grind means and group auger identical, at the same time we adopted the better way that divide bits, make get newly model auger cut function excel group auger, its structure is shown 2 times like the graph. Broach is left circular arc blade is shorter, it is the 1/3 of length of whole cutting blade about, outside blade is longer, it is the 2/3 of length of whole cutting blade about; On the right side of circular arc blade is longer, it is the 2/3 of length of whole cutting blade about, outside blade is shorter, the 1/3; that is length of whole cutting blade about at the same time left outside blade under on the right side of outside blade (high difference should be more than bore feed F, the dotted line in the graph is) of part of right blade tower above. The cutting graph of this broach sees a picture 3, in whole bore process, cutting force distributings symmetrically. When broach just began to contact workpiece, repaired short horizontal blade to have good centering effect; Symmetrical circular arc blade begins to cut work later, because circular arc blade shortens, the width that cut bits is reduced; When the workpiece of the contact that get a tip of two side, blade begins to attend cutting outside, on the right side of broach outside blade prep above is left outside blade, left outside knife is long at on the right side of outside blade, when reason bore on the right side of outside blade is cut only outside round, left outside blade cuts the circuit intermediate only. Visible, the special structure of this broach made sure the semmetry of force of the cutting on cutting blade distributings. Graph 2 get pointed blade form newly to pursue 3 get newly model cutting graph is new-style auger model have the following and main good point: Cut bits to be in advocate the cent on direction of cutting blade width becomes 3 paragraphs, the end outside blade of every paragraphs of cutting and inside the cutting rate difference of end is reduced apparently, reduced cut bits to add be out of shape, reduced cutting torque and reduced broach to wear away. It is in order to optimize the broach of the φ 15mm after exemple, on the right side of outside of blade outside upright radius is 7. 5mm, upright radius is inside 5.
5mm; Left outside upright radius is 5mm outside the edge of action of the cutting since blade, upright radius is 3mm inside; Of blade of circular arc cutting outside upright radius is 3mm, upright radius is inside 0.
75mm. Cut bits outer blade point is thick and narrow big pitch banding, platoon bits is easy, after circular arc blade shortens, show the curly quantity that cut bits to decrease, decreased to cut the dangerous sex that bits jams, because this discharges standard of bits circumstance excel group auger. If blade is ground when blade of two side cutting somewhat error of on any account, won't cause the change that bear of two side cutting changes and affects radial load. The instant that just getting has radial load, and radial load is a balance is in in bore process, this is other broach cannot with what draft. Graph 4 twist drill, group auger, get newly model the relation curve of axial force, torque and feed to prove the function of new-style broach, we undertook common twist drill, basic model group get and new-style broach gets the comparative test that cuts force. Experiment to undertake on Z525 vertical drilling machine, 195r/min of main shaft rotate speed, feed is respectively 0.
10, 0.
13, 0.
17, 0.
22, 0.
28, 0.
36mm/r, workpiece material 45 steel, the device that measure power uses KISTLER to measure power instrument and thin wall barrel type to measure the way that power instrument photograph ties, test result is shown 4 times like the graph. Test result makes clear: Feed from 0.
10 ～ 0.
22mm/r, new-style broach is opposite at twist drill auger cut torque to be reduced respectively 29.
6% , 33.
3% , 22.
5% , 13.
7% ; And opposite Yu Qun is gotten, auger cut torque to be reduced respectively 13.
9% , 21.
7% , 14.
9% , 2.
6% ; Feed from 0.
10 ～ 0.
When 36mm/r, new-style broach photograph was reduced to fighting force at the axial of twist drill 40.
9% , 39.
3% , 36.
3% , 31.
4% , 36.
7% , 36.
9% ; And opposite Yu Qun is gotten, axial fought force to reduce 10.
2% , 16.
9% , 19.
4% , 16.
7% , 14.
6% , 8.
3% . Because group getting is domestic and international established performance is gotten outstandingly model, a few kinds when what its cutting function excel introduces before the article advanced get model, so, this experiment can prove the advanced sex of new-style broach. New-style the blade cross that gets a tip is spent and not be more than a standard group auger, and auger cut function to rise apparently, because this can be popularized energetically,use. CNC Milling
CNC Machining