Use correctly of small diameter broach

The broach of 175mm, call normally small auger. Should make small get in use play is efficient, must consider a series of factors: The structure of the perfect sex of parameter of each element that is like broach itself, treatment, hole depth, installation and workpiece. Want a these mutual influences to cut the element with very sensitive process to had been handled to getting again, need has scientific innovation mind. Guhring(United States) the Mark Megal of market department manager of the company says: "In a lot of circumstances, use small get you to get an edge to consider the edge works. " although at present tool manufacturer has been in small the data that get and geometrical parameter respect completed a lot of development, do not need every thing to experiment from the beginning, but should auger in cutting a course, a lot of element tries very good control, still not be a simple work. Small the long way that get is more well-known than be being increased significantly, of the length of broach and diameter bigger than jumping over, its curve the tendency to increase. Reduce long way to compare, can reduce bending force, avoid broach to break off to be increased with bore diameter error thereby. Deeper aperture asks broach has older long way to compare. Normally hole depth exceeds 3 times diameter is " deep aperture " , and small the hole depth that get should exceed this limit commonly. It is like the diameter 3.

The broach of 175mm machines hole depth 31.

The aperture of 75mm, grow diameter comparing to amount to 10:1; And the diameter is 0.

The broach of 508mm machines hole depth 25.

The aperture of 4mm, its grow diameter comparing to achieve 50: 1. So, reduce the addition with brittleness as broach diameter, bending becomes the source that produces a lot of problems. And the brittleness that controls bit, be about to try between the hardness of cutting tool matrix and tenacity balance. Say commonly, high-speed steel broach is concessional have certain deflection and can bear to curve force accordingly, but, this kind of flexibility that high-speed steel has is out of shape ability and inferior hardness, also make its wearability is reduced, restricted the life of cutting tool thereby. And hard alloy has tall tigidity and tall hardness, can make cutting tool life longer so, treatment precision is taller. M.

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Of Ford production company auger cut Joe Kueter of manufacturing department manager to point out, the speed after the tall wearability of hard alloy makes its make Cheng Wei get achieves 3 times of high-speed steel, and life also can rise; In the meantime, the tall tigidity of hard alloy conduces to correct fixed position and the measure that maintain aperture. However, hard alloy also is not all-purpose, tigidity can make its burst apart easily high. The spot of Guhring company sells engineer Peter Jones to point out, with M35 cobalt high-speed steel does miniature bit, can mix in hard alloy common high-speed steel (it is better to be obtained between M2, M7) eclectic. He says: "In Kong Zhong generation is heated up when cutting, the Zhan that adds cutting tool is pressed, make cutting blade becomes blunt, and lay off raceway groove, cause tool damage finally. And the higher volume that contain cobalt, make the heatproof sex of M35 increases, and can longer hold edge sharp. " in addition, hard alloy broach needs to be installed carefully and be used, accurate homocentric it is particularly important to spend, the side direction bear that because differ,the heart creates can bring about broach to burst apart. Stuff of metal of 3 water chestnut (the United States) the milling of the company and auger cut a proposal of Larry Brenner of high production manager: The machine tool that should rotate in broach as far as possible (like machining center) on use small auger, he points out, the main shaft of machining center can give broach correct central line fixed position, and the prejudicial meeting of the workpiece on lathe brings about broach bending. Accordingly, if be used on lathe small auger, must affect every homocentric spent element preset is good, should notice more to hard alloy broach particularly, because its cannot suit,bend be out of shape. If be used on lathe small auger, had better turn cutting tool the installing hole of the tower is new boring one knife, and use adjustable type bores hole knife clip, so that mix bit of workpiece homocentric spend shift to groove. Brenner points out further, what should place the knife is jumpy fall to minimal. For this, should clip of knife of sex of first selection shrink, it is clip of hydraulic pressure knife next. The greatest jumpy value that end panel of canister of requirement knife chuck manages is in 0.

005 ～ 0.

Inside 0076mm limits. Eliminate initiative centering error when any broach work, begin a few turn crucial. Because begin cutting when, broach bears prejudicial force. In addition, the irregular appearance of workpiece surface can cause transverse glissade, bring about cutting tool to bend, break off, perhaps be the deviation that increases opening at least. To the broach under diametical 3mm, the centering that company of 3 water chestnut suggests it is good to use tigidity first is gotten hit a deepness to be 1 ～ the initiative aperture of 2 times diameter. What the vertex angle getting a tip that centering gets should is equal to or be more than final bore is small get vertex angle. If the vertex angle of centering getting is lesser, criterion subsequently small auger cut fashionable, two cutting blade contacts workpiece first than the tip, cause collapse blade easily. If need not centering getting, can use such method: Make small auger begin to cut fashionable feed far under subsequently normal feed. For example broach diameter 1.

613mm, hole depth 12.

7mm, normal feed gauge is surely 0.

0508mm/r, begin to use 0.

The feed of 0127mm/r is advanced 0.

254mm, also can advance first flank to begin to contact workpiece, turn again next for normal feed. This kind of method can prevent broach glissade likewise. Brenner points out, small getting the another challenge in using is to want to increase rotate speed as far as possible, in order to develop manufacturing latent capacity, but standard of the biggest rotate speed, broach often goes in front of of the machine tool. Some machine tools are in its move below top rotate speed, still did not achieve small the optimal cutting rate that get. For example the broach that the diameter is 1mm, cutting speed is achieved 91.

44m/min, rotate speed of main shaft of requirement machine tool achieves 28000r/min. By the hardness of treatment material, small to deciding those who get cutting speed and feed is initiative recommend a value to have very big effect. For example, m.

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Ford company recommends: It is with the diameter 1.

The broach of integral hard alloy of 32mm processes 1018 mild steel (when 20HRC) , its cutting speed is chosen 91.

44m/min, feed is chosen 0.

038mm/r. But this broach treatment is plastic when expecting with synthetic material, cutting speed can be amounted to 198.

12m/min, feed is amounted to 0.

127mm/r. Material of treatment difficult treatment (be like nickel radical alloy, titanium alloy) when, cutting speed is only 15.

24 ～ 18.

29m/min, feed is only 0.

0305mm/r. Alignment of the bore that divide a pace normally, auger cut miniature deep aperture to introduce series of the bore that divide a pace, namely periodic exit broach, so that break off,cut bits, prevent to jam. The bore that divide a pace also conduces to prevent to squash continuously in hole bottom, this are being machined cold when making sclerotic material, weigh particularly should. Brenner points out, think the cutting that divide a pace has to retreat bit completely commonly, actually otherwise. If use,interrupt feed (a few turn or short when) , can break bits likewise. Additional, exit broach completely to produce a horn easily still mouth and cut the share bits to stay inside aperture, must be opposite so its again cutting. These circumstances do not hope to appear. What a lot of questions often happen in bore deepness is final 20% this paragraph inside. Brenner points out, because,this is as aperture deepen gradually, the reason be caused by with the very difficult eduction that cut bits. Specific settlement method reachs the state of material because of workpiece and different. Applied engineer should define program of the cutting that divide a pace by particular case. Speak of those who machine circuit board is small auger, although pledge from broach material with the diameter bulk looks, what be used at processing tenacity data with the design is small get ten split phase to be like, but, both cutting geometry parameter has very big difference however. M.

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The Kueter of Ford company points out, although pass careful installation to debug, circuit board broach also can be used at processing harder data, but Ford company is average not so do, elaborate preparation applies to would rather the special broach of tenacity workpiece material. An important way is to shorten as far as possible groove is long, in order to increase the strength of broach. Kueter returns special specification, the user asks to get cut 25.

The deep aperture of 4mm, but the broach chamfer that we offer grows to must be not achieved 25.

4mm, offer groove to grow commonly for 9.

525mm or 12.

The broach of 7mm can. Kueter points out, some of circuit board broach is made alleged " petiole of type of a flight of stairs. " for example, a diameter is 0.

The broach of 1524mm, auger cut hole depth for 1.

524mm, groove also is made endlong 1.

524mm, but diameter of broach job section does not join from groovy end directly diameter 3.

The petiole of 175mm, pass however 0.

The diameter tries to transfer among 762mm. Think to this Kueter, get when cutting tenacity material, broach extends length to answer as far as possible short, add a paragraph to transfer so diametical structure cannot be taken. Kueter still points out, from the point of the angle of geometrical parameter, circuit board broach uses bigger helix angle normally, groove is sectional dimension also relatively other is small get thin. And what process data hard to machining stainless steel and other is small auger, use lesser helix angle and thicker groove sectional dimension. He still points out, to reduce small the stress that gets, make drill -- direction of straight radial petiole is reduced -- it is very necessary. Quantity pouring awl is commonly 0.

005 ～ 0.

127mm. Because broach chamfer is long,often be less than 25.

4mm, so every 25.

On 4mm length pour awl to be normally 0.

0127 ～ 0.

0254mm. Kueter emphasizes, want bore to have depth only, pour taper with respect to need. In waiting for treatment to titanium alloy especially, appear " time shrink " material, if did not pour taper appropriately, broach will is by cementation in aperture. When Kueter introduced an user to machine to overcome titanium alloy " time shrink " distinctive method of the phenomenon: The bit that requirement tool works supplies gets a needle to be in radial to beat be in tolerancepublic errand upper limit, such outspread when bore amounts are larger, workpiece " time shrink " unapt also hold broach in arms. Good practice proves cooling effect inside, use inside the productivity that deep to rising aperture machines cooling broach is very effective. Its advantage depends on sending the part that get a tip cutting juice directly not only, have cooling effect, and the effect that still can produce compulsive platoon bits and help to break bits. When hole depth is more than 3 times diameter, use inside its effect is more apparent when cooling broach is machined, but up to now, cool inside broach often the broach of above of 3mm of diameter of be confined to. The Colin ELdon of countrywide selling manager of company of CooL Jet system says, use HPC(high pressure correctly to cool) system, can improve productivity greatly. He reviews the real case of an user: Broach diameter 1.

397mm, hole depth 13.

335mm, workpiece material is 302 stainless steel. Use groovy refrigeration before (pressure is 4 atmosphere) , use bit of cobaltic high-speed steel, rotate speed is 1600r/min, odd a man-hour 42 seconds, broach life 175. Use double broach to machine new technology later: Above all, centering of hard alloy of the MZE that uses firm of 3 water chestnut whole is gotten, without refrigeration, rotate speed is 6000r/min, feed 0.

0254mm/r, centering hole depth 2.

54mm. The 2nd pace, use MZS of company of 3 water chestnut model inside refrigeration is small auger, rotate speed 9000rpm, feed 0.

0203mm/r, condition of the cutting that divide a pace is chief 1.

397mm, cooling fluid pressure amounts to 102 atmosphere. The sheet of two broach treatment man-hour come 16.

5 seconds (economic man-hour 60%) , cutting tool life increases 875. Score so huge gain, price rises for charge of cutting tool of every spare parts only 3.

3% . The Brenner of company of 3 water chestnut introduces, 1mm of diameter of this company production comes of 3mm small auger, cooling pressure achieves 68 atmosphere at least, change along with size of two on broach tiny and cooling hole. The smallest diameter is cooling aperture 0.

1524mm, use at the diameter the least bit. To ensure sufficient cooling current is measured, must assure to have enough pressure. To large size broach, cooling aperture diameter is achieved inside 1.

524mm, below 68 atmosphere, discharge of its cooling fluid is amounted to 16.

4 litres / cent, and fall in same pressure, with small auger get the cooling fluid discharge when cutting to be only 1.

89 litres / cent. Company of 3 water chestnut returns a proposal: Cooling system should filter drops measure small the particle to 5 micron; Use nicety filters set, use no matter inside sealed or outside sealed, should keep sealed in 68 atmosphere. Suggest to use water-solubility cooling fluid, take EP kind additive, be like sulfur, chloric etc. The 8 ～ that are water as a result of oily viscosity 10 times, should not be so use. M.

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Of Ford company newest production inside refrigeration is small get set (1mm) of the smallest diameter, increased to get core increment, this conduces to assure broach intensity. Cooling helix Kong Guan is worn inside get system, the position but the forehead of chamfer of press close to or back.  this company is dedicated at developing broach of the refrigeration inside small helix angle, outside because it conduces to,cutting bits eduction hole. Kueter points out, cooling broach should reduce number of the cutting that divide a pace greatly inside, machining cold be like,make sclerosis material 304 or when 316 stainless steel especially important. Alveolus brings company of accurate product of big challenge Starro is one pursues Swiss style thread machining and the company that other treatment serves. Cool inside small the applied respect that get and M.

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Ford company has clasp. The sale of this company and production vice-president Lee Dwyer point out: "Must know, the cooling fluid that you choose and angle of cutting tool geometry can bring what result. " be in even if maintain of Starro company extraordinary in the public errand on certain production process in ± 0.

005mm. Dwyer points out, show some getting to cut data, use at the circumstance that broach rotates normally, so Starro company must develop a lot of applying to by oneself of helix machine tool and machining center small get applied order. Dwyer points out: Centering is trick, must make the machine tool is in kilter, main shaft radial is jumpy should be less than 0.

0025mm; Cool inside small the main good point that plunge is to be able to raise cutting tool life and cutting rate. With need not the photograph of hard alloy broach of cooling fluid is compared, the cutting tool life of cooling broach raises 3 times inside, cutting rate rises 30% , specific along with workpiece material different. Small to long-term application the circumstance that get, try to optimize to each element of whole cutting system appear important all the more. Of Kyocera Tycom company industrial Tom Krueger of selling manager of whole nation of branch of miniature cutting tool points out: To small lot production, can use the standard tool with low price. But produce to the big batch of specific product, manufacturing workshop should undertake analyse and be optimizinged to whole process flow. To some kind of specific workpiece data, use parameter of the appropriative broach, geometry that get a tip, chamfer the diameter of long, helix angle and petiole and length, can obtain first-rate to use the effect. If undertake serious analysis to using the machine tool of broach again, will make productivity rises further. Krueger lists an example: On a special machine tool, it is with one diameter 0.

The broach of 0381mm processes a kind of stainless steel medical spare parts, the rotate speed of workpiece and cutting tool all is 5000rpm, rotate reversely. Because accept proposal of Kyocera Tycom company, undertake improvement to machining a process, what make a machine tool like tone is homocentric degree, result productivity twice rises. Carry out a proof, want to improve productivity, have to spend time, money, add active job. For example Starro company undertook throwing in equipment and manufacturing process respect, begin a series of small the research that gets application works. The sale vice-president Dwyer of this company points out, do not spend effort, won't have results. CNC Milling