The design of aperture treatment cutting tool is one needs to have the complex process that coordinates each other to a lot of technology difficult problem. Seco Carboloy company (be located in the United States to rest closely root city Warren) auger cut product manager Goran Melin to say, "The technical difficult problem that often is some respect gets settlement, inevitable meeting on the other hand produces new issue. " all many sided with these harmonious need, include precision of cutting tool service life, treatment and the stability that machine a process to wait normally. Need of cutting tool stylist is ceaselessly in the contradictory change of these problems find out first-rate solution. From Seco Carboloy company the PerfoMax machine of newest production places the design process of product of type broach series, the recognition that can see above is correct. Through undertaking be harmonied each other to a lot of technology difficult problem, the new-style chance that the design gives adds type bit, expanded greatly size range of pipe bent. A such harmonious process experienced in design of broach of type of new-style machine clip: In the choice that is in a lot of at aperture using that machine cutting tool, broach of machine clip type is the better solution that low cost machines normally. Introduce according to Mr Melin, broach of machine clip type goes out bit design 4 cutting blade commonly, it can differ according to processing data, choose the razor blade of different material and geometrical appearance. Normally the circumstance falls, broach cutter hub has change 40 ～ the service life of 50 razor blade. So, mix with integral type solder type broach and the look of hard alloy broach that can exchange the head are compared, reduced the manufacturing cost of every broach greatly. However, usually, use machine places the user of type broach bore to hope to have a wider treatment common difference. Because efficient the cutting blade that broach designs a kind of asymmetry normally. When broach of machine clip type uses the structure of two razor blade, a razor blade passes cutting tool center, another razor blade from inside outspread piece to whole diameter. The external diameter of cutting tool handles bit, because cutting rate is high, excise very large surplus effectively, and the cutting speed of razor blade of part of cutting tool center is equal to 0, cannot attend cutting, because this is on broach,basically be in actually only feed direction action a very inhomogenous axial cutting force. Because radial cutting power is insufficient,its are as a result, attrition resistance is too great, cause cutter hub bend be out of shape. "Before broach enters whole cutting, you can feel not steady state, " Mr Melin says, "Broach is longer, its machine condition to be not stabilized more. " when using lengthen bit so, the user begins in aperture treatment (make an appointment with 1mm) , the 30% ～ that should reduce feed rate to cutting manual to recommend a value 50% . When entering overall cutting, the commendation that presses cutting manual is worth treatment. This one proposal is very unreasonable really. Because be in process designing software, choose standard cutting dosage commonly, and cannot use machine program of manual and new collection additionally for the feed with special certain. Broach of together with lengthen is used at extremely individual situation only, choose the cutting dosage of standard broach only commonly so. But the kill that such making will reduce a spare parts to machine precision and manufacturing efficiency. Pass an analysis to compare, twist drill and broach of integral hard alloy all have two cutting blade, the evenly depart in can be being machined cuts bits, make cut bits eliminates easily and raise broach cutting rate. And broach of machine clip type (the place before be like is narrated) advocate if blade of a cutting undertakes cutting (in including to have mechanical clamp process, the person assembles error element to exist to cause) , and the bit ability that is far from cutting tool center only excises a lot of metals effectively, this will be restricted those who cut bits is effective eliminate and of feed speed rise. But because it does not have the wider first flank with twist drill peculiar head, won't produce very great attrition power, because this can be below tall cutting speed,machine (opposite at twist drill) . But regretful is, in use machine the broach that place type machines length to exceed the deep aperture of 4 times diameter, when choosing big feed cutting especially, of broach be out of shape the main technique difficult problem that becomes need to solve. Because of these reasons, broach of machine clip type is used at reaming and requirement of dimension public errand to be in more 0. 008 inches semifinishing machining circumstance. Accordingly, use machine places type broach to be able to obtain the economy treatment that the user expects, but it cannot undertake more the treatment of high accuracy. Limit a factor to overcome above, when engineer of Seco Carboloy company is designing new-style machine to place type bit, emphasize undertook the following the improvement of 5 respects works: 1.
Give what the broach when cutting arises to bend to prevent high speed, Gao Jin be out of shape, increase the diameter that get system as far as possible, in order to withhold more metallic data (the current structure with the too old space between the circle outside be aimed at former cutter hub of broach of machine clip type and broach external diameter) . 2.
Bit designs fine into tigidity cuboid structure entirely, getting the mill on body to give the deep chamfer appearance of relevant measure. Because design bit the round part of 90 ° , intensity, stiffness is good (in the light of broach of machine clip type former razor blade is triangle, square, ply more the tigidity that integrated action plays the factor such as not old structure and mechanical screw clamp is very poor) . 3.
Broach design has two cooling fluid to connect what have enough space with two into aperture to take the tilting chamfer that discharge bits a bit, drop in temperature enoughly in order to make broach cutting area gets to cool and discharge bits effectively, still can reduce the tumor that cut bits, lengthen broach service life and the exterior surface roughness that reduce treatment hardware. 4.
Broach surface design has coat of one tall wear-resisting, be in in order to prevent will drossy felt cutter hub surface, prolong broach service life. 5.
bit the design is become on matrix of tall hardness, fine grain Tu Funeng is below tall cutting speed the new-style coating of cutting, can use at machining the part that all sorts of material make. Mr Melin says, the tigidity of the broach of machine clip type of new design rises, refrigeration comes loose the function discharging bits of good, broach and cutting stability enhance hot result greatly. Can be so in a lot of treatment, raise manufacturing efficiency and precision of spare parts treatment. Include to be able to be opposite deep aperture spare parts, be machined on poorer clamping apparatus and machine to Bao Bi spare parts in tigidity etc. The virtue of low finished cost with inherent before together with, consequently very favour of benefit from door. At present new-style machine places the norms of type broach to be: Diametical limits 0.
594 ～ 2.
375 inches, auger cut deepness to be 2 ～ 5 times diameter, broach petiole gives all sorts of norms by standard production, those who include those who have 4 plane to be used at lathe is general-purpose petiole. CNC Milling