Milling cutter helix angle to examining milling machine works the influence of precision

025mm. We are being cut to essence of X8140 job precision tackle key problem the discovery in the process, the influence of milling cutter helix angle to the tall sex such as H is as high as 0 unexpectedly inside dimension 16mm direction.

006 ～ 0.

01 1mm, occupy H allow to differ about (0.

2/5 of 25mm) , this is a factor that cannot ignore undoubtedly. According to milling machine working precision general standard asks, we use milling cutter of the face that cover type (milling cutter diameter is Ø63mm, helix angle 15 ° , dextral, tine is counted 12, material W18Cr4V) , with arbor a blade is ground, standard requirement is accorded with when installation, in order to make sure with a knife outfit clip completes treatment of face of Ⅰ , Ⅱ , Ⅲ , Ⅳ . Check and accept a technology to ask to stipulate cutting parameter is: Cut deep T=0.

1 ～ 0.

3mm, main shaft rotate speed is 125 ～ 210r/min, speed taking a knife is 35 ～ 85mm/min, go against mill. Concern by the geometry of cutting tool and cutting parameter (graph 2) is calculable piece, the below one tine after the one tine when cutting is cut just is cut for interrupted cutting. From C when tooth the dot cuts A when the dot is cut, as a result of the existence of helix angle, the osculatory length of edge and workpiece surface is in every instant differs. Because the feed of every tine is very small (when S=40mm/min, N=180r/min, s=00185mm) , can think on edge every cut bit of C to form workpiece surface. When tooth from. The edge when the dot cuts A dot to be cut and workpiece contact line are nodded from C (point contact) lengthen is nodded to Ac, the length that forms workpiece surface is Cc=e. By the computation of cutting force formula is known, cutting force and cutting area are relevant. Edge is point contact in C dot and workpiece, the area is the smallest. The edge when be being cut and workpiece contact line are the longest, cutting area is the largest, cutting power is the greatest, cantilever arbor is out of shape the biggest also. The metal that cuts in C dot so should compare C the place is little. Make test specimen machines exterior Ⅰ to arrive from C dot inside C length so gradually heighten forms a rake, make H differs tall (graph 3) . Use afore-mentioned milling cutter, set cut deep T=0.

2mm, concern by the geometry when cutting calculable a treatment surface that suffers cutting strength effect 2) of width E(graph. Establish the crucial point on a bit from cut those who cut to rotate angle is Ø , criterion Ø=cos-1(D/2)-t=cos-131.

5-0.

2=6.

45952 ° D/231.

5(1)ak=DsinØ=3.

544mm2(2)e=cc=ak=3.

544=13.

° of 31mmtg β Tg15 (3) tries check, test to know repeatedly, here cutting standard falls, Ⅰ face differs to be Δ H=0 high in the H inside E length limits.

006 ～ 0. 011mm(graph 3) . For test and verify this is planted the validity of hypothesis, undertake arranging mill below the circumstance with cutting tool and cutting changeless parameter, direction of result discretion dot and go against mill contrary. We change again make a straight tine establish milling cutter to undertake essence of life is cut, do not measure almost on 16mm length direction piece differ to come high. But cutting of straight tine milling cutter is not smooth, cutting tool produces vibration namely dully a bit, exterior occurrence ripple. Accordingly, although straight tine milling cutter can exclude the effect of helix angle, but because cutting tool durability is low not applicable. This shows, milling cutter helix angle examines to precision of milling machine job is an influencing factor that cannot ignore, also should mention to the treatment of mill of essence of life of workpiece at the same time attention. Via assaying, cut to test specimen essence offer following measure: Analyse afore-mentioned pattern (1) , (2) , (3) is knowable, inside proper limits, reduce D of cutting tool diameter, reduce cut deep T, increase helix angle β , can reduce the treatment surface width that suffers cutting strength effect. , reduce thereby differ tall Δ H. The effect of ply of the smallest cutting to cutting heeds when essence of life is cut, consider the diametical D of standard cutting tool and helix angle β , choose D=40mm of cutting tool diameter, ° of =25 of helix angle β (accord with a type to establish GB1114-85) of milling cutter standard, calculable the E=4 of treatment surface width that cutting strength effect suffers when giving essence of life to cut.

26mm. Differ to energy section right now the influence of tall Δ H is 0.

0019 ～ 0.

0035mm, the 1/13 ～ 1/7 that occupies working precision only can be ignorred. Follow examining beat to eliminate check club when the radial of main shaft axes is jumpy jumpy to main shaft influence, use check club to turn relative to main shaft 90 ° take the course of action that measures result average 4 times, examining the effect that cutting tool factor also should exclude when the working precision of the machine tool, the H that the difference of the apogee that allows test specimen to take two place 16mm on 16mm direction for this proposal standard is this direction differs tall sex. Raise arbor stiffness as far as possible. Can make arbor adds the thick form that become awl gradually to awl pommel to awl handle from the place that hold a knife. CNC Milling CNC Machining