Aperture machines commonly used tooling (1)

125~0.

15)do (Do is broach diameter) . To raise the intensity of broach and stiffness, the make it that get a heart cone, get a heart to increase gradually to the rear from cutting part, its add a large number of every 100mm length to go up for 1.

4~2.

0mm. Two advocate cutting blade calls sharp angle in the umbriferous included angle on as parallel as them plane 2 Φ , if pursue 7 - 34 are shown. The sharp angle of standard twist drill 118 ° of 2 Φ ＝ , right now two advocate cutting blade is shown linear; If grind the sharp angle that give 118 ° of 2 Φ ＞ , criterion advocate cutting blade submits sunken form; Be like 2 Φ ＜ 118 ° , criterion advocate cutting blade shows convex. ② directs the part directs the share rises when bore conduct action, also be the mothball part of cutting part. Direct two helix chamfer of the part forms broach before knife face, also be the airspace that a bits, look bits and cutting current enter. The helix angle β of helix chamfer is to point to helix chamfer most outside the corkscrewed yarn of the predestined relationship spreads out linear hind with the included angle between broach axes, if pursue 7 - 34 are shown. Stand by broach center helix angle to heal more small. Helix angle β increases, can obtain bigger before horn, cutting is consequently light, discharge bits easily, but the tigidity of the intensity that can weaken cutting blade and broach. The arris edge of oriented part is the deputy cutting blade of broach namely, ever since knife face shows narrow round cylinder. Standard twist drill directs direction of straight radial petiole chases the part to be reduced gradually, its reduce an amount it is on every 100mm length 0.

03~0.

12mm, helix angle β can reduce the attrition of arris edge and workpiece hole wall, also formed pair slant horn. (2) petiole petiole is used the broach that hold clip and deliver torque. 12mm of ＜ of broach diameter Do often makes columnar power (straight handle) ; 12mm of ＞ of broach diameter Do often uses conic power. (3) cervical and cervical the join part that is petiole and working section, decline knife and point of the mark that print as the emery wheel when grinding external diameter. Small diameter broach do not make cervical. 2. The geometrical angle of twist drill cutting part by the graph 7 - show 33 times, two when broach is equivalent to be being installed instead actually inside the assorted cutting tool of aperture lathe tool, just these two inside of aperture lathe tool advocate center of work of cutting blade prep above (because have the reason that get a heart and forms horizontal blade, the radius that get a heart is) . (1) when tool reference plane and tool cutting edge plane are analysing the geometrical angle of twist drill, must clear up the tool reference plane of broach and tool cutting edge plane above all. ① tool reference plane: Cutting blade assumes office the tool reference plane of a bit, it is to pass this a little bit, and perpendicular the plane at direction of speed of this bits of cutting, if pursue 7 - 35a place is shown. Getting when cutting, if oversight feed moves, broach has circular motion only, advocate circle broach axes at on cutting blade each o'clock to make circular motion, its speed direction is in round tangent direction at this o'clock namely, if pursue 7 - the cutting career that the A in 35b chooses is perpendicular the radius way that chooses at A, the cutting career that B chooses is perpendicular the radius way that chooses at B. See not hard, cutting blade assumes office to the tool reference plane of a bit passes this to nod namely and include the plane of broach axes. The cutting speed way that goes up each a little bit as a result of cutting blade is different, the tool reference plane that orders each on cutting blade so is different also. ② tool cutting edge plane: Holding the post of the tool cutting edge plane of a bit is to include direction of speed of this bits of cutting on cutting blade, and cut the plane that machines the surface at this bits (graph 7 - the tool reference plane that 35a place shows A of point of a knife of the predestined relationship outside be broach to nod and tool cutting edge plane) . The tool cutting edge plane that orders each on cutting blade and tool reference plane are in the space is mutual and perpendicular, and its position is of change. (2) advocate the geometrical angle of cutting blade, if graph 7-36 place shows inclination of blade of 　 ① end panel,　 is convenient for the purpose of, the blade dip of broach expresses inside transverse plane normally. Broach advocate the dip of end panel blade on cutting blade is advocate cutting blade is in of transverse plane umbriferous with the included angle between this bits of tool reference plane. If pursue 7 - 36 are shown, its are worth what always lose. And advocate the dip of end panel blade that nods each on cutting blade is change, the absolute value that approachs dip of blade of broach center end panel more heals big (see a picture 7 - 36b) . Twist drill of 　 of ② tool cutting edge angle advocate the tool cutting edge angle of some bit on cutting blade is to should nod tool reference plane to go up advocate of cutting blade umbriferous with the included angle between broach feed direction. As a result of advocate the tool reference plane that orders each on cutting blade is different, tool cutting edge angle of each bits also is changed subsequently. Advocate the tool cutting edge angle that nods each on cutting blade is change, the predestined relationship is in outside big, the part that get a heart is small. Of twist drill of 　 of the horn before ③ before horn is orthogonal plane inside before the included angle between knife face and tool reference plane. As a result of advocate the tool reference plane that orders each on cutting blade is different, so advocate nod each on cutting blade before horn also is change, if pursue 7 - 36 are shown. Before horny value from outside the predestined relationship arrives auger near the heart about by + 30 ° are reduced - 30 ° , its cutting condition is very poor. Blade of cutting of 　 of the horn after ④ assumes office of a bit after horn, it is this the tool cutting edge plane of the dot and hind the included angle between knife face. The horn after broach is absent advocate the magnanimity inside section plane, be in however assume the job is planar (feed section plane) inside magnanimity (see a picture 7 - 36a) . Getting in cutting a course, what act well actually is this hind horn, measure at the same time convenient also. Of broach hind horn is blade is ground get, when blade is ground, should notice to make place of the predestined relationship outside its is ground some smallier (° of ~10 of about 8 ° ) , stand by the place that get a heart to want to be ground some more greatly (° of ~30 of about 20 ° ) . The reason that such blade grind, it is OK the horn after making and advocate the metabolic photograph of the horn before cutting blade suits, the wedge part that makes each a little bit is roughly equal, achieve its thereby sharp degree, intensity, durability is balanced relatively; The μ of resultant velocity horn that can make up for the horn after move as a result of the axial feed of broach and making each choose real work on edge to reduce this a little bit next (see a picture 7 - 36 in F-f section plane) the effect that produces; Still can change the cutting condition that horizontal blade is in in addition. (3) because 　 of the horn before the geometrical angle of horizontal blade shows 　 ① horizontal knife like graph 7-37 place is horizontal inside the substance that the tool reference plane of blade is located in cutting tool, the horn before reason horizontal blade is worth to lose (about - ° of 45 ° ~-60) , get so when cutting, serious extruding happens in horizontal blade point and cause very great axial power. 90 ° of ≈ of the horn after blade of horizontal stroke of 　 of the horn after ② horizontal blade - │ │ , 30 ° of reason ≈ ~35 ° . Tool cutting edge angle of ③ horizontal blade 90 ° of ＝ . ° of =0 of dip of blade of ④ horizontal blade. Bevel of horizontal blade of 　 of Ψ of bevel of ⑤ horizontal blade is the end panel in broach umbriferous in, horizontal blade and advocate the included angle between cutting blade. The nature when blade worries bit forms it, when sharp angle is certain, horny blade grinds correct standard twist drill after Ψ of horizontal blade bevel is ° of 47 ° ~55, after that horn heals big Ψ heals small, the length of horizontal blade can increase. CNC Milling CNC Machining