The design of aperture boring cutter reachs semifinishing machining camshaft application

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In diesel engine industry, the semifinishing machining of the camshaft aperture on crock lid is his one of difficulty in production process, the dimension precision of its aperture, form tolerancepublic errand and exterior surface roughness all have higher demand, use bore with a reamer to cut treatment commonly. But bore with a reamer cuts mental allowance small, cutting rate is low, to big batch production, go up in product line especially, achieve the requirement of tall treatment metre hard. And the production cost of high accuracy reamer is high, the initiative investment of cutting tool spends cost with what machine the razor blade in the process tall, the client sets out from economy, accept hard. For this, we are designed and made boring tool of camshaft Kong Banjing. One. The structure of boring cutter of camshaft Kong Banjing and characteristic are added after work structure describes the exterior treatment that there is camshaft opening on crock lid to finish, had set plain bearing liner, screw bolt, make make a whole. But after synthesis, because wool is bad surplus is not equal a variety of reasons, criterion inside aperture and end panel are very irregular, easy cause cutting tool vibration. Here foreword machines the requirement of the spare parts to be: Inside hole size F42.

5mm, the coaxial of 5 aperture spends F0.

03mm, ra1 of exterior surface roughness.

6. Structure of half essence boring cutter and petiole of characteristic ⑴ tool use camshaft opening the BT50 date 7:2 in MAS403 standard4 awl handle, tolerancepublic errand grade is AT3 class, arbor is effective length is 388mm. Cutting tool used integral type structure, enhanced cutting tool tigidity. Cutting part uses ⑵ two axial, radial all adjustable WALTER small-sized knife places FR671. Facilitate the end that adjusts cutting tool jumps with diameter the dimension precision that reachs cutting tool. WALTER small-sized knife places razor blade of ⑶ of razor blade of tiger of film of FR671 double color to use CCMT060204-PS4 WAK10, have super- strong wear-resisting and discern the razor blade of tiger of double lubricious coating of wear out condition, it is the special razor blade that cast machines, cutting function and life raise 75 ％ . It was reduced wear away, decreased to use up, improve work efficiency. ⑷ cutting tool used 4 to distributing equably oriented cake compose, as a result of,can bear surplus not all, the cutting strength that cause is lopsided, cause arbor each are oscillatory. And cutting tool proper motion is oriented, can increase cutting tool tigidity, improve efficiency. ⑸ cutting tool used central refrigeration, oily cutting fluid helps a bit, the cooling action of cutting fluid basically is to take away many heat in metal cutting, drop cutting temperature; The heat that reduces workpiece, cutting tool expands, raise treatment precision. In cutting process, face of the knife before cutting tool and the contact that cut bits, produce acuteness clash, pressure is very high (1Gpa above) , cutting fluid also has attrib border and lubricant effect. 2. Of the partial design parameter of boring cutter of camshaft Kong Banjing decide with what choose arbor material and heat treatment hardness certainly choose with what choose arbor material, matter to the intensity of arbor and tigidity directly, it is this cutting tool whether successful key. We chose to be equivalent to the material of domestic 20CrMnTi. Manufacturing technology is: Forging, the craft course of normalizing, rough machining, semifinishing machining, heat treatment, finish machining. Semifinished product is in machine normalizing needs before adding, its purpose is for improvement forging the abnormal organization of condition, machine at cutting with benefit, make sure the spare parts is eligible. Cementite layer ply is 0.

8-1.

2mm. Cementite hind quenchs, because carbolic content is higher,its express facing, the surface is in quenching basically is temper martensite organization after microtherm temper, have very tall hardness and wearability, hardness is HRC53-58; Its core ministry raises the temper by dipping in water of steel to show sexual effect as a result of element of Cr, Mn, this material is in quench organization of martensite of temper low carbon can be acquired after microtherm temper, those who have high intensity and enough concussion tenacity is good cooperate. Accordingly, this material is mixed via afore-mentioned cold hot-working after heat treatment, acquires property satisfies technical requirement completely. Dimension of chamfer of clip of the knife on arbor is decided really with choose basis of FR671 structure dimension to be added the dimension of the aperture inside workpiece, affirmatory knife clip can adopt axial installation only, particular case sees a picture 2. Direct a diametical dimension and precision are decided really with choose when boring hole to assure can smooth treatment, there are 4 to raise stay to locate on cutter hub. After bit is assembled, must not exceed 0 to raising the radial circle of stay to beat.

02mm. The guiding that pays stay the tool cutting edge angle that horn should be equal to tooth, the axial end points that pays stay at the same time (nadir) should under point of a knife 0.

5mm left and right sides. According to our experience, the 1-4 that the length that pays stay is a diameter times, 0 width is a diameter.

2 times. Because raise the exterior surface roughness of stay to be worth immediate impact by the exterior surface roughness of treatment aperture, be worth by the exterior surface roughness of treatment aperture to reduce, the exterior surface roughness that often takes a stay Ra ≤ 0.

1µm. From the point of working circumstance, it is OK to have two pay stay, direct namely piece 20 ° are controlled at the back of be located in a knife to place groove. Such decorating can make direct piece bear cutting force, in order to assure the dimension precision of the opening that boring gives and linearity. Material bends mechanically be out of shape theory explains, the extreme deflection of cantilever bridge is hanged with its those who extend length just become direct ratio 3 times. After increasing a stay, because cantilever length is reduced greatly, cutting tool tigidity will be great improve. Practice experience makes clear, deep Kong Shi is compared in boring, lever of edge boring cutter is circumferential solder 4 pay stay, the tigidity that raises boring cutter effectively. Two when increase raise stay to basically have damp effect, reduce vibration. Pay stay besides case outside assuring precision of bore diameter dimension and oriented action, as a result of its extruding to hole wall and attrition action, have very big effect to already machining the exterior surface roughness of aperture. Have corresponding extruding surplus to assure to pay stay, decrease to be worth by the exterior surface roughness of treatment aperture, center of requirement cutting tool does not arrive with cutting tool center to the radius of point of a knife oriented piece radius coincide. This poor value depends on by treatment material, cast-iron treatment: In ≤ of the HBS that be by the hardness of treatment material 200 when, the radius that raises stay and point of a knife - 0.

005mm ～ 0.

005mm; In ≥ of the HBS that be by the hardness of treatment material 200 when, the radius that raises stay and point of a knife 0.

002mm ～ 0.

02mm. 3. The note in use process is main speed of cutting parameter cutting: 100m/min feed speed: Rotate speed of 150mm/min main shaft: Feed of 750r/min every tine: 0.

Before 1mm/Z is used, should notice the examination raises stay margin smooth, avoid to carry, store the scathing influence that a margin maintains to raising in waiting for link machines quality. If discovery raises mouth of thorn of stay brim hairiness, collapse to wait for not smooth phenomenon, answer to be in a poor light in time with oilstone, be added in order to rise the dimension stability of workpiece, improve the exterior surface roughness of the workpiece that be added. Machine tool job should be stabilized, machining complex tigidity is close friends, prevent vibration of the workpiece that be added. Lubricating fluid is indispensible and enough, chroma is 15% the left and right sides. CNC Milling CNC Machining