Working procedure of treatment of numerical control machine tool and the design that machine a course (define)

(The main task that 1) working procedure designs: Contrail of means of installation of dosage of the specific treatment content of affirmatory working procedure, cutting, tooling, fixed position and cutting tool motion, make good preparation for work out program. (2) machines the principle of the course certainly: The set that machines a course is very important segment, machining a course is cutting tool the knife in the process is machined in cutting the point is opposite the athletic contrail at workpiece, it includes to machine the content of working procedure not only, also reflect treatment sequential arrangement, consequently treatment course is the important basis that writes machine program. 1) treatment course should assure to be machined the precision of workpiece and exterior surface roughness. 2) design machines a course to want to reduce idle stroke time, improve treatment efficiency. 3) simplifies to numerical value is calculated and reduce block, reduce process designing workload. 4) basis the circumstance such as the appearance of workpiece, stiffness, stiffness of system of mental allowance, machine tool, affirmatory loop machines a frequency. Of cutting tool of 5) reasonable design cut with the way that cuts. Use method of one-way approach location, the fixed position error that avoid transmission system backlash and arises. 6) is reasonable choose milling to treatment arranges mill mediumly or counter mill kind. Generally speaking, numerical control machine tool uses ball guide screw, athletic space is very little, because this arranges mill advantage over go against mill. (Machine tool of 3) numerical control machines a course: Lathe of 1) numerical control machines a course: If course of treatment of end panel of turning of numerical control lathe pursues 2.

4 shown A-B-0p-D, among them A is nodded to change a knife, b is nodded to be cut, C- - 0p is contrail of cutting tool cutting, 0p gives a point to cut, d is the dot that retreat a knife. Graph 2.

End panel of turning of lathe of 4 numerical control machines route chart 2.

If the treatment course that the circle outside turning of lathe of 5 numerical control machines the circle outside turning of lathe of course numerical control pursues 2.

5 show A-B-C-D-E-F, among them A is nodded to change a knife, b is nodded to be cut, C- - D- - E is contrail of cutting tool cutting, e gives a point to cut, f is the dot that retreat a knife. 2)CNC Milling machines a course: When the outline outside establishing part of plane of milling of milling cutter side edge, should along outside of outline curve tangential extension line is cut or cut, avoid to cut mark, the smooth glide that assures spare parts curved surface is crossed. Graph 2.

6 outside the treatment route chart of outline milling 2.

7 inside the treatment course of outline milling closes when milling inside when outline surface, the tangent direction feed that cutting tool also wants edge contour line and retreat a knife, if pursue 2.

7 are shown, a-B-C is cutting tool tangential cut outline contrail line, c-D-C closes for workpiece of cutting tool cutting inside outline contrail, c-E-A is cutting tool tangential cut outline contrail line. 3) aperture machines fixed position course: Want to notice the consistency of way of each opening fixed position, use method of one-way approach location namely, such location method avoided the fixed position error of because of transmission system backlash generation, raise the positional precision of aperture. If pursue 2.

8 show a picture 2.

Course of fixed position of 8 aperture treatment (the installation ① do one's best of the choice 1) workpiece of the installation of 4) workpiece and clamping apparatus accords with a design fiducial, craft installation is fiducial, fiducial the fiducial and unified principle that fastens with workpiece coordinate. ② reduces the number that hold clip, accomplish as far as possible entire work surface can be machined after holding clip. ③ uses special fixture as far as possible, decrease take machine outfit clip and adjustment time. The choice ① small lot of 2) clamping apparatus machines a spare parts, use built up fixture as far as possible, adjustable type clamping apparatus and other are general clamping apparatus. ② produces a consideration to use special fixture group by group, do one's best assembles and unassemble convenient. The fixed position of ③ clamping apparatus and clamp orgnaization component cannot affect the movement taking a knife of cutting tool. ④ assembles and unassemble the spare parts should go to the lavatory reliable, produce group by group can use pneumatic clamping apparatus, hydraulic pressure clamping apparatus and multitask clamping apparatus. The choice cutting dosage of 5) cutting dosage includes F of Ap of deepness of cutting speed Vc (or N) of main shaft rotate speed, cutting and feed, choose principle and likeness of general accuracy machine tool: When rough machining, give priority to in order to improve productivity, can choose bigger cutting to measure; When semifinishing machining and finish machining, choose minor cutting volume, in order to assure the treatment quality of workpiece. Ap of deepness of cutting of ① of dosage of cutting of lathe of 1) numerical control: Below the condition that allows in machining complex tigidity and machine tool power, can choose bigger cutting deepness, in order to reduce feed number. When the precision demand when workpiece is higher, should consider to stay have finish machining surplus, it is commonly 0.

1 ～ 0.

5mm. Computation of cutting deepness Ap is formulary: Ap= (in Dw- Dm)/2 type: Dw, diameter of the circle outside work surface, unit: Mm Dm, diameter of the circle outside the surface after already completing treatment, unit: Vc of speed of Mm ② cutting: Cutting speed reachs processability to wait for element place to decide character by workpiece material, cutting tool material, can check a watch. Computation of cutting speed Vc is formulary: In type of Vc= Π Dn/1000 (m/min) : D, the circumgyrate diameter of workpiece or point of a knife, unit: Mm N, the rotate speed of workpiece or cutting tool, unit: Speed of R/min ③ feed: Feed speed is to point to unit time inside, cutting tool is apart from along what feed direction moves, the unit is Mm/min, also can express to rotate for main shaft the feed of a week cutting tool, the unit is Mm/r. The computation of feed speed Vf: VIn type of F= N F: N, the rotate speed of lathe main shaft, unit: R/min. F, the feed of cutting tool, unit: The cutting dosage that dosage of cutting of Mm/r 2) CNC Milling chooses CNC Milling includes penetration of a cutting tool of Vf of speed of cutting speed Vc, feed, back to measure Ap and side penetration of a cutting tool to measure Ac. The selection method of cutting dosage is the durability that considers cutting tool, choose quantity of back penetration of a cutting tool or quantity of side penetration of a cutting tool first, determine feed rate next, determine cutting rate finally. ① back penetration of a cutting tool measures Ap (Duan Xi) or side penetration of a cutting tool measures Ac (circumferential mill) if pursue 2.

9 are shown, the cut dimension that carries penetration of a cutting tool on the back to measure Ap to be line of cutter shaft of parallel Yu Xi to measure, the cut size that the unit estimates Ac to be measured for line of cutter shaft of perpendicular Yu Xi for Mm; side penetration of a cutting tool, the unit is Mm, of quantity of penetration of a cutting tool of the back that carry mill and quantity of penetration of a cutting tool of circumferential mill side choose basically mix by mental allowance ask to decide to exterior quality. Graph 2.

Speed of feed of Vf of speed of feed of ② of dosage of milling of 9 milling cutter points to the opposite displacement of the workpiece inside unit time and direction of feed of milling cutter edge, the unit is Mm/min. Z of number of tooth of it and N of milling cutter rotate speed, mill and unit of Fz(of every tine feed are Mm/z) to concern. The computation of the speed that enter Jian is formulary: The: in type of Vf= FzZ N? Of Z of Jun of  of the  that chop beanstalk choose basically depend on the element such as surface roughness of surface of the mechanical function of workpiece material and cutting tool material, workpiece. The intensity when workpiece material and hardness are tall, the demand of workpiece surface surface roughness is high, workpiece tigidity difference or cutting tool intensity are low, fz value takes small cost. The prep above of every tine feed of hard alloy milling cutter is congener of high-speed steel milling cutter choose a value, can check a watch to choose. Penetration of a cutting tool of Fz, back measures feed of the cutting speed of milling of ③ cutting speed and T of cutting tool durability, every tine Ac of quantity of penetration of a cutting tool of Ap, side and mill tooth count Z to become inverse ratio, become direct ratio with D of milling cutter diameter. Its reason is Fz, Ap, Ac, Z when increasing, make at the same time working tine counts grow in quantity, edge bear and heat in metal cutting increase, accelerate cutting tool to wear away, accordingly, cutting tool durability limitted cutting rate rise. If increase milling cutter diameter, can improve medicinal powder hot condition, raise cutting rate accordingly. (The choice 1) that 6) nods to the knife is nodded and changing a knife is the start that cutting tool moves relative to workpiece to knife dot, the program begins from this, reason calls a program origin or program start again (dot removing a knife) . Its choose a principle is: ① should choose the design in the spare parts as far as possible fiducial or craft is fiducial on, be like the spare parts that locates with aperture, answer to regard pair of knives as the dot with aperture center. ② should be chosen to knife dot in convenient to the knife position, facilitating observation and detect. The computation that ③ should facilitate coordinate is worth. On the origin that is like world coordinate system or the dot that foregone coordinate is worth. ④ makes the cutting tool in machine program introduces (or return) course weak point facilitates change a knife. 2) is optional to knife dot go up in the spare parts, optional also go up in clamping apparatus or machine tool, if choose,go up in clamping apparatus or machine tool, criterion must the fixed position with workpiece is standard have certain dimension connection. If pursue 2.

10 are shown. Graph 2.

Dot of 10 pairs of knives and the affirmatory 3) of the dot that change a knife are right when the knife, should make " knife dot " with " nod to the knife " coincide, immediate to the exact extent of the knife impact machines precision, the knife of different cutting tool the dot is different. If pursue 2.

11 are shown. Graph 2.

The knife of 11 different cutting tool the logarithm that nod 4) accuses the much knife such as milling machine of lathe, boring, machining center to machine numerical control machine tool, because want to undertake changing a knife in treatment process, the position changing a knife between different process should consider when reason process designing, set the point that change a knife. Produce interference to avoid to change the cutting tool when the knife and workpiece and clamping apparatus, the dot that change a knife should be set in the proper place outside workpiece. As above pursues 2.

10 are shown. CNC Milling