The choice principle of cutting dosage

Dosage of cutting of numerical control lathe 1) below the condition that cutting deepness Ap allows in machining complex tigidity and machine tool power, choose bigger cutting deepness as far as possible, 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: In Ap= type: Dw, diameter of the circle outside work surface, unit Mmdm, diameter of the circle outside already machining the surface, unit Mm.

2) speed of cutting of smooth car of Vc of speed of cutting of smooth axis of turning of ① of cutting speed Vc reachs processability to wait for element place to decide character by the workpiece material, material of cutting tool, express reference of speed of cutting of lathe tool of the 1 circle outside be hard alloy. Computation of cutting speed Vc is formulary: In Vc= type: D, the circumgyrate diameter of workpiece or point of a knife, unit Mmn, the rotate speed of workpiece or cutting tool, unit R/min expresses reference of speed of cutting of lathe tool of the circle outside 1 hard alloy to express Ap=0 of condition of workpiece material heat treatment.

3~2mmap=2~6mmap=6~10mmf=0.

08~0.

3mm/rf=0.

3~0.

6mm/rf=0.

Mild steel of Min-1 of · of Min-1Vc/m of · of 6~1mm/rVc/m · Min-1Vc/m cuts 130~16090~11060~80 of hot-rolling of medium carbon steel of steel hot-rolling 140~180100~12070~90 easily to move 100~13070~9050~70 of hot-rolling of steel of tool of qualitative 100~13070~9050~70 alloy to move HBS<19090~12060~8050~70HBS=190~22580~11050~7040~60 of casting pig of 90~12060~8050~70 of anneal of steel of qualitative 80~11050~7040~60 tool copper of 10~20 of tall manganese steel and aluminium of copper alloy 200~250120~18090~120 and 100~18080~15060~100 of aluminium alloy of casting of aluminium alloy 300~600200~400150~200 note: The durability when steel of cutting of material of the cutting tool in the watch and casting pig is 60min about. When whorl of cutting of N of rotate speed of main shaft of ② turning whorl, the pitch that the main shaft rotate speed of lathe gets treatment work (or lead) electromotor of size, drive rises fall a variety of element influences such as character and speed of whorl interpolation operation, accordingly to different numerical control system, n of rotate speed of main shaft of choice turning whorl is put in certain difference. Tachometer of the main shaft when whorl of car of lathe of ordinary numerical control labelling below calculates formula: In type of K of N ≤ –: P, the pitch of workpiece whorl or lead, unit Mm. K, assurance coefficient, it is commonly 80. 3) speed of feed speed feed 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 principle ① of speed of ⑴ affirmatory feed can get assuring when the treatment quality of workpiece when, to rise productivity can choose higher feed rate. ② is cut off, when turning deep aperture or fine vehicle, choose inferior feed career. Idle stroke of ③ cutting tool chooses high feed rate as far as possible. ④ feed speed should suit with main shaft rotate speed and cutting deepness photograph. In the computational Vf=nf type of Vf of ⑵ feed speed: N, the rotate speed of lathe main shaft, unit R/min. F, the feed of cutting tool, unit Mm/r. Express the 2 circles outside be thick vehicle of car of hard alloy lathe tool and watch of reference of end panel feed, express 3 to choose feed by exterior surface roughness reference is expressed. The circle outside expressing thick car of lathe tool of 2 hard alloy and BXH of dimension of arbor of material of workpiece of watch of reference of end panel feed (Mm2) Ap of deepness of cutting of workpiece diameter D(mm) (Mm) 16X25200 of refractory steel of steel of structure of alloy of steel of structure of element of carbon of F(mm/r) of ≤ 3>3~5>5~8>8~12>12 feed.

3~0.

4-------------------400.

4~0.

50.

3~0.

4--------------600.

5~0.

70.

4~0.

60.

3~0.

5--------1000.

6~0.

90.

5~0.

70.

5~0.

60.

4~0.

5----4000.

8~1.

20.

7~1.

00.

6~0.

80.

5~0.

6----203025X25200.

3~0.

4----------------400.

4~0.

50.

3~0.

4------------600.

5~0.

70.

5~0.

70.

4~0.

6--------1000.

8~1.

00.

7~0.

90.

5~0.

70.

4~0.

7-----4001.

2~1.

41.

0~1.

20.

8~1.

00.

6~0.

90.

4~0.

16X25400 of 6 cast-iron copper alloy.

4~0.

5----------------600.

5~0.

80.

5~0.

80.

4~0.

6--------1000.

8~1.

20.

7~1.

00.

6~0.

80.

5~0.

7----4001.

0~1.

41.

0~1.

20.

8~1.

00.

6~0.

8----203025X25400.

4~0.

5----------------600.

5~0.

90.

5~0.

80.

4~0.

7--------1000.

9~1.

30.

8~1.

20.

7~1.

00.

5~0.

8----4001.

2~1.

81.

2~1.

61.

0~1.

30.

9~1.

10.

7~0.

9 note: 1) intermittent treatment and treatment have percussive work, the feed inside the watch should multiply coefficient K=0.

75~0.

85; 2) treatment does not have cortical workpiece, the feed inside the watch should multiply coefficient K=1.

1; 3) machines refractory steel and its alloy, feed is not more than 1mm/r; 4) processes hard steel of temper by dipping in water, should reduce feed. It is 44~56HRC when the hardness of steel, should multiply coefficient K=0.

8; When the hardness of steel is 57~62HRC, should multiply coefficient K=0.

5. Watch 3 choose feed reference to express ε of R of radius of circular arc of point of a knife of Vc(m/min) of limits of speed of cutting of Ra(µm) of surface roughness of workpiece material surface by exterior surface roughness (Mm)0.

51.

02.

Aluminium alloy of cast-iron bronze of 0 feed F(mm/r) > 5~10 is not restricted 0.

25~0.

400.

40~0.

500.

50~0.

60>2.

5~50.

15~0.

250.

25~0.

400.

40~0.

60>1.

25~2.

50.

10~0.

150.

15~0.

200.

20~0.

Alloy steel of 35 carbon steel > 5~10<500.

30~0.

500.

45~0.

600.

55~0.

70>500.

40~0.

550.

55~0.

650.

65~0.

70>2.

5~5<500.

18~0.

250.

25~0.

300.

30~0.

40>500.

25~0.

300.

30~0.

350.

30~0.

50>1.

25~2.

5<500.

100.

11~0.

150.

15~0.

2250~1000.

11~0.

160.

16~0.

250.

25~0.

35>1000.

16~0.

200.

20~0.

250.

25~0.

35 note: R ε =0.

5mm, general choice arbor is sectional for 12X12mm2; R ε =1mm, general choice arbor is sectional for 3030mm2; R ε =2mm, general choice arbor is sectional for 3045mm2. 2.

The cutting dosage that dosage of CNC Milling cutting 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) following plan institute 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 unit is Mm, the Ap when Duan Xi is cut deepness, the Ap when circumferential milling is by the width of treatment surface. The cut size that Ac of quantity of side penetration of a cutting tool measures for line of cutter shaft of perpendicular Yu Xi, the unit is Mm, the Ac when Duan Xi is spent to be machined to express bizygomatic breadth, the Ac when circumferential milling is cut deepness. 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. Surface roughness of ① workpiece surface asks to be Ra3.

2~12.

5µm, two paces milling machines cent thick mill and half essence mill, surplus of half essence mill leaves after thick mill 0.

5~1.

0mm. Surface roughness of surface of workpiece of ② of dosage of milling of graph milling cutter asks to be Ra0.

8~3.

2µm, can divide mill of thick mill, half essence mill, essence of life treatment of 3 paces milling.

5~2mm, quantity of penetration of a cutting tool of circumferential mill side is taken when mill of essence of life 0.

3~0.

5mm, quantity of penetration of a cutting tool of the back that carry mill is taken 0.

5~1mm. Speed of feed of Vf of 2) feed speed 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 Vf=fzZn type? 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, of every tine feed choose referenced watch to see a table 4. Express 4 milling cutter every age feed Fz reference expresses workpiece material steel of milling cutter of hard alloy of milling cutter of high-speed steel of milling cutter of hard alloy of milling cutter of high-speed steel of mill of essence of thick mill of Fz(mm/z) of every tine feed 0.

10~0.

150.

10~0.

250.

02~0.

050.

10~0.

15 cast-iron 0.

12~0.

200.

15~0.

Penetration of a cutting tool of Fz, back measures feed of the cutting speed of milling of 303) cutting speed and T of cutting tool durability, every tine Ae 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, Ae, 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, rise because of what durability of this cutting tool limitted cutting rate. If increase milling cutter diameter to be able to be improved,come loose hot condition, raise cutting rate accordingly. Watch 5 listed the reference of milling cutting speed is worth. The cutting speed reference when expressing 5 milling expresses workpiece material hardness (HBS) cast-iron <19021~3666~150190~2609~1845~90160~3204 of <22518~4266~150225~32512~3654~120325~4256~2136~75 of steel of milling cutter of hard alloy of milling cutter of high-speed steel of cutting speed Vc(m/min) .

5~1021~30 CNC Milling