蝸輪剃齒刀是高精度蝸輪的最后精加工刀具。蝸輪剃齒刀一般可使蝸輪加工精度提高一級(jí)。
蝸輪剃齒刀是在蝸桿的兩側(cè)螺旋面作出許多容屑槽。其前刀面通過(guò)剃齒刀軸線的為阿基米德蝸桿剃齒刀,前刃面在螺紋法向截面上的為法向直廓蝸桿剃齒刀。
蝸輪剃齒刀容屑槽分為通槽式和閉槽式兩種,前者齒數(shù)較少,制造容易,后者齒數(shù)多,適于高精度蝸輪加工,一般蝸輪剃齒刀與工作蝸桿是在同一蝸桿磨床上磨削側(cè)螺紋面。
蝸輪剃齒刀的刀齒后面是一條后角為零度的刃帶,當(dāng)加工鑄鐵蝸輪時(shí),刃帶寬度為0.35~0.4mm;加工銅蝸輪時(shí),刃帶寬度為0.15~0.2mm。
蝸輪剃齒刀的齒頂不參加工作,一般比工作蝸桿的齒頂高增大0.1mx(mx為蝸桿槽數(shù))(見(jiàn)圖5-68)。
蝸輪剃齒刀的制造精度,可按表3-140高精度蝸輪滾刀的制造公差選取。
表3-140 普通蝸輪滾刀的制造公差
序號(hào) |
項(xiàng)目 |
精度等級(jí) |
模數(shù)mm |
>0.5~1 |
>1~2.25 |
>2.25~4 |
>4~6 |
>6~8 |
>8~10 |
1 |
孔徑偏差 |
AA、A |
H5(GB1801—79) |
B、C |
H5(GB1801—79) |
2 |
軸臺(tái)徑向圓跳動(dòng)或帶柄滾刀支承部分的徑向圓跳動(dòng) |
AA |
8 |
10 |
10 |
10 |
10 |
15 |
A |
12 |
20 |
20 |
20 |
20 |
20 |
B |
15 |
20 |
20 |
20 |
20 |
20 |
C |
20 |
30 |
30 |
30 |
30 |
30 |
3 |
軸臺(tái)端面圓跳動(dòng)或帶柄滾刀支承端面的圓端面 |
AA |
5 |
8 |
8 |
8 |
10 |
10 |
A |
8 |
10 |
10 |
20 |
20 |
20 |
B |
12 |
20 |
20 |
20 |
20 |
20 |
C |
15 |
20 |
20 |
25 |
25 |
25 |
4 |
最大齒距偏差 |
AA |
±5 |
±8 |
±8 |
±10 |
±12 |
±12 |
A |
±8 |
±10 |
±10 |
±15 |
±15 |
±25 |
B |
±12 |
±15 |
±15 |
±25 |
±25 |
±35 |
C |
±20 |
±25 |
±40 |
±40 |
±40 |
±40 |
5 |
多頭蝸輪滾刀的相鄰齒距差 |
AA |
8 |
12 |
12 |
15 |
18 |
18 |
A |
12 |
15 |
15 |
25 |
25 |
40 |
B |
18 |
25 |
25 |
40 |
40 |
50 |
C |
30 |
40 |
60 |
60 |
60 |
60 |
6 |
任意三個(gè)齒距長(zhǎng)度內(nèi)最大的齒距累積誤差 |
AA |
±8 |
±12 |
±12 |
±15 |
±18 |
±18 |
A |
±12 |
±15 |
±15 |
±25 |
±25 |
±40 |
B |
±18 |
±25 |
±25 |
±40 |
±40 |
±50 |
C |
±30 |
±40 |
±60 |
±60 |
±60 |
±60 |
7 |
齒形誤差 |
AA |
5 |
8 |
10 |
12 |
15 |
20 |
A |
8 |
12 |
15 |
18 |
25 |
30 |
B |
12 |
18 |
25 |
30 |
35 |
40 |
C |
20 |
30 |
50 |
70 |
70 |
70 |
8 |
刀齒前刀面的徑向性 |
AA |
20 |
30 |
40 |
50 |
60 |
80 |
A |
25 |
40 |
50 |
70 |
90 |
120 |
B |
35 |
60 |
80 |
110 |
140 |
170 |
C |
50 |
90 |
120 |
150 |
200 |
250 |
9 |
到齒前端面與內(nèi)孔軸線的平行度(直槽滾刀) |
AA |
16 |
30 |
40 |
40 |
50 |
65 |
A |
20 |
35 |
45 |
50 |
60 |
70 |
B |
25 |
45 |
55 |
65 |
80 |
90 |
C |
30 |
45 |
55 |
65 |
80 |
90 |
10 |
容屑槽周節(jié)的最大累積誤差 |
AA |
25 |
35 |
40 |
50 |
50 |
60 |
A |
25 |
35 |
40 |
50 |
50 |
60 |
B |
30 |
35 |
40 |
50 |
60 |
70 |
C |
30 |
35 |
40 |
50 |
60 |
70 |
11 |
刀齒的徑向圓跳動(dòng)(直槽滾刀) |
AA |
20 |
20 |
20 |
30 |
40 |
40 |
A |
25 |
30 |
30 |
40 |
40 |
50 |
B |
30 |
40 |
50 |
60 |
60 |
80 |
C |
40 |
50 |
70 |
70 |
70 |
90 |
12 |
刀齒的徑向圓跳動(dòng)(螺旋槽滾刀) |
單頭 |
AA |
20 |
20 |
20 |
30 |
40 |
40 |
A |
25 |
30 |
30 |
40 |
40 |
50 |
B |
30 |
40 |
50 |
60 |
60 |
80 |
C |
40 |
50 |
70 |
70 |
70 |
90 |
多頭 |
AA |
30 |
30 |
30 |
45 |
60 |
60 |
A |
35 |
45 |
45 |
60 |
60 |
70 |
B |
40 |
60 |
70 |
80 |
80 |
100 |
C |
50 |
70 |
90 |
90 |
90 |
110 |
13 |
外徑錐度(直槽滾刀) |
AA |
20 |
30 |
30 |
40 |
40 |
50 |
A |
20 |
30 |
30 |
40 |
40 |
50 |
B |
30 |
40 |
40 |
45 |
45 |
50 |
C |
40 |
80 |
80 |
120 |
120 |
120 |
14 |
外徑錐度(螺旋槽滾刀) |
單頭 |
AA |
25 |
40 |
40 |
50 |
50 |
60 |
A |
30 |
40 |
40 |
50 |
50 |
60 |
B |
40 |
50 |
50 |
55 |
55 |
60 |
C |
50 |
90 |
90 |
130 |
130 |
130 |
多頭 |
AA |
30 |
50 |
50 |
60 |
60 |
70 |
A |
40 |
50 |
50 |
60 |
60 |
70 |
B |
50 |
60 |
60 |
65 |
65 |
70 |
C |
60 |
100 |
100 |
140 |
140 |
140 |
15 |
齒厚偏差 |
AA |
±12 |
±20 |
±25 |
±30 |
±40 |
±50 |
A |
±12 |
±20 |
±25 |
±30 |
±40 |
±50 |
B |
±12 |
±20 |
±25 |
±30 |
±40 |
±50 |
C |
±20 |
±30 |
±40 |
±50 |
±60 |
±70 |
16 |
外徑偏差 |
AA |
+0.15m①
-0.10m |
+0.25m
-0.15m |
+0.3m
-0.2m |
A |
B |
C |
±0.15m |
±0.3m |
±0.5m |
17 |
容屑槽的導(dǎo)程誤差(螺旋槽滾刀) |
|
容屑槽螺旋角βk |
βk≤10° |
βk>10° |
AA |
1.5%Pk |
1%Pk |
A |
2%Pk |
1.5%Pk |
B |
2.5%Pk |
2%Pk |
C |
3%Pk |
2.5%Pk |