图2-22所示螺纹特形轴，毛坯为φ58㎜×100㎜棒材，材料为45钢。数控车削前毛坯已粗车端面、钻好中心孔。

1．根据零件图样要求、毛坯情况，确定工艺方案及加工路线

1）对细长轴类零件，轴心线为工艺基准，用三爪自定心卡盘夹持φ58㎜外圆一头，使工件伸出卡盘175㎜，用顶尖顶持另一头，一次装夹完成粗精加工（注：切断时将顶尖退出）。

2）工步顺序

①粗车外圆。基本采用阶梯切削路线，粗车φ56㎜、SφS50㎜、φ36㎜、M30㎜各外圆段以及锥长为10㎜的圆锥段，留1㎜的余量。

②自右向左精车各外圆面：螺纹段右倒角→切削螺纹段外圆φ30㎜→车锥长10㎜的圆锥→车φ36㎜圆柱段→车φ56㎜圆柱段。

③车5㎜×φ26㎜螺纹退刀槽，倒螺纹段左倒角，车锥长10㎜的圆锥以及车5㎜×φ34㎜的槽。

④车螺纹。

⑤自右向左粗车R15㎜、R25㎜、Sφ50㎜、R15㎜各圆弧面及30°的圆锥面。

⑥自右向左精车R15㎜、R25㎜、Sφ50㎜、R15㎜各圆弧面及30°的圆锥面。

⑦切断。

2．选择机床设备

根据零件图样要求，选用经济型数控车床即可达到要求。故选用CK0630型数控卧式车床。

3．选择刀具

根据加工要求，选用三把刀具，T01为粗加工刀，选90°外圆车刀，T03为切槽刀，刀宽为3㎜，T05为螺纹刀。

同时把三把刀在自动换刀刀架上安装好，且都对好刀，把它们的刀偏值输入相应的刀具参数中。

4．确定切削用量

切削用量的具体数值应根据该机床性能、相关的手册并结合实际经验确定，详见加工程序。

5．确定工件坐标系、对刀点和换刀点

确定以工件左端面与轴心线的交点O为工件原点，建立XOZ工件坐标系。

采用手动试切对刀方法（操作与上面数控车床的对刀方法相同）把点O作为对刀点。换刀点设置在工件坐标系下X70、Z30处。

6．编写程序（该程序用于CK0630车床）

按该机床规定的指令代码和程序段格式，把加工零件的全部工艺过程编写成程序清单。该工件的加工程序如下：

N0010G59X0Z195

N0020G90

N0030G92X70Z30

N0040M03S450

N0050M06T01

N0060G00X57Z1

N0070G01X57Z-170F80

N0080G00X58Z1

N0090G00X51Z1

N0100G01X51Z-113F80

N0110G00X52Z1

N0120G91

N0130G81P3

N0140G00X-5Z0

N0150G01X0Z-63F80

N0160G00X0Z63

N0170G80

N0180G81P2

N0190G00X-3Z0

N0200G01X0Z-25F80

N0210G00X0Z25

N0220G80

N0230G90

N0240G00X31Z-25

N0250G01X37Z-35F80

N0260G00X37Z1

N0270G00X23Z-72.5

N0280G00X26Z1

N0290G01X30Z-2F60

N0300G01X30Z-25F60

N0310G01X36Z-35F60

N0320G01X36Z-63F60

N0330G00X56Z-63

N0340G01X56Z-170F60

N0350G28

N0360G29

N0370M06T03

N0380M03S400

N0390G00X31Z-25

N0400G01X26Z-25F40

N0410G00X31Z-23

N0420G01X26Z-23F40

N0430G00X30Z-21

N0440G01X26Z-23F40

N0450G00X36Z-35

N0460G01X26Z-25F40

N0470G00X57Z-113

N0480G01X34.5Z-113F40

N0490G00X57Z-111

N0500G01X34.5Z-111F40

N0510G28

N0520G29

N0530M06T05

N0540G00X30Z2

N0550G91

N0560G33D30I27.8X0.1P3Q0

N0570G01X0Z1.5

N0580G33D30I27.8X0.1P3Q0

N0590G90

N0600G00X38Z-45

N0610G03X32Z-54I60K-54F40

N0620G02X42Z-69I80K-54F40

N0630G03X42Z-99I0K-84F40

N0640G03X36Z-108I64K-108F40

N0650G00X48Z-113

N0660G01X56Z-135.4F60

N0670G00X56Z-113

N0680G00X40Z-113

N0690G01X56Z-135.4F60

N0700G00X50Z-113

N0710G00X36Z-113

N0720G01X56Z-108F60

N0730G00X36Z-45

N0740G00X36Z-45

N0750M03S800

N0760G03X30Z-54I60K-54F40

N0770G03X40Z-69I80K-54F40

N0780G02X40Z-99I0K-84F40

N0790G03X34Z-108I64K-108F40

N0800G01X34Z-113F40

N0810G01X56Z-135.4F40

N0820G28

N0830G29

N0840M06T03

N0850M03S400

N0860G00X57Z-168

N0870G01X0Z-168F40

N0880G28

N0890G29

N0900M05

N0910M02