1、13FUNCTIONS TO SIMPLIFY PROGRAMMING 13 FUNCTIONS TO SIMPLIFY PROGRAMMING 13.1 CANNED CYCLE13.2 RIGID TAPPING13FUNCTIONS TO SIMPLIFY PROGRAMMING 13.1 CANNED CYCLE Canned cycles make it easier for the programmer to create programs.With a canned cycle,a frequentlyused machining operation can be specifi
2、ed in a single block with a G function;without canned cycles,normally more than one block is required.In addition,the use of canned cycles can shorten the program to save memory.Table 13.1 lists canned cycles.13FUNCTIONS TO SIMPLIFY PROGRAMMING 13FUNCTIONS TO SIMPLIFY PROGRAMMING ExplanationsA canne
3、d cycle consists of a sequence of six operations(Fig.13.1(a).Operation 1:Positioning of axes X and Y(including also another axis)Operation 2:Rapid traverse up to point R levelOperation 3:Hole machiningOperation 4:Operation at the bottom of a holeOperation 5:Retraction to point R levelOperation 6:Rap
4、id traverse up to the initial point13FUNCTIONS TO SIMPLIFY PROGRAMMING Fig.13.1(a)Canned cycle operation sequence13FUNCTIONS TO SIMPLIFY PROGRAMMING Positioning planeThe positioning plane is determined by plane selection code G17,G18,or G19.The positioning axis is an axis other than the drilling axi
5、s.13FUNCTIONS TO SIMPLIFY PROGRAMMING Drilling axisAlthough canned cycles include tapping and boring cycles as well as drilling cycles,in this chapter,only the term drilling will be used to refer to operations implemented with canned cycles.The drilling axis is a basic axis(X,Y,or Z)not used to defi
6、ne the positioning plane,or any axis parallel to that basic axis.The axis(basic axis or parallel axis)used as the drilling axis is determined according to the axis address for the drilling axis specified in the same block as G codes G73 to G89.If no axis address is specified for the drilling axis,th
7、e basic axis is assumed to be the drilling axis.13FUNCTIONS TO SIMPLIFY PROGRAMMING 13FUNCTIONS TO SIMPLIFY PROGRAMMING Xp:X axis or an axis parallel to the X axisYp:Y axis or an axis parallel to the Y axisZp:Z axis or an axis parallel to the Z axisAssume that the U,V and W axes be parallel to the X
8、,Y,and Z axes respectively.This condition is specified by parameter No.1022.G17 G81 Z-:The Z axis is used for drilling.G17 G81 W-:The W axis is used for drilling.G18 G81 Y-:The Y axis is used for drilling.G18 G81 V-:The V axis is used for drilling.G19 G81 X-:The X axis is used for drilling.G19 G81 U
9、-:The U axis is used for drilling.13FUNCTIONS TO SIMPLIFY PROGRAMMING ExamplesG17 to G19 may be specified in a block in which any of G73 to G89 is not specified.WARNINGSwitch the drilling axis after cancelling a canned cycle.NOTEA parameter FXY(No.6200 0)can be set to the Z axis always used as the d
10、rilling axis.When FXY=0,the Z axis is always the drilling axis.Travel distance along the drilling axis G90/G91 The travel distance along the drilling axis varies for G90 and G91 as follows.13FUNCTIONS TO SIMPLIFY PROGRAMMING Fig.13.1(b)Travel distance along the drilling axis 13FUNCTIONS TO SIMPLIFY
11、PROGRAMMING Drilling modeG73,G74,G76,and G81 to G89 are modal G codes and remain in effect until cancelled.When in effect,the current state is the drilling mode.Once drilling data is specified in the drilling mode,the data is retained until modified or cancelled.Specify all necessary drilling data a
12、t the beginning of canned cycles;when canned cycles are being performed,specify data modifications only.13FUNCTIONS TO SIMPLIFY PROGRAMMING Return point level G98/G99 When the tool reaches the bottom of a hole,the tool may be returned to point R or to the initial level.These operations are specified
13、 with G98 and G99.The following illustrates how the tool moves when G98 or G99 is specified.Generally,G99 is used for the first drilling operation and G98 is used for the last drilling operation.The initial level does not change even when drilling is performed in the G99 mode.13FUNCTIONS TO SIMPLIFY
14、 PROGRAMMING Fig.13.1(c)Return point level13FUNCTIONS TO SIMPLIFY PROGRAMMING RepeatTo repeat drilling for equallyspaced holes,specify the number of repeats in K-.K is effective only within the block where it is specified.Specify the first hole position in incremental mode(G91).If it is specified in
15、 absolute mode(G90),drilling is repeated at the same position.Number of repeats K The maximum command value=9999If K0 is specified,drilling data is stored,but drilling is not performed.13FUNCTIONS TO SIMPLIFY PROGRAMMING CancelTo cancel a canned cycle,use G80 or a group 01 G code.Group 01 G codesG00
16、:Positioning(rapid traverse)G01:Linear interpolationG02:Circular interpolation or helical interpolation(CW)G03:Circular interpolation or helical interpolation(CCW)Symbols in figuresSubsequent sections explain the individual canned cycles.Figures in these explanations use the following symbols.13FUNC
17、TIONS TO SIMPLIFY PROGRAMMING Fig.13.1(d)Symbols in figures13FUNCTIONS TO SIMPLIFY PROGRAMMING 13.1.1 Highspeed Peck Drilling Cycle(G73)This cycle performs highspeed peck drilling.It performs intermittent cutting feed to the bottom of a hole while removing chips from the hole.Format 13FUNCTIONS TO S
18、IMPLIFY PROGRAMMING Fig.13.1(e)Highspeed Peck Drilling Cycle(G73)13FUNCTIONS TO SIMPLIFY PROGRAMMING ExplanationsThe highspeed peck drilling cycle performs intermittent feeding along the Zaxis.When this cycle is used,chips can be removed from the hole easily,and a smaller value can be set for retrac
19、tion.This allows,drilling to be performed efficiently.Set the clearance,d,in parameter 5114.The tool is retracted in rapid traverse.Before specifying G73,rotate the spindle using a miscellaneous function(M code).When the G73 code and an M code are specified in the same block,the M code is executed a
20、t the time of the first positioning operation.The system then proceeds to the next drilling operation.13FUNCTIONS TO SIMPLIFY PROGRAMMING When K is used to specify the number of repeats,the M code is executed for the first hole only;for the second and subsequent holes,the M code is not executed.When
21、 a tool length offset(G43,G44,or G49)is specified in the canned cycle,the offset is applied at the time of positioning to point R.Limitations Axis switchingBefore the drilling axis can be changed,the canned cycle must be cancelled.DrillingIn a block that does not contain X,Y,Z,R,or any other axes,dr
22、illing is not performed.13FUNCTIONS TO SIMPLIFY PROGRAMMING Q/RSpecify Q and R in blocks that perform drilling.If they are specified in a block that does not perform drilling,they cannot be stored as modal data.CancelDo not specify a group 01 G code(G00 to G03)and G73 in the same block.If they are s
23、pecified together,G73 is cancelled.Tool offsetIn the canned cycle mode,tool offsets are ignored.13FUNCTIONS TO SIMPLIFY PROGRAMMING 13.1.2 Lefthanded Tapping Cycle(G74)This cycle performs lefthanded tapping.In the lefthanded tapping cycle,when the bottom of the hole has been reached,the spindle rota
24、tes clockwise.13FUNCTIONS TO SIMPLIFY PROGRAMMING Fig.13.1(f)Lefthanded Tapping Cycle(G74)13FUNCTIONS TO SIMPLIFY PROGRAMMING ExplanationsTapping is performed by turning the spindle counterclockwise.When the bottom of the hole has been reached,the spindle is rotated clockwise for retraction.This cre
25、ates a reverse thread.Feedrate overrides are ignored during lefthanded tapping.A feed hold does not stop the machine until the return operation is completed.Before specifying G74,use a miscellaneous function(M code)to rotate the spindle counterclockwise.13FUNCTIONS TO SIMPLIFY PROGRAMMING When the G
26、74 command and an M code are specified in the same block,the M code is executed at the time of the first positioning operation.The system then proceeds to the next drilling operation.When K is used to specify the number of repeats,the M code is executed for the first hole only;for the second and sub
27、sequent holes,the M code is not executed.When a tool length offset(G43,G44,or G49)is specified in the canned cycle,the offset is applied at the time of positioning to point R.13FUNCTIONS TO SIMPLIFY PROGRAMMING Limitations Axis switchingBefore the drilling axis can be changed,the canned cycle must b
28、e cancelled.DrillingIn a block that does not contain X,Y,Z,R,or any other axes,drilling is not performed.RSpecify R in blocks that perform drilling.If it is specified in a block that does not perform drilling,it cannot be stored as modal data.13FUNCTIONS TO SIMPLIFY PROGRAMMING CancelDo not specify
29、a group 01 G code(G00 to G03)and G74 in the same block.If they are specified together,G74 is cancelled.Tool offsetIn the canned cycle mode,tool offsets are ignored.13FUNCTIONS TO SIMPLIFY PROGRAMMING 13.1.3 Fine Boring Cycle(G76)The fine boring cycle bores a hole precisely.When the bottom of the hol
30、e has been reached,the spindle stops,and the tool is moved away from the machined surface of the workpiece and retracted.Format13FUNCTIONS TO SIMPLIFY PROGRAMMING Fig.13.1(g)Fine Boring Cycle(G76)13FUNCTIONS TO SIMPLIFY PROGRAMMING WARNINGQ(shift at the bottom of a hole)is a modal value retained wit
31、hin canned cycles.It must be specified carefully because it is also used as the depth of cut for G73 and G83.13FUNCTIONS TO SIMPLIFY PROGRAMMING ExplanationsWhen the bottom of the hole has been reached,the spindle is stopped at the fixed rotation position,and the tool is moved in the direction oppos
32、ite to the tool tip and retracted.This ensures that the machined surface is not damaged and enables precise and efficient boring to be performed.Before specifying G76,use a miscellaneous function(M code)to rotate the spindle.When the G76 command and an M code are specified in the same block,the M co
33、de is executed at the time of the first positioning operation.The system then proceeds to the next operation.13FUNCTIONS TO SIMPLIFY PROGRAMMING When K is used to specify the number of repeats,the M code is executed for the first hole only;for the second and subsequent holes,the M code is not execut
34、ed.When a tool length offset(G43,G44,or G49)is specified in the canned cycle,the offset is applied at the time of positioning to point R.13FUNCTIONS TO SIMPLIFY PROGRAMMING Limitations Axis switchingBefore the drilling axis can be changed,the canned cycle must be cancelled.BoringIn a block that does
35、 not contain X,Y,Z,R,or any additional axes,boring is not performed.Q/RBe sure to specify a positive value in Q.If Q is specified with a negative value,the sign is ignored.Set the direction of shift in bits 4(RD1)and 5(RD2)of parameter 5101.Specify Q and R in a block that performs boring.If they are
36、 specified in a block that does not perform boring,they are not stored as modal data.13FUNCTIONS TO SIMPLIFY PROGRAMMING CancelDo not specify a group 01 G code(G00 to G03)and G76 in the same block.If they are specified together,G76 is cancelled.Tool offsetIn the canned cycle mode,tool offsets are ig
37、nored.13FUNCTIONS TO SIMPLIFY PROGRAMMING 13.1.4 Drilling Cycle,Spot Drilling(G81)This cycle is used for normal drilling.Cutting feed is performed to the bottom of the hole.The tool is then retracted from the bottom of the hole in rapid traverse.Format13FUNCTIONS TO SIMPLIFY PROGRAMMING Fig.13.1(h)D
38、rilling Cycle,Spot Drilling(G81)13FUNCTIONS TO SIMPLIFY PROGRAMMING ExplanationsAfter positioning along the X and Y axes,rapid traverse is performed to point R.Drilling is performed from point R to point Z.The tool is then retracted in rapid traverse.Before specifying G81,use a miscellaneous functio
39、n(M code)to rotate the spindle.When the G81 command and an M code are specified in the same block,the M code is executed at the time of the first positioning operation.The system then proceeds to the next drilling operation.13FUNCTIONS TO SIMPLIFY PROGRAMMING When K is used to specify the number of
40、repeats,the M code is performed for the first hole only;for the second and subsequent holes,the M code is not executed.When a tool length offset(G43,G44,or G49)is specified in the canned cycle,the offset is applied at the time of positioning to point R.13FUNCTIONS TO SIMPLIFY PROGRAMMING Restriction
41、s Axis switchingBefore the drilling axis can be changed,the canned cycle must be cancelled.DrillingIn a block that does not contain X,Y,Z,R,or any other axes,drilling is not performed.RSpecify R in blocks that perform drilling.If it is specified in a block that does not perform drilling,it cannot be
42、 stored as modal data.13FUNCTIONS TO SIMPLIFY PROGRAMMING CancelDo not specify a group 01 G code(G00 to G03)and G81 in the same block.If they are specified together,G81 is cancelled.Tool offsetIn the canned cycle mode,tool offsets are ignored.13FUNCTIONS TO SIMPLIFY PROGRAMMING 13.1.5 Drilling Cycle
43、 Counter Boring Cycle(G82)This cycle is used for normal drilling.Cutting feed is performed to the bottom of the hole.At the bottom,a dwell is performed,then the tool is retracted in rapid traverse.This cycle is used to drill holes more accurately with respect to depth.Format13FUNCTIONS TO SIMPLIFY P
44、ROGRAMMING Fig.13.1(i)Drilling Cycle Counter Boring Cycle(G82)13FUNCTIONS TO SIMPLIFY PROGRAMMING Explanations After positioning along the X and Y axes,rapid traverse is performed to point R.Drilling is then performed from point R to point Z.When the bottom of the hole has been reached,a dwell is pe
45、rformed.The tool is then retracted in rapid traverse.Before specifying G82,use a miscellaneous function(M code)to rotate the spindle.When the G82 command and an M code are specified in the same block,the M code is executed at the time of the first positioning operation.The system then proceeds to th
46、e next drilling operation.13FUNCTIONS TO SIMPLIFY PROGRAMMING When K is used to specify the number of repeats,the M code is executed for the first hole only;for the second and subsequent holes,the M code is not executed.When a tool length offset(G43,G44,or G49)is specified in the canned cycle,the of
47、fset is applied at the time of positioning to point R.13FUNCTIONS TO SIMPLIFY PROGRAMMING Restrictions Axis switchingBefore the drilling axis can be changed,the canned cycle must be cancelled.DrillingIn a block that does not contain X,Y,Z,R,or any other axes,drilling is not performed.RSpecify R in b
48、locks that perform drilling.If it is specified in a block that does not perform drilling,it cannot be stored as modal data.13FUNCTIONS TO SIMPLIFY PROGRAMMING CancelDo not specify a group 01 G code(G00 to G03)and G82 in the same block.If they are specified together,G82 is cancelled.Tool offsetIn the
49、 canned cycle mode,tool offsets are ignored.13FUNCTIONS TO SIMPLIFY PROGRAMMING 13.1.6 Peck Drilling Cycle(G83)This cycle performs peck drilling.It performs intermittent cutting feed to the bottom of a hole while removing shavings from the hole.Format13FUNCTIONS TO SIMPLIFY PROGRAMMING Fig.13.1(j)Pe
50、ck Drilling Cycle(G83)13FUNCTIONS TO SIMPLIFY PROGRAMMING ExplanationsQ represents the depth of cut for each cutting feed.It must always be specified as an incremental value.In the second and subsequent cutting feeds,rapid traverse is performed up to a d point just before where the last drilling end
