How aPriori Groups Operations onto Die Stations
The Progressive Die operation routings for a part determine the order of operations on a given GCD. All together, they provide a partial ordering of all the operations on all the part’s GCDs—only operations on the same GCD are ordered with respect to one another. aPriori further orders the operations on all GCDs by assigning operations to die stations, and ordering the die stations. (Operations assigned to the same die station are not ordered with respect to one another; they are performed at the same time on different GCDs.)
Three kinds of rules guide aPriori’s assignment of operations and ordering of die stations:
Compatibility Rules
Any two operations that are assigned to the same die station must be compatible with one another. Two operations are compatible if and only if they not incompatible, as defined below:
• Any Trimming operation is incompatible with any Edge Trimming operation.
• Two Trimming operations are incompatible if they are not both performed on complex holes.
• Any two Edge Trimming operations are incompatible.
• Any two Post Form Trimming operations are incompatible.
• Any two Cam Action Trimming operations are incompatible.
• A Cam Action Bending operation is incompatible with any operation.
• A Tipping operation is incompatible with any operation that is not another Tipping operation.
• A Tipping Back operation is incompatible with any operation that is not another Tipping Back operation.
• A Cam Piercing operation is incompatible with any other Cam Piercing operation that is performed by a different Cam unit.
• Any Cam Piercing operation is incompatible with any Restriking operation.
• Any two operations which work primarily in opposite directions are incompatible, where the direction in which an operation works is defined (in terms of properties of the GCD on which the operation is performed) as follows:
o Coining: Chamfer Direction
o Countersinking, countersink direction
o Extruding, flange direction
o Cam over bending, bend direction
o Down over bending, bend direction
o Cam Action Bending on a Straight bend, bend direction
o Embossing, direction of greater depth (for example, up, if Depth UP is greater than Depth Down)
o Shear Embossing, direction of greater depth
o A Bending operation on a Form GCD, direction of greater depth
o Any operation on a MultiBend GCD, bend direction
o A Bending operation on a Straight Bend GCD, bend direction
o Gussett Bending, bend direction
• Any Piercing operation is incompatible with any operation of one of the following kinds:
o Restriking
o Forming
o Deep Drawing
o Drawing
o Embossing
o Coining
o Bending
o Down Over Bending
o Side Action Forming
o Scoring
• Two Piercing operations are incompatible if the GCDs on which they are performed are too close to each other, that is, if the distance between them (according to the LIES_NEAR relation) is less than or equal to the product of the blank’s Thickness and the cost model variable minHoleSpacingMultiplier.
• Two bending operations are incompatible if one bend lies between the other bend and the part’s main surface.
• A Bending operation on a GCD is incompatible with a Restriking operation on another GCD, if one GCD lies between the other GCD and the main surface.
• A Bending operation on a GCD is incompatible with a Cam Piercing operation on another GCD, if one GCD lies between the other GCD and the main surface.
• Any Tapping operation is incompatible with any non-Tapping operation.
• Two Tapping operations are incompatible if the GCDs on which they are performed are too close to each other, that is, if the distance between them (according to the LIES_NEAR relation) is less than the cost model variable minimumTapSpacingDistance.
• Any two Side Action Forming operations are incompatible.
If two operations are not incompatible as defined above, they are compatible.
Precedence Rules
The precedence rules specify, for any pair of operations, whether one must be performed before the other and, if so, which must be first.
If one operation must precede another, according to these rules, the first operation must be assigned to a die station that is earlier than the die station to which the second operation is assigned.
Following are the precedence rules:
• An Extrusion, Coining, Countersinking, Piercing, or Tapping operation must precede a bending operation of any of the following types, if the bend is between the extrusion or hole and the part’s main surface, and the extrusion or hole is not orthogonal to the main surface (that is, it is not accessible from a direction that is within 15 degrees of forming a 90 degree angle with the main surface):
o Any operation on a MultiBend GCD.
o Bending
o Restriking
o Setting
o Scoring
o Down Over Bending
o Cam Action Bending
• An Embossing operation must precede a bending operation of any of the following types, if the bend is between the form and the main surface:
o Any operation on a MultiBend GCD.
o Bending
o Gussett Bending
o Cam Over Bending
o Down Over Bending
o Cam Action Bending
o Setting
o Scoring
• A Bending operation on a GCD, bend1, must precede a Bending operation on a GCD, bend2, if bend2 is between bend1 and the main surface.
• A Bending operation must precede a Cam Piercing operation, if the bend is between the pierce and the main surface.
• A Cam Action Bending operation on a GCD, bend1, must precede a Bending operation on a GCD, bend2, if bend2 is between bend1 and the main surface.
• A Cam Action Bending operation on a GCD, feature1, must precede a Restriking operation on a GCD, feature2, if feature2 is between feature1 and the main surface.
• The Cutoff operation must be preceded by every other operation.
• The Piloting operation must precede every other operation.
• The Piloting Edge Trimming operation must precede any other operation except an edge trimming operation.
• Any operation of one of the following types must precede any Repiloting operation:
o Embossing
o Restriking
o Drawing
o Deep Drawing
• Any Embossing operation must precede any Restriking operation.
• Any Edge Trimming operation must precede any operation of one of the following types:
o Cam Piercing
o Embossing
o Bending
o Drawing
o Deep Drawing
• Any Full Blanking operation must precede any operation of one of the following types:
o Embossing
o Bending
o Drawing
o Deep Drawing
o Cam Piercing
o Shear Embossing
o Operation on a MultiBend GCD
o Gusset Bending
o Cam Over Bending
o Down Over Bending
o Setting
o Scoring
o Cam Action Bending
o Stamping
o Forming
o Shear Forming
o Shear Stamping
o Restriking
o Extruding
o Coining
o Countersinking
o Side Action Forming
• Any Trimming operation must precede any operation of one of the following types:
o Bending
o Cam Piercing
o Embossing
o Shear Embossing
o Operation on a MultiBend GCD
o Gusset Bending
o Cam Over Bending
o Down Over Bending
o Setting
o Scoring
o Cam Action Bending
o Stamping
o Forming
o Shear Forming
o Shear Stamping
o Restriking
o Extruding
o Coining
o Countersinking
o Side Action Forming
o Drawing
o Deep Drawing
• Any operation of one of the following types must precede any Cam Action Piercing operation:
o Side Action Forming
o Cam Action Bending
o Down Over Bending
o Countersinking
o Restriking
• Any Bending operation must precede any Restriking operation.
• Any operation of one of the following types on a GCD, feature1, must precede any Cam Action Bending operation on a given bend, if feature1 does not lie between the bend and the main surface:
o Operation on a MultiBend GCD
o Setting
o Scoring
o Stamping
o Forming
o Drawing
o Deep Drawing
o Embossing
o Restriking
o Coining
o Bending
o ShearEmbossing
o ShearForming
o ShearStamping
• Any operation of one of the following types must precede any Cam Action Piercing operation:
o Operation on a MultiBend GCD
o Setting
o Scoring
o Stamping
o Forming
o Drawing
o Deep Drawing
o Embossing
o Restriking
o Coining
o Bending
o ShearEmbossing
o ShearForming
o ShearStamping
The screen capture below shows Bending operations preceding a Cam Action Piercing operation.
• Any operation of one of the following types must precede any Cam Trimming operation:
o Operation on a MultiBend GCD
o Setting
o Scoring
o Stamping
o Forming
o Drawing
o Deep Drawing
o Embossing
o Restriking
o Coining
o Bending
o ShearEmbossing
o ShearForming
o ShearStamping
• A Piercing operation on a hole must precede a Bending operation, if the hole is not accessible from any candidate setup axis.
• A Cam Action Piercing operation on must precede a Piercing operation on a given hole if the setup option Pierce Before or After Forms is set to holesAfterForms and the hole is accessible from a direction that is within 15 degrees of the perpendicular to the main surface.
• Any operation of one of the following types must precede a Piercing operation on a given hole if the setup option Pierce Before or After Forms is set to holesAfterForms and the hole is accessible from a direction that is within 15 degrees of the perpendicular to the main surface:
o Forming
o Deep Drawing
o Drawing
o Embossing
o Restriking
o Coining
o Setting
o Stamping
o Side Action Forming
o Cam Action Bending
o DownOverBending
o Bending
• An orthogonal hole-making operation (Piercing, Extruding, Coining, Shaving, CounterSinking, or Tapping) must precede an operation of one of the following types on a given hole if the setup option Pierce Before or After Forms is set to holesBeforeForms:
o Forming
o Deep Drawing
o Drawing
o Embossing
o Restriking
o Coining
o Setting
o Stamping
o Side Action Forming
o Cam Action Bending
o DownOverBending
o Bending
• Any Post Form Trimming operation must precede any Piercing operation.
• Any Post Form Trimming operation must precede any Cam Action Piercing operation.
• Any Cam Action Trimming operation must precede any Piercing operation.
• Any Cam Action Trimming operation must precede any Cam Action Piercing operation.
• Any operation of one of the following types must preceded any Cam Action Trimming operation:
o Forming
o Deep Drawing
o Drawing
o Embossing
o Coining
o Bending
DownOverBending
o Side Action Forming
o Scoring
o Bending
o Cam Action Bending
• Any Embossing operation must precede any Tapping operation.
• Any Cam Piercing operation must precede any Tapping operation on a hole that is orthogonal to the main surface if the setup option Pierce Before or After Forms is set to holesAfterForms.
• Any operation of one of the following types must precede and Post Form Trimming operation:
o Embossing
o Restriking
o Drawing
o DeepDrawing
o Bending
o CamActionBending
Idle Station Rules
aPriori sometimes adds idle stations before or after a given station, based on the following rules:
• Tapping: an idle station must precede a station that includes a Tapping operation, by default in aPriori starting point VPEs.
VPE administrators can customize the default with the cost model variable addIdleBeforeAfterTappingEnabled (which is set to Before and After in aPriori Starting Point VPEs).
You can override the default on a per-part basis with the PSO Add Idle Station Before After Tapping.
• Cutoff: an idle station must precede a station that includes a Cutoff operation, by default in aPriori starting point VPEs.
VPE administrators can customize the default with the cost model variable addIdleBeforeCutoffEnabled (which is set to Yes in aPriori Starting Point VPEs).
You can override the default on a per-part basis with the PSO Add IDLE Station Before CUTOFF Station.
• Tapping: an idle station must follow a station that includes a Tapping operation, by default in aPriori starting point VPEs.
VPE administrators can customize the default with the cost model variable addIdleBeforeAfterTappingEnabled (which is set to Before and After in aPriori Starting Point VPEs).
You can override the default on a per-part basis with the PSO Add Idle Station Before After Tapping.
• Trimming: an idle station must follow a station that includes a Trimming operation, by default in starting point VPEs, if the blank pitch (see Blank Pitch) is less than 80mm.
VPE administrators can use the cost model variable defaultBlakPitchThreshold to customize the blank pitch that, by default, requires an idle station. VPE administrators can use the cost model variable addIdleAfterTrimmingEnabled to specify that, by default, trimming requires no idle station, regardless of blank pitch.
• Cam Action Piercing: an idle station must follow a station that includes a Cam Action Piercing operation, by default in aPriori starting point VPEs, if the cam approach is within 45o of being parallel to the part strip flow.
VPE administrators can use the cost model variable camApproachAngleThreshold to customize the default allowable deviation from parallel for cam unit approach. VPE administrators can use the cost model variable addIdleAfterCamPierceEnabled to specify that, by default, cam piercing requires no idle station, regardless of the cam’s angle of approach.
You can override the default on a per-part basis with the PSO Add Idle Station After Cam Piercing.
• Cam Action Bending: an idle station must follow a station that includes a Cam Action Bending operation, by default in aPriori starting point VPEs, if the cam approach is within 45o of being parallel to the part strip flow.
VPE administrators can use the cost model variable camApproachAngleThreshold to customize the default allowable deviation from parallel for cam unit approach. VPE administrators can use the cost model variable addIdleAfterCamBendEnabled to specify that, by default, cam bending requires no idle station, regardless of the cam’s angle of approach.
You can override the default on a per-part basis with the PSO Add Idle Station After Cam Bending.
• Cam Action Trimming: an idle station must follow a station that includes a Cam Action Trimming operation, by default in aPriori starting point VPEs, if the cam approach is within 45o of being parallel to the part strip flow.
VPE administrators can use the cost model variable camApproachAngleThreshold to customize the default allowable deviation from parallel for cam unit approach. VPE administrators can use the cost model variable addIdleAfterCamTrimEnabled to specify that, by default, cam piercing requires no idle station, regardless of the cam’s angle of approach.
You can override the default on a per-part basis with the PSO Add Idle Station After Cam Trimming.
• Cam Action Forming: an idle station must follow a station that includes a Cam Action Forming operation, by default in aPriori starting point VPEs, if the cam approach is within 45o of being parallel to the part strip flow.
VPE administrators can use the cost model variable camApproachAngleThreshold to customize the default allowable deviation from parallel for cam unit approach. VPE administrators can use the cost model variable addIdleAfterCamFormEnabled to specify that, by default, cam piercing requires no idle station, regardless of the cam’s angle of approach.
You can override the default on a per-part basis with the PSO Add Idle Station After Cam Forming.