Operation-level Feasibility and Routing for Progressive Die
Below are the hard-tooled sheet metal operations, grouped by GCD type.
Blank
Initial operations to create the blank consist of piloting or piloting combined with edge trimming, followed by edge trimming, optional repiloting, and additional trimming if necessary.
• Piloting Edge Trimming is used by default in starting point VPEs. It is used if the setup option Enable Standalone Piloting Operation is No. This allows piloting and edge trimming to be performed on the same die station.
• Piloting is used only if the setup option Enable Standalone Piloting Operation is Yes. In this case, piloting is performed on a separate die station, prior to edge trimming.
• Edge Trimming is used if at least one of the following hold:
o Cost model variable multipleTrimsProgDie is true. (The variable is set to true in aPriori starting point VPEs.)
o Flattened part has at least one long, thin “peninsula” (see Peninsular Ratio Property for Hard Tooled Sheet Metal).
By default, the routing includes one instance of the operation for each edge to be trimmed, except the edge trimmed by the operation Trimming Piloting. So the number of instances of this operation is either the value of the cost model variable numEdgeTrimsPerPart (if the PSO Enable Standalone Piloting Operation is Yes) or one less than the value of the cost model variable numEdgeTrimsPerPart (if the PSO Enable Standalone Piloting Operation is No). In starting point VPEs, the cost model variable numEdgeTrimsPerPart is 1.
• Re Piloting must be manually included in a routing, and is always considered feasible.
• Trimming is included in the operation sequence only if at least one of the following hold:
o Cost model variable multipleTrimsProgDie is true. (The variable is set to true in aPriori starting point VPEs.)
o Flattened part has at least one long, thin “peninsula” (see Peninsular Ratio Property for Hard Tooled Sheet Metal).
By default, the routing includes one instance of the Trimming operation for each trim still to be performed. aPriori calculates the number of trims based on the blank perimeter and numEdgeTrimsPerPart (1 in starting point VPEs). This value is limited by the cost model variable maxTrimStagesProgDie (4 in starting point VPEs); in other words, the number of Trimming instances never exceeds maxTrimStagesProgDie minus numEdgeTrimsPerPart. You can override the calculated value with the PSO Direct Trim Angle Threshold.
Later operations on the blank consist of optional operations tipping, tipping back, and coining, followed by cutoff.
• Tipping must be manually included in a routing, and is always considered feasible.
• TippingBack must be manually included in a routing, and is always considered feasible.
• Coining is included in the operation sequence only if the blank is chamfered (see the Blank property Is Chamfered in the Geometric Cost Drivers pane).
• Cutoff is always included.
StraightBend
StarightBends are created with the Bending operation and several optional operations. In the following example sequence, aPriori decided to include Scoring:
• Scoring is performed if both the following hold:
o Process setup option Enable SCORING Operation is Yes. (The PSO default is No is starting point VPEs.)
o Bend is a long hem or bend is close to a large hole.
Long hem recognition compares the bend arc angle with the plant variables maxHemRecognitionAngle and minHemRecognitionAngle, and compares the bend length with the plant variable hemLengthThreshold.
Close means a distance less than the product of blank thickness and the plant variable formBasedScoringMultiplierThreshold.
Large hole recognition compares diameter with minSimpleHoleDiameterThreshold (for simple holes) and perimeter with minComplexHolePerimeterThreshold (for complex holes).
• Bending is feasible only if both the following hold:
o Bend arc angle is greater than or equal to the cost model variable flapBasedRecognitionAngle.
o Bend flap size greater than or equal to the cost model variable bendFlapSizeThreshold.
• Cam Action Bending is performed if both the following hold:
o Bend arc angle is greater than or equal to the cost model variable camBendingRecognitionAngle..
o Bend is not a standard hem. Standard hem recognition compares the bend arc angle with the plant variables maxHemRecognitionAngle and minHemRecognitionAngle, and requires that the hem is not between the main surface and any other bend or form.
• Restriking is performed if both the following hold:
o Setup option Enable Restriking Operation for Straight and Curved Bends is set to Yes (the default in starting point VPEs).
o Bend flap size greater than or equal to the cost model variable bendFlapSizeRestrikeThreshold.
• DownOverBending is performed if the following condition holds:
o Bend is a standard hem. Standard hem recognition requires that the bend arc angle is between the plant variables maxHemRecognitionAngle and minHemRecognitionAngle, and requires that the hem is not between the main surface and any other bend or form.
• Setting is performed if the following condition holds:
o Bend is a standard hem. Standard hem recognition requires that the bend arc angle is between the plant variables maxHemRecognitionAngle and minHemRecognitionAngle, and requires that the hem is not between the main surface and any other bend or form.
Form
Forming operations are divided into two categories:
• Standard forming
• Drawing
Standard forming operations are used only if both the following hold:
• At least one of the following holds:
o Deep draw ratio is less than the cost model variable deepDrawRatioThreshold. The deep draw ratio is the ratio of the form’s depth to Width (depth is either Depth Up or Depth Down, whichever is greater):
max(Depth Up, Depth Down) / SER Width < deepDrawRatioThreshold
o Form’s enclosing-rectangle area (product of SER Length and SER Width) is more than half of the part’s area (product of component Length and Width):
(form SER Length * form SER Width) / (component Length * component Width) > 0.5
o Form Sub Type is CurvedBend.
o Form Sub Type is Stamp.
• At least one of the following holds:
o Form is not too deep; that is, the sum of the form’s Depth Up and Depth Down is less than the cost model variable drawDepthThreshold:
Depth Up + Depth Down < drawDepthThreshold
o Draw ratio is less than the cost model variable drawRatioThreshold. The draw ratio is the GCD Area divided by the part’s area (product of component Length and Width):
Form Area / (Component Length * Component Width) < drawRatioThreshold
o Form’s enclosing-rectangle area (product of SER Length and SER Width) is more than half of the part’s area (product of component Length and Width).
(form SER Length * form SER Width) / (component Length * component Width) > 0.5
o Form Sub Type is CurvedBend.
o Form Sub Type is Stamp.
Standard forming operations are all optional. In the following example sequence, aPriori decided to include Embossing:
• Scoring is performed only if both the following hold:
o Cost model variable scoreBendsProgDie is true.
o Bend is a long hem or bend is close to a large hole.
Long hem recognition compares the bend arc angle with the plant variables maxHemRecognitionAngle and minHemRecognitionAngle, and compares the bend length with the plant variable hemLengthThreshold.
Close means a distance less than the product of blank thickness and the plant variable formBasedScoringMultiplierThreshold.
Large hole recognition compares diameter with minSimpleHoleDiameterThreshold (for simple holes) and perimeter with minComplexHolePerimeterThreshold (for complex holes).
• Bending is performed only if the form Sub Type is CurvedBend.
• Cam Action Bending is performed only if all the following hold:
o Form Sub Type is CurvedBend.
o Bend arc angle is greater than or equal to the cost model variable camBendingRecognitionAngle..
o Bend is not a standard hem. Standard hem recognition compares the bend arc angle with the plant variables maxHemRecognitionAngle and minHemRecognitionAngle, and requires that the hem is not between the main surface and any other bend or form.
• Stamping is performed only if the form Sub Type is Stamp
• Forming is performed only if one of the following holds:
o Form Sub Type is Tab.
o Form Sub Type is Bridge
o Form Sub Type is Emboss and form is a dimple. Dimple recognition compares form perimeter with the cost model variable maxDimplePerimeter, and compares each of depth up and depth down with the cost model variable maxDimpleDepth.
• .Embossing is included in the operation sequence only if all of the following hold:
o Form Sub Type is Emboss.
o Form is a not a dimple. Dimple recognition compares form perimeter with the cost model variable maxDimplePerimeter, and compares each of depth up and depth down with the cost model variable maxDimpleDepth.
o Form either is orthogonal to the main surface or is both relatively large and not on the edge of either the part or a complex hole.
A form is orthogonal to the main surface if it is accessible from a direction that forms an angle with the main surface of about 90 degrees. The angle must be within sideActionAxisTolerance of 90 degrees to be considered orthogonal.
A form is considered relatively large if the cost model variable formAreaAreaThreshold is less than the percentage of half the component Surface Area occupied by the form Area, that is, if formAreaThreshold < (form Area / (component Surface Area / 2) * 100.
• Side Action Forming is included in the operation sequence only if all of the following hold:
o Form Sub Type is Emboss.
o Form is not orthogonal to the main surface. A form is orthogonal to the main surface if it is accessible from a direction that forms an angle with the main surface of about 90 degrees. The angle must be within sideActionAxisTolerance of 90 degrees to be considered orthogonal.
o Form is highly deformed. A form is considered highly deformed if the cost model variable deformationThreshold is less than the percentage of half the component Surface Area occupied by the forms child GCDs:
deformationThreshold < (sum of Areas of form’s children / (component Surface Area / 2) * 100.
o Form is either on the edge of the part or on the edge of a complex hole.
o Form is relatively small. A form is considered relatively small if the cost model variable formAreaThreshold is greater than the percentage of half the component Surface Area occupied by the form Area:
formAreaThreshold > (form Area / (component Surface Area / 2) * 100.
• Restriking is included in the operation sequence only if the setup option Enable Restriking Operation for Straight and Curved Bends is set to Yes (the default in starting point VPEs) and at least one of the of the following holds:
o Form is orthogonal to the main surface. A form is orthogonal to the main surface if it is accessible from a direction that forms an angle with main surface of about 90 degrees. The angle must be within sideActionAxisTolerance of 90 degrees to be considered orthogonal.
o Form is not on the edge of either the part or a complex hole.
o Form is relatively large. A form is considered relatively large if the cost model variable formAreaAreaThreshold is less than the percentage of half the component Surface Area occupied by the form Area.
formAreaThreshold < (form Area / (component Surface Area / 2) * 100.
o Form Sub Type is not Emboss.
In addition, if the form’s Sub Type is Curved Bend, the following must hold for this operation to be included in the sequence:
o Form’s Depth up or Depth Down (whichever is larger) is less than or equal to the cost model variable bendFlapSizeRestrikeThreshold.
In addition, if the form’s Sub Type is not Curved Bend, one of the following must hold
o Form Sub Type is Emboss and form is sufficiently big. A form is considered sufficiently big if the sum of its Depth Up and Depth Down is greater than 10mm and the form is not a deep dimple. Deep dimple recognition compares form perimeter with the cost model variable maxDimplePerimeter, and compares each of depth up and depth down with the cost model variable maxDeepDimpleDepth.
o Form Sub Type is Bridge and form is sufficiently deep. A form is considered sufficiently deep if the form’s Depth Up or Depth Down (whichever is greater) is greater than the product of the blank Thickness and the cost model variable bridgeRestrikingMultiplier.
Drawing operations are divided into two categories:
• Deep drawing
• Standard drawing
• Deep Drawing is feasible only if both the following hold:
o Form’s deep draw ratio is greater than or equal to the cost model variable deepDrawRatioThreshold. The deep draw ratio is the ratio of the form’s depth to width, that is, the form’s Depth Up or Depth Down (whichever is larger) divided by the form’s SER Width.
o Form’s enclosing-rectangle area (product of SER Length and SER Width) is less than or equal to half the part’s area (product of component Length and Width).
(form SER Length * form SER Width) / (component Length * component Width) <= 0.5
This operation is performed only if the form’s Sub Type is not Stamp.
The operation, if performed, is performed between 2 and maxNumberDeepDraws (cost model variable) times. The number of times is the form’s deep draw ratio divided by the cost model variable deepDrawRatioThreshold, if within range:
# of times = rounddown(((max(Depth Up, Depth Down) / SER Width) / deepDrawRatioThreshold)
If this value is less than 2, the operation is performed twice. If this value is greater than maxNumberDeepDraws, the operation is performed maxNumberDeepDraws times.
• Standard Drawing is performed only if the form’s Sub Type is not Stamp.
The operation, if performed, is performed between 2 and maxNumberDraws (cost model variable) times. The number of times is the form’s draw ratio divided by the cost model variable drawRatioThreshold, if within range:
# of times = rounddown(((Depth Up + Depth Down) / SER Width) / drawRatioThreshold)
If this value is less than 2, the operation is performed twice. If this value is greater than maxNumberDraws, the operation is performed maxNumberDraws times.
SimpleHole
Simple hole operations are all optional. In the following example sequence, aPriori decided to include Piercing and CounterSinking:
• Piercing is feasible only if both the following hold:
o Hole is not blind.
o Operation is capable of achieving the required tolerance (to view the achievable tolerance range, see the Piercing process setup option Best/Worst Achievable Tolerance).
Piercing is included in the operation sequence only if at least one of the following holds:
o Hole is approximately orthogonal to the main surface.
o Setup option Pierce Before or After Forms is set to holesBeforeForms.
o Hole is flanged.
o Hole is countersunk.
o Hole is threaded.
o Hole is not accessible from any candidate setup axis.
• Cam Action Piercing is feasible only if all the following hold:
o Hole is not approximately orthogonal to the main surface.
o Hole is not flanged.
o Hole is not countersunk.
o Hole is not threaded.
o Hole is accessible from a candidate setup axis.
o Setup option Pierce Before or After Forms is set to holesAfterForms.
• Extruding is included in the operation sequence only if the following holds:
o Hole is flanged.
• Coining is included in the operation sequence only if all the following hold:
o Hole is flanged.
o Hole is threaded.
• Shaving is included in the operation sequence only if all the following hold:
o Hole is flanged.
o Hole is threaded.
• Countersinking is included in the operation sequence only if the following holds:
o Hole is countersunk.
• Tapping is included in the operation sequence only if all the following hold:
o In-die tapping is enabled; that is the PSO Enable In Die TAPPING operations is Yes (the default in starting point VPEs).
o Hole is threaded; that is, the isThreaded property of the GCD is true.
o Hole diameter is within range; that is, the diameter is between sizes M2 and M12 (1.78mm and 11.51 mm in starting point VPEs; specified in the lookup table toolingComponentAttributes, in the entries for holeDiameterM2 and holeDiameterM12).
ComplexHole
Complex hole operations are required and feasible under the circumstances described below.
• Cam Piercing is required only if all the following hold:
o Hole is not approximately orthogonal to the main surface.
o Hole is not flanged.
o Hole is not coined.
o Hole is accessible from a candidate setup axis.
o Setup option Pierce Before or After Forms is set to holesAfterForms.
It is feasible only if the operation is capable of achieving the required tolerance.
• Coining is required if the hole is chamfered. It is feasible only if the operation is capable of achieving the required tolerance.
• Extruding is required if the hole is flanged. It is feasible only if the operation is capable of achieving the required tolerance.
• Piercing is required only if at least one of the following holds:
o Hole is not approximately orthogonal to the main surface.
o Setup option Pierce Before or After Forms is set to holesBeforeForms.
o Hole is flanged.
o Hole is chamfered.
o Hole is not accessible from any candidate setup axis.
It is feasible only if the operation is capable of achieving the required tolerance.
• Trimming is required only if both the following hold:
o Hole is sufficiently large, that is, the hole’s Perimeter is greater than or equal to the cost model variable bigEnoughArtifactPerimeter: Perimeter > = bigEnoughArtifactPerimeter
o Hole intersects, but is not coplanar with, a sufficiently large multibend or form of Sub Type Emboss that has no bends between it and the main surface. A form is sufficiently large if it is not a dimple and the sum of Depth Up and Depth Down is greater than 25 mm. Dimple recognition compares form perimeter with the cost model variable maxDimplePerimeter, and compares each of depth up and depth down with the cost model variable maxDimpleDepth.
It is feasible only if the operation is capable of achieving the required tolerance.