Operation Assignment for Hydroforming

This section covers the following topics:

Hydroform Operations

The Hydroform Fluid Cell and Hydroform Deep Draw processes include the following operations:

• Clean Tooling: preparing the tool for use by cleaning the tool surface with wet wipes prior to forming. The GCDs it operates on are those that correspond to tool features, including forms, bends, and holes with flanges.

• Fluid Cell Forming or Deep Draw Forming: single hydroform machine cycle. In its first occurrence, the GCDs it operates on are those that correspond to tool features, including forms, bends, and holes with flanges. In subsequent occurrences (labelled with a suffix, as in Fluid Cell Forming:2), the listed GCDs are those that drive aPriori’s decision regarding the number of cycles—see the example below.

• Loading: loading the blank onto the hydroforming machine before a machine cycle, including throw pad placement if relevant. The GCDs it operates on are those that correspond to tool features, including forms, bends, and holes with flanges.

• Unloading: unloading the blank from the hydroforming machine after a machine cycle, including throw pad removal if relevant. The GCDs it operates on are those that correspond to tool features, including forms, bends, and holes with flanges.

• Visual Inspection: inspecting the part after a machine cycle. The GCDs it operates on are those that correspond to tool features, including forms, bends, and holes with flanges.

• Hand Adjusting: adjusting or creating a form that can’t be fully created by the hydroform machine. This operation must be manually included for a given GCD.

Since all occurrences of Fluid Cell Forming or Deep Draw Forming list the GCDs that drive the number-of-cycles determination, some features fully created in one cycle may be listed under a subsequent cycle. For example, for the part shown below, both Form:1 (the up bend) and StraightBend:5 (the down bend adjacent to the main surface) are listed under both occurrences of Fluid Cell Forming, even though one is fully created during the first occurrence and the other fully created during the second occurrence.

Hole-making Operations

Flanged and Countersunk holes are considered to be formed holes; they are cut out by the operations of the blanking process and then formed by the Hydroform process.

Non-formed holes are created by the Trim Drill operation sequence on the 5-Axis Mill (in the Machining process group) if at least one of the following holds for at least one hole:

• Hole has tight tolerance (required tolerance is less than the cost model variable toleranceLooseThresholdHole—2mm in starting point VPEs).

• Hole would be distorted by subsequent forming (see below).

Otherwise, non-formed holes are also created by the blanking process.

The cost model determines that a hole would be distorted by subsequent forming if at least one of the following holds:

• Hole is too close to the main surface edge. (The hole bears the Intersects relation to the MainSurface GCD, and the relation’s Distance property is less than the cost model variable holeToMainSurfaceEdgeProximityThreshold—3mm in starting point VPEs.)

• Hole intersects an emboss. (The hole bears the Intersects relation to a Form of Sub Type EMBOSS.)

Edge Trimming

If the part has a nonzero addendum, aPriori adds a secondary Machining operation, Profile Trimming on the 5-Axis Mill, which trims the addendum off. By default, a part has a nonzero addendum if one of the following holds:

• Part is a deep-draw part: the current routing is a deep draw routing.

• Part is a formed fluid-cell part: the current routing is a fluid cell routing and the part has at least one significant form whose Sub Type is EMBOSS.

• Part has a tight-tolerance edge.

With the PSO Width of Addendum Added to Blank Size, users can override the default and specify an addendum width.

For detailed information, see Width of Addendum Added to Blank Size in Coil Stock Options or Addendum Added to Blank Size in Sheet Stock Options.