RSS FeedMore info about roll forming
May 22, 2014 07:41
The secret to developing successful roll tooling—whether for tube production or roll forming—and achieving maximum roll integrity is a simple but often overlooked notion: a comprehensive approach. Such an approach comprises five steps:
Designing the roll tooling
Manufacturing and inspecting the tooling
Preparing the tube mill or roll forming machine
Using specified material and strip characteristics
Setting up and troubleshooting
Designing the Roll Tooling.
The designer should pay special attention to critical areas, such as those where interference with mating parts may occur. Involving manufacturing managers and engineers early in the project may help to uncover troublesome areas and derail problems early.
When the drawing is finished, the designer sends it to the customer for review and approval. After receiving approval, the designer develops the tooling design. When laying out the flower, the tooling designer must consider the complexity of the profile, the customer's tube mill or roll forming machine, flexibility, vertical centers, horizontal centers, gearing, and positioning for cutoff. The designer may have to consider various combinations of these parameters for possible future revisions.
The next step in roll tooling design has two parts: developing the flower diagram and designing the profile. Several computer programs are available to assist the designer. Modern programs allow the designer to eliminate stretch, minimize stress and strain, and manipulate the flower with ease.
A complete discussion of flower diagrams and profile design is beyond the scope of this article. However, several important aspects include laying out the rolls, setup, and splitting the rolls.
Laying out the Rolls. After finalizing the flower diagram, the designer begins surrounding the profile with steel, or laying out the rolls. A roll designer must flange the rolls properly. A general rule is if the material is flowing up, the flanges go up; if the material is flowing down, the flanges go down.
The designer also traps the material using metal stops, which prevent the material from wandering in the rolls and help eliminate camber from the incoming strip. Metal stops should allow for slitting tolerances as well. The design must also provide running clearance (extra room that allows the material to flow from pass to pass without being held back by the tooling) where necessary.
Setup. Two design considerations facilitate easier tooling setup: using feeler hubs and aligning material faces.
Feeler hubs are the gaps between the outer flanges of mating rolls. If the roll tooling is designed for 0.068-inch material, the designer should gap the feeler hubs at 0.068 in. This allows the setup person to use the material to set the gap.
Lining up the material faces allows a setup person to put a straightedge on the faces to check the shoulder lineup and to check the lineup from pass to pass. If the step-off is in 0.250-in. increments, this check may be done with a small tool bit or gauge block as the rolls get narrower from pass to pass. The designer indicates on the drawings any overforming of corners and the amount of step-up from pass to pass.
Related machines:
roof panel roll forming machine
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Posted May 22, 2014 07:41