Uneven inner flanging appears when material does not move toward the center at the same rate around the circumference. The finished opening may become oval, one section may fold deeper, or flange width may change near the weld seam. Because inward forming compresses material into a smaller diameter, small setup differences can quickly become visible.
Measure opening diameter, roundness, wall thickness, edge squareness, and seam condition before loading. A high section on the cut edge receives more forming than a low section. A cylinder that is already oval will also contact the tool unevenly.
Burrs and notches should be removed because they disturb material flow and may become crack starters. Weld reinforcement must be controlled when the seam differs from the surrounding wall.
An Internal Flanging Machine needs the cylinder axis, spindle axis, clamping center, and forming tool to share one reference. When these centers are offset, one side of the rim receives greater pressure during rotation.
Check locating jaws, support rings, axial stops, roller runout, and tailstock alignment. Thin cylindrical parts may need support close to the working edge so they do not move away from the tool.
Inner flanging shortens the effective circumference of the edge. If the final angle is created in one heavy movement, excess material may gather into waves or folds. A more stable sequence uses a guiding pass, intermediate passes, and a light calibration pass.
Hydraulic movement is useful because pressure can be adjusted for material and thickness. Zhuosheng’s inner-flanging equipment combines hydraulic and electric drive with PLC control, and its modular design supports shrinking, rib pressing, curling, and inward flanging.
Roller radius and approach angle determine how strain is distributed. A sharp contact concentrates pressure, while an oversized radius may push too much material before the bend line is established. Tooling should match flange width, material thickness, and required inside diameter.
Tool condition matters as much as design. Worn bearings, rough surfaces, and loose modules can all disturb forming.
| Defect pattern | Probable source | First correction |
|---|---|---|
| One side deeper | Off-center clamping | Recheck locating references |
| Waves around the rim | Excess compression | Add forming stages |
| Variation near seam | Local stiffness change | Modify path or seam preparation |
| Random folds | Unstable support | Move support closer to edge |
| Batch inconsistency | Material or setup drift | Record thickness and program data |
When diagnosing a Cylinder Inner flanging machine, do not change pressure, speed, roller position, and clamping force together. Adjust one parameter, form several parts, and compare the measurements.
Temperature also matters during long runs. Hydraulic oil warms, lubrication changes, and repeated contact increases friction. Approval should therefore include parts made after the system reaches normal operating conditions.
Measure flange width at fixed angular positions, such as every 45 or 90 degrees. Record opening diameter in two directions and compare the area near the weld seam with the opposite side. For critical parts, also measure remaining thickness at the bend.
An experienced Inner flanging machine Supplier should request drawings, material grade, seam details, diameter range, flange direction, and tolerance before selecting equipment. Uneven inner flanging is reduced by accurate blanks, concentric support, progressive compression, suitable tooling, and repeatable inspection. Pressure adjustment alone rarely solves the complete problem.
