In the realm of sheet metal stamping, the persistent challenge of burr formation remains an intricate aspect to navigate. However, by elevating the precision of craftsmanship in component production and refining stamping conditions, the incidence of burrs can be effectively curtailed.
Factors Influencing Burr Formation
1. Precision in Clearance
Burrs often arise from excessive, inadequate, or uneven die clearance. Various factors contribute to these disparities, including:
a. Mold Manufacturing Errors
Deviation in the machining of die components or poor parallelism of the base plate can lead to clearance irregularities.
b. Assembly Errors
Significant clearances in the guiding section or misalignment in concave-convex mold assembly contribute to burr formation.
c. Precision in Press Machine
Excessive guide clearance, suboptimal parallelism between the slider base and worktable surface, or inadequate perpendicularity can induce burrs during stamping.
d. Installation Errors
Incomplete cleaning of die surfaces during installation or improper fastening methods for large dies can result in misalignment, especially in pillarless dies.
e. Unreasonable Die Structure
Insufficient rigidity in the die and working section can cause imbalanced stamping forces, leading to burr formation.
2. Dull Cutting Edges
Blunting or denting of blade edges is another contributor to burrs. Factors leading to edge dulling include:
a. Material and Surface Treatment
Poor conditions of die concave and convex molds can result in inadequate wear resistance.
b. Defective Die Structure
Poor rigidity of the die can contribute to edge denting.
Inadequate lubrication during operation accelerates wear, impacting cutting edge sharpness.
d. Timely Maintenance
Failure to promptly sharpen blade edges increases the likelihood of burr formation.
3. Stamping Conditions
Improper stamping conditions, such as poor contact between the blank and molds or inappropriate relative height positions during trimming and punching, can cause burrs due to a mismatch between stamping and blade shapes.
4. Process Specifications
Non-compliance with material thickness or the use of incorrect materials can result in unreasonable clearances, leading to burrs.
5. Die Structure
Inadequate die structure can be a root cause of burr formation during the stamping process.
6. Craftsmanship of Components
Components with intricate shapes featuring protrusions or recesses are prone to burr formation due to rapid wear.
Managing Burr Occurrence
While the inevitability of burrs in stamped parts is acknowledged, corrective measures can be applied for already formed burrs. Techniques such as filing, electrolysis, rolling, and grinding can be employed to reprocess and eliminate existing burrs.
By understanding and addressing the multifaceted factors contributing to burr formation, manufacturers can master precision in sheet metal stamping, creating a path towards consistently producing high-quality, burr-free components.