1. Theme and Applicable Scope
1.1 This specification stipulates the acceptance methods for cold punching and bending dies used in sheet metal production.
1.2 This specification is applicable to the acceptance of purchased, outsourced, and self-made cold punching and bending dies.
2. Acceptance Inspection Tools
Micrometer (accuracy 0.01mm, range 25mm), Vernier caliper (accuracy 0.02mm, range 150mm), tape measure (range 3m), universal angle gauge, dial indicator (accuracy 0.01mm, range 20mm).
3. Acceptance Procedure
Before the purchased, outsourced, or self-made cold punching and bending dies are put into use, relevant quality inspection personnel must conduct an acceptance inspection organized by the mold management department. The acceptance criteria shall be based on this specification and related "Process Equipment Commissioning Card," with no less than three test pieces for acceptance.
3.1 Acceptance of Cold Punching Dies
Firstly, according to the requirements of the "Process Equipment Commissioning Card," measure the dimensions of the die to be inspected. If there are no special requirements, the tolerance for the punch die of the cold punching die is 0 to +0.02mm, and for the blanking die is 0 to -0.02mm. The fit clearance of the punch and die (new die) is selected according to the table. Then, install the die and test piece on the corresponding press for processing, check whether the test piece is processed correctly to determine the acceptance of the die.
3.2 Acceptance of Bending Dies
Firstly, measure the relevant dimensions of the die to be inspected according to the data in the "Process Equipment Commissioning Card." Apart from the dimensions specifically required by the "Process Equipment Commissioning Card," the working and installation dimensions of the die should comply with the requirements of the "Tolerance Regulations for Dimensional Tolerances of Various Product Parts without Specified Tolerances." Then, install the die on the bending machine, complete the alignment, and fasten the mounting screws. Measure the straightness of the upper and lower dies with a dial indicator, with a requirement of not more than 0.03mm/m. Finally, bend the test piece and measure the angle value. The test piece length should not be less than 2500mm (if the die to be inspected is longer than 2500mm). Measurement points are selected at the ends of the test piece, 300mm and 800mm from each end, and at the center of the test piece. Select three to seven measurement points, fill in the data in the relevant sections of the "Process Equipment Acceptance Card."
The acceptance of the angle of the test piece is evaluated based on the data.
3.3 Acceptance of Stamping Forming Dies
The acceptance of the angle of the test piece for stamping forming dies is evaluated based on the data.
