Punch die is the core process equipment in stamping process, which is mainly used for punching, forming, stretching and bending of metal or nonmetal materials. The following is a systematic introduction to the punch die:
First, the basic composition of the punch die
Upper die (punch)
Installed on the slide block of a punch press, it moves up and down with the slide block, usually including punch, punch and other working parts.
Lower die (concave die)
It is fixed on the workbench of the punching machine, and cooperates with the upper die to complete punching, including the female die, positioning device, etc.
Guide part
Guide posts, guide sleeves, etc. ensure the accurate alignment of the upper and lower dies and improve the machining accuracy.
Fixing and unloading parts
Die handle (fixed die), discharge plate (stripping waste or workpiece), spring/air cushion device, etc.
Second, the classification of punch dies
1. Classification by process type
Punching die: used for cutting, blanking and punching (such as punching the shape of hardware).
Bending die: bending a plate into a specific angle or shape (such as a U-shaped part).
Drawing die: drawing flat material into hollow parts (such as cup-shaped and shell-shaped parts).
Forming die: local deformation (bulging, flanging, necking, etc.).
Compound die: multiple processes (such as punching+blanking) can be completed by one punch.
Progressive die (continuous die): multi-station and step-by-step processing with high efficiency (suitable for mass production).
2. Classification by structure
Single-process die: one process is completed by stamping at a time.
Combination die: the collective name of compound die and progressive die.
Simple mold: low-cost mold (such as polyurethane mold and steel skin mold).
Third, the material of the punch die
Working parts:
High-carbon and high-chromium steel (Cr12, Cr12MoV), high-speed steel (SKH-9), cemented carbide (long life requirement).
Structural components:
Medium carbon steel (45#), alloy structural steel (40Cr).
Surface treatment:
Quenching, nitriding, TD treatment, chromium plating, etc. to improve wear resistance.
IV. Key Points of Mold Design and Manufacture
Design key
Gap control (material thickness 5%~10%), demoulding angle and stress distribution optimization.
Adjust die parameters according to material characteristics (such as aluminum and stainless steel).
processing technic
CNC precision machining, wire cutting (wire cut) and EDM forming.
Life factor
Material selection, heat treatment process, lubrication conditions, stamping speed, etc.
V. Application fields
Automobile manufacturing: body panels and structural parts.
Electronic appliances: heat sink, connector.
Household appliances industry: washing machine panel, air conditioning shell.
Daily necessities: stainless steel tableware, hardware accessories.
VI. Maintenance and Frequently Asked Questions
Daily maintenance: clean and lubricate regularly, and check the wear of cutting edge.
Common faults:
Excessive burr (unreasonable clearance or worn edge).
Stuck material (inaccurate positioning or failure of unloading device).
Mold cracking (improper heat treatment or overload).