Stamping press machine can be equipped with a variety of molds to plastically deform or separate metal sheets into various shapes of parts or products. This article will show you how a stamping press works from the perspective of structure, movement principle, usage steps, process types, etc.
Stamping Press Machine Components
Frame: This is the main structure of the stamping press, supporting the operation of the entire machine. Depending on the design, the frame can be divided into C-type,H-type and straight side type.
Bed/Bolster Plate: This is the bottom support structure of the stamping press, usually a large metal block used to fix the lower part of the die. In large stamping presses, the bed may have a die cushion integrated into it to apply reverse force during the deep drawing process to prevent the material from wrinkling.
Ram/Slide: It is the moving part of the punch press machine, connected to the upper part of the die, and moves in the up and down directions to complete the punching action. The movement of the slider is controlled by the drive system, and its guiding accuracy directly affects the life of the die and the processing quality.
Drive Mechanism: It is responsible for providing power to the stamping press. Common drive methods include flywheel and hydraulic system. Flywheel drive is suitable for high-speed stamping, while hydraulic system can provide more stable force output and is suitable for complex processes such as deep drawing.
Clutch and brake system: Used to control the start and stop of the slide. They are usually spring-applied, pneumatically or hydraulically released to ensure the safety and precision of the stamping press.
Die set and tooling: The core component of the stamping press, consisting of an upper die and a lower die, is used to cut, bend or form metal materials. The upper part of the die is mounted on the slider, and the lower part is fixed to the bed plate, and the processing is achieved through the movement of the slider.
Control panel and safety devices: Used to operate and monitor the operating status of the stamping press, usually including human-machine interface (HMI), pressure sensor, speed regulator, etc. Safety devices such as safety blocks, emergency stop buttons, etc. are used to prevent operators from being injured.
Different Types Of Stamping Press Working Principles
Mechanical Press
Mechanical press generates the required force through a flywheel and clutch mechanism. Its working principle is based on the storage and release of energy: the motor drives the flywheel to rotate, and the flywheel stores kinetic energy; when the stamping action occurs, the flywheel transfers the kinetic energy to the punch through the clutch, causing it to move up and down to apply force to the material. This type of press is suitable for medium and heavy stamping operations with high precision and repeatability. The drive modes of mechanical press include single-stage, double-stage, double-acting, chain (ASM) and eccentric gear.
Hydraulic Press
Hydraulic press uses hydraulic cylinders and pistons to transmit force and realizes stamping action through fluid pressure. Its working principle is based on Pascal’s principle, that is, fluid transmits pressure in a closed system, thereby pushing the piston up and down. Hydraulic stamping press can provide more refined force and speed control, and is suitable for scenarios that require high precision and complex forming operations.
Servo Press
Servo press combines the advantages of mechanical and hydraulic presses, using servo motors to accurately control force and speed. Its working principle is based on the feedback control of the servo motor, which can adjust the stamping force and stroke in real time to adapt to different processing requirements. The servo stamping press is suitable for high-precision parts and complex forming operations, and can achieve a more flexible stamping process.
Steps To Use The Stamping Press
Step 1: Material feeding
Material feeding can be done by manual, feeder, or coil. During the feeding process, it is necessary to ensure that the material is correctly placed between the dies to ensure smooth subsequent processing.
Step 2: Die alignment and setup, die closure
Install the die to the press and ensure that it is accurately positioned. It is usually necessary to place the die in the center of the tablet press and ensure that the closing height of the upper and lower dies is appropriate by adjusting the height and position of the die.
During the installation process, it is necessary to check whether the holes of the die are aligned and ensure that the axes of the upper and lower dies are consistent to avoid deformation of the die due to uneven force.
When the die is in place, start the press to lower the slider and close the upper and lower dies. During the closing process, ensure that the material is properly clamped and does not deviate or slide.
Step 3: Stroke cycle
The stroke cycle of the stamping press consists of three main stages: downward pressing, forming/cutting, and return. During the pressing process, the upper die applies pressure to the material to cause plastic deformation or separation to form the desired shape.
After the stamping is completed, the press will automatically return to prepare for the next operation.
Step 4: Ejection of finished part
After the stamping is completed, the stamping press will eject the formed part from the mold through the ejector mechanism. This process requires ensuring that the ejector mechanism can smoothly push the part out and avoid damage to the part.
Step 5: Quality checks and adjustments
After each stamping is completed, the finished product needs to be checked for quality, including size, surface quality, etc. If quality problems are found, the mold gap, pressure or other parameters need to be adjusted in time to ensure product quality.
In the trial stamping stage, the trial stamping sample can be used to check whether the mold gap is uniform and whether the stamped parts have burrs and other problems.
Types of Stamping Processes
Stamping is a forming process that uses a die and a stamping press machine to apply external force to a metal sheet to cause it to plastically deform or separate, thereby obtaining a workpiece of the desired shape and size. Here are some common process types:
Blanking – Cutting the desired shape from a larger sheet, usually used to make blanks.
Piercing – Punching holes or notches in a sheet.
Bending – Bending a material to a specific angle or curve.
Drawing – Stretching a material into a deep, hollow shape, such as a cup or container.
Coining – Pressing a pattern into a metal sheet under high pressure, often used to make precision parts such as coins and badges.
Embossing – Pressing a raised or recessed pattern into a metal sheet, often used for decoration or signs.
Flanging – Forming a vertical flange on the edge of a workpiece, usually used to enhance structural strength or prepare for subsequent processing.
Common Stamping Press Terms
Tonnage: The maximum force that the stamping press machine slide can safely apply. For mechanical stamping press machines, tonnage is usually determined by the size of the crankshaft bearings; for hydraulic stamping press machines, it is the product of the cylinder area and the oil pressure.
Stroke length: The distance the stamping press machine slide moves from top dead center to bottom dead center, usually expressed in inches or millimeters.
Shut height: The distance from the top of the stamping press machine bed to the bottom of the slide, usually measured when the slide is at bottom dead center and the adjustment mechanism is in the highest position.
Die clearance: Die clearance is the gap between the punch and the die in the blanking die.
Single vs. continuous stroke: Single stroke refers to the stamping press machine completing one stamping action in one slide movement. Continuous stroke refers to the stamping press machine completing multiple stamping actions in continuous slide movements, usually used in automated production lines.
Tooling/die terminology(punch, die shoe, stripper, etc.)
