What is a punch press machine?
A punch press is a stamping press. Stamping is increasingly used due to its advantages over traditional machining, including material and energy savings, high efficiency, low operator skill requirements, and the ability to create products not possible with mechanical processing through the use of various dies.
Stamping primarily targets sheet metal. Using dies, it can produce blanking, punching, forming, drawing, trimming, fine-blanking, shaping, riveting, and extrusion, among other applications. These applications include switches, sockets, cups, cupboards, plates, computer cases, household appliances, and kitchenware.
Working Principle
The design principle of a punch press is to convert circular motion into linear motion. The main motor generates power, driving the flywheel, which, through the clutch, drives the gears, crankshaft (or eccentric gear), and connecting rods to achieve linear motion of the slide, while the motion from the main motor to the connecting rod is circular motion. A transition point between circular and linear motion is required between the connecting rod and the slider. There are generally two types of mechanisms: a ball-type and a pin-type (cylindrical). This mechanism converts circular motion into linear motion for the slider. A punch press applies pressure to the material, causing it to plastically deform and achieve the desired shape and precision. Therefore, it requires a set of dies (upper and lower) to hold the material between them. The machine applies pressure and deformation, and the reaction force generated by the force applied to the material during processing is absorbed by the punch press.
Applications and Features
Punch presses are widely used in stamping and forming hardware components for electronics, communications, computers, home appliances, kitchenware, furniture, transportation vehicles, and automobiles, motorcycles, and bicycles.
1. ⑴ High-rigidity, high-precision frame, welded from steel plates and heat-treated to eliminate internal stress, ensures long-term stable operation without deformation.
(2) Uniform load distribution and balanced rigidity on structural components.
2. Stable High Precision: The machine's main components, including the crankshaft, gears, and drive shaft, undergo hardening heat treatment and are highly wear-resistant during grinding. This ensures long-term stable performance and high precision and stability.
3. Reliable and Safe Operation: The machine utilizes a clutch/brake combination, which differs from traditional brakes and offers high sensitivity. Combined with the dual solenoid control valve and overload protection device commonly used in international high-end equipment, this ensures precise and safe high-speed movement and stopping of the punch press's slide.
4. Automated Production, Labor-Saving, and High Efficiency. The punch press can be equipped with an automatic feeding device equipped with error detection, pre-cutting, and pre-breaking devices, enabling fully automated production with low costs and high efficiency.
5. Slide Adjustment: Slide adjustment is available in both manual and electric configurations, offering convenient, reliable, safe, and quick adjustments with an accuracy of up to 0.1mm.
Punch press classification
Classification by driving force
The slider driving force can be divided into two types: mechanical and hydraulic. For ordinary sheet metal stamping, most of the time, mechanical punch presses are used. Hydraulic punch presses are divided into oil-hydraulic punch presses and water-hydraulic punch presses according to the different liquids used. Oil-hydraulic punch presses are the most commonly used, while water-hydraulic punch presses are mostly used in large machinery or special machinery. Classification by slider movement. According to the slider movement, there are single-action, double-action, and triple-action punch presses. However, the most commonly used one is the single-action punch press with one slider. Double-action and triple-action punch presses are mainly used in the extension processing of automobile bodies and large workpieces, and their number is very small.
Classification by slider driving mechanism
(1) Crank press: A punch press that uses a crank mechanism is called a crank press. Most mechanical punch presses use this mechanism. The reason why the crank mechanism is used most is that it is easy to make, can accurately determine the lower end position of the stroke, and the slider activity curve is basically applicable to various processes. Therefore, this type of stamping is applicable to punching, bending, stretching, hot forging, warm forging, cold forging, and almost all other punching processes.
(2) Crankless Press Crankless press is also called eccentric gear press or eccentric gear press. The performance of the two structures of crankshaft punch and eccentric gear press is measured as shown in Table. The eccentric gear press structure is superior to the crankshaft structure in terms of shaft rigidity, lubrication, appearance, and maintenance. The disadvantage is that it is more expensive. When the stroke is long, the eccentric gear press is more advantageous. When the stroke is short, such as in the case of a special punching machine, the crankshaft press is better. Therefore, small machines and high-speed punching presses are also in the field of crankshaft presses.
(3) Knuckle Press A press that uses a knuckle mechanism on the slider drive is called a knuckle press. This type of punch press has a unique slider activity curve in which the slider speed becomes extremely slow near the bottom dead center (compared to a crankshaft punch press). It also accurately determines the bottom dead center position of the stroke. Therefore, this type of punch press is suitable for compression processing such as stamping and finishing. It is most commonly used in cold forging today.
(4)Friction Press: A punch press that uses friction transmission and a screw mechanism on a rail drive is called a friction press. This type of punch press is most suitable for forging and crushing operations. It can also be used for bending, forming, stretching, and other processing. It has a multi-purpose function and was widely used before the war because of its low price. However, due to the inability to determine the bottom end position of the stroke, poor processing accuracy, slow production speed, overload caused by control operation errors, and the need for skilled technology, it is gradually being eliminated today.
(5)Screw Press: A screw mechanism is used on the slider drive mechanism and is called a screw press (or screw press).
(6)Rack Press: A rack press is one that uses a rack and pinion mechanism on the slider drive mechanism. Screw presses and rack presses have almost the same characteristics, and their characteristics are roughly the same as those of hydraulic presses. In the past, it was used for pressing bushings, extrusion of debris and other items, oil pressing, packaging, and extrusion of shell casings (hot press thinning), but now it has been replaced by hydraulic presses and is no longer used except in extremely special circumstances.
