1. According to the driving force of the slider, it can be divided into two types: mechanical and hydraulic, so punch presses are divided into different driving forces according to their use:
(1) Mechanical punch
(2) Hydraulic punch
For general sheet metal stamping processing, most of them use mechanical punching machines. Depending on the liquid used, hydraulic presses include hydraulic presses and hydraulic presses. The majority of hydraulic presses are hydraulic presses, while hydraulic presses are mostly used for large machinery or special machinery.
2. Classified according to the movement of the slider:
There are single-action, double-action, and triple-action punch presses according to the movement of the slider. The only one that is used most is the single-action punch press with one slider. The double-action and triple-action punch presses are mainly used for the extension processing of automobile bodies and large-scale machining parts. , Its number is very small.
3. According to the classification of slider drive mechanism:
(1) Crankshaft punch
A punching machine that uses a crankshaft mechanism is called a crankshaft punching machine, and most mechanical punching machines use this mechanism. The reason for using crankshaft mechanism most is that it is easy to manufacture, can accurately determine the position of the lower end of the stroke, and the movement curve of the slider is generally suitable for various processing. Therefore, this type of stamping is suitable for punching, bending, stretching, hot forging, warm forging, cold forging and almost all other punching processes.
(2) No crankshaft punch
No crankshaft punch is also called eccentric gear punch. Comparing the functions of the crankshaft punch and the eccentric gear punch, as shown in Table 2, the eccentric gear punch is better than the crankshaft in terms of shaft rigidity, lubrication, appearance, and maintenance. The disadvantage is that the price is higher. When the stroke is longer, the eccentric gear punch is more advantageous, and when the stroke of the special punching machine is short, the crankshaft punch is better. Therefore, small machines and high-speed punching punches are also in the field of crankshaft punches.
(3) Toggle punch
Those who use the toggle mechanism on the slider drive are called toggle punches. This punch has a unique slider motion curve in which the speed of the slider near the bottom dead center becomes very slow (compared to a crankshaft punch). Moreover, the bottom dead center position of the stroke is also accurately determined. Therefore, this type of punch is suitable for compression processing such as embossing and finishing, and cold forging is the most used.
(4) Friction punch
A punch that uses friction transmission and a screw mechanism on the track drive is called a friction punch. This type of punch is most suitable for forging and crushing operations, and can also be used for processing such as bending, forming, and stretching. It has versatile functions because of its low price and was widely used before the war. Due to the inability to determine the position of the lower end of the stroke, poor processing accuracy, slow production speed, overload when the control operation is wrong, and the need for skilled technology in use, it is gradually being eliminated.
(5) Spiral punch
Those who use the screw mechanism on the slider drive mechanism are called screw punches (or screw punches).
(6) Rack punch
Those who use rack and pinion mechanisms on the slider drive mechanism are called rack punches. Spiral punches have almost the same characteristics as rack punches, and their characteristics are almost the same as those of hydraulic punches. It used to be used for pressing into bushings, crumbs and other items, such as squeezing, oil pressing, bundling, and ejection of bullet casings (hot-room squeezing processing), etc., but it has been replaced by hydraulic presses, unless very special No longer used outside of the situation.
(7) Link punch
A punch that uses various linkage mechanisms on the slider drive mechanism is called a linkage punch. The purpose of using the linkage mechanism is to keep the drawing speed within the limit while shortening the processing cycle during the drawing process, and to reduce the speed change of the drawing process to speed up the approach stroke and the distance from the top dead center to the processing start point. The speed of the return stroke from bottom dead center to top dead center makes it have a shorter cycle than crankshaft punching machine to improve productivity. This type of punch has been used for deep extension of cylindrical containers since ancient times, and the bed surface is relatively narrow. Recently, it has been used for the processing of automobile body panels and the bed surface is relatively wide.
(8) Cam punch
A punch that uses a cam mechanism on the slider drive mechanism is called a cam punch. The feature of this punch is to make an appropriate cam shape so that the desired slider movement curve can be easily obtained. However, due to the nature of the cam mechanism, it is difficult to convey a large force, so the punching capacity is very small.
