Classification of punch press

Working principle of punch press:

The design principle of the punch press is to convert the circular motion into linear motion, the output of the main motor, 

drive the flywheel, the clutch drives the gear, crankshaft (or eccentric gear), connecting rod and so on, to achieve the linear motion of the slider, 

from the main motor to the connecting rod motion for circular motion. The connecting rod and the slider need to have a circular motion and linear motion between the transfer point, 

the design of roughly two kinds of mechanism, one for the ball type, one for the pin type (cylindrical), through this mechanism to convert the circular motion into the linear motion of the slider. 

Punch on the material pressure, plastic deformation, and obtain the required shape and accuracy, so it must be matched with a group of die (divided into upper die and lower die), 

the material in the meantime, by the machine to exert pressure, make its deformation, processing force on the material caused by the reaction force, absorbed by the punch mechanical body

2.The classification of punch:

1. According to the driving force of the slider, it can be divided into mechanical type and hydraulic type, so the punch press can be divided into two types according to the driving force of its use:

(1) Mechanical Power Press   (2) Hydraulic Press (Hydraulic punch Press)

(3) general sheet metal stamping processing, most of the use of mechanical punch.  Hydraulic type punch uses liquid to differ according to its, have oil press type punch and water pressure type punch ,

use oil press type punch to hold the majority at present ,water pressure type punch is used at large machinery or special machinery more.

3. Classification according to the movement mode of slider:

According to the motion mode of the slide, there are single action, double action, three action and so on. 

The single action punch with one slide is the most commonly used at present. 

The double action and three action punch are mainly used in the extension processing of the car body and large workpiece, and the number is very small.

4.Classification according to slider driving mechanism:

(1) Crank Press

A punch that uses a crankshaft mechanism is called a crankshaft punch, and most mechanical punches use this mechanism. 

most common reasons for using crankshaft mechanism are that it is easy to make, the position of the end of the stroke can be correctly determined, 

and the slider motion curve is generally suitable for all kinds of processing. 

Therefore, this type of stamping is suitable for punching, bending, stretching, hot forging, warm forging, cold forging and almost all other punch processing.

(2) Crankless Press

Crankshaft type punch is also known as eccentric gear type punch. 

Crankshaft punch and eccentric gear punch two structure of the function of comparison, 

eccentric gear punch structure of shaft rigidity, lubrication, appearance, maintenance and other aspects is better than the crankshaft structure, 

the disadvantage is the higher price. When the stroke is long, the eccentric gear punch is more favorable, and if the stroke of the special machine is short, 

the crankshaft punch is better, so the minicomputer and the high-speed punching punch is also the field of the crankshaft punch.

(3) Knuckle Press (Knuckle Press)

The use of a toggle mechanism on the slider drive is called a toggle punch. 

This type of press has a unique slider motion curve where the slider speed around the bottom dead center becomes very slow (compared to the crankshaft press).

 And also correctly determine the dead point position under the stroke, therefore, this punch is suitable for embossing processing and finishing compression processing, cold forging is now the most used.