punching machine classification

Working principle of punch

The design principle of the punching machine is to convert circular motion into linear motion. The main motor generates power to drive the flywheel. The clutch drives the gear, crankshaft (or eccentric gear), connecting rod, etc., to achieve the linear motion of the slider. The movement of the connecting rod is a circular movement.
Between the connecting rod and the sliding block, there needs to be a transition point for circular motion and linear motion. There are roughly two mechanisms in its design, one is ball type, the other is pin type (cylindrical type), through which circular motion Converted into linear motion of the slider.

The punching machine the material to plastically deform it to obtain the required shape and precision. Therefore, it must be matched with a set of molds (upper mold and lower mold), the material is placed in between, and the machine applies pressure to deform it , The reaction force caused by the force applied to the material during processing is absorbed by the punch machine body.

punching machine classification

According to the driving force

The driving force of the slider can be divided into two types: mechanical type and hydraulic type. Therefore, punching machines are divided into different driving forces according to their use:

(1) Mechanical Power Press

(2) Hydraulic Press (Hydraulic Press)

For ordinary 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 giant machinery or special machinery.

According to the movement of the slider

There are single-action, double-action, and three-action presses according to the movement of the slider. The single-action press with one slider is the only one that is used most today. The double-action and three-action presses are mainly used in the extension of automobile bodies and large-scale machining parts. The number of processing is very small.

Classified by slider drive mechanism

(1) Crank Press

Presses that use crankshaft mechanisms are called crankshaft presses, crankshaft presses, and most of the mechanical presses.

Use this institution. The reason for using the crankshaft mechanism most is that it is easy to manufacture, can accurately determine the lower end position of the stroke, and the movable curve of the slider is basically practical for various processing. Therefore, this type of stamping is practical for punching, bending, stretching, hot forging, warm forging, cold forging and almost all other punching processes.

(2) Crankless Press

No crankshaft type punch is also called eccentric gear type punch, eccentric gear type punch. The function of the crankshaft punch and the eccentric gear punch is 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 long, 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 the field of crankshaft punching.

(3) Knuckle Press

Those who use the toggle mechanism on the slider drive are called toggle punches. This punch has a unique slider activity curve that the speed of the slider near the bottom dead center becomes extremely slow (as measured by a crankshaft punch). Moreover, the position of the bottom dead center of the stroke is correctly determined. Therefore, this type of punch is suitable for compression processing such as embossing and finishing, and is most commonly used in cold forging today.

(4) Friction Press

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 bending, forming, stretching, etc. It has versatile functions because of its low price and was widely used before the war. Due to the inability to determine the lower end position of the stroke, poor processing accuracy, slow production speed, overload when the control operation is wrong, and the need for skilled technology in use, these shortcomings are gradually being eliminated.

(5) Screw Press (Screw Press)

Those who use the screw mechanism on the slider drive mechanism are called screw punches (or screw punches).

(6) Rack Press

Those who use rack and pinion mechanisms on the slider drive mechanism are called rack punches. Spiral punches and rack punches have almost the same characteristics, and their characteristics are almost the same as those of hydraulic punches. In the past, it was used for pressing into bushings, crumbs and other items, such as extrusion, oil extraction, bundling, and the extrusion of bullet casings (hot squeezing processing), but now it has been replaced by hydraulic presses, unless extremely special No longer used outside of the circumstances.

(7) Link Press

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 reducing the processing cycle during the drawing process, and to use the reduction of 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 narrow, while it is used for the processing of automobile body panels and the bed surface is relatively wide.

(8) Cam Press

A punch that uses a cam mechanism on the slider drive mechanism is called a cam punch. The feature of this punch is a well-made cam shape in order to easily obtain the desired sliding curve. However, due to the nature of the cam mechanism, it is difficult to convey greater strength, so the punching capacity is very small.