The use of mechanical and hydraulic presses for forging and extrusion has already been mentioned. Die and punch assembly are widely used for sheet metal processing. These presses usually have a vertical configuration. The press is equipped with a heavy-duty flywheel driven by an electric motor. The ram is connected to the flywheel by a connecting rod and crank mechanism and moves up and down through slides located on the press frame. Let’s discuss the key process of die and punch assembly.
Press Work and Die Punch Assembly
These presses are very useful for making short and powerful strokes. These presses are mainly available in two configurations: an open frame type and a closed frame type. Open-frame presses are less rigid than closed-frame presses, but because they are open from the front and sides, they provide more access to material loading. Also called C-frame or slot press depending on its shape. Closed frame presses are used for heavy work.
Press Working Operations
There are many press operations, some of them very complex, all of which can be reduced to simple basic operations such as: Press forming is a part of sheet metal forming that primarily involves sheet metal cutting and forming operations using die and punch assembly to produce sheet metal parts on metal forming press equipment and support equipment. The chuck is the part of the tool that is attached to the press frame and inserted into the die.
A die is a fixed part of a die and punch assembly that is usually attached to a press bed. There are holes for shock absorption. The sheet metal working process is commonly referred to as cold stamping because the sheet metal is always in a cold state during processing, as the pressing operation is usually carried out at room temperature.
Plain Blanking
It demonstrates this kind of simple operation. The material used is called stock and is usually a black or colored tape. During the working stroke, the punch passes through the material, and during the return stroke, the material is lifted by the punch and removed from the scraper plate.
The stop is the size of the operator. He actually feeds the stock by hand and finds the holes to punch, as shown. The piece removed from the belt is always a blank in the die and punch assembly.
Piercing
This operation consists of a simple puncture. It differs from rum stamping in that the die (or cutting material) is scrap and is a strip blank. Piercing is nearly performed before, after or simultaneously with the cleaning operation.
Lancing
This is a process of combination of bending and cutting operation along a line of work material. No metal is cut during alignment. The punch is designed to cut on two or three sides and fold along the fourth side.
Cutting Off and Parting
A cutting operation divides the work material into single-line cuts along a straight line. When a job divides the work material into two line cuts that are cut along a straight line, it is called a split. The work piece is cut to separate it from the scrap.
Cleavage and segmentation usually occur in the last stage of the progressive matrix. Cutting is also used to cut the waste tape skeleton and exit the mold. This makes waste handling much easier.
Notching
This operation removes metal from one or both ends of the strip. Cutting serves to form the outer contour of a workpiece on a progressive die or to remove excess metal before drawing or forming a progressive die. Removing excess metal allows the metal to flow undisturbed.
Trimming
This operation cleans the excess deformed metal from the drawn or cast part and the metal required for the previous operation. It also provides smooth edges. It shows the tools for cutting horizontal flanges on a scale drawn as a separate operation.
After collecting a sufficient number of scraps from the cut shells, the rest on the floor is cut with a scrap cutter each time it passes through the press.
Conclusion
The sheet is lifted from the die and punch assembly with a spring-loaded piston. The clutch to transfer motion from the flywheel to the waste gate is controlled by the foot pedal. The arrangement is somewhat similar to the mechanism of a piston engine.
Blanks usually stay in the upper realm and are usually stunned. No corner opening required resulting in simple mold making. In some cases, a punch is attached to the shoe of the upper die and the punch is attached to the lower die.
Extrusion of seamless tubes Extrusion method refers to the metal blank into the extruder barrel, extrusion molding and extrusion rod composed of "closed" container by applying pressure to force the metal extruded rod extrusion die orifice outflow from, and access to metal plastic molding the method, which is a historic seamless manufacturing methods.
Anti- extrusion with extrusion pressure is small, extrusion ratio, extrusion speed, extrusion temperature can be reduced to improve the extrusion conditions, easy to implement isothermal / isobaric / constant extrusion, improve product performance and dimensional accuracy organizations, can reduce the margin squeeze at the end of the metal pressure, improve metal yield, etc.
; but its operation is relatively inconvenient, and the product section size by extrusion rod size restrictions.
Seamless tube extrusion process Perforated tube round → heating → three-roll rolling, rolling or extrusion → detached → sizing ( or reducing ) → cooling → straightening → hydrostatic test ( or testing ) → mark → storage rolling without the raw material is slit tube round tube, pipe cutting machine embryos to go through cutting the growth of about 1 m blank, and by conveyor belt to the furnace heating.
Heating the billet is fed into the furnace, the temperature is about 1200 degrees Celsius.
Generally more common punch is tapered roller punching machine, punching machine such high production efficiency, product quality, perforated expanding volume, you can wear a variety of steels.
