The punching press is a type of stamping press widely used in national production due to its efficiency and savings in material and energy compared to traditional mechanical processing. It requires low technical qualifications from the operator and can produce various products through applications in molds, which cannot be made through mechanical processing.
Stamping production is mainly for sheet materials and can include processes such as stamping, punching, forming, drawing, finishing, fine punching, shaping, riveting and extrusion. It is used in a variety of industries, including switch sockets, cups, cabinets, dishes, computer cases, and even missile planes.
The Punch Press can produce a wide range of accessories through its mold and has been called by various names such as punch press, punch press, recoil punch or die press.
The most common sheet metal stamping processes utilize a mechanical punch.
The hydraulic press is divided into oil pressure and water pressure types, with oil pressure accounting for most of the usage. The water pressure punch, on the other hand, is typically used for large machines or special machines.
According to the movement of the slider
According to the movement of the slider, presses can be divided into single-action, double-action and three-action types. Single-action punch is the most commonly used, while double-action and three-action punch are mainly used in the extension processing of automobile bodies and large parts, but their use is limited.
According to slider driven mechanism
(1) Crank
The press that uses a crankshaft mechanism is known as a crank press, and most mechanical punches use this mechanism.
The reason for using a crankshaft mechanism is that it is simple to construct, allows accurate determination of the bottom end of the stroke, and has a sliding activity curve that is versatile enough to be applied to a variety of processing techniques.
Therefore, this type of stamping is used for punching, bending, stretching, hot forging, intermediate temperature forging, cold forging and almost all other punch processing applications.
(2) Crankless press
A press without a crankshaft mechanism is known as a crankless press or an eccentric gear press.
The eccentric gear press has better shaft rigidity, lubrication, appearance and maintenance compared to a crankshaft press. However, it also has a higher price.
If the stroke length is long, the eccentric gear press is preferred, but if the specialized machine stroke is shorter, a crankshaft press is better. Small punches and high-speed punches also often use crankshaft presses.
(3) Joint press
A press that uses a toggle mechanism to actuate the slider is known as a toggle press or toggle press.
This press has a unique sliding activity curve that has a very slow speed near bottom dead center (compared to a crankshaft press) and also accurately determines the bottom end of the stroke.
Therefore, this press is ideal for compression stamping and finishing processes and is most commonly used in today's cold forging applications.
(4) Friction Press
A press that uses friction transmission and a screw mechanism in the punch track is known as a friction press.
This press is best suited for forging and crushing operations and can also be used for bending, forming, stretching and other processing techniques. Due to its low cost, it was widely used before the war, but because it was difficult to determine the lower end of the stroke, it had low processing accuracy, slow production speed, and a tendency to overload with control operation errors. As a result, its use has declined and it is now being phased out.
(5) Screw press
A press that uses a screw mechanism to drive the slider is known as a screw press or spiral press.
(6) Rack press
A press that uses a rack and pinion mechanism in slide drive mechanism is known as a rack press.
Spiral press and rack press have similar characteristics and are approximately equivalent to hydraulic presses. They used to be used to press bushings, debris and other items in extrusion, oil extraction, packaging and extrusion shell (hot compression fine processing), but have now been largely replaced by hydraulic presses and are only used in very special applications. situations.
(7) Link Press
A press that uses a variety of linkage mechanisms to drive the slider is known as a link press or rod press.
With a binding mechanism, the stretching speed is maintained within limits during the stretching process, and the stretching speed is reduced by slowing down the stretching process. Furthermore, the approach stroke from top dead center to the start of machining is accelerated and the rate of return to top dead center is faster than a crankshaft press, which increases productivity.
This press has been used since ancient times for deep stretching of cylindrical containers and for processing a car body when the base surface is narrow.
(8) Camera press
A press that uses a cam mechanism in the slide drive mechanism is known as a cam press.
The cam press is characterized by a suitably shaped cam that allows you to easily achieve the desired activity curve of the slider. However, the nature of the cam mechanism limits its ability to exert significant force, so its capacity is very small.
Punching Machine Mold Structure
1. Superior Matrix
The upper die is the upper half of the entire die, which is the part of the die mounted on the press slide.
- Top plate
The upper die plate is the plate-shaped part in the upper section of the die, it is close to the press slider and is fixed to the die or fixed directly to the press slider.
- Lower Data
The lower die is the lower half of the entire die, which is the part of the die mounted on the working surface of the press.
- Bottom die board
The die bottom plate is the plate-shaped part at the bottom of the die and is attached directly to the working surface of the press or pad.
- border wall
The edge wall is the side wall of the die hole.
- Edge taper
Edge taper is the slope on each side of the die hole.
- air cushion
An air cushion is a device that uses compressed air as a driving force.
- Counter recoil
The backstop is a part that supports the unidirectional force of the punch on the opposite side of the work surface.
- Bushing
A bushing is a precision tubular part that facilitates the relative movement of the upper and lower die plates, most of which are fixed to the upper die plate and used in conjunction with guide posts fixed to the lower die plate.
- Guides
Guides are plate-shaped parts with precision slotted holes for the male punch, they are used to ensure alignment between the punch and die and to provide unloading functions.
- Recommendation
A guide post is a precision cylindrical part for the relative movement of the upper and lower die plates, most of which are fixed on the lower die plate and used in conjunction with bushings fixed on the upper die plate.
- Guide pin
A guide pin is a pin-shaped part that extends into the hole in the material and guides it into the die.
- Guide Plate Matrix
A guide plate die is a die that is guided by the guide plate, it is not used when the punch is removed from the guide plate.
- Guide plate
A guide plate is a plate-like guide piece that guides the strip (strip, roll) into the die.
- Die Guide Post
The guide post die is the sliding structure of the guide post and bushing.
- Punch and Die Set
A set of punches and dies is installed on the press for the production of cutting parts and consists of upper and lower parts.
- Punch
A punch is a male workpiece that is formed directly in the die and is shaped like the work surface.
- To die
A die is a concave workpiece that provides the function of punching into the die, with the inner surface as the working surface.
- Shields
Shields are plate-shaped parts that prevent fingers or foreign bodies from entering dangerous areas of the die.
- Pressure plate
A pressure plate is a part of the die used to hold the stamping material or workpiece and control the flow of the material. In drawing dies, the pressure plate is often called the material circle.
21. Pressure bars
The pressure bar is a rib-like protrusion on a drawing die or mold that controls the flow of material.
The buckle may be a part of the die structure or pressing loop, or it may be incorporated into a separate die or pressing component.
- pressure limit
The pressure limit is a material with a rectangular cross section.
- Support plate
The backing plate is a plate-like component used to secure the model to the surface.
- Continuous Mold
The continuous mold is a die with two or more stations, where the material is fed from station to station by the stroke of the press, resulting in the gradual formation of the punch.
- Side edge
The side edge is a punch that cuts a feed opening in the side of the strip (tape, roll).
- Side plate
The side plate is a plate-like component that exerts pressure on one side of the strip (strip, roller) via a spring, pressing the other side against the plate.
- Chuck
The chuck is a rod-shaped component that moves up or down directly or indirectly.
- Crown Plaque
The crown plate is a plate-like component that acts on a die or module to move up or down directly or indirectly.
- Ring gear
The crown gear is a tooth-like protrusion on a thin punch or die, which is part of the die or tooth plate structure rather than a separate component.
- Boundary Sets
The limit assembly is a tubular component that restricts the minimum closing height of the die and is generally positioned outside the guide post.
- Limit Column
The limit column is a cylindrical member that restricts the minimum closing height of the die.
- Locating pin (board)
The locating pin (plate) ensures that the part in the mold has a constant position and is called a positioning pin or plate.
- Fixed Plate
The fixed plate is a plate-shaped component of the fixed punch.
- Fixed Discharge Plate
The fixed discharge plate is a discharge plate fixed on the die. (See “discharge plate”).
- Fixed retaining pin (plate)
Fixed retaining pin (plate) is a fixed pin (plate) that is fixed in the mold.
- Unloader
The unloader is a plateless component or device that unloads from the outer surface of the punch.
- Discharge plate
The discharge plate is a fixed or movable plate-shaped component that displaces the material or part of the punch.
The discharge panel can be made in combination with the guide plate, and its function as a guide is still called the discharge panel.
- Discharge screw
The discharge screw is a screw fixed to the ejector plate, which restricts the resting position of the ejector plate.
- Single Process Mode
Single process mode is a die that completes only one process in a single press stroke.
- Waste Cutter
There are two types of waste cutters:
- A cutting edge used to cut a complete circle of cutting residue for easy removal.
- Cutter attached to a press or mold for cutting a strip (strip, roll) of waste into a fixed length for cleaning.
41. Combination Matrix
A combined die is a set of dies that can be adjusted step by step to form various shapes such as straight lines, angles, arcs and holes.
Typically, several pairs of punching dies are required to form the flat contours.
- Front stop pin (plate)
The front stop pin (plate) is a piece that positions the material at the starting end and serves to block the movable pin (plate).
- Block
A block refers to a complete die, punch, discharge plate or fixture plate.
- Stopper
A stop (plate) is a hardened part that supports the material cut by the side blade and balances the one-sided cutting force.
It is usually used in conjunction with the side blade.
- Lock pin (plate)
The block pin (plate) is a part used to position the material in the feeding direction, and its shape can be different and is called block pin or block plate.
These include fixed block pins (plates), movable block pins (plates), and starting block pins (plates).
- Cushion
A pad is a hardened plate-shaped part that is placed between the mounting plate (or die) and the mold base to reduce compressive stress on the die holder.
Safe punch press production
As the punching machine operates at high speed and pressure, it is important to follow certain safety standards when using it for punching and forming:
- The exposed parts of the press drive must be equipped with protective covers and it is prohibited to operate or commission the machine without these covers in place.
- Before starting the machine, inspect the main fixing screws to ensure they are tight, check the mold for cracks, check that the operating mechanism, automatic stop device, clutch and brake are operating properly, and ensure that the lubrication system is not working properly. clogged or low on oil.
- When installing the mold, the slider must be at bottom dead center, the closed height must be correct, and care must be taken to avoid eccentric loads. The mold must be watertight and reliable and pass a pressure test.
- Pay close attention during operation and do not insert your hands or any tools or objects into the dangerous area. Small pieces must be handled with special tools such as tongs or feeders. If the mold sticks to the blank, use only one tool to remove it.
- If any abnormal operation or sound, such as knocking or popping, is detected, stop feeding immediately and investigate the cause. If the rotating parts are loose, the steering device fails, the mold comes loose, or any other defects are found, stop the machine and repair it.
- After finishing work on each part, be sure to remove your hands or feet from the buttons or pedals to avoid misuse.
- When operating the machine with two or more people, one person must be designated as operator and all personnel must coordinate their actions. Before finishing the work, lower the matrix, disconnect the power and carry out the necessary cleaning.
Precautions
Before work
(1) Check the lubrication of all parts and ensure that the lubrication points are fully lubricated.
(2) Make sure the mold is installed correctly and securely.
(3) Check whether the compressed air pressure is within the specified range.
(4) Make sure the switch buttons are sensitive and reliable, and be sure to turn off the steering wheel and clutch before starting the engine.
(5) Test the press by operating it several times without a workpiece and check the performance of the brake, clutch and control parts.
(6) Check the main motor for any abnormalities such as excessive heat, abnormal vibration or unusual sounds.
(7) Use a hand pump to add lithium-based oil to the slider.
(8) Adjust the feed roller gap to meet the process requirements.
(9) Maintain oil mist to meet required specifications.
(10)When starting the engine, check whether the rotation direction of the flywheel is consistent with the rotation mark.
At work
(1) Regular lubrication should be carried out at the lubrication points using a manual oil pump to supply oil.
(2) If the operation of the press is not well understood, adjustments to the press are not permitted.
(3) It is strictly prohibited to drill two layers of sheet metal at the same time.
(4) If any problems are found during operation, work must be stopped immediately and a suitable inspection must be carried out in a timely manner.
After work
(1) Disengage the flywheel and clutch, turn off the power supply and release any residual air.
(2) Clean the press and coat the work surface with anti-rust oil.
(3) Keep a record after each operation or maintenance.
