Things About Punching Machine You Should Know

Punching machine is a stamping press. In the national production, the stamping process featured materials and energy saving as well as high efficiency compared with traditional mechanical processing. It also has low technical requirements for the operator. Through a variety of mold applications the products which can’t be made through mechanical processing. Therefore, it is more and more widely used.

Stamping production is mainly for the plate. 

Through the mold, can make blanking, punching, forming, drawing, finishing, fine punch, shaping, riveting and extrusion, etc., are widely used in various fields, such as switch sockets, cups, cupboards, plates, computer cases, and even missile planes … There are a lot of accessories can be produced with a punch through the mold.

The punching machine also been called punch (press), puncher, backing-out punch, die out the press.

punch press

The features of punching machine:

  • High rigidity
  • Stable high precision
  • Reliable and safe operation
  • Automated production, labor-saving, high efficiency
  • Slider adjustment mechanism
  • Novel design, environmental protection

Working Principle Of Punching Machine

Punch design principle is to convert the circular motion into a linear motion, driven by the main motor to drive the flywheel, then drive the operation of gear, crankshaft (or eccentric gear), connecting rod through clutch for the purpose of achieving the linear motion of slider.  The movement is the circular motion from the main motor to connecting rod.

The circular motion and linear motion between the connecting rod and the slider need the transfer point. The design of roughly two kinds of structures, one for the ball, one for the pin type (cylindrical).  Through this structure, the circular motion will be converted into a linear motion of the slider. The punch presses the material so that it is plastically deformed to obtain the desired shape and accuracy. Therefore, it is necessary to fit together a set of molds (upper and lower molds), where the material is placed, and the machine is pressurized to deform it. The processing force applied to the material caused by the reaction force, absorbed by the punch machine body.

Application & Features of Punching Machine

Punching machine is widely used in stamping and forming of electronics, communications, computers, household appliances, furniture, transport (cars, motorcycles, bicycles), metal parts, etc.

1. ⑴ high rigidity, high-precision rack, adopt steel plate welding and heat treatment to eliminate the physical strength of the body to make the equipment work stable in long-term and not deformed.

⑵ uniform structural load , steel balance.

2. Stable high precision:

The main parts of the equipment such as crankshaft, gear, transmission shaft and other parts are hardened by the heat treatment in the grinding process which have a high wear resistance, long-term stability, to ensure a high precision and stability requirements.

3. Reliable and safe operation:

The reason why easy to operate, accurate positioning is due to the use of brake different from the traditional one.  Clutch / brake combination device has a high sensitivity, coupled with the international high-end equipment common double solenoid control valve and overload protection device, to ensure that the punch slider’s high-speed movement and accurate & safe stop.

4. Automated production, labor saving and high efficiency

Punching machine can be equipped with the corresponding automatic feeding device, with feed error detection, pre-cut, pre-break device, can fully realize automated production with low cost and high efficiency.

5. Slider adjustment mechanism

Slider adjustment is divided into manual adjustment and electric adjustment, convenient and reliable, safe, fast, precision up to 0.1mm.

6. Novel design , environmental protection

Using Japan and Taiwan’s advanced technology and design concepts, with low noise, low energy consumption, no pollution advantages.

Classification of Punching Machine

  • According to the driving force

Slider driving force can be divided into mechanical and hydraulic, so according to the use of the driving force the press is divided into:

(1) Mechanical Power Press

(2) Hydraulic Press

Most of the ordinary sheet metal stamping processing is using the mechanical punch. According to the use of different liquids, the hydraulic press is divided into oil pressure punch and water pressure punch. The use of oil pressure press accounted for the majority while water pressure punch is used for giant machinery or special machinery.

  • According to the slider movement

According to the movement of the slider can be divided into single-action, double action, three-action press, only the single-action punch been used by most of the people. Double moving and three-action punch mainly used in the extension processing of the car body and large parts, the number is very small.

  • According to slider driven mechanism

(1) Crank Press

The press that uses the crankshaft mechanism is called the crank punch, most of the mechanical punch uses this mechanism. The reason for using the crankshaft mechanism is that it is easy to make, and it is possible to correctly determine the lower end of the stroke and the slider activity curve is basically applicable to various processing. Therefore, this type of stamping is applied to punching, bending, stretching, hot forging, inter-temperature forging, cold forging and almost all other punch processing.

(2) Crankless Press

No crankshaft punch, also known as eccentric gear punch. The shaft rigidity, lubrication, appearance and maintenance of the eccentric gear punch structure are better than the crankshaft structure. The disadvantage is that the price is higher. When the stroke is long, the eccentric gear punch is more favorable, and if the stroke of the special machine is shorter, it is better for the crankshaft punch. So small punch and high-speed  punch press also belongs to crankshaft punch.

(3) Knuckle Press

The use of a toggle mechanism on a slider drive is called a toggle punch. This punch has a unique slider activity curve that has a very slow speed (and crankshaft punch) near the bottom dead center, and also correctly determine the deadline under the stroke. Therefore, this punch is suitable for embossing and finishing the compression process, most used for today’s cold forging.

(4) Friction Press

The use of friction transmission and screw mechanism on the track drive of punch is been called friction punch. This punch is the most suitable forging, crushing operations, can also be used for bending, forming, stretching and other processing, with a multi-purpose function, because the low price, it has been widely used before the war. Because it is impossible to determine the lower end of the stroke, the processing accuracy is poor, the production speed is slow, the control operation error will establish the overload, the need to use the skilled technical shortcomings, now is gradually being eliminated.

(5) Screw Press

In the slider drive mechanism using a screw mechanism known as the spiral punch (or screw punch).

(6) Rack Press

The use of rack and pinion mechanism on the slider drive mechanism is called a rack punch. Spiral punch and rack-type punch has almost the same characteristics, and is roughly same as the hydraulic punch. Previously is used to press into the bushings, debris and other items of the extrusion, oil extraction, packing, and the shell of the extrusion (hot squeeze thin processing), but now has been replaced by hydraulic press, unless very special of the situation is no longer used.

(7) Link Press

In the slider drive mechanism using a variety of linkage mechanism of the punch is called a rod-type punch. In the case of using the link mechanism, the stretching speed is kept within the limit while the drawing is carried out, and the speed of the drawing is reduced by the reduction of the speed of the extension process, and the approaching stroke from the top dead center to the starting point of the machining is accelerated the rate of return to the top dead center is faster than the crankshaft punch in order to increase productivity. This punch has been used since ancient times for the deep extension of the cylindrical container, the bed surface is narrow, and is used for the processing of the main body of the car.

(8) Cam Press

A punch press that uses a cam mechanism on a slider drive mechanism is called a cam punch. The punch is characterized by a properly shaped cam shape in order to easily obtain the desired slider activity curve. But the nature of the cam mechanism is difficult to convey a greater effort, so this punch capacity is very small.

Punching Machine Mold Structure

1. Upper mold
The upper mold is the upper half of the entire die, that is, the die part mounted on the press slide.

2. Upper mold base
The upper mold base is the plate shape parts on the upper section of the mold, the workpiece close to the press slider, and through the die or directly fixed with the press slide.

3. Bottom mold
The lower mold is the lower half of the whole die, that is, the die part mounted on the work surface of the press.

4. Bottom mold base
The lower die holder is a plate-like part at the bottom of the mold, which is fixed directly on the press work surface or pad.

5. Blade edge wall
The edge of the wall is the side wall of the die hole.

6. Edge slope
The slope of the edge is the slope of each side of the die hole.

7. air cushion
Air cushion is based on compressed air as the driving force of the bomb.

8. Anti-side briquettes
The backrest is a part that supports the unidirectional force punch from the other side of the work surface.

9. Bushing
The guide sleeve is a precision-oriented tubular part for the relative movement of the upper and lower mold bases, most of which are fixed in the upper mold base and used in conjunction with the guide posts fixed to the lower mold base.

10. Guides
The guide plate is a plate-like part with a punch with precision slip hole of male punch , which is used to ensure that the punch and die are aligned with each other and has discharge function.

11. Guide column
The guide column is a precision-oriented cylindrical part for the relative movement of the upper and lower mold bases, most of which are fixed to the lower die holder and are used in conjunction with the guide sleeve fixed to the upper mold base.

12. Guide pin
The push pin is a pin-shaped part that extends into the material hole and guides it in the die.

13. Guide plate mold
Guide plate mold is guided by the die, the mold is not used when the punch from the guide plate.

14. Guide plate
The guide plate is a plate-like guide part that guides the strip (strip, roll) into the die.

15. Guide column mold is the sliding mold frame of guide column, guide sleeve .

16. Punch die
Punch die is installed in the press for the production of blanking pieces, combined by the upper and lower parts.

17. Punch
The punch is a male working part that is formed directly in the die, that is, the part with the shape of the working surface.

18. Die
The die is a concave working part that directly forms the punching function in the die, that is, the part with the inner surface as the working surface.

19. Fenders
The protective plate is a plate-like part that prevents the finger or foreign matter from entering the hazardous area of the die.

20. Pressure plate
The press plate (circle) is the part of the die used to hold the stamping material or the work piece to control the flow of the material. In the drawing die, the pressing plate is mostly called the material circle.

21. Pressure bars
The press bar is a rib-like protrusion in the drawing die or drawing die which controls the flow of the material. The buckle may be a partial structure of a die or a press loop or may be embedded in a die or press separate parts.

22. Pressure threshold
The pressure threshold is a special material with a rectangular cross section. 

23. Bearing plate
The bearing plate is a plate-like part used to attach the stencil to the plane.

24. Continuous mold
The continuous mold is a die with two or more stations, and the material is fed to the station one hour by the press stroke, so that the punch is gradually formed.

25. Side edge
The side edge is a punch that cuts out the feed gap on the side of the strip (tape, roll).

26. Side plate
The side plate is a plate-like part that exerts a pressure on the strip (strip, roll) side through the spring to urge the other side against the plate.

27. Mandrel
The mandrel is a rod-shaped part that moves up or down directly or indirectly.

28. Crown plate
The crown plate is a plate-like part that is active in a die or module to act up or down directly or indirectly.

29. Ring gear
The ring gear is a denture protrusion on a fine punch or die, which is a partial structure of a die or a toothed plate rather than a separate part.

30. Limit sets
The limit sleeve is a tubular part that limits the minimum closing height of the die and is generally placed outside the guide post.

31. Limit column
The limiter column is a cylindrical member that limits the minimum closing height of the die.

32. Locating pin (plate)
Locating pin (plate) is to ensure that the workpiece in the mold has a constant position of the parts, with its shape is called the positioning pin or positioning plate.

33. Fixed plate
The mounting plate is a plate-shaped part of the fixed punch.

34. Fixed discharge plate
The fixed discharge plate is a discharge plate which is fixed on the die. (See “discharge plate”).

35. Fixed retaining pin (plate)
The fixed stop pin (plate) is a fixed pin (plate) which is fixed in the mold.

36. Unloader
The unloader is a non-plate part or device that is unloaded from the outer surface of the punch.

37. Unloading board
The unloading plate is a fixed or movable plate-shaped part that relocates the material or part from the punch. Discharge board is sometimes made with the guide plate into one, and play the role of the guide, still called discharge board.

38. Discharge screw
The discharge screw is a screw fixed to the ejector plate for restricting the rest position of the ejector plate.

39. Single process mode
The single-step mold is a die that only completes a process in a stroke of the press.

40. Waste cutter
There are two kinds of waste cutter.

1. A cutting edge used to cut a full circle of trimming scrap for easy removal.

2. A cutter attached to a press or mold for cutting a strip (strip, roll) of waste at a fixed length for cleaning.

41. Combination die
Combination die is a geometric elements (straight line, angle, arc, hole)  form a variety of pieces of the general, adjustable sets of die step by step. Flat shape of the shape of the contours of the general need for several pairs of punching die.

42. Front stopper pin (plate)
The front stopper pin (plate) is a part for positioning the material at the starting end. Used to block the pin (plate) are mobile.

43. Block
The blocks are made of a complete die, punch, unloading plate or fixing plate.

44. Stopper
The block (plate) is a hardened part for the material that is cut by the side edge of the cut, and is used to balance the single side cutting force of the side blade. The stopper (plate) is generally used in conjunction with the side blade.

45. Block pin (plate)
The baffle pin (plate) is the positioning part of the material in the feeding direction, and its shape is different and called the block pin or the baffle plate. Blocking pin (plate) is fixed block pin (plate), movable block pin (plate), the beginning with the block pin (plate), collectively.

46. Pad
The pad is a hardened plate-like part between the mounting plate (or die) and the mold base to reduce the unit compressive stress of the die holder.

Safe Production of Punching Machine

As the punch has a fast, high-pressure characteristics, so the use of punch for punching, forming must comply with certain safety regulations:
1. The drive parts exposure to the press must be fitted with a protective cover, prohibit the drive or commissioning without the protective cover.

2. Before driving, check whether the main fastening screws are loose, the mold is cracked, the operating mechanism, the automatic stopping device, the clutch, the brake is normal, the lubrication system has no clogging or lack of oil. If necessary, you can be running the machine without working.

3. The slider must be at the bottom dead center while installing the mold, closed height must be correct, try to avoid eccentric load; mold must be tight and reliable, and pass the pressure test.

4. Focus attention during working, is strictly prohibited hands and tools and other objects into the dangerous area. Small pieces must be operated with special tools (tweezers or feeders). When the mold stuck the blank, only use the tool to get rid of it.

5. When finding abnormal running or abnormal sound (such as batter, burst sound) should immediately stop feeding, check the cause. If the rotating parts loosed, the steering device failure, mold loosening, and defects, then should stop the machine and repair.

6. Every time a workpiece is finished, the hands or feet must leave the button or pedal to prevent misuse.

7. Two or more people operate the machine, one person should be set to drive, pay attention to coordination. Before getting off work the die should be down, disconnect the power, and carry out the necessary cleaning.

Precautions

Before work

⑴ check the lubrication of the various parts, and the lubrication points are fully lubricated
⑵ check whether the mold is installed correctly and reliably;
⑶ check whether the compressed air pressure is within the specified range
⑷ check the switch button is sensitive and reliable, be sure to make the flywheel and clutch off, to open the motor;
⑸ make the press several empty running, check the brake, clutch and control part of the work
⑹ check whether the main motor has abnormal heat, abnormal vibration, abnormal sound and so on
⑺ add the lithium base oil to the slider with a manual pump
⑻ check to adjust the feeder roller gap to the process requirements
⑼ check and keep the oil mist to meet the required requirements
⑽ when the motor is started, check whether the direction of rotation of the flywheel is the same as the rotary mark.

At work

⑴ should be regularly lubricated with a manual oil pump lubrication point to send lubricating oil
⑵ press performance is not familiar with, not allowed to adjust the press
⑶ absolutely prohibited at the same time punching two layers of sheet metal
⑷ found that the work should immediately stop working properly, and timely inspection.

After work

⑴ the flywheel and clutch disengagement, cut off the power, release the remaining air
⑵ wipe the press clean, work surface coated with anti-rust oil
⑶ record after each run or maintenance.

 

2017-12-07T11:41:27+00:00Stamping|

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