Analysis on the development trend of the most popu

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Analysis on the development trend of domestic punch industry

the basic characteristics of punch produced by domestic punch manufacturers mainly include two aspects: one is rigidity, which includes longitudinal rigidity - the arch of slider and workbench and the elastic elongation of frame; And the horizontal displacement of the sliding block under the influence of lateral rigidity eccentric load. The second is the motion characteristics of the slider, including perpendicularity, parallelism, straightness, etc., which have a great impact on the accuracy of the product. The accuracy of products is not only related to punches, but also related to materials, molds, lubrication, etc. we cannot only consider a certain factor. There are two basic characteristics of the punch produced by domestic punch manufacturers. One is rigidity, which includes the arch of the longitudinal rigid slider and workbench and the elastic elongation of the frame; And under the influence of lateral rigid eccentric load, Shandong has formed a horizontal displacement of sliding blocks dominated by polyurethane, fluorosilicone materials, high-performance fibers, new thermal insulation and other chemical related new materials. The second is the motion characteristics of the slider, including perpendicularity, parallelism, straightness, etc., which have a great impact on the accuracy of the product. The accuracy of products is not only related to punches, but also related to materials, molds, lubrication, etc. we cannot only consider a certain factor. Considering the elements of the punch, the accuracy of the thickness direction of the product is related to the longitudinal rigidity, while the deviation, bending or parallelism is related to the transverse rigidity and the characteristics of the motion curve. Therefore, improving these characteristics can improve the accuracy of products, prolong the service life of molds, and improve the stability of production. These characteristics of punch must be considered when selecting punch according to forming method, forming speed, productivity, etc. According to the different driving mechanisms, mechanical punches include: crankshaft punches, which are most widely used in stamping processing, elbow punches, which have the slowest speed near the bottom dead center, and connecting rod punches, which have high torque capacity and start to slow down at a high position above the bottom dead center

when forging punches are used, crankshaft punches are used when productivity is the most important; If the formability near the bottom dead center is pursued, the elbow bar punch is selected; If forming or blocking forging at a high position is required, the connecting rod punch is selected. In order to realize non cutting forming, the functional requirements of punch are higher and higher. The development trend of stamping machinery is towards high precision, high rigidity, appropriate slider motion characteristics, intelligence, multi-directional motion, and even environmental protection

development trend of mechanical punch

1. High rigidity and high functionality of general punch

then the C-shaped punch originally used as a general machine also pursues high precision and high functionality, thus developing an all-in-one gantry punch; Connecting rod punch with Aida connecting rod drive mechanism, with very slow speed near the bottom dead center and SPM unaffected. This connecting rod punch involves two eccentric connecting rods between the driving gear and the crankshaft. When the driving gear rotates, the crankshaft will move at an unequal speed due to the change of the connecting angle of the connecting rod. The difference between this connecting rod mechanism and other connecting rod mechanisms is that the connecting points of the pressure part are few and the comprehensive clearance is small. The connecting rod mechanism has higher torque capacity than the elbow rod mechanism, and can form at a higher position of the bottom dead center. The driving mode of vertical connecting rod punch is a driving mode in which two connecting rods, vertical connecting rod and fulcrum connecting rod, are added to the ordinary elbow bar mechanism, so that the connecting rod directly connected with the slider in processing can basically maintain a vertical state, so that the forming load can be vertically transmitted through the vertical connecting rod

2. Because the connecting rod of ordinary mechanical stamping machine is obliquely pressed on the sliding block, the sliding block is subjected to great adverse lateral force. Therefore, this driving mode has higher accuracy than the ordinary driving mode, and is more suitable for high-precision processing. At the position 5mm above the bottom dead center, the sliding block of the ordinary elbow bar punch receives a lateral force accounting for about 10% of the forming force, while that of the vertical connecting rod punch does not exceed 1%. This kind of stamping machine is suitable for processing that requires high alignment between upper and lower dies. Like VL drive, SL drive mode is a drive mode with almost zero lateral force acting on the slider, but its stroke can be longer, which is suitable for extrusion processing with little speed change at a higher position above the bottom dead center. This connecting rod mechanism ensures that the connecting rod remains basically vertical during operation. Vertical connecting rod punches are mostly used for forward feeding, but in the forming of complex shapes, forward feeding is used first, and the second half is processed by the composite method of multi station transportation. There are various kinds of conveying devices available, such as three-dimensional servo multi station conveying devices of sucker type or gripper type, etc

development trend of numerical control punch

numerical control punch has a CNC control system, which can set the motion mode and speed of the slider arbitrarily according to the needs of the processing method

in the actual engineering structure

1. The screw NC punch

servo machine uses AC servo motor to drive the slider through the screw. The position of the bottom dead center in the forming can be controlled by the position reading device by providing data to the position control device. Therefore, the thermal expansion and elastic deformation of the machine will not affect the accuracy of the product, and the most suitable motion mode of the slider and the position of the lower dead center will be adjusted in extremely small units. Therefore, the non cutting forming screw servo punch suitable for high precision and high function adopts the form of oil pressure motor and energy accumulator for torque control, and the position control of the bottom dead center can reach the micron level. It is an energy-saving and environmental friendly model

2. Crankshaft servo punch

CNC punch combined with AC servo motor. This kind of punch uses servo motor to replace the clutch brake and flywheel on the original punch. This kind of punch has the characteristics of servo punch whose sliding block movement mode can be set arbitrarily, and also has the torque characteristics of ordinary mechanical punch as shown in Figure 3. However, its working energy will not decrease in the low-speed region

3. Compound forming punch

compound forming is a powerful means of non cutting forming. In cold forging, block forging is an example, which controls the plastic flow of materials by controlling the actions and time charts of multiple punches and dies. The accuracy and formability of products can be improved, and even the number of processes can be shortened

the double action forming can be roughly divided into two categories: paying attention to the versatility of punch press and using the double action die base; It is easy to assemble and disassemble the molds for various kinds of production, and it can be formed by using the compound punch. Recently, not only in forging processing, but also in the diversification and improvement of the ability of sheet metal forming and forging composite forming, the punch is required not only to have multi action performance, but also to have high versatility

4. Closed die forging punches

closed die forging dies and universal forging punches have been widely used in the forming of star wheels and cross couplings. Its mold structure has blocking function and coordination function. Other closed forging punches that can save the piping time during die assembly can be divided into two types: these functions are all in the punch and the upper and lower oil cylinders are on the punch, while the coordination mechanism is on the die base

5. Sheet metal forging punch

with the popularity of sheet metal forging, it is required that the forging punch can carry out deep drawing or shorten the number of projects, so the slider and workbench must be equipped with oil cylinders. The original block forging almost uses high-capacity atmospheric action. In addition to the atmospheric action corresponding to the working method, the plate forging also requires sequential action, self-locking and other functions

6. Punch for gear forming

compound hydraulic punch for spiral gear forming. This punch has a total of sliding drive, 2 in the slider and 2 in the workbench. A total of 5 drive sources all share an oil pressure drive. In the initial stage of forming, the punch is inserted into the tooth space of the female die in the block, and the material flows from below for initial forming, just like the inner ring forging of the atmospheric ejector. In this state, the core rises and the core diameter in the center of the material changes from coarse to fine. At this time, there is a new space in the inner diameter of the workpiece, which can produce new plastic flow, so increasing the pressure material can fill the tip of the tooth shape. The processing pressure of the products processed by this method is only 1300mpa, and the collapse angle and burr of the tooth profile are very small. The formed gears can reach jis3~4 levels by using compound forming to control the material flow, which is very close to the time-consuming and high value-added non cutting forming when replacing dyes

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