In the continued tough economic environment, non cutting forming is enterprise and competitors distance and competition to win the powerful means, and environmental protection is the theme of the 21st century, as the processing method of environmental protection will be the main direction of development. Forming of high precision and high additional value is indispensable in the process of non cutting forming. In order to realize these requirements, we must understand the whole process from material to finished product. Punch is one of the important technical elements. This paper will introduce the basic characteristics of the mechanical press and the development of the high precision multi function punch which is suitable for all kinds of forming technology in recent years.
The relation between the characteristic of the mechanical punch and the precision of the product. Punching machine has the following main characteristics: two, is a rigid, which comprises a longitudinal rigidity, the slide block and the work bench of hog and frame of the elastic elongation, slider and lateral stiffness, eccentric load under the influence of the level shift. The motion of the slider, including perpendicularity, parallelism, straightness, has a great influence on the accuracy of the product. The accuracy of the product is not only related to the punch press, it is related to the material, mold, lubrication and so on, can not only consider a certain factor. Considering the factors of the punch press, the precision of the thickness direction of the product is related to the longitudinal rigidity, and the deviation, bending or parallelism is related to the characteristics of the transverse rigidity and motion curve. So to improve these characteristics, the product precision can be improved, the mold life is prolonged, the production stability can also be improved.
Universal press of high rigidity, high performance of: originally universal machine with C-shaped punch but also the pursuit of high precision, high performance, thus developed a type gantry punching machine; with Aida and connecting rod driving mechanism and in the velocity near the bottom dead center is very slow and SPM is not affected by the influence of connecting rod type punch. This connecting rod type punch in the drive gear and the crankshaft between the intervention of the two eccentric connecting rod, when the drive gear rotation, due to the link of the link angle change, the crankshaft will do not constant velocity motion. The connecting rod mechanism is different from the other connecting rod mechanism, and the connecting point of the compression part is small and the integrated clearance is small. As shown in Figure 8, connecting rod mechanism than toggle mechanism can achieve high torque capability, forming a higher position in the bottom dead center.
Servo machine is using AC servo motor by means of screw driving slider and forming lower dead point position through reading device provides data to position control device to control. Therefore, the mechanical thermal expansion and elastic deformation does not affect the product precision, adjust the slider movement of the most suitable and extremely small units to control the bottom dead center position. So the application in high precision and high performance non cutting forming screw type servo press adopts hydraulic motor and energy storage for torque control, of the bottom dead center position control can achieve micron level, energy saving and environmental protection requirements of the aircraft.
Numerical control punch combined crank type punch press and AC servo motor. This kind of punch is used as a servo motor to replace the original press on the clutch brake and flywheel. The punch has the characteristics of the servo punch which can be arbitrarily set by the movement mode of the sliding block, and has the characteristics of the torque of the machine type punch in Figure 3. But the energy in the low speed area will not be reduced
Re forming is a powerful tool for non cutting forming. In the cold forging closed die forging is an example, is by multiple punch, a concave die of action and time graph control to achieve control of material of plastic flow. The precision and formability of the product can be improved, and even the number of working steps can be reduced.
Complex dynamic forming can be roughly divided into two categories: pay attention to punch the versatility of using the compound mold complex dynamic forming; multiple variety production mold installed demolition easy using a double action press forming. Only recently in the forging processing, also in sheet metal forming and Forging Compound Forming and the diversification of capacity increase and, asked to punch not only with multi action performance, must possess the high versatility
Forming a star wheel and cross coupling has been widely used and general closed forging die forging press. Other mold assembly can be saved in the piping time of occlusion forging press can be divided into two categories: these features full in the press and on the cylinder in the press and coordination mechanism in the die seat two forms.
5, sheet metal forging press
With popularity of sheet metal forging forming, forging press for drawing or reduce the number of projects, thus requiring the slider and the worktable must with a hydraulic cylinder. Original closed die forging is almost always the atmospheric action of high capacity, sheet metal forging in addition to the requirements and method adapted to the atmospheric movement, also called with a sequence of movements, self-locking function.
6, gear forming press
The double action hydraulic press for the forming of helical gear is shown in Figure 19. This kind of punching machine is used in a total of 5, 2, and 1 driving sources, all of which are used in a sliding drive, 2 in the working platform and in the working stage.
