Forged Blanking Of Precision Forgings
- Sep 22, 2017 -

Precision forging is the production process of forgings with high strength, complex contour shape, high surface quality and strict tolerance. The basic precondition of precision forging without flying edge is the forging blanks with accurate volume. In forging steel forgings, the most commonly used blanking method is the billet shearing machine.


In die forging, forged blanks are forged in one or more multistage forging molds into a product of a certain geometrical shape. For the slender forgings (that is, the workpiece of the forging workpiece is significantly larger than its cross-section size), it usually includes a number of forging steps such as pre redistribution of blank quality, cross section forming and final forming. In traditional forging, excess materials usually become burrs of forgings and need to be removed before final forging.


In recent years, the hot forging process of steel has been greatly developed and changed. In addition to the new forging die and forging equipment, the improvement of the forging process is also manifested in the improvement of economy and forging quality. The significance of forging without burrs becomes more and more important.


Precision forging is a kind of economical technology which replaces the traditional forging of complex geometric shape forgings. For example, the connecting rod type workpiece, if does not use the precision forging to need to carry on the complex mechanical processing to achieve the precision forging the effect. The use of precision forging, the economy can achieve the it8~it10 level of tolerance. Because there is no Burr precision forging will not appear, so the omission is not only the forging of the burr process, but also to save the forged burrs occupied by metal materials. The prerequisite for this is: forging production process which is suitable for forging parts. This process includes: a quality preform that is precisely consistent with the quality of the workpiece (such as a cross wedge rolling), a thick pier in a closed forging die, a desired cross-section size, and a final precision forging.


The forging die blanks with small shape, accurate size and constant volume are the basis of normal burr-free die forging. For most steel die forgings, forged blanks are usually made from steel rod cutting equipment. Compared with saw cutting, this shearing steel bar shearing device has the characteristics of high speed and precision, and it has high material utilization rate because of the omission of saw slit.


In order to ensure the accuracy of cutting down material, it is necessary to review the blank quality and volume after blanking in the auxiliary equipment of the steel bar shearing machine, and to adjust the production process parameters such as slit size and cutting speed. Only if the shearing surface of the blank is more flat, and the steel rod axis is more perpendicular, there will be better quality of the rough cutting. At the cutting edge of the exciter (Fig. 1) can be modified at the same time several process parameters. In addition to improving the surface quality of the trimmed surface, it reduces the tilt angle of the cutting surface of the bar to less than 1 and reduces the surface wave. This type of cutting device with a vibrator is especially suitable for tailoring forged blanks that require a straight, or cut, surface without defects. Therefore, in the precision forging without burrs, it is ideal to use this kind of cutting equipment.