Closed die forging equipment selection and precautions

The example of tooth blank closed forging in Maple machinery shows that: because the closed die forging has strict requirements on the blank, the blanking length tolerance is 0.5mm, the quality tolerance is not more than 2%~3%, and the section is required to be flat, can not be tilted, and can not have indent, then the cutting precision is not enough with the general shearing machine. When circular saw or bow saw is used, the saw edge loss is large and the efficiency is low. The use of high-speed band saw cutting is more reasonable, it not only has a higher productivity (3 times of the circular saw machine, the saw loss is also small (only 1/~1/5 of the circular saw machine), the cutting section quality and dimensional accuracy can fully meet the requirements of closed precision forging of tooth billet.

Secondly, in the heating link, less and no oxidation heating is the prerequisite for closed forging of tooth billet. The oxide not only affects the quality of the forging and the subsequent cutting process, but also affects the service life of the die. At the same time, in order to obtain higher accuracy and lower surface roughness of the forging surface, it is necessary to make the forging less oxidation or no oxidation during the heating process. Medium frequency induction heating device as a heating method is more suitable, it not only has a high productivity, oxidation and decarbonization is relatively small, and the temperature control is also very accurate.

In order to reduce the oxide formed after the tooth blank heating, the use of ultra-high pressure oxide cleaning machine has become an inevitable trend. It adopts the principle of high pressure water phosphorus removal. Under the action of high pressure water pump, the water beam with high pressure is sprayed through the nozzle to wash to the surface of the billet. The oxide has undergone the process of being cut, chilled and shrunk, stripped from the base material, and washed away from the surface of the billet (or intermediate billet), so as to clean the oxide.

The final tooth blank closed should choose the screw press, used in Europe for closed die forging for many years, the forging industry in Italy has made a lot of investment in the screw press, there are hundreds of forging production lines for production. It is economical to form a production line with an induction heating unit, a preforming press and a screw press. In the actual production, the use of 3000kN friction press preforming, 4000kN friction press final forging forming, formed a production line, achieved satisfactory results, more than 1000 pieces of production.