Semi-closed type forging die used for forging of bevel gear and forging method thereof

Abstract

The invention discloses a semi-closed forging die for bevel gear forging and a forging method, comprising a toothed die, an upper punch, a back cone die and a lower punch, wherein the toothed die and the upper punch are matched and installed , the back cone mold and the lower punch are installed together; the closed space formed by the tooth mold and the back cone mold includes a cavity and a shunt structure located at the large end of the tooth mold. The shunt structure communicates with the cavity and is narrow. Clearance; when forging bevel gears, under the action of the upper punch, the blank first fills the cavity, and then presses into the shunt structure to ensure the filling fullness of the tooth profile. The mold adopts a semi-closed die forging structure, that is, the back cone die and the tooth-shaped die are closed to form a closed cavity, but a shunt structure is designed at the tooth top of the big end to make it easier to fill the cavity and avoid excessive of forming power.

Description

technical field [0001] The invention relates to a semi-closed die forging die for bevel gear forging and a forging method, belonging to the technical field of die design. Background technique [0002] With the development of plastic forming technology, the method of plastic forming to complete the processing of gears has been widely used. Traditional gear forming methods have been gradually replaced by precision forming processes such as cold forging, warm forging, and hot forging. Although the gear precision forging technology has been relatively mature after more than 60 years of development, there are still problems such as insufficient filling of the tooth profile, low gear precision, and high forming force. [0003] Open die forging can ensure that the tooth shape is full and the forming force is low. However, due to the existence of burrs, open die forging requires more materials, and the integrity and accuracy of forgings can only be guaranteed when there are more ma...

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Problems solved by technology

Therefore, the material utilization rate of closed die forging is high, but because the billet is formed in the closed die cavity around, it is easy to have problems such as insufficient tooth filling, low gear precision, and high forming force.

[0005] The movement of the traditional closed-die forging die is generally that the tooth-shaped die goes down first until it contacts the back cone die to form a closed space, and then the upper and lower punches are relatively squeezed to fill the cavity. This movement mode is easy to make the upper punch and the tooth A large gap is formed between the dies. Under the pressure of the upper punch, the material is easy to enter the gap between the upper punch and the tooth die, causing defects in the bevel gear forgings. At the same time, this movement mode, in When the upper punch is extruded, folding defects are generated on the upper surface of the bevel gear, resulting in the disadvantages of low precision of the bevel gear, poor uniformity of structure, uneven metal flow line and many defects.

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