Introduction of the Main Mold of the Cold Heading Process
The Role of the Mold in the Cold Heading Process
The process mold plays an important role in the production of cold heading. In addition to meeting the dimensional requirements of the product shape, it also meets the requirements of special cold heading process impact toughness and strength, ensuring a high service life to adapt to automation and high volume. The large need for production, therefore, the tooling has unique requirements for the structural design, material selection, heat treatment, etc. Therefore, it is indispensable for the study of the main molds in the cold heading process.
Feed Roller Design
Note: The R size should be suitable. If oversize the wire will be flattened, on the contrary, if undersize the wire will be pressed out of the four line marks, which will affect the product quality.
The feed wheel can be made of high carbon tool steel or 40Cr. The wheel groove will use surface hardened and the hardness is 58 to 60 HRC.
If the wheel groove is strained or worn, can be removed, and repaired after annealing. The roller can be repeatedly ground for 3 to 5 times, until the center distance of the two wheels cannot guarantee that the wire is pressed and the feeding is affected, then it can be discarded.
The Rule of Cutting Die
The feed end of the cutting die has a 30° bell mouth to allow the ends of the wire to pass easily. The cutting edge is easy to wear and can be made of alloy tool steel or high speed tool steel. The heat treatment hardness is 60 to 62HC. In order to improve the service life of the cutting die, the cutting die can be embedded with cemented carbide.
Rule of Cutting Knife
The edge part R size can be as follows:
The cutting edge R of the blade must be round and smooth, and the gap between the blade and the cutting die is generally about 0.1 mm. The material of the blade is T10 or 9CrSi, GCr15, and the hardness of the edge portion is 58 to 60 HRC. To improve the life of the blade. Carbide can be placed on the edge of the cutting edge. Figure:
Initial Die Design
The design principle of the initial die: obtain a large deformation ratio as much as possible, avoid the longitudinal bending of the metal fiber, and obtain excellent parts.
The size of the initial die port is generally taken as the wire diameter of dk=1.25-1.4. The bottom diameter d = do the maximum value of the wire. Generally, the initial die structure is divided into fixed and floating, as shown in the figure:
Optical Die Design
The optical die design is mainly based on the head size of the product. The structure type is as follows: