Cold heading mould is the most important process equipment in cold heading production, and it is the basis of cold heading processing, which directly affects the quality, production efficiency and safety status of cold heading special-shaped products.
The basic composition of the cold heading die: the cold heading die is mainly composed of a feeding roller, a cutting die, an olive forging die, a rod die, and an ejector rod.
(1) Feeding roller. The feeding roller is used for automatic intermittent feeding of the wire into the Lengao machine. In each stroke of the cold heading machine (in each second stroke of the double-clicking cold heading machine), the feeding roller rotates periodically according to a certain rotation angle through the intermittent cyclic action of the feeding mechanism, and sends the wire to the mould box.
(2) Cutting die. The cutting die is composed of a cutting knife and a cutting knife board. The function of the cutting die is to cut the wire delivered by the feeding roller during each stroke of the cold heading machine (double-click the cold heading machine every second stroke) The material is then sent to the lower position for upsetting by the cutting blade or clamp.
(3) Upsetting die. The upsetting die is generally divided into a pre-upsetting die (primary punching die) and a forming die (fine punching die), which are used for forming the head of the workpiece. According to the principle of gradual transition deformation, the pre-upsetting die is usually made into a conical cavity or a circular cavity. The geometric shape and dimensional accuracy of the forming die are designed according to the requirements of the finished product.
(4) Rod die. The rod die is also called the lower die or the concave die, which supports the blank during the upsetting process and is used to form the basic shape of the rod and head of the workpiece. According to needs, it can be made into split type, integral type and combined type.
(5) Ejector rod. The ejector rod is usually installed in the die, and is used to limit the length of the rod of the rod-like workpiece during the sharp forging. After the upsetting is completed, the ejector rod ejects the workpiece with the aid of the intermittent movement of the ejector mechanism. When the workpiece has special requirements, ejector rods can also be installed in the upper die. In addition, cold heading dies generally include installation and positioning parts such as die holders, clamps, and die boxes.