What are the operating points of cold heading machine equipment?

Cold upsetting is a forging method of upsetting metal bars at room temperature with dies, which is usually used to manufacture the heads of screws, bolts, rivets, etc. Cutting can be reduced or replaced. The forging blank material can be copper, aluminum, carbon steel, alloy steel, stainless steel and titanium alloy. Cold heading is mostly carried out on a special cold heading machine, where cutting, heading, accumulation, forming, chamfering, wire rolling, reducing and trimming can be completed in turn.

This paper briefly introduces the operation and key points of the equipment of the lower cold heading machine;

1. What are the characteristics of cold heading process?

(1) According to the theory of metal plastic deformation, a certain pressure is applied to the metal blank at room temperature to make it plastically deform in the mold cavity, so that the metal blank can be shaped according to the specified shape and size.

(2) High-quality metal materials with good plastic deformation, such as riveted rebar, must be selected, and their chemical composition and mechanical properties have strict standards.

(3) The cold heading bolt and nut forming machinery and equipment have reliable performance, high efficiency and stable workpiece quality.

(4) Good surface quality and high dimensional accuracy. Because there is cold working hardening during upsetting, the deformation should not be too large to reduce cracking.

Second, the reasons that affect the machining accuracy

(1) The plasticity of pure metal is better than that of alloy. Impurity elements usually cause brittleness and reduce plasticity, and various alloys have different effects on plasticity.

(2) The plasticity of single-phase metal is better than that of multi-phase metal, and the plasticity of metal decreases due to defects such as segregation, inclusion, bubbles and pores in the casting structure.

(3) The increase of strain rate not only reduces the plasticity of metal, but also improves the plasticity of metal.

(4) In the state of principal stress, the greater the number and value of compressive stress, the better the plasticity of metal, and vice versa.

(5) In the case of discontinuous deformation, the plasticity of metal can also be improved, especially when the metal with low plasticity is thermally deformed.

Third, the choice of cold heading machine equipment

(1) The crankshaft, engine block and impact connecting rod are made of high wear-resistant alloy, which has high tensile strength and good wear resistance.

(2) Equipped with frequency conversion speed regulating device, the gear efficiency is high and the torque is large.

(3) The cutting force of the arbor is transmitted in a straight line, and the force is large, stable and dynamic.

(4) Multi-station cold heading machine adopts opening and closing pliers to convey the workpiece, which is beneficial to the forming process arrangement.

(5) Equipped with fault detector and safety protection device, when the equipment fails, it will automatically stop to protect the equipment and tools to the maximum extent.

(6) The lubricating oil path is simple and efficient, which can effectively protect the punch and workpiece on the basis of ensuring circulating filtration.

Fourthly, the selection of raw materials for workpieces.

(1) In order to reduce the cracking tendency of materials as much as possible, the hardness of materials is required to be as low as possible to improve plasticity.

(2) The inch accuracy of raw materials should generally be determined according to specific requirements and process conditions.

(3) The surface quality of raw materials requires cold heading oil film, and there shall be no scratches, folds, cracks, galling, corrosion, scale, pits and other defects.

(4) Raw materials should be subjected to cold heading test, and the lower the sensitivity of materials to cold working hardening, the better.

Verb (abbreviation of verb) Selection of cold heading forming oil

(1) can minimize the oil smoke and "floating fog" and meet the strict requirements of the equipment of the cold heading machine with strong shrinkage die.

(2) Workpieces with large deformation can be completed, such as hollow, high-strength bolts, sleeves, stainless steel hollow and semi-hollow rivets.

(3) It can effectively protect the punch (punching needle) and the die, prolong the service life and reduce the comprehensive investment.

(4) The heat dissipation effect is good, and the local temperature of the workpiece and the mold is prevented from being too high in the cold forming process.

(5) It is resistant to high temperature and is not easy to produce sludge. Low odor and smoke, protecting the operating environment.

(6) It has certain rust resistance and can meet the requirements of rust prevention between processes.