Several methods of extruding pipe for extruder

When extruding the pipe, the extruder can be carried out on the extruder with an independent perforation device or on the extruder without an independent perforation device. When the extruder is extruded, the punching needle passes through the center of the billet along the axis of extrusion and forms a ring through the die hole. With the help of the pressure of the extrusion shaft, the metal is forced to form the pipe through the die hole, and its inner diameter depends on the diameter of the piercing pin, and the outer diameter depends on the diameter of the extrusion die hole.

In the forward extrusion of pipe material, hollow ingot can be produced and solid ingot can be used to press the extruder on the extrusion machine. When the hollow billet is used to extrude the pipe, a lot of additional processing is added to the drilling of the billet, and the inner surface of the billet is also oxidized during heating, which is easy to cause the inner surface defect of the extruded tube. Therefore, it is not economical to use this method to produce pipe material. This method is used only when small pipe material is produced. In modern extrusion technology, an extruder with an independent perforation device is generally used to squeeze the pipe. The production method of pipe, a part of the metal is needle top "tops", become the waste of large diameter pipe production is not economic, so use other methods to reduce the loss of the "car" is an important means to improve the rate of finished products. For example, for some sizes of large pipe material heads, as long as they can meet the requirements of other extrusion cylinder systems, they can be used as rebars to produce small size products. In addition, can also be used with extrusion method to reduce the head loss of perforation, improve the rate of finished products.

There is a certain friction between the piercing needle and the metal ingot blank when extruding the extruder, so that the uneven flow of metal in the extrusion process is slowed down. Therefore, when the pipe is extruded, the tails are generally short. The main defects of extruded pipes include internal and external surface defects, such as internal and external oxide, pressure, scratch, bubble, skin and uneven wall thickness. In order to prevent the extrusion of leather products from bleeding, extrusion and extrusion can also be used. Modern extrusion technology is widely applied to pipe extrusion and extrusion. Such as: all kinds of brass, entangles the condenser tube, such as high precision alloy waveguide. In order to ensure that the extruded products will not produce high temperature oxidation after the extrusion of the die, the water sealing and extrusion technology and the pressure protection method can be adopted. One of the most important quality problems of extruding pipe with perforated needle on horizontal extruder is the problem of pipe eccentricity. There are many factors that affect the eccentricity of extrusion pipe, but mainly due to the reasons of extrusion equipment and tools. Ensuring the concentricity of the extruder and concentricity of the extrusion tool (shaft, cylinder and die base) is the first condition to obtain uniform wall thickness of the extruded tube. It should also be concretely solved according to the situation of the equipment used and the experience accumulated in the production practice.