Piercing tool for seamless steel pipe

Posted by zora li on September 22nd, 2022

Piercing tool of seamless steel pipe is following below:

1) Roller: It is the main drive deformation tool. Usually the roller is composed of inlet cone, rolled belt (also called compression belt) and outlet cone. Its function:
a. Inlet cone: Into the tube blank and achieve tube perforation.
b. The exit cone is to achieve hair wall reduction, levelling of the capillary surface, uniform capillary wall thickness and complete capillary return.
c. Rolling belt: play a transition from the inlet cone to the exit cone.

2) Guide: It is a fixed external deformation tool, not only plays the guiding role of the tube blank and the capillary tube, making the rolling line stable, but more important is the closed hole outer ring, limiting the lateral deformation of the capillary tube - expanding diameter, play a role in controlling the diameter of the outer diameter of the capillary tube. The guide plate has the same shape as a roll and has an inlet section, a transition section, and an outlet section.

(1) The inlet section introduces the tube blank;

(2) The outlet section derives the capillary tube and limits the expansion of the capillary tube;

(3) The transition section functions as a transition.

3) Head: The shape of the head is shown in the figure. It is a deformation tool in the puncher and it is equivalent to the inner roll of a steel ring mill. During operation, the support of the head against the top bar is fixed in the axial position in the deformation zone. Practice has proved that in the process of changing the tube blank from solid to hollow, the outside diameter of the rolled part does not change much, and the expansion of the inner diameter from zero to the required value is mainly achieved by the piercing cone of the head. Because the head is charged with a very important deformation task and is exposed to the harsh working conditions surrounded by heated metal, the head is a key tool that has a major impact on capillary quality and punch productivity. The head is composed of four sections: the nose, the perforated cone, the flat belt, and the reverse taper belt. The role of each segment is: 1) The nose is used to align the blank centering hole during piercing, which is easy to work on; the axial force is applied to the center of the tube to prevent the preformed cavity to a certain extent. 2) The perforated cone is responsible for the task of perforating the tube and reducing the thickness of the capillary tube. 3) The cone angle of the flattening section is equal to the taper angle of the exit of the roll. It plays the role of both the inner and outer surfaces of the whole wall thickness of the capillary tube and the flattening capillary tube; The role is to prevent internal scratches when the capillaries break away from the head.

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