SU657884A1 - Tube-drawing mandrel - Google Patents

Description

I

FIELD: dragging. A known mandrel for drawing pipes, including an adapter mounted on the rod and a working nozzle connected to it by a bolt, mounted on the bolt with the possibility of axial movement, the spring l being installed between the adapter and the nozzle.

The purpose of the invention is to reduce the dragging force at the time of gripping the mandrel and prevent the pipe heads from breaking, as well as increasing the durability of the working nozzle. . This is achieved by the fact that the mandrel is provided with a cup spring installed between the bolt head and the working nozzle.

To prevent the working nozzle from tilting with respect to the axis of drawing, the axis of the adapter is offset relative to the axis of the working nozzle by the value of the difference between the internal diameter of the pipe being processed and the diameter of the adapter.

The drawing shows a schematic drawing of a pipe on a mandrel of the proposed construction.

The device includes a mandrel containing a working nozzle 1 installed on the bolt 2

With the possibility of axial movement and connected to the adapter 3, which is mounted on the rod 4. The adapter axis is displaced relative to the nozzle axis and an amount equal to half the difference between the inner diameter of the pipe 5 and the adapter 3 diameter. The adapter section facing the working nozzle is made conical to facilitate insertion into the pipe. Between the adapter 3 and the working nozzle 1, as well as between the working nozzle and the head of the bolt 2, cup springs 6 and 7 are installed with a compressive force equal to 10-30% of the drag force.

The device works as follows.

The pipe 5 to be machined is fed with the driven head into the fiber 8. After that, a mandrel is inserted into the workpiece, which advances to the deformation zone until it touches the pipe at the transition point of the pipe from the cylindrical part to the blocked head. In this case, due to the fact that the axis of the adapter is displaced relative to the axis of the nozzle by the value D, the working nozzle 1 is centered along the axis of the pipe, and consequently, along the axis of dragging. Then applied to pipe 5

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They bring forth effort. In this case, the spring 7 compensates for an increase in the dragging force at the moment of gripping. After completion of the dragging process, the spring 7 returns to its original position, and this elastic after-effect of the spring 7 is perceived by the spring 6 installed between the adapter 3 and the working nozzle 1. The drawing of pipes on the mandrel The known construction passes without peak loads at the initial moment of drawing, which prevents breaks of pipe heads . The average resistance of the mandrels is increased by 30%.

Claims (2)

1. Mandrel for drawing pipes, including an adapter attached to the rod and a working nozzle connected to it by a bolt, mounted on a bolt with the possibility of axial displacement 657884 Nor, moreover, between the adapter and the nozzle, a spring is installed, characterized in that, in order to reduce the force, at the moment of gripping the mandrel and thereby prevent the pipe heads from breaking, as well as to increase the durability of the working nozzle, the mandrel is provided with a cup spring and working nozzle. 2. Mandrel according to Claim I., so that, in order to prevent the working nozzle from tilting relative to the drawing axis, the adapter axis is shifted relative to the working nozzle axis by the half-difference of the internal diameter of the pipe being processed and the diameter of the adapter. Sources of information taken into account in the examination 1. The patent € ША № 2358838, kl.74-465, 1944.