SU1528593A1 - Self-setting mandrel for drawing tubes - Google Patents

Abstract

The invention relates to the drawing of pipes with internal helical ribs on a self-aligning mandrel. The purpose of the invention is to reduce the breakage of pipes and increase the wear resistance of the mandrel during the coil drawing of ribbed pipes with a rib elevation angle of 15 - 45 °. On the cylindrical hollow mandrel element 4, outer helical grooves 5 are made. It is mounted on a rod 1, made in the form of a bolt with a head 2, rotatably relative to a crimping conical hollow element 6 mounted on the same rod with an axial clearance. The bearing assembly consisting of guide rings 7 and 8 with balls 9, helps to improve the deformation of the pipe and reduce the dragging force. 1 hp f-ly, 3 ill.

Description

JV Yu

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The invention relates to the drawing of pipes with internal helical fins on a self-aligning rod.

 the invention is a reduction (.tb of the pipes and a longer wear of the mandrel at the bay drawing of ribbed pipes with the elevation angle of the ribs 15-45.

FIG. 1 shows a mandrel, a continuous slit j in FIG. 2, a support with a bearing assembly, a longitudinal slit j in FIG. 3 - section aa

and 2.

.-

The mandrel contains a core 1 in the form of a hollow with a head 2 and a nut 3, k and: a vibrating cylindrical hollow element 4 with external screw channels 5, mounted for possible rotation, crimping conical ro: jbift element 6 and thrust bearing Koniiiii node in the form of two guides, com :; 7 and 8 with balls 9.

The grooves on a cylindrical hollow element can have a different shape, triangular shaped with a rounded hollow (Fig. 2) or rectangular 1g cross section.

 The goal of raising the grooves d relative to HI-. axis of the cylindrical surface. MO-ket can also be different in the range of 15-45 °. In this case, the lower limit of this range is determined from the strengths. that at small angles c (it may be preferable under the conditions of the implementation to implement other methods and devices for producing pipes with a T-LM, LM screw profile of the inner surface among the known methods of Ti devices. The upper limit of the indicated angle variation range is limited by deformation of the pipe material during the formation of a toothed screw profile.

The proposed mandrel works in an unrivaled manner.

In the process of dragging, a gradual filling of the grooves 5 on the cylindrical hollow element 4 with the metal of the pipe | .1 occurs as the metal moves along the deformation zone along the surface, while the pipe metal moves along the entire deformation zone in the axial direction. In this case, the action of the friction forces developing in the deformation zone on the conical hollow element 6, keeps this element in a stationary state

five

thirty

35

P

five

five

50 55 NII, since the friction forces between the metal of the pipe and the conical surface are directed along the generator of the conical surface (the direction of these friction forces is shown in Fig. 1 and 2 with arrows).

The metal of the pipe filling the grooves 5 on the cylindrical element 4 forms an engagement with this element. Since the mandrel is self-aligning and remains stationary relative to the deformation zone, and the grooves on the cylindrical surface are helical (wherein the cylindrical element is mounted relative to the conical element so that it can rotate around its axis), advancing the metal of the pipe along these grooves on the cylindrical element and deep into these The grooves cause it to rotate relative to the conical element. The direction of this rotation with the direction of the helical grooves shown in FIG. 1 and 2 are marked with arrows.

The metal of the pipe teeth in the zone of the deformation zone in the mandrel of the proposed design moves only into the depths and along the grooves, as a result of which this process is close to the process taking place in the screw-nut, the cylindrical element 4 playing the role of the screw, and the nut - metal pipe with screws screwed through on the inner surface of this pipe. As a result, the force of the dragging pipe and the amount of friction forces in the deformation zone decrease, the breakage of the pipes during drawing decreases. The consequence of this is an increase in the wear resistance of the mandrel, the possibility of implementing a highly efficient bay method of manufacturing pipes with helical ribs on the inner surface, and an increase in the accuracy of the geometric parameters of the pipe.

To improve the process of deformation of the metal of the pipe allows the presence of guide rings 7 and B, which more accurately center the metal of the pipe-blank in the pre-focal zone and in the deformation zone, compared to the design shown in FIG. 1. The presence of balls 9 installed between the directional rings, allows for an additional reduction

resistance to mutual rotation of the mandrel elements.

As a result, a further reduction in the drag of the pipe is achieved, its breakage is reduced, the accuracy of the geometrical parameters of the pipe made using the proposed mandrel is improved, and its wear resistance is increased.

Thus, using the proposed mandrel, it is possible to reduce the labor intensity of the production of finned tubes by using a highly efficient bay process for their manufacture.

Claims (2)

1. Alignment tool with tube mandrel containing gauge Phie.1 0 five cylindrical and crimping conical hollow elements mounted with an axial clearance on the central rod with heads, characterized in that, in order to reduce the breakage of pipes and increase the wear resistance of the mandrel when cobbing drawing ribbed pipes with the angle of raising of the ribs 15-45, the cylindrical element is made external helical grooves and it is mounted rotatably with respect to the conical element. 2. The mandrel according to claim 1, characterized in that it is provided with a thrust bearing assembly located between the large base of the conical element and the rod head. Phie. H