DE1950474A1 - Bending mandrel with movable mandrel head for pipe bending devices, in particular for hydraulic pipe pressure bending devices - Google Patents

Description

Applicant: VBB repair shop "Clara Zetkin" Turbo generators - electric motors Erfurt, Hohenimmernstr. 16

The invention "relates to a bending mandrel with a movable mandrel head for pipe bending devices, especially for hydraulic pipe compression bending devices.

To achieve the roundness of pipes to be bent, e.g. B. Tubes for heat exchangers, on tube pressure Siege devices bending mandrels with a movable mandrel head are used. This is to ensure that the pipe wall in the pipe bend does not occur. However, since the bending mandrel has a play of approx. 1 mm - based on the inner diameter of the pipe - the pipe wall falls, especially in the area of the bending axis and afterwards, by this amount after the bending process has ended a. This makes the roundness, i.e. H. Ovality = O, not more guaranteed.

The consequences of not guaranteed roundness are with heat exchangers for steam generator tube rupture due to the thermo dynamic loads.

In addition, these bending mandrels are very prone to failure, ¹ because they are exposed to wear and soiling. It is known to use conical mandrels to support the pipe wall in the case of pre-treatment pipes to be bent. However, conical mandrels cannot be used for tubes such as those used for heat exchangers, since functionality cannot be guaranteed due to wear and tear and contamination.

The purpose of the invention is to provide a bending mandrel with a movable Mandrel head to ensure roundness, d. h, quality = Ö, to accomplish.

0098A9 / 02U

The invention is based on the object of designing the movable mandrel head and of connecting it to the bending mandrel in such a way that the required clearance between the inner pipe diameter and the mandrel is balanced during the bending process »

This is achieved in that, according to the invention, the mandrel head deflectable, stored and on the mandrel body of the bending dome is supported, - According to a feature of the invention is the Inner wall of the mandrel head is conically formed and on the stepped Part of the mandrel body stored and the mandrel head on curved sliding surfaces of the stepped mandrel body of the Bending mandrel and one on the stepped part of the mandrel body lockable disc supported.

The invention allows the mandrel head to be deflected so far that the play between the bending mandrel and the inside diameter of the pipe during of the bending process is compensated so that the pipe wall does not collapse in the pipe bend and in the area of the bending axis. This makes it possible to achieve an ovality = O in the bend. Due to the design and arrangement of the movable mandrel head is a low-wear and pollution-free construction created.

The invention is explained in more detail using an exemplary embodiment shown in the drawing. The drawing shows the bending mandrel with a movable mandrel head.

The mandrel head 2 is mounted and slidably supported on the mandrel body 1 of the bending mandrel. The locking of the mandrel head it 2 takes place via the disk 3 through the screw connection on the stepped part 5 of the mandrel body 1.

Due to the conical inner wall 6, the mandrel head 2 is mounted on the offset part 5 of the mandrel body Λ in the bending axis 7.

QQ9849 / 02U

.- 3 - ■

The mandrel head 2 is supported with its curved surface on the similarly designed surface of the mandrel body 1 and with its curved surface 9 on the similarly designed Surface of the disc 3 sliding off. ■ To compensate for the play between the inside of the pipe to be bent Rohres and the diameter of the Biegedorn.es the mandrel head 2 is mounted and supported on the mandrel body 1 j that the supporting edge Ίο of the mandrel head 2 during the bending process this amount is deflected laterally;

'As a result, the pipe wall is supported during the bending process behind the bending edge 11 of the mandrel head 2 »so that a Three-point support of the mandrel head .2 in the Rohrbiegüüg with the Support edge 1o $ of the bending wires 11 and the pressure surface 12 reached is j that prevents the pipe wall from falling down.

When bending pipes with the bending mandrel according to the invention an ovality = Ö is achieved; Through the sliding abut- ■ tion of the surfaces 8} 9 of the mandrel head 2 ah-the likewise trained Surfaces dej3 Dörnkörpers 1 and the disc 3 is one Danger of soiling and wear and tear, and thus the occurrence the inability to function is no longer possible.

98A9 / 02U

Claims (1)

Claims. 1 1. Biesedorn with movable pin head for EohrbiegeV; orrieh .- * services, in particular for hydraulic Eohr-Druck-Biege-Vorriehttmgenj characterized in that the mandrel head (2) can be deflected on the mandrel body (1) of the mandrel is stored and supported. 2 «Bending mandrel according to claim I ^ characterized '- _t that the inner wall (6) of the mandrel head (2) is conical and mounted on the stepped part (5) of the mandrel body (1), and that the mandrel head (2) is curved. Sliding surfaces (8 {9) of the stepped part (5) of the: mandrel body (2) and a lockable Seheibe (3) is supported. · ' For this 1 sheet of drawing