DE10311144B3 - Method for producing a tube with an internal profile and device for carrying out the method - Google Patents

Abstract

A pipe (1) is moved in a cold pilger rolling mill in a translatory manner in the direction (L) of the pipe's axis (3). The pipe with its inner surface sleeve (4) is rolled over a plug (6) with a negative section (5) corresponding to an inner threaded- or spiral-shape section (2) to be produced. An independent claim is also included for a device for producing a pipe with an inner threaded- or spiral-shape section.

Description

The The invention relates to methods for producing a tube with a thread-shaped or helical trending inner profile by cold pilgrims, in which the pipe translationally in the direction of the pipe axis in a cold pilger mill is moved and in which the tube with its inner lateral surface over a a negative profile corresponding to the inner profile to be produced having plug is rolled. The invention further relates to a device for producing a tube with a thread or helical Internal profiling in which the pipe is translational in the direction of the pipe axis is moved and in which the tube with its inner surface area over one a negative profile corresponding to the inner profile to be produced having plug is rolled to carry out the method.

Such a cold pilger rolling process is, for example, from the DE 43 36 422 C2 known. In order to carry out the cold pilger process, a roll stand equipped with a pair of cold pilger rollers is provided, which is driven in an oscillating manner. A crank mechanism is used for this purpose, which is driven by a motor. The crank mechanism is equipped with a counterweight to balance the inertial forces of the roll stand. The productivity of a cold pilger rolling mill is directly dependent on the number of strokes of the roll stand per unit of time, which is why, for reasons of economy, the aim is to achieve the greatest possible number of working strokes per minute. In the cited document it is further provided that the crank mechanism drives further shafts via toothings on which counterweights are arranged eccentrically with respect to the center of gravity. These counterweights rotate in the same direction and in opposite directions when the crank mechanism rotates and are thus able to generate balancing inertial forces or moments of inertia, so that overall there is a balancing of inertial forces in the entire drive system.

From the DE 962 062 C. A cold pilger rolling mill is also known in which the crankshaft for driving the rolling stand is equipped with flyweights and a vertically oscillating counterweight to balance the first order inertia forces and the inertia moments in the drive.

The DE 36 13 036 C1 discloses a drive for the roll stand of a cold pilger rolling mill, wherein a planetary crank drive is used to drive and balance mass forces and mass moments.

For different ones use cases cold-piled pipes made of metallic materials are required, whose inner lateral surface a thread-like or helical Has inner profiling. This internal profiling can, for example for forces and torque transmission are used in machine or vehicle construction; they also become Optimization of flow conditions and heat transfers in Pipes and heat exchangers needed.

Through the DE 697 06 275 T2 A cold pilger rolling process with a selectively axially and rotationally movable mandrel has become known, as a result of which an internal profile of a tube can be produced.

Around a cold pilgrim pipe with the spiral inner profile mentioned To produce, it is also known to use a rolling mandrel with a downstream insert freely rotatable plug, the plug the negative profile the desired one Has inner profiling. The twist of the inner profile The corresponding rotary movement of the plug must be carried out by the feed movement of the rolling stock can be effected. This is disadvantageous the possible Helix angle severely restricted, and also the profile depth is due to the related Feed force limited.

adversely it is still the case that the tensile rotating connection between Rolling mandrel and stopper the transferable personnel limited. The plug must be hollow to arrange a thrust bearing be trained. This is also the radial load on the plug limited.

The The invention is therefore based on the object of a method of the generic type and to create a corresponding device for carrying out the method, through that or through which it is possible will overcome the disadvantages mentioned. In particular, should the twisting movement of the stopper corresponding to the twist is no longer exclusively via the Feed movement are generated.

This The object of the invention solved, that the stopper during of the cold pilgrim process is driven so that the axial speed of progression of the thread or the helix of its Negative profile in the direction of the pipe axis of the axial speed of advance the thread or the helix of the inner profile to be produced in the direction of the pipe axis.

The stopper is preferred during of the cold pilgrim process - viewed in the direction of the pipe axis - held axially stationary.

A good synchronization of the mechanisms determining the rolling process is achieved in that it is provided in accordance with further training that the Pipe while of the cold pilgrim process, both translational and rotational is driven, the translatory and the rotary drive movement of the pipe is controlled with the rotary drive movement of the plug or adjusted in a regulated manner.

Metal Forming Advantages are achieved if according to a further embodiment it is provided that the calibration of the cold pilgrim rollers and the calibration of the negative profile of the stopper is selected that with cold pilgrims there is no stretching of the pipe in the axial area of the negative profile of the stopper.

Of the invention is further enhanced by an apparatus for manufacturing a pipe with a thread or helical trending inner profile, in which the pipe in the direction of Tube axis is moved translationally and in which the tube with its inner lateral surface over a a negative profile corresponding to the inner profile to be produced having plug is rolled, solved for performing the method according to the invention, at which the plug is connected to a rotary actuator.

Preferably the plug is axially stationary. Advantageously points the cold pilger rolling mill has a rotary drive for rotating the tube as well a translational drive for the translatory movement of the tube, the rotary drive of the plug, the rotary drive of the tube and the translational The tube is driven by a common control system are driven.

Quality forming conditions can be achieved if according to a Training is provided that the plug has an outer contour, the - apart from the negative profile - in is essentially cylindrical.

A beneficial smoothing the inner tube surface let yourself achieve when the stopper is in the feed direction of the pipe considered upstream cylindrical section.

Technically machines just lets realize the proposed cold pilger rolling mill if the Rotary drive of the plug, the rotary drive for the rotation of the pipe and / or the translational drive for the translatory movement of the tube is designed as a servo motor is or are.

By the embodiment of the invention the rotation of the inner profile corresponding to the twist Plug actively generated by a rotary drive. This gives themselves in an advantageous manner that there is no limit to the possible Twist angle results. Furthermore, the profile depth can also be increased. Possible this is due to the fact that the rotational movement corresponding to the swirl of the plug no longer only by the feed movement of the pipe must be generated.

In order to Is it possible, that pipes with a thread or helical internal profile almost without restrictions with regard to the size of the twist angle can be produced economically.

In the drawing are exemplary embodiments of the Invention shown. Show it:

1a schematically the side view of a pair of cold pilger rollers during the forward stroke of the cold pilger rolling process;

1b the corresponding view according to 1a during the return stroke;

2 schematically the drive concept of a cold pilger pipe in a cold pilger rolling mill; and

3 the pipe to be cold piled up, together with the stopper, to create an internal profile.

In 1a and 1b the cold pilger rolling process is shown schematically as such. It is used to manufacture or form a tube 1 by means of a pair of cold pilgrim rollers 12 and 13 , the pair being mounted in a roll stand (not shown). The pipe to be machined 1 is on a plug (rolling mandrel) 6 guided. The roll stand oscillates during the rolling process, with stroke frequencies of up to 300 per minute and more being possible.

The pipe 1 during the rolling process in the conveying direction L - according to the direction of the pipe axis 3 - emotional. During the advance stroke, which in 1a is schematically sketched, the pair of cold pilgrim rollers rolls 12 . 13 in the conveying direction L on the pipe 1 from; during the return stroke, which in 1b is sketched, the roll pair is rolled off 12 . 13 on the tube 1 against the direction of conveyance L (see arrows for direction of rotation and direction of translation).

To carry out the cold pilger rolling pro The rolling stand must perform an oscillating movement - that is, a reciprocating movement. In order to accomplish this, a crank mechanism is usually provided which has a crank arm with at least one crank and with a balance weight arranged eccentrically with respect to the bearing point.

In 2 the structure of a cold pilger rolling mill can be seen schematically, but only the cold pilger rolls 12 . 13 as well as the elements for translatory and rotary drive of the tube 1 are indicated.

The pipe 1 is in a known manner through the cold pilgrim rollers 12 and 13 rolled like this in connection with the 1a and 1b was explained. The finished rolled pipe 1 should be an interior profiling 2 have, which are helical or helical in the direction L of the tube axis 3 extends.

To achieve this, the inner surface area 4 of the pipe 1 via a plug that acts as a rolling mandrel 6 rolled, which has a substantially cylindrical outer contour, but on its outer circumference with a negative profile 5 is provided, that of the inner profile to be produced 2 equivalent.

The translatory and rotary movement of the pipe 1 done by a rotary drive 8th for the rotation of the pipe 1 or by a translatory drive 9 for the translatory movement of the tube 1 , In 2 the elements are only sketched very schematically.

Which is inside the tube 1 plug 6 is equally with a rotary actuator 7 Mistake. All three drives - namely the rotary drive 7 for the rotation of the plug 6 , the rotary drive 8th for the rotation of the pipe 1 and the translational drive 9 for the translatory movement of the tube 1 - are from a common control or regulation 10 controlled or regulated. The respective drives are made so that the plug 6 is driven in rotation during the rolling process so that the axial advancement speed of the thread or the helix of the negative profile 5 of the stopper 6 in the direction L of the pipe axis 3 the axial advance speed of the thread or the helix of the inner profile to be produced 2 in the direction L of the pipe axis 3 equivalent.

The plug that acts as an internal tool 6 is - as is not illustrated in more detail in the figures - held axially stationary by means of a rod in a mandrel abutment. The rotary drive 7 of the stopper 6 is done in such a way that the tangential component of the negative profile 5 that of the inner profiling 2 at the place of the stopper 6 corresponds, taking into account the translatory movement of the tube 1 as well as its rotational movement.

The assignment of the calibration of the cold pilgrim rollers 12 respectively. 13 on the one hand and the calibration of the negative profile 5 of the stopper 6 on the other hand are chosen so that essentially no stretching of the rolling stock in the area of the negative profile 5 of the stopper 6 he follows.

The drives 7 . 8th and 9 have servomotors that are controlled by the control system 10 can be controlled.

The rotation of the pipe 1 through the rotary drive 8th can be chosen so that it from the rotation of the plug 6 by means of the rotary drive 7 is subtracted, which minimizes the required angle of rotation or the required rotational speed of the plug 6 results.

The basic caliber processing of the rolls 12 . 13 can be selected in such a way that the profiling of the inner profile takes place in several rolling steps.

The negative profile 5 on the stopper 6 is a cylindrical section 11 upstream without a profile, which causes a smoothing of the inner tube surface essentially without stretching.

The work cycle running in the cold pilger mill is described below with reference to FIG 3 explained: The pipe is in the area of the inlet dead center ET 1 advanced with every crankshaft revolution of the cold pilger mill drive. Because the pipe 1 practically not stretched during the rolling process, the feed size corresponds to the tube length generated per stroke. There is no contact between the rolling stock and the rolling tool in this area. At the same time the pipe 1 around a normal angle of rotation (e.g. 31 °) around its pipe axis 3 turned. The mandrel bar is synchronized with the feed movement 14 with the plug firmly connected to it 6 rotated so that the superimposition of the feed movement of the pipe, rotation of the pipe and rotation of the plug follows the pitch of the thread or the helix.

This is followed by the rolling area in which the tapered roll calibration increasingly converts the rolling stock into the negative profile 5 presses, whereby the pipe cross-section does not decrease, ie there is no stretching of the rolling stock.

At the end of the forming section, the rolling stock expands again and releases the rolling stock, with the plug profile just behind the detachment point ends.

In the following area around the outlet dead center AT the pipe 1 and the stopper 6 rotated together by an angle of rotation (e.g. 70 °) so that on the return stroke of the roll stand in the forming zone, the spread is equalized and a release effect is achieved.

In the case of longer, relatively thin mandrel rods, the rotation of the mandrel rod is already sufficient 14 started so that a certain torsional preload is achieved. This concludes a work cycle; the next follows.

1

pipe

2

internal profiling

3

pipe axis

4

inner lateral surface of the pipe

5

negative profile

6

Plug

7

rotary drive for the Rotation of the plug

8th

rotary drive for the Rotation of the pipe

9

translational Drive for the translational

Move of the pipe

10

control or regulation

11

cylindrical Section of the plug

12

Cold pilger roll

13

Cold pilger roll

14

mandrel

L

Conveying direction / direction the pipe axis

ET

Einlauftotpunkt

AT

Auslauftotpunkt

Claims (10)

Method of making a pipe ( 1 ) with a thread-shaped or helical inner profile ( 2 ) by cold pilgrims, in which the pipe ( 1 ) in a cold pilger mill in direction (L) of the pipe axis ( 3 ) is moved translationally and in which the tube ( 1 ) with its inner surface ( 4 ) via one of the inner profiles to be produced ( 2 ) corresponding negative profile ( 5 ) having stopper ( 6 ) is rolled, characterized in that the stopper ( 6 ) is driven in rotation during the cold pilgrim process so that the axial advancement speed of the thread or the helix of its negative profile ( 5 ) in the direction (L) of the pipe axis ( 3 ) the axial advancement speed of the thread or the helix of the inner profile to be produced ( 2 ) in the direction (L) of the pipe axis ( 3 ) corresponds. A method according to claim 1, characterized in that the plug ( 6 ) during the cold pilgrim process in the direction (L) of the pipe axis ( 3 ) is held axially stationary. A method according to claim 1 or 2, characterized in that the tube ( 1 ) is driven both translationally and rotationally during the cold pilgrim process, the translatory and rotatory drive movement of the tube ( 1 ) with the rotary drive movement of the plug ( 6 ) controlled or adjusted. Method according to one of claims 1 to 3, characterized in that the calibration of the cold pilgrim rollers ( 12 . 13 ) and the calibration of the negative profile ( 5 ) of the stopper ( 6 ) are selected so that the pilgrims do not stretch the pipe ( 1 ) in the axial area of the negative profile ( 5 ) of the stopper ( 6 ) he follows. Device for manufacturing a pipe ( 1 ) with a thread-shaped or helical inner profile ( 2 ) in which the pipe ( 1 ) in the direction (L) of the pipe axis ( 3 ) is moved translationally and in which the tube ( 1 ) with its inner surface ( 4 ) via one of the inner profiles to be produced ( 2 ) corresponding negative profile ( 5 ) having stopper ( 6 ) is rolled to carry out the method according to one of claims 1 to 4, characterized in that the stopper ( 6 ) with a rotary drive ( 7 ) is connected. Device according to claim 5, characterized in that the plug ( 6 ) is axially stationary. Device according to claim 5 or 6, characterized by a rotary drive ( 8th ) for the rotation of the pipe ( 1 ) and a translational drive ( 9 ) for the translatory movement of the tube ( 1 ), the rotary drive ( 7 ) of the stopper ( 6 ), the rotary drive ( 8th ) of the pipe ( 1 ) and the translational drive ( 9 ) of the pipe ( 1 ) from a common control or regulation ( 10 ) are driven. Device according to one of claims 5 to 7, characterized in that the plug ( 6 ) has an outer contour that is substantially cylindrical. Device according to one of claims 5 to 8, characterized in that the plug ( 6 ) one in the feed direction of the pipe ( 1 ) considers the upstream cylindrical section ( 11 ) having. Device according to one of claims 5 to 9, characterized in that the rotary drive ( 7 ) of the stopper ( 6 ), a rotary drive ( 8th ) for the rotation of the pipe ( 1 ) and / or a translational drive ( 9 ) for the translatory movement of the tube ( 1 ) is or are designed as a servo motor.