DE2652801A1 - Coated pipe continuous mfr. - where pipe is rolled to smaller dia. and coated with PVC using rolling heat for hardening - Google Patents

Abstract

A coated tube is made starting from a tube (a) with a larger dia., which travels through rolls to from a tube (b) with a smaller dia. fed through a spray head for continuous coating of both the outside dia. and the bore of tube (b) with the aid of mandrel. Coating is achieved using the heat generated in rolling. The mandrel is pref. supported by the bore of tube (b) and presses the coating against that bore. Tube (a) is pref. reduced in outer dia. by up to 30%, up to 20% to form tube (b) which is given a radial coating thickness of ca. 0.5 mm. of PVC. A planetary skew rolling mill with conical rolls is pref. used to reduce tube (a) and is followed by a spraying head. The mandrel extends from the inlet side of the rolling mill to form the coating in the bore of the tube at the outlet of the spraying head. A tube 50 mm. dia. is rolled down the 35 mm. dia. and simultaneously coated with plastic, esp.

Description

Method and device for continuous

Manufacture of coated pipes ~~~~~~~~~~~~~ tie invention relates oich on a method for producing a coated pipe, in particular one by means of a displacer mounted inside the pipe in a coating tool continuously internally and externally coated pipe with openings in the pipe wall, and a device for carrying out the method in such a method it is already proposed to produce tubes with different diametres and by means of a self-contained conveying device individually via a 1angge ~ stretched mandrel and held outside the pipe through the coating tool to slide and coat You the Born in Bozug on the coating tool must be kept stationary is a technically very complex mandrel gripping device with two-way access necessary. In addition, the entire conveyor device, who is responsible for the feed of the pipes to be coated during the changeover from another tube diameter nou justier; will. The effort with which this The process of which can be increased is increased by the fact that additional heating devices are to be provided in the area of the inlet of the coating tool with which the supplied pipes are heated so that the coating material is attached adheres properly.

It is also known from general rolling technology, a so-called To use a pipe reducing rolling mill that consists of a pipe base size by reducing the diameter different. Manufactures nominal pipe sizes. Such a reducing mill is in the brochure "The planetary piercing mill" number W-313, from 1976, published by the company Siema, Siegener Maschinenbau GmbH. This planetary piercing mill contains three conical rollers that are at an angle of 1200 radially to each other are employed and revolve around the pipe so that through part of their surfaces a conical deformation zone is created. The rollers are also at an angle against the In the longitudinal direction of the pipe, the pipe is continuously forwarded during rolling is pushed. The reduced nominal diameter of the pipes can be increased to a large extent Area to be selected The heating caused by the deformation process remains insignificant Effect on the rolling stock The object of the invention is to provide a method of the type mentioned, and to create a device with which the production of internally and externally coated pipes has been significantly improved and is ratinalized.

hit the new process, starting from a few basic pipe sizes, or from only one basic pipe size, pipes coated on the inside and outside in different sizes Diameter target sizes can be produced.

According to the invention, the object is achieved with a method of the above designated type to the effect that a pipe of a diameter basic size by Rolls are continuously reduced to a high diameter and in the coating tool is transported, in which it is coated using the heat of rolling.

With this method, 131 can be efficiently coated on the inside and outside Pipes can be produced in several nominal diameter sizes. ts don't just become essential Simplifications achieved with regard to the storage of the starting material but also the manufacturing effort is kept low.

Expensive heating equipment for heating the coating tool Introduced pipes are no longer necessary.

In a preferred form of the method it is provided that the displacement body, the coating material entering the inside of the pipe against the inside wall of the pipe urges, is supported in the rolling area on the inner wall of the pipe.

This trick associated with the method according to the invention is saved it, complicated holding, gripping and control devices for securing the position of the Provide displacement body. This becomes automatic through its concern at the The inner wall of the pipe is held and enables a perfect coating process.

According to the method, it is also proposed that the pipe outer diameter up to 30%, preferably up to 20%, is reduced.

This means that there is a wide range of variation in the nominal diameters of coated Pipes given, for the production of a single pipe diameter basic size is to go out.

In an expedient example of the method, the tube is in a radial Approximately 0.5 mm thick with a PVC coating. At this Coating thickness ensures a particularly problem-free process implementation.

It is particularly suitable for carrying out the method according to the invention A device characterized by a pipe rolling device for reducing the pipe diameter at the inlet of a coating tool designed as a QWirsprit head is arranged.

This device can be constructed very compact and work with great Reliability.

A preferred embodiment of this device is characterized in that the tube rolling device as a planetary piercing mill with conical rollers is trained.

Such a rolling device is suitable for all common pipe materials to machine, whereby the conical rollers not only a clean reduction in diameter can effect in the provision on given diameter ranges, but also Force a continuous feed movement on the pipe, which is necessary to carry out of the pipe, which is reduced in diameter, is used by the coating tool will.

In a device according to the invention it is also expedient that a mandrel is supported in the interior of the tube, which has a first cylindrical section with a diameter corresponding to the pipe size inside diameter, as well as at least one other corresponding to the reduced inner pipe diameter having a cylindrical section, the sections having a frustoconical Section connected, the cone angle of which corresponds to the course of the diameter reduction area is equivalent to.

This mandrel then supports both the rolling process in reducing the diameter, as well as the coating process in.

Coating tool, with its frustoconical Section automatically supported on the pipe wall.

In a further embodiment it can also be provided that the section of the borne inside the tube one up to the coating zone in Coating tool protruding displacement body for the through the openings Has entering coating material.

This displacement body carried by the mandrel ensures; for a flawless Internal coating of the pipe running through the coating tool.

The section of the dome that has the displacement body is included expediently made smaller in diameter than the displacement body itself, so that the risk is avoided that this section of the mandrel in an undesirable There is frictional contact with the pipe and thereby the function of the displacement body is disturbed.

In a further embodiment of the device according to the invention it is also provided that the section of the mandrel extends into the coating zone extending displacement body is connected.

This configuration of the mandrel made it possible to use different displacement bodies, each adapted to different flow or adhesion properties of the coating material, to use It is unfavorable if aiage practiced on the mandrel during the rolling process Forces affect the position of the displacer, so another one hits Embodiment of the device according to the invention that the displacement body is hingedly connected to the section and is partly designed as a pipe guide.

This means that the displacement body is opposed to the mandrel in its position the coating tool secured, but he can still in the coating material swim and distribute it properly on the inner wall of the pipe.

It is also advantageous if, as in a further exemplary embodiment it is proposed that the mandrel is designed so that it can be divided between the sections, that on the section corresponding to a pipe base size in diameter Different inserts are fastened, the sections of which are in diameter different, reduced pipe inside diameters are matched. Then need for different nominal pipe sizes only the corresponding inserts in the Pipe diameter-base size adapted, thicker section can be screwed in. The tool costs are thereby reduced.

The method according to the invention is described below with reference to the drawing are explained in more detail.

They show: FIG. 1: a diagram of a device for carrying out the Method, partially in section, and FIG. 2: a detail modified from FIG. 1 from device.

In the device according to FIG. 1, a pipe (1) is of a basic diameter (1t) with openings (',) reduced in its wall in the perforation, see above that a tube (3) with a nominal diameter (31) is created. The tube (3) has at Leaving the device an inner coating (2) and an outer one Coating (4).

The procedure for reducing the diameter and coating served For this purpose, a device, which is a tube rolling device (6), expediently in the form of a planetary piercing mill, and one immediately downstream of it Coating tool (7), for example a cross-head (12). The two Device parts are aligned along a continuous axis (10).

The pipe rolling device (6) consists of three inclined to each other, conical rollers (9) driven by a planetary drive, not shown be driven. The rollers (9) form a part of their outer surfaces Deformation zone (11) through which the pipe (1) is passed. The reels (9) are also inclined against the passage axis (10) so that they apply a continuous feed movement to the continuous pipe.

A mandrel (8) is cantilevered in the inside of the tube, which is located in the Deformation zone (11) is supported on the inner wall of the pipe, so that it is in the direction of the Axis (10) remains stationary with respect to the cross-head (-12).

In the cross-head (12) is from an extruder, not shown an annular coating chamber (14) with plaited coating material loaded. This is zloieck moderately a thermoplastic material, for example PVO or the like, which is mixed with a thermally active hardener or adjusted to be thermosetting is. The tube (3) is inserted into the coating chamber (14) with the aid of a tool part (15) introduced.

The plasticized coating material is distributed around the outer circumferential surface of the pipe (3) and forms the outer coating (4-). At the same time he will too forced through the perforations (5) into the inside of the pipe and forms the inner coating there (2).

The diameter reduction and training of the interior coating will be supported by the mandrel (8). This has a rear cylindrical section (16), which is matched to the inner diameter of the pipe (1).

A frustoconical section (15) closes on section (16) on, which is puffed on the course of the deformation zone (11) and to another, leads cylindrical area (18) with a reduced diameter. The Arschnitt (13) carrier an extension (19), which is attached to the reduced inner diameter of the pipe (3) is adapted and serves as a pipe guide. The mandrel (8) finally ends in one cylindrical displacement body (2G), the outer circumference of which is the inner wall of the pipe (3) is opposite at a radial distance so that the breakthroughs (5) entering coating material in a uniform layer thickness on the inner wall of the tube (3) is pushed in the area of the mandrel (8) indicated by (21) is an articulated verb: indung provided between the individual sections, the it allows the sections (19 and 20) to center automatically inside the pipe and the displacement body (20) produces a uniform inner coating.

With this articulated connection it is avoided that through Forces exerted by the Welz process on the mandrel (8) into the displacement body (20) are transferred and there possibly to frictional contacts and thus disturbances of the coating process on the inside wall of the pipe.

In Fig. 2 another embodiment of a mandrel (8 ') is shown, whose section (16 ') corresponds to a basic pipe size and which can be universally adapted to different Reduced pipe diameter target sizes can be fitted. To that end is the mandrel (8 ') formed divisible in the area (22), for example by means of a Threaded connection. In this way, inserts are optionally screwed into section (16 '), those for different Target diameter sizes are determined. the Inserts then have sections (17 ', 17 ", 19', 19 'or 20', 20") with different ones Diameters. Of course, the mandrel (8 ') can also have an articulated Connection between the areas (19 'and 17') can be formed.

The procedure is as follows: The tube (1) is placed in the tube rolling device (6) narrow and from this reduced in diameter to the target diameter (3 '). The reduced pipe (3) then occurs immediately after leaving the rolling device (6) into the cross-head (12) and is driven by the air-forced feed movement pushed into the coating chamber (14). In the meantime, the mandrel (8) is ins Inside the pipe has been introduced and extends with its displacement body (20) to beyond the area of the coating chamber (14). The thorn lies with it its frustoconical section (17) in the deformation zone on the inner wall of the pipe and is prevented from following the advancing movement of the pipe.

The rolling of the pipe has heated it up considerably.

This heating causes a firm adhesion of the coating material, without any additional heating device, which is involved in itself would have to be.

At the exit from the cross-head (12), the pipe is coated and is slid into a cooling station or networking device, which is no longer shown, in which the coating is stabilized and finally cured.

According to the invention, for example, based on a single Basic diameter of 50 mm, coated tubes up to diameters of 35 mm The coating material completely covers the interior uI? d outside of the pipe, as well as the openings, so that an excellent against Ir.or, -o, ion and ErosIon protected pipe is produced as a coating material Thermosetting thermoplastics or plastic paints are particularly suitable. Quality Results could be achieved with PVC plastics in a hard or soft setting be, these either have a self-curing composition or with a Thrmoactive hardener or fIaf-t; vc medium.

Particular advantages of the method described are that Neither additional heating devices nor pipe feed devices for its implementation or elaborate lorn holding or control devices are necessary. The device is compact and space-saving. The production according to the described process is in particular therefore rational and economical, since as a result of only a few The required basic pipe diameter sizes enable very easy storage is.

Claims (11)

P a t e n t a n s p r ü c h e 1 Process for producing a coated R9hIus, in particular one by means of a displacer mounted inside the pipe in a coating tool continuously G'h internally and externally coated pipe with openings in the pipe wall, which means that a pipe of a diameter base size by rolling continuously to a diameter target size is reduced in size and transported into the coating tool, in which it is under Exploiting the rolling heat is coated. 2. The method according to claim 1, characterized in that g e k e n n z e i c h n e t, that the displacement body, the coating material entering the pipe interior pushes against the pipe inner wall. is supported in the rolling area on the inner wall of the pipe. 3. The method according to any one of claims 1 and 2, characterized g e -k e n It should be noted that the outer diameter of the pipe is up to 30%, preferably up to 20%, is reduced. 4. The method according to any one of claims 1 to 3, characterized g e -k e n nz e i c h n e t that the pipe in a radial thickness of approximately 0.5 mm with a coating of PVC is provided. 5. Device for performing the method according to one of the claims 1 to 4, not shown by a tube rolling device (6) for reducing of the pipe diameter, which is formed at the inlet of a cross-head (12) Coating tool (7) is arranged. 6. Apparatus according to claim 5, characterized in that g e k e n n z e i c h -n e t that the tube rolling device (6) as a planetary piercing mill with conical Rolls (9) is formed. 7. Device according to one of claims 5 and 6, characterized g e k e n n z e i c h n e t that a mandrel (8, ß ') is supported inside the tube, the one first cylindrical section (16, 16 ') with an inside diameter of the pipe basic size corresponding diameter, as well as at least one further the reduced pipe diameter Corresponding cylindrical section (18, 19, 20; 19 ', 20') has, the Sections are connected via a frustoconical section (17,17 '), the The cone angle corresponds to the course of the diameter reduction area (11). 8. VorrichtunÔ according to one of claims 4 to 7, characterized g e -k e n z e i c h n e t that the section (18, 19, 20; 19 ', 20') of the mandrel (8, 8 ') one inside the pipe protruding into the coating zone in the coating tool (7) Displacement body (20) for the coating material passing through the openings (5) (13) ice up. 9. Device according to one of claims 4 to 7, characterized g e -k e n z e i c h n e t that with the section (18) of the mandrel (8) a down into the Coating zone extending displacement body (19, 20) is connected. 10.Vorrichtung according to claim 9, characterized g e k e n n z e i c h -net, that the displacement body (19, 20) is articulated to the section (18) and in part (19) is designed as a pipe guide. 11.Vorrichtung according to claim (9), characterized g e k e n n z e i c h -n e t that the mandrel (8 ') is designed to be divisible between the sections (16' and 17 ') is such that sn is the section corresponding to a pipe base size in diameter (16 ') each different inserts can be attached, the section (1,7', 19 ', 20') in diameter to different reduced pipe inner diameters are matched.