DE19513559C2 - Device for producing deformed multi-walled tubes with one or more cavities between the walls - Google Patents

Description

The invention relates to a Device for producing deformed multi-walled tubes, which at least from one outer tube and an inner tube exist with one or more cavities between the walls of the pipes consisting of a multi-part mold with multi-part hollow die and pressure piston, from a system to prevent the Hydraulic fluid outlet from the device in Form of conical sealing shoulders or pressure-resistant round seals as well Media guidance systems to promote Hydraulic fluid in the of hollow die, Pressure pistons and sealing systems enclosed area of the device.

Such devices are particularly there needed where for reasons of thermal insulation, sound and / or Corrosion protection or because of the required Heat resistance deformed tubular components with thermally insulated wall design and if necessary with several pipe walls of different quality required are.

The main areas of application for this device are therefore the plant construction for internal combustion engines, Conveying and for air conditioning and ventilation technology.

When funding fluid media, the Further development of technology with increasingly higher ones Requirements for the use value of the used conveyor systems. In contrast to stretched multi-walled tubes with voids between the walls represents the production of deformed multi-walled tubes with cavities between the Walls due to lack of procedural and device requirements only insufficiently solved problem.

In pipe conveyor systems for gases and / or liquids it is known to be meaningful and economical desirable, the tubular components so  to design that with their help the tasks of Jacket heating, jacket cooling, reduction or the improvement of heat radiation, the reduced Noise emission, heat or corrosion resistance, mechanical stabilization and / or if necessary also the change in component natural frequency, at least be met by parts of the multi-layer pipe wall can.

It is essential that the desired Properties of the tubular conveyor systems are continuously available and due to the manufacturing process not to the straight lines Conveyance routes remain limited.

Such requirements are met, for example, by Exhaust systems for high performance internal combustion engines and of heat exchanger systems in modern boiler systems posed.

The known prior art is in EP 0494843 A1 described. There will be a facility described that from a divided die for Manufacture of multi-walled deformed pipes with Cavities between the walls should be suitable.

No pressure pistons are used. The required sealing against one Hydraulic fluid loss is said to be pressure-resistant Round seal between the die and the outer tube guarantee. This round seal unfolds its full Function when the multi-walled tube is loaded by the hydraulic fluid introduced into the die, because of the unlocked pipe ends initially unhindered the inside of the pipe can get. The assumption made that because of existing manufacturing tolerances Hydraulic fluid also between the pipe walls can penetrate, must be highly doubted. At best, the pressure fluid between the Walls up to the effective level of the round seal can penetrate so that the conditions for the Deformation only of the outer tube wall and for that Maintaining the starting position of the inner tube the disclosed solution was obviously not created will.  

The also known EP 0627272 A2 describes one Device that does not consist only of a split die but also from pressure pistons for safe Pipe closure and system sealing against There is a loss of pressure medium. The both on the shared Arranged as well as arranged on the pressure piston Sealing shoulders are provided for the widened multi-walled pipe ends to be recorded and by means of Fix press fit. Nobody sees the solution Requirements for making voids between the To create pipe walls.

The known state of the art is therefore liable for the defect that for creating voids between the Pipe walls and securing the unique geo metric nature of the inner and outer Pipe walls are not technically usable solutions Are available.

In addition, the known technical solution only limited opportunities for differentiating the Cross-sectional shape and cross-sectional dimensions of Inner and outer contour of the cavity between the Pipe walls of the deformed component compared to the prefabricated straight double-walled pipe.

The object of the invention is therefore in that the disadvantages of the known Overcoming technology and evolving device solution for the manufacture of multi-wall deformed tubular components with Cavities between the walls of the most varied Molds made up industrially or individually prefabricated multi-walled tubes also without production-related cavity between the tube walls provide. Despite the secure sealing of the Pressure medium system is said to prevent the unimpeded penetration of the Pressure medium between the pipe walls and that Deform the cavity in the desired dimension and shape can be done quickly and precisely.  

According to the invention, the object is achieved by a device with the Features of claim 1 solved.

The proposed device for manufacturing of deformed multi-walled tubes with one or several cavities between the walls consists of one multi-part mold.

Components of the mold are essentially a multi-part hollow die, pressure piston and Sealing and media guidance systems for Delivery of pressure medium between those to be deformed Pipe walls.

The inner surface of the die is smooth or profiled. This enables attachment desired profiles of the deformed if necessary Outer tube.

There are one or more between the die and the pressure piston Sealing shoulders on the die and / or on the pressure piston arranged between which, if necessary, one of the Pipe ends, preferably the conically deformed end of the outer tube, held as a sealant in the press fit becomes.

The pressure piston contains an axial bore Introduction of a support and / or forming medium serving fluid. About this axial bore basically the support and / or deformation medium under a defined pressure the closed mold fed regardless of how that as Supporting fluid inside the inner tube at the same time as a deformation medium between the inner and outer tube reached. If necessary, the pressure piston has Promotion of the fluid serving as the forming medium radial and / or axial drainage.

In the case of the production of the required starting columns the pressure piston has an annular or at least one thorn and / or chisel-shaped on Extent arranged wideners.

With the help of this expander, above all ensured that for the intrusion of the Deformation medium between the walls of the interior and Defined conveying paths are available for the outer tube.  

At the same time, the function of the Sealing shoulder for system sealing and if necessary for Forming at least one of the pipe ends for the subsequent use of the component, for example used for flange or socket formation purposes will.

If necessary, are between the die and the pressure piston Flameproof round seals are provided. this will especially necessary whenever the drainage for feeding the forming medium outside the Sealing shoulder or clamping gap systems are arranged.

In a special embodiment of the device provided that the die in the area of the axial The conical contact with the pressure piston widened outer tube gripping sealing shoulder possesses that at an angle between 10 ° and 90 ° Axis of the pressure piston is arranged.

In this case, the pressure piston also has one adequate shoulder, between which the grasped Pipe end while inserting the forming medium between the inner and outer tube in a press fit is held.

In a further variant of the device, the Area of the die forming the sealing shoulder interchangeable insert.

This enables the rational use of the Molding tool for both different Deformation tasks as well as for the elimination of mechanical signs of wear.  

Such signs of wear and tear must primarily expected in the area of the sealing shoulders.

In a special embodiment of the device the sealing shoulder on the pressure piston as a wedge-shaped Clamping gap with an inclination to the wedge surface the pressure piston axis is formed from 2 ° to 20 °.

This causes when the plunger is inserted into the Inner tube clamping edges of the Pipe walls in the wedge-shaped clamping gap below partial deformation of the material at the corresponding Pipe wall edge. The slope of the wedge surface will mainly depending on the strength of the Pipe material and the requirements of the Tightness of the press fit connection selected.

In a further special embodiment of the The device is an expander on the pressure piston bar as a sleeve with a chisel edge attached.

When inserting the pressure piston into the inner tube with this expander the outer tube end is grasped and after bent up outside. The conically deformed pipe end gets between the sealing shoulder of the die and the wedge surface of the sealing shoulder chisel-shaped front part of the sleeve-shaped Further. If necessary, contains the inside of the sleeve-shaped expander to the chisel edge leading axial drainages in the form of over the circumference distributed grooves. These grooves extend to radial Production bores for the forming medium, which in turn in connection with the axial bore of the pressure piston stand.  

In the case of using a sleeve-shaped expander on the base body of the pressure piston it is provided that between the base of the pressure piston and the sleeve-shaped expander outside the bore and groove-shaped drainages for the forming medium pressure-resistant ring seal is arranged.

If necessary, the drainage for the forming medium as radial bores and / or as annular and / or formed as axial grooves in the pressure piston, the radial holes for the distribution of the forming medium end in the ring groove on the circumference of the pressure piston. The axial grooves are in this case the ring groove in connection.

In an advantageous embodiment of the device it is provided that the shaping inner surface of the Matrix with axial, radial and / or diagonal wavy and / or angular profiles for Design of the surface structure of the outer tube Is provided.

When deforming the outer tube to create a defined cavity between the tube walls thus at the same time surface structures, for example axially or radially arranged stabilizing Wave profiles or other surface enlarging Profiling, created.

The advantages of the invention thus exist in particular in the availability of a technical solution for that rational production of deformed multi-wall pipes with one or more cavities between the Walls, the favorable conditions for a complete mechanization of the manufacturing process and for a comparatively low specific Owns energy consumption. The advantage is there also in the high variability of the applicability of the developed device for tubular components different dimensions, qualities and Surface structures.

The invention is described below in several Exemplary embodiments explained in more detail.

The attached drawing shows:

Figure 1 is a schematic longitudinal section of a mold consisting of a hollow die and pressure piston with a clamping gap for the non-cut outer tube.

FIG. 1a is a schematic cross-section AA of FIG. 1;

Figure 2 shows the schematic longitudinal section of a mold with an outer ring seal and radial drainage for the promotion of Verformmediums at the beginning of the deformation process.

FIG. 2a shows the schematic longitudinal section according to FIG. 2 at the end of the deformation process;

Fig. 3 shows the schematic longitudinal section of a molding tool consisting of hollow die and plunger without radial and axial drains, but with a gap for clamping the two pipe ends and pressure compensation openings in the inner tube;

Fig. 4 is the schematic longitudinal section of a molding tool, consisting of a template with a sealing shoulder and with interchangeable sleeve-shaped pressure piston expander;

FIG. 4a is a schematic cross-section BB of Fig. 4;

Figure 5 shows the schematic longitudinal section of a mold with interchangeable sealing shoulder insert in the die and with an annular groove and radial drainage for the promotion of the deformation medium.

Fig. 6 shows the schematic longitudinal section of a mold according to. Fig. 5, but with an annular groove and axial drainage for the promotion of the deformation medium;

FIG. 6a shows the schematic cross-section CC of Fig. 6;

Fig. 7 shows the schematic longitudinal section of the inner surface of a template for the equipment of the deformed outer tube with a radial wave-shaped surface structure;

Fig. 8 is a schematic cross-section of the inner surface of a template for the equipment of the deformed outer tube with axial profiles;

Fig. 9 shows the schematic longitudinal section of the inner surface of a die for equipping the deformed outer tube with a thread-shaped profile.

example 1

A double pipe with a nominal width of 40 mm and with a production-related distance between the two pipe walls of 0.5 mm on average should be equipped with an air gap of 10 mm on average. For this purpose, the inner tube 22 is first shown in FIG. 1 and FIG. Shortened by about 50 mm 1a. Then the prepared double pipe is deformed in a manner known per se so that a pipe bend with an angle of 60 ° is formed. This pipe bend is inserted into a split die 2 . After the die 2 has been closed , pressure pistons 3 are pushed into the axial openings in the die 2 and axially clamped against the die 2 during the subsequent shaping process. On the circumference of the pressure piston 3 , wedge-shaped surfaces are arranged so that they each form a clamping gap 15 with the cylindrical die 2 in these areas for receiving the non-cut outer tube end.

The pressure pistons 3 contain central axial bores 5 for the supply of the deforming medium 6 , which first enters the space between the inner tube wall and the end faces of the pressure pistons 3 and there takes over the function of a supporting fluid 6 . A total of four 5 mm wide axial drainages 8 are arranged on the circumference of the pressure pistons 3 , each of which extends into the region of a collar in front of the clamping gap 15 . Via this drainage 8 , the fluid introduced under pressure passes through the manufacturing gap between the tube walls. Since the outer tube ends are each held in a press fit in the clamping gap 15 between the pressure piston 3 and the die 2 , the fluid introduced acts as a deformation medium 6 when the pressure increases. Between the two press seats, the inner surface 1 of the die 2 has an enlarged diameter of 20 mm, which is taken up by the outer tube wall under the action of the deformation medium 6 .

Example 2

The task mentioned in Example 1 is alternatively achieved with the aid of a modified device according to FIGS. 2 and 2a.

Here, a pressure-resistant round seal 11 is arranged at the two outer ends of the divided die 2 , which ensures the creation of a pressure-resistant space between the die 2 and the two pressure pistons 3 .

In the present example, the prefabricated double-walled pipe bend is inserted into the die 2 with a production-related distance between the pipe walls, without individual pipe regions being cut to length beforehand.

The pressure pistons 3 are each equipped with a collar which is in engagement with the inner tube 22 .

The collar of the pressure piston 3 has a diameter which corresponds approximately to the outer diameter of the inner tube 22 .

Between the collar and the area of the pressure-resistant round seal 11 , the pressure piston 3 forms an annular gap with the inner surface 1 of the die 2 , which is connected by a total of three radial drains 7 to the central axial bore 5 of the respective pressure piston 3 .

The fluid introduced under pressure passes through the axial bore 5 as a support medium 6 between the end walls of the pressure pistons 3 and via the radial drainages 7 and the annular gap as a deformation medium 6 between the inner tube 22 and the outer tube 21 . The inner surface 1 of the die 2 has a diameter of 65 mm approximately from the levels of the end surfaces of the pressure pistons 3 .

After completion of the deformation, the outer tube 21 lies over the entire length of the die 2 on the inner surface 1 of the die 2 , while the inner tube 22 has undergone practically no further deformation under the action of the support medium 6 .

Example 3

A double pipe bend is also equipped with a modified device according to FIG. 3 with an air gap between inner pipe 22 and outer pipe 21 .

For this purpose, the pressure piston 3 has, in a range of approximately 50 mm from the end face of the pressure piston 3, an outer diameter that is 2 mm smaller than the clear dimension of the inner tube 22 .

Up to a collar, the outer diameter of which corresponds approximately to the inside diameter of the closed die 2 , the pressure piston 3 is conical, so that a wedge-shaped clamping gap 15 is formed in front of the collar. Under the axial pressure of the pressure pistons 3 , the two pipe ends are transferred into a press fit, which ensures sufficient tightness of the device even at higher pressures of the support and / or deformation medium 6 .

The pressure pistons 3 are also equipped with axial bores 5 for introducing the supporting and deforming medium 6 .

To convey the fluid between the tube walls, three pressure compensation openings 23 are provided in the inner tube 22 , approximately 60 mm from the tube end, distributed around the circumference, through which the fluid as a deformation medium 6 passes between the inner tube 22 and the outer tube 21 . Between the force fits the die 2 is in the clear dimensions expanded formed so that it comes to the expansion of the outer tube 21 up to the complete abutment against the inner surface of the die 1. 2

Example 4

According to Fig. 4 and 4a, there is a modified apparatus of a matrix 2 which is equipped at both ends with a sealing shoulder 4. The sealing shoulder 4 is designed as a conical area with an inclination of approximately 45 ° with respect to the die axis.

The pressure piston 3 is equipped with a sleeve-shaped expander 10 . The expander 10 is fixedly positioned on the outer circumference of the pressure piston 3 by a clamp connection, a pressure-resistant round seal 11 being arranged between the expander 10 and the pressure piston 3 . The expander 10 has a wedge surface 16 in the front region, which ends in an annular chisel edge 17 . The wedge surface 16 is also inclined approximately 45 ° with respect to the pressure piston axis. Between the sealing shoulder 4 of the die 2 2 and the wedge surface 16 of the expander 10 , a clamping gap 15 is created when the pressure piston 3 is axially loaded, in which the conically widened outer tube end 12 is held in a press fit. Under the expander 10 there is an annular groove 19 on the circumference of the pressure piston 3 , which is connected to the axial bore 5 of the pressure piston 3 by radial drainages 7 .

A total of four axial drainages 8 evenly distributed around the circumference establish the connection between the annular groove 19 and the starting gap 9 , which is formed between the widened end 12 of the outer tube 21 and the undeformed inner tube 22 . The fluid under pressure passes between the inner tube 22 and the outer tube 21 through this starting gap 9 and causes the deformation of the outer tube 21 until it bears against the inner surface 1 of the die 2, which is enlarged on the circumference.

Example 5

A modified device according to FIG. 5 is used to produce a deformed double-walled tube with a defined cavity between inner tube 2 and outer tube 21 .

Exchangeable wear inserts 14 are arranged on the die 2 at both ends and are equipped with a conical region 12 which is widened outwards. The approximately 35 ° inclined conical surface forms the sealing shoulder 4 of the die 2 . Analogously to this, the pressure piston 3 is also equipped with a conical area, which in turn also functions as a sealing shoulder 4 .

The previously conically widened end 12 of the outer tube 21 is held between the two sealing shoulders 4 during the deformation process under an axial load on the pressure piston 3 in an at the same time press-fitting fit. The inner tube 22 has been cut to length by approximately 60 mm before the outer tube 21 is expanded. At the same time, starting gaps 9 have been produced between the outer tube 21 and the inner tube 22 in such a way that the inner tube 22 has been deformed inward at four positions distributed around the circumference. In the area in front of the end of the inner tube 22 , the pressure piston 3 has an annular groove 19 which is connected to eight axial drains 8 in the form of approximately 3 mm wide longitudinal grooves between the annular groove 19 and the end wall of the pressure piston 3 .

The fluid introduced under pressure passes as support and deformation medium 6 through the axial bore 5 of the pressure piston 3 into the space between the end faces of the pressure piston 3 and the tube wall of the inner tube 22 and via the axial drains 8 and the annular groove 19 through the starting gaps 9 between inner tube 22 and outer tube 21 .

Example 6

Referring to FIG. 6 and 6a, the device is applied according to Example 5, dispensing with the axial drainage. 8 For this purpose, the annular groove 19 is connected to the central axial bore 5 of the pressure piston 3 by radial drainages 7 in the form of three bores distributed uniformly on the circumference. The fluid introduced under pressure thus passes through the central axial bore 5 not only as a support medium 6 in front of the end wall of the pressure piston 3 but also at the same time via the radial drains 7 into the annular groove 19 and from there as a deformation medium 6 through the starting gaps 9 between the inner tube 22 and outer tube 21 .

Example 7

A modified device according to Fig. 7 characterized through a die 2 whose inner surface is profiled 1 transversely to the longitudinal axis of the die 2 by sinusoidal waves.

The profiling 20 of the inner surface 1 of the die 2 leads, after completion of the deformation process, to a stabilized outer tube 21 which has an enlarged surface for the purpose of improved heat transfer.

Example 8

According to the Fig. 8 and 9, the inner surface 1 of the mold 2 is equipped with different profiles 20th In a partial area, the inner surface 1 of the die 2 has a radially oriented wavy profile, which in particular increases the longitudinal stability of the outer tube.

In another partial area, the inner surface 1 of the die 2 has such a profile 20 that gives the deformed outer tube 21 a wavy surface that extends helically around the circumference of the outer tube 21 to improve longitudinal and transverse stability.

Claims (10)

1. Device for producing deformed multi-walled tubes, which consist at least of an outer tube ( 21 ) and an inner tube ( 22 ), with one or more cavities between the walls of the tubes ( 21 , 22 ), consisting of a multi-part mold with Multi-part hollow die ( 2 ) and pressure piston ( 3 ), from a system for preventing the pressure fluid from escaping from the device in the form of conically shaped sealing shoulders ( 4 ) or pressure-resistant round seals ( 11 ) as well as media guidance systems for conveying pressure fluid in the hollow die ( 2 ), pressure piston ( 3 ) and sealing systems enclosed area of the device, characterized in that the sealing shoulders ( 4 ) on matrices ( 2 ) and pressure pistons ( 3 ) are formed for gripping the outer tube ( 21 ), which is flared at one end, and the pressure piston ( 3 ) with a sealing shoulder ( 4 ) in connection with a stepped radial and with a radial and axial guidance for the inner tube ( 22 ) of the multi-wall tube ( 21 , 22 ) and that the sealing shoulder ( 4 ) provided on the pressure piston ( 3 ) for forming a circumferential wedge-shaped clamping gap ( 15 ) in the form of a circumferential wedge surface ( 16 ) for the detection of the ends of the outer tube ( 21 ) or the multi-wall tube ( 21 , 22 ) is formed. 2. Device according to claim 1, characterized in that the wedge surfaces ( 16 ) of the equally on the die ( 2 ) and on the pressure piston ( 3 ) formed sealing shoulders ( 4 ) between 10 ° and 90 ° against the axis ( 13 ) of the pressure piston ( 3 ) are inclined. 3. Apparatus according to claim 1, characterized in that the wedge surfaces ( 16 ) formed only on the pressure piston ( 3 ) and with the die ( 2 ) a wedge-shaped clamping gap ( 15 ) forming sealing shoulders ( 4 ) between 2 ° and 20 ° against Axis ( 13 ) of the pressure piston ( 3 ) are inclined. 4. Device according to one of claims 1 to 3, characterized in that the sealing shoulders ( 4 ) on the pressure piston ( 3 ) and / or on the die ( 2 ) are designed as interchangeable inserts ( 14 ). 5. The device according to claim 4, characterized in that the interchangeable insert ( 14 ) on the pressure piston ( 3 ) as a sleeve ( 18 ) with a conical widening of the outer tube ( 21 ) serving annular chisel edge ( 17 ) or with the production of starting gaps ( 9 ) between the outer tube ( 21 ) and inner tube ( 22 ) serving tools. 6. Device according to one of claims 1 to 5, characterized in that arranged on the axial piston with axial and radial guides for the inner tube ( 22 ) pressure piston ( 3 ) with radial drainages ( 7 ) for the hydraulic fluid guide related axial drainages ( 8 ) the axial drainages ( 8 ) are located outside the area of the pressure piston ( 3 ) provided for guiding the inner tube ( 22 ). 7. Apparatus according to claim 5 or 6, characterized in that on the pressure piston ( 3 ) at least one with an annular groove ( 19 ) in connection with axial drainage ( 8 ) is arranged and that the axial drainage ( 8 ) in the radial Guide of the inner tube ( 22 ) provided pressure piston area and the annular groove ( 19 ) is located directly after the radial guide for the inner tube ( 22 ). 8. The device according to claim 7, characterized in that the annular groove ( 19 ) on the surface of the pressure piston ( 3 ) between the area for guiding the inner tube ( 22 ) and the sealing shoulder ( 4 ). 9. The device according to claim 7, characterized in that the annular groove ( 19 ) between the area for guiding the inner tube ( 22 ) and between the sealing shoulder ( 4 ) of the pressure piston ( 3 ) and the die ( 2 ) formed wedge-shaped Clamping gap ( 15 ) for the outer tube ( 21 ) is located. 10. Device according to one of claims 1 to 9, characterized in that on the shaping inner surface of the die ( 1 ) axial, radial and / or diagonal undulating and / or angular profiles ( 20 ) for designing the surface structure of the outer tube ( 21 ) are arranged.