EP0494843A1 - Procédé de fabrication d'une pièce tubulaire à parois double . - Google Patents

Procédé de fabrication d'une pièce tubulaire à parois double . Download PDF

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Publication number
EP0494843A1
EP0494843A1 EP92810012A EP92810012A EP0494843A1 EP 0494843 A1 EP0494843 A1 EP 0494843A1 EP 92810012 A EP92810012 A EP 92810012A EP 92810012 A EP92810012 A EP 92810012A EP 0494843 A1 EP0494843 A1 EP 0494843A1
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EP
European Patent Office
Prior art keywords
workpiece
tubes
outer tube
tube
fluid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP92810012A
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German (de)
English (en)
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EP0494843B1 (fr
Inventor
Michel Germaine François Biesemans
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Scambia Industrial Developments AG
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Scambia Industrial Developments AG
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/08—Other arrangements or adaptations of exhaust conduits
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D26/00—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces
    • B21D26/02—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces by applying fluid pressure
    • B21D26/033—Deforming tubular bodies
    • B21D26/045—Closing or sealing means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D26/00—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces
    • B21D26/02—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces by applying fluid pressure
    • B21D26/033—Deforming tubular bodies
    • B21D26/051—Deforming double-walled bodies
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D9/00—Bending tubes using mandrels or the like
    • B21D9/15—Bending tubes using mandrels or the like using filling material of indefinite shape, e.g. sand, plastic material
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/14—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having thermal insulation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/14—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having thermal insulation
    • F01N13/141—Double-walled exhaust pipes or housings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/18—Construction facilitating manufacture, assembly, or disassembly
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/18—Construction facilitating manufacture, assembly, or disassembly
    • F01N13/1883—Construction facilitating manufacture, assembly, or disassembly manufactured by hydroforming

Definitions

  • the invention relates to a method for producing a dimensionally stable, double-walled, at least partially curved line piece, in which there is an intermediate space between its mutually enclosing walls at least in a region of its length.
  • the line piece thus forms a double-walled elbow.
  • a double-walled pipe section of the type mentioned, for example with walls made of stainless steel, can serve in particular as part of an exhaust system or - in short - an exhaust of an internal combustion engine.
  • the radial distance between the outer surface of the inner wall and the inner surface of the outer wall is normally approximately 2 mm to 5 mm.
  • two straight pipes are first inserted into one another, the two pipes having the intended diameters of the inner or the outer wall of the pipe section to be produced.
  • the space between the two tubes and possibly also the interior of the inner tube are filled with a solid filling material.
  • a solid filling material This consists, for example, of sand, ice or an alloy melting at approximately 70 ° C., the ice or the alloy being filled in in the liquid state and then solidified in the tubes by cooling.
  • the pipes and the alloy must be heated above their melting temperature both for the introduction and the removal of the latter.
  • the introduction and removal of the filling material is therefore cumbersome and time-consuming for all the filling materials mentioned. If the filling material does not completely fill the space between the two tubes during the bending process or cannot flow away, there is also the risk that the two tubes will not remain coaxial to one another during bending and / or their cross-sectional shapes will change differently. The result of this is that the distance between the two tubes varies undesirably from location to location and that the two tubes may even touch each other.
  • a straight inner tube is inserted into a straight outer tube and the space between the two tubes is filled with a filling material before bending.
  • the filling material consists in this process of ethyl silicate and powder of Al2O3 and SiO2. If the filling material has reached a hard rubber-like state after being introduced between the two pipes, the pipes which are plugged into one another are bent and then heated, the filling material being sintered when heated.
  • This method like the other previously described methods, in which a filler material is introduced between the pipes to be bent, has the disadvantage that the two pipes must be held in coaxial positions with respect to one another when the filler material is filled. Furthermore, the filling material is presumably still deformable during bending in such a way that the tubes which are inserted into one another change their cross-sectional shapes differently during bending and after the bending no longer have the desired distance from one another everywhere. Furthermore, in the case of a pipe section produced by this method, there is no hollow space between the two pipes, but rather sintered filler material, which undesirably increases the weight of the pipe section and is likely to reduce the thermal insulation.
  • FR-A-2 364 710 discloses a method and a device for producing a bellows.
  • the device has clamping rings lying on the outer surface of a cylindrical bellows to be deformed and annular support parts spaced apart from one another in order to support a deformable inner sleeve arranged in the interior of the bellows in places.
  • a liquid - e.g. water - is placed in the between the originally cylindrical bellows and the Inner sleeve existing annular space introduced.
  • the bellows and the inner sleeve are then hydraulically compressed in the axial direction, so that the bellows between the clamping rings are bulged outwards and the inner sleeve between the support parts is bulged inwards and forms waves.
  • the likewise deformed inner sleeve is separated from the bellows as waste material. This known method is therefore not used to produce a curved, double-walled line piece, but rather to produce a bellows with a straight axis.
  • DE-B-1 068 206 relates to a method for producing a curved pipe fitting.
  • an originally cylindrical, seamless piece of pipe is first bent, then inserted into a cavity delimited by two molded parts and expanded in places by a pressure fluid pressed into its interior.
  • the pipe fitting produced by this method is therefore not double-walled.
  • the invention has for its object to provide a method for producing a double-walled pipe section, which eliminates disadvantages of the known methods and in which it is particularly not necessary to insert a filling material between them for bending the nested pipes, which then again after bending must be removed.
  • the invention further relates to a device for performing the method, the device according to the invention having the features of claim 8.
  • the pipes used to form the pipe section are preferably made of a metallic material, for example stainless steel, which can be provided with a thin aluminum coating to beautify the surface, at least on the outside of the pipe forming the outer wall.
  • the tubes should have uninterruptedly closed sheaths in cross section, which preferably have smooth, continuous outer and inner surfaces along their circumference.
  • each tube can have a jacket butt-welded along a weld seam, the weld seam being smoothed, for example, by post-processing.
  • the pipes may also consist of a non-metallic material, but the pipes should be bendable under plastic deformation and the outer pipe should also be expandable due to a plastic deformation.
  • the two pipes used to produce a line piece should preferably be able to be plugged into one another with at most little play and, if possible, almost play-free and snugly fitting.
  • the dimensioning depends on the accuracy of the pipes used, the desired accuracy of the pipe section to be manufactured and, above all, the cross-sectional dimensions of the commercially available pipes.
  • the tubes used are preferably circular in cross section or - more precisely - circular.
  • the radially measured distance of the outer surface of the inner tube before the expansion of the latter can be preferably at least 0.01%, for example at least 0.03% and for example at most 3% of the outer radius of the inner tube.
  • the inner tube in a line piece provided for an exhaust system of a motor vehicle can be, for example, at least about 10 mm, at most about 100 mm or possibly even more and often 15 mm to 60 mm.
  • the mentioned, radially measured distance can then be at least about 0.01 mm and at most about 1 mm and preferably at most about 0.3 mm.
  • the said radially measured distance can then be increased by at least 1 mm and for example by 2 mm to 5 mm.
  • the pipes can have an elliptical, oval or polygonal shape in cross section.
  • the polygon corners and / or even certain polygon sides are preferably replaced by curved transitions, so that the tubes have a cross-sectional shape composed partly of straight lines and partly of arches.
  • the conditions that were previously given for the radially measured distances and radii then apply to the distances measured at right angles to the surfaces of the tubes and the half outer cross-sectional dimensions of the inner tube corresponding to the outer radius of the inner tube and measured with opposing circumferential locations Rohrs.
  • the two tubes Before bending, the two tubes can, for example, be cut from long tubes with the required lengths and then inserted into one another. Thereafter, the workpiece formed from a pair of tubes which are inserted into one another - for example with the aid of a tube bending device having a mandrel which can be inserted into the inner tube - is bent into the desired shape. If, according to the previous information, the tubes inserted into each other for bending fit into each other with a small amount of play and accordingly are at least approximately in contact with one another, they remain at least approximately and practically completely coaxial with one another during bending - that is, without any special measures.
  • the fluid used to expand the outer tube is preferably a liquid, for example water or possibly a low viscosity, i.e. a low viscosity oil.
  • a gas may be used instead of a liquid.
  • its outline shape is preferably said through the cavity of a molding tool, or short - a shape, with two or possibly more mold parts which can be pressed against one another and brought to bear against one another and then separated again from one another or - in short - mold parts.
  • the mold can be closed after inserting a workpiece consisting of two tubes which are inserted into one another and bent and opened again after the outer tube has been expanded to remove the workpiece.
  • the shape is preferably designed in such a way that in the closed state it encompasses a short end section of this or - more precisely - of its peripheral surface at the opposite ends of the outer pipe arranged in it, and thereby fits the end sections of the outer pipe against one Extension ensures.
  • the entire remaining part of the outer tube located between these two end sections can then be expanded in shape.
  • the length of that part of the outer tube which is widened during the production of the tube piece is expediently at least 50%, preferably at least 80% and for example even approximately or at least 90% of the total length of the outer tube.
  • the two end sections of the outer tube are not expanded during the expansion process in accordance with the previously described embodiment of the method, at least one or both of the end portions of the workpiece having one non-expanded end portions of the workpiece can be subsequently separated from the central main portion of the workpiece if necessary. If both said workpiece end sections are cut off, the space between the two pipes in the finished pipe section then extends over the entire length of the two pipes or - if the pipes should be of unequal length - over the entire length of the shorter pipe.
  • the outer tube can, however, under certain circumstances - especially if only small demands are placed on the dimensional and dimensional accuracy of the pipe section produced - expanded without the expansion process being carried out in a hollow shape.
  • a significant advantage of the method according to the invention is also that it is largely or even completely automatic - i.e. completely automatic - in the series production of line sections with relatively simple, apparatus-related means. without manual work - can be done.
  • the method according to the invention makes it possible to produce a line section whose walls formed by two pipes only touch one another at their ends. Otherwise, there is the possibility of cutting off the mutually contacting end sections of the pipes at one end or at both ends of the line section. If the latter is done, the ends of the two pipes or walls of the pipe section can be connected to one another by flanges or other connecting elements in such a way that their surfaces facing one another are spaced apart over the entire lengths of the pipes or walls.
  • the space formed by the expansion of the outer tube between this and the inner tube can remain free in the finished pipe section, ie only contain air or even be evacuated.
  • the double-walled pipe section therefore enables both good thermal insulation and good sound insulation.
  • the inner tube can rest against the outer tube when the intermeshing tubes are bent and can be supported by a fluid or possibly in some other way when the outer tube is expanded.
  • the manufacturing process can be carried out without the jacket of the inner tube having to absorb very large compressive forces. This enables the inner tube to be made relatively thin-walled, so that it is correspondingly light and has only a small heat capacity.
  • a line piece produced by the method according to the invention can be used, for example, in an exhaust system to connect the exhaust outlet of a gasoline engine or possibly a diesel engine of a road motor vehicle to a catalytic converter.
  • the achievable good thermal insulation of a line section produced by the method according to the invention and the likewise achievable, low heat capacity of the inner wall of the line section then result, inter alia, in the advantage that the catalytic converter quickly and quickly starts to run through the exhaust gas when and after the internal combustion engine is started Temperature is heated, which is necessary to trigger the chemical reactions that are to take place in the catalyst.
  • the rapid heating of the catalytic converter to said temperature gives the advantage that the exhaust gas in the catalytic converter is freed from pollutants practically immediately from the start of the engine, without an additional auxiliary catalytic converter being provided for the start and warm-up phase of the engine and the exhaust system got to.
  • FIG. 1 shows a workpiece consisting of two straight tubes which are inserted into one another
  • 2 shows a schematic tube bending device when bending the workpiece, the latter being drawn on a smaller scale than in FIG. 1
  • 3 shows a schematic device, partly in view and partly in section, for expanding the outer tube of the workpiece, the latter being drawn on an even smaller scale than in FIG. 2
  • FIG. 4 shows a section, designated IV in FIG. 3, from the device drawn in this and the workpiece, but the latter being drawn in section and on a larger scale
  • 5 shows a plan view of the lower mold part of the shape shown in FIGS. 3, 4 for determining the outline shape of the outer tube on the same scale as FIG. 4
  • FIG. 6 shows a section corresponding to FIG. 4, but the outer tube is expanded
  • 7 shows a longitudinal section of the workpiece after the outer tube has been widened to approximately the same scale as FIG. 2
  • 8 shows a longitudinal section through the finished pipe section.
  • two metallic straight, circular-cylindrical tubes 3, 5 shown in FIG. 1 are first provided, cut off from longer, commercially available pipes, for example.
  • the outside diameter of the tube 3 is slightly smaller than the inside diameter of the tube 5.
  • the tubes 3, 5 can be formed, for example, from commercially available tubes with an outside diameter of 44.45 mm or 47.5 mm and wall thicknesses of 1.5 mm.
  • the inner radius of the tube 5 is then about 0.025 mm larger than the outer radius of the tube 3. Otherwise, the narrower tube 3 is preferably a little longer than the further tube 5.
  • the two tubes 3, 5 consist of a metallic material, namely at least essentially of stainless steel.
  • the outer surface of the further pipe 5 and, for example - depending on its type of manufacture - also the inner surface thereof can be provided with a thin, about 0.01 mm to 0.03 mm thick aluminum coating.
  • the narrower tube 3, which is no longer visible at least for the most part in the finished pipe section, can be made entirely of stainless steel or may also be provided at least on the outside with an aluminum coating.
  • the tube 3 is inserted into the tube 5 manually or mechanically by means of a suitable device, the two tubes being able to be lubricated with a lubricant, for example oil, if necessary.
  • a lubricant for example oil
  • the workpiece designated 1 in FIG. 1 is produced, which accordingly has two straight tubes 3, 5 coaxial with an axis 7.
  • the inner tube 3 protrudes at least at its end on the right in FIG. 2, namely at both ends a little - for example at least about 0.5 mm and at most about 5 mm - from the outer tube 5.
  • the device for producing a double-walled line section has, inter alia, the bending device 11 shown schematically in FIG.
  • This can consist, for example, of a tube bending device of conventional design and have a frame 13, only indicated schematically, on which a guide element 15 is rigidly but, for example, adjustably fastened and a bending disk 17, for example consisting of a roller, is pivotably mounted.
  • the latter is provided with a clamping jaw 19 for releasably fastening the workpiece 1.
  • the bending device 11 also has a rigid, but adjustable, mandrel 21 fastened to the frame 11, the free end of which fits into the inner tube 3 of the workpiece 1 with at most small, radial play.
  • the originally straight workpiece 1 can be at least partially attached to the mandrel 21 and bent by pivoting the bending disk 17 and the clamping jaw 19. This can occur at normal room temperature - i.e. by cold working - done.
  • the bending device 11 can be actuated manually or with muscle-free working, for example electrical and / or hydraulic and / or pneumatic drive means during bending and may also be designed for largely automatic operation.
  • the workpiece 1 can be bent, for example, according to FIG. 2, with two longitudinal regions spaced apart from one another along a plane, so that the axis 7 of the workpiece 1 lies in one plane after the bending and for example approximately the shape of a somewhat elongated letter S or Z. Has.
  • the device used to manufacture the double-walled line section also includes a press 31, which is shown in a simplified and schematic manner in FIG. 3.
  • This press has, for example, a frame 33 on which a lower support 35 and an upper support 37 are held.
  • the lower support 35 is rigidly connected to the frame 33, for example, belongs to it and forms approximately its base.
  • the Upper support 37 is guided vertically displaceably by columns of the frame and can be adjusted vertically with a schematically indicated adjusting device 39.
  • the adjusting device 39 has at least one hydraulic cylinder 41 fastened to the frame 33 and a piston 43 which can be displaced therein and whose shaft is connected to the upper support 37.
  • a mold 51 which can be seen in FIG. 3 and partly in FIGS. 4 to 6 and which is also referred to below as mold 51, has two mold parts 53, 55, which are also referred to below as mold parts 53, 55.
  • the one, lower molded part 53 is rigidly attached to the lower support 35.
  • the other, upper molding 55 is rigidly attached to the upper support 37.
  • the mold 51 can accordingly be closed and opened again with the help of the press, in that the upper mold part 55 is pressed against the lower mold part 53 or moved upwards away from it.
  • Each molded part 53, 55 is provided on its side facing the other molded part with an elongated recess 53a or 55a.
  • Each recess 53a, 55a has a central main section 53b and 55b and a narrower and shorter end section 53c and 55c at both ends thereof.
  • the mold When the mold is closed, that is to say when the two molded parts 53, 55 abut one another, they together delimit an elongated cavity 57 which serves to hold the workpiece 1, each of the two recesses 53a and 55a forming at least approximately and, for example, exactly half of the cavity 57 .
  • the two main recess sections 53b, 55b together form a main cavity section 57b with a circular cross section, the radius of the main cavity section 57b being at least 1 mm and, for example, at least 2 mm larger than the outer radius of the outer tube 5 of the workpiece 1.
  • the two end sections 53c, 55c of the recesses 53a and 55a together form a short, straight, circular cylindrical end section 55c of the cavity 55.
  • the radius the end sections 55c is approximately equal to the outer radius of the outer tube 5 of the workpiece 1, so that the two end sections of the outer tube 5 fit snugly, ie radially at least approximately without play into the cavity end section 57c.
  • the cavity 55 is somewhat longer than the workpiece 1, so that at least the end section 57c located in FIG. 3 at the right end of the cavity 57 has a free area of it after the workpiece has been inserted, namely both cavity end sections 57c after the Introducing the workpiece 1 have such a free area.
  • the cavity 57 and the workpiece 1 arranged therein can be arranged according to FIG. 3 such that the axis 7 of the workpiece 1 and the axis of the cavity 57 coinciding therewith lie in a vertical plane.
  • the mutually facing surfaces of the two molded parts 53 and 55 which surround the recesses 53a, 55a are then flat and horizontal in vertical sections perpendicular to the plane of the drawing in FIG.
  • the workpiece 1 and the cavity 57 were, however, drawn in FIG. 3, especially for the sake of clarity, with the axis 7 lying in a vertical plane.
  • the shape delimiting the cavity for receiving the workpiece will actually be designed in such a way that the axis of the workpiece and of the said cavity lie in a horizontal plane, ie at right angles to the direction of displacement of the upper molded part.
  • the the recesses of the two molded parts on their mutually facing sides of the surfaces can then lie in planes, namely the same as the axis of the workpiece in horizontal planes.
  • the workpieces often have spatial axes.
  • the form 51 is also provided with only sealing means 61 shown in FIGS. 4 to 6, which seal off the areas of the two cavity end sections 57c which are free after the insertion of a workpiece 1 when the form 51 is closed, with respect to the environment.
  • the sealing means 61 have, for example, two semicircular seals 63 and 65, which surround the outer tube 5 and form a ring in the groove of the molded part 53 and 55, and a seal 67.
  • seals 63, 65, 67 are shown schematically in Figures 4 to 6 as one-piece, for example rubber-elastic profile pieces, but can in reality consist of two or more parts with different strengths and elastic properties, as is the case for high pressure Seals is known.
  • the molded part 53 is provided with a hole 53d consisting approximately of a stepped bore, which connects the free area of the one cavity end section 57c to a connection 69 fastened to the molded part 53, for example welded, schematically drawn as a sleeve.
  • the at least one hydraulic cylinder 41 of the actuating device 39 is connected via at least one fluid line to a fluid source, not shown, for supplying and discharging a hydraulic fluid.
  • the adjusting device 39 and / or the fluid source can be designed to adjust the upper support 37 and the upper molded part 55 fastened to it either with a relatively small force quickly over a long distance or slowly with a large force.
  • the connection 69 is connected to a fluid source 75 via a fluid line 73.
  • the fluid line 73 is preferably as short as possible, the fluid source 75 possibly actually being attached directly to the molded part 53.
  • the fluid source 75 is designed to press a fluid 79 into the cavity 57 in the manner described above with pressure when the mold 51 is closed, and then to relieve it of the fluid pressure again and, for example, to derive at least part of the fluid present in the cavity 57 therefrom .
  • the fluid preferably consists of a liquid, namely, for example, water.
  • the fluid source 75 has, for example, a reservoir 77 for storing fluid 79 and two pump devices 81, 83.
  • the pump device 81 consists of a pump which is designed to pump a large amount of fluid per unit of time, but only to generate a relatively low pressure.
  • the pump device 83 is intended to generate a high pressure, but only needs to deliver a small amount of fluid per unit time.
  • the pump device 83 can have, for example, a multi-stage pump or several separate pumps connected in series or at least one pump and a pressure booster connected to its outlet.
  • the pump device 81 has an inlet connected to the fluid reservoir 77 and an outlet which is connected to the connection 69 via a check valve 85.
  • the pump device 83 has an inlet connected to the fluid reservoir 77 and one directly output connected to terminal 69.
  • a valve 87 which, in the open state, connects the connection 69 to the fluid reservoir 77 in order to relieve pressure.
  • the workpiece 1 bent with the bending device 11 can be further shaped using the press 31, the mold 51 and the fluid source 75.
  • the workpiece 1 is inserted into the recess 53a of the lower molded part 53 when the mold 51 is open.
  • the mold 51 is then closed with the aid of the adjusting device 39.
  • the fluid source 75 leads the connection 69 from the fluid 79 consisting of water, as indicated by an arrow in FIG. 6.
  • the fluid i.e. Water first comes from the connection 69 into the cavity end section 57c directly connected to it and then flows into the interior of the inner tube 3 and through it into the free area of the end section 57c of the left end of the workpiece 1 in FIG Cavity 57.
  • the water is supplied by the pump device 81 having a relatively high pumping rate.
  • the pumping device 81 is switched off and the pumping device 83 is switched on instead has a lower pumping rate but can generate a higher pressure than the pumping device 81.
  • the water is pressed by the fluid source 75 during the pumping process and in particular after the pumping device 83 has been switched on with such great a pressure, for example about 200 MPa to 300 MPa, into the inner pipe 3 and between the two pipes 3, 5 that the water is the main section 5b of the outer tube 5 located in the main cavity section 57b is radially stretched and expanded by plastic deformation - namely, for example, by cold deformation taking place at normal room temperature - until it abuts the inner surface of the mold 51 delimiting the cavity 57. Because the inner and outer surfaces of the inner tube 3 have the same fluid pressure, the inner tube 3 is not deformed.
  • the original i.e. Before the expansion of the tube 5 in the free area of the main cavity section 57b, air is compressed during the expansion process and / or at least for the most part is pressed out of the cavity 57 between the two molded parts 53, 55.
  • the water supply is stopped by switching off the pump device 83. Furthermore, the valve 87 is now temporarily opened and thereby the cavity 57 and that Workpiece 1 relieved of the fluid pressure, water being able to flow back from the cavity 57 and workpiece into the reservoir 77. After this pressure relief, the mold 51 is opened with the adjusting device 39 and the workpiece 1 is removed from the mold 51.
  • the press 31 and the fluid source 75 are also provided and / or connected with control means (not shown), with which the actuating device 39 of the press and the fluid source 75 can be controlled in order to carry out the previously described work operations.
  • the various work operations can be controlled manually, for example, or at least partially, either manually or automatically.
  • the interior of the inner tube 3 and the intermediate space 91 between the two tubes 3, 5 can still contain water after the expansion of the outer tube and the described pressure relief.
  • the water contained in the inner tube normally flows when the mold 51 is opened and when the workpiece 1 is subsequently removed therefrom without any particular one Measures at least for the most part out of the inner tube 3.
  • the water remaining in the intermediate space 91 after the expansion and the pressure relief can, at least in part, still remain in the intermediate space 91 when the mold 51 is opened and when the workpiece is removed therefrom. After the one end section of the workpiece 1 has been cut off, any water still present in the intermediate space 91 can then be drained out of the latter, so that the intermediate space 91 now only contains air.
  • the ends of the two tubes 3, 5 located at the left end of the workpiece 1 can now still be firmly and tightly connected to one another and connected to one another, that is to say welded, by a connecting element 95 consisting of a flange, as shown in FIG.
  • the other ends of the two pipes 3, 5 can be welded tightly and tightly to a connecting element 97, which also consists of a flange, and can thus also be indirectly connected to one another.
  • the result is the dimensionally stable line piece, designated as a whole by 99, which has two walls or jackets, which are formed by the remaining parts of the tubes 3, 5 and are at least approximately coaxial to a common axis 7 and are separated by the free space 91 over their entire lengths are.
  • the method and equipment for carrying it out can be changed in a number of ways.
  • the outline shape created when the workpiece is bent can be varied within wide limits.
  • the workpiece can be bent such that it has only a single bent area extending over part of its length or more than two such areas separated from one another by straight areas or is bent over its entire length.
  • the workpiece has to be bent for many uses in such a way that its Axis does not lie in one plane, but forms at least partly a more or less pronounced spatially curved line or curve, which is partly curved and partly straight or curved everywhere.
  • the bending device can be equipped with heating means in order to heat the workpiece before and during the bending.
  • the bending device can, for example, instead of the guide element 15, the bending disk 17 and the clamping jaw 19, a control element defining a curve and a feed slide with a displaceable support, at least two rollers rotatably mounted about fixed axes and at least one pivot arm mounted pivotably on the support exhibit. On the latter, a feeler roller rolling on the control element and scanning its curve and a bending roller can then be rotatably mounted, which acts on the workpiece and bends it in cooperation with the rollers mounted on the support.
  • the axis of the workpiece is still in one plane, this can be vertical or horizontal, as already mentioned, when expanding the outer tube, ie parallel or perpendicular to the direction of displacement of the displaceable molded part. If, on the other hand, the axis of the workpiece is spatially curved to a greater or lesser extent when it is bent, the axis of the cavity which defines the outline shape of the outer tube when the tube is expanded must of course also be correspondingly spatially curved.
  • the two mutually adjustable molded parts should also be designed with a spatially curved axis of the workpiece such that this axis runs between the mutually facing and abutting surfaces of the two molded parts when the mold is closed and the recesses of the two molded parts are left out in thought or lies in these areas.
  • the molded parts can then be designed, for example, in such a way that the axis of the workpiece and of the cavity both in a projection onto an axis analogous to the drawing plane in FIG Vertical plane as well as being curved at least in places in a projection onto a horizontal plane.
  • the shape which delimits the cavity for receiving the workpiece when the outer tube is expanded can possibly have three or even more separable molded parts.
  • the press and / or the shape serving to expand the outer tube of a workpiece for receiving it can also have locking means which have at least one adjustable element, engage mechanically with one another when the shape is closed and thereby secure the molded parts against separation until the locking means be disengaged again.
  • the shape receiving the workpiece when the outer tube is expanded and / or the fluid source used for supplying a fluid to this and to the workpiece can be provided with heating means, and the shape and / or the fluid and thus the workpiece before and / or during that Extend the outer tube to heat.
  • Such thermal deformation can reduce the fluid pressure required to expand the outer tube - given the same dimensions and with the same material of the outer tube - compared to the fluid pressure required for cold deformation.
  • connection for supplying and discharging the fluid used to expand the outer tube can take place instead of as in the figure 3 at the higher end of the cavity at the lower end.
  • suction and / or blowing agents can be provided, only after the outer tube has been widened and after the pressure has been released, but before the mold containing the workpiece is opened, as much of the liquid fluid as possible contained in the workpiece and in the cavity of the mold is drawn out suck and / or blow out.
  • either the non-expanded end sections of the outer tube and the end sections of the inner tube enclosed by these can be separated at both ends of the workpiece or at leave both ends of the workpiece on it.
  • the workpiece can be heated to such an extent before the pipes are welded with connecting elements that the water still present in the intermediate space between the two tubes evaporates and flows out of the intermediate space as steam.
  • the connecting elements can be formed from sleeves or other suitable components instead of flanges. If the line piece is used to form an exhaust system having a catalytic converter, the two pipes may perhaps be welded directly to the housing of the catalytic converter and / or another part of the exhaust system.
  • the space between the tubes can be evacuated during or after connecting the tubes with connecting elements.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Manufacturing & Machinery (AREA)
  • Bending Of Plates, Rods, And Pipes (AREA)
  • Shaping Metal By Deep-Drawing, Or The Like (AREA)
EP92810012A 1991-01-11 1992-01-08 Procédé de fabrication d'une pièce tubulaire à parois double . Revoked EP0494843B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH7091 1991-01-11
CH70/91 1991-01-11

Publications (2)

Publication Number Publication Date
EP0494843A1 true EP0494843A1 (fr) 1992-07-15
EP0494843B1 EP0494843B1 (fr) 1996-03-06

Family

ID=4178613

Family Applications (1)

Application Number Title Priority Date Filing Date
EP92810012A Revoked EP0494843B1 (fr) 1991-01-11 1992-01-08 Procédé de fabrication d'une pièce tubulaire à parois double .

Country Status (7)

Country Link
EP (1) EP0494843B1 (fr)
JP (1) JPH06170473A (fr)
CZ (1) CZ282252B6 (fr)
DE (1) DE59205528D1 (fr)
ES (1) ES2083717T3 (fr)
ZA (1) ZA9295B (fr)
ZW (1) ZW292A1 (fr)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5363544A (en) * 1993-05-20 1994-11-15 Benteler Industries, Inc. Multi-stage dual wall hydroforming
EP0686440A1 (fr) * 1994-05-12 1995-12-13 Benteler Industries, Inc. Dispositif pour hydroformage
DE19511970A1 (de) * 1995-04-18 1996-10-24 Werdau Fahrzeugwerk Verfahren zum Herstellen von verformten mehrwandigen Rohren mit Hohlräumen zwischen den Wandungen
DE19513559A1 (de) * 1995-04-18 1996-10-24 Werdau Fahrzeugwerk Vorrichtung zum Herstellen von verformten mehrwandigen Rohren mit einem oder mehreren Hohlräumen zwischen den Wandungen
EP0761335A1 (fr) * 1995-08-31 1997-03-12 Benteler Industries Inc. Procédé d'hydroformage et appareil
US5715718A (en) * 1996-02-27 1998-02-10 Benteler Automotive Corporation Hydroforming offset tube
US5790718A (en) * 1993-04-14 1998-08-04 Stripper Bags, Inc. Food portion inventory device with imprinted predetermined date indicia
EP1342515A1 (fr) * 2002-03-07 2003-09-10 Finnveden Technology AB Procédé de fabrication des sections fermées, trempées sans limitation de profile
GB2413976A (en) * 2004-05-14 2005-11-16 Fmc Technologies Manufacture of pipes
EP2327486A1 (fr) * 2009-11-26 2011-06-01 DALMINE S.p.A. Procédé de fabrication de coude de tuyau en ligne
CN103691762A (zh) * 2013-12-24 2014-04-02 南京航空航天大学 复杂形状双层管制造方法及密封装置
CN105798195A (zh) * 2016-02-04 2016-07-27 重庆祥吉机械制造有限公司 隔热罩防褶皱冲压工艺
CN109821961A (zh) * 2019-03-26 2019-05-31 桂林电子科技大学 金属双层管复合成形装置及方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2832702B2 (ja) * 1996-08-08 1998-12-09 株式会社三五 二重管の製造方法

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DE1068206B (de) * 1955-06-17 1959-11-05 Flexonics Corporation, Maywood, 111. (V. St. A.) Verfahren zum Herstellen eines gekrümmten Rohrformstückes
GB1230766A (fr) * 1967-07-28 1971-05-05
FR2364710A1 (fr) * 1977-02-04 1978-04-14 Mazier Paul Perfectionnements aux appareillages destines a la fabrication des soufflets de dilatation pour tuyauterie
FR2455930A1 (fr) * 1979-05-07 1980-12-05 Babcock & Wilcox Co Procede de fabrication de jaquette de refroidissement dilatee

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Publication number Priority date Publication date Assignee Title
DE4019899C1 (fr) * 1990-06-22 1991-12-19 Benteler Ag, 4790 Paderborn, De

Patent Citations (4)

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Publication number Priority date Publication date Assignee Title
DE1068206B (de) * 1955-06-17 1959-11-05 Flexonics Corporation, Maywood, 111. (V. St. A.) Verfahren zum Herstellen eines gekrümmten Rohrformstückes
GB1230766A (fr) * 1967-07-28 1971-05-05
FR2364710A1 (fr) * 1977-02-04 1978-04-14 Mazier Paul Perfectionnements aux appareillages destines a la fabrication des soufflets de dilatation pour tuyauterie
FR2455930A1 (fr) * 1979-05-07 1980-12-05 Babcock & Wilcox Co Procede de fabrication de jaquette de refroidissement dilatee

Non-Patent Citations (1)

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Title
PATENT ABSTRACTS OF JAPAN vol. 10, no. 381 (M-547)(2438) 19. Dezember 1986 & JP-A-61 172 625 ( TOYOTA MOTOR CORP ) 4. August 1986 *

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5790718A (en) * 1993-04-14 1998-08-04 Stripper Bags, Inc. Food portion inventory device with imprinted predetermined date indicia
US5475911A (en) * 1993-05-20 1995-12-19 Wells; Gary L. Multi-stage dual wall hydroforming
US5582052A (en) * 1993-05-20 1996-12-10 Benteler Industries, Inc. Controlled time-overlapped hydroforming
US5600983A (en) * 1993-05-20 1997-02-11 Benteler Industries, Inc. Controlled time-overlapped hydroforming
US5363544A (en) * 1993-05-20 1994-11-15 Benteler Industries, Inc. Multi-stage dual wall hydroforming
EP0686440A1 (fr) * 1994-05-12 1995-12-13 Benteler Industries, Inc. Dispositif pour hydroformage
DE19511970A1 (de) * 1995-04-18 1996-10-24 Werdau Fahrzeugwerk Verfahren zum Herstellen von verformten mehrwandigen Rohren mit Hohlräumen zwischen den Wandungen
DE19513559A1 (de) * 1995-04-18 1996-10-24 Werdau Fahrzeugwerk Vorrichtung zum Herstellen von verformten mehrwandigen Rohren mit einem oder mehreren Hohlräumen zwischen den Wandungen
DE19511970C2 (de) * 1995-04-18 1998-07-09 Werdau Fahrzeugwerk Verfahren zum Herstellen von verformten mehrwandigen Rohren mit Hohlräumen zwischen den Wandungen
EP0761335A1 (fr) * 1995-08-31 1997-03-12 Benteler Industries Inc. Procédé d'hydroformage et appareil
US5673470A (en) * 1995-08-31 1997-10-07 Benteler Automotive Corporation Extended jacket end, double expansion hydroforming
US5836065A (en) * 1995-08-31 1998-11-17 Benteler Automotive Corporation Extended jacket end, double expansion hydroforming
US5775153A (en) * 1996-02-27 1998-07-07 Benteler Automotive Corp Hydroforming offset tube
US5715718A (en) * 1996-02-27 1998-02-10 Benteler Automotive Corporation Hydroforming offset tube
EP1342515A1 (fr) * 2002-03-07 2003-09-10 Finnveden Technology AB Procédé de fabrication des sections fermées, trempées sans limitation de profile
GB2413976A (en) * 2004-05-14 2005-11-16 Fmc Technologies Manufacture of pipes
EP2327486A1 (fr) * 2009-11-26 2011-06-01 DALMINE S.p.A. Procédé de fabrication de coude de tuyau en ligne
WO2011064293A1 (fr) * 2009-11-26 2011-06-03 Dalmine S.P.A. Procédé de cintrage de tubes chemisés
CN103691762A (zh) * 2013-12-24 2014-04-02 南京航空航天大学 复杂形状双层管制造方法及密封装置
CN105798195A (zh) * 2016-02-04 2016-07-27 重庆祥吉机械制造有限公司 隔热罩防褶皱冲压工艺
CN109821961A (zh) * 2019-03-26 2019-05-31 桂林电子科技大学 金属双层管复合成形装置及方法
CN109821961B (zh) * 2019-03-26 2023-09-22 桂林电子科技大学 金属双层管复合成形装置及方法

Also Published As

Publication number Publication date
DE59205528D1 (de) 1996-04-11
CS7292A3 (en) 1992-10-14
JPH06170473A (ja) 1994-06-21
ZA9295B (en) 1992-10-28
ES2083717T3 (es) 1996-04-16
CZ282252B6 (cs) 1997-06-11
ZW292A1 (en) 1992-06-17
EP0494843B1 (fr) 1996-03-06

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