US3520163A - Method of and an apparatus for bulge forming - Google Patents

Method of and an apparatus for bulge forming Download PDF

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Publication number
US3520163A
US3520163A US685453A US68545367A US3520163A US 3520163 A US3520163 A US 3520163A US 685453 A US685453 A US 685453A US 68545367 A US68545367 A US 68545367A US 3520163 A US3520163 A US 3520163A
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Prior art keywords
bulge forming
punch
bulge
convex
forming punch
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US685453A
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English (en)
Inventor
Ichizo Otoda
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Panasonic Holdings Corp
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Matsushita Electric Industrial Co Ltd
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    • 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
    • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
    • B21D22/10—Stamping using yieldable or resilient pads
    • B21D22/12—Stamping using yieldable or resilient pads using enclosed flexible chambers
    • B21D22/125—Stamping using yieldable or resilient pads using enclosed flexible chambers of tubular products
    • 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
    • B21D15/00—Corrugating tubes
    • B21D15/04—Corrugating tubes transversely, e.g. helically
    • B21D15/10—Corrugating tubes transversely, e.g. helically by applying fluid pressure
    • B21D15/105—Corrugating tubes transversely, e.g. helically by applying fluid pressure by applying elastic material
    • 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
    • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
    • B21D22/10—Stamping using yieldable or resilient pads
    • B21D22/105—Stamping using yieldable or resilient pads of tubular products
    • 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
    • B21D26/06—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 by shock waves

Definitions

  • a split outer mould or die having a moulding surface complementally corresponding to the convex and concave contour of the formed product must be arranged onto the tubular material.
  • FIGS. 5a and 5b A bulge forming apparatus for use in this method is shown in FIGS. 5a and 5b, wherein a split die 2 having an inside moulding surface 2a complementally corresponding to the convex and concave contour of the formed product is held in a die holder ring 3 and is seated on a base plate 7.
  • a thin tubular material 6 With both ends thereof being plugged 'by packings 4 and '5, wherein the packing 4 is provided with a central bore for leading hydarulic fluid.
  • On the packing 4 is mounted a block 1' having a central bore 1a, through which a high pressure liquid is supplied.
  • the thin tubular material 6' is expanded by the internal pressure of the liquid and is bulged to follow the inside convex and concave surface 2a of the die.
  • Electrohydraulic forming This method has been developed in recent years and the products formed in this method are now on the market. This method of forming utilizes the impact force of the electric discharging and is practised by a bulge forming device as shown in FIG. 6, wherein a split die 2 has an inside moulding surface 2a complementally corresponding to the convex and concave contour of the formed product and is held in a die holder ring 3. In the die is placed a thin tubular material 6 with its bottom end being plugged by a packing 5. Electrodes 8 and 8 are opposedly arranged within the tubular material, the inside of which is then filled with water 9 as shown in FIG. 6.
  • FIGS. 7a and 7b Rubber punch bulging
  • a split die 2 and a die holder ring 3 of similar kind as those in FIG. 5 are arranged on a base plate 7.
  • a thin tubular material 6 is placed in the die, and a cylindrical bulge punch 1 of rubber is placed in the thin tubular material.
  • a metal plunger 1 having an outer diameter which is substantially equal to the inner diameter of the thin tubular material 6' is placed on the rubber punch and is applied with compression force, whereby the rubber punch is elastically compressed in axial direction as well as expanded in radial directions, thus in turn expanding the thin tubular material 6' from its inside to make it follow the convex and concave surface 2a of the die 2, as shown in FIG. 8.
  • an outer mould or die is not only indispensable but also must be a split die so that the formed product can be taken out.
  • the split die requires in addition a die holder ring to keep it closed during the bulge forming, which brings about a drawback that the bulge forming device becomes more bulky.
  • the pressurizing system the liquid bulging and the rubber punch bulging are relatively simple, but the electrohydraulic forming necessitates a condenser of a large capacity for electric discharging and also the former two bulging methods have a drawback that because the liquid flows out when the product is taken out, the operation is very difiicult.
  • a press is necessary to compress the rubber punch and the bulge forming device must be mounted on the press. Assembling and disassembling of the split die for each product is inherently bound with a low efficiency.
  • the method is characterized by the steps of inserting an elastic bulge forming punch in the shape of a thick tube having an outer contour corresponding to a required contour of a product into a thin tubular material for the product and applying pressure to the inside of said bulge forming punch to expand said bulge forming .3 punch, whereby the thin tubular material is bulged by the force exerted only from its inside with cooperation of no outer mould.
  • an object of the present invention is to provide a method of bulge forming which is simple and efiicient in process and an apparatus for bulge forming which is simple in structure and easy in operation.
  • Another object of the present invention is to provide a method of and an apparatus for bulge forming applicable to simultaneous bulge forming at several positions of an elongated thin tubular material onto which no outer mould is applicable.
  • Still another object of the invention is to provide a method of and an apparatus for bulge forming wherein the bulging force can be varied along the length to be bulged.
  • FIGS. 1a and 1b are respectively an end view and an axially sectional view of a thin tubular material to be bulged;
  • FIGS. 2a and 2b are respectively an end view and an axially sectional view of a bulged product
  • FIGS. 3a and 3b are respectively an end view and a side view of another elongated thin tubular material to be bulged;
  • FIGS. 4a and 4b are respectivly an end view and a side view of another elongated bulged product
  • FIGS. 5a and 5b are respectively a plane view and an axially sectional view of a conventional liquid bulging apparatus in schematic illustration;
  • FIG. 6 is an axially sectional view of a conventional electrohydraulic forming apparatus in schematic illustration
  • FIGS. 7a and 7b are respectively an end view and an axially sectional view of a conventional rubber punch bulging apparatus in schematic illustration;
  • FIG. 8 is an axially sectional view of the rubber punch bulging apparatus shown in FIGS. 7a and 7b, where the rubber punch is under compression in schematic illustration;
  • FIGS. 9a and 9b are respectively an end view and an axially sectional view of a bulge forming apparatus according to the present invention in schematic illustration;
  • FIGS. 10a, 10b and 100 are respectively an end view, an axially sectional view and a side view of a bulge forming punch used in the bulge forming apparatus shown in FIGS. 9a and 91);
  • FIGS. 11a and 1119 are respectively an end view and an axially sectional view of an inner punch used in the bulge forming apparatus shown in FIGS. 9a and 9b;
  • FIGS. 12a and 121) are respectively an end view and an axially sectional view of another bulge forming apparatus according to the present invention in schematic illustration;
  • FIGS. 13a and 13b are respectively an end view and an axially sectional view of a bulge forming punch used in the bulge forming apparatus shown in FIGS. 12a and 12b;
  • FIG. 14 is an axially sectional view of still other bulge forming apparatus according to the present invention in schematic illustration
  • FIGS. 15a and 15b are respectively an end view and an axially sectional view of a bulge forming punch used in the bulge forming apparatus shown in FIG. 14;
  • FIGS. 16a and 16b are respectively an axially sectional view and an end view of a stator of a canned motor manufactured according to the present invention in schematic illustration;
  • FIG. 17 is an axially sectional view of the stator shown in FIGS. 16a and 16b in the state where a stator inner liner is not yet bulged;
  • FIG. 18 is an axially sectional view of a bulge forming apparatus according to the present invention for forming a central straight portion of the stator inner liner shown in FIGS. 16a and 16b in schematic illustration;
  • FIG. 19 is an axially sectional view of the partly formed stator formed by the bulge forming apparatus shown in FIG. 18;
  • FIG. 20 is an axially sectional view of a bulge forming apparatus according to the present invention for forming corrugated portions at both ends of the stator inner liner shown in FIGS. 16a and 16b in schematic illustration;
  • FIG. 21 is an axially sectional view of another bulge forming apparatus according to the present invention for forming the corrugated portions at both ends of the stator inner liner shown in FIGS. 16a and 16b in schematic illustration;
  • FIG. 22 is an axially sectional view of a bulge forming apparatus according to the present invention for forming simultaneously the central straight portion and the corrugated portions at both ends of the stator inner liner shown in FIGS. 16a and 16b in schematic illustration.
  • the present invention relates to a method of bulge forming wherein a bulge punch in the shape of a thick tube having an outer contour corresponding to the required convex and concave contours of a product is elastically expanded in radial directions to bulge and form a thin tubular material as required without employing any outer mould or die.
  • a bulge punch in the shape of a thick tube having an outer contour corresponding to the required convex and concave contours of a product is elastically expanded in radial directions to bulge and form a thin tubular material as required without employing any outer mould or die.
  • FIGS. 9a and 9b A bulge forming punch of double structure
  • FIGS. 9a and 9b A bulge forming apparatus embodying the present invention is shown in FIGS. 9a and 9b and a bulge forming punch and an inner punch which are used in the bulge forming apparatus in FIGS. 9a and 9b are shown in FIGS. 10a to 10C and FIGS. 11a, 11b, respectively.
  • the bulge forming punch I is a thick tube being made of a hard elastic material such as rubber and having an outside contour 1a corresponding to the convex and concave contour of a product article and a central bore, as shown in FIGS. 10a to 100.
  • the inner punch which is inserted into the bulge forming punch to prevent the leakage of liquid and to transmit the radial expansion force due to hydraulic pressure to the bulge forming punch is made of a soft eleastic material such as rubber and has a shape of a tube having inwardly folded opposite ends (FIGS. 11b).
  • a punch holder 11 has a central hole 11a for introducing liquid to the inside of the inner punch 10, thus transmitting hydraulic pressure to the inside thereof.
  • the inwardly folded portions 10a of the inner punch 10 are respectively received on reduced shaft portions 11b of the punch holder 11, and opposite end walls 10b of the inner punch are restricted between a flange portion of the punch holder and an end plate 12 supported by a nut 13 screwed onto a threaded end of the punch holder, whereby it is prevented that the inner punch is extended in the axial direction or is subjected to breakage when the hydraulic pressure is applied.
  • the inner punch 10 is expanded only in the radial directions and expands the bulge forming punch 1 radially outward by the force exerted from the inside.
  • the bulge forming punch 1 which is applied with internal pressure via the inner punch 10 and is expanded in radial directions expands in turn a thin tubular material 6' by the convex and concave portion 1a and forms the matrial in the correspondingly bulged convex and concave contour.
  • the hydraulic pressure is released, whereby the bulge forming punch 1 and the inner punch 10 elastically contract to their initial configurations.
  • the nut 13 is unfastened and the end plate 12 is removed from the punch holder 11, whereby the bulged product can be readily taken out.
  • the bulge forming punch 1 is made of a hard polyurethane rubber and has a central hole of 36 mm. and an outer surface incorporating convex portions of 44 mm. outer diameter and concave portions of 42 mm. outer diameter.
  • the inner punch is made of a highnitril rubber and has a cylindrical body of 35.5 mm. outer diameter and 2 mm. thickness, which is transferred to opposite end walls of 3 mm. thickness and then to respective inwardly folded portions 10a of 23.5 mm. inner diameter and 12 mm. axial length.
  • the punch holder 11 is made of steel and has a shaft portion of 28 mm. diameter provided with steppedly reduced portions 11b of 24 mm. diameter to receive thereon the inwardly folded portions 10a of the inner punch.
  • the shaft portion is provided with an oil leading bore 11a of 6 mm. diameter along its axis and a cross bore 11c of 6 mm. diameter traversing the central bore 11a.
  • the end plate 12 is made of steel.
  • the bulge forming punch 1 and the inner punch 10 were assembled on the punch holder 11, the seam-welded stainless steel tube 6' of 46 mm. outer diameter and 0.15 thickness being mounted on the bulge forming punch 1, and thereafter the end plate 12 was mounted onto the end of the shaft porti n and clamped by the nut 13 as shown in FIG. 9b.
  • the bulge forming tools thus having been assembled, oil pressure of kg./cm. was applied via the oil leading bore 11a of the holder for approximately one second.
  • the inner punch 10 and therefore the bulge forming punch 1 were elastically expanded radially outward, thus bulging the thin seamwelded stainless steel tube 6 fitted over the bulge forming punch 1 from its inside radially outward according to the convex and concave contour of the outside surface of the bulge forming punch.
  • the formed product was in the shape as shown in FIGS. 2a and 2b, wherein the outer diameter of the convex portion was 51 mm. and the outer diameter of the concave portion was 49.2
  • the external and internal pressures exerted on the inner punch 10 were respectively about 0.40 kg./mm. and as to the bulge forming punch 1 the internal ressure exerted thereupon was about 0.40 kg./mm. and the external pressure was 0.27 kg./mm. Since these pressures were lower than the elastic limit of the rubber, there occurred no breakage in the inner punch and bulge forming punch made of the rubber.
  • the convex portion of the bulge forming punch elastically reduced its height only by about 10 percent due to the external pressure of 0.27 kg./mm. Therefore, by giving the bulge forming punch a contour which was correspondingly modified for the elastic deformation, highly precise product could be obtained.
  • FIGS. 12a and 12b A single bulge forming punch of a simple structure
  • FIGS. 12a and 12b a bulge forming punch thereof is shown in FIGS 13a and 13b.
  • the bulge forming punch 1 in FIGS. 13a and 13b is also made of a hard eleastic material such as rubber and is also a thick tube having an outside contour 1a corresponding to the convex and concave contour of a product article and a central bore as shown FIGS. 13a and 13b.
  • the bulge forming punch 1 in this example has in addition annular lips 112 at its opposite ends, which serve to prevent leakage of high pressure liquid.
  • the opposite ends of the bulge forming punch 1 are received in counterbores of two end plates 11 and 12, the diameter of each counterbore being slightly smaller than the peripheral diameter of the lip.
  • the end plate 11 is provided with an oil leading bore 11a along its axis.
  • a thin tubular material 6 of a length a little shorter than the bulge forming punch 1 is mounted on the bulge forming punch, the both ends of which, thereafter, are inserted into the counterbores of the end plates 11 and 12, which in turn are clamped together by means of bolts 14 extended through opposing holes of the two end plates, or by other suitable means.
  • bolts 14 extended through opposing holes of the two end plates, or by other suitable means.
  • the lips 1b are pressed fluid-tightly against the walls of the counterbores, whereby the leakage of liquid is prevented.
  • the bulge forming punch 1 By the radial expansion of the bulge forming punch 1, the thin tubular material 6' is expanded from its inside to follow the convex and concave contour 1a of the bulge forming punch. After the completion of the bulge forming, the hydraulic pressure is released, whereby the bulge forming punch elastically retrieves to initial shape. Accordingly, by removing one of the end plates from the bulge forming punch, the product can be readily taken out.
  • the bulge forming punch 1 is made of a hard polyurethane rubber and has the central bore 1d of 20 mm. diameter, the outer surface incorporating convex portion of 44 mm. outer diameter and concave portion of 42 mm. outer diameter and the lips of 45 mm. peripheral diameter.
  • the end plates 11 and 12 are respectively made of steel and are provided with the counterbores of 44 mm. diameter.
  • the seam-welded stainless steel tube 6' of 46 mm. outer diameter and 0.15 mm. thickness was mounted on the thus prepared bulge forming punch 1, both ends of which, thereafter, were inserted into the counterbores of the end plates 11 and 12, which in turn were clamped together by bolts 14 and nuts 5, as shown in FIG. 12.
  • the bulge forming apparatus thus having been assembled, oil pressure of kg./cm. was applied via the oil leading bore 11a of the end plate 12 for approximately one second.
  • the bulge forming punch 1 was elastically expanded radially outward, thus bulging the thin seamwelded stainless steel tube 6' fitted over the bulge forming punch 1 from its inside radially outward according to the convex and concave contour of the outside surface of the bulge forming punch.
  • formed product was in the shape as shown in FIGS. 2a and 2b, wherein the outer diameter of the convex portion was 51 mm. and the outer diameter of the concave portion was 49.2 mm.
  • the side or axial pressure and internal pressures exerted on the bulge forming punch were respectively about 1.00 kg./mm. and the external pressure exerted thereupon was about 0.27 kg./mm. Since these pressures were lower than the elastic limit of the rubber, there occurred no breakage in the bulge forming punch 1.
  • the convex portion of the bulge forming punch elastically reduced its height only a by about 10 percent due to the external pressure of 0.27
  • FIG. 14 A bulge forming punch having stepped central bore
  • FIGS. 15a and 15b A bulge forming punch having stepped central bore
  • the bulge forming punch 1 in FIGS. 15a and 15b is again made of a hard elastic material such as rubber and is again a thick tube having an outside contour 1a, 1d corresponding to the convex and concave contour of a product article and a stepped central bore 1e, 1 as shown in FIG. 15b, wherein the convex and concave portions 1a and 1d may be of same shape with same diameter, while the central bore portions 1e, 1 are correspondingly formed in different diameters to effect different expanw sions over the length thereof.
  • the other details of this bulge forming apparatus are identical with those of the Example 2.
  • the bulge forming punch 1 is made of a hard polyurethane rubber and has the central bore portions 1e of 20 mm. diameter and 1 of 23 mm. diameter, the outer surface incorporating convex portions 1a, 1d of 44 mm. outer diameter and concave portions 1a, 1d of 42 mm. outer diameter and the lips 1b of 45 mm. peripheral diameter and 2 mm. thickness.
  • the end plates 11 and 12 are respectively made of steel and are provided with the counterbores of 44 mm. diameter.
  • the seam-welded stainless steel tube 6 of 46 mm. outer diameter and 0.15 mm.
  • the side and internal pressures exerted on the bulge forming punch were respectively about 1.00 kg./mm. and the external pressures exerted on the convex portions 1a and 1d were respectively about 0.27 and 0.28 kg./mm. Since these pressures were lower than the elastic limit of the rubber, there occurred no breakage in the bulge forming punch 1.
  • the convex portions 1a and 1d of the bulge forming punch elastically reduced its height only by about percent due to the external pressures of 0.27 and 0.28 kg./mm. Therefore, by giving the bulge forming punch a contour which was correspondingly modified for the elastic deformation, highly precise products could be obtained.
  • the method of bulge forming of the present invention can be applied to the fields, to which the conventional bulge forming was not applicable.
  • the bulge forming of a stator inner liner of a canned motor will be explained in the following.
  • FIGS. 16a, and 16b A completed stator of a canned motor is shown in FIGS. 16a, and 16b and FIG. 17 shows a state in the manufacture where a liner material is freely inserted in its place but not yet fixed.
  • a stator core and stator coils 16 are canned or enclosed fluid-tightly within a space defined by an outer shell 17, the inner liner 6 and opposite end plates 18, wherein portions of the inner liner 6 opposing the stator coils 1 6 are formed into corrugation over the circumference.
  • the corrugation of the liner 6 and the sealing expansion thereof against the end plates 18 can not be carried out by the conventional method of bulge forming, wherein a split die of a larger diameter than the outer diameter of a work piece is required, such a die, however, being not applicable because of the existence of the coils 16 and the end plates 18.
  • the both ends of the inner liner 6 can be corrugated and expanded for sealing simultaneously and instantly without any requirement of a split die.
  • FIG. 18 shows the assembled state of a bulge forming apparatus for expanding the central straight portion of a stator inner liner, and the stator inner liner thus formed of its central straight portion is shown in FIG. 19.
  • FIG. 20 shows a state of a further step of manufacture, wherein the partly formed stator is assembled in a bulge forming apparatus employing a bulge forming punch of double structure.
  • the bulge forming apparatus for forming the central straight portion as shown in FIG. 18 has the following data:
  • the bulge forming punch 10 is made of a highnitril rubber and has a cylindrical portion of 45 mm. outer diameter and 2.5 mm. thickness, which is transferred to opposite end walls of 3 mm. thickness and then to respective inwardly folded portions of 29.5 mm. inner diameter and mm. length.
  • a punch holder 11 is made of steel and has a ventral shaft portion of 35 mm. diameter provided with steppedly reduced portion of 30 mm. diameter at both ends thereof to receive thereon the inwardly folded portions of the bulge forming punch 10.
  • the punch holder is provided with an oil leading 11a of 6 mm. diameter along its axis and a cross bore traversing the central bore 11a.
  • Other fitting members 19, 20, 21, 22, 23, 24 and 25 are all made of steel.
  • a bulge forming apparatus incorporating the bulge forming punches of double structure was inserted through the partly formed stator and was clamped therewith as shown in FIG. 20.
  • the bulge forming apparatus shown in FIG. has the following data: Bulge forming punches '6 and 7 spacedly arranged therein are made of a hard polyurethane rubber and have central bores of 36 mm. diameter ad the outer convex and concave portions 611 and 7a corresponding to the required shape of the product wherein the outer diameters of the convex and concave portions are respectively 44 and 42 mm.
  • Inner punches 8 and 9 are made of a highnitril rubber and each of them has a cylindrical portion of 35.5 mm. outer diameter and 2 mm. thickness, which is transferred to opposite end walls of 3 mm. thickness and then to respective inwardly folded portions of 23.5 mm. inner diameter and 12 mm, length.
  • Punch holders 11 and 13 are made of steel and each of them has a central portion of 28 mm. diameter provided with steppedly reduced portions of 24 mm. diameter at both ends thereof to receive thereon the inwardly folded portions of the inner punch 8 or 9.
  • the punch holders 11 and 13 are respectively provided with oil leading bores 11 and 13a of 6 mm. diameter along their axes and cross bores respectively traversing the central bores 35a and 37a.
  • FIG. 21 An example by a single bulge forming punch of a simple structure: Another bulge forming apparatus for finishing the both ends corrugation of the stator inner liner as shown in FIG. 16a incorporating a single bulge forming punch according to the present invention is shown in FIG. 21 in the state assembled with the partly formed stator.
  • a bulge punch 1 of this example is made of a hard polyurethane rubber and has central bore of 20 mm. diameter and the outer convex and concave portions 1a corresponding to the required corrugation of the stator inner liner, wherein the outer diameters of the convex and concave portions are respectively 44 and 42 mm.
  • the bulge forming punch is also provided at the both ends thereof with lips 1b of 45 mm.
  • the stator inner liner as shown in FIG. 16a could be formed in one process by a bulge forming apparatus incorporating a bulge forming punch having stepped central bore according to the present invention as shown in FIG. 22.
  • the bulge forming punch 1 of this example is made of a hard polyurethane rubber and has substantially same dimensions as the bulge form ing punch shown in FIG. 21, except that the bore is a stepped bore including a central bore portion 1e of 30 mm. diameter to be positioned under the stator core 30 and end bore portions 10. of 20 mm. diameter arranged at both sides thereof.
  • the bulge forming is accomplished in an instant by a hollow bulge forming punch of an elastic material having an outer contour corresponding to the required contour of a tubular material to be formed and being inserted into the tubular material without using any outer mould or die, whereby any scarring of the outside surface of the product can be avoided rendering nice appearance of the product and the possibility of application of bulge forming can be greatly broadened to the fields to which the conventional method of bulge forming was not applicable.
  • a method of forming a thin tubular material into a required shape comprising the steps of inserting a bulge forming punch made of a unitary thick tubular body of an elastic material having a non-uniform outer contour into said tubular material which is held substantially unconstrained for free expansion away from the bulge forming punch, said tubular body having an outer contour substantially corresponding to the required shape of the tubular material, and applying fluid pressure to the inside of said bulge forming punch to expand said bulge forming punch in radial directions thereof to such an extent that said thin tubular material is expanded by said bulge forming punch beyond the limit of elastic deformation thereof to follow the outer contour of the expanded bulge forming punch.
  • tubular body has a substantially uniform mean tube thickness along the axial length therof, whereby said tubular material is expanded substantially uniformly along the axial length thereof.
  • tubular body has portions of different mean tube thicknesses along the axial length thereof, whereby said tubular material is expanded to different mean diameters along the axial length thereof.
  • An apparatus for forming a thin tubular material into a required shape comprising a bulge forming punch made of a unitary thick tubular body of an elastic material adapted to be inserted into a tubular material and having a non-uniform outer contour substantially corresponding to a required shape of such tubular material, and means for applying fluid pressure to the inside of said bulge forming punch to expand said bulge forming punch in radial directions thereof to such an extent that said thin tubular material is expanded by said bulge forming punch beyond the limit of elastic deformation thereof to follow the non-uniform outer contour of the expanded bulge forming punch.
  • tubular body has a substantially uniform mean tube thickness along the axial length thereof so that said tubular material is expanded substantially uniformly along the axial length thereof.
  • tubular body has portions of different mean tube thicknesses along the axial length thereof so that said tubular material is expanded to different mean diameters along the axial length thereof.
  • tubular body has inclined annular lips at both axial ends thereof which are adapted to be inserted into counterbores of cooperating punch holding means for keeping fluid pressure applied to the inside of said bulge forming punch.
  • An apparatus for forming a thin tubular material into a required shape comprising a bulge forming punch made of a unitary thick tubular body of an elastic material adapted to be inserted into said tubular material and having a non-uniform outer contour substantially corresponding to a required shape of the tubular material, a tube means made of an elastic material having substantially the same axial length as said bulge forming punch and adapted to be inserted into said bulge forming punch, and means for applying fluid pressure to the inside of said tube means to expand said tube means and said bulge forming punch in radial directions thereof to such an extent that said thin tubular material is expanded by said bulge forming punch beyond the limit of elastic deformation thereof to follow the outer contour of the expanded bulge forming punch.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Shaping Metal By Deep-Drawing, Or The Like (AREA)
  • Casting Or Compression Moulding Of Plastics Or The Like (AREA)
  • Shaping Of Tube Ends By Bending Or Straightening (AREA)
  • Moulds, Cores, Or Mandrels (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)
US685453A 1966-12-08 1967-11-24 Method of and an apparatus for bulge forming Expired - Lifetime US3520163A (en)

Applications Claiming Priority (8)

Application Number Priority Date Filing Date Title
JP8115166 1966-12-08
JP8115266 1966-12-08
JP8504866 1966-12-22
JP8504966 1966-12-22
JP1820667 1967-03-20
JP1820567 1967-03-20
JP2554367 1967-04-19
JP2554467 1967-04-19

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US3520163A true US3520163A (en) 1970-07-14

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US685453A Expired - Lifetime US3520163A (en) 1966-12-08 1967-11-24 Method of and an apparatus for bulge forming

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US (1) US3520163A (OSRAM)
FR (1) FR1566187A (OSRAM)
GB (1) GB1202605A (OSRAM)
NL (2) NL6716519A (OSRAM)

Cited By (12)

* Cited by examiner, † Cited by third party
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US4109365A (en) * 1976-03-30 1978-08-29 Eastman Kodak Company Method for forming contoured tubing
US4321950A (en) * 1979-03-02 1982-03-30 Pont-A-Mousson S.A. Spheroidal graphite cast iron pipe and the process for producing same
US20030079327A1 (en) * 2001-10-18 2003-05-01 Durand Robert D. Method of manufacturing an axially collapsible driveshaft
RU2240190C1 (ru) * 2003-03-11 2004-11-20 Федеральное государственное унитарное предприятие Производственное объединение "Электрохимический завод" Способ изготовления гофрированных труб
US7287406B2 (en) 2004-11-30 2007-10-30 The Boeing Company Transition forming machine
CN101885018A (zh) * 2010-07-27 2010-11-17 哈尔滨工业大学 小半径波纹曲面薄壁金属筒零件粘弹塑性软模成形方法
CN102699167A (zh) * 2012-05-18 2012-10-03 张家港化工机械股份有限公司 管件上加工膨胀节用的工装
CN102699166A (zh) * 2012-05-18 2012-10-03 张家港化工机械股份有限公司 一种在管件上加工膨胀节用的工装
WO2015144999A1 (fr) * 2014-03-27 2015-10-01 Peugeot Citroen Automobiles Sa Dispositif de tube distributeur de pressions fluidiques monte a l'interieur d'un arbre de transmission
CN109772969A (zh) * 2019-02-25 2019-05-21 哈尔滨工业大学（威海） 一种金属波纹管成形装置与方法
CN112756473A (zh) * 2020-12-17 2021-05-07 重庆虎溪电机工业有限责任公司 铜薄壁骨架制作新方法
US20210299720A1 (en) * 2020-03-26 2021-09-30 Yanshan University Rolling-bulging forming hydraulic machine for tubular products

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WO2005061149A2 (en) * 2003-12-22 2005-07-07 Glud & Marstrand A/S A method and an installation for forming a metal container and a metal container for storing of foodstuff

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US2581787A (en) * 1945-12-27 1952-01-08 Dreyer Albert Manufacturing highly resilient corrugated tubes
US2557722A (en) * 1946-02-01 1951-06-19 Charles A Brauchler Method of forging hollow articles
US2825387A (en) * 1954-01-19 1958-03-04 Dunbar Kapple Inc Machine for successively convoluting tubing
US2865640A (en) * 1955-12-21 1958-12-23 Exxon Research Engineering Co Tube holding apparatus
CH350946A (fr) * 1958-01-10 1960-12-31 Keelavite Company Limited Appareil pour former au moins un renflement dans une extrémité d'un tuyau
US3379805A (en) * 1964-12-14 1968-04-23 Fred T Roberts & Company Method of making corrugated hose
US3357229A (en) * 1965-02-09 1967-12-12 Grotnes Machine Works Inc Apparatus for forming a beaded shell

Cited By (20)

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Publication number Priority date Publication date Assignee Title
US4109365A (en) * 1976-03-30 1978-08-29 Eastman Kodak Company Method for forming contoured tubing
US4321950A (en) * 1979-03-02 1982-03-30 Pont-A-Mousson S.A. Spheroidal graphite cast iron pipe and the process for producing same
US20030079327A1 (en) * 2001-10-18 2003-05-01 Durand Robert D. Method of manufacturing an axially collapsible driveshaft
US7080436B2 (en) * 2001-10-18 2006-07-25 Torque-Traction Technologies, Llc Method of manufacturing an axially collapsible driveshaft
RU2240190C1 (ru) * 2003-03-11 2004-11-20 Федеральное государственное унитарное предприятие Производственное объединение "Электрохимический завод" Способ изготовления гофрированных труб
US7287406B2 (en) 2004-11-30 2007-10-30 The Boeing Company Transition forming machine
CN101885018A (zh) * 2010-07-27 2010-11-17 哈尔滨工业大学 小半径波纹曲面薄壁金属筒零件粘弹塑性软模成形方法
CN101885018B (zh) * 2010-07-27 2013-05-29 哈尔滨工业大学 小半径波纹曲面薄壁金属筒零件粘弹塑性软模成形方法
CN102699167A (zh) * 2012-05-18 2012-10-03 张家港化工机械股份有限公司 管件上加工膨胀节用的工装
CN102699166A (zh) * 2012-05-18 2012-10-03 张家港化工机械股份有限公司 一种在管件上加工膨胀节用的工装
WO2015144999A1 (fr) * 2014-03-27 2015-10-01 Peugeot Citroen Automobiles Sa Dispositif de tube distributeur de pressions fluidiques monte a l'interieur d'un arbre de transmission
FR3019249A1 (fr) * 2014-03-27 2015-10-02 Peugeot Citroen Automobiles Sa Dispositif de tube distributeur de pressions fluidiques monte a l'interieur d'un arbre de transmission.
CN106164538A (zh) * 2014-03-27 2016-11-23 标致·雪铁龙汽车公司 被装配在传动轴内部的对流体压力进行分配的分配管装置
CN106164538B (zh) * 2014-03-27 2018-12-28 标致·雪铁龙汽车公司 被装配在传动轴内部的对流体压力进行分配的分配管装置
CN109772969A (zh) * 2019-02-25 2019-05-21 哈尔滨工业大学（威海） 一种金属波纹管成形装置与方法
CN109772969B (zh) * 2019-02-25 2020-09-18 哈尔滨工业大学（威海） 一种金属波纹管成形装置与方法
US20210299720A1 (en) * 2020-03-26 2021-09-30 Yanshan University Rolling-bulging forming hydraulic machine for tubular products
US11679426B2 (en) * 2020-03-26 2023-06-20 Yanshan University Rolling-bulging forming hydraulic machine for tubular products
CN112756473A (zh) * 2020-12-17 2021-05-07 重庆虎溪电机工业有限责任公司 铜薄壁骨架制作新方法
CN112756473B (zh) * 2020-12-17 2023-02-17 重庆虎溪电机工业有限责任公司 铜薄壁骨架制作新方法

Also Published As

Publication number Publication date
DE1602513A1 (de) 1970-12-23
NL6716519A (OSRAM) 1968-06-10
GB1202605A (en) 1970-08-19
FR1566187A (OSRAM) 1969-05-09
DE1602513B2 (de) 1975-04-03
NL137426C (OSRAM)

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