Classifications

• • 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
  • B21D9/04—Bending tubes using mandrels or the like the mandrel being rigid
• • 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
  • B21D9/05—Bending tubes using mandrels or the like co-operating with forming members
  • B21D9/07—Bending tubes using mandrels or the like co-operating with forming members with one or more swinging forming members engaging tube ends only
  • B21D9/073—Bending tubes using mandrels or the like co-operating with forming members with one or more swinging forming members engaging tube ends only with one swinging forming member
• • 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
  • B21D11/00—Bending not restricted to forms of material mentioned in only one of groups B21D5/00, B21D7/00, B21D9/00; Bending not provided for in groups B21D5/00 - B21D9/00; Twisting
  • B21D11/02—Bending by stretching or pulling over a die
• • 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
  • B21D11/00—Bending not restricted to forms of material mentioned in only one of groups B21D5/00, B21D7/00, B21D9/00; Bending not provided for in groups B21D5/00 - B21D9/00; Twisting
  • B21D11/22—Auxiliary equipment, e.g. positioning devices
• • 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
  • B21D9/16—Auxiliary equipment, e.g. machines for filling tubes with sand

Definitions

• the present invention relates to a pipe bending machine with bending mandrel having a load bearing structure which is particularly resistant to working stresses.
• Background art It is known that in a pipe bending machine with bending mandrel, an extractor is fixed in a rear portion of a machine workbench, and a mandrel rod extends longitudinally from the extractor beyond a front portion of the machine where are situated a mandrel and a bending head which is provided with a die.
• the workbench is fixed on a structure that is generally fixed to a floor.
• an object of the present invention is to manufacture a structure for a pipe bending machine with bending mandrel that is not subjected to bending stresses, when a pipe to be bent is subjected to a traction force by a bending head die.
• a pipe bending machine with bending mandrel having a load bearing structure which is particularly resistant to working stresses, in which an extractor is fixed in a rear portion of the pipe bending machine and mandrel rod extends with its longitudinal axis, from the extractor beyond a front portion of the machine, where a bending head which is provided with a die stresses a pipe to be bent, which is inserted in a mandrel, by a traction resultant force that is transmitted along the mandrel rod to the extractor that counteracts with a resultant restraining reaction, the pipe bending machine comprising a load bearing structure having a profile such that it contains inside the longitudinal axis of the mandrel rod, in such a way that the load bearing structure is subjected mainly to compression stresses.
• the above mentioned pipe bending machine is particularly advantageous as said machine, since it is not subjected to bending stresses, does not undergo in its load bearing structure deformations that worsen its working way and damage its product. Since it is the same load bearing structure that balances the tangential force applied to the die, the pipe bending machine discharges substantially only its load on a floor, thereby it needs no anchoring to the soil to prevent its deformation and increase its statics.
• Figure 1 is a perspective view of a first embodiment of a pipe bending machine having a load bearing structure according to the present invention
• Figure 2 is a schematic longitudinal cross section of the pipe bending machine in
• Figure 3 shows an enlarged detail of a right-hand end of the pipe bending machine in Figure 2;
• Figure 4 shows an enlarged detail of a left-hand end of the pipe bending machine in
• Figure 2 shows an enlarged transversal cross section of the load bearing structure of the pipe bending machine in Figure 1 ;
• Figure 6 shows a cross-sectioned perspective view of a second embodiment, that is circular, of a bearing structure of the pipe bending machine according to the present invention
• Figure 7 shows a perspective view of a third embodiment, that is reticular, of a load bearing structure of the pipe bending machine according to the present invention
• Figure 8 shows a general perspective view of the third reticular embodiment of a load bearing machine without the pipe bending machine.
• FIGS 1 and 2 a first embodiment of a load bearing structure of a pipe bending machine with bending mandrel according to the present invention is shown in a perspective view and in a schematic longitudinal cross section, respectively, is shown.
• a first embodiment of load bearing structure which is prismatic or box-shaped, is designed as 1.
• an extractor is generally indicated as 2
• a front end at right hand in Figure 2 has a front frame 3.
• the bearing structure 1 is sustained rear and in front on supporting elements 4 and 5 respectively.
• the front supporting element 5 projects forward with a step 6, on which a bending head 7 rests.
• the bending head 7 is provided with a die 8 that is equipped with a clamping mechanism 9.
• the clamping mechanism 9 is the subject-matter of another patent application of the same Applicant.
• the bending head 7 is slidingly mounted on the step 6 by means of guides 10 that are horizontally located on the same step.
• the bending head 7 contacts an abutment member 11 which is fixed to the front frame 3 of the load bearing structure
• the abutment member 11 makes a transversal sliding coupling between the load bearing structure 1 and the bending head 7.
• a bending mandrel 12, which is mounted on an end of a mandrel rod 13, is not further described as it is the subject-matter of a previous patent application of the same Applicant.
• a pipe T to be bent is positioned on the bending mandrel 12.
• the pipe T is sustained on a mandrel holder 14 of a known kind, which is shown in Figure 1 but is not represented in Figures 2 and 3 for clarity sake.
• the extractor 2 is best shown in Figure 4, that is an enlarged detail of the left-hand end of the machine.
• the extractor 2 is of a known kind and then not further described.
• the extractor is not cantilevered on the workbench, like in the existing bending machines, but according to the invention the extractor is located in a through manner in an anchoring plate 15.
• the anchoring plate 15 of the extractor 2, which is suitably strengthened by a stiffening rib 16, is fixed to a rear frame 17 as a rear portion of the load bearing structure I 5 in such a way that a restraining force, which is exercised by the extractor 2 against the traction force applied by the die 8, is discharged only on the load bearing structure 1.
• the load bearing structure 1 has the rear frame 17 that surrounds the extractor 2 at least in large part but preferably totally. For this reason it is particularly suitable that the rear portion of the load bearing structure is configured as a frame like the front frame 3.
• the load bearing structure 1 of the pipe bending machine with bending mandrel is prismatic or box-shaped.
• the load bearing structure 1 has side walls 18, 19, 20, 21. Lifting sleeves, indicated as 22, are shown.
• Openings to enter the load bearing structure 1 are generally designed as 23.
• some parts of the load bearing structure 1, for example, which are related to the side walls, can be removed.
• all the co-operating parts of the load bearing structure are supposed to be subjected to compression in order to oppose the traction force applied by the die in a pipe bending operation.
• Such resultants of forces transmitted through the mandrel rod 13 determine a compression stress on the load bearing structure 1.
• the load bearing structure 1 has a geometrical cross section having a centre somewhat far from the axis g of the mandrel rod where the existing forces are transmitted.
• Figure 5 is a transversal cross section of the load bearing structure 1, in its first box-shaped embodiment.
• the transversal cross section is substantially rectangular, and it can be pointed out that the geometrical centre of the cross section, i.e. the centre C, is not coincident with a point G that represents the intersection point of the axis g of the mandrel rod 13 in the cross section in exam.
• the moment of inertia of the resistant cross section can be modified, for example applying a strengthening plate 24 in order to make the centre of inertia coincident with the intersection point G of the axis g of the mandrel rod 13.
• a second embodiment of a load bearing structure which is particularly resistant to the working stresses is shown in a perspective view which is longitudinally cross-sectioned by a vertical symmetry plane passing through the axis g.
• the load bearing structure in the second embodiment is round tubular and is indicated as 25, and has a front frame 3 and rear frame 17 like in the first embodiment. If the extractor 2 is positioned centrally inside the load bearing structure, the load bearing structure reacts in such a way to balance, above all, the stress applied on the pipe to be bent as the force applied on the pipe by means of bending head is discharged on the round tubular structure through the vertical rest of the bending head 7 on the front frame 3.
• FIG. 7 a third embodiment of a load bearing structure according to the present invention is shown in a perspective view which is longitudinally cross- sectioned by a vertical symmetry plane passing through the axis g.
• the load bearing structure of the third embodiment is generally reticular and is indicated as 26, and has a front frame 3 and rear frame 17 like in the first embodiment.
• the load bearing structure reacts in such a way to balance, above all, the stress applied on the pipe to be bent as the force applied on the pipe by means of bending head is discharged on the reticular structure through the vertical rest of the bending head 7 on the front frame 3.
• the resistant parts of the reticular structure that are substantially beams indicated generally as 27, which are positioned in the corners of the structure, form a framework, and walls can be not present.
• An wall portion 28 can act as the straightening plate 24, which is described in the first embodiment and shown in Figure 5.
• Reinforcements and stiffening ribs for the beams 27 are desirable in order to obtain a uniform reaction of the load bearing structure 26, which is shown more in detail in the general perspective view in Figure 8, where the pipe bending machine with bending mandrel is not represented for clarity sake.
• the load bearing structure according to the invention can have solid side walls, as in the first and second embodiment, or non continuous, when it has a framework and reticular side walls, as in the third embodiment.
• the load bearing structure would also have a different polygonal transversal cross section. If the cross section is round, it can be circular or oval.
• the load bearing structure has a transversal cross section having a momentum of inertia such that the traction force applied by means of the die has a direction passing through the centre of inertia of the transversal cross section.
• a further advantage is given by the fact that the bending head is slidable mounted in said front end on guides horizontally positioned on a step resting on the soil transversally to the longitudinal direction, the bending head being in contact with an abutment member in the front end of the load bearing structure, the abutment member making a sliding coupling with the front end of the load bearing structure, hi such a way, useless flexing stresses to the load bearing structure near the bending head are avoided.
• the advantages of the load bearing structure according to the present invention are even more. It should be understood that, thanks to an optimum use of the metal material that works to compression, the load bearing structure of the described kind allows the manufacturing costs of a pipe bending machine to be reduced, as a minor quantity of material is requested with respect to the existing pipe bending machine.
• a further advantage is represented by the fact that the load bearing structure according to the invention is more able to undergo changes in its length if relevant extension pipes have to be worked, hi fact, in the bending machine with bending mandrel of the prior art, if the length of the workbench is increased, also the deformations being caused by the flexion in the working process are increased.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Bending Of Plates, Rods, And Pipes (AREA)
• Medicines Containing Material From Animals Or Micro-Organisms (AREA)

Priority Applications (8)

Applications Claiming Priority (2)

Publications (2)

Family

ID=40316559

Family Applications (1)

Country Status (12)

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Citations (3)

Family Cites Families (12)

• 2007
  • 2007-09-17 IT IT000483A patent/ITRM20070483A1/it unknown
• 2008
  • 2008-09-15 JP JP2010524627A patent/JP5438006B2/ja not_active Expired - Fee Related
  • 2008-09-15 ES ES08834239T patent/ES2741531T3/es active Active
  • 2008-09-15 US US12/678,333 patent/US20100206036A1/en not_active Abandoned
  • 2008-09-15 CA CA2699595A patent/CA2699595C/en not_active Expired - Fee Related
  • 2008-09-15 WO PCT/IT2008/000590 patent/WO2009040859A2/en active Application Filing
  • 2008-09-15 CN CN2008801074626A patent/CN101801557B/zh not_active Expired - Fee Related
  • 2008-09-15 RU RU2010115339/02A patent/RU2438819C1/ru not_active IP Right Cessation
  • 2008-09-15 KR KR1020107007987A patent/KR101562506B1/ko active IP Right Grant
  • 2008-09-15 MX MX2010002919A patent/MX2010002919A/es active IP Right Grant
  • 2008-09-15 EP EP08834239.9A patent/EP2203266B1/en active Active
  • 2008-09-15 BR BRPI0816937-3A patent/BRPI0816937B1/pt not_active IP Right Cessation

Patent Citations (3)

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