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
  • B21D39/00—Application of procedures in order to connect objects or parts, e.g. coating with sheet metal otherwise than by plating; Tube expanders
  • B21D39/04—Application of procedures in order to connect objects or parts, e.g. coating with sheet metal otherwise than by plating; Tube expanders of tubes with tubes; of tubes with rods
  • B21D39/046—Connecting tubes to tube-like fittings
• • 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
  • B21D39/00—Application of procedures in order to connect objects or parts, e.g. coating with sheet metal otherwise than by plating; Tube expanders
  • B21D39/04—Application of procedures in order to connect objects or parts, e.g. coating with sheet metal otherwise than by plating; Tube expanders of tubes with tubes; of tubes with rods

Definitions

• the present invention relates, in general, to a method for shrinking a ring fitted on the free end of a flexible pipe fitted on a rigid tubular element, said ring having at least one portion called "to shrink” whose diameter is greater to that of the pipe.
• the method implements a constriction matrix provided with an axial cavity comprising a flared section widening between a first and a second end, the cavity having a wide open end at which the diameter of said cavity is substantially equal to diameter of said flared section at the second end of the latter.
• Axial necking is commonly used for custom work of rigid tubes.
• the patent issued in the UNITED STATES under number 2314002 describes a method which attempts to use axial constriction to constrict a ring fitted on the free end of a flexible pipe.
• the necking die is first of all placed around the pipe and is then moved, on the ring, towards the free end of the pipe.
• the smallest diameter of the axial cavity is at least equal to the outside diameter of the pipe.
• the ring itself being arranged around the pipe its internal diameter is also at least equal to the external diameter of the pipe. Consequently, the effective reduction in diameter during the constriction is at most equal to the thickness of the ring.
• the reduction in diameter may not be sufficient to ensure the reliability of the holding of the pipe, ring, tubular element assembly.
• the only way to increase the amplitude of the necking, that is to say to make the reduction in diameter greater, is to increasing the thickness of the ring, which inevitably leads to an increase in the material cost and to an increase in the required shrinking power.
• the constriction is not limited to the thickness of the ring.
• the fact of moving backwards significantly improves the mechanical strength of the pipe, ring, tubular element assembly due to the behavior of the pipe material, which generally comprises rubber, during the shrinking operation.
• the volume of the excess material that is to say the volume of the material that the creep tends locally to repel
• the pressure of the material constituting the pipe inside the ring undergoes very significant local variations.
• the thickness of the ring must be relatively large.
• the material constituting this pipe is subjected both to creep and to an intense pressure variation, which affects its mechanical qualities.
• the necking is therefore carried out in a manner that is both homogeneous and progressive, so that the assembly of the ring and the pipe is solid and reliable, the latter having no bead or any accumulation of material at its end clamped between the ring and the rigid tubular element and no zone of weakness in particular in the region of the end of the ring remote from the free end of the pipe.
• the connection is ensured reliably even with rings whose thickness is relatively small.
• the relative axial movement of the ring and the necked die is stopped before the first end of the flared section reaches the end of the portion to be shrunk most distant from the free end of the pipe.
• the rear portion of the ring can be slightly flared and does not risk injuring the pipe.
• they are subjected to endurance tests. more and more severe.
• One of these tests is to oscillate the pipe relative to the ring.
• the fact that the rear portion of the ring is flared makes it possible to prevent the pipe from being damaged, or even cut, during such a test.
• FIG. 1 is a longitudinal section showing a ring fitted on the free end of a flexible pipe, itself fitted on a rigid tubular element, as well as a shrinking matrix, using which prepares to implement the method according to a first embodiment.
• FIG. 4 is a view similar to that of Figure 1, on which we are about to implement the method according to an alternative embodiment
• FIG. 1 shows a flexible pipe 10, the free end 10a of which is fitted onto a rigid tubular element 12, while a ring 14, of cylindrical shape, is fitted onto the free end 10a.
• end 10a is the front end of the flexible pipe 10.
• the ring 14 is shown before it is shrunk, and its diameter D is greater than that of the pipe 10.
• a constriction matrix 16 provided with an axial cavity 18.
• This cavity comprises a flared section l ⁇ a which widens between a first end 19a of diameter d 'and a second end 19b of diameter d .
• the diameter d is greater than the diameter D, itself greater than the diameter of.
• the cavity On the side of the first end 19a of the flared section, the cavity has a cylindrical section 18b of diameter d 'which opens onto a narrow open end 17.
• the cavity has a wide open end which, in the example shown, coincides with the second end 19b of the flared section, which is frustoconical.
• Figure 1 shows these various elements just before the start of the necking process, in a position in which the axis of the cavity is aligned with the longitudinal axis A of the flexible pipe and the wide open end 20 is directed towards the 'back.
• This tool is only shown diagrammatically in FIG. 1. It can comprise two jaws which are placed around the pipe so as to cooperate with the rear end 14b of the ring 14 to maintain the latter during the constriction.
• the necking die is placed so that at least the wide end 20 of the cavity is around the ring to be shrunk, while the first end 19a is towards the front, beyond the front end of the pipe.
• the matrix is moved relative to the neck ring in the direction of arrow F, that is to say in the direction from the front end 10a of the pipe to its rear end, less until the end 20 of the cavity is at the front end 14a of the ring.
• the actual constriction begins when the wall of the cavity begins to cooperate with the outer periphery of the ring.
• the necking matrix 16 is moved axially on the ring 14 in the direction of the arrow F, that is to say backwards.
• the relative axial displacement of the constriction matrix 16 and of the ring 14 is preferably stopped before the end of smaller diameter of the flared section 18a of the cavity does not reach the rear end 14b, the furthest from the free end 10a of the pipe 10, of this ring 14.
• the tubular element 12 has, in the vicinity of its rear end, a radial bulge 13.
• the constriction is stopped without completely restricting the ring on the bulge. This ensures a reliable connection between the elements of the connection device, while avoiding local crushing of the pipe on the bulge, which could harm its mechanical qualities.
• the ring 114 has a first portion 115a which must not be constricted.
• This portion 115a which, in the example shown, extends forwardly beyond the front end 110a of the flexible pipe 110, can serve as a housing for an annular seal 117 or be provided with a fastening member to a rigid tubular end piece to which the pipe is to be connected
• the portion 115a constitutes an axial obstacle which makes it impossible to use, under the conditions previously mentioned in relation to FIGS. 1 to 3, the shrinking matrix 16 in one piece.
• a shrinking matrix 116 is therefore used, comprising two shells 116a and 116b.
• the shells 116a and 116b are first moved away from one another to define a sufficient passage for the ring or, more precisely, for the front portion 115a of the latter.
• the axial shrinkage proper begins after bringing these two shells close to the ring until this passage is removed.
• a cavity 118 of the matrix is defined, having a flared section 118a and a cylindrical section of small diameter 118b.
• the small end 121 of the cavity located opposite the wide end 120 of the latter, is open. This makes it possible, as seen in FIG. 5, to arrange the matrix 116 around the portion 115b to be constricted, while leaving the first portion 115a of the ring 114 to protrude forwards beyond the matrix.
• the shrinking of the portion 115b is carried out by moving the matrix 116 in the direction of the arrow F, that is to say by making it pass from its start position of the shrinkage, represented in broken dashed lines, to its position of end of the constriction, shown in solid lines.
• the ring is held axially using a necking tool 122.
• the tool 122 comprises jaws which cooperate with the front part of the ring 114. More specifically, the jaws of the tool 122 are placed around the ring, immediately behind the first portion 115a of the latter, and cooperate in abutment with a shoulder 114 'to hold the ring and prevent it from moving backwards during the shrinking.
• the region 115c in which the preliminary step of radial constriction is carried out extends forwardly beyond the front end 110a of the flexible pipe, so that the possible drawbacks linked to this radial necking operation do not affect the pipe.
• the diameter of the intermediate portion 115c is immediately less than or equal to the necking diameter, in which case no preliminary step of radial necking is necessary.
• the ring is maintained axially and the matrix is displaced in the direction of arrow F, it would also be possible to carry out the constriction by axially holding the matrix and by moving the ring in the opposite direction to that of arrow F. The important thing is that the two elements which constitute the ring and the matrix are moved relative to each other in the direction of arrow F, that is to say say backwards, along the portion to shrink.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Shaping Of Tube Ends By Bending Or Straightening (AREA)
• Forging (AREA)
• Joints That Cut Off Fluids, And Hose Joints (AREA)
• Medicines Containing Material From Animals Or Micro-Organisms (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
• Medicinal Preparation (AREA)
• Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)
• Lining Or Joining Of Plastics Or The Like (AREA)
• Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
• Absorbent Articles And Supports Therefor (AREA)
• Pipe Accessories (AREA)
• Rigid Pipes And Flexible Pipes (AREA)
• Shaping By String And By Release Of Stress In Plastics And The Like (AREA)

Priority Applications (9)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9468416

Family Applications (1)

Country Status (17)

Cited By (2)

Families Citing this family (10)

Citations (3)

• 1994
  • 1994-11-02 FR FR9413063A patent/FR2726208B1/fr not_active Expired - Fee Related
• 1995
  • 1995-11-02 KR KR1019960703159A patent/KR100264241B1/ko not_active IP Right Cessation
  • 1995-11-02 WO PCT/FR1995/001438 patent/WO1996014177A1/fr active IP Right Grant
  • 1995-11-02 EP EP95939312A patent/EP0737114B1/fr not_active Expired - Lifetime
  • 1995-11-02 JP JP51509296A patent/JP3179499B2/ja not_active Expired - Fee Related
  • 1995-11-02 AT AT95939312T patent/ATE214983T1/de not_active IP Right Cessation
  • 1995-11-02 CZ CZ19961891A patent/CZ292243B6/cs not_active IP Right Cessation
  • 1995-11-02 ES ES95939312T patent/ES2173984T3/es not_active Expired - Lifetime
  • 1995-11-02 PL PL95315255A patent/PL178959B1/pl not_active IP Right Cessation
  • 1995-11-02 HU HU9601811A patent/HU214856B/hu not_active IP Right Cessation
  • 1995-11-02 CN CN95191134A patent/CN1067303C/zh not_active Expired - Fee Related
  • 1995-11-02 DE DE69526065T patent/DE69526065T2/de not_active Expired - Fee Related
  • 1995-11-02 RU RU96116854/02A patent/RU2113929C1/ru not_active IP Right Cessation
  • 1995-11-02 MX MX9602541A patent/MX9602541A/es unknown
  • 1995-11-02 BR BR9506434A patent/BR9506434A/pt not_active IP Right Cessation
  • 1995-11-02 CA CA002178740A patent/CA2178740C/en not_active Expired - Fee Related
• 1996
  • 1996-05-01 TW TW085105207A patent/TW305783B/zh active

Patent Citations (3)

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