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
  • B21D39/02—Application of procedures in order to connect objects or parts, e.g. coating with sheet metal otherwise than by plating; Tube expanders of sheet metal by folding, e.g. connecting edges of a sheet to form a cylinder
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/53—Means to assemble or disassemble
  • Y10T29/53709—Overedge assembling means
  • Y10T29/53787—Binding or covering
  • Y10T29/53791—Edge binding

Definitions

• the invention relates to crimping tools and more particularly to the pre-crimping blade fitted to said tools.
• the crimping includes a matrix on which is placed the sheet (s) to be crimped, a pre-crimping blade and a crimping blade which come to press successively on the edge of the sheet to raise and fold it.
• the flat crimp is a crimp where the piece to be crimped is folded flat.
• Crimping with a drop of water is advantageous for strengthening the edge of the part, by creating a tube shape with high inertia. It allows you to make parts, such as the front or rear of car hoods whose profile is visible to the driver. The hoods must in fact be as less aggressive as possible in the event of an accident.
• Blade profiles at 45 ° and radius blade profiles are known, but these types of blades do not allow perfect control of the crimping and present a risk of lifting the sheet metal from the die. This phenomenon generates a double line defect, if the elastic limit is exceeded, which is unsightly.
• the object of the present invention is to provide a pre-crimping blade which makes it possible to perform a pre-crimping with sheets forming a larger opening angle, beyond 107 °, and to control the folding radius of the sheet during the pre-crimping phase.
• the pre-crimping blade according to the invention has a profile such that the angle of attack ⁇ of the sheet to be crimped remains constant throughout the pre-crimping phase. Thus the force applied to the sheet always has the same angle with the sheet.
• the profile of the blade according to the invention is calculated by the following formula (1):
• - e is the thickness of the sheet to be crimped.
• ⁇ n are the different angle values taken by the edge of the sheet between the start of pre-crimping and the end of crimping, ie between 0 and the angle of sheet opening thus for example ⁇ / 2 if the sheet is opened at 90 °. If ⁇ , the value of the opening angle of the departure, is greater than 90 °, ⁇ n will vary between ⁇ / 2- ⁇ and ⁇ .
• - ⁇ is the angle of attack of the sheet, ie the angle formed by the edge of the sheet and the tangent to the crimping blade at the point of contact of the latter with the outside edge of the sheet.
• - L the height of the edge to be crimped.
• the angle ⁇ is between 40 ° and 60 °. In this range of values, the force applied to the sheet allows better reversal of the latter.
• the angle ⁇ is approximately 53 °. This angle is the optimum angle which makes it possible to bend the sheet without lifting it from the matrix.
• the blade bears on the outside point of the edge of the sheet. The result of the forces generated by the blade is concentrated towards the outside of the piece to be crimped, thus limiting plastic deformation.
• the pre-crimping is carried out on a sheet forming an angle open to more than 107 °.
• the difficulty lies in the fact that it is difficult to pre-crimp sheets forming an angle of more than 90 °, the blade according to the invention allows pre-crimping on sheets which form an angle open to more than 107 °.
• the pre-crimping is carried out on an aluminum sheet.
• Aluminum is a more flexible material than sheet metal and therefore more prone to a double line defect.
• FIG. 1 is a side view of the blade according to the invention
• FIG. 2 is a diagram showing the development of the trajectory of the edge of the sheet.
• the pre-crimping blade 1 and the die 2 constitute the crimper.
• the crimping sheet 3 as a body skin is placed on the die 2, a second sheet 4 as a lining can be placed on the crimping sheet 3.
• the pre-crimping blade 1 makes a downward movement to approach the die 2 and bend the sheet 3.
• the outer edge 30 of the sheet 3 is in contact with the profile 10 of the blade 1.
• the edge 30 slides over the profile 10 along a path 32 which performs the bending of sheet metal 3.
• the profile 10 blade 1 is remarkable in that the plane 34 of the edge 30 always has an angle ⁇ with the tangent to the profile 10 of the blade 1 whatever the position of the edge 30 relative to the blade 1.
• the angle ⁇ of the sheet 3 at the start is greater than 90 °, but it can also be greater than 107 ° up to approximately 120 °.
• the crimping sheet 3 is parallel to the die 2 and the crimping will be carried out by a crimping blade which will bring the sheet 3 into contact with the sheet 4 as can be seen in dotted lines in FIG. 1 .
• FIG. 2 details the different parameters of the path of the edge 30 of the sheet 3.
• the trajectory of the latter depends on the height of the edge to be crimped L, on a center of rotation O and on the radius of curvature ⁇ which we wish to obtain .
• the profile 10 of the blade 1 is calculated by choosing the angle of attack ⁇ relative to the neutral fiber 33 or to the edge 30 according to the formula (1) given above.
• This angle of attack ⁇ is preferably chosen to be around 53 °.
• the path of the blade 1 is rectilinear perpendicular to the matrix and the resultant of the forces generated by the latter is concentrated towards the outside of the piece to be crimped 3 thus limiting plastic deformations.
• the profile of the blade thus defined makes it possible to pre-crimp doors, hoods, shutters, steel or aluminum as well, while simplifying the edge tipping operations.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Shaping Of Tube Ends By Bending Or Straightening (AREA)
• Folding Of Thin Sheet-Like Materials, Special Discharging Devices, And Others (AREA)
• Shaping Metal By Deep-Drawing, Or The Like (AREA)
• Polishing Bodies And Polishing Tools (AREA)
• Manufacturing Of Electrical Connectors (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=28459840

Family Applications (1)

Country Status (6)

Families Citing this family (1)

Family Cites Families (10)

• 2002
  • 2002-04-15 FR FR0204686A patent/FR2838359B1/fr not_active Expired - Fee Related
• 2003
  • 2003-04-14 WO PCT/FR2003/001187 patent/WO2003086678A1/fr not_active Ceased
  • 2003-04-14 BR BR0304822-5A patent/BR0304822A/pt not_active Application Discontinuation
  • 2003-04-14 US US10/496,113 patent/US7124612B2/en not_active Expired - Fee Related
  • 2003-04-14 EP EP03740608A patent/EP1494826A1/de not_active Withdrawn
  • 2003-04-14 JP JP2003583677A patent/JP2006512208A/ja active Pending

Non-Patent Citations (1)

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