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
  • B21D17/00—Forming single grooves in sheet metal or tubular or hollow articles
  • B21D17/04—Forming single grooves in sheet metal or tubular or hollow articles by rolling
• • 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
  • B21D53/00—Making other particular articles
  • B21D53/88—Making other particular articles other parts for vehicles, e.g. cowlings, mudguards

Definitions

• the invention relates to a method and a device for notching tubes.
• tube here is meant a hollow body, in particular cylindrical, open or closed, made of metallic material or any other equivalent material.
• notching In many industrial fields, it is necessary to produce notches on hollow tubes, such notching being carried out, for example, for support bars with ratchet for handbrake, racks, or else the support frames. head of motor vehicles.
• the notches of the tubes must have sharp and clean edges to obtain a straightforward adjustment of the height of the headrest and to prevent the headrest from being easily displaced and adjusted when a pressure low is applied, for example by a child.
• Head support frames in the form of a U-shaped tube with notches are described for example in the following documents:
• Document FR-A-2 805 481 describes a method of notching tubes by stamping with a press.
• the method implements a matrix comprising a lower matrix part, an upper right matrix part and an upper left matrix part.
• a groove is provided on the lower die part to receive the notched tube.
• the upper left and right matrix parts are pressed against the notching tube, the matrix obtained having through holes through which punches stamp the tube.
• the invention aims in particular to provide a method ensuring increased productivity, greater regularity of shapes for the notches, the absence of burrs and repetitions of machining, the notches being formed without removal of material and without significant weakening of resistance of the tube.
• the invention relates, according to a first aspect, to a method of notching a tube, this method comprising a movement back and forth from at least one pressure roller, movement during which this roller comes to press locally and plastically deform the wall of the tube, the movement of the pressure roller being formed by the combination of at least two displacements, namely:
• the method comprises a step of controlling a parameter chosen from the group comprising: the bearing force of the pressure roller on the tube, the position of the roller during its contacts with the tube.
• the invention relates, according to a second aspect, to a machine for implementing the method defined above, this machine comprising means for temporarily holding at least one tube in a predetermined position and motorized drive means pressure rollers following their first movement.
• the machine has the following characters, possibly combined:
• It includes means for causing the second movement, called advance movement, of the pressure roller, in a controlled manner, these means comprising means chosen from the group comprising springs, actuators such as jacks;
• It includes means for controlling the movement of the pressure rollers as a function of at least one parameter chosen from the group comprising: the pressure force of the pressure roller on the tube, the position of the roller during its contacts with the tube;
• the servo is of electro-hydraulic type.
• the invention relates, according to a third aspect, to a headrest tube obtained by implementing the method as defined above.
• - Figure 1 is a top view of a notching machine implementing the method of the invention, according to one embodiment;
• - Figure 2 is a side view of the machine of Figure 1, according to arrow II;
• FIG. 3 is a side view of the machine of Figure 1, according to arrow III.
• the following description will be made in relation to the notching of a U-shaped tube of the type used conventionally for the headrest frames.
• the method and the device of the invention also allow the production of notches on other types of tubes, such as for example those used for racks or support bars with ratchet for hand brake.
• a U-shaped tube 1 is held in position by means 2 such as a grooved die in the working volume of a machine 3.
• the tube 1 is introduced into the volume V, by a movement along the arrow F, the two substantially parallel branches 4,5 of the tube 1 extending in the direction Dl.
• This direction D1 will be considered vertical, in the rest of this description. It is understood, however, that this provision is only arbitrarily used, in order to simplify. Indeed, as will be understood by a person skilled in the art, the operation of the machine is in no way conditioned by the arrangement of the direction Dl.
• Maintaining the position of the tube in its receiving grooves can be obtained using means such as clamping jaws, for example.
• the tube is of substantially circular section. It is understood, however, that the method according to the invention can be implemented for tubes of oval or polygonal section.
• the machine 3 is provided with three profiled rollers 6,7,8, mounted in rotation in the direction Dl.
• these three rollers 6,7,8 are mounted on a carriage sliding in the direction D2, this carriage itself being mounted articulated in the direction Dl with respect to the frame of the machine 3, frame on which is maintained the tube 1 to be notched.
• Controlled pressurization means ensure the support of the rollers 6,7,8 on the tube 1 to be notched.
• these means comprise a torsion spring mounted on the axis 10.
• these means comprise a compression spring mounted between a support stop 11 and the sliding frame 12 supporting the rollers 6,7,8, this spring being shown diagrammatically by the reference 13 in FIG. 1.
• This compression spring 13 is, as a variant, combined with the torsion spring mounted on the axis 10 of the carriage 12.
• a single acting cylinder is arranged in place of the spring 13.
• the first and second implementations mentioned above lead to a substantially rectilinear movement of the roller carrier carriage, in the direction D2.
• the carriage 12 roller carrier is controlled, in its rotational movement about the axis of rotation 10, by means such as a double-acting cylinder.
• the actuator rod movements are controlled, as a variant, as a function of the movement of the carriage.
• the actuation of the actuator rod movements is carried out as a function of the stress undergone by the carriage during the passage of a roller on the tube 1, this stress reflecting the plastic deformation force undergone by the material of the tube in the process of notching 1.
• the Applicant has found that the method as just described allows extremely significant gains in productivity, compared to the previously known methods, while ensuring great regularity in the shape of the notches, the material forming the tube does not not being thinned at the bottom of the notch.
• the machine 3 can have one, two or more than two rollers.
• the rollers can be profiled for producing one or more notches on the tube.
• the rollers can be arranged with their axes of rotation substantially parallel, as shown.
• the axes of rotation of the rollers are not aligned, for example for the formation of negative notches.
• the position of the axes of rotation of the rollers is controlled, in one embodiment, to the position or the force of the roller on the notched tube.
• the rollers can be arranged in several substantially parallel rows, so as to make two or more than two notches at the same time.
• the notches in any orientation: internal face of the tube as shown in FIG. 1 of document FR-A-2 805 481, or external face of the tube as shown in document FR-A-2 771 686, or even towards the rear of the headrest as shown in document FR-A- 2 764 850, or towards the front of the headrest as envisaged in document FR-A-2 758 296.
• the method according to the invention allows notching in very short time of headrest framework tubes, of the order of a few seconds.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Shaping Metal By Deep-Drawing, Or The Like (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=8870093

Family Applications (1)

Country Status (8)

Families Citing this family (8)

Family Cites Families (17)

• 2001
  • 2001-12-04 FR FR0115662A patent/FR2832943B1/fr not_active Expired - Fee Related
• 2002
  • 2002-12-04 US US10/497,561 patent/US20050039512A1/en not_active Abandoned
  • 2002-12-04 AU AU2002364417A patent/AU2002364417A1/en not_active Abandoned
  • 2002-12-04 JP JP2003549024A patent/JP2005511307A/ja active Pending
  • 2002-12-04 EP EP02799773A patent/EP1461170A1/fr not_active Withdrawn
  • 2002-12-04 PL PL02368743A patent/PL368743A1/xx not_active Application Discontinuation
  • 2002-12-04 WO PCT/FR2002/004181 patent/WO2003047784A1/fr active Application Filing
  • 2002-12-04 BR BR0214453-0A patent/BR0214453A/pt not_active IP Right Cessation

Non-Patent Citations (1)

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