FR2502032A1 - U-SECTION FOLDING MACHINE, ESPECIALLY FOR FRAMES OF AUTOMOTIVE VEHICLE FRAMES - Google Patents

Abstract

THIS MACHINE IS USED TO BEND AN ELONGATED PART 9 A U-SHAPED SECTION AND INCLUDES MOVABLE MEANS 15, 17A, B, 18, 19 DESTINES TO COME IN CONTACT WITH EACH WING IN A ROOM REGION, OR A BEND 20, 21 IS REALISED. OTHER MOVABLE MEANS APPLY BENDING FORCE TO SPACED END PARTS A, B OF THE PART TO FORM THE FOLDINGS, BEING IN CLOSE CONTACT WITH THE FACES OF THE WINGS 13 DURING THEIR MOVEMENT. APPLICATION IN PARTICULAR TO THE BENDING OF MOTOR VEHICLE SPINDLES.

Description

The present invention relates to the folding of pieces formed of

  U, for example in the field of manufacturing vehicle chassis frames or other commercial structures using parts formed from sheet metal or metal plates. It is often necessary to produce, in a U-section, one or more elbows or bends lying in the plane of the wings of the U-shaped section,

  that is to say involving a deformation of the wings

  turn of an axis or axes perpendicular to their planes.

  This involves drawing or compressing the material of the wings in the longitudinal direction of the part, particularly in the parts of the wing which

  will form the parts of maximum radius of the elbow

  born. The specifications of the metal used may vary so that the behavior of the material is, to some extent, unpredictable. These problems led to difficulties in folding

  U-shaped profiles, satisfactory from the point of view of

  in the finished state and the maintenance of

  patible. In particular the folding resulted in

  the appearance of undulations or folds, little

  theories and eventually leading to a weakening

  areas of the wings in the regions of the elbows or elbows.

  The object of the present invention is to provide

  a process and a machine for folding

  these in the form of U-shaped profiles, which allow a com-

  precise process of folding and obtaining improved and stable results, providing a finished piece with a clean and uniform appearance and

  having precise dimensions.

  According to the invention, there is provided a machine for folding an elongate piece having two planar wings, parallel and spaced, extending perpendicularly from a planar core of

  to form a U-shaped section, said machine

  carrying conjugate assemblies which are shaped and movable to engage tightly with the inner and outer faces of each wing at least in a region of the room, wherein folding is to be performed, said assemblies being hinged to

  allow the movement of at least a first

  relative to a second section so as to apply a folding force, acting in the planes

  wings, to parts of the room, spaced longitudinally

  tudinalement, in order to cause their relative displacement so as to form at least one fold, said

  tight contact of the faces of the wings being maintained

  said displacement to ensure that the wings

  killed in said region of the room remain flat.

  The present invention furthermore relates to a method of forming one or more bends or bends, in a piece consisting of a U-shaped profile, implementing the operating phases of the method applied by the machine defined above, and a part worked, that is, bent or bent,

  performed using said machine and / or said

  yielded. The operation can be simple, that is to say

  provide a single fold so that a first par-

  part of the piece is bent at an angle

  port to a second part or it can be multiple, that is to say provide several folds so that a first part is folded or laterally offset from one or more other parts, so as to have a crank shape or omega flattened, the shift being in a

  plane parallel to one or more of the other parts.

  So to constitute a fit piece

  flattened crank with a straight straight section

  the part laterally offset from the two end parts, which are aligned one with the other, four folds (two pairs

  opposite directions) are needed and the machine

  can not be adapted to form all of these folds in a single operating phase while maintaining the planar wings in all

folded regions.

  The machine may further comprise

  yens making it possible to fold in excess of

  to allow elastic return of parts of the material once the part is released after folding. Hereinafter will be described more particularly,

  in a non-limiting way, an embodiment practically

  the invention with reference to the accompanying drawings, in which: FIG. 1 is a top view in section of active parts of a folding press at the beginning of an operating cycle; FIG. 2 is a similar view of the press,

  in which the active parts are in their posi-

  work during the folding process; - Fig.3 shows the diagram of a folded part; Fig. 4 is a section taken along the line 4-4 of Fig. 1; and - Fig.5 is a section taken according to the

line of Figure 2.

  The example of the invention, which we will now

  describing, concerns the forming of

  chassis frames of vehicles, during which the

  said longitudinal members are made by folding from a sheet or metal plate of substantial thickness in the form of a U-shaped cross-section profile, having two spaced parallel wings, which are

  horizontally in the assembled chassis and a vertically

  tical arranged between the wings and perpendicular

to these.

  In the present example, it is necessary to work the part 9, in order to bring it to the shape represented diagrammatically by the solid lines of FIG. 3, so that it has the shape

  crank or omega flattened

  rectilinear intermediate A being offset laterally with respect to the straight end portions B.

  Firstly, a U-shaped profile is

  line using conventional methods, then we fold this profile to bring it to its final form using the process and the machine that we go

now describe.

  With reference to FIGS. 1 and 2, the machine is mounted on a horizontal hydraulic press

  standard of 400 tonnes with a main piston

  pal 10 carrying a head 11 which cooperates with a pla-

fixed water 12 of the press.

  As can be seen more clearly in FIGS. 1 and 4, the central portion of the plate 12 has spaced and parallel upper and lower guide blocks 13 defining an open channel towards the

  head 11 and extending in the transverse direction

  dirty of the press, said channel having a width which is closely matched to the distance between the

  outer faces of the wings of the spar 9.

  In the opposite ends of the channel are fixed respective buffers 14, whose outer faces are convex in a plane extending

  along the longitudinal direction of the canal.

  Between the buffers 14, the bottom of the channel is hollowed out so as to contain a longitudinal member

  mobile counterpressure 15, which can be selected

  tively, advanced or retracted by means of a piston

  hydraulic counter-pressure 16 located in the

water 12.

  The parts of the plateau 12, which are located

  laterally beyond the guide blocks 13, comprising

  each a respective hydraulic piston 17a

  reading an excess bending and whose heads can be advanced or retracted in synchronism with corresponding pistons 17b carried by the head 11 of the

main piston.

  The head 11 has a central projecting portion

  trale 18 which extends longitudinally and has a flat front face, the length of which corresponds to the length of the back pressure member 15 and which

  ends with curved end faces.

  The projecting portion 18 enters the channel between the members 13 when the head 11 moves forward; and the vertical dimension of the protrusion is such that there is a tight fit between the wings

of the spar 9.

  Likewise, the head 11 of the main piston

  carries two positioning pistons 19 whose heads

  These can be selectively advanced or retracted relative to the head 11 while cooperating with the pads 14 of the plate 12, these heads being also adapted to fit exactly between the wings of the

spar 9.

  Active parts of the piston heads 19

  extend beyond flanges l9a vertical salient-

  (see Figure 5), which come into abutment

  the outer faces of the members 13 so as to define

  a fixed clearance between the end face of the head of a piston and the face of the corresponding buffer 14, said clearance being closely adapted to the thickness of the

the spar 9 core

  The operation of the press is as follows.

  A rectilinear part (which may have a uniform or non-uniform section along its length, for example the height and / or spacing of the wings may vary along the part or in parts thereof) is arranged in the channel between the members 13, in the position indicated by

  dotted in Figure 1, the counter organ

  pressure 15 being advanced and aligned with the end generators, curved faces of the pads 14

  so that the soul is in support against these.

  The head 11 of the main piston is advanced

  so that the projecting portion 18 engages between the wings until it squeezes a central portion of the core against the counter-pressure member, a counter-pressure being applied to the piston 16 so that this counter-pressure organ greenhouse

  this part of the soul closely and

  not flat while the head 11 continues its movement in advance.

  Simultaneously, the active parts of the head

  Positioning pistons 19 also engage

  between the wings, the pistons being placed under

  so that the flanges 19a are held in abutment against the outer surfaces of the organs

  guide 13, as indicated above. This is now

  holds wings and soul in alignment, but allows end portions B to slide longitudinally along the length necessary to accommodate the shorter overall length required to form a shape

cranked flattened.

  In this position (as represented in FIG. 2), the central part of the part, which must be subjected to double folding, and in particular its

  wings are held tightly in all directions.

  by the combined faces of the plateau sets

  and the head of the main piston, including

  13, the projecting portion 18 and the heads of the pistons 19, so that none of its elements can be moved up or down from their parallel general planes. The piece is thus

  maintained during the movement of the piston head 11

  your main so as to obtain the displacement of the central region of the spar 9 laterally opposite the back pressure exerted by the member 15, and this on the distance required to create the double

  folding, so that it can not occur or

  or pleating of the spar wings, in the

  four elbows needed to obtain this form.

  It is possible to adjust at will

  of moving the center section so

  to allow a "springback" so that, when

  the room is clear of the press, the final shape

  it is within the required tolerances, even if the

  properties of the metal, in particular its elastic limit

ticity, may vary.

  The folding process described above tends to stress the metal in such a way that, when released from the press, the outer end portions B spring back to the positions indicated by B dotted lines on

Figure 5.

  An automatic correction of this phenomenon is provided thanks to a selective actuation of the pistons

  excess bending 17a, 17b which apply or maintain

  pressure on parts B during operation.

  of the press so as to flex them sufficiently to compensate for this "springback" effect,

  namely to move them to the position re-

  presented by the dotted line B2 or else

  to compensate for any excessive correction applied.

  The implementation of the invention provides a chassis spar or any other member formed of a U-shaped profile crank or omega flattened,

  with extremely tight and stable tolerances

  as well as resistance and a long service life.

  and a good appearance. In particular, the fact of

  the appearance of undulations or folds in the wings at the level of the elbows

  considerably the appearance, makes it easier to

  later, since flat top and bottom faces are retained for mounting

  other parts, etc., and can improve the relationship between

  gidity and flexural strength of the finished part.

  Holding the wings in the manner described above, particularly in the folding regions, ensures that the displacement of the wing material, which must occur during the formation of the elbows, can only be effected in the direction of travel. outside or inwards with respect to the core, that is to say that in the case of the rear bends identified at 20 in FIG. 3, the core forms the face of minimum radius of the

  elbow and that the wing should be slightly stretched long

  in particular, the present invention ensures that its width is correspondingly reduced by one

  gradual uniform manner without substantial change

  the external aspect to the finite state. In the front elbow identified by reference 21, for which the soul has a zone of maximum radius and at the level of

  the wing must be compressed and is therefore sus-

  it is possible to form corrugations or folds in the case of the use of known methods, the implementation of the present invention ensures that

  the metal is moved laterally so that

  widens slightly in a uniform gradual manner

  in this region, but still really plan.

  The present invention can be applied to other processes of folding or possibly straightening implemented on U-shaped profiles in the case where elbows, crank or omega-flattened shapes, single or double folds must be provided in the plans of the wings. Thus, for some applications only, it may be necessary to use only one locating piston and the corresponding pad, the protruding part 18 or its equivalent and its associated counterpressure device operating in such a way as to form a simple elbow. , the conformation of these elements corresponding to the degree of curvature and the required angles in the piece

  over. For some applications, it may be

  tile to provide compensation for "springback" and we can do without the pistons 17a, 17b realizing

an excess bend.

  It will also be appreciated that the present invention could be based on other forms of presses or

  folding tools, and use for example

  its verticals and / or screw presses.

Claims (2)

CLAIMS -   1.- machine for folding an elongate piece (9) comprising two spaced parallel parallel planar wings (13) extending perpendicularly   from a flat soul so as to form a profi   U-shaped, characterized in that it comprises displaceable means (15, 17a, b, 18, 19) shaped so as to come into close contact with the inner and outer faces of each wing (13) at least in one region of the elongated piece (9), wherein a folding (20, 21) is to be performed, said displaceable means (15,   17a, b, 18,19) being arranged to allow the displacement   at least a first section (17b, 18,19) relative to a second section (15,17a) so as to apply a folding force, acting in the planes   wings (13) to parts (A, B) of the allon-   (9), spaced longitudinally, with a view to provoking   their relative displacement to form at least one fold (20,21), said displaceable means being in close contact with the faces of the wings (13) during said movement, which allows the wings located in   said region of the room to remain flat.   2. Machine according to claim 1, characterized   characterized in that said first portion (A) of the elongate member is bent at an angle relative to a second portion (B) of said workpiece, forming more than one fold (20,21), resulting in a shift   of a first part (A) in relation to another part   part (B) of the elongate piece (9), said offset is   killing in a plane parallel to at least one of the others parts of the room.