FR2647390A1 - METHOD AND APPARATUS FOR STITCHING STITCHING OF WORKPIECES FROM BANDED MATERIAL - Google Patents

Abstract

The invention relates to a method and an installation for shaping by stamping, parts made from a pre-cut strip material. The method is characterized in that: - a cutting device 5 is supplied via several strips 1, 1A; - The various strip sections 15, 15A thus cut are brought into a standby position 9, 9A to constitute a buffer stock 6; - One by one, the strip sections 15, 15A are taken from their standby position in order to convey them under a stamping press 8. The invention relates to the mechanical industry in general.

Description

The invention relates to a method and a shaping plant,

  stamping, parts, from a

pre-cut strip material.

  The present invention will find its application in the field of mechanics in general and, in particular, in

building hardware.

  It is common, in many areas, to make parts by stamping, these parts being from a

  web material stored as reels.

  Thus, a reel disposed at the beginning of installation, controls the unwinding of said strip, which is then oriented towards a cut-off unit where it is cut into several sections of determined length depending on the part to achieve. Then these sections of pre-cut strip are brought under a press and

  undergo one or more stamping operations.

  In this regard, it will be specified that when it is necessary to perform several stamping operations on a part, it is common to advance the latter under the same press provided with several dies corresponding to different stamping operations to achieve. Current techniques have made it possible to develop

  presses with a particularly high production rate.

  This poses a number of problems in their diet which, of course, must be performed at an identical rate. Difficulties are, in particular, encountered when the strip materials used are of the metal type. Indeed, under these conditions, it is generally necessary to straighten said strip at the output of the coil so as to obtain, after cutting, substantially straight strip sections. This operation attempts to slow down the unwinding phase of the strip of metal material and, consequently, the feed rate of the press. In addition, it should be taken into consideration that the coils, from which the strip materials are derived, are particularly heavy and have a non-negligible inertia at the beginning of rotation and braking. This is all the more annoying that the unwinding of these coils takes place sequentially

and not continuously.

  In fact, the present invention proposes to remedy this problem posed by the feeding of a press at a rate of

  high production of pieces from a strip material.

  More specifically, the invention relates to a process for forming stamping parts from a pre-cut strip material characterized in that: - is supplied, via a plurality of strips, from separate coils, a cutting device so as to form strip sections of length corresponding to the parts to be produced; the different pre-cut strip sections are brought into a waiting position to form a buffer stock; - One takes one by one the tape sections thus stored and in the waiting position to route them, gradually,

  under the different machining stations of a stamping press.

  The invention also relates to an installation for implementing this method, an installation characterized in that it comprises: first transfer means for bringing one or more pre-cut strip sections from the cutting device into a waiting position at the entrance of a stamping machine; and second transfer means capable of taking one by one, said sections of bands in the waiting position to convey them, progressively, under them.

  different machining stations of said stamping machine.

  The advantages obtained by virtue of the present invention consist, essentially, in that it is possible to feed a stamping press by means of several reels of strip material so that this feed rate, thus multiplied, is in agreement. with the

  production rate of said stamping press.

  Other objects and advantages of the present invention

  will appear in the following description. That-

  However, this only corresponds to one embodiment which

  is given only as an indication and not limiting.

  The understanding of this description will be facilitated by

  Referring to the attached drawings and in which: - Figure 1 is a schematic view of the installation according to the invention - Figure 2 is a schematic and elevational view of an installation for the forming by stamping parts from a strip material, this installation comprising a stamping press and the various transfer means for conveying sections of strip to be shaped from a feed zone to an evacuation zone - FIGS. 3 to 5 are identical views to Figure 2 and illustrating in different positions the constituent elements of the plant during a stamping cycle - Figure 4 is a schematic view from above of the control means actuating the various means of

transfer of the strip sections.

  Reference is made more specifically to FIG.

  The present invention relates to a process for stamping parts from a pre-cut strip material. More precisely, said strip 1, in particular of the metallic type, is stored, initially, in the form of a coil 2. This latter is disposed on a reel which rotates it, preferably, sequentially so as to cause the unwinding of the strip 1. The latter passes, initially, through a rectifier 3 so that, after cutting, the strip sections obtained are substantially straight. Finally, the band 1 is inserted into a threader 4 which ensures engagement, according to a predetermined length corresponding to the length of the parts to be produced, in a device of

cutting 5.

  In fact, and according to a characteristic of the method, object of the present invention, the cutting device 5 is fed via several strips 1, 1A from separate coils 2, 2A so that the rate of this supply can be greatly increased. Indeed, as already mentioned above, it turns out that, because of the material used and its storage in the form of particularly heavy coils, feeding by means of a single strip of a stamping press is largely insufficient to allow the operation of this

  last at a maximum production rate.

  However, in the context of a supply via several bands 1, 1A arises the problem of the transfer, one by one, of the different strip sections 15, 15A from the cutting device 5 to the press.

stamp 8.

  The invention solves the problem by ensuring a buffer stock 6 of these strip portions 15, 15A from the cutting device 5, between the latter and said stamping press 8. It is sufficient, then, to take, one by one, these sections 15, 15A from their standby position 9, 9A, 9B so as to progressively transfer them, from a machining station 11, 11A, 11B, to another under said press

stamp 8.

  The present invention also relates to an installation 14 for carrying out the method as described above. This installation is shown schematically in Figure 1 and in more detail

in the following Figures 2 to 6.

  Thus, as already mentioned above in the

  description, the different bands 1, 1A feed,

  initially, a cutting device 5 so as to constitute sections of strips 15, 15A of defined length

by the final piece to realize.

  Since, this cutting device 5, these strip sections 15, 15A are taken, according to the invention, by first transfer means 16 so as to bring them into a waiting position 9, 9A at the entrance 17 of the stamping press 8. This is, in short, to create a buffer stock 6 at this input 17 of the stamping machine 8 thus allowing a high speed feed of the latter. Preferably, the first transfer means 16 are constituted, for example, by at least two arms 18 extending below the cutting device 5 and having, in their upper edge 19, housings 20, 20A able to accommodate the different sections of strips 15, 15A cut simultaneously. These arms 18 are, moreover, animated by a cyclic movement decomposing into a rise, so as to take, at the level of the cutting device 5, said strip sections 15, 15A, this rise being followed by a horizontal displacement, then a descent to deposit, again, these strip sections 15, 15A in their waiting position 9, 9A. These correspond, for example, to reservations 21, 21A, 21B arranged in a table 22 disposed at the front of the cutting device 5. These arms 18 are then animated by a second horizontal movement so as to find their initial position below the following strip sections 15 ', 15A' of

cutting device 5.

  It will be specified, however, that these arms 18 may be replaced by clamps also executing a cyclic movement to transfer the strip sections 15, 15A from the cutting device 5 to their waiting position 9, 9A. These first transfer means 16 may, again, be constituted by a transfer belt comprising support means for the strip sections 15, 15A and

  presenting a sequential type advance movement.

  According to another characteristic of the invention, the installation 14 further comprises second transfer means 23 capable of taking, one by one, the strip sections 15, 15A, 15B from their waiting position 9, 9A, 9B so as to route them towards the different

  machining stations 11, 11A to 11D under the stamping machine 8.

  In fact, these second transfer means 23 have the function of moving, stepwise, both the strip sections 15A, 15B arranged in the waiting position 9, 9A, 9B and 15C, 15D, 15E, 15F, 15G already present at the various machining stations 11, 11A to 11D under the stamping machine 8

  from entrance 17 of the latter to exit 24.

  Thus, during a stamping cycle corresponding to a rise and a descent of the press, these second transfer means 23 come to take all the strip sections 15, 15A to 15C to advance them. a step 34 so that the band section 15G, disposed initially at the outlet 24 of the stamping machine 8, is ejected from the installation 14 at a discharge ramp 33, while the sections 15B at 15F come to occupy the machining stations 11, 11A to 11D. They also ensure the transfer of the strip sections 15, 15A, from their waiting position 9, 9A to their waiting position.

following respectively 9A, 9B.

  It is clear from the foregoing description that

  the second transfer means 23 only makes it possible to release only one waiting position 9 and, more precisely, that situated as close as possible to the cutting device 5. As a result, an operating cycle of the first transfer means (16 ) generates a number of cycles of the second transfer means (23) equal to the number of strip sections (15, 15A) cut and conveyed simultaneously by said first

transfer means (16).

  Finally, this particular provision of the present invention makes it possible to prevent the feed rate of the stamping press 8 from limiting the rate of production of the latter. These second transfer means 23 may take a configuration identical to the first transfer means 16 described above. Thus, they are constituted, according to a first embodiment of at least two arms 25 extending below all the strip sections 15 A to 15G arranged both on the table 22 and in the stamping press. 8. These arms 25 comprise in their upper edge 26 housing 27, 27A to 27C equal to said strip portions 15, 15A to 15G so that they are able to move all of them a step 34 during a cycle. It decomposes, a rise of the arms 25 so as to take from their initial position the set of sections 15, 15A to 15G, mounted followed by a horizontal movement over a length corresponding to a step 34. These arms 25 then perform a descent to arrange the strip sections 15, 15A to 15G, either in their waiting position, 9A, 9B or under the machining stations 11, 11A to

  11D following, or on an evacuation ramp 33.

  Finally, these arms 25 make a second horizontal displacement so as to return to their original position. It should be noted that this cycle of the second transfer means 23 is controlled by the stamping press 8 so that the rise, followed by the displacement of a step 34 of the different strip sections and the descent of the arms 25 takes place during the phases of ascents and descents of the said

stamping machine 8.

  According to another embodiment, not shown in the various figures, these second transfer means 23 consist of grippers in number equivalent to the different strip sections 15, 15A, 15B in the waiting position and the strip sections 15C to 15G arranged under the machining stations 11, 11A to 11D. These clamps evolve, under these conditions, according to a cyclic movement so as to advance by one step 34 the different sections of the band

  , 15A to 15G at each stamping cycle.

  Moreover, to the aforementioned clamps may be substituted suction cups or any other gripping element likely to move the strip sections in the

conditions set out above.

  In all cases, both the first transfer means 16 and the second transfer means 23 can be actuated via conventional control means 28. Thus, and according to an embodiment shown in FIG. 6, it is possible to use cam shafts 29, 30 arranged below the cutting device 5 and the table 22. These camshafts 29, 30 confer the cyclic movement and according to the desired rate, the arms 18 of the first transfer means 16 or the arms 25 of the second transfer means 23. A motor 31 drives said camshafts 29, 30 through a control system. gear 32 making it possible to vary the

rotation speed.

  As already stated above in the description, the

  operation of the different transfer means 16, 23 is dependent on the frequency of the stamping cycles, a

  part, and the different phases of these cycles on the other hand.

  Also, the operation of said transfer means 16, 23 can be managed, advantageously, through a programmable electronic processing unit. Note that it ensures the drive of the camshafts 29, 30 through separate motors. The operation of the latter is then managed by said programmable processing unit so as to adjust it to the rate of the press or vice versa. Such a provision authorizes, in fact, the individual control of the various transfer means 16, 23 and, ultimately, a better

setting the installation.

  Finally, if it is difficult to accelerate the unwinding speed of a strip, in particular of metal-type material, the present invention makes it possible to solve the problem by allowing the multiplication of the feed of a press. stamping through several bands. This stamping press can thus operate at a maximum production yield of o, stems from

  definitive, a lower cost of production.

  Although the invention has been described with respect to a particular embodiment, it is understood that it is in no way limited and that various modifications of shapes, materials and combinations thereof can be made. various elements, without departing from the framework and

the spirit of the invention.

Claims (10)

claims   1. Method for stamping parts from a pre-cut strip material, characterized in that: - it feeds, via a plurality of strips (1, 1A), from separate coils (2, 2A). , a cutting device (5) so as to constitute strip sections (15, 15A, 15B) of length corresponding to the parts to be produced; the different pre-cut strip portions (15, 15A, B) are brought into a waiting position (9, 9A, 9B) to constitute a buffer stock (6); the strip sections (15, 15A, 15B) thus stored and in the standby position (9, 9A, 9B) for conveying them progressively under the various items   machining (11, 11A to 11D) of a stamping machine (8).   2. Installation for carrying out the method according to claim 1, characterized in that it comprises: - first transfer means (16) for bringing the one or more strip sections (15, 15A) precut from a device cutting device (5) in a waiting position (9,   9A) at the inlet (17) of a stamping machine (8).   - and second transfer means (23) for taking one by one said strip sections (15, 15A) in the waiting position to convey them, progressively, under the various machining stations (11, 11A to 11D) of said press stamping (8).   3. Installation according to claim 2 characterized in that the first transfer means (16) are constituted by at least two arms (18) extending below the cutting device (5) and having, in their upper edge (19), housings (20, 20A) capable of accommodating the different strip sections (15, 15A) cut simultaneously.   he 4. Installation according to claim 3 characterized in that the arms (18) are animated by a cyclic movement decomposing into a rise so as to take said cut strips (15, 15A), followed by a horizontal movement then a descent to deposit the strip sections (15, 15A) in their waiting position (9, 9A), these arms (18) then performing a second displacement   horizontally to return to their original position   below the following strip sections (15 ', 15'A) of cutting device (5).   5. Installation according to claim 2 characterized in that it comprises a table (22) disposed at the front of the cutting device (5) and the inlet (17) of the stamping press (8), this table (22) has reservations (21, 21A, 21B) corresponding to the waiting positions (9, 9A, 9B)   strip sections (15, 15A, 15B).   6. Installation according to claims 2 and 5   characterized in that the second transfer means (23) are constituted by at least two arms (25) extending below all the strip sections (15, 15A to G) arranged on the table (22). ) and under the stamping press (8), these arms (25) having, in their upper edge (26) housing (27, 27A to 27G) equal in number to said sections band (15, 15A to 15G).   7. Installation according to claim 6 characterized in that the arms (25) evolve in a cyclic movement to advance the strip sections (15, 15A to G) over a length corresponding to a step (34), this cyclic movement decomposing into a rise, so as to take, from their initial position, all the strip sections (15, 15A to 15G), followed by a first horizontal movement along the length of a step (34), then a descent to dispose the strip sections (15, 15A to G), either in their waiting position (9A, 9B) or under the following machining stations (11, 11A to 11D), or still on an evacuation ramp (33).   8. Installation according to claim 7 characterized in that the cyclic movement of the arms (25) is controlled by the stamping press (8) so that the rise, followed by the displacement of a step (34) of the different sections band (15, 15A to 15G) and the descent of the arms (25) takes place during the ascending and descending phases of said stamping machine (8).   9. Installation according to claims 4 and 7   characterized in that an operating cycle of the first transfer means (16) generates a cycle number of the second transfer means (23) equal to the number of cut and conveyed belt sections (15, 15A),   simultaneously, by said first transfer means (16).   10. Installation according to claims 3 and 6   characterized in that the arms (18, 25), respectively, of the first transfer means (16) and the second transfer means (23) are actuated by means of control means (28) consisting of cam (29, 30) whose drive is ensured, either by means of a single motor (31) and through a gear system (32) appropriate, or by means of two motors - distinct, the operation of this or these engines being adjusted to the rate of the press using a unit of   programmable electronic processing.