EP1232811B1 - Workpiece-supporting device for a bending machine - Google Patents

Description

The present invention relates to a sheet metal follower for a press brake having a lower stationary table carrying on its upper face a folding die, an attendant of the type comprising
an accompanying table pivotable by its front end about a horizontal axis of pivoting,
a lateral transfer trolley mounted on the front wall of the lower fixed table so as to be able to move horizontally along this front wall,
a vertical support wall secured to the transfer carriage and provided with vertical slides and at least one vertical ball screw capable of being rotated from its lower end,
a support structure having a vertical face plate and two lateral vertical plates extending in a direction opposite to the lower press table,
vertical guide rails integral with the front plate of the support structure and each cooperating with a corresponding slide of the support wall of the carriage, and a drive mechanism for vertically moving the front plate of the support structure,
an accompanying table hinged to the support structure about a horizontal axis parallel to the folding die, and
means carried by said support structure capable of rotating said accompanying table about its axis.

An attendant of this type is known by the patent JP 10 31 526 . Abstraction of its complicated structure due to two support structures nested one inside the other and articulated around the same horizontal pivot axis for the accompanying table, this axis is too far from the folding die to be able to ensure the accompanying table a pivoting movement having always centered the bottom of the matrix.

In addition, the combined use of gears, jacks and levers requires precision assembly which is difficult to achieve and maintain during service.

The present invention aims to eliminate or at least mitigate the disadvantages associated with the prior art and to provide a sheet attendant of the type mentioned above which allows a quick and accurate positioning, and in which the axis of articulation of the accompanying table is very close to the folding die.

This object is achieved because, at the upper end of each of the vertical side plates of the support structure, are provided
a pair of bearings spaced from each other and whose horizontal axes are aligned with each other and perpendicular to the vertical faceplate of said structure,
two depth adjustment columns, each of which is slidably housed in a corresponding pair of bearings,
a transverse vertical arm rigidly connecting the front ends of the two adjustment columns, and secured to the upper face raised relative to the upper end of the lateral plates of the support structure, support fingers whose front ends each comprise a bearing for the horizontal axis of pivoting of the accompanying table which, by its central and rear parts, covers the support structure and the organs which are integral therewith,
a rectilinear guide member provided in the central part of the accompanying table below the upper plane wall thereof and extending in the vertical median plane of the table perpendicular to the axis of pivoting thereof,
a hinge clevis slidable on the rectilinear guide member and carrying a horizontal axis parallel to the pivot axis,
an endless ball screw whose upper head is articulated on the yoke via a link axis parallel to the pivot axis of the accompanying table,
a pivoting cage fixed on either side of one of the vertical plates of the support structure so as to be pivotable about a horizontal axis parallel to the pivot axis of the accompanying table and disposed near the upper end of said structure,
a nut cooperating with the worm ball and fixed to the cage in axial displacement but rotatable relative to the latter, and a motor secured to the cage and whose output shaft is parallel to the worm at balls and rotates said screw nut by means of a toothed belt

In other words, the sheet metal attendant therefore comprises a companion table which is associated with means enabling it to execute three rectilinear movements perpendicular to each other and a pivoting movement about its front axis parallel to the extent the largest of the folding die, these means comprising a horizontal transfer means parallel to the front wall of the fixed lower table of the press brake and the largest extent of the folding die, a vertical displacement means carried by the transfer means, and secured to a supporting structure of the accompanying table, a means of horizontal displacement of the accompanying table relative to its support structure and perpendicular to the pivot axis of said accompanying table as well as means for pivoting said table about its pivot axis, said pivoting means being variable in length between its articulation on the support structure and its articulation on the accompanying table, the latter articulation being slidable along the accompanying table in a direction perpendicular to the pivot axis of said table.

With this design, the positioning of the accompanying table with respect to the folding die can be performed quickly and accurately while avoiding items requiring complicated and expensive manufacturing.

• la figure 1 montre une coupe verticale de l'accompagnateur de tôles suivant la ligne I-I de la figure 3, en position de repos de la table accompagnatrice, associé à la table inférieure fixe d'une presse plieuse ;
• la figure 2 montre une coupe verticale de l'accompagnateur de tôles suivant la ligne I-I de la figure 3, la table accompagnatrice occupant une position fortement inclinée par rapport à l'horizontale au voisinage et au-dessus de la matrice de pliage ;
• la figure 3 est une vue en plan suivant la flèche III de la figure 1 d'une partie de l'accompagnateur de tôle, la table accompagnatrice pivotable y étant indiquée en pointillé pour rendre visible les éléments montés sur la structure de support ;
• la figure 4 est une vue en coupe verticale suivant la ligne IV-IV de la figure 3 et montrant la fixation de l'extrémité frontale de la table accompagnatrice sur un bloc de liaison solidaire de l'axe de pivotement de ladite table ;
• la figure 5 est une vue en plan d'une coupe suivant la ligne brisée V-V des figures 1 et 6 montrant les éléments pour le transfert horizontal et le déplacement vertical de la structure de support et des éléments montés sur celle-ci, et
• la figure 6 est une vue agrandie en élévation d'un détail délimité par le cercle VI de la figure 1.

The object of the present invention will be better understood with the aid of the following nonlimiting description of an embodiment of the sheet metal guide, a description referring to the appended drawing in which:

• the figure 1 shows a vertical section of the sheet metal guide along the line II of the figure 3 , in the rest position of the accompanying table, associated with the fixed lower table of a press brake;
• the figure 2 shows a vertical section of the sheet metal guide along the line II of the figure 3 , the accompanying table occupying a position strongly inclined relative to the horizontal in the vicinity and above the folding die;
• the figure 3 is a plan view along arrow III of the figure 1 a part of the accompanying sheet metal, the pivotable accompanying table being indicated dashed to make visible the elements mounted on the support structure;
• the figure 4 is a vertical sectional view along line IV-IV of the figure 3 and showing the fixing of the front end of the accompanying table on a connecting block integral with the pivot axis of said table;
• the figure 5 is a plan view of a section along the broken VV line of Figures 1 and 6 showing the elements for horizontal transfer and vertical displacement of the support structure and elements mounted thereon, and
• the figure 6 is an enlarged view in elevation of a detail delimited by the circle VI of the figure 1 .

As can be seen in the accompanying drawing, and more particularly on the figures 1 and 2 , the sheet attendant 1 is mounted on a vertical front wall 2 of a lower table 3 of a non-press brake shown in more detail. At its upper end, the lower table 3 carries a folding matrix 4 whose upwardly open groove is parallel to the front wall 2.

The accompanying sheet metal 1 has at its upper end, an accompanying table 5 capable of moving rectilinearly along the axes x, Y, z and pivot about an axis 6 which is horizontal and parallel to the vertical wall 2 and to the folding matrix 4, and which is provided at the front end 7 of the accompanying table 5, this front end 7 being close to said folding die 4.

The accompanying table 5 is therefore associated with means 8, 9, 10 and 11 enabling it to execute the three rectilinear movements perpendicular to each other in the directions x, Y, z and a pivoting around the horizontal axis 6 cooperating with the front end 7 of said companion table 5.

The first (8) of these means 8, 9, 10 and 11 is a horizontal and parallel transfer means to the vertical wall 2 of the lower table 3 of the press brake and to the folding die 4. This first means 8 comprises a transfer trolley 12 mounted on the front wall 2 so as to be able to move horizontally along this wall 2. This first means 8 also comprises a guide 13 whose vertical section has the shape of a lying u whose bottom 13a is integral with the front vertical wall 2 of the table 3 and whose lateral branches 13b, 13c comprise either a guide column 14 (see upper branch 13b) or a guide groove 15 (see lower branch 13c of the section in FIG. shape of a lying u). The transfer carriage 12 comprises two lateral transfer bearings 16a, 16b, for example with ball bearings, each of which surrounds the guide column 14 with the exception of the rectilinear fixing zone 17, for example by welding, of this column 14. on the rib of the upper branch 13b of the guide 13. The transfer carriage 12 has, in addition, a guide rib 18 which engages in the groove 15 of the lower branch 13c of the guide 13. The bearings 16a, 16b and the guide rib 18 are integral with a vertical support wall 20 which is an integral part of the lateral transfer carriage 12.

The second means is a vertical displacement means 9 which comprises at least two vertical slides 21, 22 secured to the vertical support wall 20 of the transfer carriage 12 and provided on the opposite side to the lateral transfer bearings 16a, 16b and the less a vertical ball screw 23 which is for example arranged along the vertical median plane of the vertical support wall and midway of the vertical slideways 21, 22. This vertical screw 23 is integral with the support wall 20 in axial displacement. but is rotatable relative to the latter and cooperates, at its lower end with a not shown rotary motor whose housing is fixed on the lower edge of said support wall 20.

The vertical displacement means 9 further comprises a support structure 25 having a vertical front plate 25a whose face facing the support wall 20 of the carriage 12 has two vertical guide rails 26, 27 of T-section s'. each engaging in a corresponding vertical slide 21, 22 whose groove also has a T-section for retaining in vertical position said rail 26, 27 and said front plate 25a. A ball nut 19 cooperating with the vertical ball screw 23 is also part of the displacement means 9, said nut being immobile in rotation and secured to the lower part of the support structure 25 and in particular the front plate 25a thereof. this. As can be seen more particularly on Figures 1 to 3 and 5, the support structure 25 also comprises two lateral vertical plates 25b, 25c parallel to each other and perpendicular to the vertical support wall 20 and to the vertical front plate 25a to which they are rigidly fixed. It will also be noted that the upper part of the side plates 25b, 25c protrude upwardly from the upper edge of the front plate 25a and is slightly recessed therefrom in order to free up space for an element of the third moving means. rectilinear which will be discussed later.

The third means of rectilinear displacement of the accompanying table 5 is a moving means 10 allowing it to make a horizontal movement relative to the support structure 25 and perpendicular to the vertical plane of the front plate 25a thereof. This horizontal displacement means 10 comprises, at the upper part and on the outer face of each vertical plate 25b, 25c of the support structure 25, a pair 28, 29 of bearings whose bearings 28a, 28b; 29a, 29b are of identical inner diameters and spaced from each other and whose horizontal axes are aligned with one another and perpendicular to the vertical plane of the front plate 25a of said structure 25. This means 10 present , in addition, for each of the two pairs of bearings 28, 29, a depth adjustment column 30a, 30b slidably housed in a corresponding pair of bearings 28 or 29 and a transverse arm 31 rigidly connecting the front ends of the two adjustment columns 30a, 30b, this arm 31 being disposed above the front plate 25a and in front of the vertical end edges of the recessed portion of the side plates 25b and 25c. Also part of the horizontal displacement means 10, two lateral support fingers 32a, 32b fixed by their rear ends on the upper face 31a of the transverse arm 31, the upper face 31a of the latter being raised relative to the upper edges of the side plates 25b, 25c. The front end of each support pin 32a, 32b comprises a bearing 33a, 33b each receiving an end portion of the pivot axis 6 secured to the front end of the accompanying table 5 by two fixing blocks 35a and 35b traversed without play by the pivot axis 6 and fixed, on the one hand, on the front end of said table 5 and, on the other hand, on the axis 6 by locking screws 36.

The accompanying table 5 comprises a flat top plate 5a bordered on its periphery, preferably of rectangular shape, by side plates 5b, front 5c and rear 5d together forming a kind of skirt of low height. Below the upper plate 5a, and in particular in its longitudinal zone and mid-distance plates 5b are provided several holding magnets 37a, 37b for a bending sheet 34 one of which (37a) is located near the hinge axis 6 and the other (37b) to the rear portion of the accompanying table 5. It should be noted that in the horizontal position, the flat upper plate 5a of the accompanying table 5 rests on the support fingers 32a, 32b and is retained against any rearward tilting by the pivot axis 6 housed in the bearings 33a, 33b of said support fingers 32a, 32b.

To advance or retreat horizontally the accompanying table, it acts on the depth adjustment columns 30a, 30b, either manually or with the aid of a drive mechanism, such as a not shown rack drive, the rack itself which can be incorporated in a portion of each column 30a, 30b. As soon as the chosen horizontal position of the front end of the accompanying table 5 with respect to the matrix 4 is established, said table 5 is locked in this position by immobilizing the columns 30a, 30b with respect to the support structure 25.

The pivoting means 11 of the accompanying table 5 comprises a hinge member 38 slidable along a guide rod 39 provided in the central part and under the upper plate 5a of the table 5 and more precisely said, in the vertical median plane perpendicular to this upper plate 5a and to the pivot axis 6, this guide rod 39 extending rearwardly from the transverse arm 31 over at least one third of the length of the table 5 and being fixed at its ends in housing blocks 40a, 40b secured to said table 5.

The hinge member 38 comprises, on the one hand, a hinge yoke 38a mounted astride the guide rod 39 which constitutes a rectilinear guiding member for said yoke 38a, and, on the other hand, a piece connecting link 38b partially engaging in the yoke 38a and connected thereto by a horizontal axis 38c so as to be pivotable relative to said yoke 38a without hindering the sliding thereof on the guide rod 39.

The pivoting means 11 also comprises an endless ball screw 40 which cooperates with a ball nut 41 mounted to pivot on the upper part of the support structure 25 between the side plates 25b, 25c thereof, so as to able to pivot about a horizontal axis parallel to the axis 38c of the yoke 38a and to the pivot axis 6 of the accompanying table 5. The upper end of the worm 40 is secured to the connecting piece 38b which thus constitutes a screw head. Note that in horizontal position of the accompanying table 5, the worm 40 occupies a vertical position and that the axis 38c of the articulation member 38 and the pivot axis of the nut 41 cooperating with the worm 40 are located in the same vertical plane and said nut 41 surrounds in this position the upper part of the worm 40. It is thus easily understood that the pivoting means 11 is of variable active length between its fixed hinge on the support structure 25 and its movable articulation (articulation member 38) on the accompanying table 5, this movable articulation being capable of sliding along the table 5 in a direction perpendicular to the pivot axis 6 of said table 5 .

The ball nut 41 is partially housed in a pivoting cage 42 fixed on either side on one of the two side plates 25b, 25c of the support structure by means of two partially threaded horizontal joint bolts 43 , 44 which are aligned with each other and have a smooth portion through the wall of the cage 42 and constituting the horizontal axis of pivoting of the ball nut 41. The structure of a ball nut and d Since an endless ball screw is widely known, it does not seem necessary to describe it here in detail.

Note that part of the cylindrical periphery of the nut 41 cooperates with a rolling bearing 45 disposed in the pivoting cage 42 and that the enlarged upper end of the nut 41 is integral with a drive pulley 46 traversed with lateral clearance by the worm 40, this drive pulley 46 being connected by an endless belt 47 for example notched with a pulley 48 integral with the shaft of a drive motor 49 whose housing is fixed on the pivoting cage 42.

It is self-evident that the embodiment described above is given only as an example and can undergo a number of modifications without going beyond the protective framework, such as defined by the appended claims. Thus, for example, the yoke 38a of the articulation member 38, instead of being mounted astride the guide rod 39 (see figure 1 ), could as well constitute the head of the worm 40, so that the connecting piece 38b should be shaped to slide on the rod 39 while partially engaging in the yoke 38a (see figure 2 ).

Claims (9)

1. A sheet metal follower for a bending press presenting a fixed bottom table (3) carrying a bending matrix (4) on its top face, the follower being of the type comprising

   - a follower table (5) capable of pivoting at its front end about a horizontal pivot shaft (6);

   - lateral transfer means (8) mounted on a vertical front wall (2) of the bottom table (3) so as to be capable of moving horizontally along said front wall (2);

   - vertical displacement means (9) carried by the lateral transfer means (8), being vertically movable relative thereto and secured to a support structure (25) for the follower table (5) and for its horizontal pivot shaft (6); and

   - pivot means (7) for pivoting the follower table (5) about its pivot shaft (6);
   the follower being characterised in that it further comprises:

   - horizontal displacement means (10) suitable for moving the follower table (5) horizontally relative to the support structure (25) thereof and perpendicularly to the pivot shaft (6);

   - in that the active length of the pivot means (1) between its fixed hinge (43, 44) on the support structure (25) and its moving hinge (38) on the follower table (5) is variable; and

   - in that the moving hinge (38) is capable of sliding along said table (5) in a direction perpendicular to the pivot shaft (6) of said table (5).
2. A sheet metal follower according to claim 1, characterised in that
   the horizontal displacement means (10) for moving the follower table (5) comprises:

   - at the top ends and at the outside faces of each of the lateral plates (25b, 25c) of the support structure (25), a respective pair of bearings (28, 29) with the bearings (28a, 28b; 29a, 29b) in each pair being spaced apart from each other and being in alignment with each other on a respective horizontal axis perpendicular to the vertical front plate (25a) of the support structure;

   - two depth-adjustment columns (30a, 30b) each slidably received in a corresponding pair of bearings (28, 29);

   - a transverse vertical arm (31) rigidly interconnecting the front ends of the two adjustment columns (30a, 30b); and

   - lateral support fingers (32a, 32b) having their rear ends fixed to the top face (31a) of the transverse arm (31) and carrying at each front end a respective bearing (33a, 33b) receiving a corresponding end of the pivot shaft (6) of the follower table (5).
3. A sheet metal follower according to claim 1, characterised in that the top portions of the lateral plates (25b, 25c) of the support structure (25) project upwards above the top edge of the front plate (25a) thereof and are set back a little relative to said edge, and in that the transverse arm (31) is disposed above the front face (25a) and in front of the vertical front edges of the set back portions of the lateral plates (25b, 25c) of the support structure (25).
4. A sheet metal follower according to claim 1 or claim 2, characterised in that the front end of the follower table (5) is secured to its pivot shaft (6) via two fixing blocks (35a, 35b) having said shaft (6) passing therethrough snugly, and fixed firstly to the front end of the table (5) and secondly to the shaft (6) by block screws (36).
5. A sheet metal follower according to one of claims 1, 2, and 4, characterised in that the follower table (5) covers the support structure (25) and the members which are secured thereto, and in that it comprises a plane top plate (5a) surrounded around its rectangular outline by side plates (5b), a front plate (5c), and a rear plate (5d), together forming a kind of shallow skirt.
6. A sheet metal follower according to one of claims 1, 2, 4, and 5, characterised in that, when in the horizontal position, the follower table (5) rests via its plane top plate (5a) on the support fingers (32a, 32b) and is held against any rearward tilting by the pivot shaft (6) received in the bearings (33a, 33b) of said fingers (32a, 32b).
7. A sheet metal follower according to claim 1, characterised in that the moving hinge (38) of the pivot means (11) comprises firstly a hinge fork (38a) mounted astride a guide rod (39) provided in the central portion beneath the top plate (5a) of the follower table (5), and secondly a connection piece (38b) engaged partially in the fork (38a) and connected connected thereto by a horizontal pin (38c) so as to be capable of pivoting relative to said fork (38a) without impeding the sliding thereof on the guide rod (39).
8. A sheet metal follower according to claim 1 or claim 7, characterised in that the pivot means (11) further comprises a wormscrew in the form of a ball screw (40) secured at its top end to the connection piece (38b) or to the fork (38a) of the moving hinge (38), a ball nut (41) co-operating with said wormscrew (40) and mounted in a fixed position but capable of pivoting on the top portion of the support structure (25) so as to be capable of pivoting about a horizontal pin (43, 44) parallel to the pin (38c) of the moving hinge (38), and a drive motor (49) whose outlet shaft carries a pulley (48) connected by a looped belt (47) to a pulley (46) secured to the nut (41) and having the wormscrew (40) passing therethrough with clearance.
9. A sheet metal follower according to claim 8, characterised in that the ball nut (41) is mounted in a pivot cage (42) via a ball bearing (45), in that said cage (42) is hinged on the lateral plates (25b, 25c) of the support structure (25) by means of hinge bolts (43, 44), and in that the drive motor (49) is also fixed on said cage (42).

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