FR3084602A1 - TOOLS OF A PRESSING MACHINE AND A METHOD OF STAMPING IMPLEMENTING SUCH TOOLS - Google Patents

Abstract

The invention relates to a tool for a stamping press (1) comprising a bottom sole comprising a plurality of dies (61) and at least one transfer die (62). The tool also includes a turntable (7) provided with a plurality of stamped housings (71) in the working position or in the transfer position. The tool comprises an upper sole (8) carrying a plurality of punches (81, 83) respectively arranged opposite the dies (61) and housings (71) positioned in the working position, the upper sole ( 8) also carrying at least one transfer punch (82) disposed opposite the transfer matrix (62) to detach a stamp from the metal strip (9) and push it into the housing positioned in the position of transfer. The invention also relates to a press (1) provided with the tool and to a method implementing the tool.

Description

TOOLS FOR A STAMPING PRESS AND METHOD FOR STAMPING

IMPLEMENTING SUCH TOOLS

FIELD OF THE INVENTION

The present invention relates to the production by stamping of metal parts.

TECHNOLOGICAL BACKGROUND OF THE INVENTION

The documents FR2625453 and FR2625454 point out that there are two families of stamping presses. Transfer presses are characterized by the fact that the parts are individualized. They are transferred from one stamping station to the next by an external mechanism, such as pliers or transfer bars. The tool presses to be followed are characterized conversely in that a metal strip supports the stampings made in this strip and which, advancing step by step, serves as a transfer member from one station to the next. Throughout the stamping passes, each stamp remains attached to the metal strip, for example by means of straps connecting the top of the stamp to the rest of the metal strip in which it was formed.

The tool press to be followed has the advantage of keeping the stamped metal strip during its shaping and for its transfer from one station to another, which avoids sometimes complex adjustments of the mechanisms which ensure these functions in a transfer press.

However, the tool press to be followed has a major drawback preventing the production of certain parts, due to the fact that the part remaining by definition attached to the metal strip by its upper part, it is impossible to form by stamping certain operations, in particular those aimed at treating the upper part of the part, such as the so-called closing or supplying operations of external elements to be positioned on the upper part.

The invention aims to remedy these drawbacks. An object of the invention is in particular to propose a device and a single stamping method allowing the production of several pieces at once, these pieces being able to present a great variety of shape or function.

BRIEF DESCRIPTION OF THE INVENTION

With a view to achieving one of these aims, the object of the invention provides a tool for a stamping press, the press comprising a table and a slide, the tool comprising:

- a lower sole intended to be supported by the table or by the slide and having a first main surface comprising a plurality of dies, arranged in constant linear pitch along a direction of advance of a metal strip, the dies contributing to successively shaping the metal strip to form stamps integral with the strip, the first main surface also comprising at least one transfer matrix;

- a turntable having a second main surface, the tray being intended to be supported by the table or by the slide to place its second main surface parallel to the first, and provided with a plurality of stamped housings arranged at angular pitch constant, the turntable being able to move in rotation to position a part of the housings in at least one working position and another part of the housings in a transfer position in which each housing is arranged under the first main surface of the sole lower, facing each transfer matrix;

- an upper sole intended to be fixed to the slide or to the press table in order to overhang the lower sole and the turntable, the upper sole being capable of being driven by the slide in a direction normal to the first and to the second main surface and carrying a plurality of punches respectively arranged opposite the dies and housings positioned in the working position, the upper sole also carrying at least one transfer punch disposed opposite the matrix transfer to detach a stamp from the metal strip and push it into the housing positioned in the transfer position.

According to other advantageous and non-limiting characteristics of the invention, taken alone or in any technically feasible combination:

- the tool for stamping press also comprises a central part for guiding the punches fixed to the lower sole;

- the tool for stamping press also includes a guide by ball columns;

- the turntable includes a mechanism allowing the evacuation of the stampings.

The invention also provides a stamping press provided with such a tool.

According to other advantageous and non-limiting characteristics of the invention, taken alone or in any technically feasible combination:

- the stamping press includes a feed for advancing the metal strip step by step;

the press unrolling the feeding; at the stamping bandaged has a metallic reel for and feed the press at stamping has a distributor allowing the distribution of external elements on the tray turning •

The invention finally proposes a stamping process using such tools, the stamping process comprising the repetition of the following two successive steps:

- A stamping step during which a lower flange and an upper flange of a stamping press are brought closer to one another to simultaneously produce:

o The shaping of a metal strip using dies distributed at constant linear pitch on a main surface of the bottom flange, along a direction of advancement of the metal strip, and using carried punches by the upper sole to form stampings held integral with the strip;

o The detachment of at least one stamped from the metal strip and its transfer into a housing of a turntable, the plate comprising a plurality of stamped housings arranged at constant angular pitch, using a punch transfer carried by the upper sole, and a transfer matrix disposed on the main surface of the lower sole;

o The processing of at least one stamp placed in other housings of the turntable in the working position using other punches carried by the upper sole;

- A displacement step during which the metal strip of the constant linear pitch is advanced and during which the plate of the constant angular pitch is rotated.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the invention will emerge from the detailed description of the invention which will follow with reference to the appended figures in which:

Figure 1 is an overview of a stamping press comprising a tool according to the invention;

Figure 2 is a top view of the main surface of the bottom flange and the turntable of a tool according to the invention;

Figure 3 is a side view of the turntable and the fixed plate of a tool according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

A tool according to the invention is intended to be mounted on a stamping press.

There is shown in Figures 1 and 2 a block diagram of a stamping press 1 provided with a tool according to this description.

As is well known in itself, such a press 1 comprises, held by a chassis 2, a fixed table 3, a slide 4 capable of performing rectilinear back and forth movements perpendicular to the table 3. The slide 4 can by example be set in motion by a connecting rod mechanism 5a - crankshaft 5b whose rotation is ensured by a motor, as is symbolically represented in FIG. 1.

However, the invention is in no way limited to this type of mechanism, and any means making it possible to set the slide 4 in motion may be suitable.

The press 1 also includes a lower sole 6 and a turntable 7 supported by the table 3 and an upper sole 8 fixed to the slide 4.

The lower sole 6, the plate 7 and the upper sole 8 form the press tool 1 specifically designed and adapted for mass production of a specific metal part. The tool can include a guidance by ball columns, allowing to keep the coherence of the parts which compose it.

When they are mounted on the press 1 as is the case in FIG. 1, the lower sole 6 has a main surface 60 which is opposite a main face of the upper sole 8. The main surfaces, in the 'example shown, are normal to the rectilinear movement of the slide 4.

The lower sole 6 comprises on its main surface 60 a plurality of dies 61. The upper sole 8 carries a plurality of punches 81, arranged on its main surface, facing the dies 61 of the lower sole 6.

As is well known in itself, the dies 61 and the punches 81 are designed to cooperate and shape a metal strip 9 at each stamping stroke at the end of the downward travel of the slide 4. The metal strip 9 is disposed between the dies 61 and the punches 81, and progresses step by step in a direction of advance, between each stamping stroke.

One generally defines by “post” P the die-punch pair (or a plurality of such pairs) which performs a determined operation on the strip. When a station P implements a plurality of pairs, these generally carry out the same operation.

There have thus been shown on the main surface 60 of FIG. 2 four distinct positions of the tool taken as an example. Here, each station includes two identical matrix-punch pairs, which therefore makes it possible to double the rate of production of parts. One could naturally envisage having only one matrix-punch pair per station, or more than two identical pairs between them, as required.

From one station to another, the punches 81 and the dies 61 can be configured to apply a wide variety of operations to the tape. It may be a matter of cutting from the metal strip 9 a blank retained by the straps to the rest of the strip, the blank constituting the material of the stamped. It may be a plastic deformation step, in which the shape of the punch 81 and the shape of the matrix 61 respectively give its inner shape and its outer shape to the stamped. It may also be a drilling step, in which the shape of the punch 81 and / or of the die 61 allows the production of an orifice on one of the faces of the stamped. It can also be a step in which a groove is made on one of the faces of the stamped. It can also be a cutting step, the punch 81 then having the shape of a shear making it possible to cut the strip 9.

Whatever the nature of the operations carried out at each station, a plurality of dies 61 is disposed on the main surface 60 of the lower sole 6 at constant linear pitch in a direction of advancement of the strip 9. This means that the distance between two consecutive matrices 61 of this plurality is constant, equal to a distance D.

As is clearly visible in FIG. 2, in which each station comprises two dies 61, a second plurality of dies 61 is also arranged in constant linear pitch D at the main surface 60 of the bottom flange 6, in the direction of advancement.

In general, there will be as many pluralities of matrices aligned at constant linear pitch D as there are matrices per station.

By distributing in this way the dies 61 on the main surface 60 of the bottom flange 6, it is possible to apply a plurality of operations simultaneously to shape the stampings, the metal strip 9 being displaced by the pitch D constant along its direction of advancement between two stamping strokes. The strip 9 can be taken from a reel 10 carried by a reel, and its advancement in the machine can be ensured by a feeding device 11, in synchronization with the movement of the press 1.

Punches 81 of the upper sole 8 are opposite the dies 61 according to the same arrangement.

Continuing the description of FIGS. 1 and 2, the main surface 60 of the lower sole 6 comprises at least one transfer matrix 62, here two transfer matrices, in alignment with the matrices 61 and at the end of this alignment according to the direction of advancement of the strip 9. Each transfer matrix 62 is associated with a transfer punch 82, also carried by the upper sole 8, and disposed opposite the transfer matrix 62.

The transfer matrix 62 and / or the transfer punch 82 are configured in such a way that they allow the singling out of a stamped material, for example by cutting the straps which hold it to the metal strip 9. The transfer matrix 62 and / or the transfer punch 82 are also configured to move the stamped in a direction perpendicular to the main surface 60 in order to extract it from the transfer matrix. The stamped crosses the main surface 60 of the lower sole 6, to be placed in a housing of the turntable disposed under the main surface of the lower sole, as will be detailed in the following description.

By way of example, the transfer die 62 can simply be formed by a through hole whose cross section is at least equal to that of the stamped piece detached from the metal strip 9. The transfer punch 82 can in turn be configured to allow, during a stamping stroke, detachment of the stamping from the rest of the metal strip 9 by cutting the straps, during a so-called trimming operation. It can have a sharp circumference allowing a clear cutting of the straps.

The transfer punch 82 is also configured to push the stamped out of the transfer die 62 during a stamping stroke. For example, the transfer punch 82 could simply be longer than the other punches 81, of a length approximately equal to the transfer matrix 62.

Returning to the general description of Figures 1 and 2, the stamping press 1 is also provided with a turntable 7. The turntable 7 is provided with a plurality of stamping housings 71 arranged at constant angular pitch, as illustrated in figure 2.

Here, the plate is provided with eight housings arranged radially two by two with an angle of 90 ° between each group of two housings.

The stamped housings 71 can be simple lodges on the surface of the turntable 7 making it possible to hold the stamped in a predetermined position. The stamped housings 71 can also advantageously comprise or constitute matrices having a shape chosen to continue the shaping, or more generally the treatment, of the stampings. These stamps being singularized, the nature of the treatments which can be carried out on these stamps is no longer constrained by the presence of the straps. It is in particular possible to shape the upper part of these stampings, for example to carry out closing operations.

The turntable 7 is able to move in rotation. To this end, the plate 7 can have a stepping motor intended to actuate it in synchronization with the movement of the press 1. In the particular embodiment shown in FIG. 2, the motor can allow turn the table 90 ° on itself with each press movement. However, this embodiment is in no way limiting, and it is possible to envisage a continuous motor having a mechanical system rotating the plate 7 step by step. It is also conceivable that the movement of the turntable 7 is ensured by a connecting rod-crankshaft mechanism connected to the slide 4 of the press, so that the linear movement of the slide 4 transforms the linear movement into circular movement.

The movement of the turntable 7 makes it possible to position, at each step, a part of the pressed-in housings 71 in a "transfer position", defined as the position in which a housing 71 is disposed under the main surface 60 of the bottom flange 6, opposite each transfer punch 82 and each transfer matrix 62.

Thus, during a stamping stroke, the transfer punch 82 and / or the transfer die 62 cuts the straps of a stamped or a plurality of stamps, positioned at the transfer station Pt. Each stamped is driven from the transfer matrix 62 in which it rests by a transfer punch 62 to come to be placed in a pressed housing 71 of the turntable 7, located directly above the transfer matrix 62.

The upper sole 8 also carries punches 83 which allow, during a stamping stroke, to shape the stampings which have been detached from the metal strip 9 and placed in stamped housings 71 of the turntable 7 during from a previous transfer step. The term “working position” designates the position of the housings 71 of the turntable 7 arranged opposite a punch 83 of the upper sole 8.

As has already been specified, it is possible in this way to produce, with a single tool, stampings having shapes or functionalities which cannot be obtained with a tool of the state of the art.

As for the positions described above, a punch 83, cooperating with a stamped housing 71 located in the working position, can make it possible to carry out a varied number of operations. It may be the shaping of the top of the stamp, previously secured to the strip 9 by the straps, for example to close the top of the stamp inward. It may also be a question of shaping a stamped so that it has a projecting part on one of its faces. It can also be a case of crimping an external element in the stamping, such as a seal.

The tool can then include a dispenser, not shown in the figures, allowing the distribution of these external elements on the turntable 7. For example, this dispenser can include a vibrating bowl associated with a transfer belt allowing dispensing on the tray turning 7, synchronized with the movements of the turntable 7 and the press 1, external elements such as seals or plastic parts.

It is obviously possible to envisage several working positions, allowing the realization of several successive steps on the stamped parts detached from the metal strip 9. For example, one can imagine needing three stamping steps to close the top of the 'stamped. One can also imagine for the crimping of a joint to need three stages of stamping, followed by a stage of fitting the joint, followed by a stage of crimping. Depending on the necessary number of working positions, the constant angular pitch with which the housings 71 are distributed over the surface of the plate 7 will be adjusted.

According to a particular embodiment, shown from in Figure 3, the turntable 7 can be disposed on a fixed plate 72 itself supported by the table 3 of the press. The stamped housings 71 are cavities passing through the turntable. In one of the working positions, the fixed plate 72 has an orifice allowing the stampings to be removed when they are located in this working position. One can provide an evacuation punch 84 of the upper sole 8 making it possible to push the stamped through the orifice of the fixed plate 72. The fixed plate 72 and the possible evacuation punch 84 forms a particular example of a mechanism allowing the evacuation of the stampings.

A recuperator, not shown, placed directly above the orifice can make it possible to evacuate the stamped material, for example on a conveyor belt.

The press 1 can also comprise, fixed to the chassis 2 or to the lower sole 6, a central part, also called punch guide 12, as illustrated in FIG. 1. The punch guide 12 makes it possible to guide the punches 81, 82, 83 throughout the descent of the slide 4 in order to prevent them from deflecting during stamping strokes under the effect of high pressures, improving the precision of the tool.

As is clear from the description of the press which has just been detailed, the stamping process implemented by this press comprises a stamping step, during which the sole is brought closer to one another lower 6 and the upper sole 8, followed by a step of moving the strip 9.

These steps are repeated successively to manufacture parts continuously.

During the stamping step, the metal strip 9 is shaped by the dies 61 and the punches 81 distributed along the direction of advance, to form stamps integral with the strip. Simultaneously with this shaping, at least one stamping is detached from the strip 9 to be transferred into a housing 71 of the turntable 7 at a transfer position. Simultaneously also, the punches 83 carried by the upper sole 8 process the stampings placed in the housings 71 of the plate 7 arranged in the working position.

As has been made apparent by the detailed description of the stamping press 1, the present invention proposes to provide a single tool making it possible to combine the advantages of a tracking tool and a transfer tool, implementing a single upper sole, which makes it possible to produce several pieces at once, these pieces being able to present a great variety of forms or functions.

Of course, the invention is not limited to the mode of implementation described and it is possible to make variants thereof without departing from the scope of the invention as defined by the claims.

In particular, one could consider reversing the position of the soles therebetween, that is to say of fixing the lower sole 6 to the slide 4 and the upper sole 8 to the table 3. In this case, provision may be made to provide the turntable 7 of means for retaining the stampings in the housings.

Claims (9)

1. Tool for stamping press (1), the press (1) comprising a table (3) and a slide (4), the tool comprising: - a lower sole (6) intended to be supported by the table (3) or by the slide (4) and having a first main surface (60) comprising a plurality of dies (61), arranged in constant linear pitch along d '' a direction of advancement of a metal strip (9), the dies (60) helping to successively shape the metal strip (9) to form stampings integral with the strip (9), the first main surface (60) comprising also at least one transfer matrix (62); - a turntable (7) having a second main surface (70), the plate (7) being intended to be supported by the table (3) or by the slide (4) to place its second main surface (70) parallel to the first (60), and provided with a plurality of stamped housings (71) arranged at constant angular pitch, the turntable (7) being able to move in rotation to position part of the housings (71) in at at least one working position and another part of the housings (71) in a transfer position in which each housing is arranged under the first main surface (60) of the bottom flange (6), opposite each matrix transfer (62); an upper sole (8) intended to be fixed to the slide (4) or to the table (3) of the press (1) to overhang the lower sole (6) and the turntable (7), the upper sole (8) being capable of being driven by the slide (3) in a direction normal to the first and the second main surface (60, 70) and carrying a plurality of punches (81, 83) respectively arranged opposite the dies (61) and housings (71) positioned in the working position, the upper sole (8) also carrying at least one transfer punch (82) disposed opposite the transfer matrix (62) for detach a stamp from the metal strip (9) and push it into the housing positioned in the transfer position. 2. Tool for stamping press (1) according to the preceding claim comprising a central part for guiding the punches (12) fixed to the bottom flange (6). 3. Tool for stamping press (1) according to one of the preceding claims comprising a guide by ball columns. 4. Tool for stamping press (1) according to one of the preceding claims wherein the turntable (7) comprises a mechanism for the removal of stampings. 5. Stamping press (1) provided with a tool according to one of the preceding claims. 6. Stamping press (1) according to the preceding claim comprising a feed (11) for advancing step-by-step the metal strip (9). 7. Stamping press (1) according to the preceding claim comprising a reel (10) for unwinding the metal strip (9) and supplying the feed (11). 8. Stamping press (1) according to one of claims 5 to 7 comprising a distributor allowing the distribution of external elements on the turntable (7). 9. Stamping process comprising repeating the following two successive steps: - A stamping step during which a lower flange (6) and an upper flange (8) are brought closer to each other with a stamping press (1) to simultaneously produce: o The shaping of a metal strip (9) using dies (61) distributed at constant linear pitch on the main surface of the lower flange (6), along a direction of advancement of the metal strip (9), and using punches (81) carried by the upper sole (8) to form stampings held integral with the strip (9); o The detachment of at least one stamped from the metal strip (9) and its transfer into a housing (71) of a turntable (7), the plate (7) comprising a plurality of stamped housings (71) arranged at constant angular pitch, using a transfer punch (82) carried by the upper sole (8), and a transfer matrix (62) disposed on the main surface (60) of the lower sole (6); o The treatment of at least one stamp placed in other housings (71) of the turntable (7) in the working position using other punches (83) carried by the upper sole (8); - A displacement step during which the metal strip (9) is advanced by the constant linear pitch and during which the plate (7) is rotated by the constant angular pitch.