ES2299402B1 - VIBRATORY DISCRIMINATOR DEVICE FOR THE CONTINUOUS SUPPLY OF SMALL PIECES TO BE SOLDED IN AUTOMATIC WELDING FACILITIES, AND CORRUPTING SYSTEM AND DISCRIMINATOR SYSTEM. - Google Patents

Abstract

Vibrating discriminating device for the continuous supply of small parts to be welded in automatic welding installations, and corresponding bowl and discriminating system. The tank (1) is formed by a body (3) in which a track (4) is formed, which constitutes a path through which the pieces to be welded move forward due to the vibrations of the tank. The body (3) is exempt from discriminating system (2) and is provided with a housing that interrupts the track (4). The discriminating system is constituted by a replaceable element (2) that is foreign to the body (3) and that comprises discrimination means and a base that removably attaches to the body housing (3) giving continuity to the track (4 ).

Description

Vibrating discriminating device for the continuous supply of small parts to be welded in facilities automatic welding, and tank and discriminating system corresponding.

Field of the Invention

The invention is in the field of robotic systems for automatic welding of small parts, such as screws, nuts and other similar small parts, in the processes of industrial production of capital goods.

More specifically, the invention relates to a vibrating discriminating device for continuous supply of small parts to be welded in automatic welding installations, of the type comprising a vat for storage without order of pieces to be welded, a path associated with said tank and configured of so that due to the vibrations of said tank said pieces to be welded advance along that path, and a system passive discriminator to discriminate according to certain requirements for shape, size and / or position of these parts to be welded they advance along said path, so that these pieces to be welded fall by gravity in said tank, by the passive action of said system discriminator, when they do not meet these requirements.

The invention also relates to a tank and to a discriminating system that constitute essential elements of said vibratory discriminating device.

State of the art

In numerous goods production industries of equipment, such as in the automotive industry, is employ automatic screw welding facilities, nuts and other similar pieces of small size. These facilities of welding comprise robotic arms that position each piece in the location where it should be welded and that are powered by a feeder team that supplies the parts to weld in the proper position and with the desired cadence. The team feeder typically comprises a discriminating device vibratory of the type indicated at the beginning, which provides a pneumatic shuttle a succession of parts of a certain model and in a certain position. The pneumatic shuttle sends these pieces one by one to the robotic arms, with the appropriate cadence and preserving their position.

In facilities of this type, it is fundamental that the vibrating discriminator device works without failures, since if a piece is sent to the pneumatic shuttle weld that is not of the expected model, or that is not in position proper, the system crashes and a line stop occurs of production. In those industries with a production pace high and a high requirement of reliability, as is the case with the automotive industry, such a failure has a very cost high.

In vibratory discriminating devices according to the prior art, both the path by which the pieces to be welded move forward due to vibrations such as discriminating system are part of the vibratory tank and are Handmade for each type of piece to be welded. Typically, the tank is metallic and the road consists of metal guides that are welded to the tank following a spiral layout These metal guides comprise, distributed to along its path, a series of singularities that perform the function of the discriminating system, causing the pieces that they advance along the road fall back to the bottom of the tank if not meet certain requirements of shape, size or position. These singularities arranged along the guides They are shaped and handcrafted for each type of piece to weld

In these discriminating devices vibrators according to the prior art, the vats Vibrators are therefore designed for a specific model of part a Weld. If the automatic welding installation changes the model of part to be welded, it is necessary to replace the vibrating tank for another specially designed for the new part model.

On the other hand, as stated, the singularities that make the discriminating system function are handcrafted by means of a test process and adjustment made by a specialized technician. Normally you are singularities are constituted by metallic elements whose shape it can be altered manually, for example by slight strokes of hammer or exerting a force with pincers or other tool. As a result, these vibrating vats are especially delicate. Indeed, if one of these vats vibrators mounted on a production line take a hit involuntary, your discriminating system is likely to result altered and a failure occurs. Normally, the factory where the discriminating device is installed does not have a tank vibratory replacement, since its storage requires a considerable space and implies an important fixed assets, whereby when a fault occurs, we proceed to review and Repair the equipment. Such a repair is delicate and requires weather. In practice, to repair a damaged vibrating vessel is often the technician who designed it must intervene and Handmade. Normally, the technician is an outsider to the factory, whereby the repair is slow and expensive.

Another drawback of these devices known is that the expertise a specialized technician needs to design and produce a vibratory vessel by hand requires Long learning In addition, normally, the acquired technique is own of each person. For this reason, the vibrating vats independently performed by different technicians present a different design. A technician is likely to encounter difficulties. to repair a vibrating tank that has been designed and adjusted by another technician.

Summary of the invention

The invention aims to provide a vibrating discriminating device of the type indicated by principle, which can be produced in series, in a non-traditional way, and that it can be repaired quickly and at a low cost. Other objective of the invention is to provide a discriminating device vibratory whose manufacturing is less complicated and less expensive than in the current state of the art.

This purpose is achieved through a vibratory discriminating device of the type indicated by principle, characterized in that the tank is formed by a body in which is formed a track that constitutes the path by the that advance the pieces to be welded, said body being exempt from discriminating system and being provided with accommodation that interrupts that clue, and because the discriminating system is constituted by a replaceable element that is foreign to said body and that includes a means of discrimination and a basis, said base being configured so that it engages so removable to said accommodation giving continuity to said track.

Thanks to the structural characteristics of the device according to the invention, it is possible to separate the manufacturing of the Cuba, which includes the track that forms the path where advance the pieces to be welded, from the manufacturing of the system discriminator Thus, the tank can be a usable standard model for a wide variety of parts to be welded, while the system discriminator is designed for each particular model of piece a Weld. As a result, the complexity and costs of manufacture of the device according to the invention are significantly lower than in the current state of the art. On the other hand, the manufacturer of a device according to the invention Can supply to each factory, and for each production line, a single tank and a set of equal discriminatory systems. So, when a production line fails due to a deterioration of a discriminating system, this can be immediately replaced by another equal, restoring the proper operation of the line without the need to perform no adjustment It is also possible to provide several sets of Different discriminatory systems. So, when you change the model of piece to be welded it is possible to adapt the device vibratory discriminator by simply replacing the system discriminant, without the need for any adjustment.

This method is not feasible with prior art devices, since for this it would be necessary to store several vibrating vats per line of production and, as stated above, similar storage is expensive in terms of space and fixed assets material. In addition, the replacement of a vibrating vessel is a cumbersome operation, since it is necessary to empty it of the pieces to weld and disconnect it from the vibration system and the shuttle. Instead, store a set of discriminant systems according to the invention requires little space and less investment; Besides, the replacement of a discriminant system according to the invention is a Fast and reliable operation.

Preferably, in the device according to the invention the replaceable element that forms the system discriminator comprises two complementary pieces configured to be assembled removably forming a set: a first piece provided with first means of discrimination to discriminate said pieces to be welded according to a shape and a certain position and a second piece provided with a few seconds discrimination means to discriminate said parts to be welded according to a certain dimension. Thanks to this configuration modular, a set consisting of a first piece, with means of discrimination for a form and a concrete position, and several different second pieces, with means of discrimination for different dimensions. This is particularly advantageous for covering series of parts to be welded where only one dimension changes, for example in the case of series of nuts with the same base but with different heights. In this case, the manufacturing of discrimination systems is less expensive. Another advantage is that it facilitates the storage of modular systems, since these can be disassembled in two pieces.

In the case where the device according to the invention is intended to use, as parts to be welded, nuts of type for welding provided with protuberances in its base, preferably the first piece is a plate that constitutes the base and that includes a track section that gives continuity to the track and a rib that extends longitudinally in said section of track, and the second piece is a plate that presents a cantilever which, in the mounted position of said second piece, forms a roof on said track section of said first piece. How will it look more later in the detailed description of an embodiment example, the rib constitutes a first means of discrimination according to the position and shape of the nut, while the overhang constitutes a second means of discrimination according to height of the nut. This configuration has the advantage that pieces that constitute the discriminating system have a form simple that allows to manufacture them in series. They are also pieces robust, with which the discriminating system is especially resistant to shock and wear.

Preferably, the body that forms the tank and The track is one piece of plastic material, which can easily manufactured in series, by machining or by molded

In a preferred embodiment, the device according to the invention comprises an outlet duct, foreign to the body that forms the tank, which is a replaceable element and that it is removably attached to said body so that is arranged as a continuation of the final stretch of the track after the replaceable element that forms the system discriminator The outlet duct is specific for each model of piece to be welded and its function is to collect the pieces to be welded that leave the discriminating system and deliver them, maintaining the position thereof, to the next stage of the system automatic welding, which is usually a shuttle vehicle said parts to be welded towards automatic welding robots. Thanks to this arrangement, an advantageously can be provided device according to the invention formed by a single tank, a set of different discriminatory systems and a set of different outlet ducts for different models of parts to Weld.

The invention also encompasses, within the same invention unit, the tank and the discriminating system considered individually. In effect these elements are parts essentials of the vibratory discriminating device according to the invention, are mutually complementary and are characterized due to technical characteristics that provide an effect common technician In Cuba, these technical characteristics are constituted by the track formed in the Cuba itself and by the accommodation that interrupts said track while in the system discriminator are constituted by the replaceable nature of this, the means of discrimination and the base that fits in a way removable to the accommodation and gives continuity to the track.

Brief description of the drawings

Other advantages and features of the invention they can be seen from the following description in which, without no limiting character, a preferred form of embodiment of the invention, mentioning the drawings that are accompany. The figures show:

Fig. 1, a plan view of the body that forms the Cuba;

Fig. 2, a sectional view of the tank of the Fig. 1;

Fig. 3, a perspective view of the tank of Fig. 1;

Fig. 4, a perspective view similar to the Fig. 1, but where the tank has the replaceable element mounted that forms the discriminating system and also the conduit of exit;

Fig. 5, a perspective view of the element replaceable that forms the discriminating system;

Fig. 6, a view corresponding to Fig. 5, which shows the two pieces that form said element disassembled replaceable;

Fig. 7, a perspective view of the assembly replaceable which includes the outlet duct;

Figs. 8 and 9, two perspective views of the welding nut for which the system is designed discriminator of Figs. 5 and 6

Detailed description of an embodiment of the invention

The vibratory discriminating device described below by way of non-limiting example is designed for the case where the parts to be welded are welding nuts, in particular nuts of the type for spot welding which have only one of their faces protuberances that allow spot welding said nuts on a support. Specifically, the device is intended to be installed in a line of an automobile factory in which the nuts are welded to the doors of the cars. Of course, the invention also encompasses other embodiments for different types of small parts to be welded, such as screws, and for other types of production lines in which automated welding of small
pieces.

The device comprises, as elements essential of the invention, the body 3 that forms the tank 1 (Figs. 1 to 3) and discriminator system 2 (Figs. 5 and 6) that is mounted removable form in said body 3. As complementary elements which improve the invention, the replaceable assembly (18) is provided that it forms the outlet duct 12 (Fig. 7) and the junction zone 11 corresponding provided in said body 3.

The body 3 that forms the tank is one piece and is manufactured by a machining process of precision from a raw block of plastic material loaded with hardeners. Alternatively, for large series body 3 can be manufactured by a molding process. The choice of a specific plastic material and a load of appropriate hardeners do not present technical difficulties for a skilled.

As can be seen in Figs. 1 to 4, the wall inside the body 3 that forms the tank 1 has a shape conical trunk and mechanized a track 4 that runs a path coiled from bottom 17 of tank 1. In section view from Fig. 2 it can be seen that track 4 is delimited inferiorly by a spiral 19. The nuts are stored without order in the bottom 17 of the tank and traced along of the path formed by track 4, due to vibrations transmitted by a vibrating system (not shown) to which it goes said tank 1 fixed, screwed by the threaded holes 20 and centered by means of its axial hole 21. When they advance along the track 4, the nuts are supported by one of their bases on the wall conical of said track, resting on one side on the shoulder 19.

In body 3, interrupting track 4 and preferably near the end of it, it is formed a housing 5 in which an element is removably mounted replaceable 2 that constitutes a passive discriminating system. How It can be seen in more detail in Figs. 5 and 6, the system discriminator 2 is formed by two pieces 8, 9 (Fig. 6) that are assemble each other by means of screws 14 to form a set (Fig. 5). Both pieces 8 and 9 are made of carbonitrided steel and They are obtained by machining.

The first piece 8, which constitutes a base of discriminating system 2 by which the latter is coupled in the body 3, is a plate that presents a complementary form to the of housing 5 of body 3, in which it fits. Upper face of this first piece 8 constitutes a section of track 10 which, in the mounted position of discriminator system 2 in body 3, gives continuity to track 4. Said upper face of the first piece 8 it is provided with a longitudinally extending rib 6 along track section 10. As will be seen below, this rib 6 constitutes a first means of discrimination for discriminate the nuts according to their shape and position. The projections 15 provided in the two lower corners of the first piece 8 house blind threaded holes arranged on the other side of the piece (not visible in the figures) that allow the discriminating system 2 to be fixed to body 3 by screwed

The second piece 9 is a plate that is fixed to the first piece 8 by means of screws 14 and presenting a cantilever 7 forming a roof over track section 10 of said first piece 8. As will be seen later, this cantilever 7 constitutes a second means of discrimination to discriminate The nuts according to their height.

Figs. 8 and 9 illustrate the type of nut for which is designed discriminator system 2 represented in Figs. 5 and 6. This is a nut 22 of the type it presents, in only one of its faces, protrusions 23 that allow to realize a spot welding of the nut.

The discriminating system 2 is designed to that the nuts that advance along track 4 and that do not comply with requirements of shape, position and size fall by gravity to bottom 17 of the tank.

To overcome the first means of discrimination constituted by rib 6, the nut must be of the type illustrated in Figs. 8 and 9 and must be positioned in track 4 leaning on the wall of said track 4 by its face provided with protrusions 23. In this position, the two lower bulges 23 pass under said slot 6, of so that the nut is guided along track section 10. Yes the nut is in an inverted position, that is to say with its flat face  leaning on the wall of track 4, when it enters track 10 it is lifted by slot 6 and falls to the bottom 17 of the tank. For facilitate this lifting movement and prevent the nut be encased, the rib 6 has at its initial end a chamfering Also, when the nut has a different shape than the one depicted in Figs. 8 and 9, a similar effect occurs:  nut is lifted by slot 6 and falls by gravity to the bottom of the Cuba

The nuts that have surpassed these first means of discrimination and moving along track 10 must pass below cantilever 7, which constitutes a few second means of discrimination according to the height of the nut. If a nut is too high, bumps into said overhang, derails and falls down gravity at bottom 17 of the tank. Thanks to the fact that the tank is maintained in a constant vibratory state so that the nuts advance through track 4, such a nut that runs into overhang 7 is not It runs aground and falls easily to the bottom of the tank.

When a nut has exceeded the system discriminator 2, keep moving on track 4 of body 3. As can be seen in Figs. 1, 3 and 4, at its final end after accommodation 5 track 4 progressively changes its inclination until a final section 13 becomes horizontal, so that the nuts that advance through this final section 13 are in position horizontal, with its face provided with protrusions 23 supported against the horizontal wall of said final section 13.

At the end of this final section 13, the nuts they enter an outlet duct 12 that carries them by gravity towards the pneumatic shuttle that feeds on nuts the robots of automatic welding Advantageously, the conduit 12 is an element replaceable that removably mounts on body 3 and that It has specific dimensions for each specific model of nut: duct section 12 fits with little play to the nut shape horizontally, so that the nut falls by gravity through said conduit 12 maintaining the position horizontal that it had when leaving the final section 13. In the example of represented embodiment, the outlet duct 12 is arranged in a replaceable assembly 18 comprising a fixing plate 16 that it is fixed by screws (not shown) to a seat corresponding 11 provided on the outer wall of the body 3 which Cuba forms.

As stated, the discriminating system 2 represented in Figs. 5 and 6 corresponds to the nut model concrete shown in Figs. 8 and 9, which presents a base square and four protrusions 23 formed in the corners of said base. Of course, the invention is applied without any difficulty with other types of nuts, such as nuts whose base has a hexagonal, circular or other shape, and whose Bumps may have different shapes and positions. By example, the bumps may be arranged at the periphery or in a more internal position of the nut base, they can have a blunt shape or edges; they can even show up in the form of a circular continuous rib centered on the axis of the nut. All these types of nuts can be treated without difficulty with a discriminating system like that of Figs. 5 and 6, but adapted to each nut. To do this, simply adapt the design of the rib 6 and / or the cantilever 7, which can be modified in its dimensions and also in its form.

An expert in the field may design other embodiments of the vibratory discriminator device according to the invention, applicable to other types of parts to be welded, such as screws. To do this, you can design a system custom discriminator, consisting of a replaceable element that have the characteristics of the main claim but that present a different configuration from that represented in the figures. The body that forms the tank, as well as the arranged track in that body and that constitutes the path, they can also have different forms of those represented in the figures. Also, in the embodiments that incorporate a conduit output as item 12 in the figures, the latter will have a shape adapted to the shape of the pieces to be welded. All without leave the scope of the present invention.

Claims (10)

1. Vibrating discriminating device for the continuous supply of small parts to be welded in automatic welding installations, comprising a tank (1) for the unordered storage of parts to be welded, a path associated with said tank (1) and configured so that as a result of the vibrations of said tank (1) said parts to be welded advance along said path, and a passive discriminating system (2) to discriminate according to certain requirements of shape, size and / or position said parts to be welded that advance by said path, so that said parts to be welded fall by gravity in said tank (1), by the passive action of said discriminating system (2), when they do not meet said requirements, characterized in that said tank (1) is formed by a body (3) in which a track (4) is constituted which constitutes said path by which the pieces to be welded advance, said body (3) being exempt from said discriminating system (2) and being provided with a housing (5) that interrupts said track (4), and because said discriminating system is constituted by a replaceable element (2) that is foreign to said body (3) and that comprises discrimination means (6, 7) and a base (8), said base (8) being configured so as to be removably coupled to said housing (5) giving continuity to said track (4). 2. Device according to claim 1, characterized in that said replaceable element (2) forming the discriminating system comprises two complementary parts (8, 9) configured to be removably assembled to form an assembly: a first part (8) provided with first discrimination means (6) to discriminate said parts to be welded according to a certain shape and position and a second part (9) provided with second discrimination means (7) to discriminate said parts to be welded according to a given dimension. Device according to claim 2, suitable for the case in which said parts to be welded are welding nuts (22) provided with protuberances (23) at their base, characterized in that said first piece (8) is a plate constituting said base (8), said first piece (8) comprising a track section (10) that gives continuity to said track (4) and a rib (6) extending longitudinally in said track section (10), and said second piece (9) is a plate that has a cantilever (7) that, in the mounted position of said second piece (9), forms a roof on said track section (10) of said first piece (8). Device according to any one of claims 1 to 3, characterized in that said body (3) forming said tank (1) and said track (4) is made of a single piece of plastic material. Device according to any one of claims 1 to 4, characterized in that it comprises an outlet duct (12), foreign to said body forming the tank, which is a replaceable element and which is removably attached to said body (3) so that it is arranged as a continuation of the final section (13) of said track (4) after said replaceable element (2) that forms the discriminating system. 6. Cuba (1) to form a vibratory discriminating device according to claim 1, characterized in that it is formed by a body (3) in which a track (4) is formed for the progress of the pieces to be welded by the effect of vibrations of said tank, said body (3) being free of discriminating system (2) of the pieces to be welded, and said body (3) comprising a housing (5) that interrupts said track (4) and is intended for removable coupling of a discriminating system (2) of said parts to be welded. 7. Cuba (1) according to claim 6, characterized in that said body (3) forming said tank (1) and said track (4) is made of a single piece of plastic material. 8. Discriminant system (2) for forming a vibratory discriminating device according to claim 1, characterized in that it is constituted by a replaceable element (2) comprising discrimination means (6, 7) and a base (8), said base ( 8) being configured so that it is removably coupled to a housing (5) of a tank (1) giving continuity to a track (4) interrupted by said housing (5). 9. Discriminant system (2) according to claim 8, characterized in that said replaceable element (2) comprises two complementary parts (8, 9) configured to be removably assembled forming an assembly: a first part (8) provided with first means of discrimination (6) to discriminate said pieces to be welded according to a certain shape and position and a second piece (9) provided with second means of discrimination (7) to discriminate said pieces to be welded according to a given dimension. 10. Discriminant system (2) according to claim 9, characterized in that said first piece (8) is a plate constituting said base (8) and comprising a track section (10) to give continuity to said track (4), said first piece (8) comprising a rib (6) extending longitudinally in said track section (10), and said second piece (9) is a plate having a cantilever (7) which, in the assembled position of said second piece (9), forms a roof on said track section (10) of said first piece (8).