EP1205578B1 - Installation for chemical dip treatment of metal pieces - Google Patents

Abstract

An installation for the chemical treatment of metal components by immersion in a tank (9, 11) containing a chemical treatment bath, the components being submitted to a prior preparation treatment and a finishing treatment in other tanks, consists of the different treatment tanks being arranged in two parallel lines separated by an alley (3) allowing access to the tanks. A first line (1) incorporates a charging/discharging device (4) at one of its ends along with the preparation tanks (5 - 8, 10) whilst a second line (2) incorporates two chemical treatment tanks (9, 11), functioning alternately, and some finishing tanks (14 - 18). A longitudinal transfer manipulator is provided for each line and a transverse transfer device is provided to connect the two lines.

Description

The present invention relates to the design and manufacture of a chemical treatment plant by dipping parts contained in cages, or other containers, such treatment involving immersion in a tank containing a treatment bath. It applies in particular to installations in which the actual chemical treatment is a manganese phosphating treatment carried out on parts of motor vehicles. It applies equally to any similar installation, knowing that in essence the chemical treatments by dipping use relatively polluting baths.

The current manganese phosphating plants comprise a series of tanks arranged in line one behind the other in which a preparation treatment is carried out first comprising in particular a degreasing step and alkaline rinsing steps, the chemical treatment proper. comprising a phosphating step, possibly preceded by a refining step, and a finishing treatment including in particular acid rinsing, drying and cooling steps. All the tanks where these different treatments are carried out are arranged along a line at the entrance of which there is a loading device in the installation, an unloading device being provided at its outlet, at the other end. Each cage containing the parts to be treated covers the entire line. It is transferred from one tank to the next in the series by a manipulator which circulates along the line to take each cage in turn in one tank and deposit it in the next.

Such an installation has a significant length which poses congestion problems. In addition, the processing capacity can vary only to a small extent, which does not allow to adapt to very different production rates. Furthermore, it is not known how to avoid major interruptions of service, as they are necessary because of the presence of a tank that must be cleaned frequently, as is often the case for tanks where treatments are carried out chemicals, and in particular that of phosphatizing tanks. In practice, the presence of this kind of chemical treatment tank has led to a strong need for improvement of the working conditions for the workers who are responsible for the monitoring and maintenance of the facilities and who must be able to circulate safely. in the vicinity of the tanks.

Typically in installations of the type considered here, the parts to be treated are arranged in containers, or cages, which come from other manufacturing units and which are then returned in the chain. To guarantee the cleanliness of these containers, they must be completely immersed in the various tanks, in particular in the phosphatation tank to avoid a phosphatation bath / atmosphere interface and in the degreasing or pickling tanks to thoroughly clean the entire tank. container. To ensure this without exaggerating the volume of the baths, the containers are placed at the bottom of the tanks. It can not then be avoided that the manipulators used to move the containers from one tank to another are in contact with the various baths and undergo alterations. And, except for the drying steps, it can not be avoided that the manipulator leaving a bath with its charge causes liquid that may drip on nearby equipment, resulting in additional difficulties for maintaining the purity of the various baths and for the safety of the workers.

The present invention aims at providing a dip-dip chemical treatment installation in a tank containing a chemical treatment bath, for parts constituting charges contained in containers or cages which, in other tanks, are also subjected to a pre-treatment treatment and a subsequent finishing treatment, which is much more compact in terms of its size, which has a flexibility of use to adapt to very different capabilities and easy maintenance. More generally, it aims to solve the various difficulties the industry faces in this area, including those highlighted above.

The installation according to the invention is particularly remarkable in that the tanks of the different treatment stations are arranged on two parallel lines separated by an aisle allowing access to the tanks, a first line comprising a device for loading and unloading at a specific temperature. ends and preparation tanks, and a second line comprising two chemical treatment tanks which are used alternately and finishing tanks, in that a longitudinal transfer manipulator is provided in each line, to take a turn of role each charge in a tank and deposit in another, and in that it comprises transverse transfer means ensuring the connection between the two lines, in the forward direction and in the return direction.

Preferably, the loading and unloading device, which is unique because at only one end of the first line, comprises a plurality of load-receiving cells, each receiving a load at the input or at the output of the installation.

The fact of providing two parallel lines of treatment tanks makes it possible to obtain a compact installation whose length is very small compared to current installations. The aisle between the two tank lines allows maintenance personnel easy access to all tanks. In addition, the chemical treatment baths, which are particularly polluting, are used only on the second line, the first being reserved for operations that can be described as clean. And since there are two tanks operating alternately for the chemical treatment steps, the downtime for cleaning can be significantly reduced, even completely eliminated, and the overall capacity of the installation can be doubled. Among other additional advantages due to the invention, the fact of providing a single station in which the loading and unloading of the parts to be treated makes it possible to further reduce the size of the installation and that the installation can easily be integrated into a production line, since the parts to be treated return to the same place after their treatment.

The invention is embodied in various embodiments of the installation, which may in particular vary depending on whether the application envisaged leads to privileging or not the possibility of involving workers on a chemical treatment tank at a standstill while the the other is in operation as well as the rest of the different equipment of the installation. In any case, the circulation of the cages containing the charges to be treated can advantageously be organized so as never to pass a cage out of a polluting bath over a bath to keep clean and to circumscribe around the tanks of chemical treatment areas on which they may drop drops of liquid or other soiling. This avoids having to equip the tanks so-called clean areas of covers and sealing devices to the passage of the cages.

According to a first preferred embodiment of the invention, the two chemical treatment tanks are each arranged at one end of the second line and different finishing tanks are associated with them, respectively between the corresponding tank and a central zone of the installation between the two lines. It is then advantageously in this middle zone that the means for transferring charges from one line to the other are arranged.

A single manipulator can be used for this purpose, since it comprises the means giving it the degrees of freedom necessary for it to be operative both in direction to go to bring the charges to a chemical treatment tank (phosphating, for example ), in return direction to take them out of the last corresponding tank (finishing tank). According to a secondary characteristic, the plant according to the invention comprising three rinsing tanks used in the context of the preparation treatment, one of these tanks is disposed in each line while the third is arranged between the two lines, in the central aisle, the three tanks being aligned in a transverse direction so as to achieve an H arrangement of all the tanks.

According to other advantageous embodiments, the transverse transfer means comprise two separate manipulators, this solution being particularly preferred when the two chemical treatment tanks used alternately are grouped side by side on the second line. In this case, on the other hand, it will generally be preferable to adopt a so-called U configuration, consisting in arranging these link transfer means between the two lines at one end of the installation, common to the two lines, rather than in one zone. median as before. Said means then advantageously comprise, in particular in the context of a phosphating plant of metal parts, a first transfer transfer manipulator disposed at a tank of the final station of the preparation treatment and passing a cage of the first line in the second line and a second transfer transfer transfer manipulator disposed at a tank of the final station of the finishing treatment and passing a cage from the second line to the first line.

The design according to the invention advantageously allows the use of tanks having a symmetry with respect to their axis or their center so that each tank can be placed in one line or the other; you just have to turn it 180 degrees. On the side of the tank which is adjacent to the central aisle, everything relating to the power circuits, in particular the heating resistors, is arranged so that only one power supply line is used. On the other side, which is arranged outside, the control and regulation circuits are placed. In particular, in the case where the chemical treatment tanks, for example phosphating, are disposed at the end of the line, they are accessible on three of their sides, which greatly facilitates the maintenance and cleaning of these chemical treatment tanks . In all cases, the aisle separating the two lines makes it possible to obtain an intermediate position of the transverse transfer means in which the two longitudinal manipulators can move over all of their respective lines.

According to another characteristic of the invention, each cell of the loading / unloading device can receive a carriage with its load and this carriage is immobilized in the cell until the return of its load, that is to say all parts contained in the same cage. This arrangement ensures that the loads do not remain during processing, since the carriage remains prisoner until the return of its load. In addition, the work of the operators is minimized since their only actions are to enter or exit the carts in the cells, the loads are then moved by the manipulators. In particular, it is no longer necessary to push or pull piles of baskets, which simplifies the trolleys, which can be constituted by a simple trolley.

The provision of several cells in the loading and unloading device also makes it possible to provide other means of supply of loads such as wire trolleys or conveyors, the different modes of supply can "cohabit" and be used interchangeably during a treatment.

Advantageously, the installation according to the invention is made in the form of pre-assembled modules comprising the loading / unloading device or tanks with their support and their steam extraction device and at least a part of the manipulator support. This modular structure, which consists of six or seven modules, for example, delivered pre-assembled and assembled at the point of use, minimizes on-site operations.

According to yet another characteristic of the invention, the load consists of a U-shaped cage containing the parts to be treated and there is provided in each load / unloading cell, an intermediate support which has a horizontal wall upper cover and on which the cage remains attached during the entire duration of the treatment, the intermediate support being grasped by the manipulators and placed on each in such a way that the cage is suspended in the tank and immersed completely in the treatment bath.

The fact that the cage is suspended and not placed in the tank allows a much better circulation of the bath and improves the treatment of parts arranged in the bottom of the cage. Furthermore, the intermediate support allows to obtain a total immersion of the cage while protecting, thanks to its lid, the manipulator of any contact with the baths. In addition, the supports receiving the intermediate support are out of the bath, which makes it easy to perform their initial adjustment for horizontal alignment. Finally, these supports are closer to the manipulator so that there is no problem of centering the latter.

According to one embodiment of the invention, the cage comprises, at its upper part, horizontal rods which are perpendicular to the direction of translation of the longitudinal manipulators and which cooperate with hooks arranged at the lower part of the intermediate support, the hooking or unhitching of the cage on the intermediate support being obtained, in each cell, by a small horizontal displacement followed by a lifting movement of the longitudinal manipulator of the first line.

Advantageously, the intermediate support comprises measuring devices and / or a data storage device in which the processing monitoring is recorded. In particular, the intermediate supports can be equipped with on-board temperature probes and record, for each load, a follow-up of the treatment times and the temperatures. This information will be read in the loading / unloading device and recorded on a support accompanying the processed parts in the rest of the production line.

It is also advantageous in the second line to add a refining tank to each chemical treatment tank. This arrangement allows, when only one tank is used, to use the other tank as a bath preparation tank or "premix" tank. In addition, the place taken by the second refining tank does not increase the length of the installation, because the location it occupies is useful to allow the release of the manipulator and thus avoid an overflow above the second treatment tank when it is in maintenance.

According to yet another characteristic of the invention, the installation comprises cascade rinsing tanks disposed adjacently in a line, on the side of each rinsing tank, there is provided a first siphoid wall parallel to the line, which is connects to a complete partition perpendicular to the line to form, with the side wall and the upstream partition of the tank, a water inlet zone and a second siphoid wall perpendicular to the line which connects to a complete partition parallel to the line for forming with the side wall and the downstream wall of the tank, a water discharge zone, the upstream and downstream walls comprising, in the arrival and discharge water zones, an upper indentation of which the lower part is substantially at the level of the rinsing bath. The rinsing water supply is therefore on the side of the tanks and the siphonic partitions allow circulating the rinsing water around the load before it is evacuated.

Preferably, the upper part of the siphoid walls is crenellated so that the supernatant elements of the rinsing bath also circulate in the tank passing over the siphoid walls.

Advantageously, the arrival and discharge water zones are arranged on the outer sides of the line. In this way, these areas are accessible without having to enter the internal aisle separating the two lines, outside the side curtains usually provided protection.

The zone between the two zones of arrival and discharge of water constitutes a zone of measurement and sampling of the bath. This zone is in direct communication with the bath surrounding the charge, and thus measurements of the charge processing conditions can be made.

In addition, the water discharge zone constitutes a bath level control zone. The level measurement in this zone advantageously controls the supply of water to the first tank.

According to yet another characteristic of the invention, the lower part of the first siphoid wall is curved in the direction of the downstream wall of the tank. The resulting throttling makes it possible to regulate the "flushing" of the rinsing water, that is to say the proportion of rinsing water which passes under the siphoid tank and that which passes over it.

• la figure 1 est une vue de dessus d'un premier mode de réalisation de l'invention ;
• la figure 2 est une vue de dessus d'un deuxième mode de réalisation de l'invention ;
• la figure 3 est une vue de dessus d'un troisième mode de réalisation de l'invention ;
• la figure 4 représente, en perspective une cage en "U" ;
• la figure 5 représente en vue de côté, une cage, son support intermédiaire et le dispositif de préhension ;
• la figure 6 est une vue de côté du support intermédiaire ;
• la figure 7 est une vue de dessus de trois cuves de rinçage juxtaposées ;
• les figures 8 à 10 sont des coupes selon les lignes VII-VII, VIII-VIII et IX-IX de l'ensemble de cuves de la figure 7 ;
• la figure 11 est une coupe partielle de la première cloison siphoïde ;
• la figure 12 est une vue en coupe transversale montrant les deux manipulateurs longitudinaux ; et
• la figure 13 est une vue en coupe transversale montrant le manipulateur transversal de liaison.

Other characteristics and advantages of the invention will emerge from the following description of exemplary embodiments of the invention provided by way of illustration but in no way limiting, with reference to the accompanying drawings, in which:

• the figure 1 is a top view of a first embodiment of the invention;
• the figure 2 is a top view of a second embodiment of the invention;
• the figure 3 is a top view of a third embodiment of the invention;
• the figure 4 represents, in perspective a "U"cage;
• the figure 5 represents in side view, a cage, its intermediate support and the gripping device;
• the figure 6 is a side view of the intermediate support;
• the figure 7 is a top view of three juxtaposed rinsing tanks;
• the Figures 8 to 10 are sections along the lines VII-VII, VIII-VIII and IX-IX of the tank set of the figure 7 ;
• the figure 11 is a partial section of the first siphoid septum;
• the figure 12 is a cross-sectional view showing the two longitudinal manipulators; and
• the figure 13 is a cross-sectional view showing the transverse link manipulator.

The figure 1 shows schematically a top view of a first embodiment of an installation according to the present invention which is intended for a manganese phosphating treatment of parts of the automotive industry, for example transmission gears .

The different treatment tanks are arranged contiguously on two parallel lines 1 and 2 which are separated by a central aisle 3. The first line 1 comprises a device 4 for loading and unloading charges which comprises several adjacent cells 20 which can receive a trolley carrying containers containing the workpieces. Following this loading and unloading device 4 are two cooling tanks 5 and 6, then a drying tank 10, a first alkaline rinsing tank 7 and a degreasing tank 8. The second line 2 comprises at each its ends a phosphating tank 9 and 11, and each of the two phosphatation tanks, it is associated with a refining tank 12 and 13 adjacent.

After the refining tank 12 located in the vicinity of the loading and unloading station 4, there are three adjacent acid rinsing tanks 14, 15 and 16, followed by a drying tank 17 similar to the drying tank 10 of the line 1. The two drying tanks 10 and 17 are aligned in a direction perpendicular to the two lines. A third alkaline rinse tank 18 is placed adjacent to the drying station 17 after which the refining tank 13 and the phosphatizing tank 11 are located. A second alkaline rinse tank 19 is arranged in the alley 3 in transverse alignment with the first rinse tank 7 and the third alkaline rinse tank 18, these three tanks being adjacent to each other. An "H" arrangement is thus obtained for all the constituent elements of the installation.

The displacement of the charges in the first line 1 is achieved by means of a first longitudinal manipulator with two axes capable of translational movements parallel to the first line 1 and movements of descent or lifting of the load. A second longitudinal two-axis manipulator is provided for the displacement of the loads in the second line 2. There is further provided a three-axis transverse link manipulator, which can perform translational movements parallel to the lines of a rinsing tank. a drying tank, transverse translation movements between the three rinsing tanks and lifting or lowering movements of the loads.

Advantageously, the various components of the installation are assembled according to pre-assembled modules, which are mounted at the factory and which are assembled together at the work site. Each of these modules comprises one or more tanks, or the loading / unloading device with the tank support device and the vapor extraction device (not shown), as well as a part of the support on which the manipulators circulate.

In the embodiment shown, a first module comprises the loading / unloading cells 20 with a first part of the support of the longitudinal manipulator of the line 1, a second module is constituted by the two cooling tanks 5 and 6 with their support and their device for extracting vapors. A third module comprises the three alkaline rinsing tanks 7, 18 and 19 with the assembly of the transverse connecting manipulator and a part of the transverse manipulator support of the line 1 and a part of the support of the longitudinal manipulator of the line 2 A fourth module comprises degreasing tanks 8 and part of the support of the longitudinal manipulator of line 1, a fifth module comprises phosphating tanks 9 and refining 12, a sixth module comprises the three acidic rinsing tanks 14 to 16, and the seventh module comprises the phosphating tank 11 with its associated refining tank 13. These last three modules comprise part of the support of the transverse manipulator of the line 2.

The figure 2 represents a variant of the installation of the figure 1 . There are a number of constituent elements of the installation of the figure 1 with the difference that the two drying tanks 21 and 22 are arranged after the acid rinsing tanks 14 to 16 with which they constitute a module. Moreover, the two cooling tanks 23 and 24 are placed at the location of the drying tanks 10 and 17 of the installation of the figure 1 . This embodiment has only six modules instead of seven in the installation of the figure 1 , a new module grouping the three alkaline rinsing tanks and the two cooling vessels 23 and 24 and the two drying vats 21 and 22 are grouped together in the acid rinsing module 14 to 16.

The figure 3 represents another embodiment of the invention. It includes the loading and unloading device 4 with its cells 20, following which are arranged successively the degreasing tank 8 comprising two cells, the first alkaline rinse tank 7, the second alkaline rinse tank 19, and the tank third alkaline rinse 18, in which is carried out the last stage of the preparation treatment. This tank 18, which is therefore the final tank of the preparation treatment, extends over the entire width of the installation, that is to say on the lines 1 and 2 and on the aisle 3.

A first transfer transfer manipulator, which carries out the passage from the first line 1 to the second line 2, is disposed at this final tank 18. It is constituted by a transfer carriage 25 which moves longitudinally in the vessel 18 and which receives charges deposited therein by the longitudinal transfer manipulator of the first line 1 and which are taken up by the longitudinal transfer manipulator of the second line 2. It is therefore a simple manipulator with a single axis of displacement.

In the second line 2, there is, starting from the final preparation tank 18, a refining tank 12, the first phosphatizing tank 9 comprising three cells, the second phosphating tank 11, the first acid rinsing tank 14 the second acid rinse tank 15, the third acid rinse tank 16 and the two drying tanks 17 and 10.

The cooling tank 5 is arranged in the alley 3, at the end opposite the device of the loading and unloading device 4, just after the final preparation tank 18. On either side of this cooling tank 5 in each of the lines 1 and 2, there is provided a maintenance station 26 and 27 of the longitudinal transfer manipulator of the line.

There is provided a second transfer transfer manipulator 29 which is also constituted by a transfer carriage and which carries out the return of the second line 2 to the first line 1.

In the embodiment of Figures 1 and 2 the two connecting manipulators are constituted by a single manipulator with three displacement axes 63 which, as described elsewhere, performs the forward flow from the first line 1 to the second line 2 at the level of the alkaline rinsing tanks 7, 19 and 18 and the return flow from the second line 2 to the first line 1 at the drying tanks 17 and 10 in the case of the figure 1 and at the level of the cooling tanks 23 and 24 in the case of the figure 2 .

The embodiment of the figure 3 comprises four modules, in addition to the loading and unloading device 4. The first module comprises degreasing cells 8, first alkaline rinse 7 and second alkaline rinse 19. The second module groups the refining cell 12 and the cells of phosphatation constituting the first phosphatation tank 9. The third module comprises the second three-cell phosphating tank 11. The fourth module comprises the first, second and third acid rinsing tanks 14 to 16 and the drying station comprising the tanks 17 and 10. Finally, the fourth module consists of the third alkaline rinse tank 18 and the cooling station 5.

Each of the cells 20 of the loading and / or unloading device 4 can receive a carriage on which is placed a container constituting a basket in which are placed the metal parts to be treated. According to the invention, the receptacles intended to receive the parts to be treated are indeed constituted by a kind of "U" shaped cage having a bottom and two side vertical walls. This basket structure makes it possible to obtain very good circulation of the treatment baths around the parts to be treated.

Such a cage is represented on the figure 3 . It comprises a bottom 31 and two opposite vertical side walls 32. When a cage is in position in a cell 20, the side walls 32 are parallel to the direction of the line of the tanks. Each upper wall comprises two rods 33 which are perpendicular to the tank line and which cooperate with hooks arranged at the bottom of an intermediate support adapted to be gripped by a transverse manipulator or the connecting manipulator.

The figure 4 represents in section such a cage 30 above which there is an intermediate support 34, which can be grasped and transported by a manipulator 35. The intermediate support 34, which is shown in cross section on the figure 5 , comprises hooks 36 which are arranged in a plane parallel to the tank lines at the bottom of the support 34. These hooks 36 are fixed on transverse horizontal bars 37 disposed at the upper part of the intermediate support 34. Below these bars 37 is a plate 38 forming a lid, which is inclined relative to the horizontal as can be seen on the figure 5 , and which, as we can see on the figure 4 , is folded along a transverse axis, so as to have the shape of a "V" very open upwards. The bars 37 can be gripped by the manipulator 35 by means of horizontal displacement grippers.

On the figure 5 the intermediate support 34 is shown in its rest position in a cell 30. The ends of the bars 37 rest on supports 39 of the loading and unloading cell.

The figure 6 represents, in top view, the three acid rinsing tanks 14, 15 and 16, which are arranged one behind the other in the line of the installation. In this figure, we can observe suction ducts 41 of the vapors which are arranged above the tanks. One can also see in the first rinsing tank 14, a load constituted by an intermediate support 34 and a cage 30. The whole of this cage and its intermediate support is suspended above the bath, the cage 30 being completely immersed and hooked on the intermediate support 34; the ends of the bars 37 of the intermediate support 34 rest on supports 42, arranged on the edge of the tank, which have a section in the shape of a "V".

These three acid rinsing tanks 14 to 16 are arranged and arranged in such a way that the water which arrives upstream via a pipe 28 flows successively into the third rinsing tank 16, the second rinsing tank 15 and the first rinsing tank. 14, to then reach an evacuation zone from which the residual water is recovered, for example by means of a pump, and sent to the phosphatation tanks. This is possible because one is in line 2, in a set of treatment with acid medium.

The different tanks are separated from each other by total partitions, that is to say partitions that are connected to the bottom of the tank, but these partition walls 44 and 45 have, on the left side, a notch allowing the cascade from one tank to another.

According to the invention, the cascade circulation of the bath water is carried out by means of siphoid partitions which are arranged in a particular arrangement. A first siphoid partition 46 is disposed in the left part of the tank, parallel to the axis 50 of the tank line 2. This siphoid partition is connected on the one hand to the upstream partition 47 of all the tanks, and on the other hand, to a total partition 48 which is perpendicular to the axis 50 and is connected to the left side wall 49 of all the tanks. In the downstream part of each tank is a siphoidal partition 51 which is perpendicular to the axis 50 and which is connected to the side wall 49 on the one hand and, on the other hand, to a total wall 52 which is connected to it. -at the downstream wall of the tank, namely the partition wall 44 or 45 or the wall 53 separating the first rinsing tank from the discharge zone.

This arrangement is found in each of the tanks and each of the siphoid walls 46 and 51 have at its upper end passages, in the form of crenellations, the bottom is substantially at the bath of the tank. Each time, the walls 46 and 48 define a water inlet zone and the walls 51 and 52 define a water discharge zone. In each tank, between these two areas of water inlet and water discharge, a zone 54 is in direct and complete relationship with the rest of the tank. This zone is used to carry out measurements to determine the operating conditions of each of the rinsing tanks 14 to 16.

Electrical resistors 55 are still shown in the figure, which are used to heat the water of the third rinsing bath 16, as well as the supports 42 in the form of "V" on which the intermediate support 34 is placed. Figures 7 to 9 , there is shown in the tank 14 a load consisting of the cage 30 hooked on the intermediate support 34. It can also be seen, in particular on the figure 9 , the apertures 65 in the form of crenellations of the siphoid walls.

The figure 10 is a partial section showing a siphoid wall 51, parallel to the line of the tanks, and a partition wall, for example, the wall 53. It can be seen on this section, which is a section in a plane parallel to the second line 2 in the left part of the tanks, the opening 56 arranged in the total wall 53 and the slot 65 which is arranged in the upper part of the siphoid partition 51. The bottom of the opening 56 corresponds substantially to the level 57 of the bath in the when the latter is empty and the bottom of the crenellations 55 substantially corresponds to the level 58 of the tank when a charge is introduced.

According to the invention, the siphoid wall 51 is curved in its lower part, in the direction of the wall 53, so as to create a constriction which determines the "flushing" of the evacuation of the water from the tank when one introduces a charge into the latter. Advantageously, the depth and shape of this curvature 59 is determined to obtain an evacuation of the bath water at 90% below the siphoid partition 51 and 10% above by the tooth 55.

We also see on these Figures 7 to 9 a tube 60, disposed at the bottom of each tank transversely and centrally, which serves to perform a stirring of the bath by sending air bubbles. This makes it possible to obtain a good mixing of the bath under the loads and in the zones of arrival and discharge of water, with the exception of the zone 34 in which there are no disturbances and it is possible to carry out measurements as well as bathing samples.

The figure 11 is a cross-sectional view through the refining and degreasing tanks 8. The loads shown in broken lines and resting on the "V" supports 42 and the heating resistors 29 can be seen. this figure the manipulator 61 of the line No. 1 and the manipulator 62 of the line No. 2 in the raised position so as to be able to circulate over all the tanks.

The figure 12 is also a cross section through the alkaline rinsing tanks 7, 18 and 19. It can be seen in particular that the transverse connecting manipulator 63 is also in the up position so as to be able to move transversely across the three rinsing tanks 7, 18 and 19.

The installation just described works in the way that will now be specified.

Trolleys, constituted by simple wheeled tables, receive loads and are brought into one of the cells 20 of the loading / unloading device 4. The feeding can be done manually or by automatic systems, for example those using so-called wire-guided trolleys, which move on a predefined circuit.

The first operation consists in associating an intermediate support 34 which is assigned to each of the cells 20 to each of the loads constituted by a cage 30. First, the manipulator 61 comes to grip the intermediate piece 34 which rested on the supports 39, then it performs a lifting movement to release the intermediate support 34 of the supports 39. The longitudinal manipulator of the line 1 is brought into the cell in a position such that its hooks 36 are slightly offset with respect to the hooking rods 33. A downward movement is then made so that the hooks 36 are below the level of the hooking rods 33. A slight translational movement is then made in the line of the tank line so that the hooks are just below the hooking rods, and ends with a lifting movement so that the rods 33 are gripped by the hooks 36. This gives a load, constituted by the cage 30 and the intermediate support 34, which will be moved throughout the installation and immersed in the various tanks.

The charge obtained is therefore sent to the various processing stations. In a first phase, the manipulator 61 brings the charge successively into the three degreasing tanks 8, then into the first alkaline rinsing tank 7. Each time, the manipulator 61 disengages from the intermediate support 34 and places it on the V-shaped supports 42. During the treatment of a load, the manipulator 61 can manipulate other loads to pass them in different tanks.

The transverse connecting manipulator 63 then seizes the charge in the tank 7 to pass successively into the second rinsing tank 19 and the third rinsing tank 18. This link manipulator 63, when not used, is positioned above the second rinsing tank 19 so as to leave the free passage for the other two transverse manipulators 61 and 62, they can evolve over their entire line.

The charge is then taken by the longitudinal manipulator 62 of the second line, transported from the rinsing tank 18 to a refining tank, corresponding to the phosphating tank which is in operation, for example the refining tank 12. charge is then fed into the phosphating tank 9, then into the three acid rinsing tanks 14, 15 and 16. After the acidic rinsing, the charge is fed to a drying station 10 or 17 and then to the cooling station 6 or 5. When the treatment is finished, the load returns to his cell, where his carrier carriage waits for him who can then bring it back into the production line.

Of course, the installation simultaneously processes several charges, which are handled by one of the three manipulators 61 to 63. The manipulator 63 also has an intermediate position, namely above the second alkaline rinsing tank 19, where it allows the free movement of the other two transverse manipulators 61 and 62 along the entire line 1 or 2.

The plant can operate with an active phosphating tank and a phosphatizing tank being cleaned, which does not interrupt the operation of the plant for tank cleaning operations. This cleaning is further facilitated by the fact that each of the phosphating tanks 9 and 11 is accessible on three of its sides.

In the case where only one of the tanks is in operation, one can advantageously use the refining tank associated with the other tank being cleaned as a tank of "premix", that is to say as a tank in which one prepares the bath for the refining tank in operation.

The cleaning operation of a phosphatation tank is carried out safely because a partition is interposed between it and its refining tank so as to prevent access to the phosphating tank during cleaning.

In the embodiment of the figure 3 , all preparation treatment stations are arranged in the first line 1 which is therefore a "clean" line, that is to say that the charges circulate in the line without danger of falling droplets comprising a chemical during their passage over other charges arranged in a treatment station. Only, the alkaline third rinse tank 18 also extends on the aisle 3 and the second line 2.

The second line 2 comprises all the finishing treatment stations, with the exception of the cooling station 5 which is located in the aisle 3, and the chemical treatment, refining 12 and phosphating tanks 9 and 11. The second line may be considered a "dirty" line because charges with a chemical may flow over other charges being processed.

In the two lines, the different tanks are arranged in the order of the treatment steps starting from the loading and unloading device 4, in the first line 1, and in the opposite direction, starting from the third alkaline rinsing tank. 18, in the second line 2.

In this way, there is no risk of droplets of phosphatation product droplets during the transfer of charges above the charges during treatment. Indeed, each load travels all the line 2 by passing through one of the phosphating tanks 9 or 11 and returns to the dry state, so without risk of falling droplets, passing over all the tanks to reach the level of the second link manipulator 29 which passes through the cooling chamber 5, then in the first line 1. The load is then taken by the transverse manipulator of the line 1 and transferred into its cell of the loading device and reloading 4.

The cascade operation of the acidic rinse tanks will be explained with reference to Figures 6 to 9 . The level in the various tanks is regulated by means of a level measuring device disposed in the zone 43 which is not turbulent and which acts on the flow rate of the feed device 28. There is no charge in a tank, the passage of the clear water supply in the third rinse tank 16 is simply performed from below the siphoid partition 46. When a charge is introduced, in the tank 16 by example, the level goes up as shown on the figure 10 and the passage of the first bath of rinsing in the tank 15 is then 90% below the siphoid wall 46 and 10% above by the crenellations 55; in particular the supernatants are then removed from the water supply zone to the tank 16.

The water sent into the tank 16 circulates in the latter being brewed by the air bubbles sent by the pipe 60 and the bath spring in the zone 54 to pass, still 90% below the siphoid partition 51, 10 % of bath passing over crenellations with supernatants. The same phenomenon occurs for tanks 15 and 14, which ensures complete circulation of the bath, and the dirty water in zone 43 is discharged, for example by a pump, and sent to a phosphatation tank. This makes it possible to limit as much as possible the water consumption of the installation, to arrive at a very low consumption, which is, for example, less than two liters of water per m ² of treated room surface.

Thanks to the use of the intermediate support 34, the cages 30 are, in each case, completely immersed in the baths, which makes it possible to avoid any interface between a bath and the external atmosphere which could create damage to the cage . In addition, it is completely cleaned in the rinsing and degreasing tanks. It can therefore be reused and returned to the production line.

The cover 38 provides total protection of the manipulators. In addition, it allows to collect and evacuate outside the tanks condensates that can form above them.

Advantageously, the intermediate supports 34 are provided with measuring devices, such as temperature sensors, as well as data recording devices which make it possible to record the follow-up of the complete treatment, with particular reference to the temperatures and durations of the data. each treatment. At the end of the treatment, in the loading and unloading station 4, the corresponding data can be picked up and sent to an information carrier accompanying the parts in the rest of the manufacturing stations.

It can be seen that the invention makes it possible to obtain an extremely compact installation compared to current online installations. The fact of using two chemical treatment tanks makes it possible to obtain great flexibility in the capacity and the rate of operation of the installation. Indeed, when one of the two phosphating tanks 9 or 11 is considered soiled and requires cleaning, the second tank is used, which allows not to interrupt the operation of the installation which is only stopped when the second The tank is also soiled to clean the two tanks. In the case of the embodiments of Figures 1 and 2 where the two treatment tanks are arranged at one end of the second line and can be isolated, the tanks can be maintained without stopping the operation of the installation.

The arrangement of the different tanks in two lines with a central aisle makes it easy to carry out the necessary maintenance and monitoring operations.

The use of the intermediate support makes it possible to have containers that are not damaged during processing and that can therefore be reused. In particular, they can be put back into service in the production line.

The fact of providing a refining tank associated with each of the chemical treatment tanks makes it possible, when a tank is being cleaned, to use its refining tank in a premix tank for the other chemical treatment tank, which is it active, which allows to increase the rate of operation.

In a practical embodiment of the invention, eleven charging cells are provided, the complete cycle of the treatment lasts 42 minutes and charge displacement is carried out every four minutes. We can then treat 4.5 tons per hour of parts to be phosphated.

It is understood however that these indications are only there to provide an example of a practical case of implementation of the invention. It must also be retained from all the foregoing that the invention is not limited to the embodiments which have been specifically described in the course of the examples above and which, on the contrary, extends to any variant passing through equivalent means.

In particular, it can be provided that the two cooling tanks are arranged in the loading and / or unloading device in a variant according to which two additional loading / unloading cells are provided so as to obtain three cells accessible to the load-bearing carriages. The other cells, including both having a cooling tank, are closed and have only supports capable of receiving the intermediate supports. The fact of providing three loading / unloading cells makes it possible to group the movements of the manipulator, which leaves more free time for the operator who must store the empty carts corresponding to the closed cells in the vicinity of the installation.

Furthermore, it can be provided that the hooks of the intermediate support are directed in a plane perpendicular to the axis of the two lines and that the hooks arranged on one side of the support, for example the hooks arranged on the outer side of the line, are offset with respect to the other two hooks, a corresponding offset being provided for the hooking rods of the cage. In this way, the first hooking rods of the cage, which are made in the form of rings, pass next to the outer hooks of the intermediate support and are placed in the other two hooks. When the carriage is fully engaged in the cell, the rods are in their corresponding hooks a little above the bottom of the hooks, so that the catch of the cage is obtained by a single lifting movement of the manipulator. Because of the axial symmetry of the arrangement of their rods, the cages can be introduced by any side, the rods being always positioned for proper placement in the cell.

Claims (14)

1. Installation for chemical treatment by immersion of parts which are contained in cages, by immersion of each cage in a tank (9, 11) containing a chemical treatment bath, the parts being subjected in other tanks to prior preparatory treatment and to subsequent finishing treatment, the tanks of the different treatment stations being disposed in two parallel rows (1, 2) which are separated by an aisle (3) which permits access to the tanks, characterised in that a first row (1) comprises a single loading and unloading device which is disposed at one of its ends, as well as preparation tanks (7, 8, 18, 19), and a second row (2) comprises two chemical treatment tanks (9, 11) which are used alternately, and finishing tanks (10, 14-16, 17, 21, 22), in that a longitudinal transfer handler (61, 62) is provided in each row (1, 2) in order to make each cage go individually from one tank to another in the same row, and in that it comprises longitudinal transfer means (25; 63) which provide the connection between the two rows, in order to make the cages go from one row to the other in the outward and return directions.
2. Installation according to claim 1, characterised in that the said loading and unloading station comprises a plurality of cells for receipt of loads, each receiving a determined load at the intake of the installation, and the same load at the output, each cell (20) of the loading and unloading device advantageously being able to receive a carriage which supports the load, and is kept immobilised in the cell until its load returns.
3. Installation according to claim 1 or 2, characterised in that the said chemical treatment tanks (9, 11) are each disposed at one end of the second row, and the finishing tanks (14-18), in that a longitudinal transfer handler (61, 62) is provided in each row, and in that the said transverse transfer means (63) are disposed in a median position between the said two rows (1, 2), and are advantageously constituted by a single handler which is disposed at the level of a rinsing tank for the preparation treatment.
4. Installation according to claim 3, characterised in that it comprises three rinsing tanks for the preparation treatment, one disposed in each row (7, 18), and the third (9) disposed between the two rows, in the aisle (3), the three tanks being aligned according to a transverse direction such as to provide an arrangement in the form of an "H" of the tank assembly.
5. Installation according to claim 1 or claim 2, characterised in that the said chemical treatment tanks (9, 11) are grouped in adjacent positions in the second row, and in that the said transfer means comprise a first handler which is disposed at the level of a tank (19; 18) of the final station for the preparation treatment, and make a cage in the first row (1) go to the second row (2), and a second connection transfer handler (29; 63) which is disposed at the level of a tank (15; 10, 17) in the final station of the finishing treatment, and makes a cage go from the second row (2) to the first row (1).
6. Installation according to claim 5, characterised in that a tank (19; 18) of the final station of the preparation treatment is disposed between the two rows (1, 2), in the aisle (3), such as to extend along the entire width of the installation, and in that the first connection transfer handler (25) is constituted by a transfer carriage which moves transversely in the said final preparation tank (18).
7. Installation according to either of claims 5 and 6, characterised in that the final station of the finishing treatment comprises an enclosure (5) which is disposed between the two rows (1, 2), in the aisle (3), at the end opposite the loading and unloading device (4), in that the second connection transfer handler (29) between the two rows (1, 2) is disposed at the level of this final finishing enclosure (5), and in that each row (1, 2) comprises a station for maintenance of its longitudinal transfer device (61, 62), these two maintenance stations of the longitudinal transfer device (61, 62) being disposed on both sides of the said final finishing enclosure (5).
8. Installation according to any one of claims 5 to 7, characterised in that all the preparation tanks (8, 7, 19, 18) are disposed in the first row (1), in the processing order, starting from the loading and unloading device (4), and in that all the finishing tanks (14-16, 17,10) are disposed in the second row (2), in the processing order, starting from the two chemical processing tanks (9, 11), going towards the loading and unloading device (4).
9. Installation according to claim 2, optionally combined with any one of claims 3 to 8, characterised in that the load is constituted by a cage (30) in the form of a "U" containing the parts to be treated, and in that, for each cell of the loading and unloading device (4), an intermediate support (34) is provided, which has an upper horizontal wall (38) which forms a cover, and to which the cage remains fastened through the duration of the treatment, the intermediate support being grasped by the handlers and placed on each tank, such that the cage is suspended in the tank, and is totally immersed in the treatment bath.
10. Installation according to claim 9, characterised in that the cage (30) comprises on its upper part horizontal rods (33) which are perpendicular to the direction of translation of the longitudinal handler, and which co-operate with hooks (36) which are disposed on the lower part of the intermediate support, fastening or unfastening of the cage onto or off the intermediate support being obtained, in each cell, by slight horizontal displacement followed by lifting movement of the horizontal handler of the first row.
11. Installation according to claim 9 or claim 10, characterised in that the intermediate support comprises measurement devices and a data storage device in which the monitoring of the treatment is recorded.
12. Installation according to any one of the preceding claims, characterised in that, in the second row (2), a refining tank (12, 13) is added to each chemical treatment tank (9, 11).
13. Installation according to any one of the preceding claims, characterised in that it comprises tanks (14-16) for rinsing in cascade, which are disposed in an adjacent manner in a row (2), in that, on the side of each rinsing tank, a first siphonal partition (46) is provided, parallel to the row which is connected to a full partition (48) perpendicular to the row, in order to form a water intake area together with the lateral wall (49) and the upstream partition (47, 44, 45) of the tank, and a second siphonal partition (51) is provided perpendicular to the row, which is connected to a full partition (52) parallel to the row, in order to form a water discharge area together with the lateral wall (49) and the downstream wall (44, 45, 53) of the tank, the upstream and downstream walls (47, 44, 45, 53) comprising, in the water intake and output areas, an upper cut-out (56), the lower part of which is substantially at the level of the rinsing bath, the said water intake and discharge areas advantageously being disposed on the outer side of the row, the said siphonal partitions (46, 51) advantageously having pinnacles (55) in their upper part, whereas the lower part of the second siphonal partition (51) is advantageously curved in the direction of the upstream wall (53) of the tank (14, 15, 16).
14. Installation according to claim 12 or 13, characterised in that the area (54) contained between the two, water intake and discharge areas constitutes a measurement and sampling area of the bath, and in that the water discharge area constitutes an area for control of the level of the bath.

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