EP2769773B1 - Facility for surface treatment of parts by immersion - Google Patents

Description

The present invention relates to an improvement in the process of surface treatment of continuous parts using the principle of immersion and transfer of parts, such as for example the treatment of metal parts, and more particularly a conversion treatment such as, for example, anodizing of an aluminum part, or even by electrolysis.

The present invention relates more particularly to a new type of surface treatment plant.

Various processes are already known for surface treatment of parts, and more particularly of metal parts such as aluminum, steel, copper, brass, but also parts made of plastics. There may be mentioned, for example, anodic treatments of aluminum and its alloys, cathodic treatments of ferrous alloys such as steel or non-ferrous alloys such as copper or brass, metallization treatments in aqueous phases of plastics. Similarly, the surface treatment of parts by electrolysis is a well known method, which requires the implementation of an electric current for carrying out the treatment.

The parts to be subjected to an immersion surface treatment are generally fixed on supports called tools. These tools are then grouped on frames which are themselves moved from tank to tank using hoists.

In a conventional installation the parts to be treated, fixed on their supports are immersed vertically, from top to bottom, in the treatment baths where they remain stationary for the duration of the treatment. This technique has two major disadvantages for the surface treatment of parts; firstly the parts to be treated remain motionless during the treatment which makes it uneven on the different faces of each of the parts, secondly the surfaces of the tools and the chassis supporting them are themselves subjected to the treatment and thus consume a significant part of the energy and metals used for the transformation or deposition sought by the surface treatment operation.

The documents DE 37 39 602 A1 , US 2009/123658 A1 , US 2003/213429 A1 , US 826 258 A and WO 2011/123132 A1 describe previous installations.

The present invention provides a significant improvement in the treatment of parts by allowing the implementation of an oscillation stirring of the parts during the immersion phase in the treatment bath, it also makes it possible to reduce the surfaces of the supports to the minimum necessary. which parts to be treated are fixed, and to reduce the consumption of metals and energy by the surface of the supports during the treatment phase, while improving the quality of the treatment on the parts.

Thus, the surface treatment plant of parts according to the invention comprises at least one treatment tank comprising a treatment liquid in which is immersed at least in part an arm bearing on one of these ends at least one support of parts comprising a lower face and an upper face holding in position the parts to be treated, characterized in that it is rotatably mounted about an axis (X) situated on the one hand outside the vessel and on the other hand a level below the level constituted by the upper end edge of the tank.

According to a complementary feature, the general shape of the arm has a non-rectilinear shape, but concave is in the form of a C consists of several portions not in the extension of one another.

According to a complementary claim, the arm (s) have two extreme positions and that in one of the positions, the part support is kept outside the vessel so that the general plane of the support (s) is parallel. the plane determined by the surface of the liquid contained in the tank, the lower face of said support being facing towards the bottom of said tank, which allows the treated parts to properly empty excess liquid after treatment.

According to another complementary feature, the arm (s) comprise two end positions and in that one of the positions, the support (s) of parts is (are) maintained (s) so that the general plane of the support in a position in which the upper face of the support pieces is facing towards the bottom of the tank.

According to one of the embodiments, the arm (s) has / have substantially the shape of a C whose one end is fixed to the axis of rotation and its other end portion carries the part support which is intended to be immersed in the bath by the rotating action of the arm (s).

Note that the axis of rotation is rotated by the action of an engine located at a level below the level constituted by the upper edge of the tank.

According to one embodiment, the tank has an outward extension in its upper part to both protect the engine and the axis and also to recover the excess treatment liquid when the support piece is kept outside the tank.

It should be added that the part supports are held in a detachable manner on slides fixed on the end of the arm (s), opposite to the end connected to the axis of rotation.

• Les figures 1 et 2 sont des vues latérales en coupe selon A-A de l'installation.
• La figure 3 est une vue arrière de l'installation.
• La figure 4 est une vue latérale en coupe selon A-A de l'installation selon un deuxième mode de réalisation.
• Les figures 5 et 6 sont des vues latérales en coupe selon A-A de l'installation selon un troisième mode de réalisation.

Other features and advantages of the invention will become apparent from the description which follows with reference to the accompanying drawings which are given by way of non-limiting examples.

• The Figures 1 and 2 are side views in section AA of the installation.
• The figure 3 is a rear view of the installation.
• The figure 4 is a sectional side view along AA of the installation according to a second embodiment.
• The Figures 5 and 6 are side views in section along AA of the installation according to a third embodiment.

The treatment plant of the invention comprises at least one surface treatment vessel (2) of parts (5) containing a treatment liquid (4) in which the parts (5) to be treated are immersed. The parts (5) are held on at least one support (6), preferably perpendicular to the general plane (P) of the support. The support (s) (6) is / are held (s) detachably by at least one slide (7) fixed on one end (32) of one or more arms (3) movable in rotation. Said / said support (s) (6) comprises (NT) a lower face (6b) and an upper face (6a), the lower face (6b) comprising holding means on the slide, and the upper face (6b). 6a) comprises means for fixing the parts (5) to be treated.

According to the method implementing the treatment plant of the invention, each piece (5) is immersed in a tank (2), making it at least one rotational movement such that the air bubbles that can be created inside the tank are driven out, thus allowing the treatment liquid (4) to treat the entire part (5), making the treatment perfectly homogeneous.

The mobile arm (3) of the invention has substantially the shape of a C whose one end (31) is fixed to an axis of rotation (X) actuated by a motor (10), and whose another opposite free end (32) carries one or more support pieces (6) via a slide (7) for releasably holding the support (6) pieces.

According to the invention, the axis (X) of rotation is rotated by the action of a motor (10), and according to the preferred embodiment of the invention the axis (X) is located at outside the tank, at a level below the level constituted by the upper edge (2c) of said tank (2).

The / the arm of the invention is / are therefore movable (s) according to a rotational movement whose center is the axis (X) and thus allows the opposite free end (32) to that fixed to the axis (X) to be alternately immersed in the liquid (4) and emerged in a movement back and forth.

In the extreme high position, according to which the free end of the / arm (3) are / is emerged (s), the / the arm (3) are / is no longer in contact with the liquid (4). In this position, the part support held by the / the arm (3) is / are outside (EXT) of the tank (2) or at least emerged from the liquid (4), in a position in which the plane general support (P) is substantially parallel to the plane (PL) determined by the surface of the liquid treatment (4) contained in the tank (2).

In another extreme low position, according to which the free end (32) of the / of the arm (3) is immersed, the support (s) (6) of pieces is / are maintained (s) so that the general plane (P) of the / support is / are in a position in which the upper face (6a) of the support (6) of parts (5) is facing towards the bottom (2b) of the tank (2).

According to the preferred embodiment of the invention, the tank (2) comprises a bottom wall (2b) and four vertical walls (2a) forming a space containing the treatment liquid (4). One of the vertical walls comprises means for recovering (MR) excess liquid (4) carried by the treated parts, the support (s) of the workpiece (6), the slide (s) (7) and the part of the arm (s) having been immersed during the treatment. These recovery means (MR) are formed by a substantially horizontal wall portion (2d) on the upper end (2c) of one of the vertical walls (2a). According to the preferred embodiment of the invention, the upper end (2c) of one of the vertical walls (2a) of the tank (2) has an outward extension (EXT) and said wall portion (2d) is substantially inclined constituting an inclined surface whose slope is oriented towards the inside (INT) of the tank (2), repatriating the excess liquid (4) in the tank (2). Said wall portion (2d) thus comprises four sides (2a), one of which is advantageously in contact with one of the upper ends (2'c) of one of the vertical walls (2a) of the tank (2), or inside the space determined by the tank (2), the opposite side to the latter is advantageously located outside (EXT) of the tank (2) and the other two lateral sides (2a) facing one the other. The length of said walls is of length (L) at least equal to half the length (L1) corresponding to the portion (s) of arm dive (s) in the treatment liquid (4).

According to a complementary feature of the invention, the arm (3) comprises (nt) means, advantageously made by a projection (33), to prevent the surplus liquid (8) of treatment flows along said / said arm (3) and spreads on the axis (X), the engine and the ground.

According to the preferred embodiment of the invention, the motor (10) is advantageously fixed on the outer face of one of the walls (2a) of the tank (2). And according to other embodiments, the motor (10) is fixed on a support independent of the treatment tank (2).

Described in more detail, the arm (3) of the invention, and according to the preferred embodiment, comprises (s) several portions (3a, 3b, 3c). Thus, the / the arm (3) comprises (s), at its / their fixed end (31) to the motor or the axis (X) a first portion (3a) rectilinear, which in an extreme position is substantially parallel to the substantially vertical plane (Pv) formed by the walls of the tank (2), and in another extreme position is positioned to form an angle of between 90 ° and 150 ° relative to the plane (Pv) advantageously vertical walls of the tank. The second portion (3b), consecutive to the rectilinear portion (3a), is of substantially circular arc shape and the third consecutive portion (3c) is advantageously rectilinear for carrying the slide (7) holding the support (s) ( s) (6) of room (s) (5). According to a variant of this embodiment, at least two of the arm portions are in an arc.

According to an embodiment variant represented in figure 4 , the arm portions (3a, 3b, 3c, 3d) are constituted by rectilinear profiles and are four in number integrating the device with the same place for the motor (10) and the same construction of the tank (2 ). The arcuate portion of the first embodiment is in this case made by at least two rectilinear profiles and preferably three straight profiles, replacing the C-profile by a U-shaped profile.

Also, according to yet another embodiment shown in Figures 5 and 6 the / the arm comprises three portions (3a, 3b, 3c) constituted by rectilinear profiles. The / arm (3) are / is of substantially U whose one end (32) is connected to the motor (10) and the other end (31) is connected to the support (6) of parts (5). In this embodiment, the axis (X) of rotation of the motor (10) is close to the upper end of the vessel (2), and the vessel does not have an outwardly extending wall portion (EXT ) on the upper end of one of the vertical walls (2a) of the tank (2). Indeed, when the support (6) of part (5) is raised up position, the excess liquid (8) falls directly into the tank (2).

According to the invention, the arm (3) pivots (s) about the axis (X) by an amplitude greater than or equal to 90 ° and less than 180 °.

The workpiece support (6) therefore passes from a horizontal emergent position to a submerged inclined position for filling and emptying the hollow parts (5) fixed vertically on their support (6).

During the immersion time necessary for carrying out the treatment, the pieces (5) are displaced making at least one round-trip, from an upper limit position, to a lower limit position and vice versa, determined by the extreme position of the / arms, by the setting in motion of / the oscillating arms induced by the motor (10). The area in which the parts move is determined between the bottom of the tank and the surface of the liquid.

This mechanical agitation of the parts in the treatment liquid makes it possible to improve the contact between the parts and the liquid present in the tank and to improve the chemical reactivity on the parts (5). This also makes it possible to provide a better homogeneity of the treatment bath (4).

The electrical contact required for certain treatment operations, in conversion treatments or treatments with deposit, is transmitted to the parts via a braid (9) copper fixed on the axis (X). The current flows through the axis, then the oscillating arm (s) (3), in order to finally be transmitted to the supports (6) and the parts (5) to be treated.

In the case of an electrolytic depositing treatment, such as a copper plating, the parts to be treated will be subjected by the copper braid (9) to a negative polarity and the metal to be deposited fixed on an electrode will be subjected to a positive polarity. .

In the case of an electrolytic conversion treatment, such as anodizing, the parts (5) to be treated will be subjected by the copper braid (9) to a positive polarity and the electrode will be subjected to a negative polarity.

According to the device of the invention, the different vessels required for the different treatment steps are aligned side by side to form a treatment line.

The supports on which the parts are fixed are transferred from one tank to the next tank by transfer means constituted by arms and grippers connected by a common axis making it possible to move in a single transverse movement all the parts supports. one position to the next.

In the installation of the invention the conveyor chain is disposed above the vessel or tanks, and the general conveying axis is parallel to the axis of rotation of the arm or arms.

The conveyor chain comprises at least one movable carriage moving on a guide rail so as to be able to move back and forth, and allow the release of one or more cassettes including the parts already treated, and allow the establishment of one or more cassettes including the parts not yet treated.

The installation of the invention comprises at least one treatment tank and a conveyor chain, and advantageously a downstream storage line for the cassettes of the untreated parts, and an upstream storage line for the cassettes of the parts already processed.

It is understood that the axis of rotation (X) of the arm (3) is arranged on the one hand outside the tank and out of the zone occupied by the latter, and on the other hand under the plane constituted by the upper edge of the tank.

It is also understood that the general shape of the arm (3) has a non-rectilinear shape, but concave or in the form of a C consists of several portions not in the extension of one another.

Claims (10)

1. Installation for the surface treatment of parts, comprising at least one treatment tank (2) containing a treatment liquid (4) in which there is at least partially immersed an arm (3) carrying at one of its ends at least one part support (6) having a lower face (6b) and an upper face (6a) which holds in position the parts (5) to be treated, characterised in that it is rotatably mounted about an axis (X) which is situated on the one hand on the outside of the tank (2) and on the other hand at a level beneath the level constituted by the upper end edge (2c) of the tank (2).
2. Installation for the surface treatment of parts according to claim 1, characterised in that the general shape of the arm (3) has a form which is not straight but concave either in a C-shape or constituted by a plurality of portions which are not a continuation of one another.
3. Installation for the surface treatment of parts according to the preceding claim, characterised in that the arm (3) has two end positions and in that, in one of the positions, the part support (6) is held on the outside (EXT) of the tank (2) so that the general plane (P) of the support(s) (6) is parallel to the plane (PL) defined by the surface of the liquid (4) contained in the tank (2), the lower face (6b) of said support (6) facing the bottom of said tank (2), which allows excess liquid (4) to drain properly from the treated parts (5) after treatment.
4. Installation for the surface treatment of parts according to any one of the preceding claims, characterised in that the arm (3) has two end positions and in that, in one of the end positions, the part support(s) (6) is/are held so that the general plane (P) of the support (6) is in a position in which the upper face (6a) of the part support (6) faces the bottom (2b) of the tank (2).
5. Installation for the surface treatment of parts according to any one of the preceding claims, characterised in that the arm (3) substantially has the shape of a C, one of the ends (31) of which is fixed to the axis (X) of rotation and the other end portion (32) of which carries the part support (6) which is to be immersed in the bath by the rotating action of the arm (3).
6. Installation for the surface treatment of parts according to any one of the preceding claims, characterised in that the arm (3) pivots about the axis (X) with an amplitude greater than 90° and less than 180°.
7. Installation for the surface treatment of parts according to any one of the preceding claims, characterised in that the axis (X) of rotation is made to rotate by the action of a motor (10) situated at a level beneath the level constituted by the upper edge (2c) of the tank (2).
8. Installation for the surface treatment of parts according to any one of the preceding claims, characterised in that the tank (2) has in its upper portion an extension towards the outside (EXT), which allows both the motor (10) and the axis (X) to be protected and also allows excess treatment liquid (4) to be recovered when the part support (6) is held outside the tank (2).
9. Installation for the surface treatment of parts according to any one of the preceding claims, characterised in that the part supports (6) are held in a removable manner on slide members (7) which are fixed to the end (32) of the arm (3) opposite the end (31) that is connected to the axis (X) of rotation.
10. Installation for the surface treatment of parts according to any one of the preceding claims, characterised in that the supports (6) to which the parts (3) are fixed are transferred from one tank (2) to other tanks (2), which are aligned side by side to form a treatment line, by a transfer arm (3), said transfer arms being connected together by an axis so as to move all the supports (6) from one position to the next in a single transverse movement.

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