Method for coating a part of a wiping device

Abstract

A coating method (100) for at least one plastic part of a motor vehicle wiper device (1), characterized in that it comprises: – a first metallization step (101) in which at least one conductive metallic layer is deposited on at least one plastic part to obtain an electrically conductive part, – a second painting step (102) in which the at least one metallized part is coated with a layer of paint by cataphoresis. Figure 1

Description

Title of the invention: Method for coating a part of a wiping device. Technical field of the invention

[0001] The invention relates to a method for coating at least one plastic part of a motor vehicle wiper device. The invention also relates to a wiper device. Technical background

[0002] Existing wiping arms having metallic components are pre-assembled together, then placed on cradles to be painted by cataphoresis.

[0003] Cataphoresis is a painting technique that involves immersing the part in a water-soluble paint bath, with the metal part acting as the cathode. The paint particles suspended in the bath are then transferred from the anode to the cathode by means of an electric current at a specific voltage. The paint particles are then deposited uniformly on the surface of the immersed part. The paint is subsequently drained and cured in an oven.

[0004] However, this cataphoresis process is not compatible with parts that are not electrically conductive or whose electrical conductivity is insufficient, which may be the case, for example, of housings and drive arms of wiping device made of plastic material. Summary of the invention

[0005] The present invention aims to remedy at least partially the above-mentioned drawbacks.

[0006] To this end, the present invention relates to a method for coating at least one plastic part of a motor vehicle wiper device, characterized in that it comprises: - a first metallization stage during which at least one conductive metallic layer is deposited on at least one plastic part to obtain an electrically conductive part, - a second painting stage during which at least one metallized part is coated with a layer of paint by cataphoresis.

[0007] It is thus possible to paint non-conductive parts of the wiping device, or parts with insufficient electrical conductivity, by cataphoresis. Furthermore, in the case of a part produced by additive manufacturing, metallizing the plastic part makes it possible to mask layer defects that may result from additive manufacturing due to the very principle of 3D printing, which deposits the material. by successive layers. This improves the appearance of the element by masking imperfections and avoiding the need for chemical / mechanical post-treatment processes such as mechanical or chemical polishing or tribofinishing, thus simplifying the process and reducing costs.

[0008] The coating process may further include one or more of the features described below, taken alone or in combination.

[0009] At least one part made of plastic material may have been obtained by additive manufacturing.

[0010] The plastic part can be assembled to at least one other element of the wiping device before being metallized and / or before being painted. Metallizing the plastic part to create electrical conductivity in an assembly containing this part allows the second painting step to be carried out on the assembly.

[0011] At least one conductive metallic layer may be a layer of copper, nickel, chromium, aluminum, tin or an alloy such as an alloy based on at least one of the aforementioned elements as a cupro-nickel alloy.

[0012] According to one embodiment, the first metallization step is carried out by electroplating.

[0013] According to one embodiment, the first metallization step is carried out by spraying at least one redox solution in aerosol form.

[0014] At least one plastic material part of the wiping device may be a part of a wiper arm such as a housing or a drive unit or a housing cover or a drive unit cover.

[0015] At least one part of the wiping device may be a part of a wiper blade such as a mount or a lever of an articulated frame.

[0016] The invention also relates to a motor vehicle wiper device comprising a wiper arm intended to be connected to a motorized vehicle wiper mechanism and a wiper blade connected to the end of the wiper arm, characterized in that the wiper device comprises at least one part made of plastic material coated by a coating process as described above. Brief description of the figures

[0017] Other features and advantages of the invention will become apparent from the following description, given by way of example, without limitation, with reference to the accompanying drawings in which:

[0018] [Fig-1] Fig.1 shows a perspective view of a wiping device.

[0019] [Fig.2] [Fig.2] shows a flowchart of a coating process of at least a plastic material part of the wiping device of the [Fig.1].

[0020] [Fig.3] Fig.3 shows exploded view components of a wiping device according to another example of implementation.

[0021] In these figures, identical elements bear the same reference numbers. Detailed description

[0022] The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the features apply only to a single embodiment. Simple features of different embodiments can also be combined or interchanged to provide other embodiments without departing from the scope of the invention as defined by the claims.

[0023] Figure 1 shows an example of a vehicle wiper device 1. The wiper device 1 performs the function of wiping a glazed surface of the vehicle, such as the windshield or the rear window, cleaning it and possibly distributing a cleaning fluid if this is carried out on board.

[0024] The wiping device 1 includes a wiper arm 2 intended to be connected to a motorized wiping mechanism of a vehicle and a wiper blade 3 connected in an articulated manner to the end of the wiper arm 2, generally by means of an adapter 4.

[0025] The wiper arm 2 includes a drive 5 configured to be driven by a reciprocating pivoting motor and a housing 6 configured to be connected on one side to the drive 5 by a pivot joint and on the other side to the wiper blade 3.

[0026] In this example, the wiper blade 3 is a flat blade of the FlatBlade® type. This wiper blade 3 comprises a wiping blade made of a flexible material, at least one longitudinal vertebra (called a "spline" in English), a connector for the assembly and articulation of the blade 3 to the end of the wiper arm 2, in particular via the adapter 4 and a deflector (forming what is called a "spoiler" in English).

[0027] The wiping device 1 comprises at least one part made of plastic material coated by a coating process 100 comprising a first metallization step 101 and a second painting step 102.

[0028] The different stages of the coating process 100 are illustrated in [Fig.2].

[0029] During the first metallization step 101, at least one conductive metallic layer is deposited on at least one piece of plastic material to obtain an electrically conductive part.

[0030] During the second painting step 102, at least one metallized part is coated with a layer of paint by cataphoresis.

[0031] The part is for example a part of the wiper arm 2 such as the housing 6 or the drive 5 or as will be seen later, a cover 11 of the housing 6 or a cover 12 of the drive 5.

[0032] The plastic material part can be made from any type of polymer, in particular non-conductive.

[0033] The plastic material part may have been obtained by additive manufacturing (3D printing) or by injection.

[0034] First metallization step 101: at least one conductive metallic layer is deposited on at least one piece of plastic material to obtain an electrically conductive part.

[0035] At least one conductive metallic layer may be a layer of copper, nickel, chromium, aluminum, tin or an alloy such as an alloy based on at least one of the aforementioned elements as a cupro-nickel (CuNi) alloy.

[0036] The at least one conductive metallic layer has, for example, a thickness between 100m and 30pm, or between 100m and 5pm.

[0037] The first metallization step 101 may include a preliminary physical or chemical treatment phase during which micro-roughness is created on the surface of the part, for example by satin finishing or chemical attack such as by means of an acid, in order to create a good adhesion for the metallic deposit.

[0038] The first metallization step 101 can be carried out by any type of process.

[0039] According to a first embodiment, the first metallization step 101 is carried out by electroplating. Electroplating is based on electrolysis and allows the application of a metallic deposit onto a plastic part by means of a direct electric current, the metal initially being in the form of cations in solution in an electrolyte.

[0040] According to a second embodiment, the first metallization step 101 is carried out by spraying at least one redox solution in aerosol form. More specifically, for example, the simultaneous spraying of at least two aqueous aerosols, a metal in cationic form (oxidant) and a reducer, forms a liquid film in contact with the workpiece within which a redox reaction takes place.

[0041] It is also possible to carry out a reaction activation step by any means, for example by using an acidic solution of palladium chloride.

[0042] To obtain good electrical conductivity of the part, several conductive metallic layers can be deposited on the plastic part, such as, for example, at least one lower layer of copper, at least one layer nickel intermediate and a top layer of chromium or another metal more suitable for the second painting stage 102, i.e. having better electrical conductivity and / or better resistance to preparatory baths.

[0043] In the case of a part produced by additive manufacturing, metallizing the plastic part also makes it possible to mask layer defects that can result from additive manufacturing due to the very principle of 3D printing, which deposits material in successive layers. This improves the appearance of the part by masking imperfections and avoiding the need for chemical / mechanical post-treatment processes such as mechanical or chemical polishing or a tribofinishing process, thereby simplifying the process and reducing costs.

[0044] The plastic material part can be assembled to at least one other element of the wiping device 1 before being metallized and / or before being painted.

[0045] Metallizing the plastic part to create electrical conductivity in an assembly including this part allows the second painting step 102 to be carried out on the assembly.

[0046] For example, it is possible to assemble a part made of metallized plastic material with other elements of the wiping device 1, for example made of metallic material such as axles, hooks or springs or other elements made of metallized plastic material, and then to paint the assembly.

[0047] It is also possible to separately metallize different plastic material elements of the wiping device 1, then paint them, and then assemble them.

[0048] It is also possible to produce an assembly by additive manufacturing, for example a housing 6 and a drive 5 assembled, the housing 6 and the drive 5 of the arm 2 being metallized and painted assembled.

[0049] Second painting step 102: at least one metallized part is coated with a layer of paint by cataphoresis.

[0050] Cataphoresis is a painting technique that consists of immersing the part in a water-soluble paint bath, with the metal part acting as the cathode and the paint particles suspended in the bath migrating from the anode to the cathode by means of an electric current at a certain voltage. The paint particles are then deposited uniformly on the surface of the immersed part.

[0051] After the application of the paint by cataphoresis, and draining, the process may include a polymerization step in an oven at around 180°C.

[0052] It is thus possible to paint by cataphoresis parts of the wiping device which are non-conductive or whose electrical conductivity is insufficient.

[0053] Fig. 3 shows another example of an embodiment of a wiping device 1 in which the wiper blade 3 is a blade with rocker arms.

[0054] The wiper 3 has an articulated frame 7, connected to the wiper arm 2. The articulated frame 7 has a mount 8 and rocker arms 9 articulated to the mount 8, here two, each equipped with fixing claws through which a wiper blade 10 passes to be held.

[0055] The part of the wiping device 1 made of plastic material coated by the coating process 100 can be a part of the wiper blade 3 such as the mount 8 or a lever 9 of the articulated frame 7.

[0056] Furthermore, in this embodiment, the wiper arm 2 includes a cover 11 that attaches to the housing 6, for example by clipping, particularly for closing a hollow housing 6. The wiper arm 2 also includes a cover 12 that attaches to the drive 5, for example by clipping.

[0057] The part of the wiping device 1 made of plastic material coated by the coating process 100 can also be a part of the wiper arm 2 such as the housing 6 or the drive 5 or the cover 11 of the housing 6 or the cover 12 of the drive 5.

[0058] The plastic part of the wiping device 1 can be assembled to at least one other element of the wiping device 1 before being metallized and / or before being painted. More specifically, for example, the plastic mount 8 and the rocker arms 9 of the articulated frame 7 can be assembled before being metallized and / or before being painted.

Claims

Demands

1. A method for coating (100) at least one plastic part of a motor vehicle wiper device (1) characterized in that it comprises: - a first metallization step (101) during which at least one conductive metallic layer is deposited on the at least one plastic part to obtain an electrically conductive part, - a second painting step (102) during which the at least one metallized part is coated with a layer of paint by cataphoresis.

2. Coating method (100) according to the preceding claim, wherein at least one part made of plastic material was obtained by additive manufacturing.

3. Coating method (100) according to any one of the preceding claims, wherein the plastic material part is assembled to at least one other element of the wiping device (1) before being metallized and / or before being painted.

4. Coating method (100) according to any one of the preceding claims, characterized in that at least one conductive metallic layer is a layer of copper, nickel, chromium, aluminum, tin or an alloy such as an alloy based on at least one of the aforementioned elements as a cupro-nickel alloy.

5. Coating method (100) according to any one of claims 1 to 4, wherein the first metallization step (101) is carried out by electroplating.

6. Coating method (100) according to any one of claims 1 to 4, wherein the first metallization step (101) is carried out by spraying at least one redox solution in aerosol form.

7. Coating method (100) according to any one of the preceding claims, wherein at least one plastic material part of the wiping device (1) is a part of a wiper arm (2) such as a housing (6) or a drive (5) or a cover (11) of the housing (6) or a cover (12) of the drive (5).

8. A coating method (100) according to any one of claims 1 to 6, wherein at least one part of the wiping device (1) is a part of a windshield wiper blade (3) such as a mount (8) or a lever (9) of an articulated frame (7).

9. A motor vehicle wiper device (1) comprising a wiper arm (2) intended to be connected to a motorized wiper mechanism of a vehicle and a wiper blade (3) connected to the end of the wiper arm (2) characterized in that the wiper device (1) comprises at least one part of plastic material coated by a coating process (100) according to one of the preceding claims.

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