System and method for identifying a mechanical component, in particular a bearing ring

Abstract

The present invention relates to a system and method for identifying a mechanical component (1), in particular a bearing or hub bearing unit of a vehicle or a ring thereof, consisting of applying a mark (4) directly onto an exposed surface (2) of the mechanical component, using a photopolymerizable ceramic ink (5) which is printed onto the exposed surface by an inkjet printer having a resolution equal to or greater than 700 dpi and which is at least partially vitrified by employing a heat treatment (40) at a temperature equal to or greater than 700°C, preferably after fixing (30) the ceramic ink onto the exposed surface (2) by applying UV radiation. Figure 1

Description

Title of the invention: System and method for identifying a mechanical component, in particular a bearing ring Technical field of the invention

[0001] The present invention relates to a system and method for identifying a mechanical component, in particular a bearing ring. State of the prior art

[0002] As is known, in the industrial sector it is particularly necessary to verify the origin of the components used, for example during the assembly process of a machine or vehicle, and / or to be able to trace the production history of said component, both during its production process and, subsequently, when the component is assembled on a complex machine or vehicle.

[0003] For this purpose, a known method is the use of electronic labels (RFID - radiofrequency identification devices), which however cannot be used during the production process but only at the end thereof, or of marks (alphanumeric sequences, barcodes, 2D barcodes, matrix barcodes) which are formed directly on the component.

[0004] For example, in order to ensure the traceability of mechanical components that are obtained by forging, casting and / or machining by material removal and that, during the production process, must be subjected to various treatments - both thermal and chemical - (tempering, stabilization treatment, phosphating, etc.), laser marking is used, although the marks are not legible during the entire life of the component, besides being expensive and the marks are subject to chemical attacks produced both by the production processes (e.g. phosphating) and by contaminants from the environment (water, mud, humidity, etc.) in the case of components exposed to these during use, for example the rings of the bearing units of vehicle hubs.

[0005] Shot peening is also used, this being theoretically more resistant to wear, but it can cause cracking problems on said component, for example if the shot peening piston is large. Summary of the invention

[0006] The objective of the present invention is to provide a system and a method for the identification of a mechanical component, in particular a ring of a bearing or a hub bearing unit of a vehicle, which do not have the disadvantages of the prior art, both during the production stages of the component and throughout the useful life of the component, and which, at the same time, are reliable, inexpensive and do not risk damaging the component to be marked.

[0007] Therefore, according to the invention, there is obtained a system and a method for identifying a mechanical component, in particular a ring of a bearing or a hub bearing unit of a vehicle, which have the characteristics indicated in the appended claims. Brief description of the figures

[0008] The invention will now be described with reference to the attached drawings which illustrate a non-limiting example of an embodiment thereof, in which:

[0009] [Fig.l] illustrates, in the form of a functional diagram, the main steps of the identification method according to the invention incorporated in a production process diagram; and

[0010] [Fig.2] is a photographic illustration of the identification system according to the invention applied to a metallic mechanical component and obtained during tests with the method illustrated in [Fig.l]. Detailed description of the invention

[0011] Referring to [Fig.2], 1 indicates thereon, in its entirety, any mechanical component, consisting, in the example presented, of a steel ring. Mechanical component 1 is typically a component of a machine or vehicle, for example a vehicle hub bearing or bearing unit or a ring thereof.

[0012] The mechanical component 1 is, in the example presented, of cylindrical shape and is provided with an exposed surface 2 consisting, in the example presented, of a cylindrical metallic outer lateral surface of the mechanical component 1. If the mechanical component 1 is of annular shape, the exposed surface 2 could also be an inner lateral surface thereof, provided that it is easily accessible, or an annular flat front surface.

[0013] The mechanical component 1 is provided with an identification system 3 comprising the exposed surface 2 and a mark 4 applied directly to the surface 2 of the mechanical component 1.

[0014] Hereinafter, “brand” will be understood as the graphic reproduction of an alphanumeric sequence, a barcode, a 2D barcode, a matrix barcode or a logo.

[0015] According to the invention, the mark 4 is formed by means of a ceramic ink 5 applied directly to the exposed surface 2, and the ink 5, having been suitably fired, is at least partially in a vitrified state.

[0016] Preferably, the mechanical component 1 is annular in shape and the exposed surface 2 is an outer or inner lateral surface thereof.

[0017] Furthermore, as already mentioned, the mechanical component 1 and / or its exposed surface 2 on which the mark 4 has been applied are metallic.

[0018] Ceramic inks are known and are usually used for the decoration of ceramic tiles which are then fired at high temperature.

[0019] Prior to the present invention, it appears that it has not been possible to successfully apply a ceramic ink to a metal surface.

[0020] A normal ceramic ink may in fact not adhere properly to a metal surface. According to one aspect of the invention, therefore, the ceramic ink 5 used to form the mark 4 is preferably an ink photopolymerizable by means of UV radiation.

[0021] Usually, the ink 5 contains: one or more ceramic pigments, for example based on Fe, Cr, Zr, Al, Co, etc. depending on the desired color; at least one aliphatic solvent, glycol ether or aqueous; fatty diacids; esters and polyesters, preferably photopolymerizable by means of UV radiation.

[0022] For example, a typical composition of the inorganic part of the ceramic ink for obtaining a white color mark 4 is as follows:

[0023] SiO218.50%

[0024] TiO2 7.00%

[0025] ZrO219.00%

[0026] SnO2 12.10%

[0027] Fe2030.10%

[0028] BiO2 39.40%

[0029] CaO Nr %

[0030] CuO Nr%

[0031] MgO Nr %

[0032] MnO Nr %

[0033] ZnO Nr %

[0034] K2O 0.80%

[0035] Li2O 2.60%

[0036] Na2O 0.50%

[0037] Based on the description given so far, the invention therefore also relates to a method for identifying a mechanical component 1, in particular a bearing or a hub bearing unit or a ring thereof, comprising the steps of providing the mechanical component 1 with an exposed surface 2 and directly applying a mark 4 to the exposed surface 2 of the mechanical component 1.

[0038] According to the invention and with reference to the functional diagram shown in [Fig. 1], during a first step 10 of the method according to the invention, the exposed surface 2 is formed on the mechanical component 1 in any known and suitable manner, for example by machining.

[0039] Here and below, “exposed surface” will be understood as a surface of the mechanical component 1 which can be easily reached and / or is visible.

[0040] Preferably, during step 10, an attempt is made to obtain an exposed surface 2 having - at least in a region 7 thereof ([Fig.2]) intended to receive the mark 4 - a relatively high quality surface finish (low roughness) suitable for receiving a printed mark without smudging. For example, the surface 2 or only the region 7 thereof may, if necessary, be ground or simply machined on a milling lathe (in the case of a flat surface 2) or it is possible to carry out a hot or electrolytic deposition of a metal layer (not shown) on only the region 7 of a surface 2 otherwise in the raw state, for example after obtaining the mechanical component 1 by forging or casting.

[0041] Once the printable exposed surface 2 has been obtained (for example at least in the region 7), a digital printing step 20 is carried out in order to apply the mark 4 on the surface 2.

[0042] According to the invention, during the digital printing step 20, the mark 4 is printed directly onto the exposed surface 2 of the mechanical component 1 using a ceramic ink 5, for example of any known type, which is applied using an inkjet printer which, according to an important aspect of the invention, must have a resolution equal to or greater than 700 dpi (dots per inch), for example 720 dpi.

[0043] It has in fact been demonstrated that the minimum value of 700 dpi is a crucial parameter of the method according to the invention given that, at lower printing resolutions, it is not possible to guarantee the readability of the mark 4 when the latter consists of a matrix barcode, a 2D barcode or even a simple barcode.

[0044] Then, according to another important aspect of the method according to the invention, a heat treatment step 40 is carried out, said step having to be carried out after the digital printing step, since its aim is to obtain at least partial vitrification of the ceramic ink 5. During the heat treatment step 40, the exposed surface 2 and / or the entire mechanical component 1 is / are heated to a temperature and for a time sufficient to obtain at least partial vitrification of the ceramic ink 5.

[0045] For this purpose, the heat treatment step 40 is carried out by heating the digitally printed exposed surface 2 to a temperature of 200°C to 700°C or, preferably, above 700°C, depending on the type of ceramic ink used, for a few minutes, for example 2-3 minutes, in an electric or induction furnace or, preferably, by laser heating.

[0046] Laser heating offers the potential advantage of being able to heat to a given temperature only the region 7 of the surface 2 comprising the mark 4 made of ceramic ink 5, rather than having to heat the entire mechanical component 1 to said temperature. Finally, it is also possible to heat the entire mechanical component 1 in a gas oven, by appropriately choosing the ink 5 and the type of fuel to be used in order to avoid undesirable chemical reactions.

[0047] According to a preferred aspect of the invention, the ceramic ink 5 is a photopolymerizable ink and, before the heat treatment step 40, a step 30, comprising the application of radiation to the photopolymerizable ink 5 which has been digitally printed to form the mark 4, is carried out in order to fix the ink on the exposed surface 2, UV radiation being applied to the exposed surface 2 having the mark 4 printed thereon.

[0048] The step of applying radiation 30 must be carried out immediately after the digital printing step 20 and is useful to ensure satisfactory adhesion of the mark 4 on the surface 2 when the latter is a curved metal surface, as in most cases. If this step 30 were not carried out, it has in fact been demonstrated in tests that the mark 4 formed on a curved metal surface 1 could have smears which would make a matrix barcode or a 2D barcode difficult to read.

[0049] The step of applying radiation 30 is carried out using a power of at least 10 watts per inch and by passing the digitally printed exposed surface 2 in front of a UV lamp of the known type, not shown in order to simplify the illustration, for a time of one or more seconds.

[0050] It should be noted that steps 30 and 40 can also be combined, using UV radiation powerful enough to produce localized heating of region 7 and / or also only of mark 4. This latter heating method can also be used in the presence of ceramic inks without a photopolymerizable component.

[0051] The ceramic ink 5 to be used according to the invention preferably comprises one or more ceramic pigments, which are chosen according to the color to be given to the mark 4, at least one aliphatic solvent, glycol ether or aqueous, diacids fats, esters and polyesters, preferably photopolymerizable by UV radiation. A possible composition of the ceramic part is that indicated above for the white color.

[0052] It is obvious that it is possible to obtain a mark 4 with several colors using the method according to the invention. In this case, it is sufficient that step 20 is carried out by means of a multi-head printer, using ceramic inks of various colors, for example it is possible to use a four-color inkjet printer, using inks comprising pigments that reproduce the four primary colors so as to be able to create any color shade.

[0053] After the heat treatment step 40, the mechanical component 1 is indelibly marked with a mark 4 which may contain a series of production data or simply a unique code which specifically identifies the component. Steps 10 to 40 constitute overall a marking procedure M, schematically represented by a block delimited by a dashed line containing blocks 10 to 40, which may be inserted into a process diagram of a complete production process P ([Fig. 1]).

[0054] According to a possible process P illustrated by way of non-limiting example in [Fig. 1], the mechanical component 1 comprising the mark 4 is then subjected to a phosphating step 50, then to at least one other thermal and / or chemical treatment step 60. It has been demonstrated in tests that the mark 4 consisting of ceramic ink 5, at least partially vitrified by means of step 40, had the capacity to resist a chemical attack resulting from the phosphating step 50, as well as the other usual treatment steps 60, carried out for example on a component 1 consisting of a bearing ring.

[0055] According to a possible variant of the process P, not shown in order to simplify the illustration, steps 50 and 60 and possibly other machining and / or heat treatment steps could just as well be carried out before the marking procedure M which, in this case, would be carried out downstream of the production cycle and not upstream of it, as shown in [Fig.l].

[0056] According to the method described, it is also possible to insert a matrix barcode (or at least alphanumeric characters or sequence(s)) on a forged ring, using for this purpose an inkjet printer suitable for printing a surface 2 having a non-optimal surface finish if, after this operation, the component / ring 1 can be passed through a furnace, for example in order to carry out an annealing step.

[0057] According to the invention, it is possible to assign a unique name / code to the mechanical components 1 being processed, for example to each ring of a plurality of bearings or of a hub bearing unit, the advantage being that this makes it possible to know the complete history of a mechanical component 1 during its entire manufacturing process and, then, during its entire useful life.

[0058] The traceability of a mechanical component is currently rather obtained by using a large quantity of documents (mainly paper documents).

[0059] With the identification system and method according to the invention, it is therefore possible to save time and money and to provide the purchaser of the component with detailed information concerning the product purchased.

[0060] Furthermore, it should be possible, by four-color printing, to print on the mechanical component 1 a mark 4 which comprises not only a matrix barcode or other coded graphic element, but also a logo, for example a customer's logo.

[0061] All the objectives of the invention are therefore achieved.

Claims

Claims

1. Identification system (3) for a mechanical component (1), in particular a bearing or hub bearing unit of a vehicle or a ring thereof, comprising a surface (2) of the mechanical component and a mark (4) applied directly to said surface of the mechanical component; characterized in that, in combination: a) the mark (4) is formed by a ceramic ink (5) which is at least partially in a vitrified state, and b) said ceramic ink (5) is an ink photopolymerizable by means of UV radiation, configured to be photopolymerized before being at least partially vitrified.

2. Identification system according to claim 1, characterized in that the surface (2) of the mechanical component (1) is an outer or inner lateral surface of the mechanical component, which is annular in shape.

3. Identification system according to claim 1 or 2, characterized in that the mechanical component (1) and / or said surface (2) of the mechanical component on which the mark (4) is applied is / are metallic.

4. Identification system according to one of the preceding claims, characterized in that said surface (2) of the mechanical component has been machined or coated with a metallic layer by hot or electrolytic deposition so that it has low roughness.

5. Method for identifying a mechanical component (1), in particular a bearing or hub bearing unit of a vehicle or a ring thereof, comprising the steps of providing the mechanical component with an exposed surface (2) and applying a mark (4) directly onto the exposed surface of the mechanical component, characterized in that said mark (4) is obtained by means of the following steps: a) a digital printing step (20), in which the mark (4) is printed directly onto the exposed surface (2) of the mechanical component using a ceramic ink (5) and an inkjet printer having a resolution equal to or greater than 700 dpi (dots per inch); b) a heat treatment step (40), carried out after the digital printing step (20), in which said exposed surface (2) and / or the entire mechanical component (1) is / are heated to a temperature and for a time sufficient to obtain at least partial vitrification of the ceramic ink (5), the ceramic ink (5) being a photopolymerizable ink; the method comprising a step (30) of applying radiation to the photopolymerizable ink so as to fix it on the exposed surface (2), UV radiation being applied to the exposed surface having the mark (4) printed thereon, the step of applying radiation being carried out immediately after the digital printing step (20).

6. An identification method according to claim 5, characterized in that the step of applying radiation (30) is carried out using a power of at least 10 watts per inch and passing the digitally printed exposed surface (2) in front of a UV lamp.

7. Identification method according to one of claims 5 and 6, characterized in that the heat treatment step (40) is carried out by heating the digitally printed exposed surface (2) to a temperature of 200°C to 700°C or more, preferably to a temperature equal to or greater than 700°C, for a few minutes, in an electric or induction furnace, or by localized UV and / or laser heating.

8. Identification method according to one of claims 5 to 7, characterized in that the ceramic ink (5) comprises one or more ceramic pigments, at least one aliphatic solvent, glycol ether or aqueous, fatty diacids, esters and polyesters, preferably photopolymerizable by UV radiation.

9. Identification method according to one of claims 5 to 8, characterized in that said exposed surface (2) is subjected, before the digital printing step, to a machining step and / or to the application of a coating consisting of a metallic layer produced by hot or electrolytic deposition, in order to reduce its roughness.

10. 10. Mechanical component (1), in particular a ring of a bearing or a hub bearing unit, provided with an identification system (3) according to one of claims 1 to 4.

11. 11. Metallic mechanical component (1), in particular a ring of a bearing or a hub bearing unit, provided with an identification mark (4) obtained by the method according to one of claims 5 to 9.

Images