MXPA04001331A - Process for manufacturing coated bumpers. - Google Patents

Abstract

The present invention is related to a process for manufacturing a coated bumper, which includes simple and easy but effective manufacturing steps by using the same equipment used in the manufacture of traditional bumpers. Moreover, the present invention refers to a highly effective bumper useful in any type of vehicle, which presents and exceeds all aesthetic as well as mechanical and corrosion resistance characteristics of the state-of-the-art bumpers.

Description

"PROCESS FOR THE MANUFACTURE OF A COVERED BUMPER" ********** FIELD OF THE INVENTION The present invention is related to the techniques used in the manufacture of auto-parts used in the Automotive Industry, and more particularly, is related to a process for the manufacture of a coated bumper, as well as the bumper obtained by said process.

BACKGROUND OF THE INVENTION As it is widely known in the field of the Automotive Industry, the bumpers or defenses constitute an essential protection element for any type of vehicle such as compact cars, trucks, pick-up trucks, trucks, trucks. of tow (trailers), among others, since in case of a car accident facing the front bumper receives all the energy of the impact, hence the name derives, reason why they must comply with a series of standards of very rigorous security. According to the prior art, the fenders are manufactured from a metal sheet that is subjected to a process that involves a first stage of forming in which the metal sheet is molded by stamping or stamping machines with the aim of giving the sheet the form of a desired defense; a stage of physical and / or chemical cleaning, in which the surface of the defense is conditioned so that a surface finish can be applied; and a finishing stage, in which the defense is painted or subjected to a chroming process to give the defense a finish that is visually attractive and that is in harmony with the rest of the vehicle. Finally, the fenders are inspected, packed and sent to the automobile assembly plants, agencies, spare parts distributors, etc. In relation to the chrome plating process, it can be mentioned that it is one of the most used resources to give the metallic defenses aesthetic and protective characteristics, since it allows to delay the corrosion. However, due to the characteristics of an electroplating process, the waste water from the chrome plating process is characterized by the high content of heavy metals and highly polluting substances for the environment, since if there is not a treatment plant of waters, which in turn generate sludge characterized as hazardous waste requiring a disposition according to environmental regulations, said waters will go to the receiving bodies. Additionally, in order to obtain an acceptable chrome-plating it is necessary to electrochemically clean the defense, releasing to the environment substances such as caustic soda and oils; Likewise, effluents containing heavy metal compounds such as chromium, nickel, copper, etc. are discharged in the electrolytic chromium. Due to these environmental problems, the tendency of the Automotive Industry in recent years has been the elimination of chromed auto parts. The process for obtaining a chromed defense includes the steps of: (a) punching a carbon steel sheet to give the desired shape; (b) a next pre-polishing step to eliminate surface roughness and try to leave a smooth surface; (c) a first stage of mechanical cleaning and degreasing with detergent solutions; (d) a second cleaning step in an electrochemical bath, such that the surface is prepared to receive the chromium film; (e) in the next stage, the chromium film is applied to the defense, using for this a process of electroplating in one or several stages which may include successive layers of copper and nickel before the chromium layer; (f) a final washing step to remove the solutions from the electrolytic process; (g) a next stage of visual inspection to later pack it and finally send it to its final destination, which may be an assembly plant, or a distributor of automotive spare parts. It is important to note that chrome fenders have other problems related to the wear they suffer, in addition to those indicated above, since for example when a vehicle moves on highways and roads, small stones and other particles are projected and impacted at high speed against the defenses, cracking and removing portions of the chrome layer that is worth worth mentioning, it is very thin and its hardness makes it fragile in the face of impacts, exposing unprotected areas of the metal sheet to the elements, where corrosion can quickly start, resulting in the weakening and deterioration of the defense. This phenomenon of corrosion is very noticeable and accelerated in places with extreme climates, particularly where salt is used in winter to avoid the formation of ice on the pavement or on the coasts and industrial areas that have corrosive or humid atmospheres. Another disadvantage of chromed automotive fenders is that related to production costs, since to obtain a finish with high reflectivity ("mirror" grade) or a similar degree, it is required that the base metal sheet is perfectly polished and clean, which obviously increases the costs of production and labor. On the other hand, a poor polish or cleaning would cause the chrome to reveal imperfections of the base metal, making the chrome does not have the desired optical characteristics and consequently the defense loses commercial and aesthetic value. On the other hand, the defenses that receive a paint-based finish also present problems of low impact resistance at high speeds of small stones and particles, consequently the duration of said paint finishing is limited, making continuous maintenance necessary, repainting frequently the defense as an extreme case. Finally, from the aesthetic point of view, a painted defense is not as attractive as a chrome defense, a characteristic that represents a disadvantage. The process for obtaining a painted defense does not differ much from that of the chrome defense, and consists of the steps of: (a) punching a sheet of carbon steel to give the desired shape; (b) a next cleaning step based on degreasing with alkaline solutions free of detergents; (c) and then apply a layer of anticorrosive material; (d) a next stage of visual inspection to later pack it, and finally send it to the assembly plant where the paint bath is given according to the color of the body, to be later assembled. With the aim of manufacturing defenses with an acceptable appearance, in the state of the art they have tried to manufacture defenses made entirely of stainless steel, however, the costs of raw material make the product unaffordable. In this sense, it has also tried to manufacture defenses made entirely of aluminum; however, the lower hardness of this metal makes it susceptible to its surface being damaged by scratches with minor impacts and the contacts that are normally experienced in the daily use of vehicles. In addition to the above, the fact that the aluminum sheets present processing problems when it is desired to form cavities such as the plate holder, or recesses in the defense through the forming processes such as die cutting, is added. Particularly, the aluminum sheets lose optical characteristics when said cavities are molded, in addition to not reaching the appearance of required brightness. In the state of the art it is possible to find defenses with special arrangements of more than one metallic sheet, such as the truck defense described in US Pat. No. 6,325,430, whose main objective is to provide a truck defense that can be fixed to the body of the same without having to drill the surface of the defense. More particularly, said document describes a truck fender having an exterior surface with a specified mechanical finish, such as a highly reflective finish (mirror finish), which is uniform in appearance and does not have fasteners or unwanted openings that extend through the defense. The defense includes an outer sheet and a reinforcement sheet which is generally configured with a channel in the shape of a "U" and placed in the recess of a channel similarly configured in the outer sheet. The reinforcing sheet is welded to the outer sheet and has slits, each with a hole through which a fastener extends therethrough. The head of each fastener is fixed firmly and fully in that of the reinforcing sheet so that it does not interrupt or interfere with the uniform appearance of the highly reflective finish of the outer sheet. As can be seen from the above patent foreign document, the outer sheet presents an essentially flat surface and must have a recess channel in order to receive the reinforcement sheet including slits for the fasteners, said configuration made especially for the defense of a The truck represents a disadvantage when wanting to manufacture fenders for other types of vehicles, such as the fenders for trucks and light trucks, where the fenders generally include recesses or external grooves for stirrups or plate holders. Likewise, it can be noted that the reinforcing plate must have a contour on its surface different from that of the outer plate, due to this difference in the surfaces, each sheet has to be manufactured using a different mold, in addition, the placement of the fasteners that ensure the defense to the rest of the truck must be made before welding the reinforcement sheet to the external sheet, this fact implies more labor and additional costs, so from the point of view of costs, this type of defenses It is very expensive. There are other materials and processes for the manufacture of bi-metallic bumpers or fenders, such as that which comprises the following stages: (a) is made of a composite material of stainless steel bonded to a substrate of aluminum or carbon steel, in where said composite material is obtained by means of the process known as "ciad"; (b) in a next step, the composite material is given the required shape through a die-cutting or stamping process; (c) in the next stage is given a mechanical cleaning and with detergent solutions on the face of carbon steel; (d) a masking step, and for this, tapes or adhesive films are used to prevent the anticorrosive coating from being fixed to the stainless steel face; (e) in a subsequent step, a coating of anticorrosive material is applied; (f) a finishing step consisting of correcting by polishing the imperfections that the forming process has caused on the stainless steel surface; (g) it is finally packed and sent to the assembly plant or to the distributors of automotive spare parts. According to what has been described above, it can be observed that on the one hand the chromed automotive fenders present aesthetic problems that over time become corrosion problems, since as mentioned above, when the chrome fenders are in use, the stones or other particles that are projected at high speed against its surface, cause problems of "flaking" or formation of small cracks or pores of the chrome layer, being points of corrosion. Additionally, the chromed defenses present another great disadvantage, and that is that in the chrome process there are discharges to the environment of effluents with highly polluting substances.

While, on the other hand, the defenses with a paint finish also have the disadvantage that they are not so attractive from the aesthetic point of view for the public user. As a consequence of the foregoing, it has been sought to eliminate the disadvantages presented by conventional bumpers or automotive fenders found in the state of the art, developing a process for the manufacture of a coated bumper, which is highly practical, simple and economical. since it allows to use the same equipment that is used in the manufacture of traditional defenses, but with the great advantage that there are no problems of discharges of effluents containing polluting substances to the environment as do the electrochemical chromium processes, and therefore, harmful to living beings. On the other hand, the bumper obtained with the process of the present invention presents the aesthetic and corrosion resistance characteristics of the bumpers or chrome fenders, satisfactorily fulfilling the safety and quality standards required to be used in any type of vehicle. .

OBJECTS OF THE INVENTION Taking into account the defects of the prior art, it is an object of the present invention to provide a process for the manufacture of a coated bumper that is highly economical and of practical and simple steps, and yet highly efficient for the production of a bumper. manufacture of coated bumpers, since the bumpers obtained by this process present the aesthetic, mechanical and corrosion resistance characteristics of the chromed fenders. A further object of the present invention is to provide a process for the manufacture of a coated bumper that allows the use of the same equipment used in the manufacture of conventional fenders.

It is another object of the present invention to provide a process for obtaining a coated bumper that allows the preservation of the environment, since the product obtained with said process does not require electrochemical finishes that discharge effluents that include heavy metals. A further object of the present invention is to provide a coated bumper, extremely simple construction, practical and economical, and yet highly effective to be used in any type of vehicle, since it presents and exceeds all the aesthetic characteristics and mechanical resistance and the corrosion of the defenses found in the state of the art.

The novel aspects that are considered characteristic of the present invention will be established with particularity in the appended claims. However, the invention itself, both by its organization as well as by its method of operation, together with other objects and advantages thereof, will be better understood in the following detailed description of certain modalities, when read in connection with the drawings that are attached, in which: Figure 1 is a block diagram showing the sequence of stages of a process for the manufacture of a coated bumper, which is described in accordance with the principles of a particularly specific embodiment of the invention. the present invention. Figure 2 is a block diagram showing the sequence of steps of a process for manufacturing the coated bumper, which is described in accordance with the principles of a first alternative embodiment of the present invention.

Figure 3 is a front elevational view of a bi-metallic substrate obtained in one of the steps of the bumper bumper manufacturing process that is described in the first alternative embodiment of the present invention. Figure 4 is a front top perspective view of a coated bumper, constructed in accordance with the principles of a particularly specific embodiment of the present invention. Figure 5 is a front elevation and exploded view of the coated bumper shown in Figure 4 showing the elements that comprise it. Figure 6 is a rear elevational and exploded view of the coated bumper shown in Figure 4. Figure 7 is a cross-sectional sectional view taken along line AA 'of the coated bumper shown in Figure 4. Figure 8 is a top front perspective view of a coated bumper constructed in accordance with a further embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the accompanying drawings, and more particularly to Figure 1 thereof, it shows a block diagram showing the different stages of a process for the manufacture of a bumper coated according to a particularly specific embodiment of the present invention, which is described in an illustrative manner but not limiting thereof and comprising the steps of: (a) punching (100) a first metal sheet 20 to obtain a base or internal element 40 of the coated bumper 10, which is concealed when said bumper 10 is assembled to a vehicle (not shown in the figures), said first metal plate 20 is made of a carbon steel material selected from the steel of the SAE 10XX Series. (b) applying (200) on at least one of the faces of the internal element 40 a film 60 of an anticorrosive material, which is a paint that can either be water based or solvent based and is applied by means of any of the methods that are selected from electrodeposition, spraying, immersion, the use of a brush, or by any other known application method. In the specific embodiment described in the present invention, the anticorrosive film 60 is applied to the face of the inner element 40 which is exposed to the weather once the bumper 10 has been assembled to the vehicle; (c) cleaning (300) the internal element 40 to eliminate any type of grease and impurities on its faces, and for this, the internal element 40 is subjected to a degreasing process to remove all dust and any type of grease that has remained after the application of the anticorrosive film; (d) placing (400) on the other side of the inner member 40 an adhesive material that serves as a binding medium, which is applied by any known application process such as spraying (spraying), the use of a brush, extrusion, dipping , among others. In the specific embodiment of the present invention, the application is preferably made by means of an extrusion dosing device that follows the shape of the piece in an automatic application with robots. The adhesive material is selected from among acrylic adhesives, cyanoacrylate adhesives, epoxy adhesives, urethanes, or any other adhesive capable of fixedly bonding a stainless steel material to a carbon steel material; (e) stamping (100 ') separately a second metal plate 30 to obtain a coating or external element 50 that remains in the visible part of the coated bumper 10 when it has been assembled to the vehicle, which has the same shape as the element internal 40 but of slightly larger dimensions than said internal element 40, said second metallic sheet 30 is made of a stainless steel material with an elongation of at least 40%, which is selected from the stainless steels of the 300 Series, preferably using AISI 304 stainless steel; (f) cleaning (300 ') the external element 50 to eliminate any type of grease and impurities that have remained on their faces, and for this, the external element 50 is subjected to a mechanical cleaning process with solvent and / or with a detergent solution, then rinsed and then dried; (g) placing (400 ') on the face to be joined by the external element 50 the adhesive material, which is applied by any known application method in the medium, such as spraying (spraying), the use of a brush, extrusion, immersion , among others. In the specific embodiment of the present invention, the application is preferably done by means of an extrusion dosing device that follows the shape of the piece in an automatic application with robots, wherein said face to be joined is the face opposite to the face that is visible. The adhesive material is selected from among acrylic adhesives, cyanoacrylate adhesives, epoxy adhesives, urethanes, or any other adhesive layers of fixed bonding of metallic materials; (h) assembling (500) the internal element 40 and the external element 50 to form the coated bumper 10, and for this, the face to be joined of the external element 50 is coupled on the face to be joined of the internal element 40 applying pressure by means of a press harness that maintains the union of both pieces with the separation between them that requires the adhesive for an optimal adhesion and resistance, which is between 0.02 to 1.2 mm; (i) pre-cure (600) the adhesive material, wherein the coated bumper 10 obtained in the previous stage is subjected to a setting process to achieve maximum adhesion and strength, whose time and temperature depend on the type of adhesive material used to do the assembly; 0) reinforce (700) the union of the external element 50 with the internal element 40, for which any joining method is used that is selected from between engargolado, the use of rivets, the use of nuts and bolts, welding points, or combinations thereof, among others. In the process described in the specific embodiment of the present invention, a method of interlocking is used, for which the material of the external element 50 projecting from the internal element 40 is bent inwardly over the periphery of said internal element.; (k) polishing (800) the visible face of the external element 50 to give, or recover the reflective finish "mirror grade" or any other degree that could have been damaged during the process of punching and assembling, the polishing being able to be done by means of of a brushing or other known mechanical process for polishing; (I) visually inspecting (900) the coated bumper 10 to detect any appearance or dimensional defect, since the surface of the visible face must be free of cracks, dents, dehulling, die markings, etc .; (m) packing (1000) the coated bumper 10 in such a manner that it is ready to be. sent to the assembly plant for assembly in a vehicle, or sent to the distributors of spare parts or to the dealers of the assembling brands. Now, with specific reference to Figure 2 of the accompanying drawings, there is shown a block diagram indicating the sequence of the steps of an alternate process for the manufacture of the coated bumper 10, which is described in accordance with the principles of a first alternative embodiment of the present invention and comprises the steps of: (a) placing (1100) adhesive material on one of the faces of the first metal sheet 20 and second metal sheet 30, wherein said material adhesive is selected from among acrylic adhesives, cyanoacrylate adhesives, epoxy adhesives, urethanes, or any other adhesive capable of fixedly bonding a stainless steel material to a carbon steel material; (b) joining (1200) the first metal sheet 20 to the second metal sheet 30 by pressing on them to achieve a good bond between both parts, thus forming a bi-metallic substrate 70; (c) pre-cure (1300) the film of adhesive material 80, and for this, the bi-metallic substrate 70 obtained in the previous stage is subjected to a setting process to achieve maximum adhesion and strength between both parties, in where the time and temperature depend on the type of adhesive material used for the assembly; (d) die cutting (1400) the bi-metallic substrate 70 to obtain the coated bumper 10; (e) cleaning (1500) the coated bumper 10 to eliminate any type of grease and impurities left on its faces, and for this, the coated bumper 10 is subjected to a mechanical cleaning process with solvent and / or a solution detergent, rinse and then dry; (f) polishing (1600) the visible face of the coated bumper 10 to give, or recover the reflectance finish "mirror grade" or any other degree that could have been damaged during the die cutting process, the polishing being able to be done by means of a brushing or other known mechanical process for polishing; (g) visually inspecting (1700) the coated bumper 10 to detect any appearance or dimensional defect, since the visible face of the coated bumper 10 must be free of cracks, dents, dehulling, die markings, etc .; (h) packing (1800) the coated bumper 10 in such a manner that it is ready to be sent to the assembly plant for assembly in a vehicle, or sent to the spare parts distributors or to the dealers of the assembling brands. Referring more particularly to Figures 4 to 7 of the accompanying drawings, there is shown the coated bumper 10 obtained by the process described in the particularly specific embodiment of the present invention, which comprises in general terms; the internal element 40 or base which, as its name indicates, is located in the internal and concealed part of the bumper 10 when it is assembled to a vehicle, said internal element 40 includes on at least one of its faces a film 60 of anticorrosive material; the external element 50 or coating located on the internal element 40 of the bumper 10 forming the visible part of said bumper 10; said internal and external elements 50 are fixedly joined by means of the adhesive material film 80. The internal element 40 can have any shape, in such a way as to completely cover the front part of the vehicle for which it was designed. The internal element 40 is manufactured from a carbon steel sheet metal selected from the steels of the SAE 10XX Series. The external element 50 is complementary to the shape of the internal element 40, covering all or part of said internal element 40, so that said external element 50 can be of equal or slightly larger dimensions than said internal element 40. In the embodiment specific that is described in the present invention, the external element 50 is of the same shape but of slightly larger dimensions than the internal element 40, in such a way that said external element 50 can be perfectly coupled on said internal element 40 to form the coated bumper 10 of the present invention. The external element 50 is manufactured from a metal sheet, preferably made of stainless steel with a highly reflective, mirror-polished mechanical finish, as well as with an elongation of at least 40%, in such a way that it does not lose reflective or uniformity in its surface when the material is subjected to the process of stamping or stamping, so that the stainless steel is selected from among the stainless steels of the 300 Series, preferably using the AISI 304 stainless steel. The film of anticorrosive material 60 that presents the internal element 40 is applied on the face that is exposed to the weather when the bumper 10 is assembled in the vehicle. By virtue of the fact that the external element 50 is of dimensions slightly larger than those of the internal element 40, the material projecting from said external element forms a tongue that bends inwardly and on the contour of said internal element 40, in such a way that the joint is reinforced and thus prevent the outer element 50 from separating from the internal element 40 when the coated bumper 10 of the present invention is assembled in the vehicle and the latter is already in service. In further embodiments of the present invention, reinforcement of the joint can be done by any other known joining method, such as the use of through or non-through rivets, nuts and screws, welding, among others. Now, referring more specifically to Figure 9 of the accompanying drawings, there is shown a coated bumper 10 'constructed in accordance with a further embodiment of the present invention, which is obtained through the manufacturing processes. described above in the specific and first alternative modalities, respectively, of the present invention. The coated bumper 10 'comprises in general terms: an internal element 40' or base which is located in the inner and concealed part of the bumper 10 'when it is assembled to a vehicle, said internal element 40' includes in at least one of its faces a film of anticorrosive material; an external element 50 'or lining which is located on the internal element 40' of the bumper 10 'forming the visible part of said bumper 10'; said internal elements 40 'and external 50' are fixedly joined by means of the film of adhesive material. The internal element 40 'is manufactured from a carbon steel sheet metal selected from the steels of the SAE 10XX Series. The external element 50 'is different from the shape of the internal element 40' and partially covers said internal element 40 ', however, they are coupled with one another in a practical and simple way. The external element 50 'is manufactured from a metal sheet, preferably made of stainless steel with a highly reflective, mirror-polished mechanical finish, as well as with an elongation of at least 40%, in such a way that it does not lose reflective properties or uniformity in its surface when the material is subjected to the process of stamping or stamping, so that the stainless steel is selected from among the stainless steels of the 300 Series, preferably using the AISI 304 stainless steel. The film of anticorrosive material that presents the internal element 40 'is applied on the face that is exposed to the weather when the bumper 10' is assembled in the vehicle. In accordance with what has been previously described and illustrated in the accompanying drawings, it can be seen that the process of the present invention has been devised to manufacture in a much more practical, simple and economical way, and yet, more efficiently, a bumper or fender that presents all the aesthetic, mechanical and corrosion resistance characteristics of both the chrome fenders as well as the fenders found in the prior art. Therefore, it will be evident to a person skilled in the art, that the modalities described above are only illustrative but not limiting of the present invention, since numerous modifications are possible in their details, such as the sequence of the stages, the materials used in the manufacture of the bumper, the forms of the bumper, among others. Even though a particularly specific embodiment and alternative embodiments of the present invention have been described and shown in the foregoing, it should be emphasized that numerous modifications to such embodiments are possible, but without departing from the true scope of the invention. The present invention, therefore, should not be restricted except by what is within the state of the art, as well as by the spirit of the appended claims.

Claims (1)

1. NOVELTY OF THE INVENTION CLAIMS 1. Process for the manufacture of a coated bumper, characterized in that it comprises the steps of: (a) punching a first metal sheet to obtain a base or internal element of the coated bumper, which is hidden when said bumper it is assembled to a vehicle; (b) applying a film of an anticorrosive material to at least one of the faces of the internal element; (c) clean the internal element to eliminate any type of grease and impurities on their faces, subjecting it to a degreasing process to eliminate all the dust and any type of grease that has remained after the application of the anticorrosive film; (d) placing on the other face of the internal element an adhesive material that serves as a joining means, which is selected from among spraying (spraying), the use of brush, extrusion, immersion, among others; (e) separately cutting a second metal sheet to obtain a coating or external element that remains in the visible part of the coated bumper when it has been assembled to the vehicle; (f) cleaning the external element to eliminate any type of grease and impurities left on its faces, subjecting it to a mechanical cleaning process with solvent and / or with a detergent solution, then it is rinsed and then dried; (g) placing on the face to join the adhesive material from the external element, which is selected from among spraying (spraying), the use of a brush, extrusion, immersion, among others; (h) assembling the internal element and the external element to form the coated bumper, and for this, the face to be joined of the external element is coupled on the side to be joined of the internal element applying pressure by means of a press harness that maintains the union of both pieces with the separation between them that requires the adhesive for an optimal adhesion and resistance, which is between 0.02 to 1.2 mm; (i) pre-cure the adhesive material, where the coated bumper obtained in the previous stage is subjected to a setting process to achieve maximum adhesion and strength, whose time and temperature depend on the type of adhesive material used to make the assembly; (j) reinforce the joining of the external element with the internal element by any other means of attachment that is selected from between engargolado, the use of rivets, the use of nuts and bolts, welding points, or combinations thereof, among others , (k) polishing the visible face of the external element to give, or recover the reflective finish "mirror grade" or any other degree that could have been damaged during the process of punching and assembly, the polishing can be done by means of a brushing or another known mechanical process for polishing; (I) visually inspect the coated bumper to detect any appearance or dimensional defects, since the surface of the visible face must be free of cracks, dents, dehulling, die markings, etc .; and (m) packing the coated bumper in such a manner that it is ready to be sent to the assembly plant for assembly in a vehicle, or sent to the spare parts distributors or to the dealers of the assembling brands. 2. Process for manufacturing a coated bumper according to claim 1, further characterized in that the external element has the same shape as the internal element but slightly larger dimensions than said internal element. 3. Process for the manufacture of a coated bumper according to claim 1, further characterized in that the anticorrosive material is a paint that is water-based or solvent-based and is applied by any of the methods selected from electrodeposition. , spraying (spraying), immersion, the use of a brush, or any other known application method. 4. Process for the manufacture of a coated bumper according to claim 3, further characterized in that the anticorrosive film is applied on at least one of the faces of the internal element or base. 5. - Process for the manufacture of a coated bumper according to claim 3, further characterized in that the anticorrosive film is applied on the face that is exposed to the weather once the bumper has been assembled to the vehicle. 6. Process for the manufacture of a coated bumper according to claim 1, further characterized in that the adhesive material is applied by means of an extrusion dosing device that follows the shape of the piece in an automatic application with robots, in where said face to be joined is the face opposite the face that remains in contact with the weather. 7. Process for the manufacture of a coated bumper according to claim 1, further characterized in that the adhesive material is selected from acrylic adhesives, cyanoacrylate adhesives, epoxy adhesives, urethanes, or any other adhesive capable of firmly bonding metallic materials. 8. - Process for the manufacture of a coated bumper according to claim 1, further characterized in that the process used to reinforce the union of the assembly is engargolado. 9. - Process for the manufacture of a coated bumper according to claim 1, further characterized in that the first metal sheet is of a carbon steel material selected from steels of the SAE Series 10XX. 10. Process for the manufacture of a coated bumper according to claim 1, further characterized in that the second metal plate is made of a stainless steel material with an elongation of at least 40%, which is selected from among the stainless steels of the 300 Series. 11. Process for manufacturing a coated bumper according to claim 1, further characterized in that the manufacturing process comprises the steps of: (a) placing an adhesive material on one of the faces of a first metal sheet and a second metal sheet; (b) joining the first metal sheet to the second metal sheet by pressing on them to achieve a good bond between both parts, thus forming a bi-metallic substrate; (c) pre-cure the adhesive material, and for this, the bi-metallic substrate obtained in the previous stage is subjected to a setting process to achieve maximum adhesion and strength, where the time and temperature depend on the type of material adhesive used for the assembly; (d) punching the bi-metallic substrate to obtain the coated bumper; (e) clean the coated bumper to eliminate any grease and impurities left on its faces, and for this, the coated bumper is subjected to a mechanical cleaning process with solvent and / or with a detergent solution, rinse and subsequently dry off; (f) polishing the visible face of the coated bumper to give, or recover the "mirror grade" reflective finish or any other degree that may have been damaged during the die-cutting process, the polishing being possible by means of a brushing or other process known mechanical for polishing; (g) visually inspect the coated bumper to detect any appearance or dimensional defects, since the visible face of the coated bumper must be free of cracks, dents, dehulling, die markings, etc .; (h) packing the coated bumper in such a way that it is ready to be sent to the assembly plant for assembly in a vehicle, or sent to the spare parts distributors or to the concessionaires of the assembling brands. 12. Process for the manufacture of a coated bumper according to claim 11, further characterized in that the adhesive material is selected from among acrylic adhesives, cyanoacrylate adhesives, epoxy adhesives, urethanes, or any other adhesive capable of firmly bonding metallic materials. 13. - Process for the manufacture of a coated bumper according to claim 11, further characterized in that the first metal sheet is of a carbon steel material selected from among the steels of the SAE 10XX Series. 14. - Process for the manufacture of a coated bumper according to claim 11, further characterized in that the second metal sheet is made of a stainless steel material with an elongation of at least 40%, which is selected from among the stainless steels of the 300 Series. 15. - A bi-metallic substrate for the manufacture of a coated bumper, characterized in that it comprises a first metallic sheet and a second metallic sheet fixedly joined by means of an adhesive material. 16. - A bi-metallic substrate for the manufacture of a coated bumper according to claim 15, further characterized in that the adhesive material is selected from among acrylic adhesives, cyanoacrylate adhesives, epoxy adhesives, urethanes, or any other adhesive capable of bonding Fixed metallic materials. 17 - A coated bumper, characterized in that it comprises in general terms: an internal element or base that is located on the internal and hidden part of the bumper when it is assembled to a vehicle and an external element or coating that is located on the internal element of the bumper forming the visible part of said bumper, said internal and external elements are fixedly joined by means of an adhesive material. 18. A coated bumper according to claim 17, characterized in that the internal element has any shape, in such a way that it completely covers the front part of the vehicle for which it was designed. 19 - A coated bumper according to claim 18, further characterized in that the internal element includes on at least one of its faces a film of anticorrosive material. 20. - A bumper coated according to claim 19, further characterized in that the film of anticorrosive material is applied on the face that is exposed to the weather when the bumper is assembled in the vehicle. 21. A coated bumper according to claim 17, further characterized in that the internal element is manufactured from a carbon steel sheet metal selected from steels of the SAE 10XX Series. 22. - A coated bumper according to claim 17, further characterized in that the external element is of complementary shape and dimensions slightly larger than the shape and dimensions of the internal element. 23. - A coated bumper according to claim 22, further characterized in that the material protruding tongue-like external element bends in and on the contour of the internal element, in such a way that the union is reinforced and thus avoid that the external element is separated from the internal element when the coated bumper is assembled in the vehicle and the latter is already in service. 24. - A coated bumper according to claim 17, further characterized in that the external element is manufactured from a metallic substrate of stainless steel with an elongation of at least 40%, in such a way that it does not lose reflective or uniformity in its surface when the material is subjected to the process of stamping or stamping, so that the stainless steel is selected from among the stainless steels of the Series 300. 25. - A bumper coated according to claim 17, further characterized because the adhesive material is selected from among acrylic adhesives, cyanoacrylate adhesives, epoxy adhesives, urethanes, or any other adhesive capable of firmly bonding metallic materials. 26. - A coated bumper according to claim 17, further characterized in that the junction between the internal element and the external element is reinforced by any other joining method that is selected from through or non-through rivets, nuts and bolts, welding, etc. . 27. - A coated bumper according to claim 17, further characterized in that the external element has a different shape to the shape of the internal element, but they are perfectly coupled with respect to each other.