Method for spraying metallic paint on whole railway vehicle

Abstract

The invention relates to the field of rail transit, in particular to a method for spraying metallic paint on a whole railway vehicle, which comprises the following steps of: sequentially polishing the whole railway vehicle and spraying areas; the area spraying comprises first area spraying, second area spraying and third area spraying; the area of the spraying surface in the first area spraying is smaller than 0.5 m < 2 >, and spraying is carried out for three times; the area of a spraying surface in the second area spraying is 0.5-10m < 2 >, and the second area spraying comprises edge ring spraying and secondary spraying; the area of the spraying surface in the third area spraying is larger than 10 m < 2 >, and the spraying surface is evenly divided into i subareas distributed in an array mode with the area as the reference; and in the third area spraying process, subarea spraying is carried out with the column of the array subarea as the unit. According to the paint spraying method provided by the invention, the whole vehicle is coated with the metallic paint, the mirror-surface-level appearance quality is realized, and by optimizing the defect rate and the operation rhythm, the paint spraying method is greatly superior to a scheme adopting an automobile process, and the paint spraying requirement of the rail transit locomotive is met.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rail transit, in particular to a spraying method for whole vehicle metallic paint of a rail vehicle. BACKGROUND

[0002] At present, metallic paint has become a trend for vehicle body exterior coating due to its unique texture and sparkling effect, and it needs to have excellent corrosion resistance, weather resistance and aesthetic appearance.

[0003] CN111363420A discloses a zinc yellow primer coating for rail vehicles and a preparation method, the coating includes the following components: chloroether resin, 420 epoxy resin, 618 epoxy resin, iron yellow, titanium white powder, aluminum tripolyphosphate, zinc phosphate, iron-titanium powder, barium sulfate, organic bentonite, dispersant, dimethylbenzene, butyl ester, 8900 polyamide wax.

[0004] CN117548255A discloses a rail vehicle coating device, relating to the field of coating technology. The present application comprises a conveying mechanism, a supporting mechanism and a hoisting mechanism. The conveying mechanism comprises a base and moving wheels located below the base. The supporting mechanism is arranged in several groups and is spaced apart above the base. The hoisting mechanism comprises a fixed support, a cross beam, a moving beam and a hoisting assembly. The lower end of the fixed support is connected to the base. The cross beam is connected to the upper end of the fixed support. The end of the cross beam extends outside the base and is provided with a limiting rod. The moving beam is movably arranged on the cross beam and is provided with a first driving assembly which can drive the moving beam to move along the cross beam. The hoisting assembly comprises a hoist and a gripper. The hoist is installed on the moving beam. The lower end of the hoist is connected to the gripper and can drive the gripper to lift.

[0005] However, there are many challenges in the whole vehicle spraying of rail transit vehicles: the vehicle body is large in size, the length of the rail vehicle is more than 20 meters, the surface area is 8-10 times that of an ordinary car, high-efficiency spraying process is needed, and the construction difficulty is high; the metal pigments in the metallic paint need to be uniformly arranged, and large-area spraying is prone to problems such as orange peel and particles, and is greatly affected by environmental temperature and humidity.

[0006] The prior art has obvious deficiencies: the spraying process parameters for large rail transit vehicles are not standardized, the multi-layer construction parameters lack whole vehicle optimization schemes, which affects the distribution of metal pigments, the construction efficiency is low, the repair rate is high, and there are limitations in different parts and different area sizes. SUMMARY

[0007] In view of the problems in the prior art, the purpose of the present application is to provide a spraying method for whole vehicle metallic paint of a rail vehicle, in order to solve the defects of poor spraying effect, uneven distribution of metal pigments, low construction efficiency and high repair rate when the current rail vehicle is sprayed.

[0008] To achieve this purpose, the present application adopts the following technical solutions:

[0009] This invention provides a method for applying metallic paint to the entire surface of a rail vehicle, the method comprising:

[0010] The rail vehicles are sequentially subjected to whole-vehicle grinding and area spraying.

[0011] The area spraying includes: first area spraying, second area spraying and third area spraying;

[0012] The area of ​​the sprayed surface in the first area is <0.5m². 2 ;

[0013] The area of ​​the sprayed surface in the second area is 0.5-10m². 2 ;

[0014] The area of ​​the sprayed surface in the third region is >10m². 2 ;

[0015] The first area spraying includes: a first spraying, a second spraying, and a third spraying performed sequentially;

[0016] The second area spraying includes: sequential edge ring spraying, fourth spraying, and fifth spraying;

[0017] In the third area spraying, the spraying surface is divided into i equally distributed array partitions based on the area. The area of ​​each partition is 5-10% of the area of ​​the spraying area. The array has x rows and y columns, i=x×y. The third area spraying is carried out in units of the columns of the array partitions. The partition spraying includes: the sixth, seventh and eighth sprayings performed in sequence.

[0018] The whole vehicle metallic paint spraying method provided by the present invention not only gives the locomotive a unique metallic luster, but also greatly improves the locomotive's corrosion resistance and wear resistance, achieving a mirror-level appearance quality. Furthermore, by optimizing the defect rate and operation cycle, it is significantly better than the solution of applying automotive processes, and is suitable for the painting requirements of rail transit locomotives.

[0019] As a preferred technical solution of the present invention, the whole vehicle polishing includes: a first polishing and a second polishing performed sequentially.

[0020] Preferably, the sandpaper used for the first polishing is 300-500 grit sandpaper.

[0021] Preferably, the sandpaper used for the second polishing is 700-900 grit sandpaper.

[0022] As a preferred embodiment of the present invention, the direction of the first spraying is parallel to the direction of the second spraying.

[0023] Preferably, the direction of the first spraying is perpendicular to the direction of the third spraying.

[0024] As a preferred technical solution of the present invention, the paint surface formed by the first spraying and the paint surface formed by the second spraying overlap by 1 / 3 to 2 / 3.

[0025] As a preferred embodiment of the present invention, the thickness of the paint surface formed by the first spraying is 4-5 μm.

[0026] Preferably, the vertical distance between the spray gun and the sprayed surface in the first spraying is 200-250mm.

[0027] Preferably, the thickness of the paint surface formed by the second spraying is 4-5 μm.

[0028] Preferably, the vertical distance between the spray gun and the sprayed surface in the second spraying process is 200-250mm.

[0029] Preferably, the thickness of the paint surface formed by the third spraying is 5-10 μm.

[0030] Preferably, the vertical distance between the spray gun and the sprayed surface in the third spraying is 200-250mm.

[0031] Preferably, the total thickness of the paint layer formed by spraying the first area is ≤20μm.

[0032] As a preferred embodiment of the present invention, the fourth and fifth spraying directions are the same.

[0033] Preferably, the fourth spraying includes: j consecutive segmented sprayings, j≥2, wherein the paint surfaces formed by adjacent segmented sprayings overlap by 1 / 3-2 / 3.

[0034] Preferably, the fifth spraying is a continuous spraying.

[0035] As a preferred embodiment of the present invention, the thickness of the paint surface formed by the edge ring spray is 3-5 μm.

[0036] Preferably, the vertical distance between the spray gun and the sprayed surface in the edge ring spray is 200-250mm.

[0037] Preferably, the thickness of the paint surface formed by the fourth spraying is 6-8 μm.

[0038] Preferably, the vertical distance between the spray gun and the sprayed surface in the fourth spraying is 200-250mm.

[0039] Preferably, the thickness of the paint surface formed by the fifth spraying is 6-7 μm.

[0040] Preferably, the vertical distance between the spray gun and the sprayed surface in the fifth spraying is 180-230mm.

[0041] Preferably, the total thickness of the paint layer formed by spraying the second area is ≤20μm.

[0042] As a preferred technical solution of the present invention, in the partitioned spraying, the paint surfaces formed by spraying adjacent rows overlap by 1 / 3 to 2 / 3 when spraying each column.

[0043] Preferably, the paint surfaces formed when each adjacent column is sprayed overlap by 1 / 60-3 / 100 in the partitioned spraying process.

[0044] As a preferred embodiment of the present invention, the thickness of the paint surface formed by the sixth spraying is 4-5 μm.

[0045] Preferably, the vertical distance between the spray gun and the sprayed surface in the sixth spraying is 200-250mm.

[0046] Preferably, the thickness of the paint surface formed by the seventh spraying is 4-5 μm.

[0047] Preferably, the vertical distance between the spray gun and the sprayed surface in the seventh spraying process is 200-250mm.

[0048] Preferably, the thickness of the paint surface formed by the eighth spraying is 8-10 μm.

[0049] Preferably, the vertical distance between the spray gun and the sprayed surface in the eighth spraying is 180-230mm.

[0050] Preferably, the total thickness of the paint surface formed by spraying the third region is ≤20μm.

[0051] As a preferred technical solution of the present invention, the nozzle diameter of the spray gun used in the area spraying is 1.3-1.5mm.

[0052] Preferably, the operating pressure for the area spraying is 0.3-0.6 MPa.

[0053] Preferably, the spray gun moves at a constant speed of 30-50 cm / s during the area spraying.

[0054] Compared with existing technical solutions, the present invention has the following beneficial effects:

[0055] (1) High fullness: Achieved through precise film thickness combination - the film thickness of metallic paint is ≤20μm, so that the fullness of the paint surface reaches more than 96%, and the appearance and texture are comparable to the automotive grade standard.

[0056] (2) High flatness: The gradient grinding process is adopted to significantly reduce the roughness of the substrate, laying the foundation for the uniform and delicate final effect of the metallic paint. It solves the common problem of rough paint surface in rail transit coating. The number of pits per unit area is ≤2 and the paint surface uniformity (standard deviation) is ≤1.72.

[0057] (3) Increased production cycle: The traditional 3.5h painting cycle of large rail transit vehicles is reduced to 2.5h / unit, which increases efficiency by more than 28.6% and meets the needs of large-scale production.

[0058] (4) Significantly reduced rework rate: Compared with the application of automotive metallic paint coating process, the rework rate is reduced by more than 90% - when using automotive coating process for trial spraying, there was a problem that "almost required to redo the work", while this technology greatly reduces rework costs and time through zoned spraying optimization and precise film thickness control.

[0059] (5) The whole vehicle painting method optimizes the painting process so that the number of pits per unit area of ​​the resulting paint surface is ≤2, there is no sagging, the degree of defect is extremely low, the defect rate is reduced by more than 20% compared with the automotive process, the sagging phenomenon is controllable, there is no abnormal sagging, the overall coating is uniform, and the sagging hidden dangers after the automotive process is applied are solved.

[0060] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims. Detailed Implementation

[0061] To better illustrate the present invention and facilitate understanding of its technical solutions, typical but non-limiting embodiments of the present invention are as follows:

[0062] Currently, the painting of rail transit vehicles faces numerous challenges: The vehicles are enormous, with rail vehicles exceeding 20 meters in length and having a surface area 8-10 times that of ordinary cars, requiring highly efficient painting processes and presenting significant construction difficulties; metallic pigments in metallic paints need to be evenly distributed, and large-area painting easily leads to problems such as orange peel and particle formation, and is greatly affected by environmental temperature and humidity. Existing technologies have significant shortcomings: Standardization of painting process parameters for large rail transit vehicles is lacking, and there is a lack of vehicle-wide optimization schemes for multi-layer construction parameters, affecting uneven distribution of metallic pigments, resulting in low construction efficiency, high rework rates, and limitations in different areas of varying sizes. Based on this, this invention optimizes the painting process by performing step-by-step, zoned painting according to the painting boundaries of the workpiece, thereby achieving highly efficient painting of the entire rail transit vehicle. The resulting paint surface has excellent surface effects, achieving high-quality metallic paint coating, as detailed below:

[0063] I. This embodiment provides a method for applying metallic paint to the entire rail vehicle, the method comprising:

[0064] The rail vehicles are then subjected to overall grinding and area painting in sequence.

[0065] In this invention, the rail vehicle is exemplarily defined as having a length ≥ 18m, a width ≥ 3m, and a height ≥ 3.5m.

[0066] The vehicle polishing process includes: a first polishing and a second polishing performed sequentially.

[0067] The sandpaper used for the first polishing is 300-500 grit sandpaper, such as 300 grit, 400 grit or 500 grit, but not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0068] In this invention, the endpoint of the first polishing is a uniform and fine sanded surface with no gloss residue, no unpolished areas, no smooth protrusions to the touch, and meets the coating adhesion compatibility requirements. The specific design can be based on the surface roughening requirements in the painting field.

[0069] The sandpaper used for the second polishing is 700-900 grit sandpaper, such as 700 grit, 800 grit or 900 grit, but not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0070] The second polishing process aims to achieve a finely sanded texture in the target area, free of deep scratches, effectively roughening the original smooth surface, and leaving the roughened area with a rougher feel and no smooth residue. The specific design can be based on the surface roughening requirements in the painting industry.

[0071] In this invention, the endpoint of grinding can be confirmed according to the visual evaluation of the surface cleanliness of steel surface treatment before coating in GB / T 8923.1-2011 and the evaluation test of the surface cleanliness of steel surface treatment before coating in GB / T 18570.3-2005.

[0072] The area spraying includes: first area spraying, second area spraying and third area spraying.

[0073] Wherein, the area of ​​the sprayed surface in the first area spraying is <0.5m². 2 .

[0074] The area of ​​the sprayed surface in the second region is 0.5-10m². 2 For example, it could be 0.5m 2 1.45m 2 2.4m 2 3.35m 2 4.3m 2 5.25m 2 6.2m 27.15m 2 8.1m 2 9.05m 2 or 10m 2 The values ​​may include, but are not limited to, the listed values; other unlisted values ​​within this range also meet the requirements.

[0075] The area of ​​the sprayed surface in the third region is >10m². 2 .

[0076] In this invention, based on the area and structural characteristics of the vehicle body parts, the vehicle body is divided into large continuous areas, small and medium-sized irregularly shaped areas, and small precision areas for zoned spraying. For example, large continuous areas include: large flat surfaces on the side of the vehicle body (single area can reach 21m×3.5m or more), the overall flat surface of the roof, large underframes, and skirts; small and medium-sized irregularly shaped areas include modular equipment such as doors, hoods, opening and closing mechanisms, and the front end of the vehicle; small precision areas include louvers, obstacle clearers, and narrow strip decorative parts (such as areas with a width of 20cm and a length of <25cm).

[0077] The first area spraying includes: a first spraying, a second spraying, and a third spraying performed sequentially.

[0078] The direction of the first spraying is parallel to the direction of the second spraying.

[0079] The direction of the first spraying is perpendicular to the direction of the third spraying.

[0080] The paint surface formed by the first spraying and the paint surface formed by the second spraying overlap by 1 / 3 to 2 / 3.

[0081] In this invention, paint overlap refers to the overlap in area between two paint surfaces formed during two spraying processes.

[0082] The thickness of the paint surface formed by the first spraying is 4-5μm, for example, it can be 4μm, 4.1μm, 4.2μm, 4.3μm, 4.4μm, 4.5μm, 4.6μm, 4.7μm, 4.8μm, 4.9μm or 5μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0083] In the first spraying process, the vertical distance between the spray gun and the sprayed surface is 200-250mm, for example, it can be 200mm, 205mm, 210mm, 215mm, 220mm, 225mm, 230mm, 235mm, 240mm, 245mm or 250mm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0084] The thickness of the paint surface formed by the second spraying is 4-5μm, for example, it can be 4μm, 4.1μm, 4.2μm, 4.3μm, 4.4μm, 4.5μm, 4.6μm, 4.7μm, 4.8μm, 4.9μm or 5μm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0085] In the second spraying process, the vertical distance between the spray gun and the sprayed surface is 200-250mm, for example, it can be 200mm, 205mm, 210mm, 215mm, 220mm, 225mm, 230mm, 235mm, 240mm, 245mm or 250mm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0086] The thickness of the paint surface formed by the third spraying is 5-10μm, for example, it can be 5μm, 5.5μm, 6μm, 6.5μm, 7μm, 7.5μm, 8μm, 8.5μm, 9μm, 9.5μm or 10μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0087] In the third spraying process, the vertical distance between the spray gun and the sprayed surface is 200-250mm, for example, it can be 200mm, 205mm, 210mm, 215mm, 220mm, 225mm, 230mm, 235mm, 240mm, 245mm or 250mm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0088] The total thickness of the paint layer formed by spraying the first area is ≤20μm.

[0089] In this invention, the core logic of the first area spraying is as follows: For small areas without segmentation, the total thickness is controlled through "thin spraying with multiple passes" to avoid localized buildup; vertical pressure spraying ensures both thickness and appearance consistency. Spray thickness: The thickness of a single spray is controlled at 8-10 μm (thin spraying), requiring no segmentation, and can be completed in 1-2 passes (total thickness ≤ 20 μm). Spraying method: The "two horizontal pressure passes + one vertical pressure pass" process is used. The first horizontal pressure pass (short side direction) is approximately 4-5 μm thick, quickly applying a base coat; the second horizontal pressure pass (overlapping the first pass by 1 / 3-2 / 3) is approximately 4-5 μm thick, completing the base coating; the third vertical pressure pass (long side direction) is approximately 5-10 μm thick, eliminating overlap marks and ensuring uniform thickness.

[0090] The second area spraying includes: sequential edge ring spraying, fourth spraying and fifth spraying.

[0091] The fourth and fifth sprayings are applied in the same direction.

[0092] The fourth spraying includes: j consecutive segmented sprayings, j≥2, wherein the paint surfaces formed by adjacent segmented sprayings overlap by 1 / 3-2 / 3.

[0093] In this invention, segmented spraying refers to dividing the paint surface into segments, and spraying the next segment after one segment is completed.

[0094] The fifth spraying is a continuous spraying.

[0095] The thickness of the paint surface formed by the edge ring spraying is 3-5μm, for example, it can be 3μm, 3.2μm, 3.4μm, 3.6μm, 3.8μm, 4μm, 4.2μm, 4.4μm, 4.6μm, 4.8μm or 5μm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0096] The vertical distance between the spray gun and the sprayed surface in the edge ring spraying is 200-250mm, for example, it can be 200mm, 205mm, 210mm, 215mm, 220mm, 225mm, 230mm, 235mm, 240mm, 245mm or 250mm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0097] In this invention, edge ring spraying refers to spraying the paint along the edge of the spraying area during the spraying process. Specifically, the center of the nozzle moves along the boundary line of the spraying area during the spraying process.

[0098] The thickness of the paint surface formed by the fourth spraying is 6-8μm, for example, it can be 6μm, 6.2μm, 6.4μm, 6.6μm, 6.8μm, 7μm, 7.2μm, 7.4μm, 7.6μm, 7.8μm or 8μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0099] In the fourth spraying process, the vertical distance between the spray gun and the sprayed surface is 200-250mm, for example, it can be 200mm, 205mm, 210mm, 215mm, 220mm, 225mm, 230mm, 235mm, 240mm, 245mm or 250mm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0100] The thickness of the paint surface formed by the fifth spray is 6-7 μm, for example, it can be 6 μm, 6.1 μm, 6.2 μm, 6.3 μm, 6.4 μm, 6.5 μm, 6.6 μm, 6.7 μm, 6.8 μm, 6.9 μm or 7 μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0101] In the fifth spraying process, the vertical distance between the spray gun and the sprayed surface is 180-230mm, for example, it can be 180mm, 185mm, 190mm, 195mm, 200mm, 205mm, 210mm, 215mm, 220mm, 225mm or 230mm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0102] The total thickness of the paint layer formed by spraying the second area is ≤20μm.

[0103] In this invention, the core logic of the second area spraying is to balance thickness and leveling through "priming + thickening"; edge pre-spraying ensures that the overall thickness is without deviation and avoids localized excessive thinness. For example, the "edge pre-spraying + segmented horizontal continuous spraying" method can be used. ① Edge pre-spraying: Spray a thin circle around the perimeter of the plane (approximately 3-5 μm thick) to avoid insufficient thickness due to "dry edges" during the main spraying. ② First main spray (priming): Spray continuously in horizontal segments (each segment ≤ 1 m), with each segment overlapping by 1 / 3-2 / 3, achieving a thickness of 6-8 μm. ③ Second main spray (thickening): Spray in the same direction as the first spray, with an interval of 5-10 minutes (after surface drying), achieving a thickness of 6-7 μm, for a total thickness ≤ 20 μm.

[0104] In the third region spraying process, the spraying surface is divided into i partitions in an array based on the area. The area of ​​each partition is 5-10% of the area of ​​the spraying region. The array has x rows and y columns, i = x × y.

[0105] The third area spraying is carried out in sections based on the columns of the array partition.

[0106] In this invention, spraying is performed in units of columns of the array partition. This means that the painting is carried out in units of columns of the array partition, and the next column is painted only after one column has been painted according to the painting requirements.

[0107] The zoned spraying includes: the sixth, seventh, and eighth sprayings performed sequentially.

[0108] In the partitioned spraying process, the paint surfaces formed by spraying adjacent rows overlap by 1 / 3 to 2 / 3 during each column of spraying.

[0109] In the partitioned spraying process, the paint surfaces formed when each adjacent column is sprayed overlap by 1 / 60 to 3 / 100.

[0110] The thickness of the paint surface formed by the sixth spraying is 4-5μm, for example, it can be 4μm, 4.1μm, 4.2μm, 4.3μm, 4.4μm, 4.5μm, 4.6μm, 4.7μm, 4.8μm, 4.9μm or 5μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0111] In the sixth spraying process, the vertical distance between the spray gun and the sprayed surface is 200-250mm, for example, it can be 200mm, 205mm, 210mm, 215mm, 220mm, 225mm, 230mm, 235mm, 240mm, 245mm or 250mm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0112] The thickness of the paint surface formed by the seventh spraying is 4-5μm, for example, it can be 4μm, 4.1μm, 4.2μm, 4.3μm, 4.4μm, 4.5μm, 4.6μm, 4.7μm, 4.8μm, 4.9μm or 5μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0113] In the seventh spraying process, the vertical distance between the spray gun and the sprayed surface is 200-250mm, for example, it can be 200mm, 205mm, 210mm, 215mm, 220mm, 225mm, 230mm, 235mm, 240mm, 245mm or 250mm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0114] The thickness of the paint surface formed by the eighth spraying is 8-10μm, for example, it can be 8μm, 8.2μm, 8.4μm, 8.6μm, 8.8μm, 9μm, 9.2μm, 9.4μm, 9.6μm, 9.8μm or 10μm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0115] In the eighth spraying process, the vertical distance between the spray gun and the sprayed surface is 180-230mm, for example, it can be 180mm, 185mm, 190mm, 195mm, 200mm, 205mm, 210mm, 215mm, 220mm, 225mm or 230mm, but is not limited to the listed values. Other unlisted values ​​within this range also meet the requirements.

[0116] The total thickness of the paint surface formed by spraying in the third region is ≤20μm.

[0117] In this invention, the core logic of the third-area spraying is to divide the area into "small blocks + strips," transforming ultra-long / ultra-high regions into controllable small-scale spraying, adapting to the spray gun's movement radius; "multiple thin sprays + 1 thick spray" ensures the total thickness meets the standard while avoiding sagging caused by excessive thickness in a single coat, and also adapts to the orientation requirements of metallic paint aluminum powder, reducing the risk of large-area blooming. ① Following the order of "horizontal strips first, then vertical blocks," complete all horizontal strips within a vertical block before moving to the next block. ② During each spray, the spray gun moves at a uniform speed (30-50cm / s) along the longitudinal direction of the strip, with each coating overlapping by 1 / 2-2 / 3 to ensure uniform thickness within a single strip. ③ After the first 1-2 thin sprays as a base coat, after an interval of 8-12 minutes (adjusted according to the paint's surface drying speed), perform the third thick spray to increase the thickness. During the thick spray, maintain stable spray gun parameters (minimum airflow, nozzle diameter 1.3-1.5mm) to avoid blooming or sagging due to increased thickness.

[0118] The nozzle diameter of the spray gun used in the area spraying is 1.3-1.5mm, for example, it can be 1.3mm, 1.32mm, 1.34mm, 1.36mm, 1.38mm, 1.4mm, 1.42mm, 1.44mm, 1.46mm, 1.48mm or 1.5mm, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0119] The operating pressure for the area spraying is 0.3-0.6 MPa, for example, it can be 0.3 MPa, 0.33 MPa, 0.36 MPa, 0.39 MPa, 0.42 MPa, 0.45 MPa, 0.48 MPa, 0.51 MPa, 0.54 MPa, 0.57 MPa or 0.6 MPa, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0120] In the area spraying process, the spray gun moves at a constant speed of 30-50 cm / s, for example, it can be 30 cm / s, 32 cm / s, 34 cm / s, 36 cm / s, 38 cm / s, 40 cm / s, 42 cm / s, 44 cm / s, 46 cm / s, 48 ​​cm / s or 50 cm / s, but is not limited to the listed values. Other unlisted values ​​within this range are also acceptable.

[0121] In this invention, the metallic paint used in the spraying process can be selected as: acrylic resin metallic paint, such as acrylic epoxy metallic paint and acrylic polyurethane metallic paint, etc.

[0122] In this invention, the painting process can be carried out manually or in conjunction with an intelligent painting workshop, such as using laser measurement and other equipment to intelligently divide the area, and then controlling the spray gun to spray paint.

[0123] II. To illustrate the painting effect achievable by the painting method provided by this invention, the following practical example is used for explanation:

[0124] In the example below, the dimensions of the rail vehicle are: length × width × height, 21.61m × 3.63m × 3.57m. The components corresponding to the first area of ​​painting include: auxiliary lighting mounting bracket, front lighting panel mounting bracket, and coupler mounting bracket; the components corresponding to the second area of ​​painting include: air conditioning cover and front window glass mounting surface; the components corresponding to the third area of ​​painting include: the side of the car body.

[0125] Example 1

[0126] This embodiment provides a method for applying metallic paint to the entire rail vehicle, the method comprising:

[0127] The rail vehicles are sequentially subjected to whole-vehicle grinding and area spraying.

[0128] The vehicle polishing process includes: a first polishing and a second polishing performed sequentially; the first polishing uses 400-grit sandpaper; the second polishing uses 800-grit sandpaper.

[0129] The area spraying includes: first area spraying, second area spraying and third area spraying;

[0130] The area of ​​the sprayed surface in the first area is <0.5m². 2 The first area spraying includes: a first spray, a second spray, and a third spray performed sequentially; the direction of the first spray is parallel to the direction of the second spray; the direction of the first spray is perpendicular to the direction of the third spray; the paint surface formed by the first spray overlaps the paint surface formed by the second spray by 1 / 3; the thickness of the paint surface formed by the first spray is 4.5 μm; the vertical distance between the spray gun and the sprayed surface in the first spray is 225 mm; the thickness of the paint surface formed by the second spray is 4.5 μm; the vertical distance between the spray gun and the sprayed surface in the second spray is 225 mm; the thickness of the paint surface formed by the third spray is 8 μm; the vertical distance between the spray gun and the sprayed surface in the third spray is 225 mm; the total thickness of the paint surface formed by the first area spraying is 17 μm, i.e., ≤20 μm;

[0131] The area of ​​the sprayed surface in the second area is 0.5-10m². 2The second area spraying includes: sequential edge ring spraying, a fourth spraying, and a fifth spraying; the fourth and fifth sprayings are in the same direction; the fourth spraying includes: j consecutive segmented sprayings, j=5, where the paint surfaces formed by adjacent segmented sprayings overlap by 1 / 3; the fifth spraying is a continuous spraying; the thickness of the paint surface formed by the edge ring spraying is 4μm; the vertical distance between the spray gun and the sprayed surface during the edge ring spraying is 225mm; the thickness of the paint surface formed by the fourth spraying is 7μm; the vertical distance between the spray gun and the sprayed surface during the fourth spraying is 225mm; the thickness of the paint surface formed by the fifth spraying is 6.5μm; the vertical distance between the spray gun and the sprayed surface during the fifth spraying is 200mm; the total thickness of the paint surface formed by the second area spraying is 17.5, which satisfies ≤20μm;

[0132] The area of ​​the sprayed surface in the third region is >10m². 2 In the third area spraying, the spraying surface is divided into i evenly distributed array partitions based on area. The area of ​​each partition is 8% of the spraying area, and the array has x rows and y columns, i = x × y. The third area spraying is performed in units of columns within the array partitions. The partition spraying includes: a sixth, seventh, and eighth spraying performed sequentially. During each column spraying in the partition spraying, the paint overlap between adjacent rows is 1 / 3; the paint overlap between adjacent columns spraying in the partition spraying is 1 / 3. 60; the thickness of the paint surface formed by the sixth spray is 4.5 μm; the vertical distance between the spray gun and the sprayed surface in the sixth spray is 225 mm; the thickness of the paint surface formed by the seventh spray is 4.5 μm; the vertical distance between the spray gun and the sprayed surface in the seventh spray is 225 mm; the thickness of the paint surface formed by the eighth spray is 9 μm; the vertical distance between the spray gun and the sprayed surface in the eighth spray is 200 mm; the total thickness of the paint surface formed by the third region spray is 18 μm, which satisfies ≤20 μm;

[0133] The nozzle diameter of the spray gun used in the area spraying is 1.4 mm; the operating pressure of the area spraying is 0.45 MPa; and the spray gun moves at a constant speed of 40 cm / s during the area spraying.

[0134] Example 2

[0135] This embodiment provides a method for applying metallic paint to the entire rail vehicle, the method comprising:

[0136] The rail vehicles are sequentially subjected to whole-vehicle grinding and area spraying.

[0137] The vehicle polishing process includes: a first polishing and a second polishing performed sequentially; the first polishing uses 300-grit sandpaper; the second polishing uses 700-grit sandpaper.

[0138] The area spraying includes: first area spraying, second area spraying and third area spraying;

[0139] The area of ​​the sprayed surface in the first area is <0.5m². 2 The first area spraying includes: a first spray, a second spray, and a third spray performed sequentially; the direction of the first spray is parallel to the direction of the second spray; the direction of the first spray is perpendicular to the direction of the third spray; the paint surface formed by the first spray overlaps the paint surface formed by the second spray by 2 / 3; the thickness of the paint surface formed by the first spray is 4μm; the vertical distance between the spray gun and the sprayed surface in the first spray is 250mm; the thickness of the paint surface formed by the second spray is 4μm; the vertical distance between the spray gun and the sprayed surface in the second spray is 250mm; the thickness of the paint surface formed by the third spray is 10μm; the vertical distance between the spray gun and the sprayed surface in the third spray is 200mm; the total thickness of the paint surface formed by the first area spraying is 18μm, i.e., ≤20μm;

[0140] The area of ​​the sprayed surface in the second area is 0.5-10m². 2 The second area spraying includes: sequential edge ring spraying, a fourth spraying, and a fifth spraying; the fourth and fifth sprayings are in the same direction; the fourth spraying includes: j consecutive segmented sprayings, j=2, where the paint surfaces formed by adjacent segmented sprayings overlap by 2 / 3; the fifth spraying is a continuous spraying; the thickness of the paint surface formed by the edge ring spraying is 3μm; the vertical distance between the spray gun and the sprayed surface during the edge ring spraying is 250mm; the thickness of the paint surface formed by the fourth spraying is 6μm; the vertical distance between the spray gun and the sprayed surface during the fourth spraying is 250mm; the thickness of the paint surface formed by the fifth spraying is 6μm; the vertical distance between the spray gun and the sprayed surface during the fifth spraying is 230mm; the total thickness of the paint surface formed by the second area spraying is 15μm, i.e., ≤20μm;

[0141] The area of ​​the sprayed surface in the third region is >10m². 2In the third area spraying, the spraying surface is divided into i evenly distributed array partitions based on area. The area of ​​each partition is 5% of the spraying area, and the array has x rows and y columns, i = x × y. The third area spraying is performed in units of columns within the array partitions. The partition spraying includes: a sixth, seventh, and eighth spraying performed sequentially. During each column spraying in the partition spraying, the paint overlap between adjacent rows is 2 / 3; the paint overlap between adjacent columns is 3 / 4. / 100; The thickness of the paint surface formed by the sixth spray is 4μm; The vertical distance between the spray gun and the sprayed surface in the sixth spray is 250mm; The thickness of the paint surface formed by the seventh spray is 4μm; The vertical distance between the spray gun and the sprayed surface in the seventh spray is 250mm; The thickness of the paint surface formed by the eighth spray is 8μm; The vertical distance between the spray gun and the sprayed surface in the eighth spray is 230mm; The total thickness of the paint surface formed by the third area spray is 16μm, which satisfies ≤20μm;

[0142] The nozzle diameter of the spray gun used in the area spraying is 1.3 mm; the operating pressure of the area spraying is 0.6 MPa; and the spray gun moves at a constant speed of 50 cm / s during the area spraying.

[0143] Example 3

[0144] This embodiment provides a method for applying metallic paint to the entire rail vehicle, the method comprising:

[0145] The rail vehicles are sequentially subjected to whole-vehicle grinding and area spraying.

[0146] The vehicle polishing process includes: a first polishing and a second polishing performed sequentially; the first polishing uses 500-grit sandpaper; the second polishing uses 900-grit sandpaper.

[0147] The area spraying includes: first area spraying, second area spraying and third area spraying;

[0148] The area of ​​the sprayed surface in the first area is <0.5m². 2The first area spraying includes: a first spray, a second spray, and a third spray performed sequentially; the direction of the first spray is parallel to the direction of the second spray; the direction of the first spray is perpendicular to the direction of the third spray; the paint surface formed by the first spray overlaps the paint surface formed by the second spray by 1 / 3; the thickness of the paint surface formed by the first spray is 5μm; the vertical distance between the spray gun and the sprayed surface in the first spray is 200mm; the thickness of the paint surface formed by the second spray is 5μm; the vertical distance between the spray gun and the sprayed surface in the second spray is 200mm; the thickness of the paint surface formed by the third spray is 5μm; the vertical distance between the spray gun and the sprayed surface in the third spray is 250mm; the total thickness of the paint surface formed by the first area spraying is 15μm, i.e., ≤20μm;

[0149] The area of ​​the sprayed surface in the second area is 0.5-10m². 2 The second area spraying includes: sequential edge ring spraying, a fourth spraying, and a fifth spraying; the fourth and fifth sprayings are in the same direction; the fourth spraying includes: j consecutive segmented sprayings, j=4, where the paint surfaces formed by adjacent segmented sprayings overlap by 1 / 3; the fifth spraying is a continuous spraying; the thickness of the paint surface formed by the edge ring spraying is 5μm; the vertical distance between the spray gun and the sprayed surface during the edge ring spraying is 200mm; the thickness of the paint surface formed by the fourth spraying is 8μm; the vertical distance between the spray gun and the sprayed surface during the fourth spraying is 200mm; the thickness of the paint surface formed by the fifth spraying is 7μm; the vertical distance between the spray gun and the sprayed surface during the fifth spraying is 180mm; the total thickness of the paint surface formed by the second area spraying is 20μm, i.e., ≤20μm;

[0150] The area of ​​the sprayed surface in the third region is >10m². 2In the third area spraying, the spraying surface is divided into i evenly distributed array partitions based on area. The area of ​​each partition is 10% of the spraying area, and the array has x rows and y columns, i = x × y. The third area spraying is performed in units of columns within the array partitions. The partition spraying includes: a sixth, seventh, and eighth spraying performed sequentially. During each column spraying in the partition spraying, the paint overlap between adjacent rows is 1 / 3. The paint overlap between adjacent columns during the partition spraying is also... 1 / 60; the thickness of the paint surface formed by the sixth spray is 5μm; the vertical distance between the spray gun and the sprayed surface in the sixth spray is 200mm; the thickness of the paint surface formed by the seventh spray is 5μm; the vertical distance between the spray gun and the sprayed surface in the seventh spray is 200mm; the thickness of the paint surface formed by the eighth spray is 10μm; the vertical distance between the spray gun and the sprayed surface in the eighth spray is 180mm; the total thickness of the paint surface formed by the third area spray is 20μm, that is, it satisfies ≤20μm;

[0151] The nozzle diameter of the spray gun used in the area spraying is 1.5 mm; the operating pressure of the area spraying is 0.3 MPa; and the spray gun moves at a constant speed of 30 cm / s during the area spraying.

[0152] Example 4

[0153] The only difference from Example 1 is that the first coating is not performed in the first area spraying, and the corresponding reduction in thickness is simultaneously and proportionally incorporated into the second and third coatings.

[0154] Example 5

[0155] The only difference from Example 1 is that the second coating is not performed in the first area coating, and the corresponding reduction in thickness is simultaneously and proportionally incorporated into the first and third coatings.

[0156] Example 6

[0157] The only difference from Example 1 is that no third coating is applied in the first area spraying, and the corresponding reduction in thickness is simultaneously and proportionally incorporated into the first and second coatings.

[0158] Example 7

[0159] The only difference from Example 1 is that edge ring spraying is not performed in the second area spraying.

[0160] Example 8

[0161] The only difference from Example 1 is that the fourth coating is not performed in the second area spraying, and the corresponding reduction in thickness is incorporated into the fifth coating.

[0162] Example 9

[0163] The only difference from Example 1 is that the fifth coating is not performed in the second area coating, and the corresponding reduction in thickness is incorporated into the fourth coating.

[0164] Example 10

[0165] The only difference from Example 1 is that the third area is not divided into zones during spraying.

[0166] Example 11

[0167] The only difference from Example 1 is that the sixth coating is not performed in the third area spraying, and the corresponding reduction in thickness is simultaneously and proportionally incorporated into the seventh and eighth coatings.

[0168] Example 12

[0169] The only difference from Example 1 is that the seventh coating is not performed in the third area spraying, and the corresponding reduction in thickness is simultaneously and proportionally incorporated into the sixth and eighth coatings.

[0170] Example 13

[0171] The only difference from Example 1 is that the eighth coating is not performed in the third area spraying, and the corresponding reduction in thickness is simultaneously and proportionally incorporated into the sixth and seventh coatings.

[0172] Example 14

[0173] The only difference from Example 1 is that the third area spraying is performed in a row-partitioned manner.

[0174] Comparative Example 1

[0175] The only difference from Example 1 is that it applies to areas <0.5m². 2 The sprayed surface is coated using a second-zone spraying process.

[0176] Comparative Example 2

[0177] The only difference from Example 1 is that it applies to areas <0.5m². 2 The sprayed surface is coated using a third-zone spraying process.

[0178] Comparative Example 3

[0179] The only difference from Example 1 is the area of ​​0.5-10m². 2 The sprayed surface is coated using the first area spraying process.

[0180] Comparative Example 4

[0181] The only difference from Example 1 is the area of ​​0.5-10m². 2 The sprayed surface is coated using a third-zone spraying process.

[0182] Comparative Example 5

[0183] The only difference from Example 1 is that it applies to areas >10m². 2 The sprayed surface is coated using the first area spraying process.

[0184] Comparative Example 6

[0185] The only difference from Example 1 is that it applies to areas >10m². 2 The sprayed surface is coated using a second-zone spraying process.

[0186] The paint surfaces of the rail vehicles obtained in the above embodiments and comparative examples were tested. The gloss was measured according to GB / T 9754, the determination of 20°, 60° and 80° specular gloss of paint films without technical pigments; the number of pinholes per unit area was determined according to GB / T 9761, the visual colorimetric determination of paints and varnishes; and the paint surface uniformity was determined according to GB / T 13452.2, the determination of paint film thickness. The test results are shown in Table 1 below.

[0187] Table 1

[0188]

[0189] As shown in Table 1, if the solution provided by this invention does not match the corresponding method according to the spraying area (such as using a medium-area spraying method for a small area), the performance of the paint surface formed by the spraying will be significantly worse. That is, by using full-vehicle metallic paint coating, not only does the locomotive's appearance present a unique metallic luster, but it also greatly improves the locomotive's corrosion resistance and wear resistance, achieving a mirror-level appearance quality. Furthermore, by optimizing the defect rate and operation cycle, it is significantly better than the solution that adopts automotive processes, and is suitable for the painting requirements of rail transit locomotives.

[0190] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0191] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0192] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for applying metallic paint to the entire surface of a rail vehicle, characterized in that, The method for applying metallic paint to the entire vehicle includes: The rail vehicles are sequentially subjected to whole-vehicle grinding and area spraying. The area spraying includes: first area spraying, second area spraying and third area spraying; The area of ​​the sprayed surface in the first area is <0.5m². 2 ; The area of ​​the sprayed surface in the second area is 0.5-10m². 2 ; The area of ​​the sprayed surface in the third region is >10m². 2 ; The first area spraying includes: a first spraying, a second spraying, and a third spraying performed sequentially; The second area spraying includes: sequential edge ring spraying, fourth spraying, and fifth spraying; In the third area spraying, the spraying surface is divided into i equally distributed array partitions based on the area. The area of ​​each partition is 5-10% of the area of ​​the spraying area. The array has x rows and y columns, i=x×y. The third area spraying is carried out in units of the columns of the array partitions. The partition spraying includes: the sixth, seventh and eighth sprayings performed in sequence.

2. The method for applying metallic paint to a vehicle as described in claim 1, characterized in that, The vehicle polishing process includes: a first polishing and a second polishing performed sequentially; Preferably, the sandpaper used for the first polishing is 300-500 grit sandpaper; Preferably, the sandpaper used for the second polishing is 700-900 grit sandpaper.

3. The method for applying metallic paint to a vehicle as described in claim 1, characterized in that, The direction of the first spraying is parallel to the direction of the second spraying; Preferably, the direction of the first spraying is perpendicular to the direction of the third spraying.

4. The method for applying metallic paint to a vehicle as described in claim 1, characterized in that, The paint surface formed by the first spraying and the paint surface formed by the second spraying overlap by 1 / 3 to 2 / 3.

5. The method for applying metallic paint to a vehicle as described in claim 1, characterized in that, The thickness of the paint surface formed by the first spraying is 4-5 μm; Preferably, the vertical distance between the spray gun and the sprayed surface in the first spraying is 200-250mm; Preferably, the thickness of the paint surface formed by the second spraying is 4-5 μm; Preferably, the vertical distance between the spray gun and the sprayed surface in the second spraying process is 200-250 mm; Preferably, the thickness of the paint surface formed by the third spraying is 5-10 μm; Preferably, the vertical distance between the spray gun and the sprayed surface in the third spraying is 200-250mm; Preferably, the total thickness of the paint layer formed by spraying the first area is ≤20μm.

6. The method for applying metallic paint to a vehicle as described in claim 1, characterized in that, The fourth and fifth spraying directions are the same; Preferably, the fourth spraying includes: j consecutive segmented sprayings, j≥2, wherein the paint surfaces formed by adjacent segmented sprayings overlap by 1 / 3-2 / 3; Preferably, the fifth spraying is a continuous spraying.

7. The method for applying metallic paint to a vehicle as described in claim 1, characterized in that, The thickness of the paint surface formed by the edge ring spraying is 3-5 μm; Preferably, the vertical distance between the spray gun and the sprayed surface in the edge ring spray is 200-250mm; Preferably, the thickness of the paint surface formed by the fourth spraying is 6-8 μm; Preferably, the vertical distance between the spray gun and the sprayed surface in the fourth spraying is 200-250mm; Preferably, the thickness of the paint surface formed by the fifth spraying is 6-7 μm; Preferably, the vertical distance between the spray gun and the sprayed surface in the fifth spraying is 180-230mm; Preferably, the total thickness of the paint layer formed by spraying the second area is ≤20μm.

8. The method for applying metallic paint to a vehicle as described in claim 1, characterized in that, In the partitioned spraying process, the paint surfaces formed by spraying adjacent rows in each column overlap by 1 / 3 to 2 / 3. Preferably, the paint surfaces formed when each adjacent column is sprayed overlap by 1 / 60-3 / 100 in the partitioned spraying process.

9. The method for applying metallic paint to a vehicle as described in claim 1, characterized in that, The thickness of the paint surface formed by the sixth spraying is 4-5 μm; Preferably, in the sixth spraying process, the vertical distance between the spray gun and the sprayed surface is 200-250mm; Preferably, the thickness of the paint surface formed by the seventh spraying is 4-5 μm; Preferably, in the seventh spraying process, the vertical distance between the spray gun and the sprayed surface is 200-250mm; Preferably, the thickness of the paint surface formed by the eighth spraying is 8-10 μm; Preferably, in the eighth spraying process, the vertical distance between the spray gun and the sprayed surface is 180-230mm; Preferably, the total thickness of the paint surface formed by spraying the third region is ≤20μm.

10. The method for applying metallic paint to a vehicle as described in claim 1, characterized in that, The nozzle diameter of the spray gun used in the area spraying is 1.3-1.5 mm; Preferably, the operating pressure for the area spraying is 0.3-0.6 MPa; Preferably, the spray gun moves at a constant speed of 30-50 cm / s during the area spraying.

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