Device and method for directly printing appearance mark on sheet metal part

Abstract

The application provides a device and method capable of directly printing appearance marks on sheet metal parts. The device comprises a feeding platform, the feeding platform is provided with a first conveying belt capable of being driven to feed in a first direction, sheet metal parts can be supported on the first conveying belt, a sheet metal surface treatment component and a UV jet printing component are sequentially arranged along the first direction, the sheet metal surface treatment component can form a micron-level texture structure on the top surface of a jet printing target area on the sheet metal part, the UV jet printing component comprises a jet printing assembly and a UV curing lamp, the jet printing assembly can jet print a preset appearance mark on the jet printing target area on which the micron-level texture structure is formed, and the UV curing lamp is used for irradiating the jet printing target area to cure the jet printed preset appearance mark. The application improves the ink adhesion, and reduces the probability of quality problems such as ink bleeding, mark separation and color loss.

Description

Technical Field

[0001] This invention belongs to the field of process equipment design technology, specifically relating to a device and method for directly printing appearance markings on sheet metal parts. Background Technology

[0002] Currently, the external markings (such as brand logos, model numbers, energy efficiency labels, etc.) on the sheet metal spray-painted panels of air conditioner outdoor units are generally achieved using traditional screen printing or self-adhesive labeling methods. Screen printing suffers from problems such as high plate-making costs, long changeover cycles, and poor ink adhesion. Self-adhesive labeling relies on purchased finished products, which suffers from defects such as poor material consistency, low efficiency of manual application, easy peeling, and insufficient weather resistance, making it difficult to meet the stringent requirements of high-end air conditioning products for appearance quality and long-term stability.

[0003] While existing UV inkjet printing technology can achieve direct printing, when UV inkjet printing is performed directly on metal sheet metal, the adhesion between the ink and the metal substrate is insufficient, which easily leads to quality problems such as ink detachment, peeling, and color fading. Summary of the Invention

[0004] Therefore, the present invention provides an apparatus and method for directly printing appearance markings on sheet metal parts, which can overcome the shortcomings of related technologies that use UV inkjet printing technology to print corresponding appearance markings on sheet metal parts, which are prone to quality problems such as ink removal, peeling, and color fading due to insufficient adhesion between ink and metal substrate.

[0005] To address the aforementioned problems, this invention provides an apparatus capable of directly printing appearance markings on sheet metal parts, comprising a feeding platform having a first conveyor belt that can be driven to feed materials along a first direction, the sheet metal parts being supported on the first conveyor belt, and a sheet metal surface treatment component and a UV printing component being sequentially arranged along the first direction. The sheet metal surface treatment component is capable of forming a micron-level texture structure on the top surface of the printing target area on the sheet metal parts, and the UV printing component includes a printing assembly and a UV curing lamp. The printing assembly is capable of printing a preset appearance marking on the printing target area where the micron-level texture structure has been formed, and the UV curing lamp is used to irradiate the printing target area to cure the printed preset appearance marking.

[0006] In some embodiments, the sheet metal surface treatment component is a plasma treatment module.

[0007] In some embodiments, a nano-coating spraying module is also integrated into the plasma treatment module.

[0008] In some embodiments, the UV printing component further includes a first longitudinal movement drive component, wherein the UV curing lamp and the printing assembly are arranged sequentially along the first direction and the first longitudinal movement drive component is capable of driving the UV curing lamp and the printing assembly to reciprocate linearly along the first direction; and / or, the printing assembly has a plurality of printheads arranged in an array.

[0009] In some embodiments, the apparatus for directly printing appearance markings on sheet metal parts further includes a sheet metal part height adjustment component, which is used to raise the sheet metal part as it is conveyed to the printing area of ​​the printing assembly so that the distance between the printing target area of ​​the sheet metal part and the printing assembly is within a target range.

[0010] In some embodiments, the sheet metal height adjustment component includes a base plate, a lifting plate is provided on the top surface of the base plate, the lifting plate is slidably connected to the base plate through a first linear guide post assembly, and further includes a first lifting drive component for driving the lifting plate to rise and fall.

[0011] In some embodiments, the top surface of the substrate is further provided with an adsorption leveling component, which includes an adsorption plate and a second lifting drive for driving the adsorption plate to rise and fall. The adsorption plate has an adsorption plane that fits against the bottom plane of the printing target area of ​​the sheet metal part, and the adsorption plane has a negative pressure suction port.

[0012] In some embodiments, the adsorption leveling assembly further includes a force-applying plate spaced vertically and vertically from the adsorption plate. The adsorption plate is slidably connected to the force-applying plate via two spaced first guide posts. An elastic element is fitted on the radially outer side of each first guide post. The elastic element can be clamped between the force-applying plate and the adsorption plate. The force-applying plate is slidably connected to the substrate via a second guide post. The second lifting drive is drivenly connected to the force-applying plate.

[0013] In some embodiments, each of the first guide posts has a central through hole, the position of each negative pressure suction port corresponds one-to-one with the position of each of the first guide posts, and the negative pressure suction port is connected to the vacuum hose of an external vacuum pump. Each of the vacuum hoses passes through the central through hole of each of the first guide posts and is connected to each of the negative pressure suction ports.

[0014] In some embodiments, the second lifting drive includes a first telescopic member and a second telescopic member, wherein the telescopic rod of the first telescopic member can drive the second telescopic member to rise and fall, and the telescopic rod of the second telescopic member is drivenly connected to the force-applying plate; and / or, a detection sensor is provided on the adsorption plane of the adsorption plate, the detection sensor being used to detect in real time whether the sheet metal part has reached the top surface area of ​​the adsorption plate; and / or, the area and shape of the adsorption plane are adapted to the area and shape of the printing target area.

[0015] In some embodiments, the adsorption leveling assembly further includes a positioning mechanism, which includes a baffle formed on one side edge of the top surface of the substrate and a pusher. The stop side of the baffle extends along the first direction, and the pusher can be driven to reciprocate linearly along a direction perpendicular to the stop side, so as to form a clamping and positioning of the sheet metal part on opposite sides with the stop side of the baffle.

[0016] In some embodiments, the positioning mechanism further includes a first lifting limit member, which can be controlled to rise and fall on the conveying path of the sheet metal part to form a stop limit on the downstream side of the sheet metal part.

[0017] In some embodiments, the positioning mechanism further includes a second lifting limit member, which can be controlled to rise and fall on the conveying path of the sheet metal part to form a stop limit on the upstream side of the sheet metal part, and the distance between the first lifting limit member and the second lifting limit member is adjustable.

[0018] In some embodiments, the first conveyor belt comprises two belts spaced apart perpendicularly to the first direction, and the sheet metal height adjustment component is located in the space between the two first conveyor belts.

[0019] In some embodiments, the sheet metal part is an outdoor unit panel of an air conditioner, and bent side plates are formed at both ends of the outdoor unit panel in the second direction. The two first conveyor belts are respectively located on the opposite side of the two bent side plates, and the second direction is perpendicular to the first direction.

[0020] In some embodiments, the feeding platform further includes a second conveyor belt that can be driven to feed materials along the first direction, the second conveyor belt being located upstream of the first conveyor belt, and the sheet metal surface treatment component being positioned corresponding to the second conveyor belt.

[0021] In some embodiments, the feeding platform further includes a third conveyor belt that can be driven to feed materials along the first direction, the third conveyor belt being located downstream of the first conveyor belt, and a vision inspection module that is positioned corresponding to the third conveyor belt to inspect the printing quality of the appearance markings on sheet metal parts that have been printed with preset appearance markings.

[0022] The present invention also provides a method for directly printing appearance markings on sheet metal parts using the above-described apparatus, comprising the following steps:

[0023] The sheet metal surface treatment component is controlled to operate in order to form a micron-level texture structure on the top surface of the printing target area of ​​the sheet metal part;

[0024] The sheet metal part with the micron-level texture structure is transported to the printing area of ​​the printing assembly of the UV printing component;

[0025] The inkjet printing assembly is controlled to spray ink onto the target printing area to form a preset appearance mark, and the UV curing lamp is controlled to operate to cure the printed preset appearance mark.

[0026] In some embodiments, when the device for directly printing appearance markings on sheet metal parts includes a sheet metal part height adjustment component, it further includes the following before controlling the inkjet printing assembly to spray ink onto the target printing area to form a preset appearance marking:

[0027] The sheet metal height adjustment component is controlled to raise the sheet metal part so that the distance between the printing target area of ​​the sheet metal part and the printing assembly is within the target range.

[0028] In some embodiments, when the device for directly printing appearance markings on sheet metal parts includes an adsorption leveling component, before the inkjet printing component sprays ink onto the target printing area to form a preset appearance marking, and after the distance between the target printing area of ​​the sheet metal part and the inkjet printing component is within a target range, the device further includes:

[0029] The second lifting drive is controlled to raise the adsorption plate so that its adsorption plane is in contact with the bottom surface of the printing target area of ​​the sheet metal part, and the negative pressure is controlled at the negative pressure suction port to generate negative pressure to tightly adhere the sheet metal part corresponding to the printing target area to the adsorption plane of the adsorption plate.

[0030] In some embodiments, when the device capable of directly printing appearance markings on sheet metal parts includes a nano-coating spraying module, the nano-coating spraying module is controlled to spray a nano-coating onto the printing target area before the inkjet printing assembly sprays ink onto the printing target area to form a preset appearance marking and after the micron-level texture structure is formed.

[0031] The device and method provided by this invention, which can directly print appearance markings on sheet metal parts, have the following beneficial effects:

[0032] The device is equipped with both sheet metal surface treatment components and UV printing components. Before UV printing, the sheet metal surface treatment components are used to form a micron-level texture structure on the top surface of the printing target area of ​​the sheet metal part. This can significantly increase the contact area between the ink and the sheet metal part, improve ink adhesion, and reduce the probability of quality problems such as ink detachment, label detachment, and color fading. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0034] Figure 1 This is a three-dimensional structural schematic diagram of a device capable of directly printing appearance markings on sheet metal parts according to one embodiment of the present invention.

[0035] Figure 2 yes Figure 1 A three-dimensional structural diagram of the sheet metal height adjustment component from one perspective;

[0036] Figure 3 yes Figure 2 A magnified view of a section at point A in the middle;

[0037] Figure 4 yes Figure 1 A three-dimensional structural diagram of the sheet metal height adjustment component from another perspective;

[0038] Figure 5 yes Figure 1 A schematic diagram showing the positional changes of the UV inkjet printing component before and after printing (from a top-down view).

[0039] The attached figures are labeled as follows:

[0040] 1. Feeding platform; 11. First conveyor belt; 12. Second conveyor belt; 13. Third conveyor belt; 2. Sheet metal surface treatment components; 3. UV inkjet printing components; 31. Printing assembly; 32. UV curing lamp; 33. First longitudinal movement drive component; 4. Sheet metal height adjustment component; 41. Base plate; 42. Lifting plate; 421. First linear guide post assembly; 431. Adsorption plate; 4311. Negative pressure suction port; 4312. Detection sensor; 432. Second lifting drive component; 4321. First telescopic component; 4322. Second telescopic component; 433. Force plate; 4331. Second guide post; 434. First guide post; 435. Elastic component; 441. Baffle; 442. Pushing component; 443. First lifting limit component; 444. Second lifting limit component; 445. Second longitudinal movement drive component; 5. Vision inspection module; 6. Transfer platform; 7. Robot; 8. Feeding conveyor belt; 100. Sheet metal parts; 101. Printing target area. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0043] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90° or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0044] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0045] See also Figures 1 to 5 As shown, according to an embodiment of the present invention, an apparatus for directly printing appearance markings on sheet metal parts is provided, including a feeding platform 1, wherein the feeding platform 1 has a feature that can be driven along a first direction ( Figure 1 (As shown in the diagram) A first conveyor belt 11 for feeding materials is provided. Sheet metal parts 100 can be supported on the first conveyor belt 11. Sheet metal surface treatment components 2 and UV printing components 3 are arranged sequentially along the first direction. The sheet metal surface treatment components 2 can form a micron-level texture structure on the top surface of the printing target area 101 on the sheet metal parts 100. The UV printing components 3 include a printing assembly 31 and a UV curing lamp 32. The printing assembly 31 can print a preset appearance mark on the printing target area 101 where the micron-level texture structure has been formed. The preset appearance mark can be, for example, a product logo, performance parameter label, QR code, or barcode. The UV curing lamp 32 is used to irradiate the printing target area 101 to cure the printed preset appearance mark.

[0046] In this technical solution, the device is equipped with a sheet metal surface treatment component 2 and a UV inkjet printing component 3. Before UV inkjet printing, the sheet metal surface treatment component 2 is used to form a micron-level texture structure on the top surface of the inkjet printing target area 101 of the sheet metal part 100. This can significantly increase the contact area between the ink and the sheet metal part 100, improve the ink adhesion, and reduce the probability of quality problems such as ink removal, label detachment, and color fading.

[0047] In some embodiments, the sheet metal surface treatment component 2 is a plasma treatment module. The aforementioned plasma treatment module can be a commercially available part with appropriate specifications and models. Using a plasma treatment module as the sheet metal surface treatment component 2 can not only form the aforementioned micron-level texture structure on the surface of the sheet metal part 100, but also clean and activate the surface of the sheet metal part 100, further improving surface energy and ink adhesion.

[0048] In some embodiments, a nano-coating spraying module is also integrated into the plasma treatment module. Thus, after the sheet metal surface treatment component 2 performs surface treatment on the printing target area 101 of the sheet metal part 100, the nano-coating spraying module can be used to spray a nano-coating onto at least the printing target area 101. This further increases the surface energy of the sheet metal part 100 and enhances ink adhesion. The aforementioned nano-coating spraying module can be any existing coating spraying component, and the specific coating formula can be rationally designed based on the ink formula used.

[0049] In some embodiments, the UV printing component 3 further includes a first longitudinal movement drive component 33. The UV curing lamp 32 and the printing assembly 31 are arranged sequentially along the first direction, and the first longitudinal movement drive component 33 can drive the UV curing lamp 32 and the printing assembly 31 to move linearly back and forth along the first direction. The aforementioned first longitudinal movement drive component 33 can be, for example, a commercially available linear module. In a specific embodiment, the aforementioned UV curing lamp 32 and the printing assembly 31 are assembled together on a mounting plate (not indicated in the figure), and the mounting plate is drivenly connected to the aforementioned first longitudinal movement drive component 33.

[0050] In this technical solution, by arranging the UV curing lamp 32 and the printing assembly 31 at intervals along the first direction and driving them to move back and forth in a straight line along the first direction, the UV curing lamp 32 can operate synchronously to cure the ink during the printing process of the printing assembly 31 printing the appearance mark. The structure is compact and the operation efficiency is high.

[0051] In some embodiments, the printing assembly 31 has a plurality of printheads arranged in an array. Specifically, the printing assembly 31 has a large tray on the side of the tray facing the sheet metal part 100 (i.e., Figure 1Multiple printheads are arranged on the bottom side (as shown in the diagram). The spacing between each printhead should be reasonably set and adjusted according to the actual size range to be printed. The printheads form a circular or rectangular array (i.e., equal spacing). This enables the printing assembly 31 to achieve OnePass printing (i.e., single-pass printing) when printing appearance markings. Compared with the multi-pass printing (i.e., multi-stroke printing) in the prior art, the work efficiency can be further improved. At the same time, the combined driving of the multi-printhead integrated array and the first longitudinal driving component 33, combined with the corresponding path planning algorithm, can achieve the printing purpose of completing full-width printing in a single pass, printing resolution ≥1200dpi, and clear pattern edges without ghosting. In a specific embodiment, the aforementioned printing assembly 31 adopts an 8-column printhead integrated array with a total of 2560 nozzles, coupled with a 1200dpi resolution drive, to meet the OnePass printing requirements. It is understood that the aforementioned printing assembly 31 should be able to dynamically adjust the ink volume of each printhead according to the density of the printed pattern to prevent the local ink layer from being too thick or too thin. Regarding the printing path, in a specific embodiment, the path planning algorithm used by the system is based on vector scanning and dot mapping technology. Its core is to solve the relative displacement error of the multi-head array in high-speed movement and the gray smoothing of the overlapping area of ​​ink droplets, so as to ensure that the full-width printing is completed in a single pass without splicing marks.

[0052] In one specific embodiment, the UV curing lamp 32 uses a UV lamp group with a wavelength of 365nm, so that the curing time is ≤2s, ensuring the efficient execution of inkjet printing curing.

[0053] In some embodiments, the device for directly printing appearance markings on sheet metal parts further includes a sheet metal part height adjustment component 4. This component 4 is used to raise the sheet metal part 100 when it is conveyed to the printing area of ​​the printing assembly 31, so that the distance between the printing target area 101 of the sheet metal part 100 and the printing assembly 31 is within a target range. The target range is specifically selected based on the size of the printing target area 101. Theoretically, the smaller the printing target area 101, the smaller the target range. In one specific embodiment, the target range is 0.5 ± 0.1 mm. In another specific embodiment, a laser rangefinder sensor is installed on the printing assembly 31 to scan the top surface height of the sheet metal part 100 in real time, forming a control linkage with the sheet metal part height adjustment component 4 to ensure the accuracy of the target range adjustment.

[0054] In this technical solution, by setting a sheet metal height adjustment component 4, the sheet metal part 100 is driven to rise to a certain height when printing is required, so as to reduce the distance between its printing target area 101 and the printing component 31, which can ensure the printing effect. After printing is completed, the sheet metal part 100 is controlled to be lowered so that it falls back onto the first conveyor belt 11. This can adapt to the printing needs of sheet metal parts 100 of different sizes, ensure the printing effect, and prevent the sheet metal part 100 from forming physical contact with the printing component 31 and causing damage.

[0055] In some embodiments, the sheet metal height adjustment component 4 includes a base plate 41, and a lifting plate 42 is provided on the top surface of the base plate 41. The lifting plate 42 and the base plate 41 are slidably connected by a first linear guide post assembly 421. The first linear guide post assembly 421 may specifically include a guide post (not shown in the figure) and a linear bearing (not shown in the figure) slidably sleeved on the radially outer side of the guide post. It also includes a first lifting drive component (not shown in the figure) for driving the lifting plate 42 to rise and fall. The first lifting drive component may specifically be a lifting cylinder. It is understood that the size of the base plate 41 is larger than the size of the lifting plate 42, and the size of the lifting plate 42 is approximately matched with the main body plane of the sheet metal part 100. For example, the sheet metal part 100 is an outdoor unit panel of an air conditioner. Bent side plates (not shown in the figure) are formed at both ends of the outdoor unit panel of the air conditioner in the second direction. The second direction is perpendicular to the first direction. At this time, the size of the lifting plate 42 is approximately matched with the main body plane (with air vents) between the two bent side plates.

[0056] In this technical solution, the lifting and lowering drive of the sheet metal part 100 is directly realized through the lifting plate 42. During this process, the base plate 41 does not need to be driven to lift and lower as a whole, which can reduce the power demand of the aforementioned first lifting drive component and save energy.

[0057] In some embodiments, the top surface of the substrate 41 is further provided with an adsorption leveling component (not indicated in the figure). The adsorption leveling component includes an adsorption plate 431 and a second lifting drive 432 for driving the adsorption plate 431 to rise and fall. The adsorption plate 431 has an adsorption plane (not indicated in the figure) that is in contact with the bottom surface (i.e. the bottom surface of the sheet metal part 100) of the printing target area 101 of the sheet metal part 100. The adsorption plane has a negative pressure suction port 4311. In a preferred embodiment, the area and shape of the adsorption plane are adapted to the area and shape of the printing target area 101.

[0058] In this technical solution, the sheet metal part 100 corresponding to the printing target area 101 is adsorbed by the adsorption leveling component, thereby the flatness of the area can be precisely defined by the flatness of the adsorption plane, preventing insufficient flatness of the area from reducing the printing quality due to the processing size error of the sheet metal part 100 or deformation (bulge or depression) during the transfer process.

[0059] In some embodiments, the adsorption leveling assembly further includes a force-applying plate 433 spaced vertically from the adsorption plate 431. The adsorption plate 431 is slidably connected to the force-applying plate 433 via two spaced first guide posts 434. An elastic element 435 is fitted on the radially outer side of each first guide post 434. In one specific embodiment, the aforementioned elastic element 435 is a metal helical spring. The elastic element 435 can be clamped between the force-applying plate 433 and the adsorption plate 431. The force-applying plate 433 is slidably connected to the substrate 41 via a second guide post 4331. The second lifting drive member 432 is drivenly connected to the force-applying plate 433.

[0060] In this technical solution, the second lifting drive component 432 applies force to the force application plate 433, and the adsorption plate 431 and the force application plate 433 are connected by a first guide post 434 that is slidably connected and an elastic component 435 located between them to form a flexible guiding connection. This can prevent the second lifting drive component 432 from applying too much force and causing impact deformation to the sheet metal part 100.

[0061] In some embodiments, each of the first guide posts 434 has a central through hole, that is, the first guide post 434 is actually a cylinder. The position of each negative pressure suction port 4311 corresponds one-to-one with the position of each of the first guide posts 434, and the negative pressure suction port 4311 is connected to the vacuum hose of the external vacuum pump. Each vacuum hose (not shown in the figure) passes through the central through hole of each of the first guide posts 434 and is connected to each of the negative pressure suction ports 4311.

[0062] In this technical solution, the first guide post 434 serves as a guide component for the up-and-down floating of the adsorption plate 431, and also as a passage space for the vacuum hose, making the structure more compact.

[0063] In some embodiments, the second lifting drive member 432 includes a first telescopic member 4321 and a second telescopic member 4322. The first telescopic member 4321 and the second telescopic member 4322 may be telescopic cylinders. The telescopic rod of the first telescopic member 4321 can drive the second telescopic member 4322 to rise and fall, and the telescopic rod of the second telescopic member 4322 is drivenly connected to the force plate 433.

[0064] In this technical solution, the first telescopic component 4321 and the second telescopic component 4322 form a series structure in terms of stroke, which can meet the lifting stroke requirements of sheet metal parts 100 of different specifications and models, while also making the structure of the second lifting drive component 432 smaller and reducing undue space occupation.

[0065] In some embodiments, a detection sensor 4312 is provided on the adsorption plane of the adsorption plate 431. The detection sensor 4312 is used to detect in real time whether the sheet metal part 100 has reached the top surface area of ​​the adsorption plate 431. The aforementioned detection sensor 4312 can be a contact sensor or a non-contact sensor such as infrared or laser. In this way, when the detection sensor 4312 detects the sheet metal part 100, the corresponding material arrival signal can be transmitted to the corresponding control component, thereby controlling the aforementioned first conveyor belt 11 to stop operating, so as to facilitate further limiting and positioning of the sheet metal part 100.

[0066] In some embodiments, the adsorption leveling assembly further includes a positioning mechanism (not indicated in the figure). The positioning mechanism includes a baffle 441 formed on one edge of the top surface of the substrate 41 and a pusher 442. The stop side of the baffle 441 extends along the first direction. The pusher 442 can be driven to reciprocate linearly along a direction perpendicular to the stop side, so as to form a clamping and positioning of the sheet metal part 100 on opposite sides with the stop side of the baffle 441. The aforementioned pusher 442 can specifically be a pneumatic rod, etc. In a specific embodiment, two pushers 442 are provided. The two pushers 442 are spaced apart along the first direction to simultaneously apply force to one end of the sheet metal part 100.

[0067] In this technical solution, the sheet metal part 100 is accurately positioned in the second direction by the baffle 441 and the pusher 442 located on opposite sides of the sheet metal part 100. The baffle 441 is a fixed positioning reference, while the pusher 442 is a movable positioning structure. The structure design is simple and compact.

[0068] Understandably, the aforementioned detection sensor 4312, under the premise of its detection accuracy and timely control, can use the acquisition of its material arrival signal to limit the downstream end (i.e., the downstream side) of the sheet metal part 100. However, it is difficult to implement. In some embodiments, the positioning mechanism also includes a first lifting limit member 443, which can be controlled to lift and move along the conveying path of the sheet metal part 100 to form a stop limit on the downstream side of the sheet metal part 100.

[0069] In this technical solution, the first lifting limiter 443 in the raised state forms a stop limit on the downstream side of the sheet metal part 100 conveyed by the first conveyor belt 11, which makes the limit more reliable and stable, and is easier to implement.

[0070] In some embodiments, the positioning mechanism further includes a second lifting limit member 444, which can be controlled to rise and fall on the conveying path of the sheet metal part 100 to form a stop and limit on the upstream side of the sheet metal part 100. The distance between the first lifting limit member 443 and the second lifting limit member 444 is adjustable. In a specific embodiment, a corresponding second longitudinal movement drive member 445 is assembled on the bottom surface of the substrate 41 to drive the aforementioned first lifting limit member 443 and second lifting limit member 444 to move linearly towards or away from each other. The aforementioned second longitudinal movement drive member 445 can be, for example, a combination of a screw drive structure and a rotary motor.

[0071] In this technical solution, a second lifting limiter 444 is provided on the upstream side of the sheet metal part 100, and the distance between the first lifting limiter 443 and the second lifting limiter 444 can be adjusted to achieve precise adjustment of the position of the upstream and downstream sides of the sheet metal part 100, that is, to achieve precise adjustment of the position of the sheet metal part 100 in the first direction, and to ensure the position accuracy of the printing area.

[0072] In some embodiments, the first conveyor belt 11 includes two belts spaced apart along a direction perpendicular to the first direction (i.e., the aforementioned second direction), and the sheet metal height adjustment component 4 is located in the space between the two first conveyor belts 11. This allows the sheet metal height adjustment component 4 to be arranged at the space between the two first conveyor belts 11, thereby making the device structure more compact and reasonable.

[0073] In some embodiments, when the aforementioned sheet metal part 100 is an air conditioner outdoor unit panel, the two first conveyor belts 11 are respectively located on the opposite side of the two bent side plates to form a reliable limiting conveying of the sheet metal part 100.

[0074] In some embodiments, the feeding platform 1 further includes a second conveyor belt 12 that can be driven to feed materials along the first direction. The second conveyor belt 12 is located upstream of the first conveyor belt 11, and the sheet metal surface treatment component 2 is positioned correspondingly to the second conveyor belt 12. The feeding platform 1 also includes a third conveyor belt 13 that can be driven to feed materials along the first direction. The third conveyor belt 13 is located downstream of the first conveyor belt 11. A vision inspection module 5 is also included, positioned correspondingly to the third conveyor belt 13 to inspect the printing quality of the appearance markings on the sheet metal part 100 with preset appearance markings. The aforementioned second conveyor belt 12 and third conveyor belt 13 can be full-width conveyor belts to improve the conveying stability of the sheet metal part 100. The aforementioned vision inspection module 5 can use existing image recognition modules, such as camera recognition modules. This invention does not modify its specific structure or principle, but only utilizes its function to achieve intelligent detection and judgment of the quality of the printed appearance markings.

[0075] In some embodiments, the device is further equipped with a transfer platform 6 and a robot 7 disposed adjacent to it. The sheet metal parts 100 with the appearance markings printed on them are transferred (e.g., by a handling mechanism) to the transfer platform 6 after being inspected by the aforementioned vision inspection module 5. The robot 7 can place the sheet metal parts 100 on the scrap table (not shown in the figure) when the quality is unqualified (NG) and transfer the sheet metal parts 100 to the next assembly process when the quality is qualified (OK).

[0076] See details Figure 1 As shown, a feeding conveyor belt 8 is provided on the upstream side of the second conveyor belt 12, which can transport the sheet metal parts 100 placed on it to the aforementioned second conveyor belt 12, so as to realize the uninterrupted supply of materials.

[0077] To further reduce the risk of ink stripping, the UV ink formulation can be optimized. For example, in one specific embodiment, the formulation includes: acrylate monomers (60%), photoinitiator (5%), nanofiller (3%), and adhesion promoter (2%), to ensure that the ink cures quickly on the metal substrate and forms a strong bonding layer.

[0078] Tests have shown that the appearance markings printed using the device of this invention increase the surface energy of sheet metal parts by more than 50 dynes. Using the aforementioned ink formula, the UV ink adhesion reaches level 0 in the cross-cut adhesion test, and it exhibits resistance to salt spray and UV aging for over 10 years without fading or peeling. Furthermore, the one-pass direct printing assembly line operation of this invention controls the printing cycle time to 8-9 seconds per piece, meeting the "fast in, fast out" requirements of the production line, significantly improving production efficiency, supporting flexible production, reducing manpower by 1 person per shift, lowering overall costs by 30%, and significantly enhancing product competitiveness and intelligent manufacturing capabilities.

[0079] According to an embodiment of the present invention, a method for directly printing appearance markings on sheet metal parts using the above-described apparatus is also provided, comprising the following steps:

[0080] The sheet metal surface treatment component 2 is controlled to operate to form a micron-level texture structure on the top surface of the printing target area 101 of the sheet metal part 100;

[0081] The sheet metal part 100, which has formed the micron-level texture structure, is transported to the printing area of ​​the printing assembly 31 of the UV printing component 3.

[0082] The inkjet printing assembly 31 is controlled to spray ink onto the printing target area 101 to form a preset appearance mark, and the UV curing lamp 32 is controlled to operate to cure the printed preset appearance mark.

[0083] In this technical solution, the UV inkjet printing component 3 is used to directly print the appearance mark on the sheet metal part 100, which can greatly improve the mark printing efficiency. At the same time, before inkjet printing, a micron-level texture structure is formed on the top surface of the inkjet printing target area 101 of the sheet metal part 100, which can significantly increase the contact area between the ink and the sheet metal part 100, improve the ink adhesion, and reduce the probability of quality problems such as ink removal, mark detachment, and color fading.

[0084] In some embodiments, when the device for directly printing appearance markings on sheet metal parts includes a sheet metal part height adjustment component 4, it further includes the following before controlling the inkjet printing assembly 31 to spray ink onto the inkjet printing target area 101 to form a preset appearance marking:

[0085] The sheet metal height adjustment component 4 is controlled to raise the sheet metal 100 so that the distance between the printing target area 101 of the sheet metal 100 and the printing assembly 31 is within the target range, thereby ensuring printing quality. It is understood that when the aforementioned positioning mechanism is included, a positioning step is also included before raising the sheet metal 100. Specifically, the first lifting limit component 443 is controlled to rise to limit the downstream side of the sheet metal 100, and the aforementioned pushing member 442 is controlled to extend and clamp the opposite sides of the sheet metal 100 (in the second direction) between the baffle 441 and the pushing member 442. The second lifting limit component 444 is controlled to rise and its distance from the first lifting limit component 443 is adjusted to achieve precise adjustment of the position of the sheet metal 100 in the first direction.

[0086] In some embodiments, when the device for directly printing appearance markings on sheet metal parts includes an adsorption leveling component, before the inkjet printing component 31 sprays ink onto the inkjet printing target area 101 to form a preset appearance marking, and after the distance between the inkjet printing target area 101 of the sheet metal part 100 and the inkjet printing component 31 is within a target range, the device further includes:

[0087] The second lifting drive component 432 is controlled to operate and raise the adsorption plate 431 so that its adsorption plane is attached to the bottom surface of the printing target area 101 of the sheet metal part 100. The negative pressure is controlled at the negative pressure suction port 4311 to generate negative pressure to tightly attach the sheet metal part 100 corresponding to the printing target area 101 to the adsorption plane of the adsorption plate 431. This can ensure the flatness of the sheet metal part 100 position corresponding to the printing target area 101 and further improve the printing quality of the appearance marking.

[0088] It is understandable that after the appearance markings of the sheet metal part 100 are printed, all the aforementioned raised components should be controlled to descend to their initial positions so that the sheet metal part 100 falls back onto the first conveyor belt 11.

[0089] In some embodiments, when the device capable of directly printing appearance markings on sheet metal parts includes a nano-coating spraying module, before the inkjet printing assembly 31 sprays ink onto the printing target area 101 to form a preset appearance marking and after the micron-level texture structure is formed, the nano-coating spraying module is controlled to spray a nano-coating onto the printing target area 101 to further improve the surface energy of the sheet metal parts 100 and further enhance ink adhesion.

[0090] As mentioned above, after the appearance markings are printed, the sheet metal part 100 is transported to the vision inspection module 5 for printing quality inspection. If the quality is unqualified (NG), the sheet metal part 100 is placed on the scrap table (not shown in the figure). If the quality is qualified (OK), the sheet metal part 100 is transferred to the next assembly process.

[0091] In some implementations, corresponding RFID tags can be set on each sheet metal part 100, and corresponding RFID read / write heads can be set at the upstream position of the aforementioned second conveyor belt 12. This allows the order information to be read in real time when each sheet metal part 100 is conveyed to the position corresponding to the read / write head. In this way, the specific pattern, color and other information of the appearance markings on the sheet metal part 100 can be obtained. The control component forms corresponding execution instructions to control the aforementioned inkjet printing component 31 to perform related inkjet printing operations, thereby achieving seamless switching of multiple model panels (i.e., sheet metal parts 100) without manual intervention, reducing the operation threshold and error rate.

[0092] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0093] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A device capable of directly printing appearance markings on sheet metal parts, characterized in that, The system includes a feeding platform (1) with a first conveyor belt (11) that can be driven to feed materials along a first direction. A sheet metal part (100) can be supported on the first conveyor belt (11). A sheet metal surface treatment component (2) and a UV printing component (3) are arranged sequentially along the first direction. The sheet metal surface treatment component (2) can form a micron-level texture structure on the top surface of the printing target area (101) on the sheet metal part (100). The UV printing component (3) includes a printing assembly (31) and a UV curing lamp (32). The printing assembly (31) can print a preset appearance mark on the printing target area (101) where the micron-level texture structure has been formed. The UV curing lamp (32) is used to irradiate the printing target area (101) to cure the printed preset appearance mark.

2. The device for directly printing appearance markings on sheet metal parts according to claim 1, characterized in that, The sheet metal surface treatment component (2) is a plasma treatment module.

3. The device for directly printing appearance markings on sheet metal parts according to claim 2, characterized in that, A nano-coating spraying module is also integrated into the plasma treatment module.

4. The device for directly printing appearance markings on sheet metal parts according to claim 1, characterized in that, The UV printing component (3) further includes a first longitudinal movement drive component (33). The UV curing lamp (32) and the printing assembly (31) are arranged sequentially along the first direction, and the first longitudinal movement drive component (33) can drive the UV curing lamp (32) and the printing assembly (31) to move linearly back and forth along the first direction. And / or, the printing assembly (31) has a plurality of printheads arranged in an array.

5. The device for directly printing appearance markings on sheet metal parts according to claim 1, characterized in that, It also includes a sheet metal height adjustment component (4), which is used to raise the sheet metal (100) when the sheet metal (100) is transported to the printing area of ​​the printing assembly (31) so that the distance between the printing target area (101) of the sheet metal (100) and the printing assembly (31) is within the target range.

6. The apparatus for directly printing appearance markings on sheet metal parts according to claim 5, characterized in that, The sheet metal height adjustment component (4) includes a base plate (41), a lifting plate (42) is provided on the top surface of the base plate (41), the lifting plate (42) and the base plate (41) are slidably connected by a first linear guide post assembly (421), and also includes a first lifting drive component for driving the lifting plate (42) to rise and fall.

7. The device for directly printing appearance markings on sheet metal parts according to claim 6, characterized in that, The top surface of the substrate (41) is also provided with an adsorption leveling component. The adsorption leveling component includes an adsorption plate (431) and a second lifting drive (432) for driving the adsorption plate (431) to rise and fall. The adsorption plate (431) has an adsorption plane that fits with the bottom plane of the printing target area (101) of the sheet metal part (100). The adsorption plane has a negative pressure suction port (4311).

8. The apparatus for directly printing appearance markings on sheet metal parts according to claim 7, characterized in that, The adsorption leveling assembly also includes a force-applying plate (433) spaced vertically from the adsorption plate (431). The adsorption plate (431) is slidably connected to the force-applying plate (433) via two spaced first guide posts (434). Each first guide post (434) has an elastic element (435) fitted on its radial outer side. The elastic element (435) can be clamped between the force-applying plate (433) and the adsorption plate (431). The force-applying plate (433) is slidably connected to the substrate (41) via a second guide post (4331). The second lifting drive (432) is driven to connect with the force-applying plate (433).

9. The apparatus for directly printing appearance markings on sheet metal parts according to claim 8, characterized in that, Each of the first guide posts (434) has a central through hole, and the position of each of the negative pressure suction ports (4311) corresponds one-to-one with the position of each of the first guide posts (434). The negative pressure suction ports (4311) are connected to the vacuum hose of the external vacuum pump. Each of the vacuum hoses passes through the central through hole of each of the first guide posts (434) and is connected to each of the negative pressure suction ports (4311).

10. The apparatus for directly printing appearance markings on sheet metal parts according to claim 8, characterized in that, The second lifting drive component (432) includes a first telescopic component (4321) and a second telescopic component (4322), wherein the telescopic rod of the first telescopic component (4321) can drive the second telescopic component (4322) to rise and fall, and the telescopic rod of the second telescopic component (4322) is drivenly connected to the force plate (433); and / or, a detection sensor (4312) is provided on the adsorption plane of the adsorption plate (431), and the detection sensor (4312) is used to detect in real time whether the sheet metal part (100) reaches the top surface area of ​​the adsorption plate (431); and / or, the area and shape of the adsorption plane are adapted to the area and shape of the printing target area (101).

11. The apparatus for directly printing appearance markings on sheet metal parts according to claim 6, characterized in that, The adsorption leveling assembly further includes a positioning mechanism, which includes a baffle (441) formed on one side edge of the top surface of the substrate (41) and a pusher (442). The stop side of the baffle (441) extends along the first direction, and the pusher (442) can be driven to move linearly back and forth along a direction perpendicular to the stop side, so as to form a clamping and positioning of the sheet metal part (100) on the opposite sides with the stop side of the baffle (441).

12. The apparatus for directly printing appearance markings on sheet metal parts according to claim 11, characterized in that, The positioning mechanism further includes a first lifting limit member (443), which can be controlled to lift and move along the conveying path of the sheet metal part (100) to form a stop limit on the downstream side of the sheet metal part (100).

13. The apparatus for directly printing appearance markings on sheet metal parts according to claim 12, characterized in that, The positioning mechanism further includes a second lifting limit member (444), which can be controlled to lift and move along the conveying path of the sheet metal part (100) to form a stop limit on the upstream side of the sheet metal part (100), and the distance between the first lifting limit member (443) and the second lifting limit member (444) is adjustable.

14. The apparatus for directly printing appearance markings on sheet metal parts according to claim 5, characterized in that, The first conveyor belt (11) includes two belts that are spaced apart perpendicularly to the first direction, and the sheet metal height adjustment component (4) is located in the space between the two first conveyor belts (11).

15. The apparatus for directly printing appearance markings on sheet metal parts according to claim 14, characterized in that, The sheet metal part (100) is an outdoor unit panel of an air conditioner. Bending side plates are formed at both ends of the outdoor unit panel of the air conditioner in the second direction. The two first conveyor belts (11) are respectively located on the opposite side of the two bending side plates. The second direction is perpendicular to the first direction.

16. The apparatus for directly printing appearance markings on sheet metal parts according to claim 1, characterized in that, The feeding platform (1) also has a second conveyor belt (12) that can be driven to feed materials along the first direction. The second conveyor belt (12) is located upstream of the first conveyor belt (11), and the sheet metal surface treatment component (2) is positioned corresponding to the second conveyor belt (12).

17. The apparatus for directly printing appearance markings on sheet metal parts according to claim 16, characterized in that, The feeding platform (1) also has a third conveyor belt (13) that can be driven to feed along the first direction. The third conveyor belt (13) is located downstream of the first conveyor belt (11). It also includes a vision inspection module (5). The vision inspection module (5) is positioned corresponding to the third conveyor belt (13) to inspect the printing quality of the appearance markings on the sheet metal parts (100) that have been printed with preset appearance markings.

18. A method using the apparatus for directly printing appearance markings on sheet metal parts according to any one of claims 1 to 17, characterized in that, Includes the following steps: Control the operation of the sheet metal surface treatment component (2) to form a micron-level texture structure on the top surface of the printing target area (101) of the sheet metal part (100); The sheet metal part (100) with the micron-scale texture structure is transported to the printing area of ​​the printing assembly (31) of the UV printing component (3); The inkjet printing assembly (31) is controlled to spray ink onto the inkjet target area (101) to form a preset appearance mark, and the UV curing lamp (32) is controlled to run to cure the inkjet-printed preset appearance mark.

19. The method according to claim 18, characterized in that, When the device capable of directly printing appearance markings on sheet metal parts includes a sheet metal parts height adjustment component (4), it further includes the following before controlling the inkjet printing assembly (31) to spray ink onto the inkjet printing target area (101) to form a preset appearance marking: The sheet metal height adjustment component (4) is controlled to raise the sheet metal part (100) so that the distance between the printing target area (101) of the sheet metal part (100) and the printing assembly (31) is within the target range.

20. The method according to claim 19, characterized in that, When the device capable of directly printing appearance markings on sheet metal parts includes an adsorption leveling component, before the inkjet printing component (31) sprays ink onto the inkjet printing target area (101) to form a preset appearance marking, and after the distance between the inkjet printing target area (101) of the sheet metal part (100) and the inkjet printing component (31) is within the target range, it further includes: The second lifting drive (432) is controlled to operate and raise the adsorption plate (431) so that its adsorption plane is attached to the bottom surface of the printing target area (101) of the sheet metal part (100), and the negative pressure is controlled at the negative pressure suction port (4311) to generate negative pressure to tightly attach the sheet metal part (100) corresponding to the printing target area (101) to the adsorption plane of the adsorption plate (431).

21. The method according to claim 18, characterized in that, When the device capable of directly printing appearance markings on sheet metal parts includes a nano-coating spraying module, before the inkjet printing assembly (31) sprays ink onto the printing target area (101) to form a preset appearance marking and after the micron-level texture structure is formed, the nano-coating spraying module is controlled to spray a nano-coating onto the printing target area (101).

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