An automobile accessory electrophoretic coating system

Abstract

The present application belongs to the technical field of electrophoretic coating, and particularly relates to an automobile accessory electrophoretic coating system. The automobile accessory electrophoretic coating system comprises a pretreatment unit, an electrophoretic unit, a curing unit and a conveying unit. The conveying unit comprises a transmission chain and a conductive hook. In use, the workpiece is hung on the hook part, the transmission chain drives the workpiece on the hook part to move, and the workpiece is sequentially conveyed to the pretreatment unit, the electrophoretic unit and the curing unit. The workpiece is sequentially pretreated, electrophoretically neutralized and cured, ensuring continuous operation between processes and improving the electrophoretic coating efficiency of the workpiece. The conductive hooks are sequentially and intermittently fixed on the transmission chain, and a conductive part is arranged on the conductive hook. An electrically conductive part is further arranged at the electrophoretic unit. When the conductive hook moves to the electrophoretic unit, the conductive hook is in contact with and electrically connected to the electrically conductive part, so as to ensure the continuous operation of the process and solve the problem of the electrical conductivity of the workpiece entering the electrophoretic unit.

Description

Technical Field

[0001] This invention belongs to the field of electrophoretic coating technology, and specifically relates to an electrophoretic coating system for automotive parts. Background Technology

[0002] Electrophoretic coating for automotive parts is a metal coating process. The coating principle involves immersing the workpiece in a tank using a water-soluble coating. An external electric field causes pigments and resin particles suspended in the electrophoretic solution to migrate directionally and deposit onto the surface of the workpiece, which serves as one of the electrodes. Cathodic electrophoresis is a type of electrophoretic coating. It is a special coating film formation method where the workpiece acts as the cathode, and the electrophoretic coating used is cationic (positively charged). The conductive workpiece is immersed in a tank filled with a water-diluted, low-concentration electrophoretic coating, which acts as the cathode. A corresponding anode is placed in the tank, and a direct current is applied between the two electrodes. This process results in a uniform, water-insoluble coating film being deposited on the workpiece. Electrophoretic coating for automotive parts includes at least pretreatment, cathodic electrophoresis, and curing. Pretreatment includes three main parts: pre-degreasing, main degreasing, surface conditioning, and phosphating. Its purpose is to improve coating adhesion and enhance decorative and corrosion resistance. Cathodic electrophoresis involves placing the automotive parts to be coated, acting as both cathode and anode, simultaneously in a cationic coating. This is typically performed in an electrophoretic coating tank. Under the influence of a direct current electric field, the cations in the coating migrate towards the cathode and deposit onto the coated part, which serves as the cathode. Curing refers to placing the automotive parts with the electrophoretic paint applied in an environment at 170–180°C for drying and curing for 30–40 minutes, thereby curing and drying the electrophoretic paint onto the surface of the automotive parts. In existing technologies:

[0003] CN215326435U discloses a simple lifting device for electrophoretic paint treatment on the surface of automotive parts, including an electrophoretic paint treatment box. The upper end of the electrophoretic paint treatment box is provided with a fixed plate, and the lower end of the fixed plate is fixed with a telescopic cylinder. The extended end of the telescopic cylinder is fixed with a fixed block, and the fixed block is provided with a pneumatic clamping claw. The left side of the electrophoretic paint treatment box is also provided with a controller, which is electrically connected to the telescopic cylinder and the pneumatic clamping claw. The lifting device is designed to clamp the automotive parts to be treated with the pneumatic clamping claw, so that they are in the middle of the electrophoretic paint box and do not contact the bottom of the box, so that the automotive parts can be treated with better electrophoretic paint.

[0004] CN218147022U discloses a unidirectional hanger for electrophoretic coating of automotive parts. The hanger has a vertical rod welded to the middle of a horizontal main frame, with a horn hook welded to the end of the vertical rod. Multiple hangers are welded to the horizontal main frame at equal intervals in the same direction. The hangers welded to the horizontal main frame have concave grooves on their inner sides, and stops are welded to the ends of the hangers. The hangers also have serrations on the inner side of the concave grooves. This hanger, by setting multiple unidirectionally spaced hangers on the horizontal main frame, allows for simultaneous electrophoretic coating of multiple parts. The concave grooves, serrations, and stops within the hangers provide greater stability for the suspension of the parts.

[0005] CN112591611A discloses a lifting device for batch processing of automotive metal parts for electrophoretic paint treatment, including a base, a servo motor, a pull rope, a fixing frame, a first connecting gear, and a first bevel gear. Columns are welded to the upper left and right sides of the base. The servo motor is bolted to the outer wall of the column, and its output end is connected to a first rotating shaft, which is also connected to one end of the pull rope. A limiting plate is connected to the bottom of the protrusion, and the bottom of the limiting plate is connected to a clamping plate. A handle is installed at the top of the second rotating shaft. In this lifting device for batch processing of automotive metal parts for electrophoretic paint treatment, a vertical plate is provided on the right side of the handle, and both the handle and the vertical plate have fixing grooves. When the handle is rotated to a certain angle, it is easy to engage the insertion rod into the fixing groove, limiting and fixing the handle, effectively preventing the parts from falling off during processing.

[0006] Analysis of existing technologies reveals that the aforementioned automotive parts processing generally involves manually handling or using other conveying devices to transport pre-treated automotive parts to an electrophoretic coating tank. These parts are then hoisted in batches onto hoisting devices or hangers, and subsequently immersed in the electrophoretic coating tank. Direct current is applied to the workpieces for electrophoretic coating. After electrophoretic coating, the parts are manually handled or transported to the curing stage using other conveying devices. The disadvantages of this existing technology are: electrophoretic coating is difficult to integrate with the pre-treatment process and the subsequent curing process; and the efficiency of electrophoretic coating is relatively low. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides an electrophoretic coating system for automotive parts.

[0008] This invention provides an electrophoretic coating system for automotive parts, comprising a pretreatment unit, an electrophoresis unit, a curing unit, and a conveying unit. The pretreatment unit is used to pretreat the workpiece, the electrophoresis unit is used to perform cathodic electrophoresis on the workpiece, and the curing unit is used to cure the workpiece.

[0009] The conveying unit includes a drive chain and multiple conductive hooks. The drive chain is positioned above the pretreatment unit, electrophoresis unit, and curing unit, and is used to sequentially convey the workpiece to each unit. The conductive hooks are fixed to the drive chain at intervals. Each conductive hook has a hook portion at its lower end for attaching the workpiece, and a conductive portion is provided on the hook. A conductive element is also provided at the electrophoresis unit, and when the conductive hook moves to the electrophoresis unit, it contacts and electrically connects with the conductive element.

[0010] Preferably, the conveying unit further includes a hook track, which is sequentially mounted above the pretreatment unit, the electrophoresis unit, and the curing unit. The hook track is located above the transmission chain, and a roller is provided at the upper end of the conductive hook, which is slidably connected within the hook track.

[0011] Preferably, the plurality of conductive hooks are provided with hook oil receiving parts for receiving lubricating oil, and a plurality of chain oil receiving parts for receiving lubricating oil are connected below the transmission chain that is not covered by the oil receiving range of the plurality of hook oil receiving parts. The oil receiving range of the plurality of hook oil receiving parts plus the plurality of chain oil receiving parts covers all oil dripping positions of the hook track and the transmission chain.

[0012] Preferably, the conductive hook includes a load carriage connected to the transmission chain and a hook body connected below the load carriage. The hook body is movably connected to the load carriage, and the hook oil receiving part is connected to the hook body with its opening facing upward.

[0013] Preferably, the pretreatment unit includes an automatic phosphating device, which includes a reaction tank, an inclined settling tank and a slag press connected by pipes. The inclined settling tank is located above the reaction tank, and the slag press is located below the reaction tank. A phosphating liquid circulation pump is provided between the slag press and the inclined settling tank. Phosphating tanks are provided on both sides of the reaction tank, and the phosphating tanks are connected to the inclined settling tank by pipes. A spray pump is provided on the phosphating tank. The feature is that: a cylindrical inclined plate is provided below the reaction tank, and a phosphating outlet is provided at one end of the cylindrical inclined plate, which is connected to the slag press. A scraping device is provided at the other end of the cylindrical inclined plate. A slide is provided at the top of the reaction tank, and a slide platform is provided on the slide. A rotary motor is installed on the slide platform, and a phosphating frame is installed on the output shaft of the rotary motor. A blocking cylinder is provided on one side of the slide, and a blocking block is installed on the blocking cylinder. A touch switch is provided on the blocking block.

[0014] Preferably, the scraping device includes a scraping cylinder and a fan-shaped scraper. The fan-shaped scraper is mounted on the scraping cylinder and has an arc-shaped scraping part that is close to the cylindrical inclined plate.

[0015] Preferably, the pretreatment unit includes an electrophoretic immersion washing tank, which includes a washing tank body for holding washing water and a plurality of nozzles disposed on the bottom surface of the washing tank body. The plurality of nozzles are connected to a water pump, and the washing water in the washing tank body is pressurized by the water pump and sprayed out from the plurality of nozzles, circulating in the washing tank body.

[0016] Preferably, the automotive parts electrophoretic coating system further includes an electrophoretic circulating water washing device, which is located after the electrophoretic unit. The transmission chain can transport the workpiece after cathodic electrophoresis to the electrophoretic circulating water washing device. The electrophoretic circulating water washing device includes a fresh circulating water tank, an immersion washing tank, a circulating water tank, and an outlet spray water tank, which are arranged in descending order of height and connected at the top by an overflow method. The outlet spray water tank is connected to an outlet spray device and supplies it with water, and the spray water returns to the outlet spray water tank. The circulating water tank is connected to a first spray water washing device and supplies it with water, and the spray water returns to the circulating water tank. The fresh circulating water tank is connected to a second spray water washing device and supplies it with water, and the spray water returns to the fresh circulating water tank.

[0017] Preferably, the curing unit includes a burner, an air supply unit, a curing oven, a circulation unit, and a control unit. The burner is used to burn fuel gas and is connected to the air supply unit. The air supply unit is also equipped with a filter for filtering the gas after combustion by the burner. The air supply unit delivers the filtered gas to the curing oven. The curing oven has a curing chamber inside, which is connected to the air supply unit. The curing chamber receives the filtered gas and cures the coating layer of the workpiece contained therein. The curing chamber is connected to the input and output ends of the circulation unit. The curing chamber is equipped with a temperature sensor. Both the temperature sensor and the burner are signal-connected to the control unit. The control unit receives the temperature signal sent by the temperature sensor and can adjust the heat output of the burner according to the temperature signal.

[0018] Preferably, the burner is further provided with an adjustment unit for adjusting the heat output of the burner. The adjustment unit includes a gas throttle valve and an air throttle valve, which are respectively connected to the burner. The gas throttle valve is used to supply gas to the burner, and the air throttle valve is used to supply air to the burner. The gas throttle valve and the air throttle valve are respectively signal-connected to the control unit, and the control unit controls the flow rate of the gas throttle valve and the flow rate of the air throttle valve, respectively. Attached Figure Description

[0019] The above and other objects, features, and advantages of the invention will become clearer through a more detailed description of the preferred embodiments illustrated in the accompanying drawings. The same reference numerals denote the same parts throughout the drawings, and the drawings are not intentionally drawn to scale with actual dimensions; the focus is on illustrating the gist of the invention.

[0020] Figure 1 A schematic diagram of workpiece conveying and processing provided for an embodiment;

[0021] Figure 2 A schematic diagram of the overall structure of the conveying unit provided in the embodiment;

[0022] Figure 3 A schematic diagram of the conductive hook connection structure of the electrical connection section provided in the embodiment;

[0023] Figure 4 A schematic diagram of the load carriage provided in the embodiment;

[0024] Figure 5 A schematic diagram of the hook body provided for the embodiment;

[0025] Figure 6 A schematic diagram illustrating the upward and downward movement of the hook track provided in this embodiment;

[0026] Figure 7 This is a top view of the conductive hook and conductive component used in this embodiment.

[0027] Figure 8 A schematic diagram of the structure of the electrophoretic immersion washing tank provided in the embodiment;

[0028] Figure 9 A schematic diagram of the structure of the electrophoretic immersion washing tank and the conveying unit provided in the embodiment;

[0029] Figure 10 A top view of the electrophoretic immersion washing tank provided in the embodiment;

[0030] Figure 11 A schematic diagram of the internal structure of the automatic phosphating device provided in the embodiment;

[0031] Figure 12 A schematic diagram of the front structure of the automatic phosphating device provided in the embodiment;

[0032] Figure 13 A schematic diagram of the blocking cylinder structure provided for an embodiment;

[0033] Figure 14 This is a schematic diagram of the scraping device provided in the embodiment;

[0034] Figure 15 A schematic diagram of the cylindrical inclined plate structure provided in the embodiment;

[0035] Figure 16 This is a schematic diagram of the electrophoresis circulating water washing device provided in the embodiment;

[0036] Figure 17 This is a schematic diagram of the working principle of the curing unit;

[0037] Figure 18 A schematic diagram of the curing unit provided in the embodiment;

[0038] Figure 19 for Figure 2 Enlarged view of a specific area;

[0039] Figure 20 A schematic diagram of the gas distribution chamber provided for an embodiment;

[0040] Figure 21 A schematic diagram of the structure of the burner, regulating mechanism and combustion chamber connecting pipe.

[0041] Attached image labels:

[0042] Conveying unit 1000; Downward conveying section 1041, downward immersion section 1042, upward conveying section 1043, hook track 1100, transmission chain 1200, A group chain link 1221, B group chain link 1222, conductive hook 1300, hook oil receiving part 1301, load slide 1302, roller 1303, crank 1304, load part 1305, hook body 1306, connector 1307, insulating material 1308, primary hook 1309, conductive part 1310, first conductive connecting piece 1311, second conductive connecting piece 1312, chain oil receiving part 1400, chain oil receiving connector 1401, conductive part 1500, conductive slide rail 1501, conductive insertion opening 1502, side adjustment plate 1600.

[0043] Pretreatment unit 2000; washing tank 2100, washing nozzle 2101, water pump 2102, support legs 2104, tank inlet 2105, tank outlet 2106; automatic phosphating device 2200, reaction chamber 2201, cylindrical inclined plate 2202, phosphorus outlet 2203, feed hopper 2204, door 2205, observation chamber 2206, exhaust fan 2207, exhaust pipe 2208, exhaust spray mechanism 2209, exhaust gas-liquid collection tank 2210, PLC control box 221 1. Touch screen 2212, inclined settling tank 2213, heater 2214, agitator 2215, slag press 2216, phosphating liquid circulation pump 2217, phosphating tank 2218, spray pump 2219, scraper device 2220, scraper cylinder 2221, fan-shaped scraper 2222, arc-shaped scraper part 2223, arc-shaped baffle 2224, slide rail 2225, slide table 2226, rotary motor 2227, phosphating rack 2228, blocking cylinder 2229, blocking block 2230, touch switch 2231;

[0044] Electrophoresis unit 3000; electrophoretic coating tank 3100; electrophoretic auxiliary tank 3101.

[0045] Curing unit 4000; burner 4100, combustion chamber 4101, regulating mechanism 4102, gas throttle valve 4103, air throttle valve 4104, air supply mechanism 4200, combustion chamber connecting pipe 4201, filter 4202, filter chamber 4203, combustion chamber connecting port 4204, curing oven 4300, curing chamber 4301, insulation layer 4302, gas distribution chamber 4303, circulation mechanism 4400, circulating fan 4401, circulating air inlet pipe 4402, circulating air inlet 4403, circulating air outlet pipe 4403, circulation chamber 4404, workpiece 4600, curing controller 4700, temperature sensor 4800, emission mechanism 4900.

[0046] Electrophoresis circulating water washing device 5000; outlet spray water tank 5001, ultrafiltrate tank 5002, immersion water washing tank 5003, immersion water washing auxiliary tank 5031, stirring nozzle 5032, fresh ultrafiltrate tank 5004, outlet spray device 5005, first spray water washing device 5006, second spray water washing device 5007, pure water pipe 5091, ultrafiltrate return pipe 5092. Detailed Implementation

[0047] To facilitate understanding of the present invention, a more comprehensive description will be given below with reference to the accompanying drawings.

[0048] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to and integrated with the other component, or there may be an intervening component present. The terms "mounted," "one end," "the other end," and similar expressions used in this document are for illustrative purposes only.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0050] Please refer to Figures 1-21 The automotive parts electrophoretic coating system includes a pretreatment unit 2000, an electrophoresis unit 3000, a curing unit 4000, and a conveying unit 1000. The pretreatment unit 2000 is used to pretreat the workpiece 4600, the electrophoresis unit 3000 is used for cathodic electrophoresis on the workpiece 4600, and the curing unit 4000 is used for curing the workpiece 4600. In use, the workpiece 4600 is hooked onto a hook, and a drive chain 1200 moves the workpiece 4600 on the hook. The drive chain 1200 sequentially conveys the workpiece 4600 to the pretreatment unit 2000, the electrophoresis unit 3000, and the curing unit 4000. Under the conveying of the conveying unit 1000, the workpiece 4600 undergoes pretreatment, electrophoresis, and curing respectively, ensuring that the electrophoretic coating can form a continuous operation with the pretreatment process and the subsequent curing process, thereby improving the electrophoretic coating efficiency of the workpiece 4600. The conveying unit 1000 includes a transmission chain 1200 and multiple conductive hooks 1300. The conductive hooks 1300 are fixed to the transmission chain 1200 at intervals. The lower end of the conductive hook 1300 is provided with a hook part, and the conductive part 1310 is provided on the conductive hook 1300. The electrophoresis unit 3000 is also provided with a conductive element 1500. When the conductive hook 1300 moves to the electrophoresis unit 3000, it contacts and is electrically connected to the conductive element 1500 to ensure continuous operation of the process and solve the problem of conductivity of the workpiece 4600 when entering the electrophoresis unit 3000.

[0051] The conveying unit 1000 provided in the embodiment:

[0052] Please refer to Figures 2-7The conveying unit 1000 includes a hook track 1100 and a transmission chain 1200 disposed below the hook track 1100. The hook track 1100 has several conductive hooks 1300 that can move along the hook track 1100 under the drive of the transmission chain 1200. Each conductive hook 1300 has a hook oil receiving element 1301 for receiving lubricating oil. Below the transmission chain 1200, where the oil receiving area of ​​the hook oil receiving elements 1301 is not covered, several chain oil receiving elements 1400 are connected for receiving lubricating oil. The oil receiving area of ​​the hook oil receiving elements 1301 and the chain oil receiving elements 1400 covers all oil dripping points of the hook track 1100 and the transmission chain 1200. In a preferred embodiment, the hook oil receiving elements 1301 and the chain oil receiving elements 1400 are oil receiving trays with upward-facing openings and raised edges.

[0053] In a preferred embodiment, the conductive hook 1300 includes a load carriage 1302 connected to the transmission chain 1200 and a hook body 1306 connected below the load carriage 1302. The hook body 1306 is movably connected to the load carriage 1302 and always hangs naturally towards the ground. The hook oil receiving part 1301 is connected to the hook body 1306 with its opening facing upward. The load carriage 1302 is provided with a pin and a cotter pin, and the hook body 1306 is movably connected below the load carriage 1302 by the pin.

[0054] In a preferred embodiment, the hook body 1306 includes a connector 1307 connected to the load carriage 1302, an insulating material 1308, a primary hook 1309 insulated by the insulating material 1308 and connected below the connector 1307, and a conductive part 1310 disposed on the primary hook 1309. A hook oil-receiving part 1301 is connected to the connector 1307 and positioned higher than the insulating material 1308. The connector 1307 consists of a flat iron and a connector welded to the flat iron. The connector has a through hole that mates with a pin on the load carriage 1302. The primary hook 1309 consists of a flat iron and a hook welded to the flat iron. The insulating material 1308 includes an insulating gasket placed between the connector 1307 and the primary hook 1309. The primary hook 1309 and the connector 1307 are bolted together, and an insulating sleeve is fitted onto the bolt. Conductive carbon brushes are disposed at both ends of the conductive part 1310.

[0055] In a preferred embodiment, the chain oil receiving component 1400 is connected to the drive chain 1200 by two chain oil receiving connectors 14011307 of the same length. The chain oil receiving connectors 14011307 are studs.

[0056] In a preferred embodiment, the transmission chain 1200 is composed of several chain links connected together. The chain links are divided into a group A chain links 1221, whose chain hole plane is parallel to the top surface of the hook track 1100, and a group B chain links 1222, whose chain hole plane is perpendicular to the top surface of the hook track 1100. The group A chain links 1221 and the group B chain links 1222 are connected alternately. Two chain oil receiving connectors 14011307 are respectively connected to the chain hole of a group A chain link 1221. The connection method is bolting.

[0057] In a preferred embodiment, the two chain oil receiving connectors 14011307 of the chain oil receiving component 1400 are connected to the chain holes of two adjacent A group chain links 1221.

[0058] In a preferred embodiment, the chain oil receiving component 1400 is an oil receiving tray with its opening facing upwards. Two chain oil receiving connectors 14011307 are connected to the bottom surface of the chain oil receiving component 1400 by bolting. The opening range of the chain oil receiving component 1400 is larger than the interval between the two chain oil receiving connectors 14011307. The edge of the chain oil receiving component 1400 is located below the B group chain link 1222 adjacent to the chain oil receiving connector 14011307.

[0059] In a preferred embodiment, the load carriage 1302 includes a roller 1303 sliding on a hook track 1100, a crank 1304 connected to the roller 1303, and a load member 1305 connected to the crank 1304. The load member 1305 passes through the A-group chain link 1221 of the drive chain 1200 and is engaged with the drive chain 1200. The oil-receiving area of ​​the hook oil-receiving member 1301 covers the A-group chain link 1221 through which the load member 1305 passes, and the edge of the hook oil-receiving member 1301 is located below the B-group chain link 1222 adjacent to the A-group chain link 1221. The hook track 1100 is an I-beam with two hook track grooves, and the roller 1303 rolls within the hook track grooves.

[0060] In a preferred embodiment, both the hook oil receiving component 1301 and the chain oil receiving component 1400 are located below the drive chain 1200, and the distance between the hook oil receiving component 1301 and the drive chain 1200 is greater than the distance between the chain oil receiving component 1400 and the drive chain 1200. That is, the installation height of the chain oil receiving component 1400 is higher than that of the hook oil receiving component 1301.

[0061] In a preferred embodiment, the chain oil receiving component 1400 and the conductive hook 1300 are alternately arranged below the transmission chain 1200.

[0062] In a preferred embodiment, the energized section is the section where the workpiece 4600 to be coated is lowered into the coating immersion tank. The energized section is equipped with conductive elements 1500. There are two conductive elements 1500, symmetrically arranged on both sides of the suspension conveyor. The height can be adjusted by the side adjustment plate 1600 to accommodate different conductive hooks 1300. The conductive part 1310 on the conductive hook 1300 has conductive carbon brushes at both ends. Each conductive hook 1300 has two conductive carbon brushes. When entering the energized section, the conductive carbon brushes contact the conductive elements 1500 to energize the primary hook 1309 and the workpiece 4600 to be processed hanging on the primary hook 1309.

[0063] In a preferred embodiment, the conductive hook 1300 is slidably connected to the electrophoresis unit 3000. The conductive hook 1300 is provided with a conductive part 1310. The electrophoresis unit 3000 includes an electrophoretic coating tank 3100, which is provided with a conductive slide rail 1501. The conductive part 1310 slides on the conductive slide rail 1501. After the conductive part 1310 is slidably connected to the conductive slide rail 1501, the conductive part 1310 and the conductive element 1500 are electrically connected to form a circuit (i.e., a closed loop). At this time, the workpiece 4600 on the set of conductive hooks 1300 is in the electrophoretic coating state, and the electrophoretic paint is attached to the surface of the workpiece 4600. If multiple sets of conductive hooks 1300 are simultaneously slidably connected to the conductive slide rail 1501 on the conductive element 1500, then the multiple sets of conductive hooks 1300 are connected in parallel to the electrophoresis power supply circuit. Specifically, when the conductive hook 1300 slides on the conductive slide rail 1501, it will pass through the conductive slide rail 1501 at a constant speed. When the conductive part 1310 slides on the conductive slide rail 1501, both ends of the conductive part 1310 contact the conductive slide rail 1501. The conductive part 1310 has elastic tension and will adhere to the conductive slide rail 1501 when sliding, resulting in a small gap when contacting the conductive slide rail 1501. The conductive part 1310 passes through the conductive slide rail 1501 in a tensioned manner. When the two ends of the conductive part 1310 slide through the conductive slide rail 1501, they will generate frictional force for buffering, which can make the conductive part 1310 slide through the conductive slide rail 1501 at a constant speed. This prevents sparking caused by excessive gaps between the two ends of the conductive part 1310 and the conductive slide rail 1501, which would affect the conductivity stability and safety of the conductive hook 1300 and the overall operation of the electrophoresis device.

[0064] In a preferred embodiment, a conductive copper busbar is provided on the side wall of the conductive slide rail 1501. The conductive copper busbar is connected to a rectifier. The conductive copper busbar is used for conduction. The conductive copper busbar and the rectifier are existing technologies and will not be described in detail in this embodiment. The conductive part 1310 is a W-shaped conductive sheet. Conductive carbon brushes are connected to both ends of the conductive part 1310. The conductive carbon brushes are provided with conductive connection surfaces. The conductive connection surfaces are slidably connected inside the conductive slide rail 1501. A conductive copper busbar is provided inside the conductive slide rail 1501 and is slidably connected to the conductive connection surfaces. Specifically, the conductive part 1310 is a W-shaped conductive component, which includes a first conductive connecting piece 1311 and a second conductive connecting piece 1312. The first conductive connecting piece 1311 and the second conductive connecting piece 1312 are arc-shaped conductive pieces. After one end of the first conductive connecting piece 1311 and one end of the second conductive connecting piece 1312 are fixedly connected, a W-shaped conductive piece with elastic tension at both ends is formed. The W-shaped conductive piece with elastic tension passes through the conductive slide rail 1501 at a uniform speed. The W-shaped conductive piece with elastic tension sets the conductive part 1310 in place. The conductive part 1310, which is formed by two arc-shaped conductive sheets connected together, has a shape similar to a "W". When it slides on the conductive slide rail 1501, it can generate elastic compression and pass through the conductive slide rail 1501 in a tensioned manner. The tension elastic force will keep it in contact with the conductive slide rail 1501 at all times, preventing gaps between the conductive carbon brush on the conductive part 1310 and the conductive slide rail 1501. This ensures that the conductive hook 1300 passes through the conductive slide rail 1501 at a uniform speed during operation, avoiding sparking and ensuring safety and stability.

[0065] In a preferred embodiment, the conductive carbon brush is a square conductive brush. Each group of conductive parts 1310 is provided with two conductive carbon brushes, which are respectively connected to the other end of the first conductive connecting piece 1311 and the second conductive connecting piece 1312. The other end of the first conductive connecting piece 1311 and the second conductive connecting piece 1312 is a connecting end for sliding connection on the conductive slide rail 1501. Therefore, after connecting the conductive carbon brush, it is connected to the conductive slide rail 1501.

[0066] In a preferred embodiment, the conductive slide rail 1501 is further provided with a conductive insertion opening 1502. The conductive insertion opening 1502 is an open opening in the shape of an octagon. The open opening 1502 is in the shape of an octagon to facilitate the entry of the conductive part 1310 into the conductive slide rail 1501. After the conductive part 1310 enters the conductive slide rail 1501, it will generate a frictional force for buffering when it moves on the conductive slide rail 1501.

[0067] The conductive hook 1300 is provided with a conductive part 1310 with elastic tension. When the conductive component 1500 slides through the conductive slide rail 1501 on the conductive component 1500, the conductive part 1310 will pass through the conductive slide rail 1501 at a uniform speed. The electrical connection performance between the conductive component 1500 and the conductive part 1310 is stable, avoiding the generation of sparks between the conductive component 1500 and the track, and improving the stable conductivity and safety performance of the conductive hook 1300 of the electrophoresis device.

[0068] The preprocessing unit 2000 provided in this embodiment:

[0069] Before electrophoretic coating, workpiece 4600 undergoes pretreatment to improve coating adhesion and enhance decorative and corrosion resistance. The pretreatment process includes three main parts: pre-degreasing, main degreasing, and surface conditioning and phosphating. Degreasing (both main degreasing) is a preparatory step before surface conditioning and phosphating. A high-quality phosphating film can only form on a work surface where oil, rust, scale, and other foreign matter have been thoroughly removed. The pretreatment principle involves conveying the workpiece 4600 to be treated via the conveyor unit 1000, where it comes into contact with the spraying and immersion solutions. After a certain cleaning time, the cleaning process before electrophoresis is completed. The process flow is as follows: hot water wash 1 spray → pre-degreasing spray → main degreasing soaking → water wash 1 spray → water wash 2 soaking → water wash spray → fresh tap water single-pipe spray → surface conditioning spray → phosphating soaking → water wash 4 spray → water wash 5 soaking → water wash 6 spray → pure water spray → pure water wash spray → fresh pure water single-pipe spray → dripping → cathodic electrophoresis. The improved part of the pretreatment unit 2000 in this embodiment includes a water washing tank 2100 and an automatic phosphating device 2200.

[0070] Please refer to Figures 8-10 In a preferred embodiment, the washing tank 2100 is used to hold cleaning water. Several washing nozzles 2101 are arranged on the bottom surface of the washing tank 2100, and each nozzle is connected to a water pump 2102. The cleaning water in the washing tank 2100 is pressurized by the water pump 2102 and sprayed out from the nozzles 2101, circulating within the washing tank 2100. In a preferred embodiment, the washing tank 2100 has a tank inlet 2105 at the exit end of the workpiece 4600 and a tank outlet 2106 at the entry end of the workpiece 4600. This design ensures that, with continuous water exchange, the cleaning water at the exit end is cleaner than the water at the inlet end, maximizing the cleanliness of the workpiece 4600 upon exiting the tank. The washing tank 2100 is fixed to the ground by supports 2104, with its bottom suspended for easy emptying and connection to other devices.

[0071] In a preferred embodiment, the 128 water washing nozzles 2101 are arranged symmetrically around the center point of the bottom surface of the water washing tank 2100. In other embodiments, several water washing nozzles 2101 can also be arranged vertically, covering the bottom surface of the water washing tank 2100. Water sprayed from the water washing nozzles 2101 falls under the influence of gravity and is sprayed out again, thus circulating.

[0072] In a preferred embodiment, all water washing nozzles 2101 have an angle of α, satisfying 20°≤α≤80°, specifically 45°. In other embodiments, the angles of the water washing nozzles 2101 may vary.

[0073] In a preferred embodiment, the washing tank 2100 is a centrally symmetrical wide-mouth container, specifically a boat-shaped washing tank 2100.

[0074] In a preferred embodiment, the water pump 2102 is a miniature water pump 2102 connected to the bottom of the water washing nozzle 2101, with each water pump 2102 corresponding to one water washing nozzle 2101. The connection method of the water pump 2102, water washing nozzle 2101, and water washing tank 2100 is existing technology. In other embodiments, the water pump 2102 may also be one or more conventional water pumps 2102, connected to all water washing nozzles 2101 via pipelines.

[0075] The washing tank 2100 provided in the above embodiment constitutes an online electrophoretic immersion washing device. The online electrophoretic immersion washing device includes a conveying unit 1000, which has a downward conveying section 104, a downward immersion section 1042, and an upward conveying section 1043. Below the conveying unit 1000, an electrophoretic immersion washing tank 5003 is also provided. In a preferred embodiment, the conveying unit 1000 includes a track and a transmission chain 1200 disposed below the track. Several conductive hooks 1300 are provided on the track, which can move along the track under the drive of the transmission chain 1200. The workpiece 4600 to be washed is hung on the conductive hooks 1300 and enters and exits the electrophoretic immersion washing tank 5003 through the conveying unit 1000, i.e., it is connected to the production line where the conveying unit 1000 is located. The production line connects the pretreatment to the final electrophoretic immersion coating section. Several conductive hangers are equipped with oil-receiving components for collecting lubricating oil. Below the transmission chain 1200, which is not covered by the oil-receiving range of the hangers, several chain oil-receiving components 1400 are connected. The combined oil-receiving range of the hangers and chain oil-receiving components 1400 covers all oil-dripping points on the track and transmission chain 1200. The transmission chain 1200 is composed of several chain links connected together. The chain links are divided into group A chain links 1221, whose chain hole plane is parallel to the top surface of the track, and group B chain links 1222, whose chain hole plane is perpendicular to the top surface of the track. Group A chain links 1221 and group B chain links 1222 are connected alternately. Two chain oil-receiving connectors 14011307 are each connected to the chain hole of one group A chain link 1221. Two chain oil-receiving connectors 14011307 are each connected to the chain holes of two adjacent group A chain links 1221.

[0076] In a preferred embodiment, the washing tank body 2100 of the electrophoretic immersion washing tank 5003 is long and narrow, with both ends widening from bottom to top, and the whole is shaped like a boat.

[0077] In a preferred embodiment, the flared end of the washing tank 2100 at the entry point of the workpiece 4600 is parallel to the downward conveying section 104, the bottom surface of the washing tank 2100 is parallel to the lower immersion section 1042, and the flared end of the washing tank 2100 at the exit point of the workpiece 4600 is parallel to the upward conveying section 1043. The angle between the sidewalls of the two flared ends of the washing tank 2100 and the ground is 40°. When the slope of the conveying unit 1000 is gentle, conveying the workpiece 4600 is more stable, and an angle between 30° and 60° is more reasonable.

[0078] In the preferred embodiment, there are a total of 128 water washing nozzles 2101, arranged in two layers along the perimeter of the bottom surface of the water washing tank 2100, with the nozzles uniformly oriented in a counterclockwise direction. In other embodiments, the water washing nozzles 2101 may also be arranged in a single layer or multiple layers along the bottom edge of the water washing tank 2100, up to covering the bottom surface of the water washing tank 2100.

[0079] Please refer to Figures 11-15 In a preferred embodiment, the automatic phosphating device 2200 includes a reaction tank 2201, an inclined settling tank 2213 connected by pipes, and a slag press 2216. The inclined settling tank 2213 is located above the reaction tank 2201, and the slag press 2216 is located below the reaction tank 2201. A phosphating liquid circulation pump 2217 is provided between the slag press 2216 and the inclined settling tank 2213. Phosphating tanks 2218 are provided on both sides of the reaction tank 2201, and the phosphating tanks 2218 and the inclined settling tank 2216 are connected by pipes. Preferably, a valve is provided between the phosphating tank 2218 and the inclined settling tank 2213 for the pipe connection of the tank 2213; a spray pump 2219 is provided on the phosphating tank 2218, and a cylindrical inclined plate 2202 is provided below the reaction tank 2201. The cylindrical inclined plate 2202 is made into a cylindrical shape to reduce cleaning dead corners and make slag removal work more convenient. The cylindrical inclined plate 2202 can make the phosphating slag flow quickly to the slag press 2216, avoiding most of the phosphating slag from accumulating in the reaction tank 2201.

[0080] In this embodiment, a phosphorus outlet 2203 is provided at one end of the cylindrical inclined plate 2202, and the phosphorus outlet 2203 is connected to the slag press 2216. A scraping device 2220 is provided at the other end of the cylindrical inclined plate 2202. Preferably, the scraping device 2220 includes a scraping cylinder 2221 and a fan-shaped scraper 2222. The fan-shaped scraper 2222 is mounted on the scraping cylinder 2221, and an arc-shaped scraping part 2223 is provided on the fan-shaped scraper 2222. The arc-shaped scraping part 2223 is close to the cylindrical inclined plate 2202. The fan-shaped scraper 2222 can clean and scrape the cylindrical inclined plate 2202 at any time, so that the phosphating slag will not remain on the cylindrical inclined plate 2202 for a long time, and the slag removal is convenient. In some embodiments, the scraping cylinder 2221 can be replaced by a motor. An arc-shaped baffle 2224 is installed above the scraping device 2220. The arc-shaped baffle 2224 has the function of blocking the dripping phosphating liquid and preventing the phosphating liquid from accumulating excessively on the scraping device 2220.

[0081] In this embodiment, a slide 2225 is provided on the top of the reaction chamber 2201, and a slide table 2226 is provided on the slide 2225. Feeding chambers 2204 are provided on both sides of the reaction chamber 2201. The slide 2225 passes through the feeding chambers 2204. A rotary motor 2227 is installed on the slide table 2226, and a phosphating frame 2228 is installed on the output shaft of the rotary motor 2227. The rotary motor 2227 can rotate the phosphating frame 2228, so that the phosphating liquid can be sprayed evenly onto the product, thereby improving the phosphating efficiency. A blocking cylinder 2229 is installed on one side of the slide 2225. A blocking block 2230 is installed on the blocking cylinder 2229, and a touch switch 2231 is installed on the blocking block 2230. The reaction box 2201 is equipped with a PLC control box 2211 and a touch screen 2212. The touch screen 2212, the slag press 2216, the phosphating liquid circulation pump 2217, the scraper 2220, the rotary motor 2227, the blocking cylinder 2229, and the touch switch 2231 are all connected to the PLC control box 2211 via wires. During operation, when the blocking cylinder 2229 extends, the blocking block 2230 blocks the slide 2226. When the touch switch 2231 is blocked by the slide 2226, phosphating begins and timing starts. When phosphating is completed, the blocking cylinder 2229 retracts, allowing the slide 2226 to slide to the next process station. Its high level of automation improves the production efficiency of the entire phosphating process.

[0082] To facilitate manual maintenance and observation, a door 2205 is provided at the front of the reaction chamber 2201, and an observation chamber 2206 is provided on the door 2205.

[0083] To reduce exhaust gas emissions, an exhaust fan 2207 is installed at the top of the reaction chamber 2201. The exhaust fan 2207 is equipped with an exhaust pipe 2208, which is inclined downwards. An exhaust gas spraying mechanism 2209 is installed inside the exhaust pipe 2208. The exhaust gas spraying mechanism 2209 can remove some impurities in the exhaust gas. An exhaust gas liquid collection box 2210 is installed at the end of the exhaust pipe 2208. The downward inclination of the exhaust pipe 2208 is to prevent the water sprayed by the exhaust gas spraying mechanism 2209 from entering the reaction chamber 2201.

[0084] In some embodiments, a heater 2214 and a stirrer 2215 are provided in the inclined settling tank 2213.

[0085] The automatic phosphating apparatus 2200 provided in the embodiments also has at least the following advantages:

[0086] (1) A cylindrical inclined plate 2202 is provided below the reaction box 2201. A phosphorus outlet 2203 is provided at one end of the cylindrical inclined plate 2202. The phosphorus outlet 2203 is connected to the slag press 2216. A scraping device 2220 is provided at the other end of the cylindrical inclined plate 2202. The scraping device 2220 includes a scraping cylinder 2221 and a fan-shaped scraper 2222. The fan-shaped scraper 2222 can clean and scrape the cylindrical inclined plate 2202 at all times, so that the phosphating slag will not remain on the cylindrical inclined plate 2202 for a long time, and the slag removal is convenient.

[0087] (2) A cylindrical inclined plate 2202 is provided below the reaction box 2201. The cylindrical inclined plate 2202 is made into a cylindrical shape to reduce the dead corners for cleaning and make the slag removal work more convenient.

[0088] (3) A slide 2225 is provided on the top of the reaction chamber 2201. A slide table 2226 is provided on the slide 2225. A rotary motor 2227 is installed on the slide table 2226. A phosphating frame 2228 is installed on the output shaft of the rotary motor 2227. The rotary motor 2227 can rotate the phosphating frame 2228, so that the phosphating liquid can be sprayed evenly onto the product, thereby improving the phosphating efficiency.

[0089] (4) A blocking cylinder 2229 is provided on one side of the slide 2225, and a blocking block 2230 is installed on the blocking cylinder 2229; a touch switch 2231 is provided on the blocking block 2230, and a PLC control box 2211 and a touch screen 2212 are provided on the reaction box 2201. The touch screen 2212, the blocking cylinder 2229 and the touch switch 2231 are all connected to the PLC control box 2211 through wires. When the blocking cylinder 2229 extends, the blocking block 2230 blocks the slide 2226. When the touch switch 2231 is blocked by the slide 2226, phosphating begins and timing begins. When phosphating is completed, the blocking cylinder 2229 retracts, allowing the slide 2226 to slide to the next process station. Its automation level is high, which improves the production efficiency of the entire phosphating process.

[0090] The preprocessing unit 2000 provided in this embodiment:

[0091] Please refer to Figures 17-21This invention provides a curing unit 4000, which includes a burner 4100, an air supply mechanism 4200, a curing oven 4300, a circulation mechanism 4400, and a curing controller 4700. The burner 4100 is used to burn fuel gas and is connected to the air supply mechanism 4200. The air supply mechanism 4200 is also provided with a filter 4202, which is used to filter the gas after combustion in the burner 4100. The air supply mechanism 4200 delivers the filtered gas to the curing oven 4300. The curing oven 4300 has a curing chamber 4301 inside. The curing chamber 4301 is connected to the air supply mechanism 4200. The curing chamber 4301 is used to receive the filtered gas and to cure the coating of the workpiece 4600 contained therein. The curing chamber 4301 is connected to the input and output ends of the circulation mechanism 4400 respectively. The curing chamber 4301 is equipped with a temperature sensor 4800. The temperature sensor 4800 and the burner 4100 are both connected to the curing controller 4700. The curing controller 4700 receives the temperature signal sent by the temperature sensor 4800 and can adjust the heat output of the burner 4100 according to the temperature signal. In use, the burner 4100 burns the fuel gas to produce high-temperature gas. The filter 4202 filters the high-temperature gas after combustion to prevent dust in the high-temperature gas from entering the curing chamber 4301. The air supply mechanism 4200 delivers the high-temperature gas to the curing chamber 4301, and the gas in the curing chamber 4301 circulates under the drive of the circulation mechanism 4400. The temperature sensor 4800 detects the temperature of the curing chamber 4301 and sends the temperature signal to the curing controller 4700. The curing controller 4700 adjusts the heat output of the burner 4100 according to the temperature signal to control the temperature in the curing chamber 4301. Through the above settings: First, the heat generated by the burner 4100 is generally greater than that of the electric heater 2214, and the operating temperature is also higher, meaning that the present invention will be faster in raising the temperature from room temperature to the curing temperature required for the paint layer curing of the workpiece 4600. The filter 4202 can also solve the problem of dust generated by the combustion fuel entering the curing chamber 4301, thus preventing dust from affecting the curing quality of the paint layer of the workpiece 4600. Secondly, the medium used to directly heat the curing chamber 4301 in this invention is high-temperature gas. Driven by the circulation mechanism 4400, the input high-temperature gas can quickly mix with the gas in the original curing chamber 4301 and disperse to all parts of the curing chamber 4301, achieving rapid heating. Furthermore, the heat distribution in the curing chamber 4301 is more uniform. Compared with the electric heater 2214, which exchanges heat through surface contact with the air in the curing chamber 4301, this invention has significant advantages in heating speed, heat distribution uniformity, and temperature controllability.

[0092] Please refer to Figure 21In a preferred embodiment, the burner 4100 is further provided with an adjustment mechanism 4102. The adjustment mechanism 4102 is used to adjust the heat output of the burner 4100. The adjustment mechanism 4102 includes a gas throttle valve 4103 and an air throttle valve 4104. One end of the gas throttle valve 4103 and one end of the air throttle valve 4104 are respectively connected to the burner 4100. The other end of the gas throttle valve 4103 receives externally input gas and is used to deliver gas to the burner 4100. The other end of the air throttle valve 4104 receives externally input air and is used to deliver air to the burner 4100. The burner 4100; the gas throttle valve 4103 and the air throttle valve 4104 are respectively connected to the curing controller 4700. The curing controller 4700 controls the flow rate of the gas throttle valve 4103 and the air throttle valve 4104, so that the burner 4100 can increase or decrease the amount of combustion gas according to the temperature inside the curing chamber 4301. For example, when the temperature inside the curing chamber 4301 is low, under the control of the curing controller 4700, the gas flow rate through the gas throttle valve 4103 and the air flow rate through the air throttle valve 4104 are both increased, so that the heat output of the burner 4100 is increased.

[0093] Please refer to Figure 21 In a preferred embodiment, the burner 4100 further includes a combustion chamber 4101, which is connected to a gas throttle valve 4103 and an air throttle valve 4104, respectively, where gas and air are burned. The air supply mechanism 4200 also includes an air supply fan (not shown in the figure) and a combustion chamber connecting pipe 4201, one end of which is connected to the combustion chamber 4101 and the other end to a filter 4202. The air supply fan is located between the filter 4202 and the combustion chamber 4101, and sequentially transports the gas burned in the combustion chamber 4101 to the filter 4202 via the combustion chamber connecting pipe 4201. The output end of the filter 4202 is connected to the curing chamber 4301, and transports the filtered gas to the curing chamber 4301. Please refer to [reference needed]. Figure 4 and Figure 5 Furthermore, the curing unit 4000 is also equipped with a gas distribution chamber 4303; two rows of high-temperature resistant filter cotton within the gas distribution chamber 4303 form a filter cavity 4203; the filter cavity 4203 is connected to the combustion chamber 4101 via a combustion chamber connecting pipe 4201 and a combustion chamber connecting port 4204. An exhaust fan can be used as the air supply fan, which generates air pressure between the combustion chamber 4101 and the filter 4202, driving the high-temperature gas from the burner 4100 to the filter 4202 for filtration and finally into the curing chamber 4301. The specific location of the air supply fan can be within the combustion chamber connecting pipe 4201 or the combustion chamber connecting port 4204. The combustion chamber 4101 is designed to ensure complete combustion of the gas.

[0094] Please refer to Figures 18-19In a preferred embodiment, the circulation mechanism 4400 includes a circulation fan 4401, a circulation inlet pipe 4402, and a circulation outlet pipe 4403 (not shown in the figure). The output and input ends of the circulation fan 4401 are connected to the input end of the circulation inlet pipe 4402 and the output end of the circulation outlet pipe 4403, respectively. The output end of the circulation inlet pipe 4402 is connected to the curing chamber 4301 through multiple circulation inlets 4403, and the input end of the circulation outlet pipe 4403 is connected to the curing chamber 4301 through multiple circulation return ports (not shown in the figure). The high-temperature gas circulation flow direction is: output end of circulation fan 4401, circulation inlet pipe 4402, circulation inlet 4403, curing chamber 4301, circulation return port, and input end of circulation fan 4401, returning to circulation fan 4401 for recirculation. Each curing unit 4000 is equipped with two circulating air inlet pipes 4402 and a circulating fan 4401. The circulating air inlet pipes 4402 are positioned with their upper ends located at the top of the curing chamber 4301 and are arranged along the length of the curing chamber 4301. Multiple grid-shaped circulating air inlets 4403 are also arranged along the length of the upper end of the circulating air inlet pipes 4402. High-temperature gas enters the curing chamber 4301 through the circulating air inlets 4403, allowing the high-temperature gas to be rapidly dispersed within the curing chamber 4301. The lower opening of the circulating air inlet pipes 4402 is connected to the output end of the circulating fan 4401, receiving the gas supplied to the circulating fan 4401 by the circulating air outlet pipes 4403.

[0095] Please refer to Figure 20 In a preferred embodiment, the curing unit 4000 is further provided with a gas distribution chamber 4303, and the filter 4202 is a high-temperature resistant filter cotton. There are multiple high-temperature resistant filter cottons arranged in two rows at intervals in the gas distribution chamber 4303. The two rows of high-temperature resistant filter cottons enclose and form a filter cavity 4203. The filter cavity 4203 is also provided with a combustion chamber connection port 4204 communicating with it. The burner 4100 is also provided with a combustion chamber 4101. The combustion chamber connection port 4204 is connected to the combustion chamber 4101 through the combustion chamber connection pipe 4201. The outer sides of the two rows of high-temperature resistant filter cottons and the inner wall of the gas distribution chamber 4303 respectively enclose and form a circulation cavity 4404. The input end and output end of the circulation air inlet pipe 4402 are respectively connected to the circulation cavity 4404 and the curing cavity 4301. The output end of the circulation fan 4401 is connected to the circulation cavity 4404.

[0096] Please refer to Figures 18-19In a preferred embodiment, the furnace body of the curing oven 4300 is formed by an insulation layer 4302, and the cavity enclosed by the insulation layer 4302 is the curing cavity 4301. The insulation layer 4302 consists of two inner and outer stainless steel layers and an insulation rock wool layer between the two stainless steel layers. The two stainless steel layers are constructed from multiple stainless steel plates, serving to support and hold other components in place, while also clamping and fixing the insulation rock wool layer. The insulation rock wool layer can reduce the power consumption of the entire curing unit 4000 and improve the heating rate and temperature control effect.

[0097] Please refer to Figures 18-19 In a preferred embodiment, the curing oven 4300 is further provided with a conveying unit 1000, which penetrates the curing cavity 4301 and is arranged along the length of the curing cavity 4301. The conveying unit 1000 is used to hang the workpiece 4600 to be cured. The curing cavity 4301 is provided with a circulating air inlet 4403 and a circulating air return outlet, which are located on opposite sides of the conveying unit 1000. The conveying unit 1000 uses a drive chain 1200 and a conductive hook 1300, which hangs the workpiece 4600.

[0098] Please refer to Figure 17 In a preferred embodiment, the curing unit 4000 further includes a discharge mechanism 4900. The input end of the discharge mechanism 4900 is connected to the curing chamber 4301. The discharge mechanism 4900 is used to discharge the cured waste gas, or it can also maintain the air pressure inside the curing chamber 4301 by discharging part of the gas inside the curing chamber 4301. The input end of the discharge mechanism 4900 is located at the end of the circulating air inlet 4403 away from the circulating air inlet 4403, so as to discharge the cooler gas inside the curing chamber 4301. In a preferred embodiment, the discharge mechanism 4900 includes a discharge pipe and a tail gas treatment device. The input end of the discharge pipe is connected to the curing chamber 4301, and the output end of the discharge pipe is connected to the tail gas treatment device. Harmful waste gas may be generated after the paint layer is cured. At this time, the waste gas of the paint layer can be treated by the tail gas treatment device to meet the emission requirements.

[0099] The electrophoresis circulating water washing device 5000 provided in the embodiment:

[0100] Please refer to Figure 16The electrophoresis circulating water washing device 5000 provided in the embodiment includes a fresh ultrafiltrate tank 5004, an immersion washing tank 5003, an ultrafiltrate tank 5002, and an outlet spray water tank 5001, which are arranged in descending order of height and connected at the top by an overflow method. The outlet spray water tank 5001 is connected to an outlet spray device 5005 and supplies it with water, and the spray water returns to the outlet spray water tank 5001. The ultrafiltrate tank 5002 is connected to a first spray water washing device 5006 and supplies it with water, and the spray water returns to the ultrafiltrate tank 5002. The fresh ultrafiltrate tank 5004 is connected to a second spray water washing device 5007 and supplies it with water, and the spray water returns to the fresh ultrafiltrate tank 5004. In a preferred embodiment, water is supplied between each tank and the corresponding circulating water washing device by a water pump 2102, and each tank outlet 2106 is equipped with a bag filter 4202 to filter impurities. In the preferred embodiment, a total of four stages of water washing are provided. In other embodiments, the number of water washing stages can be increased as needed. The spray device 5005 in the preferred embodiment is a pressurized spray device, which pressurizes the water flow to forcefully impact the paint on the surface of the workpiece 4600. In the preferred embodiment, the water tanks at each stage are connected by overflow pipes. In other embodiments, overflow connections can also be made through conventional methods such as connected steel plates or grooves.

[0101] In a preferred embodiment, the immersion washing tank 5003 includes a boat-shaped immersion tank. In another preferred embodiment, the immersion washing tank 5003 further includes an immersion washing auxiliary tank 5031 and an outlet spray water tank 5001, which is located at the end of the boat-shaped immersion tank where the workpiece 4600 enters. In the preferred embodiment, the workpiece 4600 to be cleaned moves unidirectionally from the left end to the right end of the figure. In the preferred embodiment, the immersion washing auxiliary tank 5031 is a rectangular water tank connected to the boat-shaped immersion tank, communicating only at the top.

[0102] In a preferred embodiment, the hull-shaped immersion tank is equipped with a stirring nozzle 5032 for discharging water into the tank. A water pump 2102, connected to the pipes of the stirring nozzle 5032, is connected to the lower part of the outlet spray tank 5001 of the immersion washing sub-tank 5031. The water pump 2102 draws water from the outlet spray tank 5001 of the immersion washing sub-tank 5031 to supply water to the stirring nozzle 5032. In the preferred embodiment, the stirring nozzle 5032 is a Venturi nozzle, with multiple sets arranged along the wall of the hull-shaped immersion tank. The nozzles are interconnected by pipes and supplied with water by a single water pump 2102. In other embodiments, the stirring nozzle 5032 can be of other types, or supplied with water by multiple water pumps 2102, as long as it can achieve the function of circulating and stirring.

[0103] In a preferred embodiment, the stirring nozzle 5032 is disposed on the tank wall, and the nozzle direction is parallel to the tank wall. In the preferred embodiment, the nozzle does not spray water into the outlet spray water tank 5001 of the immersion washing auxiliary tank 5031, so that the overflow water surface is relatively calm, which is conducive to the overflow and recovery of solvent.

[0104] In a preferred embodiment, the ultrafiltrate tank 5002, the immersion washing tank 5003, and the fresh ultrafiltrate tank 5004 are connected by an ultrafiltrate reflux pipe 5092. In the preferred embodiment, the ultrafiltrate reflux pipe 5092 is connected to the ultrafiltrate outlet of the ultrafiltration machine, which includes a reverse osmosis membrane module.

[0105] The ultrafiltration tank 5002, the immersion washing tank 5003, and the fresh ultrafiltration tank 5004 are connected by a pure water pipe 5091.

[0106] In a preferred embodiment, an online electrophoretic coating device is also provided, including an electrophoretic coating tank 3100, an electrophoretic auxiliary tank 3101, and an electrophoretic circulating water washing device 5000 as described above. An outlet spray device 5005 is located above the electrophoretic auxiliary tank 3101. In this preferred embodiment, the online electrophoretic coating device is a continuous coating device. The workpiece 4600 is sequentially fed into each process via an electrophoretic suspension conveyor, ensuring seamless connection between the coating and washing processes. The outlet spray device 5005 is located above the electrophoretic auxiliary tank 3101, and the washing water falls directly into the electrophoretic auxiliary tank 3101. The water in the electrophoretic auxiliary tank 3101 is transported to an ultrafiltration machine for ultrafiltration, and the ultrafiltrate is then transported to the fresh ultrafiltrate tank 5004 via the ultrafiltrate return pipe 5092.

[0107] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An electrophoretic coating system for automotive parts, characterized in that, The automotive parts electrophoretic coating system includes a pretreatment unit, an electrophoresis unit, a curing unit, and a conveying unit. The pretreatment unit is used to pretreat the workpiece, the electrophoresis unit is used to perform cathodic electrophoresis on the workpiece, and the curing unit is used to cure the workpiece. The conveying unit includes a drive chain and multiple conductive hooks. The drive chain is positioned above the pretreatment unit, electrophoresis unit, and curing unit, and is used to sequentially convey the workpiece to each unit. The conductive hooks are fixed to the drive chain at intervals. Each conductive hook has a hook portion at its lower end for attaching the workpiece, and a conductive portion is provided on the hook. A conductive element is also provided at the electrophoresis unit, and when the conductive hook moves to the electrophoresis unit, it contacts and is electrically connected to the conductive element. The conveying unit also includes a hook track, which is sequentially mounted above the pretreatment unit, the electrophoresis unit, and the curing unit. The hook track is located above the transmission chain, and a roller is provided at the upper end of the conductive hook, with the roller slidably connected within the hook track. The plurality of conductive hooks are equipped with hook oil receiving components for collecting lubricating oil, and a plurality of chain oil receiving components for collecting lubricating oil are connected below the transmission chain where the oil receiving range of the plurality of hook oil receiving components is not covered. The chain oil receiving components are installed at a higher height than the hook oil receiving components. The oil receiving range of the plurality of hook oil receiving components and the plurality of chain oil receiving components covers all oil dripping points of the hook track and the transmission chain. The chain oil receiving component is connected to the transmission chain by two chain oil receiving connectors of the same length. The drive chain consists of several chain links connected together. The chain links are divided into group A chain links, whose chain hole plane is parallel to the top surface of the hook track, and group B chain links, whose chain hole plane is perpendicular to the top surface of the hook track. Group A chain links and group B chain links are connected alternately. The two chain oil receiving connectors of the chain oil receiving component are connected to the chain holes of two adjacent group A chain links. The opening range of the chain oil receiving component is larger than the interval between the two chain oil receiving connectors. The edge of the chain oil receiving component is located below the group B chain link adjacent to the chain oil receiving connector. The conductive hook includes a load carriage connected to the transmission chain and a hook body connected below the load carriage. The load carriage includes a crank connected to the roller and a load member connected to the crank. The load member passes through the A group chain link of the transmission chain and is engaged with the transmission chain. The oil-receiving range of the hook oil-receiving member covers the A group chain link through which the load member passes, and the edge of the hook oil-receiving member is located below the B group chain link adjacent to the A group chain link. The conductive part includes a first conductive connecting piece and a second conductive connecting piece. The first and second conductive connecting pieces are arc-shaped conductive pieces. After one end of the first conductive connecting piece and one end of the second conductive connecting piece are fixedly connected, a W-shaped conductive piece with elastic tension at both ends is formed. Conductive carbon brushes are provided at both ends of the conductive part and are respectively connected to the other ends of the first and second conductive connecting pieces. The electrophoresis unit includes an electrophoretic coating tank, on which a conductive slide rail serving as a conductive element is provided. The conductive part slides on the conductive slide rail. The other ends of the first and second conductive connecting pieces are connected to the conductive carbon brush and slidably connected to the conductive slide rail. When the conductive part slides on the conductive slide rail, it can generate elastic compression, passing through the conductive slide rail in a tensioned manner. The generated tension elasticity will always adhere to the conductive slide rail. The conductive slide rail is also provided with a conductive insertion opening, which is an open V-shaped opening to facilitate the entry of the conductive part into the conductive slide rail. After the conductive part enters the conductive slide rail, it generates a frictional force for buffering when moving on the conductive slide rail.

2. The automotive parts electrophoretic coating system as described in claim 1, characterized in that, The hook body is movably connected to the load carriage, and the hook oil receiving part is connected to the hook body with its opening facing upward.

3. The automotive parts electrophoretic coating system as described in claim 1, characterized in that, The pretreatment unit includes an electrophoretic immersion washing tank, which includes a washing tank body for holding washing water and a plurality of nozzles disposed on the bottom surface of the washing tank body. The plurality of nozzles are connected to a water pump. The washing water in the washing tank body is pressurized by the water pump and sprayed out from the plurality of nozzles, circulating in the washing tank body.

4. The automotive parts electrophoretic coating system as described in claim 1, characterized in that, The automotive parts electrophoretic coating system also includes an electrophoretic circulating water washing device, which is located after the electrophoretic unit. The transmission chain can transport the workpiece after cathodic electrophoresis to the electrophoretic circulating water washing device. The electrophoresis circulating water washing device includes a fresh circulating water tank, an immersion washing tank, a circulating water tank, and an outlet spray water tank, which are arranged in descending order of height and connected at the top by an overflow method; the outlet spray water tank is connected to an outlet spray device and supplies it with water, and the spray water returns to the outlet spray water tank; the circulating water tank is connected to a first spray washing device and supplies it with water, and the spray water returns to the circulating water tank; the fresh circulating water tank is connected to a second spray washing device and supplies it with water, and the spray water returns to the fresh circulating water tank.

5. The automotive parts electrophoretic coating system as described in claim 1, characterized in that, The curing unit includes a burner, an air supply unit, a curing oven, a circulation unit, and a control unit. The burner is used to burn fuel gas and is connected to the air supply unit. The air supply unit is also equipped with a filter for filtering the gas after combustion by the burner. The air supply unit delivers the filtered gas to the curing oven. The curing oven has a curing chamber inside, which is connected to the air supply unit. The curing chamber receives the filtered gas and cures the coating layer of the workpiece contained therein. The curing chamber is connected to the input and output ends of the circulation unit. The curing chamber is equipped with a temperature sensor. Both the temperature sensor and the burner are signal-connected to the control unit. The control unit receives the temperature signal sent by the temperature sensor and can adjust the heat output of the burner according to the temperature signal.

6. The automotive parts electrophoretic coating system as described in claim 5, characterized in that, The burner is also equipped with an adjustment unit for adjusting the heat output of the burner. The adjustment unit includes a gas throttle valve and an air throttle valve, which are respectively connected to the burner. The gas throttle valve is used to supply gas to the burner, and the air throttle valve is used to supply air to the burner. The gas throttle valve and the air throttle valve are respectively signal-connected to the control unit, and the control unit controls the flow rate of the gas throttle valve and the flow rate of the air throttle valve, respectively.

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