Full-automatic coating method for longitudinal beam and auxiliary beam of frame

Abstract

The invention discloses a full-automatic coating method for a longitudinal beam and an auxiliary beam of a frame, which comprises the following steps of: conveying the longitudinal beam to a conveying chain with an ejector pin by a sucking disc, performing pretreatment and moisture drying on the longitudinal beam on the conveying chain with the ejector pin, transferring the longitudinal beam to a powder spraying chamber, transferring the longitudinal beam to the plate chain after the powder spraying process is finished, and coating the longitudinal beam and the auxiliary beam. And the powder is conveyed to a powder leveling and drying furnace, and the whole coating process is completed. And after the powder is strongly cooled, the ejector plate chain is conveyed to a rolling shaft area to be separated and enters a bending area or a storage area. The coating quality and the production efficiency of the longitudinal beam and the auxiliary beam of the frame are remarkably improved, the purposes of energy conservation, environmental protection and intelligent production are achieved, and obvious technical advantages and practical value are achieved.

Description

Technical Field

[0001] The present invention relates to a fully automatically controlled, mechanically automated spraying coating line, in particular to an automatic transmission system suitable for a large-scale coating production line of regular frame longitudinal beams and auxiliary beams and coating equipment that meets the process characteristics of frame longitudinal beams and auxiliary beams. Background Art

[0002] In the automobile manufacturing industry, the production process of the frame, as an important structural component of the automobile, has always been the focus of attention. However, the current traditional domestic frame production model has many problems, which seriously restricts the improvement of production efficiency and product quality.

[0003] First, due to the variety of frame product specifications, especially the large difference in length, and the main and auxiliary beams adopting a buckled combination mode, the gap between the main and auxiliary beams is difficult to be effectively coated in the pre-treatment electrophoresis and spraying process. This not only affects the aesthetics of the frame, but also leads to frequent corrosion and yellow water flow after leaving the factory, which cannot meet the basic requirements such as corrosion resistance.

[0004] Secondly, the existing production process is complex and highly dependent on manual labor. From the assembly and hanging of the frame to the final storage, almost every link requires a lot of manual operation, such as using an overhead crane or electric hoist for assembly and unloading. This not only increases labor costs, but also increases the risk factor of the operation. At the same time, frequent manual operations can easily cause workpieces to collide, resulting in a large number of repainting needs, thereby reducing production efficiency and increasing manufacturing costs.

[0005] In addition, the existing production model places high demands on plant design and resource consumption. Since a large number of overhead cranes and electric hoist equipment need to be installed, the plant's building structure must have sufficient load-bearing capacity. At the same time, the coating equipment has a large demand for public power such as water, electricity, and natural gas. The way the overall frame is assembled and hung before entering the pre-treatment and electrophoresis line tank also leads to a surge in the demand for chemicals and sewage treatment, which has an adverse impact on the environment.

[0006] In terms of production efficiency, the overall efficiency is low due to the intermittent production mode. In terms of environmental protection, the painting process produces a large amount of waste gas, and the waste gas emissions during the drying process are also large, which not only increases the difficulty and cost of waste gas treatment, but also imposes a serious burden on the environment.

[0007] Finally, the existing production layout also has many shortcomings. The setting of multiple manual operation areas easily leads to cross-operation, causing chaos on site. At the same time, pre-treatment electrophoresis equipment, drying and cooling equipment, spray painting and topcoat drying and cooling equipment occupy a large area and have high investment costs, further exacerbating the low production efficiency and rising costs.

[0008] In summary, the traditional domestic frame production model has significant defects in product quality, production efficiency, resource utilization, environmental protection and cost control, and urgently needs technological innovation and process improvement. Summary of the invention

[0009] The technical problem to be solved by the present invention is to provide a fully automatic controlled, mechanically automated spraying coating line in view of the defects in the prior art, especially an automatic transmission system suitable for regular, large-scale coating production lines of frame longitudinal beams and sub-beams, and coating equipment that meets the process characteristics of frame longitudinal beams and sub-beams.

[0010] The technical solution adopted by the present invention to solve its technical problems is: the present invention provides a fully automatic painting method for frame longitudinal beams and sub-beams, which includes the following steps: placing longitudinal beam workpieces arranged in parallel at a fixed distance on a roller bed of a conveyor line through an electromagnetic suction cup; conveying the workpieces horizontally to a roller with positioning at an entrance section; performing pre-treatment, moisture drying, natural cooling, powder spraying, leveling, powder drying and powder forced cooling treatment in sequence; conveying the processed workpieces to an exit section for scanning, automatic coding and labeling; and conveying the workpieces to a lower part area or a stereoscopic warehouse for storage through a roller.

[0011] In a preferred embodiment of the present invention, pre-degreasing, degreasing, first water washing, second water washing, surface conditioning, phosphating, third water washing, fourth water washing and pure water washing are provided with drainage and water blowing between each process.

[0012] In a preferred embodiment of the present invention, in the pre-degreasing, degreasing, surface conditioning and phosphating processes, an automatic feeding system is used to supplement the liquid agent, and the system automatically feeds through a central control system or manually feeds through a single machine.

[0013] In a preferred embodiment of the present invention, under the condition of low cycle, the moisture drying step is carried out by combining a drying chamber and a forced cooling chamber, the drying chamber is composed of a gas heating device, hot air sealing and internal and external air ducts, and the forced cooling chamber is provided with an air supply and exhaust system.

[0014] In a preferred embodiment of the present invention, the powder spraying step is carried out in a powder spraying chamber, which adopts an inner and outer double-layer structure, and the inner layer is made of plastic materials such as polypropylene that does not absorb powder coating.

[0015] In a preferred embodiment of the present invention, the powder drying step includes a temperature rising zone and a temperature keeping zone, wherein the temperature rising zone adopts far infrared radiation heating, and the temperature keeping zone adopts hot air circulation.

[0016] In a preferred embodiment of the present invention, after the varnish is dried, in the powder drying step, the drying temperature is monitored in real time by a temperature probe, the temperature in the heating zone is controlled within the range of ±10°C of the set temperature, and the temperature in the insulation zone is controlled within the range of ±5°C of the set temperature.

[0017] In a preferred embodiment of the present invention, a conveying method combining a chain plate and an ejector pin is adopted, and the entire coating line is divided into three independent conveying systems: a pre-treatment section, a powder spraying section, and a drying and curing section.

[0018] In a preferred embodiment of the present invention, the waste gas generated during the powder drying process is treated by TNV incineration.

[0019] In a preferred embodiment of the present invention, before the workpiece enters the pre-processing process, the automatic scanning device completes the automatic scanning of the parallel longitudinal beams, and transmits the scanning information to the automatic coding and labeling device of the unloading process, so as to realize the intelligent tracking and identification of the workpiece. The beneficial effects of the present invention are as follows: the fully automatic coating method for the frame longitudinal beam and the auxiliary beam provided by the present invention has the following significant technical effects: First, by using electromagnetic suction cups to arrange workpieces in parallel at a fixed distance, not only the loading efficiency is improved, but also the stability and consistency of the workpieces during the transportation process are ensured. Secondly, the fully automated production line design greatly reduces manual operations, thereby reducing labor intensity and safety risks. Furthermore, the automatic feeding system introduced in the pre-treatment process not only realizes continuous online feeding, but also improves the accuracy and efficiency of feeding.

[0020] In addition, the reasonable design of moisture drying and forced cooling system effectively solves the problem of moisture on the workpiece surface before powder spraying, significantly improving the coating quality. At the same time, the design of the powder spraying room with double-layer structure inside and outside not only reduces powder adhesion, but also facilitates cleaning and improves production efficiency. The combination of far-infrared radiation heating and hot air circulation used in the powder drying process ensures the uniformity of the drying effect and energy utilization efficiency.

[0021] It is worth mentioning that the conveying method of the chain plate and ejector adopted by the present invention not only meets the conveying requirements of workpieces of different specifications, but also reduces the risk of collision and scratching of the workpieces during the transmission process. In addition, the design of the exhaust gas treatment system not only ensures that the emission meets the standards, but also realizes the recycling of heat, reflecting the dual effects of environmental protection and energy saving.

[0022] Finally, the application of intelligent code scanning and identification system realizes the whole process tracking and information management of workpieces, greatly improving the traceability and management efficiency of production. In summary, the present invention not only significantly improves the painting quality and production efficiency of frame longitudinal beams and sub-beams, but also achieves the goals of energy conservation, environmental protection and intelligent production, and has obvious technical advantages and practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which: Figure 1 It is a schematic diagram of the process of the present invention; DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] like Figure 1 As shown in the figure, a fully automatic controlled, mechanically automated spraying coating line is used. The longitudinal beam-like workpieces are arranged in parallel on the roller bed of the conveyor line at a fixed distance by the electromagnetic suction cups of the stamping line. The roller bed transports the workpieces arranged in parallel at a fixed distance to the entrance end of the coating line. The parallel workpieces are driven by the roller bed to be transported horizontally to the rollers with positioning in the entrance section. The workpieces run to the forward processing line along with the rollers and drives in the port area. When passing through the rollers, the workpieces are gradually transported to the conveyor chain with ejectors until the pre-treatment moisture is dried and passed through the natural cooling area. The workpieces are transported from the ejector line to the transition rollers, and then transported to the rollers with ejectors in the powder spraying area through the transition rollers. The workpieces move forward at a uniform speed. After the powder spraying operation is completed, they are transported by rollers to the conveyor chain with ejectors similar to the conveyor chain with ejectors to transport the workpieces from the powder spraying area to the powder leveling drying area. After strong cooling, the conveyor chain transports the workpiece to the end of the coating line. After identification, the system transports the longitudinal beams to the three-dimensional warehouse for storage through the rollers, and then the information system selects them to enter the next process.

[0028] This design is designed as an assembly line coating equipment according to the process flow. The process flow is: loading → electromagnetic suction cups place the arranged longitudinal beams in parallel onto the roller table → pre-treatment entrance → the longitudinal beams are driven by the roller table and are transmitted to the ejector conveyor line on the inlet transition area through the positioned drive under the roller table → pre-degreasing → draining → degreasing → draining → water washing 1 → draining → water washing 2 → draining → surface conditioning → draining → phosphating → draining → water washing 3 → draining → water washing 4 → draining → pure water washing 1 → draining → water drying → natural cooling → the longitudinal beams are transferred from the first stage ejector conveying to powder spraying via the positioning roller → leveling → powder drying → powder forced cooling → transported to the exit section by the second stage ejector conveyor chain → transported to the roller bed at the exit section by the ejector conveyor chain → scanning, automatic coding and labeling → the roller bed drives the longitudinal beams from the roller table to the unloading area.

[0029] (1) Pretreatment process The pretreatment system consists of pre-degreasing area, degreasing area, water washing area 1, water washing area 2, surface conditioning area, phosphating area, water washing area 3, water washing area 4, and pure water washing area. The drainage and water blowing before and after each pretreatment process, as well as the tap water, pure water supply pipelines and valves of each pretreatment tank are included in this process.

[0030] In order to facilitate feeding and realize automatic continuous online feeding, the pre-degreasing, degreasing, surface conditioning, and phosphating tanks are each equipped with an automatic feeding system, which can realize automatic feeding through the central control system and manual feeding of a single machine. The pre-treatment agent is a liquid agent, which is directly added to the auxiliary tank through the automatic feeding system. The feeding system consists of a metering pump, a reagent feeding pipeline, a valve, etc. The agent is a liquid and can be directly added from the medicine barrel. The metering pump for feeding runs stably and measures accurately. A temporary storage room, storage rack, and storage box for auxiliary materials are set up near the production line (at least to meet the storage of agents required for continuous production of 2 shifts). The online feeding system can record the time and quantity of each feeding and make statistics according to shift, day, and weekly production.

[0031] The longitudinal beam coating does not include electrophoresis. During the pre-treatment design process, after comparing the two processes of silane film treatment and phosphating film treatment, it was found that the film thickness of the silane film treatment was thinner, and it was difficult for the frame longitudinal beam to meet the salt spray resistance requirements and surface finishing.

[0032] Phosphate grains are dendritic, needle-shaped, and have many pores. As the phosphating time increases, the needle-shaped crystals slowly grow into spherical crystals, and then form a stable, thick film. In this process, the film treatment adopts the spray mode, and the selection and comparison of the schemes are investigated many times. Finally, the phosphating liquid is used, which can make the salt spray resistance of the longitudinal beam reach 600 hours, meeting the requirements.

[0033] (2) Moisture drying furnace It is particularly important to dry the moisture after pre-treatment. Considering the requirements of the powder spraying process on the material surface, the material needs to be dried and its surface temperature cooled before powder spraying. If the moisture on the material surface is not completely dried, the moisture will continue to evaporate during the powder curing stage, forming bulges. At the same time, it will also cause uneven surface, resulting in reduced quality of painted parts and difficulty in meeting factory requirements.

[0034] The moisture drying and forced cooling system consists of a drying chamber and a forced cooling chamber. It consists of a chamber body, a gas heating device, hot air sealing, internal and external air ducts, and a forced cooling chamber air supply and exhaust system. The area from moisture forced cooling to the powder spraying room is designed as a natural cooling transition zone.

[0035] (3) Powder spraying equipment The powder spraying system consists of a powder spraying room, spray gun and control system, automatic powder recovery system, automatic powder supply system, compressed air purification system and transition zone, etc. The powder spraying room adopts an inner and outer double-layer structure. The inner layer of the powder spraying room is made of plastic materials such as polypropylene that does not absorb powder coatings. The powder spraying room is required to be easy to clean and occupy a small space.

[0036] (4) Powder drying furnace After the powder spraying is completed, it enters the drying area through the powder leveling area. The drying and curing consists of a heating area and a heat preservation area. The heating area adopts far-infrared radiation heating, and the heat preservation area adopts hot air circulation. After many investigations and discussions, the powder type is confirmed, and the drying time and drying temperature are determined. Infrared radiation heating and gas combustion hot air convection insulation mode are adopted. The drying and curing chamber consists of a chamber body, a far-infrared heating system, a gas heating device, a hot air seal, an internal air duct, an external air duct, an exhaust gas purification device, and a forced cold chamber supply and exhaust system.

[0037] The drying temperature can be automatically controlled and manually set, with automatic digital display and automatic recording to ensure that the drying temperature meets the process requirements (two temperature probes are set in the heating zone and six temperature probes are set in the insulation zone to ensure that the actual temperature in the heating zone is within the range of ±10°C of the set temperature, and the actual temperature in the insulation zone is within the range of ±5°C of the set temperature). A detailed drying temperature control screen is designed in the HMI, such as the maximum temperature, minimum temperature, current temperature and process temperature. The process temperature can be set manually or remotely through the information system. An automatic alarm is issued when the real-time temperature of the drying furnace is higher than the maximum temperature or lower than the minimum temperature.

[0038] (5) Conveying equipment The conveying system is mainly composed of conveying chains, chain plates, ejectors, drive devices, guide devices, transition conveying devices and electrical control systems. The longitudinal beam powder spraying line adopts chain plate + ejector conveying method. The spacing between the chain plates and ejectors is reasonably arranged to meet the conveying requirements of various specifications of workpieces in the product definition. The conveying system of the entire line is mainly divided into three sections: pre-treatment section (feeding area-pre-treatment processes-moisture drying area), powder spraying section (powder spraying room-transition zone before curing area), drying and curing section (transition zone before curing area-drying and curing-forced cooling-unloading area). Each section uses the system belonging to this section for conveying. The conveying system is equipped with a reasonable tensioning mechanism, and the conveying speed of the conveying system in each section of the entire line must be strictly kept consistent.

[0039] (6) Waste gas treatment equipment This longitudinal beam coating line adopts powder spraying technology, and no VOC is generated in the pre-treatment drying section. No waste gas is generated in the powder spraying room, and the excess powder is reused through the powder recovery device. Generally, the waste gas generated by powder drying in existing workshops is lower than the emission standard, which is mainly related to the content of VOC components in the solid part, and is recognized as zero emission. In the powder drying furnace, a certain amount of waste gas is generated during the curing process, which is incinerated by TNV and the heat is recycled, and the discharged waste gas meets the emission standard.

[0040] (7) Intelligent applications Before the longitudinal beam enters the pre-treatment process of the powder spraying line, the automatic scanning device completes the automatic scanning of the longitudinal beams arranged in parallel, and accurately transmits the longitudinal beam specifications and models obtained by scanning to the automatic coding and pasting device of the unloading process in sequence through the line body master control system. After the longitudinal beam completes each powder spraying process, the automatic coding and pasting device automatically codes and pastes the QR code according to the longitudinal beam specifications and models obtained by scanning. The workpiece enters the offline conveying system, which quickly completes the offline process and ensures that it does not affect the subsequent longitudinal beam discharge.

[0041] The transmission rate between processes must match the production rhythm of the previous and next processes and meet the production capacity. The connecting equipment is required to have good protection for the appearance of the longitudinal beam, and the longitudinal beam cannot be deformed, collided or scratched during the transmission process.

[0042] The coating line of the present invention with full automatic control and mechanical automatic spraying is particularly suitable for the automatic transmission system of the large-scale coating production line of the frame longitudinal beam and auxiliary beam products and the coating equipment conforming to the process characteristics of the frame longitudinal beam and auxiliary beam products.

[0043] The parts to be sprayed in this operation area are mainly longitudinal beams, sub-beams, longitudinal beam assemblies, cross beams (including cross beam assemblies) and small parts of various series of frames, with longitudinal beams and sub-beams being the main coating objects.

[0044] The suction cup sends the longitudinal beam to the conveyor chain with ejector pins. The longitudinal beam undergoes pre-treatment and moisture drying process on the conveyor plate chain with ejector pins, and is transferred to the powder spraying room. After the powder spraying process is completed, it is transferred to the plate chain and transported to the powder leveling and powder drying furnace to complete the entire coating process. After the powder is forced cooled, the ejector plate chain is transported to the roller area for segmentation and then to the bending area or storage area.

[0045] Brief description of the process flow: 1) The inter-process conveying system conveys the aligned main beam or reinforcing beam to the loading and conveying device on the longitudinal beam powder spraying line. 2) The loading and conveying device on the powder spraying line simultaneously conveys multiple main beams / reinforced beams to the longitudinal beam powder spraying line. When the tail end of the main beam / reinforced beam leaves the loading and conveying device, the inter-process conveying system will reload in time. 3) Before the longitudinal beam enters the pre-treatment process of the powder spraying line, the automatic scanning device completes the automatic scanning of the main beam or reinforcing beam, and accurately transmits the longitudinal beam specifications and models obtained by scanning to the automatic coding and labeling device of the unloading process through the line body master control system according to the sequence requirements. 4) The longitudinal beam undergoes spray pre-treatment, moisture drying, automatic powder spraying, drying and curing, strong cooling and other processes in turn to complete the powder spraying production. 5) After the longitudinal beam completes each powder spraying process, the automatic coding and labeling device automatically codes and pastes the QR code according to the longitudinal beam specifications and models obtained by scanning. 6) The workpiece enters the offline conveying system, and the offline conveying system quickly completes the offline process and ensures that it does not affect the subsequent main beam / reinforced beam discharge. In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0046] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0047] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A fully automatic coating method for frame longitudinal beams and sub-beams, characterized in that: The following steps are involved: The longitudinal beam workpieces arranged in parallel at a fixed distance are placed on the roller bed of the conveyor line through electromagnetic suction cups; the workpieces are transported horizontally to the rollers with positioning in the entrance section; pre-treatment, moisture drying, natural cooling, powder spraying, leveling, powder drying and powder forced cooling treatment are carried out in sequence; the processed workpieces are transported to the exit section for scanning, automatic coding and labeling; the workpieces are transported to the unloading area or three-dimensional warehouse storage through rollers.

2. The fully automatic coating method for frame longitudinal beams and auxiliary beams according to claim 1 is characterized in that: The pretreatment steps include: pre-degreasing, degreasing, first water washing, second water washing, surface conditioning, phosphating, third water washing, fourth water washing and pure water washing, and drainage and water blowing treatment are arranged between each process.

3. The fully automatic coating method for frame longitudinal beams and sub-beams according to claim 1 is characterized in that: In the pre-degreasing, degreasing, surface conditioning and phosphating processes, an automatic feeding system is used to replenish liquid reagents. The system automatically feeds through a central control system or manually feeds a single machine.

4. The fully automatic coating method for frame longitudinal beams and sub-beams according to claim 1 is characterized in that: The moisture drying step is carried out in a combination of a drying chamber and a forced cooling chamber. The drying chamber is composed of a gas heating device, a hot air seal, and internal and external air ducts, and the forced cooling chamber is provided with an air supply and exhaust system.

5. The fully automatic coating method for frame longitudinal beams and sub-beams according to claim 1 is characterized in that: The powder spraying step is carried out in a powder spraying room, which adopts an inner and outer double-layer structure, and the inner layer is made of plastic materials such as polypropylene that do not absorb powder coatings.

6. The fully automatic coating method for frame longitudinal beams and sub-beams according to claim 1, characterized in that: The powder drying step includes a heating zone and a heat preservation zone, wherein the heating zone adopts far infrared radiation heating, and the heat preservation zone adopts hot air circulation.

7. The fully automatic coating method for frame longitudinal beams and sub-beams according to claim 6 is characterized in that: In the powder drying step, the drying temperature is monitored in real time by a temperature probe, the temperature in the heating zone is controlled within the range of ±10°C of the set temperature, and the temperature in the insulation zone is controlled within the range of ±5°C of the set temperature.

8. The fully automatic coating method for frame longitudinal beams and sub-beams according to claim 1, characterized in that: The conveying method combines chain plates and ejectors. The entire coating line is divided into three independent conveying systems: pre-treatment section, powder spraying section and drying and curing section.

9. The fully automatic coating method for frame longitudinal beams and sub-beams according to claim 1, characterized in that: The waste gas generated during the powder drying process is treated by TNV incineration.

10. The fully automatic coating method for frame longitudinal beams and sub-beams according to claim 1, characterized in that: Before the workpiece enters the pre-processing process, the parallel arranged longitudinal beams are automatically scanned by the automatic scanning device, and the scanned code information is transmitted to the automatic coding and labeling device of the unloading process to realize the intelligent tracking and identification of the workpiece.

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