Intelligent sand mold spraying process method and system

Abstract

The invention relates to an intelligent sand mold spraying process method and system, and belongs to the technical field of mechanical manufacturing automation. Functions are achieved by integrating a six-axis spraying robot, a visual positioning system, a special pit spraying device and an automatic conveying module, and the method specifically comprises the steps that a sand mold workpiece is conveyed to a work station, and a code scanning device recognizes workpiece information and calls a pre-stored digital model; a robot tail end vision device scans the workpiece to generate a dynamic deviation rectifying track, and a paint conveying and mixing system is combined to mix paint to complete cavity surface spraying; for a pit area, a Z-axis mechanical arm is adopted to drive a spray gun to revolve and rotate around the axis, and precise coating in a narrow space is achieved in cooperation with micro-motion telescopic adjustment; and after spraying, the ignition device quickly dries, and the isolation device ensures that the spray gun and flame are safely interlocked. According to the scheme, the coating uniformity and the pit coverage degree are remarkably improved, meanwhile, manual intervention and potential safety hazards are reduced, and the industrial bottlenecks that in traditional spraying, quality fluctuation is large, and special-shaped structures are difficult to treat are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of mechanical manufacturing automation, and relates to a sand mold intelligent spraying process method and system. Background Art

[0002] In the foundry industry, sand mold cavity spraying is a crucial link in the casting process, which directly affects the surface quality of castings and production efficiency. At present, traditional sand mold spraying operations mainly rely on manual operation, and workers use handheld spray guns to coat the sand mold cavity. However, this method has significant defects: First, the paint mist and volatile organic compounds generated during the spraying process pose a serious threat to the health of operators, and long-term exposure may lead to occupational diseases; second, the quality of manual spraying is highly dependent on the workers' skill level and working status, resulting in frequent problems such as uneven coating thickness, local sagging or spray leakage. Especially for complex and special-shaped surfaces (such as pits, deep holes, etc.), it is difficult to accurately control the angle and distance of the spray gun manually, which further aggravates quality fluctuations; third, the production efficiency is low, it is difficult to meet the needs of large-scale continuous production, and the waste of paint is serious, which increases production costs.

[0003] In recent years, some companies have attempted to replace manual labor with automated equipment, such as using fixed robotic arms for spraying. However, existing automation solutions still have significant limitations: First, the rigid motion trajectory of traditional robotic arms makes it difficult to adapt to the dimensional differences and positioning deviations of sand mold workpieces, requiring frequent manual program adjustments and failing to achieve flexible production. Second, due to structural limitations, conventional spraying equipment cannot penetrate deep into narrow spaces such as pits and deep holes in sand mold cavities, resulting in substandard coating results in these areas, requiring subsequent manual re-spraying. Furthermore, existing equipment lacks efficient drying and safety protection mechanisms, and the spraying and ignition processes are not effectively isolated, posing a risk of accidental ignition of flammable coatings and presenting significant safety hazards.

[0004] In terms of paint management, existing technologies mostly use open paint supply systems. The viscosity of the paint is significantly affected by the ambient temperature and humidity, which can easily lead to fluctuations in spray parameters. Incomplete pipe cleaning can also cause problems such as paint residue and clogged spray guns. At the same time, the collection and treatment capacity of spray exhaust gas is insufficient, and the concentration of harmful substances in the working environment exceeds the standard, which not only affects the life of the equipment but also poses a potential threat to the health of operators. Although a few documents mention the use of visual recognition technology to assist positioning, in actual applications, the dusty environment has a significant impact on the accuracy of the sensor, and there is a lack of dedicated correction algorithms for sand mold features, resulting in the reliability and adaptability of the automation system being difficult to meet industrial needs.

[0005] In summary, existing sand mold spraying technology, whether in manual operation or preliminary automation stage, faces multiple challenges such as health hazards, unstable quality, low efficiency, insufficient ability to handle complex structures, and safety hazards. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a highly integrated and intelligent spraying solution that can achieve unmanned operation throughout the entire process while ensuring coating quality, while having high adaptability to special-shaped structures and environmental friendliness, thereby promoting the transformation and upgrading of the casting industry towards a green, efficient and intelligent direction.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A sand mold intelligent spraying process method comprises the following steps:

[0009] (a) Transporting the sand mold workpiece to the intelligent spraying workstation, identifying the workpiece information and calling the preset digital model data;

[0010] (b) Scan the actual position and key points of the sand mold workpiece and generate the initial spraying trajectory based on the digital model data;

[0011] (c) spraying the surface of the sand mold cavity according to the trajectory and drying the coating;

[0012] (d) The truss three-axis manipulator drives the pit-specific spraying system into the sand mold pit area, adjusts the angle and position of the spray gun, and completes the pit cavity spraying and drying;

[0013] (e) The sprayed sand mold workpiece is transported to the next process, and the complex special-shaped surfaces are manually sprayed.

[0014] Optionally, the spraying process in step (c) includes:

[0015] The paint delivery and mixing system automatically mixes paint according to preset parameters;

[0016] The spray gun is connected to the paint delivery system through a high-pressure pipeline, and the spraying pressure and flow are controlled by the PLC program;

[0017] The ignition device and the spray gun are electrically interlocked, and spraying and drying are performed in stages.

[0018] Optionally, the pit-specific spraying system in step (d) includes:

[0019] The Z-axis rectangular coordinate manipulator drives the spray gun to move along the depth direction of the pit;

[0020] Servo rotary device controls the revolution and rotation of the spray gun around the center of the pit;

[0021] Micro-motion telescopic device to adjust the distance between the spray gun and the spraying surface.

[0022] Optional features include: ventilation system and paint mist collection device to process spraying exhaust gas in real time; constant humidity system to maintain workstation environmental parameters to ensure stable coating quality.

[0023] An intelligent sand mold spraying system, used in the above method, is characterized by comprising:

[0024] A six-axis spraying robot with an integrated visual recognition device, spray gun, and ignition device at the end;

[0025] The truss three-axis manipulator drives the special spraying system for pits to spray the pits;

[0026] RGV system, used for automatic conveying of sand mold workpieces;

[0027] The paint delivery system is connected to the spray gun through a high-pressure pipeline;

[0028] The master control system coordinates each component to perform spraying, drying and deviation correction operations.

[0029] Optionally, a safety isolation device is included to physically isolate the spray gun from the ignition device and control the start and stop through electrical interlocks.

[0030] Optionally, a fully enclosed explosion-proof cover is provided at the end of the six-axis spraying robot, in which a spray gun and an ignition device are integrated, and the two are separated by a partition.

[0031] Optionally, a code scanning device is also included, which is installed at the entrance of the workstation and is used to read the RFID tag of the sand mold workpiece.

[0032] Optionally, a laser displacement sensor is also included, which is arranged in the visual recognition device and is used to generate workpiece correction data.

[0033] Optionally, the paint delivery and mixing system includes:

[0034] High-pressure plunger pump, connected to the spray gun through a stainless steel pipe;

[0035] Air-controlled switching valve group to control the flow direction of paint;

[0036] Cleaning bucket and cleaning pump are used for automatic cleaning of pipelines.

[0037] This solution achieves a comprehensive intelligent upgrade of sand mold spraying operations through innovative structural design and process integration. Its beneficial effects are significantly reflected in the following dimensions:

[0038] 1. Improve spraying quality and consistency

[0039] Through the synergy of the six-axis spraying robot and the visual recognition system, this solution effectively solves the problems of uneven coating thickness, sagging or spray leakage caused by operational fluctuations in manual spraying. The visual recognition device integrated at the end of the robot can scan the actual position and cavity characteristics of the sand mold workpiece in real time, and generate a dynamic correction trajectory based on the preset digital model data to ensure that the spray gun is always close to the cavity surface at the optimal distance and angle. For complex pit structures, the pit-specific spraying system uses vertical feeding, revolution / rotation linkage and precise adjustment functions to enable the spray gun to penetrate into narrow spaces and adaptively adjust its posture, avoiding the spraying blind spots caused by insufficient freedom of movement of traditional equipment. In addition, the introduction of a constant temperature and humidity system stabilizes the viscosity of the paint and environmental parameters, further ensuring the uniformity of the coating quality and process stability.

[0040] 2. Significantly improve production efficiency and flexibility

[0041] This solution adopts a modular design. Through the linkage of an automatic conveying system, a truss manipulator, and a six-axis robot, it achieves fully automatic conveying, positioning, and spraying of sand mold workpieces. The combination of the automatic conveying system and the code scanning and recognition device can quickly identify different types of sand molds and call the corresponding spraying program, significantly reducing the time for changeovers and adjustments. The multi-axis motion capability of the truss system enables the robot to cover the entire surface of large-scale workpieces, while the independent operation modules of the pit-specific spraying system can process complex areas in parallel, significantly improving overall production efficiency compared to manual operation. At the same time, the system's flexible design supports the needs of multi-variety and small-batch production. Different sand mold specifications can be adapted through software parameter adjustments, avoiding the frequent hardware modifications caused by the rigid structure of traditional equipment.

[0042] 3. Enhance operational safety and environmental protection

[0043] This solution has been systematically optimized in terms of safety protection and environmental protection. The spray gun and ignition device are completely isolated by physical partitions, and an electrical interlocking design is adopted to ensure that spraying and drying are carried out in stages, completely eliminating the risk of accidental ignition of flammable paint. The fully enclosed explosion-proof cover at the end of the robot further blocks the direct contact between the flame and the paint. Combined with the efficient operation of the ventilation system and paint mist collection device in the workstation, the concentration of harmful substances in the exhaust gas can be reduced to below the national standard, significantly improving the working environment. In addition, the paint delivery and mixing system uses closed high-pressure pipelines and automatic cleaning functions to avoid paint volatilization and residue, which not only reduces resource waste but also reduces volatile organic compound emissions, in line with the development trend of green manufacturing.

[0044] 4. Reduce labor costs and operational complexity

[0045] Through full-process automation, this solution significantly reduces reliance on skilled workers. Positioning, spraying, and re-spraying, which traditionally require the collaboration of multiple workers in spraying operations, are now completed autonomously by robots, requiring only a small number of personnel to monitor system operation or process extremely complex surfaces. The combination of visual correction algorithms and preset programs enables the system to "teach once, reuse multiple times." Even when faced with sand mold workpieces with slight positioning deviations, it can still automatically correct the trajectory without manual intervention. In addition, the intelligent management of the paint delivery system (such as automatic paint mixing and self-cleaning of pipelines) further simplifies the operating process and reduces maintenance difficulty and training costs.

[0046] 5. Breakthrough in the technical bottleneck of special-shaped structure spraying

[0047] In response to the long-standing problem of spraying special-shaped structures such as pits and deep holes in the industry, this solution has achieved a technological breakthrough through a dedicated device. The servo rotation function of the pit-specific spraying system can drive the spray gun to perform compound motion around the pit axis, and with the millimeter-level displacement adjustment, it ensures that the nozzle and the curved surface always maintain a constant process distance. The design of the eccentric adjustment mechanism further expands the coverage of the spray gun, enabling it to adapt to pits of different diameters and depths. Compared with traditional robots that are limited by kinematic singularities and insufficient degrees of freedom, this device achieves high-precision and high-stability spraying operations in a narrow space through the innovation of non-standard mechanical structure, filling the technical gap in the industry.

[0048] 6. Extend equipment life and reliability

[0049] This solution significantly improves equipment durability through structural optimization and intelligent monitoring. For example, the truss system's guide rails and wear-resistant materials reduce mechanical wear; the paint delivery system's high-pressure pump and corrosion-resistant piping withstand long-term high-pressure operation. Furthermore, the master control system monitors the operating status of key components (such as spray gun pressure, motor temperature, and ambient temperature and humidity) in real time, and uses an early warning mechanism to proactively eliminate potential faults, ensuring the long-term stable operation of the equipment.

[0050] In summary, this solution has achieved comprehensive breakthroughs in quality, efficiency, safety, environmental protection, and adaptability through multi-dimensional structural innovation and process integration. It not only provides a feasible intelligent solution for the foundry industry, but also provides a technical template for automation upgrades in the field of high-end equipment manufacturing.

[0051] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0053] Figure 1 This is the process flow chart of this scheme;

[0054] Figure 2 This is a first-person perspective diagram of this scheme;

[0055] Figure 3 This is a second perspective diagram of this scheme;

[0056] Figure 4 This is a third-perspective diagram of this scheme.

[0057] Figure numerals: 1 workpiece conveying system, 2 sand mold workpiece, 3 precision truss system, 4 main drag chain system, 5 maintenance walkway, 6 center hole spraying special system, 7 lifting drag chain system, 8 lifting guide system, 9 main spraying robot, 10 ignition (spray drying) device, 11 robot paint spray gun, 12 ignition isolation device, 13 electrical system, 14 code scanning device, 15 center hole paint special spray gun, 16 ignition isolation device, 17 paint delivery and mixing system. DETAILED DESCRIPTION

[0058] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0059] Among them, the accompanying drawings are only for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting the present invention. In order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the dimensions of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the accompanying drawings.

[0060] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "back", etc. indicating directions or positional relationships, they are based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0061] See also Figures 1 to 4 This solution realizes the intelligent spraying operation of sand mold workpieces through the following steps. The specific implementation methods are as follows:

[0062] 1. Workpiece transportation and identification

[0063] The sand mold workpiece 2 is automatically transported along the track by an external RGV vehicle in the workpiece conveyor system 1 to the entrance of the intelligent spraying workstation. The RGV places the sand mold workpiece 2 and its bracket on the cleaning table and then exits the workstation. The barcode scanner 14 scans the RFID tag on the bracket to read the type information of the sand mold workpiece 2. Based on the recognition result, the workstation control system automatically calls the pre-stored 3D digital model data of the sand mold.

[0064] 2. Visual positioning and trajectory generation

[0065] The visual recognition device at the end of the main spraying robot 9 scans the sand mold workpiece 2, acquiring the workpiece's actual position and key coordinates using a laser displacement sensor. The workstation information system matches the scanned data with a pre-stored digital model to automatically generate an initial spray trajectory. For the first sand mold workpiece 2 processed, the operator can make minor manual corrections based on the initial trajectory. The corrected trajectory data is stored in the system for direct access for subsequent similar workpieces.

[0066] 3. Spraying and drying of cavity surface

[0067] After the paint delivery system 17 is started, the high-pressure plunger pump will transport the prepared paint to the robot paint spray gun 11 through the stainless steel pipeline. The main spray robot 9 moves along the transverse track of the precision truss system 3 to the spraying starting point, and sprays at a preset speed and paint pressure according to the generated trajectory. During the spraying process, the main drag chain system 4 controls the synchronous movement of the transverse track, and the lifting drag chain system 7 drives the lifting guide system 8 to vertically adjust the height of the robot to ensure that the spray gun 11 maintains a constant distance from the cavity surface. After the spraying is completed, the ignition device 10 at the end of the main spray robot 9 is started to quickly dry the coating. The flame intensity is regulated by the electrical system 13. At the same time, the ignition isolation device 12 physically isolates the spray gun 11 from the ignition area to prevent cross ignition.

[0068] 4. Special spraying for pit cavity

[0069] For the pit or deep hole area of the sand mold workpiece 2, the dedicated system 6 for center hole spraying is started. The lifting and guiding system 8 drives the Z-axis rectangular coordinate manipulator to carry the dedicated center hole paint spray gun 15 down to the pit entrance. The servo rotary device drives the spray gun 15 to revolve and rotate around the axis of the pit, while the micro-motion telescopic device adjusts the insertion depth of the spray gun 15 so that the nozzle always maintains the optimal spraying distance with the inner wall of the pit. The eccentric adjustment mechanism automatically adjusts the offset angle of the spray gun 15 according to the pit diameter to ensure uniform coverage of the paint. After the spraying is completed, the ignition isolation device 16 isolates the spray gun 15 from the ignition device 10, and the latter performs local drying of the pit coating.

[0070] 5. Safety protection and environmental control

[0071] The workstation's ventilation system operates continuously, directing paint mist generated by spraying to a paint mist collection device 13 for centralized treatment. Exhaust gases are then purified and discharged. A constant temperature and humidity system maintains stable temperature and humidity within the workstation to prevent fluctuations in paint viscosity. The cleaning pump in the paint delivery and mixing system 17 regularly flushes the pipelines with high pressure to prevent paint residue from clogging the spray guns. A maintenance walkway 5 is located to the side of the truss system 3 to facilitate equipment maintenance and manual re-spraying operations.

[0072] 6. Workpiece transfer and process closed loop

[0073] After spraying and drying are complete, the RGV vehicle of workpiece transport system 1 reenters the workstation and transports the sand mold workpiece 2 and the bracket to the next process. For a few complex, irregularly shaped surfaces, operators enter the workstation via maintenance walkway 5 and use a manual spray gun to perform localized re-spraying. This re-spraying data is fed back to the system to optimize subsequent automated trajectories.

[0074] Description of key component connection relationships

[0075] The workpiece conveying system 1 includes a track and an RGV vehicle, which is linked to the code scanning device 14 through electrical signals;

[0076] The longitudinal track of the precision truss system 3 is connected to the main drag chain system 4, and two sets of slides are installed on the transverse track to fix the lifting drag chain system 7 and the lifting guide system 8 respectively;

[0077] The main spraying robot 9 is fixed to the bottom of the lifting guide system 8 by bolts, and its end is integrated with a robot paint spray gun 11, a visual recognition device and an ignition device 10;

[0078] The center hole spraying system 6 is rigidly connected to the bottom of the lifting guide system 8, and the center hole paint spray gun 15 is connected to the paint delivery system 17 through a high-pressure hose;

[0079] The paint delivery and mixing system 17 includes a paint bucket, a constant temperature device, a filter and a cleaning pump, which are respectively connected to the robot paint spray gun 11 and the center hole paint special spray gun 15 through stainless steel pipes.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should all be included in the scope of the claims of the present invention.

Claims

1. A sand mold intelligent spraying process method, characterized in that: The following steps are involved: (a) transporting the sand mold workpiece (2) to the intelligent spraying workstation, identifying the workpiece information and calling the preset digital model data; (b) scanning the actual position and key points of the sand mold workpiece (2) and generating an initial spraying trajectory in combination with the digital model data; (c) spraying the surface of the sand mold cavity according to the trajectory and drying the coating; (d) The truss three-axis manipulator (3) drives the dedicated pit spraying system (6) into the sand mold pit area, adjusts the angle and position of the spray gun, and completes the pit cavity spraying and drying; (e) The sprayed sand mold workpiece (2) is transported to the next process, and the complex special-shaped curved surface is manually sprayed again.

2. The process according to claim 1, characterized in that: The spraying process described in step (c) comprises: The paint delivery and mixing system (17) automatically mixes the paint according to preset parameters; The spray gun (11) is connected to the paint delivery system (17) through a high-pressure pipeline, and the spraying pressure and flow are controlled by a PLC program; The ignition device (10) and the spray gun (11) are electrically interlocked, and spraying and drying are performed in stages.

3. The process according to claim 1, characterized in that: The pit-specific spraying system (6) in step (d) comprises: A Z-axis rectangular coordinate manipulator drives the spray gun (15) to move along the depth direction of the pit; A servo rotary device controls the spray gun (15) to revolve and rotate around the center of the pit; The micro-movement telescopic device adjusts the distance between the spray gun (15) and the spraying surface.

4. The process according to claim 1, characterized in that: Also includes: The ventilation system and paint mist collection device (13) process the spraying waste gas in real time; The constant humidity system maintains the workstation environmental parameters to ensure stable coating quality.

5. A sand mold intelligent spraying system, used to implement the method according to any one of claims 1 to 4, characterized in that: include: A six-axis spraying robot (9) having a visual recognition device, a spray gun (11) and an ignition device (10) integrated at its end; A truss three-axis manipulator (3) drives a special spraying system (6) for the pits to spray the pits; RGV system (1) for automatic conveying of sand mold workpieces (2); A paint delivery system (17) is connected to the spray guns (11, 15) via a high-pressure pipeline; The master control system coordinates each component to perform spraying, drying and deviation correction operations.

6. The sand mold intelligent spraying system according to claim 5, characterized in that: The invention also comprises a safety isolation device (12, 16) for physically isolating the spray gun (11, 15) from the ignition device (10), and controlling the start and stop through electrical interlocking.

7. The sand mold intelligent spraying system according to claim 5, characterized in that: A fully enclosed explosion-proof cover is provided at the end of the six-axis spraying robot (9), wherein a spray gun (11) and an ignition device (10) are integrated in the cover, and the two are separated by a partition (12).

8. The sand mold intelligent spraying system according to claim 5, characterized in that: It also includes a code scanning device (14) installed at the entrance of the workstation and used for reading the RFID tag of the sand mold workpiece (2).

9. The sand mold intelligent spraying system according to claim 5, characterized in that: It also includes a laser displacement sensor, which is arranged in the visual recognition device and is used to generate workpiece correction data.

10. The sand mold intelligent spraying system according to claim 5, characterized in that: The paint delivery system (17) comprises: A high-pressure plunger pump connected to a spray gun (11, 15) via a stainless steel pipe; Air-controlled switching valve group to control the flow direction of paint; Cleaning bucket and cleaning pump are used for automatic cleaning of pipelines.

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