Automated assembly method and device for a plastic front hood of a motor vehicle

Abstract

The application relates to an automatic assembly method and device for a plastic front engine cover of an automobile, and relates to the field of automatic equipment, which comprises collecting inner plate image information and outer plate image information; generating a relative running track on an engine cover outer plate according to the inner plate image information, inner plate glue coating grooves and the outer plate image information; wiping the inner plate glue coating grooves of the engine cover inner plate and controlling a preset baking mechanism to bake along a processing running track; controlling the baking mechanism to bake the engine cover outer plate along the relative running track to soften the surface, and synchronously controlling a preset air jet mechanism to carry dry ice powder along the relative running track by high-pressure airflow to generate fine and dense micropores; after the air jet is completed, controlling the baking mechanism to bake twice along the relative running track to expand the micropore aperture, and controlling a preset glue coating mechanism to coat glue along the relative running track. The application has the effects of improving the production efficiency and production quality of the plastic front engine cover of the automobile.

Description

Technical Field

[0001] This invention relates to the field of automated equipment, and in particular to an automated assembly method and apparatus for a plastic front hood for automobiles. Background Technology

[0002] The plastic front hood of an automobile is mainly composed of an inner hood panel and an outer hood panel bonded together. It has comprehensive properties such as weight reduction, noise reduction, and protection, and is widely used in the production and assembly processes of various passenger cars and new energy vehicles.

[0003] The traditional method for assembling and bonding plastic hoods in the industry is as follows: workers manually apply structural adhesive to the bonding area between the inner and outer hood panels beforehand. After the adhesive is applied, the inner and outer hood panels are transferred to the hydraulic processing station, where constant pressure is applied by hydraulic equipment to press and bond the two panels together, thus completing the assembly of the plastic hood.

[0004] However, manual gluing has a limited coating rate, and gluing a single piece of plastic hood takes a long time, making it difficult to keep up with the high-speed production pace of automated production lines, resulting in low overall production efficiency. Manual gluing also lacks precision, as operators have difficulty accurately controlling the coating position, glue thickness, and glue line uniformity, which easily leads to problems such as glue deviation, uneven glue layer thickness, local glue leakage, and glue overflow, resulting in low bonding quality of the inner and outer hood panels. Summary of the Invention

[0005] To improve the production efficiency and quality of automotive plastic front hoods, this invention provides an automated assembly method and apparatus for automotive plastic front hoods.

[0006] In a first aspect, the present invention provides an automated assembly method for automotive plastic front hoods, employing the following technical solution: An automated assembly method for a car plastic front hood includes: The inner and outer panels of the hood are placed on a pre-set processing table and fixed, and the inner panel image information and the outer panel image information of the hood are collected. The vertex of the inner panel is identified from the inner panel image information and used as a reference feature point. The glue-coating groove of the inner panel is identified from the inner panel image information and a processing trajectory is generated based on the glue-coating groove of the inner panel. The trajectory position information is generated based on the relative positional relationship between the reference feature points and the processed trajectory. Identify reference feature points corresponding to reference feature points from the outer panel image information, and generate the relative running trajectory on the outer panel of the hood based on the reference feature points and trajectory position information; Wipe the inner panel adhesive groove of the hood inner panel and control the preset baking mechanism to bake along the processing trajectory; The control baking mechanism bakes the outer panel of the hood along a relative running trajectory to soften the surface, and simultaneously controls the preset jet mechanism to spray dry ice powder with high-pressure airflow along the relative running trajectory to generate fine micropores. After the jetting is completed, the baking mechanism is controlled to perform a second baking along the relative running trajectory to expand the micropore diameter, and the preset glue coating mechanism is controlled to apply glue along the relative running trajectory. After applying the adhesive, overlap the inner and outer hood panels and control the preset clamping mechanism to press and bond them together.

[0007] By adopting the above technical solution, the gluing and pressing process of the car's front hood is fully automated. The only manual task is to transfer the glued front hood to the pressing mechanism, thereby significantly improving production efficiency. Furthermore, before gluing, the outer hood panel is pre-treated by a combination of a baking mechanism and a jetting mechanism, which creates fine micropores on the surface of the outer hood panel. When structural adhesive is applied, it can penetrate into the micropores, and after curing, it greatly improves the bonding strength between the outer and inner hood panels, thereby improving the bonding quality of the car's front hood.

[0008] Optionally, the method for controlling the baking mechanism to bake the outer panel of the hood along a relative running trajectory includes: The required bonding strength is retrieved at various points on the relative running trajectory based on the preset hood structure model. The required baking width at various points along the relative running trajectory is matched according to the required bonding strength. The vertical height distance between the baking mechanism and the outer hood panel is matched based on the required baking width. When the baking mechanism bakes the outer hood panel along the relative running trajectory, the height of the baking mechanism is controlled in real time according to the vertical height distance.

[0009] By adopting the above technical solution, the vertical height distance between the baking mechanism and the outer panel of the hood can be controlled in real time, thereby precisely controlling the width of the baking surface generated by the baking mechanism when baking the outer panel of the hood, so as to facilitate precise application of adhesive on the baking surface in the future.

[0010] Optionally, the method of using a jet mechanism to carry dry ice powder with a high-pressure airflow includes: The temperature at the nozzle position of the baking mechanism is collected in real time while moving along the relative running trajectory, and the baking path image is also collected. The actual baking width value is determined by analyzing the pre-defined baking color darkening surface features in the path baking image; The jet span distance of the jet mechanism is matched based on the actual width value of the baking process; The jet interval time is matched when the jet mechanism performs pulse jetting based on the jet span distance and the preset robotic arm moving speed. The jet mechanism is activated only when the nozzle temperature is not lower than the preset baking temperature. The jet mechanism is set with jet interval time and jet span distance and pulse jet is performed.

[0011] By adopting the above technical solution, when the jetting mechanism sprays air, a pulse jetting method is used, which makes it easier to control the jetting volume of the jetting mechanism and the amount of dry ice powder sprayed.

[0012] Optional methods for determining the jet span distance include: The starting area baking width of the preset pulse jet unit region is obtained by analyzing the path baking image; The initial span distance is obtained based on the baking width of the starting area and the preset jet area ratio; The maximum baking width in the relative running trajectory of the initial span distance is obtained by analyzing the path baking image; The jet span distance is obtained based on the maximum baking width matching, and the initial span distance is corrected.

[0013] Optionally, methods for determining the jet interval include: The first jet span distance and the second jet span distance between two adjacent preset pulse jet unit regions are obtained from the path baking image. The step center distance between the centers of the two pulse jet unit regions is calculated based on the first jet span distance and the second jet span distance. The jet interval time is calculated based on the stride center distance and the robotic arm's moving speed.

[0014] Optional, also includes: The non-glue trajectory is determined based on the glue-coating groove in the inner plate and the relative running trajectory. The entry and exit times of the non-adhesive-coated trajectory are determined based on the relative running trajectory, the non-adhesive-coated trajectory, and the robot arm's moving speed. The running time is recorded when the baking mechanism starts baking. When the running time matches the entry time, the jet mechanism is turned off; when the running time matches the exit time, the jet mechanism is turned back on.

[0015] By adopting the above technical solution and setting the timing of the jetting mechanism, the jetting mechanism can be shut off when the robotic arm moves to a position where adhesive application is not required, thus avoiding waste of dry ice powder.

[0016] Optionally, the method by which the glue-applying mechanism applies glue along a relative running trajectory includes: The thickness of the adhesive between the inner and outer hood panels after they are pressed together is set as the pressing thickness, and the width of the adhesive sprayed by the adhesive applicator on the outer hood panel is set as the adhesive applicator width. The required adhesive application height is calculated based on the pressing thickness and adhesive application width at each position point relative to the running trajectory when the adhesive is flattened to the required baking width; The instantaneous speed of the glue application mechanism at each position point relative to the relative running trajectory is matched according to the glue application height; A glue application speed curve is generated based on the instantaneous speed of glue application and the relative running trajectory; The center line of the relative running trajectory is used as the glue application path of the glue application mechanism; When the glue application mechanism moves along the relative running trajectory on the outer panel of the hood, the glue application mechanism is controlled to apply glue according to the glue application speed curve and glue application path.

[0017] Optional, also includes: The tilt angle of each position point relative to the running trajectory is determined based on the preset hood structure model; The path offset is determined based on the ratio of the extrusion volume on both sides of the center line of the relative running trajectory when the adhesive is pressed according to the tilt angle, and the required baking width at each position point of the relative running trajectory is determined according to the extrusion volume ratio. The glue application path is corrected by adjusting the path offset, and the updated glue application path is output.

[0018] By adopting the above technical solution, in order to adapt to the different inclined structures of various positions of the hood, the system automatically corrects the glue application path of the glue application mechanism on the outer panel of the hood, so that the structural glue is flattened and is in the path corresponding to the glue application groove of the inner panel.

[0019] Secondly, this application provides an automated assembly device for automotive plastic front hoods, employing the following technical solution: An automated assembly device for automotive plastic front hoods is controlled by an automated assembly method for automotive plastic front hoods. It includes a fixing platform for mounting an outer hood panel and an inner hood panel for applying adhesive, a robotic arm with integrated multi-processing functions, and a pressing mechanism for relatively pressing and bonding the outer hood panel and the inner hood panel. The robotic arm is integrated with a baking mechanism for baking, a jetting mechanism for spraying dry ice powder, and an adhesive applicator.

[0020] Optionally, the fixed platform is circumferentially provided with a plurality of support seats for supporting the outer or inner hood panel and a rotary pressing mechanism for pressing the outer or inner hood panel against the support seats; each support seat is provided with a positioning groove, and all the positioning grooves are combined to form a positioning area for the outer or inner hood panel to be embedded. The rotary clamping mechanism includes a clamping block and a drive component that drives the clamping block to rotate and move up and down.

[0021] In summary, this application includes at least one of the following beneficial technical effects: The process of applying adhesive and pressing the hood of a car is fully automated. The only manual task is to transfer the glued hood to the pressing mechanism, thereby greatly improving the production efficiency. Before applying the adhesive, the outer hood panel is pretreated by a combination of a baking mechanism and a jetting mechanism, which creates fine micropores on the surface of the outer hood panel. When the structural adhesive is applied to it, it can penetrate into the micropores. After curing, it greatly improves the bonding strength between the outer hood panel and the inner hood panel, thereby improving the bonding quality of the car's front hood. To accommodate the different tilted structures at various locations on the hood, the system automatically corrects the adhesive application path of the adhesive application mechanism on the outer panel of the hood, ensuring that the structural adhesive, after being flattened, is always within the path corresponding to the adhesive application groove on the inner panel. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of an automated assembly device for automotive plastic front hood according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the fixed platform according to an embodiment of the present invention; Figure 3 This is a flowchart of an automated assembly method for a plastic front hood of an automobile, according to an embodiment of the present invention.

[0023] The parts referred to by the numbers in the above attached figures are as follows: 1. Fixed platform; 11. Support base; 12. Positioning groove; 13. Rotary clamping mechanism; 131. Driving component; 132. Clamping block; 2. Robotic arm; 21. Mounting plate; 22. Baking mechanism; 23. Air jet mechanism; 24. Glue application mechanism; 3. Clamping mechanism; 31. Clamping platform; 32. Clamping plate; 33. Clamping cylinder. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0025] This application discloses an automated assembly device for automotive plastic front hoods.

[0026] Reference Figure 1 and Figure 2An automated assembly device for automotive plastic hoods is used to glue and bond the inner and outer hood panels of a car. It includes a fixing platform 1, a robotic arm 2, and a clamping mechanism 3. The fixing platform 1 is used to fix the inner and outer hood panels in place. The robotic arm 2 integrates a baking mechanism 22, a jetting mechanism 23, and a glue-applying mechanism 24 for surface treatment of the inner and outer hood panels. The clamping mechanism 3 is used to press and bond the inner and outer hood panels together.

[0027] Multiple support seats 11 are fixed on the fixed platform 1, and they are distributed circumferentially on the fixed platform 1. Furthermore, the support seats 11 have different heights to accommodate the different surface conditions of the inner and outer hood panels. Each support seat 11 has a positioning groove 12 on its top, and all the positioning grooves 12 are combined to form a positioning area, and the inner and outer hood panels are installed on the fixed platform 1 in an embedded manner.

[0028] Meanwhile, a rotary clamping mechanism 13 is also provided on the fixed platform 1, which includes a drive component 131 and a clamping block 132 fixed to the output end of the drive component 131. The drive component 131 can drive the clamping block 132 to rotate and lift. The drive component 131, which can output rotation and lifting actions, is an existing mature product and will not be described in detail here. When the inner or outer hood panel is installed in the positioning area, the drive component 131 drives the clamping block 132 to rotate above the edge of the inner or outer hood panel, and then drives the clamping block 132 to descend, thereby pressing the clamping block 132 against the edge position.

[0029] In this embodiment, there are two fixed platforms 1, which are used to install the inner hood panel and the outer hood panel respectively, so that the inner hood panel and the outer hood panel can be surface treated independently.

[0030] Robotic arm 2 is a conventional multi-joint industrial robot, capable of flexible movement in any posture within three-dimensional space. A mounting plate 21 is rotatably mounted on the output end of robotic arm 2, and this mounting plate 21 is driven by a motor.

[0031] The baking mechanism 22, the jetting mechanism 23, and the adhesive application mechanism 24 are all mounted on the mounting plate 21, and are respectively set at different angles on the mounting plate 21. In this embodiment, the baking mechanism 22 and the jetting mechanism 23 can be at the same angle or at different angles, depending on the actual assembly process of the hood. By rotating the mounting plate 21, the mechanism to be used can be aligned with the inner or outer panel of the hood.

[0032] In this embodiment, the baking mechanism 22 includes a flame gun for baking the inner or outer panel of the hood, and the flame gun is connected to an external argon gas source. The jetting mechanism 23 includes a jet head for spraying high-pressure gas onto the outer panel of the hood. The jet head is also connected to an external high-pressure gas source and a dry ice powder supply device, so that the high-pressure gas flow from the jet head can carry dry ice powder. The adhesive application mechanism 24 includes a glue gun connected to an external glue cartridge containing adhesive, and the glue gun sprays adhesive onto the outer panel of the hood.

[0033] The clamping mechanism 3 includes a clamping platform 31, a clamping plate 32, and a clamping cylinder 33. The clamping platform 31 has a clamping groove for simultaneously inserting the inner and outer hood panels. The clamping cylinder 33 is mounted above the clamping platform 31, with its output end facing vertically downwards. The clamping plate 32 is mounted on the output end of the clamping cylinder 33.

[0034] After the inner and outer hood panels are placed into the clamping grooves, the clamping cylinder 33 drives the clamping plate 32 to move downwards, thereby pressing the inner and outer hood panels relative to each other and further bonding them together to complete the assembly of the car's front hood.

[0035] Based on the same inventive concept, embodiments of the present invention provide an automated assembly method for automotive plastic front hoods.

[0036] An automated assembly method for automotive plastic front hoods includes the following steps: Step S1: Place both the inner and outer hood panels on the preset processing platform and fix them in place. Collect the inner panel image information of the inner hood panel and the outer panel image information of the outer hood panel.

[0037] The processing station here is the fixed platform 1. After the inner and outer hood panels are installed on different fixed platforms 1, images are then acquired from both.

[0038] The inner panel image information refers to the image obtained by taking a picture of the inner panel of the hood placed on the fixed platform 1 using an industrial camera mounted on the robotic arm 2. The inner panel of the hood can be identified from the image.

[0039] Similarly, the outer panel image information refers to the image obtained by taking a picture of the outer panel of the hood.

[0040] Step S2: Identify the vertices of the inner panel from the inner panel image information and use them as reference feature points; identify the glue-coating grooves of the inner panel from the inner panel image information and generate the processing trajectory based on the glue-coating grooves of the inner panel.

[0041] The inner hood panel has a trapezoidal structure, with the vertices referring to the four corners of the hood. The outline of the inner hood panel is identified from the image information, and the vertices are located. During image recognition, the vertices are identified using the corner features from the inner hood image information, thus matching the inner hood vertices.

[0042] In this embodiment, the inner and outer surfaces of the hood have inner panel adhesive grooves. These grooves are where adhesive is applied and bonded between the inner and outer hood panels. The shape of the inner panel adhesive grooves is fixed and this feature is pre-recorded in a database. By inputting the inner panel image information into the database and comparing it with the inner panel adhesive groove features, the inner panel adhesive grooves on the hood inner panel can be identified.

[0043] The processing trajectory refers to the movement path of the robotic arm 2's output end when performing surface treatment on the inner panel of the hood. The processing trajectory is determined by the shape of the adhesive-coating grooves on the inner panel. After identifying the adhesive-coating grooves, the system analyzes their shape contours and connects all the groove contours into the shortest path. When the adhesive-coating groove is a closed-loop contour or an open-loop line, the processing trajectory matches the shape of that closed-loop contour or open-loop line. When the adhesive-coating groove includes multiple closed-loop contours or open-loop lines, each closed-loop contour or open-loop line is a separate trajectory unit. Adjacent closed-loop contours or open-loop lines then form a separate trajectory unit, and finally, all trajectory units are connected to form the processing trajectory. In this case, a portion of the processing trajectory will inevitably not coincide with the inner panel adhesive-coating groove.

[0044] Step S3: Generate trajectory position information based on the relative positional relationship between the reference feature points and the processed trajectory.

[0045] The trajectory position information refers to the specific location of the processing trajectory within the inner hood panel. Since the vertices of the inner hood panel are fixed points, they are used as reference feature points to determine the specific locations of other features within the inner hood panel. Once the processing trajectory is obtained, its specific location within the inner hood panel—that is, the trajectory position information—can be determined based on the relative distance between the processing trajectory and each inner hood vertex.

[0046] Step S4: Identify the reference feature points corresponding to the reference feature points from the outer panel image information, and generate the relative running trajectory on the outer panel of the hood based on the reference feature points and trajectory position information.

[0047] In this embodiment, the contact surfaces of the inner and outer hood panels have the same shape.

[0048] The reference feature points refer to the positions where the outer panel of the hood abuts against the vertices of the inner panel of the hood, i.e., the vertices of the four corners of the outer panel. Consistent with step S2, image analysis of the outer panel image information yields the reference feature points.

[0049] The relative trajectory refers to the movement path of robotic arm 2 when performing surface treatment on the exterior of the hood. The relative trajectory corresponds to the processing trajectory; the processing trajectory is on the inner hood panel, and the relative trajectory is on the outer hood panel. When the inner and outer hood panels come into contact, the relative trajectory coincides with the processing trajectory. By establishing a one-to-one correspondence between the reference feature points and the baseline feature points, the trajectory position information can be mapped onto the outer hood panel, thus obtaining the relative trajectory.

[0050] Step S5: Wipe the inner panel adhesive groove of the hood inner panel and control the preset baking mechanism 22 to bake along the processing trajectory.

[0051] In this embodiment, a wiping mechanism is integrated on the robotic arm 2. The wiping mechanism has a wiping cloth for wiping the inner panel of the engine hood.

[0052] During the assembly of the front hood, the inner hood panel is first processed. A wiping mechanism cleans the adhesive grooves on the inner panel to remove dust and impurities. Then, the robotic arm 2 is adjusted to position the baking mechanism 22 towards the inner hood panel, and the baking mechanism 22 bakes the inner hood panel along its processing trajectory. This process only requires controlling the baking mechanism 22 to quickly bake the inner hood panel once along its processing trajectory, thus preheating it.

[0053] Step S6: Control the baking mechanism 22 to bake the outer panel of the engine hood along the relative running trajectory to soften the surface, and simultaneously control the preset jet mechanism 23 to carry dry ice powder with high pressure airflow along the relative running trajectory to generate fine micropores.

[0054] In this embodiment, one or two robotic arms 2 can be used. When there are two robotic arms 2, each robotic arm 2 corresponds to a fixed platform 1 and processes the inner or outer hood panel separately. When there is only one robotic arm 2, after processing the inner hood panel, the robotic arm 2 is rotated to face the fixed platform 1 where the outer hood panel is placed, and then the outer hood panel is processed.

[0055] When processing the outer hood panel, the baking mechanism 22 and the jetting mechanism 23 simultaneously face the outer hood panel. First, the baking mechanism 22 bakes the outer hood panel along a relative running path, initially softening various locations along this path. Then, the jetting mechanism 23 follows behind the baking mechanism 22, synchronously jetting along the relative running path. High-pressure airflow propels dry ice powder onto the softened outer hood panel, creating dense, fine micropores along the relative running path. When the dry ice powder touches the outer hood panel, it sublimates and does not remain within these micropores. Simultaneously, the jetting along the relative running path cleans dust from the outer hood panel.

[0056] While the baking mechanism 22 completes the initial softening of the outer hood panel, the jetting mechanism 23 also completes the jetting process at the same time.

[0057] Step S7: After the air jet is completed, control the baking mechanism 22 to perform secondary baking along the relative running trajectory to expand the micropore diameter, and control the preset glue coating mechanism 24 to apply glue along the relative running trajectory.

[0058] After the jetting is completed, the system controls the jetting head of the jetting mechanism 23 to close, and then controls the baking mechanism 22 to bake again from beginning to end along the relative running trajectory. During this baking, the surface of the hood expands thermally, which increases the diameter of the fine micropores.

[0059] After the aperture is enlarged, the angle of the mounting plate 21 on the robotic arm 2 is adjusted so that the glue application mechanism 24 faces the outer panel of the hood. The glue application mechanism 24 applies glue to the outer panel of the hood along the relative running trajectory. At this time, the glue can penetrate into the fine micropores, thereby increasing the adhesion between the glue and the outer panel of the hood.

[0060] Step S8: After applying the adhesive, overlap the inner hood panel and the outer hood panel and control the preset pressing mechanism 3 to press and glue the two together.

[0061] After preheating the inner hood panel and applying adhesive to the outer hood panel, the inner and outer hood panels are removed from the fixing platform 1 and placed on the pressing platform 31 of the pressing mechanism 3. The pressing mechanism 3 then presses the two panels together to ensure a tight bond. In this embodiment, the pressure applied by the pressing mechanism 3 to the inner and outer hood panels will not damage them.

[0062] The method for controlling the baking mechanism 22 to bake the outer panel of the engine hood along a relative running trajectory includes the following steps: Step S600: Based on the preset hood structure model, retrieve the required bonding strength at each position point on the relative running trajectory.

[0063] The hood structure model is a data model obtained by technicians in advance by modeling the structure of the hood. This data model is stored in the system and can be retrieved and used.

[0064] The required adhesive strength refers to the bonding strength needed at various locations on the inner hood's adhesive grooves when bonding the outer and inner hood panels. This required adhesive strength is determined by the hood's geometry, and the strength required at each location may differ. The required adhesive strength for each location is recorded in the hood's structural model, allowing for direct retrieval of the required adhesive strength from this model.

[0065] Step S601: Match the required baking width of the baking mechanism 22 at each position point of the relative running track when baking along the relative running track according to the required bonding strength.

[0066] The required baking width refers to the width of the baking surface along the path when the baking mechanism 22 bakes along the relative running trajectory.

[0067] The required adhesive strength between the outer and inner hood panels depends on the amount of adhesive applied at the corresponding locations. When the outer and inner hood panels are pressed together, the adhesive is flattened and spread out; the required baking width is the maximum width after the adhesive has spread out. In this embodiment, the adhesive must be applied to the baked surface. Therefore, the required baking width is directly proportional to the required adhesive strength; the greater the required adhesive strength, the greater the required baking width.

[0068] Step S602: Match the vertical height distance between the baking mechanism 22 and the outer panel of the hood based on the required baking width.

[0069] The flame emitted by the baking mechanism 22 is cone-shaped, and the diameter of the contact surface between the flame and the outer surface of the hood is the required baking width. The vertical height distance between the baking mechanism 22 and the outer surface of the hood varies, and the diameter of the contact surface between the flame and the outer surface of the hood also varies. Therefore, the vertical height distance is inversely proportional to the required baking width.

[0070] Step S603: When the baking mechanism 22 is baking the outer panel of the hood along the relative running trajectory, the height of the baking mechanism 22 is controlled in real time according to the vertical height distance.

[0071] To ensure the bonding strength of the hood meets requirements after adhesion, the vertical distance between the baking mechanism 22 and the outer hood panel needs to be adjusted in real time according to the required bonding strength at various points on the hood during the movement of the robotic arm 2, thereby forming a compliant baked relative running trajectory. In this embodiment, the mounting plate of the robotic arm 2 has a drive component that independently controls the lifting and lowering of the flame gun of the baking mechanism 22, and this drive component can be in the form of a cylinder.

[0072] The method of jetting dry ice powder using high-pressure airflow by jetting mechanism 23 includes the following steps: Step S610: While moving along the relative running trajectory, the temperature at the nozzle position of the baking mechanism 22 is collected in real time, and a baking image along the path is collected.

[0073] In this embodiment, a temperature sensor is installed on one side of the nozzle of the flame gun in the baking mechanism 22. The temperature sensor does not directly contact the flame and only detects thermal radiation. The nozzle position temperature refers to the temperature value around the nozzle of the flame gun, not the flame temperature. The system can detect the temperature around the nozzle of the flame gun through the temperature sensor to obtain the nozzle position temperature.

[0074] The path baking image refers to the image obtained by taking pictures of the relative running trajectory of the material that has been baked by the baking mechanism 22 using an industrial camera.

[0075] When the baking mechanism 22 and the jet mechanism 23 move synchronously along their relative running trajectories, the system needs to collect the nozzle position temperature and path baking images in real time.

[0076] Step S611: Analyze the preset baking color darkening surface features from the path baking image to determine the actual baking width value.

[0077] In this embodiment, the car's front hood is made of materials such as PP, modified plastic, or glass fiber reinforced plastic. After being baked by the baking mechanism 22, a color difference will occur between the baked and unbaked surfaces, mainly with the baked surface becoming darker. The feature of the darkened baked surface refers to the area along the relative running trajectory that becomes darker after being baked by the flame. The actual baking width value refers to the actual width of the baked surface when the baking mechanism 22 moves along the relative running trajectory. The width value of the darkened baked surface feature is the actual baking width value.

[0078] The system uses the feature of the baked color darkening surface as a recognition feature to identify the baked color darkening surface feature. It can identify the baked color darkening surface feature, and then analyze the identified baked color darkening surface feature to determine the width value of the baked color darkening surface feature in the path baking image. Combined with the image shooting ratio of the path baking image, the actual baking width value is obtained.

[0079] Step S612: Match the jet span distance of the jet mechanism 23 based on the actual width value of the baking.

[0080] In this embodiment, the jet mechanism 23 jets in a pulsed manner. That is, when the robotic arm 2 moves along the relative running trajectory, the jet mechanism 23 jets once every certain distance. However, the high-pressure airflow ejected by the jet mechanism 23 can continuously cover the relative running trajectory.

[0081] The jet span distance refers to the distance along the relative running trajectory extended by the jet mechanism 23 when it sprays air. In this embodiment, the coverage area of ​​the airflow sprayed by the jet mechanism 23 onto the outer surface of the hood can be approximated as a square area. The length and width of the square area are in a fixed ratio, which is generated by the technicians through a pre-set configuration of the equipment. The area of ​​the square area is determined by the height of the jet mechanism 23. The actual baking width value is the maximum width of the airflow sprayed by the jet mechanism 23, which can be used as the width value of the square area. Therefore, the jet span distance and the actual baking width value are in a fixed ratio, and the jet span distance can be obtained by matching the actual baking width value. The specific matching method will not be elaborated here, but will be described in detail in subsequent embodiments.

[0082] The jet span distance can be changed by adjusting the height between the jet mechanism 23 and the outer panel of the engine hood. In this embodiment, the mounting plate of the robotic arm 2 has a drive component that independently controls the lifting and lowering of the jet head of the jet mechanism 23. This drive component can be in the form of a cylinder.

[0083] Step S613: Match the jet interval time of the jet mechanism 23 when performing pulse jet based on the jet span distance and the preset robotic arm moving speed.

[0084] The jet interval time refers to the time interval between two adjacent jetting processes of the jetting mechanism 23. The jetting interval time is related to the jetting span distance between two adjacent jetting processes and the moving speed of the robotic arm. The specific matching method will not be elaborated here, but will be described in detail in subsequent embodiments.

[0085] The robotic arm's moving speed is a fixed parameter set by the technicians for robotic arm 2, which is the moving speed of robotic arm 2 when performing surface treatment on the engine hood.

[0086] Step S614: When the nozzle position temperature is not lower than the preset baking temperature, turn on the jet mechanism 23, set the jet interval time and jet span distance, and perform pulse jetting.

[0087] The baking temperature is a reference parameter preset by the technicians to determine whether the baking mechanism 22 is performing a baking operation. When the temperature at the nozzle position is lower than the baking temperature, it indicates that the baking mechanism 22 is not performing a baking operation. At this time, the jetting mechanism 23 also does not jet, and the jetting mechanism 23 only jets the already baked surface of the hood outer panel.

[0088] When the temperature at the nozzle position is not lower than the baking temperature, it indicates that the baking mechanism 22 is working. At this time, the jet mechanism 23 is turned on to cooperate with the baking mechanism 22 to carry out jet operation.

[0089] In this embodiment, there is a distance between the flame gun of the baking mechanism 22 and the jet head of the jet mechanism 23. The surface of the outer panel of the hood is baked first, and then after a fixed time interval, the jet head moves to the position where the baking is completed and jets air. The path baking image captured by the industrial camera is an image of the area below the flame gun where the baking is completed. The time taken for the industrial camera to complete the image acquisition and for the system to perform image analysis is less than the fixed time interval, that is, the system has enough time to acquire and analyze the image to generate the jet parameters of the jet mechanism 23.

[0090] The method for determining the jet span distance includes the following steps: Step S6120: Analyze the path baking image to obtain the preset starting area baking width of the pulse jet unit region.

[0091] The pulse jet unit area is the square area generated by each jet of the jet mechanism 23.

[0092] The starting region baking width refers to the actual baking width value at the starting position of the current pulse jet unit region. This actual baking width value is also the actual baking width value at the ending position of the previous pulse jet unit region. By performing image analysis on the baking color-deepening surface features of the previous pulse jet unit region from the path baking image, using the same analysis method as step S611, the width value at the ending position of that region is determined, thereby obtaining the starting region baking width of the current pulse jet unit region.

[0093] Step S6121: Obtain the initial span distance based on the baking width of the starting area and the preset jet area ratio.

[0094] The initial span distance is a theoretical jet span distance estimated based on the baking width of the initial area. The jet area ratio is the fixed ratio of the square area in step S612. The initial span distance is the product or quotient of the baking width of the initial area and the jet area ratio.

[0095] Step S6122: Analyze the path baking image to obtain the maximum baking width in the relative running trajectory of the initial span distance.

[0096] The actual jet span distance needs to be determined comprehensively based on the continuously changing actual baking width value of the relative running trajectory of this length distance. After determining the initial span distance, image analysis can be performed on the baking color deepening surface features of the initial span distance from the path baking image to obtain the continuous boundary contour of the baking color deepening surface features. Then, the actual baking width value of each position point on the contour is obtained by identifying the continuous boundary contour.

[0097] The maximum baking width is the maximum value among the actual baking width values ​​at each location point of the above continuous boundary contour.

[0098] Step S6123: Obtain the jet span distance based on the maximum baking width matching, and correct the initial span distance.

[0099] The jet span distance is obtained by multiplying or quotienting the maximum baking width by the proportion of the jet area. The pulse jet unit region of this jet span distance can cover the corresponding relative running trajectory. Replace this jet span distance with the initial span distance.

[0100] The method for determining the jet interval includes the following steps: Step S6130: Analyze the path baking image to obtain the first jet span distance and the second jet span distance between two adjacent preset pulse jet unit regions.

[0101] The first jet span distance is the jet span distance of the previous pulse jet unit region. The second jet span distance is the jet span distance of the current pulse jet unit region. The first jet span distance and the second jet span distance are obtained respectively by the methods in steps S6120 to S6123.

[0102] Step S6131: Calculate the step center distance between the centers of the two pulse jet unit regions based on the first jet span distance and the second jet span distance.

[0103] The stride center distance is the distance between the centers of two adjacent pulse jet unit regions. The stride center distance is the average of the first jet span distance and the second jet span distance.

[0104] Step S6132: Calculate the jet interval time based on the stride center distance and the robotic arm moving speed.

[0105] The jet mechanism 23 jets at the center of the pulse jet unit area, so the jet interval is the quotient of the step center distance and the moving speed of the robotic arm.

[0106] The method of jetting dry ice powder using high-pressure airflow by jetting mechanism 23 also includes the following steps: Step S620: Determine the non-adhesive trajectory based on the inner plate adhesive groove and the relative running trajectory.

[0107] The non-glue trajectory refers to the trajectory segment in the relative running trajectory that does not require glue application by the glue application mechanism 24, and this trajectory segment also does not require air jetting.

[0108] The inner panel adhesive groove is the area where adhesive needs to be applied. By overlaying and comparing the inner panel adhesive groove with the relative running trajectory, the difference between the two trajectories is the non-adhesive trajectory.

[0109] Step S621: Determine the entry and exit time nodes of the non-adhesive trajectory based on the relative running trajectory, the non-adhesive trajectory, and the robot arm's moving speed.

[0110] The entry time point refers to the point in time when robotic arm 2 moves along the relative running trajectory and enters the non-adhesive coating trajectory. Similarly, the exit time point refers to the point in time when robotic arm 2 leaves the non-adhesive coating trajectory.

[0111] The path length between the starting position of the non-adhesive-coated trajectory and the starting point of the relative trajectory can be analyzed from the relative trajectory. Combined with the robotic arm's movement speed, the time it takes for robotic arm 2 to move from the starting point of the relative trajectory to the starting position of the non-adhesive-coated trajectory can be calculated; this time is the entry time node. Similarly, the departure time node can be obtained from the starting point of the relative trajectory to the ending position of the non-adhesive-coated trajectory.

[0112] Step S622: Start recording the running time when the baking mechanism 22 begins baking. When the running time matches the entry time node, turn off the jet mechanism 23. When the running time matches the exit time node, turn the jet mechanism 23 back on.

[0113] Timing begins from the start point of baking by baking mechanism 22. After passing the entry time node, robotic arm 2 moves to the starting position of the non-adhesive coating trajectory, at which point the air jet mechanism 23 is turned off. After passing the exit time node, robotic arm 2 leaves the non-adhesive coating trajectory area, at which point the air jet mechanism 23 is turned back on. Throughout the entire process, baking mechanism 22 remains on.

[0114] The method for applying adhesive by the adhesive applicator 24 along a relative running trajectory includes the following steps: Step S700: Set the thickness of the adhesive between the inner and outer hood panels after they are pressed together as the pressing thickness, and set the width of the adhesive sprayed by the adhesive applicator 24 on the outer hood panel as the adhesive applicator width.

[0115] Step S701: Calculate the adhesive application height required when the adhesive at each position point relative to the running trajectory is flattened to the required baking width based on the pressing thickness and adhesive application width.

[0116] The adhesive application height refers to the height of the adhesive applied by the adhesive application mechanism 24 at various points along its relative running trajectory. In this embodiment, the width of the adhesive applied by the adhesive application mechanism 24 on the outer panel of the hood remains constant, therefore the adhesive application height directly determines the amount of adhesive applied. To ensure that the width of the adhesive reaches the required baking width when it is pressed flat to the required thickness, both the adhesive application height and the required baking width are real-time variable values.

[0117] The product of the pressing thickness and the required baking width can be used to determine the cross-sectional area of ​​the glue after it is flattened. Since the cross-sectional area remains unchanged before and after the glue is flattened, the quotient of the cross-sectional area and the glue width can be used to obtain the glue application height.

[0118] Step S702: Match the instantaneous speed of the glue application mechanism 24 at each position point on the relative running trajectory according to the glue application height.

[0119] The instantaneous glue application speed refers to the amount of glue sprayed by the glue application mechanism 24 per unit time. The instantaneous glue application speed is directly proportional to the glue application height; the higher the glue application height, the greater the instantaneous glue application speed. By changing the instantaneous glue application speed, the glue application height at various points along the relative running trajectory can be adjusted.

[0120] Step S703: Generate a glue application speed curve based on the instantaneous glue application speed and the relative running trajectory.

[0121] The adhesive application speed curve is a two-dimensional graph, with the horizontal axis representing the distance between each position point on the relative running trajectory and the starting point, and the vertical axis representing the instantaneous adhesive application speed at each position point on the relative running trajectory.

[0122] Step S704: Use the center line of the relative running trajectory as the glue application path of the glue application mechanism 24.

[0123] The adhesive application path refers to the path of the adhesive application points along the relative running trajectory of the adhesive application mechanism 24. Here, the center line of the relative running trajectory is used as the adhesive application path, so that the adhesive can be squeezed out to both sides of the center line of the relative running trajectory when flattened.

[0124] Step S705: When the glue application mechanism 24 moves along the relative running trajectory on the outer panel of the engine hood, the glue application mechanism 24 is controlled to apply glue according to the glue application speed curve and glue application path.

[0125] When the adhesive application mechanism 24 moves along the relative running trajectory to apply adhesive, it is controlled according to two parameters: the adhesive application speed curve and the adhesive application path. The adhesive application speed curve determines the amount of adhesive applied at each position point on the relative running trajectory, and the adhesive application path determines the application position of the adhesive on the outer panel of the hood.

[0126] It also includes the following steps: In this embodiment, the surface of the outer hood panel is not a complete plane; it has an inclination at various locations, which is determined by the structure of the outer hood panel. Based on this, when the adhesive on the inclined surface is flattened, it will not spread evenly to both sides, but rather more will be applied in the direction of descent along the inclined surface. Therefore, it is necessary to correct the adhesive application path so that the adhesive, after being flattened, is all within the path of the required baking width.

[0127] Step S710: Determine the tilt angle of each position point relative to the running trajectory based on the preset hood structure model.

[0128] The hood structure model includes the tilt angles of various positions on the outer hood panel. By inputting the relative running trajectory into the hood structure model, the tilt angles of various positions on the relative running trajectory can be obtained.

[0129] Step S711: Based on the ratio of the extrusion amount on both sides of the center line of the relative running trajectory when the adhesive is pressed according to the tilt angle, and determine the path offset according to the extrusion amount ratio and the required baking width of each position point of the relative running trajectory.

[0130] The extrusion ratio refers to the proportion of glue that spreads to both sides when the glue is flattened. When the tilt angle is 0, the extrusion ratio is 1. There is a correlation between the extrusion ratio and the tilt angle; this correlation is determined by pre-testing by technicians and recorded in a database. The test involves extruding glue at different tilt angles to determine the amount of glue that spreads to both sides and obtain the proportional value.

[0131] By inputting the tilt angle into the database obtained from the above experiments, the extrusion ratio can be matched.

[0132] Path offset refers to the offset of the glue's centerline from the centerline of its relative running trajectory after it has been flattened. At each point on the relative running trajectory, the midpoint of the flattened glue can be determined by the extrusion ratio. Comparing this midpoint with the midpoint corresponding to the required baking width yields the path offset at each point on the relative running trajectory. The midpoint corresponding to the required baking width lies on the centerline of the relative running trajectory.

[0133] Step S712: Correct each position point of the glue application path by the path offset, and output the updated glue application path.

[0134] The amount of correction at each point along the adhesive application path is the path offset.

[0135] In this embodiment, when the tilt direction of a position point on the relative running trajectory is the same as the direction of the relative running trajectory, no correction of the adhesive application path is required. Adhesive application path correction is only performed when the tilt direction is not perpendicular to the direction of adhesive dispensing.

[0136] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. An automated assembly method for a car plastic front hood, characterized in that, include: The inner and outer panels of the hood are placed on a pre-set processing table and fixed, and the inner panel image information and the outer panel image information of the hood are collected. The vertex of the inner panel is identified from the inner panel image information and used as a reference feature point. The glue-coating groove of the inner panel is identified from the inner panel image information and a processing trajectory is generated based on the glue-coating groove of the inner panel. The trajectory position information is generated based on the relative positional relationship between the reference feature points and the processed trajectory. Identify reference feature points corresponding to reference feature points from the outer panel image information, and generate the relative running trajectory on the outer panel of the hood based on the reference feature points and trajectory position information; Wipe the inner panel adhesive groove of the hood inner panel and control the preset baking mechanism (22) to bake along the processing running trajectory; The control baking mechanism (22) bakes the outer panel of the engine hood along the relative running trajectory to soften the surface, and simultaneously controls the preset jet mechanism (23) to carry dry ice powder with high pressure airflow along the relative running trajectory to generate fine micropores. After the jetting is completed, the baking mechanism (22) is controlled to perform secondary baking along the relative running trajectory to expand the micropore diameter, and the preset glue coating mechanism (24) is controlled to apply glue along the relative running trajectory. After applying the adhesive, overlap the inner and outer panels of the hood and control the preset pressing mechanism (3) to press and bond them together.

2. The automated assembly method for a car plastic front hood according to claim 1, characterized in that, The method for controlling the baking mechanism (22) to bake the outer panel of the hood along a relative running trajectory includes: The required bonding strength is retrieved at various points on the relative running trajectory based on the preset hood structure model. The required baking width at each position point on the relative running track is matched according to the bonding strength requirement of the baking mechanism (22) during baking along the relative running track; The vertical height distance between the baking mechanism (22) and the outer panel of the hood is matched based on the required baking width. When the baking mechanism (22) bakes the outer panel of the hood along the relative running trajectory, the height of the baking mechanism (22) is controlled in real time according to the vertical height distance.

3. The automated assembly method for a car plastic front hood according to claim 2, characterized in that, The method of using a jet mechanism (23) to carry dry ice powder with a high-pressure airflow includes: The temperature at the nozzle position of the baking mechanism (22) is collected in real time while moving along the relative running trajectory, and the baking path image is also collected. The actual baking width value is determined by analyzing the pre-defined baking color darkening surface features in the path baking image; The jet span distance of the jet mechanism (23) is matched based on the actual width value of the baking process; The jet interval time when the jet mechanism (23) performs pulse jetting is matched based on the jet span distance and the preset robotic arm moving speed. The jet mechanism (23) is activated only when the nozzle position temperature is not lower than the preset baking temperature. The jet mechanism (23) is set with jet interval time and jet span distance and pulse jet is performed.

4. The automated assembly method for a car plastic front hood according to claim 3, characterized in that, Methods for determining jet span distance include: The starting area baking width of the preset pulse jet unit region is obtained by analyzing the path baking image; The initial span distance is obtained based on the baking width of the starting area and the preset jet area ratio; The maximum baking width in the relative running trajectory of the initial span distance is obtained by analyzing the path baking image; The jet span distance is obtained based on the maximum baking width matching, and the initial span distance is corrected.

5. The automated assembly method for a car plastic front hood according to claim 3, characterized in that, Methods for determining the jet interval include: The first jet span distance and the second jet span distance between two adjacent preset pulse jet unit regions are obtained from the path baking image. The step center distance between the centers of the two pulse jet unit regions is calculated based on the first jet span distance and the second jet span distance. The jet interval time is calculated based on the stride center distance and the robotic arm's moving speed.

6. The automated assembly method for a car plastic front hood according to claim 3, characterized in that, Also includes: The non-glue trajectory is determined based on the glue-coating groove in the inner plate and the relative running trajectory. The entry and exit times of the non-adhesive-coated trajectory are determined based on the relative running trajectory, the non-adhesive-coated trajectory, and the robot arm's moving speed. The running time is recorded when the baking mechanism (22) starts baking. When the running time is consistent with the entry time node, the jet mechanism (23) is turned off; when the running time is consistent with the exit time node, the jet mechanism (23) is turned on again.

7. The automated assembly method for a car plastic front hood according to claim 2, characterized in that, The method by which the glue-applying mechanism (24) applies glue along a relative running trajectory includes: The thickness of the adhesive between the inner and outer panels of the hood is set as the pressing thickness, and the width of the adhesive sprayed by the adhesive applicator (24) on the outer panel of the hood is set as the adhesive applicator width. The required adhesive application height is calculated based on the pressing thickness and adhesive application width at each position point relative to the running trajectory when the adhesive is flattened to the required baking width; The instantaneous speed of the glue application mechanism (24) at each position point relative to the running trajectory is matched according to the glue application height. A glue application speed curve is generated based on the instantaneous speed of glue application and the relative running trajectory; The center line of the relative running trajectory is used as the glue application path of the glue application mechanism (24); When the glue application mechanism (24) moves along the relative running trajectory on the outer panel of the engine hood, the glue application mechanism (24) is controlled to apply glue according to the glue application speed curve and glue application path.

8. The automated assembly method for a car plastic front hood according to claim 7, characterized in that, Also includes: The tilt angle of each position point relative to the running trajectory is determined based on the preset hood structure model; The path offset is determined based on the ratio of the extrusion volume on both sides of the center line of the relative running trajectory when the adhesive is pressed according to the tilt angle, and the required baking width at each position point of the relative running trajectory is determined according to the extrusion volume ratio. The glue application path is corrected by adjusting the path offset, and the updated glue application path is output.

9. An automated assembly device for a car plastic front hood, controlled by an automated assembly method for a car plastic front hood as described in any one of claims 1 to 8, characterized in that, It includes a fixing platform (1) for mounting the outer hood panel and the inner hood panel for applying adhesive, a robotic arm (2) with integrated multi-processing functions, and a pressing mechanism (3) for relatively pressing and bonding the outer hood panel and the inner hood panel; the robotic arm (2) is equipped with a baking mechanism (22) for baking, a jetting mechanism (23) for spraying dry ice powder, and an adhesive applicator (24) for applying adhesive.

10. An automated assembly device for automotive plastic front hoods according to claim 9, characterized in that, The fixed platform (1) is provided with a plurality of support seats (11) for supporting the outer or inner hood panel and a rotary pressing mechanism (13) for pressing the outer or inner hood panel against the support seats (11); each support seat (11) is provided with a positioning groove (12), and all the positioning grooves (12) are combined to form a positioning area for the outer or inner hood panel to be embedded. The rotary clamping mechanism (13) includes a clamping block (132) and a drive member (131) that drives the clamping block (132) to rotate and move up and down.

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