Top cover panoramic sunroof flanging control method and system

Abstract

The invention relates to a top cover panoramic sunroof flanging control method and system, and the method comprises the steps that an upper die assembly and an insert move downwards to make contact with a plate, so that the upper die assembly applies pressing force to the plate for fixing, and the insert is used for flanging the plate; when the insert descends to a bottom dead center, the time delay execution unit and the time delay execution unit carry out pressure-maintaining time delay, so that the insert is kept static within the time delay time; and after the time delay is finished, the insert continues to move downwards and cooperates with the upper die assembly to finish plate flanging. According to the invention, when the insert moves downwards to the lower dead center, the delay execution unit is started to carry out pressure-maintaining delay, and the delay execution unit enables the insert to keep static within the delay time, so that the continuous and stable application of the pressing force is realized, and the plate material obtains sufficient plastic deformation and uniform stress distribution in the flanging area; by means of the process, local stress concentration and uneven flowing of the material caused by sudden force change when the insert rapidly and continuously descends are avoided, it is guaranteed that all parts of the plate are stressed in a balanced mode in the flanging process, and the rebound defect is restrained.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of sunroof manufacturing, in particular to a roof panoramic sunroof flanging control method and system. BACKGROUND

[0002] The roof sunroof can bring great convenience to the transparent field of view. When driving on the highway or needing to check the roof trunk or the top of the car, the sunroof of the car can provide additional field of view, making it easier for the driver to observe the driving condition of the vehicle. At the same time, the transparent design also makes the driver better grasp the driving attitude of the car, so as to timely adjust the driving direction and speed to avoid the vehicle out of control.

[0003] In the prior art, the blanking and flanging process of the sunroof component is generally realized by using ordinary hydraulic cylinders or nitrogen cylinders, but there are systematic defects: the blanking stage lacks precise control of the timing of the blanking force, resulting in uneven material flow on the sheet, which is prone to local accumulation or stretching defects; in the flanging operation, the stress change lacks uniformity management, which is prone to stress concentration, causing material cracking or rebound angle exceeding the standard; the pressure holding process relies on a simple pneumatic system, which has large stroke fluctuation and unstable air pressure control, and cannot effectively suppress the rebound phenomenon. SUMMARY

[0004] The present application provides a roof panoramic sunroof flanging control method and system, which can solve the problems of high rebound defect rate, uneven material flow and flanging stress concentration in the prior art.

[0005] In a first aspect, the present application provides a roof panoramic sunroof flanging control method, which comprises: The upper die assembly and the insert lower contact plate to fix the blanking force of the plate applied by the upper die assembly, and the insert flanges the plate; When the insert is lowered to the lower dead point, the pressure holding delay execution unit is executed, and the pressure holding delay execution unit is executed, so that the insert remains stationary within the delay time; After the delay time ends, the insert continues to descend and cooperates with the upper die assembly to complete the flanging of the plate.

[0006] In combination with the first aspect, in an embodiment, the delay execution unit comprises: a first delay nitrogen cylinder group and a second delay nitrogen cylinder group, the first delay nitrogen cylinder group comprises a plurality of first delay nitrogen cylinders; the second delay nitrogen cylinder group comprises a plurality of second delay nitrogen cylinders; wherein a plurality of first delay nitrogen cylinders are located below the plate and are arranged along the edge of the plate; a plurality of second delay nitrogen cylinders are located below the plate and are arranged in the middle of the plate.

[0007] In combination with the first aspect, in an embodiment, when the insert is lowered to the lower dead point, the pressure holding delay execution unit is executed, and the pressure holding delay execution unit is executed, specifically comprising: When the insert is descending to the lower dead point, the first delay nitrogen cylinder group is pressed down; The first delay nitrogen cylinder group provides initial blank holding force and performs pressure holding delay.

[0008] In combination with the first aspect, in an implementation, after the delay ends, when the insert continues to descend, the method further comprises: When the insert continues to descend between the lower dead point and the lower dead point, the plurality of first delay nitrogen cylinders of the first delay nitrogen cylinder group and the plurality of second delay nitrogen cylinders of the second delay nitrogen cylinder group dynamically adjust the required blank holding force according to the preset blank holding force; When the insert continues to descend to the lower dead point, the first delay nitrogen cylinder group and the second delay nitrogen cylinder group both exert the corresponding preset maximum blank holding force.

[0009] In combination with the first aspect, in an implementation, the preset blank holding force exerting requirement comprises: The first delay nitrogen cylinder and the second delay nitrogen cylinder in contact with the area on the sheet metal where the curvature is less than the curvature setting threshold and the material accumulates, start or exert the blank holding force greater than the preset blank holding force earlier than the preset start time setting value; The first delay nitrogen cylinder and the second delay nitrogen cylinder in contact with the area on the sheet metal where the curvature is greater than the curvature setting threshold and the draw depth is greater than the depth setting threshold, delay the preset start time setting value to start or exert the blank holding force less than the preset blank holding force.

[0010] In combination with the first aspect, in an implementation, the delay execution unit performs pressure holding delay through a zero rebound system.

[0011] In combination with the first aspect, in an implementation, the zero rebound system comprises a zero rebound device body, an inductive contactor, a connecting block, an air control reversing valve, and a delay control valve, the connecting block is connected with the inductive contactor; the input end of the air control reversing valve is connected with the output end of the inductive contactor through an air path pipeline, the air control reversing valve is connected with the zero rebound device body; the output end of the air control reversing valve is connected with the input end of the delay control valve, and the output end of the delay control valve is connected with the air control reversing valve.

[0012] In combination with the first aspect, in an implementation, the zero rebound system realizes pressure holding delay, specifically comprising: The connecting block triggers the inductive contactor; The inductive contactor controls the air control reversing valve to switch the air path channel to connect the delay control valve to start the pressure holding delay.

[0013] In combination with the first aspect, in an implementation, the upper die assembly is fixed to exert the blank holding force on the sheet metal, and when the insert is flanging the sheet metal, the blank holding force is adjusted through the balancing block. Before the upper mold assembly and the insert come into contact with the sheet metal and the upper mold assembly applies a pressing force to the sheet metal to fix it, the method further includes: during the mold design stage, designing the fillet radius and flange clearance of the insert based on the sheet metal thickness, sheet metal material and the design pressing force of the delay execution unit.

[0014] Secondly, this application provides a panoramic sunroof flapping control system, which includes: a first module, a second module, and a third module; the first module is used to: control the upper mold assembly and the insert to descend and contact the sheet metal, so that the upper mold assembly applies a pressing force to the sheet metal for fixing, and the insert flaps the sheet metal; the second module is used to: control the insert to descend to the lower stop point and press down the delay execution unit, the delay execution unit performs a pressure holding delay, so that the insert remains stationary during the delay time; the third module is used to: control the insert to continue descending after the delay ends, and work with the upper mold assembly to complete the sheet metal flapping.

[0015] The beneficial effects of the technical solutions provided in this application include: This application provides a method and system for controlling the flanging of a panoramic sunroof. By activating a delay execution unit to maintain pressure during the downward movement of the insert to the lower stop point, the delay execution unit keeps the insert stationary during the delay time, achieving continuous and stable application of the pressure force. This allows the sheet metal to achieve sufficient plastic deformation and uniform stress distribution in the flanging area. This process avoids local stress concentration and uneven flow of the material caused by sudden force changes when the insert continues to move rapidly downward. It ensures that the sheet metal is subjected to balanced force in all parts during the flanging process, thereby effectively suppressing springback defects and improving the dimensional accuracy and consistency of the flanging. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the process for controlling the flapping edge of the panoramic sunroof in this application; Figure 2 This is a schematic diagram of the sheet metal area; Figure 3 A schematic diagram showing the arrangement of the delayed nitrogen cylinder on the panoramic sunroof; Figure 4 This is a schematic diagram of the flanged design of a delayed nitrogen cylinder. Figure 5 The results of the first mold rebound test after using a delayed nitrogen cylinder; Figure 6 The results are from the AutoForm edge springback simulation. Figure 7 This is a schematic diagram of the zero-bounce system of this application; Figure 8 This is a schematic diagram of the modified lower mold structure; Figure 9 The results of the rebound test after the modification of the roof sunroof flange.

[0017] In the figure: 1, connecting block; 2, induction contactor; 3, gas path pipeline; 4, air control reversing valve; 5, delay control valve; 6, first pressure material device; 7, insert; 8, lower die; 9, second pressure material device; 10, balance block; 11, controller; 12, zero rebound device body; 13, press long pass system; 14, floating top device; 15, first delay nitrogen cylinder group; 16, second delay nitrogen cylinder group; 17, sheet material. DETAILED DESCRIPTION

[0018] In order to make the person skilled in the art better understand the scheme of the present application, the technical scheme in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by the person skilled in the art without creative labor belong to the scope of protection of the present application.

[0019] The present application provides a top cover panoramic sunroof flanging control method and system, which can solve the problems of high springback defect rate, uneven material flow and cracking caused by flanging stress concentration in the prior art.

[0020] In order to make the purpose, technical scheme and advantages of the present application more clear, the embodiments of the present application will be described in further detail in combination with the drawings.

[0021] In a first aspect, the embodiments of the present application provide a top cover panoramic sunroof flanging control method, which comprises: 101: The upper die assembly and the insert 7 descend to contact the sheet material, so that the upper die assembly applies a pressure material force to fix the sheet material, and the insert 7 flanges the sheet material; 102: When the insert 7 descends to the lower dead point, the delay execution unit is pressed down, and the delay execution unit delays the pressure retention, so that the insert 7 remains stationary within the delay time; 103: After the delay ends, the insert 7 continues to descend and cooperates with the upper die assembly to complete the flanging of the sheet material 17.

[0022] In the present application, the delay execution unit is enabled to delay the pressure retention when the insert 7 descends to the lower dead point, the delay execution unit makes the insert 7 remain stationary within the delay time, realizes the continuous and stable application of the pressure material force, makes the sheet material 17 obtain sufficient plastic deformation and stress uniform distribution in the flanging area, this process avoids the local stress concentration and uneven flow of the material caused by sudden force change when the insert 7 quickly continues to descend, ensures that the sheet material 17 is balanced in stress in the flanging process, thereby effectively inhibiting the springback defect, improving the size accuracy and consistency of the flanging.

[0023] First of all, it needs to be emphasized that the following words will appear in the description below, for easy understanding, the following words need to be expanded: Blank holder force: according to the AutoForm simulation analysis in the flanging process, within a certain range, as the blank holder force increases, the springback defect after unloading will decrease. However, when the blank holder force is below a certain critical value or the friction coefficient of the presser surface is small, the material will overcome the plastic deformation during the flanging process, which will cause the blank holder force to rebound, affecting the forming precision of the part. When the blank holder force is too large, the plastic flow of the material will be too large, which will cause the flanging edge to crack.

[0024] Flanging fillet: see Figure 2 As shown, through experimental research, under the same conditions of blank holder force and side wall gap, the larger the flanging fillet radius, the lower the A surface springback value near the sunroof. This is because when the flanging fillet radius is small, the plastic deformation near the fillet during flanging is large, which exacerbates work hardening. After the external force is unloaded, the sheet metal 17 rebounds greatly. Under the condition of permission, the flanging fillet radius should be increased as much as possible to reduce the negative impact of work hardening.

[0025] Flanging gap: in the past flanging process of roof sunroof, the flanging gap has an impact on springback. Generally, a gap of 1 material thickness is used for forming. When the part shape is complex, the gap will be uneven, which will easily cause the collapse of the G, H corner area of the sunroof and the distortion of the straightness of the E, F edge line, as shown in Figure 2

[0026] The ordinary sunroof can eliminate the springback defect to some extent by using the optimal parameter matching due to its small size. However, for panoramic sunroofs, the size occupies half of the roof, such as the sunroof size of 1350 mm x 860 mm shown in Figure 3 The conventional forming process cannot guarantee the shape accuracy of the A surface after flanging. At the same time, the panoramic sunroof has a negative angle along the circumference, and the shaping of the front, rear, left and right flange flanges mostly needs to use a wedge mechanism. For Figure 4 ​The process scheme shown, consider using delay nitrogen cylinder involved in forming and holding pressure. Delay nitrogen cylinder involved in forming and holding pressure is the key process to ensure the quality of parts (dimensional accuracy, no defects). Delay nitrogen cylinder structure is complex, the temperature is higher during work, need to dissipate heat, the current market commonly used delay nitrogen cylinder heat dissipation has its own type of heat dissipation and auxiliary type heat dissipation two. Considering that the delay nitrogen cylinder itself heat dissipation structure volume is larger, lead to in the mold space arrangement when easy to limit, difficult to meet the layout needs of compact sunroof mold, therefore this scheme selects to adopt auxiliary type heat dissipation mode, the temperature of delay nitrogen cylinder relies on the fan on the controller 11 to control, and is equipped with optimization space utilization and ensures the heat dissipation efficiency, and for realizing the uniform distribution of pressure load, avoid local stress concentration caused by forming defects. The delay execution unit is provided with: a first delay nitrogen cylinder group 15 and a second delay nitrogen cylinder group 16, the first delay nitrogen cylinder group 15 comprises a plurality of first delay nitrogen cylinders; the second delay nitrogen cylinder group 16 comprises a plurality of second delay nitrogen cylinders; wherein the plurality of first delay nitrogen cylinders are located below the sheet metal 17 and are arranged along the edge of the sheet metal 17; the plurality of second delay nitrogen cylinders are located below the sheet metal 17 and are arranged in the middle of the sheet metal 17.

[0027] In this application, 8 groups of delay nitrogen cylinders are used for pressure loading, of which the first delay nitrogen cylinders are arranged on both sides, each with three groups; the second delay nitrogen cylinders are arranged in the middle region, two groups. Figure 3 As shown. This distributed layout not only balances the stress distribution of the flanging area, but also significantly improves the stability of the forming process, so that the panoramic sunroof moves smoothly during flanging, effectively preventing defects such as scratches on the surface of the part caused by uneven pressure loading, thereby ensuring the accuracy and consistency of the A surface shape after flanging.

[0028] After introducing the delay execution unit, the flanging device is described: The flanging device comprises an upper die assembly, and the upper die assembly comprises a first pressure loader 6, an insert 7, a second pressure loader 9, and a balance block 10. The first pressure loader 6 and the second pressure loader 9 cooperate with the insert 7 to press the sheet metal 17. The upper die assembly applies pressure to the sheet metal 17 to fix it, and the insert 7 flanges the sheet metal 17. The balance block 10 adjusts the pressure to make the material flow uniformly and avoid wrinkles or cracks on the product.

[0029] When the upper die assembly descends, the first pressure loader 6 and the insert 7 cooperate to first contact the sheet metal 17. The 8 groups of delay nitrogen cylinders provide stable and adjustable pressure to the first pressure loader 6 through distributed arrangement, so that the sheet metal 17 obtains uniform stress distribution in the stretching stage, avoiding local stress concentration of the material. The insert 7, as a key flanging component in the upper die assembly, is responsible for flanging the sheet metal 17. During the flanging process, it contacts the sheet metal 17 to realize forming.

[0030] The second material press 9 is arranged below the plate 17 and cooperates with the lower die 8. When the insert 7 descends to the lower dead point of the die, the second material press 9 is pressed by the delay execution unit, and the delay pressure maintaining stage is started. In addition, the flanging device also comprises a zero-rebound system. The essence of the sunroof delay nitrogen cylinder flanging principle is to skillfully use the hydraulic delay function inside the nitrogen cylinder to build a mechanical time difference in the die structure, thereby ensuring the strict timing control of the two key actions of material pressing and flanging. The scheme realizes the precise material pressing control of the plate 17 through the cooperation of 8 groups of delay nitrogen cylinders (distributed in a distributed layout of 3 groups on each side and 2 groups in the middle region) and the upper die assembly. The zero-rebound system monitors and actively applies a reverse and accurate compensation force in real time during the stamping forming process. The zero-rebound system monitors the oil pressure of the cavity and the hose in real time, controls the nitrogen cylinder stroke fluctuation within 1 mm, and ensures that the insert 7 remains stationary during the delay pressure maintaining period. This process enables the plate 17 to obtain sufficient plastic deformation and stress uniform distribution in the flanging area, effectively avoids wrinkles or cracks caused by uneven material flow, and thus stabilizes the material size and shape within the tolerance range after the material is unloaded, realizing visual zero rebound.

[0031] The delay execution unit performs pressure maintaining delay, and the zero-rebound system realizes the pressure maintaining delay. The zero-rebound system comprises a zero-rebound device body 12, an inductive contactor 2, a connecting block 1, a gas control reversing valve 4, and a delay control valve 5. The connecting block 1 is connected with the inductive contactor 2. The input end of the gas control reversing valve 4 is connected with the output end of the inductive contactor 2 through a gas path pipeline 3. The gas control reversing valve 4 is connected with the zero-rebound device body 12. The output end of the gas control reversing valve 4 is connected with the input end of the delay control valve 5. The output end of the delay control valve 5 is connected with the gas control reversing valve 4. In addition, the zero-rebound system also comprises a press long path system 13, which continuously supplies gas to the inductive contactor 2, the gas control reversing valve 4, and the delay control valve 5 through the gas path pipeline 3.

[0032] The zero-rebound system realizes pressure maintaining delay, which specifically comprises that the connecting block 1 triggers the inductive contactor 2. The inductive contactor 2 controls the gas control reversing valve 4 to switch the gas path channel to connect the delay control valve 5 to start the pressure maintaining delay.

[0033] Specifically, the core of the zero-rebound system lies in the internal channel design of the pneumatic reversing valve 4, and its channel switching mechanism is crucial to the operation of the entire system. When the zero-rebound system is in its initial state, the channel of the pneumatic reversing valve 4 is in a specific connection state, preventing gas from flowing to the zero-rebound device body 12 and the delay control valve 5. When the connecting block 1 triggers the inductive contactor 2, the inductive contactor 2 connects the continuous air source provided by the compressor continuous system 13 to the pneumatic reversing valve 4, which enters through the P5 channel port. The internal channel of the pneumatic reversing valve 4 then switches. At this time, ports P1 and P4 are connected, connecting to the zero-rebound device body 12, enabling it to start working; simultaneously, ports P3 and P2 are connected, forming an air supply channel, flowing through the P2 channel port to the PIL one-way throttle valve, and then into the air tank. The air pressure in the air tank then drives the delay control valve 5, which activates its timing function and begins to switch the pneumatic reversing valve 4.

[0034] The timing function of the delay control valve 5 ensures precise control of the pressure holding time. After the delay control valve 5 completes its timing, it sends a reversing command to the pneumatic reversing valve 4, causing the internal channel of the pneumatic reversing valve 4 to switch back to its original state. This switching causes the connection between the zero rebound device body 12 and the gas source to be cut off, the zero rebound device stops supplying pressure to the delay nitrogen cylinder, and the delay pressure holding state ends.

[0035] The system's timing control mechanism is based on physical switching of the air path, eliminating the need for an electronic control system. When the mold closes, connecting block 1 triggers contactor 2, initiating the pressure-holding process. During mold opening, the system automatically terminates based on the difference between the upper mold assembly's retraction stroke and the flanging stroke: when the upper mold assembly's retraction stroke is less than the flanging stroke, connecting block 1 slowly separates from contactor 2, and the zero-rebound device body 12 continues to operate until complete separation; when the upper mold assembly's retraction stroke is greater than the flanging stroke, connecting block 1 completely separates from contactor 2, the delay control valve 5 closes, and the delayed pressure-holding state ends. This triggering mechanism based on mechanical stroke difference ensures seamless connection between the pressure-holding and mold-opening processes.

[0036] In practical applications, the zero-springback system achieves synchronized action of delay control through manual adjustment, compensating for springback on the existing formed part profile. This compensation process is achieved by modifying and re-machining the lower die 8 structure with the compensated profile, such as... Figure 8 The modified lower mold assembly structure, including eight sets of delayed nitrogen cylinders and a zero-rebound system, significantly improved the flanging accuracy. The floating ejector 14 shown in the diagram primarily serves to properly eject material when the flanging is caught on the cutting edge of the lower mold (cutting edge 8), while simultaneously ejecting the part. The dimensions of the top cover skylight, measured using a coordinate measuring machine after the modification, are as follows: Figure 9 As shown, the rebound defect in the sunroof flange area meets the requirement of ±0.5 mm.

[0037] Compared with traditional springback control methods, the zero-rebound system in this application has several technical advantages: First, the system structure is simple, consisting only of air circuit components, without a complex electronic control system, reducing the failure rate and maintenance costs; second, the system is easy to debug, and the delay time can be changed by adjusting the opening of the PIL one-way throttle valve to adapt to different material properties without the need for complex parameter settings; third, the system occupies little space, effectively saving mold space and making the distributed arrangement of the 8 sets of delayed nitrogen cylinders more compact and reasonable.

[0038] Based on the above embodiments, in this embodiment, the use of a delayed nitrogen cylinder can effectively reduce springback defects, and through rigorous experimental verification, the interference of traditional influencing factors such as flange gap and fillet radius of insert 7 has been eliminated. With the diverse forms of the floating top device 14, pressure fluctuations in the cylinder branch circuit become a key factor affecting forming quality. Through comparison of a large amount of process data, it was found that asynchronous material ejection by the floating top device 14 is one of the main causes of deformation of the formed parts, while uneven blank holder force and asynchronous operation of the floating top device 14 are the core problems causing the aforementioned defects.

[0039] In traditional applications, due to the use of manual stamping lines for debugging, delayed nitrogen cylinders face two major technical challenges in achieving zero springback control: First, the timing of the press movement and the PLC programming electrical signal cannot be precisely matched, resulting in the start-up timing of the nitrogen cylinder being out of sync with the stamping action; second, the pneumatic impact load generated during gas compression causes fluctuations in the pressing load, making it difficult to maintain a stable pressing force.

[0040] In this application, the delay is considered the essence of this system. This means that the eight delayed nitrogen cylinders do not work simultaneously, but are designed to provide support force in a specific sequence and at different times. Specifically, the delayed nitrogen cylinder system adopts a stepped pressing mode. During the downward movement of the upper mold, the eight delayed nitrogen cylinders are activated sequentially according to a preset timing. Each delayed nitrogen cylinder begins to apply pressing force at a specific time point, forming a continuous and gradual pressing process. This design ensures a gradual increase in pressing force and avoids localized stress concentration in the material caused by applying all the pressing force at once in traditional methods.

[0041] In this application, the distributed arrangement of eight sets of delayed nitrogen cylinders (three sets on each side and two sets in the middle area) and the precise coordination with the delayed control valve 5 realize the distribution and timing control of the pressing force. This stepped pressing method enables the sheet 17 to obtain a uniform force distribution during the flanging process, effectively avoiding uneven material flow caused by sudden changes in pressing force.

[0042] Therefore, when insert 7 descends to the lower dead center, the delay execution unit is pressed down, and the delay execution unit performs a pressure holding delay, specifically including: When insert 7 descends to the lower stop point, it presses down the first delayed nitrogen cylinder group 15; the first delayed nitrogen cylinder group 15 provides the initial pressing force and performs pressure holding delay.

[0043] Specifically, the six nitrogen cylinders in the first delayed nitrogen cylinder group 15 first contact the sheet metal 17 or the pressure plate. They provide an initial, relatively small pressure force (10T-20T) to initially fix the position of the sheet metal 17, but allow for slight material flow. When the insert 7 descends to the lower stop point, the connecting block 1 contacts the inductive contactor 2, triggering the inductive contactor 2 to connect the continuous air source provided by the press continuous system 13 to the pneumatic control reversing valve 4, and the internal channel of the pneumatic control reversing valve 4 is then switched. At this time, the first delayed nitrogen cylinder group 15 begins to provide the initial pressure force and enters the pressure holding delay stage. The first delayed nitrogen cylinder group 15 achieves precise control of the pressure force through the cooperation of the zero rebound device body 12 and the air circuit system. During the pressure holding delay, the zero rebound device body 12 monitors the oil pressure of the cavity and hose in real time to ensure that the stroke fluctuation of the first delayed nitrogen cylinder is strictly controlled within 1mm, so that the insert 7 remains stationary during the delayed pressure holding stage.

[0044] After the delay ends, when the insert 7 continues to move downwards, the method further includes: When the insert 7 continues to descend to between the lower dead center and the lower limit point, the multiple first delayed nitrogen cylinders of the first delayed nitrogen cylinder group 15 and the multiple second delayed nitrogen cylinders of the second delayed nitrogen cylinder group 16 dynamically adjust the pressing force of the sheet metal 17 according to the preset pressing force application requirements; when the insert 7 continues to descend to the lower dead center, both the first delayed nitrogen cylinder group 15 and the second delayed nitrogen cylinder group 16 apply the corresponding preset maximum pressing force.

[0045] Specifically, as the insert 7 continues to descend to the point between the lower stop and the lower dead center, the system, through the timing control of the delay control valve 5, causes multiple nitrogen cylinders of the first delayed nitrogen cylinder group 15 and multiple nitrogen cylinders of the second delayed nitrogen cylinder group 16 to work sequentially in a preset step-like order, gradually adjusting the pressure. During this dynamic adjustment process, the system applies pressure according to the preset pressure application requirements: the first and second delayed nitrogen cylinders, which are in contact with areas on the sheet 17 where the curvature is less than the set curvature threshold and where material is accumulated, start earlier than the preset start time setting or apply a pressure greater than the preset pressure; the first and second delayed nitrogen cylinders, which are in contact with areas on the sheet 17 where the curvature is greater than the set curvature threshold and the stretching depth is greater than the set depth threshold, start later than the preset start time setting or apply a pressure less than the preset pressure.

[0046] In this embodiment, each delayed nitrogen cylinder is controlled by an independent high-speed solenoid valve; all high-speed solenoid valves are connected to an electronic sequence controller 11. This application sequences eight groups of delayed nitrogen cylinders (multiple first delayed nitrogen cylinders and multiple second delayed nitrogen cylinders) according to actual conditions. During the sequential ignition phase, after receiving the start signal from the main controller 11, the electronic sequence controller 11 immediately sends a precise ignition current to the high-speed solenoid valve of the first delayed nitrogen cylinder, enabling it to complete the opening action in a very short time, thereby starting the delayed nitrogen cylinder's gas supply. Subsequently, the controller 11 follows a preset time sequence, sending trigger signals to the solenoid valves of subsequent delayed nitrogen cylinders at intervals (e.g., 5 milliseconds): after the first delayed nitrogen cylinder starts, it waits for a preset Δt1 time (e.g., 5 milliseconds) before sending current to the second delayed nitrogen cylinder; after the second cylinder starts, it waits for Δt2 time (e.g., 7 milliseconds) before starting the third cylinder, and so on, until all eight groups of delayed nitrogen cylinders have started sequentially. This step-by-step activation mechanism precisely controls the activation sequence of each of the eight groups, allowing the pressure to be applied to the workpiece surface in a step-by-step manner. This effectively avoids pressure fluctuations and uneven material flow that may be caused by simultaneous operation of multiple cylinders. In practical applications, the time interval parameters (such as Δt1, Δt2, etc.) can be dynamically adjusted according to the material thickness, part geometry, and process requirements.

[0047] The system implements a precise pressure control strategy based on the feeding resistance characteristics of different areas of the part: For areas prone to wrinkling (usually areas with small curvature and large material accumulation), the system increases the clamping force in advance to make the clamping force greater than the feeding resistance (e.g., 10 seconds in advance, a precise pressure of 15t is greater than the feeding resistance of 10t), effectively suppressing the material from flowing in too quickly and preventing wrinkling; For areas prone to tearing (usually areas with large curvature and large stretching depth), the system appropriately delays the clamping force or reduces the clamping force (e.g., delay time of 8 seconds or reduce the clamping force by 10t), allowing more material to flow in, supplementing the material needs of the stretching area, and preventing tearing defects.

[0048] The core of this dynamic adjustment mechanism lies in the distributed arrangement of eight sets of delayed nitrogen cylinders (3 sets on each side and 2 sets in the middle area) and the precise coordination of the delayed control valve 5, which start sequentially and provide precise pressing force to balance the stretching requirements of the straight edge area.

[0049] Subsequently, as the insert 7 continues to descend to the bottom dead center, both the first delayed nitrogen cylinder group 15 and the second delayed nitrogen cylinder group 16 apply their respective preset maximum clamping forces. Specifically, as the insert 7 continues to descend to the bottom dead center, the first delayed nitrogen cylinder group 15 and the second delayed nitrogen cylinder group 16 simultaneously enter the maximum clamping force working state. At this time, all eight delayed nitrogen cylinders reach their preset maximum working pressure, ensuring that the sheet metal 17 achieves sufficient plastic deformation and uniform stress distribution in the flanging area. By applying a uniform and sufficient clamping force at the bottom dead center, the system ensures that the springback defects in the flanging area of ​​the sunroof meet the accuracy requirements, significantly improving the accuracy and consistency of the flanging dimensions. At the same time, this control of clamping force also protects the surface of the part, avoiding scratches caused by the relative sliding between the die and the sheet metal 17 before clamping, thus ensuring the surface quality of the part.

[0050] In this application, the use of multiple sets of delayed nitrogen cylinders, rather than one or two sets, is based on a combination of advantages: Precise control of force distribution: By distributing the total support force across eight independent units, engineers can fine-tune the force required for each stage with extreme precision, much like tuning a piano. Each set of delayed nitrogen cylinders can have different pressure values ​​and delay characteristics.

[0051] Enhanced safety and reliability (advanced anti-pinch): The anti-pinch principle relies on the motor monitoring changes in current (resistance). If an obstacle is encountered during closing, the resistance increases, the current rises, and the motor immediately stops and reverses. Advantages of multiple delayed nitrogen cylinders: Using only one or two high-force delayed nitrogen cylinders results in a large initial force during closing, leading to a strong impact when encountering an obstacle, which is detrimental to anti-pinch performance. However, with eight delayed nitrogen cylinders, only a few low-force cylinders operate during the initial closing phase, providing a very gentle closing force. Upon encountering an obstacle, the motor can detect this minute change in resistance with extreme sensitivity and immediately reverse, achieving a highly sensitive, low-risk advanced anti-pinch function.

[0052] Layout flexibility and space optimization: Eight delayed nitrogen cylinders can be arranged more flexibly in the limited space around the sunroof assembly, optimizing lever arm and torque to achieve the best mechanical effect, which is difficult to achieve with a single large cylinder.

[0053] System redundancy and safety backup: If one of the delayed nitrogen cylinders fails due to extreme conditions, the remaining 7 delayed nitrogen cylinders can still provide sufficient support to safely close the sunroof or keep it open, avoiding the danger of the sunroof suddenly falling down and improving the system's fault tolerance and safety.

[0054] Optimized user experience: Multiple delayed nitrogen cylinders work together to eliminate the jerking, impact and noise during the switching process, achieving the premium feel and quietness expected of a top-tier luxury car.

[0055] Figure 5 The image shows the springback test results of the first mold trial after using a delayed nitrogen cylinder, compared with those obtained using... Figure 6 The AutoForm simulation results for edge rebound shown are different. The A-sides at the four corners of the sunroof show varying degrees of upward convexity, ranging from 0.5 to 1 mm, while the A-sides on both straight edges are sunken by 0.5 to 2.2 mm. These values ​​are out of tolerance and differ from conventional edge defects.

[0056] Based on the above embodiments, in this embodiment, before the upper mold assembly and insert 7 descend to contact the sheet metal 17 and the upper mold assembly applies a pressing force to the sheet metal 17 to fix it, the method further includes: during the mold design stage, designing the fillet radius and flange gap of the insert 7 based on the thickness of the sheet metal 17, the material of the sheet metal 17 and the design pressing force of the delay execution unit.

[0057] Specifically, in the panoramic sunroof flange process, optimizing the fillet radius and flange gap of the insert 7 during the mold design stage is a key step in ensuring flange quality. In this embodiment, before the upper mold assembly and insert 7 descend to contact the sheet 17 and apply pressure to fix it, a systematic design of the fillet radius and flange gap of the insert 7 was specifically carried out. This design fully considers the synergistic relationship between the sheet 17 thickness, the material properties of the sheet 17, and the design pressure of the delay execution unit.

[0058] Specifically, the design process begins by analyzing the thickness range and material type of sheet 17. For sheet 17 of different thicknesses, the fillet radius of insert 7 needs to be adjusted accordingly. At the same time, the ductility and strength characteristics of different materials also determine their deformation behavior during the flanging process.

[0059] The delayed execution unit provides a stable clamping force (10T-20T) through eight sets of delayed nitrogen cylinders. Precise control of this clamping force is crucial for suppressing springback defects. The flanging gap needs to be matched with the clamping force provided by the delayed nitrogen cylinders: when the delayed execution unit provides a larger clamping force, the flanging gap can be appropriately reduced to ensure sufficient constraint on the sheet metal 17 during the flanging process; when the clamping force is smaller, the flanging gap should be appropriately increased to allow adequate material flow space and avoid tearing problems caused by excessively small gaps.

[0060] See the table below:

[0061] The table above shows three typical states of flange gap: Positive gap (d=0.65mm): When the flange gap is greater than 65% of the material thickness, it is a separate flange. In this gap state, the sheet 17 has a larger flow space during the flange process, allowing the material to flow relatively freely. However, this also means that the constraint effect of the blank holder force on the material is weaker, easily leading to greater springback after flangering. In practical applications, the positive gap state is suitable for simple flange areas where springback requirements are not high, or for use when the material is relatively soft and has good ductility.

[0062] Zero-clearance state (d=0 mm): This is the ideal theoretical state, where the flanging punch and die just clamp the material thickness, with no additional clearance. In the zero-clearance state, the material is moderately constrained during flanging, ensuring proper material flow while providing sufficient constraint to suppress springback. However, the zero-clearance state requires high precision in die accuracy and material thickness tolerance, necessitating precise control in practical applications; otherwise, it can easily lead to material tearing or insufficient flanging.

[0063] Negative clearance state (d=-0.65mm): When the flanging clearance is less than 15% of the material thickness, it belongs to fine blanking flanging. In this state, the flanging punch and die exert a strong extrusion and shaping effect on the sheet metal 17, significantly increasing the constraint force of the material in the flanging area. The negative clearance state can effectively suppress springback, and is particularly suitable for the flanging process of panoramic sunroofs with high springback accuracy requirements. In practical applications, the negative clearance state can control springback defects within ±0.5mm, meeting the precision standards of high-end automotive sunroof A-sides.

[0064] In typical selections of fillet radius, R1 and R3 were chosen to differentiate the effects of small fillet radius (sharper bend, more pronounced springback) and large fillet radius (gentler bend, relatively less springback). Small fillet radius (R1) results in a larger curvature in the flanged area, making the material prone to stress concentration during flanged operation and leading to more significant springback; while large fillet radius (R3) results in a gentler curvature in the flanged area, more uniform material flow, and relatively less springback.

[0065] The selection of these flange clearance and fillet radius parameters is based on empirical values ​​or simulation results for specific working conditions (top cover window, nitrogen cylinder delay, stepped flange). During the mold design stage, the initial nitrogen pressure and clamping force can be selected with reference to these parameters according to the grade and thickness of the target material, and negative clearance structures should be given priority to suppress springback from the design source.

[0066] During actual debugging, if excessive rebound occurs on site, the direction can be quickly located and adjusted based on these parameters: If the rebound is too large, you can try increasing the nitrogen pressure or the clamping force to enhance the constraint on the sheet 17; you can reduce the flange gap (adjust to a negative gap) to increase the squeezing effect on the sheet 17 and effectively suppress the rebound; if the product design allows, you can appropriately increase the flange radius (such as from R1 to R3) to make the material flow more uniform and reduce the risk of rebound.

[0067] By optimizing the fillet radius and flanging clearance of insert 7 during the mold design stage, defects such as wrinkling and tearing that may occur during the flanging process are systematically solved, significantly improving the shape accuracy of surface A after flanging. This design method works well with the delayed nitrogen cylinder system, ensuring that sheet metal 17 achieves sufficient plastic deformation and uniform stress distribution in the flanging area during the delayed pressure holding stage, providing a reliable guarantee for the high-quality forming of the panoramic sunroof.

[0068] In summary, this application solves the problem of rebound in panoramic sunroof flanging by using a stepped segmented flanging method and parameter optimization matching; by scientifically dividing the flanging area and matching the optimal process parameters to each area, the rebound defect problem is systematically solved, transforming the sunroof flanging process from experience-driven to data-driven, and significantly improving the stability and repeatability of the process.

[0069] Secondly, this application provides a panoramic sunroof flapping control system, which includes: a first module, a second module, and a third module; the first module is used to: control the upper mold assembly and the insert 7 to descend and contact the sheet metal 17, so that the upper mold assembly applies a pressing force to the sheet metal 17 for fixing, and the insert 7 flaps the sheet metal 17; the second module is used to: control the insert 7 to descend to the lower stop point and press down the delay execution unit, the delay execution unit performs a pressure holding delay, so that the insert 7 remains stationary during the delay time; the third module is used to: control the insert 7 to continue descending after the delay ends, and work with the upper mold assembly to complete the flapping of the sheet metal 17.

[0070] In this application, a time-delay execution unit is activated when the insert 7 descends to the lower stop point to maintain pressure and delay. The time-delay execution unit keeps the insert 7 stationary during the delay time, achieving a continuous and stable application of the pressure force. This allows the sheet metal 17 to obtain sufficient plastic deformation and uniform stress distribution in the flanging area. This process avoids local stress concentration and uneven flow of the material caused by sudden force changes when the insert 7 continues to descend rapidly. It ensures that the sheet metal 17 is subjected to balanced force in all parts during the flanging process, thereby effectively suppressing springback defects and improving the dimensional accuracy and consistency of the flanging.

[0071] The functions of each module in the above-mentioned panoramic sunroof flap control system correspond to the steps in the above-mentioned panoramic sunroof flap control method embodiment, and their functions and implementation processes will not be described in detail here.

[0072] Thirdly, embodiments of this application provide a method and device for controlling the flapping edge of a panoramic sunroof. The method and device for controlling the flapping edge of a panoramic sunroof can be a personal computer (PC), a laptop computer, a server, or other devices with data processing capabilities.

[0073] In this embodiment of the application, the device for controlling the flapping edge of the panoramic sunroof may include a processor, a memory, a communication interface, and a communication bus.

[0074] The communication bus can be of any type and is used to interconnect the processor, memory, and communication interface.

[0075] The communication interface includes input / output (I / O) interfaces, physical interfaces, and logical interfaces used for interconnecting internal components of the panoramic sunroof flap control device, as well as interfaces used for interconnecting the panoramic sunroof flap control device with other devices (such as other computing devices or user equipment). Physical interfaces can be Ethernet interfaces, fiber optic interfaces, ATM interfaces, etc.; user equipment can be displays, keyboards, etc.

[0076] Memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0077] The processor can be a general-purpose processor, which can call the panoramic sunroof flap-up control method program stored in the memory and execute the panoramic sunroof flap-up control method provided in the embodiments of this application. For example, the general-purpose processor can be a central processing unit (CPU). The method executed when the panoramic sunroof flap-up control method program is called can refer to the various embodiments of the panoramic sunroof flap-up control method of this application, and will not be repeated here.

[0078] Fourthly, embodiments of this application also provide a computer-readable storage medium.

[0079] The computer-readable storage medium of this application stores a program for a method of controlling the flapping edge of a panoramic sunroof, wherein when the program is executed by a processor, it implements the steps of the panoramic sunroof flapping edge control method described above.

[0080] The method implemented when the panoramic sunroof flap-up control method program is executed can be referred to in various embodiments of the panoramic sunroof flap-up control method of this application, and will not be repeated here.

[0081] It should be noted that the sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0082] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus. The terms "first," "second," and "third," etc., are used to distinguish different objects, etc., and do not indicate a sequence, nor do they limit "first," "second," and "third" to different types.

[0083] In the description of the embodiments of this application, terms such as "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a concrete manner.

[0084] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.

[0085] In some processes described in the embodiments of this application, multiple operations or steps are included in a specific order. However, it should be understood that these operations or steps may not be executed in the order they appear in the embodiments of this application, or they may be executed in parallel. The sequence number of the operation is only used to distinguish different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed sequentially or in parallel, and these operations or steps may be combined.

[0086] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device to execute the methods described in the various embodiments of this application.

[0087] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A method for controlling the flapping edge of a panoramic sunroof, characterized in that, It includes: The upper mold assembly and insert (7) move downward to contact the sheet metal (17), so that the upper mold assembly applies a pressing force to the sheet metal (17) to fix it, and the insert (7) flangs the sheet metal (17); When the insert (7) descends to the lower stop point, the delay execution unit is pressed down. The delay execution unit performs a pressure holding delay, so that the insert (7) remains stationary during the delay time. After the delay ends, the insert (7) continues to descend and works with the upper mold assembly to complete the flanging of the sheet metal (17).

2. The method for controlling the upturned edge of the panoramic sunroof as described in claim 1, characterized in that, The delayed execution unit includes: The first delayed nitrogen cylinder group (15) includes a plurality of first delayed nitrogen cylinders; The second delayed nitrogen cylinder group (16) includes a plurality of second delayed nitrogen cylinders; Among them, multiple first delayed nitrogen cylinders are located below the plate (17) and are arranged along the edge of the plate (17); Multiple second-delay nitrogen cylinders are located below the sheet (17) and are positioned in the middle of the sheet (17).

3. The method for controlling the upturned edge of the panoramic sunroof as described in claim 2, characterized in that, When the insert (7) descends to the lower dead center, it presses down on the delay execution unit, which performs a pressure holding delay, specifically including: When the insert (7) descends to the lower dead center, it presses down the first delayed nitrogen cylinder group (15); The first delayed nitrogen cylinder group (15) provides the initial pressing force and performs a pressure holding delay.

4. The method for controlling the upturned edge of the panoramic sunroof as described in claim 3, characterized in that, After the delay ends, when the insert (7) continues to move downwards, the method further includes: When the insert (7) continues to descend to between the lower dead point and the lower dead point, the multiple first delayed nitrogen cylinders of the first delayed nitrogen cylinder group (15) and the multiple second delayed nitrogen cylinders of the second delayed nitrogen cylinder group (16) dynamically adjust the pressing force of the plate (17) according to the preset pressing force application requirements. When the insert (7) continues to descend to the bottom dead center, the first delayed nitrogen cylinder group (15) and the second delayed nitrogen cylinder group (16) both apply the corresponding preset maximum pressing force.

5. The method for controlling the upturned edge of the panoramic sunroof as described in claim 4, characterized in that, The preset pressure application requirements include: The first delayed nitrogen cylinder and the second delayed nitrogen cylinder, which are in contact with the area on the sheet (17) where the curvature is less than the curvature setting threshold and the material is piled up, start earlier than the preset start time setting value or apply a pressing force greater than the preset pressing force; The first delayed nitrogen cylinder and the second delayed nitrogen cylinder, which are in contact with the area on the sheet (17) where the curvature is greater than the curvature setting threshold and the stretching depth is greater than the depth setting threshold, delay the start-up of the preset start-up time setting or apply a pressing force less than the preset pressing force.

6. The method for controlling the upturned edge of the panoramic sunroof as described in claim 1, characterized in that: The delay execution unit performs a pressure holding delay, which is achieved through a zero-bounce system.

7. The method for controlling the upturned edge of the panoramic sunroof as described in claim 6, characterized in that, The zero rebound system includes: Zero rebound device body (12); Inductive contactor (2); Connecting block (1), which is connected to inductive contactor (2); Pneumatic reversing valve (4), the input end of the pneumatic reversing valve (4) is connected to the output end of the induction contactor (2) through the air pipeline (3), and the pneumatic reversing valve (4) is connected to the body (12) of the zero rebound device; The output end of the pneumatic directional valve (4) is connected to the input end of the delay control valve (5), and the output end of the delay control valve (5) is connected to the pneumatic directional valve (4).

8. The method for controlling the upturned edge of the panoramic sunroof as described in claim 7, characterized in that, The zero-springback system achieves pressure holding delay, specifically including: Connecting block (1) triggers inductive contactor (2); The inductive contactor (2) controls the pneumatic reversing valve (4) to switch the air path to connect the delay control valve (5) to start the pressure holding delay.

9. The method for controlling the upturned edge of the panoramic sunroof as described in claim 1, characterized in that: The upper mold assembly applies a pressing force to the sheet metal (17) to fix it. When the insert (7) flangs the sheet metal (17), the pressing force is adjusted by the balance block (10). Before the upper mold assembly and insert (7) descend to contact the sheet metal (17) and the upper mold assembly applies a pressing force to the sheet metal (17) to fix it, the method further includes: during the mold design stage, designing the fillet radius and flange gap of the insert (7) based on the sheet metal (17) thickness, sheet metal (17) material and the design pressing force of the delay execution unit.

10. A roof panoramic sunroof flap control system, characterized in that, It includes: The first module is used to: control the upper mold assembly and the insert (7) to descend and contact the sheet metal (17), so that the upper mold assembly applies a pressing force to the sheet metal (17) to fix it, and the insert (7) flanging the sheet metal (17); The second module is used to: control the insert (7) to press down the delay execution unit when it descends to the lower stop point, and the delay execution unit performs pressure holding delay so that the insert (7) remains stationary during the delay time; The third module is used to: control the insert (7) to continue to descend after the delay ends, and work with the upper mold assembly to complete the flanging of the sheet metal (17).

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