Automatic cutting and forming system of stainless steel plate and tray circulating conveying system and method

Abstract

The application discloses a kind of automatic cutting forming system of stainless steel plate, tray circulation conveying system and method.The system includes cutting device, stamping forming device, handling device and positioning and separating device.Positioning and separating device are cooperated with the grabbing suction disc of the end of handling device through adjusting seat, edge limiting plate, fixed suction disc, realize the integrated operation of accurate positioning, multiple separation and surface defect detection of stainless steel plate.The system is also provided with single piece judging mechanism based on the pressure change of vacuum pipeline and anti-overlapping separation mechanism based on weight sensor, to ensure that single plate enters processing procedure.Double-layer tray circulation conveying system realizes the closed-loop circulation of tray by upper conveying line, lower backflow line and two-end lifting mechanism, so that stainless steel plate is automatically conveyed between stacking, positioning, cutting and forming stations without manual intervention, improving the automation level and production efficiency of hand dryer shell production line.

Description

Technical Field

[0001] This invention relates to the field of stainless steel sheet stamping technology, and in particular to an automatic stainless steel sheet cutting and forming system and a double-layer pallet circulating conveying system for a hand dryer housing production line. Background Technology

[0002] Hand dryers are automated devices widely used in public restrooms. Their casings are typically made of stainless steel sheets through cutting and stamping. With increasing market demand, the manufacturing of hand dryer casings is gradually shifting from manual labor to automated production lines.

[0003] In automated stamping production lines for stainless steel sheets, automatic sheet material handling and transport are crucial. Existing technologies typically employ robotic arms in conjunction with vacuum suction cups to pick up stainless steel sheets one by one from a stack, then transport them to the stamping station for processing. For example, patent document CN206455102U discloses a multi-station automatic fixture for stamping machines, which uses a suction cup assembly in conjunction with a clamping assembly to automatically pick up and place stamped parts. However, during long-term stacking and storage of stainless steel sheets, adjacent sheets may adhere tightly due to their high surface finish, creating a vacuum-like adsorption effect, making it easy for multiple sheets to be adsorbed simultaneously during material handling. Most existing automatic feeding systems lack effective multi-sheet detection and separation mechanisms, often relying on visual inspection by operators or simple thickness limiters to determine if it is a single sheet. This reliability is insufficient; if multiple sheets enter the stamping station, it can cause damage to the mold and product scrap, or even equipment failure and safety accidents.

[0004] Furthermore, during handling and stacking, the reverse side (the side without protective film) of stainless steel sheets is prone to surface defects such as scratches and dents. Existing sheet defect detection typically uses a separate visual inspection station, requiring the sheet to be additionally positioned and fixed before inspection. This not only increases equipment investment and floor space but also adds an extra positioning-inspection-release cycle, impacting production line efficiency. Integrating defect detection with sheet positioning and separation operations into a single station is one of the key issues for improving production line efficiency.

[0005] Regarding material transfer between workstations, traditional stamping production lines often employ single-layer conveyor lines or manual handling. Single-layer conveyor lines suffer from pallet return issues, typically requiring operators to manually move empty pallets back to the loading end, or necessitating a separate return channel that occupies valuable workshop floor space. Patent document CN107081582B discloses an automated assembly line that achieves automated transfer between multiple workstations, but its conveyor system does not employ a double-layer circulation structure, meaning pallet return still requires additional floor space and manual intervention. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides an automatic stainless steel plate cutting and forming system and a double-layer pallet circulating conveying system for hand dryer housing production lines, along with their operating methods.

[0007] A first aspect of the present invention provides an automatic stainless steel sheet cutting and forming system, comprising: a cutting device for cutting stainless steel sheets; a stamping and forming device for stamping the cut stainless steel sheets; a conveying device having a gripping suction cup at its end for adsorbing stainless steel sheets; and a positioning and separation device including an adjusting seat, an edge limiting plate and a pneumatic component for driving its movement, and a fixing suction cup. The upper end of the adjusting seat has a limiting area for defining the position of the stainless steel sheet; the edge limiting plate is used to push the stainless steel sheet and limit it within the limiting area; the fixing suction cup is disposed on the adjusting seat for adsorbing the stainless steel sheet from below, and works in conjunction with the gripping suction cup from both upper and lower sides to achieve the fixing of the stainless steel sheet and the separation of multiple sheets.

[0008] Beneficial effects: The positioning and separation device enables precise positioning of stainless steel plates in the horizontal plane and reliable fixation in the vertical direction, allowing the conveying device to accurately grab the stainless steel plates at fixed points and place them with high precision at the designated positions in each workstation in accordance with the planned movement route, reducing the operation error of cutting and stamping; at the same time, the fixed suction cup and the gripping suction cup work together to adsorb from the top and bottom sides, which can effectively separate multiple plates.

[0009] Furthermore, the positioning and separation device is also equipped with a defect detection mechanism, used to perform defect detection on the surface of the stainless steel plate while it is being secured by the edge limiting plate, the fixing suction cup, and the gripping suction cup. By simultaneously performing defect detection while the plate is fully secured on the positioning and separation device, no additional fixing process is required, saving cycle time. Moreover, detection while the plate is secured ensures the accuracy and consistency of the detection results, allowing for the timely removal of plates with surface defects such as scratches and dents before forming and processing, preventing defective plates from entering subsequent processes and causing scrap, thus reducing material waste and production costs.

[0010] Furthermore, the system also includes a single-piece judgment and separation mechanism. By detecting pressure changes within the vacuum tube of the gripping suction cup, it determines whether the currently fixed stainless steel plate is a single piece or multiple pieces. If multiple pieces are determined, the excess plate is removed by a conveying device. Automatic single-piece and multiple-piece discrimination is achieved through pressure changes within the vacuum tube, utilizing the different negative pressure characteristics generated by the fixing and gripping suction cups in single-piece and multiple-piece states. The judgment principle is reliable and requires no additional complex detection equipment. When multiple pieces are determined, automatic separation is performed to ensure that only single-piece plates ultimately enter the processing stage.

[0011] Furthermore, the upper end of the adjusting seat is evenly distributed with multiple smooth ball bearings. The edge limiting plate pushes the stainless steel plate along the surface of the ball bearings to the defined area. There are four sets of edge limiting plates, of which two adjacent sets are movably installed and connected to pneumatic components, and the other two sets are fixedly installed. The two movably installed sets and the two fixed sets cooperate to form the defined area. The ball bearings allow the stainless steel plate to move by rolling friction instead of sliding friction, effectively avoiding scratches on the plate surface. The configuration of two movable and two fixed sets of the four edge limiting plates not only achieves precise positioning of the plate but also simplifies the number of pneumatic components and the control logic.

[0012] Furthermore, the defect detection mechanism includes a spiral involute groove disposed on the upper surface of the adjusting seat and a detection probe passing through the spiral involute groove. The spiral involute groove avoids the placement positions of the ball bearings and the fixed suction cup. The detection probe contacts the lower surface of the stainless steel plate and runs along the trajectory of the spiral involute groove. When it passes the defect location, the probe undergoes a displacement change, which is converted into an electrical signal output by its internal sensing element. The placement positions of the ball bearings and the fixed suction cup are pre-planned so that when the stainless steel plate is rotated 90 degrees and repositioned within the defined area, the previously obscured area falls within the effective detection path of the spiral involute groove, achieving full coverage detection. The trajectory design of the spiral involute groove enables the detection probe to perform a comprehensive detection scan of the reverse side of the plate within the set radial pitch and involute coverage range, resulting in high detection accuracy and wide coverage. By pre-planning the placement positions of the ball bearings and the fixed suction cup, combined with secondary detection after 90 degrees rotation, full coverage can be achieved, ensuring no missed areas on the plate surface without the need for complex detection equipment. The solution is simple and reliable.

[0013] Furthermore, the conveying device is equipped with an anti-overlap separation mechanism, including a weight sensor installed at the end of the conveying device. When the weight reaches a preset multi-piece threshold, the excess sheet is shaken off. The shaking action has an adaptive adjustment mechanism. When the positioning and separation device detects multiple pieces adhering, it records the adhesion tendency of that batch of sheets and automatically increases the shaking amplitude and number of shakes in steps based on the cumulative number of adhesion tendencies. If multiple consecutive determinations indicate a single piece, the shaking amplitude is automatically decreased in steps. The weight sensor can pre-separate three or more pieces adhering during the conveying stage, reducing the workload of the subsequent positioning and separation devices. The adaptive adjustment mechanism dynamically adjusts the shaking parameters according to the adhesion characteristics of the actual batch of sheets. In batches with high adhesion tendency, the separation force is strengthened to ensure the separation effect, while in batches with low adhesion tendency, the shaking amplitude is reduced to improve work efficiency, achieving an intelligent balance between separation effect and production efficiency.

[0014] This invention also provides a double-layer pallet circulating conveyor system for a hand dryer housing production line, applied to the aforementioned automatic stainless steel plate cutting and forming system. The system further includes a double-layer pallet circulating conveyor system for automatically transferring stainless steel plates between workstations. The system includes: an upper conveyor line for conveying pallets carrying stainless steel plates downstream along the processing direction; a lower return line, located below the upper conveyor line and in the opposite direction, for returning empty pallets; a loading elevator and a unloading elevator, respectively located at both ends of the upper conveyor line, for transferring pallets between the upper conveyor line and the lower return line, enabling multiple pallets to form a closed-loop circulating flow; a pallet with a positioning structure on its upper surface for limiting the movement of the stainless steel plate; and stop positioning mechanisms located at corresponding positions at each workstation for positioning and stopping the pallet at a preset position. The double-layer conveyor structure achieves closed-loop circulation of pallets through the spatial stacking of the upper and lower conveyor lines and the connection of lifting mechanisms at both ends, avoiding the manual handling of pallets and greatly improving the automation level and production cycle of the production line; multiple pallets can circulate in the system at the same time, forming a continuous flow operation; the handling device is only responsible for picking up and placing the boards from the pallets to the working area of ​​each device, simplifying the handling path and control logic.

[0015] Furthermore, the positioning structure consists of a positioning groove on the upper surface of the pallet that matches the shape of the stainless steel plate, with a flexible protective pad at the bottom of the positioning groove; the stop positioning mechanism includes a liftable stop block and a photoelectric sensor for detecting the pallet's arrival signal. The positioning groove matches the shape of the stainless steel plate, which can initially limit the plate's position during transport to prevent deviation; the flexible protective pad can prevent scratches on the reverse side of the stainless steel plate during transport; the liftable stop block, in conjunction with the photoelectric sensor, enables the pallet to stop precisely at each workstation, ensuring that the handling device accurately picks up and places the plate.

[0016] This invention also provides a working method based on the aforementioned double-layer pallet circulating conveyor system, comprising the following steps: S1 empty pallet lifting, S2 loading and conveying, S3 positioning, stopping and material handling, S4 subsequent station processing, and S5 unloading and return. Multiple pallets simultaneously circulate within the double-layer pallet circulating conveyor system, forming a continuous flow operation. This method achieves fully automated operation of stainless steel plates from material handling to forming, requiring no manual intervention. The simultaneous circulation of multiple pallets maximizes the processing capacity of each station, avoids idle waiting between stations, and improves the overall production efficiency of the hand dryer housing production line.

[0017] Furthermore, step S3 also includes: after limit adjustment, activating the fixing suction cup and the gripping suction cup to adsorb and fix the stainless steel plate from the top and bottom sides; in the fixed state, activating the defect detection mechanism to perform defect detection on the surface of the stainless steel plate; if the detection is unqualified, it is transferred to the waste material recycling area; after the detection is qualified, the pressure change in the vacuum tube of the gripping suction cup determines whether it is a single piece or multiple pieces; if it is determined to be multiple pieces, the excess plate is removed until it is determined to be a single piece. Limit adjustment, defect detection, and single piece determination are integrated into the same station and executed sequentially, completing all inspection operations in the fixed state of the plate, eliminating the need for repeated fixing and releasing, saving cycle time; the defect detection is performed before the single piece determination, so even if there is double-piece adsorption, the detection probe only contacts the exposed reverse side of the bottom plate, and the detection result is not affected by the upper plate, ensuring the accuracy of the detection.

[0018] Furthermore, in step S2, after the conveying device picks up the stainless steel sheet, it determines the weight of the picked-up sheet using a weight sensor installed at its end. When the determined weight reaches a multiple-piece threshold, the conveying device shakes to throw off the excess sheet before placing it on the pallet. By using a weight sensor to predict and separate multiple pieces during the material picking stage, three or more excess sheets can be removed in advance during the conveying process, reducing the workload of subsequent positioning and separation devices and improving overall production efficiency.

[0019] Furthermore, in step S4, after the stainless steel sheet is cut at the cutting station, it is conveyed back to the adjustment station via the upper conveyor line. After being repositioned by the positioning and separation device, it is then conveyed to the forming station for stamping. The precise positioning via the positioning and separation device after cutting eliminates positional deviations generated during the cutting process, ensuring that the positional accuracy of the sheet meets requirements during stamping and improving the dimensional accuracy and consistency of the formed product. Attached Figure Description

[0020] Figure 1 A schematic diagram showing the shape of the stainless steel sheet before and after cutting; Figure 2 A three-dimensional schematic diagram of the box-shaped structure of a hand dryer shell; Figure 3 This is a three-dimensional view of the overall layout of the automatic stainless steel plate cutting and forming system of the present invention. Figure 4 This is a three-dimensional structural diagram of the cutting device, stamping device, conveying device, and positioning and separating device of the present invention. Figure 5 A three-dimensional structural diagram showing the positioning and separation device working in conjunction with the cutting and conveying device; Figure 6 A top view of the upper surface of the adjustment seat of the positioning and separation device (including the defect detection mechanism with spiral involute groove). Figure 7This is a top view of the upper surface of the adjustment seat using the visual optical detection structure in Example 2; Figure 8 This is a schematic diagram of the stainless steel sheet processing flow. Figure 9 A detailed flowchart illustrating the process of stainless steel plate positioning, defect detection, single-piece judgment, and processing; Figure 10 A schematic diagram illustrating the principle layout of a double-layer pallet circulating conveyor system; Figure 11 A schematic diagram illustrating the working process of a double-layer pallet circulating conveyor system; Figure 12 A side view schematic diagram of the principle of a double-layer pallet circulating conveyor system; Figure 13 This is a site photo of the stainless steel sheet stacking station.

[0021] Figure label: Stainless steel sheet 01, box structure 02, cutting device 10, stamping and forming device 20, cutting and handling device 30, forming and handling device 40, positioning and separation device 50, adjusting seat 51, edge limiting plate 52, pneumatic component 53, fixed suction cup 54, ball bearing 55, gripping suction cup 60, defect detection mechanism 70, spiral involute grooving 71, visual optical inspection structure 72, double-layer pallet circulating conveyor system 80, upper layer conveyor line 81, lower layer return line 82, loading elevator 83, unloading elevator 84, pallet 85, stacking station 011, stacking station 022, cutting station 101, forming station 201, adjusting station 501. Detailed Implementation

[0022] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0023] Example 1: refer to Figure 1 , Figure 2 This embodiment provides an automatic stainless steel sheet cutting and forming system, which is used to cut rectangular stainless steel sheets 01 (such as...) Figure 1 (As shown) A box-shaped structure 02 molded into the housing of a hand dryer (as shown) Figure 2 As shown in the diagram, this process involves steps such as precise handling, defect inspection, scrap cutting, and stamping. During long-term stacking, multiple stainless steel sheets can become tightly adhered and difficult to separate. Therefore, during the handling phase, it is necessary to ensure that only a single stainless steel sheet is retrieved each time.

[0024] Specifically, refer to Figure 1 , Figure 2The forming system includes: a cutting device 10 for cutting stainless steel sheets to meet the structural shape required for subsequent stamping forming; a stamping forming device 20 for stamping the stainless steel sheets into a box-shaped structure; a cutting and conveying device 30 for conveying the stainless steel sheets to the cutting device 10; a forming and conveying device 40 for conveying the cut stainless steel sheets to the stamping forming device 20; and a positioning and separation device 50 for accurately positioning the stainless steel sheets and separating multiple sheets, ensuring that the two conveying devices can accurately grasp the stainless steel sheets at fixed points, and place the stainless steel sheets at the designated positions on the workstation with high precision in accordance with the planned movement route, reducing the operational errors of cutting and stamping forming, and avoiding the situation of multiple sheets adhering to each other.

[0025] Among them, such as Figure 1 As shown, the cutting device 10, positioning and separating device 50, and stamping forming device 20 are respectively arranged at the three corners of the rectangle; the cutting and conveying device 30 can move between the stainless steel plate stacking station 011, the positioning and separating device 50's adjustment station 501, and the cutting device 10's cutting station 101; the forming and conveying device 40 can move between the adjustment station 501, the stamping forming device 20's forming station 201, and the box-shaped finished product stacking station 022. The cutting and conveying device 30 and the forming and conveying device 40 preferably adopt a multi-degree-of-freedom robotic arm structure, and both robotic arms have gripping suction cups 60 installed at their end effectors (e.g., ...). Figure 5 As shown in the figure, it is used to grasp stainless steel plates by negative pressure adsorption.

[0026] In this embodiment, the positioning and separation device 50 achieves precise positioning of the stainless steel plate through its own structure; in conjunction with the gripping suction cups 60 of the cutting and conveying device 30 and the forming and conveying device 40, it realizes the separation of multiple pieces of stainless steel plate and further limiting and fixing, thereby facilitating defect detection at this stage.

[0027] Specifically, refer to Figure 5 , Figure 6 The positioning and separation device 50 includes: Adjustment seat 51, the upper end of which has a limiting area for defining the position of stainless steel plate, the limiting area matching the rectangular shape of stainless steel plate; The edge limiting plate 52 is provided in four sets, of which two adjacent sets are movably installed and each is equipped with a pneumatic component 53. The pneumatic component 53 is preferably a linear cylinder, which is equipped with a position sensor to limit its extension length (the position sensor is not shown in the figure). The pneumatic component 53 is used to push the edge limiting plate 52 and the stainless steel plate connected to it to move, so as to form a defined limiting area with the other two fixed edge limiting plates, and to limit the stainless steel plate within the defined area, so as to facilitate the precise gripping of the cutting and handling device 30 and the forming and handling device 40. The fixed suction cup 54 is set on the upper end of the adjustment seat 51, and an air pump (not shown in the figure) is connected below it to adsorb the lower end of the stainless steel plate through negative pressure. At the same time, it works in conjunction with the gripping suction cup 60 to further realize the reliable fixation of the stainless steel plate to facilitate defect detection. On the other hand, by fixing the lower stainless steel plate, the upper stainless steel plate can be reliably separated and gripped in single pieces.

[0028] Multiple fixed suction cups 54 and gripping suction cups 60 are provided. When the stainless steel plate is positioned in the defined area, the fixed suction cups 54 and gripping suction cups 60 are positioned in the same location. In this embodiment, four fixed suction cups are provided and distributed in a rectangular shape.

[0029] Preferably, refer to Figure 5 , Figure 6 The upper end of the adjustment seat 51 is evenly provided with a plurality of smooth balls 55. When the pneumatic component 53 pushes the edge limiting plate 52 connected to it to move, the two edge limiting plates 52 push the stainless steel plate to roll along the surface of the balls 55 to avoid scratches on the surface of the stainless steel plate.

[0030] Furthermore, since the front side of the stainless steel plate (i.e., the side that is gripped by the suction cup) is usually covered with a protective film, while the back side is not, it is easily damaged. Therefore, the positioning and separation device 50 is also equipped with a defect detection mechanism 70 (such as...). Figure 6 As shown, it is used to inspect the reverse side of stainless steel plates for surface defects such as scratches.

[0031] The defect detection mechanism 70 is activated after the stainless steel plate is fixed. The stainless steel plate is reliably fixed with zero degrees of freedom through the coordinated action of the aforementioned edge limiting plate 52, fixing suction cup 54 and gripping suction cup 60.

[0032] Among them, reference Figure 6 The defect detection mechanism 70 includes a spiral involute 71 and a detection probe (not shown in the figure). The spiral involute 71 is located on the upper surface of the adjusting seat 51, avoiding the positions of the ball bearing 55 and the fixed suction cup 54. The detection probe passes through the spiral involute 71 and contacts the reverse side of the stainless steel. By circulating along the trajectory of the spiral involute 71, it scans the reverse side of the stainless steel within a set radial pitch and involute coverage range, accurately reflecting the presence of defects on the plate surface. (The spiral involute 71 is shown in the figure.) Figure 6 As shown, its radial pitch can be adjusted according to actual conditions.

[0033] When the detection probe passes over areas with defects such as scratches or dents, its movement causes a displacement change. The internal sensing element of the probe converts this displacement change into an electrical signal output, thus detecting surface defects. Furthermore, to ensure that the corresponding portions of the ball bearings 55 and the fixed suction cups 54 are not detected, a second defect detection can be performed after the first inspection by rotating the robotic arm 90 degrees and placing it back into the designated area. The placement of the ball bearings 55 and the fixed suction cups 54 is pre-planned so that after the board is rotated 90 degrees, the previously obscured areas fall within the effective detection path of the spiral involute 71, achieving full coverage. In actual production, based on the board defect rate statistics, a second inspection can be performed only on sampled batches or high-risk batches to balance inspection coverage and production efficiency.

[0034] After passing the aforementioned defect detection, it is necessary to ensure that there is only one stainless steel plate at this point, and that multiple stainless steel plates are not adsorbed. To this end, a single-plate judgment and separation mechanism is implemented to determine whether the stainless steel plate itself is adsorbed. This is achieved through the coordinated operation of the fixed suction cup 54, the gripping suction cup 60, and the pressure sensor within their vacuum tubing (the pressure sensor is not shown in the figure). The judgment is made by real-time acquisition of the instantaneous negative pressure peak and holding pressure value of the gripping suction cup 60. The specific principle is as follows.

[0035] When the stainless steel sheet is a single piece, both its top and bottom ends are subjected to negative pressure adsorption. Therefore, the upper gripping suction cup 60 will encounter significant resistance during suction and transfer, causing the negative pressure in its internal pipeline to rise abnormally and remain for an extended period. This triggers the pressure sensor, which generates a signal indicating that it is a single piece of stainless steel. The standard operating procedure can then proceed: releasing the negative pressure of the fixed suction cup 54, maintaining the negative pressure of the gripping suction cup 60, and allowing the cutting and transporting device 30 to transport the stainless steel sheet to the cutting station 101 along the predetermined route. When the stainless steel sheet is two or more pieces, the gripping suction cup 60 only needs to overcome the adsorption force between the two adhered stainless steel sheets. The two adsorbed stainless steel sheets easily separate, causing the vacuum pipeline to depressurize rapidly. However, the negative pressure then returns to the normal calibration range, triggering the pressure sensor and generating a signal indicating that it is multiple pieces of stainless steel. Therefore, a stainless steel sheet separation operation is required. The cutting and transporting device 30 picks up the upper stainless steel sheet and transports it to the stacking station 011. The adsorption situation is then assessed using the same principle until a signal indicating that it is a single piece of stainless steel is triggered.

[0036] Furthermore, if multiple stainless steel plates are adsorbed, they need to be separated one by one, which greatly affects work efficiency. Therefore, the cutting and handling device 30 is also equipped with an anti-overlap separation mechanism, which includes a weight sensor installed at the end of the robotic arm (the weight sensor is not shown in the figure). By sensing the obvious difference between the total weight of multiple stainless steel plates and the weight of a single plate, it can accurately detect whether multiple plates are adsorbed. Then, the robotic arm is shaken to throw the excess stainless steel plates into a specific area with a protective pad to avoid damage during the fall.

[0037] It should be noted that the weight sensor mentioned above can accurately detect the situation where three or more stainless steel plates are adsorbed and overlapped. However, when only two plates overlap, the adsorption force of the gripping suction cup 60 and the weight of the stainless steel plate itself are superimposed and mixed, making it difficult for the weight sensor to accurately distinguish the weight difference between a single plate and two plates. In this case, the positioning and separation device 50 can be used to determine whether the stainless steel plate is adsorbed and to separate it.

[0038] Furthermore, the robotic arm's shaking function is equipped with an adaptive adjustment mechanism. Specifically, when two stainless steel plates are detected at adjustment station 501, the system automatically records that the batch of plates has an "adhesion tendency." For the same batch of stainless steel plates, the shaking amplitude and frequency are automatically increased in steps based on the cumulative number of "adhesion tendency" records (but with range limitations to avoid excessive impact from falling plates causing damage). If multiple consecutive records show only a single plate, the shaking amplitude is automatically decreased in steps to improve work efficiency. It should be noted that the shaking action involves the robotic arm lifting one end of the stainless steel plate above stacking station 011 and swinging it back and forth, while the other end of the plate remains within the stacking area.

[0039] In this embodiment, both the cutting device 10 and the stamping forming device 20 are existing products, so only their structures are briefly described. The cutting device 10 can be a laser or plasma cutting machine, which performs cutting processing on the four corners of the stainless steel plate (e.g., Figure 1 As shown in the figure, this ensures that the dimensional requirements of the subsequent forming process are met. The stamping forming device 20 adopts a punch press structure, including an upper die and a lower die. The stainless steel plate is placed on the lower die, and then the upper die is pressed down to form the product.

[0040] To improve the automation level and cycle efficiency of the production line, this embodiment adds a double-layer pallet circulating conveyor system 80 between each workstation to carry stainless steel plates and automatically transfer them between workstations. The robotic arm is only responsible for picking up and placing the plates from the pallet to the working area of ​​each device.

[0041] The double-layer pallet circulating conveyor system 80 includes: The upper conveyor line 81 is arranged horizontally along the direction of stacking station 011 → adjustment station 501 → cutting station 101 → forming station 201, and is used to carry the pallet containing stainless steel plates forward in sequence along the processing direction. The lower return line 82 is located directly below the upper conveyor line 81, and its conveying direction is opposite to that of the upper line. It is used to return the empty pallets after unloading from the end to the beginning. The loading elevator 83 is located at the beginning of the conveying system (on the side of the stacking station 011) and is used to lift the empty pallets returned from the lower return line 82 to the starting position of the upper conveying line 81 for reloading. The unloading elevator 84 is located at the end of the conveying system (on the side of the forming station 201) and is used to lower the empty pallet after unloading from the upper conveyor line 81 to the starting position of the lower return line 82 for return.

[0042] Multiple pallets 85 are provided and circulate between the upper conveyor line 81 and the lower return line 82. The upper surface of the pallet 85 has positioning grooves adapted to the shape of the stainless steel sheet, used to initially limit the sheet's position during transport and prevent displacement. A flexible protective pad (such as a silicone pad) is placed at the bottom of the positioning groove to prevent scratches on the reverse side of the stainless steel sheet during transport.

[0043] Both the upper conveyor line 81 and the lower return line 82 adopt roller conveyor structure or belt conveyor structure. Each workstation is equipped with a stop positioning mechanism, including liftable blocks and photoelectric sensors, to accurately stop the pallet at the preset position of each workstation so that the robotic arm can accurately pick up and place the board.

[0044] The double-layer pallet circulating conveyor system 80 works in conjunction with the cutting and handling device 30, the forming and handling device 40, and the positioning and separating device 50. Specifically: At the stacking station 011, the cutting and handling device 30 picks up the stainless steel sheet from the stack of sheet metal and places it on the tray 85 of the upper conveyor line 81. After the tray 85 moves with the upper conveyor line 81 to the corresponding position of the adjustment station 501, it is precisely positioned and stopped by the stop positioning mechanism. The cutting and handling device 30 then takes the sheet metal from the tray 85 and places it on the adjustment seat 51 of the positioning and separation device 50 to perform limit adjustment, defect detection and single piece judgment. After completion, the sheet metal is put back on the tray 85 and continues to move along the upper conveyor line 81 to the cutting station 101 and the forming station 201.

[0045] At the forming station 201, the forming and handling device 40 takes the sheet material from the pallet 85 and puts it into the stamping and forming device 20. After forming, the finished product is stacked to the stacking station 022. At this time, the empty pallet 85 is lowered by the unloading elevator 84 to the lower return line 82, returns to the beginning along the return direction, and is then lifted by the loading elevator 83 to the upper conveyor line 81 to complete one cycle.

[0046] Work methods: refer to Figures 1 to 13 This embodiment provides a method for operating a double-layer pallet circulating conveying system for a hand dryer housing production line, including the following steps: S1: Empty tray lifting: The loading elevator 83 lifts the empty tray 85 at the end of the lower return line 82 to the starting position of the upper conveyor line 81; S2: Material picking and palletizing: The cutting and handling device 30 picks up the stainless steel plate from the upper left corner of the stacking station 011 through the gripping suction cup 60 at the end of the robotic arm. The weight sensor determines the weight of the stainless steel plate. When the weight of the picked up is greater than or equal to the weight of three stainless steel plates, the robotic arm is shaken while the stainless steel plate is lifted to throw off the excess stainless steel plate. At the same time, the picked-up stainless steel plate is placed in the positioning groove of the pallet 85. The upper conveyor line 81 is started to convey the material pallet to the adjustment station 501. S3: Positioning and docking: When the pallet 85 reaches the corresponding position of the adjustment station 501, the photoelectric sensor of the stop positioning mechanism detects the pallet's arrival signal, and the stop block rises to make the pallet stop precisely. S4: Material picking and limit adjustment: The cutting and conveying device 30 takes the sheet material from the pallet 85 and places it on the upper end of the adjustment seat 51 of the positioning and separation device 50; the pneumatic component 53 is activated, which drives the edge limiting plate 52 to push the stainless steel plate along the ball 55 to the limited area. At this time, the four sides of the stainless steel plate are blocked by four sets of edge limiting plates, realizing the movement restriction in the horizontal plane. S5: Longitudinal fixation: Activate the fixing suction cup 54 and the gripping suction cup 60, so that the fixing suction cup 54 adsorbs the lower end of the stainless steel plate with negative pressure, and the gripping suction cup 60 presses the upper end with negative pressure, thereby restricting its longitudinal movement and thus achieving complete fixation of the stainless steel plate. S6: Surface Defect Detection: It should be noted that defect detection is performed before single-piece judgment because the fixed suction cup 54 and the gripping suction cup 60 have already clamped and fixed the plate during the defect detection stage. Even if there is double-piece adsorption, the detection probe only contacts the exposed reverse side of the bottom plate, and its detection result is not affected by the plate above. At the same time, if separation is performed before detection, an additional fixing-to-release cycle is required, reducing cycle efficiency. After fixing the stainless steel plate, the detection probe of the defect detection mechanism 70 is activated, causing it to run around along the trajectory of the spiral involute 71 to achieve detection and scanning of the entire reverse area of ​​the stainless steel. When the detection probe passes through the defect location such as scratches or dents, the movement of the probe changes displacement. The sensor element inside the probe converts this displacement change into an electrical signal output, thereby realizing the detection of surface defects. If the detection is qualified, the subsequent standard operating procedure is executed. If the detection is unqualified, the fixed suction cup 54 is released, and the gripping suction cup 60 and the robotic arm are used to transfer the stainless steel plate to the waste recycling area for recycling. S7: Single Piece Judgment: After the surface defect detection is qualified, the fixed suction cup 54 and the gripping suction cup 60 are kept in a negative pressure adsorption state. Then, using the single piece judgment and separation mechanism, the pressure sensor in the connecting pipe of the gripping suction cup 60 is used to determine whether the stainless steel on the adjustment station 501 is a single piece or a double piece. If it is determined to be a single piece, the subsequent standard operation process is executed. If it is determined to be a double piece, the gripping suction cup 60 and the robotic arm are used to directly transfer the stainless steel plate to the stacking station 011 for temporary placement. Then, the gripping suction cup 60 is moved to make it adsorb the stainless steel plate left on the adjustment station 501 under negative pressure, and the aforementioned principle is used to make a second judgment until it is determined to be a single piece. S8: Return the tray and transfer it to the cutting station: After determining that it is a single piece, release the fixing suction cup 54, and use the gripping suction cup 60 and the robotic arm to put the stainless steel plate back into the tray 85; the upper conveyor line 81 transfers the tray 85 to the cutting station 101. After the stop positioning mechanism accurately stops, the cutting and handling device 30 takes the plate out of the tray 85 and puts it into the cutting device 10. Through the rotating seat on the cutting device 10, the four corners of the stainless steel plate are sent into the working area of ​​the cutting device 10 in sequence to complete the cutting of the four corners. S9: Repositioning before stamping: After cutting, the stainless steel plate is placed back on the pallet 85 using the robotic arm of the cutting and handling device 30 and the gripping suction cup 60. The upper conveyor line 81 then transports the pallet 85 back to the adjustment station 501. The positioning and separation device 50 is used again to position the stainless steel plate within the limited area to achieve repositioning and meet the position accuracy requirements. S10: Transfer to forming station and stamping: After repositioning, the stainless steel plate is placed back on the tray 85. The upper conveyor line 81 transfers the tray 85 to the forming station 201. After the stop positioning mechanism accurately stops, the robotic arm and gripping suction cup 60 of the forming and handling device 40 take the positioned and cut stainless steel plate out of the tray 85 and transfer it to the forming station 201 of the stamping forming device 20, that is, the lower mold of the forming device. Then the upper mold is pressed down to apply pressure to the stainless steel plate, so that it undergoes plastic deformation according to the shape of the mold, and the forming operation of the hand dryer shell is completed. S11: Unloading and lowering: After the molding is completed, the finished product is stacked to the stacking station 022. At this time, the empty pallet 85 is lowered to the lower return line 82 by the unloading elevator 84. S12: Empty tray return: The lower return line 82 reverses the empty tray 85 back to the beginning, waiting for the loading elevator 83 to lift it again and enter the next cycle; S13: Cyclic Operation: Repeat steps S1 to S12, with multiple pallets 85 circulating simultaneously in the system to form a continuous flow operation, realizing continuous automated cutting and forming of stainless steel plates.

[0047] The entire process described above requires no manual intervention. The double-layer pallet circulation conveyor system 80 achieves closed-loop circulation of pallets through the spatial stacking of the upper and lower conveyor lines and the connection of the lifting mechanisms at both ends, avoiding the manual handling of pallets. The cutting and handling device 30 and the forming and handling device 40 are only responsible for picking up and placing the boards from the pallets to the working areas of each device. The positioning and separation device 50 plays a key role in transfer positioning, board separation and surface defect detection, ensuring processing accuracy and production efficiency, and improving the overall automation level and production cycle of the hand dryer shell production line.

[0048] Example 2: This embodiment replaces the defect detection mechanism in Embodiment 1 with a new structure, as detailed below.

[0049] refer to Figure 7 The defect detection mechanism employs a visual optical detection structure 72, preferably installed at the center of a defined area. This structure uses a high-definition camera with its own light source and image algorithms to capture differences in reflectivity and light-dark distortion on the reverse side of the stainless steel plate, thereby identifying surface defects such as scratches, dents, bulges, color differences, and indentations. Compared to Example 1, although this solution has a faster detection speed, its rate of missed detection and false positives is relatively high due to factors such as changes in lighting and limitations in computing power (due to the variety of surface defects).

[0050] The above description is merely a specific example of the present invention and does not constitute any limitation on the present invention. Obviously, those skilled in the art, after understanding the content and principles of the present invention, may make various modifications and changes in form and detail without departing from the principles and structure of the present invention; however, these modifications and changes based on the spirit of the present invention are still within the scope of protection of the claims of the present invention.

Claims

1. An automatic cutting and forming system for stainless steel plates, characterized in that, include: A cutting device (10) is used to cut stainless steel plates; Stamping forming device (20) is used to stamp and form the cut stainless steel sheet; The conveying device is equipped with a gripping suction cup (60) at its end for adsorbing stainless steel plates. Positioning and separation device (50), including: Adjustment seat (51), the upper end of which has a defined area that defines the position of the stainless steel plate; An edge limiting plate (52) and a pneumatic assembly (53) for driving its movement are used to push the stainless steel plate and confine it within the defined area; A fixed suction cup (54) is set on the adjustment seat (51) to adsorb stainless steel plates from below, and works in conjunction with the gripping suction cup (60) from the upper and lower sides to fix the stainless steel plates and separate multiple plates.

2. The automatic stainless steel plate cutting and forming system according to claim 1, characterized in that, The positioning and separation device (50) is also equipped with a defect detection mechanism (70) for detecting defects on the surface of the stainless steel plate when the stainless steel plate is fixed by the edge limiting plate (52), the fixing suction cup (54) and the gripping suction cup (60).

3. The automatic stainless steel plate cutting and forming system according to claim 1, characterized in that, It also includes a single-piece judgment and separation mechanism, which determines whether the currently fixed stainless steel plate is a single piece or multiple pieces by detecting the pressure change in the vacuum tube of the gripping suction cup (60), and removes the excess plate by the conveying device when it is determined to be multiple pieces.

4. The automatic stainless steel plate cutting and forming system according to claim 1, characterized in that, The upper end of the adjustment seat (51) is evenly provided with a plurality of smooth balls (55). The edge limiting plate (52) pushes the stainless steel plate to move along the surface of the balls (55) to the limited area. The edge limiting plate (52) is provided with four sets, of which two adjacent sets are movably installed and respectively connected to the pneumatic components (53), and the other two sets are fixedly installed. The two movably installed sets and the two fixedly installed sets cooperate to form the limited area.

5. The automatic stainless steel plate cutting and forming system according to claim 2, characterized in that, The defect detection mechanism (70) includes a spiral involute (71) disposed on the upper surface of the adjustment seat (51) and a detection probe passing through the spiral involute (71). The spiral involute (71) avoids the positions of the ball (55) and the fixed suction cup (54). The detection probe contacts the lower surface of the stainless steel plate and runs along the trajectory of the spiral involute (71). When it passes the defect position, the probe undergoes displacement and is converted into an electrical signal output through its internal sensing element. The positions of the ball (55) and the fixed suction cup (54) are pre-planned so that when the stainless steel plate is rotated 90 degrees and repositioned in the defined area, the originally blocked area falls into the effective detection path of the spiral involute (71) to achieve full coverage detection.

6. The automatic stainless steel plate cutting and forming system according to claim 1, characterized in that, The transport device is also equipped with an anti-overlap separation mechanism, including a weight sensor installed at the end of the transport device. When the weight is determined to reach the preset multi-piece threshold, the excess board is thrown off by shaking the transport device. The shaking action is equipped with an adaptive adjustment mechanism. When the positioning and separation device (50) detects multiple pieces of adsorption, it records the adhesion tendency of the batch of boards and automatically increases the shaking amplitude and number of times according to the cumulative number of adhesion tendencies. If it is determined to be a single piece multiple times in a row, the shaking amplitude is automatically decreased according to the step level.

7. A double-layer pallet circulating conveying system for a hand dryer housing production line, applied to the automatic cutting and forming system for stainless steel plates according to any one of claims 1 to 6, characterized in that, Also includes: A double-layer pallet circulating conveyor system (80) is used to carry stainless steel plates and automatically transfer them between workstations. The conveying device picks up and places stainless steel plates between the pallet (85) and each processing device. The double-layer pallet circulating conveyor system (80) includes: an upper conveyor line (81) for conveying the pallet (85) carrying the stainless steel plates to the downstream workstation along the processing direction. The lower return line (82) is located below the upper conveyor line (81) and in the opposite direction to it, and is used to return empty pallets (85); the loading elevator (83) and unloading elevator (84) are respectively located at both ends of the upper conveyor line (81), and are used to transfer pallets (85) between the upper conveyor line (81) and the lower return line (82), so that multiple pallets (85) form a closed loop circulation; the upper surface of the pallet (85) is provided with a positioning structure for limiting the stainless steel plate; and the stop positioning mechanism is set at the corresponding position of each workstation, so that the pallet (85) is positioned and stopped at the preset position.

8. The double-layer pallet circulating conveying system according to claim 7, characterized in that, The positioning structure is a positioning groove on the upper surface of the tray (85) that is adapted to the shape of the stainless steel plate, and a flexible protective pad is laid at the bottom of the positioning groove; the stop positioning mechanism includes a liftable stop block and a photoelectric sensor for detecting the tray's position signal.

9. A method of operating the double-layer pallet circulating conveying system according to claim 7 or 8, characterized in that, Includes the following steps: S1: Empty tray lifting: The loading elevator (83) lifts the empty tray (85) at the end of the lower return line (82) to the starting position of the upper conveyor line (81); S2: Loading and conveying: The handling device takes the stainless steel plate from the stacking station and places it on the pallet (85), and the upper conveyor line (81) conveys the pallet to the downstream station; S3: Positioning and material handling: When the pallet (85) arrives at the adjustment station (501) where the positioning and separation device (50) is located, the stop positioning mechanism makes the pallet (85) stop precisely. The handling device takes the stainless steel plate from the pallet (85) and puts it into the positioning and separation device (50) to perform limit adjustment. After completion, the stainless steel plate is put back into the pallet (85). S4: Subsequent station processing: The upper conveyor line (81) sequentially conveys the pallet (85) to each subsequent processing station. After the pallet is positioned and stopped by the stop positioning mechanism at each station, the handling device takes the stainless steel plate out of the pallet (85) for corresponding processing operations. S5: Unloading and Return: After processing is completed at the end station, the empty pallet (85) is lowered to the lower return line (82) by the unloading elevator (84), and then transported back to the beginning. It is then lifted by the loading elevator (83) and enters the next cycle. Multiple pallets (85) flow simultaneously in the double-layer pallet circulation conveyor system (80) to form a continuous flow operation.

10. The working method according to claim 9, characterized in that, Step S3 further includes: after the limit adjustment, starting the fixed suction cup (54) and the gripping suction cup (60) to adsorb and fix the stainless steel plate from the upper and lower sides; in the fixed state, starting the defect detection mechanism (70) to perform defect detection on the surface of the stainless steel plate. If the detection is unqualified, it is transferred to the residual material recycling area; after the detection is qualified, the pressure change in the vacuum pipeline of the gripping suction cup (60) determines whether it is a single piece or multiple pieces. If it is determined to be multiple pieces, the excess plate is removed until it is determined to be a single piece.

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