A front floor rear section assembly (SPR) riveting quality control method

Abstract

The application discloses a front floor rear section assembly (SPR) riveting quality control method, relates to the field of riveting quality control, and solves the problem that riveting parameters cannot be accurately used to effectively control the riveting quality of the SPR. The method comprises the following steps: riveting is performed by using qualified rivets, and the relative concave-convex distance between the rivet head of the qualified rivet and the upper test plate is calculated; the upper test plate and the lower test plate are riveted by using different test rivets, and different actual residual bottom thicknesses and different rivet leg opening degrees of the rivets are obtained; data when the different test rivets are riveted is analyzed; the opening uniformity of the rivet leg when the selected rivet is riveted at different uniform detection points is analyzed; test rivets are selected again according to the optimal rivet diameter, data when the different test rivets are riveted is analyzed, and the optimal rivet parameters of the selected rivet are obtained. The application can accurately use riveting parameters to effectively control the riveting quality of the SPR.

Description

Technical Field

[0001] This invention belongs to the field of SPR riveting quality control technology, specifically a method for SPR riveting quality control of the front floor rear section assembly. Background Technology

[0002] As a core structural component of the vehicle chassis, the quality of the front floor rear section assembly's SPR (self-piercing riveting) connection directly affects the vehicle's rigidity, NVH performance, and collision safety. The SPR self-piercing riveting process overcomes the shortcomings of traditional riveting processes, such as poor appearance, low efficiency, and complex processes, opening up a new way for vehicle body connections. In existing methods, when performing SPR riveting on the front floor rear section assembly, the selection of riveting parameters is mostly achieved through mechanical models or simulation technology. However, due to the differences between the simulation environment and the actual processing environment, there are certain discrepancies between the simulation data and the actual experimental data. When it is necessary to further improve the SPR riveting quality, some data differences may lead to a decrease in SPR riveting quality, thus making it impossible to accurately use the riveting parameters to effectively control the SPR riveting quality. Therefore, this invention proposes a method for controlling the quality of SPR riveting in the front floor rear section assembly. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method for controlling the quality of SPR riveting in the front floor rear section assembly.

[0004] The technical problem to be solved by this invention is: How to accurately utilize riveting parameters to effectively control the riveting quality of SPR.

[0005] The objective of this invention can be achieved through the following technical solutions: A method for quality control of SPR riveting in the front floor rear section assembly, comprising the following steps: Step S1: Use qualified rivets to rivet the upper test plate and the lower test plate together, and calculate the relative concave-convex distance between the corresponding rivet head and the upper test plate. Step S2: Use different test rivets to rivet the upper test plate and the lower test plate, and analyze the actual residual thickness of the lower test plate and the rivet foot opening of different rivets when using different rivets for riveting. Step S3: Based on the actual residual thickness of the lower test plate and the rivet leg opening of the qualified rivet when riveting, analyze the data when riveting different test rivets to obtain candidate rivets or test rivets to be rejected. Step S4: Analyze the uniformity of the opening of the rivet legs when riveting the selected rivets at different uniform detection points, and obtain the comprehensive uniform distance difference and the optimal rivet diameter when riveting different selected rivets. Step S5: Select test rivets again based on the optimal rivet diameter, and analyze the data when riveting different test rivets to obtain the optimal rivet parameters for the candidate rivets.

[0006] Further, step S1 includes the following sub-steps: Step S101: The metal plate with the same material as the upper plate in the rear section of the front floor assembly is designated as the upper test plate, and the metal plate with the same material as the lower plate in the rear section of the front floor assembly is designated as the lower test plate. Step S102: According to the stacking method of the upper and lower panels of the front floor rear section assembly, fix the upper test panel and the lower test panel on the test platform, and use qualified rivets to rivet the upper test panel and the lower test panel according to the SPR riveting process. Step S103: Measure the total thickness of the upper test plate and the lower test plate and record it as the initial thickness of the plate. At the same time, measure the distance between the head of the qualified rivet and the bottom end of the lower test plate and record it as the first measurement distance. Step S104: Subtract the first measurement distance from the initial thickness of the plate to obtain the relative concave-convex distance between the head of the qualified rivet and the upper test plate.

[0007] Furthermore, the analysis process in step S2 includes the following sub-steps: Step S201: Select multiple rivets with diameters different from qualified rivets as test rivets, and use the relative concave-convex distance as the standard concave-convex distance between the test rivet head and the upper test plate. In step S202, different test rivets are used to rivet the upper test plate and the lower test plate respectively, and steps S103 and S104 are repeated to calculate the relative concave-convex distance between the rivet head and the upper test plate in real time. Pressure is continuously applied until the relative concave-convex distance between the rivet head and the upper test plate is equal to the standard concave-convex distance.

[0008] Furthermore, the analysis process in step S2 also includes the following sub-steps: Step S203: Cut along the cross section to make qualified rivets, and at the same time measure the distance between the corresponding rivet foot surface at different positions and the bottom end of the lower test plate and record it as the second measurement distance. Compare different second measurement distances to obtain the minimum value of the second measurement distance, and record the minimum value of the second measurement distance as the actual residual bottom thickness of the lower test plate when riveting with qualified rivets. Step S204: Draw a straight line along the bottom end of the head of the qualified rivet, and record the intersection of the straight line with the outer side of any rivet foot as the first intersection point. Draw a straight line perpendicular to the upper test plate through the first intersection point and record it as the first straight line. Measure the vertical distance between the first straight line and different positions on the tip surface of the corresponding rivet foot. Step S205: Iterate through and compare different vertical distances to obtain the maximum value of the vertical distance, and record the maximum value of the corresponding vertical distance as the rivet leg opening degree of the qualified rivet when riveting with qualified rivets. By analogy, the actual residual thickness of the lower test plate and the rivet foot opening degree were obtained when different test rivets were used for riveting.

[0009] Furthermore, the analysis process in step S3 includes the following sub-steps: Step S301: When riveting with qualified rivets, the actual residual thickness of the lower test plate is taken as the standard residual thickness, and the rivet leg opening of qualified rivets is taken as the standard rivet leg opening. Step S302: When riveting with test rivets, compare the actual residual thickness of the lower test plate with the standard residual thickness, and compare the rivet leg opening with the standard rivet leg opening. If the actual residual thickness of the lower test plate is greater than the standard residual thickness when using test rivets for riveting, and the rivet leg opening is greater than the standard rivet leg opening, then the corresponding test rivet will be recorded as a candidate rivet. If the actual residual thickness of the lower test plate is less than or equal to the standard residual thickness when using test rivets, or if the rivet leg opening is less than or equal to the standard rivet leg opening, then the corresponding test rivets are rejected.

[0010] Furthermore, the analysis process in step S4 includes the following sub-steps: Step S401: Draw a straight line perpendicular to the bottom of the rivet head through the midpoint of the surface of the rivet head and record it as the second straight line. Take the intersection of the second straight line and the bottom of the rivet head as the first uniform detection point. Draw a uniform detection line perpendicular to the second straight line through the starting point of uniform detection. Record the intersection of the uniform detection line and the outer side of the rivet foot of the rivet as the first detection point and the second detection point, respectively. Step S402: Combine the first detection point and the second detection point as detection points at the uniform detection point, measure the distance between the uniform detection starting point and the first detection point and record it as the first distance, measure the distance between the uniform detection starting point and the second detection point and record it as the second distance; Step S403: Subtract the second distance from the first distance and take the absolute value to obtain the uniform distance difference of the corresponding detection point combination.

[0011] Furthermore, the analysis process in step S4 also includes the following sub-steps: Step S404: Starting from the first uniform detection point, set multiple uniform detection points along the second straight line, and repeat steps S401-S403 to calculate the uniform distance difference of different combinations of detection points. Step S405: Summing up the uniform distance differences of different detection point combinations to obtain the comprehensive uniform distance difference when riveting with the corresponding candidate rivet; Similarly, the overall uniform distance difference when riveting with different candidate rivets is calculated; Step S406: Iterate through and compare different comprehensive uniform distance differences to obtain the minimum comprehensive uniform distance difference, and record the diameter of the candidate rivet corresponding to the minimum comprehensive uniform distance difference as the optimal rivet diameter.

[0012] Furthermore, the analysis process in step S5 includes the following sub-steps: Step S501: Based on the optimal rivet diameter, select multiple rivets of different lengths as test rivets, measure the length of the different test rivets, and subtract the length of the qualified rivet from the length of the different test rivets to obtain the rivet length difference between the different test rivets and the qualified rivet. Step S502: Add the difference between the initial thickness of the board and the rivet length, and divide by two to obtain the thickness of a single board corresponding to different test rivets. Based on the thickness of the single board, reselect the upper and lower test boards, and fix the upper and lower test boards on the test platform according to the stacking method of the upper and lower boards in the front floor rear section assembly.

[0013] Furthermore, the analysis process in step S5 also includes the following sub-steps: Step S503: Repeat steps S202-S206 to analyze and obtain the actual residual thickness of the lower test plate and the rivet foot opening when riveting with different test rivets. Step S504: Obtain the actual residual thickness of the lower test plate when the candidate rivets are riveted in step S406 and use it as a reference residual thickness; obtain the rivet leg opening when the corresponding candidate rivets are riveted and use it as a reference rivet leg opening.

[0014] Furthermore, the analysis process in step S5 also includes the following sub-steps: Step S505: Repeat step S302 to compare the actual residual thickness of the lower test plate with the reference residual thickness when riveting with test rivets, and compare the rivet leg opening with the reference rivet leg opening to obtain candidate rivets or remove the corresponding test rivets. Step S506: Repeat step S4 to analyze and obtain the minimum value of the comprehensive uniform distance difference, and record the length of the candidate rivet corresponding to the minimum value of the comprehensive uniform distance as the optimal rivet length; Step S507: Record the optimal rivet diameter and optimal rivet length as the optimal rivet parameters of the candidate rivet.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. The present invention first uses qualified rivets to rivet the upper test plate and the lower test plate, and calculates the relative concave-convex distance between the corresponding rivet head and the upper test plate. Then, different test rivets are used to rivet the upper test plate and the lower test plate, thereby analyzing the actual residual bottom thickness of the lower test plate and the rivet foot opening of different rivets when riveting with different rivets. 2. This invention also analyzes the data of riveting different test rivets based on the actual residual thickness of the lower test plate and the rivet leg opening degree when riveting with qualified rivets, thereby obtaining candidate rivets or rejecting test rivets. Then, the uniformity of rivet leg opening when riveting with candidate rivets is analyzed to obtain the comprehensive uniform distance difference and optimal rivet diameter of different candidate rivets. Finally, test rivets are selected again based on the optimal rivet diameter, and the data of riveting with different test rivets is analyzed to obtain the optimal rivet parameters of candidate rivets. This invention accurately utilizes riveting parameters to effectively control the riveting quality of SPR. Attached Figure Description

[0016] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0017] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a schematic diagram of different rivets used in this invention; Figure 3 This is a schematic diagram of the initial thickness of the plate and the first measurement distance in this invention; Figure 4 This is a schematic diagram of the second measuring distance in this invention; Figure 5 This is a schematic diagram of the first intersection point in this invention; Figure 6 This is a schematic diagram of the uniform detection line and different detection points in this invention; Figure 7 This is a schematic diagram of the electronic device in this invention. Detailed Implementation

[0018] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1: Please refer to Figures 1-6 As shown, the technical solution provided by this invention is: a method for quality control of SPR riveting in a front floor rear section assembly. This method first uses qualified rivets to rivet the upper and lower test plates, then uses test rivets to rivet, ensuring the riveting depth of the test rivets is consistent with that of the qualified rivets. Next, it analyzes the data obtained when riveting with different rivets to obtain candidate rivets or to eliminate test rivets. Then, it analyzes the comprehensive uniform distance difference and optimal rivet diameter when riveting with different candidate rivets. Finally, it selects test rivets again based on the optimal rivet diameter and obtains the optimal rivet parameters for the candidate rivets. The method includes the following steps: In this embodiment, the rear section of the front floor assembly is composed of two layers of sheet metal riveted together. The sheet metal of the same material as the rear section of the front floor assembly is designated as the test sheet. While SPR riveting of the rear section of the front floor assembly using currently accepted rivets meets the acceptable quality standard, this embodiment uses test rivets of different diameters and lengths to further improve the SPR riveting quality beyond the acceptable standard. This yields the optimal rivet parameters for improving the SPR riveting quality. Step S1: Use qualified rivets to rivet the upper test plate and the lower test plate together, and calculate the relative concave-convex distance between the corresponding rivet head and the upper test plate. In this embodiment, step S1 includes the following sub-steps: Step S101: The metal plate with the same material as the upper plate in the rear section of the front floor assembly is designated as the upper test plate, and the metal plate with the same material as the lower plate in the rear section of the front floor assembly is designated as the lower test plate. Step S102: According to the stacking method of the upper and lower panels of the front floor rear section assembly, fix the upper test panel and the lower test panel on the test platform, and use qualified rivets to rivet the upper test panel and the lower test panel according to the SPR riveting process. For step S103, please refer to [link / reference]. Figure 3 As shown, the total thickness of the upper and lower test plates is measured and recorded as the initial thickness of the plates. At the same time, the distance between the head of the qualified rivet and the bottom end of the lower test plate is measured and recorded as the first measurement distance. It needs to be explained that when a properly fitted rivet is embedded in the upper and lower layers of the sheet metal, it will cause deformation of the sheet metal, thus leading to... Figure 3 The middle and lower layers of the board have some protrusions. The initial thickness of the board represents the thickness of the undeformed parts of the upper and lower layers of the board. Step S104: Subtract the first measurement distance from the initial thickness of the plate to obtain the relative concave-convex distance between the head of the qualified rivet and the upper test plate. It should be explained that the relative concave-convex distance can be negative. When the relative concave-convex distance is negative, the head of the qualified rivet is above the upper test plate, which means that the head protrudes from the upper test plate. When the relative concave-convex distance is positive, the head of the qualified rivet is inside the upper test plate, which means that the head is recessed into the upper test plate.

[0020] Step S2: Use different test rivets to rivet the upper test plate and the lower test plate, and analyze the actual residual thickness of the lower test plate and the rivet foot opening of different rivets when using different rivets for riveting. In this embodiment, the analysis process in step S2 includes the following sub-steps: Step S201: Select multiple rivets with diameters different from qualified rivets as test rivets, and use the relative concave-convex distance as the standard concave-convex distance between the test rivet head and the upper test plate. Step S202: Use different test rivets to rivet the upper test plate and the lower test plate respectively, and repeat steps S103 and S104 to calculate the relative concave-convex distance between the rivet head and the upper test plate in real time. Continue to apply pressure until the relative concave-convex distance between the rivet head and the upper test plate is equal to the standard concave-convex distance. For step S203, please refer to... Figure 4 As shown, the qualified rivet is cut along the cross section. At the same time, the distance between the qualified rivet and the bottom of the lower test plate at different positions on the surface of the rivet foot is measured and recorded as the second measurement distance. The different second measurement distances are compared to obtain the minimum value of the second measurement distance. The minimum value of the second measurement distance is recorded as the actual residual bottom thickness of the lower test plate when riveting with qualified rivets. For step S204, please refer to... Figure 5 As shown, draw a straight line along the bottom end of the head of the qualified rivet, and record the intersection of the straight line with the outer side of any rivet foot as the first intersection point. Draw a straight line perpendicular to the upper test plate through the first intersection point and record it as the first straight line. Measure the vertical distance between the first straight line and different positions on the tip surface of the corresponding rivet foot. Step S205: Iterate through and compare different vertical distances to obtain the maximum value of the vertical distance, and record the maximum value of the corresponding vertical distance as the rivet leg opening degree of the qualified rivet when riveting with qualified rivets. By analogy, the actual residual thickness of the lower test plate and the rivet foot opening degree were obtained when different test rivets were used for riveting.

[0021] Step S3: Based on the actual residual thickness of the lower test plate and the rivet leg opening of the qualified rivet when riveting, analyze the data when riveting different test rivets to obtain candidate rivets or test rivets to be rejected. In this embodiment, the analysis process in step S3 includes the following sub-steps: Step S301: When riveting with qualified rivets, the actual residual thickness of the lower test plate is taken as the standard residual thickness, and the rivet leg opening of qualified rivets is taken as the standard rivet leg opening. Step S302: When riveting with test rivets, compare the actual residual thickness of the lower test plate with the standard residual thickness, and compare the rivet leg opening with the standard rivet leg opening. If the actual residual thickness of the lower test plate is greater than the standard residual thickness when using test rivets for riveting, and the rivet leg opening is greater than the standard rivet leg opening, then the corresponding test rivet will be recorded as a candidate rivet. If the actual residual thickness of the lower test plate is less than or equal to the standard residual thickness when using test rivets, or if the rivet leg opening is less than or equal to the standard rivet leg opening, then the corresponding test rivets are rejected. In this embodiment, the rivet foot opening represents the width of the opening between the tail of the qualified rivet and the test rivet. The larger the rivet foot opening, the stronger the shear and tensile strength between the upper and lower test plates, the larger the actual residual thickness, and the less likely the lower test plate is to be crushed. It should be noted that if all test rivets are rejected, a rivet with a diameter different from the test rivet diameter is selected and tested again.

[0022] Step S4: Analyze the uniformity of the opening of the rivet legs when riveting the selected rivets at different uniform detection points, and obtain the comprehensive uniform distance difference and the optimal rivet diameter when riveting different selected rivets. In this embodiment, the analysis process in step S4 includes the following sub-steps: For step S401, please refer to... Figure 6As shown, a straight line perpendicular to the bottom of the rivet head is drawn through the midpoint of the surface of the rivet head and recorded as the second straight line. The intersection of the second straight line and the bottom of the rivet head is taken as the first uniform detection point. A uniform detection line perpendicular to the second straight line is drawn through the starting point of the uniform detection. The intersection of the uniform detection line and the outer side of the rivet foot is recorded as the first detection point and the second detection point, respectively. Step S402: Combine the first detection point and the second detection point as detection points at the uniform detection point, measure the distance between the uniform detection starting point and the first detection point and record it as the first distance, measure the distance between the uniform detection starting point and the second detection point and record it as the second distance; Step S403: Subtract the second distance from the first distance and take the absolute value to obtain the uniform distance difference of the corresponding detection point combination; Step S404: Starting from the first uniform detection point, set multiple uniform detection points along the second straight line, and repeat steps S401-S403 to calculate the uniform distance difference of different combinations of detection points. Step S405: Summing up the uniform distance differences of different detection point combinations to obtain the comprehensive uniform distance difference when riveting with the corresponding candidate rivet; Similarly, the overall uniform distance difference when riveting with different candidate rivets is calculated; Step S406: Iterate through and compare different comprehensive uniform distance differences to obtain the minimum comprehensive uniform distance difference, and record the diameter of the candidate rivet corresponding to the minimum comprehensive uniform distance difference as the optimal rivet diameter.

[0023] Step S5: Select test rivets again based on the optimal rivet diameter, and analyze the data when riveting different test rivets to obtain the optimal rivet parameters for the candidate rivets. In this embodiment, the analysis process in step S5 includes the following sub-steps: Step S501: Based on the optimal rivet diameter, select multiple rivets of different lengths as test rivets, measure the length of the different test rivets, and subtract the length of the qualified rivet from the length of the different test rivets to obtain the rivet length difference between the different test rivets and the qualified rivet. Step S502: Add the difference between the initial thickness of the board and the rivet length, and divide by two to obtain the thickness of a single board corresponding to different test rivets. Based on the thickness of the single board, reselect the upper test board and the lower test board, and fix the upper test board and the lower test board on the test platform according to the stacking method of the upper and lower boards in the front floor rear section assembly. In this embodiment, the difference in rivet length can be negative. When the difference in rivet length is less than zero, the thickness of the upper and lower test plates needs to be reduced. When the difference in rivet length is greater than zero, the thickness of the upper and lower test plates needs to be increased. Step S503: Repeat steps S202-S206 to analyze and obtain the actual residual thickness of the lower test plate and the rivet foot opening when riveting with different test rivets. Step S504: Obtain the actual residual thickness of the lower test plate when the rivets to be selected are riveted in step S406 and use it as a reference residual thickness; obtain the rivet leg opening when the corresponding rivets to be selected are riveted and use it as a reference rivet leg opening. Step S505: Repeat step S302 to compare the actual residual thickness of the lower test plate with the reference residual thickness when riveting with test rivets, and compare the rivet leg opening with the reference rivet leg opening to obtain candidate rivets or remove the corresponding test rivets. Step S506: Repeat step S4 to analyze and obtain the minimum value of the comprehensive uniform distance difference, and record the length of the candidate rivet corresponding to the minimum value of the comprehensive uniform distance as the optimal rivet length; Step S507: Record the optimal rivet diameter and optimal rivet length as the optimal rivet parameters of the candidate rivet; It should be explained that when riveting with rivets of a fixed length is required, the optimal rivet diameter corresponding to the fixed length rivet can be obtained through analysis in steps S1-S4. At the same time, when riveting with rivets of a fixed diameter is required, the optimal rivet length corresponding to the fixed diameter rivet can be obtained through analysis in steps S501-S506.

[0024] Example 2: This embodiment of the invention also provides an electronic device for running the aforementioned SPR riveting quality control method for a front floor rear section assembly; see also Figure 7 The schematic diagram of an electronic device provided by the embodiment of the present invention shown above includes a memory and a processor. The memory is used to store one or more computer instructions, which are executed by the processor to implement the above-mentioned SPR riveting quality control method for the front floor rear section assembly. Furthermore, Figure 7 The electronic device shown also includes a communication bus and a communication interface, with the processor, communication interface and memory connected via the communication bus; The memory may include high-speed random access memory (RAM) and may also include non-volatile memory, such as at least one disk storage device. Communication between this system network element and at least one other network element is achieved through at least one communication interface (which can be wired or wireless), such as the Internet, wide area network, local area network, metropolitan area network, etc. The communication bus can be an ISA bus, PCI bus, or EISA bus, etc. The communication bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 7 The symbol is represented by only one double-headed arrow, but this does not mean that there is only one communication bus or one type of communication bus. The processor may be an integrated circuit chip with signal processing capabilities. In implementation, the steps of the above methods can be completed by integrated logic circuits in the processor's hardware or by software instructions. The processor can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it can also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this invention. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this invention can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in the memory, and the processor reads the information in the memory and, in conjunction with its hardware, completes the steps of the method described in the foregoing embodiments.

[0025] In embodiment three, this invention also provides a computer storage medium storing computer-executable instructions. When these computer-executable instructions are called and executed by a processor, they cause the processor to implement the aforementioned SPR riveting quality control method for a front floor rear assembly. For specific implementation details, please refer to the method embodiment, which will not be repeated here. The computer program product of the SPR riveting quality control method for the front floor rear section assembly provided in this embodiment of the invention includes a computer storage medium storing program code. The instructions included in the program code can be used to execute the method in the preceding method embodiment. For specific implementation, please refer to the method embodiment, which will not be repeated here.

[0026] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the system and / or device described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0027] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0028] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for quality control of SPR riveting in the rear section of the front floor assembly, characterized in that, The methods include: Step S1: Use qualified rivets to rivet the upper test plate and the lower test plate together, and calculate the relative concave-convex distance between the corresponding rivet head and the upper test plate. Step S2: Use different test rivets to rivet the upper test plate and the lower test plate, and analyze the actual residual thickness of the lower test plate and the rivet foot opening of different rivets when using different rivets for riveting. The analysis process in step S2 includes the following sub-steps: Step S201: Select multiple rivets with diameters different from qualified rivets as test rivets, and use the relative concave-convex distance as the standard concave-convex distance between the test rivet head and the upper test plate. Step S202: Use different test rivets to rivet the upper test plate and the lower test plate respectively, and repeat steps S103 and S104 to calculate the relative concave-convex distance between the rivet head and the upper test plate in real time. Continue to apply pressure until the relative concave-convex distance between the rivet head and the upper test plate is equal to the standard concave-convex distance. Step S203: Cut along the cross section to make qualified rivets, and at the same time measure the distance between the corresponding rivet foot surface at different positions and the bottom end of the lower test plate and record it as the second measurement distance. Compare different second measurement distances to obtain the minimum value of the second measurement distance, and record the minimum value of the second measurement distance as the actual residual bottom thickness of the lower test plate when riveting with qualified rivets. Step S204: Draw a straight line along the bottom end of the head of the qualified rivet, and record the intersection of the straight line with the outer side of any rivet foot as the first intersection point. Draw a straight line perpendicular to the upper test plate through the first intersection point and record it as the first straight line. Measure the vertical distance between the first straight line and different positions on the tip surface of the corresponding rivet foot. Step S205: Iterate through and compare different vertical distances to obtain the maximum value of the vertical distance, and record the maximum value of the corresponding vertical distance as the rivet leg opening degree of the qualified rivet when riveting with qualified rivets. Similarly, the actual residual thickness of the lower test plate and the rivet foot opening of the test rivets were obtained when riveting was performed using different test rivets. Step S3: Based on the actual residual thickness of the lower test plate and the rivet leg opening of the qualified rivet when riveting, analyze the data when riveting different test rivets to obtain candidate rivets or test rivets to be rejected. Step S4: Analyze the uniformity of the opening of the rivet legs when riveting the selected rivets at different uniform detection points, and obtain the comprehensive uniform distance difference and the optimal rivet diameter when riveting different selected rivets. Step S5: Select test rivets again based on the optimal rivet diameter, and analyze the data when riveting different test rivets to obtain the optimal rivet parameters for the candidate rivets.

2. The method for controlling the SPR riveting quality of the front floor rear section assembly according to claim 1, characterized in that, Step S1 includes the following sub-steps: Step S101: The metal plate with the same material as the upper plate in the rear section of the front floor assembly is designated as the upper test plate, and the metal plate with the same material as the lower plate in the rear section of the front floor assembly is designated as the lower test plate. Step S102: According to the stacking method of the upper and lower panels of the front floor rear section assembly, fix the upper test panel and the lower test panel on the test platform, and use qualified rivets to rivet the upper test panel and the lower test panel according to the SPR riveting process. Step S103: Measure the total thickness of the upper test plate and the lower test plate and record it as the initial thickness of the plate. At the same time, measure the distance between the head of the qualified rivet and the bottom end of the lower test plate and record it as the first measurement distance. Step S104: Subtract the first measurement distance from the initial thickness of the plate to obtain the relative concave-convex distance between the head of the qualified rivet and the upper test plate.

3. The method for controlling the SPR riveting quality of the front floor rear section assembly according to claim 1, characterized in that, The analysis process in step S3 includes the following sub-steps: Step S301: When riveting with qualified rivets, the actual residual thickness of the lower test plate is taken as the standard residual thickness, and the rivet leg opening of qualified rivets is taken as the standard rivet leg opening. Step S302: When riveting with test rivets, compare the actual residual thickness of the lower test plate with the standard residual thickness, and compare the rivet leg opening with the standard rivet leg opening. If the actual residual thickness of the lower test plate is greater than the standard residual thickness when using test rivets for riveting, and the rivet leg opening is greater than the standard rivet leg opening, then the corresponding test rivet will be recorded as a candidate rivet. If the actual residual thickness of the lower test plate is less than or equal to the standard residual thickness when using test rivets, or if the rivet leg opening is less than or equal to the standard rivet leg opening, then the corresponding test rivets are rejected.

4. The method for controlling the SPR riveting quality of the front floor rear section assembly according to claim 1, characterized in that, The analysis process in step S4 includes the following sub-steps: Step S401: Draw a straight line perpendicular to the bottom of the rivet head through the midpoint of the surface of the rivet head and record it as the second straight line. Take the intersection of the second straight line and the bottom of the rivet head as the first uniform detection point. Draw a uniform detection line perpendicular to the second straight line through the starting point of uniform detection. Record the intersection of the uniform detection line and the outer side of the rivet foot of the rivet as the first detection point and the second detection point, respectively. Step S402: Combine the first detection point and the second detection point as detection points at the uniform detection point, measure the distance between the uniform detection starting point and the first detection point and record it as the first distance, measure the distance between the uniform detection starting point and the second detection point and record it as the second distance; Step S403: Subtract the second distance from the first distance and take the absolute value to obtain the uniform distance difference of the corresponding detection point combination.

5. The method for controlling the SPR riveting quality of the front floor rear section assembly according to claim 4, characterized in that, The analysis process in step S4 also includes the following sub-steps: Step S404: Starting from the first uniform detection point, set multiple uniform detection points along the second straight line, and repeat steps S401-S403 to calculate the uniform distance difference of different combinations of detection points. Step S405: Summing up the uniform distance differences of different detection point combinations to obtain the comprehensive uniform distance difference when riveting with the corresponding candidate rivet; Similarly, the overall uniform distance difference when riveting with different candidate rivets is calculated; Step S406: Iterate through and compare different comprehensive uniform distance differences to obtain the minimum comprehensive uniform distance difference, and record the diameter of the candidate rivet corresponding to the minimum comprehensive uniform distance difference as the optimal rivet diameter.

6. The method for controlling the SPR riveting quality of the front floor rear section assembly according to claim 1, characterized in that, The analysis process in step S5 includes the following sub-steps: Step S501: Based on the optimal rivet diameter, select multiple rivets of different lengths as test rivets, measure the length of the different test rivets, and subtract the length of the qualified rivet from the length of the different test rivets to obtain the rivet length difference between the different test rivets and the qualified rivet. Step S502: Add the difference between the initial thickness of the board and the rivet length, and divide by two to obtain the thickness of a single board corresponding to different test rivets. Based on the thickness of the single board, reselect the upper and lower test boards, and fix the upper and lower test boards on the test platform according to the stacking method of the upper and lower boards in the front floor rear section assembly.

7. The method for controlling the SPR riveting quality of the front floor rear section assembly according to claim 6, characterized in that, The analysis process in step S5 also includes the following sub-steps: Step S503: Repeat steps S202-S206 to analyze and obtain the actual residual thickness of the lower test plate and the rivet foot opening when riveting with different test rivets. Step S504: Obtain the actual residual thickness of the lower test plate when the candidate rivets are riveted in step S406 and use it as a reference residual thickness; obtain the rivet leg opening when the corresponding candidate rivets are riveted and use it as a reference rivet leg opening.

8. The method for controlling the SPR riveting quality of the front floor rear section assembly according to claim 7, characterized in that, The analysis process in step S5 also includes the following sub-steps: Step S505: Repeat step S302 to compare the actual residual thickness of the lower test plate with the reference residual thickness when riveting with test rivets, and compare the rivet leg opening with the reference rivet leg opening to obtain candidate rivets or remove the corresponding test rivets. Step S506: Repeat step S4 to analyze and obtain the minimum value of the comprehensive uniform distance difference, and record the length of the candidate rivet corresponding to the minimum value of the comprehensive uniform distance as the optimal rivet length; Step S507: Record the optimal rivet diameter and optimal rivet length as the optimal rivet parameters of the candidate rivet.

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