A quality judgment control system for fasteners

Abstract

This invention relates to the field of intelligent fastener assessment technology, and more particularly to a quality assessment and control system for fasteners. The system includes a visual inspection and analysis module for acquiring microscopic images of the fastener to determine wear degree and surface defect values. Based on these values, a wear coefficient is determined to assess the fastener's wear compliance. In response to unacceptable fastener wear, the preload torque and positioning deviation of several force-applying components used to fix the fastener are determined based on the degree of wear non-compliance. The system can determine the fastener's own quality through its wear degree and surface defect values, and assess the fastening quality of the fastener based on the position of the fastener after fixing. This comprehensive assessment of fastener quality allows for a dynamic balance between processing efficiency and fastener life while ensuring processing accuracy.

Description

Technical Field

[0001] This invention relates to the field of intelligent fastener assessment technology, and more particularly to a quality assessment and control system for fasteners. Background Technology

[0002] In machining processes, especially in operations such as whirl milling of internal holes or threads, the condition of fasteners directly affects the stability, safety, service life, machining accuracy, and efficiency of the connection structure. Traditionally, fastener quality assessment relies heavily on manual inspection or periodic replacement, which is subjective, inefficient, and lacks standardized evaluation. Particularly in high-precision assembly scenarios, microscopic wear or surface defects in fasteners are difficult to detect with the naked eye, potentially leading to uneven preload distribution, decreased positioning accuracy, and consequently impacting the entire machining process.

[0003] Chinese Patent Publication No. CN120976099A discloses an inspection system for precision fasteners, comprising: a construction module for uploading standard structural parameters of components, constructing a standard 3D model of the components in a 3D scene using the standard structural parameters, and simultaneously storing the constructed standard 3D model; and a capture module for acquiring image data of the components to be inspected, segmenting the image data, and capturing the image of the components to be inspected from the image data. It is evident that the aforementioned inspection system for precision fasteners has the following problems:

[0004] The quality of a fastener cannot be determined solely by its wear and surface defects. Instead, the quality of its fastening is determined by the position of the fastener after it has been fixed. This comprehensive assessment of the fastener's quality allows for a dynamic balance between processing efficiency and fastener lifespan while ensuring processing accuracy. Summary of the Invention

[0005] Therefore, the present invention provides a quality judgment and control system for fasteners to overcome the problem in the prior art that the quality of fasteners cannot be determined by the wear degree value and surface defect value of the fasteners, but can be determined by the position of the fastener after the fastener is fixed to the fastener, and then the quality of the fasteners can be comprehensively judged to dynamically balance the processing efficiency and the life of the fasteners while ensuring processing accuracy.

[0006] To achieve the above objectives, the present invention provides a quality judgment and control system for fasteners, comprising,

[0007] The visual inspection and analysis module is used to acquire microscopic images of fasteners to determine wear degree values ​​and surface defect values, determine the wear coefficient based on the wear degree values ​​and surface defect values, determine the fastener wear qualification, and in response to fastener wear failure, determine the preload torque and positioning deviation of several force-applying parts for fastening the fastener to be fixed according to the degree of fastener wear failure.

[0008] The fastening module includes fasteners, several force-applying parts, several positioning parts, and a control unit. In response to unqualified fastener wear, the control unit determines the fastener's usability based on a wear coefficient and a critical coefficient. Based on the unqualified fastener, a fastener processing strategy is determined according to the redefined wear coefficient. Based on the qualified fastener, the number of positioning parts is determined according to the positioning deviation. Several force-applying parts fix the part to be fixed according to a determined pre-tightening torque and drive the part to be fixed to rotate at a preset speed.

[0009] The position detection and analysis module is used to acquire the position data of the fixed part, determine the actual accuracy score, judge the position qualification, and in response to the position failure, determine the fixation quality evaluation parameter by combining the wear coefficient, compare the fixation quality evaluation parameter with the preset quality threshold, judge the fixation quality qualification, and based on the fixation quality failure, redetermine the rotation speed according to the second excess value of the fixation quality evaluation parameter relative to the preset quality threshold.

[0010] Furthermore, the visual inspection and analysis module acquires microscopic images to determine the wear amount of several individual fasteners, and determines the maximum deviation value based on the wear amount of several individual fasteners;

[0011] Compare the maximum deviation value with the preset deviation value to determine the passability of synchronous wear;

[0012] In response to non-compliance of synchronous wear, the fastener's fixing accuracy is determined to be in failure, an alarm is issued, and a fastener handling strategy is determined.

[0013] Furthermore, the visual inspection and analysis module acquires a microscopic image of the fastener to determine the surface defect value, compares the surface defect value with a preset defect value, and judges the surface qualification of the fastener.

[0014] In response to surface defects of fasteners, the fastener's securing safety is determined to have failed, an alarm is issued, and a fastener handling strategy is determined.

[0015] Furthermore, the process by which the visual inspection and analysis module determines the wear qualification of fasteners includes,

[0016] Based on synchronous wear qualification and fastener surface qualification, the wear coefficient is determined by the wear degree value and surface defect value determined by the wear amount of several individual fasteners. The wear coefficient is compared with the preset coefficient threshold to determine the fastener wear qualification.

[0017] In response to unqualified fastener wear, the fastener fixing accuracy of the fastener to be fixed is improved to compensate for the fixing deviation caused by fastener wear.

[0018] Furthermore, the control unit responds to determining that the fixing accuracy of the fastener is improved, and the adjustment amount of the fixing accuracy is determined based on a first excess value of the wear coefficient relative to a preset coefficient threshold, wherein the adjustment amount is positively correlated with the first excess value.

[0019] Furthermore, the process by which the visual inspection and analysis module determines the qualification of fasteners based on the wear coefficient and the critical coefficient includes:

[0020] By comparing the wear coefficient with the critical coefficient, the suitability of the fasteners for use can be determined.

[0021] In response to unqualified fastener use, the wear weight value is re-determined based on the ratio of the first deviation of the maximum deviation value from the preset deviation value to the second deviation of the surface defect value from the preset defect value, thereby re-determining the wear coefficient.

[0022] Furthermore, the control unit responds to redetermining the rotational speed, the speed adjustment value being negatively correlated with the second excess value, wherein the larger the second excess value, the smaller the adjusted rotational speed.

[0023] Furthermore, the process of determining the suitability of the location includes,

[0024] Compare the actual accuracy score with the target accuracy score to determine the position's suitability.

[0025] In response to the qualified position, the fastening module drives the part to be fastened to rotate at a preset speed.

[0026] Furthermore, in response to a position failure, the position detection and analysis module obtains the historical fixing time of the component to be fixed to determine a compensation coefficient, and determines the fixing quality evaluation parameters based on the compensation coefficient.

[0027] Furthermore, the process of determining the actual accuracy score includes obtaining the type of the component to be fixed, determining the position data of the component to be fixed based on the type of the component to be fixed, and determining the actual accuracy score based on the position data. Specifically, if the type of the component to be fixed is a rotating body, the position data determined includes concentricity deviation value and circular runout value. If the type of the component to be fixed is a non-rotating body, the position data determined includes axis deviation and end face perpendicularity.

[0028] Compared with the prior art, the beneficial effect of the quality judgment and control system for fasteners of the present invention is that the quality of the fastener itself is determined by the wear degree value and surface defect value of the fastener, and the fixing quality of the fastener to the fastener is determined by the position of the fastener after the fastener is fixed. In this way, the quality of the fastener is comprehensively judged so as to dynamically balance the processing efficiency and the fastener life while ensuring the processing accuracy.

[0029] Furthermore, by quantifying the wear degree of individual fasteners, the key parameters for overall fastener failure are determined through the maximum range of wear degrees among several individual fasteners. This avoids situations where, during overall use, the same fasteners, due to being fixed to the same component, result in identical wear locations, leading to severe wear on a single fastener. This can cause sudden structural instability when replacing different components due to changes in the force pattern. Consequently, when the fastener drives the component to rotate, it affects the positioning accuracy and assembly reliability of the component. For example, when machining the inner hole or internal thread of a part with a non-rotating outer contour, uneven force on the outer contour can lead to sudden structural instability. During the machining of the inner hole or internal thread, the ideal rotation axis may deviate from the actual rotation axis, causing the roundness and coaxiality of the machined hole to exceed tolerances, severely affecting the assembly accuracy of the part. As another example, when the component to be fastened is a milling cutter, if the fasteners wear out synchronously, it can cause the milling cutter to be installed off-center, generating severe vibration during cutting. This not only reduces the surface finish but also accelerates tool wear and may even lead to tool breakage. Meanwhile, the rotational imbalance force will be transmitted to the spindle system, which will damage the bearing precision and affect the overall stability of the machine after long-term use. Therefore, when abnormal synchronous wear is detected, the machine must be stopped immediately for fastener repair or replacement.

[0030] Furthermore, by quantifying surface defect values ​​based on crack depth, scratch area ratio, and morphological complexity of the fastener surface, the potential safety hazards on the fastener surface can be fully reflected. When crack depth is too deep or scratches are concentrated, it indicates a risk of stress concentration, which can easily lead to fatigue crack propagation under alternating loads, ultimately causing fastener breakage. There may also be a risk of insufficient fastener connection strength. For example, when fixing a part to be drilled, if one of the jaws of a three-jaw chuck has dense scratches and excessively deep cracks, after the fixed part rotates, under turning or milling conditions, the radial force may be insufficient, causing the part to loosen and affecting machining accuracy. In some cases, excessive radial impact force may even cause the fastener to fail instantly, leading to serious safety accidents such as workpiece ejection or tool collision. Especially at the moment when the part to be drilled rotates at low speed and the milling cutter cuts in at high speed, the impact load increases sharply. If the fastener has a stress concentration area caused by hidden cracks or scratches at this time, it is very easy to cause brittle fracture within milliseconds. If the three-jaw chuck fails, the workpiece will detach from its original position due to centrifugal force and collide violently with the rotating tool. This can cause tool chipping, spindle misalignment, and may trigger a chain reaction of vibrations in the equipment, affecting the operating accuracy of other components. Even if the workpiece does not fly out, the failure of the three-jaw chuck may cause the workpiece to move, resulting in out-of-tolerance milling dimensions, product scrap, or even affecting subsequent assembly accuracy. If the fastener is fixing a milling cutter, even tiny cracks or scratches at the connection interface can cause stress concentration. At the moment of high-speed rotation and contact with the workpiece for cutting, high-frequency vibrations and impact loads are generated, causing the cracks to propagate rapidly, leading to sudden fracture of the milling cutter connection, cutting failure, or even tool body shattering and flying out, endangering the safety of the equipment and operators. This is especially true when the milling cutter rotates at high speed to mill holes on a low-speed rotating workpiece, particularly in high-precision machining scenarios such as threaded holes, where even tiny surface defects can trigger a chain reaction of failures. In this case, the alternating shear force and radial impact on the fastener are superimposed, causing cracks to propagate along grain boundaries and reducing fatigue life.

[0031] Furthermore, even when fastener wear coefficients are substandard but no safety hazards exist, improving the fixing precision of subsequent fasteners can compensate for insufficient fastener quality and inadequate fastening effect. This achieves a synergistic balance between system fault tolerance and performance optimization, extending the actual service life of fasteners and reducing equipment maintenance frequency and costs. Simultaneously, when fastener wear is low, fixing precision requirements can be relaxed, reducing assembly time and complexity, enabling faster assembly tasks, improving production line efficiency, reducing production difficulty, and ensuring system stability. By dynamically adjusting fixing precision requirements during assembly, a dynamic balance between production efficiency and equipment safety is achieved, further optimizing production line cycle time.

[0032] Furthermore, by adjusting the fixing accuracy between the fastener and the part to be fixed while the fastener wear coefficient is unqualified but not yet failed, the decrease in connection reliability caused by wear is compensated, thus achieving dynamic assurance of assembly quality. The control unit adjusts the preload torque application strategy based on the real-time wear coefficient, and by increasing the number of locating pins to ensure the positioning rigidity of the part to be fixed, it meets the adaptive adjustment requirements of the assembly process. It actively compensates for positioning and clamping deviations before wear causes the connection performance to degrade, thereby maintaining connection reliability while ensuring assembly cycle time. This fully meets the quality requirements of the fastener and the fixing quality requirements of the fastener when the part to be fixed is a drilled part with stable and reliable movement at low speed. It can also meet the stringent requirements of dynamic balance and vibration resistance performance when the part to be fixed is a milling cutter under high-speed cutting conditions. By using multi-data collaborative judgment to determine the quality of the fastener and the fixing quality of the milling cutter, it achieves precise suppression of small imbalances under high-speed rotation conditions.

[0033] Furthermore, by dynamically compensating for the axis deviation, the fastener can ensure that the fastener-fixed part meets the concentricity requirement while compensating for the wear coefficient. For the rotating part to be fixed, the concentricity qualification can be determined by the circular runout value, thereby compensating for the deviation of the milling cutter during fixing caused by the wear coefficient, so as to ensure the running stability of the rotating body under high-speed rotation conditions and maintain ideal cutting accuracy and surface quality during milling.

[0034] Furthermore, by re-correcting the end face perpendicularity deviation to optimize the clamping force distribution, balanced force application is ensured, and end face tilting caused by local stress concentration is reduced. This ensures the perpendicularity of the end face to the milling cutter and the machining accuracy of the workpiece. When the part to be fixed is a milling cutter, the coaxiality can also be detected after the milling cutter is installed by the circular runout value. The concentricity deviation value further ensures the perpendicularity of the milling cutter to the machining end face, thereby ensuring the uniformity of the force and wear on the milling cutter. At the same time, it can also enhance the uniformity of the force on the fastener, avoiding the non-uniform impact on the quality of the fastener when the milling cutter contacts the workpiece, which could lead to fastener loosening or fatigue damage and reduce the quality of the fastener.

[0035] Furthermore, by dynamically adjusting the fixing accuracy to compensate for the positioning deviation caused by wear when the fasteners are worn and unqualified, and then fixing the fasteners to the parts to be fixed according to the adjusted fixing accuracy, the actual fixing accuracy of the fasteners to the parts to be fixed is checked to verify the feasibility of compensating for the positioning deviation caused by wear by adjusting the fixing accuracy. Based on the verification results, the quality of fastener fixing to the parts to be fixed is optimized. At the same time, the rotation speed is dynamically adjusted according to the current fixing quality to achieve a balance between fastener quality and production efficiency while ensuring processing safety and processing accuracy. This avoids efficiency loss caused by excessively extending the service life of fasteners, as well as waste of fastener quality caused by excessive pursuit of production efficiency. It also avoids resource waste caused by premature replacement or repair when the fasteners can still meet production needs. This achieves synergistic optimization of cost control and processing performance, improves equipment utilization and process stability while ensuring the continuity of the processing process, and ensures that the production system achieves a balance between economy and reliability. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the quality judgment and control system for fasteners according to the present invention;

[0037] Figure 2 A flowchart for determining the wear coefficient in this invention;

[0038] Figure 3 A flowchart for determining the fixing accuracy of fasteners in this invention;

[0039] Figure 4 This is a flowchart for determining the fastener rotation speed according to the present invention. Detailed Implementation

[0040] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0041] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0042] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0043] Furthermore, it should be noted that, in the description of this 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 this invention according to the specific circumstances.

[0044] Please see Figure 1 The following is a detailed description of an embodiment of a quality assessment control system for fasteners.

[0045] This invention provides a quality assessment and control system for fasteners, comprising:

[0046] The visual inspection and analysis module is used to acquire microscopic images of fasteners to determine wear degree values ​​and surface defect values, determine the wear coefficient based on the wear degree values ​​and surface defect values, determine the fastener wear qualification, and in response to fastener wear failure, determine the preload torque and positioning deviation of several force-applying parts for fastening the fastener to be fixed according to the degree of fastener wear failure.

[0047] The visual inspection and analysis module is used to acquire microscopic images of the fasteners and determine a wear coefficient based on these images. The wear coefficient includes a wear degree value and a surface defect value. The wear degree value is determined based on the wear amount of several individual fasteners. The wear degree value is determined by assigning a single weight to each individual fastener based on its wear amount. The wear amount of each individual fastener is calculated using the grayscale distribution characteristics and edge blurring of the microscopic image. Since the fastener comprises several individual fasteners, the wear degree value quantifies the overall wear condition of the fastener. Therefore, the wear degree value is determined by comprehensively considering the wear amounts of multiple individual fasteners. Because the wear locations of individual fasteners are not the same, the wear amount determined for different wear locations of an individual fastener has different degrees of influence on the wear degree value. Therefore, different single weights are set to correspond to different wear conditions of individual fasteners, thereby determining the wear degree value based on the wear amount of each individual fastener. The wear degree value is determined by a corresponding single weight to comprehensively evaluate the overall wear degree of the fastener. For example, when a part is fixed by a three-jaw chuck, if the wear amounts of the three jaws are calculated to be 0.2mm, 0.21mm, and 0.23mm respectively based on the grayscale distribution characteristics and edge ambiguity of the microscopic image, it is not sufficient to simply average or sum the three wear amounts to determine the overall wear condition of the three-jaw chuck. Different weights need to be assigned to the wear amount of each jaw. For example, if 0.23mm is mainly end face wear rather than wear on the contact surface with the part, then the corresponding single weight needs to be reduced. If 0.2mm is mainly wear on the contact surface with the part, then its corresponding single weight needs to be increased. By matching the corresponding single weight to the wear amount obtained under different conditions, the wear degree value can be more accurately determined to reflect the wear condition of the fastener.

[0048] Specifically, the visual inspection and analysis module acquires microscopic images to determine the wear amount of several individual fasteners, and determines the maximum deviation value based on the wear amount of several individual fasteners.

[0049] Compare the maximum deviation value with the preset deviation value to determine the passability of synchronous wear;

[0050] In response to non-compliance of synchronous wear, the fastener's fixing accuracy is determined to be in failure, an alarm is issued, and a fastener handling strategy is determined.

[0051] The wear degree value is determined based on the wear amount of several individual fasteners. The wear degree value is determined by the wear amount of several individual fasteners and their corresponding individual weights. At the same time, the maximum deviation value of several wear amounts on the same fastener is obtained. The maximum deviation value is compared with the preset deviation value to determine the synchronous wear qualification.

[0052] If the maximum deviation value is less than the preset deviation value, then the synchronous wear is qualified; this indicates that the wear of each individual fastener is uniform, the overall force of the fastener is balanced, and it can continue to be used to fix the parts to be fixed.

[0053] If the maximum deviation value is greater than or equal to the preset deviation value, then the synchronous wear is unqualified and an alarm needs to be triggered directly. The fastener handling strategy should be to repair or replace the fastener. If the synchronous wear is unqualified and the fastener is used to fix the part to be fixed, the part to be fixed will not be fixed accurately. After fixing the part to be fixed, the part to be fixed will deviate significantly from the target fixing shape. Therefore, there is no need to perform subsequent quality judgment and the fastener is directly judged to be unqualified.

[0054] This invention quantifies the wear degree of individual fasteners and determines the key parameters for overall fastener failure by using the maximum range of wear degrees among several individual fasteners. This avoids situations where, during overall use, the same fasteners, due to being fixed to the same component, result in identical wear locations, leading to severe wear on a single fastener. This can cause sudden structural instability when replacing different components due to changes in stress patterns. Consequently, when the fastener drives the component to rotate, it affects the positioning accuracy and assembly reliability. For example, when machining a non-rotating part with a central inner hole or internal thread, uneven stress on the outer contour can lead to sudden structural instability. During inner hole or internal thread machining, the ideal rotation axis may deviate from the actual rotation axis, causing the roundness and coaxiality of the machined hole to exceed tolerances, severely affecting the assembly accuracy of the part. Furthermore, when the component to be fastened is a milling cutter, if the fasteners wear out synchronously, it can cause the milling cutter to be installed off-center, generating severe vibrations during cutting. This not only reduces the surface finish but also accelerates tool wear and may even lead to tool breakage. Meanwhile, the rotational imbalance force will be transmitted to the spindle system, which will damage the bearing precision and affect the overall stability of the machine after long-term use. Therefore, when abnormal synchronous wear is detected, the machine must be stopped immediately for fastener repair or replacement.

[0055] Specifically, the visual inspection and analysis module acquires microscopic images of the fastener to determine surface defect values, compares the surface defect values ​​with preset defect values, and judges the surface qualification of the fastener.

[0056] In response to surface defects of fasteners, the fastener's securing safety is determined to have failed, an alarm is issued, and a fastener handling strategy is determined.

[0057] The surface defect value is quantified based on the area ratio and morphological complexity of crack and scratch regions in the image. This surface defect value characterizes the crack depth and scratch density on the fastener surface. By comparing the surface defect value with a preset defect value, the surface qualification of the fastener is determined.

[0058] If the surface defect value is less than the preset defect value, the surface is deemed qualified, indicating that the fastener surface is reliable and can continue to be used. The possibility of breakage is low, and the current working condition can be maintained.

[0059] If the surface defect value is greater than or equal to the preset defect value, the surface is deemed unqualified. In response to the determination of surface unqualification, it indicates that the crack depth of the fastener has exceeded the safety limit when fixing the part to be fixed. This is likely to occur when fixing the part to be fixed. During the movement of the part to be fixed, the fastener is prone to breakage. Therefore, an alarm is triggered at this time, and no further quality judgment is required. The fastener is directly determined to be unqualified. If both the wear degree value and the surface defect value are qualified, the wear coefficient is determined based on the synchronous wear qualification and the surface qualification.

[0060] This invention quantifies surface defects by measuring crack depth, scratch area ratio, and morphological complexity on the fastener surface. This allows for a comprehensive reflection of potential safety hazards on the fastener's surface. Excessively deep cracks or concentrated scratches indicate stress concentration risk, making the fastener susceptible to fatigue crack propagation under alternating loads, ultimately leading to fastener breakage. It may also indicate insufficient fastener connection strength. For example, when fixing a part to be drilled, if one jaw of a three-jaw chuck has dense scratches and excessively deep cracks, the part may become loose due to insufficient clamping force during turning or milling under radial stress, affecting machining accuracy. In severe cases, excessive radial impact force could cause instantaneous fastener failure, leading to workpiece ejection or tool collision. Particularly during the moment when the part to be drilled rotates at low speed while the milling cutter cuts in at high speed, the impact load increases sharply. If the fastener has hidden cracks or stress concentration areas caused by scratches at this time, brittle fracture can easily occur within milliseconds. If the three-jaw chuck fails, the workpiece will detach from its original position due to centrifugal force and collide violently with the rotating tool. This can cause tool chipping, spindle misalignment, and may trigger a chain reaction of vibrations in the equipment, affecting the operating accuracy of other components. Even if the workpiece does not fly out, the failure of the three-jaw chuck may cause the workpiece to move, resulting in out-of-tolerance milling dimensions, product scrap, or even affecting subsequent assembly accuracy. If the fastener is fixing a milling cutter, even tiny cracks or scratches at the connection interface can cause stress concentration. At the moment of high-speed rotation and contact with the workpiece for cutting, high-frequency vibrations and impact loads are generated, causing the cracks to propagate rapidly, leading to sudden fracture of the milling cutter connection, cutting failure, or even tool body shattering and flying out, endangering the safety of the equipment and operators. This is especially true when the milling cutter rotates at high speed to mill holes on a low-speed rotating workpiece, particularly in high-precision machining scenarios such as threaded holes, where even tiny surface defects can trigger a chain reaction of failures. In this case, the alternating shear force and radial impact on the fastener are superimposed, causing cracks to propagate along grain boundaries and reducing fatigue life.

[0061] Specifically, the process by which the visual inspection and analysis module determines the wear qualification of fasteners includes:

[0062] Please see Figure 2As shown, the process of determining the wear coefficient is explained in detail; based on the synchronous wear qualification and the surface qualification of the fastener, the wear coefficient is determined according to the wear degree value and surface defect value determined by the wear amount of several individual fasteners, and the wear coefficient is compared with the preset coefficient threshold to determine the wear qualification of the fastener;

[0063] In response to unqualified fastener wear, the fastener fixing accuracy of the fastener to be fixed is improved to compensate for the fixing deviation caused by fastener wear.

[0064] Please see Figure 3 The process of determining the fixing accuracy is explained in detail. The wear coefficient is calculated by weighted summation of wear degree value, wear weight value, surface defect value, and defect weight value. The wear coefficient is compared with the preset coefficient threshold to determine the wear qualification of the fastener and to determine the fixing accuracy of the fastener to fix the part to be fixed.

[0065] In calculating the wear coefficient, a weighted sum is calculated by setting preset weight values ​​for the wear degree value and the surface defect value. However, in reflecting the overall wear of fasteners, the wear degree value has a greater impact on the accuracy of the fastener in fixing the component to be fastened, while the surface defect value has a greater impact on the safety of the fastener in fixing the component to be fastened. Therefore, in determining the wear qualification of fasteners through the wear coefficient, the wear coefficient cannot be simply determined by adding the wear degree value and the surface defect value. Instead, the wear coefficient is determined by matching the corresponding weight values ​​according to the degree of influence of the wear degree value and the surface defect value on the determination of the wear qualification of fasteners. For example, the wear weight value is set to 0.65 and the defect weight value is set to 0.35 for the calculation of the wear coefficient.

[0066] If the wear coefficient is less than the preset coefficient threshold, the fastener is deemed to be of acceptable wear, indicating that assembly according to historical fixed precision can still meet the current processing precision requirements and it can continue to be used.

[0067] If the wear coefficient is greater than or equal to a preset threshold, the fastener is deemed unqualified due to wear. In response to this, the wear coefficient is compared to a critical coefficient to determine the fastener's usability. If the wear coefficient is less than the critical coefficient, the fastener is deemed usable and can be adjusted to meet the fixing requirements. If the wear coefficient is greater than or equal to the critical coefficient, the fastener is deemed unqualified. Based on this unqualified condition, the wear weight and defect weight values ​​are redefined to redetermine the wear coefficient, and the fastener's usability is reassessed. If the fastener is still deemed unqualified, an alarm is triggered, and the fastener is repaired or replaced. The critical coefficient is a calibration value used to evaluate the fastener's usability, determined by integrating the wear data of multiple fasteners used in the past until they could no longer meet the fastener's fixing requirements and the yield rate was unqualified under the condition of meeting production efficiency. During the process of redetermining the wear coefficient, since the previous determination of the wear coefficient used a value based on... The weighted values ​​corresponding to wear degree values ​​and surface defect values ​​concentrated in a large amount of historical fastener data are used to quickly determine the wear coefficient to evaluate the fastener's suitability for use. However, when a fastener is unqualified, the weighted values ​​corresponding to wear degree values ​​and surface defect values ​​concentrated in a large amount of historical fastener data should not be used again. Instead, the wear coefficient should be re-determined based on the weighted values ​​corresponding to wear degree values ​​and surface defect values ​​in the current case of unqualified fastener use. For example, if the wear degree value deviates more significantly than the surface defect value deviates less significantly during the current determination of the wear coefficient, the weighted values ​​used in the previous determination should not be used. Instead, the wear weighted value corresponding to the wear degree value should be increased to make a targeted tendency judgment for the current fastener, rather than using the weighted values ​​corresponding to wear degree values ​​and surface defect values ​​concentrated in a large amount of historical fastener data to determine the wear coefficient for the fastener's suitability for use again.

[0068] The wear weight value is re-determined based on the ratio of the first degree of deviation of the maximum deviation value from the preset deviation value to the second degree of deviation of the surface defect value from the preset defect value;

[0069] In response to unqualified fastener wear, and based on the qualified condition of the fasteners in use, the fastening accuracy of the fasteners used to fix the parts to be fixed is determined and adjusted to compensate for the fixing deviation caused by fastener wear.

[0070] By adjusting the preload torque and positioning deviation of several force-applying parts included in the fastener, the positional offset caused by wear is dynamically compensated, ensuring that the parts to be fastened can still be kept within the allowable tolerance range during the assembly process.

[0071] This invention addresses the issue of insufficient fastener quality and inadequate fastening effect by improving the fixing precision of fasteners when their wear coefficient is substandard but no safety hazards exist. This achieves a synergistic balance between system fault tolerance and performance optimization, extending the actual service life of fasteners and reducing equipment maintenance frequency and costs. Simultaneously, when fastener wear is low, fixing precision requirements can be relaxed, reducing assembly time and complexity, enabling faster assembly tasks, improving production line efficiency, reducing production difficulty, and ensuring system stability. By dynamically adjusting the fixing precision requirements during assembly, a dynamic balance is achieved between production efficiency and equipment safety, further optimizing production line cycle time.

[0072] Please see Figure 4 The process of determining the rotational speed of the fastening module is described in detail. The fastening module includes fasteners, several force-applying parts, and several positioning parts. In response to unqualified fastener wear, the control unit determines the fastener's usability based on the wear coefficient and critical coefficient. Based on the unqualified fastener usage, the control unit determines the fastener processing strategy based on the re-determined wear coefficient. Based on the qualified fastener usage, the control unit determines the number of positioning parts according to the determined positioning deviation. Several force-applying parts fix the part to be fixed according to the determined pre-tightening torque, and drive the part to be fixed to rotate at a preset rotational speed.

[0073] Specifically, the process by which the visual inspection and analysis module determines the qualification of fasteners based on the wear coefficient and the critical coefficient includes comparing the wear coefficient and the critical coefficient to determine the qualification of fasteners.

[0074] In response to unqualified fastener use, the wear weight value is re-determined based on the ratio of the first deviation of the maximum deviation value from the preset deviation value to the second deviation of the surface defect value from the preset defect value, thereby re-determining the wear coefficient.

[0075] The preload torque is applied by a torque wrench, and the positioning deviation is determined by the number of positioning parts. For example, when the fastener wear is acceptable, two positioning pins are used to position the part to be fixed. When the fastener wear is unacceptable, three positioning pins are used to enhance the positioning rigidity and increase the positioning accuracy. When the degree of unacceptable fastener wear reaches the deviation critical coefficient, four positioning pins are used to further increase the positioning accuracy of the part to be fixed by over-positioning to compensate for the positioning inaccuracy caused by extreme wear.

[0076] Specifically, the control unit responds to determining that the fixing accuracy of the fastener is improved, and the adjustment amount of the fixing accuracy is determined based on a first excess value of the wear coefficient relative to a preset coefficient threshold, wherein the adjustment amount is positively correlated with the first excess value.

[0077] The larger the initial exceedance value, the greater the adjustment amount should be to ensure that the actual fixing accuracy of the component to be fixed meets the target accuracy requirements. The determination of the preset coefficient threshold also needs to consider the tolerance range of the fixing accuracy to avoid problems such as overly pursuing fixing accuracy to compensate for the initial exceedance value, leading to incomplete assembly or excessively slow assembly speed, resulting in reduced production efficiency. It also avoids stress concentration due to excessive adjustment, which could cause deformation of the component to be fixed or secondary damage to the fasteners. The preset coefficient threshold should be dynamically calibrated based on historical wear data and actual measured accuracy on the production line to ensure that the compensation strategy is implemented within a safe, efficient, and feasible range, achieving synergistic optimization of quality and efficiency.

[0078] This invention compensates for the decrease in connection reliability caused by wear when the fastener's wear coefficient is unqualified but it has not failed. This is achieved by adjusting the fixing accuracy between the fastener and the part to be fixed, thus dynamically ensuring assembly quality. The control unit adjusts the preload torque application strategy based on the real-time wear coefficient. Combined with increasing the number of locating pins to ensure the positioning rigidity of the part to be fixed, it also meets the adaptive adjustment requirements of the assembly process. It actively compensates for positioning and clamping deviations before wear causes the connection performance to degrade, thereby maintaining connection reliability while ensuring assembly cycle time. This fully meets the quality requirements of fasteners and the fixing quality requirements of fasteners when the part to be fixed is a drilled part with stable and reliable movement at low speeds. It also meets the stringent requirements of dynamic balance and vibration resistance when the part to be fixed is a milling cutter under high-speed cutting conditions. By using multi-data collaborative judgment to determine the quality of the fastener and the fixing quality of the milling cutter, it achieves precise suppression of small imbalances under high-speed rotation conditions.

[0079] The position detection and analysis module acquires the position data of the fixed part, determines the actual accuracy score, and judges the position qualification. The control unit responds to the position failure by determining the fixation quality evaluation parameters based on the wear coefficient, compares the fixation quality evaluation parameters with the preset quality threshold, judges the fixation quality qualification, and, based on the fixation quality failure, redetermines the rotation speed according to the second excess value of the fixation quality evaluation parameters relative to the preset quality threshold.

[0080] Specifically, the process of determining the actual accuracy score includes obtaining the type of the part to be fixed, determining the position data of the part to be fixed based on the type of the part, and determining the actual accuracy score based on the position data. Wherein, determining the position data based on the type of the part to be fixed as a rotating body includes concentricity deviation and circular runout values; determining the position data based on the type of the part to be fixed as a non-rotating body includes axial deviation and end face perpendicularity. The position detection and analysis module can use a coordinate measuring machine (CMM) to obtain concentricity deviation and circular runout values ​​for tools such as milling cutters for rotating bodies, and axial deviation and end face perpendicularity for non-rotating parts. The following uses axial deviation and end face perpendicularity as examples.

[0081] The component to be fixed is fixed based on the determined preload torque and positioning deviation. The axial deviation and end face perpendicularity of the component after fixing are obtained to determine the actual accuracy score.

[0082] The axial deviation is calculated based on the angle difference between the preset rotation axis and the actual rotation axis of the component to be fixed.

[0083] Compare the axis deviation with the preset axis threshold to determine the concentricity qualification. If the axis deviation is less than the preset axis threshold, the concentricity is qualified. If the axis deviation is greater than or equal to the preset axis threshold, the concentricity is unqualified.

[0084] The axial deviation is the vector angle between the theoretical rotation axis and the actual rotation axis of the part in the spatial coordinate system. Based on the concentricity non-compliance, the preload torque of several force-applying parts is re-determined, and the preload torque is adjusted to change the force distribution and reduce the deformation offset of the part to be fixed. Thus, the clamping force distribution of several single fixing parts is adjusted by the preload torque of several force-applying parts to compensate for the axial offset caused by assembly deviation. The axial deviation and the perpendicularity of the end face are checked again until the actual accuracy scoring requirements are met.

[0085] This invention uses dynamic compensation for axial deviation to ensure that the fastener-fixed parts can meet concentricity requirements while compensating for wear coefficient. For rotating parts, concentricity can be determined by the circular runout value, thereby compensating for the deviation of the milling cutter during fixing caused by wear coefficient, ensuring the stability of the rotating body under high-speed rotation conditions and maintaining ideal cutting accuracy and surface quality during milling.

[0086] Specifically, the process for determining the verticality of the end face is explained in detail;

[0087] Compare the end face perpendicularity with the preset perpendicularity to determine the end face perpendicularity qualification. If the end face perpendicularity is less than the preset perpendicularity, the end face perpendicularity is judged to be qualified. If the end face perpendicularity is greater than or equal to the preset perpendicularity, the end face perpendicularity is judged to be unqualified.

[0088] Based on the issue of non-perpendicular end face, the preload torque of several force-applying components is adjusted. Adjusting the preload torque changes the force distribution, reduces the deformation and displacement of the part to be fixed, and optimizes the force balance of the part to be fixed under clamping conditions. This reduces the issue of non-perpendicular end face, thereby addressing the perpendicularity of the machined end face of the drilled part to the milling cutter axis. It avoids drilling axis offset and hole diameter distortion caused by end face tilt, ensuring the accuracy of milling on the machined end face. It also avoids uneven tool wear caused by different wear on the inclined surface of the milling cutter under axial force, which would lead to a decrease in tool life. For rotating parts to be fixed, the concentricity deviation value can be used to determine the perpendicularity of the end face, achieving the same technical purpose. It can also effectively ensure the perpendicularity requirement between the axis of rotation and the machining plane, ensuring that rotating bodies such as milling cutters are uniformly stressed during high-speed rotation, ensuring the precise machining and uniform wear of the parts to be fixed by fasteners, and thus ensuring that the fasteners are subjected to uniform impact, thereby extending the service life of the fasteners and ensuring the quality of the fasteners and the parts to be fixed.

[0089] This invention optimizes the clamping force distribution by re-correcting the end face perpendicularity deviation, ensuring balanced force application and reducing end face tilting caused by local stress concentration. This ensures the perpendicularity of the end face to the milling cutter and the machining accuracy of the workpiece. When the part to be fixed is a milling cutter, the coaxiality can also be detected after the milling cutter is installed by the circular runout value. The concentricity deviation value further ensures the perpendicularity of the milling cutter to the machining end face, thereby ensuring the uniformity of the force and wear on the milling cutter. At the same time, it can also enhance the uniformity of the force on the fastener, avoiding non-uniform impact on the quality of the fastener when the milling cutter contacts the workpiece, which could lead to loosening or fatigue damage of the fastener and reduce the quality of the fastener.

[0090] Specifically, in response to a position failure, the position detection and analysis module obtains the historical fixing time of the component to be fixed to determine the compensation coefficient, and determines the fixing quality evaluation parameters based on the compensation coefficient.

[0091] Based on the concentricity and end face perpendicularity being qualified, the actual accuracy score is determined according to the axis deviation, axis weight, end face perpendicularity, and vertical weight. Actual accuracy score = axis deviation × Qi × axis weight + end face perpendicularity × Qj × vertical weight.

[0092] Among them, Qi and Qj are compensation coefficients used to correct the dimensional difference between the axis deviation and the perpendicularity of the end face. The lower the actual accuracy score, the better the fixing effect.

[0093] The position is deemed qualified by comparing the actual accuracy score with the target accuracy score. If the actual accuracy score is less than the target accuracy score, the position is deemed qualified; if the actual accuracy score is greater than or equal to the target accuracy score, the position is deemed unqualified.

[0094] Specifically, the process of determining the position qualification includes comparing the actual accuracy score with the target accuracy score to determine the position qualification; in response to the position qualification, the fastening module drives the part to be fixed to rotate at a preset speed. Thus, when the position is qualified, the quality of the fastener fixing the part to be fixed is guaranteed, eliminating the need to adjust the speed to reduce the impact load on the parts, tools, and fasteners during processing. It allows the system to directly enter the processing flow under optimal conditions, effectively improving processing efficiency and system stability. Simultaneously, it reduces energy loss and time costs caused by speed adjustment, further ensuring the dynamic balance of the rotating body under high-speed operation, reducing vibration interference with processing accuracy, and ensuring that the fastener remains reliably locked during continuous operation, thereby achieving the requirements of high-precision and high-stability automated processing.

[0095] Based on the positional non-compliance, a fixed quality evaluation parameter is determined using a combination of wear coefficients. This fixed quality evaluation parameter is determined based on the wear coefficient and the actual accuracy score. The fixed quality evaluation parameter is calculated as follows: Fixed Quality Evaluation Parameter = Wear Coefficient × Actual Accuracy Score × Adjustment Factor × Compensation Coefficient. The adjustment factor is dynamically adjusted based on the number of times the fastener is used, reflecting the impact of material fatigue on positioning stability. The compensation coefficient is adjusted based on the historical fastening time of the part to be fastened. For example, if the part to be fastened is a machined part that has not been fastened before, the compensation coefficient is 1. If the part to be fastened is a milling cutter or other tool used for machining other parts and has been used multiple times, the compensation coefficient increases with the duration of fastening to reflect the deteriorating effect of cumulative wear on positioning accuracy. The fixed quality is then compared with a preset quality threshold to determine the pass / fail status of the fastening.

[0096] Compare the fixed quality evaluation parameters with the preset quality threshold. If the fixed quality evaluation parameters are less than the preset quality threshold, the fixed quality is judged to be qualified. If the fixed quality evaluation parameters are greater than or equal to the preset quality threshold, the fixed quality is judged to be unqualified.

[0097] Based on the condition that the fastener is of good quality, the current speed is output as the working speed. Under the condition that the fastener quality is good and the fastening effect is good, the preset speed is used to ensure processing efficiency, processing yield and processing reliability.

[0098] Specifically, the control unit responds to redetermining the rotational speed, and the speed adjustment value is negatively correlated with the second excess value, wherein the larger the second excess value, the smaller the adjusted rotational speed.

[0099] Based on the condition of unqualified fixed quality, the rotational speed of the fastener is determined. The rotational speed of the fastener is negatively correlated with the second excess value of the fixed quality evaluation parameter relative to the preset quality threshold. The larger the second excess value, the lower the rotational speed of the fastener. This reduces the accumulation of dynamic stress during the assembly process and slows down the trend of wear aggravation. When the fastener quality is poor or the fastener tightening effect is not ideal, the rotational speed is reduced to ensure the stability and reliability of the machining process. When the fastener fixes tools such as milling cutters, reducing the rotational speed ensures the smoothness of the milling process and avoids tool breakage or workpiece surface quality degradation due to increased vibration. When the fastener fixes parts, reducing the rotational speed can effectively reduce the impact of cutting force fluctuations on positioning accuracy, prevent workpiece displacement or fixture loosening, and ensure the safety and dimensional stability of the machining process.

[0100] This invention dynamically adjusts the fixing accuracy to compensate for positioning deviations caused by wear when fasteners are worn and unqualified. After fixing the fasteners to the parts to be fixed according to the adjusted fixing accuracy, the actual fixing accuracy of the fasteners to the parts to be fixed is checked to verify the feasibility of compensating for positioning deviations caused by wear by adjusting the fixing accuracy. Based on the verification results, the quality of fastener fixing to the parts to be fixed is optimized. At the same time, the rotation speed is dynamically adjusted according to the current fixing quality to achieve a balance between fastener quality and production efficiency while ensuring processing safety and processing accuracy. This avoids efficiency loss caused by excessively extending the service life of fasteners, as well as waste of fastener quality caused by excessive pursuit of production efficiency. It also avoids resource waste caused by premature replacement or repair when the fasteners can still meet production needs. Thus, it achieves synergistic optimization of cost control and processing performance, improves equipment utilization and process stability while ensuring the continuity of the processing, and ensures that the production system achieves a balance between economy and reliability.

[0101] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A quality judgment and control system for fasteners, characterized in that, include, The visual inspection and analysis module is used to acquire microscopic images of fasteners to determine wear degree values ​​and surface defect values. Based on the wear degree values ​​and surface defect values, it determines the wear coefficient and judges the wear qualification of fasteners. In response to the fastener wear failure, it determines the pre-tightening torque and positioning deviation of several force-applying parts of the fastener to be fixed according to the degree of fastener wear failure. It determines the adjustment of the fastener to improve the fixing accuracy of the fastener to be fixed. The adjustment amount of fixing accuracy is determined according to the first excess value of the wear coefficient relative to the preset coefficient threshold. The surface defect value is quantified by the crack depth, the area ratio of the scratch area and the morphological complexity of the fastener surface. The wear coefficient is calculated by weighted summation of wear degree value, wear weight value, surface defect value and defect weight value. The fastening module includes fasteners, several force-applying parts, several positioning parts, and a control unit. In response to unqualified fastener wear, the control unit determines the qualified use of the fastener based on the wear coefficient and the critical coefficient. Based on the unqualified use of the fastener, the control unit determines the fastener treatment strategy based on the re-determined wear coefficient. The process involves determining the number of positioning parts based on the positioning deviation according to the fastener's performance, and using several force-applying parts to fix the component to be fixed according to a determined pre-tightening torque. The component to be fixed is then rotated at a preset speed. The visual inspection and analysis module determines the fastener's performance based on the wear coefficient and critical coefficient. By comparing the wear coefficient with the critical coefficient, the suitability of the fasteners for use can be determined. In response to the use of unqualified fasteners, the wear weight value is re-determined based on the ratio of the first deviation of the maximum deviation value from the preset deviation value to the second deviation of the surface defect value from the preset defect value, thereby re-determining the wear coefficient. The position detection and analysis module is used to acquire the position data of the fixed part, determine the actual accuracy score, judge the position qualification, and in response to the position failure, determine the fixation quality evaluation parameter by combining the wear coefficient, compare the fixation quality evaluation parameter with the preset quality threshold, judge the fixation quality qualification, and based on the fixation quality failure, redetermine the rotation speed according to the second excess value of the fixation quality evaluation parameter relative to the preset quality threshold.

2. The quality judgment and control system for fasteners according to claim 1, characterized in that, The visual inspection and analysis module acquires microscopic images to determine the wear amount of several individual fasteners, and determines the maximum deviation value based on the wear amount of several individual fasteners. Compare the maximum deviation value with the preset deviation value to determine the passability of synchronous wear; In response to non-compliance of synchronous wear, the fastener's fixing accuracy is determined to be in failure, an alarm is issued, and a fastener handling strategy is determined.

3. The quality judgment and control system for fasteners according to claim 2, characterized in that, The visual inspection and analysis module acquires microscopic images of the fastener to determine surface defect values, compares the surface defect values ​​with preset defect values, and judges the surface qualification of the fastener. In response to surface defects of fasteners, the fastener's securing safety is determined to have failed, an alarm is issued, and a fastener handling strategy is determined.

4. The quality judgment and control system for fasteners according to claim 3, characterized in that, The process by which the visual inspection and analysis module determines the wear qualification of fasteners includes the following steps. Based on synchronous wear qualification and fastener surface qualification, the wear coefficient is determined by the wear degree value and surface defect value determined by the wear amount of several individual fasteners. The wear coefficient is compared with the preset coefficient threshold to determine the fastener wear qualification. In response to unqualified fastener wear, the fastener fixing accuracy of the fastener to be fixed is improved to compensate for the fixing deviation caused by fastener wear.

5. The quality judgment and control system for fasteners according to claim 4, characterized in that, The control unit responds to determining that the fixing accuracy of the fastener is improved, and the adjustment amount of the fixing accuracy is determined according to a first excess value of the wear coefficient relative to a preset coefficient threshold, wherein the adjustment amount is positively correlated with the first excess value.

6. The quality judgment and control system for fasteners according to claim 1, characterized in that, The control unit responds to redetermining the rotational speed, and the speed adjustment value is negatively correlated with the second excess value, wherein the larger the second excess value, the smaller the adjusted rotational speed.

7. The quality judgment and control system for fasteners according to claim 1, characterized in that, The process of determining the suitability of a location includes: Compare the actual accuracy score with the target accuracy score to determine the position's suitability. In response to the qualified position, the fastening module drives the part to be fastened to rotate at a preset speed.

8. The quality judgment and control system for fasteners according to claim 1, characterized in that, The position detection and analysis module responds to position non-compliance by obtaining the historical fixing time of the component to be fixed to determine the compensation coefficient, and then determines the fixing quality evaluation parameters based on the compensation coefficient.

9. The quality judgment and control system for fasteners according to claim 1, characterized in that, The process of determining the actual accuracy score includes obtaining the type of the component to be fixed, determining the position data of the component to be fixed based on the type of the component to be fixed, and determining the actual accuracy score based on the position data. Specifically, if the type of the component to be fixed is a rotating body, the position data determined includes the concentricity deviation value and the circular runout value. If the type of the component to be fixed is a non-rotating body, the position data determined includes the axis deviation and the end face perpendicularity.

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