Method and system for bulge forming of a vehicle body component

Abstract

The present application relates to the technical field of metal part stamping, and particularly relates to a bulging stamping method and system for a vehicle body part, which acquires the image of the adhesive strip overflowing the die cavity in the acquisition period of the morphological feature, and determines the surface morphological feature vectors corresponding to the first sub-region and the second sub-region in each overflowed adhesive segment; determines whether the support structure of the stamping adhesive head is abnormal in form by the difference in the angle between the surface morphological feature vectors of the first sub-region and the second sub-region; determines the support form abnormality category of the stamping adhesive head by the position distribution of the overflowed adhesive segment with abnormal support structure form; and finally determines the stamping adjustment mode according to the support form abnormality category of the stamping adhesive head; the micro-morphological features of the overflowed surface of the adhesive head are captured in real time in the batch rapid production of the bulging stamping of the vehicle body part to quickly locate the abnormalities and perform differentiated adjustment stamping strategies, and the efficiency and accuracy of abnormality identification in batch rapid stamping are improved.

Description

Technical Field

[0001] This invention relates to the field of metal parts stamping technology, and more particularly to a bulging stamping method and system for automotive body parts. Background Technology

[0002] In the bulging stamping process of vehicle body parts, especially when using petal-shaped mold cavities to form complex curved surfaces, the stamping head, as a key force-transmitting component, directly affects the forming quality due to its compatibility with the mold cavity. Uneven local stress and material performance degradation of the stamping head can easily lead to irregular overflow patterns, resulting in defects such as wrinkles and dimensional deviations on the surface of the vehicle body parts. Existing technologies mostly rely on manual inspection or single sensor monitoring of the stamping head status, which cannot directly reflect the microscopic morphological characteristics of the overflow surface. Furthermore, when anomalies are detected, traditional methods cannot implement differentiated processing, leading to low adjustment efficiency, increased production costs, and difficulty in meeting the mass production requirements of high-precision vehicle body parts. Therefore, how to monitor the abnormal shape of the stamping head's support structure in real time and accurately, and to make targeted adjustments based on the anomaly category, has become a key technical challenge for improving the quality and efficiency of bulging stamping of vehicle body parts.

[0003] For example, Chinese Patent Publication No. CN112264516A discloses a sheet metal bulging stamping device and a die-based stamping method. The device includes a lower die base, a bulging workpiece, a stretching workpiece, a lower forming die, and an upper die fixing plate. Four evenly distributed lower guide blocks are fixedly installed on the upper surface of the lower die base, and the lower guide blocks are symmetrically distributed near the center of the lower die base. The lower forming die and the lower guide blocks each have matching inclined surfaces on their adjacent sides. This device can conveniently and stably bulge the stretching workpiece by pressing it with the lower guide blocks and the first and second forming sliders.

[0004] The following problems still exist in the existing technology:

[0005] Existing technologies do not consider the rapid and accurate identification of abnormalities in the morphology of stamping heads during the mass production of body parts through bulging stamping. Existing technologies cannot capture the microscopic morphological features of the overflowing surface of the stamping head in real time to quickly locate abnormalities, and cannot make differentiated adjustments to the stamping strategy, which affects the efficiency and accuracy of abnormality identification in mass rapid stamping. Summary of the Invention

[0006] To address this, the present invention provides a method and system for bulging stamping of vehicle body parts, which overcomes the problems of existing technologies in the rapid mass production of vehicle body parts by failing to capture the microscopic morphological characteristics of the overflowing surface of the rubber head in real time to quickly locate anomalies and failing to make differentiated adjustments to the stamping strategy.

[0007] To achieve the above objectives, the present invention provides a method for bulging and stamping a vehicle body component, comprising:

[0008] The image of the rubber strip overflowing from the mold cavity during the bulging stamping process is obtained within a preset morphological feature acquisition time period. The overflowing rubber strip is divided into several overflow segments within the rubber strip image. The surface morphology representation vectors corresponding to the first sub-region and the second sub-region are determined in each overflow segment.

[0009] The presence of an abnormal support structure morphology of the stamping head is determined based on the angle difference between the surface morphology representation vector of the first sub-region and the surface morphology representation vector of the second sub-region.

[0010] In response to the determination result that there is an abnormal support structure in the stamping head, the location distribution of the overflow rubber segment with abnormal support structure is obtained to determine the type of abnormal support structure of the stamping head.

[0011] The stamping adjustment method is determined based on the abnormal support shape of the stamping head, including determining the supporting explicit sub-cavity of the petal-shaped mold cavity based on the location of the overflowing glue segment with abnormal structural shape, and adjusting the height position of the supporting explicit sub-cavity after closing; or, issuing an alarm prompt to replace the stamping head.

[0012] Furthermore, the process of acquiring the adhesive strip image includes:

[0013] The stamping stroke value of the stamping head is obtained in advance, and the first moment when the stamping head reaches the first stamping stroke value and the second moment when the stamping head reaches the second stamping stroke value are determined based on the stamping stroke value;

[0014] The surface image of the stamping rubber head that overflows from the mold cavity during the acquisition period is obtained as a rubber strip image;

[0015] The time period for acquiring the morphological features is determined based on the first time and the second time.

[0016] Furthermore, the process of determining the first sub-region and the second sub-region within each overflow adhesive strip segment includes:

[0017] Within the image of the adhesive strip, the adhesive strip is divided into several overflow segments with the same length value along a direction perpendicular to the stamping direction;

[0018] Within each overflow adhesive segment, a boundary line is determined based on the width value to divide the overflow adhesive segment into a first sub-region and a second sub-region.

[0019] The first sub-region and the second sub-region have the same length and the same width.

[0020] Furthermore, the process of determining the surface morphology representation vector is as follows:

[0021] The normal vector of the first sub-region is determined as the first surface morphology representation vector, and the normal vector of the second sub-region is determined as the second surface morphology representation vector.

[0022] Furthermore, the process of determining whether the stamping head has an abnormal support structure includes:

[0023] Calculate the vector angle between the first surface morphology representation vector and the second surface morphology representation vector within each overflow segment;

[0024] The overflow adhesive segment whose vector angle does not meet the morphological analysis conditions is identified as having an abnormal morphological structure of the supporting structure.

[0025] The morphological analysis condition is that the vector angle is less than or equal to a preset vector angle reference value.

[0026] Furthermore, the location of the overflow adhesive segment with abnormal support structure morphology is obtained, including:

[0027] A rectangular coordinate system is constructed with the center of the section of the stamping head perpendicular to the stamping direction as the origin;

[0028] The position of the centroid of the overflowing adhesive segment with abnormal support structure shape in the rectangular coordinate system is determined as the position of the overflowing adhesive segment with abnormal support structure shape.

[0029] Furthermore, the process of determining the abnormal support shape category of the stamping rubber head includes:

[0030] Combine the overflowing adhesive segments with abnormal shapes in adjacent support structures into adhesive segments with obvious abnormal performance.

[0031] If the abnormal visible rubber segments are centrally symmetrically distributed based on the origin of the rectangular coordinate system, then the abnormal support shape of the stamping rubber head is determined to be the first abnormal category.

[0032] If there are abnormally exhibiting visible rubber segments that are not centrally symmetrically distributed based on the origin of the rectangular coordinate system, then the abnormal support shape of the stamping rubber head is determined to be the second abnormal category.

[0033] Furthermore, the process of determining the stamping adjustment method based on the abnormal support shape of the stamping head includes:

[0034] If the abnormal support shape of the stamping head is classified as the first abnormal category, then the weakly supported explicit petal cavity of the petal mold cavity is determined according to the position of the overflowing section of the abnormal structure, and the height position of the weakly supported explicit petal cavity after closing is adjusted.

[0035] If the support abnormality of the stamping head is classified as the second abnormality category, an alarm prompting to replace the stamping head will be issued.

[0036] Further, adjusting the height position of the supported dominant sub-cavity after closing includes:

[0037] Determine the location of the overflowing glue segments with abnormal structural morphology in the petal-shaped mold cavity within the abnormally manifested glue segments.

[0038] The sub-petal mold cavity containing the overflowing glue segment with abnormal structural morphology is identified as the supporting explicit sub-cavity.

[0039] The average angle between the first and second surface morphology representation vectors within the overflow segment based on the morphological anomaly is adjusted to lower the height position of the supporting explicit sub-cavity after closure.

[0040] Furthermore, the present invention also provides a bulging stamping system for a vehicle body component, comprising:

[0041] The image acquisition unit is used to acquire images of the rubber strip overflowing from the mold cavity during the bulging stamping process within a preset morphological feature acquisition time period;

[0042] A vector annotation unit, which is connected to the image acquisition unit, is used to divide the overflowing adhesive strip into several overflow segments within the adhesive strip image, and to determine the surface morphology representation vectors corresponding to the first sub-region and the second sub-region within each overflow segment.

[0043] The data analysis unit, which is connected to the vector annotation unit, is used to determine whether there is an abnormal support structure morphology of the stamping head based on the angle difference between the surface morphology representation vector of the first sub-region and the surface morphology representation vector of the second sub-region.

[0044] An anomaly classification unit, which is connected to the data analysis unit, is used to determine the anomaly category of the stamping head's support shape based on the location distribution of overflowing adhesive segments with abnormal support structure morphology.

[0045] The stamping adjustment unit is connected to the anomaly classification unit and the data analysis unit respectively, and is used to determine the stamping adjustment method according to the anomaly category of the support shape of the stamping rubber head.

[0046] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention acquires images of the rubber strip overflowing from the mold cavity within a time period by obtaining morphological features, and determines the surface morphological representation vectors corresponding to the first sub-region and the second sub-region within each overflow rubber segment; it determines whether there is an abnormal support structure morphology of the stamping rubber head by the angle difference between the surface morphological representation vectors of the first sub-region and the second sub-region; it determines the support morphological abnormality category of the stamping rubber head by the positional distribution of the overflow rubber segments with abnormal support structure morphology; and finally determines the stamping adjustment method according to the support morphological abnormality category of the stamping rubber head. Thus, it realizes the real-time capture of the microscopic morphological features of the rubber head overflow surface in the mass rapid production of body parts bulging stamping to quickly locate abnormalities and to carry out differentiated adjustment stamping strategies, thereby improving the efficiency and accuracy of abnormality identification in mass rapid stamping.

[0047] Furthermore, this invention achieves precise locking of the effective morphological feature acquisition window by mapping the stamping head stroke value to the time. During the bulging stamping process of the vehicle body parts, the stroke change of the stamping head directly determines the degree of compression of the head by the mold cavity: when the stroke does not reach the first stamping stroke value, the head is insufficiently compressed, and the overflowing rubber strip has an unstable shape, failing to reflect the true state of the support structure; when the stroke reaches the second stamping stroke value, the head has completed the bulging action. Therefore, by determining the first time corresponding to the first stamping stroke value and the second time corresponding to the second stamping stroke value through pre-acquired stamping stroke values, and thus setting the morphological feature acquisition period, the window period in which the head is in a stable overflow stage can be accurately screened. The rubber strip image acquired during this period presents a rubber strip morphology that is representative of the data.

[0048] Furthermore, this invention quantifies the differences in the normal vector directions of the sub-regions of the overflowing rubber strip surface to infer the stress balance of the stamping rubber head support structure, thereby identifying abnormal support structure morphology. From the perspective of the correlation logic between surface morphology and support structure, the surface morphology of the overflowing rubber strip is a direct reflection of the stress state of its support structure. If the rubber head support structure is uniform and the stress is balanced, when the rubber strip overflows under the pressure of the mold cavity, the first and second sub-regions symmetrically distributed along the midline of the overflowing rubber segment within the same rubber segment will form symmetrical surfaces due to consistent stress, and the angle between the surface normal vectors of the two sub-regions will be small. Conversely, if the local support structure of the rubber head is abnormal, the stress on the corresponding rubber segment will be unbalanced, resulting in asymmetrical distortion of the surface morphology of the first and second sub-regions, and the angle between the normal vectors of the two sub-regions will also deviate significantly from the normal value. By calculating the angle between the first and second surface morphology characterization vectors, the abstract feature of morphological symmetry is transformed into a quantifiable numerical index: realizing the real-time capture of the microscopic morphological characteristics of the overflowing rubber head surface in the rapid mass production of body parts by bulging stamping.

[0049] Furthermore, this invention establishes a direct correlation between the symmetrical distribution characteristics of abnormally exhibited rubber segments and their causes: when the abnormal rubber segments are centrally symmetrically distributed, it indicates that their stress imbalance has overall and symmetrical characteristics, which is usually related to the overall assembly accuracy of the petal-shaped mold cavity and the unevenness of the joints between the various mold sub-cavities of the petal-shaped mold cavity. Conversely, when the abnormal rubber segments are not centrally symmetrical, their stress imbalance has local and asymmetrical characteristics, which is more indicative of local defects in the material or structure of the stamping head itself. By quantitatively analyzing the symmetry of the abnormal distribution using a coordinate system, accurate classification of the root causes of the anomalies can be achieved.

[0050] Furthermore, this invention matches corresponding solutions based on the category of abnormal support morphology. Under the first abnormality category, the essence of the abnormal phenomenon is uneven stress caused by overall assembly or structural problems of the petal-shaped mold cavity. This systemic problem can be eliminated by adjusting the mold parameters. By locating the corresponding weak support explicit petal cavity at the abnormal rubber segment position and adjusting its closing height, the smoothness of the mold joint can be directly improved, and the stress on the rubber head can be balanced. The abnormal phenomenon of the second abnormality category is the local material performance degradation or structural defects of the stamping rubber head itself. Since the local performance degradation of the rubber head is irreversible, timely replacement prompts can avoid batch product quality problems caused by rubber head defects. Thus, a differentiated adjustment stamping strategy is realized to ensure the stability and quality consistency of the bulging stamping of body parts.

[0051] Furthermore, the average angle between the first and second surface morphology characterization vectors in this invention directly reflects the degree of excessive compression of the rubber segment. The larger the angle, the greater the interference pressure on the rubber head in that area due to the high cavity height, and the more severe the morphological distortion. Adjusting the height of the sub-cavity after closure based on this average angle essentially reduces the excessive compression on the rubber head by lowering the relative height of the sub-cavity, balancing the stress state of the rubber head in each area, restoring the symmetry of the rubber strip overflow shape, and ultimately eliminating the abnormal support structure morphology caused by the cavity height deviation. This achieves a precise match between the mold cavity height compensation amount and the degree of excessive compression, avoiding batch forming defects caused by uneven internal height after the petal-shaped mold cavity is closed. Attached Figure Description

[0052] Figure 1 This is a step diagram of the bulging stamping method for a vehicle body component according to an embodiment of the present invention;

[0053] Figure 2 This is a schematic diagram of the first surface morphology characterization vector and the second surface morphology characterization vector according to an embodiment of the present invention;

[0054] Figure 3 This is a schematic diagram of the distribution of dominant colloidal segments in the first abnormality category according to an embodiment of the present invention;

[0055] Figure 4This is a schematic diagram of the distribution of dominant colloidal segments in the second abnormal category of this invention.

[0056] Figure 5 This is a step diagram illustrating the process of adjusting the height position of the supporting dominant sub-cavity after closure, according to an embodiment of the present invention.

[0057] Figure 6 This is a system block diagram of the bulging stamping system for a vehicle body component according to an embodiment of the present invention;

[0058] In the figure: 1-overflowing segment, 2-regional boundary line, 3-first surface morphology characterization vector, 4-second surface morphology characterization vector, 5-first anomalous dominant segment, 6-second anomalous dominant segment, 7-third anomalous dominant segment, 8-fourth anomalous dominant segment. Detailed Implementation

[0059] 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.

[0060] 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.

[0061] It should be noted that in the description of this invention, the terms "upper," "lower," "inner," "outer," etc., which indicate the direction or positional relationship, are based on the direction or positional relationship shown in the 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.

[0062] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation" and "connection" 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.

[0063] Please see Figure 1 The diagram shows the steps of a bulging stamping method for a vehicle body component according to an embodiment of the present invention. The bulging stamping method for a vehicle body component according to the present invention includes:

[0064] Step S100: Obtain an image of the rubber strip overflowing from the mold cavity during the bulging stamping process within a preset morphological feature acquisition time period. Divide the overflowing rubber strip into several overflow segments within the rubber strip image. Determine the surface morphological characterization vectors corresponding to the first sub-region and the second sub-region within each overflow segment.

[0065] In the implementation of this invention, for the bulging forming of complex curved surfaces or hollow structural parts such as car body parts, the stamping head is the core functional component for realizing the plastic deformation of materials. Through its own shape change after being squeezed, the stamping head evenly transmits the mold closing force and stamping driving force to the workpiece to be formed, ultimately making the workpiece conform to the mold cavity contour and completing the bulging process. High elasticity and high compressive strength polymer elastic materials, such as polyurethane rubber, are often used. In the actual production and processing process, the stamping head also needs to be replaced according to the results of product error detection.

[0066] Step S200: Determine whether the stamping head has an abnormal support structure based on the angle difference between the surface morphology representation vector of the first sub-region and the surface morphology representation vector of the second sub-region.

[0067] Step S300: In response to the determination result that there is an abnormal support structure of the stamping head, the location distribution of the overflow rubber segment with abnormal support structure is obtained to determine the type of abnormal support structure of the stamping head.

[0068] Step S400: Determine the stamping adjustment method according to the abnormal support shape of the stamping head, including determining the supporting explicit sub-cavity of the petal-shaped mold cavity according to the position of the overflowing glue segment with abnormal structural shape, and adjusting the height position of the supporting explicit sub-cavity after closing; or, issue an alarm prompt to replace the stamping head.

[0069] This invention does not limit the specific structure of the petal-shaped mold cavity. The petal-shaped mold cavity includes several mold sub-cavities. Each mold sub-cavity can close to form a mold cavity and each mold sub-cavity can open to facilitate the removal of the stamped workpiece inside the mold cavity. This is a mold structure commonly used by those skilled in the art, and will not be described in detail here.

[0070] Specifically, the height position of each mold sub-cavity after being closed in the petal-shaped mold cavity can be finely adjusted individually by adjusting the height adjustment mechanism of the mold sub-cavities. This is a technical means well known to those skilled in the art and will not be elaborated here.

[0071] Specifically, the process of acquiring the adhesive strip image includes:

[0072] The stamping stroke value of the stamping head is obtained in advance, and the first moment when the stamping head reaches the first stamping stroke value and the second moment when the stamping head reaches the second stamping stroke value are determined based on the stamping stroke value;

[0073] The surface image of the stamping rubber head that overflows from the mold cavity during the acquisition period is obtained as a rubber strip image;

[0074] The time period for acquiring the morphological features is determined based on the first time and the second time.

[0075] In this invention, the first and second stamping stroke values ​​are predetermined based on the maximum stamping stroke value of the stamping head. The maximum stamping stroke value of the stamping head is the stroke from the start of stamping to the furthest stamping position. The first stamping stroke value is the product of the maximum stamping stroke value and the first stamping stroke value coefficient, and the second stamping stroke value is the product of the maximum stamping stroke value and the second stamping stroke value coefficient. Preferably, in this implementation, the first stamping stroke value coefficient can be 0.9, and the second stamping stroke value coefficient can be 0.95. That is, the rubber strip image is the image of the stamping head between the first and second stamping stroke values. During this period, the change in the stamping stroke of the stamping head is small, so the degree of morphological change is almost unchanged. Moreover, during this period, the stamping stroke of the stamping head is close to the maximum stamping stroke value, and the morphology of the rubber segment overflowing from the mold cavity also has strong data representativeness.

[0076] Those skilled in the art will understand that this invention achieves precise locking of the effective morphological feature acquisition window by mapping the stamping head stroke value to the time. During the bulging stamping process of body parts, the stroke change of the stamping head directly determines the degree of compression of the head by the mold cavity: when the stroke does not reach the first stamping stroke value, the head is insufficiently compressed, and the overflowing rubber strip has an unstable shape, failing to reflect the true state of the support structure; when the stroke reaches the second stamping stroke value, the head has completed the bulging action. Therefore, by determining the first time corresponding to the first stamping stroke value and the second time corresponding to the second stamping stroke value through pre-acquired stamping stroke values, and thus setting the morphological feature acquisition period, the window period in which the head is in a stable overflow stage can be accurately screened, and the rubber strip morphology presented in the rubber strip image acquired during this period is representative of the data.

[0077] Specifically, the process of determining the first sub-region and the second sub-region within each overflow adhesive strip segment includes:

[0078] Within the image of the adhesive strip, the adhesive strip is divided into several overflow segments with the same length value along a direction perpendicular to the stamping direction;

[0079] Within each overflow adhesive segment, a boundary line is determined based on the width value to divide the overflow adhesive segment into a first sub-region and a second sub-region.

[0080] The first sub-region and the second sub-region have the same length and the same width.

[0081] In this invention, the length of the overflow rubber segment perpendicular to the stamping direction can be set by those skilled in the art. For example, for a cylindrical or square stamping head, the length of the overflow rubber segment can be set to 1 / n of the perimeter of the cylindrical or square cross section. Preferably, the value of n can be 8.

[0082] In this invention, the region boundary line is the midline of the width value of the overflow adhesive segment, that is, the region boundary line divides the overflow adhesive segment into two sub-regions with equal width values: a first sub-region and a second sub-region.

[0083] It is understandable that in the bulging and stamping of body parts, the uniformity of the support structure of the stamping head will directly reflect the symmetry of the overflow rubber strip. If the support structure is normal, the force on each part will be balanced when the rubber strip is squeezed and overflows, and its shape should show good symmetry. If the local support performance is insufficient, the shape of the corresponding area of ​​the rubber strip will be distorted. Based on this technical principle, this invention divides the rubber strip into several overflow rubber segments of the same length along the stamping direction to ensure that each rubber segment can reflect the support force state of the corresponding area. The area boundary line is determined based on half the width of the rubber segment, and each overflow rubber segment is equally divided into a first sub-region and a second sub-region with completely consistent length and width.

[0084] Specifically, please refer to Figure 2 As shown, this is a schematic diagram of the first surface morphology characterization vector and the second surface morphology characterization vector according to an embodiment of the present invention. The process of determining the surface morphology characterization vector is as follows:

[0085] The normal vector of the first sub-region is determined as the first surface morphology representation vector, and the normal vector of the second sub-region is determined as the second surface morphology representation vector.

[0086] Please see Figure 2 As shown, the overflow adhesive segment 1 is divided into upper and lower parts by the region boundary line 2. On the surface of the upper part of the overflow adhesive segment, a rectangular detection area with a preset area is determined as the first sub-region. On the surface of the lower part of the overflow adhesive segment, a rectangular detection area with a preset area is determined as the second sub-region. The first surface morphology representation vector 3 of the first sub-region is determined based on the coordinates of the four vertices of the first sub-region. The second surface morphology representation vector 4 of the second sub-region is determined based on the coordinates of the four vertices of the second sub-region.

[0087] The area of ​​the preset region is determined based on the surface area of ​​each part of the overflow adhesive segment. Preferably, the area of ​​the preset region of the first sub-region is 1 / 4 of the surface area of ​​the upper part of the overflow adhesive segment, and the area of ​​the preset region of the second sub-region is 1 / 4 of the surface area of ​​the lower part of the overflow adhesive segment.

[0088] In this invention, the process of determining the first surface morphology representation vector can be as follows: obtain the position coordinates of the four vertices of the first sub-region, and add the normal vectors of the plane determined by any three of the four vertices to obtain the vector of the first sub-region. Similarly, the process of determining the second surface morphology representation vector can be as follows: obtain the position coordinates of the four vertices of the second sub-region, and add the normal vectors of the plane determined by any three of the four vertices to obtain the vector of the second sub-region.

[0089] Specifically, the normal vector of the first sub-region can be determined by using the position coordinates of the four vertices of the first sub-region through an image algorithm, and the normal vector of the second sub-region can be determined by using the position coordinates of the four vertices of the second sub-region through an image algorithm. Determining the normal vector of a surface is an existing image processing technique, which will not be elaborated here.

[0090] Specifically, the process of determining whether the stamping head has an abnormal support structure includes:

[0091] Calculate the vector angle between the first surface morphology representation vector and the second surface morphology representation vector within each overflow segment;

[0092] The overflow adhesive segment whose vector angle does not meet the morphological analysis conditions is identified as having an abnormal morphological structure of the supporting structure.

[0093] The overflow adhesive segment whose vector angle meets the morphological analysis conditions is determined to be free of abnormal morphological support structure.

[0094] The morphological analysis condition is that the vector angle is less than or equal to a preset vector angle reference value.

[0095] In the implementation of this invention, the preset vector angle reference value can be obtained from pre-test calculations. The average value of the vector angle between the first surface morphology representation vector and the second surface morphology representation vector in several overflow segments of the same specification product during several historical stamping processes is pre-tested. The calculated average value of the vector angle is determined as the vector angle reference value. Preferably, in the bulging stamping production of the reinforcing plate on the B-pillar of an aluminum alloy car body with a thickness of 1.2mm, under the condition of using a stamping equipment with a clamping force of 500kN and the stamping head being made of polyurethane rubber, the vector angle reference value is taken as 50°.

[0096] Understandably, this invention uses the difference in the normal vector direction of the overflowing sub-regions of the rubber strip to infer the stress balance of the stamping head support structure, thereby identifying abnormal support structure morphology. From the perspective of the correlation between surface morphology and support structure, the surface morphology of the overflowing rubber strip from the stamping head is a direct reflection of the stress state of its support structure. If the rubber head support structure is uniform and the stress is balanced, when the rubber strip overflows due to the extrusion of the mold cavity, the first and second sub-regions symmetrically distributed along the midline of the overflowing rubber segment within the same rubber segment will form symmetrical surfaces due to consistent stress, and the angle between the surface normal vectors of the two sub-regions will be small. Conversely, if the local support structure of the rubber head is abnormal, the stress on the corresponding rubber segment will be unbalanced, resulting in asymmetrical distortion of the surface morphology of the first and second sub-regions, and the angle between the normal vectors of the two sub-regions will also deviate significantly from the normal value.

[0097] By calculating the angle between the first and second surface morphology characterization vectors, the abstract characteristic of morphological symmetry is transformed into a quantifiable numerical index: when the vector angle is less than or equal to the preset reference value, it indicates that the surface morphology of the two sub-regions is symmetrical, the corresponding rubber segment is under balanced force, and the rubber head support structure is normal; when the vector angle exceeds the preset reference value, it indicates that the surface morphology of the two sub-regions has become significantly asymmetrical, thus realizing the real-time capture of the micro-morphological characteristics of the rubber head overflow surface in the mass rapid production of body parts by bulging and stamping.

[0098] Specifically, the location of the overflow adhesive segment due to abnormal support structure morphology is obtained, including:

[0099] A rectangular coordinate system is constructed with the center of the section of the stamping head perpendicular to the stamping direction as the origin;

[0100] The position of the centroid of the overflowing adhesive segment with abnormal support structure shape in the rectangular coordinate system is determined as the position of the overflowing adhesive segment with abnormal support structure shape.

[0101] Understandably, this invention achieves precise quantification of abnormal locations by establishing a standardized coordinate system. A rectangular coordinate system is constructed with the center of the vertical cross-section of the stamped rubber head as the origin, and the centroid coordinates of the abnormal overflow rubber segment are used as its location identifier. Essentially, through the standardized transformation of spatial coordinates, the physical position on the rubber strip is converted into calculable mathematical coordinates, thus providing a unified reference standard for abnormal locations.

[0102] Specifically, please refer to Figure 3 as well as Figure 4 As shown, Figure 3 This is a schematic diagram of the distribution of dominant colloidal segments in the first abnormality category according to an embodiment of the present invention. Figure 4 This is a schematic diagram of the distribution of visible rubber segments in the second abnormal category of this invention. The process of determining the abnormal support morphology category of the stamping rubber head includes:

[0103] Combine the overflowing adhesive segments with abnormal shapes in adjacent support structures into adhesive segments with obvious abnormal performance.

[0104] If the abnormal visible rubber segments are centrally symmetrically distributed based on the origin of the rectangular coordinate system, then the abnormal support shape of the stamping rubber head is determined to be the first abnormal category.

[0105] If there are abnormally exhibiting visible rubber segments that are not centrally symmetrically distributed based on the origin of the rectangular coordinate system, then the abnormal support shape of the stamping rubber head is determined to be the second abnormal category.

[0106] Understandably, if the number of abnormally manifested rubber segments is odd, the abnormal support shape of the stamping rubber head is directly classified as the second abnormal category.

[0107] Please see Figure 3 as well as Figure 4 As shown, the first abnormal manifestation, manifest segment 5, consists of two adjacent segments with abnormally shaped overflow adhesive structures; the second abnormal manifestation, manifest segment 6, consists of two adjacent segments with abnormally shaped overflow adhesive structures; the third abnormal manifestation, manifest segment 7, consists of only one segment with abnormally shaped overflow adhesive structure; and the fourth abnormal manifestation, manifest segment 8, consists of two adjacent segments with abnormally shaped overflow adhesive structures. Figure 3 In the sample, the dominant colloid segment 5, representing the first abnormality, and the dominant colloid segment 6, representing the second abnormality, are centrally symmetrically distributed, thus classifying it as the first abnormality category; Figure 4 In the study, the dominant colloid segment 7, which exhibits the third abnormality, and the dominant colloid segment 8, which exhibits the fourth abnormality, are not centrally symmetrically distributed, and therefore belong to the second abnormality category.

[0108] Understandably, this invention establishes a direct correlation between the symmetrical distribution characteristics of abnormally exhibited rubber segments and their causes: when abnormal rubber segments are centrally symmetrically distributed, it indicates that their stress imbalance has overall and symmetrical characteristics, which is usually related to the overall assembly accuracy of the petal-shaped mold cavity and the unevenness of the joints between the sub-cavities of the petal-shaped mold cavity. Conversely, when abnormal rubber segments are not centrally symmetrical, their stress imbalance has local and asymmetrical characteristics, which is more indicative of local defects in the material or structure of the stamping head itself. By quantitatively analyzing the symmetry of the abnormal distribution using a coordinate system, accurate classification of the root causes of the anomalies can be achieved.

[0109] Specifically, the process of determining the stamping adjustment method based on the abnormal support shape of the stamping head includes:

[0110] If the abnormal support shape of the stamping head is classified as the first abnormal category, then the weakly supported explicit petal cavity of the petal mold cavity is determined according to the position of the overflowing section of the abnormal structure, and the height position of the weakly supported explicit petal cavity after closing is adjusted.

[0111] If the support abnormality of the stamping head is classified as the second abnormality category, an alarm prompting to replace the stamping head will be issued.

[0112] In this invention, an alarm prompt for replacing the stamping head can be displayed on the monitor. Displaying device prompts on the monitor is existing technology and will not be described in detail here.

[0113] Understandably, this invention matches corresponding solutions based on the category of abnormal support morphology. Under the first category of abnormality, the essence of the abnormal phenomenon is uneven stress caused by overall assembly or structural problems of the petal-shaped mold cavity. This systemic problem can be eliminated by adjusting the mold parameters. By locating the corresponding weak support explicit petal cavity at the abnormal rubber segment position and adjusting its closing height, the smoothness of the mold joint can be directly improved, and the stress on the rubber head can be balanced. The second category of abnormality is the local material performance degradation or structural defects of the stamping rubber head itself. Since the local performance degradation of the rubber head is irreversible, timely replacement prompts can avoid batch product quality problems caused by rubber head defects. Thus, a differentiated stamping strategy is realized to ensure the stability and quality consistency of the bulging stamping of body parts.

[0114] Specifically, please refer to Figure 5 The diagram illustrates the steps of adjusting the height position of the supporting dominant sub-cavity after closure according to an embodiment of the present invention. Adjusting the height position of the supporting dominant sub-cavity after closure includes:

[0115] Step S401: Determine the location of the overflowing glue segments with abnormal structural morphology in the petal-shaped mold cavity of the abnormally manifested glue segments.

[0116] Step S402: The sub-petal mold cavity where the overflow glue segment with abnormal structural shape is located is identified as the supporting explicit sub-cavity;

[0117] Specifically, in the implementation of this invention, the positioning of the mold sub-cavities is achieved by numbering the mold sub-cavities of the petal-shaped mold cavity. For example, if the petal-shaped mold cavity includes 6 mold sub-cavities, and the central angle of each mold sub-cavity is 60°, then the mold sub-cavities can be numbered 1-6.

[0118] Step S403: Based on the average value of the vector angle between the first surface morphology representation vector and the second surface morphology representation vector within the overflow segment with abnormal morphology, the height position of the supporting explicit sub-cavity after adjustment and closure is lowered.

[0119] In the implementation of this invention, in the bulging stamping production of the reinforcing plate on the B-pillar of an aluminum alloy car body with a thickness of 1.2mm, a stamping equipment with a clamping force of 500kN is used, and the stamping head is made of polyurethane rubber. If the average value of the vector angle between the first surface morphology representation vector and the second surface morphology representation vector within the overflow section with abnormal morphology is within the range of (50°, 52°), the height can be reduced by 0.3mm at the currently set initial height position of the supporting explicit sub-cavity. If the average value of the vector angle between the first surface morphology representation vector and the second surface morphology representation vector within the overflow section with abnormal morphology is greater than 52°, the height can be reduced by 0.5mm at the currently set initial height position of the supporting explicit sub-cavity.

[0120] Understandably, in this invention, the supporting explicit sub-cavity is positioned higher than other sub-cavities, which can cause excessive compression of the rubber head in the corresponding area during mold closing and stamping. This localized interference pressure disrupts the force balance of the rubber head, resulting in distorted shape of the overflowing rubber strip at that location, manifested as a larger angle between the first and second surface morphology representation vectors. Therefore, by tracing the abnormal rubber segment location back to its corresponding mold sub-cavity, the supporting explicit sub-cavity causing excessive compression due to its excessive height can be accurately located.

[0121] Understandably, from the perspective of adjustment amount and degree of abnormality, the average angle between the first and second surface morphology characterization vectors directly reflects the degree of excessive compression of the rubber segment. The larger the angle, the greater the interference pressure on the rubber head in that area due to the excessive cavity height, and the more severe the morphological distortion. Based on this average angle, lowering the height position of the sub-cavity after closure essentially reduces the excessive compression on the rubber head by lowering the relative height of the sub-cavity, balancing the stress state of the rubber head in each area, restoring the symmetry of the rubber strip overflow shape, and ultimately eliminating the abnormal support structure morphology caused by the cavity height deviation. This achieves a precise match between the mold cavity height compensation amount and the degree of excessive compression, avoiding batch forming defects caused by uneven internal height after the petal-shaped mold cavity is closed.

[0122] Specifically, please refer to Figure 6 The diagram shown is a system block diagram of the bulging stamping system for a vehicle body component according to an embodiment of the present invention. The present invention also provides a bulging stamping system for a vehicle body component, comprising:

[0123] The image acquisition unit is used to acquire images of the rubber strip overflowing from the mold cavity during the bulging stamping process within a preset morphological feature acquisition time period;

[0124] Specifically, the present invention does not limit the image acquisition unit, which can be an industrial high-definition camera, and will not be elaborated here.

[0125] A vector annotation unit, which is connected to the image acquisition unit, is used to divide the overflowing adhesive strip into several overflow segments within the adhesive strip image, and to determine the surface morphology representation vectors corresponding to the first sub-region and the second sub-region within each overflow segment.

[0126] Specifically, the present invention does not limit the vector annotation unit, which can be an image processor used to determine the surface morphology representation vectors of different sub-regions through a pre-stored algorithm.

[0127] The data analysis unit, which is connected to the vector annotation unit, is used to determine whether there is an abnormal support structure morphology of the stamping head based on the angle difference between the surface morphology representation vector of the first sub-region and the surface morphology representation vector of the second sub-region.

[0128] An anomaly classification unit, which is connected to the data analysis unit, is used to determine the anomaly category of the stamping head's support shape based on the location distribution of overflowing adhesive segments with abnormal support structure morphology.

[0129] Specifically, the present invention does not limit the data analysis unit and the anomaly classification unit. Preferably, both can be data processors used for data calculation and comparison to output the final calculation results.

[0130] The stamping adjustment unit is connected to the anomaly classification unit and the data analysis unit respectively, and is used to determine the stamping adjustment method according to the anomaly category of the support shape of the stamping rubber head.

[0131] Specifically, the present invention does not limit the stamping adjustment unit, which can be constructed using logic components, such as field-programmable logic components, microprocessors, etc., which will not be elaborated here.

[0132] 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.

[0133] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for bulging and stamping a vehicle body component, characterized in that, include: The image of the rubber strip overflowing from the mold cavity during the bulging stamping process is obtained within a preset morphological feature acquisition time period. The overflowing rubber strip is divided into several overflow segments within the rubber strip image. The surface morphology representation vectors corresponding to the first sub-region and the second sub-region are determined in each overflow segment. The presence of an abnormal support structure morphology of the stamping head is determined based on the angle difference between the surface morphology representation vector of the first sub-region and the surface morphology representation vector of the second sub-region. In response to the determination result that there is an abnormal support structure in the stamping head, the location distribution of the overflow rubber segment with abnormal support structure is obtained to determine the type of abnormal support structure of the stamping head. The stamping adjustment method is determined based on the abnormal support shape of the stamping head, including determining the supporting explicit sub-cavity of the petal-shaped mold cavity based on the location of the overflowing glue section with abnormal structural shape, and adjusting the height position of the supporting explicit sub-cavity after closing; or issuing an alarm prompt to replace the stamping head.

2. The bulging stamping method for vehicle body parts according to claim 1, characterized in that, The process of acquiring an image of the adhesive strip includes: The stamping stroke value of the stamping head is obtained in advance, and the first moment when the stamping head reaches the first stamping stroke value and the second moment when the stamping head reaches the second stamping stroke value are determined based on the stamping stroke value; The surface image of the stamping rubber head that overflows from the mold cavity during the acquisition period is obtained as a rubber strip image; The time period for acquiring the morphological features is determined based on the first time and the second time.

3. The bulging stamping method for vehicle body parts according to claim 2, characterized in that, The process of determining the first and second sub-regions within each overflow adhesive strip segment includes: Within the image of the adhesive strip, the adhesive strip is divided into several overflow segments with the same length value along a direction perpendicular to the stamping direction; Within each overflow adhesive segment, a boundary line is determined based on the width value to divide the overflow adhesive segment into a first sub-region and a second sub-region. The first sub-region and the second sub-region have the same length and the same width.

4. The bulging stamping method for body parts according to claim 3, characterized in that, The process of determining the surface morphology representation vector is as follows: The normal vector of the first sub-region is determined as the first surface morphology representation vector, and the normal vector of the second sub-region is determined as the second surface morphology representation vector.

5. The bulging stamping method for a vehicle body component according to claim 4, characterized in that, The process of determining whether the stamping head has an abnormal support structure includes: Calculate the vector angle between the first surface morphology representation vector and the second surface morphology representation vector within each overflow segment; The overflow adhesive segment whose vector angle does not meet the morphological analysis conditions is identified as having an abnormal morphological structure of the supporting structure. The morphological analysis condition is that the vector angle is less than or equal to a preset vector angle reference value.

6. The bulging stamping method for a vehicle body component according to claim 5, characterized in that, The location of the overflow adhesive segment due to abnormal support structure morphology is obtained, including: A rectangular coordinate system is constructed with the center of the section of the stamping head perpendicular to the stamping direction as the origin; The position of the centroid of the overflowing adhesive segment with abnormal support structure shape in the rectangular coordinate system is determined as the position of the overflowing adhesive segment with abnormal support structure shape.

7. The bulging stamping method for a vehicle body component according to claim 6, characterized in that, The process for determining the type of abnormal support shape of the stamping rubber head includes: Combine the overflowing adhesive segments with abnormal shapes in adjacent support structures into adhesive segments with obvious abnormal performance. If the abnormal visible rubber segments are centrally symmetrically distributed based on the origin of the rectangular coordinate system, then the abnormal support shape of the stamping rubber head is determined to be the first abnormal category. If there are abnormally exhibiting visible rubber segments that are not centrally symmetrically distributed based on the origin of the rectangular coordinate system, then the abnormal support shape of the stamping rubber head is determined to be the second abnormal category.

8. The bulging stamping method for a vehicle body component according to claim 7, characterized in that, The process of determining the stamping adjustment method based on the abnormal support shape of the stamping head includes: If the abnormal support shape of the stamping head is classified as the first abnormal category, then the weakly supported explicit petal cavity of the petal mold cavity is determined according to the position of the overflowing section of the abnormal structure, and the height position of the weakly supported explicit petal cavity after closing is adjusted. If the support abnormality of the stamping head is classified as the second abnormality category, an alarm prompting to replace the stamping head will be issued.

9. The bulging stamping method for a vehicle body component according to claim 8, characterized in that, Adjusting the height position of the supported explicit sub-cavity after closing includes: Determine the location of the overflowing glue segments with abnormal structural morphology in the petal-shaped mold cavity within the abnormally manifested glue segments. The sub-petal mold cavity containing the overflowing glue segment with abnormal structural morphology is identified as the supporting explicit sub-cavity. The average angle between the first and second surface morphology representation vectors within the overflow segment based on the morphological anomaly is adjusted to lower the height position of the supporting explicit sub-cavity after closure.

10. A bulging stamping system for a vehicle body component, used to perform the bulging stamping method for a vehicle body component according to any one of claims 1-9, characterized in that, include: The image acquisition unit is used to acquire images of the rubber strip overflowing from the mold cavity during the bulging stamping process within a preset morphological feature acquisition time period; A vector annotation unit, which is connected to the image acquisition unit, is used to divide the overflowing adhesive strip into several overflow segments within the adhesive strip image, and to determine the surface morphology representation vectors corresponding to the first sub-region and the second sub-region within each overflow segment. The data analysis unit, which is connected to the vector annotation unit, is used to determine whether there is an abnormal support structure morphology of the stamping head based on the angle difference between the surface morphology representation vector of the first sub-region and the surface morphology representation vector of the second sub-region. An anomaly classification unit, which is connected to the data analysis unit, is used to determine the anomaly category of the stamping head's support shape based on the location distribution of overflowing adhesive segments with abnormal support structure morphology. The stamping adjustment unit is connected to the anomaly classification unit and the data analysis unit respectively, and is used to determine the stamping adjustment method according to the anomaly category of the support shape of the stamping rubber head.

Images