Measuring method and measuring device for skin stretch forming

Abstract

The application discloses a kind of measuring method and measuring device for skin stretch forming, belong to skin processing technical field.The measuring method for skin stretch forming of the application, skin is measured on line in stretch forming production, to record the actual reading of multiple laser distance measuring pieces after stretch forming production is completed, then according to the theoretical cross section line fitting actual cross section of skin on preset cross section, actual cross section line on preset cross section of skin can be measured, not only reduce skin stretch forming state evaluation difficulty, but also can fully evaluate skin stretch forming precision.The measuring device for skin stretch forming of the application, the position of laser distance measuring piece can be substantially adjusted by dismounting and mounting piece;By sliding second slide rail and laser distance measuring piece, the position of laser distance measuring piece in first direction and second direction can be fine adjusted, and operation is convenient.

Description

Technical Field

[0001] This invention relates to the field of skin processing technology, and in particular to a measurement method and measuring device for skin stretching and forming. Background Technology

[0002] Aircraft skin is a crucial component of aircraft sheet metal parts, widely used in aircraft fuselages and wings, directly shaping the aircraft's aerodynamic form. Skin stretch forming is the primary manufacturing process for aircraft skin. Through the relative movement of a die and a stretch forming machine clamp, the metal sheet undergoes plastic deformation under the combined action of tension and bending moment, gradually conforming to the die to obtain the desired shape.

[0003] Large curvature skin parts such as aircraft (such as leading edge, trailing edge, flaps, ailerons, etc.) are usually processed by skin stretching machines. These machines generally clamp metal sheet blanks with jaws, and the movement of the jaws will cause the metal sheet to undergo plastic deformation and fit into the mold, thus achieving the stretching and forming of the skin.

[0004] Due to elastic and plastic deformation, the skin formed by stretching will spring back to some extent after the jaws are released. Therefore, after the skin stretching is completed, it needs to be measured to assess the difference between the stretched skin and the theoretical parameters of the skin. However, in the existing technology, the stretching state of the skin is difficult to assess, and the stretching accuracy is insufficiently evaluated, which in turn affects the quality of the skin stretching production. Summary of the Invention

[0005] The purpose of this invention is to provide a measurement method and device for skin stretching forming, which reduces the difficulty of evaluating the skin stretching state and can fully evaluate the skin stretching accuracy.

[0006] To achieve the above objectives, the following technical solution is provided:

[0007] A measurement method for skin stretch forming, used to inspect skin stretched and formed by a stretching die, the skin including two clamping ends respectively connected to two stretching fixtures; the measurement method for skin stretch forming includes the following steps:

[0008] Multiple laser rangefinders are arranged on the same preset cross section below the forming mold. The multiple laser rangefinders are used to measure the distance between the two clamping end faces facing the forming mold and the corresponding laser rangefinder.

[0009] The positions of the multiple laser rangefinders are calibrated;

[0010] The positions of the multiple laser rangefinders obtained through calibration are mapped onto the stretch digital model of the skin to determine the zero-point positions of the multiple laser rangefinders and to determine the theoretical cross-sectional line of the skin on the preset cross-section.

[0011] The skin is produced by stretching;

[0012] After the stretching process is completed, record the actual readings of multiple laser rangefinders.

[0013] Based on multiple actual readings and the theoretical cross-sectional line, the actual cross-sectional line of the skin on the preset cross-section is fitted.

[0014] As a preferred embodiment of the above-mentioned measurement method for skin stretching forming, the method further includes the following steps:

[0015] Based on the actual cross-sectional line and the theoretical cross-sectional line, the distribution of the molding gap of the skin on the preset cross-section is calculated; the molding gap is the gap between the skin and the forming die.

[0016] As a preferred embodiment of the above-mentioned measurement method for skin stretching forming, the method further includes the following steps:

[0017] Multiple target points are selected on the theoretical cross-sectional line, and the tangential direction and / or curvature of the multiple target points are calculated;

[0018] Based on the actual cross-sectional line and the theoretical cross-sectional line, calculate the molding gap at multiple target points; the molding gap is the gap between the skin and the forming die.

[0019] Based on the molding gap at multiple target points, and with the principle of continuous tangential direction and / or minimum curvature change, the actual longitudinal section line of the skin on the longitudinal section where the multiple target points are located is fitted; the longitudinal section is perpendicular to the preset cross section.

[0020] As a preferred embodiment of the above-mentioned measurement method for skin stretching forming, the method further includes the following steps:

[0021] The actual contour of the skin is fitted based on the actual cross-sectional line and multiple actual longitudinal cross-sectional lines.

[0022] As a preferred embodiment of the above-mentioned measurement method for skin stretching forming, the method further includes the following steps:

[0023] Based on the theoretical profile and the actual profile of the skin, calculate the overall molding gap distribution of the skin and / or the springback of the skin.

[0024] As a preferred technical solution of the above-mentioned measurement method for skin stretching and forming, the plurality of target points include a plurality of preset target points, which are points on the theoretical cross-sectional line corresponding to the plurality of laser rangefinders.

[0025] As a preferred technical solution of the above-mentioned measurement method for skin stretching and forming, the position of the plurality of laser rangefinders is calibrated, including the following steps:

[0026] Set calibration references; the calibration references include mold references set on the forming die and / or external references set outside the forming die;

[0027] The calibration reference and multiple laser rangefinders are simultaneously scanned by a 3D scanner to calibrate the positions of the multiple laser rangefinders.

[0028] As a preferred technical solution of the above-mentioned measurement method for skin stretching and forming, the skin is produced by stretching and forming, including the following steps:

[0029] Begin forming production and monitor the readings of the multiple laser rangefinders;

[0030] Determine whether the skin is within the range of all the laser rangefinders. If yes, continue the stretching process to produce the skin. If not, adjust the installation position of the laser rangefinders that are outside the range until the skin is within the range of all the laser rangefinders, and then continue the stretching process to produce the skin.

[0031] As a preferred technical solution of the above-mentioned measurement method for skin stretching and forming, recording the actual readings of multiple laser rangefinders includes the following steps:

[0032] After the stretching process is completed, wait for the readings of the multiple laser rangefinders to stabilize before recording the actual readings of the multiple laser rangefinders.

[0033] To achieve the above objectives, a measuring device for skin stretch forming is also provided, for use in the measuring method for skin stretch forming as described in any of the preceding claims, the measuring device for skin stretch forming comprising a detection module, the detection module comprising:

[0034] The adjustment mechanism includes a mounting component, a first slide rail, and a second slide rail. The mounting component is used to be installed below the forming die. The first slide rail is fixed to the mounting component, and the second slide rail is slidably disposed on the first slide rail along a first direction.

[0035] A laser rangefinder is slidably disposed on a second slide rail along a second direction, and the laser rangefinder is used to detect the distance between the skin and the laser rangefinder; the first direction is perpendicular to the second direction;

[0036] The locking assembly includes a first locking member and a second locking member, wherein the first locking member is used to lock or unlock the first slide rail and the second slide rail, and the second locking member is used to lock or unlock the laser rangefinder and the second slide rail.

[0037] As a preferred technical solution of the above-mentioned measuring device for skin stretching and forming, it is used to inspect the skin stretched and formed by stretching die, wherein the skin includes two clamping ends respectively connected to two stretching clamps;

[0038] The detection module is provided in multiple ways, and the multiple detection modules are arranged on the same preset cross section below the forming mold. The multiple detection modules are divided into two detection units, and the laser rangefinders of the two detection units are respectively facing the two clamping end faces on the side facing the forming mold.

[0039] As a preferred technical solution of the above-mentioned measuring device for skin stretching and forming, a magnetic component is provided below the stretching die, and the mounting component is a magnetic suction component, which is attracted and fixed to the magnetic component.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0041] The measurement method for skin stretching and forming of the present invention first installs multiple laser rangefinders to determine a preset cross-section, and uses this preset cross-section as the benchmark for skin measurement and evaluation. Then, the positions of the multiple laser rangefinders are calibrated to ensure the reliability of the measurement results. Then, the skin is measured online during the stretching production process. After the stretching production is completed, the actual readings of the multiple laser rangefinders are recorded. Then, the actual cross-section is fitted according to the theoretical cross-sectional line of the skin on the preset cross-section, thereby achieving the purpose of measuring the actual cross-sectional line of the skin on the preset cross-section. This not only reduces the difficulty of evaluating the stretching state of the skin, but also fully evaluates the stretching accuracy of the skin.

[0042] The measuring device for skin stretching and forming of the present invention allows for significant adjustment of the position of the laser rangefinder by disassembling and assembling the mounting components; and allows for fine adjustment of the position of the laser rangefinder in the first and second directions by sliding the second slide rail and the laser rangefinder, making operation convenient. Attached Figure Description

[0043] Figure 1 This is a flowchart of a measurement method for skin stretching forming in an embodiment of the present invention;

[0044] Figure 2 This is a detailed flowchart of the measurement method for skin stretching forming in an embodiment of the present invention;

[0045] Figure 3 This is a schematic diagram of the theoretical cross-sectional line and the actual cross-sectional line on the preset cross-section in an embodiment of the present invention;

[0046] Figure 4 This is a schematic diagram of the theoretical longitudinal section line and the actual transverse and longitudinal section lines in an embodiment of the present invention;

[0047] Figure 5 This is a schematic diagram of the measuring device and stretching die used for skin stretching forming in an embodiment of the present invention;

[0048] Figure 6 This is a schematic diagram of the structure used for skinning and forming mold in an embodiment of the present invention;

[0049] Figure 7 This is a schematic diagram of the measuring device used for skin stretching and forming in an embodiment of the present invention;

[0050] Figure 8 This is a schematic diagram of a measuring device and a partial structure of the skin used for skin stretching and forming in an embodiment of the present invention.

[0051] Figure label:

[0052] 100. Skin; 200. Pull-out mold; 300. Pull-out slide rail; 400. Preset cross section; 1. Adjustment mechanism; 11. Mounting component; 12. First slide rail; 13. Second slide rail; 2. Laser rangefinder. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0054] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0055] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0056] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0057] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" 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. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0058] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0059] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0060] like Figure 1 As shown, this embodiment provides a measurement method for skin stretching and forming, used to inspect skin stretched and formed by stretching die, the skin including two clamping ends respectively connected to two stretching jigs.

[0061] The measurement method for skin stretch forming includes the following steps:

[0062] S1. Multiple laser rangefinders are arranged on the same preset cross section below the forming mold. The multiple laser rangefinders are used to measure the distance between the two clamping end faces facing the forming mold and the corresponding laser rangefinder.

[0063] In existing skin forming processes, the forming mold is typically mounted on a forming slide rail, and the mold and slide rail are locked together by locking devices. In this embodiment, multiple laser rangefinders can be mounted on the forming slide rail, thus preventing interference between the laser rangefinders and the forming mold, and facilitating installation. Alternatively, a separate mounting bracket can be provided below the forming mold to mount the laser rangefinders; this embodiment does not limit the method of mounting the laser rangefinders.

[0064] It should be noted that the multiple laser rangefinders are divided into two groups, each group including multiple laser rangefinders. The laser emitters of the two groups of laser rangefinders are oriented in different directions, and thus the two clamping end faces facing the forming mold are measured by the laser rangefinders on both sides respectively.

[0065] This embodiment does not limit the model and structure of the laser rangefinder, as long as it can be measured using laser technology.

[0066] S2. Calibrate the positions of multiple laser rangefinders.

[0067] Optionally, the positions of multiple laser rangefinders are calibrated, including the following steps:

[0068] Set calibration references; calibration references include mold references set on the forming die or external references set outside the forming die;

[0069] The calibration benchmark and multiple laser rangefinders are scanned simultaneously using a 3D scanner to calibrate the positions of the multiple laser rangefinders.

[0070] A 3D scanner is used to simultaneously scan the calibration benchmark and multiple laser rangefinders to ensure the calibration accuracy of the multiple laser rangefinders, thereby improving the reliability of the measurement results.

[0071] It should be noted that the outer surface of the forming die is a precision-machined surface. In this embodiment, the die reference set on the forming die is used as the calibration reference, which simplifies the calibration process and improves the efficiency of measurement work.

[0072] In this embodiment, the calibration method for multiple laser rangefinders is not limited, as long as the positions of multiple laser rangefinders can be accurately calibrated.

[0073] S3. Map the positions of the multiple laser rangefinders obtained through calibration to the stretch digital model of the skin to determine the zero-point positions of the multiple laser rangefinders and to determine the theoretical cross-sectional line of the skin on the preset cross-section.

[0074] It should be noted that, since the cross-section of the skin is different at different locations, in other words, the shape of the skin is different at different locations, the position of the laser rangefinder needs to be calibrated after the laser rangefinder is installed.

[0075] By mapping the positions of multiple laser rangefinders onto the stretched digital model of the skin, the theoretical readings of the laser rangefinders can be determined and used as the zero-point position of the laser rangefinders, which helps to improve the accuracy of the measurement results of the laser rangefinders.

[0076] S4. The skin is produced by stretching.

[0077] Optionally, the skin is produced by stretching, including the following steps:

[0078] Begin forming production, and collect and record readings from multiple laser rangefinders;

[0079] Determine if the skin is within the range of all laser rangefinders. If so, continue the stretching process to produce the skin. If not, adjust the installation position of the laser rangefinders that are outside the range until the skin is within the range of all laser rangefinders, and then continue the stretching process to produce the skin.

[0080] The above steps ensure that all laser rangefinders function properly, thereby improving the reliability and accuracy of measurement results.

[0081] During the stretch forming process, real-time monitoring of the readings of multiple laser rangefinders facilitates the determination of the validity of the laser rangefinder measurement results and provides possibilities for optimizing the skin stretch forming process and monitoring skin quality.

[0082] For example, when determining whether the skin is within the range of the laser rangefinder, if the reading of the laser rangefinder remains at the maximum range for a long time, it can be considered that the skin is outside the range of the laser rangefinder.

[0083] S5. After completing the stretching production, record the actual readings of multiple laser rangefinders.

[0084] It is understandable that after the stretching production is completed, the actual readings of multiple laser rangefinders are recorded only after the readings of the multiple laser rangefinders have stabilized, thereby ensuring the reliability of the measurement results of the multiple laser rangefinders.

[0085] S6. Based on multiple actual readings and theoretical cross-sectional lines, fit the actual cross-sectional line of the skin on the preset cross-section.

[0086] For example, the actual cross-sectional line of the skin on a preset cross-section can be obtained by interpolating and fitting multiple actual readings based on the shape function fitted to the theoretical cross-sectional line.

[0087] The measurement method for skin stretching and forming in this embodiment first installs multiple laser rangefinders to determine a preset cross-section, and uses this preset cross-section as the benchmark for skin measurement and evaluation. Then, the positions of the multiple laser rangefinders are calibrated to ensure the reliability of the measurement results. Then, the skin is measured online during the stretching production process. After the stretching production is completed, the actual readings of the multiple laser rangefinders are recorded. Then, the actual cross-section is fitted according to the theoretical cross-sectional line of the skin on the preset cross-section, thereby achieving the purpose of measuring the actual cross-sectional line of the skin on the preset cross-section. This not only reduces the difficulty of evaluating the skin stretching state, but also fully evaluates the skin stretching accuracy.

[0088] Optionally, after step S6, the following steps are also included:

[0089] Based on the actual cross-sectional line and the theoretical cross-sectional line, calculate the distribution of the molding gap on the preset cross-section of the skin; the molding gap is the gap between the skin and the forming die.

[0090] Since both the actual cross-sectional line and the theoretical cross-sectional line are located in the same stretching mold, it is convenient to quickly calculate the distribution of the molding gap on the preset cross-section of the skin, and the distribution of the molding gap can also be viewed intuitively.

[0091] Optionally, after step S6, the following steps are also included:

[0092] Select multiple target points on the theoretical cross-section line and calculate the tangential direction and / or curvature of the multiple target points;

[0093] Based on the actual and theoretical cross-sectional lines, calculate the molding gap at multiple target points; the molding gap is the gap between the skin and the forming die.

[0094] Based on the molding gap at multiple target points, and taking into account the principle of continuous tangential direction and / or minimum curvature change, the actual longitudinal section line of the skin on the longitudinal section where the multiple target points are located is fitted; the longitudinal section is perpendicular to the preset cross section.

[0095] By comparing the actual longitudinal section lines of the skin with the theoretical profile, the distribution of the mold gap on multiple longitudinal sections of the skin produced by stretch forming can be viewed intuitively, which is helpful for further and more fully evaluating the stretch forming accuracy of the skin.

[0096] Optionally, after fitting the actual longitudinal section lines of the skin at the longitudinal sections where multiple target points are located, the following steps are also included:

[0097] The actual contour of the skin is fitted based on the actual cross-sectional line and multiple actual longitudinal cross-sectional lines.

[0098] By comparing the actual contour of the skin with the theoretical contour, the overall mold gap distribution of the skin produced by the stretch forming process can be viewed intuitively, which is helpful for further evaluating the stretch forming accuracy of the skin.

[0099] Optionally, after fitting the actual contour of the skin, the following steps are also included:

[0100] Based on the theoretical and actual contours of the skin, calculate the overall mold gap distribution and / or the springback of the skin.

[0101] By calculating the overall mold gap distribution and / or the springback of the skin, the skin stretching accuracy and forming quality can be accurately evaluated.

[0102] Optionally, the multiple target points include multiple preset target points, which are points on the theoretical cross-sectional line corresponding to multiple laser rangefinders. It should be noted that the aforementioned multiple actual readings represent the mold gaps at the multiple preset target points. This setting simplifies the calculation process and improves measurement efficiency.

[0103] For example, Figure 2 This is a detailed flowchart of the measurement method for skin stretching and forming provided in this embodiment. The following is in conjunction with... Figure 2 The measurement methods used for skin stretching and forming are described in detail above.

[0104] The measurement method for skin stretch forming includes the following steps:

[0105] S101. Multiple laser rangefinders are arranged on the same preset cross section below the forming mold. The multiple laser rangefinders are used to measure the distance between the two clamping end faces facing the forming mold and the corresponding laser rangefinder.

[0106] S102. Calibrate the positions of multiple laser rangefinders.

[0107] S103. Map the positions of the multiple laser rangefinders obtained through calibration to the stretch digital model of the skin to determine the zero-point positions of the multiple laser rangefinders and determine the theoretical cross-sectional line of the skin on the preset cross-section.

[0108] For example, a drawing model is created in a host computer using CAD software.

[0109] S104. Begin the stretching production process to create the skin, and collect and record readings from multiple laser rangefinders.

[0110] For example, multiple laser rangefinders can be connected to a host computer for communication. The host computer includes a data acquisition system, enabling it to acquire and record the readings of the multiple laser rangefinders in real time. Both the host computer and the data acquisition system are existing technologies and will not be described in detail here.

[0111] S105. Determine whether the skin is within the range of all laser rangefinders. If yes, proceed to S107; otherwise, proceed to S106.

[0112] S106. Adjust the installation position of the laser rangefinder that is outside the range until the skin is within the range of all laser rangefinders.

[0113] S107. Continue the stretching process to produce the skin.

[0114] S108. After completing the stretching production, wait for the readings of multiple laser rangefinders to stabilize, and then record the actual readings of the multiple laser rangefinders.

[0115] S109. Based on multiple actual readings and theoretical cross-sectional lines, fit the actual cross-sectional line of the skin on the preset cross-section.

[0116] like Figure 3 As shown, the solid line is the actual cross-sectional line of the skin on the preset cross-section, and the dashed line is the theoretical cross-sectional line of the skin on the preset cross-section. The film gap of the skin on the preset cross-section can be evaluated by comparing the actual cross-sectional line and the theoretical cross-sectional line.

[0117] S110. Select multiple preset target points on the theoretical cross-section line, and calculate the tangent direction and curvature of the multiple preset target points. The multiple preset target points are the points on the theoretical cross-section line corresponding to multiple laser rangefinders.

[0118] S111. Based on multiple actual readings and adhering to the principles of continuous tangent direction and minimal curvature change, fit the actual longitudinal section line of the skin on the longitudinal section where multiple target points are located; the longitudinal section is perpendicular to the preset cross section.

[0119] like Figure 4 As shown, the solid line is the actual longitudinal section line of the skin on one of the longitudinal sections, and the dashed line is the theoretical longitudinal section line of the skin on that longitudinal section. The film gap of the skin on that longitudinal section can be evaluated by comparing the actual longitudinal section line and the theoretical longitudinal section line.

[0120] S112. Fit the actual contour of the skin based on the actual cross-sectional line and multiple actual longitudinal cross-sectional lines.

[0121] In other words, step S112 uses a full-field interpolation method to fit the actual contour of the skin.

[0122] By fitting the actual contour of the skin, the relationship between the actual stretching process deviation of the skin and the movement position deviation of the stretching fixture can be evaluated, thereby fully assessing the stretching state and stretching accuracy of the skin.

[0123] S113. Based on the theoretical and actual contours of the skin, calculate the overall mold gap distribution and springback of the skin.

[0124] The measurement method for skin stretch forming in this embodiment takes into account the development needs of high quality and high precision for skin parts. Under the conditions of limited space in the stretch forming machine and complex skin materials, it makes full use of the structural characteristics of skin stretch forming. It breaks through the difficulties in evaluating the stretching state and insufficient stretching accuracy in the traditional production process. It can realize real-time feedback of skin stretching quality in the production process. In other words, it can realize online measurement and feedback, thereby greatly accelerating the process of subsequent optimization and quality evaluation. It can be applied to the mass production of skin and improve the current level of digitalization and intelligence in skin production.

[0125] The measurement method for skin stretching forming in this embodiment is based on measuring the deviation between the actual contour and the theoretical contour of the skin at the lower edge of the stretching mold of the skin using multiple laser rangefinders, and obtaining the overall mold gap distribution of the skin by combining the proposed full-field interpolation method.

[0126] This embodiment also provides a measuring device for skin stretching and forming, which, when applied to the above-mentioned measuring method for skin stretching and forming, can improve the convenience of installation and position adjustment of the laser rangefinder, thereby improving the efficiency of measurement work and the accuracy of measurement results.

[0127] like Figure 5-8 As shown, the measuring device for skin stretching and forming includes a detection module, which includes an adjustment mechanism 1, a laser rangefinder 2, and a locking assembly. The adjustment mechanism 1 includes a mounting component 11, a first slide rail 12, and a second slide rail 13. The mounting component 11 is used to install below the stretching die 200. The first slide rail 12 is fixed to the mounting component 11, and the second slide rail 13 is slidably disposed on the first slide rail 12 along a first direction. The laser rangefinder 2 is slidably disposed on the second slide rail 13 along a second direction. The laser rangefinder 2 is used to detect the distance between the skin 100 and the laser rangefinder 2. The first direction is perpendicular to the second direction. The locking assembly includes a first locking member and a second locking member. The first locking member is used to lock or unlock the first slide rail 12 and the second slide rail 13, and the second locking member is used to lock or unlock the laser rangefinder 2 and the second slide rail 13.

[0128] The measuring device for skin stretching and forming in this embodiment allows for significant adjustment of the position of the laser rangefinder 2 by disassembling and assembling the mounting component 11; and fine-tuning of the position of the laser rangefinder 2 in the first and second directions by sliding the second slide rail 13 and the laser rangefinder 2. This convenient operation improves the adaptability of the measuring device for skin stretching and forming, ensures that the laser rangefinder 2 is in the optimal measuring position, and improves the accuracy of the measurement results.

[0129] Specifically, the first locking element is a first set screw, which is threadedly connected to the second slide rail 13. When the second slide rail 13 slides to the appropriate position, the first set screw is rotated to press against the first slide rail 12, thereby locking the second slide rail 13 and the first slide rail 12. The second locking element is a second set screw, which is threadedly connected to the laser rangefinder 2. When the laser rangefinder 2 slides to the appropriate position, the second set screw is rotated to press against the second slide rail 13, thereby locking the laser rangefinder 2 and the second slide rail 13.

[0130] For example, the laser rangefinder 2 is a laser sensor, which has a simple structure and is easy to assemble.

[0131] Specifically, there are multiple detection modules, which are arranged on the same preset cross section 400 below the forming mold 200. The multiple detection modules are divided into two detection units, and the laser rangefinders 2 of the two detection units are respectively facing the two clamping end faces on the side facing the forming mold 200.

[0132] Optionally, a magnetic component is provided below the forming die 200, and the mounting component 11 is a magnetic suction component, which is attracted and fixed to the magnetic component. Using magnetic suction to fix the mounting component 11 can further improve the ease of assembly and disassembly of the mounting component 11 and improve the efficiency of measurement work.

[0133] This embodiment does not limit the shape and structure of the magnetic attractor. For example, the magnetic attractor has a suction cup-like structure, which is beneficial to improving the adsorption stability.

[0134] For example, the working principle of the measuring device for skin stretching forming in this embodiment is as follows:

[0135] It should be noted that the forming die 200 is usually mounted on the forming slide rail 300, and the forming die 200 and the forming slide rail 300 are locked together by a locking device. The forming slide rail 300 is a magnetic component made of ferromagnetic material or the like.

[0136] The magnetic attachments of the two sets of detection modules are respectively attached and fixed to both sides of the pull-shaped slide rail 300, and the two sets of detection modules are evenly distributed on both sides of the pull-shaped slide rail 300. Then, according to the theoretical numerical model of the skin 100, the laser rangefinder 2 and the second slide rail 13 are slid to initially adjust the position of the laser rangefinder 2, thus completing the installation of the laser rangefinder 2. Since the installation accuracy of the magnetic attachments is limited, this step can ensure the measurement accessibility of the laser rangefinder 2, thereby ensuring that the skin 100 is within the measurement range of all laser rangefinders 2.

[0137] The measuring device for skin stretching and forming in this embodiment has a mounting component 11 that is connected to the stretching slide rail 300 by magnetic adsorption, which is convenient for disassembly and assembly. It can also be matched with different stretching dies 200 to measure different skins 100. By adjusting the position of the second slide rail 13 and the laser rangefinder 2, it can be ensured that the skin 100 is within the range of all laser rangefinders 2, which has strong versatility and high measurement accuracy.

[0138] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A measurement method for skin stretch forming, used to inspect skin stretched and formed by a stretching die, the skin comprising two clamping ends respectively connected to two stretching clamps, characterized in that, The measurement method for skin stretch forming includes the following steps: Multiple laser rangefinders are arranged on the same preset cross section below the forming mold. The multiple laser rangefinders are used to measure the distance between the two clamping end faces facing the forming mold and the corresponding laser rangefinder. The positions of the multiple laser rangefinders are calibrated; The positions of the multiple laser rangefinders obtained through calibration are mapped onto the stretch digital model of the skin to determine the zero-point positions of the multiple laser rangefinders and to determine the theoretical cross-sectional line of the skin on the preset cross-section. The skin is produced by stretching; After the stretching process is completed, record the actual readings of multiple laser rangefinders. Based on multiple actual readings and the theoretical cross-sectional line, fit the actual cross-sectional line of the skin on the preset cross-section; Multiple target points are selected on the theoretical cross-sectional line, and the tangential direction and / or curvature of the multiple target points are calculated; the multiple target points include multiple preset target points, which are points on the theoretical cross-sectional line corresponding to the multiple laser rangefinders; Based on the actual cross-sectional line and the theoretical cross-sectional line, calculate the molding gap at multiple target points; the molding gap is the gap between the skin and the forming die. Based on the molding gap at multiple target points, and with the principle of continuous tangential direction and / or minimum curvature change, the actual longitudinal section line of the skin on the longitudinal section where the multiple target points are located is fitted; the longitudinal section is perpendicular to the preset cross section. The actual contour of the skin is fitted based on the actual cross-sectional line and multiple actual longitudinal cross-sectional lines; Based on the theoretical profile and the actual profile of the skin, calculate the overall molding gap distribution of the skin and / or the springback of the skin.

2. The measurement method for skin stretching forming according to claim 1, characterized in that, It also includes the following steps: Based on the actual cross-sectional line and the theoretical cross-sectional line, the distribution of the molding gap of the skin on the preset cross-section is calculated; the molding gap is the gap between the skin and the forming die.

3. The measurement method for skin stretching forming according to claim 1, characterized in that, The positions of the multiple laser rangefinders are calibrated, including the following steps: Set calibration references; the calibration references include mold references set on the forming die and / or external references set outside the forming die; The calibration reference and multiple laser rangefinders are simultaneously scanned by a 3D scanner to calibrate the positions of the multiple laser rangefinders.

4. The measurement method for skin stretching forming according to claim 1, characterized in that, The skin is produced by stretching, including the following steps: Begin forming production and monitor the readings of the multiple laser rangefinders; Determine whether the skin is within the range of all the laser rangefinders. If yes, continue the stretching process to produce the skin. If not, adjust the installation position of the laser rangefinders that are outside the range until the skin is within the range of all the laser rangefinders, and then continue the stretching process to produce the skin.

5. The measurement method for skin stretching and forming according to claim 1, characterized in that, Recording the actual readings of multiple laser rangefinders includes the following steps: After the stretching process is completed, wait for the readings of the multiple laser rangefinders to stabilize before recording the actual readings of the multiple laser rangefinders.

6. A measuring device for skin stretching and forming, characterized in that, The measurement method for skin stretch forming as described in any one of claims 1-5, wherein the measuring device for skin stretch forming includes a detection module, the detection module comprising: The adjustment mechanism includes a mounting component, a first slide rail, and a second slide rail. The mounting component is used to be installed below the forming die. The first slide rail is fixed to the mounting component, and the second slide rail is slidably disposed on the first slide rail along a first direction. A laser rangefinder is slidably disposed on a second slide rail along a second direction, and the laser rangefinder is used to detect the distance between the skin and the laser rangefinder; the first direction is perpendicular to the second direction; The locking assembly includes a first locking member and a second locking member, wherein the first locking member is used to lock or unlock the first slide rail and the second slide rail, and the second locking member is used to lock or unlock the laser rangefinder and the second slide rail; The measuring device for stretching and forming skin is used to inspect the skin stretched and formed by stretching die, the skin including two clamping ends respectively connected to two stretching jigs; The detection module is provided in multiple ways, and the multiple detection modules are arranged on the same preset cross section below the forming mold. The multiple detection modules are divided into two detection units, and the laser rangefinders of the two detection units are respectively facing the two clamping end faces on the side facing the forming mold.

7. The measuring device for skin stretching and forming according to claim 6, characterized in that, A magnetic component is provided below the forming die, and the mounting component is a magnetic suction component, which is attracted and fixed to the magnetic component.

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