Automobile casting deformation defect detection device and detection method

Abstract

The application discloses an automobile casting deformation defect detection device and a detection method. The device comprises a rack, a rotating disc movably arranged on the rack, a positioning and clamping mechanism arranged on the rotating disc and used for clamping a target automobile casting to a preset position, a light emitting device and a transparent target plate arranged on the rack and located on two sides of the positioning and clamping mechanism respectively, the light emitting device is used for emitting light to the target automobile casting, so that the light passes through a first process hole or a second process hole and forms a light spot on the transparent target plate, and an industrial camera arranged on the rack and used for collecting a light spot image, the industrial camera is located on a side of the transparent target plate away from the positioning and clamping mechanism. The application has the advantages of improving detection precision and detection efficiency.

Description

Technical Field

[0001] This application relates to the field of automotive casting processing technology, and in particular to an automotive casting deformation defect detection device and detection method. Background Technology

[0002] Automotive parts are often manufactured using casting processes, resulting in castings. These castings are subject to deformation due to factors such as internal stress, external stress, uneven temperature, material properties, and processing operations. Therefore, for some core structural castings, it is necessary to inspect for casting deformation defects to ensure that the castings meet dimensional requirements. For castings with multiple process holes, especially those with a unique structure where the holes intersect vertically, it is crucial to ensure that the centerlines of each process hole meet the process requirements. Existing testing devices typically use simple testing mechanisms that rely on manual operation combined with visual inspection. This approach is not only inefficient and prone to human error, but also has low accuracy. Furthermore, the simple testing mechanism needs to be inserted into the process hole during the testing process, which can easily damage the product. Summary of the Invention

[0003] The main purpose of this application is to provide a device and method for detecting deformation defects in automotive castings, aiming to solve the technical problem of low accuracy in the detection of deformation in existing testing institutions.

[0004] To achieve the above objectives, this application provides an automotive casting deformation defect detection device for detecting a target automotive casting. The target automotive casting has multiple first process holes along its length direction, and the target automotive casting also has a second process hole, which perpendicularly penetrates one of the first process holes. The device includes a frame with a turntable movably mounted on it. The turntable is equipped with a positioning and clamping mechanism for holding a target automotive casting to a preset position. The frame is also equipped with a light emitting device and a transparent target plate located on both sides of the positioning and clamping mechanism. The light emitting device emits light towards the target automotive casting so that the light passes through a first process hole or a second process hole and forms a light spot on the transparent target plate. The frame is also equipped with an industrial camera for capturing images of the light spot, which is located on the side of the transparent target plate away from the positioning and clamping mechanism.

[0005] Optionally, the outer walls of the target automotive casting on both sides of the first process hole have reference surfaces; the positioning and clamping mechanism includes two clamping plates, and each clamping plate is provided with an array of flexible thin film pressure sensors that contact the reference surfaces on the side that is close to each other. Both the array of flexible thin film pressure sensors and the clamping plates are provided with clearance holes that cooperate with the corresponding first process holes. The bottom of the two clamping plates is connected to a bidirectional linear drive mechanism set in the turntable through support rods. The bidirectional linear drive mechanism is used to drive the two support rods to move closer or further apart.

[0006] Optionally, the turntable has a receiving groove, and the bidirectional linear drive mechanism includes a bidirectional lead screw with two threaded sections in opposite directions. A lead screw nut is threaded onto the two threaded sections. A guide rail that is slidably connected to the lead screw nut is provided at the bottom of the receiving groove. One end of the bidirectional lead screw is movably connected to the inner side wall of the receiving groove through a bearing, and the other end of the bidirectional lead screw is connected to a first motor located on the side wall of the turntable. A second motor located on the frame is connected to the bottom of the turntable.

[0007] Optionally, a vertical reference line is provided on the side of the transparent target plate closest to the industrial camera. When the multiple first process holes do not deform, the line connecting the centers of the corresponding light spots coincides with the reference line.

[0008] Optionally, a light shield is provided on the frame, and the light emitting device and the positioning clamping mechanism are both located inside the light shield. The side of the light shield near the transparent target plate has multiple light-emitting holes that match the positions of the corresponding first process hole and second process hole. The diameter of the corresponding light-emitting hole is larger than the diameter of the corresponding first process hole or second process hole.

[0009] Optionally, a cover plate is hinged to the top of the light shield, directly opposite the positioning and clamping mechanism area, and a handle is provided on the top of the cover plate.

[0010] Optionally, it also includes a controller, and the light emitting device, industrial camera, first motor and second motor are all electrically connected to the controller.

[0011] To achieve the above objectives, this application also provides a detection method based on the above-described automotive casting deformation defect detection device, comprising the following steps: The target automotive casting is clamped to the first preset position by a positioning and clamping mechanism; The target automotive casting, after being clamped, is rotated to a second preset position using a turntable; wherein, the second preset position is the position where all the first process holes are directly facing the transparent target plate; The light emitting device is activated so that the light passes through all the first process holes and forms a corresponding light spot on the transparent target plate, and the image of the first light spot on the transparent target plate is captured by an industrial camera. The first spot image is preprocessed to identify the corresponding first spot outline circle; A virtual line is obtained by connecting the centers of multiple first light spot contour circles, and it is determined whether the virtual line coincides with the reference line. If not, output the first type of defect information; if yes, rotate the target automotive casting to the third preset position using a turntable. The first type of defect information is that the first process hole has an offset of the hole axis line, and the third preset position is the position where the second process hole is directly opposite the transparent target plate. The second spot image on the transparent target plate is acquired by an industrial camera, and the second spot image is preprocessed to identify the corresponding second spot outline circle; The preprocessed second spot image is fused with the preprocessed first spot image, and it is determined whether the center of the outline circle of the second spot coincides with the center of the outline circle of the first spot. If not, output the second type of defect information; if yes, mark the target automotive casting as a qualified product. The second type of defect information is that the first process hole has a hole axis offset.

[0012] Optionally, between the steps of clamping the target automobile casting to the first preset position using the positioning clamping mechanism and rotating the clamped target automobile casting to the second preset position using the turntable, the following steps are further included: The pressure values ​​at each corresponding point were acquired by two array-type flexible thin-film pressure sensors. Obtain the pressure difference between the maximum and minimum pressure values ​​collected by the same array of flexible thin-film pressure sensors, and determine whether the pressure difference is less than a preset pressure difference threshold. If not, output the third type of defect information; if yes, proceed to the next step. The third type of defect information is that the two reference surfaces of the target automobile casting are not parallel.

[0013] Optionally, if it is determined that the virtual line coincides with the baseline reference line, the following steps are also included: The measured center distances of two adjacent first light spot contour circles are obtained respectively, and it is determined whether the measured center distances are equal to the preset corresponding theoretical center distances. If not, output the first type of defect information; if yes, proceed to the next step.

[0014] The beneficial effects that this application can achieve are as follows: This application uses a positioning and clamping mechanism to clamp and fix the target automotive casting. First, a turntable rotates the casting so that the first process hole faces the transparent target plate. At this point, a light emitting device emits light that simultaneously passes through multiple first process holes and forms light spots on the transparent target plate. Due to the transparency of the target plate, an industrial camera on the other side can also capture the corresponding light spot image. Then, machine vision recognition technology is used to determine whether the light spot features in the image meet the acceptance criteria, thereby indirectly detecting whether the first process hole of the target automotive casting is deformed or shifted. If the detection is successful, the turntable is rotated 90° so that the second process hole faces the transparent target plate. The industrial camera then captures the light spot image again to detect whether the second process hole is deformed or shifted. With the turntable setup, this process does not require disassembling the target automotive casting, allowing for rapid and separate deformation detection of the first and second process holes at different locations, improving detection efficiency. Combined with machine vision recognition technology, minute deformation defects can be captured, improving detection accuracy. Furthermore, the detection process achieves non-contact measurement of the first and second process holes, avoiding scratches and ensuring product quality. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0016] Figure 1 This is a three-dimensional structural diagram of the target automobile casting in an embodiment of this application; Figure 2 This is a schematic diagram of the planar structure of the target automobile casting in an embodiment of this application (left: frontal view, right: side view). Figure 3 This is a schematic diagram of the structure of an automotive casting deformation defect detection device according to an embodiment of this application (the arrow points to the direction of light emission). Figure 4 This is a schematic diagram of the connection structure between the positioning clamping mechanism and the bidirectional linear drive mechanism in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of an automotive casting deformation defect detection device in another detection state according to an embodiment of this application (the arrow points to the direction of light emission). Figure 6 This is a schematic diagram illustrating the principle of identifying the offset of the first process hole based on the first spot image in an embodiment of this application. Figure 7This is a schematic diagram illustrating the principle of identifying the offset of the second process hole based on the fusion of the first spot image and the second spot image in an embodiment of this application.

[0017] Figure label: 110 - Target automotive casting; 111 - First process hole; 112 - Second process hole; 113 - Reference surface; 120 - Frame; 130 - Turntable; 131 - Receiving groove; 140 - Positioning and clamping mechanism; 141 - Clamping plate; 1411 - Clearance hole; 142 - Array-type flexible thin-film pressure sensor; 143 - Support rod; 150 - Light emitting device; 160 - Transparent target plate; 161 - Reference line; 170 - Industrial camera; 180 - Bidirectional linear drive mechanism; 181 - Bidirectional lead screw; 182 - Lead screw nut; 183 - Guide rail; 184 - First motor; 190 - Second motor; 210 - Light shield; 211 - Light emission hole; 212 - Cover plate; 220 - Controller; 230 - First light spot outline circle; 240 - Virtual line; 250 - Second light spot outline circle.

[0018] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0020] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0021] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0023] Example 1 Reference Figures 1-7 This embodiment provides an automotive casting deformation defect detection device for detecting a target automotive casting 110. The target automotive casting 110 has a plurality of first process holes 111 along its length direction, and the target automotive casting 110 also has a second process hole 112, which vertically penetrates one of the first process holes 111. The device includes a frame 120, on which a turntable 130 is movably mounted. The turntable 130 is equipped with a positioning and clamping mechanism 140 for clamping a target automotive casting 110 to a preset position. The frame 120 is equipped with a light emitting device 150 and a transparent target plate 160 located on both sides of the positioning and clamping mechanism 140. The light emitting device 150 is used to emit light towards the target automotive casting 110 so that the light passes through a first process hole 111 or a second process hole 112 and forms a light spot on the transparent target plate 160. The frame 120 is also equipped with an industrial camera 170 for acquiring images of the light spot. The industrial camera 170 is located on the side of the transparent target plate 160 away from the positioning and clamping mechanism 140.

[0024] In this embodiment, after the target automobile casting 110 is clamped and fixed by the positioning and clamping mechanism 140, the target automobile casting 110 is first rotated by the turntable 130 until the first process hole 111 is directly facing the transparent target plate 160. At this time, the light emitting device 150 emits light that passes through multiple first process holes 111 and forms a light spot on the transparent target plate 160. Due to the transparency of the transparent target plate 160, the industrial camera 170 on the other side of the transparent target plate 160 can also capture the corresponding light spot image. Then, machine vision recognition technology can be used to determine whether the light spot features in the light spot image meet the qualification standard, thereby indirectly detecting whether there is deformation or displacement in the first process hole 111 of the target automobile casting 110. If the inspection is successful, the turntable 130 is rotated 90° so that the second process hole 112 is aligned with the transparent target plate 160. The industrial camera 170 then captures a spot image again to detect whether the second process hole 112 is deformed or misaligned. With the turntable 130 in place, this process can quickly and efficiently detect the deformation of the first process hole 111 and the second process hole 112 at different locations without disassembling the target automotive casting 110, thus improving inspection efficiency. In addition, the machine vision recognition technology can capture minute deformation defects, improving inspection accuracy. Furthermore, the inspection process achieves non-contact measurement of the first process hole 111 and the second process hole 112, avoiding scratches on the process holes and ensuring product quality.

[0025] It should be noted that the bottom of the turntable 130 is movably connected to the frame 120 via a movable shaft; the light emitting device 150 can be a laser lamp or an illumination lamp with a certain light intensity, which can form a clear light spot on the transparent target plate 160. The diameters of the multiple first process holes 111 can be the same or different, but they must meet the process condition that the line connecting their centers in the vertical direction is a vertical straight line.

[0026] As an optional implementation, the outer walls of the target automotive casting 110 on both sides of the first process hole 111 have reference surfaces 113; the positioning and clamping mechanism 140 includes two clamping plates 141, and each clamping plate 141 is provided with an array of flexible thin film pressure sensors 142 that contact the reference surfaces 113 on the side that is close to each other. Both the array of flexible thin film pressure sensors 142 and the clamping plates 141 are provided with clearance holes 1411 that cooperate with the corresponding first process hole 111. The bottom of the two clamping plates 141 is connected to a bidirectional linear drive mechanism 180 provided in the turntable 130 through a support rod 143. The bidirectional linear drive mechanism 180 is used to drive the two support rods 143 to move closer or further apart.

[0027] In this embodiment, during clamping, the target automobile casting 110 is placed on the turntable 130. A bidirectional linear drive mechanism 180 drives the two support rods 143 to move closer together, thereby causing the two clamping plates 141 to clamp and fix the target automobile casting 110. The design of the clearance hole 1411 after clamping ensures that it does not obstruct the passage of light. Since the parallelism of the two reference surfaces 113 on both sides of the target automobile casting 110 (i.e., both reference surfaces 113 need to meet flatness requirements) also needs to meet process requirements, ensuring the parallelism of the two reference surfaces 113 is crucial for the positioning clamping mechanism 140 to accurately clamp the target automobile casting 110. Otherwise, unevenness on one or both sides of the reference surface 113 could lead to clamping deviations, affecting the accuracy of subsequent process hole deformation detection. Therefore, pressure data at different measurement points on the corresponding reference surface 113 can be detected by array-type flexible thin-film pressure sensors 142 on both sides. By comparing the maximum and minimum pressure data, the flatness of the corresponding reference surface 113 can be indirectly detected to determine whether it is parallel. If the detection fails, there is no need to proceed to the subsequent process hole detection, saving time and costs. At this time, the casting is reworked and polished until the reference surface 113 meets the parallelism requirements before proceeding to the next detection step. In summary, the positioning and clamping mechanism 140 in this embodiment has both clamping and parallelism detection functions for the reference surface 113. It can be used for detection immediately after installation, further improving detection efficiency.

[0028] It should be noted that the array-type flexible thin-film pressure sensor 142 is existing technology. It has built-in lateral driving electrodes and longitudinal sensing electrodes, and the intersection of rows and columns is an independent pressure sensing unit. The circuit scans each row / column in a time-division manner, and can read the resistance change of each coordinate point one by one. The signals of each sensing point are isolated from each other. Single-point pressing and multi-point simultaneous pressing can output the pressure value of each point separately, and a pressure distribution map can be generated. Here, a reference positioning line can be set at the top center position of the clamping plate 141, and the centering line of the target car casting 110 is also marked at the corresponding position. By aligning the centering line with the reference positioning line, the target car casting 110 is clamped at the center position of the turntable 130. Alternatively, a positioning post can be set at the center position of the turntable 130. The positioning post can cooperate with the central shaft hole of the target car casting 110 for rapid positioning. The height of the positioning post should not obstruct the first process hole 111 and the second process hole 112.

[0029] As an optional implementation, the turntable 130 has a receiving groove 131, and the bidirectional linear drive mechanism 180 includes a bidirectional lead screw 181. The bidirectional lead screw 181 has two threaded sections with opposite thread directions. A lead screw nut 182 is threaded onto the two threaded sections. A guide rail 183 is provided at the bottom of the receiving groove 131 and is slidably connected to the lead screw nut 182. One end of the bidirectional lead screw 181 is movably connected to the inner side wall of the receiving groove 131 through a bearing, and the other end of the bidirectional lead screw 181 is connected to a first motor 184 located on the side wall of the turntable 130. A second motor 190 located on the frame 120 is connected to the bottom of the turntable 130.

[0030] In this embodiment, when clamping is required, the first motor 184 drives the bidirectional lead screw 181 to rotate, which in turn drives the two lead screw seats 182 to move closer to each other, thereby driving the two support rods 143 and the corresponding clamping plates 141 to move closer synchronously, thus achieving automatic clamping. When it is necessary to release, the output shaft of the first motor 184 can rotate in the opposite direction, making the operation quick. The second motor 190 can drive the turntable 130 to rotate in the opposite direction, which facilitates precise control of the rotation angle to ensure detection accuracy.

[0031] As an optional implementation, a vertical reference line 161 is provided on the side of the transparent target plate 160 near the industrial camera 170. When the multiple first process holes 111 do not deform, the line connecting the centers of the corresponding light spots coincides with the reference line 161.

[0032] In this embodiment, by setting the reference line 161, when the light spot is projected onto the transparent target plate 160, the center of the light spot is identified and a line is drawn. If the first process hole 111 is deformed to a certain extent, causing the overall axis to shift, the line connecting the centers of the light spots will be offset from the reference line 161. Thus, the deformation defect of the first process hole 111 can be quickly determined by judging whether the line coincides with the reference line 161, which is more efficient than using coordinate calculation.

[0033] It should be noted that the reference line 161 here may have a certain line width. When there is a slight deviation in the line connecting the centers of the light spots, it is all within the line width range, thus representing that a certain amount of process error and measurement error is allowed.

[0034] As an optional implementation, a light shield 210 is provided on the frame 120. The light emitting device 150 and the positioning and clamping mechanism 140 are both located inside the light shield 210. The light shield 210 has a plurality of light-emitting holes 211 on the side near the transparent target plate 160, which are matched with the positions of the corresponding first process hole 111 and second process hole 112. The aperture of the corresponding light-emitting hole 211 is larger than the aperture of the corresponding first process hole 111 or second process hole 112.

[0035] In this embodiment, the light-blocking cover 210 reduces light scattering and blocks unwanted light. The light-emitting hole 211 allows only the light from the first process hole 111 or the second process hole 112 to pass through and be projected onto the transparent target plate 160, thereby forming a clear light spot and improving recognition accuracy.

[0036] As an optional implementation, a cover plate 212 is hinged to the top of the light shield 210, which faces the positioning and clamping mechanism 140. The top of the cover plate 212 is provided with a handle. By opening the cover plate 212, the casting to be inspected can be placed on the turntable 130.

[0037] As an optional implementation, it also includes a controller 220, a light emitting device 150, an industrial camera 170, a first motor 184 and a second motor 190, all of which are electrically connected to the controller 220, thereby realizing the recognition of image data and feeding it back to each actuator to perform relative actions, and can feed the detection results back to the terminal (e.g., a computer or mobile phone). The detection process runs fully automatically and can directly receive the detection results without human intervention.

[0038] Example 2 Reference Figures 1-7 This embodiment provides a detection method for the automotive casting deformation defect detection device based on the above embodiment, including the following steps: The target automotive casting 110 is clamped to the first preset position by the positioning and clamping mechanism 140; The target automotive casting 110, after being clamped, is rotated to a second preset position by the turntable 130; wherein, the second preset position is the position where all the first process holes 111 are directly opposite the transparent target plate 160; The light emitting device 150 is activated so that the light passes through all the first process holes 111 and forms a corresponding light spot on the transparent target plate 160, and the image of the first light spot on the transparent target plate 160 is captured by the industrial camera 170. The first light spot image is preprocessed to identify the corresponding first light spot outline circle 230; A virtual line 240 is obtained by connecting the centers of multiple first light spot contour circles 230, and it is determined whether the virtual line 240 coincides with the reference line 161. If not, output the first type of defect information; if yes, rotate the target automobile casting 110 to the third preset position via turntable 130. The first type of defect information is that the first process hole 111 has a hole axis offset, and the third preset position is the position where the second process hole 112 is directly opposite the transparent target plate 160. The industrial camera 170 acquires the image of the second light spot on the transparent target plate 160, and preprocesses the image of the second light spot to identify the corresponding second light spot outline circle 250. The preprocessed second spot image is fused with the preprocessed first spot image, and it is determined whether the center of the second spot outline circle 250 coincides with the center of the first spot outline circle 230. If not, output the second type of defect information; if yes, mark the target automotive casting 110 as a qualified product. The second type of defect information is that the first process hole 111 has a hole axis offset.

[0039] In this embodiment, after clamping the target car casting 110 to the first preset position (i.e., the center position of the turntable 130), the target car casting 110 is rotated by the turntable 130 to a position where the first process hole 111 is directly opposite the transparent target plate 160. If the first process hole 111 is already directly opposite the transparent target plate 160 after clamping, there is no need to rotate. Then, light is emitted by the light emitting device 150, passing through all the first process holes 111 and forming corresponding light spots on the transparent target plate 160. The industrial camera 170 can then capture the first light spot image on the transparent target plate 160. The first light spot image is preprocessed (including grayscale processing, binarization processing, etc.) to form a circular or near-circular pattern with a black and white contour curve, which is convenient for subsequent recognition. The first light spot contour circle 230 can be obtained by edge fitting of the circular pattern. At the same time, the centers of multiple first light spot contour circles 230 are connected to form a virtual line 240. The overlap between the virtual line 240 and the reference line 161 is judged. Furthermore, it can indirectly detect whether there is any deviation in the centerline of the first process hole 111. If the detection is qualified, the next step of detection can be carried out. At this time, the target automobile casting 110 can be rotated by rotating the turntable 130 by 90° to the position where the second process hole 112 is directly opposite the transparent target plate 160. Similarly, the second light spot contour circle 250 can be obtained by image processing based on the acquired second light spot image. Since the first process hole 111 is qualified and there is no deviation, it can be directly used as the reference benchmark for the second light spot contour circle 250. If the second process hole 112 is not deformed or deviated, the corresponding second light spot contour circle 250 should theoretically be concentric with the first light spot contour circle 230. That is, the centerlines of the second process hole 112 and the first process hole 111 meet the vertical requirement on the horizontal plane. At this time, the overlap between the center of the second light spot contour circle 250 and the center of the first light spot contour circle 230 can be used to determine whether there is any deviation in the second process hole 112. The detection is accurate and efficient.

[0040] It should be noted that the center of the first light spot outline circle 230 can be magnified to form a black dot. The center of the second light spot outline circle 250 within the range of the black dot can be considered as qualified, thus indicating that a certain amount of process error and measurement error is allowed.

[0041] As an optional implementation, between the steps of clamping the target automobile casting 110 to the first preset position by the positioning clamping mechanism 140 and rotating the clamped target automobile casting 110 to the second preset position by the turntable 130, the following steps are further included: The pressure values ​​at each corresponding point are acquired by two array-type flexible thin-film pressure sensors 142; The pressure difference between the maximum and minimum pressure values ​​collected by the same array of flexible thin-film pressure sensors 142 is obtained, and it is determined whether the pressure difference is less than a preset pressure difference threshold. If not, output the third type of defect information; if yes, proceed to the next step. The third type of defect information is that the two reference surfaces 113 of the target automobile casting 110 are not parallel.

[0042] In this embodiment, the parallelism of the two reference surfaces 113 on both sides of the target automotive casting 110 also needs to meet the process requirements. Furthermore, ensuring the parallelism of the two reference surfaces 113 is crucial for guaranteeing the accuracy of subsequent process hole inspections. Otherwise, unevenness on one or both sides of the reference surfaces 113 can cause clamping deviations, affecting the accuracy of subsequent process hole deformation detection. Therefore, pressure data at different measurement points on the corresponding reference surfaces 113 can be detected using array-type flexible thin-film pressure sensors 142 on both sides. The pressure difference between the maximum and minimum pressure data collected by the same array-type flexible thin-film pressure sensor 142 is then compared with a preset pressure difference threshold. If the pressure difference is greater than the threshold, it indicates that the reference surface 113 on one side is uneven, causing fluctuations in the pressure data at the corresponding measurement point. This indirectly detects the flatness of the corresponding reference surface 113, thus determining whether it is parallel. If the detection fails, there is no need to proceed to subsequent process hole inspections, saving time and costs. The casting is then reworked and polished until the reference surfaces 113 meet the parallelism requirements before proceeding to the next inspection step.

[0043] As an optional implementation, if it is determined that the virtual line 240 coincides with the reference line 161, the following steps are also included: The measured center distances of two adjacent first light spot contour circles 230 are obtained respectively, and it is determined whether the measured center distances are equal to the preset corresponding theoretical center distances. If not, output the first type of defect information; if yes, proceed to the next step. In this embodiment, considering the special case (which is relatively rare) where the deformation offset direction of the first process hole 111 is all in the vertical direction, the line connecting the corresponding first spot contour circles 230 will also coincide with the reference line 161. Therefore, by further verifying whether the measured center distance of two adjacent first spot contour circles 230 is equal to the corresponding theoretical center distance, the existence of the above-mentioned special case is confirmed, further improving the detection accuracy. Of course, if the offset direction and offset distance of all first process holes 111 are equal, the detection method by comparing the center distance will fail. However, castings are affected by stress, materials, and other factors, and the deformation direction and degree are basically without obvious rules. Therefore, the probability of the above-mentioned offset situation occurring is extremely low and can be ignored.

[0044] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A device for detecting deformation defects in automotive castings, characterized in that, Used for inspecting target automotive castings, the target automotive castings have multiple first process holes along their length direction, and the target automotive castings also have a second process hole, which perpendicularly penetrates one of the first process holes. The device includes a frame with a turntable movably mounted on it. The turntable is equipped with a positioning and clamping mechanism for holding a target automotive casting to a preset position. The frame is also equipped with a light emitting device and a transparent target plate located on both sides of the positioning and clamping mechanism. The light emitting device emits light towards the target automotive casting so that the light passes through a first process hole or a second process hole and forms a light spot on the transparent target plate. The frame is also equipped with an industrial camera for capturing images of the light spot, which is located on the side of the transparent target plate away from the positioning and clamping mechanism.

2. The automotive casting deformation defect detection device as described in claim 1, characterized in that, The outer walls of the target automotive casting on both sides of the first process hole have reference surfaces; the positioning and clamping mechanism includes two clamping plates, and each clamping plate is provided with an array of flexible thin film pressure sensors that contact the reference surfaces on the side that is close to each other. Both the array of flexible thin film pressure sensors and the clamping plates are provided with clearance holes that cooperate with the corresponding first process holes. The bottom of the two clamping plates is connected to a bidirectional linear drive mechanism set in the turntable through support rods. The bidirectional linear drive mechanism is used to drive the two support rods to move closer or further apart.

3. The automotive casting deformation defect detection device as described in claim 2, characterized in that, The turntable has a receiving groove. The bidirectional linear drive mechanism includes a bidirectional lead screw with two threaded sections in opposite directions. A nut seat is threaded onto the two threaded sections. A guide rail is provided at the bottom of the receiving groove and is slidably connected to the nut seat. One end of the bidirectional lead screw is movably connected to the inner wall of the receiving groove through a bearing. The other end of the bidirectional lead screw is connected to a first motor located on the side wall of the turntable. A second motor located on the frame is connected to the bottom of the turntable.

4. The automotive casting deformation defect detection device as described in claim 2 or 3, characterized in that, A vertical reference line is set on the side of the transparent target plate closest to the industrial camera. When the multiple first process holes do not deform, the line connecting the centers of the corresponding light spots coincides with the reference line.

5. The automotive casting deformation defect detection device as described in claim 1, characterized in that, A light-blocking cover is installed on the frame. The light emitting device and the positioning and clamping mechanism are both located inside the light-blocking cover. Multiple light-emitting holes are opened on the side of the light-blocking cover near the transparent target plate, which are matched with the positions of the corresponding first process hole and second process hole. The diameter of the corresponding light-emitting hole is larger than the diameter of the corresponding first process hole or second process hole.

6. The automotive casting deformation defect detection device as described in claim 5, characterized in that, The top of the light shield is hinged to a cover plate directly opposite the positioning and clamping mechanism area, and a handle is provided on the top of the cover plate.

7. The automotive casting deformation defect detection device as described in claim 3, characterized in that, It also includes a controller, a light emitting device, an industrial camera, a first motor, and a second motor, all of which are electrically connected to the controller.

8. A detection method based on the automotive casting deformation defect detection device as described in claim 4, characterized in that, Includes the following steps: The target automotive casting is clamped to the first preset position by a positioning and clamping mechanism; The target automotive casting, after being clamped, is rotated to a second preset position using a turntable; wherein, the second preset position is the position where all the first process holes are directly facing the transparent target plate; The light emitting device is activated so that the light passes through all the first process holes and forms a corresponding light spot on the transparent target plate, and the image of the first light spot on the transparent target plate is captured by an industrial camera. The first spot image is preprocessed to identify the corresponding first spot outline circle; A virtual line is obtained by connecting the centers of multiple first light spot contour circles, and it is determined whether the virtual line coincides with the reference line. If not, output the first type of defect information; if yes, rotate the target automotive casting to the third preset position using a turntable. The first type of defect information is that the first process hole has an offset of the hole axis, and the third preset position is the position where the second process hole is directly opposite the transparent target plate. The second spot image on the transparent target plate is acquired by an industrial camera, and the second spot image is preprocessed to identify the corresponding second spot outline circle; The preprocessed second spot image is fused with the preprocessed first spot image, and it is determined whether the center of the outline circle of the second spot coincides with the center of the outline circle of the first spot. If not, output the second type of defect information; if yes, mark the target automotive casting as a qualified product. The second type of defect information is that the first process hole has a hole axis offset.

9. The detection method as described in claim 8, characterized in that, Between the steps of clamping the target automobile casting to the first preset position using the positioning clamping mechanism and rotating the clamped target automobile casting to the second preset position using the turntable, the following steps are also included: The pressure values ​​at each corresponding point were acquired by two array-type flexible thin-film pressure sensors. Obtain the pressure difference between the maximum and minimum pressure values ​​collected by the same array of flexible thin-film pressure sensors, and determine whether the pressure difference is less than a preset pressure difference threshold. If not, output the third type of defect information; if yes, proceed to the next step. The third type of defect information is that the two reference surfaces of the target automobile casting are not parallel.

10. The detection method as described in claim 8, characterized in that, If it is determined that the virtual line coincides with the baseline reference line, the following steps are also included: The measured center distances of two adjacent first light spot contour circles are obtained respectively, and it is determined whether the measured center distances are equal to the preset corresponding theoretical center distances. If not, output the first type of defect information; if yes, proceed to the next step.

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