Thrust rod center distance measuring device and measuring method

Abstract

The invention relates to a device and a method for measuring the center distance of a thrust rod, and belongs to the field of vehicle part detection. According to the technical scheme, the thrust rod center distance measuring equipment comprises a box body, a main body platform is arranged in the box body, a jig is arranged on the main body platform, a camera adjusting module is arranged on one side of the jig, two industrial cameras are installed on the camera adjusting module, telecentric lenses are installed on the industrial cameras, and a light source adjusting module is arranged on the other side of the jig. Two parallel light sources are mounted on the light source adjusting module; the system further comprises a control terminal which is electrically connected with the industrial camera and used for receiving images shot by the industrial camera and processing and analyzing the images. The industrial camera is matched with the parallel light source, so that non-contact visual detection on the two ends of the thrust rod is realized; the control terminal automatically processes image data, the detection efficiency is greatly improved, meanwhile, personal errors are reduced, the consistency and accuracy of measurement results are guaranteed, and the problems that traditional three-coordinate detection is low in efficiency and high in cost are solved.

Description

Technical Field

[0001] This invention relates to the field of vehicle component inspection, and in particular to a thrust rod center distance measuring device and method. Background Technology

[0002] The thrust rod is a core component of the suspension system in heavy-duty commercial vehicles, and its center distance directly affects the vehicle's driving stability and safety. Different types of suspension require thrust rods with specific center distances, making center distance measurement a crucial quality control step in the thrust rod production process. With the increasing demands for product quality consistency in the heavy-duty commercial vehicle industry, there is an urgent need for efficient and accurate thrust rod center distance measurement methods to support mass production.

[0003] Currently, the industry mainly relies on coordinate measuring machines (CMMs) for high-precision detection of thrust rod center distance. The detection method involves using a precision probe to contact the inner wall of the spherical pin mounting hole and key contour surfaces of the thrust rod point by point, collecting coordinate data from a large number of discrete points. Specialized software then fits, models, and calculates the data to derive the center distance dimension. However, this approach has significant technical drawbacks: high equipment purchase and maintenance costs, significantly increasing enterprise production costs; cumbersome detection process, requiring a long time for data collection and calculation for single-piece inspection, making it unsuitable for the rapid detection needs of mass production scenarios; and the need for skilled technicians for operation, coupled with insufficient equipment flexibility, making it difficult to quickly respond to the detection needs of thrust rods of different specifications, severely restricting production efficiency.

[0004] Existing coordinate measuring machine (CMM) inspection solutions suffer from contradictions between high precision and high efficiency, and an imbalance between high cost and practicality, failing to meet the actual needs of the heavy commercial vehicle manufacturing industry for simultaneous optimization of production efficiency and product quality. Summary of the Invention

[0005] This invention addresses the problems of low efficiency and high cost in current three-coordinate measuring machine methods for detecting the center distance of thrust rods by providing a thrust rod center distance measuring device.

[0006] To address the aforementioned problems, the present invention provides a thrust rod center distance measuring device, comprising a housing containing a main platform, a fixture on the main platform, a camera adjustment module on one side of the fixture, two industrial cameras mounted on the camera adjustment module, each industrial camera equipped with a telecentric lens, and a light source adjustment module on the other side of the fixture, equipped with two parallel light sources. The two industrial cameras and the two parallel light sources are aligned and used to capture images of both ends of the thrust rod. The device also includes a control terminal electrically connected to the industrial cameras for receiving and processing the images captured by the industrial cameras. Through the cooperation of the industrial cameras and parallel light sources, combined with the precise imaging characteristics of the telecentric lenses, non-contact visual inspection of both ends of the thrust rod is achieved, avoiding damage to the workpiece caused by contact measurement. The control terminal automatically processes the image data, eliminating the need for manual calculations, significantly improving inspection efficiency, reducing human error, and ensuring the consistency and accuracy of measurement results. This solves the problems of low efficiency and high cost associated with traditional coordinate measuring machines (CMMs).

[0007] As a preferred implementation of a thrust rod center distance measuring device, the light source adjustment module includes a fixed base and a third slide rail. Both the fixed base and the third slide rail are mounted on the main platform, and the sliding direction of the third slide rail is parallel to the direction of the thrust rod in the fixture. One parallel light source is fixedly mounted on the fixed base, and the other parallel light source is movably mounted on the third slide rail. The movable parallel light source adjusts the distance between itself and the fixed light source via the third slide rail, adapting to thrust rods of different lengths. This ensures uniform illumination of the spherical pin assemblies at both ends of the thrust rod, avoiding image blurring caused by differences in workpiece size, improving the stability and clarity of image acquisition, and providing a high-quality foundation for subsequent data processing.

[0008] As a preferred implementation of a thrust rod center distance measuring device, the camera adjustment module has the same structure as the light source adjustment module. On the camera adjustment module, one industrial camera is mounted on a fixed base, and the other industrial camera is movably mounted on a third slide rail. The identical structure and synchronized adjustment of the camera adjustment module and light source adjustment module ensure that the industrial camera is always precisely aligned with the parallel light source, guaranteeing the stability and accuracy of the shooting angle. The movable camera design further expands the device's adaptability to thrust rods of different sizes, eliminating the need to replace dedicated detection components, reducing equipment adaptation costs, and improving the flexibility of use on the production floor.

[0009] As a preferred embodiment of a thrust rod center distance measuring device, the main platform is equipped with a loading / unloading station and a detection station. The detection station is located between the parallel light source and the industrial camera, and the loading / unloading station is located to one side of the detection station. Both the loading / unloading station and the detection station share a first slide rail and a switching drive mechanism. The fixture is slidably mounted on the first slide rail and connected to the moving end of the switching drive mechanism. The separate design of the loading / unloading station and the detection station, combined with the switching drive mechanism, allows the fixture to automatically switch stations, enabling parallel operation of detection and loading / unloading. The next workpiece can be placed without waiting for the detection to complete, significantly shortening the overall cycle of single-piece detection and improving the detection efficiency of batch production. The fixture moves smoothly via the first slide rail, ensuring the positional stability of the workpiece during station switching and avoiding measurement deviations caused by displacement.

[0010] As a preferred implementation of a thrust rod center distance measuring device, a positioning sensor is provided at one end of the first slide rail corresponding to the detection station. The positioning sensor can accurately detect whether the fixture has reached the preset detection position, and promptly feed back the positioning signal to trigger subsequent actions such as shooting and turning on the light source. This avoids imaging misalignment or measurement failure caused by fixture position deviation, ensures the automated and accurate triggering of the detection process, and improves the reliability of equipment operation and the consistency of measurement results.

[0011] As a preferred embodiment of a thrust rod center distance measuring device, the fixture includes a base plate and a top plate, with a lifting mechanism between the top and base plates. The bottom surface of the base plate has a sliding groove that is slidably connected to the first slide rail. The top surface of the top plate has a material clamping mechanism. The material clamping mechanism can stably clamp the thrust rod workpiece, preventing workpiece swaying or displacement during testing and ensuring the stability of the measurement reference. The lifting mechanism can drive the top plate to rise and fall, adjusting the workpiece height. This facilitates separate imaging of the upper and lower parts of the spherical pin assembly by an industrial camera, eliminating the need for manual workpiece flipping and improving the automation and ease of operation of the testing process.

[0012] As a preferred embodiment of a thrust rod center distance measuring device, the top surface of the base plate and the bottom surface of the top plate are respectively provided with second slide rails. The lifting mechanism includes four support rods, which are cross-hinged in pairs. One of the mutually hinged support rods has its lower end hinged to the base plate and its upper end slidably connected to the second slide rail on the top plate. The lower end of the other support rod is hinged to the second slide rail on the base plate and connected to a linear motor, and its other end is hinged to the top plate. Stabilizing blocks are also provided at the four corners of the base plate, and telescopic rods are installed on the stabilizing blocks. The upper ends of the four telescopic rods are respectively connected to the four corners of the top plate. The cross-hinged support rods, in conjunction with the linear motor drive, realize the smooth lifting and lowering of the top plate, ensuring the levelness of the workpiece during the lifting process and avoiding imaging deviations caused by tilting. The telescopic rods at the four corners further enhance the stability and load-bearing capacity of the top plate, preventing structural deformation caused by workpiece weight or lifting action, ensuring the accuracy of workpiece position during measurement, and improving the reliability of detection data.

[0013] As a preferred embodiment of a thrust rod center distance measuring device, a fourth slide rail is mounted on the top surface of the top plate. This fourth slide rail is perpendicular to the first slide rail. A material clamping mechanism is slidably mounted on the fourth slide rail. The material clamping mechanism includes four clamping blocks, arranged in pairs facing each other, each used to clamp both ends of the thrust rod. The spacing between the clamping blocks can be adjusted via the fourth slide rail to accommodate thrust rod workpieces of different thicknesses, improving the device's versatility. The four clamping blocks, facing each other in pairs, can fix the workpiece from multiple directions, ensuring coaxiality and positioning accuracy during the inspection process, avoiding measurement errors caused by unstable clamping, and facilitating quick clamping and disassembly, thus improving loading and unloading efficiency.

[0014] On the other hand, the present invention also provides a method for measuring the center distance of a thrust rod, comprising the following steps: S1. Place the thrust rod workpiece on the fixture at the loading and unloading station, and the shifting drive mechanism moves the fixture to the inspection station; S2. After the positioning sensor detects that the fixture is in place, the parallel light source is turned on, and the industrial camera takes a picture of the upper part of the push rod ball pin; the lifting mechanism rises, and the industrial camera takes a picture of the lower part of the push rod ball pin assembly; S3. The control terminal performs size determination; S4. The shifting drive mechanism moves the fixture back to the loading and unloading station, removes the push rod tool, and then repeats steps S1-S3.

[0015] The entire measurement process is automated, with automatic workstation switching, automatic shooting, and automatic data processing. No manual intervention is required in the core measurement steps, which greatly reduces the labor intensity of operators. The process steps are clear and closely connected, reducing unnecessary waiting time, improving the efficiency of single-piece inspection, meeting the rapid inspection needs of mass production, and avoiding random errors caused by manual operation, thus ensuring the consistency of measurement results.

[0016] Step S3 includes: S31. After the positioning sensor detects that the fixture is in place, the parallel light source is turned on. The industrial camera first captures the upper part of the spherical pin assembly. The obtained upper projection image is the contour projection of the spherical pin assembly under the illumination of the parallel light source. Then, the contour edge line on the projection image is fitted with a straight line. The contour edge line is the line formed by the outer edge of the spherical pin assembly on the projection image, which is the basis for subsequent calculations. Then, the fixture lifting drive mechanism rises, and the industrial camera captures the lower part of the spherical pin assembly. The obtained lower projection image is also the contour projection of the spherical pin assembly under the illumination of the parallel light source. Then, the contour edge line of the lower part is fitted with a straight line. S32. Select four specified side lines, calculate the center line through two of them, and calculate the distance between the other side line and the center line; shift one of the side lines outward by a specified distance to form a new side line, and the intersection of the new side line and the fourth side line is the reference measurement point. Construct four reference measurement points in the same way. S33. Select four designated edge lines on the projection drawing of the spherical pin assembly. The four edge lines correspond to the edge contour lines of the spherical pin assembly in different orientations. Two of them form a set of opposite edge lines, and the other two form another set of edge lines in different orientations. Calculate the center line using the opposite edge lines. The center line is the symmetrical reference line of the spherical pin assembly and is used to locate the reference position. Then calculate the vertical distance between one of the edge lines in the other set and the center line. The vertical distance reflects the degree of offset of the edge line relative to the symmetrical reference. Shift the remaining edge line in the other set outward by a designated hole distance H. The designated hole distance H is the preset standard spacing of the thrust rod spherical pin mounting holes. After the shift, a new edge line is formed. The intersection of the new edge line and the corresponding edge line is a reference measurement point. Construct four reference measurement points P1, P2, P3, and P4 in the same way. The four reference measurement points correspond to the center positions of the upper and lower mounting holes of the spherical pin assembly, respectively, and serve as the core reference points for calculating the center distance. S34. Based on the perpendicular distance between the edge line and the center line, the specified hole distance H obtained in step S33, and the preset standard size parameters of the thrust rod, including the standard width of the spherical pin assembly and the preset reference length, calculate the angle deviation values ​​corresponding to the four reference measurement points respectively. The angle deviation values ​​reflect the degree of angular offset of the actual reference point relative to the standard position, and correct the position deviation. Combined with the angle deviation values, calculate the angle deviation correction value for each reference measurement point. The angle deviation correction value is used to adjust the coordinate position of the reference measurement point and eliminate the measurement error caused by the angle offset. S35. Calculate the straight-line distances between reference measurement points P1 and P2, and P3 and P4 respectively, which correspond to the actual spacing between the upper and lower mounting holes of the spherical pin assembly, respectively. These are direct measurement data. After obtaining the two distance values, calculate the average of these two values. This average value is the center distance dimension of the thrust rod, that is, the final standard distance between the centers of the spherical pin mounting holes at both ends of the thrust rod.

[0017] First, by precisely coordinating a parallel light source and an industrial camera, clear projection images of the upper and lower parts of the spherical pin assembly are obtained, and straight-line fitting of the contour edges is performed. This provides accurate basic data for subsequent calculations, avoiding projection interference and contour extraction errors. Next, through scientifically standardized edge selection, centerline calculation, and edge translation logic, benchmark measurement points are constructed to ensure precise correspondence between the measurement benchmark and the center of the spherical pin mounting hole, eliminating random errors caused by manual marking. Then, by calculating angle deviation values ​​and correction values, positional offsets caused by workpiece clamping tilt and machining errors are specifically eliminated, further calibrating the coordinates of the benchmark measurement points and reducing systematic errors. Finally, by calculating the distance between two sets of benchmark measurement points and taking the average, multiple sets of data are fully utilized to offset random errors from single-position measurements, ensuring the accuracy and reliability of the center distance calculation results. The entire process is fully automated, requiring no manual intervention in the core calculation stages. This ensures measurement accuracy and consistency while significantly improving dimensional judgment efficiency, perfectly adapting to the rapid inspection needs of mass production scenarios.

[0018] As can be seen from the above technical solutions, the advantages of this invention are as follows: This device achieves non-contact visual inspection of both ends of the push rod by using an industrial camera, a telecentric lens, and a parallel light source in a direct alignment. This avoids damage to the workpiece caused by contact measurement and automatically processes image data through a control terminal, eliminating the need for manual conversion, significantly improving inspection efficiency and reducing human error, effectively solving the pain points of low efficiency and high cost of traditional coordinate measuring machines (CMMs). The movable design of the light source adjustment module and camera adjustment module can flexibly adapt to push rods of different lengths, ensuring imaging stability and accurate shooting angles. No special components need to be replaced, reducing adaptation costs and improving usability. The separate layout of the loading / unloading station and the inspection station, along with the linkage of the switching drive mechanism, enables parallel operation of inspection and loading / unloading, shortening the single-piece inspection cycle. Combined with the precise positioning of the first slide rail and the positioning sensor, it ensures the smooth movement of the fixture and the automated triggering of the inspection process, improving equipment operation reliability. Reliability and measurement consistency: The material clamping mechanism of the fixture adjusts the spacing of the clamping blocks via the fourth slide rail to adapt to workpieces of different thicknesses, achieving stable clamping in multiple directions and ensuring workpiece coaxiality and positioning accuracy. The lifting mechanism, combined with cross-hinged support rods and four-corner telescopic rods, enables smooth lifting and lowering of the top plate, preventing workpiece tilting or structural deformation and providing a stable reference for upper and lower part imaging. In terms of measurement methods, from the acquisition of upper and lower projection images of the spherical pin assembly and contour edge fitting, to the scientific construction of reference measurement points, calculation of angle deviation values ​​and correction values, and then taking the average of the distance between two sets of reference points as the final center distance, the entire process is automated. It eliminates systematic and random errors caused by projection interference, clamping tilt, and processing errors through multi-stage data calibration, ensuring the accuracy and reliability of measurement results. At the same time, the process is closely connected, greatly reducing the labor intensity of operators, and perfectly adapting to the comprehensive requirements of inspection efficiency, accuracy, versatility and stability in mass production scenarios. Attached Figure Description

[0019] To more clearly illustrate the technical solution of this patent, the drawings used in the description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this patent. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a structural schematic diagram of a specific embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of the structure of the light source adjustment module in a specific embodiment of the present invention.

[0022] Figure 3 This is a schematic diagram of the fixture in a specific embodiment of the present invention.

[0023] Explanation of main figure symbols 1. Housing, 2. Main platform, 3. First slide rail, 4. Industrial camera, 5. Telecentric lens, 6. Parallel light source, 7. Light source adjustment module, 701. Fixed base, 702. Third slide rail, 8. Camera adjustment module, 9. Positioning drive mechanism, 10. Fixture, 101. Base plate, 103. Lifting mechanism, 104. Linear motor, 105. Material clamping mechanism, 1051. Fourth slide rail, 1052. Clamping block, 106. Second slide rail, 107. Support rod, 108. Top plate, 109. Telescopic rod, 1010. Stabilizing block, 11. Position sensor, 12. Control terminal, 13. Electrical control cabinet, 14. Loading and unloading station, 15. Inspection station. Detailed Implementation

[0024] To make the objectives, features, and advantages of this patent more apparent and understandable, the technical solutions of this patent will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this patent, and not all embodiments. Based on the embodiments of this patent, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this patent.

[0025] like Figure 1 As shown, the thrust rod center distance measuring device in this embodiment uses the housing 1 as the mounting base. The main platform 2 is fixedly installed inside the housing 1 by bolts. The main platform 2 is a horizontally arranged rigid plate structure, providing stable support for each functional module and preventing measurement accuracy from being affected by foundation sway during equipment operation. The main platform 2 is scientifically divided into loading / unloading stations 14 and inspection stations 15. The inspection station 15 is located in the middle of the platform, and the loading / unloading station 14 is located to one side of the inspection station 15. The two are connected by two parallel first slide rails 3, which are fixed to the top surface of the main platform 2 by bolts. Their extension direction is consistent with the length direction during thrust rod inspection, ensuring accurate fixture movement path.

[0026] The fixture 10 slides along the first slide rail 3 via a groove 102 on its bottom surface. The clearance design between the groove and the slide rail ensures smooth sliding without jamming. The bottom side of the fixture 10 is fixedly connected to the moving end of the shifting drive mechanism 9 by bolts. The shifting drive mechanism 9 adopts a linear module, and its fixed end is bolted to the bottom surface of the main platform 2. Driven by a motor, it drives the fixture 10 to move smoothly between the loading / unloading station 14 and the inspection station 15 along the first slide rail 3. Compared with traditional manual transfer, this significantly improves the station switching efficiency and avoids workpiece position deviation caused by manual operation. At the end of the first slide rail 3 near the inspection station 15, a positioning sensor 11 is fixedly installed by a bracket. The detection end of the positioning sensor 11 faces the direction of movement of the fixture 10, enabling real-time and accurate detection of whether the fixture 10 has reached the preset detection position. It promptly feeds back a signal to trigger subsequent processes, avoiding imaging misalignment or measurement failure due to fixture position deviation. This ensures the automated and accurate triggering of the inspection process, improving the reliability of equipment operation and the consistency of measurement results.

[0027] The inspection station 15 has a light source adjustment module 7 and a camera adjustment module 8 symmetrically arranged on both sides. Both are vertically fixed to the top surface of the main platform 2 by bolts. This symmetrical layout ensures the symmetry and accuracy of the visual inspection. Figure 2 As shown, the light source adjustment module 7 consists of a fixed base 701 and a third slide rail 702. The fixed base 701 and the third slide rail 702 are arranged coaxially along the length of the push rod. One parallel light source 6 is fixedly installed on the top surface of the fixed base 701 through a threaded connector. The other parallel light source 6 is slidably engaged with the third slide rail 702 through a slider. The slider has a locking bolt on its side. Loosening the bolt allows for flexible adjustment of the position of the parallel light source 6, and locking it securely achieves a stable fixation. This module can accurately adapt to push rods of different lengths and specifications, ensuring uniform illumination of the spherical pin assemblies at both ends of the push rod by the light source. This avoids blurring of images due to differences in workpiece size and provides a high-quality image foundation for subsequent data processing.

[0028] The camera adjustment module 8 has the same structure as the light source adjustment module 7. The mounting directions of its fixed base 701 and third slide rail 702 are parallel to those of the light source adjustment module 7. Two industrial cameras 4 are respectively mounted on the fixed base 701 and the slider of the third slide rail 702 of the camera adjustment module 8, and each industrial camera 4 has a telecentric lens 5 mounted at its lens end. The telecentric lens 5 has precise imaging characteristics, effectively eliminating perspective errors and ensuring consistent imaging proportions of the workpiece contour at different positions, thus improving the accuracy of dimensional measurement. The two industrial cameras 4 and two parallel light sources 6 are arranged facing each other, forming two symmetrical vision inspection units, respectively used to photograph the spherical pin assemblies at both ends of the push rod, achieving non-contact inspection and avoiding damage to the workpiece surface caused by traditional contact measurement. At the same time, compared with the point-by-point acquisition of coordinate measuring machines, it significantly improves inspection efficiency.

[0029] A human-machine interface terminal (i.e., control terminal 12) is fixedly mounted on the side of the enclosure 1 via a bracket. The human-machine interface terminal is electrically connected to components such as the industrial camera 4, the positioning sensor 11, and the displacement drive mechanism 9 via wires. It can receive detection data in real time, display measurement results intuitively, and conveniently issue control commands, eliminating the need for complex manual data conversion, reducing human error, and ensuring the consistency of measurement results. An electrical control cabinet 13 is installed inside the enclosure 1 below the main platform 2. It integrates a power module, control circuit board, and relay components, providing a stable power supply to the entire equipment. Pre-programmed control enables coordinated operation of various components, ensuring a smooth and seamless detection process. The equipment's detection start button adopts a two-handed control design, integrated next to the human-machine interface terminal. Operators must press both hands simultaneously to start the detection, effectively avoiding accidental triggering during single-handed operation and improving operational safety.

[0030] like Figure 3 As shown, the jig 10 consists of a base plate 101, a top plate 108, and a lifting mechanism 103 in the middle. The base plate 101 is a horizontal rectangular plate, and the sliding groove 102 on the bottom surface precisely matches the first slide rail 3 to ensure that the jig moves smoothly without deviation. The top surface of the base plate 101 and the bottom surface of the top plate 108 are both fixedly mounted with second slide rails 106 by bolts. The second slide rails 106 are arranged in a direction perpendicular to the first slide rail 3 to provide guidance for the movement of the lifting mechanism.

[0031] The lifting mechanism 103 includes four support rods 107, which are hinged in pairs to form a parallelogram structure. This design enables the smooth lifting and lowering of the top plate 108, preventing tilting during the lifting process. Of the hinged support rods 107, one has its lower end hinged to the top surface of the base plate 101 via a hinge, and its upper end slidingly engages with the second slide rail 106 on the bottom surface of the top plate 108 via a slider. The lower end of another support rod 107 also slides with the second slide rail 106 on the top surface of the base plate 101 via a slider, and this slider is fixedly connected to the output end of a linear motor 104 via a coupling. The fixed end of the linear motor 104 is bolted to the side of the base plate 101, and the upper end of the support rod 107 is hinged to the bottom surface of the top plate 108. Precise driving by the linear motor 104 allows for precise control of the lifting height of the top plate 108, facilitating separate imaging of the upper and lower parts of the spherical pin assembly by an industrial camera without the need for manual workpiece rotation, thus improving the automation and ease of operation of the inspection process. Stabilizing blocks 1010 are fixedly installed at the four corners of the base plate 101 by bolts. Telescopic rods 109 are slidably inserted inside the stabilizing blocks 1010. The upper ends of the telescopic rods 109 are fixedly connected to the mounting holes at the four corners of the top plate 108 by threads. This can further enhance the stability and load-bearing capacity of the top plate 108 when it is raised or lowered, prevent structural deformation caused by the weight of the workpiece or the lifting action, ensure the accuracy of the workpiece position during the measurement process, and improve the reliability of the test data.

[0032] Two parallel fourth slide rails 1051 are bolted to the top surface of the top plate 108. The direction of the fourth slide rails 1051 is perpendicular to the first slide rail 3. The material clamping mechanism 105 slides with the fourth slide rails 1051 via a slider, allowing for flexible adjustment of the clamping distance to accommodate push rod workpieces of different thicknesses, thus improving the equipment's versatility. The material clamping mechanism 105 includes four clamping blocks 1052, arranged in pairs facing each other, each pair corresponding to one end of the push rod. The clamping surfaces of the clamping blocks 1052 are equipped with rubber anti-slip pads, which enhance clamping stability and prevent damage to the workpiece surface. Powered by pneumatic drive, the mechanism uses a cylinder to move synchronously towards the center along the fourth slide rails 1051, achieving stable clamping of the push rod workpiece. This ensures no shaking or displacement of the workpiece during testing, guaranteeing the stability of the measurement reference. Simultaneously, the flexible clamping design driven by pneumatics facilitates quick clamping and disassembly, improving loading and unloading efficiency.

[0033] Example 2 This embodiment further provides a method for measuring the center distance of a thrust rod, including the following steps: S1. Place the thrust rod workpiece on the fixture 10 at the loading / unloading station 14, and the shifting drive mechanism 9 moves the fixture 10 to the inspection station 15. S2. After the positioning sensor 11 detects that the fixture 10 is in place, the parallel light source 6 is turned on, and the industrial camera takes a picture of the upper part of the push rod ball pin; the lifting mechanism 103 rises, and the industrial camera takes a picture of the lower part of the push rod ball pin assembly. S3. The control terminal 12 performs size determination, specifically including: S31. After the positioning sensor detects that the fixture is in place, the parallel light source is turned on. The industrial camera first captures the upper part of the spherical pin assembly. The obtained upper projection image is the contour projection of the spherical pin assembly under the illumination of the parallel light source. Then, the contour edge line on the projection image is fitted with a straight line. The contour edge line is the line formed by the outer edge of the spherical pin assembly on the projection image, which is the basis for subsequent calculations. Next, the fixture lifting drive mechanism rises, and the industrial camera captures the lower part of the spherical pin assembly. The obtained lower projection image is also the contour projection of the spherical pin assembly under the illumination of the parallel light source. Then, the contour edge line of the lower part is fitted with a straight line. The parallel light source ensures the clarity and integrity of the projection image. The straight line fitting process can accurately extract the contour edge line features, eliminate projection interference factors, and provide accurate and reliable basic data for subsequent benchmark point construction. This avoids measurement errors caused by inaccurate contour extraction and improves the accuracy of center distance calculation. S32. Select four specified edge lines, calculate the center line using two of them, and calculate the distance between the other edge line and the center line. Shift one of the edge lines outward by a specified distance to form a new edge line. The intersection of the new edge line and the fourth edge line is the benchmark measurement point. Construct four benchmark measurement points sequentially using the same method. The method of constructing benchmark measurement points through edge line calculation and translation is scientific and highly repeatable, ensuring the accuracy and consistency of benchmark measurement point positioning. It eliminates the need for manual benchmark marking, avoiding errors caused by manual marking, and provides a stable reference for subsequent angle deviation correction and center distance calculation, thus improving the reliability of the measurement method. S33. Select four designated edge lines on the projection drawing of the spherical pin assembly. These four edge lines correspond to the edge contour lines of the spherical pin assembly in different orientations. Two of these edge lines form a pair of opposite edge lines, and the other two form another pair of edge lines in different orientations. Calculate the center line using these opposite edge lines. The center line is the symmetrical reference line of the spherical pin assembly and is used to locate the reference position. Then calculate the perpendicular distance between one edge line from the other pair of edge lines and the center line. The perpendicular distance reflects the degree of offset of the edge line relative to the symmetrical reference. Shift the remaining edge line from the other pair of edge lines outward by a designated hole distance H. The designated hole distance H is the preset standard spacing of the thrust rod spherical pin mounting holes. After the shift, a new... The intersection of the new edge line and the corresponding edge line is a reference measurement point. Four reference measurement points, P1, P2, P3, and P4, are constructed sequentially using the same method. These four reference measurement points correspond to the center positions of the upper and lower mounting holes of the spherical pin assembly, serving as the core reference points for calculating the center distance. A center line is constructed based on the symmetry of the spherical pin assembly, and the edge line is translated using a preset hole position distance to ensure precise correspondence between the reference measurement points and the center of the mounting holes, eliminating the influence of symmetry deviations generated during workpiece machining or clamping. The four reference measurement points cover the upper and lower mounting holes, providing a comprehensive reference for subsequent bidirectional distance measurements, improving the comprehensiveness and accuracy of the center distance calculation. S34. Based on the perpendicular distance between the edge line and the center line, the specified hole distance H obtained in step S33, and the preset standard size parameters of the thrust rod (including the standard width of the spherical pin assembly and the preset reference length), calculate the angle deviation values ​​corresponding to the four reference measurement points. The angle deviation values ​​reflect the degree of angular offset of the actual reference point relative to the standard position, and correct the position deviation. Combined with the angle deviation values, calculate the angle deviation correction value for each reference measurement point. The angle deviation correction value is used to adjust the coordinate position of the reference measurement point and eliminate the measurement error caused by the angle offset. Through the calculation of the angle deviation value and the correction value, the influence of angle offset caused by workpiece placement, processing error, or clamping tilt is specifically eliminated, and the coordinates of the reference measurement point are accurately calibrated to further improve the positioning accuracy of the reference point. The correction process is based on the preset standard parameters and actual measurement data. The method is scientific and rigorous, effectively reducing system errors and ensuring the accuracy of subsequent center distance calculations. S35. Calculate the straight-line distances between reference measurement points P1 and P2, and P3 and P4 respectively, which correspond to the actual spacing between the upper and lower mounting holes of the spherical pin assembly, and are direct measurement data. After obtaining the two distance values, calculate the average of these two values. This average value is the center distance of the thrust rod, that is, the final standard distance between the centers of the spherical pin mounting holes at both ends of the thrust rod. By calculating the distances of the two sets of reference points at the upper and lower parts and taking the average, the random error of single-position measurement can be offset, and the reliability of the results can be improved by making full use of multiple sets of measurement data. The calculation logic is simple and efficient, and the final center distance can be quickly obtained. Combined with the automatic calculation of the control terminal, the detection efficiency is further improved, ensuring that the measurement results are both accurate and can meet the rapid detection requirements of mass production. S4. The shifting drive mechanism 9 drives the fixture 10 to move back to the loading / unloading station 14, removes the push rod tool, and then repeats steps S1-S3.

[0034] As can be seen from the above embodiments, the beneficial effects of the present invention are as follows: The device adopts a vision inspection unit composed of an industrial camera, a telecentric lens, and a parallel light source to achieve non-contact inspection, avoiding damage to the workpiece caused by contact measurement, and significantly improving inspection efficiency compared to coordinate measuring machine (CMM) inspection; The movable design of the light source and camera adjustment module, combined with the adjustable spacing function of the material clamping mechanism, can flexibly adapt to push rods of different lengths and thicknesses without the need to replace special components, significantly improving the equipment's versatility and adaptability; The fixture, through a cross-hinged lifting mechanism and four corner stabilizing telescopic rods, achieves smooth lifting and stable clamping of the workpiece, ensuring the stability of the measurement benchmark and avoiding measurement errors caused by workpiece shaking or tilting; The separate layout of the loading / unloading station and the inspection station, combined with a switching drive mechanism and a positioning sensor, enables automatic station switching and precise positioning, allowing inspection and loading / unloading operations to be performed in parallel, greatly shortening the single-piece inspection cycle and meeting the needs of mass production. At the measurement method level, the process involves acquiring upper and lower projection images, fitting contour lines, scientifically constructing benchmark measurement points, correcting angle deviations, and averaging multiple sets of data. This eliminates the influence of projection interference, clamping tilt, and machining errors at each stage, ensuring high accuracy and consistency in center distance measurement. The entire process is automated, eliminating the need for manual conversion and reducing human error. The equipment integrates a data storage module, supporting the association of inspection data with workpiece barcodes for easy quality traceability and statistical analysis. The dual-hand control start button design enhances operational safety. The overall solution balances inspection efficiency, measurement accuracy, versatility, and operational safety, effectively solving the problems of large errors in traditional manual measurement and high costs and low efficiency of coordinate measuring machine (CMM) inspection. It provides an efficient and reliable quality control method for the production of thrust rods for heavy-duty commercial vehicles, ensuring consistent product quality.

[0035] The above description of the disclosed embodiments enables those skilled in the art to implement or use this patent. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this patent. Therefore, this patent is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A thrust rod center distance measuring device, comprising a housing (1), wherein a main platform (2) is provided in the housing (1), characterized in that, The main platform (2) is provided with a fixture (10). A camera adjustment module (8) is provided on one side of the fixture (10). Two industrial cameras (4) are installed on the camera adjustment module (8). A telecentric lens (5) is installed on the industrial camera (4). A light source adjustment module (7) is provided on the other side of the fixture (10). Two parallel light sources (6) are installed on the light source adjustment module (7). The two industrial cameras (4) and the two parallel light sources (6) are facing each other and are used to photograph the two ends of the push rod respectively. The platform also includes a control terminal (12). The control terminal (12) is electrically connected to the industrial camera (4) and is used to receive the images captured by the industrial camera and process and analyze them.

2. The thrust rod center distance measuring device according to claim 1, characterized in that, The light source adjustment module (7) includes a fixed base (701) and a third slide rail (702). The fixed base (701) and the third slide rail (702) are both installed on the main platform (2). The sliding direction of the third slide rail (702) is parallel to the direction of the push rod in the fixture (10). One parallel light source (6) is fixedly installed on the fixed base (701), and the other parallel light source (6) is movably installed on the third slide rail (702).

3. The thrust rod center distance measuring device according to claim 2, characterized in that, The camera adjustment module (8) has the same structure as the light source adjustment module (7). On the camera adjustment module (8), one industrial camera (4) is mounted on the fixed base (701) of the camera adjustment module (8), and the other industrial camera (4) is movably mounted on the third slide rail (702) of the camera adjustment module (8).

4. The thrust rod center distance measuring device according to claim 1, characterized in that, The main platform (2) is provided with a loading / unloading station (14) and a testing station (15). The testing station (15) is located between the parallel light source (6) and the industrial camera (4). The loading / unloading station (14) is located on one side of the testing station (15). The loading / unloading station (14) and the testing station (15) are jointly provided with a first slide rail (3) and a shifting drive mechanism (9). The fixture (10) is slidably mounted on the first slide rail (3) and connected to the moving end of the shifting drive mechanism (9).

5. The thrust rod center distance measuring device according to claim 4, characterized in that, On the first slide rail (3), a positioning sensor (11) is provided at one end corresponding to the detection station.

6. The thrust rod center distance measuring device according to claim 2, characterized in that, The fixture (10) includes a base plate (101) and a top plate (108). A lifting mechanism (103) is provided between the top plate (108) and the base plate (101). A sliding groove (102) is provided on the bottom surface of the base plate (101). The sliding groove (102) is slidably connected to the first slide rail (3). A material clamping mechanism (105) is provided on the top surface of the top plate (108).

7. The thrust rod center distance measuring device according to claim 6, characterized in that, The top surface of the base plate (101) and the bottom surface of the top plate (108) are respectively provided with second slide rails (106). The lifting mechanism (103) includes four support rods (107), which are hinged to each other in pairs. The lower end of one of the hinged support rods (107) is hinged to the base plate (101), and the upper end is slidably connected to the second slide rail (106) on the top plate (108). The lower end of the other support rod is hinged to the second slide rail (106) on the base plate (101) and connected to a linear motor (104). The other end is hinged to the top plate (108). The four corners of the base plate (101) are also provided with stabilizing blocks (1010). Telescopic rods (109) are installed on the stabilizing blocks (1010). The upper ends of the four telescopic rods (109) are respectively connected to the four corners of the top plate (108).

8. The thrust rod center distance measuring device according to claim 6, characterized in that, The top surface of the top plate (108) is equipped with a fourth slide rail (1051), which is perpendicular to the first slide rail (3). The material clamping mechanism (105) is slidably mounted on the fourth slide rail (1051). The material clamping mechanism includes four clamping blocks (1052), which are arranged in pairs facing each other and are used to clamp the two ends of the push rod respectively.

9. A method for measuring the center distance of a thrust rod, characterized in that, Includes the following steps: S1. Place the thrust rod workpiece on the fixture (10) of the loading and unloading station (14), and the shifting drive mechanism (9) moves the fixture (10) to the inspection station (15). S2. After the positioning sensor (11) detects that the fixture (10) is in place, the parallel light source (6) is turned on, and the industrial camera takes a picture of the upper part of the push rod ball pin; the lifting mechanism (103) rises, and the industrial camera takes a picture of the lower part of the push rod ball pin assembly. S3. The control terminal (12) performs size determination; S4. The shifting drive mechanism (9) drives the fixture (10) to move back to the loading and unloading station (14), removes the push rod tool, and then repeats steps S1-S3.

10. The method for measuring the center distance of a thrust rod according to claim 9, characterized in that, Step S3 includes: S31. After the positioning sensor detects that the fixture is in place, the parallel light source is turned on. The industrial camera first captures the upper part of the spherical pin assembly. The obtained upper projection image is the contour projection of the spherical pin assembly under the illumination of the parallel light source. Then, the contour edge line on the projection image is fitted with a straight line. The contour edge line is the line formed by the outer edge of the spherical pin assembly on the projection image, which is the basis for subsequent calculations. Then, the fixture lifting drive mechanism rises, and the industrial camera captures the lower part of the spherical pin assembly. The obtained lower projection image is also the contour projection of the spherical pin assembly under the illumination of the parallel light source. Then, the contour edge line of the lower part is fitted with a straight line. S32. Select four specified side lines, calculate the center line through two of them, and calculate the distance between the other side line and the center line; shift one of the side lines outward by a specified distance to form a new side line, and the intersection of the new side line and the fourth side line is the reference measurement point. Construct four reference measurement points in the same way. S33. Select four designated edge lines on the projection drawing of the spherical pin assembly. The four edge lines correspond to the edge contour lines of the spherical pin assembly in different orientations. Two of them form a set of opposite edge lines, and the other two form another set of edge lines in different orientations. Calculate the center line using the opposite edge lines. The center line is the symmetrical reference line of the spherical pin assembly and is used to locate the reference position. Then calculate the vertical distance between one of the edge lines in the other set and the center line. The vertical distance reflects the degree of offset of the edge line relative to the symmetrical reference. Shift the remaining edge line in the other set outward by a designated hole distance H. The designated hole distance H is the preset standard spacing of the thrust rod spherical pin mounting holes. After the shift, a new edge line is formed. The intersection of the new edge line and the corresponding edge line is a reference measurement point. Construct four reference measurement points P1, P2, P3, and P4 in the same way. The four reference measurement points correspond to the center positions of the upper and lower mounting holes of the spherical pin assembly, respectively, and serve as the core reference points for calculating the center distance. S34. Based on the perpendicular distance between the edge line and the center line, the specified hole distance H obtained in step S33, and the preset standard size parameters of the thrust rod, including the standard width of the spherical pin assembly and the preset reference length, calculate the angle deviation values ​​corresponding to the four reference measurement points respectively. The angle deviation values ​​reflect the degree of angular offset of the actual reference point relative to the standard position, and correct the position deviation. Combined with the angle deviation values, calculate the angle deviation correction value for each reference measurement point. The angle deviation correction value is used to adjust the coordinate position of the reference measurement point and eliminate the measurement error caused by the angle offset. S35. Calculate the straight-line distances between reference measurement points P1 and P2, and P3 and P4 respectively, which correspond to the actual spacing between the upper and lower mounting holes of the spherical pin assembly, respectively. These are direct measurement data. After obtaining the two distance values, calculate the average of these two values. This average value is the center distance dimension of the thrust rod, that is, the final standard distance between the centers of the spherical pin mounting holes at both ends of the thrust rod.

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