A common rail fuel injection nozzle orifice projection laser detection tool

Abstract

The application discloses a kind of common rail injection nozzle orifice projection laser detection tool, it is related to injection nozzle laser detection technical field, the application includes laser detection table and multiple injection nozzle needle valve body, installation plate is fixedly installed in the laser detection table, and rotaryly installed with installation plate is carousel, multiple with corresponding injection nozzle needle valve body cooperation's placement disc are rotaryly installed on the carousel, and multiple flexible clamping assemblies are installed on each placement disc.The advantages are that: the application realizes the inner and outer synchronous centering of needle valve body and flexible clamping, and can complete the detection of needle valve body inner and outer diameter deviation in clamping process, in addition, the automatic detection of multiple stations can be completed during detection, effectively solve the problems of single clamping function, easy to damage workpiece and low detection efficiency in prior art, provide a tooling solution with high precision, high stability and high automation degree for common rail injection nozzle orifice projection laser detection.

Description

Technical Field

[0001] This invention relates to the field of laser inspection technology for fuel injectors, and more particularly to a laser inspection fixture for the projection of nozzle holes on a common rail fuel injector. Background Technology

[0002] Common rail injectors are the core actuators of the high-pressure common rail fuel injection system in diesel engines. The front end of the needle valve body is machined with multiple tiny nozzles with a diameter of only 0.15-0.50mm. The geometric accuracy of the nozzles (diameter, roundness, taper, and position) directly determines the fuel atomization quality, injection flow consistency, and combustion efficiency, thereby affecting the engine's power, economy, and emissions. Therefore, high-precision, full-scale inspection of the nozzle nozzles in the needle valve body is a key step in ensuring the quality of injector products.

[0003] Existing projection laser inspection devices for nozzles of needle valve bodies mostly use an internal positioning mandrel in conjunction with an external clamping mechanism to clamp the workpiece. During inspection, the laser source and industrial camera are respectively arranged on both sides of the nozzle, and the geometric dimensions are measured by capturing the silhouette of the nozzle outline. Such devices meet the needs of single-piece, offline inspection to a certain extent.

[0004] However, existing technologies still have the following shortcomings: Firstly, the clamping scheme can only limit the needle valve body radially or at the end face, and cannot simultaneously obtain the inner and outer diameter information of the needle valve body. Additional measurement is required, which affects the detection efficiency. Secondly, traditional clamping mechanisms have limited control accuracy in clamping force on thin-walled precision needle valve bodies, making it difficult to balance fixed rigidity and workpiece protection. During high-speed rotation testing, unreliable clamping can easily introduce micro-vibrations and positional shifts, thus limiting measurement accuracy.

[0005] Therefore, there is an urgent need to develop a new type of testing fixture that combines multifunctional integration with high-stability clamping. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a common rail fuel injector nozzle projection laser inspection fixture, which solves the problems mentioned in the background section.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A common rail fuel injector nozzle projection laser inspection fixture includes a laser inspection stage and multiple fuel injector needle valve bodies. A mounting plate is fixedly installed inside the laser inspection stage, and a turntable is rotatably mounted on the mounting plate. Multiple placement discs that cooperate with corresponding fuel injector needle valve bodies are rotatably mounted on the turntable. Each placement disc is equipped with multiple flexible clamping components for fixing the fuel injector needle valve body. Each flexible clamping component includes a flexible bidirectional sliding mechanism and an inner clamping plate and an outer clamping plate slidably mounted on the placement disc. The flexible bidirectional sliding mechanism allows the inner and outer clamping plates to slide in opposite directions on the placement disc to achieve clamping of the fuel injector needle valve body. The mounting plate is equipped with a drive assembly for intermittently rotating the turntable and the placement plate. The drive assembly includes a drive motor fixedly mounted on the bottom of the mounting plate.

[0008] Furthermore, the placement tray has a sliding groove, and a first slider and a second slider are slidably installed in the sliding groove. The first slider is fixedly connected to the outer clamping plate, and the second slider is fixedly connected to the inner clamping plate.

[0009] Furthermore, the flexible bidirectional sliding mechanism comprises a threaded sleeve, a screw, a first bevel gear, a first damping bearing, a connecting shaft, and a second damping bearing. The threaded sleeve and the screw are rotatably mounted in the sliding groove. The threaded sleeve is threadedly connected to the second slider, and the screw is threadedly connected to the first slider. The connecting shaft is mounted on the end of the screw near the center point of the placement plate via the second damping bearing. The first bevel gear is fixedly mounted on the connecting shaft, and the first damping bearing is mounted between the threaded sleeve and the screw.

[0010] Furthermore, a servo motor is fixedly installed inside the placement tray, and a second bevel gear is fixedly connected to the output end of the servo motor. The second bevel gear meshes with multiple first bevel gears, and the damping coefficient of the second damping bearing is greater than that of the first damping bearing.

[0011] Furthermore, a movable groove is provided at one end of the screw located inside the threaded sleeve, and a movable rod is slidably installed in the movable groove. A sliding sleeve that slides with the screw is fixedly installed on the movable rod, and a protrusion is fixedly installed on the side wall of the sliding sleeve. A spiral groove that mates with the protrusion is provided on the inner wall of the threaded sleeve. A push rod that slides with the screw is fixedly installed at the end of the movable rod away from the center point of the placement tray, and a fixed rack is installed at the end of the push rod outside the placement tray. A mounting base is fixedly installed on the side wall of the placement tray, and a rotating shaft is rotatably installed on the mounting base. A fixed gear that meshes with the fixed rack is fixedly installed at the bottom of the rotating shaft. An indicator disk that is rotatably connected to the rotating shaft is fixedly installed on the side wall of the placement tray, and a pointer is fixedly installed at the top of the rotating shaft.

[0012] Furthermore, a guide rail is fixedly installed on the side wall of the placement tray, the fixed rack is rotatably connected to the push rod, a guide groove is provided on the guide rail, a guide rod that slides with the guide groove is fixedly installed on the side wall of the fixed rack, and a lighting lamp is fixedly installed on the placement tray, and the lighting lamp is concentric with the placement tray.

[0013] Furthermore, a fixed shaft rotatably connected to the turntable is fixedly installed at the bottom of the placement tray, and a rotating gear is fixedly installed at the bottom of the fixed shaft. A support shaft rotatably connected to the mounting plate is fixedly installed at the bottom of the turntable, and a fixed gear ring is fixedly installed on the support shaft. A drive shaft, a transmission shaft, and a round shaft are rotatably installed on the mounting plate. The drive shaft is fixedly connected to the output end of the drive motor. A chain drive structure is installed between the transmission shaft and the round shaft. A drive gear meshing with the rotating gear is installed on the round shaft. An incomplete gear one that cooperates with the fixed gear ring is fixedly installed on the drive shaft. An incomplete gear two is also fixedly installed on the drive shaft. A transmission gear that cooperates with the incomplete gear two is fixedly installed on the transmission shaft.

[0014] Furthermore, the sum of the included angles of the toothed portions on the first incomplete gear and the toothed portions on the second incomplete gear is less than 360°, and the toothed portions on the first incomplete gear and the toothed portions on the second incomplete gear are staggered.

[0015] Furthermore, a fixed disk is fixedly installed on the top of the circular shaft, an annular groove is opened in the drive gear to rotate with the fixed disk, and a torsion spring is installed between the annular groove and the fixed disk. A rubber ring that is in contact with the annular groove is fixedly installed on the side wall of the fixed disk.

[0016] Compared with existing technologies, the advantages of this invention are: 1. By designing the damping coefficient difference between the first and second damping bearings in the flexible bidirectional sliding mechanism, the clamping action of the inner clamping plate first supporting the inner hole and the outer clamping plate then clamping the outer circle is realized. In a single clamping, the spatial position information of the inner and outer diameters of the needle valve body is obtained simultaneously, and the workpiece is self-centered with high precision at the rotation center of the placement plate. The consistency of the detection coordinate system can be guaranteed without additional measurement procedures, which significantly improves the clamping efficiency and positioning accuracy.

[0017] 2: Through the linkage design of the screw internal moving rod, spiral groove, fixed rack, pointer and indicator plate, the relative displacement of the inner and outer clamping plates is converted into the deflection angle of the pointer. The operator can intuitively read the displacement difference between the inner and outer clamping plates, so as to simultaneously judge whether there is a deviation in the inner and outer diameter of the fuel injector needle valve body during the clamping process, without the need for subsequent additional inspection, which greatly improves the overall efficiency.

[0018] 3: Through the design of the drive components, the intermittent linkage between the revolution of the turntable and the rotation of the placement plate is realized, ensuring that the placement plate completes at least one rotation during the inspection station for laser full-circumference scanning, effectively improving the cycle efficiency of batch inspection.

[0019] In summary, this invention achieves synchronous centering and flexible clamping of the needle valve body, and can detect the deviation of the inner and outer diameters of the needle valve body during clamping. In addition, it can perform automated multi-station inspection during inspection, effectively solving the problems of single clamping function, easy damage to workpieces and low inspection efficiency in the prior art. It provides a tooling solution with high precision, high stability and high degree of automation for common rail injector nozzle projection laser inspection. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a common rail fuel injector nozzle projection laser detection fixture proposed in this invention; Figure 2 for Figure 1 Enlarged schematic diagram of the structure at the central turntable; Figure 3 for Figure 2 A structural diagram from another perspective; Figure 4 for Figure 2 Top view; Figure 5 for Figure 4 Schematic diagram of the structure of surface AA; Figure 6 for Figure 3 Enlarged structural diagram of part a; Figure 7 for Figure 5 Enlarged structural diagram of part b in the middle; Figure 8 for Figure 5 Enlarged structural diagram of section c; Figure 9 for Figure 5 Enlarged structural diagram of part d in the middle; Figure 10 for Figure 7 Enlarged structural diagram of part e in the middle; Figure 11 for Figure 2 An enlarged schematic diagram of the structure of one of the placement plates after the fuel injector needle valve body has been removed; Figure 12 for Figure 11 A schematic diagram of the structure after removing the placement tray; Figure 13 for Figure 12 An enlarged schematic diagram of the structure at one of the screws.

[0021] In the diagram: 1. Laser inspection stage; 2. Mounting plate; 3. Turntable; 4. Injector needle valve body; 5. Placement plate; 6. Slide groove; 7. First slider; 8. Second slider; 9. Inner clamping plate; 10. Outer clamping plate; 11. Threaded sleeve; 12. Screw; 13. Bevel gear one; 14. Servo motor; 15. Bevel gear two; 16. First damping bearing; 17. Connecting shaft; 18. Second damping bearing; 19. Moving groove; 20. Moving rod; 21. Sliding sleeve; 22. Protrusion; 23. Spiral groove; 24. Push rod; 2 5. Fixed rack, 26. Mounting base, 27. Rotating shaft, 28. Fixed gear, 29. Indicator dial, 30. Pointer, 31. Rotating gear, 32. Support shaft, 33. Drive shaft, 34. Fixed gear ring, 35. Incomplete gear one, 36. Incomplete gear two, 37. Transmission shaft, 38. Transmission gear, 39. Round shaft, 40. Chain drive structure, 41. Drive gear, 42. Annular groove, 43. Fixed disc, 44. Torsion spring, 45. Lighting lamp, 46. Guide rail, 47. Guide rod, 48. Guide groove. Detailed Implementation

[0022] Reference Figures 1-13 A common rail fuel injector nozzle projection laser inspection fixture includes a laser inspection stage 1 and multiple fuel injector needle valve bodies 4 to be inspected. A horizontally arranged mounting plate 2 is fixedly installed inside the laser inspection stage 1. A turntable 3 is rotatably installed on the mounting plate 2. Multiple placement plates 5 are uniformly rotatably installed on the turntable 3 along its circumference. Each placement plate 5 is used to support one fuel injector needle valve body 4.

[0023] Each placement plate 5 is equipped with multiple circumferentially distributed flexible clamping components for secure and non-destructive clamping of the fuel injector needle valve body 4. The flexible clamping components include a flexible bidirectional sliding mechanism and an inner clamping plate 9 and an outer clamping plate 10 slidably mounted on the placement plate 5. The inner clamping plate 9 is used to press against the central inner hole wall of the fuel injector needle valve body 4, and the outer clamping plate 10 is used to hold the outer cylindrical surface of the fuel injector needle valve body 4. The flexible bidirectional sliding mechanism is used to drive the inner clamping plate 9 and the outer clamping plate 10 to slide synchronously in opposite directions along the radial direction on the placement plate 5, thereby achieving self-centering clamping of the fuel injector needle valve body 4.

[0024] The upper surface of the placement plate 5 is provided with a radially extending groove 6. A first slider 7 and a second slider 8 are slidably installed in the groove 6. The top of the first slider 7 is fixedly connected to the outer clamping plate 10, and the top of the second slider 8 is fixedly connected to the inner clamping plate 9. The flexible bidirectional sliding mechanism is specifically composed of a threaded sleeve 11, a screw 12, a bevel gear 13, a first damping bearing 16, a connecting shaft 17, and a second damping bearing 18. Both the threaded sleeve 11 and the screw 12 are rotatably installed in the slide groove 6, and the threaded sleeve 11 and the screw 12 are coaxially sleeved. The first damping bearing 16 is installed between the threaded sleeve 11 and the screw 12. The external thread of the threaded sleeve 11 is threadedly connected to the second slider 8, and the external thread of the screw 12 is threadedly connected to the first slider 7. The connecting shaft 17 is installed at one end of the screw 12 near the center of the placement disk 5 through the second damping bearing 18. The first bevel gear 13 is fixedly installed on the connecting shaft 17. The servo motor 14 is fixedly installed at the center of the placement disk 5. The output end of the servo motor 14 is fixedly connected to the second bevel gear 15. The second bevel gear 15 meshes with multiple first bevel gears 13 at the same time, and the damping coefficient of the second damping bearing 18 is greater than the damping coefficient of the first damping bearing 16. When the servo motor 14 starts, it drives multiple bevel gears 13 to rotate simultaneously via bevel gear 2 15. At the same time, multiple connecting shafts 17 rotate simultaneously, driving multiple screws 12 and multiple threaded sleeves 11 to rotate. The inner clamping plate 9 and the outer clamping plate 10 move from the inner and outer side walls of the injector needle valve body 4 and approach the injector needle valve body 4. Since the inner diameter of the injector needle valve body 4 is small, the inner clamping plate 9 will first contact the inner wall of the injector needle valve body 4. At this time, the movement of the inner clamping plate 9 is hindered by the resistance. The action of the first damping bearing 16 keeps the threaded sleeve 11 stationary relative to the screw 12. The screw 12 continues to rotate, causing the outer clamping plate 10 to continue to approach the injector needle valve body 4 and fix its outer wall. When the outer clamping plate 10 has also completed the fixation of the injector needle valve body 4, if bevel gear 2 15 continues to rotate, then under the action of the second damping bearing 18, the screw 12 will move relative to the connecting shaft 17. While remaining stationary, the inner and outer sides of the injector needle valve body 4 are fixed, achieving a clamping action of first tightening the inner side and then gripping the outer side. Simultaneously, the inner and outer diameter position information of the injector needle valve body 4 is acquired, and it is positioned with high precision at the rotation center of the placement plate 5. The consistency of the detection coordinate system can be guaranteed without additional measurement procedures. On the other hand, the flexible overload protection of the first damping bearing 16 and the second damping bearing 18 effectively limits the peak value of the clamping force, avoiding the indentation or deformation caused by traditional rigid clamping to the thin-walled precision needle valve body. It takes into account both the requirements of high rigidity clamping and workpiece protection. After all the injector needle valve bodies 4 are fixed, the servo motor 14 is turned off. After the detection is completed, the fixing of the injector needle valve body 4 can be released simply by rotating the servo motor 14 in the reverse direction. Then, the multiple inner clamping plates 9 and the outer clamping plates 10 can be reset by continuously rotating the servo motor 14 in the reverse direction.

[0025] A movable groove 19 is provided at one end of the screw 12 located inside the threaded sleeve 11. A movable rod 20 is slidably installed in the movable groove 19. A sliding sleeve 21 is fixedly installed on the movable rod 20. The sliding sleeve 21 is slidably sleeved on the outer wall of the screw 12, and a protrusion 22 is fixedly installed on the side wall of the sliding sleeve 21. A spiral groove 23 is provided on the inner wall of the threaded sleeve 11 to slide with the protrusion 22. A push rod 24 is fixedly installed at the end of the moving rod 20 away from the center of the placement plate 5. The push rod 24 moves through the screw 12 and extends to the outside of the placement plate 5. A fixed rack 25 is rotatably installed at its end. A mounting base 26 is fixedly installed on the side wall of the placement plate 5. A rotating shaft 27 is rotatably installed on the mounting base 26. A fixed gear 28 that meshes with the fixed rack 25 is fixedly installed at the bottom of the rotating shaft 27. An indicator plate 29 is fixedly installed on the side wall of the placement plate 5. A pointer 30 is fixedly installed at the top of the rotating shaft 27. A guide rail 46 is also fixedly installed on the side wall of the placement plate 5. A guide groove 48 is opened on the guide rail 46. A guide rod 47 that slides with the guide groove 48 is fixedly installed on the side wall of the fixed rack 25. When the threaded sleeve 11 rotates relative to the screw 12 (i.e., when the inner clamping plate 9 is clamped relative to the outer clamping plate 10), the protrusion 22 slides relative to the spiral groove 23, generating an axial force that pushes the moving rod 20 to move outward along the moving groove 19. The moving rod 20 pushes the push rod 24 and the fixed rack 25 to move linearly. The smooth movement is ensured by the cooperation of the guide rod 47 and the guide groove 48. The fixed rack 25 drives the fixed gear 28 and the rotating shaft 27 to rotate, which ultimately causes the pointer 30 to deflect on the indicator dial 29. The operator can visually judge the relative displacement between the inner clamping plate 9 and the outer clamping plate 10 by observing the indication scale of the pointer 30. By observing the change in displacement, it can be determined whether the inner and outer diameters of the injector needle valve body 4 deviate from the standard size, which cannot be measured separately.

[0026] A drive assembly is installed at the bottom of the mounting plate 2. The drive assembly is used to drive the turntable 3 to revolve intermittently to switch work positions and to drive the placement disk 5 located at a specific work position to rotate intermittently to meet the requirements of workpiece rotation scanning during laser projection inspection. The drive assembly includes a drive motor fixedly installed at the bottom of the mounting plate 2. A fixed shaft extending downward is fixedly installed at the bottom of the placement disk 5. The fixed shaft is rotatably connected to the turntable 3. A rotating gear 31 is fixedly installed at the bottom end of the fixed shaft. A support shaft 32 is fixedly installed at the bottom center of the turntable 3. The support shaft 32 is rotatably connected to the mounting plate 2. A fixed gear ring 34 is fixedly installed on the support shaft 32. A drive shaft 33, a transmission shaft 37, and a round shaft 39 are also rotatably installed on the mounting plate 2. The drive shaft 33 is fixedly connected to the output end of the drive motor. A chain drive structure 40 is installed between the transmission shaft 37 and the round shaft 39. A drive gear 41 that intermittently meshes with the rotating gear 31 is installed at the top of the round shaft 39. An incomplete gear 35 that meshes with a fixed gear ring 34 is fixedly mounted on the drive shaft 33. An incomplete gear 36 is also fixedly mounted on the drive shaft 33. A transmission gear 38 that meshes with the incomplete gear 36 is fixedly mounted on the transmission shaft 37. The sum of the included angle of the toothed portion of the incomplete gear 35 and the included angle of the toothed portion of the incomplete gear 36 is less than 360°, and the toothed portions of the two are staggered in the circumferential direction. When the drive motor drives the drive shaft 33 to rotate continuously, if the incomplete gear 35 meshes with the fixed gear ring 34, the drive turntable 3 will rotate one station to achieve station conversion. When the incomplete gear 35 disengages and the incomplete gear 36 meshes with the transmission gear 38, the power is transmitted to the round shaft 39 through the transmission shaft 37 and the chain drive structure 40. The drive gear 41 rotates and drives the corresponding rotating gear 31 to rotate, so that the placement disk 5 in the detection station completes one rotation, which allows the laser detection system to collect the full circumference contour data of the nozzle. The staggered incomplete gears ensure that the revolution of the turntable 3 and the rotation of the placement disk 5 do not interfere with each other in terms of timing, realizing the automated cycle control of "rotation-detection-rotation", which greatly improves the batch detection efficiency.

[0027] To eliminate the instantaneous rigid impact when the drive gear 41 and the rotating gear 31 separate or mesh during the rotation of the turntable 3, and to ensure the smoothness of the self-rotation start, a fixed plate 43 is fixedly installed on the top of the round shaft 39. An annular groove 42 that rotates with the fixed plate 43 is opened in the center hole of the drive gear 41. A torsion spring 44 is installed between the annular groove 42 and the fixed plate 43. Since the positions of the incomplete gear 1 35 and the incomplete gear 2 36 are staggered, the self-rotation of the turntable 3 and the self-rotation of the placement plate 5 occur at different times. When the turntable 3 rotates, the drive gear 41 remains stationary. The rotation of the turntable 3 drives the rotating gear 31 to revolve, which in turn drives the drive gear 41 to rotate. At this time, the presence of the torsion spring 44 can make the drive gear 41 rotate relative to the round shaft 39 at a certain angle, so that the round shaft 39 remains stationary, and avoids the action of the turntable 3 rotating through the round shaft 39 to transmit to the drive shaft 33, which would have an adverse effect on the self-rotation of the turntable 3. Meanwhile, when the chain drive structure 40 drives the round shaft 39 to rotate, the power is transmitted to the drive gear 41 through the buffer flexibility of the torsion spring 44, effectively absorbing the vibration caused by the meshing backlash between the drive gear 41 and the rotating gear 31, avoiding the shaking of the placement disk 5 at the beginning of its rotation, and further improving the imaging clarity and measurement accuracy of the laser projection detection. A rubber ring that is in contact with the inner wall of the annular groove 42 is also fixedly installed on the side wall of the fixed disk 43. The design of the rubber ring can improve the connection stability between the round shaft 39 and the drive gear 41.

[0028] The transmission ratio between the incomplete gear 35 and the fixed gear ring 34 is adjusted according to the specific number of placement disks 5, so that the angle through which the toothed part of the incomplete gear 35 drives the fixed gear ring 34 to rotate for each revolution is equal to the central angle between two adjacent placement disks 5 (i.e., 360° / N, where N is the number of placement disks 5). The transmission ratio between the drive gear 41 and the rotating gear 31 should be such that the number of rotations completed by the placement disk 5 is not less than one revolution during each revolution of the drive shaft 33.

[0029] The servo motor 14 can be an ACM6004M2H servo motor, and the drive motor can be a motor that can only rotate in one direction, which is common in daily life and work. The chain drive structure 40 is existing technology, and its working principle and specific structure will not be described here.

[0030] The laser inspection station 1 is also equipped with a conventional laser inspection component, which includes a laser profilometer, an industrial camera, a backlight source, and an industrial control computer (not shown in the figure). The laser profilometer and the industrial camera are both fixedly mounted on the mounting plate 2 by brackets, and are located on both sides of the placement plate 5 at the inspection station. The emitting end of the laser profilometer faces the nozzle orifice area of ​​the fuel injector needle valve body 4, and is used to project a beam of line laser to form a profile light strip on the outer surface of the needle valve body. The lens of the industrial camera is arranged at a specific angle (e.g., 30°-45°) with the optical axis of the laser profilometer, and is used to capture the diffuse reflection image generated by the laser light strip at the edge of the nozzle. The backlight source is installed on the opposite side of the industrial camera to provide uniform parallel backlighting to enhance the contrast of the nozzle silhouette. An illumination lamp 45 is also fixedly installed at the center of the placement plate 5. The light beam emitted by the lamp shines outward from the inside of the injector needle valve body 4, forming a composite illumination field with the laser profilometer and the backlight source. The industrial control computer has a built-in image acquisition card and dedicated measurement software to process the image data acquired by the camera in real time.

[0031] Among them, the laser profilometer, industrial camera, backlight source and industrial control computer are all existing products, and their working principles and specific structures will not be described in detail here.

[0032] During testing, the operator places the injector needle valve body 4 to be tested onto the various placement plates 5 on the turntable 3 in sequence, starts the servo motor 14, and drives the inner clamping plate 9 and the outer clamping plate 10 through the flexible bidirectional sliding mechanism to complete the self-centering flexible clamping. Subsequently, the drive motor starts, and the incomplete gear 35 first meshes with the fixed gear ring 34, driving the turntable 3 to rotate one station and sending the first workpiece into the testing station. At this time, the incomplete gear 35 disengages, and the turntable 3 stops revolving. When the workpiece enters the inspection station, the incomplete gear 36 immediately meshes with the transmission gear 38. The power is transmitted to the drive gear 41 through the chain transmission structure 40, driving the placement disk 5 to complete one rotation at a constant low speed. During the rotation of the placement disk 5, the laser profilometer continuously projects a line laser onto the conical surface of the nozzle needle valve body 4. The line laser covers the distribution area of ​​all nozzles. As the workpiece rotates, the laser beam sweeps across the edge of each nozzle in sequence. The industrial camera synchronously acquires the laser beam image at each angle position at a high frame rate. At the same time, the backlight source and the illumination lamp 45 continuously supplement the light, so that the nozzle edge presents a sharp light and dark boundary in the image, which is convenient for subsequent edge extraction. The sequence of images captured by the industrial camera is transmitted to the industrial control computer in real time. The measurement software built into the industrial control computer first preprocesses each frame of the image, including median filtering for noise reduction, adaptive threshold segmentation, and sub-pixel edge extraction algorithm, to accurately identify the upper and lower edge lines of the laser light stripe. Then, the software uses the principle of triangulation to convert the pixel coordinates of the light stripe in the image coordinate system into three-dimensional spatial point cloud data based on the spatial geometric relationship between the laser profilometer, the industrial camera, and the workpiece surface. By stitching and fitting the point cloud data of all frames within a week, the complete three-dimensional shape of the four conical surfaces of the fuel injector needle valve body is reconstructed. Based on this, the software automatically identifies and segments the elliptical projection contour of each nozzle, calculates key geometric parameters such as the diameter, roundness, taper, and position relative to the axis of the needle valve body of each nozzle, and performs a qualification judgment according to the preset tolerance zone. The measurement data and judgment results are displayed on the industrial control computer screen in real time and stored in the database to generate an inspection report for quality traceability. After the current workpiece completes one rotation scan, the incomplete gear 2 36 disengages, and the incomplete gear 1 35 meshes with the fixed gear ring 34 again. The turntable 3 continues to rotate one station, moving the inspected workpiece out of the inspection station and sending the next workpiece to be inspected into the inspection station. This cycle repeats, realizing multi-station continuous automated inspection.

[0033] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A common rail fuel injector nozzle projection laser inspection fixture, comprising a laser inspection stage (1) and multiple fuel injector needle valve bodies (4), characterized in that, The laser detection stage (1) is fixedly installed with a mounting plate (2), and a turntable (3) is rotatably installed on the mounting plate (2). Multiple placement plates (5) that cooperate with the corresponding fuel injector needle valve body (4) are rotatably installed on the turntable (3). Multiple flexible clamping components are installed on each placement plate (5). The flexible clamping components are used to fix the fuel injector needle valve body (4). The flexible clamping components include a flexible bidirectional sliding mechanism and an inner clamping plate (9) and an outer clamping plate (10) that are slidably installed on the placement plate (5). The flexible bidirectional sliding mechanism is used to make the inner clamping plate (9) and the outer clamping plate (10) slide in opposite directions on the placement plate (5) to achieve clamping of the fuel injector needle valve body (4). A drive assembly is installed on the mounting plate (2). The drive assembly is used to make the turntable (3) and the placement plate (5) rotate intermittently. The drive assembly includes a drive motor fixedly installed at the bottom of the mounting plate (2). The placement tray (5) is provided with a sliding groove (6), and a first slider (7) and a second slider (8) are slidably installed in the sliding groove (6). The first slider (7) is fixedly connected to the outer clamping plate (10), and the second slider (8) is fixedly connected to the inner clamping plate (9). The flexible bidirectional sliding mechanism consists of a threaded sleeve (11), a screw (12), a bevel gear (13), a first damping bearing (16), a connecting shaft (17), and a second damping bearing (18). The threaded sleeve (11) and the screw (12) are rotatably installed in the sliding groove (6). The threaded sleeve (11) is threadedly connected to the second slider (8), and the screw (12) is threadedly connected to the first slider (7). The connecting shaft (17) is installed at one end of the screw (12) near the midpoint of the placement disk (5) through the second damping bearing (18). The bevel gear (13) is fixedly installed on the connecting shaft (17), and the first damping bearing (16) is installed between the threaded sleeve (11) and the screw (12). A servo motor (14) is fixedly installed inside the placement plate (5), and a bevel gear (15) is fixedly connected to the output end of the servo motor (14). The bevel gear (15) meshes with multiple bevel gears (13). The damping coefficient of the second damping bearing (18) is greater than that of the first damping bearing (16). The screw (12) has a movable groove (19) at one end inside the threaded sleeve (11), and a movable rod (20) is slidably installed in the movable groove (19). A sliding sleeve (21) that slides with the screw (12) is fixedly installed on the movable rod (20), and a protrusion (22) is fixedly installed on the side wall of the sliding sleeve (21). A spiral groove (23) that mates with the protrusion (22) is opened on the inner wall of the threaded sleeve (11). A spiral groove (23) that mates with the protrusion (22) is fixedly installed at the end of the movable rod (20) away from the midpoint of the placement plate (5). A push rod (24) is dynamically engaged, and a fixed rack (25) is installed at one end of the push rod (24) outside the placement plate (5). A mounting base (26) is fixedly installed on the side wall of the placement plate (5), and a rotating shaft (27) is rotatably installed on the mounting base (26). A fixed gear (28) that meshes with the fixed rack (25) is fixedly installed at the bottom of the rotating shaft (27). An indicator disk (29) that is rotatably connected to the rotating shaft (27) is fixedly installed on the side wall of the placement plate (5), and a pointer (30) is fixedly installed at the top of the rotating shaft (27).

2. The common rail fuel injector nozzle projection laser inspection fixture according to claim 1, characterized in that, A guide rail (46) is fixedly installed on the side wall of the placement tray (5). The fixed rack (25) is rotatably connected to the push rod (24). A guide groove (48) is provided on the guide rail (46). A guide rod (47) that slides with the guide groove (48) is fixedly installed on the side wall of the fixed rack (25). A lighting lamp (45) is fixedly installed on the placement tray (5), and the lighting lamp (45) is concentric with the placement tray (5).

3. The common rail injector nozzle orifice projection laser inspection fixture according to claim 1, characterized in that, The bottom of the placement tray (5) is fixedly mounted with a fixed shaft that is rotatably connected to the turntable (3), and a rotating gear (31) is fixedly mounted at the bottom of the fixed shaft. The bottom of the turntable (3) is fixedly mounted with a support shaft (32) that is rotatably connected to the mounting plate (2), and a fixed gear ring (34) is fixedly mounted on the support shaft (32). The mounting plate (2) is rotatably mounted with a drive shaft (33), a transmission shaft (37), and a round shaft (39). The drive shaft (33) is fixedly connected to the output end of the drive motor. A chain drive structure (40) is installed between the drive shaft (37) and the round shaft (39). A drive gear (41) that meshes with the rotating gear (31) is installed on the round shaft (39). An incomplete gear one (35) that cooperates with the fixed gear ring (34) is fixedly installed on the drive shaft (33). An incomplete gear two (36) is also fixedly installed on the drive shaft (33). A transmission gear (38) that cooperates with the incomplete gear two (36) is fixedly installed on the drive shaft (37).

4. The common rail injector nozzle orifice projection laser inspection fixture according to claim 3, characterized in that, The sum of the included angle between the toothed portion of the incomplete gear one (35) and the included angle between the toothed portion of the incomplete gear two (36) is less than 360°, and the toothed portion of the incomplete gear one (35) and the toothed portion of the incomplete gear two (36) are staggered.

5. The common rail fuel injector nozzle projection laser inspection fixture according to claim 3, characterized in that, A fixed disk (43) is fixedly installed on the top of the circular shaft (39). An annular groove (42) is opened in the drive gear (41) to rotate with the fixed disk (43). A torsion spring (44) is installed between the annular groove (42) and the fixed disk (43). A rubber ring that is in contact with the annular groove (42) is fixedly installed on the side wall of the fixed disk (43).

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