A multi-workpiece positioning fixture of a three-dimensional coordinate measuring machine

Abstract

The utility model discloses a kind of multi-workpiece positioning fixtures of three-dimensional coordinate measuring machine, it is related to positioning technical field.The multi-workpiece positioning fixture of three-dimensional coordinate measuring machine, including workbench, the upper surface of workbench is provided with strip-shaped recess, the lateral side of recess is fixedly installed with positioning pin, the axis of positioning pin is perpendicular to the upper surface of workbench, for forming precision cooperation with the workpiece positioning hole of corresponding station, every described recess is slidably connected with clamping block, the side of clamping block towards workpiece is equipped with the positioning surface compatible with the outer wall of workpiece, workbench is as rigid bearing foundation, provides stable installation datum for all components, ensure that positioning pin, recess and the like structure keep accurate relative position in measurement process, guarantee overall structure stability, positioning pin and the precision cooperation of workpiece positioning hole combine the clamping block pressing and fixing guided by recess, can simultaneously realize unified datum positioning to multiple workpieces, greatly reduce auxiliary time, significantly improve batch measurement efficiency.

Description

Technical Field

[0001] This utility model relates to the field of positioning technology, and in particular to a multi-workpiece positioning fixture for a three-dimensional coordinate measuring machine. Background Technology

[0002] In the field of 3D coordinate measurement, traditional measurement and positioning methods have many problems that need to be solved. In batch workpiece measurement scenarios, routine operations often require each workpiece to be clamped and positioned individually. Each clamping requires recalibrating the benchmark, which not only consumes a lot of auxiliary time, but also makes it difficult to meet the needs of efficient batch inspection, resulting in low overall measurement efficiency and failing to meet the requirements of rapid quality verification in batch production. Due to the lack of a unified positioning benchmark system, different workpieces are prone to positioning deviations during clamping due to differences in operation methods and placement positions. This results in poor consistency of measurement data for the same batch of workpieces, frequent data fluctuations, which seriously affect the accurate judgment of product quality. In some cases, misjudgment may even lead to qualified workpieces being rejected or unqualified workpieces flowing into the next stage. Patent application CN202322332517.8 discloses a coordinate measuring machine (CMM) fixture. This solution addresses the problem that most traditional CMM fixtures lack a shifting mechanism, requiring repeated clamping and disassembly to change the workpiece position, resulting in low efficiency. However, this solution does not address the motion control of the measuring mechanism. Traditional drive and guide structures lack sufficient precision, easily leading to offset, shaking, or jamming during movement. This prevents the measuring components from accurately reaching the preset measurement position, affecting the accuracy of the measurement data and increasing the difficulty of subsequent data correction. Furthermore, traditional positioning structures have limited adaptability, typically requiring customized fixtures, which not only increases equipment investment costs but also necessitates additional time for further processing. The replacement and adjustment of fixtures reduce the overall utilization rate of equipment, especially in multi-variety, small-batch production scenarios, where this limitation is more pronounced. In addition, the overall structural rigidity of traditional solutions is insufficient, making them prone to slight deformation or displacement under external environmental vibration or measurement forces, leading to changes in workpiece positioning. The lack of a stable synchronization mechanism in data recording and storage makes data loss or recording chaos more likely, reducing the reliability and traceability of measurement results and posing significant challenges to quality traceability and problem troubleshooting. These issues make it difficult to meet the high standards and strict requirements of measurement work in the precision manufacturing field. These problems collectively restrict the application of 3D coordinate measurement technology in efficient, accurate, and universal measurement scenarios, and urgently require more optimized technical solutions to address them. Utility Model Content

[0003] The purpose of this utility model is to at least solve one of the technical problems existing in the prior art, and to provide a multi-workpiece positioning fixture for a three-dimensional coordinate measuring machine that can solve the problem of low positioning efficiency.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a multi-workpiece positioning fixture for a three-dimensional coordinate measuring machine, including a worktable. A strip-shaped groove is formed on the upper surface of the worktable. A positioning pin is fixedly installed on the side of each groove. The axis of the positioning pin is perpendicular to the upper surface of the worktable and is used to form a precision fit with the workpiece positioning hole of the corresponding station. A locking block is slidably connected in each groove. The side of the locking block facing the workpiece is provided with a positioning surface adapted to the outer wall of the workpiece. The locking block can be pressed and fixed by sliding along the groove to fit tightly against the outer wall of the workpiece.

[0005] Preferably, at least two grooves are provided at intervals along the length of the worktable, and each groove is parallel to the others.

[0006] Preferably, the positioning pins on the side of the groove are distributed at intervals along the width direction of the worktable, and the locating pin axes on the same side of the groove are coplanar.

[0007] Preferably, the positioning surface of the card block is an arc-shaped surface or a plane that matches the contour of the outer wall of the workpiece.

[0008] Preferably, the lower end of the card block that matches the groove is an inverted trapezoid.

[0009] Preferably, the worktable is provided with a frame around it, and two Y-axis supports are fixedly installed on the frame. The two Y-axis supports are provided with guide rails, and Y-axis sliders are slidably connected to the guide rails. Y-axis lead screws are rotatably installed on the Y-axis supports, and the Y-axis sliders are threaded onto the two Y-axis lead screws.

[0010] Preferably, an X-axis lead screw is rotatably mounted inside the Y-axis slider, and two guide rods are fixedly mounted inside the Y-axis slider. An X-axis slider is slidably sleeved on the guide rods, and the X-axis slider is threaded onto the X-axis lead screw.

[0011] Preferably, a guide rail is fixedly installed inside the X-axis slider, and a Z-axis slider is slidably connected to the guide rail. A Z-axis lead screw is rotatably installed on the X-axis slider, and the Z-axis slider is threaded onto the Z-axis lead screw. A rangefinder is fixedly installed on the Z-axis slider. Stepper motors are fixedly installed on the Y-axis support, Y-axis slider, and X-axis slider. The Y-axis lead screw, X-axis lead screw, and Z-axis lead screw are respectively fixedly installed on the output shaft of the corresponding stepper motor.

[0012] Compared with the prior art, the beneficial effects of this utility model are: (1) The multi-workpiece positioning fixture of the three-dimensional coordinate measuring machine has a worktable as a rigid load-bearing foundation, which provides a stable installation reference for all components, ensuring that the positioning pins, grooves and other structures maintain accurate relative positions during the measurement process, and ensuring the overall structural stability. The precise fit between the positioning pins and the workpiece positioning holes, combined with the groove-guided clamping block, can simultaneously achieve unified reference positioning for multiple workpieces, greatly reducing auxiliary time and significantly improving batch measurement efficiency. Moreover, the positioning consistency of each workpiece is strong, avoiding measurement deviations caused by single clamping differences. The guide rail on the Y-axis support and the Y-axis lead screw work together with the stepper motor to drive the Y-axis slider to move smoothly. The X-axis slider achieves precise guidance and sliding through the X-axis lead screw and guide rod. The Z-axis slider completes height adjustment with the help of the Z-axis lead screw and guide rail. The combination of the lead screw and guide rail of the three-stage motion system, driven by the stepper motor, ensures that the rangefinder can move accurately along the preset trajectory, reducing offset or shaking during the movement process, greatly improving the measurement position control accuracy, and providing reliable motion guarantee for the rangefinder to obtain accurate data. This 3D coordinate measuring machine features a multi-workpiece positioning fixture. The sliding fit design of the groove and the locking block allows the locking block to adapt to the outer wall contour of workpieces of different sizes. The layout of the positioning pins is compatible with workpieces with different positioning holes, eliminating the need for custom-made fixtures for specific workpieces. This significantly enhances the fixture's versatility and reduces equipment investment costs. The frame enhances the overall structural rigidity, and together with the stable support of the worktable, it reduces the impact of external vibrations on the positioning pins, locking blocks, and moving parts of each axis during measurement. The locking blocks firmly press against the workpiece to prevent workpiece displacement during measurement. The stable drive of the stepper motor ensures the consistency of movement of each axis. The real-time storage of measurement data in the data box further ensures the reliability and traceability of the measurement results, effectively reducing human error and improving the overall quality and efficiency of measurement work. Attached Figure Description

[0013] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of a multi-workpiece positioning fixture for a three-dimensional coordinate measuring machine according to the present invention; Figure 2 This is a cross-sectional schematic diagram of a multi-workpiece positioning fixture for a three-dimensional coordinate measuring machine according to the present invention; Figure 3 This is a schematic cross-sectional view of a multi-workpiece positioning fixture for a three-dimensional coordinate measuring machine according to this utility model; Figure 4 This is a schematic cross-sectional view of a multi-workpiece positioning fixture for a three-dimensional coordinate measuring machine according to this utility model.

[0014] Reference numerals: 1. Worktable; 2. Groove; 3. Locking block; 4. Positioning pin; 5. Workpiece; 6. Frame; 7. Y-axis support; 8. Guide rail; 9. Y-axis lead screw; 10. Y-axis slider; 11. X-axis lead screw; 12. Guide rod; 13. Rangefinder; 14. Z-axis slider; 15. Z-axis lead screw; 16. Stepper motor; 17. X-axis slider; 18. Data box. Detailed Implementation

[0015] This section will describe in detail the specific embodiments of the present utility model. The preferred embodiments of the present utility model are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present utility model, but they should not be construed as limiting the scope of protection of the present utility model.

[0016] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0017] In the description of this utility model, terms such as greater than, less than, and exceeding are understood to exclude the stated number, while terms such as above, below, and within are understood to include the stated number. The use of terms like "first" and "second" is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the quantity or sequence of the indicated technical features.

[0018] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0019] Please see Figure 1-4 This utility model provides a technical solution: a multi-workpiece positioning fixture for a three-dimensional coordinate measuring machine, including a worktable 1, on which a groove 2 is provided, and two positioning pins 4 are fixedly installed on the side of each groove 2. The axis of the positioning pins 4 is perpendicular to the upper surface of the worktable 1 and is used to form a precise fit with the positioning hole of the workpiece 5 at the corresponding station. A locking block 3 is slidably connected in each groove 2. The side of the locking block 3 facing the workpiece 5 is provided with a positioning surface adapted to the outer wall of the workpiece. The locking block 3 can be pressed and fixed by sliding along the groove 2 to fit tightly against the outer wall of the workpiece 5. The worktable 1 provides a load-bearing foundation for the overall structure. The grooves 2 on its surface provide a sliding guide track for the locking blocks 3. Two positioning pins 4 on the side of each groove 2 are vertically fixed to the worktable 1. Through precise matching with the positioning holes of the workpiece 5, the translation and rotational freedom of the workpiece 5 in the horizontal direction are restricted to achieve initial reference positioning. The locking blocks 3 slidably connected in the groove 2 have their positioning surfaces facing the workpiece 5 adapted to the outer wall of the workpiece. By sliding along the groove 2 until they are in close contact with the outer wall of the workpiece 5, the workpiece 5 is firmly fixed by the pressure force to ensure that the workpiece 5 does not move during the measurement process. The workbench 1 is surrounded by a frame 6. Two Y-axis supports 7 are fixedly installed on the frame 6. Guide rails 8 are provided on the two Y-axis supports 7. Y-axis sliders 10 are slidably connected to the guide rails 8. A Y-axis lead screw 9 is rotatably mounted on the Y-axis support 7, and a Y-axis slider 10 is threaded onto the two Y-axis lead screws 9. The frame 6 around the worktable 1 provides mounting support for the Y-axis motion assembly. The two Y-axis supports 7 fixed on the frame 6 are the mounting carriers for the Y-axis guide rail 8 and the Y-axis lead screw 9. The guide rail 8 guides and limits the sliding of the Y-axis slider 10, ensuring that the Y-axis slider 10 moves smoothly along a straight line. The Y-axis lead screw 9, which is rotatably mounted on the Y-axis support 7, is threadedly connected to the Y-axis slider 10. When the Y-axis lead screw 9 rotates, it drives the Y-axis slider 10 to move along the guide rail 8 in the Y-axis direction through thread transmission, thereby realizing the position adjustment of the measuring mechanism in the Y-axis. An X-axis lead screw 11 is rotatably installed inside the Y-axis slider 10. Two guide rods 12 are fixedly installed inside the Y-axis slider 10. An X-axis slider 17 is slidably sleeved on the guide rods 12. The X-axis slider 17 is threaded onto the X-axis lead screw 11. The Y-axis slider 10 serves as the mounting base for the X-axis motion assembly. Inside, the X-axis lead screw 11 is rotatably mounted and threadedly connected to the X-axis slider 17. Meanwhile, two guide rods 12 are fixedly mounted and pass through the X-axis slider 17 to guide the sliding of the X-axis slider 17 and prevent deviation or shaking during movement. When the X-axis lead screw 11 rotates, it drives the X-axis slider 17 to move along the guide rods 12 in the X-axis direction through threaded transmission, thereby realizing the position adjustment of the measuring mechanism in the X-axis. Another guide rail 8 is fixedly installed inside the X-axis slider 17. The Z-axis slider 14 is slidably connected to the guide rail 8. The Z-axis lead screw 15 is rotatably installed on the X-axis slider 17. The Z-axis slider 14 is threaded onto the Z-axis lead screw 15. The guide rail 8 fixed inside the X-axis slider 17 provides sliding guidance for the Z-axis slider 14. The Z-axis lead screw 15 rotatably mounted on the X-axis slider 17 is threadedly connected to the Z-axis slider 14. When the Z-axis lead screw 15 rotates, it drives the Z-axis slider 14 to move along the guide rail 8 in the Z-axis direction, adjusting the height position of the rangefinder 13. The rangefinder 13 fixed on the Z-axis slider 14 is used to measure the dimensions of the workpiece 5. The data box 18 on the X-axis slider 17 is responsible for receiving and storing the measurement data transmitted by the rangefinder 13. A rangefinder 13 is fixedly mounted on the Z-axis slider 14, and a data box 18 is fixedly mounted on the X-axis slider 17. Stepper motors 16 are fixedly mounted on the Y-axis support 7, Y-axis slider 10, and X-axis slider 17. Y-axis lead screw 9, X-axis lead screw 11, and Z-axis lead screw 15 are fixedly mounted on the output shaft of stepper motor 16. The stepper motors 16 fixed on the Y-axis support 7, Y-axis slider 10, and X-axis slider 17 provide rotational power for the Y-axis lead screw 9, X-axis lead screw 11, and Z-axis lead screw 15, respectively. When the stepper motor 16 is working, its output shaft drives the corresponding lead screw to rotate. Through the threaded transmission between the lead screw and the slider, the rotational motion of the motor is converted into the linear motion of the slider, thereby realizing precise position adjustment in each axis direction. Working principle: First, the positioning hole of workpiece 5 is inserted into the positioning pin 4 on the worktable 1 to complete the benchmark positioning. The locking block 3 in the groove 2 is pushed to fit tightly against the outer wall of workpiece 5 and pressed and fixed. Then, the stepper motors 16 of each axis are started. The Y-axis lead screw 9 drives the Y-axis slider 10 to move along the guide rail 8 on the Y-axis. The X-axis lead screw 11 drives the X-axis slider 17 to move along the guide rod 12 on the X-axis. The Z-axis lead screw 15 drives the Z-axis slider 14 to move along the guide rail 8 on the Z-axis. The rangefinder 13 is adjusted to the position to be measured on workpiece 5. The rangefinder 13 measures workpiece 5 and the data is transmitted to the data box 18 for storage. After the measurement is completed, the lead screws are reversed to reset the mechanism. The locking block 3 is released and workpiece 5 is removed, completing one measurement cycle. Structural Description: Worktable 1: It is set as a rigid flat plate structure and serves as the basic load-bearing component of the fixture. The upper surface has high machining accuracy and good flatness. Its function is to provide an installation reference for positioning components such as groove 2, positioning pin 4 and frame 6, to support workpiece 5 and all auxiliary structures, to ensure the stability of the overall structure during the measurement process, and to maintain the relative positional accuracy between each component. Groove 2: Set on the upper surface of the worktable 1, it has a strip-shaped through groove structure along the length of the worktable. At least one groove is opened and they can be distributed in parallel at intervals. Its function is to provide a sliding guide channel for the clamping block 3, restrict the movement trajectory of the clamping block 3 only along the length of the groove, ensure the straightness of the movement path of the clamping block 3, and ensure that the clamping position of the workpiece 5 is accurate and controllable. The locking block 3 is a block structure that slides with the groove 2 through a gap. It has a positioning surface (such as a plane or arc surface) that is adapted to the outer wall contour of the workpiece 5 on the side facing the workpiece 5. Its function is to slide along the groove 2 and fit closely to the outer wall of the workpiece 5, and use the pressing force to fix the workpiece 5 next to the positioning pin 4, so as to prevent the workpiece 5 from shifting during measurement and enhance the positioning stability. Positioning pin 4: It is set as a cylindrical or prismatic structure, vertically fixed on the upper surface of the worktable 1 and located next to the groove 2. Each set of workstations corresponds to two positioning pins 4. Its function is to restrict the translation and rotation freedom of the workpiece 5 in the horizontal direction by precisely cooperating with the preset positioning hole of the workpiece 5, providing a unified positioning reference for the workpiece 5, and ensuring the accuracy of the initial position of the workpiece 5. Workpiece 5: Set as the part to be measured, it needs to be machined with positioning holes that match the positioning pin 4 and placed at the positioning station on the worktable 1. Its function is to serve as the measurement object. Through the synergistic action of the positioning pin 4 and the clamping block 3, it achieves stable positioning and ensures that the three-dimensional coordinate measuring machine can accurately detect its dimensional parameters.

[0020] Frame 6: It is set as a rectangular frame structure and is fixedly installed on the four edges of the worktable 1, forming a rigid connection with the worktable 1. Its function is to provide an installation carrier for the Y-axis support 7, improve the installation stability of the Y-axis motion components, and ensure that the motion reference in the Y-axis direction remains relatively fixed with the positioning reference of the worktable 1.

[0021] Y-axis support 7: It is set as two symmetrically distributed block-shaped support structures, which are fixedly installed on both sides of the frame 6. Its function is to serve as the mounting base for the Y-axis guide rail 8 and the Y-axis lead screw 9, provide support and guiding reference for the movement of the Y-axis slider 10, and ensure the straightness and stability of the movement in the Y-axis direction. Guide rail 8: It is set as a linear guide rail structure and is installed in parallel on the opposite inner surfaces of the two Y-axis supports 7. At the same time, a guide rail of the same type is also installed in the X-axis slider 17. Its function is to provide sliding guidance for the Y-axis slider 10 and the Z-axis slider 14, restrict the movement direction of the slider to only along the guide rail axis, reduce the frictional resistance when the slider moves, and ensure the smoothness and straightness of the movement. Y-axis lead screw 9: It is set as a precision ball screw structure, with both ends rotatably mounted on the Y-axis support 7, forming a threaded connection with the Y-axis slider 10. Its function is to convert the rotational motion of the stepper motor 16 into the linear motion of the Y-axis slider 10, and drive the Y-axis slider 10 to move along the guide rail 8 in the Y-axis direction through threaded transmission, so as to realize the Y-axis position adjustment of the measuring mechanism. Y-axis slider 10: It is set as a box-type slider structure, which is slidably connected to the guide rail 8 and threadedly engaged with the Y-axis lead screw 9. Its function is to serve as the mounting carrier for the X-axis lead screw 11 and guide rod 12, drive the X-axis motion assembly to move along the Y-axis direction, realize the position adjustment of the measuring mechanism in the Y-axis direction, and expand the measurement range. X-axis lead screw 11: It is set as a precision ball screw structure and is rotatably installed inside the Y-axis slider 10. It forms a threaded connection with the X-axis slider 17. Its function is to convert the rotational motion of the corresponding stepper motor 16 into the linear motion of the X-axis slider 17, drive the X-axis slider 17 to move along the guide rod 12 in the X-axis direction, and realize the X-axis position adjustment of the measuring mechanism. Guide rod 12: It is set as two parallel cylindrical optical axes, which are fixedly installed inside the Y-axis slider 10 and pass through the X-axis slider 17. Its function is to provide guidance and support for the sliding of the X-axis slider 17, prevent the X-axis slider 17 from deflecting or shaking when it moves, and ensure the straightness and stability of the movement in the X-axis direction. Rangefinder 13: Set as a three-dimensional coordinate measurement sensor, fixedly installed on the Z-axis slider 14, with the measuring end facing the workpiece 5 on the worktable 1. Its function is to act as a measurement execution component, to detect parameters such as the size and form and position tolerance of the workpiece 5 by transmitting and receiving measurement signals, and to transmit the measurement data to the data box 18. Z-axis slider 14: It is configured as a slider structure, which is slidably connected to the guide rail 8 inside the X-axis slider 17 and threadedly engaged with the Z-axis lead screw 15. Its function is to carry the rangefinder 13 and move it along the Z-axis direction. By adjusting the position, the rangefinder 13 can maintain a suitable measurement distance from the workpiece 5 to meet the measurement needs of workpieces of different heights.

[0022] Z-axis lead screw 15: It is set as a precision ball screw structure and is rotatably mounted on the X-axis slider 17. It forms a threaded connection with the Z-axis slider 14. Its function is to convert the rotational motion of the corresponding stepper motor 16 into the linear motion of the Z-axis slider 14, drive the Z-axis slider 14 to move along the guide rail 8 in the Z-axis direction, and realize the height position adjustment of the rangefinder 13. Stepper motor 16: It is fixedly installed on the Y-axis support 7, Y-axis slider 10 and X-axis slider 17 respectively. The output shaft is fixedly connected to the corresponding Y-axis lead screw 9, X-axis lead screw 11 and Z-axis lead screw 15. Its function is to serve as a power source, drive the lead screw to rotate by outputting a precise rotation angle, realize the precise position control of each axis slider, and ensure the motion accuracy of the measuring mechanism. X-axis slider 17: It is set as a box-type slider structure, which is slidably connected to the guide rod 12 and threadedly engaged with the X-axis lead screw 11. The guide rail 8 and Z-axis lead screw 15 are installed inside. Its function is to support the Z-axis motion component and the data box 18. While moving with the Y-axis slider 10, it can move independently along the X-axis direction, driving the rangefinder 13 to realize the position adjustment in the X-axis direction. Data box 18: It is set as a data processing and storage device and is fixedly installed on the X-axis slider 17. Its function is to receive the measurement data transmitted by the rangefinder 13, perform temporary storage and preliminary processing, provide a basis for subsequent data analysis, and ensure the integrity and traceability of the measurement data.

[0023] This multi-workpiece positioning fixture of the 3D coordinate measuring machine brings many significant benefits through the synergistic effect of its components. The worktable 1, as a rigid load-bearing foundation, provides a stable installation reference for all components, ensuring that structures such as the positioning pin 4 and groove 2 maintain precise relative positions during measurement, thus guaranteeing the overall structural stability. The precise fit between the positioning pin 4 and the positioning hole of the workpiece 5, combined with the clamping block 3 guided by the groove 2, allows for simultaneous unified reference positioning of multiple workpieces 5, significantly reducing auxiliary time, greatly improving batch measurement efficiency, and ensuring strong positioning consistency for each workpiece 5, avoiding the need for single clamping. To mitigate measurement deviations caused by differences, the guide rail 8 on the Y-axis support 7, in conjunction with the Y-axis lead screw 9, and the stepper motor 16 drive the Y-axis slider 10 to move smoothly. The X-axis slider 17 achieves precise guiding sliding through the X-axis lead screw 11 and the guide rod 12. The Z-axis slider 14 achieves height adjustment with the help of the Z-axis lead screw 15 and the guide rail 8. The combination of lead screw and guide rail in the three-stage motion system, driven by the stepper motor 16, ensures that the rangefinder 13 can move precisely along the preset trajectory, reducing offset or shaking during the movement process, significantly improving the accuracy of measurement position control, and providing reliable motion assurance for the rangefinder 13 to obtain accurate data. The sliding fit design of the groove 2 and the clamping block 3 allows the clamping block 3 to adapt to the outer wall contour of workpieces 5 of different sizes. The layout of the positioning pin 4 is compatible with workpieces 5 with different positioning holes. There is no need to customize special fixtures for specific workpieces 5, which significantly enhances the versatility of the fixture and reduces the equipment investment cost. The frame 6 enhances the overall structural rigidity and, together with the stable support of the worktable 1, reduces the impact of external vibration on the positioning pin 4, the clamping block 3 and the moving parts of each axis during the measurement process. The clamping block 3 firmly presses against the workpiece 5 to prevent the workpiece 5 from shifting during the measurement. The stable drive of the stepper motor 16 ensures the consistency of the movement of each axis. The real-time storage of measurement data in the data box 18 further ensures the reliability and traceability of the measurement results, effectively reduces human operation errors, and improves the overall quality and efficiency of the measurement work.

[0024] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A multi-workpiece positioning fixture for a three-dimensional coordinate measuring machine, comprising a worktable (1), characterized in that: The workbench (1) has a strip groove (2) on its upper surface, and a positioning pin (4) is fixedly installed on the side of each groove (2). The axis of the positioning pin (4) is perpendicular to the upper surface of the workbench (1) and is used to form a precise fit with the positioning hole of the workpiece (5) of the corresponding work station. Each groove (2) is slidably connected with a locking block (3). The locking block (3) has a positioning surface adapted to the outer wall of the workpiece on the side facing the workpiece (5). The card block (3) can be pressed and fixed to the outer wall of the workpiece (5) by sliding along the groove (2).

2. The multi-workpiece positioning fixture for a three-dimensional coordinate measuring machine according to claim 1, characterized in that: The groove (2) is provided at least two at intervals along the length of the workbench (1), and each groove (2) is parallel to the other.

3. The multi-workpiece positioning fixture for a three-dimensional coordinate measuring machine according to claim 2, characterized in that: The positioning pins (4) on the side of the groove (2) are distributed at intervals along the width direction of the worktable (1), and the axial axes of the positioning pins (4) on the side of the same groove (2) are coplanar.

4. The multi-workpiece positioning fixture for a three-dimensional coordinate measuring machine according to claim 3, characterized in that: The positioning surface of the card block (3) is an arc-shaped surface or a plane that matches the outer wall contour of the workpiece (5).

5. A multi-workpiece positioning fixture for a three-dimensional coordinate measuring machine according to claim 4, characterized in that: The lower end of the matching block (3) of the groove (2) is an inverted trapezoid.

6. A multi-workpiece positioning fixture for a three-dimensional coordinate measuring machine according to claim 5, characterized in that: The workbench (1) is surrounded by a frame (6), and two Y-axis supports (7) are fixedly installed on the frame (6). The two Y-axis supports (7) are provided with guide rails (8), and Y-axis sliders (10) are slidably connected on the guide rails (8). Y-axis lead screws (9) are rotatably installed on the Y-axis supports (7), and the Y-axis sliders (10) are threaded onto the two Y-axis lead screws (9).

7. A multi-workpiece positioning fixture for a three-dimensional coordinate measuring machine according to claim 6, characterized in that: An X-axis lead screw (11) is rotatably installed inside the Y-axis slider (10). Two guide rods (12) are fixedly installed inside the Y-axis slider (10). An X-axis slider (17) is slidably sleeved on the guide rods (12). The X-axis slider (17) is threaded onto the X-axis lead screw (11).

8. A multi-workpiece positioning fixture for a three-dimensional coordinate measuring machine according to claim 7, characterized in that: The X-axis slider (17) is fixedly installed with a guide rail (8), and the Z-axis slider (14) is slidably connected on the guide rail (8). The Z-axis lead screw (15) is rotatably installed on the X-axis slider (17). The Z-axis slider (14) is threaded onto the Z-axis lead screw (15). The rangefinder (13) is fixedly installed on the Z-axis slider (14). The Y-axis support (7), Y-axis slider (10), and X-axis slider (17) are all fixedly installed with stepper motors (16). The Y-axis lead screw (9), X-axis lead screw (11), and Z-axis lead screw (15) are respectively fixedly installed on the output shaft of the corresponding stepper motor (16).

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