A floating three-point micrometer for sheet flatness detection

Abstract

The utility model relates to a kind of floating three-point micrometer for sheet part flatness detection in micro field, including reference frame and floating measurement unit, wherein reference frame is rigid tripod, and floating measurement unit is set at the upper surface triangle of rigid tripod. Floating measurement unit includes linear bearing, measuring column, measuring head, digital dial gauge and constant force spring, measuring column is slidably connected at the inner cavity center of linear bearing, constant force spring is sleeved on the outer surface upper portion of measuring column, and the top end and bottom end of constant force spring are respectively attached with the lower surface of measuring head and the upper surface of linear bearing, and measuring head is set at the top end of measuring column;Digital dial gauge is set directly below linear bearing, and the detection end of digital dial gauge is installed with measuring rod, the top end of measuring rod is attached with the bottom end of measuring column, and constant force spring provides constant measuring force for measuring column, so that the pressure is always consistent when the measuring head of three floating measurement units is contacted with sheet part surface.

Description

Technical Field

[0001] This utility model relates to the field of micrometry, specifically to a floating three-point micrometer for detecting the flatness of thin plates. Background Technology

[0002] Thin sheet metal parts are widely used in industries such as electronics, automobiles, and aerospace. Their flatness accuracy is directly related to the fit, structural stability, and overall performance of subsequent product assembly. Therefore, the flatness inspection of thin sheet metal parts is an indispensable quality control link in the industrial production process. The relevant testing equipment mainly belongs to the field of precision mechanical measurement technology. It needs to be adapted to the testing needs of thin sheet metal parts of different materials and thicknesses, and in particular, it needs to take into account the measurement stability of easily deformable thin sheet metal parts.

[0003] Existing micrometers for the flatness of thin plates have significant shortcomings in terms of measurement force control and ease of operation. On the one hand, most devices lack a dedicated structure to provide a constant measurement force, or the elastic force of the elastic components used is prone to change with compression, making it difficult to maintain consistent pressure when the probe contacts the surface of the thin plate. This can lead to irreversible damage to easily deformable thin plates due to excessive pressure, and fluctuations in the measurement force can cause different stress states for each measurement, thus introducing reading deviations and affecting the accuracy of the measurement results. On the other hand, existing testing methods often require multi-step calibration and debugging of the equipment before measurement, and after measurement, additional calculation tools or complex formulas are needed to derive the flatness error. This not only increases the operational complexity for operators but also prolongs the overall time required for a single test, making it difficult to meet the actual needs of efficient testing in industrial production. Utility Model Content

[0004] The purpose of this invention is to solve the above-mentioned defects and provide a floating three-point micrometer for flatness detection of thin plates. A constant force spring is sleeved on the upper part of the outer surface of the measuring column, and its top and bottom ends are respectively in contact with the lower surface of the probe and the upper surface of the linear bearing. This ensures that the pressure of the probes of the three floating measuring units is always consistent when they contact the surface of the thin plate, thus solving the technical problem that the pressure is difficult to keep consistent when the probes contact the surface of the thin plate due to the prior art.

[0005] The objective of this utility model is achieved through the following means:

[0006] A floating three-point micrometer for flatness inspection of thin plates includes a reference frame and a floating measuring unit. The reference frame is a rigid tripod. The floating measuring unit is located on the upper triangular part of the rigid tripod. The floating measuring unit includes a linear bearing, a measuring column, a probe, a digital dial indicator, and a constant force spring. The measuring column is slidably connected to the center of the inner cavity of the linear bearing. The constant force spring is sleeved on the upper part of the outer surface of the measuring column. The probe is located at the top of the measuring column. The top and bottom ends of the constant force spring are respectively in contact with the lower surface of the probe and the upper surface of the linear bearing. The digital dial indicator is located directly below the linear bearing. A measuring rod is installed on the detection end of the digital dial indicator. The top end of the measuring rod is in contact with the bottom end of the measuring column.

[0007] First, ensure that the reference frame and its component rigid tripod are placed stably without tilting or shaking. Then, check the three floating measuring units set at the triangles on the upper surface of the rigid tripod: confirm that the measuring column can slide smoothly at the center of the inner cavity of the linear bearing without jamming; confirm that the constant force spring is sleeved on the upper part of the outer surface of the measuring column, and that the top of the constant force spring is in close contact with the lower surface of the probe and the bottom end is in close contact with the upper surface of the linear bearing; confirm that the digital micrometer is fixed directly below the linear bearing, and that the top of the probe of the digital micrometer is in close contact with the bottom end of the measuring column. At the same time, start the digital micrometer and ensure that it is in the normal reading state.

[0008] The thin sheet to be tested is slowly and steadily placed on the probes of the three floating measurement units, ensuring that the lower surface of the sheet can contact the top of the three probes, and avoiding tilting the sheet.

[0009] The weight of the thin plate acts on the probe, causing it to exert downward pressure. The probe drives the measuring column connected to it to slide downward along the center of the inner cavity of the linear bearing. During the sliding process of the measuring column, the constant force spring sleeved on the upper part of its outer surface is compressed. Through its own characteristics, the constant force spring always applies a constant reaction force to the probe, ensuring that the probe and the surface of the thin plate maintain a gentle and stable contact. At the same time, the bottom of the downward sliding measuring column generates a downward thrust on the measuring rod of the digital micrometer. The measuring rod transmits the thrust signal to the digital micrometer, which converts the signal into a corresponding height reading and displays it in real time.

[0010] Record the height readings displayed by the digital dial gauges in the three floating measurement units respectively, calculate the difference between the three readings, and the result is the flatness error of the thin plate to be tested.

[0011] Furthermore, the upper surface of the rigid tripod is provided with a sliding groove, and a sliding plate is slidably connected to the inner cavity of the sliding groove. Both the sliding groove and the sliding plate are T-shaped. A support seat is connected to the top of the sliding plate, and the two sides of the upper surface of the support seat are connected to the two sides of the linear bearing.

[0012] The combination of the T-shaped slide and the slide plate, while maintaining the rigidity of the rigid tripod structure, breaks the limitation of the fixed relative positions of the original measuring components. It can be adapted to the inspection of thin plates of different sizes, eliminating the need for customizing multiple sets of reference frames and reducing equipment investment costs. The wear-resistant protective layer on the inner wall of the slide can extend the service life of the structure and reduce the frequency of maintenance. The fixed operation after adjustment ensures that the position of each component is stable during measurement, without affecting the detection accuracy. At the same time, it improves the compatibility of a single machine with workpieces of different sizes, from small PCB boards to large silicon steel sheets, and improves the utilization rate of the equipment.

[0013] Furthermore, a fixing plate is installed at the rear end of the upper surface of the support base, a stud is threadedly connected to the upper surface of the fixing plate, an anti-slip pressure plate is installed at the bottom end of the stud, and anti-slip grooves are evenly formed on the lower surface of the anti-slip pressure plate.

[0014] The direct contact between the anti-slip pressure plate and the upper surface of the rigid tripod upgrades the fixing reference of the support from the cooperation of the sliding plate and the sliding groove to the rigid connection with the body of the rigid tripod. Combined with the interlocking effect of the anti-slip groove, it greatly improves the anti-displacement ability of the support after adjustment, effectively resists the offset of the support caused by equipment vibration or external force interference during the measurement process, and ensures the detection accuracy.

[0015] Furthermore, the measuring column has an internal threaded interface at its top center, and a connecting screw is threaded into the inner cavity of the internal threaded interface. The top of the connecting screw is connected to the lower surface of the measuring head.

[0016] The threaded connection between the internal thread interface and the connecting screw enables quick disassembly and replacement of the probe, breaking through the limitations of the original integrated and fixed probe. It can flexibly adapt the probe according to the surface characteristics of the workpiece, avoiding measurement errors caused by workpiece damage or unstable contact. The tightness of the threaded connection ensures the positional accuracy of the probe after installation, without affecting the core function of the measuring column in transmitting displacement. It simplifies the probe replacement operation, improves detection efficiency and the adaptability of the equipment to different workpieces.

[0017] Furthermore, a circular connecting groove is formed at the center of the upper surface of the support base, and a circular connecting plate is added to the inner cavity of the circular connecting groove. The upper surface of the circular connecting plate is connected to the lower surface of the digital dial indicator.

[0018] The combination of the circular connecting groove and the circular connecting plate provides a precise initial installation reference for the digital micrometer, avoiding reading errors caused by installation misalignment and improving detection accuracy. As a transition component, the circular connecting plate can reduce the installation stress of the digital micrometer when directly mounted on the support, protect the precision internal structure of the digital micrometer, and extend its service life. At the same time, it lays the foundation for the rapid disassembly and assembly of the digital micrometer, facilitating the calibration, maintenance, and replacement of the equipment.

[0019] Furthermore, a side insertion hole is provided at the center of both sides of the circular connecting plate, and a side insertion rod is inserted into the inner cavity of the side insertion hole. The end of the side insertion rod is inserted into and connected to the inner wall of the circular connecting groove on both sides. A compression spring is added between the end of the side insertion rod and the inner wall of the circular connecting groove. An outer connecting handle is slidably connected to both sides of the center of the upper surface of the support base, and the lower surface of the outer connecting handle is connected to the corresponding side insertion rod.

[0020] This structure creates a quick-release positioning and installation mechanism for the digital dial indicator, overcoming the limitations of traditional bolt-fastened installation which is cumbersome and time-consuming. It significantly shortens the time required for each installation and disassembly, improving calibration and maintenance efficiency. The elastic force of the compression spring ensures that the side insertion rod is in close contact with the inner wall of the circular connecting groove, guaranteeing the stability of the circular connecting plate. At the same time, it avoids the axial displacement of the measuring rod caused by uneven bolt tightening, ensuring consistent coaxiality in each installation and reducing calibration workload. The external connecting handle design eliminates the need for additional tools during installation and disassembly, making operation convenient and further enhancing the ease of use of the equipment.

[0021] The beneficial effects of this utility model are as follows: The constant force spring is sleeved on the upper part of the outer surface of the measuring column, and its top and bottom ends are respectively in contact with the lower surface of the probe and the upper surface of the linear bearing. This structural arrangement can provide a constant measuring force for the measuring column, so that the pressure of the probes of the three floating measuring units when in contact with the surface of the thin plate is always consistent and gentle. This avoids damaging the thin plate due to excessive pressure and eliminates the reading error caused by fluctuation of measuring force, making the measurement reading more accurate and reliable. It is especially suitable for easily deformable thin plates.

[0022] In actual testing, the thin plate is simply placed on the probes of the three floating measuring units, and the relative height difference of each measuring point can be directly read by the three digital dial indicators. The subsequent calculation of the flatness error of the thin plate is simple and does not require complicated operation steps, which greatly improves the convenience and efficiency of the flatness test of the thin plate. Attached Figure Description

[0023] Figure 1 This is a three-dimensional structural diagram of a floating three-point micrometer for flatness detection of thin plates according to the present invention.

[0024] Figure 2 This is a schematic diagram of the floating measurement unit structure of a floating three-point micrometer for flatness detection of thin plates according to the present invention.

[0025] Figure 3 This is a schematic diagram of the measuring column and probe separation structure of a floating three-point micrometer for flatness detection of thin plates according to the present invention.

[0026] Figure 4 This is a partial cross-sectional view of the support structure of a floating three-point micrometer for flatness detection of thin plates according to the present invention.

[0027] Figure 5 This invention relates to a floating three-point micrometer for flatness inspection of thin sheet metal parts. Figure 4 Enlarged structural diagram at point A in the middle;

[0028] Figure 6 This is a bottom view of the anti-slip pressure plate and its connection structure of a floating three-point micrometer for flatness detection of thin plates according to the present invention.

[0029] In the diagram, 1. Reference frame; 2. Floating measuring unit; 3. Rigid tripod; 4. Slide groove; 5. Linear bearing; 6. Measuring column; 7. Probe; 8. Digital dial indicator; 9. Measuring rod; 10. Constant force spring; 11. Connecting screw; 12. Internal thread interface; 13. Support base; 14. Circular connecting groove; 15. Circular connecting plate; 16. Side insertion hole; 17. Side insertion rod; 18. Compression spring; 19. External connecting handle; 20. Slide plate; 21. Fixing plate; 22. Stud; 23. Anti-slip pressure plate. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0031] In this embodiment, refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 A floating three-point micrometer for flatness inspection of thin plates includes a reference frame 1 and a floating measuring unit 2. The reference frame 1 is a rigid tripod 3. The floating measuring unit 2 is located on the upper triangular part of the rigid tripod 3. The floating measuring unit 2 includes a linear bearing 5, a measuring column 6, a probe 7, a digital micrometer 8, and a constant force spring 10. The measuring column 6 is slidably connected to the center of the inner cavity of the linear bearing 5. The constant force spring 10 is sleeved on the upper part of the outer surface of the measuring column 6. The probe 7 is located at the top of the measuring column 6. The top and bottom ends of the constant force spring 10 are respectively in contact with the lower surface of the probe 7 and the upper surface of the linear bearing 5. The digital micrometer 8 is located directly below the linear bearing 5. A measuring rod 9 is installed on the detection end of the digital micrometer 8. The top end of the measuring rod 9 is in contact with the bottom end of the measuring column 6.

[0032] First, ensure that the reference frame 1 and its component rigid tripod 3 are placed stably without tilting or shaking. Then, check the three floating measuring units 2 set at the triangular positions on the upper surface of the rigid tripod 3: confirm that the measuring column 6 can slide smoothly at the center of the inner cavity of the linear bearing 5 without jamming; confirm that the constant force spring 10 is sleeved on the upper part of the outer surface of the measuring column 6, and that the top of the constant force spring 10 is in close contact with the lower surface of the probe 7 and the bottom is in close contact with the upper surface of the linear bearing 5; confirm that the digital micrometer 8 is fixed directly below the linear bearing 5, and that the top of the probe 9 at the detection end of the digital micrometer 8 is in close contact with the bottom of the measuring column 6. At the same time, start the digital micrometer 8 and ensure that it is in the normal reading state.

[0033] The thin sheet to be tested is slowly and steadily placed on the probes 7 of the three floating measurement units 2, ensuring that the lower surface of the thin sheet can contact the top of the three probes 7, and avoiding the thin sheet being placed at an angle.

[0034] The weight of the thin plate acts on the probe 7, causing it to exert downward pressure. The probe 7 drives the measuring column 6 connected to it to slide downward along the center of the inner cavity of the linear bearing 5. During the sliding process of the measuring column 6, the constant force spring 10 sleeved on the upper part of its outer surface is compressed. Through its own characteristics, the constant force spring 10 always applies a constant reaction force to the probe 7, ensuring that the probe 7 maintains a gentle and stable contact with the surface of the thin plate. At the same time, the bottom end of the downward sliding measuring column 6 generates a downward thrust on the measuring rod 9 of the digital micrometer 8. The measuring rod 9 transmits the thrust signal to the digital micrometer 8, which converts the signal into a corresponding height reading and displays it in real time.

[0035] Record the height readings displayed by the digital micrometer 8 in the three floating measurement units 2 respectively, calculate the difference between the three readings, and the result is the flatness error of the thin plate to be tested;

[0036] The constant force spring 10 in the floating measuring unit 2 is sleeved on the upper part of the outer surface of the measuring column 6, and its two ends are respectively attached to the lower surface of the probe 7 and the upper surface of the linear bearing 5. When the measuring column 6 slides along the linear bearing 5, the constant force spring 10 can continuously provide a constant force to the probe 7, ensuring that the contact force between the three probes 7 and the surface of the thin plate is consistent and gentle. This avoids damaging the easily deformable thin plate due to excessive contact force and eliminates the problem of unstable reading of the digital micrometer 8 due to fluctuations in measuring force, making the reading more accurate and reliable.

[0037] The measuring column 6 is slidably connected to the center of the inner cavity of the linear bearing 5. The linear bearing 5 can limit the sliding direction of the measuring column 6, ensure its coaxiality and stability during the sliding process, and reduce the interference of sliding deviation on the measurement results. A digital micrometer 8 is used as the reading component. The digital micrometer 8 is attached to the bottom of the measuring column 6 through the measuring rod 9, which can accurately capture the minute displacement changes of the measuring column 6. It has high resolution, making the overall measurement accuracy far superior to the traditional feeler gauge measurement method, and the repeatability of multiple measurements is good.

[0038] The inspection process does not require complicated equipment debugging or operation procedures. Simply place the thin plate to be inspected stably on the three probes 7, and the height readings of the three measuring points can be directly read by the digital dial indicator 8. The flatness error can then be obtained by calculating the difference between the three readings. Compared with the cumbersome operation and long inspection cycle of the coordinate measuring machine, this device has higher inspection efficiency and is more suitable for the rapid inspection needs of the workshop.

[0039] The core structure of the device consists of a reference frame 1 and three floating measurement units 2. The components of the floating measurement units 2 are all conventional industrial parts, eliminating the need for customized and expensive core components. Compared with costly coordinate measuring machines, this device has extremely low manufacturing costs and is easy to promote and apply in various production workshops.

[0040] like Figure 1 and Figure 4 As shown, a groove 4 is provided on the upper surface of the rigid tripod 3. A slide plate 20 is slidably connected to the inner cavity of the groove 4. Both the groove 4 and the slide plate 20 are T-shaped. A support seat 13 is connected to the top of the slide plate 20. The two sides of the upper surface of the support seat 13 are connected to the two sides of the linear bearing 5.

[0041] The slide plate 20, pre-fixed to the top of the support base 13, is slid into the inner cavity of the slide groove 4. The T-shaped structure acts as a limiting element to prevent the slide plate 20 from detaching from the slide groove 4 during sliding. Then, the upper surface of the support base 13 is fixedly connected to both sides of the linear bearing 5, ensuring no relative looseness between the linear bearing 5 and the support base 13. Based on the dimensions of the thin sheet to be inspected, the support base 13 is pushed to move the slide plate 20 along the length of the slide groove 4. The spacing between the linear bearing 5 and subsequent related measuring components is adjusted. Once the spacing matches the workpiece size, the slide plate 20 is fixed to the slide groove 4 using locking components. The internal structure prevents displacement of the slide plate 20 during measurement. The cooperation between the T-shaped slide 4 and the slide plate 20, while maintaining the rigidity of the rigid tripod 3 structure, breaks the limitation of the original fixed relative position of the measuring components. It can be adapted to the detection of thin plates of different sizes, eliminating the need to customize multiple sets of reference frames 1 and reducing equipment investment costs. The wear-resistant protective layer on the inner wall of the slide 4 can extend the service life of the structure and reduce the frequency of maintenance. The adjusted fixed operation ensures that the position of each component is stable during measurement, without affecting the detection accuracy. At the same time, it improves the compatibility of a single device with workpieces of different sizes, from small PCB boards to large silicon steel sheets, and improves equipment utilization.

[0042] like Figure 6 As shown, a fixing plate 21 is installed on the rear end of the upper surface of the support base 13. A stud 22 is threadedly connected to the upper surface of the fixing plate 21. An anti-slip pressure plate 23 is installed at the bottom end of the stud 22. Anti-slip grooves are evenly provided on the lower surface of the anti-slip pressure plate 23.

[0043] Rotate the stud 22 clockwise to drive the anti-slip pressure plate 23 to slowly descend via the threaded transmission. During this process, observe the contact state between the anti-slip pressure plate 23 and the upper surface of the rigid tripod 3 until the lower surface of the anti-slip pressure plate 23 is completely in contact with the upper surface of the rigid tripod 3. Continue to fine-tune the stud 22 to make the anti-slip groove on the lower surface of the anti-slip pressure plate 23 tightly engage with the upper surface of the rigid tripod 3. Utilize the self-locking characteristic of the thread to maintain the contact pressure and complete the fixation of the support base 13. The direct contact between the anti-slip pressure plate 23 and the upper surface of the rigid tripod 3 upgrades the fixing reference of the support base 13 from the cooperation between the slide plate 20 and the slide groove 4 to a rigid connection with the body of the rigid tripod 3. Combined with the engagement effect of the anti-slip groove, it greatly improves the anti-displacement capability of the support base 13 after adjustment, effectively resisting the offset of the support base 13 caused by equipment vibration or external force interference during the measurement process, and ensuring the detection accuracy.

[0044] like Figure 3 As shown, the top center of the measuring column 6 is provided with an internal thread interface 12, and the inner cavity of the internal thread interface 12 is threaded with a connecting screw 11. The top of the connecting screw 11 is connected to the lower surface of the measuring head 7.

[0045] Based on the surface characteristics of the thin sheet to be inspected, a suitable probe 7 is selected. The lower surface of the probe 7 is pre-fixed to the top of the connecting screw 11. Align the bottom of the connecting screw 11 with the internal thread interface 12, and rotate the probe 7 clockwise to make the connecting screw 11 and the internal thread interface 12 tightly connected, thus completing the installation of the probe 7. When replacing the probe 7, rotate the original probe 7 counterclockwise, remove it, and then install the new probe 7 according to the above steps. The threaded connection between the internal thread interface 12 and the connecting screw 11 enables quick disassembly and replacement of the probe 7, breaking through the limitation of the original integrated fixed probe 7. The probe 7 can be flexibly adapted according to the surface characteristics of the workpiece, avoiding measurement errors caused by workpiece damage, such as pressure damage to a soft PCB board or unstable contact. The tightness of the threaded connection ensures the positional accuracy of the probe 7 after installation and does not affect the core function of the measuring column 6 in transmitting displacement. It simplifies the probe 7 replacement operation, improves inspection efficiency, and enhances the adaptability of the equipment to different workpieces.

[0046] like Figure 4 As shown, a circular connecting groove 14 is provided at the center of the upper surface of the support base 13, and a circular connecting plate 15 is added to the inner cavity of the circular connecting groove 14. The upper surface of the circular connecting plate 15 is connected to the lower surface of the digital micrometer 8.

[0047] A circular connecting groove 14 is machined at the center of the upper surface of the support base 13 according to a preset size, ensuring that the inner wall of the circular connecting groove 14 is smooth and that its size matches the outer diameter of the circular connecting plate 15. The lower surface of the digital micrometer 8 is fixedly connected to the upper surface of the circular connecting plate 15, ensuring that the axes of the digital micrometer 8 and the measuring rod 9 coincide with the central axis of the circular connecting plate 15. The circular connecting plate 15, with the digital micrometer 8 already connected, is placed into the inner cavity of the circular connecting groove 14. The cooperation between the circular connecting groove 14 and the circular connecting plate 15 achieves the initial positioning of the digital micrometer 8, ensuring that its measuring rod 9 is accurately aligned with the measuring component below. The cooperation between the circular connecting groove 14 and the circular connecting plate 15 provides a precise initial installation reference for the digital micrometer 8, avoiding reading errors caused by installation offset and improving detection accuracy. As a transition component, the circular connecting plate 15 can reduce the installation stress of the digital micrometer 8 directly mounted on the support base 13, protect the internal precision structure of the digital micrometer 8, and extend its service life. At the same time, it lays the foundation for the rapid disassembly and assembly of the digital micrometer 8, facilitating the calibration, maintenance, and replacement of the equipment.

[0048] like Figure 5 As shown, a side insertion hole 16 is provided at the center of both sides of the circular connecting plate 15. A side insertion rod 17 is inserted and connected to the inner cavity of the side insertion hole 16. The end of the side insertion rod 17 is inserted and connected to the inner wall of the circular connecting groove 14 on both sides. A compression spring 18 is added between the end of the side insertion rod 17 and the inner wall of the circular connecting groove 14. An outer connecting handle 19 is slidably connected to both sides of the center of the upper surface of the support base 13. The lower surface of the outer connecting handle 19 is connected to the corresponding side insertion rod 17.

[0049] When disassembling the digital micrometer 8, slide the outer connecting handle 19 outward to retract the side insertion rod 17 into the side insertion hole 16. The compression spring 18 is compressed, and the end of the side insertion rod 17 disengages from the inner wall of the circular connecting groove 14, allowing the circular connecting plate 15 and the digital micrometer 8 to be removed. During installation, after inserting the circular connecting plate 15, release the outer connecting handle 19. The compression spring 18 extends and pushes the side insertion rod 17 back to its original position and fix it in place. This structure creates a quick-release positioning and installation mechanism for the digital micrometer 8, overcoming the limitations of traditional bolt-tightening installation and disassembly, which is cumbersome and time-consuming. It significantly shortens the time for each disassembly and assembly, and improves calibration and maintenance efficiency. The elastic force of the compression spring 18 ensures that the side insertion rod 17 is in close contact with the inner wall of the circular connecting groove 14, ensuring the stable fixation of the circular connecting plate 15. At the same time, it avoids the axial displacement of the measuring rod 9 caused by uneven bolt tightening, ensuring consistent coaxiality in each installation and reducing calibration workload. The design of the outer connecting handle 19 makes disassembly and assembly without additional tools, making operation convenient and further improving the ease of use of the equipment.

[0050] The following is the usage process of a floating three-point micrometer for flatness inspection of thin plates in this embodiment: According to the size of the thin plate to be inspected, slide plate 20, which is pre-fixed to the top of support base 13, is aligned with the inner cavity of slide groove 4 on the upper surface of rigid tripod 3 and slid in. The T-shaped design of slide groove 4 and slide plate 20 prevents them from separating. Support base 13 is pushed to drive slide plate 20 to slide along the length of slide groove 4. The spacing of linear bearing 5 and associated measuring components is adjusted. After the spacing is appropriate, the stud 22 of the fixing plate 21 at the rear end of the upper surface of support base 13 is rotated clockwise. The anti-slip pressure plate 23 is driven to slowly descend through the threaded transmission until the lower surface of anti-slip pressure plate 23 is completely in contact with the upper surface of rigid tripod 3. The stud 22 is then finely adjusted to make the anti-slip groove on the lower surface of anti-slip pressure plate 23 tightly engage with the upper surface of rigid tripod 3, thus completing the fixing of support base 13.

[0051] Select the appropriate probe 7 according to the surface characteristics of the thin plate to be tested, align the bottom end of the connecting screw 11 fixed on the lower surface of the probe 7 with the internal thread interface 12 at the center of the top of the measuring column 6, and rotate the probe 7 clockwise to make the connecting screw 11 and the internal thread interface 12 tightly connected, thus completing the installation of the probe 7.

[0052] Place the circular connecting plate 15, which is fixedly connected to the lower surface of the digital micrometer 8, into the inner cavity of the circular connecting groove 14 at the center of the upper surface of the support base 13. Slide the outer connecting handles 19 on both sides of the center of the upper surface of the support base 13 outward, causing the side insertion rod 17 to retract into the side insertion holes 16 at the center of both sides of the circular connecting plate 15. The compression spring 18 is compressed. After the circular connecting plate 15 is placed in place, release the outer connecting handles 19. The compression spring 18 extends and pushes the side insertion rod 17 to reset, so that the end of the side insertion rod 17 is inserted and connected to both sides of the inner wall of the circular connecting groove 14, thus completing the installation of the digital micrometer 8.

[0053] Ensure that the reference frame 1 and the rigid tripod 3 are placed stably without tilting or shaking. Check the three floating measuring units 2 set at the triangle on the upper surface of the rigid tripod 3. Confirm that the measuring column 6 can slide smoothly without jamming at the center of the inner cavity of the linear bearing 5. Confirm that the constant force spring 10 is sleeved on the upper part of the outer surface of the measuring column 6 and that the top end is in close contact with the lower surface of the probe 7 and the bottom end is in close contact with the upper surface of the linear bearing 5. Confirm that the top end of the measuring rod 9 of the digital micrometer 8 is in close contact with the bottom end of the measuring column 6. Start the digital micrometer 8 and ensure that it is in the normal reading state.

[0054] The thin sheet to be tested is slowly and steadily placed on the probes 7 of the three floating measuring units 2, ensuring that the lower surface of the thin sheet can contact the top of the three probes 7 without tilting.

[0055] The weight of the thin plate acts on the probe 7, causing it to exert downward pressure. The probe 7 drives the measuring column 6 to slide downward along the center of the inner cavity of the linear bearing 5. During the sliding process, the measuring column 6 compresses the constant force spring 10, which applies a constant reaction force to the probe 7. At the same time, the bottom of the sliding measuring column 6 exerts a downward thrust on the measuring rod 9. The measuring rod 9 transmits the thrust signal to the digital dial indicator 8, which converts the signal into a height reading and displays it in real time.

[0056] Record the height readings displayed by the digital micrometer 8 in the three floating measurement units 2 respectively, calculate the difference between the three readings, and obtain the flatness error of the thin plate to be tested;

[0057] If it is necessary to replace the thin plate to be tested or to perform equipment maintenance, slide the outer connecting handle 19 outward to disengage the side insert rod 17 from the inner wall of the circular connecting groove 14, remove the circular connecting plate 15 and the digital dial indicator 8, rotate the probe 7 counterclockwise to disengage the connecting screw 11 from the internal thread interface 12 to replace the probe 7, rotate the stud 22 counterclockwise to disengage the anti-slip pressure plate 23 from the upper surface of the rigid tripod 3, and then push the support seat 13 to adjust the position of the slide plate 20 in the slide groove 4.

[0058] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A floating three-point micrometer for flatness inspection of thin plates, comprising a reference frame and a floating measuring unit, characterized in that: The reference frame is a rigid tripod. The floating measuring unit is set on the upper triangular part of the rigid tripod. The floating measuring unit includes a linear bearing, a measuring column, a probe, a digital dial indicator, and a constant force spring. The measuring column is slidably connected to the center of the inner cavity of the linear bearing. The constant force spring is sleeved on the upper part of the outer surface of the measuring column. The probe is set at the top of the measuring column. The top and bottom ends of the constant force spring are respectively in contact with the lower surface of the probe and the upper surface of the linear bearing. The digital dial indicator is set directly below the linear bearing. A measuring rod is installed on the detection end of the digital dial indicator. The top end of the measuring rod is in contact with the bottom end of the measuring column.

2. The floating three-point micrometer for flatness inspection of thin plates according to claim 1, characterized in that: The upper surface of the rigid triangular frame is provided with a sliding groove, and a sliding plate is slidably connected to the inner cavity of the sliding groove. Both the sliding groove and the sliding plate are T-shaped. A support seat is connected to the top of the sliding plate, and the two sides of the upper surface of the support seat are connected to the two sides of the linear bearing.

3. The floating three-point micrometer for flatness inspection of thin plates according to claim 2, characterized in that: A fixing plate is installed at the rear end of the upper surface of the support base. A stud is threadedly connected to the upper surface of the fixing plate. An anti-slip pressure plate is installed at the bottom end of the stud. Anti-slip grooves are evenly formed on the lower surface of the anti-slip pressure plate.

4. The floating three-point micrometer for flatness inspection of thin plates according to claim 1, characterized in that: The measuring column has an internal threaded interface at its top center, and a connecting screw is threaded into the inner cavity of the internal threaded interface. The top of the connecting screw is connected to the lower surface of the measuring head.

5. A floating three-point micrometer for flatness inspection of thin plates according to claim 2, characterized in that: The upper surface of the support base has a circular connecting groove at its center, and a circular connecting plate is added to the inner cavity of the circular connecting groove. The upper surface of the circular connecting plate is connected to the lower surface of the digital dial indicator.

6. The floating three-point micrometer for flatness inspection of thin plates according to claim 5, characterized in that: The circular connecting plate has side insertion holes at the center of both sides. Side insertion rods are inserted into the inner cavity of the side insertion holes. The ends of the side insertion rods are inserted into the inner walls of the circular connecting grooves on both sides. A compression spring is added between the ends of the side insertion rods and the inner walls of the circular connecting grooves. External connecting handles are slidably connected to the center of the upper surface of the support base on both sides. The lower surface of the external connecting handles is connected to the corresponding side insertion rods.

Images