A device and method for measuring the coefficient of friction

Abstract

The present application belongs to the technical field of micro drill friction coefficient measurement, and particularly relates to a friction coefficient measurement device and a measurement method. The friction coefficient measurement device comprises: a power structure, including a rotating table and a force applying member located above the rotating table, the rotating table being used to drive a target object to rotate and having a rotating surface arranged upward and used to fix the target object; a balance structure, including a support column adjacent to the rotating table, a cantilever beam rotationally connected to the support column, and a clamping head arranged at one end of the cantilever beam and used to clamp a micro drill, the other end of the cantilever beam being arranged in a suspended manner, and a plane determined by a rotation track of the cantilever beam being perpendicular to the rotating surface; and a sensing and analyzing structure connected to the cantilever beam and connected at a position between the clamping head and the support column and used to measure a deformation amount of the cantilever beam. The present application can simulate a real machining condition of the micro drill to accurately measure the friction coefficient of the micro drill.

Description

Technical Field

[0001] This invention belongs to the field of micro-drill friction coefficient measurement technology, and particularly relates to a friction coefficient measuring device and method. Background Technology

[0002] Currently, the line width and spacing of printed circuit boards (PCBs) are constantly decreasing, and high-hardness, high-filler ratio fillers, modified glass fibers, and modified resins are widely used in PCB manufacturing, all of which bring huge challenges to the drilling and machining of PCBs.

[0003] Micro-drilling of printed circuit boards (PCBs) refers to the process of creating tiny holes on PCBs using micro-drilling tools. Micro-drilling tools, or micro-drills for short, are small-sized drill bits used for drilling holes in PCBs. Drilling is essential in PCB manufacturing because holes are used to mount electronic components and connect circuits. Micro-drilling tools are typically made of cemented carbide or cemented carbide welded to high-speed steel, resulting in a high coefficient of friction. Therefore, micro-coated drill bits with low friction, high hardness, and high wear resistance are highly sought after and favored.

[0004] The surface friction coefficient of micro-coated drill bits is an important indicator of their surface properties; however, accurately measuring the friction coefficient of micro-coated drill bits during actual drilling has become a challenge in the industry. Currently, the main (indirect) method for characterizing the friction coefficient of micro-coated drill bits is to deposit a coating on a planar (or curved) substrate using a micro-drill bit coating process, and this method is relatively easy to implement. However, in this method, the contact pattern between the thin film layer on the planar (or curved) substrate and the friction object differs somewhat from the contact pattern between the micro-coated drill bit and the workpiece during actual drilling.

[0005] Therefore, this method cannot accurately determine the friction coefficient of micro-coated drill bits in actual PCB drilling. Summary of the Invention

[0006] The purpose of this application is to provide a friction coefficient measuring device, which aims to solve the problem of how to improve the simulation effect of the real working process of micro-drills and improve the accuracy of micro-drill friction coefficient measurement.

[0007] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0008] In a first aspect, a friction coefficient measuring device is provided for measuring the friction coefficient of a micro-drill during the machining process of a target object, the friction coefficient measuring device comprising:

[0009] The power structure includes a rotating platform and a force-applying component located above the rotating platform. The rotating platform is used to drive the target object to rotate and has an upward-facing rotating surface for fixing the target object.

[0010] The balancing structure includes a support column adjacent to the rotary table, a cantilever beam rotatably connected to the support column, and a chuck head disposed at one end of the cantilever beam for holding the micro-drill; the other end of the cantilever beam is suspended in the air, and the plane determined by the rotation trajectory of the cantilever beam is perpendicular to the rotation plane; and

[0011] The sensing analysis structure is connected to the cantilever beam and the connection position is located between the clamping head and the support column. The sensing analysis structure is used to acquire and analyze the deformation of the cantilever beam and obtain the friction coefficient of the micro-drill based on the deformation.

[0012] The force-applying component is connected to the clamping head and drives the micro-drill to abut against the target object.

[0013] In some embodiments, the clamping head has a positioning hole, one end of the micro drill is inserted into the positioning hole, and the other end of the micro drill is exposed from the positioning hole.

[0014] In some embodiments, the positioning hole has an adjustment hole that communicates with the external space in its hole wall, and the balancing structure further includes a positioning member, one end of which is inserted into the positioning hole and abuts against the micro drill.

[0015] In some embodiments, the balancing structure further includes a positioning insert disposed within the positioning hole, the positioning insert having a receiving hole, the insertion end of the micro drill being located in the receiving hole, and the positioning member abutting against the positioning insert.

[0016] In some embodiments, the receiving hole includes a first hole segment adapted to the micro drill and a second hole segment communicating with the first hole segment. The diameter of the second hole segment is larger than the diameter of the first hole segment or the outer diameter of the micro drill. The micro drill is partially inserted into the first hole segment, and a filler is provided between the hole wall of the second hole segment and the micro drill. The micro drill is exposed in the second hole segment.

[0017] In some embodiments, the balancing structure further includes a suspended plate connected to the support column and a balancing adjustment member with one end slidably connected to the suspended plate in a vertical direction, the other end of the balancing adjustment member being used to restrict the rotation of the cantilever beam.

[0018] In some embodiments, the suspended plate has a threaded hole, the balance adjustment member has an external thread adapted to the threaded hole, and the balance adjustment member is screwed into the threaded hole.

[0019] In some embodiments, the balancing structure further includes a gravity hammer connected to the cantilever beam, the support column being located between the gravity hammer and the clamping head, and the connection position between the gravity hammer and the cantilever beam being adjustable along the length direction of the cantilever beam.

[0020] In some embodiments, the sensing analysis structure includes a strain gauge, a signal acquisition unit, and a signal processor. The strain gauge is connected to the cantilever beam and senses the deformation of the cantilever beam. The signal acquisition unit acquires the deformation signal of the strain gauge and transmits the deformation signal to the signal processor.

[0021] Secondly, a measurement method is provided, which includes the following steps:

[0022] Prepare the friction coefficient measuring device as described above;

[0023] Fix the target object to the rotating surface;

[0024] The micro-drill is connected to the chuck, and the lower end of the micro-drill extends toward the target object;

[0025] Rotate the cantilever beam so that the lower end of the micro-drill contacts the upper surface of the target object;

[0026] The force-applying component is connected to the clamping head to drive the micro-drill downward to abut against the target object;

[0027] The rotary table drives the target object to rotate so that the inductive analysis structure can measure the friction coefficient of the micro-drill.

[0028] The beneficial effects of this application are as follows: the friction coefficient measuring device includes a power structure, a balance structure, and an induction analysis structure. The power structure includes a rotary table and a force-applying component. The balance structure includes a support column, a cantilever beam, and a clamping head. The rotary table can fix the printed circuit board and drive it to rotate in the horizontal plane. The force-applying component is connected to the clamping head, and under its own gravity, the micro-drill located on the clamping head abuts against the printed circuit board. This can simulate the real processing of the micro-drill, improve the simulation of the real working conditions of the micro-drill, and accurately measure the friction coefficient of the micro-drill. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or exemplary technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1This is a schematic diagram illustrating the structural principle of the friction coefficient measuring device provided in the embodiments of this application;

[0031] Figure 2 yes Figure 1 A schematic diagram of the assembly of the clamping head and the cantilever beam;

[0032] Figure 3 yes Figure 2 A schematic diagram of the assembly of the clamping head and the positioning insert;

[0033] Figure 4 This is a flowchart of a measurement method provided for another embodiment of this application.

[0034] The following are the labeling elements in the figure:

[0035] 100. Friction coefficient measuring device; 101. Printed circuit board; 102. Micro drill; 200. Induction analysis structure; 201. Signal processor; 202. Signal acquisition device; 203. Strain gauge; 300. Power structure; 301. Rotary table; 3011. Rotation surface; 304. Force application component; 303. Weight; 302. Tray; 400. Balancing structure; 401. Clamping head; 402. Cantilever beam; 403. Gravity hammer; 404. Support column; 405. Balancing adjustment component; 406. Suspension plate; 4011. Positioning hole; 409. Positioning component; 407. Positioning insert; 408. Filler; 4071. First hole section; 4072. Second hole section; 4073. Accommodating hole; 4074. Abutment position; 4012. Adjustment hole; Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the scope of this application.

[0037] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly or indirectly attached to that other component. When a component is referred to as "connected to" another component, it can be directly or indirectly connected to that other component. The terms "upper," "lower," "left," "right," etc., indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, and are for ease of description only, not to 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 application. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. "A plurality" means two or more, unless otherwise explicitly defined.

[0038] Please see Figures 1 to 3 This application provides a friction coefficient measuring device 100 for measuring the friction coefficient of a micro-drill 102 during the machining of a target object. The target object is a printed circuit board 101. In other embodiments, the target object can be other structural components requiring drilling; this is not limited and can be selected according to actual conditions. In this embodiment, the micro-drill is a micro-coated drill bit. In other embodiments, the micro-drill can be other drill bits; this is not limited and can be selected according to actual conditions.

[0039] The friction coefficient measuring device 100 includes a power structure 300, a balancing structure 400, and a sensing and analysis structure 200. The power structure 300 includes a rotating platform 301 and a force-applying member 304 located above the rotating platform 301. The rotating platform 301 is used to drive the target object to rotate and has an upward-facing rotating surface 3011 for fixing the target object. It is understood that the rotating platform 301 can be fixed by bearings and driven by a servo motor. The servo motor and the rotating platform 301 can be connected by a gear mechanism or a belt mechanism; this is mature existing technology and will not be elaborated here. The rotating surface 3011 is located on the upper surface of the rotating platform 301 and is horizontally positioned.

[0040] Please see Figures 1 to 3The balancing structure 400 includes a support column 404 adjacent to the rotary table 301, a cantilever beam 402 rotatably connected to the support column 404, and a clamping head 401 disposed at one end of the cantilever beam 402 for clamping the micro-drill 102. The other end of the cantilever beam 402 is suspended to balance the micro-drill 102 on the clamping head 401, so that the lower end of the micro-drill 102 just contacts the surface of the printed circuit board 101 to be drilled, and the micro-drill 102 does not apply pressure to the printed circuit board 101. It can be understood that the cantilever beam 402 can rotate in a vertical plane about its junction with the support column 404, that is, the plane determined by the rotation trajectory of the cantilever beam 402 is perpendicular to the rotation surface 3011.

[0041] Please see Figures 1 to 3 The sensing analysis structure 200 is connected to the cantilever beam 402 and is located between the clamping head 401 and the support column 404. The sensing analysis structure 200 is used to acquire and analyze the deformation of the cantilever beam 401 and obtain the friction coefficient of the micro drill 102 based on the deformation.

[0042] The force-applying component 304 is connected to the clamping head 401 and, under its own weight, drives the micro-drill 102 to abut against the target object. This causes the micro-drill 102 to apply a drilling force F to the printed circuit board 101. The direction of the drilling force F is perpendicular to the surface of the printed circuit board 101, and the value of the drilling force F is related to the weight of the force-applying component 304. By measuring the weight of the force-applying component 304, the value of the drilling force F can be obtained. The printed circuit board 101 applies a frictional force f to the micro-drill 102. Under the action of the frictional force f, the cantilever beam 402 will deform. By measuring the amount of deformation of the cantilever beam 402, the frictional force f experienced by the micro-drill 102 can be obtained. Then, according to the formula μ = f / F, where μ is the coefficient of friction of the micro-drill 102, the coefficient of friction of the micro-drill 102 can be measured and obtained. It can be understood that μ is the kinetic friction coefficient of the micro-drill 102.

[0043] The friction coefficient measuring device 100 provided in this embodiment includes a power structure 300, a balance structure 400, and a sensing analysis structure 200. The power structure 300 includes a rotary table 301 and a force-applying component 304. The balance structure 400 includes a support column 404, a cantilever beam 402, and a clamping head 401. The rotary table 301 can fix the printed circuit board 101 and drive the printed circuit board 101 to rotate in the horizontal plane. The force-applying component 304 is connected to the clamping head 401, and under its own gravity, the micro-drill 102 located on the clamping head 401 abuts against the printed circuit board 101, thereby simulating the real processing situation of the micro-drill 102 to accurately measure the friction coefficient of the micro-drill 102.

[0044] Please see Figures 1 to 3It is understandable that the micro drill 102 is positioned at the rotation center of the printed circuit board 101, thereby preventing the micro drill 102 from shaking and enabling the micro drill 102 to accurately transmit the frictional force to the cantilever beam 402.

[0045] In some embodiments, the clamping head 401 has a positioning hole 4011, one end of the micro drill 102 is inserted into the positioning hole 4011, and the other end of the micro drill 102 is exposed from the positioning hole 4011.

[0046] Optionally, the upper end of the micro drill 102 is connected to the clamping head 401 through the positioning hole 4011, and the lower end of the micro drill 102 is exposed through the positioning hole 4011 to drill the printed circuit board 101. The length of the exposed part of the micro drill 102 is 1~2mm, thereby ensuring the rigidity of the micro drill 102 during the measurement of the coefficient of friction.

[0047] Please see Figures 1 to 3 In some embodiments, the positioning hole 4011 has an adjustment hole 4012 communicating with the external space in its hole wall. The balancing structure 400 also includes a positioning element 409, one end of which is inserted into the positioning hole 4011 and abuts against the micro drill 102. It is understood that the positioning element 409 allows the micro drill 102 to be stably connected to the clamping head 401. Optionally, the hole wall of the positioning hole 4011 and the positioning element 409 can be threaded together, and two positioning holes 4011 are arranged at intervals along the axial direction of the micro drill 102, each containing a positioning element 409, to enhance the stability of the connection between the micro drill 102 and the clamping head 401.

[0048] Please see Figures 1 to 3 Optionally, the micro-drill 102 is arranged vertically along its axis, and there is a gap between the upper end face of the micro-end and the bottom of the positioning hole 4011. By moving the micro-drill 102 vertically, the length of the exposed end of the micro-drill 102 can be adjusted, thereby adjusting the relative position between the micro-drill 102 and the printed circuit board 101 to accommodate micro-drills 102 of different lengths.

[0049] Please see Figures 1 to 3 In some embodiments, the balancing structure 400 further includes a positioning insert 407 disposed in the positioning hole 4011. The positioning insert 407 has a receiving hole 4073. The insertion end of the micro drill 102 is located in the receiving hole 4073, and the positioning member 409 abuts against the positioning insert 407.

[0050] Optionally, the positioning inlay 407 is made of photosensitive resin. The photosensitive resin material can be printed into the positioning inlay 407 using 3D printing technology. Then, the upper end of the micro-end is inserted into the receiving hole 4073, thereby realizing the connection between the positioning inlay 407 and the micro-drill 102.

[0051] Please see Figures 1 to 3 Photosensitive resin is a special type of material whose molecular structure contains chemical groups that are sensitive to ultraviolet or visible light. These chemical groups react upon exposure to light, causing changes in the material's physical or chemical properties. Photosensitive resin is widely used in the fabrication of microstructures, microelectronics, MEMS (microelectromechanical systems), optical components, and 3D printing. In 3D printing, photosensitive resin can be rapidly molded using photopolymerization technology. By using computer-aided design software to import 3D model data into a 3D printer, the printer can then irradiate the surface of the photosensitive resin with light of a specific intensity and wavelength, causing it to solidify. The advantages of photosensitive resin include high precision, fast molding speed, low production cost, and wide applicability.

[0052] Please see Figures 1 to 3 It is understandable that the positioning insert 407 is wrapped around the insertion end of the micro-drill 102, and the photosensitive resin is an organic material with good toughness and elasticity, which can offset and buffer the unexpected vibrations of the micro-drill 102 during processing, improve the reliability of the micro-drill 102, and prevent the micro-drill 102 from breaking.

[0053] Please see Figures 1 to 3 In some embodiments, the receiving hole 4073 includes a first hole segment 4071 adapted to the micro drill 102 and a second hole segment 4072 communicating with the first hole segment 4071. The diameter of the second hole segment 4072 is larger than the diameter of the first hole segment 4071 or the outer diameter of the micro drill 102. The micro drill 102 is partially inserted into the first hole segment 4071, and a filler 408 is provided between the hole wall of the second hole segment 4072 and the micro drill 102. The micro drill 102 is exposed in the second hole segment 4072.

[0054] Please see Figures 1 to 3It is understood that the cross-sectional shape of the first hole segment 4071, the second hole segment 4072, and the micro drill 102 are all circular. The diameter of the first hole segment 4071 is equal to or slightly smaller than the diameter of the corresponding position of the micro drill 102, so that the micro drill 102 is tightly inserted into the first hole segment 4071. The diameter of the second hole segment 4072 is larger than the diameter of the first hole segment 4071, and the second hole segment 4072 is located below the first hole segment 4071. This facilitates the insertion of the micro drill 102 into the first hole segment 4071 and improves the convenience of connecting the micro drill 102 with the positioning insert 407. Then, the filler 408 is poured into the gap between the hole wall of the second hole segment 4072 and the micro drill 102, so that the second hole segment 4072 and the micro drill 102 are connected without gaps, which can improve the reliability and stability of the micro drill 102 during the measurement process. The filler 408 is a mixture of metallographic adhesive powder and metallographic curing agent to form a filling resin. After the micro drill 102 is inserted into the first hole section 4071, the filling resin is poured into the second hole section 4072. After the filling resin is cured, the micro drill 102 can be measured.

[0055] Please see Figures 1 to 3 It is understandable that positioning inserts 407 can be mass-produced. Since the first hole segment 4071 has appropriate elasticity, micro-drills 102 of different diameters can be inserted into the first hole segment 4071, and then filling resin is poured into the second hole segment 4072, thereby enabling rapid measurement of micro-drills 102 of different diameters and improving measurement efficiency.

[0056] Understandably, the filler 408 has good toughness and elasticity, which can also offset and buffer the unexpected vibrations of the micro-drill 102, thereby improving the reliability and stability of the micro-drill 102 during the measurement process.

[0057] Please see Figures 1 to 3 Optionally, the positioning insert 407 is cylindrical, and the central axis of the positioning insert 407 coincides with the central axis of the micro drill 102. The abutment position 4074 of the positioning insert 407 for the positioning member 409 to abut is set in a plane, so that there is sufficient contact position between the positioning member 409 and the positioning insert 407.

[0058] Please see Figures 1 to 3 Optionally, the positioning insert 407 has a clearance hole at the position corresponding to the positioning member 409. One end of the positioning member 409 is inserted into the clearance hole and directly abuts against the micro drill 102. The positioning member 409 is a bolt made of metal material. By abutting hard material against hard material, the reliability and stability of the micro drill 102 in the measurement process can be improved, and the influence of elastic deformation of the positioning insert 407 on the measurement can be avoided, thereby improving the accuracy of the friction coefficient measurement result.

[0059] In some embodiments, the balancing structure 400 further includes a suspended plate 406 connected to the support column 404 and a balancing adjustment member 405 slidably connected to the suspended plate 406 at one end in the vertical direction, the other end of the balancing adjustment member 405 being used to restrict the rotation of the cantilever beam 402.

[0060] Please see Figures 1 to 3 It is understandable that the lower end of the balance adjustment component 405 is located directly above the cantilever beam 402, thereby limiting the rotation of the cantilever beam 402. By adjusting the length of the lower end of the balance adjustment component 405, the rotation range of the cantilever beam 402 can be adjusted, so that the friction coefficient measuring device 100 can be adapted to micro-drills 102 of different weights.

[0061] Please see Figures 1 to 3 In some embodiments, the suspended plate 406 has a threaded hole, and the balance adjustment member 405 has an external thread adapted to the threaded hole. The balance adjustment member 405 is screwed into the threaded hole. It can be understood that the balance adjustment member 405 is a bolt. By rotating the bolt, the length of the lower end of the balance adjustment member 405 can be adjusted, thereby adjusting the rotation range of the cantilever beam 402.

[0062] Please see Figures 1 to 3 In some embodiments, the balancing structure 400 further includes a gravity hammer 403 connected to the cantilever beam 402, the support column 404 is located between the gravity hammer 403 and the clamping head 401, and the connection position between the gravity hammer 403 and the cantilever beam 402 is adjustable along the length direction of the cantilever beam 402.

[0063] It is understandable that the gravity hammer 403 has a sliding hole, and the gravity hammer 403 is connected to the cantilever beam 402 through the sliding hole. Thus, the gravity hammer 403 with the sliding hole can adjust its connection position with the cantilever beam 402, thereby adapting to micro drills 102 of different gravity magnitudes, sizes, and materials.

[0064] Please see Figures 1 to 3In some embodiments, the sensing and analysis structure 200 includes a strain gauge 203, a signal acquisition unit 202, and a signal processor 201. The strain gauge 203 is connected to the cantilever beam 402 and senses the deformation of the cantilever beam 402. The signal acquisition unit 202 acquires the deformation signal of the strain gauge 203 and transmits the deformation signal to the signal processor 201. The strain gauge 203 is a sensor used to measure the strain of an object. They typically consist of tiny resistive elements attached to the surface of the object to be measured. When the object is subjected to force and undergoes strain, the resistance value of the strain gauge 203 also changes slightly. By measuring the change in resistance value, the deformation of the cantilever beam 402 can be calculated. Furthermore, by analyzing the deformation of the cantilever beam 402, the frictional force experienced by the micro-drill 102 can be calculated. The deformation signal is the resistance change signal of the strain gauge 203. The signal acquisition unit 202 is used to acquire the resistance change of the strain gauge 203, and then the signal processor 201 analyzes the resistance change of the strain gauge 203 to calculate the friction force on the micro drill 102.

[0065] Please see Figures 1 to 3 In some embodiments, the force-applying component 304 includes a tray 302 connected to the clamping head 401 and a weight 303 disposed within the tray 302. It is understood that the weight of the tray 302 and the weight 303 can be directly measured and both are used to drive the micro-drill 102 to abut against the printed circuit board.

[0066] Optionally, multiple weights 303 can be set, with the weight of each weight 303 increasing in an arithmetic or geometric sequence. This allows different driving forces to be applied to the micro-drill 102, enabling repeated measurement and calibration of the friction coefficient of the micro-drill 102.

[0067] Please see Figure 4 Another objective of this application is to provide a measurement method comprising the following steps:

[0068] S1: Prepare the friction coefficient measuring device 100 as described above, and set the rotating surface 3011 horizontally;

[0069] S2: The printed circuit board 101 is fixed to the rotating surface 3011 and can rotate under the drive of the rotating table 301;

[0070] S3: Connect the micro drill 102 to the clamping head 401, and extend the lower end of the micro drill 102 toward the target object;

[0071] S4: Rotate the cantilever beam 402 so that the cantilever beam 402 drives the micro drill 102 to rise or fall, so that the lower end of the micro drill 102 just contacts the upper surface of the printed circuit board 101 without applying any force to the printed circuit board 101.

[0072] S5: Connect the force-applying component 304 to the clamping head 401 to drive the micro drill 102 to abut and press against the printed circuit board 101 downwards;

[0073] S6: The rotary table 301 drives the printed circuit board 101 to rotate so that the inductive analysis structure 200 analyzes and measures the friction coefficient of the micro-drill 102.

[0074] The above are merely optional embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A device for measuring the coefficient of friction, used to measure the coefficient of friction of a micro-drill during the machining of a target object, characterized in that, The device for measuring the coefficient of friction includes: The power structure includes a rotating platform and a force-applying component located above the rotating platform. The rotating platform is used to drive the target object to rotate and has an upward-facing rotating surface for fixing the target object. The balancing structure includes a support column adjacent to the rotary table, a cantilever beam rotatably connected to the support column, and a chuck head disposed at one end of the cantilever beam for holding the micro-drill; the other end of the cantilever beam is suspended in the air, and the plane determined by the rotation trajectory of the cantilever beam is perpendicular to the rotation plane; and The sensing and analysis structure is connected to the cantilever beam, and the connection position is located between the clamping head and the support column. The sensing and analysis structure is used to acquire and analyze the deformation of the cantilever beam, and obtain the friction coefficient of the micro-drill based on the deformation. The force-applying component is connected to the clamping head and drives the micro-drill to abut against the target object; The clamping head has a positioning hole, one end of the micro drill is inserted into the positioning hole, and the other end of the micro drill is exposed from the positioning hole; The positioning hole has an adjustment hole that connects to the external space. The balancing structure also includes a positioning element, one end of which is inserted into the positioning hole and abuts against the micro drill. The balancing structure further includes a positioning insert disposed within the positioning hole. The positioning insert has a receiving hole, the insertion end of the micro-drill is located in the receiving hole, and the positioning element abuts against the positioning insert. The positioning insert is wrapped around the insertion end of the micro-drill. The receiving hole includes a first hole section adapted to the micro drill and a second hole section communicating with the first hole section. The diameter of the second hole section is larger than the diameter of the first hole section. The micro drill is partially inserted into the first hole section, and a filler is provided between the hole wall of the second hole section and the micro drill. The micro drill is exposed in the second hole section. The positioning insert is made of photosensitive resin, and the filler is made of filling resin. Both the photosensitive resin and the filling resin are tough and elastic to counteract and buffer accidental vibrations to the micro-drill.

2. The friction coefficient measuring device as described in claim 1, characterized in that: The balancing structure also includes a suspended plate connected to the support column and a balancing adjustment component that is slidably connected to the suspended plate at one end in the vertical direction. The other end of the balancing adjustment component is used to limit the rotation of the cantilever beam.

3. The friction coefficient measuring device as described in claim 2, characterized in that: The suspended plate has a threaded hole, and the balance adjustment component has an external thread that matches the threaded hole. The balance adjustment component is screwed into the threaded hole.

4. The friction coefficient measuring device as described in any one of claims 1-2, characterized in that: The balancing structure also includes a gravity hammer connected to the cantilever beam, the support column is located between the gravity hammer and the clamping head, and the connection position between the gravity hammer and the cantilever beam is adjustable along the length direction of the cantilever beam.

5. The friction coefficient measuring device as described in any one of claims 1-2, characterized in that: The sensing analysis structure includes a strain gauge, a signal acquisition unit, and a signal processor. The strain gauge is connected to the cantilever beam and senses the deformation of the cantilever beam. The signal acquisition unit collects the deformation signal of the strain gauge and transmits the deformation signal to the signal processor.

6. A measurement method, characterized in that, Includes the following steps: Prepare a device for measuring the coefficient of friction as described in any one of claims 1-5; Fix the target object to the rotating surface; The micro-drill is connected to the chuck, and the lower end of the micro-drill extends toward the target object; Rotate the cantilever beam so that the lower end of the micro-drill contacts the upper surface of the target object; The force-applying component is connected to the clamping head to drive the micro-drill downward to abut against the target object; The rotary table drives the target object to rotate, so that the inductive analysis structure can analyze and obtain the friction coefficient of the micro-drill.

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