Force sensor

Abstract

The invention relates to the technical field of sensors, in particular to a force sensor. The force sensor comprises a cylindrical shell, an elastic body and a top cover, wherein the cylindrical shell is provided with an accommodating space and two axial ends of the cylindrical shell are opened; the elastic body is accommodated in the accommodating space; the top cover is fixed on the elastic body and is axially separated from one end of the cylindrical shell; the elastic body comprises a central table fixedly connected with the top cover, three cross beams extending from the peripheral side of the central table in the length direction to the direction close to the cylindrical shell in the radial direction, and a bottom plate fixedly connected with the end, away from the top cover, of the cylindrical shell; and the three vertical beams respectively extend towards the top cover along the direction parallel to the axial direction from one side, close to the top cover, of the bottom plate in the length direction. Compared with the prior art, the strain response of the first strain gauge and the strain response of the second strain gauge are respectively adjusted by adjusting the lengths, the widths and the heights of the cross beam and the vertical beam, the surface mounting precision is improved, and therefore the accuracy and the precision of the force sensor are improved.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and more particularly to a force sensor. Background Technology

[0002] As robots become increasingly intelligent and human-like, intelligent control places increasingly stringent demands on the force sensing capabilities of sensor systems. The six-dimensional force sensor, a core component capable of simultaneously and accurately measuring the three-dimensional orthogonal force components Fx / Fy / Fz and the three-dimensional orthogonal torque components Mx / My / Mz at a single point in space, is a crucial supporting technology for realizing intelligent robot operations and dexterous maneuvers, holding an irreplaceable and vital position in the field of robotics.

[0003] In the application scenarios of humanoid dexterous hands, the fingertips need to make direct contact with the object and generate contact force during the grasping and manipulation of the object. The six-dimensional force sensor can directly detect the contact force and torque information between each fingertip of the dexterous hand and the grasped object, providing rich and accurate force sensing data for the core functions of the dexterous hand such as multi-finger collaborative operation and compliant control. It is the most complex and technically challenging force sensing component in the humanoid dexterous hand sensing system.

[0004] Currently, the mainstream six-dimensional force sensor elastomer structures in the industry mainly include the cross-beam structure and the three-strain beam structure, which is widely used both domestically and internationally. Among them, the three-strain beam structure, which only requires one strain gauge along the length of the main beam, is theoretically easier to miniaturize than the cross-beam structure, and has therefore received considerable research and application. However, when the sensor size needs to be reduced to a specific range, such as a sensor diameter less than or equal to 30mm, the inherent defects of this structure become increasingly apparent: On the one hand, as the length of the main beam decreases, and considering that strain gauges need to be placed on the upper and lower surfaces and both sides of the main beam in a three-strain beam structure, the size of the strain gauges themselves imposes strict limitations on the height and width of the main beam. This results in minimal deformation of the main beam when the sensor detects force and torque, and a corresponding decrease in the strain that the strain gauges can sense, failing to meet the basic requirements for sensor detection sensitivity. On the other hand, the reduction in sensor size drastically reduces its internal space, greatly complicating the strain gauge placement process and significantly increasing the difficulty of strain gauge placement, severely affecting the sensor's assembly accuracy and production yield.

[0005] In summary, the existing mainstream six-dimensional force sensors, due to their inherent design flaws, cannot achieve further miniaturization to a diameter of less than 10mm. They are also difficult to fit into the narrow installation space of humanoid dexterous finger joints or fingertips, and cannot meet the practical application requirements of miniaturized and high-precision force sensing in dexterous hands. This restricts the development of humanoid dexterous hands towards more refined and flexible operation.

[0006] Therefore, it is necessary to provide a new force sensor to solve the above-mentioned technical problems. Summary of the Invention

[0007] The purpose of this invention is to provide a force sensor that is small in size, has better decoupling effect, and high-precision force sensing.

[0008] To achieve the above objectives, the present invention provides a force sensor comprising a cylindrical housing having a receiving space and openings at both ends along the axial direction, an elastic body housed within the receiving space, and a top cover fixed to the elastic body and axially spaced from one end of the cylindrical housing.

[0009] The elastomer includes a central platform fixedly connected to the top cover, three crossbeams extending radially from the outer periphery of the central platform towards the cylindrical shell, a base plate fixedly connected to one end of the cylindrical shell away from the top cover, three vertical beams extending from the side of the base plate near the top cover towards the top cover in a direction parallel to the axial direction, and three connecting portions fixedly connecting the side of each crossbeam away from the central platform to the side of each vertical beam away from the base plate in the length direction. The three crossbeams are evenly spaced along the circumference of the cylindrical shell and have the same height along the axial direction of the cylindrical shell, and the three vertical beams are evenly spaced along the circumference of the cylindrical shell. Each of the crossbeams includes a first surface facing the top cover and a second surface facing the bottom plate, as well as two connecting sides connecting the first surface and the second surface. The two connecting sides of each crossbeam are parallel to the length direction of the corresponding crossbeam. Each crossbeam is provided with two first strain gauges, which are respectively installed on the first surface and the second surface. Each vertical beam includes a third surface and a fourth surface that are perpendicular to the first surface and the second surface of the corresponding connected horizontal beam and are arranged opposite to each other. The third surface and the fourth surface are both parallel to the two connecting sides of the corresponding connected horizontal beam. Each vertical beam is provided with two second strain gauges, which are respectively installed on the third surface and the fourth surface.

[0010] Preferably, the strain gauges of the two first strain gauges of each crossbeam are oriented parallel to the length direction of the corresponding crossbeam, and the strain gauges of the two second strain gauges of each vertical beam are oriented parallel to the length direction of the corresponding vertical beam.

[0011] Preferably, the orthographic projection of the vertical beam toward the top cover falls entirely on the corresponding connected horizontal beam.

[0012] Preferably, the distance between the two connecting sides of the vertical beam and the corresponding connected horizontal beam on the top cover is equal.

[0013] Preferably, each of the connecting portions is perpendicular to the length direction of the corresponding connected crossbeam and parallel to the length direction of the corresponding connected vertical beam.

[0014] Preferably, the three crossbeams are of the same size, and the three vertical beams are of the same size.

[0015] Preferably, the axial distance between the top cover and the end of the cylindrical outer shell near the top cover is 0.5~1mm.

[0016] Preferably, the top cover includes a cylindrical top cover body, a positioning groove formed by an axial recess of the top cover body away from the elastic body towards the elastic body, a positioning post formed by an axial extension of the top cover body near the elastic body towards the central platform, a central bolt hole axially penetrating the top cover body and the positioning post, and a plurality of threaded holes axially penetrating the top cover body; the positioning groove, the positioning post, and the central bolt hole are coaxially arranged with the top cover body, and the bolt passes through the positioning groove and the central bolt hole in sequence to form a threaded connection with the central platform to fix the top cover to the central platform.

[0017] Preferably, the diameter of the positioning groove is larger than the diameter of the central bolt hole.

[0018] Preferably, the inner circumferential side of the cylindrical shell is radially spaced from the side of the crossbeam and the vertical beam near the inner circumferential side of the cylindrical shell, and the radial distance is 0.2~0.4mm.

[0019] Preferably, the top cover, the cylindrical outer shell, and the elastomer are all made of any one of the following materials: aluminum alloy, magnesium alloy, titanium alloy, and stainless steel.

[0020] Preferably, the distance between the first strain gauge and the central platform is 0.5~1mm, the distance between the second strain gauge and the base plate is 0.5~1mm, and the diameter of the cylindrical shell is less than 10mm.

[0021] Preferably, the distance between the side of the bottom plate away from the top cover and the side of the top cover away from the bottom plate is less than 10 mm.

[0022] Compared with the prior art, the force sensor of the present invention includes a cylindrical shell with a receiving space and open at both ends along the axial direction, an elastic body housed in the receiving space, and a top cover fixed to the elastic body and axially spaced from one end of the cylindrical shell. The elastic body includes a central platform fixedly connected to the top cover, three crossbeams extending radially from the outer periphery of the central platform towards the cylindrical shell in the length direction, a base plate fixedly connected to the end of the cylindrical shell away from the top cover, three vertical beams extending from the side of the base plate near the top cover in the length direction towards the top cover in a direction parallel to the axial direction, and three connecting parts fixedly connecting the side of each crossbeam away from the central platform in the length direction to the side of each vertical beam away from the base plate in the length direction. The three crossbeams are evenly spaced along the circumference of the cylindrical shell. The three vertical beams are equally spaced along the axial direction of the cylindrical shell. Each horizontal beam includes a first surface facing the top cover, a second surface facing the bottom plate, and two connecting sides connecting the first and second surfaces. The two connecting sides of each horizontal beam are parallel to the length direction of the corresponding horizontal beam. Each horizontal beam is provided with two first strain gauges, which are respectively installed on the first and second surfaces. Each vertical beam includes a third surface and a fourth surface that are perpendicular to the first and second surfaces of the corresponding connected horizontal beam and are arranged opposite to each other. The third and fourth surfaces are parallel to the two connecting sides of the corresponding connected horizontal beam. Each vertical beam is provided with two second strain gauges, which are respectively installed on the third and fourth surfaces. This invention improves the strain response of the first and second strain gauges and enhances the mounting accuracy by setting the structure, position, and connection method of the horizontal and vertical beams, thereby improving the accuracy and precision of the force sensor. Furthermore, the decoupled structure of the horizontal and vertical beams decouples the mounting process of the first and second strain gauges, facilitating the mounting process of the miniature force sensor, reducing the difficulty of the mounting process, and improving the mounting accuracy, thus enhancing the accuracy and precision of the force sensor. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 This is a three-dimensional structural diagram of the force sensor provided in an embodiment of the present invention; Figure 2 This is an exploded three-dimensional structural diagram of the force sensor provided in an embodiment of the present invention; Figure 3 For along Figure 1 Cross-sectional view of line AA in the middle; Figure 4 For along Figure 1 Cross-sectional view of the middle BB line; Figure 5 This is a three-dimensional structural diagram of the elastic body of the force sensor provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the top cover of the force sensor provided in an embodiment of the present invention.

[0024] In the diagram, 100 is the force sensor; 1 is the cylindrical outer shell; 2 is the top cover; 21 is the top cover body; 22 is the positioning post; 23 is the central bolt hole; 24 is the threaded hole; 25 is the positioning groove; 26 is the bolt; 3 is the elastic body; 31 is the central platform; 32 is the crossbeam; 321 is the first surface; 322 is the second surface; 323 is the connecting side; 33 is the connecting part; 34 is the vertical beam; 341 is the third surface; 342 is the fourth surface; 35 is the base plate; 351 is the base plate body; 352 is the fixing threaded hole; 41 is the first strain gauge; 42 is the second strain gauge; and 20 is the receiving space. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Combination Figures 1 to 6 As shown, an embodiment of the present invention provides a force sensor 100, which includes a cylindrical outer shell 1 having a receiving space 20 and opening at both ends along the axial direction, an elastic body 3 housed in the receiving space 20, and a top cover 2 fixed to the elastic body 3 and axially spaced from one end of the cylindrical outer shell. The elastic body 3 includes a central platform 31 fixedly connected to the top cover 2, three crossbeams 32 extending radially from the outer periphery of the central platform 31 toward the cylindrical outer shell 1, a base plate 35 fixedly connected to one end of the cylindrical outer shell 1 away from the top cover 2, three vertical beams 34 extending from the side of the base plate 35 near the top cover 2 toward the top cover 2 in a direction parallel to the axial direction, and three connecting parts 33 fixedly connecting the side of each crossbeam 32 away from the central platform 31 in the length direction to the side of one vertical beam 34 away from the base plate 35 in the length direction. The three crossbeams 32 are evenly spaced along the circumference of the cylindrical outer shell 1 and have the same height along the axial direction of the cylindrical outer shell 1, and the three vertical beams 34 are evenly spaced along the circumference of the cylindrical outer shell 1.

[0027] Each of the crossbeams 32 includes a first surface 321 facing the top cover 2 and a second surface 322 facing the bottom plate 35, as well as two connecting side surfaces 323 connecting the first surface 321 and the second surface 322. The two connecting side surfaces 323 of each crossbeam 32 are parallel to the length direction of the corresponding crossbeam 32. Each crossbeam 32 is provided with two first strain gauges 41, which are respectively installed on the first surface 321 and the second surface 322.

[0028] Each vertical beam 34 includes a third surface 341 and a fourth surface 342 that are perpendicular to the first surface 321 and the second surface 322 of the corresponding connected horizontal beam 32 and are arranged opposite to each other. The third surface 341 and the fourth surface 342 are both parallel to the two connecting sides 323 of the corresponding connected horizontal beam 32. Each vertical beam 34 is provided with two second strain gauges 42, which are respectively installed on the third surface 341 and the fourth surface 342.

[0029] Specifically, the strain gauge of the first strain gauge 41 is oriented along the length of the crossbeam 32 (i.e., the direction of the central platform 31 near the cylindrical shell 1), and the strain gauge of the second strain gauge 42 is oriented along the length of the vertical beam 34 (i.e., the axial direction of the cylindrical shell 1). The two adjacent crossbeams 32 form a 120° angle along their length extensions. By adjusting the structure, position arrangement, and connection method between the crossbeams 32 and the vertical beams 34, the strain response of the first strain gauge 41 and the second strain gauge 42 is improved, the bonding process of the first strain gauge 41 and the second strain gauge 42 is decoupled, the bonding accuracy is improved, and thus the accuracy and precision of the force sensor 100 are improved.

[0030] Specifically, when the force sensor 100 detects forces Fx (force along the X-axis), Fy (force along the Y-axis), and Mz (torque about the Z-axis), the response is measured through three vertical beams 34; when the force sensor 100 detects forces Fz (force along the Z-axis), Mx (torque about the X-axis), and My (torque about the Y-axis), the response is measured through three horizontal beams 32. Through the design of the horizontal beams 32 and vertical beams 34, the strain response of the force sensor 100 is decoupled.

[0031] In this embodiment, the strain gauges of the two first strain gauges 41 of each crossbeam 32 are parallel to the length direction of the corresponding crossbeam 32, and the strain gauges of the two second strain gauges 42 of each vertical beam 34 are parallel to the length direction of the corresponding vertical beam 34. Since the strain gauges (sensitive gauges) of the first strain gauge 41 and the second strain gauges 42 are crucial for sensing strain, if the strain gauges of the first strain gauge 41 and the second strain gauge 42 are not aligned with the principal strain direction of the tested object, the measurement results will be distorted due to interference from shear strain or non-principal strain directions. This invention sets the directions of the strain gauges of the first strain gauge 41 and the second strain gauge 42 so that their directions are aligned with the principal strain direction of the tested object, thereby accurately reflecting the deformation of the material and improving the performance of the force sensor 100.

[0032] In this embodiment, the orthographic projection of the vertical beam 34 toward the top cover 2 falls entirely on the correspondingly connected horizontal beam 32, thereby making the internal space of the force sensor 100 more compact, while facilitating the installation of the first strain gauge 41 and the second strain gauge 42 and improving the patching accuracy.

[0033] In this embodiment, the distance between the two connecting sides 323 of the vertical beam 34 and the corresponding horizontal beam 32 on the top cover 2 is equal, thereby improving the stability and detection accuracy of the force sensor 100. In this embodiment, each of the connecting portions 33 is perpendicular to the length direction of the corresponding connected crossbeam 32 and parallel to the length direction of the corresponding connected vertical beam 34, thereby improving the stability of the connection between the connecting portion 33 and the crossbeam 32 and the vertical beam 34, and enhancing the stability of the force sensor 100.

[0034] In this embodiment, the three horizontal beams 32 are of the same size, and the three vertical beams 34 are of the same size, thereby improving the stability and detection accuracy of the force sensor 100.

[0035] In this embodiment, the axial distance between the top cover 2 and the cylindrical outer shell 1 near the end of the top cover 2 is 0.5~1mm, thereby creating a deformation space between the top cover 2 and the cylindrical outer shell 1, which improves the stability and reliability of the force sensor 100.

[0036] In this embodiment, the top cover 2 includes a cylindrical top cover body 21, a positioning groove 25 formed by an axial recess from the side of the top cover body 21 away from the elastic body 3 towards the elastic body 3, a positioning post 22 formed by an axial extension from the side of the top cover body 21 near the elastic body 3 towards the central platform 31, a central bolt hole 23 axially penetrating the top cover body 21 and the positioning post 22, and a plurality of threaded holes 24 axially penetrating the top cover body 21. The positioning groove 25, the positioning post 22, and the central bolt hole 23 are coaxially arranged with the top cover body 21. A bolt 26 passes through the positioning groove 25 and the central bolt hole 23 in sequence and forms a threaded connection with the central platform 31 to fix the top cover 2 to the central platform 31. The threaded holes 24 are used to connect with external measuring components (such as fingertips). Positioning by the positioning post 22 makes the installation accuracy more accurate when the top cover body 21 is fixedly connected to the central platform 31, thereby improving the accuracy and precision of the force sensor 100.

[0037] In this embodiment, the diameter of the positioning groove 25 is larger than the diameter of the central bolt hole 23, which facilitates the installation of the bolt 26 and saves space.

[0038] In this embodiment, the inner circumferential side of the cylindrical outer shell 1 is radially spaced from the side of the crossbeam 32 and the vertical beam 34 near the inner circumferential side of the cylindrical outer shell 1, with a radial distance of 0.2~0.4mm. This ensures that the crossbeam 32 and the vertical beam 34 have sufficient deformation space to avoid contact with the cylindrical outer shell 1, thereby avoiding impacting the detection accuracy of the force sensor 100 and improving the reliability of the force sensor 100.

[0039] In this embodiment, the top cover 2, the cylindrical outer shell 1, and the elastomer 3 are all made of any one of the following materials: aluminum alloy, magnesium alloy, titanium alloy, and stainless steel. This results in high structural strength and good performance for the top cover 2, the cylindrical outer shell 1, and the elastomer 3, while also being easy to manufacture and cost-effective. The elastomer 3 can also be a non-metallic material, as long as it can undergo elastic deformation in its recovery state.

[0040] In this embodiment, the distance between the first strain gauge 41 and the central platform 31 is 0.5~1mm, and the distance between the second strain gauge 42 and the base plate 35 is 0.5~1mm, thereby improving the accuracy and precision of the force sensor 100.

[0041] In this embodiment, the diameter of the cylindrical outer shell 1 is less than 10 mm, which makes the structure of the force sensor 100 more compact and the size of the force sensor 100 smaller.

[0042] In this embodiment, the distance from the side of the base plate 35 away from the top cover 2 to the side of the top cover 2 away from the base plate 35 is less than 10mm, thereby making the structure of the force sensor 100 more compact and the size of the force sensor 100 smaller.

[0043] In this embodiment, the base plate 35 includes a base plate body 351 fixedly connected to the cylindrical outer shell 1 and a fixing threaded hole 352 formed through the base plate body 351. The fixing threaded hole 352 is used to connect with a sensor fixing component (such as a knuckle), thereby improving the connection stability between the force sensor 100 and the sensor fixing component.

[0044] Compared with the prior art, the force sensor of the present invention includes a cylindrical shell with a receiving space and open at both ends along the axial direction, an elastic body housed in the receiving space, and a top cover fixed to the elastic body and axially spaced from one end of the cylindrical shell. The elastic body includes a central platform fixedly connected to the top cover, three crossbeams extending radially from the outer periphery of the central platform towards the cylindrical shell in the length direction, a base plate fixedly connected to the end of the cylindrical shell away from the top cover, three vertical beams extending from the side of the base plate near the top cover in the length direction towards the top cover in a direction parallel to the axial direction, and three connecting parts fixedly connecting the side of each crossbeam away from the central platform in the length direction to the side of each vertical beam away from the base plate in the length direction. The three crossbeams are evenly spaced along the circumference of the cylindrical shell. The three vertical beams are equally spaced along the axial direction of the cylindrical shell. Each horizontal beam includes a first surface facing the top cover, a second surface facing the bottom plate, and two connecting sides connecting the first and second surfaces. The two connecting sides of each horizontal beam are parallel to the length direction of the corresponding horizontal beam. Each horizontal beam is provided with two first strain gauges, which are respectively installed on the first and second surfaces. Each vertical beam includes a third surface and a fourth surface that are perpendicular to the first and second surfaces of the corresponding connected horizontal beam and are arranged opposite to each other. The third and fourth surfaces are parallel to the two connecting sides of the corresponding connected horizontal beam. Each vertical beam is provided with two second strain gauges, which are respectively installed on the third and fourth surfaces. This invention improves the strain response of the first and second strain gauges and enhances the mounting accuracy by setting the structure, position, and connection method of the horizontal and vertical beams. This, in turn, improves the accuracy and precision of the force sensor. Furthermore, the decoupled structure of the horizontal and vertical beams decouples the mounting process of the first and second strain gauges, facilitating the mounting process of the miniature force sensor, reducing its complexity, and improving mounting accuracy, thus further enhancing the accuracy and precision of the force sensor.

[0045] The above description is merely an embodiment of the present invention. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements all fall within the protection scope of the present invention.

Claims

1. A force sensor comprising a cylindrical casing having a receiving space and being open at both axial ends, an elastic body received in the receiving space, and a top cover fixed to the elastic body and axially spaced from one end of the cylindrical casing, characterized in that the elastic body comprises a central platform fixedly connected with the top cover, three cross beams respectively extending in a radial direction from an outer circumferential side of the central platform toward the cylindrical casing in a lengthwise direction, a bottom plate fixedly connected with the cylindrical casing away from the top cover at one end, three vertical beams respectively extending in a direction parallel to the axial direction from one side of the bottom plate toward the top cover in a lengthwise direction, and three connecting portions respectively fixedly connecting one side of each of the cross beams away from the central platform in the lengthwise direction with one side of each of the vertical beams away from the bottom plate in the lengthwise direction, the three cross beams being equally spaced in a circumferential direction of the cylindrical casing and having equal heights in the axial direction of the cylindrical casing, and the three vertical beams being equally spaced in the circumferential direction of the cylindrical casing. Each of the cross beams comprises a first surface facing the top cover, a second surface facing the bottom plate, and two connecting side surfaces connecting the first surface and the second surface, the two connecting side surfaces of each of the cross beams being parallel to the lengthwise direction of the corresponding cross beam, and two first strain gauges being provided on each of the cross beams and mounted on the first surface and the second surface, respectively. Each of the vertical beams comprises a third surface and a fourth surface which are perpendicular to the first surface and the second surface of the corresponding connected cross beam and are oppositely arranged, and the third surface and the fourth surface are both parallel to the two connecting side surfaces of the corresponding connected cross beam, and two second strain gauges being provided on each of the vertical beams and mounted on the third surface and the fourth surface, respectively. The direction of the strain grid of the two first strain gauges of each of the cross beams is parallel to the lengthwise direction of the corresponding cross beam, and the direction of the strain grid of the two second strain gauges of each of the vertical beams is parallel to the lengthwise direction of the corresponding vertical beam.

2. The force sensor of claim 1, wherein, The vertical projection of the vertical beam toward the top cover completely falls on the corresponding connected cross beam.

3. The force sensor of claim 1, wherein, The interval of the vertical projection of the two connecting side surfaces of the vertical beam and the corresponding connected cross beam on the top cover is equal.

4. The force sensor of claim 1, wherein, Each of the connecting portions is perpendicular to the lengthwise direction of the corresponding connected cross beam and parallel to the lengthwise direction of the corresponding connected vertical beam.

5. The force sensor of claim 1, wherein, The three cross beams have the same size, and the three vertical beams have the same size.

6. The force sensor of claim 1, wherein, The axial distance between the top cover and the one end of the cylindrical casing close to the top cover is 0.5-1 mm.

7. The force sensor of claim 1, wherein, ​ 8. The force sensor of claim 1, wherein, The top cover comprises a cylindrical top cover body, a positioning groove formed by a side surface of the top cover body away from the elastic body and recessed axially towards the elastic body, a positioning column formed by a side surface of the top cover body close to the elastic body and extending axially towards the center platform, a center bolt hole axially penetrating the top cover body and the positioning column, and a plurality of threaded holes axially penetrating the top cover body; the positioning groove, the positioning column, the center bolt hole and the top cover body are coaxially arranged, and a bolt is sequentially threaded through the positioning groove and the center bolt hole to form a threaded connection with the center platform to fix the top cover and the center platform.

9. The force sensor of claim 8, wherein, The aperture of the positioning groove is larger than the aperture of the center bolt hole.

10. The force sensor of claim 1, wherein, The inner circumferential side of the cylindrical shell is radially spaced from the side of the cross beam and the vertical beam close to the inner circumferential side of the cylindrical shell, and the radial distance is 0.2-0.4 mm.

11. The force sensor of claim 1, wherein, The top cover, the cylindrical shell and the elastic body are all made of any one of aluminum alloy, magnesium alloy, titanium alloy and stainless steel.

12. The force sensor of claim 1, wherein, The distance between the first strain gauge and the center platform is 0.5-1 mm, and the distance between the second strain gauge and the bottom plate is 0.5-1 mm; the diameter of the cylindrical shell is less than 10 mm.

13. The force sensor of claim 1, wherein, The distance from the side of the bottom plate away from the top cover to the side of the top cover away from the bottom plate is less than 10 mm.

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