Multi-space posture flexible shaft friction measuring device and measuring method thereof

Abstract

The application discloses a kind of multi-space posture flexible shaft friction measuring device and its measuring method, including turntable, force measuring instrument, drive device is arranged in the bottom of the turntable, drive turntable rotates along its axis, rotation positioning device is arranged in the top of the turntable, limiting device, the limiting device is arranged in the central position of the turntable, and the rotation positioning device is arranged in the side of limiting device;Fixed positioning device is also arranged outside the turntable, and the fixed positioning device is adjustable in X / Y direction position;The force measuring instrument is arranged in the end of the soft shaft to be measured, for detecting the corresponding friction force size under the bending space posture of soft shaft.

Description

Technical Field

[0001] This invention relates to the field of CNC equipment technology, specifically to a multi-space posture flexible shaft friction force measuring device and its usage method. Background Technology

[0002] Flexible shafts, as a new type of flexible transmission component, are currently widely used in mobile machine tools, the automotive industry, agricultural machinery, and aerospace vehicles. The primary application of flexible shafts is spatial transmission, where the driving and driven devices transmit force and displacement spatially through relative motion. Their axes can bend to facilitate transmission in complex spatial conditions. Common flexible shafts for transmission can be classified into sliding and rolling types based on the structure of their transmission core. The transmission component of a sliding flexible shaft consists of a multi-strand wound steel wire core, which is separated from the outer sleeve by an inner liner. Transmission is achieved through the relative sliding between the central core and the inner liner.

[0003] During the transmission of force and displacement, flexible shafts undergo corresponding changes in spatial orientation. However, existing research still lacks a comprehensive system and equipment for studying the dynamics and statics of flexible shafts under multiple spatial bending orientations, and research on flexible shaft friction is also lacking. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a multi-space posture flexible shaft friction force measuring device and its usage method, which can realize friction measurement of flexible shaft under different bending spatial postures. It has good versatility, is easy to install, can avoid the problem of excessive local curvature in the bending state of the flexible shaft, and occupies less space.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: In a first aspect, the present invention provides a multi-space posture flexible shaft friction force measuring device, comprising a turntable and a force measuring instrument. A driving device is provided at the bottom of the turntable to drive the turntable to rotate along its axis. A rotation positioning device and a limiting device are provided at the top of the turntable. The limiting device is located at the center of the turntable, and the rotation positioning device is located on one side of the limiting device. A fixed positioning device is also provided on the outside of the turntable. The fixed positioning device is adjustable in the X / Y direction. The force measuring instrument is located at the end of the flexible shaft to be measured and is used to detect the magnitude of the friction force corresponding to the bending spatial posture of the flexible shaft.

[0006] As a further technical solution, the rotary positioning device consists of a first base, a knob, a first chuck, a first slide bar, and a first screw; the first base is fixed on the turntable, the knob is connected to the first screw, the first chuck is threadedly engaged with the first screw, and the first screw drives the first chuck to slide along the first slide bar.

[0007] As a further technical solution, the first chuck includes a first half-chuck and a second half-chuck; the first screw and the first slide rod pass through the bottom of the first half-chuck, and the second half-chuck is detachably connected to the first half-chuck through a connector. The second half-chuck and the first half-chuck have semi-circular holes, and the two semi-circular holes are assembled together to form a circular hole to clamp the end of the flexible shaft.

[0008] As a further technical solution, the limiting device consists of a second base, a spring, a limiting block, and a limiting rod; the second base is L-shaped, and two L-shaped second bases are symmetrically arranged about the axis of the disc; two limiting rods are arranged vertically, with both ends of the limiting rods mounted on the two second bases, and two limiting blocks are fitted on the limiting rods, with a compressed spring provided on the limiting rod between the limiting blocks and the base.

[0009] As a further technical solution, the two limiting blocks can move axially on the limiting rod, and the limiting blocks have V-shaped grooves.

[0010] As a further technical solution, the fixing and positioning device includes a fixing frame, on which an X-axis screw is provided. The X-axis knob is connected to the X-axis screw, and the X-axis screw drives the first base to move along the X-axis to accommodate flexible shafts of various lengths. A Y-axis screw is provided on the first base, and the Y-axis knob is connected to the Y-axis screw. The Y-axis screw drives the second chuck to move left and right in the Y-direction, which can be adjusted during the initial clamping of the flexible shaft to ensure that it is located on the centering axis.

[0011] As a further technical solution, the fixing frame is mounted on the housing of the drive device at the bottom of the fixed turntable.

[0012] As a further technical solution, the second chuck includes a third half-chuck and a fourth half-chuck; the Y-axis screw passes through the bottom of the third half-chuck, and the fourth half-chuck is detachably connected to the third half-chuck via a connector. The third and fourth half-chucks have semi-circular holes, and the two semi-circular holes are assembled together to form a circular hole to clamp the end of the flexible shaft.

[0013] As a further technical solution, a Y-axis slide rod is provided parallel to the Y-axis screw; and an X-axis slide rod is provided parallel to the X-axis screw.

[0014] A second aspect of the present invention provides a method for measuring friction force using a multi-space attitude flexible shaft measuring device. In the initial state, the end of the flexible shaft is secured by a fixed positioning device and a rotary positioning device, the limiting device limits the middle part of the flexible shaft, and the fixed positioning device ensures the straight state of the flexible shaft in the initial state by adjusting in the X and Y directions. Start the drive unit, which rotates the disc and flexible shaft to the required angle. The force measuring instrument is connected to the flexible shaft mandrel, and the tensile force measuring instrument measures the frictional force of the flexible shaft.

[0015] One or more technical solutions of the present invention have the following beneficial effects: The multi-space posture flexible shaft friction force measuring device provided by this invention features a fixed positioning device that can move in the Y direction, ensuring that the clamping centers of the fixed positioning device, rotary positioning device, and limiting device are on the same horizontal plane as the center of the flexible shaft. This guarantees that the flexible shaft is initially in a straight state, avoiding additional friction caused by local bending of the flexible shaft in its initial state. In the initial state, the fixed positioning device and rotary positioning device secure the ends of the flexible shaft, while the limiting device limits the middle of the flexible shaft. The fixed positioning device, through adjustment in the X and Y directions, ensures the straightness of the flexible shaft in its initial state. The drive device is activated, rotating the disk and flexible shaft by the required angle, which can be adjusted according to different experiments. A force measuring instrument is connected to the flexible shaft mandrel, enabling the measurement of the flexible shaft friction force at different rotation angles. This achieves multi-space posture flexible shaft friction force detection. During rotation, both ends of the flexible shaft are fixed by the rotary positioning device and the fixed positioning device, while the middle of the flexible shaft is restricted by the limiting block of the limiting device, ensuring a bending posture.

[0016] The limiting device of the multi-space posture flexible shaft friction force measuring device provided by the present invention achieves the limiting of the middle part of the flexible shaft by the limiting block located on the limiting rod being clamped by the spring force; when the flexible shaft is bent, the inner and outer limiting blocks can move together with the flexible shaft under the action of the spring force, preventing the local curvature of the flexible shaft from being too large during the bending process, which would damage the internal key components and affect the friction measurement.

[0017] The fixed positioning device of the multi-space attitude flexible shaft friction force measuring device provided by the present invention moves in the X direction to adapt to flexible shafts of various lengths and ensure the initial straight state of the flexible shaft.

[0018] In this invention, the clamps of both the fixed positioning device and the rotary positioning device can be adjusted by fastening screws to adjust the size of the clamp holes, thereby accommodating flexible shafts of various diameters and ensuring the firmness of the clamping of the flexible shaft ends.

[0019] This invention drives the turntable shaft to rotate via a drive device, enabling precise motion output and rapid response, while ensuring the accuracy of the bending angle. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the multi-space attitude flexible shaft friction force measuring device of the present invention; Figure 2 This is a partial view of the multi-space attitude flexible shaft friction force measuring device of the present invention; Figure 3 This is a top view of the multi-space attitude flexible shaft friction force measuring device of the present invention; Figure 4 This is a schematic diagram of the transmission structure of the multi-space attitude flexible shaft friction force measuring device of the present invention; In the diagram: 1. Drive device; 2. Force measuring instrument; 3. Turntable; 4. Rotary positioning device; 5. Limiting device; 6. Fixed positioning device; 11. Coupling; 12. First motor; 13. Motor shaft; 14. Driving bevel gear; 15. Driven bevel gear; 16. Turntable shaft; 42. Second motor; 43. First base; 44. Knob; 45. First chuck; 46. Fastening screw; 47. First slide rod; 48. First screw; 49. Positioning screw; 51. Second base; 52. Fixing screw; 53. Spring; 54. Limiting block; 55. Limiting rod; 61. Fixing bracket; 62. Bolt; 63. Nut; 64. Left side plate; 65. Front side plate; 66. X-axis knob; 67. X-axis screw; 68. Third base; 69. Second chuck; 610. Y-axis knob; 611. Y-axis screw; 612. X-axis slide rod; 613. Y-axis slide rod; Detailed Implementation The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Example 1 In a typical embodiment of the present invention, such as Figures 1-4 As shown, a multi-space posture flexible shaft friction force measuring device is provided, including a driving device 1 and a turntable 3. A micro-force measuring instrument 2, a rotary positioning device 4, and a limiting device 5 are arranged on the turntable 3. A fixed positioning device 6 is arranged on the outside of the turntable and is fixed to the housing of the driving device 1 by a fixing frame. In this embodiment, the limiting device 5 and the rotary positioning device 4 are fixed to the radial direction of the turntable 3 by screws, and the center height of their clamping parts is the same, ensuring that the flexible shaft can maintain a straight state during the initial clamping process and can rotate synchronously with the turntable 3. The fixed positioning device 6 is adjustable in the X / Y direction. The fixed positioning device can move in the Y direction, thereby ensuring that the clamping centers of the fixed positioning device, the rotary positioning device, and the limiting device are located on the same horizontal plane as the center of the flexible shaft, ensuring that the flexible shaft is initially in a straight state and avoiding additional friction caused by local bending of the flexible shaft in the initial state. By moving the fixed positioning device in the X direction, it can adapt to flexible shafts of various lengths and ensure the initial straight state of the flexible shaft.

[0022] Furthermore, in the initial state, the ends of the flexible shaft are secured by a fixed positioning device and a rotary positioning device, while a limiting device limits the middle of the flexible shaft. The fixed positioning device ensures the linear state of the flexible shaft in the initial state through adjustment in the X and Y directions. The drive device is then activated, rotating the disk and flexible shaft by the required angle, which can be adjusted according to different experiments. A force measuring instrument is connected to the flexible shaft mandrel, and the tensile force measuring instrument can measure the frictional force of the flexible shaft at different rotation angles, thus achieving multi-space posture frictional force detection. During rotation, both ends of the flexible shaft are fixed by the rotary positioning device and the fixed positioning device, while the middle of the flexible shaft is restricted by the limiting block of the limiting device, ensuring a bending posture.

[0023] Furthermore, the aforementioned drive device 1 includes a coupling 11, a motor 12, a motor shaft 13, a driving bevel gear 14, a driven bevel gear 15, and a turntable shaft 16; The turntable 3 is equipped with a turntable shaft 16, which is connected to a driven bevel gear 15 in a coupling to achieve rotation of the turntable shaft 16. The driven bevel gear 15 meshes with a driving bevel gear 14, which is connected to a motor shaft 13 to achieve power output. The coupling 11 is equipped with a driving bevel gear 14 and a driven bevel gear 15 with the same number of teeth and module. The transmission mechanism drives the driving bevel gear 14 to rotate via the motor shaft 13, which in turn drives the driven bevel gear 15, which meshes with the driving bevel gear 14, to rotate vertically. See details below. Figure 4 ; In this embodiment, as Figure 2 As shown, the rotary positioning device 4 consists of a first base 43, a knob 44, a first chuck 45, a fastening screw 46, a first slide rod 47, a first screw 48, and a positioning screw 49. The turntable 3 has threaded holes on its surface. The first base 43 is fixed to the turntable 3 at a corresponding position by the positioning screw 49. The knob 44 is connected to the first screw 48. The first chuck 45 has a through hole for the first slide rod 47 to pass through and a threaded hole for the first screw 48 to engage. Specifically, when the knob 44 drives the first screw 48 to rotate, the first chuck 45, which engages with the first screw 48, can rotate. Simultaneously, the first chuck 45 is restricted by the first slide rod 47, limiting its rotation to left and right movement along the direction of the first slide rod 47. This can be adjusted during the initial clamping of the flexible shaft to ensure it is on the centering axis, ensuring the flexible shaft remains straight before bending. Furthermore, the first chuck 45 is divided into a second half-chuck and a first half-chuck. The bottom of the first half-chuck has a first slide rod 47 and a first screw 48 passing through it. The second half-chuck and the first half-chuck have semi-circular holes. The two semi-circular holes are assembled together to form a circular hole to clamp the end of the flexible shaft. The two parts of the first chuck 45 are connected by a fastening screw 46. The distance of the first chuck 45 can be adjusted by rotating the fastening screw 46 to accommodate the ends of flexible shafts of various diameters and to ensure that the ends of the flexible shafts can be securely clamped without loosening.

[0024] like Figure 1 and Figure 2 As shown, the limiting device 5 consists of a second base 51, a fixing screw 52, ​​a spring 53, a limiting block 54, and a limiting rod 55. Specifically, the limiting device 5 is located at the axis of the turntable 3, and the base 51 is fixed to the turntable 3 by the fixing screw 52. The second base 51 is L-shaped, and two L-shaped second bases 51 are symmetrically arranged about the axis of the turntable, with through holes for the limiting rod 55 to pass through. The two limiting rods 55 are arranged vertically, with both ends of the limiting rods 55 mounted on the two L-shaped bases 51. Two limiting blocks 54 are fitted on the limiting rods 55. A compressed spring 53 is provided on the sliding section between the limiting block 54 and the second base 51. The limiting block 54 can move axially on the limiting rod 55, and the limiting block 54 has a V-shaped groove to facilitate positioning of the flexible shaft. At the same time, the spring force of the spring 53 can be used to adjust the clamp for flexible shafts of different diameters. In this embodiment, the limiting block 54 can slide relative to the limiting rod 55. When the limiting part clamps the flexible shaft, under the action of the spring force, the limiting block can clamp according to the relative diameter of the flexible shaft, ensuring the external shape of the flexible shaft. When the flexible shaft needs to be bent in multiple spatial postures, the limiting device 5 ensures that the local curvature of the flexible shaft is not too small, which would cause excessive local sliding friction and damage to key components.

[0025] like Figure 2 and Figure 3 As shown, in this embodiment, the fixed positioning device 6 is mounted on the motor housing by a fixing frame and does not rotate synchronously with the turntable 3. In the initial state, the fixed positioning device 6, the limiting device 5, and the rotating positioning device 4 are located on the same turntable diameter, and the center height of the clamping parts of the three are the same, ensuring that the flexible shaft can maintain a straight state during the initial clamping process.

[0026] Further, the fixing and positioning device 6 consists of a fixing frame 61, bolts 62, nuts 63, a left side plate 64, a front side plate 65, an X-axis knob 66, an X-axis screw 67, a third base 68, a second clamp 69, a Y-axis knob 610, a Y-axis screw 611, an X-axis slide bar 612, and a Y-axis slide bar 613. Specifically, the fixing frame 61 is fixed to the housing of the motor 8 by bolts 62 and nuts 63, and the other end is fixed to the left side plate 64 by bolts 62 and nuts 63. The left side plate 64 is connected to the front and rear side plates 65; the two ends of the X-axis screw 67 are rotatably connected to the front and rear side plates 65; the X-axis knob 66 ​​is connected to the X-axis screw 67; and the X-axis screw 67 drives the third base 68 to move along the X-axis to accommodate flexible shafts of various lengths. A Y-axis screw 611 is provided on the third base 68. The Y-axis knob 610 is connected to the Y-axis screw 611. The Y-axis screw 611 drives the second chuck 69 to move left and right in the Y direction. It can be adjusted during the initial clamping process of the flexible shaft to ensure that it is located on the centering axis. Specifically, the third base 68 has a through hole for the slide rod to pass through and a threaded hole for the X-direction screw 67 to engage; specifically, when the X-direction knob 66 ​​drives the X-direction screw 67 to rotate, the third base 68 engaged with the X-direction screw 67 can rotate, while the third base 68 is restricted by the X-direction slide rod 612, and the rotational movement is restricted to back-and-forth movement along the X-direction slide rod 612 in the X direction, so as to accommodate flexible shafts of various lengths.

[0027] Specifically, the second chuck 69 has a through hole for the slide rod to pass through and a threaded hole for the Y-axis screw 611 to engage. When the Y-axis knob 610 drives the Y-axis screw 611 to rotate, the second chuck 69, which engages with the Y-axis screw 611, can rotate. At the same time, the second chuck 69 is restricted by the Y-axis slide rod 613, and the rotational movement is restricted to left and right movement along the Y-axis slide rod 613 in the Y direction. It can be adjusted during the initial clamping process of the flexible shaft to ensure that it is located on the centering axis. Furthermore, the second chuck 69 is divided into a third half-chuck and a fourth half-chuck, with semi-circular holes on the third and fourth half-chucks. The two semi-circular holes are combined together to clamp the end of the flexible shaft. The third and fourth half-chucks of the second chuck 69 are connected by fastening screws. The distance of the second chuck 69 can be adjusted by rotating the fastening screws to accommodate flexible shaft ends of various diameters, and to ensure that the flexible shaft end can be securely clamped without loosening.

[0028] Specifically, the multi-space attitude flexible shaft friction force measuring device provided in this embodiment has two states when in use. The first state is the initial straight state without bending.

[0029] In the initial state, the motor 12 is not started. The middle part of the flexible shaft to be tested is clamped and fixed by the limiting block 54 of the limiting device 5. The adjusting knobs of the rotary positioning device 4 and the fixed positioning device 6 are adjusted to ensure that the clamping center of the first chuck 45 of the rotary positioning device 4, the clamping center of the second chuck 69 of the fixed positioning device 6, and the clamping center of the limiting block 54 of the limiting device 5 are in the same straight line position. The end of the flexible shaft is fixed by adjusting the fastening screws on the first chuck 45 and the second chuck 69. Further, the X-direction knob 66 ​​of the fixed positioning device 6 is adjusted to ensure that the flexible shaft is in a straight state.

[0030] The second method involves actually bending the flexible shaft and measuring the magnitude of the frictional force.

[0031] In this state, motor 12 starts, and the motor shaft 13 rotates, transmitting the motion to the turntable shaft 16 via coupling 11. The turntable 3 drives the limiting device 5, the rotation positioning device 4, and the clamped flexible shaft on the turntable 3 to rotate by a specified angle, and motor 12 shuts off. Subsequently, displacement is applied to the micro-force measuring instrument 2 connected to the flexible shaft spindle, and the magnitude of the force output by the force measuring instrument 2 is read, which is the magnitude of the frictional force corresponding to the bending spatial posture of the flexible shaft.

[0032] During this process, both ends of the flexible shaft are fixed by the rotary positioning device 4 and the fixed positioning device 6. The middle part of the flexible shaft is restricted by the limit block 54 to ensure the bending posture. At the same time, the limit blocks 54 on both the inner and outer sides can move together with the flexible shaft under the elastic force of the spring 53 to prevent the local curvature of the flexible shaft from being too large during the bending process, which would damage the internal critical components and affect the friction measurement.

[0033] Example 2 This embodiment provides a method for using a multi-space posture flexible shaft friction force measuring device, including: in the initial state, the end of the flexible shaft is secured by a fixed positioning device and a rotary positioning device, the limiting device limits the middle part of the flexible shaft, and the fixed positioning device ensures the linear state of the flexible shaft in the initial state by adjusting in the X and Y directions; the motor is started, and the motor shaft drives the disc and the flexible shaft to rotate by the required angle through a coupling; the micro-force sensor is connected to the flexible shaft spindle, and the friction force of the flexible shaft is measured by pulling.

[0034] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A multi-space attitude flexible shaft friction force measuring device, characterized in that, The device includes a turntable and a force measuring instrument. A drive device is installed at the bottom of the turntable to drive it to rotate along its axis. A rotation positioning device and a limiting device are installed at the top of the turntable. The limiting device is located at the center of the turntable, and the rotation positioning device is located to one side of the limiting device. The limiting device consists of a second base, a spring, a limiting block, and a limiting rod. The second base is L-shaped, and two L-shaped second bases are symmetrically arranged about the axis of the turntable. Two limiting rods are arranged vertically, with both ends of the limiting rods mounted on the two second bases. Two limiting blocks are fitted onto the limiting rods, and a compressed spring is installed on the limiting rod between the limiting blocks and the second bases. A fixed positioning device is also installed on the outside of the turntable, and the fixed positioning device is adjustable in the X / Y directions. The force measuring instrument is installed at the end of the flexible shaft to be measured and is used to detect the magnitude of the friction force corresponding to the bending spatial posture of the flexible shaft.

2. The multi-space attitude flexible shaft friction force measuring device as described in claim 1, characterized in that, The rotary positioning device consists of a first base, a knob, a first chuck, a first slide bar, and a first screw. The first base is fixed on the turntable, the knob is connected to the first screw, the first chuck is threadedly engaged with the first screw, and the first screw drives the first chuck to slide along the first slide bar.

3. The multi-space attitude flexible shaft friction force measuring device as described in claim 2, characterized in that, The first chuck includes a first half-chuck and a second half-chuck; the first screw and the first slide rod pass through the bottom of the first half-chuck, and the second half-chuck is detachably connected to the first half-chuck through a connector. The second half-chuck and the first half-chuck have semi-circular holes, and the two semi-circular holes are assembled together to form a circular hole to clamp the end of the flexible shaft.

4. The multi-space attitude flexible shaft friction force measuring device as described in claim 1, characterized in that, The two limiting blocks can move axially on the limiting rod, and the limiting blocks have V-shaped grooves.

5. The multi-space attitude flexible shaft friction force measuring device as described in claim 1, characterized in that, The fixed positioning device includes a fixed frame, on which an X-axis screw is provided. An X-axis knob is connected to the X-axis screw, and the X-axis screw drives a third base to move along the X-axis. A Y-axis screw is provided on the third base, on which a Y-axis knob is connected. The Y-axis screw drives a second chuck to move left and right in the Y-axis direction. Adjustments can be made during the initial clamping of the flexible shaft to ensure that it is located on the centering axis.

6. The multi-space attitude flexible shaft friction force measuring device as described in claim 5, characterized in that, The mounting bracket is attached to the housing of the drive unit at the bottom of the fixed turntable.

7. The multi-space attitude flexible shaft friction force measuring device as described in claim 5, characterized in that, The second chuck includes a third half-chuck and a fourth half-chuck; the Y-axis screw passes through the bottom of the third half-chuck, and the fourth half-chuck is detachably connected to the third half-chuck via a connector. The third and fourth half-chucks have semi-circular holes, and the two semi-circular holes are assembled together to form a circular hole to clamp the end of the flexible shaft.

8. The multi-space attitude flexible shaft friction force measuring device as described in claim 5, characterized in that, A Y-axis slide rod is provided parallel to the Y-axis screw; an X-axis slide rod is provided parallel to the X-axis screw.

9. The method for measuring friction force of a multi-space attitude flexible shaft as described in any one of claims 1-8, characterized in that, as follows: In the initial state, the end of the flexible shaft is secured by a fixed positioning device and a rotary positioning device, the limiting device limits the middle part of the flexible shaft, and the fixed positioning device ensures the straight state of the flexible shaft in the initial state by adjusting in the X and Y directions. Start the drive unit, which rotates the disc and flexible shaft to the required angle. The force measuring instrument is connected to the flexible shaft mandrel, and the tensile force measuring instrument measures the frictional force of the flexible shaft.

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