Wide-temperature-range variable-curvature flexible shaft friction force detection device

Abstract

The invention provides a wide-temperature-range variable-curvature flexible shaft friction force detection device. The wide-temperature-range variable-curvature flexible shaft friction force detection device comprises a working platform, a bending mechanism and a curvature radius detection mechanism, the bending mechanism is used for bending the flexible shaft; the curvature radius detection mechanism is arranged below the flexible shaft and is used for detecting the curvature radius of the flexible shaft; a first rail and a second rail are arranged in the flexible shaft in the extending direction of the flexible shaft; a friction force detection mechanism is arranged in the flexible shaft and comprises a ball, a retainer, an S-shaped tension and pressure sensor and a miniature trolley; the ball is arranged between the first track and the second track and is in sliding connection with the first track and the second track; the retainer is arranged on the outer side of the ball and is rotatably connected with the ball, so that the ball can roll in the retainer; the two ends of the S-shaped tension and pressure sensor are fixedly connected with the retainer and the miniature trolley respectively; and the micro trolley is arranged on the second track.

Description

Technical Field

[0001] This invention relates to the field of flexible transmission technology, and more specifically, to a friction force detection device for a flexible shaft with a wide temperature range and variable curvature. Background Technology

[0002] The detection of friction force and radius of curvature of flexible shafts is one of the key factors in achieving high-precision flexible transmission. Currently, devices or methods for measuring the friction force and radius of curvature of flexible shafts include rolling bearing friction force detection devices, friction force and rolling friction coefficient measuring devices, and ray tracing methods for measuring the radius of curvature. However, these devices or methods can only measure either friction force or radius of curvature individually, and most methods for measuring the radius of curvature are only applicable to measuring the radius of curvature of optical mirrors. Existing technologies cannot simultaneously measure the friction force and radius of curvature of flexible shafts, nor can they meet the requirements for detecting friction force and radius of curvature under different bending states of flexible shafts. Summary of the Invention

[0003] In view of this, the present invention proposes a wide-temperature-range variable curvature flexible shaft friction force detection device to solve the problems existing in the prior art.

[0004] To achieve the above objectives, the present invention proposes a wide-temperature-range variable curvature flexible shaft friction force detection device, including a working platform and a bending mechanism and a curvature radius detection mechanism disposed on the working platform;

[0005] The bending mechanism is used to bend the flexible shaft;

[0006] The radius of curvature detection mechanism is located below the flexible shaft and is used to detect the radius of curvature of the flexible shaft;

[0007] The flexible shaft has a first track and a second track arranged along its extension direction.

[0008] The flexible shaft is equipped with a friction detection mechanism, which includes a ball bearing, a cage, an S-shaped tension / compression sensor, and a miniature carriage.

[0009] The ball bearing is disposed between the first track and the second track, and is slidably connected to the first track and the second track;

[0010] The retainer is disposed outside the ball and rotatably connected to the ball so that the ball can roll within the retainer;

[0011] The two ends of the S-shaped tension / compression sensor are fixedly connected to the cage and the miniature vehicle, respectively.

[0012] The miniature vehicle is positioned on the second track.

[0013] In one embodiment, the friction force detection mechanism further includes a force measuring backplate, an amplifier power supply, an amplifier, and a data acquisition card disposed on the miniature vehicle;

[0014] One side of the force-measuring backplate is fixedly connected to the rear end of the miniature vehicle, and the other side of the force-measuring backplate is fixedly connected to one end of the S-shaped tension and compression sensor via a force-measuring pull wire.

[0015] The amplifier is electrically connected to the S-type tension / compression sensor via a data line;

[0016] The amplifier power supply is electrically connected to the amplifier;

[0017] The acquisition card is electrically connected to the amplifier via a data cable.

[0018] In one embodiment, the friction detection mechanism further includes a Bluetooth module and a mobile monitoring device mounted on the miniature vehicle;

[0019] The Bluetooth module is used to send the signals acquired by the acquisition card to the mobile monitoring device.

[0020] In one embodiment, the friction detection mechanism further includes a temperature sensor, a buzzer, and a Bluetooth disconnect module disposed on the miniature vehicle;

[0021] The temperature sensor is used to monitor the temperature of the test environment inside the flexible shaft and is connected to the Bluetooth module.

[0022] The buzzer is connected to the temperature sensor via a data cable;

[0023] If the ambient temperature exceeds the set temperature range during testing, the buzzer is used to emit an alarm sound, and the Bluetooth disconnect module is used to disconnect the Bluetooth module from the mobile monitoring device.

[0024] In one embodiment, the microcar has a servo motor, a driver, a pulse generator, and a motor power supply;

[0025] The servo motor is used to drive the miniature vehicle to move;

[0026] The servo motor is connected to the driver via a motor power line and an encoder line;

[0027] The driver is connected to the power supply of the motor.

[0028] The pulse generator is connected to the driver via a pulse line.

[0029] In one embodiment, the bending mechanism includes a support column, a support plate, a support shaft, a support wheel, and a vertical force-applying component;

[0030] Two support columns are arranged side by side, and the bottom of the support columns is fixedly connected to the working platform;

[0031] The support plate is fixedly installed on the top of the support column, and the side wall of the support plate has multiple horizontal adjustment grooves.

[0032] Multiple support shafts are provided in the horizontal direction, and one end of each support shaft is slidably connected to the horizontal adjustment groove.

[0033] The support wheel is disposed on the other end of the support shaft, and the support wheel is used to support the flexible shaft;

[0034] The vertical force-applying component is disposed on the support plate and is used to apply a downward thrust to the flexible shaft between adjacent support wheels.

[0035] In one embodiment, the vertical force-applying component includes a vertical adjustment push rod, a hydraulic cylinder, and a hydraulic system;

[0036] The fixed end of the hydraulic cylinder is fixedly connected to the support plate, and the movable end of the hydraulic cylinder is fixedly connected to the vertical adjustment push rod, which is used to contact the flexible shaft.

[0037] The hydraulic system is connected to the hydraulic cylinder.

[0038] In one embodiment, the radius of curvature detection mechanism includes a linear motion mechanism, a radar rotator, and a lidar;

[0039] The extension direction of the linear motion mechanism is the same as the direction of the vertical downward projection of the flexible shaft;

[0040] The lidar is mounted on the linear motion mechanism via the lidar rotator and is used to monitor the radius of curvature of the flexible shaft.

[0041] In one embodiment, the linear motion mechanism includes a fixed bracket, a motor, a coupling, a lead screw, a guide rail, and a slide table;

[0042] The fixed bracket is fixedly mounted on the working platform;

[0043] Two guide rails are provided, and the two guide rails are arranged parallel to each other on the fixed bracket;

[0044] The slide table is slidably connected to the guide rail;

[0045] The lead screw is connected to the middle thread of the slide table for transmission.

[0046] The motor is fixedly connected to one end of the lead screw via the coupling;

[0047] The radar rotator is mounted on top of the slide.

[0048] In one embodiment, the flexible shaft has a protective sleeve, the interior of which has a double-locking sleeve, and the first track and the second track are disposed inside the double-locking sleeve.

[0049] Compared with existing technologies, the advantages of this invention lie in integrating the friction force measurement system and the radius of curvature detection system onto the same working platform, thereby achieving simultaneous measurement of the friction force and radius of curvature of the flexible shaft under different bending states. This solves the problem that existing technologies can only measure either friction force or radius of curvature individually. The bending mechanism actively changes the bending shape of the flexible shaft, while the radius of curvature detection mechanism monitors changes in its radius of curvature in real time. Simultaneously, the internal friction force detection mechanism responds synchronously, measuring the internal friction force of the flexible shaft under different radii of curvature.

[0050] The ball rolls between the first and second tracks, simulating the transmission contact inside the flexible shaft. The frictional force it experiences is transmitted to the S-shaped tension / compression sensor through the cage. This sensor accurately converts the force signal into an electrical signal, thus enabling direct and quantitative measurement of the transmission friction force. The curvature radius detection mechanism and friction force detection mechanism of this device do not rely on specific conditions such as optical mirrors and are specifically designed for flexible shafts in mechanical transmission components. Therefore, its application scope is more focused and suitable for the field of flexible transmission, exhibiting greater professionalism and practicality. Attached Figure Description

[0051] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. In the drawings:

[0052] Figure 1 This is a schematic diagram of the friction force detection device for a wide temperature range variable curvature flexible shaft in an embodiment of the present invention;

[0053] Figure 2 For the present invention Figure 1 Enlarged view of a portion of point A in the middle;

[0054] Figure 3 For the present invention Figure 2 Enlarged view of a section at point B in the middle;

[0055] Figure 4 For the present invention Figure 2 Enlarged view of a section at point C;

[0056] Figure 5 For the present invention Figure 4 Enlarged view of a section at point D;

[0057] Figure 6 This is a schematic diagram of the linear motion mechanism in an embodiment of the present invention;

[0058] Figure 7 For the present invention Figure 6 Enlarged view of a section at point E in the middle;

[0059] Figure 8 This is a schematic diagram of the hydraulic system in an embodiment of the present invention.

[0060] Reference numerals: 1. Working platform; 2. Bending mechanism; 201. Support column; 202. Support column connecting plate; 203. Support wheel; 204. Support shaft; 205. Vertical adjustment push rod; 206. Hydraulic cylinder; 207. Horizontal adjustment groove; 208. Support plate; 3. Linear movement mechanism; 301. Motor; 302. Coupling; 303. Guide rail; 304. Lead screw; 305. Slide table; 306. Radar rotator; 307. LiDAR; 4. Hydraulic system; 401. Oil tank; 402. Hydraulic valve; 403. Oil filter; 404. Hydraulic pump; 405. 406. Oil pipe; 5. Return oil tank; 6. Flexible shaft; 501. Protective sleeve; 502. Double-lock sleeve; 503. First track; 504. Ball bearing; 505. Cage; 506. Second track; 6. Miniature carriage; 601. S-type tension / compression sensor; 602. Force measuring backplate; 603. Amplifier power supply; 604. Amplifier; 605. Data acquisition card; 606. Bluetooth module; 607. Buzzer; 608. Temperature sensor; 609. Servo motor; 610. Driver; 611. Motor power supply; 612. Pulse generator; 614. Bluetooth power switch. Detailed Implementation

[0061] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0062] Reference Figure 1This embodiment proposes a friction force detection device for a flexible shaft with a wide temperature range and variable curvature, including a working platform 1 and a bending mechanism 2 and a curvature radius detection mechanism disposed on the working platform 1. By integrating the friction force measurement system and the curvature radius detection system on the same working platform 1, the friction force and curvature radius of the flexible shaft 5 under different bending states are measured simultaneously, solving the problem that existing technologies can only measure friction force or curvature radius individually.

[0063] The bending mechanism 2 is used to bend the flexible shaft 5; the radius of curvature detection mechanism is located below the flexible shaft 5 and is used to detect the radius of curvature of the flexible shaft 5; the flexible shaft 5 has a first track 503 and a second track 506 arranged along its extension direction; the flexible shaft 5 is provided with a friction detection mechanism.

[0064] The bending mechanism 2 actively changes the bending shape of the flexible shaft 5, while the radius of curvature detection mechanism monitors the changes in its radius of curvature in real time. At the same time, the internal friction force detection mechanism can respond synchronously and measure the internal friction force of the flexible shaft 5 under different radii of curvature.

[0065] Reference Figure 2 The friction detection mechanism includes a ball 504, a cage 505, an S-shaped tension / compression sensor 601, and a miniature carriage 6. The ball 504 is disposed between the first track 503 and the second track 506 and is slidably connected to the first track 503 and the second track 506. The cage 505 is disposed outside the ball 504 and is rotatably connected to the ball 504 so that the ball 504 can roll within the cage 505. The two ends of the S-shaped tension / compression sensor 601 are fixedly connected to the cage 505 and the miniature carriage 6, respectively. The miniature carriage 6 is disposed on the second track 506.

[0066] In the above embodiment, the ball bearing 504 rolls between the first track 503 and the second track 506, simulating the transmission contact inside the flexible shaft. The frictional force it experiences is transmitted to the S-type tension / compression sensor 601 through the cage 505. This sensor can accurately convert the force signal into an electrical signal, thereby realizing direct and quantitative measurement of the transmission friction force. The curvature radius detection mechanism and friction force detection mechanism of this device do not depend on specific conditions such as optical mirrors, and are specifically designed for the flexible shaft 5 of mechanical transmission components. Therefore, its application scope is more focused and more suitable for the field of flexible transmission, and it has stronger professionalism and practicality.

[0067] In some embodiments, refer to Figure 3The friction force detection mechanism also includes a force measuring backplate 602, an amplifier power supply 603, an amplifier 604, and a data acquisition card 605 mounted on the miniature vehicle 6. One side of the force measuring backplate 602 is fixedly connected to the rear end of the miniature vehicle 6, and the other side of the force measuring backplate 602 is fixedly connected to one end of the S-shaped tension and compression sensor 601 via a force measuring cable. The amplifier 604 is electrically connected to the S-shaped tension and compression sensor 601 via a data cable. The amplifier power supply 603 is electrically connected to the amplifier 604. The data acquisition card 605 is electrically connected to the amplifier 604 via a data cable.

[0068] In the above embodiment, the raw, weak electrical signal collected by the S-type tension / compression sensor 601 is transmitted to the amplifier 604 via a data cable. The amplifier power supply 603 provides independent and stable power to the amplifier, ensuring that the signal can be amplified without loss and stably. The amplified signal is then transmitted to the data acquisition card 605 via the data cable, where the data acquisition card 605 performs a high-precision conversion from analog to digital signal. This system greatly improves the signal-to-noise ratio and accuracy of friction force measurement data.

[0069] In some embodiments, the friction detection mechanism further includes a Bluetooth module 606 and a mobile monitoring device mounted on the miniature vehicle 6; the Bluetooth module 606 is used to send the signal acquired by the acquisition card 605 to the mobile monitoring device.

[0070] In the above embodiments, the friction force signal digitized by the acquisition card 605 can be transmitted to a mobile monitoring device (such as a laptop, tablet, or smartphone) via the Bluetooth module 606 without relying on a physical data cable. This completely solves the problem of data interruption caused by wire length limitations, wire tangling, or loose interfaces during movement, making it particularly suitable for measurement scenarios when the miniature car 6 moves over long distances or within a complexly curved flexible shaft 5.

[0071] In some embodiments, the friction detection mechanism further includes a temperature sensor 608, a buzzer 607, and a Bluetooth disconnect module mounted on the miniature vehicle 6. The temperature sensor 608 monitors the ambient temperature inside the flexible shaft 5 and is communicatively connected to the Bluetooth module 606. The buzzer 607 is connected to the temperature sensor 608 via a data cable. When the ambient temperature exceeds a set temperature range, the buzzer 607 emits an alarm sound. The Bluetooth disconnect module disconnects the Bluetooth module 606 from the mobile monitoring device. This prevents unreliable or erroneous test data from being sent to the mobile monitoring device under abnormal environments (such as high temperatures causing signal drift or low temperatures causing component malfunctions), thus avoiding misleading subsequent analysis.

[0072] In the above embodiments, the device can directly and in real-time monitor the temperature of the internal testing environment of the flexible shaft 5. This enables the device to conduct experiments within a controllable temperature range. When the temperature exceeds the set range, the buzzer 607 will immediately sound an alarm, providing the experimenter with the most direct and timely on-site warning, preventing damage to precision components such as the S-type tension / compression sensor 601 and amplifier 604, or inaccurate measurement data due to abnormal temperature.

[0073] In some embodiments, refer to Figure 4 and Figure 5 The miniature car 6 has a servo motor 609, a driver 610, a pulse generator 612, and a motor power supply 611. The servo motor 609 is used to drive the miniature car 6 to move. The servo motor 609 is connected to the driver 610 through a motor power line and an encoder line. The driver 610 is connected to the motor power supply 611. The pulse generator 612 is connected to the driver 610 through a pulse line.

[0074] In the above embodiments, by integrating a servo motor 609 as a power source, and combining it with a driver 610 and a pulse generator 612, high-precision motion control capability is provided for the microcar 6. Each pulse signal emitted by the pulse generator 612 precisely controls the angle and speed of rotation of the servo motor 609 through the driver 610, thereby achieving precise control of the travel distance and speed of the microcar 6 on the second track 506 of the flexible shaft 5.

[0075] In some embodiments, the bending mechanism 2 includes a support column 201, a support plate 208, a support shaft 204, a support wheel 203, and a vertical force-applying component; two support columns 201 are arranged side by side, and the bottom of the support column 201 is fixedly connected to the working platform 1; the support plate 208 is fixedly mounted on the top of the support column 201 through a support column connecting plate 202, and the side wall of the support plate 208 has multiple horizontal adjustment grooves 207; multiple support shafts 204 are arranged in the horizontal direction, and one end of the support shaft 204 is slidably connected to the horizontal adjustment groove 207; the support wheel 203 is disposed on the other end of the support shaft 204, and the support wheel 203 is used to support the flexible shaft 5; the vertical force-applying component is disposed on the support plate 208, and is used to apply a downward thrust to the flexible shaft 5 between adjacent support wheels 203.

[0076] In the above embodiments, the horizontal distance between the multiple support wheels 203 can be easily adjusted. By changing the relative positions of these fulcrums, the bending shape of the flexible shaft 5 can be precisely controlled, thereby actively and regularly changing its radius of curvature. By setting a vertical force-applying element above the flexible shaft 5 between adjacent support wheels 203 and applying a downward thrust, one or more controllable bending points can be formed on the flexible shaft. This design can simulate the various bending shapes experienced by the flexible shaft in real working conditions such as passing around pulleys and through bends in complex mechanical systems, making the measurement data of friction and curvature more valuable for engineering reference.

[0077] In some embodiments, the vertical force-applying component includes a vertical adjustment push rod 205, a hydraulic cylinder 206, and a hydraulic system 4. The fixed end of the hydraulic cylinder 206 is fixedly connected to the support plate 208, and the movable end of the hydraulic cylinder 206 is fixedly connected to the vertical adjustment push rod 205. The vertical adjustment push rod 205 is used to contact the flexible shaft 5. As the final actuating component, the end of the vertical adjustment push rod 205 can maintain a precise contact position with the flexible shaft 5. By adjusting the pressure of the hydraulic system 4, the magnitude of the downward thrust can be precisely controlled, thereby quantitatively controlling the degree of bending of the flexible shaft 5. The hydraulic system 4 is connected to the hydraulic cylinder 206.

[0078] Reference Figure 8 The hydraulic system 4 includes an oil tank 401, hydraulic valves 402, an oil filter 403, a hydraulic pump 404, oil pipes 405, and a return oil tank 406, etc. Their connections are existing technology and will not be described in detail here. The hydraulic system 4 drives the hydraulic cylinder 206, providing a smooth, continuous, and powerful linear thrust. This force is precisely transmitted to the flexible shaft 5 through the vertical adjustment push rod 205.

[0079] In some embodiments, the radius of curvature detection mechanism includes a linear motion mechanism 3, a radar rotator 306, and a lidar 307; the extension direction of the linear motion mechanism 3 is the same as the direction in which the flexible shaft 5 extends vertically downward; the lidar 307 is mounted on the linear motion mechanism 3 via the radar rotator 306 and is used to monitor the radius of curvature of the flexible shaft 5.

[0080] The lidar 307, by emitting a laser beam and receiving signals reflected from the surface of the flexible shaft 5, can quickly and accurately acquire three-dimensional coordinate data of a large number of points on the lower surface of the flexible shaft. Mounting the lidar 307 on the linear motion mechanism 3 allows the lidar to scan along the entire projected length of the flexible shaft 5. The linear motion mechanism 3 provides longitudinal (length) movement, while the lidar rotator 306 can provide lateral or pitch rotation. Together, they ensure that the lidar 307 can comprehensively cover and scan the entire curved section of the flexible shaft 5 from the optimal angle.

[0081] In some embodiments, refer to Figure 6 and Figure 7 The linear motion mechanism 3 includes a fixed bracket, a motor 301, a coupling 302, a lead screw 304, a guide rail 303, and a slide table 305. The fixed bracket is fixedly mounted on the work platform 1. There are two guide rails 303, which are arranged parallel to each other on the fixed bracket. The slide table 305 is slidably connected to the guide rails 303. The lead screw 304 is threadedly connected to the middle of the slide table 305. The motor 301 is fixedly connected to one end of the lead screw 304 through the coupling 302. The radar rotator 306 is mounted on the top of the slide table 305.

[0082] In the above embodiment, a transmission method is adopted in which the motor 301 drives the lead screw 304 to rotate through the coupling 302, so as to accurately convert the rotational motion of the motor into the linear motion of the slide table 305. This lead screw transmission has high precision, high rigidity and self-locking capability, which can ensure that the radar rotator 306 and the lidar 307 mounted on the top of the slide table 305 can achieve precise displacement without slippage along the guide rail 303.

[0083] In some embodiments, the flexible shaft 5 has a protective sleeve 501, and the inside of the protective sleeve 501 has a double-locking sleeve 502, with a first track 503 and a second track 506 disposed inside the double-locking sleeve 502.

[0084] In one specific embodiment, friction force is measured by a miniature vehicle equipped with an S-shaped tension / compression sensor 601. The two ends of the S-shaped tension / compression sensor 601 are connected to a retainer 505 and a force-measuring backplate respectively via force-measuring wires, and the force-measuring wires are ensured to be short enough to minimize the influence of the vertical component force on the friction force measurement and improve measurement accuracy.

[0085] Since the sensor's output signal is relatively small, it is amplified by amplifier 604 and collected and converted by acquisition card 605. The output signals of the sensor and acquisition card 605 are output to the APP via Bluetooth module for remote monitoring. The Bluetooth module is also connected to the temperature sensor to realize real-time temperature monitoring. When the temperature exceeds the set temperature range (-55℃~70℃), the buzzer will sound an alarm. At this time, the power can be disconnected by Bluetooth power switch 614 to realize remote control interruption of the test.

[0086] During the measurement process, the miniature car achieves uniform speed movement through a servo control system. The servo system includes a servo motor. The servo motor is connected to the driver via motor power lines and encoder lines; the driver is connected to the power supply via driver power lines; the power supply is connected to the motor pulse generator via pulse generator power lines; the pulse generator 612 is connected to the driver via pulse lines; the power supply is equipped with a Bluetooth switch, which allows remote control of the miniature car to be turned on or off via an app.

[0087] The bending mechanism 2 achieves different degrees of bending of the flexible shaft mainly through horizontal and vertical adjusters. The vertical force-applying component pushes the flexible shaft to bend it, and the support shaft moves to different positions along the horizontal adjustment groove 207 to adjust the different distances between the support wheels 203 in the same group, so that the flexible shaft exhibits different curvatures.

[0088] The radius of curvature detection system is implemented using a ball screw slide equipped with a lidar 307. The lidar 307 emits a scanning laser to scan the curved surface of the flexible shaft, thereby acquiring point cloud information containing three-dimensional coordinate data from the lidar 307 on the flexible shaft surface. Using this coordinate data, a mathematical model (such as the least squares method) is used to fit the equation of the flexible shaft's centerline curve. Based on the fitting result, the radius of curvature of the flexible shaft can be calculated by applying the curvature formula at the target point. Furthermore, point cloud information from components such as the bottom edge of the support plate 208 may be mixed in during the scanning process; this type of information should be removed as noise to improve the accuracy of the radius of curvature measurement.

[0089] The measurement of friction and radius of curvature of the flexible shaft mechanism is mainly divided into two cases: the straight state and the bent state of the flexible shaft. When the flexible shaft is in a straight state, its curvature is 0, and its radius of curvature is close to infinite. The miniature car is controlled by a servo system on the second track of the flexible shaft. The force measuring wire drives the retainer 505 to drive the ball to make uniform linear motion. The force measured by the S-shaped tension and compression sensor 601 is the required friction force. In the straight state, the friction force is required to be 1N≤f≤4N. For the bent state of the flexible shaft, the bending mechanism 2 is used to dynamically change the magnitude and direction of the force applied to the flexible shaft through horizontal and vertical adjusters, so as to adjust different degrees of bending of the flexible shaft mechanism and thus achieve randomness of the curvature of the flexible shaft mechanism. Note: the radius of curvature R of the flexible shaft is ≤200mm. Simultaneously, the radar information emitted and received by the lidar 307 is used to scan the profile of the flexible shaft and convert it into point cloud coordinate information. After processing, the coordinate information of the central axis of the flexible shaft can be obtained, and then the radius of curvature of the flexible shaft can be calculated. The microcar is controlled by the servo system to move at a constant speed on the second track of the flexible shaft. In order to meet the requirement of friction force of 5N≤f≤8N under the bending state of the flexible shaft, the radius of curvature of the flexible shaft is relatively large. At this time, the movement of the microcar within a short distance can be regarded as uniform linear motion. Then the force measured by the S-shaped tension and compression sensor 601 is the required friction force.

[0090] The specific implementation method is as follows:

[0091] Step 1: Bending mechanism 2 achieves relatively random bending of the flexible shaft.

[0092] The vertical adjuster pushes the flexible shaft with a vertical adjustment push rod to bend the flexible shaft. The support shaft moves to different positions along the horizontal adjustment groove 207 to adjust the different distances between the support wheels 203 in the same group, so that the flexible shaft presents a bend with different curvatures.

[0093] Step 2: Measure the friction force by making the miniature car move at a constant speed.

[0094] The flexible shaft mechanism mainly consists of a protective sleeve, a double-locking sleeve, a first track, ball bearings, and a second track, with a relatively small internal space. The miniature car is equipped with an S-shaped tension / compression sensor 601 and a servo system. The miniature car is connected to the flexible shaft retainer 505 via a force-measuring cable, which is also connected to the S-shaped tension / compression sensor 601 to ensure the detection of frictional force. The S-shaped tension / compression sensor 601 is equipped with a Bluetooth module, enabling remote monitoring of real-time force data. The miniature car is controlled by a servo motor to maintain uniform linear motion on the track.

[0095] Step 3: Use LiDAR 307 to scan the flexible shaft profile and detect the radius of curvature.

[0096] A ball screw slide table equipped with a lidar 307 is positioned below the flexible shaft to perform a linear scan of the flexible shaft's profile. A rotation mechanism between the slide table and the lidar 307 assists in adjusting the lidar 307's angle, thereby supplementing the scanning area and achieving a comprehensive scan of the flexible shaft's profile. The lidar 307 emits a radar signal; after colliding with entities such as the flexible shaft, the signal bounces back to the radar's transmission point. The ball screw slide table maintains a relatively low feed speed to ensure the integrity of the collected signal. The collected radar signals yield point cloud coordinate information of the flexible shaft's profile and other entities. Point cloud coordinates other than those of the flexible shaft's profile are considered noise and removed during post-processing. Further processing of the flexible shaft's profile point cloud coordinate information allows for the calculation of the flexible shaft's centerline coordinates, enabling the fitting of the flexible shaft's centerline and subsequently calculating the flexible shaft's radius of curvature.

[0097] Step 4: The temperature sensor detects the ambient temperature inside the flexible shaft.

[0098] The miniature car is equipped with a temperature sensor connected to a buzzer. The sensor is also paired with a Bluetooth module, which transmits temperature information to an app for temperature monitoring. If the temperature exceeds the set test range of -55℃ to 70℃, the buzzer will sound an alarm. In this case, the test can be interrupted remotely via the Bluetooth power switch 614.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A wide-temperature-range variable curvature flexible shaft friction force detection device, characterized in that, It includes a working platform (1) and a bending mechanism (2) and a radius of curvature detection mechanism disposed on the working platform (1); The bending mechanism (2) is used to bend the flexible shaft (5); The radius of curvature detection mechanism is located below the flexible shaft (5) and is used to detect the radius of curvature of the flexible shaft (5); The flexible shaft (5) has a first track (503) and a second track (506) arranged along its extension direction. The flexible shaft (5) is equipped with a friction detection mechanism, which includes a ball (504), a cage (505), an S-shaped tension and compression sensor (601), and a miniature trolley (6). The ball bearing (504) is disposed between the first track (503) and the second track (506) and is slidably connected to the first track (503) and the second track (506); The retainer (505) is disposed on the outside of the ball (504) and rotatably connected to the ball (504) so ​​that the ball (504) can roll within the retainer (505); The two ends of the S-type tension and compression sensor (601) are fixedly connected to the cage (505) and the miniature vehicle (6), respectively; The miniature vehicle (6) is mounted on the second track (506).

2. The wide-temperature-range variable curvature flexible shaft friction force detection device according to claim 1, characterized in that, The friction force detection mechanism also includes a force measuring backplate (602), an amplifier power supply (603), an amplifier (604), and a data acquisition card (605) mounted on the miniature vehicle (6). One side of the force measuring backplate (602) is fixedly connected to the rear end of the miniature vehicle (6), and the other side of the force measuring backplate (602) is fixedly connected to one end of the S-shaped tension and compression sensor (601) through a force measuring pull wire. The amplifier (604) is electrically connected to the S-type tension / compression sensor (601) via a data line; The amplifier power supply (603) is electrically connected to the amplifier (604); The acquisition card (605) is electrically connected to the amplifier (604) via a data cable.

3. The wide-temperature-range variable curvature flexible shaft friction force detection device according to claim 2, characterized in that, The friction detection mechanism also includes a Bluetooth module (606) and a mobile monitoring device mounted on the miniature vehicle (6); The Bluetooth module (606) is used to send the signal acquired by the acquisition card (605) to the mobile monitoring device.

4. The wide-temperature-range variable curvature flexible shaft friction force detection device according to claim 3, characterized in that, The friction detection mechanism also includes a temperature sensor (608), a buzzer (607), and a Bluetooth disconnect module mounted on the miniature vehicle (6); The temperature sensor (608) is used to monitor the test environment temperature inside the flexible shaft (5) and is communicatively connected to the Bluetooth module (606); The buzzer (607) is connected to the temperature sensor (608) via a data cable; If the ambient temperature exceeds the set temperature range during testing, the buzzer (607) is used to emit an alarm sound, and the Bluetooth disconnect module is used to disconnect the Bluetooth module (606) from the mobile monitoring device.

5. The wide-temperature-range variable curvature flexible shaft friction force detection device according to claim 1, characterized in that, The microcar (6) has a servo motor (609), a driver (610), a pulse generator (612) and a motor power supply (611). The servo motor (609) is used to drive the miniature vehicle (6) to move; The servo motor (609) is connected to the driver (610) via a motor power line and an encoder line; The driver (610) is connected to the motor power supply (611); The pulse generator (612) is connected to the driver (610) via a pulse line.

6. The wide-temperature-range variable curvature flexible shaft friction force detection device according to claim 1, characterized in that, The bending mechanism (2) includes a support column (201), a support plate (208), a support shaft (204), a support wheel (203), and a vertical force-applying component; Two support columns (201) are arranged side by side, and the bottom of the support columns (201) is fixedly connected to the working platform (1); The support plate (208) is fixedly installed on the top of the support column (201), and the side wall of the support plate (208) has a plurality of horizontal adjustment grooves (207). Multiple support shafts (204) are provided in the horizontal direction, and one end of the support shaft (204) is slidably connected to the horizontal adjustment groove (207); The support wheel (203) is disposed on the other end of the support shaft (204), and the support wheel (203) is used to support the flexible shaft (5). The vertical force-applying component is disposed on the support plate (208) and is used to apply a downward thrust to the flexible shaft (5) between adjacent support wheels (203).

7. The wide-temperature-range variable curvature flexible shaft friction force detection device according to claim 6, characterized in that, The vertical force-applying component includes a vertical adjustment push rod (205), a hydraulic cylinder (206), and a hydraulic system (4); The fixed end of the hydraulic cylinder (206) is fixedly connected to the support plate (208), and the movable end of the hydraulic cylinder (206) is fixedly connected to the vertical adjustment push rod (205). The vertical adjustment push rod (205) is used to contact the flexible shaft (5). The hydraulic system (4) is connected to the hydraulic cylinder (206).

8. The wide-temperature-range variable curvature flexible shaft friction force detection device according to claim 1, characterized in that, The radius of curvature detection mechanism includes a linear motion mechanism (3), a radar rotator (306), and a lidar (307). The extension direction of the linear motion mechanism (3) is the same as the direction of the vertical downward projection of the flexible shaft (5); The lidar (307) is mounted on the linear motion mechanism (3) via the lidar rotator (306) and is used to monitor the radius of curvature of the flexible shaft (5).

9. The wide-temperature-range variable curvature flexible shaft friction force detection device according to claim 8, characterized in that, The linear motion mechanism (3) includes a fixed bracket, a motor (301), a coupling (302), a lead screw (304), a guide rail (303), and a slide table (305). The fixed bracket is fixedly installed on the working platform (1); Two guide rails (303) are provided, and the two guide rails (303) are arranged in parallel on the fixed bracket; The slide table (305) is slidably connected to the guide rail (303); The lead screw (304) is connected to the slide (305) by a threaded transmission at the middle. The motor (301) is fixedly connected to one end of the lead screw (304) via the coupling (302); The radar rotator (306) is mounted on top of the slide (305).

10. The wide-temperature-range variable curvature flexible shaft friction force detection device according to claim 1, characterized in that, The flexible shaft (5) has a protective sleeve (501), and the inside of the protective sleeve (501) has a double-locking sleeve (502), and the first track (503) and the second track (506) are disposed inside the double-locking sleeve (502).

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