A hardness testing apparatus for a badminton racket handle

Abstract

The application relates to the technical field of hardness testing, and particularly discloses a hardness testing device for a racket pole of a badminton racket, which comprises a support table, a vertical plate, a detection unit, a loading mechanism and a clamping mechanism. The vertical plate is fixed to one side of the support table and inlaid with the detection unit, the top of the vertical plate is locked with the loading mechanism, and the clamping mechanism is installed on the other side of the support table. The loading mechanism converts the rotary motion into stable and vertical linear loading motion of the pressure head through a transmission system composed of a motor, a cam piece, an L-shaped pressure rod, a connecting rod and a precision guide pair; the clamping mechanism drives the symmetrically arranged connecting rod amplification mechanism through a cylinder to make the upper and lower pressing frames move synchronously and firmly clamp the racket handle. The displacement and force sensing module integrated with the detection unit collects data in real time, an internal data processing module automatically draws a force-displacement curve and calculates the hardness value or the elastic modulus. The application realizes high precision and high efficiency of the hardness testing of the racket pole, and has the advantages of strong universality, convenient operation and objective and reliable results.

Description

Technical Field

[0001] This invention relates to the field of hardness and softness testing technology, specifically to a device for testing the hardness of a badminton racket shaft. Background Technology

[0002] A badminton racket generally consists of a head, shaft, handle, and the joint between the frame and shaft. The length of a racket does not exceed 68 centimeters, of which the handle and shaft do not exceed 42 centimeters, the frame does not exceed 25 centimeters in length, and the width is 20 centimeters. With the development of science and technology, rackets are developing towards lighter weight, stiffer frames, more flexible shafts, and less air resistance.

[0003] Currently, Chinese patent application number CN201820304165.1 discloses a device for testing the hardness of badminton racket shafts. The device includes a fixed base, a test frame welded to the top of the fixed base, a deformation drawing board embedded inside the test frame, a limiting block slidably connected to one side of the test frame on the fixed base via a sliding limiting block, a racket body embedded in the center line of the test frame via a racket placement sleeve, and a pressure rod embedded in the top center of the test frame via a ring sleeve, the pressure rod being snapped into the racket body via a ring snap-fit ​​bracket, and a weight holder welded to the top of the pressure rod. By providing a deformation drawing board, the deformation curve of the racket can be drawn on the board and compared with the original lines, thus facilitating the testing of the racket's hardness. This makes the device for testing the hardness of badminton racket shafts more convenient to use and improves its quality.

[0004] However, the existing technology uses static weight loading and manual recording on a deformation plotter, which makes the loading process difficult to control precisely and inefficient. Furthermore, the clamping mechanism does not provide sufficient constraint on the lever, which can easily introduce test errors. At the same time, the entire data acquisition and result interpretation process is highly dependent on manual labor, resulting in strong subjectivity and insufficient accuracy and objectivity in the test results. Summary of the Invention

[0005] The purpose of this invention is to provide a device for testing the hardness of badminton racket shafts, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a badminton racket shaft stiffness testing device, comprising a support, feet, a vertical plate, a detection unit, a loading mechanism, and a clamping mechanism. Feet are fixed at all four ends of the bottom of the support. A vertical plate is fixedly connected to the left rear side of the top of the support, and a detection unit is embedded inside the vertical plate. The detection unit has a built-in displacement sensing module for real-time detection of the deflection deformation of the badminton racket shaft under pressure. A loading mechanism is locked and fixed to the top of the vertical plate. A clamping mechanism is installed on the right front side of the top of the support. The loading mechanism includes a frame whose bottom rear side is fastened to the vertical plate, and the top rear side of the frame is locked and fixed. The device has a drive structure with a roller slidingly contacting its front side. The roller is rotatably connected to the inner side of the top of the pressure rod, and the bottom rear side of the pressure rod is rotatably connected to the inside of the pad. The bottom of the pad is fastened to the frame. A connecting rod is rotatably connected to the front of the pressure rod, and the bottom of the connecting rod is rotatably connected to a sliding column. The sliding column slides through the inside of the slot, and a pressure head is locked and fixed at the bottom end of the sliding column. The rear of the slot is fixed to the frame. A spring is connected to the middle side of the bottom of the pressure rod, and the bottom end of the spring is connected to the frame. A force sensing module is installed inside the connection between the pressure head and the sliding column to detect the pressure value applied by the pressure head to the badminton racket shaft in real time.

[0007] Preferably, the pressure rod has an L-shaped structure, and the two sides of the L-shaped corner are inserted and rotated inside the pad. A reinforcing rib is provided between the two L-shaped rods, and an arc-shaped groove is provided at the bottom of the pressure head.

[0008] Preferably, a rectangular through slot is provided on the front side of the top of the carrier, and the spring is disposed inside the rectangular through slot. The left and right sides of the sliding column are triangular, and the two triangular parts are slidably connected to the two V-shaped grooves inside the slot seat, respectively.

[0009] Preferably, the drive structure includes a first column and a second column respectively locked and fixed to the left and right sides of the top of the carrier frame. A first motor is locked and fixed to the left side of the first column, and a second motor is locked and fixed to the right side of the second column. A lead screw is connected to the left output end of the second motor. A threaded groove is formed on the left half of the outer surface of the lead screw, and the outer side of the threaded groove is threadedly connected to an internal threaded sleeve. A displacement block is fixedly wrapped around the outer surface of the internal threaded sleeve. A rotating sleeve is rotatably inserted through the bottom side of the displacement block. A cam is installed on the right side of the rotating sleeve, and a shaft is rotatably inserted through the rotating sleeve and the cam. The lead screw is rotatably connected to the upper side inside the first column and the second column. The shaft is rotatably connected to the middle side inside the first column and the second column, and the left side of the shaft is connected to the right output end of the first motor. The front part of the cam contacts and rotates with a roller.

[0010] Preferably, the cam component consists of three disc-shaped cams and a connecting component connected therebetween to form an integral unit. By changing the position of the shift block, the roller can sequentially contact the three disc-shaped cams.

[0011] Preferably, a sliding key is provided laterally on the outer surface of the shaft, and the sliding key is inserted and slidably inside the rotating sleeve and the cam component. The three disc-shaped cams of the cam component and the rear ends of the connecting parts are flush, and there are two connecting parts. The front sides of the two connecting parts are inclined and cooperate with the three disc-shaped cams to allow the roller to smoothly transition between the three disc-shaped cams.

[0012] Preferably, the clamping mechanism includes a slide that is fixed to the support at its bottom. An internal threaded seat is provided on the top right side of the slide, and a screw is threadedly connected to the internal threaded seat. The right end of the screw is fixed to a handwheel, and the left end of the screw is connected to a sliding plate. A support block is fixedly connected to the top of the sliding plate. Positioning units are provided on both the left and right sides of the support block to clamp and position the two sides of the badminton racket handle. The positioning unit includes a first pressing structure fixed to the front side of the support block and a second pressing structure correspondingly provided on the rear side of the support block. The first pressing structure and the second pressing structure have the same structure and size and are arranged symmetrically in opposite directions.

[0013] Preferably, the second pressing structure includes a support plate frame fixedly connected to the rear side of the support block. A cylinder is locked and fixed inside the support plate frame at the middle and rear side. A rod is connected to the front output shaft of the cylinder. Sliding sleeves are slidably connected to the upper and lower sides of the outer surface of the rod. A first support rod and a second support rod are rotatably connected to the left and right sides of the sliding sleeves, respectively. The other end of the first support rod is rotatably connected to the side of the support plate frame, and the other end of the second support rod is rotatably connected to the pressing frame. The pressing frame slides longitudinally through the front side of the support plate frame.

[0014] Preferably, the sliding sleeve, the first support rod, the second support rod, and the pressure frame are all provided in two sets, and are arranged symmetrically in the middle of the support plate frame. The connection between the second support rod and the pressure frame is located outside the sliding part between the pressure frame and the support plate frame.

[0015] Preferably, the detection unit further includes a data processing module electrically connected to the force sensing module and the displacement sensing module, configured as follows:

[0016] Receive and record the pressure value and the corresponding deflection deformation, and plot the force-displacement curve in real time;

[0017] Based on the slope of the linear segment of the force-displacement curve, the stiffness value or elastic modulus of the racket shaft is automatically calculated and output.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] This invention effectively shields external interference and potential collisions by embedding the detection unit within the upright plate, providing a stable working environment for the precision sensor and ensuring the accuracy of data acquisition from the source. Locking the loading mechanism to the top of the upright plate ensures its positional stability and alignment during frequent application of test forces, fundamentally reducing test errors caused by mechanism swaying. Simultaneously, the clamping mechanism is independently positioned in the front area of ​​the support, providing ample and unobstructed operating space for the operator, making the clamping and retrieval of the handle smoother and more efficient. This overall layout balances the inherent precision requirements of the equipment with the external human-machine interface experience.

[0020] This invention employs an integrated multi-cam drive structure, which can be axially switched via motor drive. This allows a single device to quickly provide multiple test strokes and load ranges, adapting to various pressure bar types from low to high hardness without hardware replacement, greatly enhancing the device's versatility. Simultaneously, the drive amplifies and transmits force and displacement through an L-shaped pressure bar lever mechanism, combined with a high-rigidity precision guide pair composed of a sliding column and a V-groove, ultimately converting rotational motion into pure and stable vertical linear motion of the pressure head. This not only achieves micron-level precise loading control but also effectively suppresses off-center loading and swaying, ensuring consistent test conditions.

[0021] The clamping mechanism of this invention adopts a composite structure with front-to-back symmetry and upper-lower linkage. When the cylinder is activated, the unique linkage amplification mechanism drives the upper and lower pressure frames to move synchronously and evenly toward the center, constraining the handle from multiple directions simultaneously, forming a self-centered and stable clamping effect, effectively preventing the handle from twisting, slipping, or loosening during testing. In addition, the integrated intelligent detection and data processing system can collect pressure and displacement data in real time and synchronously, automatically draw force-displacement curves, and calculate the final hardness value or elastic modulus according to a preset algorithm, minimizing subjective errors introduced by human operation, reading, and calculation, making the test results highly repeatable and authoritative. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention;

[0023] Figure 2 This is a schematic diagram of the loading mechanism of the present invention;

[0024] Figure 3 This is a schematic diagram of the driving structure of the present invention;

[0025] Figure 4 This is a schematic diagram of the clamping mechanism of the present invention;

[0026] Figure 5 This is a schematic diagram of the connection between the internal thread seat and the screw of the present invention;

[0027] Figure 6 This is a schematic diagram of the second pressure structure of the present invention;

[0028] Figure 7 For the present invention Figure 6 Left view of the second pressure structure in the middle.

[0029] In the diagram: Support-1, Foot-2, Vertical Plate-3, Detection Unit-4, Loading Mechanism-5, Clamping Mechanism-6, Frame-51, Drive Structure-52, Roller-53, Pressure Rod-54, Pad-55, Connecting Rod-56, Sliding Column-57, Slot Seat-58, Pressure Head-59, Spring-510, First Column-521, Second Column-522, First Motor-523, Second Motor-524, Lead Screw-525, Internal Threaded Sleeve -526, Shifting block -527, Rotating sleeve -528, Cam component -529, Shaft rod -5210, Slide car -61, Internal thread seat -62, Screw rod -63, Handwheel -64, Shifting plate -65, Support block -66, First pressing structure -67, Second pressing structure -68, Support plate frame -681, Cylinder -682, Straight rod -683, Slide sleeve -684, First support rod -685, Second support rod -686, Pressing frame -687. Detailed Implementation

[0030] To further explain the technical solution of the present invention, a detailed description is provided below through specific embodiments.

[0031] Please see Figure 1 This invention provides a device for testing the hardness of badminton racket shafts, including a support 1, feet 2, a vertical plate 3, a detection unit 4, a loading mechanism 5, and a clamping mechanism 6. Feet 2 are fixed to all four ends of the bottom of the support 1. The vertical plate 3 is fixedly connected to the top left rear side of the support 1, and the detection unit 4 is embedded inside the vertical plate 3. Embedding the detection unit 4 within the vertical plate 3 protects the precision sensor from external interference and collisions, while also making the device structure compact and aesthetically pleasing. The detection unit 4 has a built-in displacement sensing module for real-time detection of the deflection deformation of the badminton racket shaft under pressure, providing core deformation data for subsequent hardness calculations. The loading mechanism 5 is locked and fixed to the top of the vertical plate 3 to facilitate the application of test force downwards and ensure the positional stability of the loading mechanism 5 under frequent movements. The clamping mechanism 6 is installed on the top right front side of the support 1. Positioning the clamping mechanism 6 independently in front of the support 1 facilitates the operator's loading and unloading of the racket shaft, optimizing the human-machine operation process.

[0032] The detection unit 4 also includes a data processing module, which is electrically connected to the force sensing module and the displacement sensing module. Its configuration is as follows:

[0033] It receives and records the pressure value and the corresponding deflection deformation, and plots the force-displacement curve in real time, realizing automatic data acquisition. The force-displacement curve can intuitively reflect the elastic characteristics of the handle and provide graphical basis for analysis.

[0034] Based on the slope of the linear segment of the force-displacement curve, the system automatically calculates and outputs the stiffness value or elastic modulus of the racket shaft, completing the conversion from raw data to physical parameters and directly providing quantitative results. This eliminates human calculation errors and improves testing efficiency and objectivity.

[0035] Please see Figures 1-3 This invention provides a device for testing the hardness of badminton racket shafts. The loading mechanism 5 includes a frame 51 that is fastened to the bottom rear side of a vertical plate 3. A drive structure 52 is locked to the top rear side of the frame 51. A roller 53 is slidably contacted on the front side of the drive structure 52. Through the contact and cooperation between the drive structure 52 and the roller 53, the roller 53 converts the rotational motion into a low-friction rolling contact, effectively reducing the wear and energy loss of moving parts. The roller 53 is rotatably connected to the inner side of the top of the pressure rod 54, and the bottom rear side of the pressure rod 54 is rotatably connected to the inside of the pad 55. The bottom of the pad 55 is fastened to the frame 51 to form the fulcrum of the lever structure, so that the pressure rod 54 can swing around the pad 55 in a seesaw manner, converting the downward pressure at the rear into the downward stroke at the front.

[0036] A connecting rod 56 is rotatably connected to the front of the pressure rod 54, and the bottom of the connecting rod 56 is rotatably connected to the sliding column 57. The connecting rod 56 converts the swing of the pressure rod 54 into the linear motion of the sliding column 57. The sliding column 57 slides through the slot seat 58, and a pressure head 59 is locked and fixed at the bottom end of the sliding column 57. The rear of the slot seat 58 is fixed to the carrier 51. The slot seat 58 guides and limits the sliding column 57, ensuring that the pressure head 59 can only perform linear motion in the vertical direction, preventing uneven loading and jamming. A spring 510 is connected to the middle side of the bottom of the pressure rod 54, and the spring 510... The bottom end is connected to the carrier 51, and the spring 510 provides restoring force. After the drive structure 52 releases the force, it can automatically and quickly lift and reset the entire lever mechanism and the pressure head 59, preparing for the next test. A force sensing module is installed inside the connection between the pressure head 59 and the slide column 57 to detect the pressure value applied by the pressure head 59 to the badminton racket shaft in real time. The force sensing module is set at the position closest to the point of force application, which can measure the real load applied to the racket shaft most directly and accurately, avoiding the influence of force loss in the intermediate links on the data.

[0037] The pressure rod 54 has an L-shaped structure, and the two sides of the L-shaped corner are inserted into the pad 55 for rotation. Using the lever principle, a longer lever arm is used to amplify the displacement of the drive end, thereby obtaining a precise and controllable micro-displacement at the pressure head 59 end to adapt to the scenario where the test requires fine loading. A reinforcing rib is set between the two L-shaped rods to improve the overall structural rigidity, ensure that it deforms very little when bearing load, and ensure the accuracy of force transmission.

[0038] The bottom of the pressure head 59 has an arc-shaped groove, which increases the contact area between the pressure head 59 and the cylindrical handle, making the load distribution more uniform. At the same time, it prevents the pressure head 59 from slipping off the handle during testing, thus improving the safety and accuracy of the test. The top front side of the carrier frame 51 has a rectangular through slot, through which the spring 510 is installed. This provides space for the movement of the spring 510 and also plays a certain guiding role. The left and right sides of the sliding column 57 are triangular, and the two triangular parts are slidably connected to the two V-shaped grooves inside the slot seat 58. The cooperation between the triangular shape and the V-shaped groove forms a precision sliding pair, which has the effect of automatic centering and alignment. It can effectively eliminate gaps, ensure the high precision and high rigidity of the movement of the sliding column 57, and avoid radial swaying.

[0039] The drive structure 52 includes a first column 521 and a second column 522, which are respectively locked and fixed to the left and right sides of the top of the carrier 51, providing a solid and symmetrical support for the drive component 52 and ensuring the smooth operation of the entire drive system. A first motor 523 is locked and fixed to the left side of the first column 521, and a second motor 524 is locked and fixed to the right side of the second column 522. A lead screw 525 is connected to the left output end of the second motor 524. A threaded groove is opened on the left half of the outer surface of the lead screw 525, and the outer side of the threaded groove is threadedly connected to the inner threaded sleeve 526. The second motor 524 is used as a power source, so that the lead screw 525 converts the rotational motion of the second motor 524 into linear motion through its cooperation with the inner threaded sleeve 526. A displacement block 527 is wrapped and fixed on the outer surface of the inner threaded sleeve 526, thereby accurately positioning and holding the displacement block 527 in a designated position.

[0040] A rotating sleeve 528 rotatably runs through the bottom of the shift block 527. A cam 529 is mounted on the right side of the rotating sleeve 528. The rotating sleeve 528 allows the cam 529 to rotate freely within the shift block 527 and move laterally with the shift block 527, achieving a combined rotational and translational motion. A shaft 5210 runs through both the rotating sleeve 528 and the cam 529. The left side of the shaft 5210 is connected to the right output end of the first motor 523. The shaft 5210 serves as the core transmission shaft, responsible for transmitting the power of the first motor 523 to the cam 529. The lead screw 525 is rotatably connected to the upper side of the first column 521 and the second column 522. The shaft 5210 is rotatably connected to the middle side of the first column 521 and the second column 522 to provide support through the two columns and maintain its positional accuracy. The front of the cam 529 contacts and rotates with the roller 53 to transmit the power of the drive structure 52 to the roller 53, which is the key interface for the subsequent lever mechanism.

[0041] The cam component 529 consists of three disc-shaped cams and connecting parts that form a whole. By changing the position of the shift block 527, the roller 53 can sequentially contact the three disc-shaped cams, realizing the integration of multiple stroke specifications on one component. The appropriate cam can be switched and selected by axial movement, thereby conducting tests within the optimal range and improving testing efficiency and flexibility. The outer surface of the shaft 5210 is provided with a sliding key, which is inserted and slides inside the rotating sleeve 528 and the cam component 529, so that the cam component 529 can move with the shaft 5210. The 10-axis rotates synchronously to transmit torque and can slide on the shaft 5210 to switch positions, thus decoupling the functions of power transmission and position adjustment. The three disc-shaped cams of the cam component 529 and the rear ends of the connecting parts are flush. There are two connecting parts, and the front sides of the two connecting parts are inclined. They cooperate with the three disc-shaped cams to allow the roller 53 to smoothly transition between the three disc-shaped cams. This guides the roller 53 to slide in and out smoothly when switching between different cams, avoiding rigid impact and jamming, and ensuring the smoothness and reliability of the mechanism switching.

[0042] Please see Figure 1 , Figures 4-7 The present invention provides a hardness testing device for badminton racket shafts. The clamping mechanism 6 includes a slide 61 whose bottom is fastened to a support 1. An internal thread seat 62 is provided on the top right side of the slide 61, and a screw 63 is threadedly connected inside the internal thread seat 62. The right end of the screw 63 is fastened to a handwheel 64, and the left end of the screw 63 is connected to a moving plate 65, so as to convert the rotation of the handwheel 64 into the linear movement of the moving plate 65 through the threaded pair.

[0043] A support block 66 is fixedly connected to the top of the sliding plate 65. Positioning units are provided on both sides of the support block 66 to clamp and position the badminton racket handle on both sides, achieving symmetrical clamping of the handle and effectively preventing the racket shaft from twisting or tipping over during testing. The positioning unit includes a first pressing structure 67 fastened to the front side of the support block 66 and a second pressing structure 68 correspondingly set on the rear side of the support block 66. The first pressing structure 67 and the second pressing structure 68 have the same structure and size and are arranged symmetrically in opposite directions, ensuring a balanced distribution of clamping force, centered force on the racket shaft, avoiding the introduction of additional bending moment due to eccentric clamping, and ensuring the accuracy of test data.

[0044] The second pressing structure 68 includes a support plate frame 681 fixedly connected to the rear side of the support block 66. Inside the support plate frame 681, a cylinder 682, which serves as a power source for clamping force, is locked and fixed to the middle and rear side, providing a stable and controllable linear driving force. The output shaft at the front of the cylinder 682 is connected to a straight rod 683. Sliding sleeves 684 are slidably connected to the upper and lower sides of the outer surface of the straight rod 683. The left and right sides of the sliding sleeves 684 are respectively rotatably connected to a first support rod 685 and a second support rod 686. The other end of the first support rod 685 is rotatably connected to the side of the support plate frame 681, and the other end of the second support rod 686 is rotatably connected to the pressing frame 687. The first support rod 685 and the second support rod 686 together with the sliding sleeves 684 form an amplification mechanism, which amplifies the small stroke of the cylinder 682 into the large clamping stroke of the pressing frame 687.

[0045] The sliding sleeve 684, the first support rod 685, the second support rod 686, and the pressure frame 687 are all provided in two sets, and are arranged symmetrically in the middle of the support plate frame 681. They can apply clamping force from both the top and bottom directions at the same time, forming a self-centered clamping point, effectively restricting the vertical and horizontal freedom of the racket handle, and making the clamping more stable and reliable. The pressure frame 687 slides longitudinally through the front side of the support plate frame 681. The connection between the second support rod 686 and the pressure frame 687 is located outside the sliding point between the pressure frame 687 and the support plate frame 681, which further optimizes the stroke and force amplification ratio. This allows the cylinder 682 to drive the pressure frame 687 to generate a large clamping stroke and sufficient clamping force with a smaller thrust and stroke, realizing labor-saving and efficient power transmission.

[0046] The working principle of the badminton racket shaft stiffness testing device of the present invention is as follows:

[0047] First, during operation, the equipment is prepared and the racket handle is clamped. The handle of the badminton racket is placed in the two first pressing structures 67 and the second pressing structure 68 above the support block 66, and the cylinder 682 is activated. The cylinder 682 pushes the straight bar 683 to move away from the cylinder 682, so that the upper and lower sliding sleeves 684 slide on the straight bar 683 under the action of the first support rod 685. This drives the two second support rods 686 to transmit the linear thrust of the cylinder 682 to the two pressure frames 687 on the upper and lower sides, so that the four pressure frames 687 move closer together from the upper and lower directions, thereby stably and reliably clamping the racket handle.

[0048] Second, the drive structure 52 starts working and performs precise loading actions. The first motor 523 starts, driving the shaft 5210 and the cam 529 mounted on it to rotate at a constant speed. When the test stroke needs to be adjusted, the second motor 524 starts, driving the displacement block 527 along with the cam 529 to move laterally along the shaft 5210 through the cooperation of the lead screw 525 and the internal threaded sleeve 526. This causes the roller 53 to contact one of the three cams of different sizes, thereby realizing stepless switching of the test stroke. During the rotation, the contour of the cam 529 pushes the roller 53, converting the rotational motion into a periodic reciprocating downward pressing action.

[0049] Third, the downward pressure of the roller 53 acts on the rear end of the L-shaped pressure rod 54. The pressure rod 54 uses its connection point with the pad 55 as a fulcrum, amplifying and changing the direction of the movement at the rear end like a lever, and then pushing the slide column 57 through the connecting rod 56 at the front end. Under the precise guidance of the V-shaped groove in the slot seat 58, the slide column 57 overcomes the resistance of the spring 510 and performs a strictly vertical linear motion, ultimately causing the pressure head 59 fixed at its end to precisely press down on the racket with a set stroke. At the same time, the force sensing module embedded at the connection between the pressure head 59 and the slide column 57 detects and feeds back the pressure value applied to the racket in real time.

[0050] Fourth, the detection unit 4 operates synchronously with the data processing system to complete data acquisition, analysis, and result output. During the pressing process of the pressure head 59, the displacement sensing module in the detection unit 4 continuously monitors the deflection deformation of the racket arm. The data processing module synchronously receives pressure data from the force sensing module and displacement data from the displacement sensing module, and plots the force-displacement curve in real time. Finally, the system automatically analyzes the slope of the linear segment of the curve, calculates the stiffness value or elastic modulus of the racket arm according to the preset algorithm, and directly displays or outputs the quantitative result.

[0051] Fifth, after the subsequent test, the drive structure 52 is unloaded, and under the restoring force of the spring 510, the entire lever mechanism and the pressure head 59 quickly reset, ready for the next test; after one test, the operator can turn the handwheel 64, which drives the entire clamping mechanism 6 to move along the slide 61 through the screw 63, thereby changing the lateral position of the badminton racket, so as to change the contact position between the racket shaft and the pressure head 59, and realize the testing of different parts of the racket shaft.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for testing the hardness of a badminton racket shaft, comprising a support (1), wherein pads (2) are fixed at all four ends of the bottom of the support (1), and a vertical plate (3) is fixedly connected to the top left rear side of the support (1), and a detection unit (4) is embedded inside the vertical plate (3), wherein the detection unit (4) has a built-in displacement sensing module for real-time detection of the deflection deformation of the badminton racket shaft under pressure, characterized in that: The top of the upright plate (3) is locked with a loading mechanism (5), and the top right front side of the support (1) is equipped with a clamping mechanism (6). The loading mechanism (5) includes a frame (51) whose bottom rear side is fastened to the upright plate (3). The top rear side of the frame (51) is locked with a driving structure (52). The front side of the driving structure (52) is slidably in contact with a roller (53). The roller (53) is rotatably connected to the top inner side of the pressure rod (54), and the bottom rear side of the pressure rod (54) is rotatably connected to the inside of the pad (55). The bottom of the pad (55) is fastened to the frame (51). The pressure rod (54) A connecting rod (56) is rotatably connected to the front part, and the bottom of the connecting rod (56) is rotatably connected to the sliding column (57). The sliding column (57) slides through the inside of the slot seat (58), and the bottom end of the sliding column (57) is locked and fixed with a pressure head (59). The rear part of the slot seat (58) is fixed to the carrier frame (51). A spring (510) is connected to the middle side of the bottom of the pressure rod (54), and the bottom end of the spring (510) is connected to the carrier frame (51). A force sensing module is set inside the connection between the pressure head (59) and the sliding column (57) to detect the pressure value applied by the pressure head (59) to the badminton racket shaft in real time. The clamping mechanism (6) includes a slide (61) that is fastened to the support (1) at the bottom. An internal thread seat (62) is provided on the right side of the top of the slide (61), and a screw (63) is threaded inside the internal thread seat (62). The right end of the screw (63) is fastened to the handwheel (64), and the left end of the screw (63) is connected to the sliding plate (65). A support block (66) is fixedly connected to the top of the sliding plate (65). Positioning units are provided on both the left and right sides of the support block (66) to clamp and position the two sides of the badminton racket handle. The positioning unit includes a first pressing structure (67) fastened to the front side of the support block (66) and a second pressing structure (68) correspondingly provided on the rear side of the support block (66). The first pressing structure (67) and the second pressing structure (68) have the same structure and size and are arranged in a symmetrical manner in front and back.

2. The badminton racket shaft stiffness testing device according to claim 1, characterized in that: The pressure rod (54) has an L-shaped structure, and the two sides of the L-shaped corner are inserted and rotated inside the pad (55). A reinforcing rib is provided between the two L-shaped rods, and an arc-shaped groove is provided at the bottom of the pressure head (59).

3. The badminton racket shaft stiffness testing device according to claim 1, characterized in that: The top front side of the carrier (51) has a rectangular through slot, and the spring (510) is installed inside the rectangular through slot. The left and right sides of the sliding column (57) are triangular, and the two triangular parts are slidably connected to the two V-shaped grooves inside the slot seat (58).

4. The badminton racket shaft stiffness testing device according to claim 1, characterized in that: The drive structure (52) includes a first column (521) and a second column (522) respectively locked and fixed to the left and right sides of the top of the carrier (51). A first motor (523) is locked and fixed to the left side of the first column (521), and a second motor (524) is locked and fixed to the right side of the second column (522). A lead screw (525) is connected to the left output end of the second motor (524). A threaded groove is opened on the left half of the outer surface of the lead screw (525), and the outer side of the threaded groove is threadedly connected to an inner threaded sleeve (526). A displacement block (527) is wrapped and fixed on the outer surface of the inner threaded sleeve (526). (527) A rotating sleeve (528) is rotatably inserted through the bottom side of the inside. A cam (529) is installed on the right side of the rotating sleeve (528). A shaft (5210) is rotatably inserted through the inside of both the rotating sleeve (528) and the cam (529). The lead screw (525) is rotatably connected to the upper side inside the first column (521) and the second column (522). The shaft (5210) is rotatably connected to the middle side inside the first column (521) and the second column (522). The left side of the shaft (5210) is connected to the right output end of the first motor (523). The front part of the cam (529) contacts and rotates with the roller (53).

5. The badminton racket shaft stiffness testing device according to claim 4, characterized in that: The cam component (529) consists of three disc-shaped cams and connecting parts connected between them to form a whole. By changing the position of the shift block (527), the roller (53) can contact the three disc-shaped cams in sequence.

6. The badminton racket shaft stiffness testing device according to claim 5, characterized in that: The outer surface of the shaft (5210) is provided with a sliding key, which is inserted and slides inside the rotating sleeve (528) and the cam (529). The rear ends of the three disc-shaped cams and the connecting parts of the cam (529) are flush. There are two connecting parts, and the front sides of the two connecting parts are inclined and cooperate with the three disc-shaped cams to allow the roller (53) to smoothly transition between the three disc-shaped cams.

7. The badminton racket shaft stiffness testing device according to claim 1, characterized in that: The second pressure structure (68) includes a support plate frame (681) fixedly connected to the rear side of the support block (66). A cylinder (682) is locked and fixed inside the support plate frame (681) at the middle and rear side. A rod (683) is connected to the front output shaft of the cylinder (682). Sliding sleeves (684) are slidably connected to the upper and lower sides of the outer surface of the rod (683). A first support rod (685) and a second support rod (686) are rotatably connected to the left and right sides of the sliding sleeves (684). The other end of the first support rod (685) is rotatably connected to the side of the support plate frame (681). The other end of the second support rod (686) is rotatably connected to the pressure frame (687). The pressure frame (687) slides longitudinally through the front side of the support plate frame (681).

8. The badminton racket shaft stiffness testing device according to claim 7, characterized in that: The sliding sleeve (684), the first support rod (685), the second support rod (686) and the pressure frame (687) are all provided in two sets, and are arranged symmetrically in the middle of the support plate frame (681). The connection between the second support rod (686) and the pressure frame (687) is located outside the sliding part of the pressure frame (687) and the support plate frame (681).

9. The badminton racket shaft stiffness testing device according to claim 1, characterized in that: The detection unit (4) also has a data processing module inside, which is electrically connected to the force sensing module and the displacement sensing module, and its configuration is as follows: Receive and record the pressure value and the corresponding deflection deformation, and plot the force-displacement curve in real time; Based on the slope of the linear segment of the force-displacement curve, the stiffness value or elastic modulus of the racket shaft is automatically calculated and output.

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