A strength detector for screw performance detection

Abstract

The application discloses a strength detector for screw performance detection, which comprises a rack, a head clamping module, a thread assembly module, a vibration loading module and a tensile loading module, and relates to the technical field of detection devices. The strength detector for screw performance detection is coaxially arranged with the head clamping module and the thread assembly module by adopting a vertical gantry frame, and directly engages the screw rod part with the thread by screwing the thread assembly module, so that abnormal fracture caused by stress concentration at the clamping position is avoided. Meanwhile, the vibration motor is elastically mounted on the bottom plate by means of a floating platform and an elastic support mechanism, the output end of the vibration motor is connected with the thread assembly module through a dynamic force sensor, and the tensile loading module mounted on the upper cross beam is cooperated, so that axial tensile load and high-frequency vibration excitation are synchronously applied to the measured screw on the same device, the detection working condition is true, and the composite stress state that the screw simultaneously bears the pre-tightening force and vibration in actual service is restored.

Description

Technical Field

[0001] This invention relates to the field of testing device technology, and in particular to a strength detector for testing the performance of screws. Background Technology

[0002] As a basic fastener, screws are widely used in machinery manufacturing, construction engineering, automotive industry, aerospace and other fields. In actual service, screws often bear axial preload tensile load and continuous vibration excitation from equipment operation. Tensile strength and vibration loosening resistance are two core indicators for measuring the overall quality of screws. The former directly determines the load-bearing capacity of screws under static load, while the latter is related to the connection reliability under dynamic working conditions.

[0003] In the process of realizing this invention, the inventors discovered at least the following problems in the prior art: Currently, existing equipment for screw performance testing generally suffers from limited functionality and distorted simulation of operating conditions. On the one hand, conventional universal testing machines can only perform static tensile tests, and their clamping method often uses wedge-shaped jaws to directly engage the threaded section, which easily causes stress concentration at the clamping point, leading to abnormal screw fracture and making it difficult to obtain accurate tensile strength data. On the other hand, existing vibration testing devices typically only perform loosening tests on standard bolt specimens and cannot introduce high-frequency vibration excitation while applying axial preload. The test conditions are severely disconnected from actual service conditions. This disconnect between tensile and vibration functions and the deviation of the test method from the actual stress state has become a prominent technical bottleneck restricting the improvement of screw performance testing accuracy and efficiency.

[0004] Therefore, the aforementioned technical problems need to be solved. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention proposes a strength detector for screw performance testing, which solves the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the basic technical solution proposed by this invention is as follows: A strength detector for testing screw performance includes: The frame is a vertical gantry structure, including a base plate, columns, and an upper crossbeam; The head clamping module is installed below the upper crossbeam and is used to fix the head of the screw being tested. Its clamping axis is distributed along the vertical direction. The thread assembly module is located below the head clamping module and is used to engage with the threaded shank of the screw being tested. The vibration loading module is installed above the base plate and includes a floating platform, an elastic support mechanism and a vibration motor. The vibration motor is fixed on the floating platform and its output end is connected to the thread assembly module through a dynamic force sensor to apply vibration to the screw under test. The tensile loading module is installed on the upper crossbeam and connected to the head clamping module, and is used to apply tensile load to the screw being tested.

[0007] Preferably, the head clamping module adopts a straight wedge self-locking clamping structure, including: A fixed plate, horizontally installed, has three guide grooves on its surface that extend radially and penetrate the thickness of the plate body; Three grippers are slidably embedded in the corresponding guide grooves. The top of each gripper extends upward through the guide groove and forms an outer conical surface. A gripping block for contacting the screw head is installed at the lower part of each gripper. The movable cone sleeve is located above the fixed plate, and its bottom is provided with an inner cone surface that fits properly with the outer cone surface; A clamping actuator is used to drive the movable tapered sleeve to move axially, and through the tapered surface engagement, the three jaws synchronously retract radially inward to clamp the screw head, or synchronously expand radially outward to release the screw head. A reset spring is provided between the guide groove and the gripper, which is used to drive the gripper to open and reset radially outward when the movable cone sleeve releases the pressure on the gripper.

[0008] Preferably, the lower inner side of the gripper is provided with a U-shaped groove, and the clamping block is hinged to the U-shaped groove by a rotating shaft. The clamping block is a regular triangular prism structure, and its three working surfaces are respectively provided with: a conical groove for adapting to countersunk screws; a concave spherical groove for adapting to ball head or hemispherical head screws; and a flat recessed groove for adapting to cylindrical head or hexagonal head screws.

[0009] Preferably, spring beads distributed vertically are embedded on the inner side of the U-shaped groove away from the bottom of the gripper, and positioning grooves that engage with and match the spring beads are provided at the three apex corners of the top surface of the clamping block.

[0010] Preferably, the clamping actuator is suspended below the tensile loading module via a static tensile / compression sensor. The tensile loading module includes a tensile actuator mounted on the upper crossbeam. The output end of the tensile actuator passes through the upper crossbeam and is fixedly connected to a lifting frame. The lifting frame is slidably assembled with the column via a linear guide pair. The bottom of the static tensile / compression sensor is rigidly connected to the clamping actuator and the fixed plate via an adapter.

[0011] Preferably, the threaded assembly module includes: A threaded sleeve has an internal thread section at the top for accommodating a screw shank and a tapered shank at the bottom. A hexagonal screwing part is provided outside the internal thread section and above the tapered shank. An external thread section extends downward from the bottom end of the tapered shank, and a lock nut is screwed onto the external thread section. The base is fixed to the top of the dynamic force sensor. The top of the base is provided with a conical hole for the conical shank to be adapted, and the bottom is provided with a limiting groove for the locking nut to be adapted and accommodated. A through hole for the external thread section to pass through is connected between the conical hole and the limiting groove.

[0012] Preferably, the top of the threaded sleeve is provided with a relief section, which is the optical axis with an outer diameter smaller than the inner circle diameter of the three jaws in the clamping state. When the screw head is clamped, the relief section can extend into the space between the three jaws to avoid interference with the jaws.

[0013] Preferably, the elastic support mechanism consists of several air springs arranged in a rectangular array between the floating platform and the base plate. The vibration loading module further includes a vertical guide mechanism, which includes at least two guide rods and linear bearings that cooperate with them. The guide rods are vertically fixed to the base plate, and the linear bearings are embedded in the floating platform.

[0014] Preferably, a plurality of leveling and shock-absorbing pads arranged in a rectangular array are fixedly installed on the bottom surface of the base plate to support and level the frame.

[0015] The beneficial effects of this invention are: The technical solution of this invention employs a vertical gantry frame to coaxially arrange the head clamping module and the thread assembly module in the vertical direction. The thread assembly module engages with the screw shank instead of directly engaging the threads with the traditional clamp, thus separating the screw clamping area from the actual stress-bearing area. This avoids abnormal fractures caused by stress concentration at the clamping point. Simultaneously, a floating platform and elastic support mechanism elastically mount the vibration motor on the base plate, connecting its output end to the thread assembly module via a dynamic force sensor. This motor works in conjunction with the tensile loading module mounted on the upper beam, enabling simultaneous application of axial tensile load and high-frequency vibration excitation to the screw under test on the same equipment. This accurately reflects the combined stress state of the screw under preload and vibration during actual service, significantly improving the accuracy and efficiency of screw tensile strength and vibration-resistant loosening performance testing. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the frame structure of the present invention; Figure 3This is a schematic diagram of the vibration loading module of the present invention; Figure 4 This is a schematic diagram of the head clamping module of the present invention; Figure 5 This is a schematic cross-sectional view of the movable cone sleeve of the present invention; Figure 6 This is a schematic diagram of the structure of the fixing disk of the present invention; Figure 7 This is a schematic diagram of the gripper structure of the present invention; Figure 8 This is a schematic diagram of the structure of the clamping block of the present invention; Figure 9 This is a schematic diagram of the installation structure of the spring top ball of the present invention; Figure 10 This is a schematic diagram of the structure of the stretch loading module of the present invention; Figure 11 This is a schematic diagram of the installation structure of the threaded assembly module of the present invention; Figure 12 This is a schematic diagram of the threaded assembly module of the present invention; Figure 13 This is a structural diagram of a commonly available screw head type. Figure 14 This is a schematic diagram of the vertical guide mechanism of the present invention; Explanation of reference numerals in the attached figures: 100. Rack; 110. Base plate; 120. Column; 130. Upper crossbeam; 140. Linear guide pair; 1110. Leveling and shock-absorbing pads; 200. Head clamping module; 210. Fixed plate; 220. Gripper; 230. Clamping block; 240. Movable cone sleeve; 250. Clamping actuator; 260. Return spring; 270. Static tension / compression sensor; 280. Adapter; 2110. Guide groove; 2210, outer conical surface; 2220, U-shaped groove; 2230, spring-loaded ball; 2310, Rotating shaft; 2320, Conical groove; 2330, Concave spherical groove; 2340, Flat recessed groove; 2350, Positioning groove; 2410. Inner cone surface; 300. Threaded assembly module; 310. Threaded sleeve; 320. Base; 3110, Internal thread section; 3120, Tapered shank; 3130, Hexagonal screw-on part; 3140, External thread section; 3150, Lock nut; 3160, Displacement section; 3210, tapered hole; 3220, limiting groove; 3230, through hole; 400. Vibration loading module; 410. Floating platform; 420. Elastic support mechanism; 430. Vibration motor; 440. Dynamic force sensor; 450. Vertical guide mechanism; 4210. Air spring; 4510, guide rod; 4520, linear bearing; 500. Stretch loading module; 510. Tension actuator; 520. Lifting frame. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Please see Figure 1-3 This invention provides a technical solution: a strength detector for screw performance testing, comprising: a frame 100, which is a vertical gantry structure, including a base plate 110, a column 120, and an upper crossbeam 130; a head clamping module 200, installed below the upper crossbeam 130, for fixing the head of the screw to be tested, with its clamping axis distributed vertically; a thread assembly module 300, located below the head clamping module 200, for engaging with the threaded shank of the screw to be tested; a vibration loading module 400, installed above the base plate 110, including a floating platform 410, an elastic support mechanism 420, and a vibration motor 430, the vibration motor 430 being fixed on the floating platform 410, its output end being connected to the thread assembly module 300 via a dynamic force sensor 440, for applying vibration to the screw to be tested; and a tensile loading module 500, installed on the upper crossbeam 130 and connected to the head clamping module 200, for applying tensile load to the screw to be tested.

[0019] Based on the above structural configuration, the strength detector for screw performance testing comprises a frame 100, a head clamping module 200, a thread assembly module 300, a vibration loading module 400, and a tensile loading module 500. The frame 100 adopts a vertical gantry structure, with a base plate 110 serving as the load-bearing foundation for the entire device. Two uprights 120 are vertically mounted on the base plate 110, and an upper crossbeam 130 is mounted on top of the two uprights 120, forming a stable frame that provides installation support for the remaining modules. The head clamping module 200 is installed below the upper crossbeam 130, with its clamping axis distributed vertically, used to fix the head of the screw being tested from above. The thread assembly module 300 is located directly below the head clamping module 200, used for... The screw assembly module 300 is threadedly engaged with the threaded shank of the screw under test, simulating the engagement state of the screw with a nut or threaded hole in actual use. This allows vibration excitation and tensile load to be transmitted to the screw shank through a real threaded pair. The vibration loading module 400 is mounted above the base plate 110, and its vibration motor 430 is fixed on the floating platform 410. The floating platform 410 is elastically connected to the base plate 110 through an elastic support mechanism 420, so that the excitation force generated by the vibration motor 430 can be transmitted to the thread assembly module 300 through the dynamic force sensor 440, thereby applying high-frequency vibration to the screw under test. The tensile loading module 500 is mounted on the upper crossbeam 130 and connected to the head clamping module 200. It is used to apply an axial tensile load to the screw under test, which can simulate... The preload or working tension that the screw experiences in actual service is measured by the various modules arranged sequentially from top to bottom along the same vertical axis. This allows the vibration loading module 400 and the tensile loading module 500 to work independently or collaboratively, thereby achieving a composite detection function of simultaneously applying axial tensile load and high-frequency vibration excitation to the screw under test on a single device. This accurately reflects the stress state of the screw under actual working conditions. Specifically, during operation, the screw to be tested is first screwed into the thread assembly module 300 from above with the shank facing down, so that the screw shank and the thread assembly module 300 form a threaded engagement. At this time, the screw head is located above the thread assembly module 300. Then, the tensile loading module 500 is activated, causing the head clamping module 200 to move vertically downwards. Okay, once the head clamping module 200 reaches the position of the screw head, it clamps and fixes the screw head. At this time, the screw is simultaneously constrained by the head clamping modules 200 at both ends and the thread assembly module 300, and is in a vertical state. After clamping is completed, the test is performed according to the testing requirements. In the static tensile test mode, the tensile loading module 500 applies an axially upward tensile load to the screw. By measuring the relationship between the tensile force and the screw elongation, the tensile strength of the screw is obtained. In the vibration test mode, the tensile loading module 500 first applies a preset axial preload to the screw, and then the vibration motor 430 is started. The excitation force generated by the vibration motor 430 is transmitted to the thread assembly module 300 via the dynamic force sensor 440.The vibration energy is then transmitted to the screw shank via a threaded connection, applying vibration to the screw. The vibration motor 430 is fixed on the floating platform 410, which is elastically connected to the base plate 110 via an elastic support mechanism 420, concentrating the vibration energy to the sample and reducing its diffusion to the frame 100. The dynamic force is monitored by the dynamic force sensor 440, which can evaluate the screw's anti-loosening performance under vibration conditions. In the tensile-vibration composite test mode, the tensile loading module 500 and the vibration loading module 400 work together to simultaneously apply tensile load and vibration excitation to the screw, simulating the composite stress state of the screw in actual service. After the test, if the screw breaks under tensile load, the head clamping module 200 releases the remaining head part and removes it, and the remaining shank part is unscrewed from the thread assembly module 300. If the screw fails to loosen under vibration conditions, the head clamping module 200 releases and the screw is removed directly. If a preset cyclic vibration test is performed before failure, the head clamping module 200 releases and the screw is removed as a whole. The strength detector for screw performance testing, screwed out of the thread assembly module 300, uses a vertical gantry frame 100 to coaxially arrange the head clamping module 200 and the thread assembly module 300 vertically. The thread assembly module 300 engages with the screw shank instead of directly engaging the thread with a traditional clamp, separating the screw clamping area from the actual stress-bearing area. This avoids abnormal fractures caused by stress concentration at the clamping point. Simultaneously, a vibration motor 430 is elastically mounted on the base plate 110 via a floating platform 410 and an elastic support mechanism 420. Its output is connected to the thread assembly module 300 via a dynamic force sensor 440 and works in conjunction with the tensile loading module 500 mounted on the upper beam 130. This allows for the simultaneous application of axial tensile load and high-frequency vibration excitation to the screw under test on the same equipment. This accurately reflects the combined stress state of the screw under preload and vibration during actual service, significantly improving the accuracy and efficiency of screw tensile strength and vibration-resistant loosening performance testing.

[0020] Further, please refer to Figure 4-7The head clamping module 200 adopts a straight wedge self-locking clamping structure, including: a fixed plate 210, horizontally mounted, with three radially extending guide grooves 2110 on its surface that penetrate the thickness of the plate; three grippers 220, which are slidably embedded in their respective guide grooves 2110, with the top of each gripper 220 penetrating the guide groove 2110 upwards and forming an outer conical surface 2210, and a clamping block 230 for contacting the screw head installed at the lower part of the gripper 220; and a movable conical sleeve 240 located on the fixed plate 210. Above, at its bottom, there is an inner conical surface 2410 that fits properly with the outer conical surface 2210; a clamping actuator 250 is used to drive the movable conical sleeve 240 to move axially, and through the conical surface cooperation, the three jaws 220 synchronously retract radially inward to clamp the screw head, or synchronously expand radially outward to release the screw head; and a return spring 260 is disposed between the guide groove 2110 and the jaws 220, and is used to drive the jaws 220 to open radially outward to return to their original position when the movable conical sleeve 240 releases the pressure on the jaws 220.

[0021] When the head clamping module 200 is working, the clamping actuator 250 drives the movable cone sleeve 240 to move downward. The inner cone surface 2410 of the movable cone sleeve 240 simultaneously presses the outer cone surface 2210 of the top of the three jaws 220. Under the wedge action of the cone surface, the three jaws 220 move radially towards the center along the guide groove 2110 of the fixed plate 210. The clamping block 230 installed at the lower part of the jaws 220 closes down accordingly, and evenly clamps the screw head from three directions to achieve automatic centering and clamping. Since the cone surface has a force amplification effect, a small driving force can generate a large radial clamping force, ensuring reliable clamping. When it is necessary to loosen the screw, the clamping actuator 250 drives the movable cone sleeve 240 to move upward. The inner cone surface 2410 and the outer cone surface 2210 disengage. Under the elastic force of the return spring 260, the jaws 220 open outward and reset along the guide groove 2110, releasing the screw head.

[0022] Further, please refer to Figure 7 and Figure 8 The lower inner side of the gripper 220 is provided with a U-shaped groove 2220. The clamping block 230 is hinged in the U-shaped groove 2220 through a rotating shaft 2310. The clamping block 230 is a regular triangular prism structure. Its three working surfaces are respectively provided with: a conical groove 2320 for adapting to countersunk screws; a concave spherical groove 2330 for adapting to ball head or hemispherical head screws; and a flat recessed groove 2340 for adapting to cylindrical head or hexagonal head screws.

[0023] Combination Figure 13As shown, A-countersunk screws, B-spherical head screws, C-ball head screws, D-cylindrical head screws, and E-hexagonal head screws. The conical groove 2320 has a cone angle that matches the conical surface of the countersunk screw head, allowing for surface contact during clamping and ensuring stable clamping. The concave spherical groove 2330 has a spherical radius that adapts to the head contours of both hemispherical and ball head screws, ensuring a close fit without damaging the screw head surface during clamping. The flat recessed groove 2340 adapts to the flat end faces of both cylindrical and hexagonal head screws, using a recessed step to axially limit and circumferentially position the screw head. When testing screws with different head types, the operator only needs to rotate the clamping block 230 to align the working surface matching the screw head type towards the inner center, thus completing the head type switching without disassembling or replacing any parts.

[0024] Further, please refer to Figure 8 and Figure 9 The inner side of the U-shaped groove 2220 away from the bottom of the gripper 220 is fitted with spring top beads 2230 distributed in the vertical direction, and the three corners of the top surface of the clamping block 230 are provided with positioning grooves 2350 that are adapted to engage with the spring top beads 2230.

[0025] When the operator needs to switch working surfaces, the clamping block 230 is rotated. After rotating to the target working surface, the top ball is engaged in the corresponding positioning groove 2350 under the action of the spring force, producing a clear sense of positioning and indicating to the operator that the position has been switched. At the same time, the engagement between the spring top ball 2230 and the positioning groove 2350 can circumferentially position the clamping block 230, preventing the clamping block 230 from rotating freely during clamping and testing, and ensuring that the working surface always faces the screw head accurately.

[0026] Further, please refer to Figure 1 and Figure 10 The clamping actuator 250 is suspended below the tension loading module 500 via the static tension and compression sensor 270. The tension loading module 500 includes a tension actuator 510 mounted on the upper crossbeam 130. The output end of the tension actuator 510 passes through the upper crossbeam 130 and is fixedly connected to a lifting frame 520. The lifting frame 520 is slidably assembled with the column 120 via a linear guide pair 140. The bottom of the static tension and compression sensor 270 is rigidly connected to the clamping actuator 250 and the fixed plate 210 via an adapter 280.

[0027] During operation, the tension actuator 510 drives the lifting frame 520 to move vertically along the linear guide 140. The lifting frame 520 drives the clamping actuator 250 and the fixed plate 210 to move up and down synchronously through the static tension / compression sensor 270 and the adapter 280. When performing a tensile test, the tension actuator 510 drives the lifting frame 520 to move upward. The tensile load is transmitted to the screw head in sequence through the static tension / compression sensor 270, the adapter 280, the fixed plate 210, the gripper 220 and the clamping block 230. The static tension / compression sensor 270 is connected in series in the force transmission path to directly measure the axial force acting on the screw and outputs the force signal to the control system in real time. Since the static tension / compression sensor 270 is arranged on one side of the fixed end and is independent of the vibration loading module 400 below, the inertial force generated during vibration loading will not interfere with the static force measurement, ensuring the accurate separation of static force and dynamic force measurement.

[0028] Further, please refer to Figure 11 and Figure 12 The threaded assembly module 300 includes: a threaded sleeve 310, the upper part of which is an internal threaded section 3110 for accommodating the screw rod, and the lower part is a tapered shank 3120. A hexagonal screwing part 3130 is provided outside the internal threaded section 3110 and above the tapered shank 3120. An external threaded section 3140 extends downward from the bottom end of the tapered shank 3120, and a locking nut 3150 is screwed onto the external threaded section 3140; a base 320, fixed to the top of the dynamic force sensor 440, with a tapered hole 3210 adapted to the tapered shank 3120 at the top and a limiting groove 3220 for accommodating the locking nut 3150 at the bottom. A through hole 3230 for the external threaded section 3140 to pass through is connected between the tapered hole 3210 and the limiting groove 3220.

[0029] When installing the threaded sleeve 310, first place the locking nut 3150 in the limiting groove 3220 at the bottom of the base 320. The limiting groove 3220 limits the locking nut 3150 circumferentially and axially, so that it can only move slightly axially within the groove and cannot rotate. Then, insert the tapered shank 3120 into the tapered hole 3210 of the base 320 from top to bottom. The external threaded section 3140 at the bottom of the tapered shank 3120 passes through the through hole 3230 and extends into the limiting groove 3220, contacting the pre-placed locking nut 3150. At this time, the operator uses a wrench to hold the hexagonal turning part 3130 and rotate the threaded sleeve 310. The external threaded section 3140 rotates accordingly and gradually screws into the locking nut 3150. As the threaded sleeve 310 continues to rotate, the locking nut 3150 is constrained by the limiting groove 3220 and cannot rotate. Under the influence of the thread, the external thread section 3140 moves downward relative to the locking nut 3150. The resulting thread pull pulls the tapered shank 3120 downward into the tapered hole 3210, achieving a tight fit and reliable locking of the tapered surface. When replacing the threaded sleeve 310, the threaded sleeve 310 is rotated in the opposite direction, and the external thread section 3140 is screwed out from the locking nut 3150. The tapered shank 3120 then exits from the tapered hole 3210, making it easy to remove the threaded sleeve 310. The hexagonal screwing part 3130 is provided for the operator to use a wrench to hold and easily screw the threaded sleeve 310 into or out of the screw rod.

[0030] Further, please refer to Figure 12 The top of the threaded sleeve 310 is provided with a relief section 3160. The relief section 3160 is a light axis with an outer diameter smaller than the diameter of the inscribed circle of the three jaws 220 in the clamping state. When the screw head is clamped, the relief section 3160 can extend into the space between the three jaws 220 to avoid interference with the jaws 220.

[0031] The outer diameter of the clearance section 3160 is smaller than the diameter of the inscribed circle formed by the three jaws 220 in the clamped state. Therefore, when the screw head is clamped by the clamping block 230, the clearance section 3160 at the top of the threaded sleeve 310 can freely extend into the internal space between the jaws 220 without contacting or colliding with the jaws 220 or the clamping block 230. This structure allows the internal thread section 3110 of the threaded sleeve 310 to extend upward as far as possible to the root of the screw head, making full use of the effective thread length of the screw shank, improving the load-bearing capacity of the threaded fit and the stability of force transmission during testing.

[0032] Further, please refer to Figure 14The elastic support mechanism 420 consists of several air springs 4210, which are arranged in a rectangular array between the floating platform 410 and the base plate 110. The vibration loading module 400 also includes a vertical guide mechanism 450, which includes at least two guide rods 4510 and linear bearings 4520 that cooperate with them. The guide rods 4510 are vertically fixed on the base plate 110, and the linear bearings 4520 are embedded in the floating platform 410.

[0033] Air spring 4210 forms an elastic support between floating platform 410 and base plate 110. When vibration motor 430 works, it vibrates on air spring 4210 along with floating platform 410. The low stiffness and high damping characteristics of air spring 4210 effectively isolate the transmission of vibration energy to base plate 110 and frame 100. The guide rod 4510 of vertical guide mechanism 450 is vertically fixed on base plate 110. Linear bearing 4520 embedded in floating platform 410 is precisely slidably engaged with guide rod 4510, restricting floating platform 410 to reciprocate only in the vertical direction, eliminating lateral sway and torsion, and ensuring that the vibration direction is strictly consistent with screw axis.

[0034] Further, please refer to Figure 2 Several leveling and shock-absorbing pads 1110 arranged in a rectangular array are fixedly installed on the bottom surface of the base plate 110 to support and level the frame 100.

[0035] The leveling and shock-absorbing pads 1110 contact the ground to provide secondary shock absorption and further isolate the vibration transmission between the equipment and the ground. In addition, the support height of each pad can be adjusted to make the base plate 110 level, ensuring the verticality and centering accuracy of the entire machine installation.

[0036] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A strength detector for testing the performance of screws, characterized in that, include: The frame (100) is a vertical gantry structure, including a base plate (110), a column (120) and an upper crossbeam (130). The head clamping module (200) is installed below the upper crossbeam (130) and is used to fix the head of the screw being tested. Its clamping axis is distributed in the vertical direction. The thread assembly module (300) is located below the head clamping module (200) and is used to engage with the threaded shank of the screw being tested; The vibration loading module (400) is installed above the base plate (110) and includes a floating platform (410), an elastic support mechanism (420) and a vibration motor (430). The vibration motor (430) is fixed on the floating platform (410), and its output end is connected to the thread assembly module (300) through a dynamic force sensor (440) for applying vibration to the screw under test. The tensile loading module (500) is installed on the upper crossbeam (130) and connected to the head clamping module (200) for applying tensile load to the screw being tested.

2. A strength detector for screw performance testing according to claim 1, characterized in that, The head clamping module (200) adopts a straight wedge self-locking clamping structure, including: The fixed plate (210) is horizontally installed, and three guide grooves (2110) are provided on its surface, which extend radially and penetrate the thickness of the plate body. Three grippers (220) are slidably embedded in the corresponding guide grooves (2110). The top of the gripper (220) extends upward through the guide groove (2110) and forms an outer conical surface (2210). A clamping block (230) for contacting the screw head is installed at the lower part of the gripper (220). The movable cone sleeve (240) is located above the fixed plate (210), and its bottom is provided with an inner cone surface (2410) that fits the outer cone surface (2210). A clamping actuator (250) is used to drive the movable cone sleeve (240) to move axially, and through the cone surface engagement, the three jaws (220) synchronously retract radially inward to clamp the screw head, or synchronously expand radially outward to release the screw head; A reset spring (260) is provided between the guide groove (2110) and the gripper (220) for driving the gripper (220) to open and reset radially outward when the movable cone sleeve (240) releases the pressure on the gripper (220).

3. A strength detector for screw performance testing according to claim 2, characterized in that, The lower inner side of the gripper (220) is provided with a U-shaped groove (2220). The clamping block (230) is hinged in the U-shaped groove (2220) through a rotating shaft (2310). The clamping block (230) is a regular triangular prism structure, and its three working surfaces are respectively provided with: a conical groove (2320) for adapting to countersunk screws; a concave spherical groove (2330) for adapting to ball head or hemispherical head screws; and a flat recessed groove (2340) for adapting to cylindrical head or hexagonal head screws.

4. A strength detector for screw performance testing according to claim 3, characterized in that, The inner side of the U-shaped groove (2220) away from the bottom of the gripper (220) is fitted with spring top beads (2230) distributed in the vertical direction. The three apex corners of the top surface of the clamping block (230) are provided with positioning grooves (2350) that are adapted to engage with the spring top beads (2230).

5. A strength detector for screw performance testing according to claim 2, characterized in that, The clamping actuator (250) is suspended below the tensile loading module (500) via a static tensile and compressive sensor (270). The tensile loading module (500) includes a tensile actuator (510) mounted on the upper crossbeam (130). The output end of the tensile actuator (510) passes through the upper crossbeam (130) and is fixedly connected to a lifting frame (520). The lifting frame (520) is slidably assembled with the column (120) via a linear guide pair (140). The bottom of the static tensile and compressive sensor (270) is rigidly connected to the clamping actuator (250) and the fixed plate (210) via an adapter (280).

6. A strength detector for screw performance testing according to claim 2, characterized in that, The threaded assembly module (300) includes: The threaded sleeve (310) has an internal thread section (3110) at the upper part for accommodating the screw rod and a tapered shank (3120) at the lower part. A hexagonal screwing part (3130) is provided outside the internal thread section (3110) and above the tapered shank (3120). An external thread section (3140) extends downward from the bottom end of the tapered shank (3120), and a lock nut (3150) is screwed onto the external thread section (3140). The base (320) is fixed to the top of the dynamic force sensor (440). The top of the base is provided with a conical hole (3210) adapted to the conical shank (3120), and the bottom is provided with a limiting groove (3220) for the locking nut (3150) to be adapted and accommodated. A through hole (3230) is provided between the conical hole (3210) and the limiting groove (3220) for the external thread section (3140) to pass through.

7. A strength detector for screw performance testing according to claim 6, characterized in that, The top of the threaded sleeve (310) is provided with a relief section (3160), which is an optical axis with an outer diameter smaller than the inner circle diameter of the three jaws (220) in the clamping state. When the screw head is clamped, the relief section (3160) can extend into the space between the three jaws (220) to avoid interference with the jaws (220).

8. A strength detector for screw performance testing according to claim 1, characterized in that, The elastic support mechanism (420) consists of a plurality of air springs (4210), which are arranged in a rectangular array between the floating platform (410) and the base plate (110). The vibration loading module (400) also includes a vertical guide mechanism (450), which includes at least two guide rods (4510) and a linear bearing (4520) that cooperates with them. The guide rods (4510) are vertically fixed on the base plate (110), and the linear bearing (4520) is embedded in the floating platform (410).

9. A strength detector for screw performance testing according to claim 1, characterized in that, The bottom surface of the base plate (110) is fixedly equipped with a number of leveling and shock-absorbing pads (1110) arranged in a rectangular array, which are used to support and level the frame (100).

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