Suspension type gravity unloading test device with adjustable boundary conditions

Abstract

The invention provides a suspension type gravity unloading test device with adjustable boundary conditions, which comprises a support frame, a slide way and a ventilation slide rail component, the slide way is fixedly arranged on the support frame, the ventilation slide rail component is slidably connected on the slide way, a slide rail connecting plate is arranged between the ventilation slide rail component and the slide way, and the slide rail connecting plate is fixedly connected with the support frame. The position of the ventilation sliding rail is adjusted and fixed through the sliding rail connecting plate, a plane fixing plate is arranged on one side of the supporting frame, the plane fixing plate and the ventilation sliding rail component are arranged in parallel, a root fixing device is arranged on the plane fixing plate and used for fixing the root of a detection piece, and an air floating sliding block is arranged on the ventilation sliding rail component and used for fixing the root of the detection piece. The air floating sliding block is connected with the ventilation sliding rail component in a sliding mode, a suspension rope is connected to the air floating sliding block, the lower end of the suspension rope is sequentially connected with a turn buckle, a spring and a tension sensor, the tail end of the suspension rope is fixedly connected to a detection piece, and convenience can be provided for influence analysis by adjusting boundary conditions according to different detection pieces in a microgravity ground test.

Description

Technical Field

[0001] The invention belongs to the field of aerospace technology experiments, and in particular relates to a suspended gravity unloading test device with adjustable boundary conditions. Background Art

[0002] During space missions, space mechanisms (such as solar panels, robotic arms, and deployable antennas) must perform complex movements (deployment, retraction, rotation, docking, etc.) with high precision and reliability in a microgravity environment. To ensure their stable operation on orbit, ground-based testing is essential to obtain accurate dynamic parameters, verify mechanism performance, and provide a data basis for on-orbit control strategies. However, the ground gravity environment significantly alters the mechanism's dynamic characteristics (such as mass distribution, inertial response, joint friction, and structural deformation), resulting in systematic deviations between key parameters such as hinge torque and friction effects and actual space conditions. Therefore, there is an urgent need to develop ground-based test equipment that can accurately simulate the microgravity environment in space and possess high dynamic response characteristics (to reproduce the transient loads in complex movements) to truly verify mechanism design, control algorithms, and system reliability.

[0003] While current mainstream microgravity simulation devices (such as suspended counterweights and air-bearing platforms) can partially compensate for gravity, their test results are often highly dependent on artificially imposed boundary conditions (such as suspension point constraints, guide mechanism friction, and air-bearing platform disturbances). These ground-imposed boundary conditions differ significantly from the free / flexible boundaries in space, resulting in the "microgravity environment" parameters acquired on the ground failing to truly reflect on-orbit conditions. Therefore, in ground-based microgravity testing, accurately analyzing and quantifying the impact of boundary conditions on test results (especially target dynamic parameters) is crucial. This not only provides a direct basis for optimizing microgravity simulation devices (such as suspension system configuration and compensation force control strategies), but also is key to ensuring that ground-based test data accurately reflects the on-orbit performance of space mechanisms and provides reliable support for stable control. This patent aims to facilitate the analysis of the impact of boundary conditions in ground-based microgravity testing. Summary of the Invention

[0004] In view of this, the present invention aims to propose a suspended gravity unloading test device with adjustable boundary conditions, so as to facilitate the analysis of the influence of boundary conditions in ground tests of space mechanisms.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows: A suspended gravity unloading test device with adjustable boundary conditions, characterized in that it comprises a support frame, a slideway, and a ventilation slide rail component, wherein the slideway is fixedly mounted on the support frame, the ventilation slide rail component is slidably connected to the slideway, a position adjustment member is provided between the ventilation slide rail component and the slideway, the ventilation slide rail moves along the slideway via the position adjustment member, and the ventilation slide rail is positioned relative to the support frame via a positioning member; A mounting plate is provided on one side of the support frame, the mounting plate is arranged parallel to the ventilation slide rail component, and a root fixing piece is provided on the mounting plate for fixing the root of the detection piece; An air-floating slider is provided on the ventilation slide rail component, and the air-floating slider is slidably connected to the ventilation slide rail component. A suspension rope is connected to the air-floating slider, and a basket bolt for adjusting the suspension force is provided on the upper part of the suspension rope, and a spring for controlling the suspension stiffness is provided in the middle part of the suspension rope. A tension sensor is provided at the lower part of the suspension rope, and the end of the suspension rope is fixedly connected to the middle part of the length direction of the detection part; the tension sensor is electrically connected to the control center display, and is used to adjust the suspension unloading force through the basket bolt and the sensor, and can monitor data in real time.

[0006] Furthermore, the support frame is formed by a combination of multiple grooved support members, the first support frame and the second support frame are arranged parallel to the upper surface of the support frame and on the same horizontal plane, the slides are respectively arranged on the first support frame and the second support frame, and the two sides of the ventilation slide rail component are slidably connected to the slides through position adjustment members. The shape of the support frame is not limited to a rectangle. Such an arrangement can ensure that the support frame is large enough.

[0007] Furthermore, the ventilation slide component is a hollow triangular prism with an air inlet on one side and a completely closed side on the other side. A row of equally spaced air outlets are provided in the middle of the two side surfaces of the ventilation slide component. After the ventilation slide component is ventilated, the air-floating slider can slide along the ventilation slide component without contact by swinging the detection part; compressed air enters from the air inlet and is discharged from the air outlet to form an air film so that the air-floating slider can slide along the ventilation slide component without contact, thereby reducing the influence of friction on the detection data.

[0008] The adjusting screw is fixedly mounted on the adjusting screw and the adjusting screw is installed in the adjusting screw position, and the adjusting screw is installed in the adjusting screw position, and the adjusting screw is installed in the adjusting screw position.

[0009] Furthermore, the lower side of the air-floating slider is composed of two rectangular inclined planes with side surfaces forming a V-shape, and the angle of the V-shape is less than 0.5° from the angle of the two side surfaces of the ventilation slide rail component; the upper surface of the air-floating slider is a rectangular plane and is arranged horizontally, the long side of the rectangular plane is parallel to the sliding direction of the air-floating slider, and the short side of the rectangular plane is perpendicular to the sliding direction of the air-floating slider, and the long sides of the rectangular plane are provided with lifting ears, and the lifting ears are connected to the suspension rope; the short sides of the rectangular plane are provided with outwardly protruding semicircular bosses, and the semicircular bosses are provided with threaded holes, and the threaded holes are provided with damping adjustment bolts; a counterweight fixing stud is provided in the center of the rectangular plane, and the counterweight fixing stud is fixedly connected to the counterweight plate with a nut, and a through hole is provided in the middle of the counterweight plate corresponding to the counterweight fixing stud arranged on the rectangular plane. By adjusting the damping adjustment bolt, the contact force of the ventilation slide rail component is changed, thereby changing the Coulomb damping between the air-floating slider component and the ventilation slide rail component. By adjusting the number of counterweights fixedly connected by the fixing studs and nuts, the mass of the air-floating slider component can be adjusted, and the lifting ears on both sides provide connection points for the suspension rope, so that the force on the air-floating slider can be balanced through the connection on both sides.

[0010] Furthermore, a semicircular soft rubber head is provided at the tail of the damping adjustment bolt. By providing the soft rubber head, the hard collision between the adjustment bolt and the contact parts is reduced, which makes it easier to smoothly adjust the Coulomb damping.

[0011] Furthermore, the root fixing device is a root clamp composed of a clamp positioning clamp, a torsion spring and a connecting clamp, one end of the torsion spring is fixedly connected to the clamp positioning clamp, and the other end is connected to the connecting clamp; the clamp positioning clamp is a rectangular plate with a through hole, which is fixedly connected to the mounting plate by a fastening screw passing through the through hole on the clamp positioning clamp; the connecting clamp is provided with a through hole, and the root of the test piece is fixedly connected to the connecting clamp by a fastener, and a torsion spring is arranged between the clamp positioning plate and the connecting clamp. During the experiment, the root stiffness control torsion spring of different stiffness can be replaced to adjust the root torsional stiffness of the test piece.

[0012] Furthermore, the torsion spring is composed of two sections of left-handed and right-handed torsion springs, and the torsion springs at both ends are connected by a central U-shaped transition ring. The ends of the two torsion springs are straight arms, and one side of the straight arms at the ends of the two torsion springs is fixedly set on a connecting splint. The connecting splint is composed of two identical splints with holes to be passed through, and the other side is fixedly connected between the fixture positioning plate and the mounting plate. The fixture positioning plate and the mounting plate are fastened by tightening screws to fix the end of the torsion spring, and the root torsional stiffness of the detection part is controlled by replacing the torsion spring.

[0013] Furthermore, when active driving is required, the root fixing part is a root driving motor, and the detection part is fixedly connected to the output shaft of the root driving motor at the root, and swings as the output shaft rotates, so as to detect the unloading state of the spatial mechanism. The root active driving boundary condition influence analysis experiment. The root fixing part is selected according to the test requirements. For tests with root fixing requirements, the mounting plate should be used as the root boundary. At this time, the root clamp should be fixedly connected to the mounting plate fixed on the support frame. For tests with root driving requirements, the root driving motor should be used as the root boundary. At this time, the sample should be connected to the root driving motor fixed on the support frame. Furthermore, the system includes a laser displacement sensor, which is fixed to one side of the inspection object via a tripod. The data collected by the laser displacement sensor is transmitted to a computer. By irradiating the inspection object with laser light near its free end, the motion trajectory data of the inspection object can be detected and analyzed in real time, enabling real-time monitoring of the object's displacement under unloading force, such as elastic deformation, plastic deformation, or loosening.

[0014] Compared with the prior art, the suspended gravity unloading test device with adjustable boundary conditions described in the present invention has the following advantages: 1. The rationality of the loading position and size of the unloading force directly determines the stability, accuracy and energy efficiency of the system. By setting the position adjustment slider of the adjustment position, the suspension unloading position can be adjusted quickly and conveniently. The core principle of unloading force loading is to dynamically match the center of gravity. The line of action of the unloading force must pass through or be close to the center of gravity of the unloaded object to avoid additional torque causing the object to tilt or rotate. This design can load the unloading force to the appropriate position according to the different parts being tested, and the suspension unloading force can be easily adjusted by adjusting the basket bolts. The stiffness of the suspension has a significant impact on the dynamic characteristics of the test part in the suspension unloading state. The appropriate size of spring can be selected according to the different test requirements to conveniently adjust the stiffness of the suspension to the appropriate range, thereby improving the efficiency of analyzing the influence of suspension stiffness on ground tests of space mechanisms.

[0015] 2. By setting the damping adjustment bolts and counterweights of the air-floating slider component, the sliding damping and inertia adjustment of the air-floating slider component can be conveniently and quickly adjusted, which facilitates the experimental analysis of the influence of the additional inertia and damping of the suspension boundary on the ground test of the space mechanism.

[0016] 3. By setting up the root clamp, the disassembly and assembly of the root stiffness control torsion spring can be facilitated. Replacing the root stiffness control torsion spring with different stiffness can adjust the root torsional stiffness of the test piece, thereby making it very convenient to adjust the root constraint stiffness of the test piece during the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings: Figure 1 This is a schematic structural diagram of a suspended gravity unloading test device with adjustable boundary conditions according to an embodiment of the present invention; Figure 2 This is a schematic structural diagram of the ventilation rail component and the position adjustment component according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the air-floating slider structure described in an embodiment of the present application; Figure 4 This is a structural diagram of the root fixing device described in Example 1 of the present application; Figure 5 The second embodiment of the present application is a structural schematic diagram of a multi-parameter adjustable root fixing device with a driven suspended gravity unloading test device.

[0018] Description of reference numerals: 1-Support frame; 101-First support frame; 102-Second support frame; 2-Ventilation slide rail component; 3-Air floating slider; 4-Detection component; 5-Suspension rope; 6-Basket bolt; 7-Spring; 8-Tension sensor; 9-Root fixing piece; 10-Root drive motor; 11-Display; 12-Position adjustment slider; 1201 Roller; 1202-Tightening adjustment piece; 13-Slideway; 14-Slide rail connecting plate; 15-Slide rail positioning groove; 16-Slide rail positioning through hole; 17-Air inlet; 18-Air outlet; 19-Lifting ear; 20-Damping adjustment bolt; 21-Semicircular soft rubber head; 22-Fixing stud; 23-Counterweight plate; 24-Clamp positioning splint; 25-Torsion spring; 26-Connecting splint; 27-Mounting plate; 28-Laser displacement sensor; 29-Tripod; 30-Computer; 31-Position adjustment piece. DETAILED DESCRIPTION

[0019] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0020] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0021] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0022] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0023] like Figure 1 As shown, a suspended gravity unloading test device with adjustable boundary conditions includes a support frame 1, a slide 13 and a ventilation slide rail component 2. The slide 13 is fixedly arranged on the support frame 1. The ventilation slide rail component 2 is slidably connected to the slide. A position adjustment member 31 is provided between the ventilation slide rail component and the slide. The ventilation slide rail moves along the slide rail via the position adjustment member and is positioned relative to the support frame via a positioning member. A mounting plate 27 is provided on one side of the support frame. The mounting plate 27 is arranged parallel to the ventilation slide rail component 2. A root fixing piece 9 is provided on the mounting plate for fixing the root of the detection piece. An air-floating slider 3 is provided on the ventilation slide rail component 2, and the air-floating slider is slidably connected to the ventilation slide rail component. A suspension rope 5 is connected to the air-floating slider. A basket bolt for adjusting the tightness of the suspension rope 5 is provided on the upper part of the suspension rope 5. A spring for controlling the suspension stiffness is provided in the middle part of the suspension rope. A tension sensor is provided at the lower part of the suspension rope. The core principle of unloading force loading is to dynamically match the center of gravity. The line of action of the unloading force must pass through or be close to the center of gravity of the unloaded object to avoid additional torque causing the object to tilt or rotate. The ventilation slide rail component is adjusted to the top of the unloading point of the detected part 4 through the position adjustment part, and the end of the suspension rope is fixedly connected to the middle unloading point of the detection part 4 in the length direction; the tension sensor is electrically connected to the control center display to display the value of the suspension unloading force, and the suspension unloading force is adjusted through the basket bolt and the sensor, and the data can be monitored in real time.

[0024] Specifically, the support frame 1 is formed by a combination of multiple grooved support members. The first support frame 101 and the second support frame 102 are arranged parallel to the upper surface of the support frame and in the same horizontal plane. The slide 13 is respectively arranged on the first support frame 101 and the second support frame 102. The two sides of the ventilation slide rail component 2 are slidably connected to the slide 13 through position adjustment members 31. The shape of the support frame is not limited to a rectangle. Such an arrangement can ensure that the support frame is large enough.

[0025] Specifically, if Figure 2 As shown, the ventilation slide member 2 is a hollow triangular prism with an air inlet 17 on one side and a completely closed side on the other side. A row of equally spaced air outlet holes 18 are provided in the middle of the two side surfaces of the ventilation slide member 2. After the ventilation slide member 2 is ventilated, the air-floating slider 3 can slide along the ventilation slide member without contact by swinging the detection part; compressed air is introduced from the air inlet hole and discharged from the air outlet hole to form an air film so that the air-floating slider can slide along the ventilation slide member without contact, thereby reducing the influence of friction on the detection data.

[0026] Specifically, the position adjustment member 31 includes a position adjustment slider 12 and a slide rail connecting plate 14. A roller 1201 is fixedly provided on the lower surface of the position adjustment slider 12. The roller 1201 slides relatively with the inner groove of the slide. The position adjustment slider 12 is also provided with a fastening adjustment member 1202 for adjusting the roller; a threaded hole is provided in the middle of the position adjustment slider 12, and the slide rail connecting plate 14 is provided with a countersunk hole corresponding to the position of the threaded hole on the position adjustment slider. The position adjustment slider 12 is fixedly connected to the slide rail connecting plate 14 by screws; the four corners of the slide rail connecting plate 14 are provided with slide rail positioning through holes 16; the lower surface of the ventilation slide rail component 2 Two slide rail positioning grooves 15 are provided, and the spacing between the two slide rail positioning grooves corresponds to the slide rail positioning through holes 16 on the four corners of the slide rail connecting plate 14. The ventilation slide rail component 2 is fixedly connected to the slide rail connecting plate 14 by screws passing through the four slide rail positioning through holes 16. The position adjustment part is arranged on the ventilation slide rail component to enable the ventilation slide rail component to move on the slide. The position of the ventilation slide rail component can be flexibly adjusted according to the needs of the experiment. The cooperation between the roller on the adjustment slider and the fastening adjustment part is similar to the caster under the table and chair. After moving to a certain position, it can be immobilized by pressing the brake lock, and it can be moved after unlocking.

[0027] Specifically, if Figure 3 As shown, the lower side of the air-floating slider 3 is composed of two rectangular inclined planes with V-shaped side surfaces, and the V-shaped angle is 0.5° less than the angle between the two side surfaces of the ventilation slide member; the upper surface of the air-floating slider 3 is a rectangular plane and is arranged horizontally, the long side of the rectangular plane is parallel to the sliding direction of the air-floating slider, and the short side of the rectangular plane is perpendicular to the sliding direction of the air-floating slider, and ears 19 are provided on both sides of the long side of the rectangular plane, and the ears 19 are connected to the suspension rope 5; the ears on both sides provide connection points for the suspension rope, and the air-floating slider can be balanced by the connection on both sides. On both sides of the short side of the rectangular plane are provided with outwardly protruding semicircular bosses, each of which is provided with a threaded hole, in which a damping adjustment bolt 20 is provided; a counterweight fixing stud 22 is provided in the center of the rectangular plane, and the counterweight fixing stud 22 is fixedly connected to a counterweight plate 23 with a nut, and a through hole is provided in the middle of the counterweight plate 23 corresponding to the counterweight fixing stud provided on the rectangular plane. By adjusting the damping adjustment bolt 20, the contact force of the ventilation slide member 2 is changed, thereby changing the Coulomb damping between the air-floating slider member 3 and the ventilation slide member 2. The weight of the air-floating slider member 3 is adjusted by adjusting the number of counterweight plates 23 fixedly connected by the fixing stud 22 and the nut.

[0028] Specifically, a semicircular soft rubber head 21 is provided at the tail of the damping adjustment bolt 20. The provision of the soft rubber head reduces the hard collision between the adjustment bolt and the contact component, making it easier to smoothly adjust the Coulomb damping.

[0029] Specifically, if Figure 4As shown, the root fixing part 9 is a root clamp composed of a clamp positioning clamp plate 24, a torsion spring 25 and a connecting clamp plate 26. One end of the torsion spring 25 is fixedly connected to the clamp positioning clamp plate 24, and the other end is connected to the connecting clamp plate 26; the clamp positioning clamp plate 24 is a rectangular plate with a through hole, which is fixedly connected to the mounting plate 27 by fastening screws passing through the through hole on the clamp positioning clamp plate 24; the connecting clamp plate 26 is provided with a through hole, and the connecting clamp plate is composed of two identical clamps with through holes. The root of the test piece is fixedly connected to the connecting clamp plate by a fastener, and a torsion spring is arranged between the clamp positioning plate and the connecting clamp plate. During the experiment, the root stiffness control torsion springs of different stiffnesses can be replaced to adjust the root torsional stiffness of the test piece.

[0030] Specifically, the torsion spring 25 is composed of two sections of left-handed and right-handed torsion springs. The torsion springs at both ends are connected by a central U-shaped transition ring. The ends of the two torsion springs are straight arms. One side of the straight arms at the ends of the two torsion springs is fixedly set on the connecting clamp 26, and the other side is fixedly connected to the other side between the fixture positioning plate 24 and the mounting plate. The root torsional stiffness of the detection part is controlled by replacing the torsion spring. The design of the torsion spring of the root clamp is used as a means to adjust the torsional stiffness of the root boundary.

[0031] Specifically, when active driving is required, the root fixing part 9 is the root driving motor, and the root of the detection part 4 is fixedly connected to the root driving motor. When the spatial mechanism is unloaded and the root is actively driven, a test can be carried out to test the influence of the suspension boundary conditions on the structural dynamic characteristics.

[0032] Specifically, the system also includes a laser displacement sensor 28, which is fixed to one side of the inspection object via a tripod 29. The data collected by the laser displacement sensor 28 is transmitted to a computer 30. By illuminating the inspection object with laser light at the measurement point, the motion trajectory data of the inspection object can be detected and analyzed in real time.

[0033] Example 1: like Figure 1 As shown, using this design tool, when conducting an analysis test on the impact of unloading state boundary conditions on a spatial mechanism, the specific steps are as follows: 1) Select the root stiffness control torsion spring 25 corresponding to the root torsional stiffness required for the test, and secure the root of the test piece 4 with the root fixing member 9. Refer to Table 1 for the selection and adjustment range of the torsion spring.

[0034] 2) Use the position adjustment part to adjust the ventilation rail component 2 to the position just above the unloading point of the inspected part 4, then press the fastening adjustment part to lock the roller to fix the position of the ventilation rail component; 3) Select the spring 7 with the required suspension stiffness for the test. Connect the test piece 4 to the lugs 19 on both sides of the air-floating slider member 3 via the suspension rope 5. Adjust the unloading force using the turnbuckle 6 connected in series to the suspension rope 5. Observe the unloading force value shown on the display 11 until the value meets the test requirements. 4) By adjusting the number of counterweights 23 on the air-floating slider component 3 to the required counterweight for the test; by adding or removing counterweights or adjusting the counterweight positions, align the center of gravity of the slider with the load-bearing center of the air film to ensure that the air film is evenly distributed on the bottom surface of the slider.

[0035] 5) Irradiating the laser of the laser displacement sensor 28 to a position close to the free end of the object to be detected can monitor the displacement of the object under the action of the unloading force in real time, such as elastic deformation, plastic deformation or loosening.

[0036] 6) Use the inflation device to ventilate the air inlet 17 of the ventilation slide member and the air outlet 18 on both sides of the ventilation slide member, so that an air film is formed between the air floating slider 3 and the ventilation slide member 2, so that the air floating slider moves on the ventilation slide member without contact.

[0037] 7) Excite the test piece with a hammer or by setting a displacement excitation. During the test, the Coulomb damping is adjusted by adjusting the damping adjustment bolt 20 on the air-floating slider component 3. The adjustment bolt controls the normal pressure between the air-floating slider and the ventilated rail component by adjusting the compression of the preloaded semicircular soft rubber head, thereby adjusting the friction force and achieving the purpose of suspended sliding damping analysis.

[0038] 8) The data collected by the tension sensor and the laser displacement sensor are transmitted to the control center and the computer 30 for monitoring and analysis. The tension sensor data monitors the unloading force of the suspension rope in real time to ensure that it matches the gravity of the object; the laser displacement sensor collects its response signal, and then the computer 30 records the data for further analysis and processing.

[0039] Example 2: like Figure 5 As shown, using this fixture, when conducting an analysis test on the influence of active drive boundary conditions on the root of a spatial mechanism in an unloaded state, the specific steps are as follows: 1) The root of the detection member is fixedly connected to the output shaft of the root drive motor 10. After the drive motor is started, the detection member can swing along with the rotation of the output shaft; 2) Use the position adjustment part to adjust the ventilation rail component 2 to the position just above the unloading point of the inspected part 4, then press the fastening adjustment part to lock the roller to fix the position of the ventilation rail component; 3) Select the spring 7 corresponding to the suspension stiffness required for the test, connect the test piece 4 to the lugs 19 on both sides of the air-floating slider member 3 via the suspension rope 5, and adjust the unloading force using the turnbuckle 6 connected in series to the suspension rope 5. Observe the unloading force value shown on the display 11 until the value shown meets the test requirements.

[0040] 4) By adjusting the number of counterweights 23 on the air-floating slider component 3 to the required counterweight for the test, and by adding or removing counterweights or adjusting the counterweight positions, the center of gravity of the slider is aligned with the load-bearing center of the air film to ensure that the air film is evenly distributed on the bottom surface of the slider.

[0041] 5) Irradiating the laser of the laser displacement sensor 28 to a position close to the free end of the object to be detected can monitor the displacement of the object under the action of the unloading force in real time, such as elastic deformation, plastic deformation or loosening.

[0042] 6) Use the inflation device to ventilate the air inlet 17 of the ventilation slide member and the air outlet 18 on both sides of the ventilation slide member, so that an air film is formed between the air floating slider 3 and the ventilation slide member 2, so that the air floating slider moves on the ventilation slide member without contact.

[0043] 7) Start the drive motor to drive the test piece to rotate along with the output shaft. During the test, the Coulomb damping is adjusted by adjusting the damping adjustment bolt 20 on the air-floating slider component 3. The adjusting bolt adjusts the compression of the pre-tightened semicircular soft rubber head to control the positive pressure between the contact surface of the air-floating slider and the ventilated slide component, thereby adjusting the friction force to achieve the purpose of suspension sliding damping analysis.

[0044] 8) The data collected by the tension sensor and the laser displacement sensor are transmitted to the control center and the computer 30 for monitoring and analysis. The tension sensor data monitors the unloading force of the suspension rope in real time to ensure that it matches the gravity of the object; the laser displacement sensor collects its response signal, and then the computer 30 records the data for further analysis and processing.

[0045] Table 1: Basis and scope of boundary condition adjustment Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than 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 they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

[0046] The embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A suspended gravity unloading test device with adjustable boundary conditions, characterized by: The ventilation slide comprises a support frame, a slideway and a ventilation slide rail component, wherein the slideway is fixedly arranged on the support frame, the ventilation slide rail component is slidably connected to the slideway, and a position adjustment member is provided between the ventilation slide rail component and the slideway. The ventilation slide rail moves along the slideway through the position adjustment member, and the ventilation slide rail and the support frame are positioned by the positioning member. A mounting plate is provided on one side of the support frame, the mounting plate is arranged parallel to the ventilation slide rail component, and a root fixing piece is provided on the mounting plate for fixing the root of the detection piece; The ventilation slide rail component is provided with an air float slider, and the air float slider is slidingly connected to the ventilation slide rail component. The air float slider is connected to a suspension rope, and the upper part of the suspension rope is provided with a basket bolt for adjusting its tightness, and the middle part of the suspension rope is provided with a spring for controlling the suspension stiffness, and the lower part of the suspension rope is provided with a tension sensor, and the end of the suspension rope is fixedly connected to the middle part of the length direction of the detection part; the tension sensor is electrically connected to the control center display.

2. The suspended gravity unloading test device with adjustable boundary conditions according to claim 1, characterized in that: The support frame is formed by a combination of multiple grooved support members, the first support frame and the second support frame are arranged parallel to the upper surface of the support frame and in the same horizontal plane, the slides are respectively arranged on the first support frame and the second support frame, and the two sides of the ventilation slide rail component are slidably connected to the slides through position adjustment members.

3. The suspended gravity unloading test device with adjustable boundary conditions according to claim 1, characterized in that: The ventilation slide component is a hollow triangular prism with an air inlet hole on one side and a completely closed side on the other side. A row of equally spaced air outlet holes are provided in the middle of the two side surfaces of the ventilation slide component. After the ventilation slide component is ventilated, the air floating slider can slide along the ventilation slide component without contact through the swing detection part.

4. The suspended gravity unloading test device with adjustable boundary conditions according to claim 1, characterized in that: The position adjustment member includes a position adjustment slider and a slide rail connecting plate, a roller is fixedly provided on the lower surface of the position adjustment slider, the roller cooperates with the inner groove of the slide to slide relative to each other, and the position adjustment slider is also provided with a fastening adjustment member for adjusting the roller; a threaded hole is provided in the middle of the position adjustment slider, and the slide rail connecting plate is provided with a countersunk hole corresponding to the position of the threaded hole on the position adjustment slider, and the position adjustment slider is fixedly connected to the slide rail connecting plate by screws; the four corners of the slide rail connecting plate are provided with slide rail positioning through holes; Two slide rail positioning grooves are provided on the lower surface of the ventilation slide rail component. The spacing between the two slide rail positioning grooves corresponds to the slide rail positioning through holes on the four corners of the slide rail connecting plate. The ventilation slide rail component is fixedly connected to the slide rail connecting plate by screws passing through the slide rail positioning through holes.

5. The suspended gravity unloading test device with adjustable boundary conditions according to claim 1, characterized in that: The lower side of the air-floating slider is composed of two rectangular inclined planes with V-shaped side surfaces, and the angle of the V-shape is less than 0.5° from the angle between the two side surfaces of the ventilation slide rail component; the upper surface of the air-floating slider is a rectangular plane and is arranged horizontally, the long side of the rectangular plane is parallel to the sliding direction of the air-floating slider, and the short side of the rectangular plane is perpendicular to the sliding direction of the air-floating slider, and ears are provided on both sides of the long side of the rectangular plane, and the ears are connected to the suspension rope; semicircular bosses protruding outward are provided on both sides of the short side of the rectangular plane, and threaded holes are provided on the semicircular bosses, and damping adjustment bolts are provided in the threaded holes; a counterweight fixing stud is provided in the center of the rectangular plane, and the counterweight fixing stud is fixedly connected to the counterweight plate with a nut, and a through hole is provided in the middle of the counterweight plate corresponding to the counterweight fixing stud provided on the rectangular plane.

6. The suspended gravity unloading test device with adjustable boundary conditions according to claim 5, characterized in that: A semicircular soft rubber head is provided at the tail of the damping adjustment bolt.

7. The suspended gravity unloading test device with adjustable boundary conditions according to claim 1, characterized in that: The root fixing part is a root clamp composed of a clamp positioning clamp plate, a torsion spring and a connecting clamp plate, one end of the torsion spring is fixedly connected to the clamp positioning clamp plate, and the other end is connected to the connecting clamp plate; the clamp positioning clamp plate is a rectangular plate with a through hole, which is fixedly connected to the mounting plate by a fastening screw passing through the through hole on the clamp positioning clamp plate; the connecting clamp plate is provided with a through hole, and the root of the detection part is fixedly connected to the connecting clamp plate by a fastener.

8. The suspended gravity unloading test device with adjustable boundary conditions according to claim 7, characterized in that: The torsion spring consists of two sections of left-handed and right-handed torsion springs, and the torsion springs at both ends are connected by a central U-shaped transition ring. The ends of the two torsion springs are straight arm fixed ends. One side of the straight arms at the ends of the two torsion springs is fixedly set on the connecting splint, and the other side is fixedly connected between the fixture positioning plate and the mounting plate, and the torsion spring is clamped and fixed by fasteners.

9. The suspended gravity unloading test device with adjustable boundary conditions according to claim 1, characterized in that: When active driving is required, the root fixing member is a root driving motor, and the root of the detection member is fixedly connected to the output shaft of the root driving motor and swings as the output shaft rotates.

10. The suspended gravity unloading test device with adjustable boundary conditions according to any one of claims 1 to 9, characterized in that: It also includes a laser displacement sensor, which is fixed on one side of the detection part through a tripod. The laser of the laser displacement sensor 28 irradiates the position of the detection part close to the free end, and the data collected by the laser displacement sensor is transmitted to the computer.

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