Stabilizer bar structure for limiting single degree of freedom in NVH test

Abstract

The utility model relates to the field of vibration testing, and discloses a stabilizer bar structure for limiting single degree of freedom in an NVH (Noise Vibration and Harshness) test, which is arranged between a base and a vibration table, can limit the degree of freedom of the vibration table, and comprises a fixed seat, a movable seat and a stabilizer bar body, the stabilizer bar body is arranged between the fixed seat and the movable seat and can rigidly restrain the fixed seat and the movable seat in the radial direction, limiting single-degree-of-freedom devices are arranged at the two ends of the stabilizer bar body respectively, and the stabilizer bar body is hinged to the fixed seat and the movable seat through the limiting single-degree-of-freedom devices. Through the structural design combining elastic deformation and rigid constraint, the non-target degree of freedom is precisely limited, and the problem that a traditional spring piece limiting single-degree-of-freedom device is prone to displacement in the non-target direction in a vibration test is effectively solved.

Description

Technical Field

[0001] This utility model relates to the field of vibration testing, specifically to a stabilizer bar structure for restricting a single degree of freedom in NVH testing. Background Technology

[0002] In the field of vibration testing, especially in NVH (noise, vibration, and harshness) testing, it is necessary to effectively restrict the degrees of freedom of the vibration table in order to obtain accurate test data. Currently, commonly used methods for restricting a single degree of freedom mainly include spring plate structures, slide rail structures, and rigid connection structures.

[0003] Spring plate structures are a common type of device for restricting a single degree of freedom. They achieve constraint on a vibration table in a specific direction through the elastic deformation of the spring plate. For example, CN205748870U discloses a single-degree-of-freedom torsional vibration device that uses a planar spiral spring to provide stiffness and a sleeve to restrict the vertical and lateral vibrations of the structure, providing only the torsional degree of freedom. However, in practical applications, this structure can produce displacement in non-target directions due to the nonlinear characteristics of the spring plate, leading to errors in the test data.

[0004] Slide rail structures are another commonly used method for restricting a single degree of freedom. For example, the single-degree-of-freedom ultra-low frequency vertical vibration isolation system disclosed in CN101225865B achieves passive vibration isolation in the ultra-low frequency range through the cooperation of a zero-point generating mechanism and a zero-stiffness mechanism. However, under high-frequency vibration conditions, slide rail structures are prone to generating significant noise due to friction and gaps between the slide rail and the slider, making it difficult to meet the accuracy requirements of NVH testing.

[0005] Rigid connection structures directly connect the base and the vibration table through rigid components. For example, CN103808499B discloses a method and apparatus for testing the dynamic stiffness of a vibration isolator, which uses a static loading device, a combined vibrating mass block, and an elastic simply supported beam to establish a single-degree-of-freedom damped vibration system in the vibration isolation direction. However, this type of structure is prone to fatigue fracture at the connection points under long-term impact loads, affecting the service life of the equipment.

[0006] Furthermore, existing six-degree-of-freedom vibration excitation systems, such as the one disclosed in CN104865034B, while capable of providing multi-degree-of-freedom vibration excitation, are structurally complex, costly, and difficult to precisely control vibration in a single degree of freedom. While the seismic-resistant precision mapping device disclosed in CN110701443B uses a buffer device to absorb vibrations, it primarily targets the vibration protection of mapping instruments and is not suitable for the precise limitation of the vibration table's degrees of freedom in NVH testing.

[0007] In summary, existing single-degree-of-freedom (DOF) limiting devices suffer from the following problems: First, multi-DOF interference; traditional spring-loaded single-DOF limiting devices are prone to non-target displacement during vibration testing, leading to experimental data errors. Second, they are unsuitable for NVH testing; the slide rail structure is ill-suited for high-frequency vibration conditions, generating significant noise during such conditions. Third, they lack fatigue resistance; rigid connection structures are prone to fracture under long-term impact loads, affecting equipment lifespan. Therefore, there is an urgent need for a stabilizer bar structure that can accurately limit a single degree of freedom, is suitable for NVH testing, and possesses good fatigue resistance. Utility Model Content

[0008] The present invention aims to provide a stabilizing bar structure for limiting a single degree of freedom in NVH testing, so as to limit the range of motion of the vibration table.

[0009] To achieve the above objectives, this utility model adopts the following technical solution: a stabilizer bar structure for limiting a single degree of freedom in NVH testing, positioned between a base and a vibration table to limit the degree of freedom of the vibration table, comprising a fixed base, a movable base, and a stabilizer bar body. The fixed base is fixedly connected to the base, and the movable base is fixedly connected to the vibration table. The stabilizer bar body is positioned between the fixed base and the movable base and provides radial rigid constraint to both the fixed base and the movable base. Each end of the stabilizer bar body is equipped with a single-degree-of-freedom limiting device, which is hinged to the fixed base and the movable base via the single-degree-of-freedom limiting device. Through the structural design of the single-degree-of-freedom limiting device, which combines elastic deformation with rigid constraint, non-target degrees of freedom are precisely limited, effectively solving the problem that traditional spring-loaded single-degree-of-freedom limiting devices easily generate non-target direction displacements during vibration testing.

[0010] Furthermore, the single degree of freedom limiting device includes a housing and a single degree of freedom limiting unit. The housing is fixedly connected to the stabilizer bar body. The single degree of freedom limiting unit includes an elastic rod, a connecting block, and an external rubber sleeve. One end of the elastic rod is threadedly connected to the stabilizer bar body, and the other end is threadedly connected to the connecting block. The external rubber sleeve is embedded in the housing and elastically abuts against the fixed seat or movable seat through its free end. The fixed seat and movable seat are hinged to the connecting block.

[0011] Furthermore, a flange connection end is fixed to the end of the stabilizer bar body, and the housing includes a hollow tube and a flange cover, with the hollow tube connected to the flange connection end by screws.

[0012] Furthermore, the external rubber sleeve includes a steel sleeve, the outer wall of which is fixed with a vulcanized rubber sleeve, the steel sleeve is embedded inside the flange cover, and the vulcanized rubber sleeve is located between the flange cover and the fixed seat or the movable seat.

[0013] Furthermore, the connecting block is a cone with a radially arranged variable diameter threaded hole. The variable diameter threaded hole includes a first threaded section and a second threaded section. The first threaded section is located on the narrow end side of the cone and is adapted to the elastic rod, while the second threaded section is located on the wide end side and is adapted to the connecting screw.

[0014] Furthermore, the outer rubber sleeve is fitted with an inner rubber sleeve that abuts against the free end of the connecting block, and the free end of the inner rubber sleeve abuts against the connecting block.

[0015] Furthermore, the fixed seat and the movable seat are provided with mounting holes, and the mounting holes are rotatably provided with connecting screws. The connecting screws pass through the fixed seat or the movable seat and are fixedly connected to the connecting block, pressing the internal rubber sleeve.

[0016] Furthermore, the elastic rod is a rod-shaped member made of highly elastic material and having external threaded sections at both ends.

[0017] The beneficial effects of this utility model are as follows: The structural design, combining the elastic deformation of the rubber sleeve and elastic rod with the rigid constraint of the threaded connection, can accurately restrict non-target degrees of freedom, effectively solving the problem of non-target displacement easily generated in vibration tests by traditional spring-plate single-degree-of-freedom limiting devices, and significantly improving the accuracy of test data; the rubber sleeve and elastic rod do not generate noise during deformation, making this structure particularly suitable for noise-sensitive NVH vibration testing, overcoming the defect of traditional slide rail structures generating significant noise during high-frequency vibration; the single-degree-of-freedom limiting stabilizer device adopts a modular design, supporting quick disassembly, facilitating multi-degree-of-freedom control of the vibration table, and improving the flexibility of the testing system; the high-elasticity material and split-structure design effectively disperse impact loads, significantly extending the service life of the equipment, and solving the problem of easy breakage of traditional rigid connection structures under long-term impact loads. Attached Figure Description

[0018] Figure 1 This is a three-dimensional view of an embodiment of the present utility model;

[0019] Figure 2 This is a schematic diagram of the split structure of a single-degree-of-freedom device as defined in an embodiment of the present invention;

[0020] Figure 3 This is a partial cross-sectional view of an embodiment of the present utility model;

[0021] Figure 4 This is a schematic diagram of the external sleeve structure of this utility model. Detailed Implementation

[0022] The following detailed description illustrates the specific implementation method:

[0023] The reference numerals in the accompanying drawings include: fixed seat 11, movable seat 12, stabilizer bar body 13, flange connection end 131, single degree of freedom limiting device 2, hollow tube 211, flange cover 212, elastic rod 22, connecting block 23, inner rubber sleeve 24, outer rubber sleeve 25, steel sleeve 251, and vulcanized rubber sleeve 252.

[0024] Example

[0025] The basic implementation examples are as follows: Figure 1-4 As shown, Figure 1-4 The diagram shows a stabilizer structure for restricting a single degree of freedom in NVH testing. It is positioned between the base and the shaking table and restricts the degree of freedom of the shaking table. Figure 1 As shown, it includes a single-degree-of-freedom limiting device 2, a fixed seat 11, a movable seat 12, and a stabilizing rod body 13. The single-degree-of-freedom limiting device 2 is disposed at both ends of the stabilizing rod body 13. The fixed seat 11 is fixedly connected to the base, and the movable seat 12 is fixedly connected to the vibration table.

[0026] The single-degree-of-freedom limiting device 2 includes a housing and a single-degree-of-freedom limiting unit. The housing includes a hollow tube 211 and a flange cover 212. The hollow tube 211 has a cylindrical structure, and one end of the hollow tube 211 has a flange that matches the flange connection end 131. The flange has six bolt holes evenly distributed on it, and is fixedly connected to the flange connection end 131 by M8 bolts. The flange cover 212 has a disc-shaped structure with a through hole in the center for accommodating an external rubber sleeve 25. The outer edge of the flange cover 212 has six bolt holes evenly distributed on it, and is fixedly connected to the other end of the hollow tube 211 by M8 bolts. The hollow tube 211 is connected to the flange connection end 131 by screws.

[0027] like Figure 2 As shown, the single-degree-of-freedom limiting unit includes an elastic rod 22, a connecting block 23, an outer rubber sleeve 25, and an inner rubber sleeve 24. One end of the elastic rod 22 is threadedly connected to the stabilizing rod body 13, and the other end is threadedly connected to the connecting block 23. In this embodiment, the elastic rod 22 is made of a high-elasticity alloy material, and both ends are provided with external thread sections with a thread specification of M20×1.5. The elastic modulus of the elastic rod 22 is 210 GPa, exhibiting good elastic deformation capacity and fatigue strength.

[0028] The connecting block 23 has a tapered structure. In this embodiment, the small end has a diameter of 30mm, the large end has a diameter of 40mm, and the length is 30mm. The connecting block 23 has a variable-diameter threaded hole along its center. The small end has a first threaded section with an M20×1.5 thread specification, compatible with the elastic rod 22; the large end has a second threaded section with an M16×1.5 thread specification, compatible with the connecting screw. The connecting block 23 is made of high-strength alloy steel, and its surface has been hardened to a hardness of HRC45 or higher.

[0029] The outer rubber sleeve 25 is embedded in the housing and elastically abuts against the fixed seat 11 or the movable seat 12 through its free end, such as Figure 4 As shown, the outer rubber sleeve 25 includes a steel sleeve 251 and a vulcanized rubber sleeve 252. The steel sleeve 251 has a cylindrical structure. The vulcanized rubber sleeve 252 covers the outer wall of the steel sleeve 251 in a stepped manner. In this embodiment, the vulcanized rubber sleeve 252 is made of rubber material with a hardness of Shore A60-70, which has good elasticity and vibration damping performance.

[0030] like Figure 3 As shown, the inner rubber sleeve 24 is a ring-shaped structure made of rubber material with a hardness of Shore A50-60. One end of the inner rubber sleeve 24 is pressed against the large end face of the connecting block 23, and the other end is fitted onto the embedded end of the outer rubber sleeve 25 and pressed against the end face of the flange cover 212 to form an elastic support structure.

[0031] The outer rubber sleeve 25 includes a steel sleeve 251, with a vulcanized rubber sleeve 252 fixed to the outer wall of the steel sleeve 251. The steel sleeve is embedded inside the flange cover 212, and the vulcanized rubber sleeve 252 is located between the flange cover 212 and the fixed seat 11 or the movable seat 12. The connecting block 23 is a cone with a radially arranged variable diameter threaded hole, which includes a first threaded section and a second threaded section. The first threaded section is located on the narrow end side of the cone and is adapted to the elastic rod 22, while the second threaded section is located on the wide end side and is adapted to the connecting screw. An inner rubber sleeve 24 is fitted onto the embedded end of the outer rubber sleeve 25 and abuts against the free end of the connecting block 23. The free end of the inner rubber sleeve 24 abuts against the connecting block 23. The fixed seat 11 and the movable seat 12 are provided with mounting holes, and connecting screws are rotatably installed in the mounting holes. The connecting screws pass through the fixed seat 11 or the movable seat 12 and are fixedly connected to the connecting block 23, pressing against the inner rubber sleeve 24. The elastic rod 22 is a rod-shaped member made of highly elastic material and with external threaded sections at both ends.

[0032] In this embodiment, the fixed seat 11 includes a welded base plate and a mounting plate. The base plate is fixedly connected to the base by bolts, and the mounting plate has a mounting hole in the center. The movable seat 12 has the same structure as the fixed seat 11 and is fixedly connected to the vibration table by bolts. The stabilizing rod body 13 is disposed between the fixed seat 11 and the movable seat 12 and can provide rigid constraint to the fixed seat 11 and the movable seat 12 in the radial direction.

[0033] like Figure 2 As shown, a flange connection end 131 is fixed to the end of the stabilizer bar body 13. The flange connection end 131 is a disc-shaped structure that is fixedly connected to the stabilizer bar body 13 by welding. The center of the flange connection end 131 has a threaded hole that matches the outer diameter of the threaded section of the elastic bar. Six bolt holes for connecting to the hollow tube 211 are evenly distributed on the outer edge of the flange connection end 131.

[0034] During assembly, the connecting screw passes through the mounting hole of the fixed seat 11 or the movable seat 12 and is threadedly connected to the second threaded section of the connecting block 23, and applies a preload to the internal rubber sleeve 24. The fixed seat 11 and the movable seat 12 are hinged to the connecting block 23.

[0035] In practical applications, the installation process of the stabilizer bar structure is as follows: First, the fixed seat 11 is installed on the base, and the movable seat 12 is installed on the vibration table; then, the single-degree-of-freedom limiting devices 2 at both ends of the stabilizer bar body 13 are connected to the fixed seat 11 and the movable seat 12 respectively; finally, by adjusting the tightness of the connecting screws, the preload of the inner rubber sleeve 24 and the outer rubber sleeve 25 is controlled, thereby achieving precise limitation of the degree of freedom of the vibration table.

[0036] The working principle of the stabilizer bar structure is as follows: the stabilizer bar body 13 provides radial rigid constraint on the fixed seat 11 and the movable seat 12, limiting the radial displacement of the vibration table; the single-degree-of-freedom limiting device 2, through the coordinated action of the elastic rod 22, the connecting block 23, the inner rubber sleeve 24, and the outer rubber sleeve 25, allows the vibration table to rotate to a limited extent in a specific direction, while providing rigid constraint in other directions. When the vibration table moves in the allowed degree-of-freedom direction, the elastic rod 22 undergoes elastic deformation, and the inner rubber sleeve 24 and the outer rubber sleeve 25 provide appropriate damping, ensuring that the movement of the vibration table is smooth and controllable.

[0037] The advantages of this stabilizer bar structure are: through the carefully designed single-degree-of-freedom limiting device 2, the degree of freedom of the vibration table can be precisely controlled to meet the specific requirements of NVH testing; the use of elastic rod 22 and rubber sleeve structure has good vibration reduction and damping characteristics, which can effectively suppress vibration transmission; the structure is compact, easy to install, simple to maintain, and suitable for various NVH testing scenarios.

[0038] The above descriptions are merely embodiments of this utility model. Commonly known technical solutions and / or characteristics are not described in detail here. It should be noted that the technical means used to solve problems in the above embodiments of this utility model can be combined to solve multiple technical problems simultaneously. For those skilled in the art, several modifications and improvements can be made without departing from the technical solution of this utility model, and these should also be considered within the scope of protection of this utility model. These modifications will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A stable bar structure for limiting single degree of freedom of NVH test, which is arranged between a base and a vibration table and can limit the degree of freedom of the vibration table, characterized in that: It includes a fixed seat, a movable seat, and a stabilizer bar body. The fixed seat is fixedly connected to the base, the movable seat is fixedly connected to the vibration table, and the stabilizer bar body is set between the fixed seat and the movable seat and can provide rigid constraint on the fixed seat and the movable seat in the radial direction. Each end of the stabilizer bar body is provided with a limiting single degree of freedom device, and is hinged to the fixed seat and the movable seat through the limiting single degree of freedom device.

2. The stabilizer bar structure for NVH test restriction single degree of freedom according to claim 1, characterized in that: The single degree of freedom limiting device includes a housing and a single degree of freedom limiting unit. The housing is fixedly connected to the stabilizer bar body. The single degree of freedom limiting unit includes an elastic rod, a connecting block and an external rubber sleeve. One end of the elastic rod is threadedly connected to the stabilizer bar body and the other end is threadedly connected to the connecting block. The external rubber sleeve is embedded in the housing and elastically abuts against the fixed seat or movable seat through its free end. The fixed seat and movable seat are hinged to the connecting block.

3. A stabilizer bar structure for NVH test limiting single degree of freedom according to claim 2, characterized in that: The stabilizer bar body has a flange connection end fixed to its end. The housing includes a hollow tube and a flange cover. The hollow tube is screwed to the flange connection end.

4. The stabilizer bar structure for NVH test restriction single degree of freedom according to claim 3, characterized in that: The external rubber sleeve includes a steel sleeve, the outer wall of which is fixed with a vulcanized rubber sleeve. The steel sleeve is embedded inside the flange cover, and the vulcanized rubber sleeve is located between the flange cover and the fixed seat or the movable seat.

5. A stabilizer bar structure for NVH test limiting single degree of freedom according to claim 4, characterized in that: The connecting block is a cone with a radially arranged variable diameter threaded hole. The variable diameter threaded hole includes a first threaded section and a second threaded section. The first threaded section is located on the narrow end side of the cone and is adapted to the elastic rod, while the second threaded section is located on the wide end side and is adapted to the connecting screw.

6. A stabilizer bar structure for NVH test limiting single degree of freedom according to claim 5, characterized in that: An inner rubber sleeve is fitted onto the outer rubber sleeve and abuts against the free end of the connecting block. The free end of the inner rubber sleeve abuts against the connecting block.

7. A stabilizer bar structure for NVH test limiting single degree of freedom according to claim 6, characterized in that: The fixed seat and the movable seat are provided with mounting holes, and the mounting holes are rotatably provided with connecting screws. The connecting screws pass through the fixed seat or the movable seat and are fixedly connected to the connecting block, pressing the internal rubber sleeve.

8. A stabilizer bar structure for NVH test limiting single degree of freedom according to claim 7, characterized in that: An elastic rod is a rod-shaped member made of highly elastic material and with external threaded sections at both ends.

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