A low-frequency nonlinear isolation device robust to work position deviations

Abstract

The application discloses a low-frequency nonlinear vibration isolation device which is robust to working position deviation and belongs to the technical field of mechanical vibration and noise control. In order to solve the problem that the existing nonlinear vibration isolation device has a small displacement range for obtaining low-frequency vibration isolation performance, is seriously limited and cannot meet complex actual working condition application, the vibration isolation device comprises a support frame unit, a load table unit and two nonlinear vibration isolation units. The load table unit is arranged at the center of the support frame unit in the vertical direction, the bottom of the load table unit is fixedly connected with the inner bottom surface of the support frame unit, the two nonlinear vibration isolation units are oppositely arranged on the two sides of the load table unit, one end of each nonlinear vibration isolation unit is hingedly connected with one side of the load table unit, and the other end of each nonlinear vibration isolation unit is slidingly connected with the support frame unit. The application is used for effectively isolating low-frequency vibration in the case that the working position deviates.

Description

Technical Field

[0001] This invention belongs to the field of mechanical vibration and noise control technology, and specifically relates to a low-frequency nonlinear vibration isolation device that is robust to working position deviation. Background Technology

[0002] Nonlinear vibration isolation devices with high static and low dynamic stiffness characteristics can effectively improve the stability and static load-bearing capacity of vibration isolation systems, exhibiting outstanding low-frequency vibration isolation performance. One of the main design principles of this type of vibration isolator is to achieve high static and low dynamic stiffness characteristics by connecting positive and negative stiffness elastic elements in parallel at the static equilibrium position. By rationally optimizing the geometric and stiffness parameters of the positive and negative stiffness elements, it can possess both excellent load-bearing capacity and superior low-frequency vibration isolation performance. However, existing similar vibration isolators have a small displacement range for achieving low-frequency vibration isolation performance, making their vibration isolation effect extremely sensitive to the location of the load-bearing object. This makes them unsuitable for complex actual working conditions and hinders the full realization of their theoretical performance advantages. This limitation seriously hinders their widespread application in engineering. Summary of the Invention

[0003] In order to solve the problem that existing nonlinear vibration isolation devices have a small displacement range for achieving low-frequency vibration isolation performance, which is a serious limitation and cannot meet the needs of complex actual working conditions, this invention provides a low-frequency nonlinear vibration isolation device that is robust to working position deviation.

[0004] A low-frequency nonlinear vibration isolation device with robustness to working position deviation is disclosed. The vibration isolation device includes a support frame unit, a platform unit, and two nonlinear vibration isolation units. The platform unit is vertically disposed at the center of the support frame unit, and the bottom of the platform unit is fixedly connected to the inner bottom surface of the support frame unit. The two nonlinear vibration isolation units are disposed opposite to each other on both sides of the platform unit, and one end of each nonlinear vibration isolation unit is hinged to one side of the platform unit, and the other end of each nonlinear vibration isolation unit is slidably connected to the support frame unit.

[0005] Furthermore, the support frame unit includes a U-shaped support body and two horizontal slide rails. The two horizontal slide rails are respectively arranged horizontally on one side inner wall of the U-shaped support body, and the two horizontal slide rails are symmetrically arranged along the center line of the length direction of the U-shaped support body. The axes of the two horizontal slide rails are collinear. One end of each horizontal slide rail is fixedly connected to one side inner wall of the U-shaped support body. The other end of each nonlinear vibration isolation unit is sleeved on a horizontal slide rail, and the other end of each nonlinear vibration isolation unit is slidably connected to the horizontal slide rail it is on.

[0006] Furthermore, the platform unit includes a vertical slide rail, a vertical spring, and a platform. The vertical slide rail is arranged vertically at the center of the inner bottom surface of the U-shaped bracket body, and the bottom end of the vertical slide rail is fixedly connected to the inner bottom surface of the U-shaped bracket body. The platform is sleeved on the top end of the vertical slide rail, and the platform is slidably connected to the vertical slide rail. The vertical spring is arranged between the platform and the U-shaped bracket body, and the vertical spring is sleeved on the outer circular surface of the vertical slide rail. The top end of the vertical spring is fixedly connected to the bottom surface of the platform, and the bottom end of the vertical spring is fixedly connected to the inner bottom surface of the U-shaped bracket body. One end of each nonlinear vibration isolation unit is hinged to one side of the platform.

[0007] Furthermore, the horizontal slide rail is positioned lower than the initial position of the stage;

[0008] Furthermore, the nonlinear vibration isolation unit includes an elastic sliding component and two connecting rod components. The elastic sliding component is correspondingly sleeved on a horizontal slide rail and is slidably connected to the horizontal slide rail. Each connecting rod component is disposed on one side of the elastic sliding component, and the two connecting rod components are disposed opposite each other along the plane containing the center line of the horizontal slide rail width direction. One end of each connecting rod component is hinged to one side of the elastic sliding component, and the other end of each connecting rod component is hinged to one side of the platform.

[0009] Furthermore, the elastic sliding assembly includes a horizontal spring and two sliding blocks. The two sliding blocks are both sleeved on a horizontal slide rail, and each sliding block is slidably connected to the horizontal slide rail. The horizontal spring is disposed between the two sliding blocks and is sleeved on the outer circumference of the horizontal slide rail. The two ends of the horizontal spring are respectively fixedly connected to a sliding block.

[0010] The linkage assembly includes a long link and a short link. One end of the long link is located on the side of the sliding block away from the stage unit in the elastic sliding assembly, and the long link is hinged to the sliding block by a pin. The other end of the long link is hinged to the stage. One end of the short link is located on the side of the sliding block close to the stage unit in the elastic sliding assembly, and the short link is hinged to the sliding block by a pin. The other end of the short link is hinged to the stage. The short link and the long link are hinged to the stage by the same pin.

[0011] Furthermore, the platform has two symmetrically machined grooves along the center line of the width direction of the U-shaped bracket body on the side facing the horizontal slide rail. Each groove has a hinge shaft along the width direction of the U-shaped bracket body. The other end of the short connecting rod and the other end of the long connecting rod are rotatably connected to the same hinge shaft.

[0012] The beneficial effects of this application compared to the prior art are:

[0013] This application proposes a low-frequency nonlinear vibration isolation device that is robust to working position deviations. By combining a double-linkage rod with a linear spring, a novel nonlinear vibration isolation device with high static and low dynamic characteristics is formed. Compared to traditional nonlinear vibration isolation devices, the low stiffness range of this invention is significantly expanded. Even if the position of the load-bearing object deviates from the designed working position, this invention can still maintain a low initial vibration isolation frequency (i.e., excellent low-frequency vibration isolation performance). In other words, the low-frequency vibration isolation performance of this invention is robust to working position deviations, has stronger adaptability to complex engineering environments, and has broad prospects for widespread application.

[0014] This application proposes a low-frequency nonlinear vibration isolation device that is robust to working position deviations. By combining a double connecting rod with a movable spring for differential system design, a vibration isolation device with softening nonlinear characteristics is obtained. This solves the problem of low-frequency vibration isolation performance degradation caused by hardening phenomenon in traditional nonlinear vibration isolators, widens the vibration isolation range, and enhances the stability of the vibration isolator. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the shaft side of the vibration isolation device described in this application;

[0016] Figure 2 This is a front view schematic diagram of the vibration isolation device described in this application;

[0017] Figure 3 This is a top view of the vibration isolation device described in this application;

[0018] Figure 4 This is a side view of the vibration isolation device described in this application;

[0019] Figure 5 This is a comparison diagram of the force-displacement curves of the vibration isolator described in this application and the existing three-spring design structure;

[0020] Figure 6 This is a comparison diagram of the stiffness-displacement curves of the vibration isolator described in this application and the existing three-spring design structure;

[0021] Figure 7 This is a comparison diagram of the low-frequency vibration isolation performance of the vibration isolator described in this application and the existing three-spring design structure under the condition of an equivalent linear system, based on the working position deviation.

[0022] Figure 8 This is a comparison chart showing the low-frequency vibration isolation performance of the vibration isolator described in this application and the existing three-spring design structure under the condition of an equivalent linear system, based on the working position deviation. Figure 7 (Enlarged schematic diagram);

[0023] Figure 9 This is a diagram illustrating the softening nonlinearity advantage of the vibration isolator described in this application.

[0024] The diagram shows: 1. U-shaped support body; 2. Horizontal slide rail; 3. Sliding block; 4. Long connecting rod; 5. Short connecting rod; 6. Horizontal spring; 7. Vertical slide rail; 8. Vertical spring; 9. Platform; and 10. Weight. Detailed Implementation

[0025] Specific implementation method one: Combining Figures 1 to 9 This embodiment describes a low-frequency nonlinear vibration isolation device that is robust to working position deviations. The vibration isolation device includes a support frame unit, a platform unit, and two nonlinear vibration isolation units. The platform unit is vertically positioned at the center of the support frame unit, and its bottom is fixedly connected to the inner bottom surface of the support frame unit. The two nonlinear vibration isolation units are positioned opposite each other on both sides of the platform unit, with one end of each nonlinear vibration isolation unit hinged to one side of the platform unit and the other end of each nonlinear vibration isolation unit slidably connected to the support frame unit.

[0026] Specific Implementation Method Two: Combining Figures 1 to 8 This embodiment differs from specific embodiment one in that the support frame unit includes a U-shaped support body 1 and two horizontal slide rails 2. The two horizontal slide rails 2 are respectively arranged horizontally on one inner wall of the U-shaped support body 1, and are symmetrically arranged along the centerline of the length direction of the U-shaped support body 1. The axes of the two horizontal slide rails 2 are collinear. One end of each horizontal slide rail 2 is fixedly connected to one inner wall of the U-shaped support body 1. The other end of each nonlinear vibration isolation unit is sleeved on one horizontal slide rail 2, and the other end of each nonlinear vibration isolation unit is slidably connected to the horizontal slide rail 2 it is located on. Other components and connection methods are the same as in specific embodiment one.

[0027] In this embodiment, the horizontal slide rail 2 provides guidance for the sliding of the nonlinear vibration isolation unit, making its movement more accurate under the influence of amplitude. It can only move along the axis of the horizontal slide rail 2, avoiding the nonlinear vibration isolation unit from moving off-center along the slide rail.

[0028] Specific implementation method three: Combining Figures 1 to 9This embodiment differs from Specific Embodiment Two in that the platform unit includes a vertical slide rail 7, a vertical spring 8, and a platform 9. The vertical slide rail 7 is vertically positioned at the center of the inner bottom surface of the U-shaped support body 1, and its bottom end is fixedly connected to the inner bottom surface of the U-shaped support body 1. The platform 9 is fitted onto the top end of the vertical slide rail 7 and is slidably connected to it. The vertical spring 8 is positioned between the platform 9 and the U-shaped support body 1, and is fitted onto the outer circumferential surface of the vertical slide rail 7. The top end of the vertical spring 8 is fixedly connected to the bottom surface of the platform 9, and its bottom end is fixedly connected to the inner bottom surface of the U-shaped support body 1. One end of each nonlinear vibration isolation unit is hinged to one side of the platform 9. Other components and connections are the same as in Specific Embodiment Two.

[0029] In this embodiment, the platform unit includes a vertical spring 8. When the weight 10 is placed on the platform 9, the platform 9 will slide down along the vertical slide rail 7. During this process, the vertical spring 8 mainly plays a supporting role, which is used to absorb the amplitude generated by the weight 10 on the platform 9 and achieve the initial vibration isolation effect.

[0030] Specific implementation method four: Combination Figures 1 to 9 This embodiment differs from Specific Embodiment Three in that the horizontal slide rail 2 is positioned lower than the initial position of the platform 9. Other components and connections are the same as in Specific Embodiment Three.

[0031] Specific Implementation Method Five: Combining Figures 1 to 9 This embodiment differs from Specific Embodiment Four in that the nonlinear vibration isolation unit includes an elastic sliding component and two connecting rod components. The elastic sliding component is correspondingly sleeved on a horizontal slide rail 2 and is slidably connected to the horizontal slide rail 2. Each connecting rod component is disposed on one side of the elastic sliding component, and the two connecting rod components are arranged opposite each other along the plane containing the center line of the width direction of the horizontal slide rail 2. One end of each connecting rod component is hinged to one side of the elastic sliding component, and the other end of each connecting rod component is hinged to one side of the platform 9. Other components and connection methods are the same as in Specific Embodiment Four.

[0032] Specific Implementation Method Six: Combination Figures 1 to 9 This embodiment differs from specific embodiment five in that the elastic sliding component includes a horizontal spring 6 and two sliding blocks 3. The two sliding blocks 3 are both sleeved on a horizontal slide rail 2, and each sliding block 3 is slidably connected to the horizontal slide rail 2. The horizontal spring 6 is disposed between the two sliding blocks 3 and is sleeved on the outer circumference of the horizontal slide rail 2. The two ends of the horizontal spring 6 are respectively fixedly connected to one sliding block 3.

[0033] The linkage assembly includes a long link 4 and a short link 5. One end of the long link 4 is located on the side of the elastic sliding assembly away from the sliding block 3 of the stage unit, and the long link 4 is hinged to the sliding block 3 by a pin. The other end of the long link 4 is hinged to the stage 9. One end of the short link 5 is located on the side of the elastic sliding assembly close to the sliding block 3 of the stage unit, and the short link 5 is hinged to the sliding block 3 by a pin. The other end of the short link 5 is hinged to the stage 9. The short link 5 and the long link 4 are hinged to the stage 9 by the same pin. Other components and connection methods are the same as in specific embodiment five.

[0034] The core of this application is described in conjunction with specific embodiments five and six. By combining a double connecting rod with a linear spring, a novel nonlinear vibration isolation device with high static and low dynamic characteristics is formed, which significantly increases the low stiffness range of the nonlinear vibration isolation device. Even if the position of the load-bearing object deviates from the designed working position, the present invention can still maintain a low initial vibration isolation frequency (i.e., excellent low-frequency vibration isolation performance). On this basis, with the addition of an elastic sliding component, it can slide axially along the horizontal guide rail 2 after being affected by the amplitude. It is a differential system design that combines a double connecting rod with a movable spring, resulting in a vibration isolation device with softened nonlinear characteristics. This solves the problem of low-frequency vibration isolation performance degradation caused by the hardening phenomenon of traditional nonlinear vibration isolators, widens the vibration isolation range, and enhances the stability of the vibration isolator.

[0035] Specific implementation method seven: Combination Figures 1 to 9 This embodiment differs from Specific Embodiment Six in that the platform 9 has two symmetrically machined grooves along the centerline of the width direction of the U-shaped bracket body 1 on the side facing the horizontal slide rail 2. Each groove has a hinge shaft along the width direction of the U-shaped bracket body 1. The other ends of the short connecting rod 5 and the long connecting rod 4 are rotatably connected to the same hinge shaft. Other components and connection methods are the same as in Specific Embodiment Six.

[0036] The present invention has been disclosed above with preferred embodiments, but it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed structure and technical content to create equivalent embodiments without departing from the scope of the present invention. However, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

[0037] Working principle

[0038] When using this application, the various components are first assembled together according to the connection relationship described in specific embodiments one to seven. When the weight 10 is placed on the platform 9, the platform 9 will slide along the length extension direction of the vertical slide rail 7 due to the influence of the weight of the weight. As the platform 9 moves longitudinally, the vertical spring 8 is in a compressed state. During this process, it absorbs part of the amplitude of the platform 9. As the platform 9 moves longitudinally, the linkage assembly located on the platform 9 will also transfer the amplitude to the corresponding sliding block 3 as the position of the platform 9 changes. When the sliding block 3 is impacted by the amplitude, it will slide laterally along the horizontal slide rail 2. The horizontal spring 8 located between the two sliding blocks 3 will be compressed and changed as the sliding block 3 moves. During this process, the amplitude is absorbed a second time.

[0039] Based on the nonlinear vibration isolation device proposed in this application, force-displacement curves and stiffness-displacement curves of the traditional three-spring structure and the present invention were calculated and compared, as shown in the attached figures. Figure 5 and Figure 6 As shown, it can be seen that if the load-bearing capacity of the two designs is kept the same, the low stiffness range obtained by the present invention is wider than that of the three-spring design.

[0040] The force transmissibility curves for the two structures are attached. Figure 7 and Figure 8 As shown in the figure, the vibration isolation performance of the two structures is comparable at the designed working position. However, when deviating from the designed working position by 0.02m, the low-frequency vibration isolation performance of the present invention is significantly better than that of the three-spring structure. That is, the low-frequency vibration isolation performance of the present invention is not sensitive to the deviation of the working position, has robustness, and is more adaptable to complex engineering environments. The nonlinear vibration isolation device designed in this invention uses common engineering materials, making it economical and feasible.

[0041] The force transmissibility curve of the structure is attached. Figure 9 As shown in the figure, the three-spring structure exhibits nonlinear hardening, especially when the spring frequency f... d2 Greater than the critical frequency f c2 To ensure the stable operation of the structure, the initial vibration isolation frequency of the structure must be f. d2 In this case, the vibration isolation zone of the structure will be affected by the jump frequency f. d2 The present invention enables the structure to exhibit nonlinear softening, and the vibration isolation range is not affected by the drop frequency f. d1 The impact, because in this case, the critical frequency f c1 It will always be greater than the drop frequency f d1 This invention solves the defects caused by nonlinear hardening, widens the vibration isolation range, and enhances the stability of the vibration isolator.

Claims

1. A low-frequency nonlinear vibration isolation device with robustness to working position deviation, characterized in that: The vibration isolation device includes a support frame unit, a platform unit, and two nonlinear vibration isolation units. The platform unit is vertically positioned at the center of the support frame unit, and its bottom is fixedly connected to the inner bottom surface of the support frame unit. The two nonlinear vibration isolation units are positioned opposite each other on both sides of the platform unit, with one end of each nonlinear vibration isolation unit hinged to one side of the platform unit and the other end of each nonlinear vibration isolation unit slidably connected to the support frame unit. The support frame unit includes a U-shaped support body (1) and two horizontal slide rails (2). The stage unit includes a vertical slide rail (7), a vertical spring (8), and a stage (9). The nonlinear vibration isolation unit includes an elastic sliding component and two linkage components; The elastic sliding assembly includes a horizontal spring (6) and two sliding blocks (3). The two sliding blocks (3) are both sleeved on a horizontal slide rail (2), and each sliding block (3) is slidably connected to the horizontal slide rail (2). The horizontal spring (6) is disposed between the two sliding blocks (3) and is sleeved on the outer circular surface of the horizontal slide rail (2). The two ends of the horizontal spring (6) are respectively fixedly connected to a sliding block (3). The linkage assembly includes a long link (4) and a short link (5). One end of the long link (4) is located on the side of the sliding block (3) away from the stage unit in the elastic sliding assembly, and the long link (4) is hinged to the sliding block (3) by a pin. The other end of the long link (4) is hinged to the stage (9). One end of the short link (5) is located on the side of the sliding block (3) near the stage unit in the elastic sliding assembly, and the short link (5) is hinged to the sliding block (3) by a pin. The other end of the short link (5) is hinged to the stage (9). The short link (5) and the long link (4) are hinged to the stage (9) by the same pin.

2. The low-frequency nonlinear vibration isolation device with robustness to working position deviation according to claim 1, characterized in that: The two horizontal slide rails (2) are respectively set on the inner wall of one side of the U-shaped bracket body (1) in the horizontal direction, and the two horizontal slide rails (2) are symmetrically set along the center line of the length direction of the U-shaped bracket body (1). The axes of the two horizontal slide rails (2) are collinear. One end of each horizontal slide rail (2) is fixedly connected to the inner wall of one side of the U-shaped bracket body (1). The other end of each nonlinear vibration isolation unit is sleeved on a horizontal slide rail (2), and the other end of each nonlinear vibration isolation unit is slidably connected to the horizontal slide rail (2) where it is located.

3. A low-frequency nonlinear vibration isolation device with robustness to working position deviation as described in claim 2, characterized in that: The vertical slide rail (7) is set vertically at the center of the inner bottom surface of the U-shaped bracket body (1), and the bottom end of the vertical slide rail (7) is fixedly connected to the inner bottom surface of the U-shaped bracket body (1). The platform (9) is sleeved on the top end of the vertical slide rail (7), and the platform (9) is slidably connected to the vertical slide rail (7). The vertical spring (8) is set between the platform (9) and the U-shaped bracket body (1), and the vertical spring (8) is sleeved on the outer circular surface of the vertical slide rail (7). The top end of the vertical spring (8) is fixedly connected to the bottom surface of the platform (9), and the bottom end of the vertical spring (8) is fixedly connected to the inner bottom surface of the U-shaped bracket body (1). One end of each nonlinear vibration isolation unit is hinged to one side of the platform (9).

4. A low-frequency nonlinear vibration isolation device with robustness to working position deviation as described in claim 3, characterized in that: The horizontal slide rail (2) is positioned below the initial position of the stage (9).

5. A low-frequency nonlinear vibration isolation device with robustness to working position deviation as described in claim 4, characterized in that: The elastic sliding component is fitted onto a horizontal slide rail (2) and is slidably connected to the horizontal slide rail (2). Each link component is set on one side of the elastic sliding component, and the two link components are set opposite each other along the plane of the center line of the width direction of the horizontal slide rail (2). One end of each link component is hinged to one side of the elastic sliding component, and the other end of each link component is hinged to one side of the platform (9).

6. A low-frequency nonlinear vibration isolation device with robustness to working position deviation as described in claim 5, characterized in that: The platform (9) has two grooves symmetrically machined along the center line of the width direction of the U-shaped bracket body (1) on the side facing the horizontal slide rail (2). Each groove has a hinge shaft along the width direction of the U-shaped bracket body (1). The other end of the short connecting rod (5) and the other end of the long connecting rod (4) are rotatably connected to the same hinge shaft.

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