A nonlinear multi-degree-of-freedom vibration reduction device

Abstract

The present invention relates to the field of vibration reduction technology, and in particular to a nonlinear multi-degree-of-freedom vibration reduction device, comprising a static platform, a first dynamic platform and a second dynamic platform arranged therebetween, wherein a triangular hole is provided on the second dynamic platform; and further comprising: three spatial rods, which pass through the triangular hole and each of the spatial rods is ball-hinged with a corner of the triangular hole, one end of each of the spatial rods is ball-hinged with the static platform and the hinge point is arranged in a triangle, and the other end is ball-hinged with the first dynamic platform and the hinge point is arranged in a triangle, and spring damping modules are arranged between two of the three spatial rods; and a plurality of elastic support members are arranged between the static platform and the second dynamic platform; the vibration reduction device of the present invention has multiple degrees of freedom, good multi-directional vibration reduction effect, and converts linear vibration reduction into a nonlinear vibration reduction method of trigonometric function, thereby expanding the vibration reduction frequency range.

Description

Technical Field

[0001] The invention relates to the technical field of vibration reduction, and in particular to a nonlinear multi-degree-of-freedom vibration reduction device. Background Art

[0002] Vibration is a common phenomenon in aerospace, automotive and navigation fields, which can reduce the service life of equipment and cause fatigue damage. Therefore, it is very necessary to suppress vibration within a reasonable range.

[0003] The existing linear shock absorber can only achieve vibration isolation effect when the excitation frequency is greater than √2 times the natural frequency, and has poor adaptability to large frequency range vibration changes. In order to improve the low-frequency vibration reduction performance of the linear shock absorber, the stiffness of the shock absorber should be designed to be small enough to make the natural frequency of the shock absorption system low enough. However, the reduction in stiffness will lead to larger deviations and reduce the stability of the shock absorption system.

[0004] At present, general spring shock absorbers can effectively control vibrations and swings of various frequencies. Their main structure is a spring and a damper. Through the internal hydraulic structure of the damper piston rod, the oscillation and impact of the spring rebounding after absorbing vibrations are suppressed. However, this type of device has a narrow vibration reduction frequency range and can only perform vibration reduction work in a single direction. It has a weak ability to reduce vibration when subjected to impact vibrations in multiple directions, has poor vibration reduction performance, and still has the defects of traditional linear shock absorbers in terms of stiffness. Summary of the invention

[0005] The purpose of the present invention is to provide a nonlinear multi-degree-of-freedom vibration reduction device to solve the problem that the prior art can only reduce vibration in one direction and has a narrow vibration reduction frequency band. In order to achieve the above purpose, the present invention solves the problem through the following technical solutions:

[0006] The present invention provides a nonlinear multi-degree-of-freedom vibration reduction device, comprising a static platform, a first dynamic platform and a second dynamic platform arranged therebetween, wherein the second dynamic platform is provided with a triangular hole; and further comprising:

[0007] Three spatial rods pass through the triangular hole and each of the spatial rods is articulated with a corner ball of the triangular hole, one end of each of the spatial rods is articulated with the static platform ball and the articulation points are arranged in a triangular shape, and the other end is articulated with the first dynamic platform ball and the articulation points are arranged in a triangular shape, and a spring damping module is provided between two of the three spatial rods;

[0008] A plurality of elastic supporting members are arranged between the static platform and the second dynamic platform.

[0009] As a further technical solution, the linear spring stiffness in the spring damping module is adjustable.

[0010] As a further technical solution, the stiffness of the linear spring is adjusted by piezoelectric ceramics.

[0011] As a further technical solution, the first moving platform is provided with a plurality of vibration sensors for detecting the vibration of the platform.

[0012] As a further technical solution, a controller is also included to control the vibration sensor and the piezoelectric ceramic.

[0013] As a further technical solution, each of the spatial rods is provided with a vibration isolation mass block, and the vibration isolation mass block is located between the first moving platform and the second moving platform.

[0014] As a further technical solution, two of the three spatial rods cross and pass through the triangular hole.

[0015] As a further technical solution, the three ball joints on the same spatial rod are not colinear.

[0016] As a further technical solution, the three ball joints of the different spatial rods on the same level are arranged in an equilateral triangle.

[0017] As a further technical solution, the elastic support members are springs, of which at least three are provided and evenly distributed.

[0018] The beneficial effects of the present invention are as follows:

[0019] (1) The present invention transforms linear vibration reduction into a nonlinear vibration reduction method of trigonometric function by connecting spring damping modules between two spatial rods, thereby expanding the vibration reduction frequency range.

[0020] (2) The present invention adopts a structure composed of spatial rods. The spatial rods are ball-jointed with the static platform, the first dynamic platform, and the second dynamic platform. The ball joints can rotate and can be combined with a number of elastic support members to achieve movement in multiple directions. Therefore, the device can achieve a multi-degree-of-freedom vibration reduction effect and has a strong ability to reduce vibration when subjected to impact vibrations in multiple directions.

[0021] (3) The spring damping module of the present invention can achieve adjustable nonlinear stiffness, can adapt to a large frequency vibration reduction range, and realize adaptive vibration reduction characteristics. After the vibration sensor transmits data to the controller, the controller adjusts the piezoelectric ceramics in the spring damping module to adjust the stiffness of the linear spring, thereby improving the system adjustment capability.

[0022] (4) The elastic support member of the present invention supports the structure, prevents the instability of the rod system caused by multi-degree-of-freedom movement, and utilizes the vibration absorption effect of the elastic support member to improve the vibration reduction frequency domain and stability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their description are used to explain the present invention and do not constitute a limitation of the present invention. It should also be understood that these drawings are shown for simplicity and clarity and are not necessarily drawn to scale. The present invention will now be described and explained with additional features and details through the use of the accompanying drawings, in which:

[0024] Figure 1 A schematic diagram of the structure of a vibration reduction device in an embodiment of the present invention is shown;

[0025] Figure 2 A schematic diagram of a spring damping module in an embodiment of the present invention is shown.

[0026] In the figure: 1, static platform; 21, first elastic support member; 22, second elastic support member; 23, third elastic support member; 24, fourth elastic support member; 3, second moving platform; 41, first space rod; 42, second space rod; 43, third space rod; 51, first spring damping module; 511, piezoelectric ceramic; 512, linear spring; 513, damping; 52, second spring damping module; 53, third spring damping module; 61, first vibration isolation mass block; 62, second vibration isolation mass block; 63, third vibration isolation mass block; 7, first moving platform; 81, first vibration sensor; 82, second vibration sensor; 83, third vibration sensor. DETAILED DESCRIPTION

[0027] The technical solutions in typical embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0028] like Figure 1 and Figure 2 As shown, this embodiment provides a nonlinear multi-degree-of-freedom vibration reduction device, including a static platform 1, a first dynamic platform 7 and a second dynamic platform 3 arranged therebetween, the second dynamic platform 3 having a triangular hole; and further including three spatial rods and a plurality of elastic support members. The static state of the static platform 1 is relative to the motion of the first dynamic platform 7 and the second dynamic platform 3.

[0029] There are three spatial rods, namely the first spatial rod 41, the second spatial rod 42 and the third spatial rod 43. The three spatial rods pass through the triangular hole and each spatial rod is ball-hinged with a corner of the triangular hole. It can be understood that when the spatial rod is hinged with the corner of the triangular hole, a rod needs to be extended on its side to facilitate connection with the corner. One end of each spatial rod is ball-hinged with the static platform 1 and the hinge point is arranged in a triangle, and the other end is ball-hinged with the first moving platform 7 and the hinge point is arranged in a triangle. A spring damping module is provided between two of the three spatial rods.

[0030] It is not difficult to understand that there are three spring damping modules, namely the first spring damping module 51, the second spring damping module 52, and the third spring damping module 53. The first spring damping module 51 is connected to the first space rod 41 and the second space rod 42, the second spring damping module 52 is connected to the second space rod 42 and the third space rod 43, and the third spring damping module 53 is connected to the third space rod 43 and the first space rod 41.

[0031] By connecting spring damping modules between two spatial rods, linear vibration reduction is transformed into a nonlinear vibration reduction method of trigonometric function, thereby expanding the vibration reduction frequency range.

[0032] A structure composed of spatial rods (approximately triangular pyramids at the top and bottom) is adopted. The spatial rods and the static platform 1, the first moving platform 7, and the second moving platform 3 are all ball-jointed. The ball joints can realize rotation and combined with a number of elastic support members, it can realize movement in multiple directions, and thus the device can achieve multi-degree-of-freedom vibration reduction effects.

[0033] like Figure 1 As shown, during the setting process, due to structural limitations, the triangular hole opened on the second moving platform 3 is relatively small, and two of the three spatial rods are used to cross through the triangular hole, so that the outer diameter of the triangle formed by the hinge point of the spatial rod and the first moving platform is larger, thereby ensuring stable support under vibration conditions. Figure 1 In the direction shown, the second spatial rod 42 and the third spatial rod 43 intersect at the triangular hole, so that the hinge points of the two spatial rods and the static platform and the first dynamic platform are not on the same side.

[0034] The space member rod in this embodiment is not a straight rod, so the three ball joints on the same space member are not collinear.

[0035] The three ball joints of different spatial rods on the same level are arranged in an equilateral triangle. That is, the triangular hole is an equilateral triangle, and the ball joint points on the first moving platform 7 and the static platform 1 are also equilateral triangles, ensuring the stability of vibration isolation.

[0036] like Figure 2 As shown, the spring damping module includes a piezoelectric ceramic 511, a linear spring 512, and a damping 513. The stiffness of the linear spring 512 in the spring damping module is adjustable, and the stiffness of the linear spring 512 is adjusted by the piezoelectric ceramic 511.

[0037] The spring damping module can realize adjustable nonlinear stiffness, adapt to a large frequency vibration reduction range, and realize adaptive vibration reduction characteristics.

[0038] A controller and several vibration sensors for detecting platform vibration are provided on the first moving platform 7. The controller controls the vibration sensors and piezoelectric ceramics. The vibration sensors include a first vibration sensor 81, a second vibration sensor 82 and a third vibration sensor 83, which are arranged separately.

[0039] The controller automatically adjusts the piezoelectric ceramics through the vibration sensor signal, thereby adjusting the stiffness of the spring damping module. After the vibration sensor transmits the data to the controller, the controller adjusts the piezoelectric ceramics in the spring damping module to adjust the stiffness of the linear spring, thereby improving the system's adjustment capability.

[0040] Each spatial rod is provided with a vibration isolation mass block, and the vibration isolation mass block is located between the first moving platform 7 and the second moving platform 3. There are three vibration isolation mass blocks, namely the first vibration isolation mass block 61, the second vibration isolation mass block 62, and the third vibration isolation mass block 63, which are respectively fixed to the first spatial rod 41, the second spatial rod 42, and the third spatial rod 43. The vibration isolation mass block can isolate the remaining part of the spatial rod from vibration.

[0041] A plurality of elastic support members are provided between the static platform 1 and the second dynamic platform 3. The elastic support members are springs, at least three of which are evenly distributed. In this embodiment, four elastic support members are provided, namely, a first elastic support member 21, a second elastic support member 22, a third elastic support member 23, and a fourth elastic support member 24.

[0042] The elastic support members support the structure, preventing the instability of the rod system caused by multi-degree-of-freedom movement, and utilizing the vibration absorption effect of the elastic support members to improve the vibration reduction frequency domain and stability of the system.

[0043] The first moving platform 7 is subjected to vibration, and the spatial rod is connected to the second moving platform 3 and the static platform 1 by ball joints to rotate and transmit vibration, and the left and right movement of the four elastic supports can make the second moving platform 3 drive the spatial rod to move left and right to transmit vibration, ensuring that the system can transmit vibration in multiple degrees of freedom. The signal output end of the controller is connected to the piezoelectric ceramic 511 in the spring damping 513 module. After the vibration sensor on the first moving platform 7 transmits data to the controller, the spring damping 513 module adjusts the piezoelectric ceramic 511 according to the control system, thereby adjusting the stiffness of the linear spring 512. Since the spring damping 513 modules are respectively connected to the spatial rods in pairs, the linear vibration reduction effect composed of the linear spring 512 and the damping 513 is transformed into a trigonometric function nonlinear vibration reduction effect, thereby achieving the effect of increasing the vibration reduction frequency and autonomously adjusting the stiffness. The vibration isolation mass block can isolate the remaining vibration of the rod.

[0044] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A nonlinear multi-degree-of-freedom vibration reduction device, It is characterized in that It includes a static platform, a first dynamic platform and a second dynamic platform arranged between the two, wherein the second dynamic platform is provided with a triangular hole; and further includes: Three spatial rods pass through the triangular hole and each of the spatial rods is articulated with a corner ball of the triangular hole, one end of each of the spatial rods is articulated with the static platform ball and the articulation points are arranged in a triangular shape, and the other end is articulated with the first dynamic platform ball and the articulation points are arranged in a triangular shape, and a spring damping module is provided between two of the three spatial rods; A plurality of elastic support members are arranged between the static platform and the second moving platform; the stiffness of the linear spring in the spring damping module is adjustable; the stiffness of the linear spring is adjusted by piezoelectric ceramics, and a plurality of vibration sensors for detecting platform vibration are arranged on the first moving platform. The device also includes a controller for controlling the vibration sensors and the piezoelectric ceramics.

2. A nonlinear multi-degree-of-freedom vibration reduction device as claimed in claim 1, It is characterized in that Each of the spatial rods is provided with a vibration isolation mass block, and the vibration isolation mass block is located between the first moving platform and the second moving platform.

3. A nonlinear multi-degree-of-freedom vibration reduction device as claimed in claim 1, It is characterized in that Two of the three spatial rods cross and pass through the triangular hole.

4. A nonlinear multi-degree-of-freedom vibration reduction device as claimed in claim 1, It is characterized in that The three ball joints on the same spatial rod are not collinear.

5. A nonlinear multi-degree-of-freedom vibration reduction device as claimed in claim 1, It is characterized in that The three ball joints of the different spatial rods on the same level are arranged in an equilateral triangle.

6. A nonlinear multi-degree-of-freedom vibration reduction device as claimed in claim 1, It is characterized in that The elastic supporting members are springs, at least three of which are evenly distributed.

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