Composite shock absorber with positive rigidity and negative rigidity

Abstract

The invention relates to the technical field of air bag damping, in particular to a composite damper with positive and negative stiffness. The switching part is located above the air bag and comprises a first switching piece and a second switching piece, the second switching piece is fixed to the top of the air bag, a platform is fixed to the upper portion of the first switching piece, a connecting piece is arranged between the first switching piece and the second switching piece, and the connecting piece is in contact connection with the first switching piece or the second switching piece at least through one point; the adjusting device is arranged in the axial direction of the air bag; the two ends of the flexible hinge are connected to the top of the adjusting device and the second adapter piece respectively, and when the instrument is placed on the platform, the first adapter piece and the second adapter piece reduce the frequency of the air bag in the horizontal direction through relative movement of the connecting piece.

Description

Technical Field

[0001] The invention relates to the technical field of airbag shock absorption, and in particular to a composite shock absorber with positive and negative stiffness. Background Art

[0002] In the field of vibration control, airbag technology is widely used in various mechanical systems as an effective means of vibration reduction. Traditionally, in order to reduce the natural frequency in the vertical direction (i.e., vertical direction), people tend to set the airbag in a positive position. This setting method does achieve a significant frequency reduction effect in the vertical direction, effectively reducing the impact of vertical vibration on the mechanical system.

[0003] However, the performance of the airbag in the horizontal direction (i.e., lateral or longitudinal) is not satisfactory. Due to the geometric shape and material properties of the airbag, its horizontal movement characteristics when placed upright are difficult to accurately set, resulting in the horizontal vector natural frequency being difficult to achieve a smaller ideal value. This means that although the vertical vibration is effectively controlled, the vibration problem in the horizontal direction is still prominent and cannot meet the higher requirements for vibration control.

[0004] In order to overcome this problem, researchers began to explore the possibility of placing the airbag in an inverted position. After the airbag was placed in an inverted position, its vertical natural frequency reduction effect did not change significantly and it still maintained its original effectiveness. This discovery provides strong support for the application of airbag technology in vertical vibration control.

[0005] More importantly, the inverted airbag has shown new potential in the horizontal direction. Compared with the upright airbag, the inverted airbag can more effectively cope with the influence of low horizontal vector frequency. This is because the inverted placement changes the force state and vibration mode of the airbag, making it have better shock absorption performance in the horizontal direction. This discovery provides new ideas and methods for optimizing the vibration performance of mechanical systems in the horizontal direction.

[0006] However, it is worth noting that although the inverted airbag has significant shock-absorbing advantages in the horizontal direction, the inverted pendulum structure itself has instability problems.

[0007] Therefore, the present application develops a composite shock absorber with positive and negative stiffness to solve the problems existing in the prior art. Summary of the invention

[0008] The purpose of the present invention is to provide a composite shock absorber with positive and negative stiffness to solve the problem in the prior art that the airbag cannot reduce the horizontal frequency when reducing the vertical frequency.

[0009] The technical solution of the present invention is: a composite shock absorber with positive and negative stiffness, comprising: Airbags; an adapter, located above the airbag, comprising a first adapter and a second adapter, wherein the second adapter is fixed to the top of the airbag, a platform is fixed above the first adapter, a connecting member is provided between the first adapter and the second adapter, and the connecting member is connected to the first adapter or the second adapter through at least one point contact; An adjusting device is arranged along the axial direction of the airbag; A flexible hinge, both ends of which are respectively connected to the top of the adjusting device and the second adapter. When the instrument is placed on the platform, the first adapter and the second adapter reduce the frequency of the airbag in the horizontal direction through the relative movement of the connecting member.

[0010] Preferably, the first adapter has a concave first arcuate surface, the first arcuate surface is located on a side of the first adapter adjacent to the second adapter, the connecting member is fixed on the second adapter and is arranged as a spherical surface protruding relative to the second adapter, and the spherical surface is in point contact with the concave arcuate surface.

[0011] Preferably, a concave second arc-shaped surface is symmetrically arranged on a surface adjacent to the first adapter and the second adapter, and the connecting member is spherical and is in point contact with the two second arc-shaped surfaces respectively.

[0012] Preferably, an inwardly concave third arc surface and a frustum surface opposite to the third arc surface are respectively provided on adjacent surfaces of the first adapter and the second adapter, the connecting member is spherical, and is in line contact with the frustum surface and point contact with the third arc surface respectively, the frustum surface and the third arc surface are each provided with three, and are arranged in a circular arc array with the center of the first adapter as the center.

[0013] Preferably, a plurality of groups of concave fourth arcuate surfaces are symmetrically arranged on one adjacent surface of the first adapter and the second adapter, the connecting member is spherical and is in point contact with the plurality of groups of fourth arcuate surfaces, and the plurality of groups of fourth arcuate surfaces are arranged in an arc array with the center of the first adapter as the center.

[0014] Preferably, the flexible hinge includes a first elastic part, a second elastic part and a connecting block, the first elastic part and the second elastic part are sequentially connected through the connecting block to form a long strip, and the first elastic part and the second elastic part are deformed in two directions.

[0015] Preferably, the adjusting device includes a fixed column, a third elastic part, a supporting part, a sliding part and a rotating part, the two supporting parts are connected to the two ends of the third elastic part, the supporting part located at the top of the third elastic part is connected to the second adapter through the flexible hinge, the sliding part is slidably arranged on the third elastic part and fixedly connected to the rotating part, the rotating part is rotatably connected to the fixed column, and when the rotating part rotates, the sliding part is driven to slide on the third elastic part, thereby changing the relative distance between the upper surface of the sliding part and the lower surface of the supporting part of the third elastic part.

[0016] Preferably, the third elastic part includes two leaf springs, both ends of the two leaf springs are respectively fixed on the supporting part, and the sliding part includes a second connecting block located between the two leaf springs and a first connecting block and a third connecting block located on both sides of the second connecting block, and the first connecting block and the third connecting block are both attached to the second connecting block and locked by screws; wherein, the contact surfaces of the first connecting block and the second connecting block respectively extend toward each other to form two first extension parts, and the contact surfaces of the second connecting block and the third connecting block respectively extend toward each other to form two second extension parts to define the sliding space corresponding to the two leaf springs.

[0017] Preferably, notches are provided on the upper surface and the lower surface of the second connection block, and the first connection block and the third connection block both extend toward the second connection block and are respectively located in the corresponding notches.

[0018] Preferably, the rotating part includes a first gear and a second gear, the first gear is rotatably connected to the fixed column, and the second gear is fixedly connected to one side of the locked first connecting block, the second connecting block and the third connecting block, and meshes with the first gear.

[0019] Compared with the prior art, the advantages of the present invention are: (1) The inverted pendulum structure formed by the airbag and the adapter provides vertical buffering, and the positive stiffness of the flexible hinge effectively absorbs and disperses the vibration energy in the vertical and horizontal directions, significantly reduces the vibration frequency of the shock absorber in the horizontal direction, and improves the stability and accuracy of the instrument; (2) The connection method between the first adapter and the second adapter (such as point contact or line contact) allows a certain degree of relative movement while maintaining the overall stability of the structure, which can reduce the impact of relative displacement caused by vibration on the airbag and maintain the stability of the airbag when subjected to external force. At the same time, the arc surface or frustum surface set on the first adapter is used to limit the extreme position, thereby reducing the horizontal vibration transmitted to the airbag; (3) The elastic properties of the flexible hinge in two directions can accurately determine the horizontal movement angle of the airbag, ensuring the stable movement of the airbag in a specific direction, thereby improving the overall accuracy and stability of the instrument; (4) By designing the extensions and notches between the first connection block, the second connection block and the third connection block, the connection strength between the connection blocks is increased, preventing them from falling apart when the screws are removed; (5) The position of the sliding part on the elastic part can be conveniently adjusted by the rotating part (including the first gear and the second gear), and the relative distance between the upper surface of the sliding part and the lower surface of the supporting part can be adjusted according to actual needs, thereby changing the stiffness of the elastic part to meet the stiffness requirements of different precision machinery. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Figure 1a is a side cross-sectional view of the adapter portion corresponding to the first embodiment of the present invention; Figure 1b is a side cross-sectional view of the adapter portion corresponding to the second embodiment of the present invention; Figure 1c It is a side cross-sectional view of the adapter portion corresponding to the third embodiment of the present invention; Figure 1d is a side cross-sectional view of the adapter portion corresponding to the fourth embodiment of the present invention; Figure 1e It is a side cross-sectional view of the adapter portion corresponding to the fifth embodiment of the present invention; Figure 2 This is an exploded schematic diagram of the adapter portion of the fourth embodiment of the present invention; Figure 3 It is a structural schematic diagram of a composite shock absorber with positive and negative stiffness according to the present invention; Figure 4 is a schematic structural diagram of the flexible hinge of the present invention; Figure 5 A top view of the assembly of the flexible hinge and the airbag according to the present invention; Figure 6 It is a structural schematic diagram of the regulating device of the present invention; Figure 7 It is an exploded schematic diagram of the sliding part of the present invention; Figure 8 It is a structural schematic diagram of the sliding part of the present invention; Figure 9a This is the first horizontal frequency simulation result diagram under the same time condition when the airbag is not equipped with the adapter; Figure 9b This is the second horizontal frequency simulation result diagram under the same time condition when the airbag is not equipped with the adapter; Fig.10a This is a diagram of the first horizontal frequency simulation result of the shock absorber under the same time conditions when the diameter of the connecting piece is 40 mm in the first embodiment of the present invention; Fig.10b This is a second horizontal frequency simulation result diagram of the shock absorber under the same time conditions when the diameter of the connecting piece in the first embodiment of the present invention is 40 mm; Fig.11a This is a diagram of the first horizontal frequency simulation result of the shock absorber under the same time conditions when the diameter of the connecting piece is 50 mm in the first embodiment of the present invention; Fig.11b This is a second horizontal frequency simulation result diagram of the shock absorber under the same time conditions when the diameter of the connecting piece in the first embodiment of the present invention is 50 mm; Fig.12a This is a diagram showing the first horizontal frequency simulation result of the shock absorber in the fourth embodiment of the present invention under the same time conditions; Figure 12b This is a diagram of the second horizontal frequency simulation result of the shock absorber in the fourth embodiment of the present invention under the same time conditions.

[0021] Among them: 1. Airbag; Adapter; 21, first adapter; 22, second adapter; 23, connector; 231, spherical surface; 24, first arc surface; 25, second arc surface; 26, third arc surface; 27, truncated cone surface; 28, fourth arc surface; Adjusting device; 31. fixing column; 32. third elastic part; 321. leaf spring; 33. supporting part; 34. sliding part; 341. first connecting block; 342. second connecting block; 343. third connecting block; 344. first extending part; 345. second extending part; 346. notch; 35. rotating part; 351. first gear; 352. second gear.

[0022] 4. Flexible hinge; 41. First elastic part; 42. Second elastic part; 43. Connecting part. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with specific embodiments: As shown in Figure 1- Figure 3As shown, a composite shock absorber with positive and negative stiffness includes an airbag 1, an adapter 2, an adjustment device 3 and a flexible hinge 4. The airbag 1 serves as a shock-absorbing foundation, provides vertical buffering, and is placed inverted. The bottom of the airbag 1 contacts the base platform and can swing in any direction. The bottom of the airbag 1 forms a hinge-like structure, and the adapter 2 is located on the top of the airbag 1, including a first adapter 21 and a second adapter 22. The second adapter 22 is fixed to the top of the airbag 1, and a platform is fixed above the first adapter 21 for placing instruments. A connecting member 23 is provided between the first adapter 21 and the second adapter 22, and the connecting member 23 is connected to the adapter by at least one point contact, thereby realizing a rigorous inverted pendulum structure, and the inverted pendulum structure is a negative stiffness structure, wherein the two ends of the flexible hinge 4 are respectively connected to the second adapter 22 and the adjusting device 3, and the airbag 1 is connected to one end of the flexible hinge 4 and fixed by the adjusting device 3, and the flexible hinge 4 is a positive stiffness structure, and the parallel connection of positive and negative stiffness is realized by the parallel connection of the inverted pendulum structure and the flexible hinge 4, so as to reduce the vibration frequency of the shock absorber in the horizontal direction, and effectively absorb and disperse the vibration energy in the vertical and horizontal directions. At the same time, the adjusting device 3 includes a fixed column 31, an elastic part 32, a supporting part 33, a sliding part 34 and a rotating part 35, and the sliding part 34 slides on the elastic part 32 to realize the stiffness adjustment function of the elastic part 32 to adapt to the stiffness requirements of different instruments. Embodiment 1:

[0024] like Figure 1a As shown, a first arcuate surface 24 is provided on a surface adjacent to the first adapter 21 and the second adapter 22, and a corresponding connecting member 23 is fixedly arranged on the second adapter 22, and protrudes as a spherical surface 231 relative to the second adapter 22, and the spherical surface 231 is in point contact with the first arcuate surface 24, and the diameter of the spherical surface 231 is smaller than the diameter of the first arcuate surface 24, so that there is a certain relative movement between the first adapter 21 and the second adapter 22, so that the connecting member 23 forms a "hinge" connection between the first adapter 21 and the second adapter 22, and forms an inverted pendulum structure together with the airbag 1, and the diameter of the spherical surface 231 is smaller than the diameter of the first arcuate surface 24, which means that the movement range of the spherical surface 231 within the arcuate surface is limited, and when there is horizontal vibration, the stability of the inverted pendulum structure within a certain range can be guaranteed. Embodiment 2:

[0025] like Figure 1bAs shown, the first adapter 21 and the second adapter 22 are symmetrically provided with a concave second arc surface 25 on the adjacent surface, and the connecting member 23 is spherical and is in point contact with the two second arc surfaces 25 respectively. The point contact design allows a certain degree of relative freedom of movement between the first adapter 21 and the second adapter 22, which helps to reduce the relative displacement caused by vibration directly transmitted to the airbag 1, resulting in a large horizontal displacement of the airbag 1. The adapter 2 vibrates after being subjected to force, and the spherical connecting member 23 can roll freely in the second arc surface 25, thereby effectively reducing the vibration transmission and improving the shock absorption effect. In addition, the symmetrically arranged second arc surface 25 makes the first adapter 21 and the second adapter 22 more evenly stressed in the horizontal direction, reduces the sliding friction caused by excessive local force, reduces the first adapter 21 and the second adapter 22, reduces the impact of vibration on the airbag 1 in the horizontal direction, and ensures the accuracy and reliability during the working process. Embodiment three:

[0026] like Figure 1c As shown, a concave third arc surface 26 and a frustum surface 27 opposite to the third arc surface 26 are respectively provided on one side adjacent to the first adapter 21 and the second adapter 22. The connector 23 is spherical and is in line contact with the frustum surface 27 and point contact with the third arc surface 26. The line contact design between the spherical connector 23 and the frustum surface 27 allows the connector 23 to have a certain relative sliding freedom in the horizontal direction, so that the first adapter 21 can be offset at different angles and distances relative to the second adapter 22. The specific rotation angle is 0°-2°, and the stability within this range is maintained. In addition, the line contact design between the frustum surface 27 and the spherical connector 23 can more effectively disperse and withstand forces from different directions. Embodiment 4:

[0027] like Figure 1dAs shown, a concave third arc surface 26 and a truncated cone surface 27 opposite to the third arc surface 26 are respectively provided on the adjacent surfaces of the first adapter 21 and the second adapter 22, and there are three truncated cone surfaces 27 and three third arc surfaces 26, and they are arranged in an arc array with the center of the first adapter 21 as the center of the circle. The connecting member 23 is spherical and is in line contact with the truncated cone surface 27 and in point contact with the third arc surface 26. When the connecting member 23 is vibrated, the spherical connecting member 23 can be in the truncated cone surface 27 and the third arc surface 26. Free rolling or micro-motion, thereby effectively dispersing and absorbing vibration energy. At the same time, the three connecting parts 23 correspond to the three third arc-shaped surfaces 26 and the frustum surface 27, which can realize the effect of automatic leveling, ensure the good contact between the connecting parts 23 and the arc-shaped surfaces and the frustum surface 27, and reduce the wear caused by friction. At the same time, a rigid element is arranged above the first adapter 21, which is a rigid support in the horizontal direction. The design of multiple spherical connecting parts 23 can avoid the influence of rigid support on horizontal frequency. Embodiment five:

[0028] like Figure 1e As shown, three groups of concave fourth arc surfaces 28 are symmetrically arranged on a surface adjacent to the first adapter 21 and the second adapter 22, and the connecting member 23 is spherical and is in point contact with the two second arc surfaces 25 respectively, which helps to achieve a smoother and more continuous control effect during the movement of the inverted pendulum and reduce the problem of discontinuous movement or jitter caused by excessive rigidity of the connecting part.

[0029] It should be noted that in Example 1, Example 3, Example 4, and Example 5, the bottom of the airbag 1 is in contact with the base platform. When the instrument is placed on the platform to generate pressure on the airbag 1, the airbag 1 can swing in any direction, thereby forming a hinge-like structure, and the first adapter 21 and the second adapter 22 arranged on the top of the airbag 1 are in contact with the connecting member 23 respectively, and at least one point contact is provided, thereby forming an inverted pendulum structure, wherein the connecting member 23 and the first adapter 21 and the second adapter 22 are not fixed, forming a free hinge, so that the first adapter 21 and the second adapter 22 move relative to each other on the connecting member 23, and the arc surface or the frustum 27 arranged on the first adapter 21 limits the movement of the first adapter 21, and the first adapter 21 can rotate and move at an angle of 0° to 2°, and the first adapter 21 in the limit state is limited to prevent the airbag 1 from being subjected to obvious horizontal vibration due to excessive movement, and a slight offset reduces the horizontal vibration transmitted to the airbag 1, thereby reducing the frequency in the horizontal direction.

[0030] Furthermore, the second adapter 22 is connected to the flexible hinge 4, and the flexible hinge 4 is fixed on the adjusting device 3. The horizontal frequency is further reduced through the flexible hinge 4, the adjusting device 3 and the adapter 2, and can adapt to more different and complex instrument requirements.

[0031] In the second embodiment, only one spherical connector 23 is provided, and the diameter of the connector is relatively small, so that the adapter 2 and the airbag 1 form a strict inverted pendulum structure, which cannot reduce the frequency in the horizontal direction. Therefore, the two ends of the flexible hinge 4 are respectively connected to the second adapter 22 and the adjustment device 3, so that the frequency in the horizontal direction is reduced through the cooperation of the flexible hinge 4 and the adjustment device 3.

[0032] For further explanation, in Example 1, Example 2, Example 3, Example 4 and Example 5, after the adapter 2 is installed, during the shock absorption process, the adapter 2 only constrains the horizontal vibration, and the inverted pendulum structure only constrains the vertical vibration, and neither constrains the relative rotation, and only the inverted pendulum structure is in contact with the upper platform, while other structures are not in contact, so that the shock absorber can not only achieve the effect of shock absorption, but also make the horizontal frequency reduction effect better.

[0033] according to Figure 9a and Figure 9b As shown, when the airbag 1 is not installed with the adapter 2, its horizontal frequency is 3.5 Hz. After the adapter 2 is installed, Fig.10a and Fig.10b As shown, when the diameter of the connecting member 23 in the first embodiment is 40 mm, the corresponding horizontal frequency of the shock absorber is about 1.5 Hz. Fig.11a and Fig.11b As shown, when the diameter of the connecting member 23 in the first embodiment is 50 mm, the corresponding horizontal frequency of the shock absorber is significantly higher than the horizontal frequency when the diameter of the connecting member 23 is 40 mm. It can be concluded that when the diameter of the connecting member 23 is gradually reduced, the horizontal frequency is also gradually reduced; Fig.12a and Figure 12b As shown, it is a simulation diagram of the horizontal frequency of the shock absorber of the fourth embodiment, and Figure 9a and Figure 9b By comparison, it can slightly reduce the horizontal frequency of the shock absorber.

[0034] like Figure 4-Figure 5 As shown, the flexible hinge 4 includes a first elastic portion 41 and a second elastic portion 42, which are connected in sequence into a long strip through a connecting portion 43. When the airbag 1 is subjected to an external force, the first elastic portion 41 and the second elastic portion 42 of the flexible hinge 4 will be deformed. Due to the elastic characteristics of the flexible hinge 4, it can return to its original state after the external force is removed, thereby achieving a shock-absorbing effect. In addition, the flexible hinge 4 can also effectively control the movement angle of the airbag 1 in the horizontal direction, ensuring the stable movement of the airbag 1 in a specific direction.

[0035] Furthermore, the first elastic portion 41 and the second elastic portion 42 are arranged perpendicular to each other and deform in two directions perpendicular to each other. Since the first elastic portion 41 and the second elastic portion 42 are deformed in two perpendicular directions respectively, when the airbag 1 is subjected to external force, no matter which direction the external force comes from, the flexible hinge 4 can limit the horizontal displacement of the airbag 1 through the deformation of its two elastic portions, thereby improving the overall accuracy and stability of the instrument.

[0036] Specifically, in the present application, the first elastic part 41 and the second elastic part 42 are both composed of two leaf springs arranged opposite to each other, and the flexible hinge 4 transmits horizontal displacement to the leaf spring structure, thereby achieving the effect of parallel connection of the positive and negative stiffness of the horizontal leaf spring and the airbag 1; at the same time, the flexible hinge 4 also decouples the movement of the top support of the airbag 1, isolates the factors such as bending moment and vertical displacement that affect the stiffness of the leaf spring, so that the force transmitted to the leaf spring is perpendicular to the surface of the leaf spring, and further, the two leaf spring structures are placed at 90°, and the positive and negative stiffness of the airbag 1 in the horizontal direction (lateral and longitudinal) can be connected in parallel through force decomposition, and the setting of the two flexible hinges 4 can further share the vibration, thereby reducing the horizontal frequency.

[0037] like Figure 6-Figure 8 As shown, the third elastic part 32 includes two leaf springs 321, and the two ends of the two leaf springs 321 are respectively fixed on the corresponding support parts 33, and the sliding part 34 includes a first connecting block 341, a second connecting block 342 and a third connecting block 343, wherein the second connecting block 342 is located between the two leaf springs 321, and the first connecting block 341 and the third connecting block 343 are respectively located on both sides of the second connecting block 342 and are close to the second connecting block 342. The three connecting blocks are locked by screws to prevent the third elastic part 32 from reducing water by deformation. When the frequency of the horizontal vector affects the airbag 1, the sliding part 34 slides down, causing the stiffness of the third elastic part 32 to change, thereby failing to reduce the impact of the current horizontal vector frequency on the precision machinery. When the rotating part 35 rotates, it drives the sliding part 34 to slide on the third elastic part 32, thereby changing the relative distance between the upper surface of the sliding part 34 and the lower surface of the supporting part 33, thereby changing the deformation length of the third elastic part 32, and then changing the stiffness of the third elastic part 32 to adapt to the stiffness requirements of different precision machinery.

[0038] like Figure 7-Figure 8As shown, in order to prevent the first connecting block 341, the second connecting block 342 and the third connecting block 343 from falling and scattering directly when the screw is removed when adjusting the position of the sliding portion 34, the contact surfaces of the first connecting block 341 and the second connecting block 342 extend toward each other to form two first extension portions 344, and the contact surfaces of the second connecting block 342 and the third connecting block 343 extend toward each other to form two second extension portions 345 to define the sliding space corresponding to the two leaf springs 321, and the upper surface and the lower surface of the second connecting block 342 are further provided with notches 346, and the first connecting block 341 The first and third connecting blocks 341 and 343 extend toward the second connecting block 342 and extend into the corresponding notches 346. The notches 346 formed on the upper and lower surfaces of the second connecting block 342 provide accommodation space for the extended parts of the first and third connecting blocks 341 and 343, so that the connecting blocks are mutually constrained in the vertical direction, further preventing them from falling. The first and third connecting blocks 341 and 343 extend toward the second connecting block 342 and extend into the corresponding notches 346, which not only increases the connection strength between the connecting blocks, but also makes them less likely to fall apart when the screws are removed.

[0039] In order to more accurately control the position of the sliding part 34 on the elastic part, the rotating part 35 includes a first gear 351 and a second gear 352. The first gear 351 is rotatably connected to the fixed column 31, and the second gear 352 is meshed with the first gear 351. The second gear 352 is fixedly connected to the first connecting block 341, the second connecting block 342 and one side of the third connecting block 343 after locking. The first gear 351 rotates to make the second gear 352 move up and down, and drives the sliding part 34 to move, thereby completing the adjustment of the stiffness of the elastic part.

[0040] Specifically, the first gear 351 and the second gear 352 are both herringbone gears. The unique tooth shape of the herringbone gears can distribute the load on the teeth more evenly, thereby significantly enhancing the bearing capacity of the gears and helping to compensate for slight misalignment, preventing the first gear 351 from moving along its own axial direction during rotation and causing misalignment with the second gear 352, thereby affecting the stiffness of the corresponding elastic part after the sliding part 34 is adjusted.

[0041] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the scope of protection of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention.

Claims

1. A composite shock absorber with positive and negative stiffness, characterized in that: include: Airbag (1); an adapter part (2) located above the airbag (1), the adapter part (2) comprising a first adapter part (21) and a second adapter part (22), the second adapter part (22) being fixed to the top of the airbag (1), a platform being fixed above the first adapter part (21) for placing instruments, a connecting part (23) being provided between the first adapter part (21) and the second adapter part (22), the connecting part (23) being connected to the first adapter part (21) or the second adapter part (22) by at least one point contact; An adjusting device (3) is arranged along the axial direction of the airbag (1); A flexible hinge (4), wherein both ends of the flexible hinge (4) are respectively connected to the top of the adjusting device (3) and the second adapter (22); when the instrument is placed on the platform, the first adapter (21) and the second adapter (22) reduce the frequency of the airbag (1) in the horizontal direction through the relative movement of the connecting member (23).

2. A positive and negative stiffness composite shock absorber according to claim 1, characterized in that: The first adapter (21) has a concave first arcuate surface (24), the first arcuate surface (24) being located on a surface of the first adapter (21) adjacent to the second adapter (22), the connecting member (23) being fixed to the second adapter (22) and being arranged as a spherical surface (231) protruding relative to the second adapter (22), the spherical surface (231) being in point contact with the concave arcuate surface.

3. A positive and negative stiffness composite shock absorber according to claim 1, characterized in that: A concave second arc-shaped surface (25) is symmetrically arranged on one side adjacent to the first adapter (21) and the second adapter (22); the connecting member (23) is spherical and is in point contact with the two second arc-shaped surfaces (25).

4. A positive and negative stiffness composite shock absorber according to claim 1, characterized in that: A concave third arcuate surface (26) and a truncated cone surface (27) opposite to the third arcuate surface (26) are respectively provided on adjacent surfaces of the first adapter (21) and the second adapter (22); the connecting member (23) is spherical and is in line contact with the truncated cone surface (27) and in point contact with the third arcuate surface (26); a plurality of truncated cone surfaces (27) and a plurality of third arcuate surfaces (26) are provided and are arranged in an arc array with the center of the first adapter (21) as the center of the circle.

5. The positive and negative stiffness composite shock absorber according to claim 1, characterized in that: A plurality of groups of inwardly concave fourth arcuate surfaces (28) are symmetrically arranged on a surface adjacent to the first adapter (21) and the second adapter (22); the connecting member (23) is spherical and is in point contact with the plurality of groups of the fourth arcuate surfaces (28); and the plurality of groups of the fourth arcuate surfaces (28) are arranged in an arc array with the center of the first adapter (21) as the center of the circle.

6. The positive and negative stiffness composite shock absorber according to claim 1, characterized in that: The flexible hinge (4) comprises a first elastic portion (41), a second elastic portion (42) and a connecting portion (43); the first elastic portion (41) and the second elastic portion (42) are connected in sequence via the connecting portion (43) to form a long strip shape; and the first elastic portion (41) and the second elastic portion (42) are deformed in two directions.

7. The positive and negative stiffness composite shock absorber according to claim 1, characterized in that: The adjusting device (3) comprises a fixed column (31), a third elastic part (32), a supporting part (33), a sliding part (34) and a rotating part (35); the two supporting parts (33) are connected to two ends of the third elastic part (32); the supporting part (33) located at the top of the third elastic part (32) is connected to the second adapter (22) via the flexible hinge (4); the sliding part (34) is slidably arranged on the third elastic part (32) and is fixedly connected to the rotating part (35); the rotating part (35) is rotatably connected to the fixed column (31); when the rotating part (35) rotates, the sliding part (34) is driven to slide on the third elastic part (32), thereby changing the relative distance between the upper surface of the sliding part (34) and the lower surface of the supporting part (33) of the third elastic part (32).

8. A positive and negative stiffness composite shock absorber according to claim 7, characterized in that: The third elastic portion (32) comprises two leaf springs (321), the two ends of the two leaf springs (321) are respectively fixed on the supporting portion (33), the sliding portion (34) comprises a second connecting block (342) located between the two leaf springs (321) and a first connecting block (341) and a third connecting block (343) located on both sides of the second connecting block (342), the first connecting block (341) and the third connecting block (343) both being attached to the second connecting block (342) and being screwed; wherein the contact surfaces of the first connecting block (341) and the second connecting block (342) respectively extend towards each other to form two first extension portions (344), and the contact surfaces of the second connecting block (342) and the third connecting block (343) respectively extend towards each other to form two second extension portions (345) to define a sliding space corresponding to the two leaf springs (321).

9. A positive and negative stiffness composite shock absorber according to claim 8, characterized in that: The upper surface and the lower surface of the second connection block (342) are both provided with notches (346), and the first connection block (341) and the third connection block (343) both extend toward the second connection block (342) and are respectively located in the corresponding notches (346).

10. A positive and negative stiffness composite shock absorber according to claim 7, characterized in that: The rotating part (35) comprises a first gear (351) and a second gear (352), wherein the first gear (351) is rotatably connected to the fixed column (31), and the second gear (352) is fixedly connected to one side of the locked first connecting block (341), the second connecting block (342) and the third connecting block (343), and meshes with the first gear (351).

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