Quasi-zero stiffness shock absorber
By using a combination of curved sliding surface and elastic parts in the shock absorber, a constant output force under extreme operating conditions is achieved, and the problem of unstable acceleration response of mechanical vibration reduction equipment is solved, ensuring the safety of the equipment and stability.
Patent Information
- Application Number
- CN202420918978.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-29
- Publication Date
- 2025-01-07
- Estimated Expiration
- 2034-04-29
AI Technical Summary
When mechanical vibration reduction and isolation equipment cope with vibration or impact loads, the change in the stiffness of the vibration reduction and isolation equipment causes the acceleration response of the vibration reduction and isolation object to be unable to ensure that it is in a stable range, and there are stability and safety hazards under extreme operating conditions, especially in transportation and storage. It is particularly prominent when it comes to equipment or dangerous items.
A quasi-zero stiffness shock absorber is designed, using sliding parts and an internal hollow shell. The inner peripheral wall of the shell forms a curved sliding surface, and a constant axial force is provided through the elastic member to ensure that the resistance end outputs force during the slip process. Basically constant, achieving constant output force of the shock absorber.
Under extreme operating conditions, ensure that the acceleration response of the vibration-reducing object is maintained in a stable range, ensuring safety, reducing the peak of acceleration response, and avoiding the instability of the equipment under extreme conditions.
Smart Images
Figure CN222315766U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of shock absorbers, in particular to a quasi-zero stiffness shock absorber. Background Art
[0002] When dealing with vibration or impact loads, current mechanical vibration reduction and isolation equipment is limited by the change in the stiffness of the vibration reduction equipment. The upper limit of the acceleration response of the vibration reduction and isolation object cannot be guaranteed to be within a stable range. When the working conditions change drastically, the stability and safety of the vibration reduction and isolation object cannot be guaranteed. This poses certain risks to the transportation and storage of precision equipment, dangerous goods, important items, etc. Utility Model Content
[0003] In order to solve at least one technical problem mentioned in the background technology, the purpose of the utility model is to provide a quasi-zero stiffness shock absorber.
[0004] In order to achieve the above purpose, the utility model provides the following technical solutions:
[0005] A quasi-zero stiffness shock absorber comprises a sliding component and a hollow shell, wherein at least part of the inner peripheral wall of the shell forms a first sliding surface, the first sliding surface is a curved surface, and the first sliding surface is configured to gradually approach the central axis of the shell along the axial direction of the shell;
[0006] The sliding component includes a shaft body that is movably arranged on the shell along the axial direction of the shell, a telescopic assembly that is arranged in the shell and fixedly connected to the shaft body, and an elastic member arranged in the telescopic assembly; at least one end of the shaft body extends out of the shell as a force-bearing end;
[0007] The telescopic assembly can be movable and telescopic along the radial direction of the housing, and the telescopic assembly includes a resistance end that can slide along the axial direction of the housing in contact with the first sliding surface, and the elastic member is used to provide a radial elastic force F to drive the resistance end to resist the first sliding surface;
[0008] The first sliding surface includes a first sliding section, and the curvature of the first sliding section is configured so that when the abutment end is at any position in the axial direction of the first sliding section, the axial force F0 parallel to the axial direction of the housing formed by decomposing the elastic force F provided by the elastic member on the abutment end is equal.
[0009] As an optional embodiment of the utility model, the telescopic assembly includes a limit shell fixed on the shaft body, and a plurality of telescopic blocks arranged on the limit shell in sequence along the circumference of the limit shell, and the telescopic blocks can move relative to the limit shell along the radial direction of the outer shell; the abutment end is located on the telescopic block.
[0010] As an optional implementation of the utility model, the elastic member is arranged between the limiting shell and the telescopic block to cause the telescopic block to move radially outward so that the abutting end abuts against the first sliding surface.
[0011] As an optional embodiment of the utility model, the limit shell has an axially extending cavity inside, the shaft body is inserted into the cavity, and the elastic member includes a spring arranged in the cavity, one end of the spring is fixed to the shaft body, and the other end is fixed to the telescopic block.
[0012] As an optional implementation of the present invention, the telescopic assembly further includes a guide column, and the guide column is used to guide the telescopic block to move radially relative to the limiting shell along the outer shell.
[0013] As an optional implementation of the present invention, the abutment end includes a universal ball bearing.
[0014] As an optional implementation of the present invention, the first sliding surface further includes a second sliding segment connected to the first sliding segment along the axial direction of the shell, and the first sliding segment is closer to the central axis of the shell than the second sliding segment.
[0015] As an optional implementation of the present invention, the inner peripheral wall of the shell is further formed with a second sliding surface, the first sliding surface and the second sliding surface are mirror-symmetrical to each other, and the symmetry plane is a radial plane of the shell.
[0016] As an optional implementation of the present invention, the shaft body is penetrated on the housing through a linear bearing.
[0017] As an optional implementation of the present invention, the radial cross-section of the inner circumferential wall of the shell is circular.
[0018] Compared with the prior art, the advantages of adopting this solution are:
[0019] In the present solution, by controlling the curvature of the first sliding section, when the abutment end is at any position on the axial direction of the first sliding section, the axial force F0 parallel to the axial direction of the shell formed by the decomposition of the elastic force F provided by the elastic member on the abutment end is equal. This is equivalent to, during the shock absorption process, when the abutment end slides axially along the first sliding section, the axial force F0 output by the spring to it is basically constant, that is, the output force of the shock absorber is basically constant. In this way, it can be ensured that when dealing with extreme working conditions, the acceleration response of the seismic isolation object can be maintained in a stable range. As long as the response formation does not exceed the limit formation, the acceleration response peak value of the seismic isolation object is always less than the design index, thereby ensuring the safety of the seismic isolation object. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is a structural schematic diagram of the utility model;
[0021] Figure 2 It is a cross-sectional view of Example 1 of the utility model;
[0022] Figure 3 It is a structural schematic diagram of the sliding component in the utility model;
[0023] Figure 4 It is a cross-sectional view of the sliding component of the utility model;
[0024] Figure 5 It is a cross-sectional view of the housing in Embodiment 1 of the present utility model;
[0025] Figure 6 is a decomposition diagram of the forces of the universal ball bearing in the first sliding section;
[0026] Figure 7 A further exploded diagram of the forces of the universal ball bearing in the first sliding section;
[0027] Figure 8 It is a cross-sectional view of the housing in Embodiment 2 of the present utility model;
[0028] Fig. 9 This is a relationship diagram between the axial force F0 and the axial displacement of the abutting end on the first sliding surface of the utility model. DETAILED DESCRIPTION
[0029] The following is an explanation and description of the technical scheme of the embodiment of the utility model in conjunction with the drawings of the embodiment of the utility model, but the following embodiment is only a preferred embodiment of the utility model, not all. Based on the embodiment in the implementation mode, other embodiments obtained by those skilled in the art without creative work are all within the protection scope of the utility model.
[0030] In the following description, terms such as "inside", "outside", "up", "down", "left", "right", etc. that indicate directions or positional relationships are only used to facilitate the description of the embodiments and simplify the description, and do not indicate or imply that the referred device or element must have a specific direction, be constructed and operate in a specific direction. Therefore, it should not be understood as a limitation on the present invention.
[0031] Example 1
[0032] This embodiment provides a quasi-zero stiffness shock absorber, specifically a unidirectional quasi-zero stiffness shock absorber.
[0033] This embodiment includes a sliding component and a hollow shell 1, wherein the radial cross section of the inner peripheral wall of the shell 1 is circular. In addition, it is worth noting that the radial direction and axial direction claimed in this embodiment can be understood as the radial direction and axial direction of the shell 1.
[0034] like Figure 2 and Figure 5 As shown, the inner peripheral wall of the housing 1 at least partially forms a first sliding surface L1 , and the first sliding surface L1 extends axially along the housing 1 .
[0035] In addition, in this embodiment, the first sliding surface L1 is a curved surface, and the first sliding surface L1 is configured to gradually approach the central axis of the housing 1 along the axial direction of the housing 1. Figure 2 Taking the perspective as an example, along the axial direction of the housing 1 from left to right, the first sliding surface L1 gradually approaches the central axis of the housing 1 .
[0036] like Figure 3 and Figure 4 As shown, the sliding component includes a shaft 21, a telescopic component 22 and an elastic member; Figure 2 As shown, the shaft body 21 is movably arranged on the shell 1 along the axial direction of the shell 1. Preferably, the shaft body 21 and the shell 1 are coaxially arranged, and a linear bearing 211 is fixed at the end of the shell 1. The shaft body 21 is movably arranged in the linear bearing 211. The linear bearing 211 can make the shaft body 21 move more smoothly; at least one end of the shaft body 21 extends out of the shell 1 as a force-bearing end.
[0037] The telescopic component 22 is arranged in the shell and fixedly connected to the shaft body 21, wherein the telescopic component 22 can move and retract radially along the shell 1, and the telescopic component 22 includes a contact end that can slide axially along the shell 1 in accordance with the first sliding surface L1, that is, the contact end contacts the first sliding surface L1 for axial movement.
[0038] The elastic member is arranged in the telescopic assembly 22 and is mainly used to provide an elastic force F along the radial direction of the housing 1 . Driven by the elastic force F, the telescopic assembly 22 tends to extend, so that the abutting end abuts against the first sliding surface L1 .
[0039] like Figure 2 and Figure 5 As shown, the first sliding surface L1 is composed of a first sliding section L11 and a second sliding section L12 which are connected in sequence along the axial direction of the housing 1. Figure 2 In the viewing direction, the first sliding segment L11 is located on the right side of the second sliding segment L12 , and from left to right, the left end of the first sliding segment L11 is the right end of the second sliding segment L12 .
[0040] The curvature of the first sliding section L11 is constructed as follows, that is, the curvature of the first sliding section L11 needs to meet the following conditions: when the contact end is at any position on the axial direction of the first sliding section L11, the axial force F0 parallel to the axial direction of the shell 1 formed by the decomposition of the elastic force F provided by the elastic member on the contact end is equal, which is equivalent to that during the shock absorption process, when the contact end slides axially along the first sliding section L11, the axial force F0 output by the spring 23 to it is basically constant, that is, the output force of the shock absorber is basically constant, which is equivalent to the stiffness change being zero, that is, zero stiffness. In this way, it can be ensured that when dealing with extreme working conditions, the acceleration response of the seismic isolation object can also be maintained in a stable range. As long as the response formation does not exceed the limit formation, the acceleration response peak value of the seismic isolation object is always less than the design index, thereby ensuring the safety of the seismic isolation object.
[0041] The axial force F0 can be specifically understood as: Figure 6 As shown, the abutting end is subjected to a radial elastic force F provided by a spring 23 to abut against the first sliding section L11 of the curved surface structure. The elastic force F is decomposed into a force F1 parallel to the tangent direction of the first sliding section L11 and a force F2 perpendicular to the force F1 through the sliding surface; Figure 7 As shown, the force F1 can be decomposed into an axial force F0 parallel to the axial direction of the housing 1. The axial force F0 is equivalent to the output force of the shock absorber, which is opposite to the force applied by the shock-isolating object and is used to achieve shock absorption.
[0042] The entire shock absorption process can be specifically divided into two stages. The first stage is that the abutment end slides from the left end of the second sliding segment L12 (i.e., the zero point position) along the second sliding segment L12 to the right end of the second sliding segment L12 (i.e., the left end of the first sliding segment L11); the second stage is that it slides from the left end of the first sliding segment L11 along the first sliding segment L11 to the right end of the first sliding segment L11; during the entire process, the relationship between the output force of the shock absorber (i.e., the axial force F0) and the axial displacement S of the abutment end on the first sliding surface L1 can be referred to. Fig. 9 As shown (for details, please refer to Fig. 9 The curve in the first quadrant of the
[0043] In the first stage, as the resistance end moves forward, the axial force F0 gradually increases until it reaches the left end of the first sliding section L11, where it reaches the maximum. In the subsequent second stage, the current axial force F0 is maintained forward, so that the shock absorber performs shock isolation with a stable output force.
[0044] In the first stage, the axial force F0 mainly provides support for the equipment to ensure stability under small load excitation; the second stage is the force value stability range, which is the main energy absorption stage of the shock absorber. The output force value of this stage can be designed according to the quality of the equipment and the maximum acceleration that the equipment can withstand. When the energy absorption is completed, the resistance end returns to the zero position again.
[0045] The quasi-zero stiffness claimed in this embodiment can be understood as follows: when the shock absorber takes effect, the force applied by the shock absorber to the equipment (i.e., the seismic isolation object) increases (the first stage), and the force remains constant until entering the second stage. The stiffness changes during the force increase process, and the stiffness change is zero during the constant force process. Therefore, it is called a quasi-zero stiffness shock absorber.
[0046] Among them, Figure 3 and Figure 4 As shown, the telescopic assembly 22 includes a limit shell 221 fixed on the shaft body 21, and a plurality of telescopic blocks 222 arranged on the limit shell 221 in sequence along the circumference of the limit shell 221. For example, four limit blocks are used in this embodiment. Preferably, the telescopic blocks 222 are distributed in an array on the limit shell 221.
[0047] The limiting shell 221 is generally circular in shape, and the telescopic block 222 can move relative to the limiting shell 221 along the radial direction of the housing 1. Specifically, a cavity 2211 extending along the axial direction of the limiting shell 221 is provided in the middle of the limiting shell 221, and the shaft body 21 is disposed in the cavity 2211; Figure 3 As shown, a movable groove 2212 communicating with the cavity 2211 for the telescopic block 222 to be inserted into is provided on the surface of the limiting shell 221 corresponding to the position of the telescopic block 222 , and the telescopic block 222 is movably inserted into the movable groove 2212 , so that the telescopic block 222 can move radially relative to the limiting shell 221 .
[0048] In this embodiment, the abutment end is located on the telescopic block 222, wherein the outer side surface of the telescopic block 222 is a conical surface structure with a high middle and low sides, and the abutment end is arranged in the middle position of the outer side surface of the telescopic block 222, wherein the abutment end preferably adopts a universal ball bearing 223, so that the ball of the universal ball bearing 223 can roll forward on the first sliding surface L1 to reduce friction.
[0049] The elastic member is disposed between the limiting shell 221 and the telescopic block 222 to cause the telescopic block 222 to move radially outward so that the abutting end abuts against the first sliding surface L1. Specifically:
[0050] like Figure 3 and Figure 4As shown, the elastic member can be a spring 23, and the spring 23 is arranged in the cavity 2211, wherein the number of the springs 23 can be multiple and they are distributed in sequence along the length direction of the cavity 2211 and the spring 23 extends radially along the cavity 2211, one end of the spring 23 is fixed to the shaft body 21, and the other end is fixed to the telescopic block 222, and the spring 23 provides a radial outward elastic force for the telescopic block 222.
[0051] In order to guide the radial movement of the telescopic block 222, the telescopic assembly 22 also includes a guide column 224, which is used to guide the radial movement of the telescopic block 222 along the outer shell 1 relative to the limiting shell 221. Specifically, the guide column 224 extends radially along the limiting shell 221, and the guide column 224 is fixed to the telescopic block 222, and is movably arranged on the shaft body 21 along the radial direction of the cavity 2211, and plays a guiding role through the guide column 224.
[0052] Example 2
[0053] In embodiment 1, it is equivalent to a one-way shock absorber, that is, Figure 2 Taking the perspective as an example, when the shaft 21 is forced to move to the right, it plays a shock absorbing role. This embodiment further provides a bidirectional shock absorber based on the embodiment 1. The difference between the shock absorber provided in the embodiment 1 is that in this embodiment, Figure 8 As shown, the inner peripheral wall of the housing 1 is further formed with a second sliding surface L2 , the first sliding surface L1 and the second sliding surface L2 are mirror-symmetrical to each other, and the symmetry plane is a radial plane of the housing 1 .
[0054] It can be understood that the first slip surface L1 is symmetrically turned leftward with the aforementioned symmetry plane as the symmetry reference to become the second slip surface L2. The structures of the first slip surface L1 and the second slip surface L2 are basically the same, and the difference is that the two directions are opposite; in this way, the purpose of bidirectional shock absorption can be achieved. For example, when the shaft body 21 is forced to move to the right, shock absorption can be achieved through the cooperation of the first slip surface L1, and when the shaft body 21 is forced to move to the left, shock absorption can be achieved through the cooperation of the second slip surface L2.
[0055] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that 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, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention.
Claims
1. A quasi-zero stiffness shock absorber, characterized in that: It comprises a sliding component and a hollow shell, wherein at least a part of the inner peripheral wall of the shell forms a first sliding surface, the first sliding surface is a curved surface, and the first sliding surface is configured to gradually approach the central axis of the shell along the axial direction of the shell; The sliding component includes a shaft body that is movably arranged on the shell along the axial direction of the shell, a telescopic assembly that is arranged in the shell and fixedly connected to the shaft body, and an elastic member arranged in the telescopic assembly; at least one end of the shaft body extends out of the shell as a force-bearing end; The telescopic assembly can be movable and telescopic along the radial direction of the housing, and the telescopic assembly includes a resistance end that can slide along the axial direction of the housing in contact with the first sliding surface, and the elastic member is used to provide a radial elastic force F to drive the resistance end to resist the first sliding surface; The first sliding surface includes a first sliding section, and the curvature of the first sliding section is configured so that when the abutment end is at any position in the axial direction of the first sliding section, the axial force F0 parallel to the axial direction of the housing formed by decomposing the elastic force F provided by the elastic member on the abutment end is equal.
2. A quasi-zero stiffness shock absorber according to claim 1, characterized in that: The telescopic assembly includes a limiting shell fixed on the shaft body, and a plurality of telescopic blocks sequentially arranged on the limiting shell along the circumference of the limiting shell, and the telescopic blocks can move relative to the limiting shell along the radial direction of the outer shell; the abutment end is located on the telescopic block.
3. A quasi-zero stiffness shock absorber according to claim 2, characterized in that: The elastic member is arranged between the limiting shell and the telescopic block to cause the telescopic block to move radially outward so that the abutting end abuts against the first sliding surface.
4. A quasi-zero stiffness shock absorber according to claim 3, characterized in that: The limiting shell has an axially extending cavity inside, the shaft body is arranged in the cavity, and the elastic member includes a spring arranged in the cavity, one end of the spring is fixed to the shaft body, and the other end is fixed to the telescopic block.
5. A quasi-zero stiffness shock absorber according to any one of claims 2 to 4, characterized in that: The telescopic assembly further comprises a guide column, and the guide column is used for guiding the telescopic block to move along the radial direction of the outer shell relative to the limiting shell.
6. The quasi-zero stiffness shock absorber according to claim 1, characterized in that: The abutment end includes a universal ball bearing.
7. The quasi-zero stiffness shock absorber according to claim 1, characterized in that: The first sliding surface also includes a second sliding segment connected to the first sliding segment along the axial direction of the shell, and the first sliding segment is closer to the central axis of the shell than the second sliding segment.
8. The quasi-zero stiffness shock absorber according to claim 1, characterized in that: The inner peripheral wall of the shell is also formed with a second sliding surface, the first sliding surface and the second sliding surface are mirror-symmetrical to each other, and the symmetry plane is a radial plane of the shell.
9. The quasi-zero stiffness shock absorber according to claim 1, characterized in that: The shaft body is penetrated on the shell through a linear bearing.
10. The quasi-zero stiffness shock absorber according to claim 1, characterized in that: The radial cross section of the inner peripheral wall of the shell is circular.