A non-smooth vibration absorber with asymmetric stiffness

Abstract

A non-smooth vibration absorber with asymmetric stiffness comprises a plurality of first columns and a central second column vertically disposed between a parallel upper base and a lower base, wherein the first columns are evenly distributed along the circumference of the upper / lower base with the second column as the center. An annular mass block is disposed around the periphery of all the first columns, and the mass block is capable of sliding up and down along the guide rails on the first columns. A plurality of second springs are fixed horizontally and evenly spaced between the inner wall of the mass block and the outer wall of the second column, for generating a pulling force perpendicular to the second column on the mass block. A plurality of first springs are vertically and evenly spaced between the bottom of the mass block and the top surface of the lower base, for providing an elastic force perpendicular to the lower base on the mass block. When the mass block is in static equilibrium, the second spring is in a freely extended state. When the vibration absorber is activated, the mass block separates from the first spring during upward movement.

Description

Technical Field

[0001] The present invention relates to the technical field of vibration reduction, and in particular to a non-smooth vibration absorber with asymmetric stiffness. Background Art

[0002] Purely nonlinear stiffness and quasi-zero stiffness vibration absorbers have the characteristics of wide-band vibration absorption and light weight. However, the vibration absorption performance of the vibration absorber in the vertical direction will be affected by the weight of the mass block. Under the influence of gravity, the spring will be pre-stretched when the mass block is in a static equilibrium state, resulting in problems such as reduced vibration absorption performance, increased activation threshold, and induction of additional resonance peaks in the system. Non-smooth vibration absorbers with asymmetric stiffness, while maintaining the advantages of wide-band vibration absorption and light weight, introduce vertical compression springs inside the vibration absorber to offset the adverse effects of the mass block weight on the nonlinear vibration absorber, constructing non-smooth characteristics with completely different stiffness characteristics on the upper and lower sides of the static equilibrium position. Crucially, there is no connection between the vertical spring and the mass block, which does not introduce linear stiffness into the vibration absorber, and the collision between the two can also help improve the vibration absorption performance.

[0003] Currently, in vertical applications of traditional pure nonlinear and quasi-zero-stiffness nonlinear vibration absorbers, under the influence of gravity, the springs will pre-stretch when the mass is in static equilibrium. This can lead to problems such as reduced vibration absorption performance, increased activation thresholds, and the induction of additional resonance peaks in the system. To address this issue, the use of supporting compression springs is considered to avoid pre-stretching the springs when the mass is in the central equilibrium position, thereby alleviating these issues. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides a non-smooth vibration absorber with asymmetric stiffness, which can alleviate the technical problems in the existing technology of pure nonlinear stiffness and quasi-zero stiffness vibration absorbers, such as decreased vibration absorption performance, increased activation threshold and induction of additional resonance peaks due to spring pre-stretching under the influence of gravity.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A non-smooth vibration absorber with asymmetric stiffness, comprising an upper base and a lower base arranged in parallel, the lower base having a through hole for connecting to a structure to be damped, a plurality of first columns and a second column vertically arranged between the upper and lower bases, the second columns being arranged along a center extension line of the upper and lower bases, and the first columns being evenly distributed around the upper / lower base with the second column as the center.

[0007] An annular mass block is sleeved around the periphery of all the first columns, allowing the mass block to slide up and down along the outer wall of the first column; a plurality of second springs are fixed horizontally and evenly spaced between the inner wall of the mass block and the outer wall of the second column, for generating a pulling force perpendicular to the direction of the second column on the mass block;

[0008] A plurality of first springs are vertically and evenly spaced between the bottom of the mass block and the top surface of the lower base, for providing an elastic force perpendicular to the lower base to the mass block, and the first spring and the second spring are both located between two adjacent first columns;

[0009] Moreover, one end of the first spring is fixedly connected to the lower base, and the other end is a free end capable of contacting the bottom of the mass block;

[0010] When the non-smooth vibration absorber is not activated, the mass block is in a static equilibrium position, the second spring is in a freely extended state, the first spring is compressed, and its top contacts the bottom surface of the mass block. The upward elastic force exerted by the first spring on the mass block is equal to the weight of the mass block, thereby avoiding pre-stretching of the second spring caused by the weight of the mass block itself;

[0011] When the non-smooth vibration absorber is activated by external excitation, the mass block moves up and down. When the mass block moves upward, it separates from the first spring. The second spring connected to the mass block generates nonlinear stiffness, which enables the non-smooth vibration absorber to have a wide-band vibration absorption capability. When the mass block moves downward, it collides with the first spring. The first spring is compressed and gives the mass block an upward force.

[0012] Furthermore, a plurality of sliders are arranged at intervals on the inner wall of the mass block; the first column is fixedly connected to a guide rail on the outer wall of the mass block, and the sliders are slidably connected to the guide rail.

[0013] Furthermore, the first column is fixedly connected to the upper base and the lower base respectively through brackets.

[0014] Furthermore, one end of the second spring is fixedly connected to a second spring seat located on the inner wall of the mass block, and the other end of the second spring is fixedly connected to a second spring seat located on the outer wall of the second column.

[0015] Furthermore, a gasket is provided at the contact point between the bottom of the mass block and the end of the first spring.

[0016] Preferably, a gasket is bonded to the bottom of the mass block and the end of the first spring respectively to offset the noise generated when the two collide.

[0017] Preferably, the mass block is octagonal, the number of the first columns is 4, and the number of the first springs and the second springs are both 4.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The non-smooth vibration absorber of the present invention includes first and second springs arranged horizontally and vertically. When the vibration absorber is inactive, the second spring is in a freely extended state, and only the first spring is compressed. When the vibration absorber is activated, the second spring generates nonlinear stiffness, which enables the non-smooth vibration absorber to have a wide-band vibration absorption capability. The friction between the slider and the guide rail during the movement of the mass block can also dissipate some energy. The first spring is fixed at only one end, with the other end being free, thereby offsetting the gravity of the mass block.

[0020] The vibration absorber can alleviate the technical problems existing in the prior art of pure nonlinear stiffness vibration absorbers, such as decreased vibration absorption performance, increased activation threshold, and induction of additional resonance peaks due to spring pre-stretching under the influence of gravity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the structure of the non-smooth vibration absorber with asymmetric stiffness according to the present invention;

[0022] Figure 2 yes Figure 1 main view.

[0023] Figure 3 yes Figure 1 Front view of the second spring of the non-smooth vibration absorber.

[0024] In the picture:

[0025] 1: Upper base 2: First column 3: Guide rail

[0026] 4: Slider 5: Mass block 6: Gasket

[0027] 7: First spring 8: First spring seat 9: Bracket

[0028] 10: Second column 11: Second spring seat 12: Second spring

[0029] 13: Vertical angle bracket 14: Lower base DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions, beneficial effects and significant improvements of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the drawings provided in the examples of the present invention. Obviously, all the described embodiments are only partial embodiments of the present invention, rather than all embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] The non-smooth vibration absorber with asymmetric stiffness according to the present invention will be further described below with reference to the accompanying drawings.

[0032] like Figure 1-2 As shown, a non-smooth vibration absorber with asymmetric stiffness includes an upper base 1 and a lower base 14 arranged in parallel, four first columns 2 and one second column 10 vertically arranged between the upper base 1 and the lower base 14, the second column 10 being centrally arranged between the upper base 1 and the lower base 14, and the second column 10 being connected to the upper base 1 and the lower base 14 respectively by bolts and nuts via a plurality of L-shaped vertical angle brackets 13. The four first columns 2 are evenly distributed between the upper base 1 and the lower base 14 along the circumference of the upper / lower base with the second column as the center, and the first columns 2 are connected to the upper base 1 and the lower base 14 respectively by bolts and nuts via a plurality of L-shaped brackets 9. The top surfaces of the first columns 2 and the second columns 10 are fixed to the bottom of the upper base 1, and the bottom surfaces of the first columns 2 and the second columns 10 are fixed to the top surface of the lower base 14. An annular mass block 5 is sleeved around the periphery of all first columns 2, and the distance between its bottom surface and the upper surface of the lower base 14 is 1 / 3 of the distance between the mass block and the first spring to prevent the mass block from over-compressing the first spring and causing a collision between the mass block and the lower base 14. The mass block 5 is a regular octagonal ring, and four sliders 4 and four second spring seats 11 are fixed on the inner wall of the mass block 5. The sliders 4 or second spring seats 11 are spaced apart on the inner wall of each side of the mass block 5; the sliders 4 and second spring seats are evenly spaced apart on the inner wall of the mass block 5, and the outer wall of the mass block 5 with the sliders 4 facing the first column 2 is fixedly connected to the guide rail 3 by bolts and nuts. The size of the slider 4 is adapted to the track width of the guide rail 3, and the slider 4 can slide along the guide rail 3, thereby causing the mass block 5 to slide up and down along the guide rail 3; four second springs 12 (such as Figure 3 As shown), it is used to generate a pulling force perpendicular to the direction of the second column 10 on the mass block. Four second spring seats 11 are installed around the inner wall of the mass block 5 and the outer wall of the second column 10 respectively by bolts and nuts. One end of the four second springs 12 is connected to the second spring seat 11 located on the inner wall of the mass block 5 by threads and toothed rods, and the other end is also connected to the second spring seat 11 located on the outer wall of the second column 10 by threads and toothed rods. Four first springs 7 are vertically arranged between the bottom of the mass block 5 and the top surface of the lower base 14, which are used to provide the mass block 5 with an elastic force perpendicular to the upper surface of the lower bottom surface. The first springs 7 are evenly distributed and located between two adjacent first columns 2; one end of a rubber gasket 6 is fixed to the bottom of the mass block 5 by strong glue, and the size of the gasket 6 is adapted to the diameter of the first spring 7. Its position is opposite to the position of the first spring 7 and can contact the top of the first spring; the bottom of the first spring 7 is fixed on the corresponding first spring seat 8, and the first spring seat 8 is fixed to the top surface of the lower base by bolts and nuts at intervals. As shown Figure 1As shown, four screws protruding from the side wall of the first spring seat 8 are circumferentially provided on the side wall of the first spring seat 8 for fixing one end of the first spring 7 on the first spring seat 8 .

[0033] The lower base 14 has a plurality of first through holes and four second through holes. The first through holes are used to fix the vertical angle frame 13, the bracket 9 and the first spring seat 8, and the second through holes are used to connect the vibration-damped structure.

[0034] During use, when the non-smooth vibration absorber is not activated, the mass block 5 is in a static equilibrium position, the gasket 6 on the bottom surface of the mass block 5 contacts the top of the first spring 7, and the first spring 7 is compressed. At this time, the upward elastic force / support force applied to the mass block 5 is equal to the gravity of the mass block 5, so as to offset the gravity of the mass block 5 itself, and avoid the technical problems of reduced vibration absorption performance, increased activation threshold and induction of additional resonance peaks caused by the pre-stretching of the second spring 12 due to the gravity of the mass block 5. At this time, the second spring 12 is in a free extension state, that is, it is not stretched or compressed; when the external excitation amplitude increases to a certain extent, the vibration energy of the vibration reduction structure is transmitted to the non-smooth vibration absorber, the non-smooth vibration absorber is activated, and the lower base 14 moves up / down accordingly, and the mass block 5 slides back and forth along the guide rail, and generates friction dissipation energy with the friction pair formed by the slider 4 and the guide rail 3;

[0035] When the mass block 5 moves upward, it separates from the first spring 7. At this time, the four second springs 12 connected to the inner wall of the mass block 5 generate pure nonlinear stiffness. The pure nonlinear stiffness enables the vibration absorber to have a wide-band vibration absorption capability.

[0036] After the upward movement reaches the maximum amplitude, the mass block 5 moves downward along the guide rail 3, and then collides with the first spring 7, consuming the energy of the mass block 5, and then compressing the first spring 7. The compressed first spring 7 gives the mass block 5 an upward force. After the downward movement reaches the maximum amplitude, the mass block 5 moves upward along the guide rail 3. The mass block 5 performs the above-mentioned up and down reciprocating motion to achieve the vibration reduction effect.

[0037] The number of the first columns 2 is determined according to actual conditions, but is not less than 3. The present invention does not limit the shape of the mass block, and the mass block can be in the shape of a polygonal ring or a circular ring.

[0038] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described systems and devices can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

Claims

1. A non-smooth vibration absorber with asymmetric stiffness, comprising an upper base (1) and a lower base (14) arranged in parallel, characterized in that: The lower base (14) has a through hole for connecting to a vibration-damped structure, a plurality of first columns (2) and a second column (10) are vertically arranged between the upper base (1) and the lower base (14), the second column (10) is arranged along the center extension line of the upper base (1) and the lower base (14), and the first columns (2) are evenly distributed along the circumference of the upper / lower base with the second column (10) as the center; An annular mass block (5) is sleeved around the periphery of all first columns (2) and is capable of enabling the mass block (5) to slide up and down along the outer wall of the first column (2); a plurality of second springs (12) are fixedly arranged horizontally and evenly spaced between the inner wall of the mass block (5) and the outer wall of the second column (10) for generating a pulling force perpendicular to the direction of the second column on the mass block (5); A plurality of first springs (7) are vertically and evenly spaced between the bottom of the mass block (5) and the top surface of the lower base (14), for providing an elastic force perpendicular to the lower base (14) to the mass block, wherein the first spring (7) and the second spring (12) are both located between two adjacent first columns 2; Moreover, one end of the first spring (7) is fixedly connected to the lower base (14), and the other end is a free end capable of contacting the bottom of the mass block (5); When the non-smooth vibration absorber is not activated, the mass block (5) is in a static equilibrium position, the second spring (12) is in a free extension state, the first spring (7) is compressed, and its top contacts the bottom surface of the mass block (5), and the first spring (7) gives the mass block (5) an upward elastic force equal to the weight of the mass block (5), thereby avoiding pre-stretching of the second spring (12) caused by the weight of the mass block (5); When the non-smooth vibration absorber is activated by external excitation, the mass block (5) moves up and down. When the mass block (5) moves upward, it separates from the first spring (7). The second spring (12) connected to the mass block (5) generates nonlinear stiffness so that the non-smooth vibration absorber has a wide-band vibration absorption capability. When the mass block (5) moves downward, it collides with the first spring (7). The first spring (7) is compressed to give the mass block (5) an upward force. A plurality of sliders (4) are arranged at intervals on the inner wall of the mass block (5); the first column (2) is fixedly connected to a guide rail on the outer wall of the mass block (5); the sliders (4) are slidably connected to the guide rail (3), and friction exists between the sliders and the guide rail when the mass block (5) moves.

2. The non-smooth vibration absorber according to claim 1, characterized in that: The first upright column (2) is fixedly connected to the upper base (1) and the lower base (14) respectively via brackets.

3. The non-smooth vibration absorber according to claim 1, characterized in that: One end of the second spring (12) is fixedly connected to a second spring seat (11) located on the inner wall of the mass block (5), and the other end is fixedly connected to a second spring seat (11) located on the outer wall of the second column (10).

4. The non-smooth vibration absorber according to claim 1, characterized in that: A gasket (6) is provided at the contact point between the bottom of the mass block (5) and the end of the first spring (7).

5. The non-smooth vibration absorber according to claim 4, characterized in that: A gasket (6) is bonded to the bottom of the mass block (5) and the end of the first spring (7).

6. The non-smooth vibration absorber according to claim 1, characterized in that: The mass block is octagonal, and the number of the first column (2), the first spring (7), and the second spring (12) are all four.

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