Shock absorber based on elastic beam boundary loading inclined inerter structure

Abstract

The invention belongs to the technical field of shock absorbers, and particularly relates to a shock absorber based on an elastic beam boundary loading inclined inerter structure, which comprises an elastic beam, an inerter structure and a bottom plate, the two ends of the elastic beam are movably connected with guide rods, the guide rods are fixedly connected to the bottom plate, the outer sides of the guide rods are sleeved with springs, the upper ends of the springs are connected with the guide rods, and the lower ends of the springs are connected with the inerter structure. The lower end is connected with the bottom plate; one end of a long shell of the inerter structure is connected with a lead screw nut, one end of a short shell of the inerter structure is connected with a lead screw bearing, a lead screw is connected into the lead screw nut in a threaded mode and rotationally connected into the lead screw bearing, and the lead screw is further connected with a flywheel. The side faces of the two ends of the elastic beam are each rotationally connected with a long shell of an inerter structure, short shells of the inerter structures are each rotationally connected with a supporting column, and the lower ends of the supporting columns are fixedly connected to the bottom plate. The inclined inerter is loaded on the boundary of the elastic beam, vibration suppression is carried out on the elastic beam, the amplitude during resonance is effectively reduced, and therefore the vibration reduction effect is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of vibration dampers, and in particular relates to a vibration damper based on an elastic beam boundary loading inclined inertia capacity structure. Background Art

[0002] As a basic structural unit, elastic beams are widely used and are indispensable in engineering fields such as construction, aviation, aerospace, and shipbuilding. These structures are always affected by various external excitations and produce complex vibrations. If they are not effectively controlled, the structural stability and working accuracy of the system may be greatly affected by vibration, resulting in damage to the mechanical precision structure, reduced accuracy, indicator drift, and other problems. Therefore, in order to avoid these problems, we must effectively suppress the vibration of the machine. Existing shock absorbers have the following problems: 1) Complex structure: Hydraulic shock absorbers have a relatively complex structure, high maintenance costs, and are prone to failure; 2) High technical requirements: Electromagnetic shock absorbers use electromagnetic force to adjust the shock absorption effect, which is extremely expensive and the technology is relatively complex; 3) Aging problem: Plastic spring shock absorbers are prone to aging and have a short service life. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a shock absorber based on an inclined inertia capacitor structure with elastic beam boundary loading, in which an inclined inertia capacitor is loaded on the boundary of the elastic beam to suppress the vibration of the elastic beam, so that the amplitude at resonance is effectively reduced, thereby achieving a vibration reduction effect.

[0004] The present invention is implemented in this way, providing a shock absorber based on an elastic beam boundary loading inclined inertia capacity structure, comprising an elastic beam, an inertia capacity structure and a bottom plate, wherein the elastic beam is arranged in parallel with the bottom plate, two ends of the elastic beam are respectively connected to a linear bearing, two guide rods are provided and respectively connected in the linear bearings, and the lower ends of the guide rods are fixedly connected to the bottom plate, a spring is sleeved on the outer side of the guide rod, the upper end of the spring is connected to the linear bearing, and the lower end is fixedly connected to the bottom plate;

[0005] The inertia structure includes a long housing and a short housing, a lead screw nut is connected to one end of the long housing close to the short housing, a lead screw bearing is connected to one end of the short housing close to the long housing, a lead screw is threadedly connected in the lead screw nut and rotatably connected in the lead screw bearing, and a portion of the lead screw passing through the lead screw bearing is connected to a flywheel;

[0006] The side surfaces at both ends of the elastic beam are rotatably connected to one end of a long shell of an inertia structure away from the short shell, and one end of the short shell of the inertia structure away from the long shell is rotatably connected to a support column, and the lower end of the support column is fixedly connected to the bottom plate.

[0007] Preferably, an axle support is provided on the bottom plate below the guide rod, a fixing ring is provided above the axle support, the lower end of the guide rod is fixedly connected to the axle support, and the lower end of the spring is connected to the fixing ring.

[0008] Further preferably, both sides of both ends of the elastic beam are rotatably connected to the long shell of the inertia-accommodating structure through a connecting structure, and the support column is also rotatably connected to the short shell of the inertia-accommodating structure through a connecting structure.

[0009] Further preferably, the connecting structure includes a connecting bearing seat, a connecting rod and a connecting bearing. The connecting bearing seat is fixed on both sides of the two ends of the elastic beam and the support column. Two parallel connecting arms are provided on the connecting bearing seat. The two ends of the connecting rod are fixedly connected to the two connecting arms. The connecting bearing is rotatably connected to the connecting rod. The ends of the long shell and the short shell of the inertial structure that are away from each other are respectively fixedly connected to the outer walls of the connecting bearings of the corresponding connecting structure.

[0010] Further preferably, connecting plates are respectively provided at ends of the long shell and the short shell of the inertial structure that are away from each other, and connecting holes connected to the connecting bearing are provided on the connecting plates.

[0011] Further preferably, a limit ring is fixedly connected to one side of the lead screw bearing located in the short housing, and the limit ring is rotatably and limitably connected to the lead screw.

[0012] Further preferably, a fixing ring is provided on the lead screw at a side of the flywheel away from the lead screw bearing, and the fixing ring fixes the flywheel on the lead screw.

[0013] Compared with the prior art, the advantages of the present invention are:

[0014] The present invention provides a vibration damper based on an oblique inertia capacitor structure loaded on the boundary of an elastic beam. When the elastic beam itself is forced to vibrate, mechanical resonance is easily generated. When the resonance occurs, the vibration of the structure is very violent, which may lead to unpredictable behavior. The present invention uses an oblique inertia capacitor to load the boundary of the elastic beam to suppress the vibration of the elastic beam, so that the amplitude at the resonance is effectively reduced, thereby achieving the effect of vibration reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The overall structure diagram of the shock absorber based on the elastic beam boundary loading inclined inertia capacity structure provided by the present invention;

[0016] Figure 2 This is the overall structural diagram of the inertial structure;

[0017] Figure 3 It is the overall structural diagram of the connection structure;

[0018] Figure 4The transient response time history under initial displacement excitation: (a) left end point of the beam; (b) midpoint of the beam;

[0019] Figure 5 The wavelet transform time-frequency diagram of transient response under initial displacement excitation: (a) left end point of uncontrolled system beam; (b) midpoint of uncontrolled system beam; (c) left end point of inclined inertia capacity structure beam; (d) midpoint of inclined inertia capacity structure beam;

[0020] Figure 6 The vibration reduction effect of the vibration reducer based on the elastic beam boundary loading inclined inertia structure provided by the present invention is U=0.001m: (a) main resonance at the left end point of the beam; (b) main resonance at the middle point of the beam;

[0021] Figure 7 The vibration reduction effect of the vibration reducer based on the elastic beam boundary loading inclined inertia structure provided by the present invention is U=0.002m: (a) main resonance at the left end point of the beam; (b) main resonance at the middle point of the beam;

[0022] Figure 8 The vibration reduction effect U=0.003m of the vibration reducer based on the elastic beam boundary loading inclined inertia capacity structure provided by the present invention: (a) main resonance at the left end point of the beam; (b) main resonance at the middle point of the beam. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0024] refer to Figure 1 , Figure 2 and Figure 3 The present invention provides a shock absorber based on an elastic beam boundary loading inclined inertia capacity structure, comprising an elastic beam 1, an inertia capacity structure 4 and a bottom plate 10, wherein the elastic beam 1 is arranged in parallel with the bottom plate 10, and the two ends of the elastic beam 1 are respectively connected to a linear bearing 6, two guide rods 3 are provided and respectively connected in the linear bearing 6, and the lower ends of the guide rods 3 are fixedly connected to the bottom plate 10, and a spring 7 is sleeved on the outer side of the guide rod 3, and the upper end of the spring 7 is connected to the linear bearing 6, and the lower end is fixedly connected to the bottom plate 10;

[0025] The inertia structure 4 includes a long housing 14 and a short housing 21. A lead screw nut 16 is connected to one end of the long housing 14 close to the short housing 21, and a lead screw bearing 17 is connected to one end of the short housing 21 close to the long housing 14. A lead screw 15 is threadedly connected in the lead screw nut 16 and rotatably connected in the lead screw bearing 17. The part of the lead screw 15 that passes through the lead screw bearing 17 is connected to the flywheel 19.

[0026] The side surfaces at both ends of the elastic beam 1 are rotatably connected to one end of a long shell 14 of an inertia structure 4 away from the short shell 21, and one end of the short shell 21 of the inertia structure 4 away from the long shell 14 is rotatably connected to a support column 2, and the lower end of the support column 2 is fixedly connected to the base plate 10.

[0027] When the shock absorber based on the elastic beam boundary loading inclined inertia capacity structure provided by the present invention is in use, the base plate 10 is fixed to the vibrating device by bolts. When vibration occurs, the elastic beam 1 moves axially along the guide rod 3, driving the spring 7 to perform upward and downward telescopic movement. The inertia capacity structure 4 telescopes up and down along with the end of the elastic beam 1. During the telescopic process, the lead screw 15 is threadedly connected to the lead screw nut 16, so the lead screw 15 rotates in the lead screw nut 16 and the lead screw bearing 17, that is, the telescopic movement of the inertia capacity structure 4 is converted into the rotation of the lead screw 15, and the rotation of the lead screw 15 drives the flywheel 19 fixedly connected thereto to rotate, thereby obtaining a large inertia with a very small mass, affecting the vibration in the form of a parametric mass, and thus achieving a vibration reduction effect.

[0028] In order to optimize the connection method between the guide rod 3 and the base plate 10, as an improvement of the technical solution, an axle support 9 is provided on the base plate 10 below the guide rod 3, and a fixing ring 8 is provided above the axle support 9. The lower end of the guide rod 3 is fixedly connected to the axle support 9, and the lower end of the spring 7 is connected to the fixing ring 8.

[0029] In order to facilitate the connection between the inertial structure 4 and the elastic beam 1 and the support column 2, as an improvement of the technical solution, the two sides of the two ends of the elastic beam 1 are rotatably connected to the long shell 14 of the inertial structure 4 through the connecting structure 5, and the support column 2 is also rotatably connected to the short shell 21 of the inertial structure 4 through the connecting structure 5.

[0030] As a specific implementation method of the connecting structure 5, the connecting structure 5 includes a connecting bearing seat 13, a connecting rod 12 and a connecting bearing 11. The connecting bearing seat 13 is fixed on both sides of the two ends of the elastic beam 1 and the support column 2. Two parallel connecting arms are provided on the connecting bearing seat 13. The two ends of the connecting rod 12 are fixedly connected to the two connecting arms. The connecting bearing 11 is rotatably connected to the connecting rod 12. The ends of the long shell 14 and the short shell 21 of the inertial structure 4 that are away from each other are respectively fixedly connected to the outer walls of the connecting bearing 11 of the corresponding connecting structure 5.

[0031] Specifically, connecting plates are respectively provided at the ends of the long shell 14 and the short shell 21 of the inertia structure 4 that are away from each other, and connecting holes connected to the connecting bearing 11 are provided on the connecting plates.

[0032] In order to further limit the position of the screw bearing 17 on the screw 15, as an improvement of the technical solution, a limit ring 18 is fixedly connected to the side of the screw bearing 17 located in the short housing 21, and the limit ring 18 is rotatably and limitably connected to the screw 15.

[0033] The so-called limiting connection, for example, can be provided with an annular groove on the lead screw 15 and an annular protrusion on the limiting ring 18, and the annular groove matches the annular protrusion.

[0034] In order to facilitate the replacement of the flywheel 19, as an improvement of the technical solution, a fixing ring 20 is provided on the lead screw 15 at the side of the flywheel 19 away from the lead screw bearing 17, and the fixing ring 20 fixes the flywheel 19 on the lead screw 15. According to the needs of different systems, the flywheel 19 can be replaced in time to achieve a better vibration reduction effect.

[0035] The following is a comparative analysis of the vibration reduction effect:

[0036] The expression of the inertia coefficient b of the inertia structure is:

[0037] b=2m(πr / P) 2

[0038] Among them, P is the lead of the screw 15, m is the mass of the flywheel, and r is the radius of the flywheel 19.

[0039] Therefore, the inertia parameters of an ideal ball screw inertia container are completely dependent on the lead of the ball screw and the mass and radius of the flywheel. By substituting actual parameters, the inertia container structure can provide the controlled system with an inertia that is many times its own mass, and the inertia container parameters can be regulated by adjusting the lead of the ball screw and the mass and radius of the flywheel.

[0040] Applying the generalized Hamiltonian principle, the dynamic equation of the elastic beam is derived through variational and distribution integrals:

[0041]

[0042] The boundary conditions of the elastic beam are:

[0043]

[0044] Where: E, L, ρ, Λ, A, l and I are Young's modulus, length, density, viscous damping coefficient, cross-sectional area, inertia container length and moment of inertia of the elastic beam structure respectively; K L With K R are the stiffness coefficients of the vertical constraint springs at both ends of the elastic beam structure; B L With B R are the inertia coefficients of the inertia containers at both ends of the elastic beam structure; C L With CR are the damping coefficients of the two ends of the elastic beam structure; C HL With C HR are the damping coefficients of the oblique damping at both ends of the elastic beam structure; W L With W R are the lateral vibration displacements at both ends of the elastic beam structure; δ represents the Dirac function; T is the time coordinate, X is the axial coordinate of the elastic beam, and W(X, T) is the lateral vibration displacement of the elastic beam structure; U L =U R =U(X, T) is the base excitation acting on the elastic beam structure.

[0045] Using the above dynamic equation, the transient response time history of the elastic beam structure supported only by springs (uncontrolled system) and the shock absorber based on the elastic beam boundary loading inclined inertia structure provided by the present invention (shock absorber system in the figure, with inerter) are compared on the software. The results are as follows: Figure 4 As shown in (a) and (b), it can be found that the transient response of the present invention has a faster decay speed.

[0046] The transient response time history is analyzed by wavelet transform and the following is obtained: Figure 5 (a)(b)(c)(d) Time-frequency diagram. As shown in the figure, both the uncontrolled system and the present invention contain only one main frequency component. That is to say, under the selected parameter conditions, the introduction of the inclined inertia structure has no effect on the natural frequency of the free attenuation vibration of the system, and it is significantly reduced compared with the maximum amplitude of the uncontrolled system. It can be seen that the inclined inertia system has an effective vibration reduction effect on the transient response of the lateral vibration of the elastic beam.

[0047] Steady-state response:

[0048] The vibration reduction performance of the present invention for steady-state response is evaluated by the vibration reduction percentage. The maximum amplitude of the main resonance of the elastic beam without the inclined inertia system is recorded as A u The maximum amplitude of the main resonance of the elastic beam of the present invention is recorded as A i , then the vibration reduction percentage of the present invention is

[0049]

[0050] Given a basic excitation amplitude of U = 0.001 m, the steady-state amplitude-frequency response curves of the uncontrolled system and the present invention are as follows: Figure 6 As shown. Among them, Figure 6 (a) shows the vibration reduction effect of the present invention on the first-order main resonance of the left end point of the elastic beam, Figure 6(b) is the vibration reduction effect of the present invention on the first-order main resonance of the midpoint of the elastic beam. Obviously, the present invention has a significant vibration reduction effect on the main resonance response of the elastic beam. The vibration reduction percentage of the first-order main resonance at the left end point of the beam is 53.4%. The vibration reduction percentage of the first-order main resonance at the midpoint of the beam is 53.1%. By comparison, it can be found that the vibration reduction effect of the present invention on the first-order main resonance is excellent, but the vibration reduction effect on the third-order main resonance is not great, and the vibration reduction effect at the end point is better than the vibration reduction effect at the midpoint.

[0051] The influence of the basic excitation amplitude on the vibration reduction effect of the present invention is discussed below. When the basic excitation amplitude is U=0.002m and U=0.003m, the vibration reduction effect of the present invention is respectively as follows: Figure 7 (a)(b) and Figure 8 (a)(b). By comparing the vibration reduction effects of the present invention under three basic excitation amplitudes, it is found that for the first-order main resonance, the change of the excitation amplitude has a significant effect on the vibration reduction effect. For example, the vibration reduction percentage of the present invention is 53.4% ​​when the left endpoint first-order main resonance is at a small excitation amplitude of U=0.001m, and the vibration reduction percentages are 64.5% and 68.5% when the medium excitation amplitude is U=0.002m and the large excitation amplitude is U=0.003m, respectively. Compared with the small excitation amplitude, the vibration reduction percentages have increased by 11.1% and 15.1%, respectively. Obviously, the larger the basic excitation amplitude, the better the vibration reduction effect of the present invention. In addition, the amplitude-frequency response curve of the present invention finds that the larger the basic excitation amplitude, the stronger the effect of weakening the nonlinear hardening phenomenon of the first-order main resonance response. The change of the basic excitation amplitude has a relatively small effect on the vibration reduction effect of the inclined inertial capacity system at the third-order main resonance.

Claims

1. A shock absorber based on an elastic beam boundary loading inclined inertia volume structure, characterized in that: The invention comprises an elastic beam (1), an inertia structure (4) and a bottom plate (10), wherein the elastic beam (1) is arranged in parallel with the bottom plate (10), and the two ends of the elastic beam (1) are respectively connected to a linear bearing (6), and two guide rods (3) are provided, which are respectively connected to the linear bearings (6), and the lower ends of the guide rods (3) are fixedly connected to the bottom plate (10), and a spring (7) is sleeved on the outer side of the guide rods (3), and the upper end of the spring (7) is connected to the linear bearing (6), and the lower end is fixedly connected to the bottom plate (10); The inertia structure (4) comprises a long housing (14) and a short housing (21), a lead screw nut (16) is connected to one end of the long housing (14) close to the short housing (21), a lead screw bearing (17) is connected to one end of the short housing (21) close to the long housing (14), a lead screw (15) is threadedly connected in the lead screw nut (16) and rotatably connected in the lead screw bearing (17), and a portion of the lead screw (15) passing through the lead screw bearing (17) is connected to a flywheel (19); The side surfaces at both ends of the elastic beam (1) are rotatably connected to one end of a long shell (14) of an inertia-capacitance structure (4) away from the short shell (21), and one end of the short shell (21) of the inertia-capacitance structure (4) away from the long shell (14) is rotatably connected to a support column (2), and the lower end of the support column (2) is fixedly connected to the bottom plate (10).

2. The vibration absorber based on the elastic beam boundary loading inclined inertia structure according to claim 1 is characterized in that: An axle support (9) is provided on the bottom plate (10) below the guide rod (3), a fixing ring (8) is provided above the axle support (9), the lower end of the guide rod (3) is fixedly connected to the axle support (9), and the lower end of the spring (7) is connected to the fixing ring (8).

3. The shock absorber based on elastic beam boundary loading inclined inertia structure according to claim 1 is characterized in that: The two sides of both ends of the elastic beam (1) are rotatably connected to the long shell (14) of the inertia-capacity structure (4) through a connecting structure (5), and the support column (2) is also rotatably connected to the short shell (21) of the inertia-capacity structure (4) through the connecting structure (5).

4. The shock absorber based on the elastic beam boundary loading inclined inertia structure according to claim 3 is characterized in that: The connecting structure (5) comprises a connecting bearing seat (13), a connecting rod (12) and a connecting bearing (11); the connecting bearing seat (13) is fixed on both sides of the two ends of the elastic beam (1) and the supporting column (2); two parallel connecting arms are provided on the connecting bearing seat (13); the two ends of the connecting rod (12) are fixedly connected to the two connecting arms; the connecting bearing (11) is rotatably connected to the connecting rod (12); and the ends of the long shell (14) and the short shell (21) of the inertial structure (4) that are away from each other are respectively fixedly connected to the outer wall of the connecting bearing (11) of the corresponding connecting structure (5).

5. The vibration absorber based on the elastic beam boundary loading inclined inertia structure according to claim 4 is characterized in that: A connecting plate is provided at each end of the long shell (14) and the short shell (21) of the inertia structure (4) which are away from each other, and a connecting hole connected to the connecting bearing (11) is provided on the connecting plate.

6. The shock absorber based on elastic beam boundary loading inclined inertia structure according to claim 1 is characterized in that: A limiting ring (18) is fixedly connected to one side of the lead screw bearing (17) located inside the short housing (21), and the limiting ring (18) is rotatably and position-limitingly connected to the lead screw (15).

7. The vibration absorber based on elastic beam boundary loading inclined inertia structure according to claim 1 is characterized in that: A fixing ring (20) is provided on the lead screw (15) at a side of the flywheel (19) away from the lead screw bearing (17), and the fixing ring (20) fixes the flywheel (19) on the lead screw (15).

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