CN115263985A - Constant-value quasi-zero stiffness vibration isolation structure and method based on negative stiffness mechanism of three pairs of inclined rods - Google Patents

Abstract

The invention discloses a constant value quasi-zero stiffness vibration isolation structure and method based on three pairs of inclined rod negative stiffness mechanisms, wherein the vibration isolation structure comprises a fixing plate, a support, a transverse guide rod, an inclined rod hinge support, a support connecting block, a vertical guide rod, a vertical spring, a hollow tube, a load disc and a transverse spring; brackets are symmetrically arranged on two sides of the fixed plate, a vertical guide rod is arranged in the middle of the fixed plate, a support connecting block is arranged on the upper portion of the vertical guide rod, and a vertical guide rod linear bearing connected with the vertical guide rod is arranged on the support connecting block; a vertical spring is arranged on a vertical guide rod between the bottom of the support connecting block and the fixed plate; three transverse guide rods are arranged on each bracket at equal intervals, and each transverse guide rod is provided with a transverse spring; three pairs of inclined rods are arranged, one end of each inclined rod is hinged with the U-shaped groove through a shaft rod, and the other end of each inclined rod is hinged with an inclined rod hinge support; the bolt penetrates through the hollow pipe and is connected with the support connecting block to fix the load-bearing disc.

Description

Constant value quasi-zero stiffness vibration isolation structure and method based on negative stiffness mechanism of three pairs of oblique bars

technical field

The invention relates to the field of vibration control, in particular to a constant-value quasi-zero stiffness vibration isolation structure and method based on the negative stiffness mechanism of three pairs of oblique bars.

Background technique

A quasi-zero stiffness model of a single pair of oblique rods studied in literature [1], with a cubic nonlinear stiffness factor, under large excitations, the transmissibility bends to the right, reducing the vibration isolation frequency band; and the parameter design method given in this literature Complex (including several inequalities), not easy to design and apply. The technical solutions in the above documents cannot obtain the zero-stiffness characteristic of a straight line near the static equilibrium point, cannot reduce the resonance frequency of the linear oscillator, and are affected by nonlinear factors; under large-scale excitation conditions, the vibration isolation frequency band will bend to the right due to nonlinearity And lower.

Literature [2] proposed a constant value quasi-zero stiffness debugging method based on the vibration isolator constructed by the negative stiffness mechanism of a single pair of oblique bars. In the form of different structures and different debugging methods, this application proposes another constant value quasi-zero stiffness structure, which is completely different from the literature [2] in terms of structure and debugging methods. The horizontal spring in document [2] needs a larger stiffness, but the horizontal spring in this patent application needs a smaller stiffness, which is more suitable for a smaller size space in structure. Although they are all constant value quasi-zero stiffness structures, they are in There are some noticeable differences in usage.

references:

[1] Thanh Danh Le, Kyoung Kwan Ahn, A vibration isolation system in low frequency excitation region using negative stiffness structure for vehicleseat, Journal of Sound and Vibration, 2011, 330, 6311-6335.

[2] Zhao Feng, Cao Shuqian, Hou Yuanhang, Li Bo, Song Qian, A zero-stiffness vibration isolation structure and method formed by a single pair of inclined bars with negative stiffness mechanism [P], CN202111347500.9, 2022-03-01.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies in the prior art, and provide a constant value quasi-zero stiffness vibration isolation structure and method based on the negative stiffness mechanism of three pairs of oblique bars.

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

A constant value quasi-zero stiffness vibration isolation structure based on the negative stiffness mechanism of three pairs of oblique rods, including fixed plates, brackets, transverse guide rods, oblique rods, oblique rod hinge supports, support connecting blocks, vertical guide rods, and vertical springs , a hollow tube, a load plate and a transverse spring; the two sides of the fixed plate are symmetrically equipped with brackets, the middle part of the fixed plate is equipped with a vertical guide rod, and the upper part of the vertical guide rod is equipped with a support connecting block. A vertical guide rod linear bearing connected to the vertical guide rod is installed on the support connecting block; a vertical spring is installed on the vertical guide rod between the bottom of the support connecting block and the fixed plate;

The left and right ends of the connecting block of the support are connected with a slanting bar hinge support, and the slanting bar hinge support is a U-shaped structure; each of the supports is equidistantly installed with three linear bearings through the fixing parts, each The linear bearing is equipped with horizontal guide rods, and each horizontal guide rod is provided with a U-shaped groove at one end facing the vertical guide rod, and a spring clip is provided on the horizontal guide rod next to the U-shaped groove, and each gap between the spring clip and the fixing piece A transverse spring is installed on each transverse guide rod;

Three oblique rods are symmetrically arranged on both sides of the vertical guide rod, one end of the oblique rod is hinged with the U-shaped groove through the shaft rod, and the other end is hinged with the hinged support of the oblique rod;

The two sides of the connecting block of the support are respectively provided with connecting holes, the connecting holes are provided with a hollow tube, and the top of the hollow tube is provided with a load plate, and the bolts pass through the hollow tube to connect with the connecting holes and fix the load plate.

Further, a thick vertical through hole is provided in the middle of the bracket for the passage of the transverse guide rod, and two parallel thin vertical through holes are arranged on both sides of the thick vertical through hole, and the fixing member is fastened with The bolts and the connecting plate fixedly connected with the linear bearing, the middle part of the connecting plate is provided with a through hole for the passage of the transverse guide rod, and the two sides of the connecting plate are provided with bolt holes, and the connecting plate passes through the bolt holes through fastening bolts It is connected with the thin vertical through hole and the nut to be fixed on the bracket.

Further, three circular through holes are arranged at equal intervals on the bracket, and the fixing member adopts a snap spring, and the linear bearing and the bracket are fixed by the snap spring.

The present invention also provides a method for debugging a constant value quasi-zero stiffness vibration isolation structure based on the negative stiffness mechanism of the above three pairs of oblique bars, including:

S1. According to the parameter condition of the quasi-zero stiffness characteristic, determine the precompression δ ₂ of the transverse spring in the initial state, the projected length a of the distance between the hinge points at both ends of the oblique rod in the horizontal direction, and the length of the vertical spring, so that In the initial state, δ ₂ =a, the initial state refers to the state where the intersection of three pairs of oblique rods is in contact with the top of the free-length vertical spring;

和

使参数α和α₁满足

S2. Set the stiffnesses of the three pairs of transverse springs from top to bottom in the constant-value quasi-zero stiffness vibration isolation structure as k ₁ , k ₃ and k ₁ respectively, and the stiffness of the vertical springs k ₂ , by determining the stiffness of the transverse springs k ₁ and k ₃ , determine the stiffness k ₂ of the vertical spring, and construct the dimensionless parameter

and

Make parameters α and α ₁ satisfy

若起始隔振频率不满足设计要求，则重复步骤S1至S3。S3. After determining the above parameters, draw the force-displacement curve fx. Stiffness characteristics, calculate the stiffness value K, and calculate the initial vibration isolation frequency according to the relationship between the vibration isolation mass m on the load plate

If the initial vibration isolation frequency does not meet the design requirements, repeat steps S1 to S3.

Compared with the prior art, the beneficial effects brought by the technical solution of the present invention are:

1. The present invention proposes a constant-value quasi-zero-stiffness vibration isolator constructed with three pairs of oblique rods and a horizontal spring negative-stiffness mechanism. This structure is proposed for the first time in the research of constant-value quasi-zero stiffness.

2. The present invention proposes a quasi-zero-stiffness vibration isolation structure constructed by three pairs of oblique rods with negative stiffness mechanism, and performs parameter design to obtain force and stiffness expressions that are completely different from those of the prior art; at the position of the static equilibrium point, let the stiffness Equal to zero and the second order derivative of stiffness equal to zero, obtain two zero stiffness parameter conditions, and adjust the constant quasi-zero stiffness on demand according to the parameter conditions is a new debugging method, which is simple to debug and has excellent accuracy. In parameter design (theoretical and technical analysis), the position of the so-called static equilibrium point is the state where the three pairs of diagonal bars are symmetrical to the center (or the state where the middle pair of diagonal bars is horizontal). Three pairs of horizontal springs have the same free length.

3. Through the constant value quasi-zero stiffness debugging method of the present invention, the zero stiffness characteristic of a straight line near the static equilibrium point can be obtained, and a wider range of constant value quasi-zero stiffness characteristics can be obtained, which can reduce the resonance frequency of the linear vibrator, and No nonlinear factors are attached; compared with the traditional quasi-zero stiffness vibration isolator with weak cubic nonlinear characteristics, the vibration isolation frequency band will not be reduced due to nonlinear bending to the right under large excitation conditions.

4. The invention solves the problem of the third-order nonlinearity of the traditional quasi-zero stiffness vibration isolator, and can be used for low-frequency vibration isolation problems of large excitation amplitude and variable load conditions. The invention is a constant-value quasi-zero stiffness vibration isolation structure, and has infinitely many static equilibrium positions in terms of specific application effects.

5. The invention can be applied to the engineering application of low-frequency vibration isolation, and solves the contradictory problem that the traditional linear stiffness vibration isolation system needs small dynamic stiffness but produces large static deformation during low-frequency vibration isolation.

Description of drawings

Fig. 1 is a schematic structural view of a quasi-zero-stiffness constant-value vibration isolation structure of the present invention.

Figures 2a and 2b are a front view and a left side view of one embodiment of the bracket, respectively.

Fig. 3a and Fig. 3b are the front view and the left side view of another embodiment of the bracket respectively.

Fig. 4 is a front view of the oblique rod.

Fig. 5a and Fig. 5b are the front view and the top view of the tilt bar hinge support respectively.

Figures 6a and 6b are a front view and a top view, respectively, of the transverse guide rod.

Fig. 7a and Fig. 7b are the front view and the top view of the connecting block of the support respectively.

Fig. 8a and Fig. 8b are simplified mechanical schematic diagrams of the constant-value quasi-zero stiffness vibration isolation structure of the present invention, respectively.

Figure 9a and Figure 9b are schematic diagrams of stiffness-displacement curves and force-displacement curves, respectively.

Reference signs: 1-fixed plate, 2-bracket, 3-transverse guide rod linear bearing, 4-transverse guide rod, 5-spring clamp, 6-radial bearing, 7-slanting rod, 8-slanting rod hinge support Seat, 9-support connecting block, 10-vertical guide rod, 11-vertical spring, 12-hollow tube, 13-loading plate, 14-vertical guide rod linear bearing, 15-transverse spring, 16-thick vertical through hole , 17-thin vertical through hole.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

As shown in Figure 1, this embodiment provides a constant value quasi-zero stiffness vibration isolation structure based on the negative stiffness mechanism of three pairs of oblique bars, including a fixed plate 1, a bracket 2, a transverse guide rod 4, an oblique rod 7, and an oblique rod hinge Support 8, support connecting block 9, vertical guide rod 10, vertical spring 11, hollow tube 12, load plate 13 and transverse spring 15;

Supports 2 are installed symmetrically on both sides of the fixed plate 1, and the bottom of the support 2 is fixedly connected with the fixed plate 1 through standard bolts. The middle part of the fixed plate 1 is equipped with a vertical guide rod 10, and the top of the vertical guide rod 10 is equipped with a support connecting block 9, and the vertical guide rod linear bearing 14 connected with the vertical guide rod 10 is installed on the support connecting block 9; A vertical spring 11 is installed on the vertical guide rod 10 between the bottom of the connecting block 9 and the fixed plate 1;

The left and right ends of the support connecting block 9 are connected with a slanting bar hinge support 8, and the slanting bar hinge support 9 is a U-shaped structure; each support 2 is equidistantly installed with three linear bearings through fixing parts, and each linear bearing Horizontal guide rods 4 are installed, and one end of each horizontal guide rod 4 facing the vertical guide rod 10 is provided with a U-shaped groove, and a spring clip 5 is arranged on the lateral guide rod next to the U-shaped groove, and the spring clip 5 and the fixing part A transverse spring 15 is installed on each transverse guide rod 4 between them;

Two sides of the vertical guide rod 10 are symmetrically arranged with three oblique rods 7 respectively. The structure of the oblique rods 7 is shown in FIG. 4 . Groove is hinged by radial bearing 6 and bearing pin. Specifically, there is a round hole at the end of the oblique rod 7 (Fig. 4), and this round hole fits with the outer ring of the radial bearing (the radial bearing is relatively small, with an outer diameter of 5mm, an inner diameter of 2mm, and a thickness of about mm, the sales platform Mostly called miniature bearings), insert one end of the oblique rod 7 with the radial bearing into the transverse guide rod 4 (the right end of Figure 6b), and then insert the pin shaft into the small hole at the right end of Figure 6a, and also pass through the radial bearing inner hole. Now the oblique rod 7 and the transverse guide rod 4 are hinged together by radial bearings.

Both sides of the support connecting block 9 are respectively provided with connecting holes, the connecting holes are provided with hollow tubes 12, and the top of the hollow tubes 12 is provided with a loading plate 13 and passes through the hollow tubes 12 to connect with the connecting holes to fix the loading plate 13 by bolts.

Specifically, as shown in Fig. 2a and Fig. 2b, in this embodiment, three circular through holes are arranged at equal intervals on the bracket 2, and the fixing part adopts a circlip, and the standard linear bearing 3 has the characteristics of a circlip groove, and the The guide rod linear bearing 3 is connected to the bracket 2 through a standard snap spring to constrain the lateral displacement of the lateral guide rod linear bearing 3 .

In the specific implementation process, the bracket 2 can also adopt the structure shown in Fig. 3a and Fig. 3b. In this embodiment, a thick vertical through hole 16 is provided in the middle of the bracket for the passage of the transverse guide rod 4, and the thick vertical through hole 16 Two parallel thin vertical through-holes 17 are arranged on both sides of the hole 16. Fastening bolts and connecting plates are used as fixing parts. Linear bearings for connecting transverse guide rods are installed in the middle of the connecting plate. Bolts are arranged on both sides of the connecting plate. hole, the connecting plate passes through the bolt hole and the thin vertical through hole 17 and is connected and fixed on the support 2 by fastening bolts.

See Figures 5a and 5b. In this embodiment, the hinge support 8 of the inclined bar is a U-shaped structure, which is composed of a bottom plate and two side plates. The bottom plate is provided with bolt holes for connecting with the support connecting block 9, and the two side plates The upper part is symmetrically provided with three shaft holes, which are used for hinged connection with the oblique rod.

As shown in Figures 6a and 6b, one end of the transverse guide rod is provided with a U-shaped groove, and the side plates on both sides of the U-shaped groove are symmetrically opened with shaft holes for the hinged connection of the oblique rod. The groove of spring clip 5.

As shown in Figures 7a and 7b, the two ends of the support connecting block are provided with bolt holes for connecting the hinge support 8, the middle part is provided with bearing holes, and the two sides are provided with connection holes for fixing the load plate.

In this embodiment, the inclined bar hinge support 8 is connected to the support connecting block 9 by studs, and the support connecting block 9, the hollow tube 12, the load plate 13, and the vertical guide rod linear bearing 14 are fastened to the Together, the vibration-isolation mass force on the load plate 13 can be transmitted to the three pairs of diagonal rods 7 . The transverse guide rod 4 can move in the horizontal direction with low friction after being constrained by the transverse guide rod linear bearing 3 . The transverse spring 15 is constrained axially by the spring clip 5 and the linear bearing 3 of the transverse guide rod, and the elastic force of the transverse spring can be transmitted to the load plate 13 through the inclined rod 7 to obtain the vertical force supporting force, especially to obtain the load in the vertical direction. stiffness properties. The vertical spring 11 is constrained by the vertical guide rod 10, and the vertical displacement is limited by the vertical guide rod linear bearing 14 and the fixed plate 1, so that the load plate 13 obtains load-bearing capacity.

The mechanical schematic diagram of the constant value quasi-zero stiffness vibration isolation structure constructed by the negative stiffness mechanism of three pairs of oblique bars in the initial state is shown in Fig. 8a and Fig. 8b. k ₂ is the stiffness of the vertical spring, f _h is the inward elastic force produced by the transverse spring (or horizontal extension spring), f _{h_u} is the elastic force produced by the upper pair of transverse springs with stiffness k ₁ under the condition of precompression δ in the initial state, f _{h_m} is the elastic force produced by the middle pair of transverse springs with stiffness k ₃ under the condition of initial state precompression δ ₁ , and f _{h_l} is the elastic force produced by the lower pair of transverse springs with stiffness k ₁ under the condition of initial state precompression δ ₂ The elastic force of , h is the vertical distance from the initial state to the static equilibrium position, the initial state is the state where the intersection of the three pairs of oblique rods is in contact with the upper end of the vertical spring in the free state, x is the displacement from the initial position, y is the distance from Displacement from static equilibrium position. a is the projected length in the horizontal direction of the distance between the hinge points at both ends of the oblique bar in the initial state; the ratio α of the transverse spring stiffness to the vertical spring stiffness of the upper and lower pairs; the ratio α of the transverse spring stiffness to the vertical spring stiffness of the middle pair ₁ ; δ refers to the precompressed length of the upper pair of transverse springs in the initial state; δ ₁ refers to the precompressed length of the middle pair of transverse springs in the initial state; δ ₂ refers to the precompressed length of the lower pair of transverse springs in the initial state. The vertical distance from the horizontal position of the upper oblique spring to the horizontal position of the lower oblique spring is 2d, and the middle position of 2d is the static equilibrium position.

表达式，求表达式

对

的一阶导数，可得无量纲刚度

见公式(2)；公式(3)为参数表达式；在静平衡位置，对无量纲刚度

求二阶导数并令刚度等于零，可获得零刚度特性的参数条件，见公式(4)。以静平衡位置为零点位移，静态平衡点为图8a中2d的中间位置(中间杆处于水平的状态)，静平衡点附近的准零刚度特性如图8b所示，具有恒值准零刚度的特性(通过双对斜杆负刚度机制可以把垂直弹簧的动态刚度降低成恒值准零刚度的状态，且同时保持较高的静态刚度以承受载荷)，特别是恒值准零刚度可以根据需要进行调节。First, the expression of the applied force f is obtained. In order to analyze the characteristics of a wider range of structural parameters, the applied force f and its expression are infinitely stiffened, see formula (1), and the dimensionless applied force can be obtained

expression, seek expression

right

The first derivative of , the dimensionless stiffness can be obtained

See formula (2); formula (3) is a parametric expression; at the static equilibrium position, for dimensionless stiffness

Finding the second order derivative and setting the stiffness equal to zero can obtain the parameter condition of the zero stiffness characteristic, see formula (4). Taking the static equilibrium position as the zero point displacement, the static equilibrium point is the middle position of 2d in Figure 8a (the middle rod is in a horizontal state), the quasi-zero stiffness characteristics near the static equilibrium point are shown in Figure 8b, and the quasi-zero stiffness with constant value Characteristics (the dynamic stiffness of the vertical spring can be reduced to a state of constant quasi-zero stiffness through the negative stiffness mechanism of double pairs of oblique rods, and at the same time maintain a high static stiffness to bear the load), especially the constant quasi-zero stiffness can be customized according to the needs Make adjustments.

Diagonal rods and transverse springs produce vertical negative stiffness, which is called the negative stiffness mechanism of double pairs of oblique rods, which are connected in parallel with the positive stiffness of vertical springs, near the static equilibrium point (the static equilibrium point is that the upper and lower pairs of oblique rods are in a symmetrical position up and down) , according to the debugging method of formula (5), the constant value quasi-zero stiffness characteristic can be obtained in the vertical direction.

无量纲应用力，

无量x纲位移，α、α₁无量纲刚度，

斜杆倾斜角度，γ无量纲初始位置，

初始状态下无量纲压缩量。Among them, P ₁ to P ₉ are intermediate variables.

Dimensionless applied force,

Dimensionless x _- dimensional displacement, α, α1 dimensionless stiffness,

Angle of inclined bar, γ dimensionless initial position,

The dimensionless compression amount in the initial state.

并且横向弹簧的预压缩长度δ等于斜杆的下对斜杆在初始状态下的两铰接点之间的水平长度a。若满足上述两个条件，恒值准零刚度特性可以获得。The debugging method of constant quasi-zero stiffness (shown in Figure 8b) makes the ratio α of the selected transverse spring stiffness to vertical spring stiffness satisfy

And the pre-compression length δ of the transverse spring is equal to the horizontal length a between the two hinge points of the lower pair of diagonal rods in the initial state. If the above two conditions are satisfied, the constant quasi-zero stiffness property can be obtained.

This embodiment is to realize a structure and debugging method of constant quasi-zero stiffness mechanical properties, which belongs to the research scope of quasi-zero stiffness vibration isolation, and is applied to low-frequency vibration isolation engineering problems below a dozen hertz, such as the low-frequency vibration caused by waves to ships. Excitation and response, low-frequency excitation caused by vehicles to the human body, low-frequency excitation and response caused by spacecraft adjustment, the invention is applied to the engineering application of low-frequency vibration isolation, and solves the problem that the traditional linear stiffness vibration isolation system needs small dynamic stiffness in low-frequency vibration isolation But there is a paradoxical problem of large static deformation.

The specific debugging method is as follows:

In the first step, according to the structural description of this application, a vibration isolation structure with constant value and quasi-zero stiffness of three pairs of oblique rods with negative stiffness mechanism is produced;

In the second step, according to the formula (5), determine the pre-compression amount δ of the transverse spring in the initial state, the projected length a of the oblique rod in the horizontal direction, and the length of the vertical spring, so that δ=a in the initial state;

和

使参数α和α₁满足

The third step, according to formula (5), determine the stiffness k ₁ and k ₃ of the transverse spring, determine the stiffness k ₂ of the vertical spring, and construct the dimensionless parameter

and

Make parameters α and α ₁ satisfy

若起始隔振频率不满足设计要求，则重复第二到第四步。The fourth step, after determining the above parameters, draw the force-displacement curve fx, as shown in Figure 9b, where Figure 9a is the corresponding constant value stiffness curve, the force-displacement curve is a straight line with a constant stiffness characteristic, and calculate the stiffness value K , according to the relationship between the vibration isolation mass m, calculate the initial vibration isolation frequency

If the initial vibration isolation frequency does not meet the design requirements, repeat steps 2 to 4.

The present invention finally tests a vibration isolator with constant quasi-zero stiffness characteristics, which solves the problem of cubic nonlinearity of traditional quasi-zero stiffness vibration isolators, and can be used for low-frequency vibration isolation problems with large excitation amplitude and variable load conditions. A traditional cubic nonlinear stiffness vibration isolator has only one static equilibrium position, while the present invention is a constant-value quasi-zero stiffness vibration isolator with infinitely many static equilibrium positions.

The present invention is not limited to the embodiments described above. The above description of the specific embodiments is intended to describe and illustrate the technical solution of the present invention, and the above specific embodiments are only illustrative and not restrictive. Without departing from the gist of the present invention and the scope of protection of the claims, those skilled in the art can also make many specific changes under the inspiration of the present invention, and these all belong to the protection scope of the present invention.

Claims (4)

1. A constant value quasi-zero stiffness vibration isolation structure based on three pairs of inclined rod negative stiffness mechanisms is characterized by comprising a fixing plate, a support, a transverse guide rod, an inclined rod hinge support, a support connecting block, a vertical guide rod, a vertical spring, a hollow tube, a load disc and a transverse spring; the two sides of the fixed plate are symmetrically provided with brackets, the middle part of the fixed plate is provided with a vertical guide rod, the upper part of the vertical guide rod is provided with a support connecting block, and the support connecting block is provided with a vertical guide rod linear bearing connected with the vertical guide rod; a vertical spring is arranged on a vertical guide rod between the bottom of the support connecting block and the fixed plate;

the left end and the right end of the support connecting block are connected with an inclined rod hinge support which is of a U-shaped structure; three linear bearings are arranged on each bracket at equal intervals through a fixing piece, each linear bearing is provided with a transverse guide rod, one end of each transverse guide rod, facing the vertical guide rod, is provided with a U-shaped groove, a spring clamping plate is arranged on the transverse guide rod beside the U-shaped groove, and a transverse spring is arranged on each transverse guide rod between the spring clamping plate and the fixing piece;

two sides of the vertical guide rod are symmetrically provided with three inclined rods respectively, one end of each inclined rod is hinged with the U-shaped groove through a shaft rod, and the other end of each inclined rod is hinged with an inclined rod hinge support;

the support is characterized in that connecting holes are formed in two sides of the support connecting block respectively, hollow pipes are arranged on the connecting holes, and a load carrying disc is arranged at the top end of each hollow pipe and penetrates through the hollow pipes through bolts to be connected and fixed with the connecting holes.

2. The constant-value quasi-zero-stiffness vibration isolation structure based on the three-pair-diagonal-rod negative-stiffness mechanism is characterized in that a thick vertical through hole for a transverse guide rod to pass through is formed in the middle of the support, two parallel thin vertical through holes are formed in two sides of the thick vertical through hole, the fixing piece is a connecting plate fixedly connected with a fastening bolt and a linear bearing, a through hole for the transverse guide rod to pass through is formed in the middle of the connecting plate, bolt holes are formed in two sides of the connecting plate, and the connecting plate penetrates through the bolt holes and the thin vertical through holes through bolts to be connected and fixed on the support through nuts.

3. The constant-value quasi-zero-stiffness vibration isolation structure based on the three pairs of inclined rod negative stiffness mechanisms is characterized in that three circular through holes are formed in the support at equal intervals, the fixing piece adopts a clamp spring, and the linear bearing and the support are fixed through the clamp spring.

4. A method for debugging a constant quasi-zero stiffness vibration isolation structure based on the three pairs of diagonal rod negative stiffness mechanisms of claims 1-3, comprising:

s1, determining the precompression delta of the transverse spring in the initial state according to the parameter condition of the quasi-zero stiffness characteristic ₂ The projection length a of the distance between the hinged points at the two ends of the inclined rod in the horizontal direction and the length of the vertical spring are used for ensuring that the distance is delta under the initial state ₂ = a, initial state means a state where the intersection of three pairs of diagonal rods is in contact with the tip of a vertical spring of free length;

s2, setting the stiffness of three pairs of transverse springs from top to bottom in the constant value quasi-zero stiffness vibration isolation structure to be k respectively ₁ 、k ₃ And k ₁ Stiffness k of vertical spring ₂ By determining the stiffness k of the transverse spring ₁ And k ₃ Determining the stiffness k of the vertical spring ₂ Building dimensionless parameters

And

let parameters alpha and alpha ₁ Satisfy the requirement of

S3, after the parameters are determined, drawing a force displacement curve f-x, wherein f is the force applied to the load-bearing disc, x is the displacement from the initial position, the force displacement curve is an inclined straight line with constant rigidity, calculating the rigidity value K, and calculating the initial vibration isolation frequency according to the relation between the vibration isolation masses m on the load-bearing disc

And if the initial vibration isolation frequency does not meet the design requirement, repeating the steps S1 to S3.

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