Debugging method of compact horizontal direction constant value quasi-zero stiffness vibration isolator

Abstract

The invention relates to a debugging method of a compact horizontal constant quasi-zero stiffness vibration isolator, in the vibration isolator, a constant quasi-zero stiffness unit comprises a first horizontal elastic element, a first inclined rod and a first vertical elastic element, and a constant force unit comprises a second horizontal elastic element, a second inclined rod and a second vertical elastic element; one end of the first horizontal elastic element is fixed, the other end of the first horizontal elastic element is sequentially hinged with the first inclined rod and the first vertical elastic element, and the other end of the first vertical elastic element is fixed; one end of the second horizontal elastic element is fixed, the other end of the second horizontal elastic element is sequentially hinged with the second inclined rod and the second vertical elastic element, and the other end of the second vertical elastic element is fixed; and obtaining the constant force applied by the constant force unit when the constant value quasi-zero stiffness unit is in static balance according to a debugging method. Compared with the prior art, the compact quasi-zero-stiffness vibration isolator has the advantages that the purpose of miniaturized and compact quasi-zero-stiffness vibration isolation can be achieved; and by debugging the vibration isolator, the constant-value quasi-zero stiffness unit can be located at a static balance position, and the like.

Description

Technical Field

[0001] This invention relates to quasi-zero stiffness vibration isolators, and more particularly to a method for debugging a compact horizontal constant-value quasi-zero stiffness vibration isolator. Background Technology

[0002] Quasi-zero stiffness vibration isolators are a new type of vibration isolation device with significant application potential in fields such as precision instruments. Their core principle involves combining positive stiffness elements (such as common linear springs, providing stable elastic support) with negative stiffness mechanisms (such as pre-compression springs generating negative stiffness through pre-compression, magnetic systems achieving negative stiffness through magnetic pole action, and mechanical levers forming negative stiffness through mechanical conversion). Within a specific operating range, the positive and negative stiffnesses precisely cancel each other out, forming a "quasi-zero stiffness" state. This design allows the isolator to maintain low stiffness characteristics even near static conditions, effectively reducing the system's natural frequency and thus achieving highly efficient and reliable vibration isolation across a wide frequency range from low to ultra-low frequencies.

[0003] A search revealed that application publication number CN117722466A discloses a horizontally oriented, fully tension-spring-loaded, negative-stiffness, quasi-zero-stiffness vibration isolation structure and its debugging method. Specifically, the vibration isolation structure includes a main body and an auxiliary mechanism. The main body provides quasi-zero stiffness characteristics in the horizontal direction, while the auxiliary mechanism simulates constant force characteristics in the horizontal direction. Both the main body and the auxiliary mechanism include negative-stiffness and positive-stiffness mechanisms, which are connected in parallel. The negative-stiffness mechanisms are symmetrical about the longitudinal direction, and the second diagonal braces are arranged in a cross configuration, with the ends of the intersecting second diagonal braces connected by negative-stiffness tension springs. However, this prior art uses four second diagonal braces, resulting in a large number of parts and hindering miniaturization.

[0004] In summary, the technical problem that needs to be solved is how to design a small and compact quasi-zero stiffness vibration isolator. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art, which has a large number of parts and a large volume, and to provide a method for debugging a compact horizontal constant-value quasi-zero stiffness vibration isolator.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] According to one aspect of the present invention, a method for debugging a compact horizontal constant-value quasi-zero stiffness vibration isolator is provided. The constant-value quasi-zero stiffness vibration isolator includes a constant-value quasi-zero stiffness unit, a constant force unit, and a fixing frame. The constant-value quasi-zero stiffness unit includes a first horizontal elastic element, a first inclined rod, and a first vertical elastic element. The constant force unit includes a second horizontal elastic element, a second inclined rod, and a second vertical elastic element. The first horizontal elastic element and the second horizontal elastic element are located on the same horizontal line.

[0008] One end of the first horizontal elastic element is fixed to the fixed frame, and the other end is hinged to one end of the first diagonal rod at the first hinge point; the other end of the first diagonal rod is hinged to one end of the first vertical elastic element, and the other end of the first vertical elastic element is fixed to the fixed frame; one end of the second horizontal elastic element is fixed to the fixed frame, and the other end is hinged to one end of the second diagonal rod at the second hinge point; the other end of the second diagonal rod is hinged to one end of the second vertical elastic element, and the other end of the second vertical elastic element is fixed to the fixed frame; the first hinge point and the second hinge point are rigidly connected;

[0009] The debugging method specifically includes debugging the constant value quasi-zero stiffness element and the constant force element. The debugging method for the constant value quasi-zero stiffness element is as follows:

[0010] S1.1, Determine the dimensionless pre-compression of the first vertical elastic element in the initial state. The dimensionless projection length of the first inclined rod in the vertical direction The stiffness ratio α1 of the first vertical elastic element and the first horizontal elastic element, and the displacement x1 of the first hinge point from its initial position, yield the dimensionless applied force acting on the constant-value quasi-zero stiffness element. and dimensionless stiffness The expression:

[0011]

[0012] in,

[0013] S1.2, at the static equilibrium position, let Equal to 0, let right The second derivative is equal to 0, thus obtaining the parametric condition for quasi-zero stiffness characteristics. α1 = 1; This ensures that the parameter values ​​satisfy the parametric relationships 0 < α1 < 1 and α1 < 1. It can achieve constant quasi-zero stiffness characteristics;

[0014] S1.3, Plot f1-x1 of the constant-value quasi-zero stiffness element based on the parametric conditions of the quasi-zero stiffness characteristic, where f1 is the applied force on the constant-value quasi-zero stiffness element. When the time-constant quasi-zero stiffness element is in static equilibrium, determine whether it meets the design requirements for bearing capacity and vibration isolation frequency band. If it does not meet the design requirements, repeat steps S1.1 to S1.3.

[0015] The debugging method for the constant force unit is as follows:

[0016] S2.1, Determine the dimensionless pre-compression of the second vertical elastic element in the initial state. The vertical projection length a2 and dimensionless projection length of the second inclined rod The stiffness ratio α2 of the second vertical elastic element and the second horizontal elastic element, and the displacement x2 of the second hinge point from its initial position, yield the dimensionless applied force acting on the constant force element. and dimensionless stiffness The expression:

[0017]

[0018] in,

[0019] S2.2, at the static equilibrium position, let Equal to 0, let right The second derivative is equal to 0, thus obtaining the parametric condition for quasi-zero stiffness characteristics. α2=1; according to α2 = 1 yields the constant force value of the constant force unit;

[0020] S2.3, Plot the force-displacement curve f2-x2 based on the parametric conditions of the quasi-zero stiffness characteristics of the constant force element, where f2 is the applied force applied by the constant force element. The time-constant quasi-zero stiffness element is in static equilibrium position. If the static equilibrium position is not satisfied, repeat steps S2.1 to S2.3.

[0021] As a preferred technical solution, the first horizontal elastic element is a first helical spring, the second horizontal elastic element is a second helical spring; the first vertical elastic element is a third helical spring, the second vertical elastic element is a fourth helical spring; the first hinge point and the second hinge point are connected by a connecting rod; the first helical spring, the second helical spring, the third helical spring and the fourth helical spring are compression springs.

[0022] As a preferred technical solution, the first helical spring, the second helical spring, the third helical spring and the fourth helical spring are sleeved on the guide rod.

[0023] As a preferred technical solution, when the constant-value quasi-zero stiffness unit is in its initial state, the first horizontal elastic element is in its free length state; when the constant-force unit is in its initial state, the second horizontal elastic element is in its free length state.

[0024] As a preferred technical solution, constant force is achieved by adjusting the connecting rod length l0. Under the action, the quasi-zero stiffness unit is in a static equilibrium position. Only a compact horizontal constant value quasi-zero stiffness vibration isolator can reach the static equilibrium position, and the horizontal constant value quasi-zero stiffness is successfully debugged.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1) The constant value quasi-zero stiffness unit in the horizontal direction of the present invention consists of a diagonal bar and two compression springs. It has a simple structure and few parts, and can realize a miniaturized and compact quasi-zero stiffness vibration isolator in the horizontal direction.

[0027] 2) The constant force unit in the horizontal direction of the present invention consists of a diagonal bar and two compression springs. It has a simple structure and few parts, and can realize a miniaturized and compact constant force structure.

[0028] 3) The horizontal constant value quasi-zero stiffness vibration isolator of the present invention is composed of a horizontal constant value quasi-zero stiffness unit and a constant force unit. It has a simple structure, few parts, and can achieve quasi-zero stiffness in the horizontal direction, thus achieving the purpose of miniaturization and compact quasi-zero stiffness vibration isolation. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the constant-value quasi-zero stiffness vibration isolator of the present invention;

[0030] Figure 2 This is a schematic diagram of the initial state of the constant-value quasi-zero stiffness element of the present invention;

[0031] Figure 3 This is a schematic diagram of the static equilibrium state of the constant-value quasi-zero stiffness unit of the present invention;

[0032] Figure 4 This is a schematic diagram of the initial state of the constant force unit of the present invention;

[0033] Figure 5 This is a schematic diagram of the static equilibrium state of the constant force unit of the present invention;

[0034] Figure 6 This is a stiffness-displacement curve of the constant-value quasi-zero stiffness element of the present invention;

[0035] Figure 7 This is a force-displacement curve of the constant-value quasi-zero stiffness element of the present invention;

[0036] Figure 8 This is a stiffness-displacement curve of the constant force unit of the present invention;

[0037] Figure 9 This is a force-displacement curve diagram of the constant force unit of the present invention;

[0038] The numbers in the diagram are as follows:

[0039] 10. First horizontal elastic element; 11. First diagonal bar; 12. First vertical elastic element; 13. First hinge point; 20. Second horizontal elastic element; 21. Second diagonal bar; 22. Second vertical elastic element; 23. Second hinge point. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0041] Example 1

[0042] like Figure 1 As shown, this embodiment provides a compact horizontal constant-value quasi-zero stiffness vibration isolator, including a constant-value quasi-zero stiffness unit, a constant force unit, and a fixing frame.

[0043] The constant-value quasi-zero stiffness unit includes a first horizontal elastic element 10, a first inclined rod 11, and a first vertical elastic element 12. One end of the first horizontal elastic element 10 is fixed to a fixed frame, and the other end is hinged to one end of the first inclined rod 11 at a first hinge point 13. The other end of the first inclined rod 11 is hinged to one end of the first vertical elastic element 12, and the other end of the first vertical elastic element 12 is fixed to the fixed frame. The first vertical elastic element 12 performs reciprocating linear motion in the vertical direction. During operation, the first vertical elastic element 12 remains vertical. The first horizontal elastic element 10 can be a first helical spring, and the first vertical elastic element 12 can be a third helical spring. The first and third helical springs are sleeved on a guide rod, which supports and prevents radial buckling instability caused by axial (horizontal) forces. The first inclined rod 11 and the first vertical elastic element 12 generate negative stiffness in the horizontal direction, and are connected in parallel with the first horizontal elastic element 10 in the horizontal direction, producing quasi-zero stiffness characteristics in the horizontal direction.

[0044] The constant force unit includes a second horizontal elastic element 20, a second inclined rod 21, and a second vertical elastic element 22. One end of the second horizontal elastic element 20 is fixed to the fixed frame, and the other end is hinged to one end of the second inclined rod 21 at a second hinge point 23. The other end of the second inclined rod 21 is hinged to one end of the second vertical elastic element 22 at the second hinge point 23, and the other end of the second vertical elastic element 22 is fixed to the fixed frame. The second vertical elastic element 22 performs reciprocating linear motion in the vertical direction. During operation, the second vertical elastic element 22 remains vertical. The second horizontal elastic element 20 can be a second helical spring, and the second vertical elastic element 22 can be a fourth helical spring. The second and fourth helical springs are sleeved on the guide rod, which supports and prevents radial buckling instability caused by axial (horizontal) forces. The second inclined rod 21 and the second vertical elastic element 22 generate negative stiffness in the horizontal direction, and are connected in parallel with the second horizontal elastic element 20 in the horizontal direction, producing quasi-zero stiffness characteristics in the horizontal direction.

[0045] The first horizontal elastic element 10 and the second elastic element are located on the same horizontal line. The first hinge point 13 and the second hinge point 23 are connected by a connecting rod with a length of l0.

[0046] like Figure 2 and Figure 4 As shown, when the vibration isolator is in its initial state, the first inclined rod 11 is inclined toward the direction of the first horizontal elastic element 10; the second inclined rod 21 is inclined toward the direction of the second horizontal elastic element.

[0047] like Figure 3 and Figure 5 As shown, when the vibration isolator is in a static equilibrium state, the first horizontal elastic element 10 retracts from the end fixed to the fixed frame compared to the initial state; the second horizontal elastic element 20 retracts from the end fixed to the fixed frame compared to the initial state.

[0048] Example 2

[0049] This embodiment provides a debugging method for a compact horizontal constant-value quasi-zero stiffness vibration isolator in Embodiment 1. The specific steps are as follows:

[0050] Mechanical analysis was performed on the constant quasi-zero stiffness element in the initial state to determine the dimensionless pre-compression of the first vertical elastic element 12 in the initial state. The dimensionless projection length of the first inclined rod 11 in the vertical direction The stiffness ratio α1 between the first vertical elastic element 12 and the first horizontal elastic element 10 yields the dimensionless applied force acting on the constant-value quasi-zero stiffness unit. The expression for f1 is given, where f1 is the applied force acting on the constant quasi-zero stiffness element.

[0051]

[0052] Dimensionless application force right Differentiating, we obtain the dimensionless stiffness of the constant-value quasi-zero stiffness element. The expression,

[0053]

[0054] At the static equilibrium position, let the dimensionless stiffness of the constant quasi-zero stiffness element be... To obtain the quasi-zero stiffness characteristic, the parameter conditions must be met such that the parameter values ​​satisfy the parameter relationships 0 < α1 < 1 and α1 < α1 < 1. It can achieve constant quasi-zero stiffness characteristics;

[0055]

[0056] Based on the parametric conditions of the quasi-zero stiffness characteristics of the constant-value quasi-zero stiffness element α1 = 1, plot the stiffness-displacement curve of the constant-value quasi-zero stiffness element as follows: Figure 6 As shown, the force-displacement curve is as follows: Figure 7 As shown, apply force After the constant value quasi-zero stiffness element is in static equilibrium position, when the quasi-zero stiffness element is in static equilibrium position, it is determined whether the vibration isolator meets the design requirements of bearing capacity and vibration isolation frequency band. If it does not meet the design requirements, the mechanical analysis of the constant value quasi-zero stiffness element in the initial state is performed again.

[0057] in, k1 represents the linear stiffness of the first vertical elastic element 12, k2 represents the linear stiffness of the first horizontal elastic element 10, a1 represents the projected length of the first inclined rod 11 in the vertical direction under the initial condition, δ1 is the pre-compression of the first vertical elastic element 12 in the initial state, x1 represents the displacement of the first hinge point 13 from the initial position, y1 represents the displacement of the first inclined rod 11 from the static equilibrium position (vertical state), h1 represents the distance between the first hinge point 13 from the initial position to the static equilibrium position, and the dimensionless form of h1 is... Dimensionless displacement and The relationship conforms to

[0058] Mechanical analysis is performed on the constant force element in the initial state to determine the dimensionless pre-compression of the second vertical elastic element 22 in the initial state. The dimensionless projection length of the second inclined rod 21 in the vertical direction The stiffness ratio α2 between the second vertical elastic element 22 and the second horizontal elastic element 20 yields the dimensionless application force applied by the constant force unit. The expression,

[0059]

[0060] Dimensionless application force right Differentiating, we obtain the dimensionless stiffness of the constant-value quasi-zero stiffness element. The expression,

[0061]

[0062] At the static equilibrium position, let the dimensionless stiffness of the constant force element be equal to 0, and let the second derivative of the dimensionless stiffness of the constant force element with respect to the dimensionless displacement be equal to 0, to obtain the parametric conditions for the quasi-zero stiffness characteristic. The stiffness-displacement curve is shown below. Figure 8 As shown,

[0063]

[0064] Based on the parameter condition α2=1, of the quasi-zero stiffness characteristics of the constant-value quasi-zero stiffness element. Once a constant force is obtained, the force-displacement curve is plotted as follows: Figure 9 As shown, a constant force brings the quasi-zero stiffness element to a static equilibrium position. Applying a force... When the nonlinear quasi-zero stiffness element is in static equilibrium position, when the constant force element is in static equilibrium position, it is determined whether the vibration isolator meets the static equilibrium position. If it does not meet the design requirements, the mechanical analysis of the constant force element in the initial state is performed again.

[0065] The dimensionless parameter is, k3 represents the linear stiffness of the second vertical elastic element 22, k4 represents the linear stiffness of the second horizontal elastic element 20, a2 represents the projected length of the second inclined rod 21 in the vertical direction under the initial condition, δ2 is the pre-compression of the second vertical elastic element 22 in the initial state, x2 represents the displacement of the second hinge point 23 from the initial position, y2 represents the displacement of the second inclined rod 21 from the static equilibrium position, h2 represents the distance between the second hinge point 23 from the initial position and the static equilibrium position, and the dimensionless form of h2 is... Dimensionless displacement and The relationship conforms to

[0066] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for debugging a compact horizontal constant-value quasi-zero stiffness vibration isolator, characterized in that, The constant-value quasi-zero stiffness vibration isolator includes a constant-value quasi-zero stiffness unit, a constant-force unit, and a fixing frame. The constant-value quasi-zero stiffness unit includes a first horizontal elastic element (10), a first inclined rod (11), and a first vertical elastic element (12). The constant-force unit includes a second horizontal elastic element (20), a second inclined rod (21), and a second vertical elastic element (22). The first horizontal elastic element (10) and the second horizontal elastic element (20) are located on the same horizontal line. One end of the first horizontal elastic element (10) is fixed to the fixed frame, and the other end is hinged to one end of the first inclined rod (11) at the first hinge point (13); the other end of the first inclined rod (11) is hinged to one end of the first vertical elastic element (12), and the other end of the first vertical elastic element (12) is fixed to the fixed frame; one end of the second horizontal elastic element (20) is fixed to the fixed frame, and the other end is hinged to one end of the second inclined rod (21) at the second hinge point (23); the other end of the second inclined rod (21) is hinged to one end of the second vertical elastic element (22), and the other end of the second vertical elastic element (22) is fixed to the fixed frame; the first hinge point (13) and the second hinge point (23) are rigidly connected; The debugging method specifically includes debugging the constant value quasi-zero stiffness element and the constant force element. The debugging method for the constant value quasi-zero stiffness element is as follows: S1.1, Determine the dimensionless pre-compression of the first vertical elastic element (12) in the initial state. The dimensionless projection length of the first inclined rod (11) in the vertical direction The stiffness ratio α1 of the first vertical elastic element (12) and the first horizontal elastic element (10), and the displacement x1 of the first hinge point (13) from its initial position, are used to obtain the dimensionless applied force on the constant-value quasi-zero stiffness element. and dimensionless stiffness The expression: in, S1.2, at the static equilibrium position, let Equal to 0, let right The second derivative is equal to 0, thus obtaining the parametric condition for quasi-zero stiffness characteristics. Make the parameter values ​​satisfy the parametric relationships 0 < α1 < 1 and It can achieve constant quasi-zero stiffness characteristics; S1.3, Plot f1-x1 of the constant-value quasi-zero stiffness element based on the parametric conditions of the quasi-zero stiffness characteristic, where f1 is the applied force on the constant-value quasi-zero stiffness element. When the time-constant quasi-zero stiffness element is in static equilibrium, determine whether it meets the design requirements for bearing capacity and vibration isolation frequency band. If it does not meet the design requirements, repeat steps S1.1 to S1.

3. The debugging method for the constant force unit is as follows: S2.1, Determine the dimensionless pre-compression of the second vertical elastic element (22) in the initial state. The vertical projection length a2 and dimensionless projection length of the second inclined rod (21) The stiffness ratio α2 of the second vertical elastic element (22) and the second horizontal elastic element (20), and the displacement x2 of the second hinge point (23) from its initial position, are used to obtain the dimensionless applied force on the constant force element. and dimensionless stiffness The expression: in, S2.2, at the static equilibrium position, let Equal to 0, let right The second derivative is equal to 0, thus obtaining the parametric condition for quasi-zero stiffness characteristics. according to α2 = 1 yields the constant force value of the constant force element; S2.3, Plot the force-displacement curve f2-x2 based on the parametric conditions of the quasi-zero stiffness characteristics of the constant force element, where f2 is the applied force applied by the constant force element. The time-constant quasi-zero stiffness element is in static equilibrium position. If the static equilibrium position is not satisfied, repeat steps S2.1 to S2.

3.

2. The debugging method for a compact horizontal constant-value quasi-zero stiffness vibration isolator according to claim 1, characterized in that, The first horizontal elastic element (10) is a first helical spring, and the second horizontal elastic element (20) is a second helical spring; the first vertical elastic element (12) is a third helical spring, and the second vertical elastic element (22) is a fourth helical spring; the first hinge point (13) and the second hinge point (23) are connected by a connecting rod; the first helical spring, the second helical spring, the third helical spring and the fourth helical spring are compression springs.

3. The debugging method for a compact horizontal constant-value quasi-zero stiffness vibration isolator according to claim 2, characterized in that, The first, second, third, and fourth helical springs are sleeved on the guide rod.

4. The debugging method for a compact horizontal constant-value quasi-zero stiffness vibration isolator according to claim 1, characterized in that, When the constant-value quasi-zero stiffness unit is in its initial state, the first horizontal elastic element (10) is in its free length state; when the constant force unit is in its initial state, the second horizontal elastic element (20) is in its free length state.

5. The debugging method for a compact horizontal constant-value quasi-zero stiffness vibration isolator according to claim 1, characterized in that, By adjusting the connecting rod length l0, a constant force is achieved. Under the action, the quasi-zero stiffness unit is in a static equilibrium position. Only a compact horizontal constant value quasi-zero stiffness vibration isolator can reach the static equilibrium position, and the horizontal constant value quasi-zero stiffness is successfully debugged.

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