A continuous multi-stage constant quasi-zero stiffness vibration isolator for bearing working conditions with large changes in mass

Abstract

The present application relates to the technical field of quasi-zero stiffness vibration isolator, and discloses a continuous multi-stage constant quasi-zero stiffness vibration isolator for working conditions with large changes in carrying mass. The adjustment mode of single-stage constant quasi-zero stiffness is that the ratio of the total stiffness of horizontal tension spring to the total stiffness of vertical tension spring is less than and close to 0.25, and in the initial state, the pre-stretching length of the horizontal tension spring is adjusted to be twice the horizontal component of the inclined rod in the initial state, so as to adjust it to a constant quasi-zero stiffness vibration isolation structure. On the basis of the single-stage constant quasi-zero stiffness structure, the adjustment mode of multi-stage constant quasi-zero stiffness characteristics is realized. The height of the vertical spring top fixed plate corresponding to different masses of the object to be isolated is pre-stored in the control system. According to the mass of the object to be isolated, the control system drives the vertical driving structure to move the vertical spring top fixed plate to the preset position through the control system, so as to adjust the position of the vertical tension spring, to realize the isolation of the object to be isolated with different masses, and to make the isolated mass be in the static balance position with the best isolation effect, that is, to realize the multi-stage constant quasi-zero stiffness isolation effect.

Description

Technical Field

[0001] This invention relates to the field of vibration isolator technology, and in particular to a continuous multi-stage constant value quasi-zero stiffness vibration isolator. Background Technology

[0002] Quasi-zero stiffness (QZS) vibration isolators are a superior type of low-frequency vibration isolator, which solves the contradiction between the low-frequency vibration isolation requirements and the large load-bearing capacity of linear stiffness vibration isolators.

[0003] Traditional quasi-zero stiffness vibration isolators have a three-dimensional nonlinear stiffness characteristic and only one static equilibrium position, thus corresponding to only one isolation mass. When the load mass changes, the isolation mass deviates from the static equilibrium position, causing an increase in dynamic stiffness and degrading the vibration isolation performance, such as an increase in the transmissivity amplitude and the initial isolation frequency. As shown in Chinese invention patent CN202210975179.7, it is only applicable to working conditions with small changes in load mass (such as a 10% change in the theoretical isolation mass) and cannot adapt to large changes in load mass.

[0004] Chinese invention patent CN201610338012.4 discloses a tension-type quasi-zero stiffness vibration isolator and its implementation method. It uses an adjustable nut that can be moved up and down to adjust the vertical position of the main spring to ensure that objects of different masses can be placed on it in a balanced position. However, since it is manually adjusted by adjusting the nut, it cannot accurately adjust the height of the nut according to different masses. In addition, its stiffness-displacement is nonlinear, which makes it impossible to accurately control the vibration isolation effect.

[0005] Furthermore, in the aforementioned prior art, vibration isolation is achieved by using a horizontal tension spring in conjunction with a vertical compression spring. However, since the vertical stiffness is constructed by compressing the spring, the spring is prone to buckling and instability. Therefore, a guide rod is often required to guide the spring. A large frictional damping will be generated between the guide rod and the spring, causing the isolation mass and displacement excitation of low-frequency vibrations below 3Hz to move synchronously (without relative motion), ultimately leading to the failure of low-frequency vibration isolation. Summary of the Invention

[0006] This invention provides a continuous multi-stage constant-value quasi-zero stiffness vibration isolator for bearing loads with large changes in mass, in order to solve the above-mentioned technical problems.

[0007] according to Figure 1-3The present invention provides a continuous multi-stage constant value quasi-zero stiffness vibration isolator for bearing loads with large changes in mass. The quasi-zero stiffness vibration isolator includes a fixed plate, with side supports symmetrically arranged on the left and right sides of the fixed plate. Side slide rails are fixedly arranged above the two side supports, and side sliders are slidably connected above the two side slide rails. Diagonal rod outer supports are fixedly arranged above the side sliders. Diagonal rods are rotatably connected to the inner side of the diagonal rod outer supports through first pins. Diagonal rod inner supports are rotatably connected to the other side of the two diagonal rods through second pins. The diagonal rod inner supports are fixedly connected to the main slide rail. A vibration isolation platform is connected above the main slide rail. Horizontal tension springs are arranged between the two first pins, and two horizontal tension springs are arranged symmetrically on the front and rear sides of the first pins.

[0008] Preferably, bearings are provided at the connection ends of the outer support and the diagonal rod to reduce the frictional resistance between the outer support, the diagonal rod, and the first pin; bearings are provided at the connection ends of the diagonal rod and the inner support to reduce the frictional resistance between the diagonal rod, the inner support, and the second pin.

[0009] Preferably, a pad is provided between the outer support of the inclined rod and the side slider to adjust the height of the outer support of the inclined rod so that the outer supports of the inclined rod on both sides are kept at the same height and no interference occurs in the movement of the components.

[0010] Preferably, the inner support of the diagonal rod is connected to the main slide rail through the inner support fixing plate of the diagonal rod.

[0011] It also includes a vertical spring top fixing plate and a vertical spring bottom fixing plate. The vertical spring bottom fixing plate is fixedly connected below the main slide rail. Two vertical tension springs are symmetrically arranged between the top and bottom fixing plates. A vertical drive structure drives the vertical spring top fixing plate to rise and fall, changing the position of the vertical tension springs to adapt to vibration-isolated objects of different masses. It is equipped with a control system that pre-stores the height of the vertical spring top fixing plate corresponding to objects of different masses. Based on the mass of the object to be isolated, the control system drives the vertical drive structure to move the vertical spring top fixing plate to the preset position.

[0012] Preferably, the bottom fixing plate of the vertical tension spring is fixed to the main slide rail by the slide rail fixing plate.

[0013] Preferably, the vertical drive structure includes a motor, a lead screw, and a nut. The output shaft of the motor is fixedly connected to the lead screw, the lead screw and the nut are threaded together, the nut is fixedly connected to one end of a connecting plate, the other end of the connecting plate is fixedly connected to a connecting seat, and a vertical spring top fixing plate is fixedly connected to the top of the connecting seat. Preferably, the motor is a stepper motor. Preferably, the lead screw is a ball screw.

[0014] Preferably, the connecting seat is further provided with a main slider, which is used to guide the main slide rail. Preferably, rollers are symmetrically arranged inside the main slider to reduce the resistance of the relative movement between the main slide rail and the main slider.

[0015] Figure 4 This is a schematic diagram of constant-value quasi-zero stiffness mechanics, through which force analysis is performed.

[0016] The expression for force f is as follows:

[0017]

[0018] Where k1 represents the total stiffness of the horizontal tension spring, k2 represents the total stiffness of the vertical tension spring, x is the displacement from the initial position O, y is the displacement from the static equilibrium position (the inclined rod is in a horizontal state), a is the horizontal component of the inclined rod in the initial state, δ represents the pretension of the horizontal tension spring in the initial state, and h is the distance from point O to the static equilibrium position in the initial state.

[0019] The applied force f and its expression are made dimensionless. The dimensionless applied force

[0020]

[0021] in, Stiffness ratio of horizontal tension spring to vertical tension spring intermediate variables And x = y + h;

[0022] Utilizing dimensionless application force For dimensionless displacement The dimensionless stiffness of the system can be obtained by taking the first derivative.

[0023]

[0024] K is a dimensionless stiffness.

[0025] At the static equilibrium position, for dimensionless stiffness Find the second derivative and let it be zero. Since it equals zero, the parameter conditions for zero stiffness characteristics are α = 0.25 and...

[0026] The ratio α of the total stiffness of the horizontal tension spring to the total stiffness of the vertical tension spring should satisfy α < 0.25 and α → 0.25 (α approaches 0.25). Where m is the vibration isolation mass, ω qIt is the initial vibration isolation frequency required by the design; and in the initial state, the pre-tension length δ of the horizontal tension spring is adjusted to be twice the horizontal component a of the inclined rod in the initial state, i.e., δ = 2a, thereby adjusting it into a constant value quasi-zero stiffness vibration isolation structure.

[0027] Based on the vibration isolation requirements for large-scale variable load-bearing mass, the vibration isolation capacity and the number of static equilibrium points within a single static equilibrium point range are designed. This involves designing multiple consecutive levels of constant quasi-zero stiffness based on a single-stage constant quasi-zero stiffness and the range of vibration isolation mass variation. Figure 5 As shown, the vibration isolation capacity of a single static equilibrium point is calculated using the above formula to determine the displacement range and corresponding magnitude of the changing force near each static equilibrium point. X0, X1, X2, X3, and X4 represent different positions of the top fixed plate of the vertical spring, while the vertical axis represents the corresponding load-bearing mass. The displacement and force corresponding to two adjacent static equilibrium positions transition smoothly, avoiding sudden force changes and impact phenomena that occur when adjusting the load-bearing mass due to quasi-zero stiffness with nonlinear stiffness. In principle, this invention can infinitely increase the number of static equilibrium points, thus infinitely improving the adaptability to changes in load-bearing mass.

[0028] A method of using the above-mentioned continuous multi-stage constant-value quasi-zero stiffness vibration isolator for bearing large changes in mass, the method comprising the following steps:

[0029] (1) Place the object to be isolated on the vibration isolation platform at the top of the main slide rail;

[0030] (2) The control system has a pre-stored height of the top fixing plate of the vertical spring corresponding to different masses of objects to be isolated. According to the mass of the object to be isolated, the control system drives the vertical drive structure to move the top fixing plate of the vertical spring to the preset position.

[0031] (3) At this time, under the action of the vibration isolation mass, the quasi-zero stiffness vibration isolator is adjusted to the static equilibrium position, that is, the inclined bar is adjusted to the horizontal state, so that the quasi-zero stiffness vibration isolator enters the optimal working position.

[0032] (4) When there is a need for a change in load capacity, repeat steps (1) to (3).

[0033] In step 2, the control system drives the motor, which in turn drives the lead screw to rotate. This causes the nut to move the connecting plate and the connecting seat longitudinally, thereby moving the top fixed plate of the vertical spring and adjusting the position of the vertical tension spring to meet different vibration isolation requirements.

[0034] The beneficial effects of the above-described technical solution of the present invention are as follows:

[0035] (1) The compression spring in the vertical direction in the prior art is set as a vertical tension spring to avoid vibration isolation failure due to excessive friction damping and improve the vibration isolation effect.

[0036] (2) The ratio of the total stiffness of the horizontal tension spring to the total stiffness of the vertical tension spring. Furthermore, in the initial state, the pre-tension length of the horizontal tension spring is adjusted to twice the horizontal component of the diagonal bar in the initial state, thus adjusting it into a constant value quasi-zero stiffness vibration isolation structure.

[0037] (3) Based on the single-level constant value quasi-zero stiffness structure, a multi-level constant value quasi-zero stiffness characteristic adjustment method is realized. The height of the vertical spring top fixing plate corresponding to different masses of the object to be isolated is stored in the control system. According to the mass of the object to be isolated, the control system drives the vertical drive structure to move the vertical spring top fixing plate to the preset position to adjust the position of the vertical tension spring, so as to realize the vibration isolation of the object to be isolated of different masses and make the vibration isolation mass at the static equilibrium position of the best vibration isolation effect, that is, to realize the multi-level constant value quasi-zero stiffness vibration isolation effect. Attached Figure Description

[0038] Figure 1 This is a front view of the quasi-zero stiffness vibration isolator of the present invention;

[0039] Figure 2 This is a partial top view of the quasi-zero stiffness vibration isolator of the present invention;

[0040] Figure 3 This is a partial side view of the quasi-zero stiffness vibration isolator of the present invention;

[0041] Figure 4 This is a schematic diagram of constant-value quasi-zero stiffness mechanics;

[0042] Figure 5 Mechanical characteristics achieved by quasi-zero stiffness low-frequency vibration isolators used to withstand conditions with large changes in mass.

[0043] The components are: 1. Fixed plate; 2. Side support column; 3. Side slide rail; 4. Side slider; 5. Pad; 6. Diagonal rod outer support; 7. First pin; 8. Diagonal rod; 9. Second pin; 10. Diagonal rod inner support; 11. Diagonal rod inner support fixing plate; 12. Main slide rail; 13. Horizontal tension spring; 14. Main slider; 15. Main slider connecting seat; 16. Connecting plate; 17. Nut; 18. Lead screw; 19. Vertical tension spring top fixing plate; 20. Vertical tension spring; 21. Vertical tension spring bottom fixing plate; 22. Slide rail fixing plate; 23. Motor. Detailed Implementation

[0044] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0045] according to Figure 1-3The present invention provides a continuous multi-stage constant value quasi-zero stiffness vibration isolator for bearing large changes in mass. The quasi-zero stiffness vibration isolator includes a fixed plate 1, side support columns 2 symmetrically arranged on the left and right sides of the fixed plate 1, side slide rails 3 fixedly arranged above the two side support columns 2, side sliders 4 slidably connected above the two side slide rails 3, and diagonal rod outer supports 6 fixedly arranged above the side sliders 4. Diagonal rods 8 are rotatably connected to the inner side of the diagonal rod outer supports 6 through first pins 7. Diagonal rod inner supports 10 are rotatably connected to the other side of the two diagonal rods 8 through second pins 9. Diagonal rod inner supports 10 are fixedly connected to the main slide rail 12. A vibration isolation platform is connected above the main slide rail 12. A horizontal tension spring 13 is arranged between the two first pins 7, and two horizontal tension springs 13 are arranged symmetrically on the front and rear sides of the first pins 7.

[0046] Preferably, bearings are provided at the connection ends of the outer support 6 and the diagonal rod 8 to reduce the frictional resistance between the outer support 6, the diagonal rod 8 and the first pin 7; bearings are provided at the connection ends of the diagonal rod 8 and the inner support 10 to reduce the frictional resistance between the diagonal rod 8, the inner support 10 and the second pin 9.

[0047] Preferably, a pad 5 is provided between the outer support 6 of the inclined rod and the side slider 4 to adjust the height of the outer support 6 of the inclined rod, so that the outer supports 6 of the inclined rod on both sides are at the same height and there is no interference between the movement of the parts.

[0048] Preferably, the inner support 10 of the diagonal rod is connected to the main slide rail 12 through the inner support fixing plate 11 of the diagonal rod.

[0049] It also includes a vertical tension spring top fixing plate 19 and a vertical tension spring bottom fixing plate 21. The vertical tension spring bottom fixing plate 21 is fixedly connected below the main slide rail 12. Two vertical tension springs 20 are symmetrically arranged between the spring top fixing plate 19 and the vertical tension spring bottom fixing plate 21. The vertical tension spring top fixing plate 19 is driven to rise and fall by a vertical drive structure, changing the position of the vertical tension springs 20 to adapt to vibration-isolated objects of different masses. It is equipped with a control system, which pre-stores the height of the vertical tension spring top fixing plate 19 corresponding to objects of different masses to be vibration-isolated. According to the mass of the object to be vibration-isolated, the control system drives the vertical drive structure to move the vertical tension spring top fixing plate 19 to the preset position.

[0050] Preferably, the bottom fixing plate 21 of the vertical tension spring is fixed to the main slide rail 12 by the slide rail fixing plate 22.

[0051] Preferably, the vertical drive structure includes a motor 23, a lead screw 18, and a nut 17. The output shaft of the motor 23 is fixedly connected to the lead screw 18. The lead screw 18 and the nut 17 are threaded together. The nut 17 is fixedly connected to one end of a connecting plate 16. The other end of the connecting plate 16 is fixedly connected to a connecting seat 15. A vertical tension spring top fixing plate 19 is fixedly connected to the top of the connecting seat 15. Preferably, the motor 23 is a stepper motor. Preferably, the lead screw 18 is a ball screw.

[0052] Preferably, the connecting seat 15 is further provided with a main slider 14, which is used to guide the main slide rail 12. Preferably, rollers are symmetrically arranged inside the main slider 14 to reduce the resistance of the relative movement between the main slide rail 12 and the main slider 14.

[0053] Figure 4 This is a schematic diagram of constant-value quasi-zero stiffness mechanics, through which force analysis is performed.

[0054] The expression for force f is as follows:

[0055]

[0056] Where, k1 represents the total stiffness of the horizontal tension spring 13, k2 represents the total stiffness of the vertical tension spring 20, x is the displacement from the initial position O, y is the displacement from the static equilibrium position (the inclined rod is in a horizontal state), a is the horizontal component of the inclined rod in the initial state, δ represents the pretension of the horizontal tension spring 13 in the initial state, and h is the distance from point O to the static equilibrium position in the initial state.

[0057] The applied force f and its expression are made dimensionless. The dimensionless applied force

[0058]

[0059] in, Stiffness ratio of horizontal tension spring 13 to vertical tension spring 20 intermediate variables And x = y + h;

[0060] Utilizing dimensionless application force For dimensionless displacement The dimensionless stiffness of the system can be obtained by taking the first derivative.

[0061]

[0062] K is a dimensionless stiffness;

[0063] At the static equilibrium position, for dimensionless stiffness Find the second derivative and let it be zero. Since it equals zero, the parameter conditions for zero stiffness characteristics are α = 0.25 and...

[0064] The ratio α of the total stiffness of the horizontal tension spring 13 to the total stiffness of the vertical tension spring 20 is such that α < 0.25 and α → 0.25 (α approaches 0.25). Where m is the vibration isolation mass, ω q It is the initial vibration isolation frequency required by the design; and in the initial state, the pre-tension length δ of the horizontal tension spring 13 is adjusted to be twice the horizontal component a of the inclined rod in the initial state, i.e., δ = 2a, thereby adjusting it into a constant value quasi-zero stiffness vibration isolation structure.

[0065] Based on the vibration isolation requirements for large-scale variable load-bearing mass, the vibration isolation capacity and the number of static equilibrium points within a single static equilibrium point range are designed. This involves designing multiple consecutive levels of constant quasi-zero stiffness based on a single-stage constant quasi-zero stiffness and the range of vibration isolation mass variation. Figure 5 As shown, the vibration isolation capacity of a single static equilibrium point is calculated using the above formula to determine the displacement range and corresponding magnitude of the changing force near each static equilibrium point. X0, X1, X2, X3, and X4 represent different positions of the top fixing plate 19 of the vertical tension spring, while the vertical axis represents the corresponding load-bearing mass. The displacement and force corresponding to two adjacent static equilibrium positions transition smoothly, avoiding sudden force changes and impact phenomena that can occur with quasi-zero stiffness due to nonlinear stiffness during load-bearing mass adjustments. In principle, this invention can infinitely increase the number of static equilibrium points, thus infinitely improving the adaptability to changes in load-bearing mass.

[0066] A method for using a continuous multi-stage constant-value quasi-zero stiffness vibration isolator for bearing conditions with large changes in mass, the method comprising the following steps:

[0067] 1. Place the object to be isolated on the vibration isolation platform at the top of the main slide rail 12;

[0068] 2. The control system has pre-stored the height of the top fixing plate 19 of the vertical tension spring corresponding to objects of different masses to be isolated. According to the mass of the object to be isolated, the control system drives the vertical drive structure to move the top fixing plate 19 of the vertical tension spring to the preset position.

[0069] 3. At this point, under the action of the vibration isolation mass, the quasi-zero stiffness vibration isolator is adjusted to the static equilibrium position, that is, the inclined bar is adjusted to a horizontal state, so that the quasi-zero stiffness vibration isolator enters the optimal working position.

[0070] 4. When there is a need for a change in load-bearing capacity, repeat steps (1) to (3).

[0071] In step 2, the control system drives the motor 23, which in turn drives the lead screw 18 to rotate. This causes the nut 17 to move the connecting plate 16 and the connecting seat 15 longitudinally, thereby moving the top fixing plate 19 of the vertical tension spring and adjusting the position of the vertical tension spring 20 to meet different vibration isolation requirements.

[0072] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method of using a continuous multi-stage constant-value quasi-zero stiffness vibration isolator for bearing conditions with large variations in mass, characterized in that: The quasi-zero stiffness vibration isolator includes a fixed plate, with side pillars symmetrically arranged on the left and right sides of the fixed plate. Side slide rails are fixedly arranged above the two side pillars, and side sliders are slidably connected above the two side slide rails. An outer support for a diagonal rod is fixedly arranged above the side sliders. A diagonal rod is rotatably connected to the inner side of the outer support for the diagonal rod through a first pin. An inner support for the diagonal rod is rotatably connected to the other side of the two diagonal rods through a second pin. The inner support for the diagonal rod is fixedly connected to the main slide rail. A vibration isolation platform is connected above the main slide rail. A horizontal tension spring is arranged between the two first pins, and two horizontal tension springs are arranged symmetrically on the front and rear sides of the first pins. It also includes a vertical spring top fixing plate and a vertical spring bottom fixing plate. The vertical spring bottom fixing plate is fixedly connected below the main slide rail. Two vertical tension springs are symmetrically arranged between the spring top fixing plate and the vertical spring bottom fixing plate. The vertical spring top fixing plate is driven to rise and fall by the vertical drive structure to change the position of the vertical tension spring. It is also equipped with a control system, which has a pre-stored height of the vertical spring top fixing plate corresponding to objects of different masses to be isolated. According to the mass of the object to be isolated, the control system drives the vertical drive structure to move the vertical spring top fixing plate to the preset position, so as to realize the vibration isolation of objects of different masses and put the vibration isolation mass in the static equilibrium position of the best vibration isolation effect. The range of values ​​for the ratio α of the total stiffness of the horizontal tension spring to the total stiffness of the vertical tension spring is: Where m is the vibration isolation mass, ω q It is the initial vibration isolation frequency required by the design. δ represents the preload of the horizontal tension spring in the initial state, h is the distance from point O to the static equilibrium position in the initial state, a is the horizontal component of the inclined rod in the initial state, and k2 represents the total stiffness of the vertical tension spring. intermediate variables Furthermore, in the initial state, the pre-tension length of the horizontal tension spring is adjusted to be twice the horizontal component of the diagonal bar in the initial state; The vertical drive structure includes a motor, a lead screw, and a nut. The output shaft of the motor is fixedly connected to the lead screw, the lead screw and the nut are threaded together, the nut is fixedly connected to one end of the connecting plate, the other end of the connecting plate is fixedly connected to the connecting seat, and a vertical spring top fixing plate is fixedly connected to the top of the connecting seat. The method of use includes the following steps: (1) Place the object to be isolated on the vibration isolation platform at the top of the main slide rail; (2) The control system has a pre-stored height of the top fixing plate of the vertical spring corresponding to different masses of objects to be isolated. According to the mass of the object to be isolated, the control system drives the vertical drive structure to move the top fixing plate of the vertical spring to the preset position. (3) At this time, under the action of the vibration isolation mass, the quasi-zero stiffness vibration isolator is adjusted to the static equilibrium position, that is, the inclined bar is adjusted to the horizontal state, so that the quasi-zero stiffness vibration isolator enters the optimal working position. (4) When there is a need for a change in load-bearing capacity, repeat steps (1) to (3); Based on the vibration isolation requirements for large-scale variable load capacity, design the vibration isolation capacity and the number of static equilibrium points within a single static equilibrium point range.

2. The method of using the continuous multi-stage constant-value quasi-zero stiffness vibration isolator for bearing large changes in mass as described in claim 1, characterized in that, A pad is provided between the outer support of the diagonal bar and the side slider to adjust the height of the outer support of the diagonal bar so that the outer supports of the diagonal bar on both sides are at the same height and there is no interference between the movement of the parts.

3. The method of using the continuous multi-stage constant-value quasi-zero stiffness vibration isolator for bearing large changes in mass as described in claim 2, characterized in that, The motor is a stepper motor, and the lead screw is a ball screw.

4. The method of using the continuous multi-stage constant-value quasi-zero stiffness vibration isolator for bearing large changes in mass as described in claim 3, characterized in that, The connecting seat is also equipped with a main slider, which is used to guide the main slide rail.

5. The method of using the continuous multi-stage constant-value quasi-zero stiffness vibration isolator for bearing large changes in mass as described in claim 4, characterized in that, Rollers are symmetrically arranged inside the main slider to reduce the resistance of the relative motion between the main slide rail and the main slider.

6. The method of using the continuous multi-stage constant-value quasi-zero stiffness vibration isolator for bearing conditions with large changes in mass as described in claim 5, characterized in that, The bottom fixing plate of the vertical tension spring is fixed to the main slide rail through the slide rail fixing plate.

7. The method of using the continuous multi-stage constant-value quasi-zero stiffness vibration isolator for bearing large changes in mass as described in claim 6, characterized in that, In step 2, the control system drives the motor, which in turn drives the lead screw to rotate. This causes the nut to move the connecting plate and the connecting seat longitudinally, thereby moving the top fixed plate of the vertical spring and adjusting the position of the vertical tension spring to meet different vibration isolation requirements.

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