Line spectrum damping device and method based on dynamic anti-resonance

Abstract

The invention provides a line spectrum damping device and method based on dynamic anti-resonance, the line spectrum damping device comprises a main mass block, a positive stiffness spring, a base, an inertial element and a self-adjusting element, the upper end and the lower end of the positive stiffness spring are fixed between the main mass block and the base respectively, and the inertial element comprises a lever and an inertial mass block; the lever is movably clamped and positioned through a flexible hinge mechanism fixed on the main mass block and the base, the inertia mass block is fixed at one end of the lever and is connected with the base through a negative stiffness mechanism, the self-adjusting element is fixed on the base, and two fulcrums are arranged at the top end of the self-adjusting element and are respectively contacted with the lever; the lever ratio of the damping device can be adjusted in real time according to the excitation frequency, automatic adjustment of the vibration isolation frequency is achieved, the vibration isolation effect is enhanced, and meanwhile the weight is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of vibration reduction and isolation design, and in particular to a line spectrum vibration reduction device and method based on dynamic anti-resonance. Background Art

[0002] In order to reduce the underwater radiated noise caused by the vibration of mechanical equipment, various vibration isolation technologies are used in mechanical equipment. Vibration isolation technologies represented by double-layer vibration isolation and floating raft vibration isolation have played an important role in vibration noise control. However, the intermediate mass of the double-layer vibration isolation device and the raft of the floating raft vibration isolation are multi-modal elastic bodies, which may affect the vibration isolation performance. The vibration isolation effect is always unsatisfactory. Due to the elastic effect of the raft itself, the classic floating raft vibration isolation technology cannot effectively isolate the line spectrum vibration, and the radiated noise always contains some line spectrum components.

[0003] The vibration isolator formed based on the dynamic anti-resonance vibration isolation technology is a new type of vibration isolator that cleverly combines vibration isolation and vibration absorption. A simple dynamic anti-resonance vibration isolation system is composed of an inertial element (composed of a rigid rod and a counterweight) in addition to the conventional equipment of springs and dampers. Under the excitation of mechanical equipment, the inertial element reciprocates up and down to generate an inertial force, the size of which is related to the concentrated mass at the end and the amplification ratio of the lever. If the parameters are selected reasonably, when the frequency of the exciting force is equal to the anti-resonance frequency of the system, the transmission of the exciting force to the foundation can be completely offset. Therefore, in the absence of damping, a vibration isolation effect with a zero transmission rate can be achieved, and in the presence of damping, the transmission rate is also very small. The dynamic anti-resonance system has a vibration isolation efficiency of more than 90% near the anti-resonance frequency point, and at the same time overcomes the shortcomings of large static deformation and low stiffness of traditional vibration isolators, and the vibration isolation efficiency is much higher than that of conventional vibration isolation devices. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a line spectrum vibration elimination device and method based on dynamic anti-resonance in response to the above-mentioned problems. The introduction of a self-adjusting mechanism (elastic fin-type actuator) can adjust the lever ratio of the vibration isolator in real time according to the excitation frequency, so as to achieve the purpose of coinciding the vibration isolation frequency with the excitation frequency, thereby realizing automatic adjustment of the vibration isolation frequency.

[0005] The embodiment of the present application is implemented as follows:

[0006] An embodiment of the present application provides a line spectrum vibration elimination device based on dynamic anti-resonance, characterized in that it includes a main mass block, a positive stiffness spring, a base, an inertial element and a self-adjusting element. The upper and lower ends of the positive stiffness spring are respectively fixed between the main mass block and the base. The inertial element includes a lever and an inertial mass block. The lever is movably clamped and positioned by a flexible hinge mechanism fixed to the main mass block and the base. The inertial mass block is fixed to one end of the lever and connected to the base through a negative stiffness mechanism. The self-adjusting element is fixed to the base, and two fulcrums are provided on the top end to contact the lever respectively. The horizontal combined force acting on the lever drives the lever to move laterally for self-adjustment.

[0007] In some optional embodiments, a linear bearing is laid on the base, and the self-adjusting element and the negative stiffness mechanism are respectively moved along the linear bearing via a slider.

[0008] In some optional embodiments, the self-adjusting element is an elastic fin-type actuator, including a V-shaped block, an inertia block, a leaf spring and a connecting block. The left and right ends of the V-shaped block are fixed upward to one end of the inertia block, and the other end of the inertia block is connected to one end of the connecting block through a leaf spring. The leaf spring consists of multiple pieces, which are symmetrically connected up and down. The other end of the connecting block is connected to the slider, and rubber pads are respectively embedded in the left and right ends of the V-shaped block.

[0009] In some optional embodiments, the flexible hinge mechanism includes an intermediate ball bearing and an intermediate hinge support, and two side ball bearings and two side hinge supports, the two side hinge supports are concave seat structures, the intermediate hinge support is arranged corresponding to the inner grooves of the two side hinge supports, and are connected by pre-stressed connectors, the vertical height of the intermediate ball bearing is greater than the vertical height of the two side ball bearings, and the lever is inserted into the gap between the intermediate ball bearing and the two side ball bearings to clamp and position them.

[0010] In some optional embodiments, the pre-stressing connecting member includes a pre-stressing bolt, a pre-stressing nut and a pre-stressing coil spring. The middle hinge support and the hinge supports on both sides are symmetrically provided with an upper fixing block and a lower fixing block. The pre-stressing bolt passes through the lower fixing block and the upper fixing block in sequence. The pre-stressing coil spring is sleeved on the pre-stressing bolt. The pre-stressing nut is threadedly connected to the pre-stressing bolt to compress the pre-stressing coil spring.

[0011] In some optional embodiments, the two sides of the hinge supports are connected to a connecting base provided below via lateral leaf springs, and the intersection of the extension of the lateral leaf springs coincides with the center position formed by the intermediate ball bearing and the ball bearings on both sides.

[0012] In some optional embodiments, a limit block is provided at the outer end of the linear bearing.

[0013] In some optional embodiments, the positive stiffness spring is a semicircular corrugated periodic beam structure, which is symmetrically arranged between the main mass block and the base.

[0014] In some optional embodiments, the negative stiffness mechanism includes a negative stiffness bracket and pairs of springs or disc springs or electromagnets or bistable beams symmetrically arranged on the negative stiffness bracket, and both ends of the inertia block are respectively connected to the pairs of springs or disc springs or electromagnets or bistable beams.

[0015] A method for using a line spectrum vibration elimination device based on dynamic anti-resonance, characterized in that it includes the following contents:

[0016] When the excitation frequency of the elastic fin-type actuator changes, the lever is subjected to unbalanced force and rotates at a small angle around the instantaneous rotation center. The rubber pads at the left and right ends of the V-shaped block deform differently, resulting in unequal forces generated by the vibration of the rubber pads on both sides. The horizontal resultant force acting on the lever is not zero, and the lever will move in the direction of the resultant force until the resultant force on the lever is zero. The lever stops moving and the lever ratio remains unchanged. At this time, the instantaneous center of the lever coincides with the center of the flexible hinge mechanism fixed on the main mass block, and the vibration isolation frequency matches the excitation frequency, thereby realizing automatic adjustment of the vibration isolation frequency. At the same time, the lever enables the inertial mass to achieve inertia amplification, and the vibration isolation effect is enhanced through the negative stiffness mechanism.

[0017] The beneficial effects of the present application are: 1. The present application provides a line spectrum vibration reduction device and method based on dynamic anti-resonance. By introducing a self-adjusting element (elastic fin-type actuator), the lever ratio of the vibration reduction device can be adjusted in real time according to the excitation frequency, so as to achieve the purpose of coincidence of the vibration isolation frequency with the excitation frequency, thereby realizing automatic adjustment of the vibration isolation frequency; 2. The introduction of the lever enables the vibration isolation device to achieve inertia amplification of the inertial mass. On this basis, a negative stiffness device is introduced to enhance the vibration isolation effect while reducing the weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A cross-sectional view of an anti-resonance vibration reduction device according to an embodiment of the present application;

[0020] Figure 2 This is a schematic diagram of the anti-resonance vibration elimination device according to an embodiment of the present application;

[0021] Figure 3 The force transmission characteristic curve and the mechanical system vibration excitation characteristic diagram of the embodiment of the present application;

[0022] Figure 4 It is a schematic structural diagram of an elastic fin type actuator according to an embodiment of the present application;

[0023] Figure 5 A schematic diagram of the structure of a flexible hinge mechanism according to an embodiment of the present application;

[0024] Figure 6 Schematic diagram of a negative stiffness mechanism according to an embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0027] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0028] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0029] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0030] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0031] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0032] The features and performance of the present application are further described in detail below in conjunction with the embodiments.

[0033] like Figure 1 As shown, based on this, the present invention proposes a line spectrum vibration elimination device based on dynamic anti-resonance, including a main mass block 1, a positive stiffness spring 2, a base 3, an inertial element and a self-adjusting element 4, the upper and lower ends of the positive stiffness spring are respectively fixed between the main mass block and the base, the inertial element includes a lever 5 and an inertial mass block 6, the lever is movably clamped and positioned by a flexible hinge mechanism 7 fixed on the main mass block and the base, the inertial mass block is fixed to one end of the lever and connected to the base through a negative stiffness mechanism 8, the self-adjusting element is fixed on the base, and two fulcrums are provided on the top end to contact the lever respectively, and the horizontal combined force acting on the lever drives the lever to move horizontally for self-adjustment.

[0034] For low-frequency vibrations, traditional passive control methods have the problem of a large mass ratio. The dynamic anti-resonance structure can use a smaller mass to suppress low-frequency vibrations by introducing levers and negative stiffness structures. Once the vibration isolation frequency of the traditional inertial device is determined, it cannot be changed and the bandwidth is narrow. The introduction of self-adjusting elements can adjust the lever ratio of the vibration isolation device in real time according to the excitation frequency, so as to achieve the purpose of coinciding the vibration isolation frequency with the excitation frequency, thereby realizing automatic adjustment of the vibration isolation frequency.

[0035] A linear bearing 9 is laid on the base, and the self-adjusting element and the negative stiffness mechanism move along the linear bearing through a slider 10. A limit block 11 is provided at the outer end of the linear bearing to prevent the slider from sliding off the linear bearing during the movement of the lever.

[0036] In order to illustrate the working principle of the vibration isolator based on the principle of dynamic anti-resonance, the structure is simplified as follows: Figure 2 The dynamic anti-resonance structure shown is composed of Figure 2 It can be seen that the vibration isolator mainly includes: main mass block M, main stiffness k, length L 1 The length of the lever between the two hinges is L 2 , where: the gravity generated by M represents the static load carried by each vibration reduction device under actual working conditions, k represents the dynamic stiffness of the vibration reduction device at each machine foot, x, y, z represent the main mass block, base, inertial mass m respectively is displacement, further assuming that the lever is a light and rigid rod, and the vibration is a small amplitude vibration, the relationship between the three displacements can be obtained as z = αx + (1-α) y, α is the lever ratio, It is known from vibration theory that the displacement transmission rate at this time is the same as the force transmission rate of the reaction force on the base obtained by the excitation force acting on the main mass block.

[0037] Using the Lagrange equation, the dynamic equation of the vibration isolator can be obtained as shown below:

[0038]

[0039] Where: μ is the mass ratio of the vibration reduction device,

[0040] ω 0 is the natural frequency of the main mass block,

[0041] From the above formula, the force transmission rate of the vibration reduction device can be obtained as follows:

[0042]

[0043] The force transmission rate and the vibration excitation of the mechanical system vary with frequency. Figure 3As shown, it can be seen that when the peak frequency of the excitation force of the mechanical system is the same as the dynamic anti-resonance frequency of the mechanical system, the transmission of the vibration of the mechanical system to the base can be controlled.

[0044] Example 1

[0045] like Figure 4 As shown, the self-adjusting element in this embodiment is an elastic fin-type actuator, including a V-shaped block 41, an inertia block 42, a leaf spring 43 and a connecting block 44. The left and right ends of the V-shaped block are fixed upward to one end of the inertia block, and the other end of the inertia block is connected to one end of the connecting block through a leaf spring. The leaf springs are multiple and symmetrically connected up and down. The other end of the connecting block is connected to the slider. Rubber pads 45 are respectively embedded in the left and right ends of the V-shaped block.

[0046] When the excitation frequency of the elastic fin type actuator changes, if the forces generated by the two rubber pads due to vibration are not equal, the resultant force acting on the lever is not zero, and the lever will move in the direction of the resultant force until the resultant force on the lever is zero, the lever stops moving, and the lever ratio remains unchanged.

[0047] The V-block is bolted to the inertia block to minimize the movement of the V-block due to the force applied by the rubber pad. To counteract the residual movement, the inertia block is connected to the connection block by four leaf springs arranged in parallel.

[0048] The above-mentioned slider can have a locking function and can be fixed at any position. The connection block of the elastic fin type actuator fixes the elastic fin type actuator on the linear bearing through the slider. The slider is mainly used to adjust the axial displacement of the actuator so that the two rubber pads of the actuator are symmetrically placed directly below the flexible hinge mechanism of the main mass block. In the initial state, the rubber pad contacts the lever with a very small compression force.

[0049] Example 2

[0050] like Figure 5 As shown, in this embodiment, the flexible hinge mechanism includes a middle ball bearing 71 and a middle hinge support 72, and two side ball bearings 73 and two side hinge supports 74. The two side hinge supports are concave seat structures. The middle hinge support is arranged corresponding to the inner grooves of the two side hinge supports and connected by a pre-pressed connector 75. The vertical height of the middle ball bearing is greater than the vertical height of the two side ball bearings. The lever is inserted into the gap between the middle ball bearing and the two side ball bearings for clamping and positioning. The upper and lower surfaces of the lever are processed with sliding grooves so that it can slide freely along its own axis.

[0051] In this embodiment, the pre-stressed connector includes a pre-stressed bolt 751, a pre-stressed nut 752 and a pre-stressed coil spring 753. An upper fixing block 754 and a lower fixing block 755 are symmetrically arranged on the middle hinge support and the hinge supports on both sides. The pre-stressed bolt passes through the lower fixing block and the upper fixing block in sequence. The pre-stressed coil spring is sleeved on the pre-stressed bolt. The pre-stressed nut is screwed with the pre-stressed bolt to compress the pre-stressed coil spring. A slight pre-tightening force is applied to the lever through the pre-stressed connector to prevent it from drifting during self-adjustment and reduce the noise generated during vibration.

[0052] The two sides of the hinge supports are connected to the connecting base 757 provided below through the lateral leaf springs 756. The intersection of the extension of the lateral leaf springs coincides with the center position formed by the middle ball bearing and the ball bearings on both sides, ensuring that the lever can rotate around the instantaneous center of the flexible hinge mechanism.

[0053] In some optional embodiments, the positive stiffness spring is a semicircular corrugated periodic beam structure and is symmetrically arranged between the main mass block and the base.

[0054] Negative stiffness mechanisms can be implemented in various forms, such as double springs, disc springs, electromagnets, bistable beams, etc. No matter which method is used, they only need to be placed between the inertial mass block and the linear bearing.

[0055] Example 3

[0056] like Figure 6 As shown, in this embodiment, the negative stiffness mechanism includes a negative stiffness bracket 81 and springs 82 symmetrically arranged on the negative stiffness bracket in pairs, and both ends of the inertia block are respectively connected to the paired springs.

[0057] On the basis of lever structure amplifying the inertial force generated by the inertial mass, a negative stiffness mechanism is introduced. The force generated by the negative stiffness is in phase with the inertial mass, further increasing the equivalent mass of the coupling system. Compared with the general positive stiffness mechanism, a smaller inertial mass can be used to generate a larger inertial force.

Claims

1. A line spectrum vibration elimination device based on dynamic anti-resonance, characterized in that: It includes a main mass block, a positive stiffness spring, a base, an inertial element and a self-adjusting element. The upper and lower ends of the positive stiffness spring are respectively fixed between the main mass block and the base. The inertial element includes a lever and an inertial mass block. The lever is movably clamped and positioned by a flexible hinge mechanism fixed on the main mass block and the base. The inertial mass block is fixed to one end of the lever and connected to the base through a negative stiffness mechanism. The self-adjusting element is fixed on the base, and two fulcrums are provided on the top end to contact the lever respectively. The horizontal combined force acting on the lever drives the lever to move horizontally for self-adjustment.

2. A line spectrum vibration elimination device based on dynamic anti-resonance according to claim 1, characterized in that: A linear bearing is laid on the base, and the self-adjusting element and the negative stiffness mechanism move along the linear bearing via a slider respectively.

3. The line spectrum vibration elimination device based on dynamic anti-resonance according to claim 2, characterized in that: The self-adjusting element is an elastic fin-type actuator, which includes a V-shaped block, an inertia block, a leaf spring and a connecting block. The left and right ends of the V-shaped block are fixed upward to one end of the inertia block, and the other end of the inertia block is connected to one end of the connecting block through a leaf spring. The leaf springs are multiple and symmetrically connected up and down. The other end of the connecting block is connected to the slider. Rubber pads are embedded in the left and right ends of the V-shaped block respectively.

4. A line spectrum vibration elimination device based on dynamic anti-resonance according to claim 2 or 3, characterized in that: The flexible hinge mechanism includes an intermediate ball bearing and an intermediate hinge support, and ball bearings on both sides and hinge supports on both sides. The hinge supports on both sides are concave seat structures. The intermediate hinge support is arranged corresponding to the inner grooves of the hinge supports on both sides and is connected by pre-stressed connectors. The vertical height of the intermediate ball bearing is greater than the vertical height of the ball bearings on both sides. The lever is inserted into the gap between the intermediate ball bearing and the ball bearings on both sides to clamp and position them.

5. The line spectrum vibration elimination device based on dynamic anti-resonance according to claim 4, characterized in that: The pre-stressed connecting part includes a pre-stressed bolt, a pre-stressed nut and a pre-stressed coil spring. The middle hinge support and the hinge supports on both sides are symmetrically provided with an upper fixing block and a lower fixing block. The pre-stressed bolt passes through the lower fixing block and the upper fixing block in sequence. The pre-stressed coil spring is sleeved on the pre-stressed bolt. The pre-stressed nut is threadedly connected to the pre-stressed bolt to compress the pre-stressed coil spring.

6. The line spectrum vibration elimination device based on dynamic anti-resonance according to claim 5, characterized in that: The two sides of the hinge supports on both sides are connected to the connecting base provided below through lateral leaf springs, and the intersection of the extension of the lateral leaf springs coincides with the center position formed by the middle ball bearing and the ball bearings on both sides.

7. The line spectrum vibration elimination device based on dynamic anti-resonance according to claim 6, characterized in that: The outer end of the linear bearing is provided with a limit block.

8. A line spectrum vibration elimination device based on dynamic anti-resonance according to claim 6 or 7, characterized in that: The positive stiffness spring is a semicircular corrugated periodic beam structure and is symmetrically arranged between the main mass block and the base.

9. The line spectrum vibration elimination device based on dynamic anti-resonance according to claim 8, characterized in that: The negative stiffness mechanism comprises a negative stiffness bracket and pairs of springs or disc springs or electromagnets or bistable beams symmetrically arranged on the negative stiffness bracket, and the two ends of the inertia block are respectively connected to the pairs of springs or disc springs or electromagnets or bistable beams.

10. A method for using the line spectrum vibration elimination device based on dynamic anti-resonance according to claim 7 or 9, characterized in that: The invention includes the following contents: when the excitation frequency of the elastic fin-type actuator changes, the lever is subjected to unbalanced force and rotates at a small angle around the instantaneous rotation center. The rubber pads at the left and right ends of the V-shaped block deform differently, resulting in unequal forces generated by the vibration of the rubber pads on both sides. Then, the horizontal resultant force acting on the lever is not zero, and the lever will move in the direction of the resultant force until the resultant force on the lever is zero. Then the lever stops moving and the lever ratio remains unchanged. At this time, the instantaneous center of the lever coincides with the center of the flexible hinge mechanism fixed on the main mass block, and the vibration isolation frequency matches the excitation frequency, thereby realizing automatic adjustment of the vibration isolation frequency. At the same time, the lever enables the inertial mass to achieve inertia amplification, and enhances the vibration isolation effect through the negative stiffness mechanism.

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