Bidirectional frequency-avoiding vibration absorber assembly and bidirectional inherent frequency determination method

Abstract

The bidirectional frequency-avoiding vibration absorber assembly comprises a mass block and a damping unit, the damping unit is installed and connected to the inner side of the mass block, the damping unit comprises an outer sleeve and an installation support, the outer sleeve is installed on the outer side of the installation support in a sleeving mode, and the installation support is provided with a rectangular section; the installation support comprises two symmetrically-arranged long-edge end faces and two symmetrically-arranged short-edge end faces, second rubber damping bodies are connected between the long-edge end faces and the inner wall of the outer sleeve, and first rubber damping bodies are connected between the short-edge end faces and the inner wall of the outer sleeve. Different inherent frequencies are achieved on one vibration absorber in two directions forming a 90-degree angle, a vibration absorber assembly product capable of avoiding the frequencies in the two directions is obtained, the use amount of automobile parts can be effectively reduced through application of the vibration absorber assembly, and the light weight of the whole automobile and the reduction of the automobile cost are facilitated.

Description

Technical Field

[0001] This invention relates to the field of automotive parts technology, and more specifically, to a bidirectional frequency-avoiding vibration absorber assembly and a method for determining bidirectional natural frequencies. Background Technology

[0002] Traditional automotive chassis vibration absorbers use cylindrical mounting brackets and outer sleeves for their damping units, and the damping rubber is also a solid cylindrical structure. This rotating structure results in isotropic characteristics in the diameter direction, meaning that a single component can only exhibit one natural frequency characteristic. Therefore, in applications requiring different frequencies in two directions, it is necessary to manufacture and install two vibration absorbers with different frequencies on the vehicle body. This approach increases the number of parts and costs, and the increased number of components also reduces installation reliability and increases the overall vehicle weight, which is detrimental to vehicle lightweighting. Therefore, designing and manufacturing a vibration absorber product that can have different natural frequencies in two directions that are 90° apart is extremely urgent. Summary of the Invention

[0003] The purpose of this invention is to address the needs of the prior art and provide a bidirectional frequency-avoiding vibration absorber assembly and a method for determining bidirectional natural frequencies. This invention modifies the mounting bracket into a rectangular cross-section structure and designs the damping unit as a hollow structure in which a rectangular rubber damping body is connected only between the long and short sides of the rectangular cross-section of the mounting bracket and the outer sleeve. By adjusting the width, height, and thickness of the rubber damping body, different natural frequencies can be achieved in two directions that are 90° apart on a single vibration absorber.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A bidirectional frequency-avoiding vibration absorber assembly includes a mass block and a damping unit. The damping unit is installed and connected to the inner side of the mass block. The damping unit includes an outer sleeve and a mounting bracket. The outer sleeve is fitted onto the outer side of the mounting bracket. The mounting bracket has a rectangular cross-section and includes two symmetrically arranged long side end faces and two symmetrically arranged short side end faces. A second rubber damping body is connected between the long side end faces and the inner wall of the outer sleeve, and a first rubber damping body is connected between the short side end faces and the inner wall of the outer sleeve.

[0006] Furthermore, the mass block has a first through hole and a second through hole on its inner side, the first through hole and the second through hole are connected vertically, the diameter of the first through hole is larger than that of the second through hole, and the damping unit is interference-fitted to the second through hole through an outer sleeve.

[0007] Furthermore, a step is formed at the connection between the first through hole and the second through hole, and one end of the outer sleeve forms a flange on the outer diameter side, which is installed in contact with the step.

[0008] Furthermore, the mounting bracket is centrally mounted on the inner side of the outer casing, and the two first rubber damping bodies are of the same size, as are the two second rubber damping bodies.

[0009] Furthermore, a hollow cavity is formed between the first and second rubber damping bodies at adjacent positions.

[0010] A method for determining a bidirectional natural frequency, applied in a bidirectional frequency-avoiding vibration absorber assembly, includes the following steps:

[0011] S1. The theoretical dynamic stiffness k of the rubber damper is calculated as follows:

[0012] Theoretical dynamic stiffness k of rubber damper

[0013]

[0014] In the formula, the static elastic modulus of the rubber damper is set to G, the width of the rubber damper is set to b, the height of the rubber damper is set to h, and the thickness of the rubber damper is set to t.

[0015] S2. Substituting the theoretical dynamic stiffness k of the rubber damper into the calculation, the theoretical vibration absorber frequency f is obtained:

[0016] Theoretical vibration absorber frequency f

[0017]

[0018] The mass of the mass block is set to m in the formula.

[0019] In summary, the present invention has the following beneficial effects:

[0020] This invention modifies the mounting bracket into a rectangular cross-section structure and designs the damping unit as a hollow structure where a rectangular rubber damping body is connected only between the long and short sides of the rectangular cross-section of the mounting bracket and the outer sleeve. By adjusting the width, height, and thickness of the rubber damping body, different natural frequencies can be achieved in two directions at 90° to each other on a single vibration absorber. This invention yields a vibration absorber assembly that can bidirectionally avoid frequencies. The application of this invention can effectively reduce the amount of automotive parts used, which is beneficial for achieving vehicle lightweighting and reducing vehicle costs. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural diagram of a bidirectional frequency-avoiding vibration absorber assembly according to this embodiment;

[0022] Figure 2This is a front view of the end of a bidirectional frequency-avoiding vibration absorber assembly according to this embodiment;

[0023] Figure 3 for Figure 2 Sectional view along direction AA.

[0024] Figure label:

[0025] Mass block 1, first through hole 11, second through hole 12, step 13, damping unit 2, outer sleeve 21, flange 211, mounting bracket 22, long side end face 221, short side end face 222, first rubber damping body 23, second rubber damping body 24, hollow cavity 25. Detailed Implementation

[0026] 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 embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] During vehicle motion, each sub-component has a natural frequency or vibration modal frequency when subjected to vibration excitation. When these sub-component systems are integrated, the natural frequencies or vibration modal frequencies of each sub-component cannot be decoupled (frequency avoidance). When the natural frequencies or vibration modal frequencies of the sub-components are close, it will cause resonance in the main system, resulting in excessive vibration amplitude. The dynamic vibration absorber is a spring-mass-damping auxiliary system attached to the main system (the object being damped). Its core idea is "using motion to control motion." The purpose of the dynamic vibration absorber is to suppress the vibration of the main system at a specific frequency (usually near its resonance frequency). When the main system resonates, the vibration absorber generates an inertial force with a direction opposite to and similar amplitude to the excitation force of the main system, thereby counteracting the excitation. The force significantly reduces the vibration of the main system. At this point, the vibration energy is transferred to the shock absorber mass block, causing it to vibrate significantly and dissipate through damping. Traditional automotive chassis shock absorbers have cylindrical mounting brackets and outer sleeves for their damping units, and the damping rubber is also a cylindrical solid structure. This rotating structure causes the parts to exhibit isotropic characteristics in the diameter direction, meaning that a part can only exhibit one inherent frequency characteristic. In application scenarios where two different frequencies in two directions are required, it is necessary to manufacture and install two shock absorbers with different frequencies on the vehicle body. This approach increases the number of parts and raises costs. Furthermore, the increased number of parts reduces installation reliability and increases the overall vehicle weight, which is not conducive to vehicle lightweighting.

[0028] For this reason, such as Figures 1 to 3As shown, this embodiment discloses a bidirectional frequency-avoiding vibration absorber assembly, including a mass block 1 and a damping unit 2. The damping unit 2 is installed and connected to the inner side of the mass block 1. The damping unit 2 includes an outer sleeve 21 and a mounting bracket 22. The outer sleeve 21 is fitted onto the outer side of the mounting bracket 22. The mounting bracket 22 has a rectangular cross-section, therefore the mounting bracket 22 includes two symmetrically arranged long side end faces 221 and two symmetrically arranged short side end faces 222. A second rubber damping body 24 is connected between the long side end face 221 and the inner wall of the outer sleeve 21, and a first rubber damping body 23 is connected between the short side end face 222 and the inner wall of the outer sleeve 21. Since the mounting bracket 22 is centrally installed inside the outer sleeve 21, the two first rubber damping bodies 23 formed are of the same size, and the two second rubber damping bodies 24 formed are... The first rubber damping bodies 23 and the second rubber damping bodies 24, which are of the same size, are distributed at 90° to each other. Since the mounting bracket 22 has a rectangular cross section, the sizes of the first rubber damping bodies 23 and the second rubber damping bodies 24 are different. The present invention also designs a hollow cavity 25 between the first rubber damping bodies 23 and the second rubber damping bodies 24 at adjacent positions, so that the first rubber damping bodies 23 and the second rubber damping bodies 24 at adjacent positions do not affect each other. This can obtain two different natural frequency effects in the 90° direction. In the present invention, the rubber damping bodies are connected to the outer wall of the mounting bracket 22 and the inner wall of the outer sleeve 21 by means of adhesive bridging and vulcanization under heat and pressure. After the rubber damping bodies are formed, the three are combined into a complete damping unit 2.

[0029] like Figure 1 As shown, the mass block 1 of the present invention is cylindrical, and a first through hole 11 and a second through hole 12 are provided on the inner side of the mass block 1. The first through hole 11 and the second through hole 12 are connected vertically. The diameter of the first through hole 11 is larger than that of the second through hole 12, so that the damping unit 2 can be installed from the position of the first through hole 11. The outer sleeve 21 is also cylindrical, and the damping unit 2 is interference-fitted to the second through hole 12 through the outer sleeve 21. Figure 3 As shown, the present invention forms a step 13 at the connection of the first through hole 11 and the second through hole 12. One end of the outer sleeve 21 forms a flange 211 on the outer diameter side. After the damping unit 2 is installed, its flange 211 contacts the step 13 for installation. The step 13 defines the installation position.

[0030] In this invention, the width, height and thickness of the rubber damper are adjusted to achieve two different natural frequencies in two directions that are 90° apart.

[0031] A bidirectional natural frequency determination method, applied in a bidirectional frequency-avoiding vibration absorber assembly, is used for the theoretical design of two natural frequency values, and includes the following steps:

[0032] S1. The theoretical dynamic stiffness k of the rubber damper is calculated as follows:

[0033] Theoretical dynamic stiffness k of rubber damper

[0034]

[0035] In the formula, the static elastic modulus of the rubber damper is set as G, which is determined according to the material of the rubber damper. In the actual product, the value of G for the rubber damper is G = 1.68 MPa. The width of the rubber damper is set as b (in mm), the height of the rubber damper is set as h (in mm), and the thickness of the rubber damper is set as t (in mm). The dimensions of the rubber damper refer to the main body dimensions of the first rubber damper 23 and the second rubber damper 24 (see...). Figure 2 and Figure 3 (marks in the text)

[0036] S2. Substituting the theoretical dynamic stiffness k of the rubber damper into the calculation, the theoretical vibration absorber frequency f is obtained:

[0037] Theoretical vibration absorber frequency f

[0038]

[0039] In the formula, the mass of mass block 1 is set to m (in g), and the average mass of mass block 1 in the actual vibration absorber product is m = 307 g.

[0040] Example:

[0041] To manufacture a bidirectional frequency-avoiding vibration absorber assembly, two different natural frequencies are formed in the direction of the first rubber damper 23 and the direction of the second rubber damper 24, which are 90° apart.

[0042] First rubber damper body, direction 23:

[0043] G=1.68MPa, b=23mm, h=30mm, t=8mm, m=307g

[0044]

[0045]

[0046] Second rubber damper body in 24 directions:

[0047] G=1.68MPa, b=18mm, h=30mm, t=14mm, m=307g

[0048]

[0049]

[0050] The frequency of the above-mentioned vibration absorber is a theoretically calculated value (used as the basis for preliminary theoretical design). It has been verified based on actual measured data of the product. The deviation is within ±1%, and the difference between theoretical design and actual results is small. It can be used as the basis for design.

[0051] The vibration absorber assembly of the present invention forms two different natural frequencies in the direction of the first rubber damper 23 and the direction of the second rubber damper 24, and the two natural frequencies are set at 90° to each other. By concentrating the two frequencies in one assembly component, the bidirectional frequency avoidance function requirement of the product is achieved. The application of the present invention can effectively reduce the amount of automotive parts used (it can replace the original installation method of two vibration absorber components), which is conducive to achieving vehicle lightweighting and reducing vehicle costs.

[0052] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A bidirectional frequency-avoiding vibration absorber assembly, characterized in that, The device includes a mass block (1) and a damping unit (2). The damping unit (2) is installed and connected to the inside of the mass block (1). The damping unit (2) includes an outer sleeve (21) and a mounting bracket (22). The outer sleeve (21) is fitted onto the outside of the mounting bracket (22). The mounting bracket (22) has a rectangular cross section. The mounting bracket (22) includes two symmetrically arranged long side end faces (221) and two symmetrically arranged short side end faces (222). A second rubber damping body (24) is connected between the long side end face (221) and the inner wall of the outer sleeve (21). A first rubber damping body (23) is connected between the short side end face (222) and the inner wall of the outer sleeve (21).

2. The bidirectional frequency-avoiding vibration absorber assembly according to claim 1, characterized in that, The mass block (1) has a first through hole (11) and a second through hole (12) on its inner side. The first through hole (11) and the second through hole (12) are connected vertically. The diameter of the first through hole (11) is larger than that of the second through hole (12). The damping unit (2) is interference-fitted to the second through hole (12) through the outer sleeve (21).

3. The bidirectional frequency-avoiding vibration absorber assembly according to claim 2, characterized in that, A step (13) is formed at the connection between the first through hole (11) and the second through hole (12). One end of the outer sleeve (21) forms a flange (211) on the outer diameter side. The flange (211) is installed in contact with the step (13).

4. The bidirectional frequency-avoiding vibration absorber assembly according to claim 1, characterized in that, The mounting bracket (22) is centrally mounted inside the outer sleeve (21), and the two first rubber damping bodies (23) are the same size, and the two second rubber damping bodies (24) are the same size.

5. The bidirectional frequency-avoiding vibration absorber assembly according to claim 1, characterized in that, A hollow cavity (25) is formed between the first rubber damper (23) and the second rubber damper (24) at adjacent positions.

6. A method for determining a bidirectional natural frequency, applied in a bidirectional frequency-avoiding vibration absorber assembly as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. The theoretical dynamic stiffness k of the rubber damper is calculated as follows: Theoretical dynamic stiffness k of rubber damper In the formula, the static elastic modulus of the rubber damper is set to G, the width of the rubber damper is set to b, the height of the rubber damper is set to h, and the thickness of the rubber damper is set to t. S2. Substituting the theoretical dynamic stiffness k of the rubber damper into the calculation, the theoretical vibration absorber frequency f is obtained: Theoretical vibration absorber frequency f In the formula, the mass of the mass block (1) is set to m.

Images