Rubber bushing dynamic stiffness testing device and method

Abstract

This invention relates to the field of automotive manufacturing technology, and more particularly to a device and method for testing the dynamic stiffness of rubber bushings. The device includes a fixed sleeve, a fixed shaft, a fixed bracket, a vibration sensor, and a test platform. The fixed sleeve is adapted to be fitted onto the outer ring of the rubber bushing. The fixed shaft has a first connecting section, an mounting section, and a second connecting section connected in sequence. The surface of the mounting section is roughened and rigidly connected to the bushing. The fixed bracket is connected to the fixed shaft and includes a detection rod and a U-shaped portion. The U-shaped portion includes a crossbar and two parallel support rods. The crossbar connects between the two support rods, and the detection rod connects between the two support rods. The vibration sensor is located on the detection rod. By rigidly connecting the roughened surface on the mounting section to the bushing, the roughened surface can reduce the probability of axial rotation of the rubber bushing during testing; furthermore, the rigid connection between the roughened surface and the bushing can reduce the influence of the connection method on the accuracy of the dynamic stiffness test.

Description

Technical Field

[0001] This invention relates to the field of automobile manufacturing technology, and in particular to a device and method for testing the dynamic stiffness of rubber bushings. Background Technology

[0002] The noise, vibration, and harshness (NVH) characteristics of a vehicle affect its lifespan and comfort, and these effects are directly felt by the user. NVH is one of the primary concerns in the automotive manufacturing industry. In automotive suspension design, bushings are widely used to connect two moving parts. This not only reduces wear between parts but also mitigates vibration, reduces noise, and improves vehicle comfort.

[0003] A bushing consisting of an intermediate rubber body and a metal sleeve is called a rubber bushing. Due to the nonlinear properties of rubber, the dynamic stiffness of rubber bushings exhibits significant nonlinear characteristics. Since the dynamic stiffness of rubber bushings plays a crucial role in the noise level of vehicles, it is necessary to test its dynamic stiffness during the initial design phase of the rubber bushing.

[0004] However, in existing technologies, the dynamic stiffness measured by rubber bushing dynamic stiffness testing devices and methods differs significantly from the value obtained in actual applications of the bushing. Summary of the Invention

[0005] This invention provides a device and method for testing the dynamic stiffness of rubber bushings, which solves the defects of existing devices and methods for testing the dynamic stiffness of rubber bushings, such as large discrepancies between the test results and actual values ​​and low accuracy, thereby improving the accuracy of the device and method for testing the dynamic stiffness of rubber bushings.

[0006] This invention provides a device for testing the dynamic stiffness of rubber bushings, comprising:

[0007] A retaining sleeve, the retaining sleeve being adapted to be fitted onto the outer ring of the rubber bushing;

[0008] A fixed shaft has a first connecting section, a mounting section, and a second connecting section connected in sequence. The surface of the mounting section is rough. The fixed shaft passes through the inner ring of the rubber bushing, and the rough surface is rigidly connected to the bushing.

[0009] A fixed bracket is connected to a fixed shaft. The fixed bracket includes a detection rod and a U-shaped portion. The U-shaped portion includes a crossbar and two parallel support rods. The crossbar is connected between the two support rods, and the two support rods are located on one side of the crossbar. One end of the detection rod is connected to the crossbar, and the detection rod is located on the other side of the crossbar and connected between the two support rods. A first connecting segment is connected to one of the two support rods, and a second connecting segment is connected to the other of the two support rods.

[0010] A vibration sensor is disposed on the detection rod;

[0011] The test stand is connected to the fixed sleeve and the fixed bracket.

[0012] According to the present invention, a dynamic stiffness testing device for a rubber bushing is provided, wherein the fixing sleeve is an integrally molded part and includes a fastening part and a connecting part. The fastening part is wrapped around the outer periphery of the rubber bushing, the connecting part is connected to the outer peripheral wall of the fastening part, and the connecting part is connected to the testing platform.

[0013] The thickness of the fastening part in the radial direction of the rubber bushing is L1.

[0014] The thickness of the connecting part in the circumferential direction of the rubber bushing is L2, where L2 is greater than L1;

[0015] The thickness of the fastening part in the axial direction of the rubber bushing is W1.

[0016] The thickness of the connecting part in the axial direction of the rubber bushing is W2, where W2 is greater than or equal to W1.

[0017] According to the present invention, a rubber bushing dynamic stiffness testing device is provided on the connecting part, wherein the multiple mounting holes are spaced apart along the axial direction of the rubber bushing.

[0018] According to the present invention, a rubber bushing dynamic stiffness testing device is provided, wherein the fixing sleeve has a notch, and the notch penetrates the fastening part in the axial direction of the fastening part.

[0019] According to the present invention, the first connecting section and the second connecting section are both plate-shaped structures, and each of the support rods is provided with a mounting groove, wherein the first connecting section and the second connecting section are embedded in the corresponding mounting groove.

[0020] According to the present invention, a dynamic stiffness testing device for rubber bushings is provided, wherein the cross-section of the mounting section is circular.

[0021] According to the present invention, a rubber bushing dynamic stiffness testing device is provided, wherein a limiting part is provided on the peripheral wall of the mounting section, and the limiting part is used to axially position the rubber bushing.

[0022] According to the present invention, a dynamic stiffness testing device for rubber bushings is provided, wherein the cross-section of the mounting section is elliptical.

[0023] According to the present invention, a rubber bushing dynamic stiffness testing device further includes a filler sleeve, which is sleeved on the mounting section and located between the mounting section and the inner ring of the rubber bushing.

[0024] The present invention also provides a method for testing the dynamic stiffness of a rubber bushing, wherein the method is applied to the rubber bushing dynamic stiffness testing device described above, and includes:

[0025] S1, acquire the passive side vibration signal of the rubber bushing to be tested;

[0026] S2, Input signal is input to the fixed bracket, the input signal is a vibration white noise signal;

[0027] S3, acquire the response vibration signal detected by the vibration sensor;

[0028] S4, compare the similarity between the response vibration signal and the passive side vibration signal;

[0029] S5. If the similarity is less than 95%, divide the passive side signal by the response vibration signal to obtain a ratio, multiply the ratio by the input signal to obtain a new input signal, and repeat steps S2-S5.

[0030] If the similarity is greater than or equal to 95%, then proceed to step S6;

[0031] S6, input the input signal into the fixed sleeve and record the response signal detected by the vibration sensor;

[0032] S7. Based on the response signal, plot the dynamic stiffness curve of the rubber bushing.

[0033] The rubber bushing dynamic stiffness testing device provided by this invention features a mounting section with a rough surface, which is rigidly connected to the bushing. On one hand, the rough surface increases friction, reducing the probability of axial rotation of the rubber bushing during testing; on the other hand, the rigid connection between the rough surface and the bushing reduces the impact of the connection method on the accuracy of the dynamic stiffness test. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0035] Figure 1 This is one of the structural schematic diagrams of a rubber bushing mounted on a rubber bushing dynamic stiffness testing device;

[0036] Figure 2 This is the second schematic diagram of the structure of the rubber bushing installed on the rubber bushing dynamic stiffness testing device;

[0037] Figure 3 yes Figure 1 Bottom view;

[0038] Figure 4 This is a schematic diagram of the fixed shaft provided by the present invention;

[0039] Figure 5 yes Figure 4 The top view of the fixed axis shown;

[0040] Figure 6 This is a cross-sectional view of the fixing sleeve provided by the present invention.

[0041] Figure label:

[0042] 100. Rubber bushing;

[0043] 200. Fixing sleeve; 210. Fastening part; 220. Connecting part; 221. Mounting hole;

[0044] 300, Fixed shaft; 310, First connecting section; 320, Mounting section; 330, Second connecting section; 340, Connecting hole;

[0045] 400. Fixed bracket; 410. Detection rod; 420. U-shaped part; 421. Crossbar; 422. Support rod; 4221. Mounting groove;

[0046] 500. Vibration sensor. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this 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 this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0048] The following is combined with Figures 1-6 This invention describes a rubber bushing dynamic stiffness testing device. The rubber bushing consists of an intermediate rubber body and a metal sleeve. Due to the inherent nonlinear properties of rubber, the dynamic stiffness of the rubber bushing exhibits significant nonlinear characteristics. The dynamic stiffness of the rubber bushing plays a crucial role in the noise level of a vehicle; therefore, its dynamic stiffness needs to be tested during the initial design phase of the rubber bushing.

[0049] See Figure 1 As shown, the rubber bushing dynamic stiffness testing device according to an embodiment of the present invention includes: a fixed sleeve 200, a fixed shaft 300, a fixed bracket 400, a vibration sensor 500, and a testing table.

[0050] Specifically, the fixing sleeve 200 is adapted to be fitted onto the outer ring of the rubber bushing 100. The fixing shaft 300 has a first connecting section 310, a mounting section 320, and a second connecting section 330 connected in sequence, with the surface of the mounting section 320 being rough. The fixing shaft 300 passes through the inner ring of the rubber bushing 100, and the rubber bushing 100 is mounted on the mounting section 320, with the rough surface on the mounting section 320 rigidly connected to the bushing. On the one hand, the rough surface can increase friction and reduce the probability of axial rotation of the rubber bushing 100 during testing; on the other hand, the rigid connection between the rough surface and the rubber bushing 100 can reduce the impact of the connection method on the accuracy of the dynamic stiffness test.

[0051] The fixed bracket 400 is connected to the fixed shaft 300. The fixed bracket 400 includes a detection rod 410 and a U-shaped portion 420. The U-shaped portion 420 includes a crossbar 421 and two parallel support rods 422. The crossbar 421 is connected between the two support rods 422. One end of the detection rod 410 is connected to the crossbar 421, and the other end of the detection rod 410 is adapted to be connected to the test bench. The two support rods 422 are located on one side of the crossbar 421, and the detection rod 410 is located on the other side of the crossbar 421, and the detection rod 410 is connected between the two support rods 422. A first connecting section 310 is connected to one of the two support rods 422, and a second connecting section 330 is connected to the other of the two support rods 422. For example, in Figure 1 In the example, the support rod 422 is located above the crossbar 421, the detection rod 410 is located below the crossbar 421, and the connection between the crossbar 421 and the detection rod 410 is located between the two support rods 422.

[0052] See Figure 1 and Figure 3As shown, the vibration sensor 500 is mounted on the detection rod 410, meaning it is located between the two support rods 422. This improves the accuracy of the vibration sensor 500 in detecting the vibration signal of the inner ring of the rubber bushing 100. The test bench is connected to the fixing sleeve 200 and the fixing bracket 400. The outer ring of the rubber bushing 100 is fixed by the fixing sleeve 200, and the inner ring of the rubber bushing 100 is fixed by the fixing shaft 300 and the fixing bracket 400. Thus, the signal required for testing can be applied to the outer ring of the rubber bushing 100 from the fixing sleeve 200, and the vibration signal of the inner ring of the rubber bushing 100 can be detected by the vibration sensor 500 on the detection rod 410.

[0053] According to an embodiment of the present invention, the rubber bushing dynamic stiffness testing device includes a mounting section 320 with a rough surface, and the rough surface on the mounting section 320 is rigidly connected to the bushing. On the one hand, the rough surface can increase the frictional force and reduce the probability of the rubber bushing 100 rotating axially during the test; on the other hand, the rigid connection between the rough surface and the rubber bushing 100 can reduce the influence of the connection method on the accuracy of the dynamic stiffness test.

[0054] See Figure 1 and Figure 2 As shown, according to some embodiments of the present invention, the fixing sleeve 200 is an integrally molded part, which can enhance the strength of the fixing sleeve 200, improve its ability to withstand dynamic loads, and extend its service life. The fixing sleeve 200 includes a fastening part 210 and a connecting part 220. The fastening part 210 has an annular structure, and the rubber bushing 100 is embedded in the inner ring of the fastening part 210. The fastening part 210 wraps around the outer periphery of the rubber bushing 100 to fix the rubber bushing 100. The connecting part 220 is connected to the outer peripheral wall of the fastening part 210, and the connecting part 220 protrudes from the outer peripheral wall of the fastening part 210. The connecting part 220 is adapted to be connected to a test bench.

[0055] In some embodiments, the connecting part 220 is provided with a plurality of mounting holes 221, and the connecting part 220 can be fixedly connected to the test bench through the mounting holes 221 and threaded connectors. There can be a plurality of mounting holes 221, which are spaced apart along the axial direction of the rubber bushing 100 to improve the stability of the connection and prevent the fixed sleeve from moving relative to the test bench under the influence of vibration during the test.

[0056] The thickness of the fastening part 210 in the radial direction of the rubber bushing 100 is L1, and the thickness of the connecting part 220 in the circumferential direction of the rubber bushing 100 is L2, where L2 is greater than L1. The thickness of the fastening part 210 in the axial direction of the rubber bushing 100 is W1, and the thickness of the connecting part 220 in the axial direction of the rubber bushing 100 is W2, where W2 is greater than or equal to W1. This improves the strength of the connecting part and makes the connection between the connecting part and the test bench more stable. It is understood that W1 can be greater than L1. For example, in Figure 1 and Figure 6 In the example, W1 is greater than L1, in which case the axis of the mounting hole 221 is perpendicular to the axis of the rubber bushing 100. Of course, W1 can be less than L1, in which case the axis of the mounting hole 221 is parallel to the axis of the rubber bushing 100.

[0057] See Figure 6 As shown, according to some embodiments of the present invention, the fixing sleeve 200 has a notch, and the notch penetrates the fastening portion 210 along its axial direction. The notch on the fixing sleeve 200 extends along the axial direction of the fastening portion 210 and penetrates both ends of the fastening portion 210 and the connecting portion 220, respectively, dividing the connecting portion 220 into two parts. Thus, when the test bench is connected to the connecting portion 220 using threaded components, such as bolts and nuts, the degree of notch opening can be controlled by adjusting the threaded components, thereby changing the size of the inner ring of the fastening portion 210 to adjust the clamping degree of the rubber bushing 100, improving the fit between the test conditions and the actual working conditions of the rubber bushing 100, thereby improving the accuracy of the test results. Furthermore, the fixing sleeve 200 can also be used to fix the outer ring of rubber bushings 100 of different sizes.

[0058] See Figure 4 and Figure 5 As shown, according to some embodiments of the present invention, both the first connecting segment 310 and the second connecting segment 330 are plate-shaped structures, and each support rod 422 is provided with a mounting groove 4221. The first connecting segment 310 and the second connecting segment 330 are embedded in the corresponding mounting groove 4221. In some embodiments, both the first connecting segment 310 and the second connecting segment 330 may be provided with connecting holes 340, and corresponding positions on the support rod 422 are also provided with connecting holes 340. The first connecting segment 310 and the second connecting segment 330 can be fixedly connected to the support rod 422 by threaded parts.

[0059] According to some embodiments of the present invention, a limiting portion is provided on the peripheral wall of the mounting section 320, the limiting portion abutting against the end of the rubber bushing 100, and the limiting portion is used for axial positioning of the rubber bushing 100. The limiting portion can be integrally formed with the mounting section 320, for example, the limiting portion can be a shoulder machined on the mounting section 320; of course, the limiting portion can also be a component detachably connected to the mounting section 320.

[0060] See Figure 4 and Figure 5 As shown, according to some embodiments of the present invention, the cross-section of the mounting section 320 is circular. In some embodiments, the diameter of the cross-section of the mounting section 320 gradually increases along the axial direction of the rubber bushing 100, that is, the longitudinal section of the mounting section 320 is an isosceles trapezoid. In this case, the limiting part is the side of the mounting section 320 where the diameter of the cross-section is larger than the inner diameter of the rubber bushing 100. On the side of the mounting section 320 where the cross-sectional diameter is smaller, the position of the rubber bushing 100 can be restricted by an expansion sleeve. Furthermore, the position of the rubber bushing 100 on the mounting section 320 can be adjusted by adjusting the expansion sleeve, thereby changing the fit between the rubber bushing 100 and the mounting section 320. For example, adjusting the expansion sleeve to make the rubber bushing 100 and the mounting section 320 have an interference fit can make the test environment closer to the actual working conditions of the rubber bushing 100, thereby improving the accuracy of the dynamic stiffness test results.

[0061] According to some embodiments of the present invention, the cross-section of the mounting section 320 is elliptical to accommodate rubber bushings 100 with different inner ring shapes. In some embodiments, the dynamic stiffness testing device for the rubber bushing 100 further includes a filler sleeve, which is fitted onto the mounting section 320 and located between the mounting section 320 and the inner ring of the rubber bushing 100.

[0062] Depending on the shape and structure of the components to be connected by the rubber bushing, the inner ring of the rubber bushing can be other shapes, such as elliptical or irregular shapes. When the cross-section of the mounting section 320 is elliptical, it can be used in conjunction with a filler sleeve to fill the gap between the mounting section 320 and the inner ring of the rubber bushing 100, improving the accuracy of the vibration sensor 500. Furthermore, by replacing the filler sleeve, rubber bushings 100 with different inner ring shapes can be fixed, avoiding the need to redesign the fixed shaft 300, thus saving costs. It should be noted that the filler sleeve is a rigid component.

[0063] According to an embodiment of the present invention, a method for testing the dynamic stiffness of a rubber bushing is applied to the rubber bushing dynamic stiffness testing device described above, and includes:

[0064] S1. Acquire the passive side vibration signal of the rubber bushing to be tested. Install the rubber bushing to be tested on the vehicle and measure the passive side vibration signal of the rubber bushing while the vehicle is in motion. For example, when vibration is input from the outer ring of the rubber bushing, the vibration is transmitted to the inner side of the rubber bushing, and the vibration signal measured on the inner ring of the rubber bushing is the passive side vibration signal.

[0065] S2, input an input signal to the fixed bracket 400. The input signal is a vibration white noise signal, which makes the amplitude and frequency of the vibration experienced by the rubber bushing during the test random, just as the vibration experienced by the vehicle during driving is also random. Using a vibration white noise signal for testing can improve the fit between the test conditions and actual working conditions.

[0066] S3, acquire the response vibration signal detected by the vibration sensor 500.

[0067] S4, compare the similarity between the response vibration signal and the passive side vibration signal.

[0068] S5. If the similarity is less than 95%, divide the passive side signal by the response vibration signal to obtain the ratio, multiply the ratio by the input signal to obtain the new input signal, and repeat steps S2-S5; if the similarity is greater than or equal to 95%, then execute step S6.

[0069] S6, input the input signal into the fixed sleeve 200 and record the response signal detected by the vibration sensor 500.

[0070] S7. Based on the response signal, plot the dynamic stiffness curve of the rubber bushing.

[0071] By correcting the input signals during the testing process through steps S1-S5, the influence of the structure of the rubber bushing dynamic stiffness testing device on the test results can be reduced, thereby improving the accuracy of the test results.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for testing the dynamic stiffness of a rubber bushing, characterized in that, include: A retaining sleeve, the retaining sleeve being adapted to be fitted onto the outer ring of a rubber bushing; A fixed shaft has a first connecting section, a mounting section, and a second connecting section connected in sequence. The surface of the mounting section is rough. The fixed shaft passes through the inner ring of the rubber bushing, and the rough surface is rigidly connected to the bushing. The cross-section of the mounting section is elliptical. A fixed bracket is connected to a fixed shaft. The fixed bracket includes a detection rod and a U-shaped portion. The U-shaped portion includes a crossbar and two parallel support rods. The crossbar is connected between the two support rods, and the two support rods are located on one side of the crossbar. One end of the detection rod is connected to the crossbar, and the detection rod is located on the other side of the crossbar and connected between the two support rods. A first connecting segment is connected to one of the two support rods, and a second connecting segment is connected to the other of the two support rods. A vibration sensor is disposed on the detection rod; A test stand, which is connected to the fixed sleeve and the fixed bracket; It also includes a filler sleeve, which is fitted onto the mounting section and located between the mounting section and the inner ring of the rubber bushing; The device is configured to perform the following steps: S1, acquire the passive side vibration signal of the rubber bushing to be tested; S2, Input signal is input to the fixed bracket, the input signal is a vibration white noise signal; S3, acquire the response vibration signal detected by the vibration sensor; S4, compare the similarity between the response vibration signal and the passive side vibration signal; S5. If the similarity is less than 95%, divide the passive side vibration signal by the response vibration signal to obtain a ratio, multiply the ratio by the input signal to obtain a new input signal, and repeat steps S2-S5. If the similarity is greater than or equal to 95%, then proceed to step S6; S6, input the input signal into the fixed sleeve and record the response signal detected by the vibration sensor; S7. Based on the response signal, plot the dynamic stiffness curve of the rubber bushing.

2. The rubber bushing dynamic stiffness testing device according to claim 1, characterized in that, The fixing sleeve is a one-piece molded part and includes a fastening part and a connecting part. The fastening part wraps around the outer periphery of the rubber bushing, and the connecting part is connected to the outer peripheral wall of the fastening part. The connecting part is connected to the test platform. The thickness of the fastening part in the radial direction of the rubber bushing is L1. The thickness of the connecting part in the circumferential direction of the rubber bushing is L2, where L2 is greater than L1; The thickness of the fastening part in the axial direction of the rubber bushing is W1. The thickness of the connecting part in the axial direction of the rubber bushing is W2, where W2 is greater than or equal to W1.

3. The rubber bushing dynamic stiffness testing device according to claim 2, characterized in that, The connecting part is provided with a plurality of mounting holes, which are spaced apart along the axial direction of the rubber bushing.

4. The rubber bushing dynamic stiffness testing device according to claim 3, characterized in that, The retaining sleeve has a notch, and the notch penetrates the fastening part in the axial direction of the fastening part.

5. The rubber bushing dynamic stiffness testing device according to claim 1, characterized in that, Both the first connecting segment and the second connecting segment are plate-shaped structures, and each of the support rods is provided with a mounting groove. The first connecting segment and the second connecting segment are embedded in the corresponding mounting groove.

6. The rubber bushing dynamic stiffness testing device according to claim 1, characterized in that, The peripheral wall of the installation section is provided with a limiting part, which is used to axially position the rubber bushing.

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