Glass plate damping structure

Abstract

A glass plate damping structure (10) comprises: a glass plate (11) that is attached to a vehicle body (1); and at least one vibration suppression unit (12) that is provided to the glass plate (11). The vibration suppression unit (12) has elasticity at which resonance occurs with the natural frequency and modal mass in the natural mode of vibration of the glass plate (11), and includes an elastic portion (13) that is adhered to the glass plate (11) and a rigid portion (14) that has higher rigidity than the elastic portion (13) and that is stacked on the elastic portion (13).

Description

Vibration damping structure of glass plate

[0001] The present invention relates to a vibration damping structure of a glass plate.

[0002] Patent Document 1 discloses laminated glass intended to improve sound insulation. This laminated glass includes two glass sheets and an intermediate film sandwiched between the two glass sheets. The intermediate film is formed of two types of resin films laminated together.

[0003] Japanese Patent Application Laid-Open No. 2007-91491

[0004] With laminated glass, it is possible to improve sound insulation. However, the manufacturing process of laminated glass is relatively complicated, and the manufacturing cost tends to increase.

[0005] An object of the present invention is to provide a vibration damping structure of a glass plate that can improve sound insulation while suppressing manufacturing costs.

[0006] The vibration damping structure of a glass plate according to one aspect of the present invention includes a glass plate attached to a vehicle body and at least one vibration suppression portion provided on the glass plate. The vibration suppression portion includes an elastic portion adhered to the glass plate and a rigid portion laminated on the elastic portion. The elastic portion has an elasticity that causes resonance at the natural frequency and modal mass in the natural vibration mode of the glass plate. The rigid portion has a higher rigidity than the elastic portion.

[0007] According to the present invention, it is possible to provide a vibration damping structure of a glass plate that can improve sound insulation while suppressing manufacturing costs.

[0008] FIG. 1 is a side view showing an example of a vehicle body to which the vibration damping structure of a glass plate according to an embodiment is applied. FIG. 2 is an enlarged view of the vibration damping structure of a glass plate shown in FIG. 1. FIG. 3 is a cross-sectional view taken along line A-A in FIG. 2. FIG. 4A is a diagram showing the vibration analysis result of a comparative example. FIG. 4B is a diagram showing the vibration analysis result of an example. FIG. 5 is a graph showing the frequency characteristics of the equalized acoustic radiation power in the comparative example and the example. FIG. 6A is a cross-sectional view of the vibration damping structure of a glass plate according to a first modification of the embodiment. FIG. 6B is a cross-sectional view of the vibration damping structure of a glass plate according to a second modification of the embodiment.

[0009] The glass plate vibration damping structure 10 according to the embodiment will be described below with reference to the drawings. In the following description, elements having the same function will be denoted by the same reference numeral, and redundant explanations will be omitted.

[0010] For the sake of explanation, an example of applying the glass plate vibration damping structure 10 to an opera window (rear quarter window) 2 will be used (see Figure 1). However, the windows to which the glass plate vibration damping structure 10 can be applied are not limited to the opera window described above, but can be applied to various windows such as the front, side, rear, and roof windows. Furthermore, the glass plate vibration damping structure 10 can be applied to both stationary and movable glass plates.

[0011] First, the configuration of the glass plate vibration damping structure 10 will be described. Figure 1 is a side view showing an example of a vehicle body to which the glass plate vibration damping structure 10 according to the embodiment is applied. In Figure 1, FR and RR indicate the front and rear of the vehicle in the longitudinal direction, respectively. As shown in Figure 1, the glass plate vibration damping structure 10 is applied, for example, to an opera window 2, and dampens the vibration (bending vibration) of the glass plate 11 that constitutes the opera window 2. This makes it possible to dampen the transmission of sound through the opera window 2.

[0012] Figure 2 is an enlarged view of the glass plate vibration damping structure 10 shown in Figure 1. As shown in Figure 2, the glass plate vibration damping structure 10 comprises a glass plate 11 attached to the vehicle body 1 and at least one vibration suppression part 12 provided on the glass plate 11. The glass plate 11 is a single pane of glass, i.e., one glass plate. The glass plate 11 in the example shown in Figure 2 has a roughly triangular shape and is attached to the vehicle body 1 as an opera window 2 (see Figure 1). As shown in Figure 2, the vibration suppression part 12 is provided along the edge 11a of the glass plate 11. However, the position of the vibration suppression part 12 is not limited to the vicinity of the edge 11a, as long as the natural vibration of the glass plate 11 is efficiently suppressed.

[0013] Figure 3 is a cross-sectional view taken along line A-A in Figure 2. It shows IN, OUT, the inner and outer sides in the vehicle width direction, respectively. As shown in Figure 3, the glass plate 11 is bonded to the vehicle body 1 by an adhesive (adhesive layer) 17 such as glass glue. The adhesive 17 is applied, for example, along the edge of the opening as an opera window 2. The adhesive 17 has elasticity that suppresses the transmission of stress from the vehicle body 1 to the glass plate 11, and this elasticity is sufficiently lower than that of the elastic part 13 (see Figure 3), which will be described later. That is, even after curing, the adhesive 17 remains sufficiently softer than the elastic part 13.

[0014] The glass plate 11 may have a light-shielding layer 15 on its edge 11a. The light-shielding layer 15 is, for example, a black ceramic layer. The light-shielding layer 15 prevents the adhesive 17 and vibration damping part 12 located between the glass plate 11 and the vehicle body 1 from being visible, thereby enhancing the design of the opera window 2.

[0015] As shown in Figure 3, the vibration damping section 12 is attached, for example, to the inner surface 11b of the glass plate 11. However, the surface to which the vibration damping section 12 is attached is not limited to the inner surface 11b, but may also be the outer surface 11c. The vibration damping section 12 includes an elastic section 13 and a rigid section 14. The elastic section 13 and the rigid section 14 are laminated together. The elastic section 13 is formed of an elastomer such as rubber and has, for example, a strip-shaped (ribbon-shaped) form with a predetermined thickness and width. One surface of the elastic section 13 in the thickness direction is bonded to the glass plate 11, and the other surface in the same direction is bonded to the rigid section 14. The vibration damping section 12 is separated from the vehicle body 1. Therefore, vibrations and stresses from the vehicle body 1 are not transmitted to the glass plate 11 via the vibration damping section 12.

[0016] The elastic part 13 has elasticity that resonates with the natural frequency and mode mass of the natural vibration mode of the glass plate 11. This elasticity is defined, for example, by Young's modulus. For example, the natural frequency of the elastic part 13 is the coincidence frequency (for example, the coincidence limit frequency) determined by the thickness of the glass plate 11.

[0017] The rigid body portion 14 is formed from a material having higher rigidity than the elastic portion 13, and for example, has a strip-like (ribbon-like) shape with a predetermined thickness and width. The material of the rigid body portion 14 is a metal such as steel, or a synthetic resin such as carbon fiber reinforced plastic. However, the material of the rigid body portion 14 is not limited to those listed here. The rigid body portion 14 is in surface contact with the elastic portion 13. The surface contact of the highly rigid rigid body portion 14 with the elastic portion 13 suppresses the divergence of vibrations in the elastic portion 13, i.e., the generation and increase of self-excited vibrations. In other words, the vibration energy of the glass plate 11 is absorbed and attenuated by the resonance of the elastic portion 13.

[0018] Furthermore, if the glass plate 11 has a polygonal shape, the vibration suppression part 12 may be provided on the edge 11a of the glass plate 11, excluding the corners where the sides of the polygon intersect. For example, as shown in Figure 2, if the glass plate 11 is roughly triangular, the vibration suppression part 12 may be omitted in the area within the dashed circle indicating the three corners 19.

[0019] Next, the vibration suppression of the glass plate 11 by the glass plate vibration damping structure 10 will be explained. Figure 4A shows the vibration analysis results of the glass plate 11 in the comparative example. On the other hand, Figure 4B shows the vibration analysis results of the glass plate 11 in the embodiment. Numerical analysis using the well-known finite element method was employed for these vibration analyses, and it was assumed that the glass plate 11, vehicle body 1, and adhesive 17 were the same. The thickness of the glass plate 11 was 3.5 mm and its mass was 640 g. A 3.5 kHz vibration generated by the coincidence effect due to this thickness was applied to the glass plate 11.

[0020] In the comparative example shown in Figure 4A, the vibration suppression unit 12 is not attached to the glass plate 11. Therefore, as shown in this figure, it can be seen that large-amplitude vibrations due to the 3.5 kHz vibration mode are present across the entire surface of the glass plate 11.

[0021] On the other hand, in the embodiment shown in Figure 4B, the vibration suppression part 12 is attached to almost the entire circumference of the edge of the glass plate 11. In this example, the elastic part 13 has a thickness of 2 mm and a Young's modulus of 2.45 N / mm². ２The vibration suppression part 12 is made of rubber and has elasticity that resonates with vibrations around 3.5 kHz. On the other hand, the rigid body part 14 was made of iron with a thickness of 0.65 mm. The total mass of the vibration suppression part 12 was 98 g. As shown in Figure 4B, it can be seen that the amplitude due to the 3.5 kHz vibration mode is reduced across the entire surface of the glass plate 11 by the vibration suppression part 12.

[0022] Figure 5 is a graph showing the frequency characteristics of the equalized acoustic radiation power in the comparative example and embodiment described above. The elastic portion 13 of the vibration suppression portion 12 has elasticity that resonates with vibrations around 3.5 kHz. Therefore, it can be confirmed that the vibration in the frequency range R shown in the figure is attenuated by up to about 5 dB.

[0023] Figure 6A is a cross-sectional view of a glass plate vibration damping structure 10 according to a first modified example of the embodiment. As shown in Figure 6A, the glass plate vibration damping structure 10 may include a plurality of vibration damping parts 12 arranged on the glass plate 11 at intervals from each other. That is, at least one vibration damping part 12 may include a plurality of vibration damping parts arranged on the glass plate 11 at intervals from each other. In this case, the elasticity of the elastic part 13 differs among the plurality of vibration damping parts 12. That is, the elastic part 13 of the plurality of vibration damping parts 12 has elasticity that resonates at natural frequencies and mode masses in different natural vibration modes. However, the spacing between the vibration damping parts 12 is set to a value that allows each elastic part 13 to expand and contract independently. That is, the vibration damping parts 12 are separated from each other by a distance that allows each elastic part 13 to expand and contract independently.

[0024] Figure 6B is a cross-sectional view of a glass plate vibration damping structure 10 according to a second modified example of the embodiment. As shown in Figure 6B, the elastic portion 13 is laminated in the lamination direction with the rigid portion 14 and may include a plurality of elastic layers 13a having different elasticities from each other.

[0025] (1) The glass plate vibration damping structure 10 according to this embodiment comprises a glass plate 11 attached to the vehicle body 1 and at least one vibration suppression part 12 provided on the glass plate 11. The vibration suppression part 12 includes an elastic part 13 and a rigid part 14. The elastic part 13 has elasticity that includes the natural frequency of the glass plate 11 within its resonance region. The rigid part 14 has higher rigidity than the elastic part 13.

[0026] According to the above configuration, the elastic part 13 resonates in accordance with the natural vibration of the glass plate 11. On the other hand, the rigid part 14 suppresses the self-dispersion of the vibration of the elastic part 13. Therefore, the vibration energy due to the natural vibration of the glass plate 11 is consumed by the resonance energy of the elastic part 13, and the natural vibration is attenuated. In other words, the sound of the natural vibration generated in the glass plate 11 is attenuated, and the sound insulation effect is improved.

[0027] The natural vibration of the glass plate 11 is attenuated by bonding the vibration suppression part 12 to the glass plate 11. In other words, the natural vibration can be attenuated without deforming the structure of the glass plate 11 itself. This means that sound insulation can be improved while manufacturing costs can be reduced.

[0028] (2) The glass plate 11 may have a polygonal shape. In this case, the vibration suppression part 12 may be provided on the edge 11a of the glass plate 11, excluding the corners 19 where the sides of the polygon intersect. The natural vibration of the glass plate 11 is caused by a standing wave formed by the combination of the traveling wave and the reflected wave of its frequency. Therefore, at the corners 19, where the amplitude of the natural vibration is likely to intersect at an acute angle with respect to the direction of propagation of these waves, the back-and-forth between the traveling wave and the reflected wave is less likely to occur, and the effect of suppressing the natural vibration by the vibration suppression part 12 may be relatively low. In this case, even if the placement of the vibration suppression part 12 at the corners 19 is omitted, the natural vibration of the glass plate 11 can be sufficiently suppressed. Furthermore, by scattering the vibration suppression parts 12, the vibration suppression parts 12 can be formed into a highly versatile shape such as a linear shape. That is, the dependence on the shape of the glass plate 11 is reduced, and an increase in manufacturing costs can be suppressed.

[0029] (3) The glass plate 11 may be supported on the vehicle body 1 via an adhesive (adhesive layer) 17 having lower elasticity than the elastic portion 13. The vibration suppression portion 12 and the adhesive 17 may be located between the light-shielding layer 15 formed on the edge portion 11a of the glass plate 11 and the vehicle body 1. The adhesive 17 supports the glass plate 11 while suppressing the transmission of stress from the vehicle body 1 to the glass plate 11. On the other hand, the light-shielding layer 15 prevents the adhesive 17 and vibration suppression portion 12 located between the glass plate 11 and the vehicle body 1 from being visible. In addition, since the vibration suppression portion 12 is hidden between the vehicle body 1 and the light-shielding layer 15, it is possible to prevent the aesthetic appearance from being compromised.

[0030] (4) The natural frequency may also be the coincidence frequency of the glass plate 11. In this case, the elastic part 13 resonates with vibrations at the coincidence frequency. Therefore, it is possible to attenuate sounds at the coincidence frequency and the surrounding frequencies.

[0031] (5) The glass plate vibration damping structure 10 may include a plurality of vibration suppression parts 12 arranged on the glass plate 11 at intervals. The elasticity of the elastic part 13 may differ among the plurality of vibration suppression parts 12. In this case, damping of vibrations of natural frequencies corresponding to the elasticity of each part can be obtained.

[0032] (6) The elastic portion 13 is laminated in the lamination direction with the rigid portion 14 and may include a plurality of elastic layers 13a having different elasticities from each other. In this case, the elastic portion 13 has an elasticity that is a composite of the elasticities of each of the plurality of elastic layers 13a. By appropriately selecting and combining a plurality of elastic layers 13a having different elasticities, an elasticity that can dampen vibrations of a desired natural frequency can be obtained.

[0033] The embodiments described above are merely illustrative examples provided to facilitate understanding of the invention. The technical scope of the invention is not limited to the specific technical matters disclosed in the embodiments described above, but also includes various modifications, changes, and alternative technologies that can be easily derived therefrom.

[0034] 1. Vehicle body 10. Glass plate vibration damping structure 11. Glass plate 11a. Edge 12. Vibration suppression part 13. Elastic part 13a. Elastic layer 14. Rigid part 17. Adhesive (adhesive layer) 19. Corner

Claims

1. A glass plate vibration damping structure comprising: a glass plate attached to a vehicle body; and at least one vibration damping portion provided on the glass plate, wherein the vibration damping portion includes: an elastic portion having elasticity that resonates at the natural frequency and mode mass of the natural vibration mode of the glass plate and is bonded to the glass plate; and a rigid portion having higher rigidity than the elastic portion and being laminated to the elastic portion.

2. The glass plate has a polygonal shape, and the vibration suppression portion is provided on the edge of the glass plate, excluding the corners where the sides of the polygon intersect, according to claim 1.

3. The glass plate vibration damping structure according to claim 1 or 2, wherein the glass plate is supported by the vehicle body via an adhesive layer having lower elasticity than the elastic portion, and the vibration damping portion and the adhesive layer are located between a light-shielding layer formed on the edge of the glass plate and the vehicle body.

4. The glass plate vibration damping structure according to any one of claims 1 to 3, wherein the natural frequency is the coincidence frequency of the glass plate.

5. The glass plate vibration damping structure according to any one of claims 1 to 3, wherein the at least one vibration damping portion includes a plurality of vibration damping portions arranged on the glass plate at intervals, and the elasticity of the elastic portion differs among the plurality of vibration damping portions.

6. The glass plate vibration damping structure according to any one of claims 1 to 3, wherein the elastic portion is laminated in the lamination direction with the rigid portion and comprises a plurality of elastic layers having different elasticities from each other.

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