Door glass vibration damping structure and vibration damping stabilizer

Abstract

To provide a door glass vibration damping structure and vibration damping stabilizer that suppresses door glass resonance while minimizing mass increase at low cost, thereby improving sound insulation and lifting performance. [Solution] The vibration-damping stabilizer 1 has a clamping member 11 and an elastic member 12. The clamping member 11 is attached to the door glass 3. The elastic member 12 is interposed between the door glass 3 and the clamping member 11. The loss coefficient tanδ of the elastic member 12 is 0.3 or more.

Description

Technical Field

[0004] , , , , , , , , , , , , , , , , , , , ,

[0003] ,

[0005]

[0001] The present invention relates to a vibration damping structure and a vibration damping stabilizer for automobile door glass.

Background Art

[0002] Automobile door glass generally uses tempered glass with a thickness of 3 to 5 mm (Patent Document 1, etc.). For thin and hard glass, a coincidence phenomenon occurs due to the resonance between the natural frequency and the incident sound. Since the coincidence frequency varies depending on the plate thickness of the glass, assuming the plate thickness, it occurs in a frequency band with high auditory sensitivity of about 2000 to 4000 Hz, and by reducing the transmission loss of the glass, it becomes one of the factors of vehicle interior noise.

[0003] Therefore, in order to compensate for the reduction in transmission loss due to coincidence, a door glass structure has been proposed in which the glass plate is thickened to improve sound insulation based on the mass law (Patent Document 2). Also, a door glass structure has been proposed in which sound insulation is achieved by laminating thin glass through a resin film to suppress the coincidence frequency (resonance) (Patent Document 3).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, a door glass structure with a thicker glass plate, as described in Patent Document 2, results in increased mass. Furthermore, a glass vibration damping structure with an interposed resin film, as described in Patent Document 3, increases manufacturing costs, and because the rigidity of the glass itself is low, raising and lowering the glass at high speeds may cause a large displacement due to the pressure difference between the inside and outside of the vehicle, potentially impairing the ease of raising and lowering the door glass.

[0006] This invention has been made in view of the above circumstances, and aims to provide a door glass vibration damping structure and vibration damping stabilizer that suppress door glass resonance at low cost while minimizing mass increase, and improving sound insulation and lifting performance. [Means for solving the problem]

[0007] Therefore, one aspect of the present invention comprises a vibration damping member attached to a door glass and an elastic member interposed between the door glass and the vibration damping member. The loss coefficient tanδ of the elastic member is 0.3 or greater. [Effects of the Invention]

[0008] According to the present invention described above, it is possible to provide a door glass vibration damping structure and vibration damping stabilizer that suppresses door glass resonance at low cost while minimizing mass increase, thereby improving sound insulation and lifting performance. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 9, section AA, shows a cross-sectional view of an automobile door equipped with a vibration-damping stabilizer according to Embodiment 1 of the present invention. [Figure 2] A plan view of the door glass illustrating the mounting position of the vibration-damping stabilizer shown in Figure 1. [Figure 3] An example of Chladni figures on a glass plate based on various vibration frequencies. [Figure 4] The relationship between spring constant and strain. [Figure 5] Characteristic diagrams showing the relationship between the loss coefficient tanδ and temperature for various elastic materials. [Figure 6](a) Plan view of an automobile door equipped with a vibration-damping stabilizer according to Embodiment 2 of the present invention, (b) Enlarged plan view of the vibration-damping stabilizer. [Figure 7] (a) Cross-sectional view of embodiment 1 of the vibration damping stabilizer of embodiment 2, (b) Cross-sectional view of embodiment 2 of the vibration damping stabilizer. [Figure 8] (a) Cross-sectional view of embodiment 3 of the vibration damping stabilizer of embodiment 2, (b) Cross-sectional view of embodiment 4 of the vibration damping stabilizer. [Figure 9] Front view of a door to which the vibration-damping stabilizer of the present invention is applied. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the drawings.

[0011] [Embodiment 1] The vibration damping stabilizer 1 of Embodiment 1, which is one aspect of the door glass vibration damping structure of the present invention shown in Figure 1, is applied to the door glass 3 of the automobile door 2 illustrated in Figure 9.

[0012] Door 2 comprises a door body 21 and a door sash 22 that extends upward in an arch shape from the door waist portion 23 of the door body 21. A glass opening W is formed between the door body 21 and the door sash 22, and a glass run 24 is attached to the periphery of this glass opening W.

[0013] As shown in Figure 1, the door glass 3 extends and retracts from a door waist opening 230 that opens above the door waist portion 23, and is positioned to move up and down along the vertical edges 221 and 222 of the door sash 22 shown in Figure 9. This door glass 3 is made movable up and down by a window regulator (not shown) mounted inside the door body 21.

[0014] A pair of waist seals 4, an inner waist seal 4a and an outer waist seal 4b, are arranged in the door waist portion 23 of the door body 21.

[0015] The inner vehicle waist seal 4a is mounted on the upper edge portion of the door inner panel 5 covered by the door trim 7, and seals between the door glass 3 and the door inner panel 5. The inner vehicle waist seal 4a has a mounting base portion 40a provided for attachment to the door inner panel 5, and a pair of seal lips 41a projecting substantially parallel to each other in upper and lower two stages at this mounting base portion 40a and capable of elastically contacting the door glass 3.

[0016] The outer vehicle waist seal 4b is arranged along the upper edge portion of the door outer panel 6 covered by the belt mold 8, and seals between the door glass 3 and the door outer panel 6. The outer vehicle waist seal 4b has a mounting base portion 40b provided for attachment to the door outer panel 6, and a pair of seal lips 41b projecting substantially parallel to each other in upper and lower two stages at this mounting base portion 40b and capable of elastically contacting the door glass 3.

[0017] As shown in FIG. 2, the vibration damping stabilizer 1 is provided singly or plurally on the door glass 3 at a portion on the lower end side of the door glass 3.

[0018] The vibration damping stabilizer 1 has a sandwiching member 11 as a vibration damping member attached to the door glass 3 as shown in FIGS. 1 and 3. The sandwiching member 11 sandwiches the door glass 3 via an elastic member 12.

[0019] The glass plate has a natural frequency called the coincidence frequency. The coincidence frequency of the glass plate varies depending on the thickness of the glass plate, but is generated by surface vibration of 2000 Hz or more and 4000 Hz or less.

[0020] The waves of the surface vibration of the glass plate can be represented by a Chladni figure 30 with different rules as illustrated in FIG. 3 depending on the frequency, plate thickness, and side length (shape). The Chladni figure 30 visualizes the nodes 31 (the boundaries of surface vibration) of the natural vibration of the glass plate. In the Chladni figure 30, the portion where the vibration is small and the powder is concentrated is called a node 31, and the portion where the vibration is large and the powder is less is called an antinode 32.

[0021] Figure 3 shows an example of a Chladni figure 30 on a glass plate. When a glass plate with dimensions of 300 mm x 300 mm and a thickness of 4.0 mm is vibrated by a sweep tone from a 2 kHz to 3 kHz excitation speaker, Chladni figures of different shapes are observed at coincidence frequencies from 1 kHz to 4 kHz. Figures (a), (b), (c), and (d) show the Chladni figures obtained at condensed frequencies of 1695 Hz, 2830 Hz, 3065 Hz, and 3425 Hz, respectively.

[0022] In order to dampen the vibration of the door glass 3, it is necessary to efficiently transmit the vibration to the vibration-damping stabilizer 1. Since the vibration is small at the nodes 31 of the Chladni figure 30, the vibration-damping stabilizer 1 can be efficiently transmitted to the elastic member 12 of the vibration-damping stabilizer 1 by attaching the stabilizer 1 to the area including the antinode 32.

[0023] Since the door glass 3 for automobiles does not have a simple shape, it is difficult to predict the Chladni figure. Therefore, the mounting position of the vibration-damping stabilizer 1 is determined in advance based on the Chladni figure 30 obtained through excitation experiments.

[0024] The clamping member 11 is made of a channel-shaped steel plate capable of clamping the lower end portion of the door glass 3 via an elastic member 12, as shown in Figure 1, for example. Examples of the steel material include well-known rust-resistant steel materials such as hot-dip galvanized steel plates, but well-known spring steel plates such as SUS304-CSP are used to apply preload (clamping force) to the elastic member 12.

[0025] When the aforementioned spring steel plate is used, the clamping member 11 is set to the minimum size in the longitudinal direction in order to fix and hold the elastic member 12 and to reduce the mounting space and mass of the vibration damping stabilizer 1.

[0026] Furthermore, in order to efficiently transmit the vibrations of the door glass 3 to the elastic member 12, the spring constant of the clamping member 11 is adjusted to be appropriately high. To adjust the spring constant to be high, for example, a convex portion (not shown) that is curved inward is formed on a pair of side portions 111 of the clamping member 11. From the relationship between the spring constant and the amount of strain shown in Figure 4, the elastic member 12, which has a low spring constant, is compressed when clamped by the clamping member 11, which has a high spring constant, and becomes preloaded (a state in which a load is applied in advance) from the clamping member 11, and a spring constant equivalent to that of the clamping member 11 is obtained. In this way, the clamping member 11 can transmit the vibrations of the door glass 3 to the elastic member 12 by clamping the door glass 3 with the spring constant of the elastic member 12 increased in advance.

[0027] The elastic member 12 is not particularly limited as long as it can ensure a loss coefficient tanδ of 0.3 or higher; well-known rubber materials and synthetic resin materials can be used (for example, Patent Documents 1-3). The loss coefficient tanδ represents the ratio of the loss modulus to the storage modulus of the elastic member. The loss modulus indicates the viscosity (stickiness, resistance to returning to its original shape) of the elastic member. The greater the viscosity, the greater the energy loss. The storage modulus indicates the elasticity (rebounding property) of the elastic member.

[0028] Examples of the rubber material include butyl rubber, butadiene rubber, ethylene propylene diene rubber, isoprene rubber, chloroprene rubber, nitrile rubber, neoprene rubber, acrylic rubber, urethane rubber, silicone rubber, and fluororubber. Examples of the synthetic resin material include plastic elastomers such as polyester resin, acrylic resin, urethane resin, vinyl chloride resin, and styrene-based resin.

[0029] Figure 5 shows the relationship between the loss coefficient tanδ and temperature for various elastic materials (samples S1-S4). Sample S1 is a non-PVC resin (mainly composed of mica and polyester resin). Sample S2 is butyl rubber. Sample S3 is a styrene resin. Sample S4 is ethylene propylene diene rubber.

[0030] For elastic materials, the higher the loss coefficient tanδ, the higher the vibration damping performance, while the spring constant (stiffness) tends to decrease. As shown in the figure, in particular, by applying samples S1 to S3, which have a loss coefficient tanδ of 0.8 to 1.3 at room temperature (20 to 35°C), to the elastic member 12, it is possible to improve the vibration damping performance of the vibration damping stabilizer 1 while suppressing the decrease in the spring constant.

[0031] When the vibration damping stabilizer 1 described above is adjusted so that the total mass of the clamping member 11 and the elastic member 12 is between 5% and 15% of the mass of the door glass 3, it is possible to achieve both miniaturization of the vibration damping stabilizer 1 and weight reduction of the automobile.

[0032] The effects and benefits of the vibration-damping stabilizer 1 of this embodiment will be explained with reference to Figures 1 to 5.

[0033] There are two types of vibration damping stabilizers for automobile door glass 3: open type and constrained type, but the constrained type provides a higher vibration damping effect. In the vibration damping stabilizer 1 of this embodiment, the door glass 3 is restrained by being clamped by the clamping member 11 via the elastic member 12 of the vibration damping stabilizer 1.

[0034] In the case of surface vibration of the door glass 3, as illustrated in Figure 3, the wave caused by vibration propagation appears as a Chladni figure 30 due to shape factors such as the thickness of the door glass 3 and the length of each side, as well as the frequency. Since the antinode 32 of the Chladni figure 30 vibrates the most, it has been experimentally confirmed that by setting the vibration-damping stabilizer 1 in the area including the antinode 32, the surface vibration can be transmitted to the elastic member 12, enabling efficient vibration damping and suppressing the generation of the Chladni figure 30.

[0035] Vibration isolation and vibration damping using the elastic member 12 are different approaches. Vibration damping reduces vibration energy by converting energy into heat or other forms of energy using a material with a high loss coefficient tanδ that constitutes the elastic member 12 (damping). On the other hand, vibration isolation prevents resonance by shifting the frequency by changing the mass and spring constant (stiffness) of the natural frequency (without damping). Materials with a high loss coefficient tanδ generally have high viscosity and low spring constant. The vibration damping stabilizer 1 is intended for damping and has a high loss coefficient tanδ. Thus, vibration isolation and vibration damping are mutually exclusive characteristics and cannot be improved simultaneously.

[0036] In the vibration-damping stabilizer 1 of this embodiment, the damping effect is enhanced by adjusting the loss coefficient tanδ of the elastic member 12 to 0.3 or higher. In particular, as shown in Figure 5, by adjusting the loss coefficient tanδ to 0.8 or higher and 1.3 or lower, a good damping effect of 12 to 19 dB for surface vibration at 3500 Hz at room temperature can be obtained while suppressing a decrease in the spring constant, thus achieving both vibration isolation and vibration damping.

[0037] Furthermore, from the perspective of minimizing the mounting space and reducing the weight of the vehicle, the vibration-damping stabilizer 1 needs to be miniaturized and its mass minimized. In addition, in order to efficiently transmit the surface vibration of the door glass 3 to the elastic member 12 of the vibration-damping stabilizer 1, the spring constant (rigidity) of the clamping member 11 needs to be increased.

[0038] In the vibration-damping stabilizer 1, a channel-shaped spring steel plate is applied to the clamping member 11, which can clamp the door glass 3 via an elastic member 12. This increases the preload (clamping force) of the clamping member 11 and improves the spring constant. This increased preload is then applied to the elastic member 12, efficiently transmitting the surface vibration of the door glass 3. Consequently, the rigidity of the vibration-damping stabilizer 1 is improved, and its size and mass are minimized.

[0039] As described above, the vibration-damping stabilizer 1 of this embodiment can suppress the resonance of the door glass at a low cost while minimizing the increase in mass, thereby improving sound insulation and lifting performance.

[0040] [Embodiment 2] The vibration-damping stabilizer 1 of the present invention can also take the form of the vibration-damping stabilizer 1 of Embodiment 2 shown in Figure 6. Specific examples of Embodiment 2 will be described below.

[0041] In Figure 7, the vibration-damping stabilizer 1 has a weight 13 or washer 15 attached via an elastic member 12 as a vibration-damping member at the lower end of the door glass 3.

[0042] In Embodiment 1 of Figure (a), the elastic member 12 and the weight 13 are in the shape of washers. The elastic member 12 is interposed between the door glass 3 and the weight 13. The weight 13 is made of the same steel material as the clamping member 11 in Embodiment 1, for example. The weight 13 is fixed to the aforementioned location via the elastic member 12 by screwing a nut 14b onto a bolt 14a inserted through the fixing hole 33 of the door glass 3 and the weight 13. The elastic member 12 may be integrally molded (vulcanized and bonded) with the weight 13.

[0043] In embodiment 2 of Figure (b), the elastic member 12 is grommet-shaped with a ring-shaped weight 13 attached, and is interposed between the door glass 3 and the washer 15. The washer 15 is made of the same steel material as the clamping member 11 in embodiment 1, similar to the weight 13. The weight 13 is then fixed to the aforementioned location via the elastic member 12 by screwing a nut 14b onto a bolt 14a inserted through the fixing hole 33 of the door glass 3, the washer 15, the elastic member 12, and the bolt 14a.

[0044] In Figure 8, the vibration-damping stabilizer 1 has a weight 13 installed as a vibration-damping member that is fixed by the fastener via an elastic member 12 at the lower end of the door glass 3, in the area including the antinodes 32 of the Chladni figures 30 on both surfaces of the door glass 3.

[0045] In the embodiment example 3 of Figure 8(a), the elastic member 12 is also in the shape of a washer and is interposed between the door glass 3 and the weight 13. The weight 13 is then fixed to the aforementioned location via the elastic member 12 by screwing a nut 14b onto a bolt 14a that is inserted through the fixing hole 33 of the weight 13, the elastic member 12, and the door glass 3.

[0046] In embodiment example 4 of Figure 8(b), the elastic member 12 is grommet-shaped and fitted into the fixing hole 33 of the door glass 3. The weight 13 is washer-shaped. The weight 13 is fixed to the aforementioned location via the elastic member 12 by screwing a nut 14b onto a bolt 14a that is inserted through the weight 13 and the elastic member 12.

[0047] It is clear that the vibration-damping stabilizer 1 of Embodiment 2 described above can achieve the same effects as the vibration-damping stabilizer 1 of Embodiment 1.

[0048] In particular, according to Embodiment 2, a plurality of vibration-damping stabilizers 1 can be arbitrarily set in the lower end portion of the door glass 3, according to the number of portions including the antinodes 32 of the Chladni figure 30. Furthermore, preload can be arbitrarily applied to the elastic member 12 by adjusting the mass, rigidity of the weight 13, fasteners (bolts 14a, nuts 14b), and washers 15, as well as the fastening force of the fasteners. Therefore, resonance of the door glass 3 can be arbitrarily suppressed, and the sound insulation and lifting / lowering properties of the door glass 3 can be further improved. [Explanation of Symbols]

[0049] 1...Vibration damping stabilizer, 11...Clamping member, 12...Elastic member, 13...Weight, 14a...Bolt, 14b...Nut, 15...Washer 2...door 3...Door glass, 30...Chladni figure, 31...Node, 32...Ventra

Claims

1. A vibration damping member attached to the door glass, An elastic member interposed between the door glass and the vibration damping member, It has, The loss coefficient tanδ of the elastic member is 0.3 or greater. A door glass vibration damping structure that features this characteristic.

2. The door glass vibration damping structure according to claim 1, characterized in that the coincidence frequency of the door glass that forms the Chladni figure of the door glass is 2000 Hz or more and 4000 Hz or less.

3. The door glass vibration damping structure according to claim 1, characterized in that the loss coefficient tanδ is 0.5 or more and 1.3 or less.

4. The door glass vibration damping structure according to claim 1, characterized in that the vibration damping member consists of a channel-shaped spring steel plate that sandwiches the door glass via the elastic member.

5. The door glass vibration damping structure according to claim 1, characterized in that the vibration damping member consists of a ring-shaped or washer-shaped steel plate fixed to the door glass via the elastic member.

6. The door glass vibration damping structure according to claim 1, characterized in that the total mass of the vibration damping member and the elastic member is 5% or more and 15% or less of the mass of the door glass.

7. A vibration damping stabilizer characterized by comprising the door glass vibration damping structure described in claim 1.

Images