Window glass vibration damping material

Abstract

To provide a window glass vibration damping member which enhances the effect of suppressing noise in a vehicle such as an automobile in particular.MEANS FOR SOLVING THE PROBLEM: There is provided a window glass vibration damping member 40 attached to the lower side of a vertically movable window glass 20 of a vehicle such as an automobile, in which a substantially U-shaped channel 50 of a rigid member sandwiches the lower side of the window glass 20 via a viscoelastic member 41. The viscoelastic member 41 has an exterior side surface part 41 abutting on the exterior side surface of the window glass 20, an interior side surface part 42 abutting on the interior side surface of the window glass 20, and a groove part 45 connecting the exterior side surface part 41 to the interior side surface part 42 and formed of a lower surface part 44 abutting on the bottom surface 22 of the window glass. A depth h of the groove part 45 is 2.5 mm to 10 mm.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a window glass vibration damping member that has an improved effect of suppressing noise, particularly inside a vehicle such as an automobile. [Background technology]

[0002] In vehicles such as automobiles, one of the demands of users is high quietness. There are many sources of noise, one of which is the window glass attached to the door and its surroundings. For example, the vibration of the vehicle body while driving can cause the window glass to vibrate, and this vibration can generate noise.

[0003] One technique for reducing noise caused by this vibration is described in Patent Document 1 below. As shown in Fig. 9, a window glass vibration-damping member 40 is attached to the bottom edge of the window glass 20. The window glass vibration-damping member 40 has a structure in which a U-shaped metallic channel 50 holds the bottom edge of the window glass 20 via a viscoelastic member 41, which is a rubber member. The rubber member, which is the viscoelastic member 41, has a groove portion 45 that corresponds to the thickness of the window glass 20 and the insertion depth into the viscoelastic member 41.

[0004] The document states that the window glass vibration-damping member 40 was attached to the lower edge of the window glass 20 of an actual vehicle, and the noise inside the vehicle was measured during steady driving at a speed of 100 km / h. As a result, it was confirmed that the sound pressure was reduced by about 1.0 dB compared to when the window glass vibration-damping member 40 was not attached, and that the sound pressure was reduced particularly in the frequency band of 1 to 4 kHz. Patent Document 1 does not mention the depth of the groove portion 45. Moreover, the depth of the groove portion 45 of the window glass vibration-damping member used in vehicles on the market is generally in the range of 14 mm to 16 mm. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2002-321526 A Summary of the Invention [Problem to be solved by the invention]

[0006] Meanwhile, with the spread of electric vehicles, there is a demand for further improvements in quietness, and the same is also required for the window glass attached to the door and its surroundings. Although it is possible to improve quietness by thickening the window glass to increase the rigidity of the window glass, thickening the window glass increases the weight by a number of kilograms, and on the other hand, it is not possible to respond to the demand for lighter vehicle bodies. [Means for solving the problem]

[0007] The present invention aims to provide a window glass vibration damping member that reduces noise inside the vehicle by focusing on the depth of the groove portion of the viscoelastic material of the window glass vibration damping member into which the lower edge portion of the window glass is inserted, in order to further reduce noise caused by vibration of the window glass and further improve quietness.

[0008] In order to solve the above problems, the present invention of claim 1 is a window glass vibration damping member that is attached to the lower edge of a window glass of a vehicle such as an automobile that can be raised and lowered, wherein the window glass vibration damping member is characterized in that an approximately U-shaped channel of a rigid member clamps the lower edge of the window glass via a viscoelastic member, the viscoelastic member has a groove formed by an outer side portion that abuts against the outer side of the window glass, an inner side portion that abuts against the inner side of the window glass, and a lower surface portion that is connected to the outer side portion and the inner side portion and abuts against the bottom of the window glass, and the depth of the groove is 2.5 mm to 10 mm.

[0009] In the present invention of claim 1, the window glass vibration damping member has a substantially U-shaped channel of a rigid member that clamps the lower edge of the window glass via a viscoelastic member, the viscoelastic member has a groove formed by an outer side surface portion that abuts against the outer side surface of the window glass, an inner side surface portion that abuts against the inner side surface of the window glass, and a lower surface portion that is connected to the outer side surface portion and the inner side surface portion and abuts against the bottom surface of the window glass, the groove has a depth of 2.5 mm to 10 mm, so that when the window glass vibrates due to vibration of the vehicle body while traveling, a canceling effect based on a phase shift in the vibration between the window glass and the window glass vibration damping member is utilized to reduce the vibration energy of the window glass, and as a result, the generation of noise can be reduced.

[0010] If the groove depth of the window glass vibration damping member is less than 2.5 mm, it is difficult for the window glass vibration damping member to clamp the bottom edge of the window glass, which is not preferable. Also, if the groove depth of the window glass vibration damping member exceeds 10 mm, the noise reduction effect of the window glass vibration damping member decreases.

[0011] The present invention of claim 2 is the invention of claim 1, wherein protrusions for pressing the outer side surface portion and the inner side surface portion of the viscoelastic member are provided on the outer side surface and the inner side surface of the window glass of the channel. Bottom The window glass vibration damping member is formed higher.

[0012] In the present invention of claim 2, protrusions for pressing the outer side surface portion and the inner side surface portion of the viscoelastic member are provided on the outer side surface and the inner side surface of the window glass of the channel. Bottom Since it is formed higher up, the window glass vibration damping member can be securely clamped at a predetermined position below the window glass. Effect of the Invention

[0013] The window glass vibration damping member has a substantially U-shaped channel of a rigid member that clamps the bottom edge of the window glass via a viscoelastic member, the viscoelastic member having a groove formed by an outer side portion that abuts against the outer side portion of the window glass, an inner side portion that abuts against the inner side portion of the window glass, and a bottom surface portion that is connected to the outer side portion and the inner side portion and abuts against the bottom surface of the window glass, the window glass is inserted into the groove of the window glass vibration damping member to a depth of 2.5 mm to 10 mm, so that when the window glass vibrates due to vibrations of the vehicle body while traveling, a canceling effect based on a phase shift in the vibrations between the window glass and the window glass vibration damping member is utilized to reduce the vibration energy of the window glass, and as a result, the generation of noise can be reduced. [Brief description of the drawings]

[0014] [Figure 1] 1 is a schematic perspective view of an automobile door glass structure used in an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of a window glass vibration-damping member used in an embodiment of the present invention. [Diagram 3] FIG. 1 is a diagram illustrating noise measurement. [Figure 4] 1A is a graph showing the results of noise measurement of an embodiment of the present invention, and FIG. 1B is a graph showing the degree of effect of the embodiment of the present invention. [Diagram 5] 10 is a diagram illustrating a method for measuring the relationship between acceleration and time regarding vibration of a window glass and a window glass vibration damping member. FIG. [Figure 6] 10 is a graph showing the relationship between acceleration and time when the depth h at which the window glass is inserted into the groove of the window glass vibration-damping member is 5 mm according to an embodiment of the present invention. [Figure 7] 10 is a graph showing the relationship between acceleration and time when the depth h at which the window glass is inserted into the groove of the window glass vibration-damping member is 4 mm according to an embodiment of the present invention. [Figure 8] 10 is a graph showing the relationship between acceleration and time when the depth h at which the window glass is inserted into the groove of the window glass vibration-damping member is 3 mm according to an embodiment of the present invention. [Figure 9] 1 is a cross-sectional view of a conventional window glass vibration-damping member (Patent Document 1). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] 1 is a schematic perspective view of an automobile door glass structure used in an embodiment of the present invention, which uses a wire-type door window regulator 60 as a mechanism for raising and lowering a window glass 20. In this embodiment, a front door of a vehicle will be taken as an example. Note that the same names and symbols are used to describe the same parts as in the background art.

[0016] (Door glass structure) The door 1 is composed of an inner panel (not shown) and an outer panel 12, and is integrally formed with a door body 13 that houses the window glass 20 when it is lowered, and a window sash 14 that supports the window glass 20 when it is raised. A pair of run channels 16, 17 are provided on both sides inside the door body 13 of the automobile door 1 to guide the front and rear ends of the vehicle when the window glass 20 is raised and lowered. A center guide rail 61 is fixed between the run channels 16, 17. A carrier plate 62 is attached to the center guide rail 61 so as to be movable up and down. The window glass 20 is connected to the door window regulator 60 by screwing the carrier plate 62 to connection holes 21, 21 (FIG. 3) provided in the lower side of the window glass 20 with connection bolts 64, 64. In the embodiment of the present invention, a window glass 20 having a thickness of 4 mm is used.

[0017] Further, the carrier plate 62 is connected to the drive motor 30 via a wire cable 63, and by pulling the wire cable 63 with the drive motor 30, the carrier plate 62 and the window glass 20 can be raised and lowered.

[0018] In FIG. 1, the position of the window glass 20 indicated by the two-dot chain line indicates a state in which the window glass 20 is completely retracted into the door body 13, that is, a state in which the window glass 20 is fully open.

[0019] (Window glass vibration damping member 40) As shown in Fig. 1, two window glass vibration damping members 40 are attached to the lower edge of the window glass 20. This is due to the constraints of the door glass structure in which the connecting holes 21, 21 are connected to the door window regulator 60 by connecting bolts 64, 64 at the center of the lower edge of the window glass 20. Two window glass vibration damping members 40, each with a length of 100 mm in the vehicle longitudinal direction, are used. However, the length is not limited to 100 mm. Also, window glass vibration damping members 40 with different lengths in the vehicle longitudinal direction may be used.

[0020] In addition, since the window glass vibration damping member 40 has a greater vibration reducing effect the wider the area it covers at the bottom edge of the window glass 20, a long window glass vibration damping member may be used, or a plurality of short window glass vibration damping members, each 50 mm in length, may be used. In short, the window glass vibration damping member can be installed taking into consideration its positional relationship with the door window regulator 60 and the space between it and surrounding parts.

[0021] Fig. 2 is a cross-sectional view of a window glass vibration-damping member 40 according to an embodiment of the present invention. Note that Fig. 2 shows the respective shapes and positional relationship of the window glass 20, the viscoelastic member 41 that is the window glass vibration-damping member 40, and the substantially U-shaped channel 50, and does not show the shape of the window glass vibration-damping member 40 when attached to the window glass 20.

[0022] The window glass vibration damping member 40 has an exterior side portion 42 that abuts the exterior side surface of the window glass 20, an interior side portion 43 that abuts the interior side surface of the window glass 20, and a bottom surface portion 44 that connects the exterior side portion 42 and the interior side portion 43.The window glass vibration damping member 40 is composed of a viscoelastic member 41 in which a groove portion 45 of depth h is formed by the exterior side portion 42, the interior side portion 43 and the bottom surface portion 44, and a substantially U-shaped channel 50 that covers the exterior side surface of the viscoelastic member 41.The channel 50 is configured to clamp the bottom edge of the window glass 20.

[0023] The viscoelastic member 41 is made of butyl rubber, and the thicknesses of the vehicle exterior side portion 42 and the vehicle interior side portion 43 are the same, 1.5 mm, and the thickness of the underside portion 44 is 4.0 mm. However, the thicknesses of the vehicle exterior side portion 42 and the vehicle interior side portion 43 are not limited to 1.5 mm, and the thickness of the underside portion 44 is not limited to 4.0 mm.

[0024] It has been confirmed that the thickness of the lower surface portion 44 linearly exhibits a vibration damping effect up to 8 mm, and when the thickness exceeds 8 mm, the degree of decrease gradually decreases, and the thickness tends to saturate at around 14 mm, and the vibration damping effect is maintained up to about 100 mm. Therefore, the thickness of the lower surface portion 44 is preferably set to 4 mm to 14 mm, particularly from the viewpoints of vibration damping effect, prevention of interference with surrounding parts, and increase in the weight of the entire window glass vibration damping member. Regarding the thickness of the lower surface portion 44, in the relationship between frequency and acceleration (dB) described later, the acceleration value decreases overall in the frequency range exceeding 1 kHz, and a particularly noticeable decrease is obtained in the range from 4 kHz to 6 kHz (a slightly higher frequency range).

[0025] Regarding the thickness of the underside portion 44, when the window glass 20 vibrates due to vibration of the vehicle body while traveling, the window glass 20 undergoes bending deformation. At that time, the channel 50, which is a rigid member integrated with the window glass 20, restrains the expansion and contraction of the surface of the window glass 20 due to bending deformation. At that time, shear stress is generated in the window glass vibration-damping member 40, but this shear stress itself can be absorbed by the viscoelastic member 41, and it is considered that as the underside portion 44 of the window glass vibration-damping member 40 becomes thicker, the degree of absorption of vibration energy increases and vibration can be further damped.

[0026] Also, an upward protrusion may be formed on the bottom surface 22 side of the lower surface 44 of the window glass 20, the cross section of which is an isosceles triangle, semicircle, trapezoid, or the like, and the height of which is 1 mm to 2.5 mm, protruding upward from the bottom surface 22. In this case, a significant vibration damping effect is obtained in terms of the relationship between frequency and acceleration (dB), particularly at 2 kHz. This is because the bottom surface 22 of the window glass 20 is attached by abutting and crushing the upward protrusion 49 formed on the upper part 44 of the viscoelastic member 41, which is crushed, and distortion occurs when the window glass 20 vibrates due to the distortion, and the vibration energy generated by the vibration is converted into heat, thereby damping vibrations of a specific frequency (band) and reducing the generation of noise.

[0027] Rubber or synthetic resin is preferably used as the viscoelastic member 41. Usable rubber materials are not particularly limited, but examples thereof include, other than butyl rubber, butadiene rubber, ethylene propylene diene rubber, isoprene rubber, chloroprene rubber, nitrile rubber, neoprene rubber, acrylic rubber, urethane rubber, silicone rubber, fluororubber, etc. Examples of synthetic resin materials include plastic elastomers such as acrylic resin, urethane resin, vinyl chloride resin, and styrene thermoplastic resin.

[0028] On the other hand, the channel 50 is made of metal, and in the first embodiment, a hot-dip galvanized steel sheet is used as the material. As described above, the channel 50 needs to clamp, i.e., restrain, the lower edge portion of the window glass 20 together with the viscoelastic member 41, and therefore is required to have high rigidity. The material is not particularly limited as long as it can restrain the viscoelastic member 41, and specific examples include metal and FRP. As the metal material, steel is preferably used in view of cost and ease of processing. In this embodiment, the plate thickness of the channel 50 is 1.2 mm. From the viewpoint of clamping the lower edge portion of the window glass 20 together with the viscoelastic member 41, the plate thickness of the channel 50 is preferably 0.5 mm to 2.0 mm.

[0029] Above the channel 50, protrusions 51 and 52 are formed on the side of the channel 50, and inclined portions 53 and 54 are formed above the protrusions 51 and 52 at the opening of the channel 50, widening in a direction away from the window glass 20. In this embodiment, the distance from the upper end of the channel 50 to the bent portions of the protrusions 51 and 52 is 2.5 mm. The distance from the upper end of the channel 50 to the bent portions of the protrusions 51 and 52 is not limited to 2.5 mm. However, in order to clamp the lower side of the window glass 20 by the channel 50, it is preferable that the distance from the upper end of the channel 50 to the bent portions of the protrusions 51 and 52 is 1.5 mm or more. Also, it is preferable that the depth of the groove 45 of the viscoelastic member 41 below the bent portions of the protrusions 51 and 52 of the channel 50 is 1.5 mm or more.

[0030] It is possible to insert the window glass 20 into the groove 45 of the viscoelastic member 41 inside the channel 50 even if the protrusions 51, 52 are not formed. However, in the present invention, since the depth h of the groove 45 is shallow, if the protrusions 51, 52 are not formed, the lower edge of the window glass 20 is fixed to the viscoelastic member 41 using an adhesive or the like in order to clamp the lower edge of the window glass 20.

[0031] (Installation of window glass vibration damping member 40) The window glass vibration damping member 40 is attached by inserting the lower edge portion of the window glass 20 into the groove portion 45 of the viscoelastic member 41 and then inserting the window glass 20 with the viscoelastic member 41 attached thereto into the channel 50 .

[0032] 2, the opening of the channel 50 is formed with inclined portions 53, 54 that widen in the direction away from the window glass 20, so that the window glass 20 to which the viscoelastic member 41 is attached can be smoothly inserted into the channel 50. In addition, the channel 50 receives the viscoelastic member 41 as the protrusions 51, 52 widen in the direction away from the window glass 20.

[0033] 2, a gap S is formed below the protrusions 51, 52 of the channel 50 between the vehicle exterior side surface portion 42 and the vehicle interior side surface portion 43 of the viscoelastic member 41, so that the window glass 20 to which the viscoelastic member 41 is attached can easily move downward within the channel 50. Note that the gap S may be formed only on either the vehicle exterior side surface portion 42 side or the vehicle interior side surface portion 43 side, or no gap S may be formed.

[0034] Then, the bottom surface 22 of the window glass 20 comes into contact with the upper surface of the lower surface portion 44 of the viscoelastic member 41, thereby completing the installation of the window glass vibration-damping member 40.

[0035] In Figure 2, the upper end of the channel 50 is shown to be coincident with the upper ends of the exterior side portion 42 and the interior side portion 43 of the viscoelastic member 41, but the upper ends of the exterior side portion 42 and the interior side portion 43 of the viscoelastic member 41 may be located below or above the upper end of the channel 50.

[0036] (Verification of effectiveness; noise measurement method) Fig. 3 is a diagram explaining noise measurement. A sound source 70 is placed at the position of a human ear inside the vehicle (the dotted circle in Fig. 3). Twenty acceleration pickups 71 (vibration level meters) that receive vibrations from the window glass 20 are attached to the outside of the vehicle. The acceleration pickups 71 are the sensor part of the vibration level meter, and output an electrical signal proportional to the vibration acceleration.

[0037] Since the frequency characteristics sensed by the human ear are geometric, an octave analysis was used for the analysis. Within the audible frequency range for noise, the sound pressure level for each band is measured through a bandpass filter set to a standard of 1 / 3 octave. Please refer to JIS C 1513:2002 for the characteristics of bandpass filters.

[0038] (Confirmation of effectiveness; noise measurement results) Figure 4(a) is a graph of the results of noise measurement, showing the results for the window glass 20 only (without the window glass vibration-damping member 40 attached) (■ + dashed line) and the results for the window glass vibration-damping member 40 of the present invention attached, with ◆ representing the measurement result when the depth h of the groove portion 45 is 10 mm, ▼ representing the measurement result when the depth h of the groove portion 45 is 5 mm, and ● representing the measurement result when the depth h of the groove portion 45 is 3 mm. Note that in Figure 4(a), the smaller the acceleration (dB) value, the more the vibration of the window glass 20 is suppressed.

[0039] As is clear from FIG. 4(a), by installing the window glass vibration-damping member 40, as the depth h of the groove portion 45 becomes shallower from 10 mm to 5 mm to 3 mm, the acceleration (dB) value decreases overall in the frequency range above 1 kHz, and a particularly significant vibration damping effect is observed in the range from 2.5 kHz to 5 kHz.

[0040] FIG. 4(b) is a graph showing the degree of effect of the embodiment of the present invention, specifically, the degree of vibration damping effect with respect to the depth h of the groove portion 45 at a frequency of 4 kHz. FIG. 4(b) also shows that the effect is greater toward the right side from the left end (window glass only). As is clear from FIG. 4(b), the effect becomes greater as the depth h of the groove portion 45 becomes shallower from 10 mm to 8 mm to 5 mm to 4 mm to 3 mm. Note that FIG. 4(b) shows the results at a frequency of 4 kHz, but a similar tendency to FIG. 4(a) was observed in the frequency range from 2.5 kHz to 5 kHz, that is, the effect becomes greater as the depth h of the groove portion 45 becomes shallower.

[0041] Fig. 5 is a diagram for explaining a method for measuring the relationship between acceleration and time regarding the vibration of the window glass 20 and the window glass vibration-damping member 40. The sound source 70 was placed at the position of a human ear inside the vehicle, as in Fig. 3. An acceleration pickup 71 (vibration level meter) was attached to the exterior side of the window glass 20 at a position 10 mm above the exterior side of the window glass vibration-damping member 40 and the belt line molding 18.

[0042] Fig. 6 to Fig. 8 are graphs showing the relationship between time and acceleration, with Fig. 6 being a graph connecting the measurement points when the depth h of the groove portion 45 of the window glass vibration-damping member 40 is 5 mm, Fig. 7 being a graph connecting the measurement points when the depth h is 4 mm, and Fig. 8 being a graph connecting the measurement points when the depth h is 3 mm. The solid line shows the measurement results for the window glass vibration-damping member 40, and the dashed line shows the measurement results for the window glass 20.

[0043] When the depth h of the groove 45 of the window glass vibration damping member 40 is 5 mm (Fig. 6), the waveforms of the window glass 20 and the window glass vibration damping member 40 are close to being in opposite phase on the time axis (horizontal axis). On the other hand, when the depth h of the groove 45 of the window glass 20 and the window glass vibration damping member 40 is 3 mm (Fig. 8), a considerable phase shift was observed. Also, it was observed that the magnitude of vibration seen on the acceleration axis (vertical axis) was smaller when the depth was 3 mm than when the depth was 5 mm.

[0044] This trend in the relationship between the phase shift and the magnitude of vibration was observed as the depth went from 5 mm (Figure 6) to 4 mm (Figure 7) to 3 mm (Figure 8). Therefore, it is believed that as the depth h of the groove portion 45 of the window glass vibration-damping member 40 becomes shallower, the phase shift in the relationship between time and acceleration regarding the vibration of the window glass 20 and the window glass vibration-damping member 40 occurs, and that the vibration is suppressed by a canceling effect due to this phase shift.

[0045] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the object of the present invention.

[0046] For example, in the above first and second embodiments, the window glass vibration damping member 40 is applied to a door glass structure using a wire-type door window regulator 60 as a lifting and lowering mechanism for the window glass 20, but it is also possible to apply it to a door glass structure using another type, for example, an X-type door window regulator.

[0047] For example, the lower surface portion 44 of the above embodiment may be made thicker and / or an upper protrusion 49 may be formed on the lower surface portion 44, which comes into elastic contact with the bottom surface 22 of the window glass 20. In this case, the effect of making the lower surface portion 44 thicker and / or the effect of forming the upper protrusion 49 is added to the effect of the above embodiment, making it possible to further suppress vibration of the window glass 20.

[0048] For example, in the above embodiment, the window glass vibration damping members 40 are attached to two locations in the front-rear direction of the vehicle, but they may be attached to only one location. [Explanation of symbols]

[0049] 1 Door 20 Window Glass 22 Bottom 40 Window glass vibration damping material 41 Viscoelastic materials 42 Vehicle outside side 43 Inside side of the car 44 Bottom part 45 Groove 50 Channels 51, 52 Projection part 53, 54 Slope 60 Door window regulator 70 Sound Sources 71 Acceleration Pickup h Groove depth

Claims

1. A window glass vibration damping member that is attached to a lower edge portion of a window glass of a vehicle such as an automobile that can be raised and lowered, The window glass vibration damping member has a substantially U-shaped channel of a rigid member that clamps a lower edge portion of the window glass via a viscoelastic member, The viscoelastic member has an exterior side surface portion that abuts against an exterior side surface of the window glass, an interior side portion that abuts against an interior side surface of the window glass; a groove portion formed by a lower surface portion that is connected to the vehicle exterior side surface portion and the vehicle interior side surface portion and that abuts against a bottom surface of the window glass, A window glass vibration damping member, wherein the depth of the groove is from 2.5 mm to 10 mm.

2. 2. The window glass vibration damping member according to claim 1, wherein a protrusion portion that presses against the exterior side portion and the interior side portion of the viscoelastic member is formed above the bottom surface of the window glass on the exterior and interior sides of the channel of the window glass.

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