Pneumatic tire

Abstract

This invention relates to a pneumatic tire for vehicles, and more specifically, to a pneumatic tire with a highly efficient resonance sound reduction material. Therefore, this invention provides a pneumatic tire comprising a tread portion (100), a sidewall portion (200), and a bead portion (300), characterized in that an airtight layer (400) is provided inside the tire, and a plurality of resonance sound reduction materials (500) are provided at equal intervals on the airtight layer (400).

Description

Technical Field

[0001] This invention relates to a pneumatic tire for vehicles, and more specifically, to a pneumatic tire having a structure for reducing tire resonance noise. Background Technology

[0002] Noise generated during vehicle operation is a crucial factor in determining driver comfort. The main sources of noise include wind noise, engine noise, road noise, and tire noise, which can be categorized by frequency (Hz). In recent years, with the shift from internal combustion engine vehicles to electric vehicles, noise that was not a major issue in internal combustion engine vehicles has begun to cause inconvenience for drivers. The most representative noise is the resonance sound generated by the tires.

[0003] Tire resonance produces a sharp peak at around 200Hz, similar to the "thump" sound of a basketball bouncing off the ground. It is a noise with an inherent frequency generated in the cavity between the tire and the rim when the tire continuously collides with the ground.

[0004] Current commercially available technology for reducing tire resonance noise involves attaching a strip of sound-absorbing porous foam along the circumference inside the tire. This technology typically involves attaching a single long strip to the airtight layer inside the tire, but there are also cases where the long strip is divided into multiple strips and attached along the circumference inside the tire.

[0005] The present invention aims to overcome the shortcomings of commercial methods for reducing tire resonance noise and to provide a technology for achieving efficient resonance noise reduction with a small amount of material.

[0006] The following is an examination of relevant prior art documents. The reference numerals in the drawings in the following prior art documents are not related to this invention.

[0007] Korean Patent Registration No. 10-1775797, entitled "Tire Resonance Sound Reduction Material Fixing Structure with Resonance Sound Reduction Material Fixing Strips and Tire Manufactured Thereof," relates to a tire resonance sound reduction material fixing structure and its manufacturing method for attaching and fixing resonance sound reduction material to a tire. More specifically, it provides a technology for fixing a tire resonance sound reduction material, the fixing structure comprising: a resonance sound reduction material for reducing noise generated inside the tire; a bonding portion made of a stretchable material and bonded to the inner surface of the tire; and a pressing portion for pressing the resonance sound reduction material tightly against the tire's airtight layer and maintaining this tightness. The pressing portion includes multiple resonance sound reduction material fixing strips, and when the pressing portion extends and contracts, it applies downward pressure to the upper surface of the resonance sound reduction material. Because this fixing structure does not require an additional adhesive layer, it simplifies the attachment process of the resonance sound reduction material and has the advantage of firmly attaching and fixing the resonance sound reduction material to the inner surface of the tire without damaging the tire. However, the above technology suffers from the problem of residual vibration generated during pressing and contraction.

[0008] Korean Patent Publication No. 10-2021-0022383, entitled "Tire Including a Sealant Layer and a Resonance Reduction Material Layer," relates to a tire including a sealant layer and a resonance reduction material layer. More specifically, it relates to a tire comprising: a resonance reduction material layer attached to the inner side of the tire; and a sealant layer disposed between the inner side of the tire and the resonance reduction material layer, and having a sealant for attaching the resonance reduction material layer to the inner side of the tire, wherein the resonance reduction material layer comprises a non-woven fabric. However, the above-mentioned technology suffers from the disadvantage of inconvenience in setting up the resonance reduction material layer.

[0009] Korean Patent No. 10-1775797, "Tire Resonance Reduction Material Fixing Structure with Resonance Reduction Material Fixing Strip and Tire Manufactured Thereof", Registration Date: August 31, 2017.

[0010] Korean Patent Publication No. 10-2021-0022383, "Tire including a sealant layer and a resonance sound reduction material layer", Publication date: March 3, 2021. Summary of the Invention

[0011] The problem the invention aims to solve The traditional commercial approach involves using polyurethane foam, a representative sound-absorbing material, attached to the inside of the tire in a circumferential manner. While this method reduces resonance noise generated in the tire's cavity, it requires a large volume of sound-absorbing material and therefore a significant amount of adhesive (e.g., approximately 150g to 300g of sound-absorbing material per tire, or approximately ~g when using a glue-type adhesive). Using such a large volume of sound-absorbing material and adhesive not only increases tire costs but is also inefficient at cooling the heat generated on the tire surface during vehicle operation.

[0012] Therefore, the present invention aims to solve the problems of the prior art described above. The embodiments of the present invention provide an inflatable tire in which the resonance sound reduction material is optimally configured on the inner side of the tire.

[0013] means for solving problems To achieve the above objectives, the present invention is configured as a pneumatic tire, the pneumatic tire including a tread portion 100, a sidewall portion 200 and a bead portion 300, the pneumatic tire being characterized in that an airtight layer 400 is provided inside the tire, and a plurality of resonance sound reduction materials 500 are provided at equal intervals on the airtight layer 400.

[0014] In an embodiment of the present invention, the pneumatic tire is characterized in that the lower surface of the resonance sound reducing material 500 that contacts the inner side of the tire has a wider area than the upper surface of the resonance sound reducing material 500.

[0015] In an embodiment of the present invention, the pneumatic tire is characterized in that the width w of the resonance sound reduction material 500 is 60% to 100% of the width bw of the tire belt layer 110, and the height h is 30% to 90% of the sidewall height sh.

[0016] In an embodiment of the present invention, the pneumatic tire is characterized in that the lower side length d of the cross-section of the resonance sound reduction material 500 is 5~15cm and the upper side length d' is 1~5cm.

[0017] In an embodiment of the present invention, the pneumatic tire is characterized in that the density of the resonance sound-reducing material 500 is 20 kg / m³. 3 Up to 50kg / m 3 .

[0018] In an embodiment of the present invention, the pneumatic tire is characterized in that the minimum distance minXn between the resonance sound reduction materials 500 is defined as ((Ln*d) / n) - minXn ≤ 20mm, where L: the inner circumference length of the tire, d: the lower side length of the cross section of the resonance sound reduction material, n: the number of blocks, and Xn: the length between the resonance sound reduction materials.

[0019] In an embodiment of the present invention, the pneumatic tire is characterized in that the maximum distance maxXn between the resonance sound reducing materials 500 is defined as maxXn - ((Ln*d) / n) ≤ 20mm, where L: the inner circumference length of the tire, d: the lower side length of the cross section of the resonance sound reducing material, n: the number of blocks, and Xn: the length between the resonance sound reducing materials.

[0020] In an embodiment of the present invention, the pneumatic tire is characterized in that two to nine of the resonance sound reduction materials 500 are provided on the airtight layer 400.

[0021] In an embodiment of the present invention, the pneumatic tire is characterized in that the plurality of resonance sound-reducing materials 500 are arranged radially with respect to the central axis of the bead portion 300 and at an arrangement angle θ of 40° to 180°.

[0022] Invention Effects The effect of the present invention as described above is that even if only 30% of the resonance sound is reduced in total material weight using the prior art, a 93% reduction in resonance sound compared to the prior art can be expected.

[0023] This allows for tire weight reduction and can be expected to yield additional benefits such as high fuel efficiency.

[0024] The effects of this invention are not limited to those described above, but should be understood to include all effects that can be inferred from the detailed description of the invention or the inventive structure described in the claims. Attached Figure Description

[0025] Figure 1 This is a longitudinal sectional view of the pneumatic tire of the present invention.

[0026] Figure 2 This is a longitudinal sectional view of an embodiment of the pneumatic tire of the present invention that uses six resonance sound-reducing materials.

[0027] Figure 3 This is a cross-sectional view of the pneumatic tire of the present invention.

[0028] Figure 4 This is a perspective view of an embodiment of the resonance sound reduction material of the present invention.

[0029] Figure 5 (a) and (b) are perspective views of another embodiment of the resonant sound reduction material of the present invention.

[0030] Figure 6 (a), (b), (c), and (d) are cross-sectional views illustrating various embodiments of the resonant sound-reducing material of the present invention.

[0031] Figure 7 (a) and (b) to Figure 8 (a) and (b) are perspective views of other embodiments of the shape of the resonant sound reducing material of the present invention.

[0032] Figure 9 This is a table summarizing the test results of one embodiment of the present invention.

[0033] Figure 10 This is a graph comparing the resonant sound reduction material of the present invention with the noise of the prior art based on frequency evaluation. Detailed Implementation

[0034] According to a preferred embodiment of the present invention, a pneumatic tire is provided, the pneumatic tire including a tread portion 100, a sidewall portion 200 and a bead portion 300, characterized in that an airtight layer 400 is provided inside the pneumatic tire, and a plurality of resonance sound reduction materials 500 are provided at equal intervals on the airtight layer 400.

[0035] In describing the present invention below, detailed descriptions of relevant known functions or configurations will be omitted if it is determined that a specific description of such functions or configurations would unnecessarily obscure the gist of the invention.

[0036] The embodiments of the present invention can be modified in various ways and can take many forms. Therefore, specific embodiments will be illustrated in the accompanying drawings and described in detail in this specification or application. However, this is not intended to limit the embodiments of the present invention to a specific form of disclosure. It should be understood that the present invention includes all modifications, equivalents, and even substitutions that fall within the scope of the ideas and techniques of the present invention.

[0037] When a constituent element is referred to as being "connected to" or "joined to" another constituent element, it may be directly connected to or joined to the other constituent element, but it should also be understood that there may be other constituent elements in between. Conversely, when a constituent element is referred to as being "directly connected to" or "directly joined to" another constituent element, it should be understood that there are no other constituent elements in between. Other expressions used to describe the relationship between constituent elements, such as "between" and "immediately adjacent to," or "adjacent to" and "directly adjacent to," should also be interpreted in the same way.

[0038] The terminology used in this specification is for illustrative purposes only and is not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprising" or "having" are intended to indicate the presence of the stated features, numbers, steps, actions, constituent elements, components, or combinations thereof, and should not be construed as precluding the possibility of the presence or addition of one or more other features or numbers, steps, actions, constituent elements, components, or combinations thereof.

[0039] Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings illustrating embodiments thereof.

[0040] The term "upper surface of the resonant sound-reducing material" as used throughout the specification of this invention refers to the surface in contact with air, which is formed to be wider than the lower surface of the resonant sound-reducing material.

[0041] Furthermore, the term "lower surface of the resonance sound reducing material" as used throughout the specification of this invention refers to the surface that contacts the inner side of the tire, and has a wider contact area with the tire interior than the upper surface of the resonance sound reducing material.

[0042] This invention provides a configuration in which block-shaped structures are arranged at regular intervals inside a tire to prevent the formation of resonant sound. The wavelength of the tire's resonant sound is similar to the circumferential length of the central part of the space between the tire and the rim. This is because the tire continuously collides with the ground, impacting the internal cavity of the tire. The internal cavity of the tire acts like a wind instrument, vibrating at its natural frequency.

[0043] The present invention provides the same effect as placing a structure inside a flute and blowing air into it to prevent the production of a resonant sound, by placing a structure inside a tire to prevent the formation of a resonant sound.

[0044] Figure 1 This is a longitudinal sectional view of the pneumatic tire of the present invention. Figure 2 This is a longitudinal sectional view of an embodiment of the pneumatic tire of the present invention that utilizes six resonance-reducing materials. Figure 1 and Figure 2 As shown, the present invention provides a pneumatic tire, which includes a tread portion 100, a sidewall portion 200 and a bead portion 300. An airtight layer 400 is provided inside the tire, and a plurality of resonance sound reduction materials 500 are provided at equal intervals on the airtight layer 400.

[0045] Multiple resonance sound-reducing materials 500 are arranged radially with an arrangement angle θ of 40° to 180°, with the central axis of the bead portion 300 as a reference.

[0046] More specifically, the arrangement angle θ between adjacent resonant sound reducing materials 500 in the plurality of resonant sound reducing materials 500 can be from 40° to 180°, but more preferably from 51° to 90°.

[0047] Here, the arrangement angle θ is defined as the angle formed by the central axis of the adjacent resonant sound reducing material 500 and the bead portion 300.

[0048] Specific reference Figure 1 and Figure 2 The resonance sound reducing material 500 can be formed in 2 to 9 units on the airtight layer 400, but more preferably in 4 to 7 units.

[0049] Furthermore, the lower surface of the resonance sound reduction material 500 is formed to have a wider area than the upper surface of the resonance sound reduction material 500 that contacts the inner side of the tire.

[0050] In one embodiment, the cross-section of the resonant sound-reducing material 500 may have a trapezoidal shape, but is not limited to this.

[0051] However, the reason why the structure of the resonance sound reduction material 500 is a trapezoidal column is that the structure will be subjected to a force in the opposite direction to the tire acceleration direction. If this causes deformation, it may affect the resonance sound reduction effect. Therefore, this is to minimize the deformation.

[0052] If resonance-reducing material is not evenly applied to the inner sidewall of the tire, the tire's dynamic balance may be disrupted, leading to increased rolling resistance (RRc) or vehicle vibration, causing inconvenience to the driver. To minimize these problems, an optimal adhesion distance conforming to the following formula was derived experimentally.

[0053] That is, the minimum distance minXn between the resonant sound reducing materials 500 preferably satisfies the following formula 1.

[0054] Formula 1: (Ln*d) / n) - minXn ≤ 20mm (Where, L: the inner circumference length of the tire, d: the lower side length of the cross-section of the resonance sound reduction material, n: the number of blocks, Xn: the length between the resonance sound reduction materials) Furthermore, the maximum distance maxXn between the resonant sound-reducing materials (500) preferably satisfies the following formula 2.

[0055] Formula 2: maxXn - ((Ln*d) / n) ≤ 20mm Where L: the inner circumference length of the tire, d: the lower side length of the cross section of the resonant sound reducing material, n: the number of blocks, and Xn: the length between the resonant sound reducing materials.

[0056] Figure 3 This is a cross-sectional view of the pneumatic tire of the present invention. Figure 4 This is a perspective view of an embodiment of the resonance sound reduction material of the present invention.

[0057] To effectively reduce resonance noise generated inside the tire using a partition, selecting an appropriate size that allows it to function as a partition is crucial. It has been confirmed that resonance noise is reduced when at least 40% of the total cross-sectional area of ​​the tire is blocked by the partition. To meet this condition, the width of the resonance noise reducing material 500 is preferably 60% to 100% of the width of the tire belt layer. Furthermore, the height of the resonance noise reducing material is suitable to be 30% to 90% of the tire sidewall height, preferably 40% to 80%. In addition, to maintain the shape and attachment of the partition according to the tire's direction of travel, the upper horizontal length of the structure is suitable to be 1 to 5 cm, and the lower horizontal length is suitable to be 5 cm to 15 cm.

[0058] Reference Figure 4 The area of ​​the tire contact surface on the lower surface of the resonance sound reduction material 500 is greater than the area of ​​the upper surface of the resonance sound reduction material 500 in contact with the air.

[0059] That is, the resonance sound reduction material 500 can have a trapezoidal shape that slopes upwards from the lower surface of the resonance sound reduction material 500 toward the central axis of the bead portion 300, and becomes narrower and more inclined towards the upper surface.

[0060] That is, such as Figure 3 and Figure 4 As shown, the lower side length d of the cross-section of the resonant sound reducing material 500 is preferably 5~15cm, and the upper side length d' is preferably 1~5cm. The density of the resonant sound reducing material 500 is preferably 20kg / m³. 3 Up to 50kg / m 3 .

[0061] The trapezoidal shape described above can form a stable structure, which can prevent the decrease in durability caused by fatigue due to the movement of the resonant sound reducing material 500 in the direction of travel, and can be expected to achieve the effect of preventing residual vibration.

[0062] Furthermore, as described above, the width w of the resonance sound-reducing material 500 is preferably 60% to 100% of the width bw of the tire belt layer 110, and the height h is preferably 40% to 80% of the sidewall height sh. If the height and width of the resonance sound-reducing material 500 are too large, there is a concern that residual vibrations may occur due to irregular movement during driving. Therefore, the above-mentioned numerical limits are meaningful.

[0063] Figure 5 This is a perspective view of another embodiment of the resonance sound reduction material of the present invention. Figure 5 (a) is an embodiment of the trapezoidal cross-section of the resonant sound reducing material 500, in which the left and right sides are concave inward. Figure 5 (b) is an embodiment of the trapezoidal cross-section of the resonance sound reduction material 500 with the left and right sides concave outwards.

[0064] The resonance sound reduction material 500 according to another embodiment of the present invention can be as follows: Figure 5 As shown in (a), the opposing sides of the resonant sound-reducing material 500 are concave inward, or as... Figure 5 As shown in (b), the opposing sides of the resonant sound-reducing material 500 bulge outward.

[0065] Figure 6 This is a cross-sectional view showing several embodiments of the resonant sound-reducing material of the present invention. Figure 6 (a) is Figure 4 sectional view, Figure 6 (b) is Figure 4 A cross-sectional view of a modified example. Figure 6 (c) is Figure 5 Sectional view of (a), Figure 6 (d) is Figure 5 (b) is a sectional view.

[0066] First, according to one embodiment of the present invention, the resonant sound reduction material 500, such as Figure 6 As shown in (a), the material is formed with a virtual central axis that reduces the resonance sound by about 500 degrees as a reference, and is symmetrical on both sides.

[0067] Secondly, according to a modified embodiment of the present invention, the resonant sound reducing material 500, such as Figure 6 As shown in (b), the material is formed as a left-right asymmetry with reference to a virtual central axis that reduces the resonance sound by about 500.

[0068] Specific reference Figure 6 (b) The lower surface of the resonance sound reducing material 500 and one side surface of the resonance sound reducing material 500 Figure 6In (b), the left side is at a 90-degree angle, while the lower surface of the resonance sound reducing material 500 is at the same angle as the other side of the resonance sound reducing material 500. Figure 6 The right side of (b) forms an acute angle, thus reducing the resonance sound of the material by 500, making it asymmetrical on the left and right.

[0069] Secondly, according to another embodiment of the present invention, the resonant sound reducing material 500, such as Figure 6 As shown in (c), the material is formed with a virtual central axis that reduces the resonance sound by about 500 degrees as a reference, and is symmetrical on both sides.

[0070] Secondly, according to another embodiment of the present invention, the resonant sound reduction material 500, such as Figure 6 As shown in (d), the material is formed with a virtual central axis that reduces the resonance sound by about 500 degrees as a reference, and is symmetrical on both sides.

[0071] Figure 7 This is an embodiment where the bottom of the resonant sound reducing material 500 is formed as a cuboid, wherein... Figure 7 (a) is an embodiment where the height of the cuboid portion is less than half the height of the resonant sound reducing material 500. Figure 7 (b) is an embodiment in which the height of the cuboid portion is greater than or equal to half the height of the resonant sound reduction material 500.

[0072] Reference Figure 7 (a) The resonant sound reducing material 500 is configured such that the height of the cuboid portion at the bottom is less than 1 / 2 of the height of the resonant sound reducing material 500.

[0073] On the other hand, refer to Figure 7 (b) The resonant sound reducing material 500 is configured such that the height of the cuboid portion at the bottom is greater than or equal to 1 / 2 of the height of the resonant sound reducing material 500.

[0074] Figure 8 This is an embodiment where the length of the upper surface of the resonant sound reduction material 500 is less than the length of the lower surface of the resonant sound reduction material 500, wherein... Figure 8 Example (a) is an embodiment in which the length of the upper surface of the resonant sound reducing material 500 is greater than 1 / 2 of the length or area of ​​the lower surface of the resonant sound reducing material 500. Figure 8 (b) is an embodiment in which the length of the upper surface of the resonant sound reducing material 500 is less than 1 / 2 of the length of the lower surface of the resonant sound reducing material 500.

[0075] Reference Figure 8In (a), the resonant sound reducing material 500 is configured such that the length or area of ​​the upper surface of the resonant sound reducing material 500 is greater than 1 / 2 of the length or area of ​​the lower surface of the resonant sound reducing material 500.

[0076] On the other hand, the resonant sound reducing material 500 is configured such that the length or area of ​​the upper surface of the resonant sound reducing material 500 is less than 1 / 2 of the length or area of ​​the lower surface of the resonant sound reducing material 500.

[0077] The Figure 5 , Figure 7 and Figure 8 The shape of the resonance sound reduction material can be selected by taking into account the material, weight and sound absorption performance of the resonance sound reduction material.

[0078] Example Figure 9 This is a table summarizing the test results of one embodiment of the present invention. Figure 10 This is a graph comparing the resonant sound reduction material of the present invention with the noise of the prior art based on frequency evaluation.

[0079] exist Figure 9 and Figure 10 In the examples where foam was not used, there was no resonance noise reduction effect, while in the comparative examples of the prior art using foam, there was a reduction effect of 5.8 dB. In contrast, the partition structure of the present invention recorded a resonance noise reduction effect of 5.4 dB.

[0080] That is, it has been confirmed that, compared with tires using Ref. Foam, the present invention achieves a 93% reduction in Cavity Noise (dB) compared with tires using Foam, even though Foam is used at only 30% of the weight.

[0081] The pneumatic tire of the present invention, which is equipped with resonance sound reduction material as described above, can be applied to various vehicles such as racing cars, electric cars, and ordinary vehicles.

[0082] The technical concept of the present invention described above has been specifically described in preferred embodiments. However, it should be noted that the above embodiments are for illustrative purposes only and not for limiting purposes. Furthermore, those skilled in the art should understand that various embodiments are possible within the scope of the technical concept of the present invention. Therefore, the true scope of protection of the present invention should be determined by the technical concept of the appended claims.

Claims

1. A pneumatic tire, comprising: The tread portion, side portion, and bead portion are characterized in that, An airtight layer is provided inside the pneumatic tire; Multiple resonance-reducing materials are evenly spaced on the airtight layer.

2. The pneumatic tire according to claim 1, characterized in that, The lower surface of the resonance sound-reducing material (500) has a wider area than the upper surface of the resonance sound-reducing material (500) that contacts the inner side of the tire.

3. The pneumatic tire according to claim 1, characterized in that, The width (w) of the resonance sound-reducing material (500) is 60% to 100% of the width (bw) of the tire belt layer (110), and the height (h) is 30% to 90% of the sidewall height (sh).

4. The pneumatic tire according to claim 1, characterized in that, The lower side length (d) of the cross section of the resonant sound reducing material (500) is 5~15cm, and the upper side length (d') is 1~5cm.

5. The pneumatic tire according to claim 1, characterized in that, The density of the resonant sound reducing material (500) is 20~50 kg / m³. 3 .

6. The pneumatic tire according to claim 1, characterized in that, The minimum distance minXn between the resonant sound-reducing materials (500) satisfies the following relationship: ((Ln*d) / n) - minXn ≤ 20mm; Where L: the inner circumference length of the tire, d: the lower side length of the cross section of the resonant sound reducing material, n: the number of blocks, and Xn: the distance between the resonant sound reducing materials.

7. The pneumatic tire according to claim 1, characterized in that, The maximum distance maxXn between the resonant sound-reducing materials (500) satisfies the following relationship: maxXn - ((Ln*d) / n) ≤ 20mm; Where L: the inner circumference length of the tire, d: the lower side length of the cross section of the resonant sound reducing material, n: the number of blocks, and Xn: the distance between the resonant sound reducing materials.

8. The pneumatic tire according to claim 1, characterized in that, Two to nine of the resonant sound-reducing materials (500) are provided on the airtight layer (400).

9. The pneumatic tire according to claim 1, characterized in that, The plurality of resonance sound-reducing materials (500) are arranged radially with an arrangement angle (θ) of 40° to 180°, with the central axis of the bead portion (300) as a reference.

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