Pneumatic tire

Abstract

The present invention relates to an automotive pneumatic tire and, more specifically, to a pneumatic tire provided with an efficient resonance sound reduction material. To this end, the present invention provides a pneumatic tire comprising a tread portion (100), a sidewall portion (200), and a bead portion (300), wherein an inner liner layer (400) is installed inside the tire, and a plurality of resonance sound reduction materials (500) are installed at equal intervals in the inner liner layer (400).

Description

pneumatic tires

[0001] The present invention relates to a pneumatic tire for a vehicle, and more particularly, to a pneumatic tire having a structure for reducing tire resonance noise.

[0002] The noise generated while driving a car is a crucial factor in determining a comfortable driving environment for drivers. Noise sources can broadly be categorized into wind noise, engine noise, road noise, and tire noise, and can be categorized by frequency (Hz). With the recent shift from internal combustion engines to electric vehicles, noise that was not a significant issue in internal combustion engines is now causing discomfort for drivers. The most common noise is tire resonance.

[0003] Tire resonance noise occurs as a sharp peak at about 200 Hz, and is a noise with a natural frequency that is generated in the cavity between the tire and the rim as the tire continuously collides with the ground, similar to the resonant sound of a basketball bouncing on the floor.

[0004] The currently commercialized technology for reducing tire resonance involves attaching a circumferentially band-shaped, porous foam for sound absorption inside the tire. Typically, a single, long band is attached to the tire's inner liner, but in some cases, multiple strips are attached circumferentially inside the tire.

[0005] The present invention aims to overcome the shortcomings of commercially available methods for reducing tire resonance noise and to provide a technology for reducing resonance noise efficiently with a small amount.

[0006] Below, we examine related prior art documents. The identification codes in the following prior art documents are unrelated to the present invention.

[0007]

[0008] Korean Patent No. 10-1775797, 'Tire resonance reduction material fixing structure having a resonance reduction material fixing band and a tire manufactured including the same', relates to a tire resonance reduction material fixing structure that attaches and fixes a resonance reduction material to a tire and a manufacturing method thereof, and more specifically, the tire resonance reduction material fixing structure comprises a plurality of resonance reduction material fixing bands, each of which includes a resonance reduction material for reducing noise generated inside a tire, a bonding portion made of an elastic material and bonded to the inner surface of the tire, and a pressing portion having a function of contacting the resonance reduction material with an inner liner of the tire and maintaining the contact state, wherein the pressing portion applies downward pressure to the upper surface of the resonance reduction material while being expanded and then contracted, and since a separate adhesive layer is not applied, the resonance reduction material attachment process is facilitated, and the resonance reduction material can be firmly attached and fixed to the inner surface of the tire without causing damage to the tire. It provides technology related to this. However, the above technology had the problem of causing residual vibration during pressurization and contraction.

[0009]

[0010] Korean Patent Publication No. 10-2021-0022383, "Tire including a sealant layer and a resonance sound reduction layer," relates to a tire including a sealant layer and a resonance sound reduction layer, and more specifically, to a tire including a resonance sound reduction layer attached to an inner surface of a tire; and a sealant layer disposed between the inner surface of the tire and the resonance sound reduction layer, the sealant layer including a sealant that attaches the resonance sound reduction layer to the inner surface of the tire, wherein the resonance sound reduction layer includes a non-woven fabric. However, the above technology had a disadvantage in that installation of the resonance sound reduction layer was not easy.

[0011]

[0012] Korean Patent No. 10-1775797, 'Tire resonance reduction material fixing structure having a resonance reduction material fixing band and tire manufactured including the same', registered on August 31, 2017.

[0013] Korean Patent Publication No. 10-2021-0022383, "Tire including a sealant layer and a resonance reduction material layer," published on March 3, 2021.

[0014]

[0015] Conventional commercial methods utilize polyurethane foam, a typical sound-absorbing material, and attach it in a circular shape inside the tire. While this method can reduce resonance noise generated from the tire's internal cavity, it requires a large volume of resonance noise-reducing material, which in turn requires a large amount of adhesive (approximately 150 to 300 g of resonance noise-reducing material per tire, or ~ g when using glue-type adhesive). The use of large volumes of resonance noise-reducing material and adhesive not only increases the cost of tires, but is also ineffective in dissipating the heat generated on the tire surface during driving.

[0016] Accordingly, the present invention is intended to solve the problems of the above-described prior art, and has as a technical problem to be solved the problem of providing a pneumatic tire that implements the installation of an optimal resonance noise reduction material on the inside of the tire.

[0017]

[0018] The present invention, in order to achieve the above-described purpose, provides a pneumatic tire comprising a tread portion (100), a sidewall portion (200), and a bead portion (300), wherein an inner liner layer (400) is installed inside the tire, and a plurality of resonance sound reduction materials (500) are installed at equal intervals in the inner liner layer (400).

[0019] In an embodiment of the present invention, the lower surface of the resonance sound reduction material (500) may be formed to have a wider area than the upper surface of the resonance sound reduction material (500) that contacts the inner surface of the tire.

[0020] In an embodiment of the present invention, the width (w) of the resonance noise reduction material (500) may be 60 to 100% of the width (bw) of the tire belt (110), and the height (h) may be 30 to 90% of the sidewall height (sh).

[0021] In an embodiment of the present invention, the lower length (d) of the cross-section of the resonance sound reduction material (500) may be 5 to 15 cm, and the upper length (d') may be 1 to 5 cm.

[0022] In an embodiment of the present invention, the density of the resonance sound reduction material (500) is 20 to 50 kg / m 3 It can be characterized by being.

[0023] In an embodiment of the present invention, the minimum distance minXn between the resonance sound reduction materials (500) may be defined as ((Ln*d) / n) - minXn ≤ 20 mm (wherein, L: inner circumferential length of the tire, d: lower length of the cross-section of the resonance sound reduction material, n: number of blocks, Xn: length between the resonance sound reduction materials).

[0024] In an embodiment of the present invention, the maximum distance maxXn between the resonance sound reduction materials (500) may be defined as maxXn - ((Ln*d) / n) ≤ 20 mm (L: inner circumferential length of the tire, d: lower length of the cross-section of the resonance sound reduction material, n: number of blocks, Xn: length between the resonance sound reduction materials).

[0025] In an embodiment of the present invention, the resonance sound reduction material (500) may be characterized in that 2 to 9 are formed in the inner liner layer (400).

[0026] In an embodiment of the present invention, the plurality of resonance sound reduction materials (500) may be characterized in that they are arranged radially to have an arrangement angle (θ) of 40° to 180° based on the central axis of the bead portion (300).

[0027]

[0028] The effect of the present invention according to the above configuration is that a resonance sound reduction effect of 93% compared to the conventional technology can be expected even when the total weight of the resonance sound reduction material is only 30% of that of the conventional technology.

[0029] Accordingly, it is possible to reduce the weight of tires and expect additional benefits such as higher fuel efficiency.

[0030] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the composition of the invention described in the claims.

[0031]

[0032] Figure 1 is a longitudinal cross-sectional view of the pneumatic tire of the present invention.

[0033] Figure 2 is a cross-sectional view of an example in which six resonance noise reduction materials of the pneumatic tire of the present invention are applied.

[0034] Figure 3 is a cross-sectional view of the pneumatic tire of the present invention.

[0035] Figure 4 is a perspective view of one embodiment of a resonance sound reduction material of the present invention.

[0036] Figures 5 (a) and (b) are perspective views of another embodiment of the resonance sound reduction material of the present invention.

[0037] Figures 6 (a), (b), (c), and (d) are cross-sectional views showing cross-sections of various embodiments of the resonance sound reduction material of the present invention.

[0038] Figures 7 (a), (b) to 8 (a), (b) are perspective views of other embodiments of the shape of the resonance sound reduction material of the present invention.

[0039] Figure 9 is a table summarizing the test results of one embodiment of the present invention.

[0040] Figure 10 is a graph evaluating noise according to frequency of the resonance noise reduction material of the present invention and the prior art.

[0041]

[0042] The most preferred embodiment according to the present invention is characterized in that, in a pneumatic tire comprising a tread portion (100), a sidewall portion (200), and a bead portion (300), an inner liner layer (400) is installed inside the tire, and a plurality of resonance sound reduction materials (500) are installed at equal intervals in the inner liner layer (400).

[0043]

[0044] In describing the present invention below, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

[0045] Since embodiments according to the concept of the present invention can be modified in various ways and take on various forms, specific embodiments are illustrated in the drawings and described in detail in this specification or application. However, this is not intended to limit embodiments according to the concept of the present invention to a specific disclosed form, and it should be understood that the present invention includes all modifications, equivalents, and alternatives included within the spirit and technical scope of the present invention.

[0046] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components in between. Conversely, when a component is referred to as being "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between. Other expressions that describe the relationship between components, such as "between" and "directly between" or "adjacent to" and "directly adjacent to", should be interpreted similarly.

[0047] The terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the present invention. The singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, it should be understood that the terms "comprises" or "has" indicate the presence of a described feature, number, step, operation, component, part, or combination thereof, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0048] Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings showing embodiments of the present invention.

[0049] The term “upper surface of the resonance reduction material” used throughout the specification of the present invention refers to a surface that comes into contact with air and is formed wider than the lower surface of the resonance reduction material.

[0050] In addition, the term “lower surface of the resonance reduction material” used throughout the specification of the present invention refers to a surface that comes into contact with the inner surface of the tire, and is formed so that the area in contact with the inside of the tire is wide and wider than the upper surface of the resonance reduction material.

[0051]

[0052] The present invention provides a configuration that prevents the formation of resonance by placing block-shaped structures spaced apart within a tire. The wavelength of tire resonance is similar to the circumferential length of the center of the space between the tire and the rim. This is because the tire continuously collides with the ground, impacting the tire's internal cavity, which then acts like a wind instrument, vibrating at its own frequency.

[0053] The present invention provides a function of preventing the formation of resonance sound by placing a structure inside a tire, just as a structure placed inside a tire prevents sound (resonance sound) from being produced when wind is blown.

[0054]

[0055] Fig. 1 is a longitudinal cross-sectional view of a pneumatic tire of the present invention, and Fig. 2 is a longitudinal cross-sectional view of an embodiment in which six resonance noise reduction materials of the pneumatic tire of the present invention are applied. The present invention provides a pneumatic tire, as illustrated in Figs. 1 and 2, comprising a tread portion (100), a sidewall portion (200), and a bead portion (300), wherein an inner liner layer (400) is installed inside the tire, and a plurality of resonance noise reduction materials (500) are installed at equal intervals in the inner liner layer (400).

[0056] A plurality of resonance sound reduction materials (500) are arranged radially so as to have an arrangement angle (θ) of 40° to 180° based on the central axis of the bead portion (300).

[0057] More specifically, the arrangement angle (θ) between adjacent resonance reduction materials (500) among a plurality of resonance reduction materials (500) may be 40° to 180°, but is more preferably 51° to 90°.

[0058] Here, the arrangement angle (θ) is defined as the angle formed by the central axes of the adjacent resonance reduction material (500) and the bead portion (300).

[0059] Specifically, referring to FIGS. 1 and 2, 2 to 9 resonance sound reduction materials (500) may be formed in the inner liner layer (400), but it is more preferable that 4 to 7 resonance sound reduction materials (500) are formed in the inner liner layer (400).

[0060] In addition, 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 comes into contact with the inner surface of the tire.

[0061] For example, the cross-section of the resonance sound reduction material (500) may have a trapezoidal shape, but is not limited thereto.

[0062] However, the reason why the structure of the above resonance noise reduction material (500) is a trapezoidal column is that the structure receives force in the direction opposite to the tire's acceleration direction, and if deformation occurs as a result, it can affect the resonance noise reduction effect, so this is to be minimized.

[0063] Failure to evenly distribute the blocks across the inner surface of the tire can disrupt the tire's dynamic balance, leading to increased rolling resistance (RRc) or vibration, potentially resulting in driver discomfort. To minimize this, the optimal installation spacing was experimentally derived using the equation below.

[0064]

[0065] That is, it is preferable that the minimum distance minXn between the resonance sound reduction materials (500) satisfies the following equation 1.

[0066]

[0067] Equation 1) ((Ln*d) / n) - minXn ≤ 20mm

[0068] (Here, L: inner circumference of tire, d: lower length of cross-section of resonance reduction material, n: number of blocks, Xn: length between resonance reduction materials)

[0069]

[0070] In addition, it is preferable that the maximum distance maxXn between the resonance sound reduction materials (500) satisfies the following equation 2.

[0071]

[0072] Equation 2) maxXn - ((Ln*d) / n) ≤ 20mm

[0073] (Here, L: inner circumference of tire, d: lower length of cross-section of resonance reduction material, n: number of blocks, Xn: length between resonance reduction materials)

[0074]

[0075] Figure 3 is a cross-sectional view of a pneumatic tire of the present invention, and Figure 4 is a perspective view of one embodiment of a resonance noise reduction material of the present invention.

[0076] In order to effectively reduce the resonance noise generated inside the tire by the bulkhead, it is important to select an appropriate size for the bulkhead to perform its role. When looking at the cross-section of the tire, it was confirmed that the resonance noise is reduced when more than 40% of the total cross-sectional area is blocked by the bulkhead. To satisfy this, the width of the resonance noise reduction material (500) is preferably 60 to 100% of the tire belt width. In addition, the height of the resonance noise reduction material is appropriately 30 to 90%, preferably 40 to 80%, of the side wall height. In addition, in order to maintain the shape and attachment of the bulkhead according to the tire driving direction, the upper horizontal length of the structure is appropriately 1 to 5 cm, and the lower horizontal length is appropriately 5 to 15 cm.

[0077] Referring to Fig. 4, the area of ​​the lower surface (tire contact surface) of the resonance sound reduction material (500) is formed to be wider than the area of ​​the upper surface (surface in contact with air) of the resonance sound reduction material (500).

[0078] That is, the resonance sound reduction material (500) may have a trapezoidal shape in which the width becomes narrower and slopes toward the upper surface of the resonance sound reduction material (500) from the lower surface of the resonance sound reduction material (500) toward the central axis of the bead portion (300).

[0079] That is, as shown in FIGS. 3 and 4, the lower length (d) of the cross-section of the resonance sound reduction material (500) of the resonance sound reduction material is preferably 5 to 15 cm, and the upper length (d') is preferably 1 to 5 cm. The density of the resonance sound reduction material (500) is preferably 20 to 50 kg / m. 3 It is desirable that.

[0080] The above-described trapezoidal shape forms a stable structure, which can prevent the problem of reduced durability due to fatigue caused by the movement of the resonance sound reduction material (500) in the direction of travel, and can be expected to have the effect of preventing the occurrence of residual vibrations.

[0081] In addition, as described above, the width (w) of the resonance noise reduction material (500) is preferably 60 to 100% of the width (bw) of the tire belt (110), and the height (h) is preferably 40 to 80% of the sidewall height (sh). If the height and width of the resonance noise reduction material (500) are excessively large, there is a risk that residual vibrations due to irregular behavior during driving may occur. Therefore, the above numerical limitations are significant.

[0082] Fig. 5 is a perspective view of another embodiment of the resonance sound reduction material of the present invention. Fig. 5 (a) is an embodiment in which the left and right sides of the trapezoidal cross-section of the resonance sound reduction material (500) are concave inward, and Fig. 5 (b) is an embodiment in which the left and right sides of the trapezoidal cross-section of the resonance sound reduction material (500) are concave outward.

[0083] According to another embodiment of the present invention, the resonance sound reduction material (500) may have the opposite side surfaces of the resonance sound reduction material (500) concavely recessed inward as shown in (a) of FIG. 5, or the opposite side surfaces of the resonance sound reduction material (500) may protrude convexly outward as shown in (b) of FIG. 5.

[0084] Fig. 6 is a cross-sectional view showing various examples of a resonance sound reduction material of the present invention. Fig. 6 (a) is a cross-sectional view of Fig. 4, Fig. 6 (b) is a cross-sectional view of a modified example of Fig. 4, Fig. 6 (c) is a cross-sectional view of Fig. 5 (a), and Fig. 6 (d) is a cross-sectional view of Fig. 5 (b).

[0085] First, according to one embodiment of the present invention, the resonance sound reduction material (500) is formed to be symmetrical left and right with respect to an imaginary central axis that divides the resonance sound reduction material (500) into left and right sides, as shown in (a) of FIG. 6.

[0086] Next, according to a modified example of one embodiment of the present invention, the resonance sound reduction material (500) is formed to be asymmetrical left and right based on an imaginary central axis that divides the resonance sound reduction material (500) into left and right, as shown in (b) of FIG. 6.

[0087] Specifically, referring to (b) of FIG. 6, the lower surface of the resonance sound reduction material (500) and one side of the resonance sound reduction material (500) (left side in (b) of FIG. 6) form a 90-degree angle, while the lower surface of the resonance sound reduction material (500) and the other side of the resonance sound reduction material (500) (right side in (b) of FIG. 6) form an acute angle, so that the resonance sound reduction material (500) becomes asymmetrical from left to right.

[0088] Next, according to another embodiment of the present invention, the resonance sound reduction material (500) is formed to be symmetrical left and right based on an imaginary central axis that divides the resonance sound reduction material (500) into left and right sides, as shown in (c) of FIG. 6.

[0089] Next, according to another embodiment of the present invention, the resonance sound reduction material (500) is formed to be symmetrical left and right with respect to an imaginary central axis that divides the resonance sound reduction material (500) into left and right sides, as shown in (d) of FIG. 6.

[0090]

[0091] FIG. 7 is an example in which the bottom of the resonance sound reduction material (500) is formed as a rectangular solid. FIG. 7 (a) is an example in which the height of the rectangular solid is less than half the height of the resonance sound reduction material (500), and FIG. 7 (b) is an example in which the height of the rectangular solid is more than half the height of the resonance sound reduction material (500).

[0092] Referring to (a) of Fig. 7, the resonance sound reduction material (500) is formed so that the height of the rectangular prism portion located at the bottom is less than half the height of the resonance sound reduction material (500).

[0093] Meanwhile, referring to (b) of Fig. 7, the resonance sound reduction material (500) is formed so that the height of the rectangular solid portion located at the bottom is more than half the height of the resonance sound reduction material (500).

[0094] FIG. 8 is an example of a case where the length of the upper surface of the resonance sound reduction material (500) is smaller than the length of the lower surface of the resonance sound reduction material (500). FIG. 8 (a) is an example of a case where the length of the upper surface of the resonance sound reduction material (500) is larger than 1 / 2 of the length or area of ​​the lower surface of the resonance sound reduction material (500), and FIG. 8 (b) is an example of a case where the length of the upper surface of the resonance sound reduction material (500) is smaller than 1 / 2 of the length of the lower surface of the resonance sound reduction material (500).

[0095] Referring to (a) of Fig. 8, the resonance sound reduction material (500) is formed so that the length or area of ​​the upper surface of the resonance sound reduction material (500) is greater than half the length or area of ​​the lower surface of the resonance sound reduction material (500).

[0096] Meanwhile, the resonance sound reduction material (500) is formed so that the length or area of ​​the upper surface of the resonance sound reduction material (500) is smaller than half the length or area of ​​the lower surface of the resonance sound reduction material (500).

[0097] The shapes of the resonance sound reduction material of the above Figs. 5, 7 and 8 can be selected by considering the material, weight and sound absorption performance of the resonance sound reduction material.

[0098]

[0099] Example

[0100] Figure 9 is a table summarizing the test results of one embodiment of the present invention. Figure 10 is a graph evaluating the noise according to frequency of the resonance noise reduction material of the present invention and the prior art.

[0101] In the examples in which the foam was not applied in FIGS. 9 and 10, there was no resonance noise reduction effect, while the conventional comparative example in which the foam was applied had a reduction effect of 5.8 dB. In contrast, the technology of the partition structure of the present invention recorded a resonance low-noise effect of 5.4 dB.

[0102]

[0103] That is, it was confirmed that the present invention has a cavity noise dB reduction effect of 93% of that of tires using foam, even though the foam weight used in the tires using Ref. Foam is only 30% of that of tires using foam.

[0104]

[0105] The pneumatic tire having the resonance noise reduction material of the embodiment of the present invention having the above-described configuration installed can be applied to various vehicles such as racing cars, electric vehicles, and general vehicles.

[0106]

[0107] While the technical concepts of the present invention described above have been specifically described in preferred embodiments, it should be noted that the above embodiments are intended for illustrative purposes only and are not intended to be limiting. Furthermore, those skilled in the art will appreciate that various embodiments are possible within the scope of the technical concepts of the present invention. Therefore, the true scope of technical protection of the present invention should be determined by the technical concepts of the appended claims.

Claims

1. In a pneumatic tire comprising a tread portion (100), a sidewall portion (200), and a bead portion (300), An inner liner layer (400) is installed inside the tire, A pneumatic tire characterized in that a plurality of resonance noise reduction materials (500) are installed at equal intervals in the inner liner layer (400).

2. In paragraph 1, A pneumatic tire characterized in that the lower surface of the resonance noise reduction material (500) is formed to have a wider area than the upper surface of the resonance noise reduction material (500) that contacts the inner surface of the tire.

3. In paragraph 1, A pneumatic tire characterized in that the width (w) of the above resonance noise reduction material (500) is 60 to 100% of the width (bw) of the tire belt (110), and the height (h) is 30 to 90% of the sidewall height (sh).

4. In paragraph 1, A pneumatic tire, characterized in that the lower length (d) of the cross-section of the above resonance noise reduction material (500) is 5 to 15 cm, and the upper length (d') is 1 to 5 cm.

5. In paragraph 1, The density of the above resonance sound reduction material (500) is 20 to 50 kg / m 3 A pneumatic tire characterized by:

6. In paragraph 1, A pneumatic tire characterized in that the minimum distance minXn between the above resonance sound reduction materials (500) is defined as ((Ln*d) / n) - minXn ≤ 20 mm (wherein, L: inner circumferential length of the tire, d: lower length of the cross-section of the resonance sound reduction material, n: number of blocks, Xn: length between the resonance sound reduction materials).

7. In paragraph 1, A pneumatic tire characterized in that the maximum distance maxXn between the above resonance sound reduction materials (500) is defined as maxXn - ((Ln*d) / n) ≤ 20 mm (L: inner circumferential length of the tire, d: lower length of the cross-section of the resonance sound reduction material, n: number of blocks, Xn: length between the resonance sound reduction materials).

8. In paragraph 1, A pneumatic tire characterized in that the resonance noise reduction material (500) is formed in 2 to 9 pieces in the inner liner layer (400).

9. In paragraph 1, A pneumatic tire, characterized in that the above plurality of resonance sound reduction materials (500) are arranged radially to have an arrangement angle (θ) of 40° to 180° based on the central axis of the bead portion (300).

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