KR20180048315A - Tire for reducing cavity noise - Google Patents

Abstract

The present invention relates to a tire for reducing a resonance sound. A block-shaped porous foamed material sound absorber is attached to the inner surface of the tire, and the tire of the present invention exhibits equal sound absorption performance compared to a tire that is coated with the sound absorber at the whole surface of the inner surface thereof via adjusting the density, the height, the number of attachment, and the like of the sound absorber.

Description

{TIRE FOR REDUCING CAVITY NOISE}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a resonance sound reducing tire, in which a porous foamed sound absorbing body in the form of a block is attached to an inner surface of a tire, and a sound absorption body on the inner surface of the tire is coated And more particularly, to a resonance sound reducing tire which exhibits a sound absorption performance equivalent to that of a conventional tire.

There is a growing interest in car and tire companies due to the noise generated in the tire cavity of a moving vehicle. Such noise is caused by a sound having sharp peaks in the vehicle, which is uncomfortable to the driver and causes a reduction in ride comfort. Particularly, as the standard of the tire mounted on a vehicle is peaceful and inches up, the tire resonance noise is becoming an important problem to be solved.

Various studies have been conducted to reduce such resonance tones. (Patent Literature 1), a cylindrical foamed sound absorbing body having a hollow portion is attached to the inner surface of a tire (Patent Document 2), or a porous sound absorbing material A method of attaching a porous sound-absorbing material so as to have a ratio of a cross-sectional area of 23 to 29% (Patent Document 3) is known.

However, when the inside of the tire is entirely coated with a sound absorbing material, the weight of the tire increases, which adversely affects the fuel consumption performance and the uniformity performance deteriorates.

Korean Patent Registration No. 10-089392 entitled "Pneumatic Tire" Korean Patent Laid-Open Publication No. 10-2009-0120911 entitled "Resonance Noise Reduction Method of Tire" Korean Patent Laid-Open Publication No. 10-2015-0123684 "Resonance tone reduction tire"

The present invention is an improved invention designed to simultaneously solve the problem of reducing the fuel consumption due to the increase in the weight caused by applying the sound absorbing material to the entire inner surface of the tire and the problem of lowering the uniformity performance.

That is, according to the present invention, two to five porous foamed sound absorbing bodies are attached on the opposite side of the tire from the heaviest side, instead of attaching the sound absorbing body in the circumferential direction to the entire inner surface of the tire. do. As a result, it is possible to solve the problem of reduction in fuel consumption due to the application of the sound absorbing agent over the entire surface, and to improve the sound absorbing performance equivalent to that of the entire application without affecting the uniformity performance.

In order to solve the above-described problems, the present invention provides a tire for resonance noise reduction having two to five porous foamed sound absorbing bodies in block form at an angle of 90 degrees in the circumferential direction.

As the number of the porous foamed sound absorbing materials is increased, the sound absorption performance tends to be improved. When three or more porous foamed sound absorbing materials are applied, a blemish performance equivalent to that of the front application can be obtained. However, if the number of the porous foamed sound absorbing members is more than 5, the problem may arise due to the increase in weight. Therefore, the porous foamed sound absorbing body may preferably be attached by 3 to 5, more preferably 3 to 4.

In one embodiment of the present invention, the porous foamed sound absorbing body is made of any one material selected from the group consisting of a porous melamine foam foam and a urethane foam foam. According to a preferred embodiment of the present invention, the porous foamed sound absorbing body uses a porous melamine resin foamed foam. Since the melamine resin foamed foam is light and bulky compared to the urethane foam foamed foam, it is advantageous in reducing the resonance sound, and additionally effects such as sound insulation / frequency shifting can be obtained and the sound intensity can be further lowered.

In one embodiment of the present invention, the porous foamed sound absorbing body has a density of 20 to 45 kg / m 3. According to the present invention, it is preferable to use a sound absorbing material having a density of 30 to 40 kg / m < 3 >.

In one embodiment of the present invention, the porous foamed sound absorbing body may be in the form of a polyhedron block selected from the group consisting of a tetrahedron, a hexahedron, a hexahedron, and an octahedron. In addition, the porous foamed sound absorbing material having a polyhedral block shape may have a volume of 20 x ^{10 4} to 240 x 10 ⁴ mm in terms of sound absorption. According to the present invention, if the volume of the porous foamed sound absorbing body is similar, the sound absorbing performance of the sound absorbing body exhibits a similar tendency.

In a preferred embodiment of the present invention, the porous foamed sound absorbing body may be in the form of a hexahedral block having a length and a width of 100 to 180 mm and a height of 20 to 75 mm.

In a preferred embodiment of the present invention, the porous foamed sound absorbing body has a lateral top length of 10 to 40 mm, a lateral bottom length of 100 to 180 mm, a longitudinal length of 100 to 180 mm, and a height of 20 to 75 mm It may be in the form of a hexagonal block having a trapezoidal cross-sectional area.

In a preferred embodiment of the present invention, the porous foamed sound absorbing body has a lateral top length of 10 to 40 mm, a lateral bottom length of 100 to 180 mm, a longitudinal length of 100 to 180 mm, 20 mm and a center height of 21 to 75 mm.

According to the present invention, the sound absorbing performance of the porous foamed sound absorbing body is influenced by the volume of the block, and is influenced by the height change of the block in the vertical vibration.

In one embodiment of the present invention, the porous foamed sound absorbing body is attached to the inner surface of the tire using an adhesive. The adhesive may be a thermoplastic polyurethane (TPU) type or a thermoplastic polyacrylic type material. In a preferred embodiment of the present invention, the porous foamed sound absorbing body may be attached to the inner surface of the tire by a thermoplastic polyurethane (TPU) type or a thermoplastic polyacryl type adhesive tape.

As described above, the resonance sound reducing tire provided by the present invention has the effect of improving the fuel economy, maintaining the uniformity performance and improving the sound absorption performance due to the weight reduction compared to the tire in which the entire inner surface is coated with the sound absorbing material .

Further, the resonance sound reducing tire provided by the present invention is a polyhedral block, and it is possible to obtain the effect of reducing the vibration under the control of the height of the block within the volume range in which the sound absorption performance of the block is maximized.

Therefore, the resonance sound reducing tire provided in the present invention is useful as an air pressure tire.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph showing a sound absorption performance according to the height of a sound absorbing body at the time of attaching the sound absorbing body to the inner surface of a tire.
FIG. 2 is a graph showing a sound absorption performance according to the height of a sound absorbing body when one sound absorbing body is attached to the inner surface of the tire.
FIG. 3 is a photograph showing the vibration reduction performance according to the height and length of the block type sound absorbing body.

The present invention relates to a resonance sound reducing tire to which a porous foamed sound absorbing body in the form of a block is attached to the inner surface of a tire. According to the present invention, the resonance sound can be efficiently reduced by controlling the density, height, and number of the foamed foam foamed foam used as the sound absorbing body.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

[Example]

Example 1: Production of tire for reducing resonance noise

A porous foamed sound absorbing body prepared by foaming a melamine resin was prepared. The sound absorbing body was in the form of a hexahedron block having dimensions of 130 * 100 * 75 가로 in height × height 32 ㎏ / ㎥.

Four manufactured sound absorbing blocks were attached to the inner surface of the tire 245 / 45R19 at 0 degree, 90 degree, 180 degree, and 270 degree, respectively, to produce a resonance sound reducing tire. . In order to easily attach the sound absorbing body to the inner surface of the tire, a double-faced tape having a thermoplastic polyurethane (TPU) type adhesive applied thereto was attached to one surface of the sound absorbing body.

Comparative Example 1. Manufacture of a tire for reducing resonance noise

To prepare a porous foamed sound absorbing body produced by foaming an ether type urethane resin. The sound absorbing body is 120 * 700 * 20 mm in height, width and height, and has a density of 30 kg / m 3. On the inner surface of the tire 245 / 45R19, a butyl-based gel-type sealant as an adhesive was applied over the entire surface to a thickness of 1 to 2 mm. The sound absorbing body prepared above was attached to the entire circumference of the tire inner surface to produce a resonance sound reducing tire.

Comparative Example 2. Manufacture of tire for reducing resonance noise

To prepare a porous foamed sound absorbing body produced by foaming an ether type urethane resin. The sound absorbing body is 120 * 700 * 20 mm in height, width and height, and has a density of 30 kg / m 3. Polyether solid type adhesive was applied to the inner surface of the tire 245 / 45R19, and five lines were applied in the circumferential direction of the tire so as to have a width of 10 mm and an interval of 20 mm. The sound absorbing body prepared above was attached to the entire circumference of the tire inner surface to produce a resonance sound reducing tire.

The sound absorption performance of the resonance sound reducing tire manufactured in each of Example 1, Comparative Example 1 and Comparative Example 2 is shown in Table 1 below.

division tire Weight increase ^* Highest noise
(dB) Example 1

0.05Kg 104.7 Comparative Example 1

2Kg 105.3 Comparative Example 2

1.5Kg 105.8 Control Example Unused tires (245 / 45R19) - 114.9 * Weight increase relative to the weight of unattached tires

According to the results of Table 1, it can be seen that the resonance sound reducing tire of Example 1 was excellent in sound absorption performance even though the weight increase was relatively small.

[Experimental Example]

Experimental Example 1. Sound Absorption Effect According to Height of the Sound Absorbing Body

In this experimental example, the sound absorbing body foamed with melamine resin was attached to the entire inner surface of the tire. At this time, the sound absorbing body was attached to the inner surface of the tire by using a thermoplastic polyacryl type adhesive tape.

Table 2 below shows the result of preparing the sound absorbing effect according to the height H of the sound absorbing body at the time of attaching the porous foamed sound absorbing body at the front.

[Attachment of sound absorbing body front]

division density
(kg / m ³ ) Height
(mm) Highest noise
(dB) Experiment 1-1

32
10 107.8 Experiment 1-2 20 105.7 Experiment 1-3 25 105.5 Experiment 1-4 35 104.2 Experiment 1-5 75 102.8

According to the results of Table 2, the sound absorption effect tends to increase as the height of the sound absorbing body is increased even when the porous foamed sound absorbing body is attached at the front.

In addition, FIG. 1 is a graph showing the result of measuring the noise level by frequency when the sound absorbing body is entirely coated so that the height H is 10, 20, and 25 mm.

Experimental Example 2: Sound absorption effect according to height when a single sound absorbing body was attached

In this experimental example, a sound absorbing body in the shape of a hexahedron block having a height of 130 * 100 * height (H) was prepared in the same manner as in Example 1. The manufactured sound-absorbing material was attached to the tire in the circumferential direction of the tire using a thermoplastic polyacryl-type adhesive tape.

Table 3 below shows the result of preparing the sound absorbing effect according to the height H of the sound absorbing body when one sound absorbing body is attached.

division density
(kg / m ³ ) Attach
Count Height
(mm) Highest noise
(dB) Experiment 1-3
32
Front 25 105.5 Experiment 2-1 One 25 113.5 Experiment 2-2 One 35 110.7 Experiment 2-3 One 75 107.1

According to the results of Table 3, the sound absorption effect tends to increase as the height H of the sound absorbing body becomes higher, as in the case of front-side attachment of the porous foamed sound absorbing body.

According to the above Table 3, when the sound absorber having a block shape is attached with a height of 25 mm or 75 mm, it shows a sound absorption difference of -6.4 dB. And, in case of attaching the sound absorbing body of 25 mm height, there is a difference of -8 dB sound absorbing effect for the case of one attachment at the front attachment. However, when the sound absorbing body of 75 mm block type was attached, the sound absorbing effect difference was only 1.6 dB in comparison with the tire attached to the front side at 25 mm height. Therefore, it can be seen that a tire having a sound absorbing performance equivalent to that of the front surface coating can be manufactured by adjusting the height of the sound absorbing body in block form.

Fig. 2 is a graph showing the noise level of a tire having a block type sound absorbing body having a height H of 25 or 75 mm, as compared with a tire having a sound absorbing body coated with a sound absorbing body at a height of 25 mm.

Experimental Example 3: Sound absorbing effect according to the number of the sound absorbing body attached in a block form

In this experimental example, a sound absorbing body in the shape of a hexahedron block having a height of 130 * 100 * height (H) was prepared in the same manner as in Example 1. The manufactured sound absorbing body was attached in the direction of 90 degrees with respect to the circumferential direction of the tire by using a thermoplastic polyacryl type adhesive tape.

Table 4 below shows the result of preparing the sound absorption effect according to the number of the sound absorption bodies attached in a block shape.

division density
(kg / m ³ ) Count Height
(mm) Highest noise
(dB) Experiment 3-1 0 0 0 114.9 Experiment 3-2

32

4 20 111.4 Experiment 3-3 4 25 110.7 Experiment 3-4 4 35 106.5 Experiment 3-5 One
75 107.1 Experiment 3-6 2 106.4 Experiment 3-7 3 105.0 Experiment 3-8 4 104.7

According to Table 4, it can be confirmed that the sound absorbing efficiency according to the height (H) is improved in comparison with the case where one block sound absorber is attached (Table 2).

In addition, as the number of block type sound absorbers increases, the sound absorption efficiency tends to increase. When three or more block type sound absorbers are attached, the sound absorption efficiency is equivalent to that of the front attachment. When four pieces of the sound absorbing body having a height of 75 mm were attached, it can be confirmed that there is a sound absorption effect of -10.2 dB in comparison with the tire not having the sound absorbing body. According to the experimental results, it is found that the melamine resin foamed foam not only absorbs sound but also has additional effects such as sound insulation / frequency shift, thereby effectively lowering the noise figure.

Experimental Example 4. Preparation of Sound Absorption Effect According to Density of Sound Absorbing Body

In this experimental example, a sound absorbing body in the form of a hexahedron block having the dimensions of 130 * 100 * 75 in height, width and height was manufactured in the same manner as in Example 1, except that the foam density was varied. The manufactured sound-absorbing material was adhered in the circumferential direction of the tire using a thermoplastic polyacryl-type adhesive tape.

Table 5 below shows the result of preparing the sound absorption effect according to the density of the sound absorption body in block form.

division density
(kg / m3) Height
(mm) Highest noise
(dB) Experiment 4-1 0 0 114.9 Experiment 4-2 20 10 110.2 Experiment 4-3 30 10 109.3 Experiment 4-4 32 10 107.8 Experiment 4-5 44 10 109.7

According to the results of Table 5, the sound absorption efficiency tends to increase while the density of the sound absorption body increases. The tire exhibiting the highest sound absorption efficiency when a foam having a density of 32 kg / m 3 is used and the sound absorption body is not attached -1), which is 7.1 dB. On the other hand, the use of foam with a density of 44 kg / m < 3 > When a foamed foam having a density of 20 to 45 kg / m < 3 > is used, a sound absorbing material suitable for attaining the object of the present invention can be produced.

EXPERIMENTAL EXAMPLE 5. Performance Evaluation of Vehicle Uniformity

This experimental example is for confirming the change of the uniformity characteristic after the block type sound absorbing body according to the present invention is attached to the tire.

division Characteristic value RFV (kgf) Deviation D / B (g) Deviation Unattached Attach Unattached Attach Experiment 5-1 25 mm
(5.9 g) 8.64 8.64 0 76.4 68.2 -8.2 6.35 6.64 0.29 59.8 56.3 -3.5 9.52 9.18 -0.34 53.4 46.9 -6.5 Experiment 5-2 50 mm
(11.8) 7.47 8.25 0.78 51.7 33 -18.7 7.67 7.91 0.24 38.2 37.5 -0.7 9.18 7.45 -1.73 35.2 48.4 13.2 Experiment 5-3 65 mm
(14.5) 8.84 9.38 0.54 47.9 46.4 -1.5 7.71 8.25 0.54 29.8 50.6 20.8 8.69 8.74 0.05 32.6 26.9 -5.7 Experiment 5-4 75 mm
(15.6) 8.4 8.79 0.39 38.8 33.1 -5.7 7.62 8.11 0.49 42.6 60.6 18 9.52 10.16 0.64 55.4 56.5 1.1

According to Table 6, it is judged that there is no influence of RFV (radial force variation) after the sound absorbing body is attached in the range of the deviation of 1 in RFV. Also, it can be seen that the change amount of the D / B after attachment of the sound-absorbing material is also at a level where the product can be managed.

Experimental Example 6. Evaluation of Sound Absorption Performance According to Height, Length, and Cross-sectional Area of Sound Absorbing Body

The present experimental example is to confirm the sound absorption performance according to the height and length changes of the block type sound absorbing body according to the present invention.

The block type sound absorbing body was an octahedral block type sound absorbing body having a density of 32 kg / m 3 foamed with melamine resin, and the cross sectional area was maintained at 3000 mm 2 and the width was 120 mm. That is, the sound absorbing body of the octahedral block type has the same volume of 36 × 10 ⁴ ㎣, but the sound absorbing body is manufactured by changing the length and height of the sound absorbing body. Four pieces of the sound absorbing bodies thus manufactured were attached in the circumferential direction of the tire using a thermoplastic polyacryl type adhesive tape.

division density
(kg / m3) Number of attachments Sound absorption body shape volume
(㎣) Highest noise
(dB) Experiment 6-1 0 0 - 0 119.3 Experiment 6-2



32

4

36x10 ⁴ 107.3 Experiment 6-3 4

36x10 ⁴ 109.0 Experiment 6-4 4

36x10 ⁴ 108.0

According to Table 7, the tires (Experiments 6-2, 6-3, and 6-4) to which the humps were attached in comparison with the tire without the sound absorbing material (Experiment 6-1) showed a sound absorption effect of about 10 dB . Experiments 6-2, 6-3 and 6-4 show that the sound absorption effect is almost unaffected by the height and length changes, and that the sound absorption effect is the same as the volume of 36x10 ⁴ ㎣, . That is, according to Table 7, it can be confirmed that the sound absorption effect of the sound-absorbing material is affected by the size change of the cross-sectional area but is not affected by the change of the length and height.

Experimental Example 7. Evaluation of Vibration Reduction Performance According to Height and Length of Sound Absorbing Body

In order to confirm the vibration reduction performance according to the height and length of the block type sound absorbing body according to the present invention, the vertical vibration according to the speed of the tire was measured, and the results are shown in FIG. As the sound absorbing body, four pieces of the block type sound absorbing bodies (6-2, 6-3, 6-4) prepared in Example 6 were attached to the tires respectively.

3, the vibration generation regions of the tires B, C, and D to which the block type sound absorbing bodies 6-2, 6-3, and 6-4 are attached in comparison to the sound absorbing body non-attachment tires A are significantly reduced can confirm.

It can also be seen that there is a difference in the vertical vibration due to the change in the length and height of the sound absorbing body. That is, it can be seen that the tire B has a higher height than the other tires, and the vibration is more strongly generated in the specific region than the tires C and D with the adsorbent having a lower height have. It can be confirmed that the tire C with the sound absorbing body 6-3 among the tires B, C, and D with the block-type sound absorbing body is particularly excellent in the vibration reduction effect.

According to the results of Experimental Examples 6 and 7, the sound absorption performance of the block type sound absorption body is affected by the volume of the sound absorption body, and the vibration reduction performance is influenced by the height of the sound absorption body.

Claims (9)

On the inner surface of the tire, two to five porous foamed sound absorbing bodies in block form are attached at an angle of 90 degrees in the circumferential direction.
The method according to claim 1,
Wherein the porous foamed sound absorbing body is made of any one material selected from the group consisting of a porous melamine foam foam and a urethane foam foam.
The method according to claim 1,
Wherein the porous foamed sound absorbing body has a density of 20 to 45 kg / m < 3 >.
The method according to claim 1,
Wherein the porous foam foam absorbing body is in the form of a polyhedral block selected from the group consisting of a tetrahedron and an octahedron.
5. The method of claim 4,
Wherein the porous foamed sound absorbing body has a volume of 20 x ^{10 4} to 240 x 10 ⁴ pounds.
5. The method of claim 4,
Wherein the porous foamed sound absorbing body is in the form of a hexahedron block having a length and a length of 100 to 180 mm and a height of 20 to 75 mm.
5. The method of claim 4,
The porous foamed sound absorbing body is a cubic block having a trapezoidal cross section having a transverse upper end length of 10 to 40 mm, a transverse bottom end length of 100 to 180 mm, a longitudinal length of 100 to 180 mm, and a height of 20 to 75 mm ) Type resonance noise reducing tire.
5. The method of claim 4,
The porous foamed sound absorbing body may have a width of 10 to 40 mm, a width of 100 to 180 mm, a length of 100 to 180 mm, a height of both ends of 10 to 20 mm, Wherein the shape of the resonance sound reducing tire is a shape of an octahedral block having a diameter of 75 mm.
The method according to claim 1,
Wherein the porous foamed sound absorbing body is attached to the inner surface of the tire using a thermoplastic polyurethane (TPU) type or thermoplastic polyacryl type adhesive.

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