KR20090010938A - Pneumatic tire with the sound absorber - Google Patents

Abstract

A noise reduced pneumatic tire is provided to prevent that the natural frequency of tire and noise frequency are resonant. A noise reduced pneumatic tire comprises a noise removal structure(30) formed with the porous material, a noise removal space(V) formed in the inner side of noise removal structure, a bonding layer(40) welding the noise removal structure to the inner surface of the tire(20). The noise removal structure includes a flat part(31) adhered to the tire inner surface, a pair of side parts(33) which is protruded to the tire radius direction inner side from the floor part. The noise removal space is formed by the floor part, side part and inside portion(35).

Description

Pneumatic tire with the sound absorber}

The present invention relates to a low noise tire, and to a low noise pneumatic tire capable of reducing driver's fatigue due to noise by reducing low and high frequency noise generated during driving.

In general, pneumatic tires are used to fill the air to absorb the vibrations due to irregular road surface to enhance the durability of the vehicle and give a comfortable ride to the vehicle occupants. In addition, a tread pattern including a plurality of grooves and grooves is formed on the tire tread in contact with the road surface, thereby improving steering and driving performance of the vehicle.

However, the tread pattern of a pneumatic tire when driving a vehicle generates noise when it comes into contact with an irregular road surface or when an impact is applied from the outside, and the noise is transmitted to the inside of the tire filled with air, so that the tire itself vibrates, for example, the air inside. The sound is amplified like a resonance tube that amplifies the sound, and the frequency of the noise and the shape of the material, for example, a U-shaped structure that is filled with air to fill the inside of the tire causes a resonance phenomenon. Is further amplified.

The resonance frequency due to the structure of the tire has a specific frequency inherent to the tire corresponding to an integer multiple of the speed of sound divided by the circumferential length of the air layer.

In order to solve the above problems, a pneumatic tire capable of reducing noise has been disclosed as shown in FIG.

The conventional low noise pneumatic tire 100 is provided with a sound absorbing material 120 on the inner surface of the tire (110).

The sound absorbing material 120 is made of a porous material, and configured to have a volume of 20% or less of the tire 110 volume.

Accordingly, the low noise pneumatic tire 100 was able to reduce the noise by the porous sound absorbing material 120 when the noise occurs.

However, when the low noise pneumatic tire 100 is configured to have the sound absorbing material 120 to have 20% or more of the volume of the tire 110, the amount of air charged in the tire 110 is relatively low, and the tire performance is lowered. By using only the sound absorbing material 120, the noise reduction effect is insignificant, there was a problem that the amplification of the noise to the resonance phenomenon.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and reduces the low frequency broadband noise that may be generated during driving, and in particular, a specific frequency of high frequency, for example, a frequency of noise or a tire that is most prone to fatigue. The purpose of the present invention is to provide a low noise pneumatic tire that can reduce the driver's fatigue due to noise by preventing resonance due to the specific frequency of the motor.

In order to achieve the above object, the present invention provides a bottom plate attached to the inner surface of the tire, a pair of side walls protruding radially inward from the bottom plate and spaced apart from each other, and face each other from the end of each side wall A noise canceling structure formed of a porous material, the inner bent portion being protruded to be formed integrally with the sidewalls; At least one noise reduction space formed by the bottom plate, the side wall, and the inner bent portion; And an adhesive layer comprising an adhesive for bonding the bottom plate and the tire inner surface, a first primer applied between the bottom plate and the adhesive, and a second primer applied between the tire inner surface and the adhesive. It features.

In addition, in the present invention, the noise reduction space is characterized in that the plurality of partitions formed by at least one or more partitions formed between the side walls protruding radially inwardly from the bottom plate.

In addition, in the present invention, the adhesive is characterized in that the double-sided adhesive tape.

According to the present invention, by combining the noise canceling structure to the inner surface of the tire, not only can reduce the broadband noise of the low frequency, but also reduce the noise of the same frequency as the resonance frequency of the high frequency to prevent the amplification of the noise, As a result, the driver's fatigue is reduced.

Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, before describing the structure of the pneumatic tire of the present invention, the Helmholtz resonance principle applied to the present invention will be briefly described.

In general, Helmholtz Resonance Principle is a device consisting of an enclosed space with a small hole or snout, and when a special standing wave enters the resonator through a narrow snout, a new out of phase It is transformed into a vibration of the form and it comes out of the resonator. Therefore, the phase cancellation for a specific frequency (Phase Cancellation) occurs to eliminate the specific standing wave is a principle that can reduce the noise, a slight change in the structure can change the resonance frequency.

This Helmholtz resonance frequency is calculated by the following equation.

Where f is the resonance frequency of Helmholtz, C is the sound velocity of the fluid, S is the cross-sectional area of the fluid inlet, L is the length of the neck, and V is the volume of the resonance space.

Since the resonant frequency of the Helmholtz can be varied by the variables of S, L and V, it is possible to widen the variable frequency bandwidth. For example, the resonance frequency can be increased by reducing the neck length L of the resonator.

Example  One

2 is a sectional view of a pneumatic tire according to a first embodiment of the present invention, FIG. 3 is a partially enlarged sectional view showing an adhesive layer according to the first embodiment of the present invention, and FIG. It is a graph showing the loudness according to the frequency band of a pneumatic tire and a conventional pneumatic tire.

As shown in FIG. 2, the low noise pneumatic tire 10 according to the present embodiment has an adhesive layer 40 for adhering the tire 20, the noise canceling structure 30, and the tire 20 and the noise canceling structure 30. It is composed of

Since the tire 20 is the same as the structure of a general pneumatic tire, description thereof will be omitted.

The noise canceling structure 30 is made of a porous material, and the bottom plate 31 adhered to the inner surface of the tire 20 at a position corresponding to the tread portion 21 of the tire 20, and the bottom plate 31. A pair of side walls 33 are formed to have a predetermined height radially inward from the tire 20).

The side walls 33 are formed to be spaced apart from each other by a predetermined distance in the width direction of the tire 20, and the inner side to have a predetermined length and thickness in the width direction of the tire 20 from the radially inner end of the tire 20 of the side wall 33. The bent portions 35 are formed to protrude to face each other.

That is, the sidewalls 33 are formed in a shape of an L-shape integrally with the inner bent portion 35 and are symmetrically spaced apart from each other by a predetermined distance.

In addition, a noise removing space (V) surrounded by the side wall 33, the bottom plate 31 and the inner bent portion 35 is formed, the noise between the opposite ends of the inner bent portion (35) A suction port S is formed, and noise is sucked into the noise removing space V through the noise suction port S. The noise suction opening S is formed in a shape that is continuously opened in the circumferential direction.

The noise reduction structure 30 is made of a porous material to reduce the noise of the low frequency band around 200Hz, the noise reduction space (V) can reduce the noise of the high frequency band of 1000Hz or more by using the Helmholtz resonance principle.

In addition, the thicker the bottom plate 31 of the noise canceling structure 30, the longer the length of the low frequency band noise is passed, the noise reduction performance of the low frequency band around 200Hz is improved, the thickness of the bottom plate 31 Is preferably determined according to the extent that the performance of the tire does not decrease and the noise reduction performance.

As shown in FIG. 3, the noise reduction structure 30 is attached to the inner surface of the tire 20 by an adhesive layer 40. The adhesive layer 40 is composed of an adhesive 41 and a first primer 41a and a second primer 41b applied to the adhesive 41, and the first primer 41a is formed of the adhesive 41. Located between the bottom plate 31 of the noise canceling structure 30, the second primer 41b is located between the adhesive 41 and the inner surface of the tire 20.

The first and second primers 41a and 42b are liquid as adhesion promoters which are applied to improve adhesion of respective adhesion surfaces, and are evaporated and become invisible after attachment. In addition, the adhesive 41 is preferably composed of a bond or double-sided adhesive tape, the first and second primers (41a, 41b) is configured separately to the bottom plate 31 or the inner surface of the tire (20). It is also possible to apply.

Here, the noise of the tire is largely below 500Hz based on 500Hz, and the low frequency band is called STRUcture-borne noise, and the high frequency band above 500Hz is called air-borne noise. The vibration generated from the tire is transmitted by the suspension system of the vehicle to the interior of the vehicle, and the noise is caused by the vibration. The air transfer noise is the noise generated from the tire directly into the vehicle interior through the air.

The adhesive layer 40 improves the lateral uniformity and prevents generation of the solid transfer noise. The lateral uniformity receives the tire to the left and right sides when the tire is created in the vehicle and contacts the road surface. The force means, and the worse the lateral uniformity, the greater the vibration of the tire, and the vibration is transmitted to the inside of the vehicle through the suspension system to generate noise, so that the noise reduction structure 30 to the adhesive layer 40 ) Is firmly adhered to the tire 20, thereby preventing the vibration of the tire due to the vibration of the noise reduction structure 30.

Therefore, the adhesive layer 40 may prevent the generation of noise in the low frequency band of 500 Hz or less generated due to the vibration of the tire 20, thereby improving noise reduction performance.

The operation and effects between the components in the present embodiment described above will be described.

The pneumatic tire 10 of the present embodiment has the noise elimination structure based on the Helmholtz resonance principle to prevent the noise frequency and the specific frequency of the tire 20 from resonating after calculating a specific frequency inherent in the tire 20. It is configured to reduce the same noise frequency that the tire 20 resonates by adjusting the thickness of the inner bent portion L, the volume of the noise removing space V, and the area of the noise suction port S of the tire 30. ) To the inner surface. At this time, the fluid inlet of Equation 1 is the noise inlet (S), the length of the neck is the thickness of the inner bent portion (L), the resonance space corresponds to the equation (1) so as to correspond to the noise removal space (V) The calculation will determine the noise frequency you want to reduce.

The pneumatic tire 10 configured as described above can reduce the noise of the low frequency band around 200Hz due to the noise canceling structure 30 formed in the porous form when the noise is generated, and the specific frequency of the high frequency band of 1000Hz or more, or the frequency of noise that is uncomfortable for humans. By reducing the noise in the noise removal space (V) and at the same time to prevent the occurrence of noise in the low frequency band below 500Hz to the adhesive layer 40, it is possible to lower the fatigue of the driver due to the noise.

The above-described effects in the present embodiment can be seen in a graph showing the loudness according to the frequency band of the pneumatic tire (dotted line) and the general pneumatic tire (solid line) according to the first embodiment of FIG.

In the graph of FIG. 4, the horizontal axis represents the loudness (dB), the vertical axis represents the frequency (Hz), and are measured inside the vehicle, respectively. Here, the general pneumatic tire (solid line) represents the pneumatic tire of the first embodiment ( 10) is a tire from which the noise canceling structure 30 is removed, and the noise canceling structure 30 is configured to reduce the sound of 1000 Hz, which is easy for a person to feel fatigue.

As shown in FIG. 4, the pneumatic tire according to the present embodiment was detected to have a lower loudness (dB) in the overall frequency band than the general pneumatic tire. In particular, the noise reduction structure 30 detects the noise 3 to 4dB lower in the 250Hz band, the noise is detected 3dB lower in the 1000Hz band of the Helmholtz resonance set in the present embodiment, the adhesive layer in the band below 500Hz It can be seen that the noise is reduced by 40 so that the tire according to the present embodiment is significantly lower than the general pneumatic tire.

Example  2

FIG. 6 is a cross-sectional view of the pneumatic tire according to the second embodiment, and as shown in FIG. 2, the pneumatic tire 10 according to the present embodiment has the same configuration and the same effect as the first embodiment. .

However, in the present embodiment, the partition wall 39 protruding from the bottom plate 31 is further formed between the side walls 33 of the noise canceling structure 30. The partition 39 may reduce a plurality of noise frequencies by dividing a plurality of noise removing spaces V formed between the side walls 33.

In addition, a plurality of barrier ribs 39 may be formed, and the distance and thickness of each of the barrier ribs 39 may vary according to the frequency to be reduced.

If the operation and effects between the components of the present embodiment configured as described above are explained,

The pneumatic tire 10 allows the partition 39 between both sidewalls 33 to reduce the frequency of noise equal to a number of specific frequencies, for example, the frequency of noise that is undesired to human and the resonance frequency of the tire 20. Calculate and determine the thickness and location of the bulkhead.

Accordingly, the pneumatic tire 10 can further reduce the number of specific frequencies by the Helmholtz resonance principle to the effect of the first embodiment, thereby reducing the number of specific noises and reducing the driver's fatigue due to the noise.

Although the present invention has been described with respect to preferred embodiments, the present invention is not limited thereto, and those skilled in the art will be able to make various modifications and applications within the scope of the present invention.

1 is a cross-sectional view showing a conventional low noise pneumatic tire.

2 is a sectional view of a pneumatic tire according to a first embodiment of the present invention.

3 is a partially enlarged cross-sectional view showing an adhesive layer according to the first embodiment of the present invention.

Fig. 4 is a graph showing the loudness according to the frequency band of the pneumatic tire and the conventional pneumatic tire according to the first embodiment of the present invention.

5 is a pneumatic tire sectional view according to the second embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

10: low noise pneumatic tire 20: tire

21: Tread 30: Noise canceling structure

31: bottom plate 33: side wall

35: inner bent portion 40: adhesive layer

41a, 41b: first and second primer V: noise canceling space

S: Noise intake L: Inner bend thickness

Claims (3)

A bottom plate 31 attached to the inner surface of the tire 20, a pair of side walls 33 protruding radially inward from the bottom plate 31, and spaced apart from each other at a predetermined distance, and ends of the respective side walls 33. A noise canceling structure (30) formed of an inner bent part (35) integrally formed with the side wall (33) and protruding from each other so as to face each other from the part; At least one noise reduction space (V) formed by the bottom plate (31), the side wall (33) and the inner bent portion (35); Adhesive 41 for joining the bottom plate 31 and the inner surface of the tire 20, the first primer 41a applied between the bottom plate 31 and the adhesive 41, and the tire 20 A low noise pneumatic tire, comprising: an adhesive layer (40) comprising a second primer (41b) applied between an inner surface and the adhesive. The method of claim 1, The noise reduction space (V) is formed in a plurality of partitions formed by at least one or more partitions 39 formed between the side walls 33, protruding from the bottom plate 31 in the radially inward direction of the tire. Low noise pneumatic tires. The method according to claim 1 or 2, The adhesive 41 is a low noise pneumatic tire, characterized in that the double-sided adhesive tape.

Images