Low-noise pocket-like wheel protection

Abstract

Low-noise pocket-like wheel guard, comprising: a protector (100) installed to face a surface of a tire in a vehicle, wherein a noise reduction pocket (200) is formed to protrude within the protector (100) toward an interior of the vehicle, the noise reduction pocket comprising: an inlet (210) formed on an inner surface of the protector (100); and a space (220) configured to protrude from the inlet to an exterior of the shelter, wherein the inlet (210) is formed in a portion of a surface of the protector (100) in which the sound field of the vibration frequency corresponding to the peak point of the tire tread noise has been formed, thereby preventing the formation of a sound field in the protector (100).

Description

BACKGROUNDTechnical field

[0001] The present invention relates to a low-noise bag-type wheel guard, and more particularly, to a low-noise bag-type wheel guard capable of effectively suppressing a high-frequency peak noise, which is a tire tread component and intensifies a running noise inside a vehicle. State of the art

[0002] A wheel guard, or wheel arch, is installed in a vehicle to enhance its aesthetic appearance by covering the body and to prevent tire contaminants from entering the body. However, a study found that tire tread noise is generated during vehicle movement in a frequency range of 800 Hz to 1200 Hz.

[0003] Meanwhile, a study found that tire pattern noise is generated during vehicle travel in a frequency range of 800 Hz to 1200 Hz (SW Hwang, MJ Bang, GH Rho, and CT Cho, “The study on Tire Pattern Noise,” the collected proceedings of the Spring Meeting of the Korean Society for Noise and Vibration Engineering, pages 310 to 313, 2006).

[0004] Tire tread noise is perceived by a user inside the vehicle due to a peak noise characteristic. Furthermore, an acoustic constructive interference phenomenon is generated depending on the distance between a tire surface and the wheel guard or wheel house, which intensifies the running noise audible inside the vehicle.

[0005] Fig. Figure 1 is a graph illustrating running noise recorded inside a vehicle with installed wheel guards and a vehicle without installed wheel guards according to the prior art. As shown in Fig. As shown in Figure 1, the peak of the tire noise measured inside the vehicle is higher when the wheel guard is installed. When the wheel guard is installed, vibrations of a frequency corresponding to the peak of the tire tread noise are concentrated at a specific portion of the wheel guard to form a sound field.

[0006] Fig. Figure 2 shows results of a sound field analysis of the wheel guard according to the state of the art. As in Fig. As shown in Figure 2, a strong sound field is concentrated at an end portion of one side of the wheel guard at a frequency (e.g., in the range of 800 Hz to 1200 Hz) of the tire tread noise. Therefore, vibrations of the frequency corresponding to the peak point of the tire tread noise can be dissipated to form the sound field in the wheel guard, thereby amplifying the peak point of the tire tread noise. Furthermore, since the tire tread noise enters the vehicle interior in a state where the peak point is increased, the running noise detected in the vehicle interior is intensified.

[0007] Furthermore, DE 10 2013 206 509 A1 discloses a low-noise pocket-type wheel guard comprising an arcuate guard facing a tire surface in a vehicle and a noise-reducing pocket protruding within the guard toward an interior of the vehicle. Similar disclosures can also be found in DE 197 10 029 A1, DE 195 40 263 A1, DE 195 40 259 C1, DE 42 41 518 C1, and JP 2013-23 007 A. SUMMARY

[0008] The present invention is based on the object of providing a low-noise pocket-type wheel guard capable of effectively suppressing a high-frequency peak noise, which is a tire tread component and intensifies a running noise detected inside a vehicle.

[0009] According to the present invention, a low-noise pocket-type wheel guard has the features of claim 1. Embodiments of the invention are defined in the subclaims. Furthermore, the guard can be arc-shaped.

[0010] The inlet may be located on one side of an end portion of both end portions of the guard in a rearward direction of the vehicle. The guard may be formed in the shape of an arc, and the noise reduction pocket may include a first pocket located on one side of an end portion of both end portions of the guard in a rearward direction of the vehicle, and a second pocket formed to be closer to a center portion of the guard than the first pocket.

[0011] A wavelength tube principle can be applied to calculate the height of a room perpendicular to an imaginary line parallel to the ground and in the same direction as the vehicle's direction of travel. The height of the room can be calculated using the following equation 1: Equation 1 h=(1 / 4)×(c / f), where h is the height of the room, c is the speed of sound (approximately 340 m / s) and f is a target frequency (in the range of approximately 700 Hz to 1400 Hz).

[0012] An expansion tube principle can be applied to calculate the length of the inlet perpendicular to an imaginary line parallel to the ground. The length of the inlet can be calculated using the following equation 2: a=(1 / 2)×(c / f)=2×h where a is the length of the inlet, c is the speed of sound (approximately 340 m / s), f is a target frequency (in the range of approximately 700 Hz to 1400 Hz) and h is the height of the room 220.

[0013] Further, the noise reduction pocket may be formed as two or more noise reduction pockets to be arranged from one side of an end portion of both end portions of the guard in a rearward direction of the vehicle toward the center portion of the guard, and since the two or more noise reduction pockets are formed to be closer to the center portion of the guard, the target frequencies used in the calculations of the length of the inlet and the height of the space can be set to be lower.

[0014] Furthermore, the height of the space may include a first height corresponding to a dimension of an edge of a lower surface of the space that is closest to the floor, a second height corresponding to a dimension of an edge of an upper surface of the space that is farther from the floor than the lower surface of the space, the target frequencies used in the calculations of the first height and the second height may be different from each other, and a low target frequency among the target frequencies used in the calculations of the first height and the second height may be used in the calculation of the length of the inlet.

[0015] The length of the inlet perpendicular to an imaginary line parallel to the ground can be determined in a range of approximately 12 cm to 24 cm and the height of the space perpendicular to an imaginary line parallel to the ground and in the same direction as the direction of travel of the vehicle can be determined in a range of approximately 6 cm to 12 cm. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will now be described in detail with reference to embodiments thereof which are illustrated in the accompanying drawings, in which Fig. 1 is a graph illustrating a running noise in an interior of a vehicle with a wheel guard installed and a vehicle without a wheel guard installed according to the prior art; Fig. Figure 2 is a diagram illustrating results of a wheel guard sound field analysis according to the prior art; Fig. 3 is a perspective view illustrating a low-noise bag-type wheel guard according to an embodiment of the present invention; the Fig. 4 to 6 cross-sectional views illustrating main sections of the low-noise pocket-type wheel guard made of Fig. 3 according to an embodiment of the present invention; Fig. 7 is a cross-sectional view illustrating a length of an inlet and a height of a space according to an embodiment of the present invention; Fig. 8 is a graph in which a target frequency is set according to an embodiment of the present invention; Fig. 9 shows graphs illustrating results of noise measurement in a forward-backward direction of the wheel guard according to an embodiment of the present invention; Fig. 10 is a graph illustrating running noise detected within the vehicle according to an embodiment of the present invention; Fig. 11 is a schematic diagram illustrating a wavelength tube principle according to an embodiment of the present invention; and Fig. 12 is a schematic diagram illustrating an expansion tube principle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0017] It is understood that the term “vehicle” or “vehicle-” or other similar terms used herein includes motor vehicles in general such as passenger cars, including sports utility vehicles (SUVs), buses, trucks, various commercial vehicles, watercraft, including various boats and ships, aircraft and the like, and includes hybrid vehicles, electric vehicles, internal combustion engine vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other vehicles powered by alternative fuels (e.g., fuels derived from resources other than petroleum).

[0018] Although an embodiment is described in which a plurality of units are used to perform the example process, it is understood that the example processes may also be performed by one or a plurality of modules. Furthermore, it is understood that the term controller refers to a hardware device including a memory and a processor. The memory is configured to store the modules, and the processor is specifically configured to execute the modules to perform one or more processes described elsewhere.

[0019] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It is further understood that the terms “comprising” and / or “comprising,” when used in this specification, indicate the presence of stated features, numbers, steps, acts, elements, and / or components, but do not preclude the presence or addition of one or more features, numbers, steps, acts, elements, components, and / or groups thereof. The term “and / or” as used herein includes any combination of one or more of the stated enumerations.

[0020] Unless specifically stated or obvious from the context, the term "approximately" used herein should be understood as within a normal engineering tolerance range, for example, within 2 standard deviations of the mean. "Approximately" can be understood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless the context otherwise indicates, all numerical values ​​stated herein are accompanied by the term "approximately."

[0021] Hereinafter, a low-noise bag-type wheel guard according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0022] As in the Fig. 3 to 7, a low-noise pocket-type wheel guard according to an embodiment of the present invention may include a guard 100 installed in a vehicle to face a surface T of a tire, and a noise reduction pocket 200 formed to protrude in the guard 100 toward an interior of the vehicle. Fig. The guard 100 shown in Figure 3 may be formed in an arc shape. Furthermore, the guard 100 may be formed to have a diameter larger than that of the tire based on a center point of the tire. The guard 100 may be made of an iron material. A guide and the like for increasing airflow may be formed in the guard 100.

[0023] As in the Fig. 4 to 7, it is assumed that a distance d between the protector 100 and the surface T of the tire is in the range of approximately 6 to 12 (centimeters) cm. The noise reduction pocket 200 may include an inlet 210 having a length a formed on an inner surface of the protector 100, and a space 220 formed to protrude toward the exterior of the protector 100 by the length a of the inlet 210. The inlet 210 may be formed in a portion of the surface of the protector 100 in which the sound field of the vibration frequency corresponding to the peak point of the tire tread noise has been formed. The inlet 210 may be formed to have the length a which is 1 / 2 a wavelength of the vibration frequency of the peak point. The space 220 may be formed to have a height h which is 1 / 4 wavelength size of the oscillation frequency of the peak point.The 1 / 4 wavelength size can be obtained by dividing a speed of sound by the vibration frequency.

[0024] As the tire tread noise moves along the protector 100, a wavelength corresponding to the peak point oscillates toward the space 220, thus preventing the formation of the sound field. Furthermore, no amplification of the tire tread noise due to the sound field is generated because the sound field can be prevented from forming in the protector 100.

[0025] As in Fig. 2, the inlet 210 may be arranged on one side of an end portion of both end portions of the guard 100 in a rearward direction of the vehicle. As shown in Fig. As shown in FIG. 9, the vibration frequency corresponding to the peak point of the tire tread noise was not increased due to the guard 100 on one side of one end portion of the two end portions of the guard 100 in a forward direction of the vehicle. Therefore, the noise reduction pocket 200 may not be formed at the end portion of the two end portions of the guard 100 in the vehicle direction.

[0026] As in Fig. As shown in Fig. 5, the noise reduction pocket 200 may include a first pocket 201 disposed on one side of the end portion of the two end portions of the guard 100 in the rearward direction of the vehicle, and a second pocket 202 disposed closer to a central portion of the guard 100 than the first pocket 201. Since two or more noise reduction pockets 200 are formed in the guard 100, it may be possible to prevent the formation of sound fields of different frequencies (see Fig. 8).

[0027] As in Fig. 6, an inner wall surface of the space 220 facing a rear side of the vehicle may be formed in an inclined shape. However, with reference to Fig. 7, the length a of the inlet 210, which is perpendicular to an imaginary line parallel to the ground, can be determined in a range of approximately 12 cm to 24 cm. The height h of the space 220, which is perpendicular to an imaginary line parallel to the ground and in the same direction as a direction of travel of the vehicle, can be determined in a range of approximately 6 cm to 12 cm. Fig. 7, a dotted line represents a waveform of tire noise propagation.

[0028] Furthermore, the length a of the inlet 210 and the height h of the space 220 can be arithmetically determined by a wavelength tube principle in which a sound wave reflected from a distal end of a tube is reflected back at an inlet end to control a noise at the inlet end (see Fig. 11), and from an expansion tube principle of reducing noise transmission sensitivity by abruptly changing an area to a pipe or pipeline (see Fig. 12). The height h of the space 220, which is perpendicular to the imaginary line parallel to the ground and in the same direction as the direction of travel of the vehicle, can be calculated by the following equation 1. h=(1 / 4)×(c / f) where h is the height of the room 220, c is the speed of sound (approximately 340 m / s) and f is a target frequency (in the range of approximately 700 Hz to 1400 Hz).

[0029] Furthermore, the length a of the inlet 210, which is perpendicular to the imaginary line parallel to the ground, can be calculated by the following equation 2. a=(1 / 2)×(c / f)=2×h where a is the length of the inlet 210, c is the speed of sound (approximately 340 m / s), f is the target frequency (in the range of approximately 700 Hz to 1400 Hz) and h is the height of the room 220.

[0030] As in Fig. 5, when two or more noise reduction pockets 200 are formed to be arranged from one side of the end portion of the two end portions of the guard 100 in the rearward direction of the vehicle toward the central portion of the guard 100, the target frequencies used in the calculations of the length a of the inlet 210 and the height h of the space 220 can be set to be lower or less (compared with the provision of one noise reduction pocket), since the two or more noise reduction pockets 200 are formed to be closer to the central portion of the guard 100.

[0031] As in Fig. 6, when an inner wall of the noise reduction bag 200 is inclined toward the rear of the vehicle, the target frequencies can be set as follows. For the height h of the space 220, if a dimension of an edge of a lower surface of the space 220 closest to the ground is referred to as the first height h1, and a dimension of an edge of an upper surface of the space 220 farther from the ground than the lower surface of the space 220 is referred to as the second height h2, different target frequencies can be substituted for the calculation of the first height h1 and the second height h2. Furthermore, a low target frequency among the target frequencies substituted for the calculation of the first height h1 and the second height h2 can be substituted for the calculation of the length a of the inlet 210.

[0032] As described above, according to the low-noise bag-type wheel guard according to an embodiment of the present invention, the noise reduction bag 200 can be formed at the end portion of the guard in which a sound field is expected to be formed due to the tire tread noise, the formation of the sound field due to the tire tread noise can be restrained and prevented.

[0033] As in Fig. As shown in Figure 10, when one embodiment of the present invention was used, the peak point in a target frequency range was lower according to the measurement than when no embodiment of the present invention was used. Therefore, Fig. 10 that a high-frequency peak noise, which is a tire tread component that intensifies the running noise detected in the interior of the vehicle, can be effectively suppressed.

[0034] According to the above-mentioned low-noise pocket-type wheel guard according to an embodiment of the present invention, since a noise reduction pocket can be formed at the end portion of the guard where a sound field is expected to be formed due to tire tread noise, the formation of a sound field due to tire tread noise can be contained and prevented. Accordingly, a high-frequency peak noise, which is a tire tread component that intensifies running noise detected inside the vehicle, can be effectively suppressed.

Claims

[1] Low-noise pocket-type wheel guard, comprising: a protector (100) installed to face a surface of a tire in a vehicle, wherein a noise reduction pocket (200) is formed to protrude within the protector (100) toward an interior of the vehicle, the noise reduction pocket comprising: an inlet (210) formed on an inner surface of the protector (100); and a space (220) configured to protrude from the inlet to an exterior of the shelter, wherein the inlet (210) is formed in a portion of a surface of the protector (100) in which the sound field of the vibration frequency corresponding to the peak point of the tire tread noise has been formed, thereby preventing the formation of a sound field in the protector (100). [2] A low-noise bag-type wheel guard according to claim 1, wherein the inlet (210) is arranged on one side of an end portion of both end portions of the guard (100) in a rearward direction of the vehicle. [3] A low-noise bag-type wheel guard according to claim 1, wherein the guard (100) is arcuately formed and wherein the noise reduction bag (200) comprises: a first pocket (201) arranged on one side of an end portion of both end portions of the protector (100) in a rearward direction of the vehicle; and a second pocket (202) configured to be located closer to a central portion of the protector (100) than the first pocket (201). [4] A low-noise bag-type wheel guard according to claim 1, wherein a wavelength tube principle is applied to a calculation of a height of the space perpendicular to an imaginary line parallel to the ground and in the same direction as a traveling direction of the vehicle. [5] A low-noise pocket-type wheel guard according to claim 4, wherein the height of the space (220) is calculated by the following equation 1: h=(1 / 4)×(c / f) where h is the height of the room (220), c is the speed of sound and f is a target frequency. [6] A low-noise bag-type wheel guard according to claim 5, wherein an expansion tube principle is applied to a calculation of a length of the inlet (210) perpendicular to an imaginary line parallel to the ground. [7] A low-noise pocket-type wheel guard according to claim 6, wherein the length of the inlet (210) is calculated by the following equation 2: a=(1 / 2)×(c / f)=2×h Where a is the length of the inlet (210), c is the speed of sound, f is a target frequency and h is the height of the room. [8] A low-noise pocket-type wheel guard according to claim 7, wherein: the noise reduction pocket (200) is formed as two or more noise reduction pockets to be arranged from one side of an end portion of both end portions of the guard (100) in a rearward direction of the vehicle toward the central portion of the guard (100); and since the two or more noise reduction pockets (200) are formed to be located closer to the central portion of the guard (100), the target frequencies used in the calculations of the length of the inlet (210) and the height of the space (220) are set to become lower. [9] A low-noise pocket-type wheel guard according to claim 7, wherein the height of the space (220) comprises: a first height (h1) corresponding to a dimension of an edge of a lower surface of the space (220) closest to the floor; and a second height (h2) corresponding to a dimension of an edge of an upper surface of the space (220) which is further from the ground than the lower surface of the space (220), and where the target frequencies used in the calculations of the first height (h1) and the second height (h2) differ from each other, and wherein a lowest target frequency among the target frequencies used in the calculations of the first height (h1) and the second height (h2) is used in the calculation of the length (a) of the inlet (210).

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