A tire pattern structure for reducing tire aerodynamic noise across the entire frequency band

Abstract

The present invention discloses a tire tread structure that reduces tire aerodynamic noise across the entire frequency band. This relates to the field of tire tread pattern structures. A side branch-shaped pattern groove is provided on the tire's central tread block. The side branch-shaped pattern groove structure comprises longitudinal grooves and transverse grooves. The longitudinal grooves extend along the circumference of the tire's central tread block, and the transverse groove centerlines form an acute angle with the longitudinal groove centerlines. By providing the side branch-shaped pattern grooves and V-shaped rib structures on the tire's central and western tread blocks, the present invention reduces tire aerodynamic noise across the entire frequency band.

Description

Technical Field

[0001] The invention relates to a tread pattern structure of a radial tire for a passenger car, and in particular to a tire pattern structure capable of reducing tire aerodynamic noise in all frequency bands. Background Art

[0002] Under pressure from energy and environmental concerns, new energy vehicles will undoubtedly become the future direction of automotive development. While engine noise from new energy vehicles has been significantly optimized and controlled, tire noise, a significant component of vehicle noise and part of urban road noise pollution, has yet to be effectively optimized and controlled.

[0003] Studies have shown that when a vehicle is traveling at high speed, the tire noise is mainly caused by the mutual flow and disturbance of the air around the tire, which is called aerodynamic noise. European patent EP2014485 proposes to reduce the air column resonance noise by opening a branch pipe in the longitudinal pattern groove, and this method does not sacrifice the hydroplaning performance of the tire, but does not consider the impact of the gas vortex formed by the opening of the branch pipe on the medium and low frequency aerodynamic noise; Chinese patent CN102848859B reduces tire noise by setting a non-smooth rectangular groove on the pattern groove wall, but this solution is difficult to implement in the actual process production. Chinese patent CN111873719A improves the turbulent structure near the wall of the main groove by arranging regularly arranged conical protrusions on the bottom surface of the main groove, reduces the rupture caused by mutual collision and abnormal separation between vortices, reduces the intensity of turbulence and pulsating pressure, and thus effectively reduces the aerodynamic noise of the tire. However, this solution is very difficult to implement in the actual process production and is not conducive to engineering implementation. Summary of the Invention

[0004] In response to the deficiencies in the prior art, the present invention provides a tire pattern structure that reduces tire aerodynamic noise across the entire frequency band. By providing branch pipe-shaped pattern grooves and V-shaped rib structures on the central and western tread blocks of the tire, the tire's aerodynamic noise across the entire frequency band is reduced.

[0005] The present invention achieves the above technical objectives through the following technical means.

[0006] A tire pattern structure with full-band tire aerodynamic noise reduction, wherein a branch-tube-shaped pattern groove is provided on the tire's central pattern block, the branch-tube-shaped pattern groove structure comprising a longitudinal groove and a transverse groove, wherein the longitudinal groove is along the circumferential direction of the tire's central pattern block, and the centerline of the transverse groove forms an acute angle with the centerline of the longitudinal groove.

[0007] In the above solution, one end of the transverse groove is connected to the longitudinal groove, and the other end is arranged at the edge of the central tread block of the tire.

[0008] In the above solution, the branch pipe-shaped pattern grooves are evenly arranged on the central tread block of the tire, and there are two rows of branch pipe-shaped pattern grooves along the circumferential direction of the central tread block of the tire.

[0009] In the above solution, the angle between the longitudinal groove centerline and the transverse groove centerline of the branch tube pattern groove is 60°-90°.

[0010] In the above scheme, the longitudinal groove is a rectangular groove, and the width of the rectangular groove is one-quarter to one-third of the width of the tire center tread block; the ratio of the rectangular groove length to the rectangular groove width is 3:1.

[0011] In the above solution, the transverse groove is a parallelogram groove, the width of the opening of the transverse groove close to the edge of the central pattern block is half the width of the rectangular groove, and the horizontal distance from the opening to the long side of the longitudinal groove is twice the width of the rectangular groove.

[0012] In the above solution, the depth of the branch tube-shaped groove is 25%-50% of the depth of the longitudinal grooves on both sides of the middle pattern block.

[0013] In the above solution, a V-shaped rib structure is arranged along the bottom of the longitudinal grooves on both sides of the central tread block of the tire.

[0014] In the above solution, the bottom length S of the V-shaped rib structure is 0.5-2.2 mm, and the angle α is 45°-90°.

[0015] In the above solution, the V-shaped rib structure has several rows arranged continuously along the axial direction of the longitudinal groove bottom, and the V-shaped rib structure is arranged to be upwardly convex at the longitudinal groove bottom.

[0016] Beneficial effects:

[0017] The side branch grooves in this invention utilize the interference of sound waves to reduce acoustic energy and thus radiated noise, thereby reducing air column resonance noise. V-shaped ribs are arranged in the longitudinal grooves of the side branch grooves to achieve a shark-like drag reduction effect by breaking up vortices. This improves the vortices induced by the added side branch structure and the original tread structure, reducing the intensity of turbulence and pulsating pressure, and effectively reducing the tire's aerodynamic noise. The V-shaped ribs in the longitudinal grooves can also change the fundamental frequency of the air column, enhancing the noise reduction effect of the side branch structure. Staggering the side branch structures left and right can also mimic the cat's paw vibration damping structure, thereby reducing vibration noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a simplified diagram of the Helmholtz resonance cavity structure for silencing;

[0019] Figure 2 This is a diagram of the V-shaped rib structure of shark skin;

[0020] Figure 3A schematic structural diagram of a tire pattern structure capable of reducing tire aerodynamic noise across the entire frequency band, according to an embodiment of the present invention;

[0021] Figure 4 It is a schematic diagram of the arrangement of the V-shaped rib structure in the longitudinal groove;

[0022] Figure 5 A three-dimensional image of a single-pitch pattern according to an embodiment of the present invention;

[0023] Figure 6 for Figure 3 An enlarged schematic diagram of the side branch pipe structure involved;

[0024] Figure 7 for Figure 4 An enlarged schematic diagram of the V-shaped rib structure involved;

[0025] Figure 8 for Figure 3 The spectral characteristics of the 1 / 3 frequency doubling of the tire shown are compared between a tire with staggered tread grooves for the branch pipe structure, a tire with staggered tread grooves for the branch pipe structure and a V-shaped rib structure at the bottom of the longitudinal groove, and an original tire without the staggered tread grooves and the V-shaped rib structure.

[0026] Figure 9 for Figure 3 Schematic diagram of turbulent kinetic energy of the grooves of the staggered side branch pipe structure on the tread;

[0027] Figure 10 Schematic diagram of turbulent kinetic energy with staggered side branch grooves and V-shaped ribs at the bottom of the longitudinal grooves;

[0028] Figure 11 A comparison of the turbulent kinetic energy of the original tire without the tread and with the staggered branch pipe structure and V-rib structure added.

[0029] The reference numerals are as follows: 1-middle pattern block; 2-branch tube-shaped pattern groove; 3-longitudinal groove. DETAILED DESCRIPTION

[0030] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0031] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "axial", "radial", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0032] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0033] A side branch pipe structure, or resonant muffler, consists of both a resonant sound-absorbing structure and a side branch pipe structure, with a Helmholtz resonator branching off the main pipe. When a sound wave reaches the intersection of the small holes in the Helmholtz resonant cavity, a sudden change in acoustic impedance causes some of the sound energy to be reflected back, while some is transmitted into the small holes and resonant cavity. Due to the dissipative effect of the acoustic impedance of the Helmholtz cavity, some of the sound energy is consumed, leaving only a portion to continue propagating along the pipe, thus achieving the purpose of muffler. However, the presence of this structure can induce large-scale vortices in the longitudinal grooves, affecting the turbulent structure near the wall within the longitudinal grooves, increasing collisions and abnormal separation between vortices, and increasing mid- and low-frequency aerodynamic noise.

[0034] Animals in nature have developed remarkable adaptability to their environments. For example, sharks boast exceptional speeds in the water, demonstrating superior drag reduction capabilities. The V-ribbed structure of shark skin prevents vortices from forming or breaks up eddies that are about to form, thereby limiting the boundary layer's adhesion to the skin's surface and reducing drag. The V-ribbed structure's ability to break up and suppress vortices also works on gases. While not ideal for small-scale gas vortices, it significantly reduces mid- and low-frequency aerodynamic noise by increasing the size of the vortexes induced by the bypass structure.

[0035] The side branch structure relies on the interference of sound waves to reduce acoustic energy and thus radiated noise. The bionic shark-like V-rib structure breaks up and suppresses vortices, reducing turbulence intensity and pulsating pressure, thereby reducing aerodynamic noise. The V-rib structure breaks up and suppresses vortices induced by the side branch structure and the original tread structure. This noise reduction does not affect the noise reduction effect of the side branch structure, which is achieved through the interference of sound waves. The presence of the V-rib structure also changes the gas volume in the tread groove, further increasing the side branch structure's effect on reducing air column resonance noise. This theory guides the tread design of low-noise tires.

[0036] By arranging a branch-shaped groove on the tire's center tread block 1 and placing a V-shaped rib structure at the bottom of the longitudinal groove 3, which is affected by the branch structure, the branch structure resonates to reduce high-frequency air column resonance noise. The V-shaped rib structure breaks up the vortices induced by the branch structure, reducing mid- and low-frequency noise while also changing the fundamental frequency of air column resonance, optimizing the noise reduction effect of the branch structure and thus reducing tire aerodynamic noise. Furthermore, the staggered arrangement of the branch-shaped grooves can reduce vibration and vibration noise.

[0037] The branch tube-shaped pattern groove 2 has a longitudinal rectangular groove length of 8.2 mm and a width of 2.4 mm.

[0038] The side branch tube shaped pattern groove 2 has a width of 1 mm near the opening of the longitudinal groove of the transverse parallelogram groove, and a horizontal distance of 4 mm from the opening to the long side of the longitudinal rectangular groove of the side branch tube pattern groove. The angle between the center line of the longitudinal groove and the center line of the transverse groove of the side branch tube pattern structure is 60°-90°.

[0039] The side branch tube shaped groove 2 has a groove depth of 25%-50% of the depth of the longitudinal grooves on both sides of the middle pattern block.

[0040] The side branch pipe grooves 2 are 31 mm apart on the same side, and the distance between adjacent side branch pipe grooves on the left and right sides in the longitudinal direction is 7.5 mm.

[0041] V-shaped rib structure, the bottom of the V-shaped rib structure is 1mm, the height is 0.5mm, and the angle is 90°; the V-shaped rib structure is arranged continuously along the circumference of the tire longitudinal groove bottom; the V-shaped rib structure is arranged completely in the middle of the longitudinal groove bottom length; the V-shaped rib structure is arranged as an upward convex at the longitudinal groove bottom.

[0042] Combined with attachment Figures 3 to 7 As shown, the present invention arranges a branch-shaped pattern structure on the central tread block of the tire, and arranges a V-shaped rib structure at the bottom of the longitudinal groove affected by the branch-shaped pattern structure, thereby achieving interference of sound waves to reduce sound energy while reducing airflow instability caused by vortex disturbances, which further causes aerodynamic noise.

[0043] Combined with attachment Figures 3 to 7 As shown, while all tread patterns except the center pattern remain unchanged, a branch pipe pattern structure is installed on the center block. V-shaped ribs are arranged circumferentially along the bottom of the longitudinal grooves affected by the branch pipe pattern structure. The branch pipe grooves are 8.2mm long and 2.4mm wide. The transverse parallelogram grooves are 1mm long near the longitudinal groove opening, and the horizontal distance from the opening to the long side of the branch pipe longitudinal rectangular groove is 4mm. The angle between the longitudinal and transverse groove centerlines of the branch pipe pattern is 60°-90°. The depth of the branch pipe pattern groove is 25%-50% of the depth of the longitudinal grooves on either side of the center block. The branch pipe grooves on the same side are approximately 31mm apart, while the distance between the branch pipe grooves on opposite sides in the direction of vehicle travel is 7.5mm. The V-shaped rib structure at the bottom of the longitudinal groove has a base of 1 mm, a height of 0.5 mm, and an angle of 90°. The V-shaped rib structure is completely arranged in the middle of the length of the longitudinal groove bottom and is arranged to bulge upward at the bottom of the longitudinal groove.

[0044] for Figures 8 to 11 The finite element analysis process is as follows: First, a 205 / 55R16 tire model with a complex tread pattern was established in Abaqus software. Explicit rolling analysis was performed under the conditions of an inflation pressure of 0.21 MPa, a load of 3800 N, and a rolling speed of 70 km / h. Information on the rolling deformation of the tread grooves was extracted, the deformation characteristics were analyzed, and a CFD fluid simulation model was established. The relative motion between the tire and air was simulated in FLUENT by specifying the relative air velocity. Using tread deformation as a boundary condition, dynamic mesh technology was used to reproduce the volume change characteristics of the tread grooves during rolling. The aerodynamic noise of the tire was derived using the FW-H acoustic analogy equation.

[0045] Please refer to Figure 8 Compared with the original tire, the tire aerodynamic noise of the tire with staggered side branch structure grooves at 2000Hz-4000Hz is significantly reduced, especially at 3200Hz, the peak value caused by the air column is effectively reduced. This proves that the side branch structure is effective for the air column resonance noise. Compared with the side branch structure grooves with staggered arrangement on the tread and the V-shaped rib structure arranged at the bottom of the longitudinal groove, the effect of reducing high-frequency noise still exists at 2000-4000Hz, and the peak value of the air column resonance only appears at 4000Hz due to the change in the volume of the air column. This proves that the V-shaped rib structure does not affect the noise reduction effect of the side branch structure on high-frequency noise, but further reduces the high-frequency noise. At 500-2000Hz, the V-shaped rib structure effectively breaks up the vortex induced by the addition of the side branch structure and the vortex induced by the pattern structure itself, so that the aerodynamic noise of the medium and low frequencies is effectively reduced.

[0046] Please refer to Figure 9-11 Compared with the turbulent kinetic energy of the original tire, the tread has a staggered arrangement of the side branch structure grooves. It can be seen that the existence of the side branch structure increases the turbulent kinetic energy at the inner wall of the groove, increases the change in the fluid velocity gradient, and easily causes the fluid to become unstable and form vortices, thereby increasing the generation of eddy noise. The turbulent kinetic energy has a clear tendency to concentrate near the wall of the inner wall of the groove, which will increase the rupture caused by mutual collision and abnormal separation between vortices, increase the intensity of turbulence and pulsating pressure, and thus increase and reduce the aerodynamic noise of the tire. The turbulent kinetic energy of the tread with a staggered arrangement of the side branch structure grooves and the V-shaped rib structure at the bottom of the longitudinal groove is obviously far away from the near wall of the inner wall of the groove, and the turbulent kinetic energy in the groove is reduced compared with the original tire.

[0047] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0048] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A tire pattern structure with full-band tire aerodynamic noise reduction, characterized in that: A branch tube-shaped pattern groove is opened on the central pattern block of the tire, and the branch tube-shaped pattern groove structure includes a longitudinal groove and a transverse groove, wherein the longitudinal groove is along the circumferential direction of the central pattern block of the tire, and the center line of the transverse groove forms an acute angle with the center line of the longitudinal groove; a V-shaped rib structure is arranged along the longitudinal groove bottom on both sides of the central pattern block of the tire; the bottom length S of the V-shaped rib structure is 0.5-2.2mm, and the angle α is 45°-90°; the V-shaped rib structure has several rows, which are arranged axially continuously along the longitudinal groove bottom on both sides of the central pattern block of the tire, and the V-shaped rib structure is arranged as an upward convex at the longitudinal groove bottom on both sides of the central pattern block of the tire; one end of the transverse groove is connected to the longitudinal groove, and the other end is arranged at the edge of the central pattern block of the tire.

2. The tire tread structure for reducing tire aerodynamic noise in all frequency bands according to claim 1, characterized in that: The branch pipe-shaped pattern grooves are evenly arranged on the central pattern block of the tire, and there are two rows of branch pipe-shaped pattern grooves along the circumferential direction of the central pattern block of the tire.

3. The tire tread structure for reducing tire aerodynamic noise in all frequency bands according to claim 1, characterized in that: The included angle between the longitudinal groove centerline and the transverse groove centerline of the branch pipe pattern groove is 60°-90°.

4. The tire tread structure for reducing tire aerodynamic noise in all frequency bands according to claim 1, characterized in that: The longitudinal grooves are rectangular grooves, and the width of the rectangular grooves is one-quarter to one-third of the width of the tire center tread block; the ratio of the rectangular groove length to the rectangular groove width is 3:

1.

5. The tire tread structure for reducing tire aerodynamic noise in all frequency bands according to claim 1, characterized in that: The transverse groove is a parallelogram groove. The width of the opening of the transverse groove close to the edge of the central pattern block is half the width of the rectangular groove, and the horizontal distance from the opening to the long side of the longitudinal groove is twice the width of the rectangular groove.

6. The tire tread structure for reducing tire aerodynamic noise in all frequency bands according to claim 1, characterized in that: The depth of the branch tube-shaped groove is 25%-50% of the depth of the longitudinal grooves on both sides of the central pattern block.

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