Patent Application
20240208270
The present disclosure relates to a pneumatic tire.
Patent Document 1 below discloses a pneumatic tire in which a convex pattern indicating a brand, logo, etc. are formed on sidewall portions of the tire.
In order to improve the visibility of the convex pattern, a portion of a non-black rubber layer (e.g., white rubber layer) is exposed on the raised surface of the convex pattern.
After driving a vehicle on icy and snowy roads or grounds, a large amount of snow and ice adheres to the surface of the tread together with mud. Therefore, when the vehicle is stopped in such a state, snow and ice adhering to the tread may turn into muddy water and flow down the tire sidewall portions.
In the case of a tire of which sidewall portions are provided with convex pattern made form non-black rubber such as white rubber, stains caused by muddy water are likely to be noticeable, and the appearance of the convex pattern may be impaired.
The present disclosure was made in view of the above-mentioned circumstances, and a primary objective of the present disclosure is to provide a pneumatic tire capable of suppressing deterioration of the appearance of the convex pattern provided on the sidewall portions.
According to the present disclosure, a pneumatic tire comprises:
Therefore, in the pneumatic tire according to the present disclosure, deterioration of the appearance of the raised part can be suppressed.
An embodiment of present disclosure will now be described in detail in conjunction with accompanying drawings.
In this embodiment, the tire 1 is a pneumatic tire for passenger cars, suitably used as a winter tire intended for driving on icy and snowy roads or ground.
The present disclosure is however, not limited to such a tire, and may be applied to a pneumatic tire for heavy duty vehicles, for example.
In the case that the tire 1 is a kind of pneumatic tires for which various standards have been established:
In the case that the tire 1 is a tire for which various standards are not yet established:
In this application including specification and claims, dimensions and positions of each part or portion of the tire refer to those measured under the standard state unless otherwise noted,
The tire 1 comprises a tread portion 2, a first sidewall portion 3A, a second sidewall portion 3B, a first bead portion 4A, and a second bead portion 4B.
The first sidewall portion 3A and the second sidewall portion 3B extend inward in the tire radial direction from the tread portion 2. The first sidewall portion 3A and the second sidewall portion 3B have a substantially same structure.
The first bead portion 4A is continuous to the inner side in the tire radial direction of the first sidewall portion 3A. The second bead portion 4B is continuous to the inner side in the tire radial direction of the second sidewall portion 3B. The first bead portion 4A and the second bead portion 4B have a substantially same structure.
The structure and configuration of the first sidewall portion 3A described below can be applied to the second sidewall portion 3B.
Further, the tire 1 comprises a carcass 6 and a tread reinforcing layer 7.
The carcass 6 extends from the first bead portion 4A to the second bead portion 4B through the first sidewall portion 3A, the tread portion 2, and the second sidewall portion 3B.
The tread reinforcing layer 7 is disposed radially outside the carcass 6 in the tread portion 2.
In the present disclosure, a pair of tread edges, namely, a first tread edge T1 and a second tread edge T2, of the tread portion 2 are defined as the axially outermost edges of the ground contacting patch of the tire when the tire under its standard state is placed on a horizontal flat surface at a camber angle of 0 degrees and loaded by 70% of the normal load.
In
As shown in Fig. and Fig., the first sidewall portion 3A has a reference surface 9 having a first color, and is provided with a raised part 10 which protrudes from the reference surface 9. The first color of the reference surface 9 in this example is black.
As shown in
Here, the protruding height h is defined as the maximum height in the tire axial direction from the reference surface 9 at the root of the raised part 10 immediately outside in the tire radial direction to the axially outermost point of the raised part 10.
As shown in
In
The raised part 10 has a top surface 11 facing outward in the tire axial direction, and the top surface 11 has a second color different from the first color. In
The second color in this example is white. Namely, the different-colored rubber member 26 is made from white rubber.
However, the present disclosure is not limited to such white rubber, and various colors may be adopted for the top surface 11.
As shown in
Each of the shoulder lateral grooves 13 extends outwardly in the tire axial direction beyond the tread edge T1, and has a bottom surface smoothly merged into the reference surface 9 of the first sidewall portion 3A.
As shown in
The first block wall surface 16 extends inwardly in the tire radial direction from the first tread edge T1 on the shoulder block 15 while inclining outwardly in the tire axial direction.
The first block wall surface 16 has an inner edge 25 in the tire radial direction, which is spaced apart from the bottom surface of the shoulder lateral groove 13, and a minimum distance LI from the inner edge 25 to the bottom surface is not less than 3 mm in a tire meridian section as shown in
As a result, when driving on a snowy road or ground, the shoulder blocks 15 sink into the snow together with the first block wall surfaces 16, and shear the snow, thereby increasing snow traction.
Further, such a configuration can be expected to suppress damage of the bottom surface 13d of the shoulder lateral groove 13 near the inner edge 25.
The first block wall surface 16 in this example is inclined at a constant angle with respect to the tire radial direction.
In the case of the first block wall surface 16 having a variable angle with respect to the tire radial direction,
the inner edge 25 corresponds to a position where the first block wall surface 16 is no longer inclined in the above-mentioned direction, namely, inclined to the axially outside toward the radially inside.
The inner edge 25 of the first block wall surface 16 is located axially inside a straight line 20 passing through a position corresponding to the midpoint of the protruding height h of the raised part.
Therefore, when the tire 1 with such configuration is stopped after driving on an icy and snowy road or ground, even if muddy water formed by melted snow and ice on the tread flows down to the inner edge 25, the dripping hits the reference surface 9 of the first sidewall portion 3A or the side surface of the raised part 10 and flows down, therefore, the muddy water becomes difficult to reach the top surface 11 of the raised part 10 and adhere thereto. As a result, the appearance of the raised part 10 can be maintained.
Hereinafter, configurations of the present embodiment will be detailed.
Note that each configuration described below indicates a specific example in the present embodiment, therefore, the present disclosure can exhibit the above-described effects even if it does not include the configuration described below.
Further, even if any one of the configurations described below is applied alone to the tire of the present disclosure having the above-mentioned characteristics, an improvement in performance in accordance with the applied configuration can be expected.
Furthermore, when some of the configurations described below are applied in combination, a combined performance improvement in accordance with the applied configurations can be expected.
As shown in
while inclined to the axially outside at a constant angle, to have a radially inner edge. Thus, the first block wall surface 16 is an inclined flat surface.
The angle θ1 of the first block wall surface 16 with respect to the tire radial direction is, for example, in a range from 20 to 30 degrees.
The present disclosure is however, not limited to this example, and the first block wall surface 16 may be smoothly curved.
As shown in
The present disclosure is however, not limited to such configuration.
The first block wall surface 16 in this embodiment is provided with at least one narrow groove 22 extending from the first tread edge T1 at least to the inner edge 25 of the first block wall surface 16.
Preferably, the narrow groove 22 traverses the ground contacting top surface of the shoulder block 15 from the first tread edge T1 toward the inside in the tire axial direction. Such narrow grooves 22 improve the on-snow performance, and help to prevent muddy water from adhering to the top surface 11 of the raised part 10 by dispersing the path for muddy water to flow down.
As shown in
The second block wall surface 17 is connected to the radially inner edge 25 of the first block wall surface 16.
The second block wall surface 17 is parallel to the tire radial direction, or alternatively, inclined to the inside in the tire axial direction toward the inside in the tire radial direction from the radially inner edge 25 of the first block wall surface 16.
The third block wall surface 18 is connected to the radially inner edge of the second block wall surface 17.
The third block wall surface 18 is inclined to the outside in the tire axial direction toward the inside in the tire radial direction from the radially inner edge of the second block wall surface 17.
The angle θ2 of the second block wall surface 17 with respect to the tire radial direction is not more than 50 degrees, preferably not more than 20 degrees. This prevents muddy water from dripping from the radially inner edge 25 of the first block wall surface 16, making it easier for muddy water to flow down along the second block wall surface 17, and making it difficult for muddy water to adhere to the top surface 11 of the raised part 10.
In order to prevent muddy water from adhering to the top surface 11 of the raised part 10, it is preferred that, between the radially inner edge 25 of the first block wall surface 16 and the raised part 10, the muddy water is guided to flow down along the outer surface of the tire so that the muddy water flows at a relatively slow speed. From this point of view, the angle θ3 of the third block wall surface 18 with respect to the tire radial direction is set in a range from 10 to 20 degrees, for example.
From a similar point of view, it is preferred that the axially outer surface of the tire between the radially inner edge 25 of the first block wall surface 16 and the raised part 10, has a portion or portions where the angle with respect to the tire radial direction is 10 degrees or less, and the total length in the tire radial direction of such portion or portions is not more than 6.5 times the protruding height h.
The raised part 10 has a radially outer side surface 28 facing outward in the tire radial direction and extending from the reference surface 9 of the first sidewall portion 3A to the top surface 11.
The angle θ4 between the radially outer side surface 28 and the reference surface 9 is set in a range from 80 to 98 degrees. Thereby, the muddy water flowing down along the reference surface 9 of the first sidewall portion 3A is reduced in flowing force, and flows sideways. As a result, the muddy water becomes difficult to reach the top surface 11 of the raised part 10 and adhere thereto.
As shown in
Such ribs 30 can direct the flow of muddy water along the tire circumferential direction, and can further suppress muddy water from adhering to the top surface 11 of the raised part 10.
As shown in
When the radially inner edge 25 is interrupted by the narrow groove 22 as in the present embodiment, the center position 25c is determined by filling up the narrow groove 22.
In this embodiment, since “M” is formed by the raised part 10, the radially outer side surface 28 in this example includes a recess 29 which is concave inwardly in the tire radial direction when viewed from the side of the tire as shown in
Further, the center position in the tire circumferential direction of the recess 29 (in this embodiment, corresponds to the center position 28c of the radially outer side surface 28) is shifted in the tire circumferential direction from the center position 25c in the tire circumferential direction of the radially inner edge 25 of the first block wall surface 16. Thereby, it is possible to suppress muddy water from entering the recess 29.
As shown in
As shown in
While detailed description has been made of preferable embodiments of the present disclosure, the present disclosure can be embodied in various forms without being limited to the illustrated embodiments.
Based on the structure shown in
Further, a comparative example tire was manufactured. The comparative example tire was the same as the working example tire, excepting that the radially inner edge of the first block wall surface was located on the outer side in the tire axial direction than the straight line extending parallel to the tire radial direction passing through the position corresponding to the midpoint of the protruding height of the raised part.
These test tires were tested for the performance that maintains the appearance of the raised part (hereinafter, the appearance maintaining performance) as follows.
A test car to which the test tires were attached, was driven on a ground covered with compacted snow of about 5 cm thickness for about 10 minutes, then kept in a pit at a room temperature of 5 degrees C. or above. After the snow and ice on the tires had completely melted, the appearance of the raised part was visually observed and evaluated into ten ranks wherein the higher the rank number, the better the appearance.
From the test results, it was confirmed that, in comparison with the comparative example tire, the working example tire according to the present disclosure was able to suppress deterioration of the appearance of the raised part.
The present disclosure is as follows:
A pneumatic tire comprising: a tread portion having a first tread edge; and a first sidewall portion extending inward in the tire radial direction from the tread portion,
wherein
The pneumatic tire according to Present Disclosure 1, wherein
The pneumatic tire according to Present Disclosure 1 or 2, wherein
The pneumatic tire according to Present Disclosure 1, 2 or 3, wherein
The pneumatic tire according to Present Disclosure 1, 2, 3 or 4, wherein
The pneumatic tire according to Present Disclosure 1, 2, 3, 4 or 5, wherein
The pneumatic tire according to Present Disclosure 4, wherein
The pneumatic tire according to any one of Present Disclosures 1 to 3 and 5 to 7, wherein
The pneumatic tire according to any one of Present Disclosure 4, wherein
The pneumatic tire according to any one of Present Disclosures 1 to 8, wherein
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-209933 | Dec 2022 | JP | national |
