pneumatic tires

Abstract

To provide a pneumatic tire in which irregularity of external surface of a sidewall generated during tire molding is made hardly visible, and appearance of the sidewall can be improved.SOLUTION: A pneumatic tire includes a sidewall extending in a tire radial direction. The sidewall includes a belt-like decorative region on an external surface thereof, which extends in a tire circumferential direction. The decorative region has a plural kinds of V-shaped pattern areas each of which is a polygonal area including a V-shaped reference line different from the other V-shaped pattern areas as outline. A plurality of V-shaped ridges are arrayed at a prescribed interval from the V-shaped reference line in the polygonal area. The plural kinds of V-shaped pattern areas are partially overlapped.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to pneumatic tires. [Background technology]

[0002] A pneumatic tire is formed by winding various strip-shaped tire components around the outer circumferential surface of a building drum, expanding the components to a toroidal shape to form a green tire, and then vulcanizing and molding the green tire. After vulcanization and molding, the outer surface of the tire sidewall is prone to appearing as localized irregularities at the joints between the winding start and end ends of the strip-shaped tire components, and these irregularities have been a cause of degrading the appearance quality of the tire.

[0003] It has been known to provide a decorative area on the outer surface of the sidewall to make such localized irregularities less noticeable. For example, Patent Document 1 below discloses a pneumatic tire in which a decorative area is formed by overlapping a first ridge group consisting of a plurality of ridges extending in the radial direction, a second ridge group consisting of ridges with the same specifications as the first ridge group, a third ridge group consisting of a plurality of ridges arranged concentrically with each other, and a fourth ridge group consisting of ridges with the same specifications as the third ridge group.

[0004] The decorative area in Patent Document 1 is primarily intended to make irregularities on the outer surface of the sidewall less noticeable, and there is room for further improvement in terms of enhancing the aesthetic appearance of the sidewall through the configuration of the decorative area. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-37387 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present disclosure is to provide a pneumatic tire that can make unevenness that occurs on the outer surface of the sidewall during tire molding less noticeable and can improve the aesthetic appearance of the sidewall. [Means for solving the problem]

[0007] A pneumatic tire according to the present disclosure includes a sidewall extending in a tire radial direction, the sidewall has a strip-shaped decorative area extending along the tire circumferential direction on an outer surface thereof, the decorative region has a plurality of types of V-shaped pattern regions, Each of the V-shaped pattern regions is a polygonal region including a V-shaped reference line on its contour, which is different for each V-shaped pattern region, and the polygonal region includes a plurality of V-shaped ridges arranged in parallel and spaced apart from each other from the V-shaped reference line, The plurality of types of V-shaped pattern regions partially overlap each other.

[0008] In this disclosure, a V-shape simply means a figure in which the ends of two line segments are connected, and the lengths of the two line segments may be the same or different, and the angle between the two line segments is not particularly limited. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of a main part of a pneumatic tire according to an embodiment of the present invention taken along a tire meridian plane; [Figure 2] FIG. 1 is a front view of a pneumatic tire according to an embodiment of the present invention; [Figure 3] Enlarged view of area III in Figure 2 [Figure 4] Enlarged view of region IV in Figure 3 [Figure 5A] Enlarged view of region IV in Figure 3 (only the first V-shaped pattern region is shown) [Figure 5B] Enlarged view of region IV in Figure 3 (only the second V-shaped region is shown) [Figure 5C] Enlarged view of region IV in Figure 3 (only the third V-shaped region is shown) [Figure 5D]Enlarged view of region IV in Figure 3 (only the fourth V-shaped region is shown) [Figure 5E] Enlarged view of region IV in Figure 3 (only the fifth V-shaped region is shown) [Figure 5F] Enlarged view of region IV in Figure 3 (only the sixth V-shaped region is shown) [Figure 5G] Enlarged view of region IV in Figure 3 (only the seventh V-shaped region is shown) [Figure 5H] Enlarged view of region IV in Figure 3 (only the eighth V-shaped region is shown) [Figure 5I] Enlarged view of region IV in Figure 3 (only the ninth V-shaped region is shown) [Figure 5J] Enlarged view of region IV in Figure 3 (only the 10th V-shaped region is shown) [Figure 5K] Enlarged view of region IV in Figure 3 (only the 11th V-shaped region is shown) [Figure 5L] Enlarged view of region IV in Figure 3 (only the 12th V-shaped region is shown) [Figure 5M] Enlarged view of region IV in Figure 3 (only the linear pattern region is shown) [Figure 6] 5A is an enlarged cross-sectional view of a main part taken along the line VI-VI in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, one embodiment of a pneumatic tire will be described with reference to Figures 1 to 6. Note that in each figure, the dimensional ratios in the drawing do not necessarily match the actual dimensional ratios, and the dimensional ratios between the drawings do not necessarily match either.

[0011] 1, a pneumatic tire 1 according to this embodiment includes a pair of beads 1b, 1b each having a bead core 1a, and a pair of sidewalls 2, 2 extending outward in the tire radial direction D2 from each bead 1b. The pneumatic tire 1 also includes a tread 1c connected to outer ends of the pair of sidewalls 2, 2 in the tire radial direction D2. Although not shown, various grooves, such as circumferential grooves and lug grooves, that form a tread pattern are provided on the outer peripheral surface of the tread 1c.

[0012] In each drawing, the tire axial direction D1 is a direction parallel to the tire rotational axis 1d (see FIG. 2) which is the rotation center of the pneumatic tire 1, the tire radial direction D2 is a diameter direction of the pneumatic tire 1, and the tire circumferential direction D3 is a direction around the tire rotational axis 1d. The tire equatorial plane S1 is a plane perpendicular to the tire rotational axis 1d and located at the center of the pneumatic tire 1 in the tire axial direction D1, and the tire meridian plane is a plane including the tire rotational axis 1d and perpendicular to the tire equatorial plane S1.

[0013] In the tire axial direction D1, the inner side refers to the side closer to the tire equatorial plane S1, and the outer side refers to the side farther from the tire equatorial plane S1. In the tire radial direction D2, the inner side refers to the side closer to the tire rotational axis 1d, and the outer side refers to the side farther from the tire rotational axis 1d.

[0014] The pneumatic tire 1 includes a carcass 1e that spans between a pair of bead cores 1a, 1a, and an inner liner 1f that is disposed inside the carcass 1e and has an excellent function of preventing gas permeation in order to maintain air pressure. The carcass 1e and the inner liner 1f are disposed along the inner circumference of the tire, spanning the beads 1b, sidewalls 2, and tread 1c.

[0015] The sidewall 2 includes a sidewall rubber 2a disposed on the outer side of the carcass 1e in the tire axial direction D1. As shown in Fig. 2, the sidewall rubber 2a includes a decorative region 3 disposed in a partial region of the outer surface 2b. The decorative region 3 is formed on the outer surface 2b of the sidewall 2 in a certain region in the tire radial direction D2 that includes the tire maximum width position 2c.

[0016] In this embodiment, the decorative area 3 has an arc shape extending along the tire circumferential direction D3. The decorative area 3 includes an inner circumferential edge 3a and an outer circumferential edge 3b extending in the tire circumferential direction D3, and a first side edge 3c and a second side edge 3d connecting the ends of the inner circumferential edge 3a and the outer circumferential edge 3b. Note that in this embodiment, the first side edge 3c and the second side edge 3d are polygonal, but the shapes of the first side edge 3c and the second side edge 3d are not particularly limited and may be linear, for example.

[0017] 2, the decorative region 3 may be formed only in a portion of the sidewall 2 in the tire circumferential direction D3, or may be formed over the entire circumference of the sidewall 2 in the tire circumferential direction D3. Furthermore, multiple decorative regions 3 may be formed along the tire circumferential direction D3 of the sidewall 2. When multiple decorative regions 3 are formed, the decorative regions 3 are preferably arranged at equal intervals in the tire circumferential direction D3.

[0018] The decorative region 3 is configured by arranging a plurality of unit patterns 30 at equal intervals at a predetermined angle in the tire circumferential direction D3. The plurality of unit patterns 30 are preferably arranged at equal intervals at an angle of 5 to 15 degrees in the tire circumferential direction D3. In the example of Fig. 3, the plurality of unit patterns 30 are arranged at equal intervals at an angle of 10 degrees in the tire circumferential direction D3.

[0019] The unit pattern 30 has multiple types of V-shaped pattern regions 31a-31l, which partially overlap one another. By partially overlapping the different types of V-shaped pattern regions 31a-31l, the degree of diffuse reflection of light changes, resulting in variations in the black color of the rubber. As a result, as shown in Figures 3 and 4, a decorative region 3 with varying shades of black is formed on the outer surface 2b of the sidewall 2, making unevenness in the outer surface 2b of the sidewall 2 less noticeable and improving the aesthetic appearance of the sidewall 2.

[0020] For ease of explanation, FIGS. 5A to 5L show the first to twelfth V-shaped pattern regions 31a to 31l of the unit pattern 30 individually.

[0021] As shown in Fig. 5A, the first V-shaped pattern region 31a is a polygonal region that includes the first V-shaped reference line 32a in its outline. Specifically, the first V-shaped pattern region 31a is a polygonal region that is surrounded by the first V-shaped reference line 32a, a portion of the outer peripheral edge 3b, a first side 35a, and a second side 36a. Note that the first V-shaped reference line 32a, the first side 35a, and the second side 36a shown in Fig. 5A are imaginary lines that define the first V-shaped pattern region 31a and do not appear in an actual tire.

[0022] In this embodiment, although a portion of the outer peripheral edge 3b is actually slightly curved, the portion of the outer peripheral edge 3b is also considered to be included in one of the sides constituting the polygon. Similarly, the portion of the inner peripheral edge 3a is also considered to be included in one of the sides constituting the polygon.

[0023] The first V-shaped reference line 32a is formed by connecting two line segments 33a and 34a. A first side 35a extends from an end 331a of the line segment 33a. An end 341a of the line segment 34a is located on the outer peripheral edge 3b.

[0024] The first V-shaped pattern region 31a includes a plurality of first V-shaped ridges 40a arranged in parallel and spaced apart from each other from the first V-shaped reference line 32a within the polygonal region. Note that some of the first V-shaped ridges 40a may overlap the first V-shaped reference line 32a. The first V-shaped ridge 40a is formed by connecting two ridges 41a and 42a. The ridge 41a is parallel to the line segment 33a, and the ridge 42a is parallel to the line segment 34a.

[0025] The ends 411a of the protrusions 41a are aligned on the first side 35a. The ends 421a of the protrusions 42a are aligned on the outer peripheral edge 3b. When the first V-shaped ridges 40a are arranged in order from the first V-shaped reference line 32a so that the ends 411a of the protrusions 41a are aligned on the first side 35a, the second side 36a is a line segment that overlaps with the protrusion 42a of the first V-shaped ridge 40a that is farthest from the first V-shaped reference line 32a. The angle and length of the first side 35a are set appropriately.

[0026] As shown in Fig. 5B, the second V-shaped pattern region 31b is a polygonal region that includes the second V-shaped reference line 32b in its outline. Specifically, the second V-shaped pattern region 31b is a region surrounded by the second V-shaped reference line 32b, a portion of the outer circumferential edge 3b, and the first side 35b. Note that the second V-shaped reference line 32b and the first side 35b shown in Fig. 5B are imaginary lines that define the second V-shaped pattern region 31b and do not appear in an actual tire.

[0027] The second V-shaped reference line 32b is formed by connecting two line segments 33b and 34b. A first side 35b extends from an end 331b of the line segment 33b. An end 341b of the line segment 34b is located on the outer peripheral edge 3b.

[0028] The second V-shaped pattern region 31b includes a plurality of second V-shaped ridges 40b arranged in parallel and spaced apart from each other from the second V-shaped reference line 32b within the polygonal region. Note that some second V-shaped ridges 40b may overlap the second V-shaped reference line 32b. The second V-shaped ridge 40b is formed by connecting two ridges 41b and 42b. The ridge 41b is parallel to the line segment 33b, and the ridge 42b is parallel to the line segment 34b.

[0029] Ends 411b of ridges 41b are aligned with first side 35b and outer peripheral edge 3b. Ends 421b of ridges 42b are aligned with outer peripheral edge 3b. The angle and length of first side 35b are set appropriately.

[0030] As shown in Fig. 5C, the third V-shaped pattern region 31c is a polygonal region that includes the third V-shaped reference line 32c in its outline. Specifically, the third V-shaped pattern region 31c is an area surrounded by the third V-shaped reference line 32c, a portion of the inner circumferential edge 3a, a portion of the outer circumferential edge 3b, a first side 35c, a second side 36c, and a third side 37c. Note that the third V-shaped reference line 32c, the first side 35c, the second side 36c, and the third side 37c shown in Fig. 5C are imaginary lines that define the third V-shaped pattern region 31c and do not appear in an actual tire.

[0031] The third V-shaped reference line 32c is formed by connecting two line segments 33c and 34c. An end 331c of the line segment 33c is located on the inner circumferential edge 3a. An end 341c of the line segment 34c is located on the outer circumferential edge 3b.

[0032] The third V-shaped pattern region 31c includes a plurality of third V-shaped ridges 40c arranged in parallel and spaced apart from each other from the third V-shaped reference line 32c within the polygonal region. Note that some third V-shaped ridges 40c may overlap the third V-shaped reference line 32c. The third V-shaped ridge 40c is formed by connecting two protrusions 41c and 42c. The protrusion 41c is parallel to the line segment 33c, and the protrusion 42c is parallel to the line segment 34c.

[0033] The ends 411c of the protrusions 41c are aligned with the third side 37c and the inner peripheral edge 3a. The ends 421c of the protrusions 42c are aligned with the first side 35c and the outer peripheral edge 3b. When the third V-shaped ridges 40c are arranged in order from the third V-shaped reference line 32c so that the ends 421c of the protrusions 42c are aligned with the first side 35c, the second side 36c is a line segment that overlaps with the protrusion 41c of the third V-shaped ridge 40c that is farthest from the third V-shaped reference line 32c. The angles and lengths of the first side 35c and the third side 37c are set appropriately.

[0034] As shown in Fig. 5D, the fourth V-shaped pattern region 31d is a polygonal region that includes the fourth V-shaped reference line 32d in its outline. Specifically, the fourth V-shaped pattern region 31d is a region surrounded by the fourth V-shaped reference line 32d, a first side 35d, a second side 36d, and a third side 37d. Note that the fourth V-shaped reference line 32d, the first side 35d, the second side 36d, and the third side 37d shown in Fig. 5D are imaginary lines that define the fourth V-shaped pattern region 31d and do not appear in an actual tire.

[0035] The fourth V-shaped reference line 32d is formed by connecting two line segments 33d and 34d. A third side 37d extends from an end 331d of the line segment 33d. A first side 35d extends from an end 341d of the line segment 34d.

[0036] The fourth V-shaped pattern region 31d includes a plurality of fourth V-shaped ridges 40d arranged in parallel and spaced apart from each other from the fourth V-shaped reference line 32d within the polygonal region. Note that there may be fourth V-shaped ridges 40d that overlap the fourth V-shaped reference line 32d. The fourth V-shaped ridge 40d is formed by connecting two protrusions 41d, 42d. The protrusion 41d is parallel to the line segment 33d, and the protrusion 42d is parallel to the line segment 34d.

[0037] Ends 411d of protrusions 41d are aligned with the second side 36d and the third side 37d. Ends 421d of protrusions 42d are aligned with the first side 35d and the second side 36d. The angles and lengths of the first side 35d, the second side 36d, and the third side 37d are set appropriately.

[0038] As shown in Fig. 5E, the fifth V-shaped pattern region 31e is a polygonal region whose outline includes the fifth V-shaped reference line 32e. As described above, the decorative region 3 is configured by a plurality of unit patterns 30 arranged at equal intervals at a predetermined angle in the tire circumferential direction D3. In Fig. 5E, the left end of the left-side fifth V-shaped pattern region 31e and the right end of the right-side fifth V-shaped pattern region 31e are connected to form a single fifth V-shaped pattern region 31e. Specifically, the fifth V-shaped pattern region 31e is an area surrounded by the fifth V-shaped reference line 32e, a portion of the inner circumferential edge 3a, and the first, second, third, and fourth sides 35e, 36e, 37e, and 38e. It should be noted that the fifth V-shaped reference line 32e, the first side 35e, the second side 36e, the third side 37e, and the fourth side 38e shown in FIG. 5E are imaginary lines for defining the fifth V-shaped pattern area 31e, and do not appear on the actual tire.

[0039] The fifth V-shaped reference line 32e is formed by connecting two line segments 33e and 34e. An end 331e of the line segment 33e is located on the inner circumferential edge 3a. A first side 35e extends from an end 341e of the line segment 34e.

[0040] The fifth V-shaped pattern region 31e includes a plurality of fifth V-shaped ridges 40e arranged in parallel and spaced apart from one another from the fifth V-shaped reference line 32e within the polygonal region. Note that there may be fifth V-shaped ridges 40e that overlap the fifth V-shaped reference line 32e. The fifth V-shaped ridge 40e is formed by connecting two ridges 41e and 42e. The ridge 41e is parallel to the line segment 33e, and the ridge 42e is parallel to the line segment 34e.

[0041] The end 411e of the protrusion 41e is aligned with the fourth side 38e and the inner peripheral edge 3a. The end 421e of the protrusion 42e is aligned with the first side 35e. When the fifth V-shaped ridges 40e are arranged in order from the fifth V-shaped reference line 32e so that the end 421e of the protrusion 42e is aligned with the first side 35e, the second side 36e and the third side 37e are line segments that overlap with the protrusion 42e and the protrusion 41e of the fifth V-shaped ridge 40e that is farthest from the fifth V-shaped reference line 32e. The angles and lengths of the first side 35e and the fourth side 38e are set appropriately.

[0042] As shown in Fig. 5F, the sixth V-shaped pattern region 31f is a polygonal region that includes the sixth V-shaped reference line 32f in its outline. Specifically, the sixth V-shaped pattern region 31f is an area surrounded by the sixth V-shaped reference line 32f, a portion of the outer peripheral edge 3b, and the first side 35f. Note that the sixth V-shaped reference line 32f and the first side 35f shown in Fig. 5F are imaginary lines that define the sixth V-shaped pattern region 31f and do not appear in an actual tire.

[0043] The sixth V-shaped reference line 32f is formed by connecting two line segments 33f and 34f. An end 331f of the line segment 33f is located on the outer peripheral edge 3b. A first side 35f extends from an end 341f of the line segment 34f.

[0044] The sixth V-shaped pattern region 31f includes a plurality of sixth V-shaped ridges 40f arranged in parallel and spaced apart from one another from the sixth V-shaped reference line 32f within the polygonal region. Note that some sixth V-shaped ridges 40f may overlap the sixth V-shaped reference line 32f. The sixth V-shaped ridge 40f is formed by connecting two protrusions 41f and 42f. The protrusion 41f is parallel to the line segment 33f, and the protrusion 42f is parallel to the line segment 34f.

[0045] Ends 411f of the ridges 41f are aligned with the outer peripheral edge 3b. Ends 421f of the ridges 42f are aligned with the first side 35f. The angle and length of the first side 35f are set appropriately.

[0046] As shown in Fig. 5G, the seventh V-shaped pattern region 31g is a polygonal region that includes the seventh V-shaped reference line 32g in its outline. Specifically, the seventh V-shaped pattern region 31g is a polygonal region that is surrounded by the seventh V-shaped reference line 32g, a first side 35g, a second side 36g, and a third side 37g. Note that the seventh V-shaped reference line 32g, the first side 35g, the second side 36g, and the third side 37g shown in Fig. 5G are imaginary lines that define the seventh V-shaped pattern region 31g and do not appear in an actual tire.

[0047] The seventh V-shaped reference line 32g is formed by connecting two line segments 33g and 34g. A first side 35g extends from an end 331g of the line segment 33g. A third side 37g extends from an end 341g of the line segment 34g.

[0048] The seventh V-shaped pattern region 31g includes a plurality of seventh V-shaped ridges 40g arranged in parallel and spaced apart from each other from the seventh V-shaped reference line 32g within the polygonal region. Note that some of the seventh V-shaped ridges 40g may overlap the seventh V-shaped reference line 32g. The seventh V-shaped ridge 40g is formed by connecting two protrusions 41g and 42g. The protrusion 41g is parallel to the line segment 33g, and the protrusion 42g is parallel to the line segment 34g.

[0049] The ends 411g of the protrusions 41g are aligned on the first side 35g. The ends 421g of the protrusions 42g are aligned on the third side 37g. When the seventh V-shaped ridges 40g are arranged in order from the seventh V-shaped reference line 32g so that the ends 411g of the protrusions 41g are aligned on the first side 35g, the second side 36g is a line segment that overlaps with the protrusion 42g of the seventh V-shaped ridge 40g that is farthest from the seventh V-shaped reference line 32g. The angles and lengths of the first side 35g and the third side 37g are set appropriately.

[0050] As shown in Fig. 5H, the eighth V-shaped pattern region 31h is a polygonal region that includes the eighth V-shaped reference line 32h in its outline. Specifically, the eighth V-shaped pattern region 31h is a polygonal region surrounded by the eighth V-shaped reference line 32h, a portion of the inner circumferential edge 3a, a portion of the outer circumferential edge 3b, a first side 35h, and a second side 36h. Note that the eighth V-shaped reference line 32h, the first side 35h, and the second side 36h shown in Fig. 5H are imaginary lines that define the eighth V-shaped pattern region 31h and do not appear in an actual tire.

[0051] The eighth V-shaped reference line 32h is formed by connecting two line segments 33h and 34h. An end 331h of the line segment 33h is located on the inner circumferential edge 3a. An end 341h of the line segment 34h is located on the outer circumferential edge 3b.

[0052] The eighth V-shaped pattern region 31h includes a plurality of eighth V-shaped ridges 40h arranged in parallel and spaced apart from each other from the eighth V-shaped reference line 32h within the polygonal region. Note that some eighth V-shaped ridges 40h may overlap the eighth V-shaped reference line 32h. The eighth V-shaped ridge 40h is formed by connecting two protrusions 41h and 42h. The protrusion 41h is parallel to the line segment 33h, and the protrusion 42h is parallel to the line segment 34h.

[0053] An end 411h of the protrusion 41h is aligned with the inner peripheral edge 3a and the first side 35h. An end 421h of the protrusion 42h is aligned with the outer peripheral edge 3b and the second side 36h. The angles and lengths of the first side 35h and the second side 36h are set appropriately.

[0054] As shown in Fig. 5I, the ninth V-shaped pattern region 31i is a polygonal region that includes the ninth V-shaped reference line 32i in its outline. Specifically, the ninth V-shaped pattern region 31i is a polygonal region surrounded by the ninth V-shaped reference line 32i, a first side 35i, a second side 36i, and a third side 37i. Note that the ninth V-shaped reference line 32i, the first side 35i, the second side 36i, and the third side 37i shown in Fig. 5I are imaginary lines that define the ninth V-shaped pattern region 31i and do not appear in an actual tire.

[0055] The ninth V-shaped reference line 32i is formed by connecting two line segments 33i and 34i. A first side 35i extends from an end 331i of the line segment 33i. A third side 37i extends from an end 341i of the line segment 34i.

[0056] The ninth V-shaped pattern region 31i includes a plurality of ninth V-shaped ridges 40i arranged in parallel and spaced apart from each other from the ninth V-shaped reference line 32i within the polygonal region. Note that some ninth V-shaped ridges 40i may overlap the ninth V-shaped reference line 32i. The ninth V-shaped ridge 40i is formed by connecting two protrusions 41i and 42i. The protrusion 41i is parallel to the line segment 33i, and the protrusion 42i is parallel to the line segment 34i.

[0057] The ends 411i of the protrusions 41i are aligned on the first side 35i. The ends 421i of the protrusions 42i are aligned on the third side 37i. When the ninth V-shaped ridges 40i are arranged in order from the ninth V-shaped reference line 32i so that the ends 411i of the protrusions 41i are aligned on the first side 35i, the second side 36i is a line segment that overlaps with the protrusion 42i of the ninth V-shaped ridge 40i that is farthest from the ninth V-shaped reference line 32i. The angles and lengths of the first side 35i and the third side 37i are set appropriately.

[0058] It should be noted that a plurality of ridges 43i and 44i may be arranged on the outside of the ninth V-shaped pattern region 31i in parallel with the line segments 33i and 34i.

[0059] As shown in Fig. 5J, the tenth V-shaped pattern region 31j is a polygonal region that includes the tenth V-shaped reference line 32j in its outline. Specifically, the tenth V-shaped pattern region 31j is a polygonal region surrounded by the tenth V-shaped reference line 32j, a first side 35j, a second side 36j, a third side 37j, and a fourth side 38j. Note that the tenth V-shaped reference line 32j, the first side 35j, the second side 36j, the third side 37j, and the fourth side 38j shown in Fig. 5J are imaginary lines that define the tenth V-shaped pattern region 31j and do not appear in an actual tire.

[0060] The tenth V-shaped reference line 32j is formed by connecting two line segments 33j and 34j. A first side 35j extends from an end 331j of the line segment 33j. A fourth side 38i extends from an end 341j of the line segment 34j.

[0061] The tenth V-shaped pattern region 31j includes a plurality of tenth V-shaped ridges 40j arranged in parallel and spaced apart from each other from the tenth V-shaped reference line 32j within the polygonal region. Note that there may be tenth V-shaped ridges 40j that overlap the tenth V-shaped reference line 32j. The tenth V-shaped ridge 40j is formed by connecting two ridges 41j and 42j. The ridge 41j is parallel to the line segment 33j, and the ridge 42j is parallel to the line segment 34j.

[0062] An end 411j of the ridge 41j is aligned with the first side 35j. An end 421j of the ridge 42j is aligned with the fourth side 38j. Only the ridge 42j is provided between the second side 36j and the fourth side 38j. The third side 37j is a line segment parallel to the ridge 42j. The angles and lengths of the first side 35j, the second side 36j, and the fourth side 38j are set appropriately.

[0063] It should be noted that a plurality of ridges 43j and 44j may be arranged in parallel with the line segments 33j and 34j on the outside of the tenth V-shaped pattern region 31j.

[0064] As shown in Fig. 5K, the eleventh V-shaped pattern region 31k is a polygonal region that includes the eleventh V-shaped reference line 32k in its outline. Specifically, the eleventh V-shaped pattern region 31k is a polygonal region that is surrounded by the eleventh V-shaped reference line 32k, a portion of the outer peripheral edge 3b, a first side 35k, and a second side 36k. Note that the eleventh V-shaped reference line 32k, the first side 35k, and the second side 36k shown in Fig. 5K are imaginary lines that define the eleventh V-shaped pattern region 31k and do not appear in an actual tire.

[0065] The eleventh V-shaped reference line 32k is formed by connecting two line segments 33k and 34k. A first side 35k extends from an end 331k of the line segment 33k. A second side 36k extends from an end 341k of the line segment 34k.

[0066] The eleventh V-shaped pattern region 31k includes a plurality of eleventh V-shaped ridges 40k arranged in parallel at intervals from each other from the eleventh V-shaped reference line 32k within the polygonal region. Note that there may be an eleventh V-shaped ridge 40k that overlaps the eleventh V-shaped reference line 32k. The eleventh V-shaped ridge 40k is formed by connecting two protrusions 41k and 42k. The protrusion 41k is parallel to the line segment 33k, and the protrusion 42k is parallel to the line segment 34k.

[0067] An end 411k of the ridge 41k is aligned with the outer peripheral edge 3b and the first side 35k. An end 421k of the ridge 42k is aligned with the outer peripheral edge 3b and the second side 36k. The angles and lengths of the first side 35k and the second side 36k are set appropriately.

[0068] It should be noted that a plurality of ridges 43k and 44k may be arranged on the outside of the eleventh V-shaped pattern region 31k in parallel with the line segments 33k and 34k.

[0069] As shown in Fig. 5L, the twelfth V-shaped pattern region 31l is a polygonal region that includes the twelfth V-shaped reference line 32l in its outline. Specifically, the twelfth V-shaped pattern region 31l is a polygonal region surrounded by the twelfth V-shaped reference line 32l, a portion of the outer peripheral edge 3b, a first side 35l, and a second side 36l. Note that the twelfth V-shaped reference line 32l, the first side 35l, and the second side 36l shown in Fig. 5L are imaginary lines that define the twelfth V-shaped pattern region 31l and do not appear in an actual tire.

[0070] The twelfth V-shaped reference line 32l is formed by connecting two line segments 33l and 34l. A first side 35l extends from an end 331l of the line segment 33l. An end 341l of the line segment 34l is located on the outer peripheral edge 3b.

[0071] The twelfth V-shaped pattern region 31l includes a plurality of twelfth V-shaped ridges 40l arranged in parallel and spaced apart from one another from the twelfth V-shaped reference line 32l within the polygonal region. Note that there may be twelfth V-shaped ridges 40l that overlap the twelfth V-shaped reference line 32l. The twelfth V-shaped ridge 40l is formed by connecting two ridges 41l and 42l. The ridge 41l is parallel to the line segment 33l, and the ridge 42l is parallel to the line segment 34l.

[0072] The ends 411l of the protrusions 41l are aligned on the first side 35l. The ends 421l of the protrusions 42l are aligned on the outer peripheral edge 3b. When the twelfth V-shaped ridges 40l are arranged in order from the twelfth V-shaped reference line 32l so that the ends 411l of the protrusions 41l are aligned on the first side 35l, the second side 36l is a line segment that overlaps with the protrusion 42l of the twelfth V-shaped ridge 40l that is farthest from the twelfth V-shaped reference line 32l. The angle and length of the first side 35l are set appropriately.

[0073] It should be noted that a plurality of ridges 43l and 44l may be arranged on the outside of the twelfth V-shaped pattern region 31l in parallel with the line segments 33l and 34l.

[0074] In addition to the V-shaped pattern regions 31a to 31l, the decorative region 3 may also have a linear pattern region 50 as shown in Fig. 5M. The linear pattern region 50 has a plurality of ridges 51 arranged in parallel and spaced apart from one another.

[0075] It is preferable that the decorative area 3 has four or more types of V-shaped pattern areas 31a to 31l. By providing four or more types of V-shaped pattern areas 31a to 31l, it is possible to effectively achieve shades of black.

[0076] The decorative area 3 preferably has an area where at least 12 types of V-shaped pattern areas 31a to 31l partially overlap. By providing an area where at least 12 types of V-shaped pattern areas 31a to 31l overlap, clear shading of black can be achieved.

[0077] The V-shaped angle θ of the first to twelfth V-shaped reference lines 32a to 32l (for example, the angle θ between line segment 33a and line segment 34a in the case of the first V-shaped reference line 32a shown in FIG. 5A) is preferably 60 to 120°. By setting the V-shaped angle θ to 60 to 120°, the V-shaped ridges 40a to 40l of the V-shaped pattern regions 31a to 31l are more likely to overlap with each other, making it easier to create black shading. More preferably, the V-shaped angle θ of the first to twelfth V-shaped reference lines 32a to 32l is 90°.

[0078] It is also preferable that the first to twelfth V-shaped reference lines 32a to 32l all have the same V-shaped angle θ. By making the V-shaped angle θ the same, the V-shaped ridges 40a to 40l of the V-shaped pattern regions 31a to 31l can easily overlap with each other, making it easier to create shades of black.

[0079] Fig. 6 is a cross-sectional view of the first V-shaped pattern region 31a taken along line VI-VI shown in Fig. 5A. In Fig. 6, the dashed line indicates a reference plane S2 (also referred to as a reference profile) of the outer surface 2b. In this embodiment, the reference plane S2 of the outer surface 2b is located at the same position in the tire axial direction D1 as the outer surface 2b of the sidewall 2 in a portion where the decorative region 3 is not formed.

[0080] The decorative region 3 has a recess 4 recessed from a reference plane S2 of the outer surface 2b. The recess 4 is formed over the entire decorative region 3. The depth of the recess 4 from the reference plane S2 is, for example, 0.3 to 1.5 mm.

[0081] The protrusions 41a of the first V-shaped ridge 40a are formed to protrude from the bottom of the recess 4. The positions of the protrusion ends 410a of the protrusions 41a may be the same or different positions relative to the reference plane S2 of the outer surface 2b. Figure 6 shows an example in which the protrusion ends 410a of the protrusions 41a are recessed from the reference plane S2 of the outer surface 2b.

[0082] The ridges 41a have a generally triangular cross section. However, the ridges 41a may have a cross section with rounded vertices. The ridges 41a protrude from the bottom of the recess 4 to a height H1 of, for example, 0.2 mm or more. The ridges 41a have a width W1 of, for example, 0.1 mm or more. The spacing P1 between the adjacent ridges 41a is, for example, 0.6 to 1.0 mm.

[0083] The ridges 42a of the first V-shaped ridge 40a have the same cross-sectional shape as the ridges 41a. The ridges constituting the second to twelfth V-shaped ridges 40b to 40l also have the same cross-sectional shape as the ridges 41a. Furthermore, the ridges 51 constituting the linear pattern region 50 shown in FIG. 5M also have the same cross-sectional shape as the ridges 41a.

[0084] As described above, the pneumatic tire 1 according to this embodiment has a sidewall 2 extending in the tire radial direction D2, and the sidewall 2 has a band-shaped decorative region 3 extending on its outer surface 2b along the tire circumferential direction D3, and the decorative region 3 has multiple types of V-shaped pattern regions 31a-31l, and each V-shaped pattern region 31a-31l is a polygonal region whose outline includes a different V-shaped reference line 32a-32l for each V-shaped pattern region 31a-31l, and the polygonal region has multiple V-shaped ridges 40a-40l arranged in parallel and spaced apart from each other from the V-shaped reference line 32a-32l, and the multiple types of V-shaped pattern regions 31a-31l partially overlap each other.

[0085] According to this pneumatic tire 1, the degree of diffuse reflection of light is changed by partially overlapping the multiple types of V-shaped pattern regions 31a to 31l, and therefore a decorative region 3 with varying shades of black is formed on the outer surface 2b of the sidewall 2. As a result, irregularities on the outer surface 2b of the sidewall 2 are made less noticeable, and the aesthetic appearance of the sidewall 2 can be improved.

[0086] Furthermore, in the pneumatic tire 1 according to this embodiment, the V-shaped reference lines 32a to 32l of the V-shaped pattern regions 31a to 31l have a V-angle of 60 to 120 degrees.

[0087] With this configuration, the V-shaped ridges 40a to 40l tend to overlap each other, making it easier to achieve different shades of black.

[0088] Furthermore, in the pneumatic tire 1 according to this embodiment, the V-shaped reference lines 32a to 32l of the multiple types of V-shaped pattern regions 31a to 31l are configured so that the V-shaped angles are all the same.

[0089] With this configuration, the V-shaped ridges 40a to 40l tend to overlap each other, making it easier to achieve different shades of black.

[0090] Furthermore, in the pneumatic tire 1 according to this embodiment, the decorative region 3 has four or more types of V-shaped pattern regions 31a to 31l.

[0091] This configuration allows for effective shading of black.

[0092] In addition, in the pneumatic tire 1 according to this embodiment, the V-shaped pattern areas 31a, 31b, 31c, 31e, 31f, 31h, 31i, 31k, and 31l are configured to contact the inner peripheral edge 3a or the outer peripheral edge 3b of the decorative area 3.

[0093] According to this configuration, irregularities on the outer surface 2b of the sidewall 2 can be effectively made less noticeable.

[0094] The above-mentioned dimensional values, positional relationships, and magnitude relationships are measured when the pneumatic tire 1 is mounted on a standard rim, inflated to the standard internal pressure, and in a standard state with no load. For example, the tire maximum width position 2c is the position in the tire radial direction D2 of the position where the dimension in the tire axial direction D1, excluding structures such as patterns and letters protruding from the outer surface 2b of the sidewall 2, is maximum when the pneumatic tire 1 is mounted on a standard rim, inflated to the standard internal pressure, and in a no-load state. A standard rim is a rim defined for each pneumatic tire 1 by a standard system including the standard on which the pneumatic tire 1 is based; for example, it is called a standard rim in the case of JATMA, and a "Measuring Rim" in the cases of TRA and ETRTO.

[0095] The normal internal pressure is the air pressure determined for each pneumatic tire 1 by the standards set forth in the standard system, including the standards on which the pneumatic tire 1 is based. For truck and bus tires and light truck tires, the normal internal pressure is the maximum air pressure for JATMA, the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" for TRA, and "INFLATION PRESSURE" for ETRTO. For passenger car tires, the normal internal pressure is usually 180 kPa, but for tires labeled "Extra Load" or "Reinforced," the normal internal pressure is 220 kPa.

[0096] The pneumatic tire 1 is not limited to the configurations of the above-described embodiments, nor is it limited to the above-described effects. It goes without saying that various modifications can be made to the pneumatic tire 1 without departing from the spirit of the present invention. For example, the configurations and methods of the above-described embodiments may be arbitrarily adopted and combined, and one or more of the configurations and methods of the various modified examples described below may be arbitrarily selected and adopted in the configurations and methods of the above-described embodiments.

[0097] (1) In the pneumatic tire 1 according to the above embodiment, the V-shaped reference lines 32a-32l of each V-shaped pattern region 31a-31l are configured so that the V-shaped angle is 60-120°. However, the pneumatic tire 1 is not limited to this configuration. Even if the V-shaped angle is other than 60-120°, it is possible to overlap the V-shaped ridges 40a-40l with each other to create a black shade.

[0098] (2) In the pneumatic tire 1 according to the above embodiment, the V-shaped reference lines 32a-32l of the multiple types of V-shaped pattern regions 31a-31l are configured so that the V-shaped angles are all the same. However, the pneumatic tire 1 is not limited to this configuration. For example, even if the V-shaped reference lines 32a-32l have different V-shaped angles, it is possible to overlap the V-shaped ridges 40a-40l with each other to create a black shade.

[0099] (3) In the pneumatic tire 1 according to the above embodiment, the decorative region 3 has four or more types of V-shaped pattern regions 31a-31l. However, the pneumatic tire 1 is not limited to this configuration. Even if the decorative region 3 is composed of three or fewer types of V-shaped pattern regions 31a-31l, it is possible to overlap the V-shaped ridges 40a-40l with each other to create different shades of black.

[0100] (4) In addition, in the pneumatic tire 1 according to this embodiment, the V-shaped pattern regions 31a, 31b, 31c, 31e, 31f, 31h, 31i, 31k, and 31l are configured to be in contact with the inner circumferential edge 3a or the outer circumferential edge 3b of the decorative region 3. However, the pneumatic tire 1 is not limited to this configuration. The V-shaped pattern regions 31d, 31g, and 31j may be spaced apart from the inner circumferential edge 3a and the outer circumferential edge 3b of the decorative region 3. [Explanation of symbols]

[0101] 1...pneumatic tire, 2...sidewall, 2a...sidewall rubber, 2b...outer surface, 2c...maximum tire width position, 3...decorative area, 3a...inner peripheral edge, 3b...outer peripheral edge, 3c...first side edge, 3d...second side edge, 4...indentation, 30...unit pattern, 31a to 31l...first to twelfth V-shaped pattern areas, 32a to 32l...first to twelfth V-shaped reference lines, 40a to 40l...first to twelfth V-shaped ridges, θ...V angle, D1...tire axial direction, D2...tire radial direction, D3...tire circumferential direction, S2...reference plane of outer surface

Claims

1. The tire has a sidewall extending in a radial direction, the sidewall has a strip-shaped decorative area extending along the tire circumferential direction on an outer surface thereof, the decorative region has a plurality of types of V-shaped pattern regions, Each of the V-shaped pattern regions is a polygonal region including a V-shaped reference line on its contour, which is different for each V-shaped pattern region, and the polygonal region includes a plurality of V-shaped ridges arranged in parallel and spaced apart from each other from the V-shaped reference line, The pneumatic tire, wherein the plurality of types of V-shaped pattern regions partially overlap each other.

2. The pneumatic tire according to claim 1, wherein the V-shaped reference line in each V-shaped pattern region has a V-shaped angle of 60 to 120 degrees.

3. The pneumatic tire according to claim 1 or 2, wherein the V-shaped reference lines of the plurality of types of V-shaped pattern regions all have the same V-angle.

4. The pneumatic tire according to claim 1 , wherein the decorative region has four or more types of the V-shaped pattern regions.

5. The pneumatic tire according to claim 1 , wherein the V-shaped pattern region is in contact with an inner circumferential edge or an outer circumferential edge of the decorative region.

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