pneumatic tires

Abstract

Pneumatic tires with a designated mounting direction in relation to a vehicle, comprising: in a tread section (1) main grooves (9) running in the circumferential direction of the tire; and a sipe (11) extending in the transverse direction of the tire, arranged in ribs (10) defined by the main grooves (9); wherein the sipe (11) comprises a rim on a front side (11A) and a rim on a rear side (11B), the rim on the front side (11A) and the rim on the rear side (11B) being arranged opposite each other; the edge on the front side (11A) and the edge on the back side (11B) each comprise a beveled section (12) that is shorter than one lamella length of the lamella (11); a non-beveled area (13) in which other beveled sections (12) are not present, is provided on sections opposite the beveled sections (12) of the lamella (11); and for all beveled sections (12) formed on grooves other than the main grooves (9), which at least include the beveled sections (12) of the lamella (11), a total projection area A IN the beveled sections (12) arranged on a vehicle assembly inside, and a total projection area A OUT the beveled sections (12) arranged on a vehicle assembly exterior, a ratio A IN > A OUT fulfill.

Description

Technical field

[0001] The present invention relates to a pneumatic tire and in particular to a pneumatic tire with a designated vehicle mounting direction, which can provide improved steering stability performance on dry road surfaces and improved steering stability performance on wet road surfaces in a compatible manner and furthermore improved noise performance by designing a sipe chamfer shape. State of the art

[0002] In the prior art, a pneumatic tire tread pattern consists of multiple sipes within a rib defined by multiple main grooves. Providing such sipes ensures drainage properties and provides steering stability on wet road surfaces. However, if a large number of sipes are arranged in a tread section to improve steering stability on wet surfaces, the stiffness of the ribs decreases, which has the disadvantage of impairing steering stability on dry road surfaces.Furthermore, if a large number of sipes are arranged in the tread section, it is difficult to achieve noise performance (noise reduction) and steering stability performance on wet road surfaces in a compatible manner, as the popping noise and rolling noise are directed towards the outside of the vehicle while driving, and the noise of the tire tends to increase.

[0003] Several pneumatic tires have been proposed in which sipes are formed in a tread pattern and chamfered (see, for example, JP 2013-537134 A). When the sipes are formed and chamfered, edge effects may be lost depending on the shape of the chamfers, and depending on the dimensions of the chamfers, the improvement in steering stability performance on dry road surfaces and the improvement in steering stability performance on wet road surfaces may be insufficient. Bibliography

[0004] EP 3 025 874 A1 discloses a pneumatic tire equipped with a tread section. The tread section has continuous main grooves running circumferentially around the tire, comprising shoulder main grooves and an intermediate crown main groove. The tread section is subdivided into inner and outer shoulder rib areas outside the respective shoulder main grooves and intermediate central rib areas. The central rib areas have central narrow grooves, subdivided into a first, second, and third central narrow groove. All central narrow grooves have an axially outer end connected to the shoulder main groove, as well as a slot-shaped narrow section and a wide section. A slightly chamfered area is formed on the groove walls of the wide section.

[0005] EP 2 899 041 A1 discloses a pneumatic tire comprising a tread section, an outer shoulder groove, an inner shoulder groove, a central groove, and a plurality of crown sipes, each comprising a first sipe, a second sipe, and a third sipe. The tread section is subdivided into inner and outer crown rib sections and shoulder rib sections.

[0006] EP 3 015 286 A1 discloses a pneumatic tire comprising a tread section with an inner tread edge, an outer tread edge, an inner main shoulder groove, an outer main shoulder groove, a central main groove, an inner center rib area, an inner shoulder rib area, an outer center rib area, and an outer shoulder rib area. Each center rib area is provided with a plurality of narrow center grooves. The shoulder rib areas are provided with lateral shoulder grooves and narrow shoulder grooves. The narrow shoulder grooves have a lamellar section and a narrow groove section.The narrow groove section has a chamfered section whose groove width gradually decreases towards the radial inside, and an inner section which extends from the chamfered section towards the radial inside, while the inner section maintains the same groove width as the lamellar section.

[0007] JP 2013 035 345 A discloses a pneumatic tire having a circumferential rib section with a groove extending in the width direction. The groove has a first groove section and a second groove section connected to the first groove section. A sidewall of the first fine groove section has a depth equal to that of the first groove section and is chamfered, becoming shallower in the direction opposite to that sidewall. A sidewall located on the opposite side of the first fine groove section has a depth equal to that of the second fine groove section and is chamfered, becoming shallower in the direction opposite to that sidewall. Brief description of the technical problem

[0008] One object of the present invention is to provide a pneumatic tire with a designated vehicle mounting direction which can provide improved steering stability performance on dry road surfaces and improved steering stability performance on wet road surfaces in a compatible manner and furthermore improved noise performance by designing a sipe chamfer shape. Solution to the problem

[0009] To fulfill the above-described problem, a pneumatic tire according to an embodiment of the present invention is a pneumatic tire with a designated mounting direction in relation to a vehicle, which includes the following: in a tread section main grooves that run in the circumferential direction of the tire; and a lamella running in the transverse direction of the tire, which is arranged in ribs determined by the main grooves; wherein the lamella includes an edge on a front side and an edge on a rear side, with the edge on the front side and the edge on the rear side being arranged opposite each other; The edge on the front side and the edge on the back side each enclose a beveled section that is shorter than one lamella length of the lamella; a non-beveled area, in which other beveled sections are not present, is provided on sections opposite the beveled sections of the lamella; and for all beveled sections formed on grooves other than the main grooves, including at least the beveled sections of the lamella, a total projection area A IN the beveled sections arranged on a vehicle assembly inside, and a total projection area A OUTthe beveled sections arranged on a vehicle assembly exterior, a ratio A IN > A OUT fulfill. Advantageous effects of the invention

[0010] In one embodiment of the present invention, the pneumatic tire has a designated mounting direction with respect to a vehicle and includes sipes that extend transversely in the tire direction in ribs defined by the main grooves. The chamfered section, which is shorter than the sipe length, is provided at both the leading and trailing edges of the sipe, and the non-chamfered areas, where other chamfered sections are not present, are located on the sections opposite the chamfered sections of the sipe. Thus, the chamfered sections enhance water drainage, and the chamfered edges in the non-chamfered areas effectively remove a film of water. Consequently, steering stability on wet road surfaces can be significantly improved.Furthermore, the chamfered section and the non-chamfered area at the front and rear edges are positioned side by side in this manner. This maximizes the wet-weather performance improvement described above during braking and driving. Additionally, compared to a conventional chamfered lamella, the chamfered area can be minimized, thus improving steering stability on dry road surfaces. Consequently, steering stability on both dry and wet surfaces can be improved in a compatible manner. Furthermore, the vehicle mounting surface contributes significantly to noise reduction.Thus, for all beveled sections, including at least the beveled sections of the lamellae that are beveled sections formed on grooves other than the main grooves, the total projection area A can be calculated. OUT The chamfered sections located on the exterior of the vehicle assembly are relatively small, resulting in a reduction of noise generated while driving. Consequently, steering stability performance on both dry and wet road surfaces can be improved in a well-balanced manner.

[0011] In one embodiment of the present invention, a maximum depth x (mm) of the lamella and a maximum depth y (mm) of the chamfered sections preferably satisfy a ratio of the following formula (1); and The sipe width is constant in a region extending from an end section of the chamfered portion, located on the inner side of the tire in the radial direction, to the groove base of the sipe. This minimizes the chamfered area compared to a conventional chamfered sipe, thereby improving steering stability performance on dry road surfaces. Consequently, steering stability performance on both dry and wet road surfaces can be improved in a compatible manner. x×0,1≤y≤x×0,3+1,0

[0012] In one embodiment of the present invention, the total projection area A IN the beveled sections located on the inside of the vehicle assembly, and the total projection area A OUTthe chamfered sections located on the outer surface of the vehicle assembly, preferably formula (2). In this way, a noise reduction effect can be achieved and both the steering stability performance on dry road surfaces and the steering stability performance on wet road surfaces can be improved. More preferably, the range is 10% to 30%. 3%≤(AIN−AOUT) / AIN×100%≤50%

[0013] In one embodiment of the present invention, the lamella is preferably arranged in two or more ribs of the ribs defined by the main grooves. In this way, the steering stability performance on dry road surfaces and the steering stability performance on wet road surfaces can be improved in a well-balanced manner.

[0014] In one embodiment of the present invention, all chamfered sections are preferably configured by the chamfered section of the lamella. In this way, the steering stability performance on dry road surfaces and the steering stability performance on wet road surfaces can be improved in a well-balanced manner.

[0015] “Projection area of ​​the chamfered sections” is the area that is measured when the chamfered section is projected in a normal direction to the road contact surface of the tread section. Brief description of the drawings Fig. Figure 1 is a meridian section view illustrating an air tire according to an embodiment of the present invention. Fig. Figure 2 is a top view showing an example of a tread section of the pneumatic tire according to an embodiment of the present invention. Fig.Figure 3 is a perspective view illustrating a section of a tread section of a pneumatic tire according to an embodiment of the present invention. Fig. Figure 4 is a top view illustrating a section of a tread section of a pneumatic tire according to an embodiment of the present invention. Fig. 5 is a top view showing a lamella and a beveled section on it, located in the tread section of Fig. 4 are trained, illustrated. Fig. Figure 6 is a cross-sectional view along a line XX in the direction of the arrow in Fig. 4. Fig. Figure 7 is a top view illustrating another modified example of a tread section of a pneumatic tire according to an embodiment of the present invention. Fig.Figure 8 is a top view illustrating another modified example of a lamella and beveled sections thereon of a pneumatic tire according to an embodiment of the present invention. Fig. 9A and Fig. Figure 9B are top views illustrating another modified example of a lamella and beveled sections thereon of a pneumatic tire according to an embodiment of the present invention. Fig. Figure 10 is a cross-sectional view along a line YY in the direction of the arrow from Fig. 4. Description of embodiments

[0016] Configurations of embodiments of the present invention are described in detail below with reference to the accompanying drawings. Fig. 1 and Fig. 2 denotes CL the tire center line.

[0017] As in Fig.As illustrated in Figure 1, a pneumatic tire according to one embodiment of the present invention has a designated mounting direction with respect to a vehicle. “IN” indicates the side inward of the tire centerline CL with respect to the vehicle when the tire is mounted on the vehicle (hereinafter referred to as the “vehicle mounting inside”), and “OUT” indicates the side outward of the tire centerline CL with respect to the vehicle when the tire is mounted on the vehicle (hereinafter referred to as the “vehicle mounting outside”). As shown in Figure 1, a pneumatic tire according to one embodiment of the present invention has a designated mounting direction with respect to a vehicle. Fig. As illustrated in Figure 1, the pneumatic tire includes an annular tread section 1 extending in the circumferential direction of the tire, a pair of sidewall sections 2, 2 arranged on both sides of the tread section 1, and a pair of bead sections 3, 3 arranged inwards from the sidewall sections 2 in the radial direction of the tire.

[0018] A carcass layer 4 is arranged between the pair of bead sections 3, 3. The carcass layer 4 encloses a plurality of reinforcing cord threads running radially in the tire direction and is folded back from the inside of the tire to the outside of the tire around a tire bead core 5, which is arranged in each of the tire bead sections 3. A bead filler 6 with a triangular cross-sectional shape, formed from a rubber compound, is arranged on the outer circumference of the bead core 5.

[0019] A plurality of belt layers 7 are embedded on an outer circumferential side of the carcass layer 4 in the tread section 1. Each belt layer 7 encloses a plurality of reinforcing cords inclined with respect to the tire's circumferential direction, the reinforcing cords of the different layers being arranged crosswise. The angle of inclination of the reinforcing cords in the belt layers 7, with respect to the tire's circumferential direction, is in a range of, for example, 10° to 40°. Steel cord threads are preferably used as the reinforcing cord threads of the belt layers 7. To improve high-speed durability, at least one belt cover layer 8, formed by arranging reinforcing cords at an angle of, for example, no more than 5° with respect to the tire's circumferential direction, is arranged on an outer circumferential side of the belt layers 7.Preferably, nylon, aramid or similar organic glass fiber threads are used as the reinforcing cords of the belt cover layer 8.

[0020] It should be noted that the tire internal structure described above is a typical example of a pneumatic tire and that pneumatic tires are not limited to this.

[0021] Fig.Figure 2 illustrates an example of a tread section of a pneumatic tire according to an embodiment of the present invention. Four main grooves 9 extending in the circumferential direction of the tire are formed in a tread section 1. The main grooves 9 include a pair of inner main grooves 9A, 9A', which are arranged on both sides of the tire centerline CL, and a pair of outer main grooves 9B, 9B', which are arranged on the outermost side in the transverse direction of the tire. Ribs 10 are defined in the tread section 1 by the four main grooves 9. The ribs 10 include a central rib 100A, which is arranged on the tire centerline CL, a pair of intermediate ribs 100B, 100C, which are arranged transversely outwards from the central rib 100A, and a pair of shoulder ribs 100D, 100E, which are arranged transversely outwards from the intermediate ribs 100B, 100C.

[0022] The lamellae 11, which enclose a pair of chamfered sections 12, are formed in both the central rib 100A and the intermediate ribs 100B and 100C. The lamellae 11 include a lamella 110A located in the central rib 100A and lamellae 110B and 110C located in the intermediate ribs 100B and 100C. The chamfered sections 12 include a chamfered section 120A formed on lamella 110A, a chamfered section 120B formed on lamella 110B, and a chamfered section 120C formed on lamella 110C.

[0023] The sipes 110A are inclined in the same direction with respect to the tire's transverse direction and are formed in the central rib 100A with intervals in the tire's circumferential direction. One end of the sipe 110A is connected to the inner main groove 9A, and the other end terminates blindly within the central rib 100A. That is, the sipe 110A is a semi-closed sipe.

[0024] The sipes 110B are inclined in the same direction relative to the tire's transverse direction and are formed in the intermediate rib 100B with circumferential spacing. One end of the sipe 110B is connected to the inner main groove 9A, and the other end is connected to the outer main groove 9B. That is, the sipe 110B is an open sipe. The sipes 110C are inclined in the same direction relative to the tire's transverse direction and are formed in the intermediate rib 100C with circumferential spacing. One end of the sipe 110C terminates blindly within the intermediate rib 100C, and the other end is connected to the outer main groove 9B. That is, the sipe 110C is a semi-closed sipe.

[0025] Lug grooves 200, which are not connected to the outer main groove 9B, run in the tire transverse direction, are inclined in the same direction with respect to the tire transverse direction, and are formed in the shoulder ribs 100D, 100E with intervals in the tire circumferential direction. The lug grooves 200 include lug grooves 200A, which are formed in the shoulder rib 100D, and lug grooves 200B, which are formed in the shoulder rib 100E.

[0026] Fig. 3, Fig. 4, Fig. 5 to Fig. Figure 6 illustrates a section of a tread section of a pneumatic tire according to an embodiment of the present invention. Fig. 3, Fig. 4 to Fig. 5 indicates Tc the tire's circumferential direction and Tw indicates the tire's lateral direction. As in Fig.As illustrated in Figure 3, the ribs 10 enclose the sipes 11, which run transversely in the tire direction, and blocks 101, which are defined by the sipes 11. The blocks 101 are arranged side by side in the circumferential direction of the tire. The sipes 11 are narrow grooves with a groove width of 1.5 mm or less.

[0027] As in Fig. As illustrated in Figure 4, the sipes 11 have an overall curved shape and are formed in the rib 10 with intervals in the tire's circumferential direction. The sipe 11 encloses an edge 11A on its leading side (with respect to a direction of rotation R) and an edge 11B on its trailing side (with respect to the direction of rotation R). The chamfered sections 12 are formed on edge 11A on the leading side and on edge 11B on the trailing side.

[0028] The chamfered sections 12 include a chamfered section 12A on the front side with respect to the direction of rotation R and a chamfered section 12B on the rear side with respect to the direction of rotation R. Non-chamfered areas 13 are provided on sections opposite the chamfered sections 12, where no other chamfered sections are present. In other words, a non-chamfered area 13B is provided on the rear side with respect to the direction of rotation R on a section opposite chamfered section 12A, and a non-chamfered area 13A is provided on the front side with respect to the direction of rotation R on a section opposite chamfered section 12B.The chamfered section 12 and the non-chamfered area 13, in which other chamfered sections are not present, are arranged adjacent to each other at the edge 11A on the front side and at the edge 11B on the rear side of the lamella 11 in this manner.

[0029] As in Fig. Figure 5 illustrates the lengths of the sipe 11 and the chamfered sections 12A, 12B in the tire transverse direction as a sipe length L and as chamfer lengths L respectively. A , L B determined. The lamella length L and the bevel lengths L A , L B The lengths in the tire transverse direction from one end section to the other are given for each of the sipes 11 and each of the chamfered sections 12A, 12B. The chamfer lengths L A , L B The beveled sections 12A, 12B are shorter than the lamella length L of lamella 11.

[0030] Fig.Figure 6 is a view perpendicular to the direction of the lamella, with the running surface section 1 cut away vertically. As in Fig.As illustrated in Figure 6, the maximum depth of the sipe 11 is x (mm) and the maximum depth of the chamfered section 12 is y (mm), and the sipe 11 and the chamfered section 12 are designed such that the maximum depth y (mm) is less than the maximum depth x (mm). The maximum depth x of the sipe 11 is preferably 3 mm to 8 mm. A sipe width W of the sipe 11 is substantially constant in a region from an end section 121, which is located on the radially inward side of the chamfered section 12, to the groove bottom of the sipe 11. For example, in a configuration where a protrusion is arranged on the groove wall of the sipe 11, the sipe width W does not include the height of the protrusion.Furthermore, in a configuration where the lamella width of lamella 11 gradually narrows towards the groove bottom, the width of lamella 11 is essentially measured as the lamella width that does not include the narrow section.

[0031] In the pneumatic tire described above, all chamfered sections formed on grooves other than the main grooves 9, including at least the chamfered sections 12 of the sipes 11, fulfill a total projection area A IN all beveled sections located on the vehicle assembly interior, and an entire projection area A OUT of all beveled sections arranged on the vehicle assembly exterior, the ratio A IN > A OUT In the embodiment of Fig.2, since only the lamellae 11 are provided with a chamfered section, all chamfered sections formed on grooves other than the main grooves 9 (the lamellae 11 and the lug grooves 200) are configured by the chamfered sections 12, and the total projection area A IN The area of ​​all beveled sections 120A, 120B, which are arranged on the inside of the vehicle assembly, is less than the total projection area A OUT all beveled sections 120C that are located on the vehicle assembly exterior.

[0032] Thus, one method for calculating the total projection area A is... IN to make all beveled sections located on the vehicle assembly exterior larger than the total projection area A OUTThe total number of lamellae 11 arranged on the outside of the vehicle assembly may be less than the total number of lamellae 11 arranged on the inside of the vehicle assembly, provided that a beveled section is provided on a groove in addition to the lamella 11 (for example, a lamella or a lug groove) arranged on the inside of the vehicle assembly, and so on. Also, as described in Fig.Figure 7 shows that the total number of lamellae 11 on the vehicle mounting inside and the vehicle mounting outside can be the same, and the shape of the beveled sections 12 of the lamellae 11 on the vehicle mounting inside and the vehicle mounting outside can be very different, and the total projection area of ​​the beveled sections 12 of the lamellae 11 on the vehicle mounting outside can be made relatively small, and the relationship A IN > A OUT can be fulfilled.

[0033] As in Fig.As illustrated in Figure 7, the tread section 1 is defined by four main grooves 9 running in the circumferential direction of the tire and includes the central rib 100A, which is located on the tire centerline CL, the pair of intermediate ribs 100B, 100C, which are located outwards in the transverse direction of the tire from the central rib 100A, and the pair of shoulder ribs 100D, 100E, which are located outwards in the transverse direction of the tire from the intermediate ribs 100B, 100C. No grooves are formed in the central rib 100A, the sipes 110B, 110C, including the pair of chamfered sections 120B, 120C, are formed in the intermediate ribs 100B and 100C, respectively, and the lug grooves 200A, 200B are formed in the shoulder ribs 100D and 100E, respectively.Additionally, the chamfered sections 120B, 120C have an outer edge profile line that is not parallel to the ridge line of the lamellae 110B, 110C. The width of the chamfered section 120B increases from the middle side of the rib 10 to the side of the main groove 9, and the width of the chamfered section 120C decreases from the middle side of the rib 10 to the side of the main groove 9. Furthermore, since chamfered sections are only provided in the lamellae 11, all chamfered sections that are formed on the grooves other than the main grooves 9 (the lamellae 11 and the stud grooves 200) are formed by the chamfered sections 120B, 120C. This means that the total projection area A. IN all beveled sections 120B that are arranged on the vehicle mounting inside, and the total projection area A OUT of all beveled sections 120C that are arranged on the vehicle assembly exterior, the ratio A IN> A OUT fulfill.

[0034] In the pneumatic tire described above, the chamfered section 12, which is shorter than the sipe length L of the sipe 11, is provided at both the edge 11A on the front side and the edge 11B on the rear side of the sipe 11. The non-chamfered areas 13, where other chamfered sections are not present, are located on the sections opposite the chamfered sections 12 of the sipe 11. Thus, the water drainage effect can be improved with the chamfered sections 12, and a water film can be effectively removed by the edge effect in the non-chamfered areas 13, where the chamfered section 12 is not provided. As a result, steering stability performance on wet road surfaces can be significantly improved.Furthermore, the chamfered section 12 and the non-chamfered area 13, in which chamfered sections are not present, are arranged side by side at edge 11A on the front side and at edge 11B on the rear side in this manner. Thus, the effect of improving wet performance, as described above, can be maximized during braking and driving. Additionally, the vehicle mounting surface contributes significantly to noise performance. Therefore, for all chamfered sections, including at least the chamfered sections of the lamellae that are chamfered sections formed on grooves other than the main grooves, the total projection area A can be... OUTThe chamfered sections located on the exterior of the vehicle assembly are relatively small, resulting in a reduction of noise generated while driving. Consequently, steering stability performance on both dry and wet road surfaces can be improved in a well-balanced manner.

[0035] In the pneumatic tire described above, the maximum depth x (mm) and the maximum depth y (mm) preferably satisfy the ratio of formula (1) below. By providing the sipes 11 and the chamfered sections 12 such that they satisfy the ratio of formula (1) below, the chamfered area can be minimized compared to a known chamfered sipe, thus improving steering stability performance on dry road surfaces. Consequently, steering stability performance on dry and wet road surfaces can be improved in a compatible manner. Here, if y < x × 0.1, the flow effect from the chamfered sections 12 is insufficient, and if y > x × 0.3 + 1.0, the stiffness of the rib 10 is reduced, leading to a reduction in steering stability performance on dry road surfaces.In particular, the ratio y ≤ x × 0.3 + 0.5 is preferably satisfied. x×0,1≤y≤x×0,3+1,0

[0036] For all beveled sections, a total projection area A fulfills IN the beveled sections arranged on the inside of the vehicle assembly, and a total projection area A OUT The following formula (2) applies to the chamfered sections arranged on the vehicle assembly exterior. More preferably, the range is 10% to 30%. By adjusting the total projection area difference between the total projection area A IN the beveled sections on the inside of the vehicle assembly and the total projection area A OUTThe beveled sections on the outside of the vehicle mounting surface can thus achieve a noise reduction effect and improve both steering stability performance on dry roads and steering stability performance on wet roads. 3%≤(AIN−AOUT) / AIN×100%≤50%

[0037] In the pneumatic tire described above, the sipes 11 are preferably arranged in two or more of the ribs 10 of the plurality of ribs 10 defined by the main grooves 9. With the sipes 11 arranged in two or more of the ribs 10 in this way, the steering stability performance on dry road surfaces and the steering stability performance on wet road surfaces can be improved in a well-balanced manner.

[0038] In particular, all chamfered sections, which include at least the chamfered sections 12 of the lamellae 11, which are chamfered sections formed in grooves other than the main grooves 9, are preferably configured by the chamfered section 12 of the lamellae 11. In such a case, the total projection area difference (A IN - A OUT ) between the total projection area A IN all beveled sections on the vehicle assembly interior and the total projection area A OUT all beveled sections on the vehicle assembly exterior equal to the total projection area difference (A IN ' - A OUT ') between the total projection area A IN ' of the beveled sections 12 of the louvers 11 on the vehicle mounting side and the total projection area A OUT' of the chamfered sections 12 of the lamellae 11 on the vehicle mounting exterior. If all chamfered sections described above are configured in this way only by the chamfered section 12, the steering stability performance on dry road surfaces and the steering stability performance on wet road surfaces can be improved in a balanced manner.

[0039] Fig. Figure 8 is a diagram illustrating another modified example of a lamella and chamfered sections thereon, which are formed in the tread section of a pneumatic tire according to an embodiment of the present invention. The in Fig. The illustrated lamella 11 is formed with an inclination angle θ relative to the tire circumference. This inclination angle θ refers to the angle formed by an imaginary line (which is shown in Fig.8 (illustrated by a dashed line), which connects both end sections of the lamella 11, and forms the side surface of the block 101. The angle of inclination θ has an angle of inclination on the acute-angled side and an angle of inclination on the obtuse-angled side. In Fig.Figure 8 illustrates the angle of inclination θ on the acute-angled side. The angle of inclination θ is the angle of inclination of the sipe 11 at the interval spacing within the rib 10. Here, the angle of inclination θ on the acute-angled side is preferably 40° to 80° and more preferably 50° to 70°. With the sipe 11 inclined in this way with respect to the tire circumference, the pattern stiffness can be improved, and the steering stability performance on dry road surfaces can be further improved. However, if the angle of inclination θ is less than 40°, the resistance to uneven wear deteriorates. If the angle of inclination θ exceeds 80°, the pattern stiffness cannot be sufficiently improved.

[0040] In one embodiment of the present invention, the side exhibiting the angle of inclination θ on the acute-angled side of the lamella 11 is designated as the acute-angled side, and the side exhibiting the angle of inclination θ on the obtuse-angled side of the lamella 11 is designated as the obtuse-angled side. The chamfered sections 12A, 12B formed at the edges 11A, 11B of the lamella 11 are formed on the acute-angled side of the lamella 11. The chamfered surface of the lamella 11 on the acute-angled side in this manner further improves its resistance to uneven abrasion. Alternatively, the chamfered sections 12A, 12B can be formed on the obtuse-angled side of the lamella 11.The chamfered section 12 formed in this way on the obtuse-angled side of the lamella 11 increases the edge effect and further improves steering stability performance on wet road surfaces.

[0041] In one embodiment of the present invention, the overall shape of the lamella 11 described above is curved, which can improve steering stability performance on wet road surfaces. However, a section of the lamella 11 can have a curved or bent shape in a top view. With the lamella 11 designed in this way, the total amount of edges 11A, 11B of the lamellae 11 is increased, and the steering stability performance on wet road surfaces can be improved.

[0042] As in Fig.As shown in Figure 8, a chamfered section 12 is arranged at edge 11A on the front side and at edge 11B on the back side of the lamella 11. The chamfered sections 12 arranged in this way improve the resistance to uneven abrasion. However, if two or more chamfered sections 12 are formed both at edge 11A on the front side and at edge 11B on the back side of the lamella 11, the number of nodes increases, which tends to worsen the resistance to uneven abrasion.

[0043] The maximum width of the chamfered section 12, measured in the direction perpendicular to the lamella 11, is defined as the width W1. Here, the maximum width W1 of the chamfered section 12 preferably corresponds to 0.8 to 5.0 times the lamella width W of the lamella 11, and more preferably to 1.2 to 3.0 times. By thus appropriately defining the maximum width W1 of the chamfered section 12 with respect to the lamella width W, the steering stability performance on dry road surfaces and the steering stability performance on wet road surfaces can be improved in a compatible manner.If the maximum width W1 of the chamfered section 12 is less than 0.8 times the lamella width W of the lamella 11, the steering stability performance on wet road surfaces cannot be sufficiently improved, and if the maximum width W1 is more than 5.0 times the lamella width W, the steering stability performance on dry road surfaces cannot be sufficiently improved.

[0044] Furthermore, the outer edge section of the chamfered section 12 is designed parallel to the longitudinal direction of the lamella 11. With the chamfered section 12 thus running parallel to the lamella 11, the resistance to uneven wear can be improved, and the steering stability performance on dry road surfaces and the steering stability performance on wet road surfaces can be improved in a compatible manner.

[0045] As in Fig.As illustrated in Figure 8, the end sections of the chamfered sections 12A, 12B, located near the main grooves 9, are connected to the main grooves 9 arranged on both sides of the rib 10. The chamfered sections 12A, 12B configured in this way further improve steering stability performance on wet road surfaces. Alternatively, the end sections of the chamfered sections 12A, 12B located near the main grooves 9 can terminate blindly within the rib 10 without being connected to the main grooves 9. The chamfered sections 12A, 12B configured in this way further improve steering stability performance on dry road surfaces.

[0046] Fig. 9A and Fig.Figure 9B are diagrams illustrating another modified example of a lamella and chamfered sections thereon, which are formed in the tread section of a pneumatic tire according to an embodiment of the present invention. As in Fig. As illustrated in Figure 9A, the chamfered section 12A and the chamfered section 12B are designed such that a portion of each chamfered section 12A, 12B overlaps in a central section of the sipe 11. Here, the length in the tire transverse direction of the overlapping section, which is a section in which the chamfered section 12A and the chamfered section 12B overlap, is defined as the overlap length L1. On the other hand, as in Fig.Figure 9B illustrates that when a section of both the chamfered section 12A and the chamfered section 12B do not overlap and are separated by a certain distance, the ratio of the overlap length L1 to the lamella length L is expressed as a negative value. The overlap length L1 of the overlapping section is preferably -30% to 30% of the lamella length L, and more preferably -15% to 15%. By appropriately defining the overlap length L1 of the chamfered section 12 in relation to the lamella length L in this way, the steering stability performance on dry road surfaces and the steering stability performance on wet road surfaces can be improved in a compatible manner.Here, if the overlap length L1 is more than 30%, the steering stability performance on dry road surfaces is not sufficiently improved, and if the overlap length L1 is less than -30%, the steering stability performance on wet road surfaces is not sufficiently improved.

[0047] Fig. Figure 10 shows a view of the lamella, cut open along its direction of travel. As in Fig.As illustrated in Figure 10, the lamella 11 incorporates a raised ground section 14 in a longitudinal section of the lamella 11. The raised ground section 14 comprises a raised ground section 14A located in the central section of the lamella 11 and raised ground sections 14B located at both end sections of the lamella 11. By providing the raised ground section 14 in the lamella 11 in this manner, the steering stability performance on dry road surfaces and the steering stability performance on wet road surfaces can be improved in a compatible manner. The raised ground section 14 of the lamella 11 can be located at the end section and / or not at the end section of the lamella 11.

[0048] The height in the tire radial direction of the raised floor section 14, which is formed in the lamella 11, is called height H. 14determined. For the raised bottom section 14A, which is not formed at the end section of the lamella 11, the maximum height from the groove bottom of the lamella 11 to the upper surface of the raised bottom section 14A is defined as height H. 14A determined. The height H 14A preferably corresponds to 0.2 to 0.5 times the maximum depth x of the lamella 11 and more preferably to 0.3 to 0.4 times. By defining the height H 14A By raising the height of the raised floor section 14A, which is not located at the end section of the lamella 11, to a suitable height, the stiffness of block 101 can be improved and the drainage effect can be maintained. As a result, steering stability performance on wet road surfaces can be improved. Here, if the height H 14A if the maximum depth x of the lamella 11 is less than 0.2 times, the stiffness of the block 101 is not sufficiently improved, and if the height H 14AIf the depth x of the lamella 11 is more than 0.5 times the maximum depth x, the steering stability performance on wet road surfaces cannot be sufficiently improved.

[0049] For the raised bottom sections 14B, which are formed at both end sections of the lamella 11, the maximum height from the groove bottom of the lamella 11 to the upper surface of the raised bottom section 14B is defined as height H. 14B determined. The height H 14B preferably corresponds to 0.6 to 0.9 times the maximum depth x of the lamella 11 and more preferably to 0.7 to 0.8 times. By defining the height H 14B By raising the raised floor sections 14B, which are arranged at the end sections of the lamella 11, to a suitable height, the stiffness of the block 101 can be improved and the steering stability performance on dry road surfaces can be enhanced. Here, if the height H 14Bif the maximum depth x of the lamella 11 is less than 0.6 times, the stiffness of the block 101 is not sufficiently improved, and if the height H 14B If the depth x of the lamella 11 is more than 0.9 times the maximum depth x, the steering stability performance on wet road surfaces cannot be sufficiently improved.

[0050] The length in the tire transverse direction of the raised ground section 14 of the lamella 11 is defined as length L 14 determined by the elevated ground. The lengths L 14A , L 14B The length of the raised floor of the raised floor sections 14A, 14B preferably corresponds to 0.3 to 0.7 times the lamella length L and more preferably to 0.4 to 0.6 times. With the lengths L thus suitably determined 14A , L 14BThe raised floor of the raised floor sections 14A, 14B can improve steering stability performance on dry road surfaces and steering stability performance on wet road surfaces in a compatible manner. Examples

[0051] Tires according to a conventional example 1, 2, and examples 1 to 5 were manufactured. The tires have a size of 245 / 40R19 and an intended mounting direction with respect to a vehicle and include, in a tread section, circumferential main grooves, ribs defined by the main grooves, and sipes extending transversely within the ribs. The tires are configured as specified in Table 1: chamfer arrangement (both sides or one side), size relationship between sipe length L and chamfer lengths L A , L B, chamfer provided on the section facing the chamfered section, size relationship between the total projection area A IN all beveled sections on the vehicle assembly interior and the total projection area A OUT all beveled sections on the vehicle mounting exterior, slat width, total projection area difference between all beveled sections on the vehicle mounting interior and all beveled sections on the vehicle mounting exterior ((A IN - A OUT ) / A IN × 100%), the number of ribs with slats that include beveled sections, and the total projection area difference between beveled sections of the slats on the vehicle mounting inside and beveled sections of the slats on the vehicle mounting outside ((A IN - A OUT ') / A IN ' × 100 %).

[0052] Note in Table 1 that if the value of the “total area projection difference between all beveled sections on the vehicle assembly inside and all beveled sections on the vehicle assembly outside” is equal to the value of the “total area projection difference between beveled sections of slats on the vehicle assembly inside and beveled sections of slats on the vehicle assembly outside”, this means that all beveled sections include at least the beveled sections of the slats that are beveled sections formed on grooves other than the main grooves, configured by the beveled part of the slat.

[0053] These test tires were subjected to a sensory evaluation by a test driver regarding steering stability performance on dry and wet roads, as well as a sensory evaluation of noise performance. The corresponding results are given in Table 1.

[0054] During the sensory evaluation of steering stability performance on dry and wet road surfaces, the test tires were mounted on a 19 × 8.5 J rim on a vehicle and inflated to a pressure of 260 kPa. The evaluation results are expressed as index values, with the results of Prior Art Example 1 assigned an index value of 100. Higher index values ​​indicate better steering stability performance on both dry and wet road surfaces.

[0055] The sensory evaluation of noise performance was carried out using the test tires on a vehicle-mounted wheel with a rim size of 19 × 8.5 J, inflated to a pressure of 260 kPa. The evaluation results are expressed as index values, with the results of State of the Art 1 being assigned an index value of 100. Higher index values ​​indicate superior noise performance. [Table 1-I] Example of the state of the art 1 Example of the state of the art 2 Example 1 Example 2 Bevel arrangement (both sides or one side) Both sides On one page Both sides Both sides Size ratio between slat length L and bevel lengths L A , L B L = L A , L B L = L A L > L A ,L B L > L A , L B Bevel provided on the section opposite the beveled section Yes No No No Size ratio between total projection area A IN all beveled sections on the inside of the vehicle assembly and the entire projection surface A OUT all beveled sections on the vehicle assembly exterior A IN = A OUT A IN = A OUT A IN >A OUT A IN >A OUT slat width Constant Does it change? Changes Constant Total projection area difference between all chamfered sections on the inside of the vehicle assembly and all chamfered sections on the outside of the vehicle assembly (A) IN - A OUT ) / A IN × 100 %) 0 % 0% 3% 3 % Number of ribs with lamellae including beveled sections 1 1 1 1 Total projection area difference between beveled sections of the slats on the inside of the vehicle mounting and beveled sections of the slats on the outside of the vehicle mounting (A) IN ' - A OU ') / A IN ' × 100 %) 0% 0% 3% 3% Steering stability performance on dry road surfaces 100 90 105 106 Steering stability performance on wet road surfaces 100 105 105 106 noise level 100 100 102 102 [Table 1-II] Example 3 Example 4 Example 5 Bevel arrangement (both sides or one side) Both sides Both sides Both sides Size ratio between slat length L and bevel lengths L A , L B L > L A , L B L > L A , L B L > L A , L B Bevel provided on the section opposite the beveled section No No No Size ratio between total projection area A IN all beveled sections on the inside of the vehicle assembly and the entire projection surface A OUT all beveled sections on the vehicle assembly exterior A IN > A OUT A IN > A OUT A IN > A OUT slat width Constant Constant Constant Total projection area difference between all chamfered sections on the inside of the vehicle assembly and all chamfered sections on the outside of the vehicle assembly (A) IN - A OUT ) / A IN × 100 %) 20 % 20 % 20 % Number of ribs with lamellae including beveled sections 1 3 3 Total projection area difference between beveled sections of the slats on the inside of the vehicle mounting and beveled sections of the slats on the outside of the vehicle mounting (A) IN ' - A OU ') / A IN ' × 100 %) 3% 3% 20 % Steering stability performance on dry road surfaces 107 108 109 Steering stability performance on wet road surfaces 107 108 109 noise level 102 104 104

[0056] As can be seen from Table 1, the tires of examples 1 to 5 exhibit improved noise performance and improved steering stability performance on both dry road surfaces and wet road surfaces due to the design of the chamfered sections formed on the sipes. List of reference symbols 1 tread section 2 Side wall section 3 bead section 9 Main groove 10th rib Block 101 11 lamella 11A Edge on front 11B Edge on back 12 Beveled section 12A Beveled section on front 12B Beveled section on back 13 Non-beveled area 13A Non-beveled area on front 13B Non-beveled area on back

Claims

[1] Pneumatic tires with a designated mounting direction in relation to a vehicle, comprising: in a tread section (1) main grooves (9) running in the circumferential direction of the tire; and a sipe (11) extending in the transverse direction of the tire, arranged in ribs (10) defined by the main grooves (9); wherein the sipe (11) comprises a rim on a front side (11A) and a rim on a rear side (11B), the rim on the front side (11A) and the rim on the rear side (11B) being arranged opposite each other; the edge on the front side (11A) and the edge on the back side (11B) each comprise a beveled section (12) that is shorter than one lamella length of the lamella (11); a non-beveled area (13) in which other beveled sections (12) are not present, is provided on sections opposite the beveled sections (12) of the lamella (11); and for all beveled sections (12) formed on grooves other than the main grooves (9), which at least include the beveled sections (12) of the lamella (11), a total projection area A IN the beveled sections (12) arranged on a vehicle assembly inside, and a total projection area A OUT the beveled sections (12) arranged on a vehicle assembly exterior, a ratio A IN > A OUT fulfill. [2] Pneumatic tires according to claim 1, wherein a maximum depth x (mm) of the lamella (11) and a maximum depth y (mm) of the chamfered sections (12) satisfy a ratio of formula (1); and a lamella width of the lamella (11) is constant in a region from an end section (121) of the chamfered section (12) arranged on an inside in the tire radial direction to a groove bottom of the lamella (11); x×0,1≤y≤x×0,3+1,0 [3] Pneumatic tires according to claim 1 or 2, wherein the entire projected area A IN the beveled sections (12) located on the inside of the vehicle assembly, and the entire projected area A OUT the beveled sections (12) located on the outside of the vehicle assembly satisfy formula (2); 3%≤(AIN−AOUT) / AIN×100%≤50% [4] Pneumatic tire according to any one of claims 1 to 3, wherein the slat (11) is arranged in two or more ribs (10) of the ribs (10) defined by the main grooves (9). [5] Pneumatic tire according to claim 4, wherein all chamfered sections (12) are configured by the chamfered section (12) of the lamella (11).

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