Tyre for motorcycles

Abstract

The present application maintains off-road performance and resistance to uneven wear, and further improves transition characteristics and lightness during cornering. A motorcycle tire (1) has a tread portion (2). The tread portion (2) is divided into a substantially triangular first region (S1) surrounded by a first inclined main groove (3), a second inclined main groove (4), and a first tread end (Te1). The first region (S1) is divided into a plurality of blocks (6) by a plurality of sub-grooves (5). The ratio (A2 / A1) of the area A1 of the block tread surface (7a) of the largest block (7) to the area A2 of the block tread surface (8a) of the smallest block (8) is 40% to 80%.

Description

Technical Field

[0001] This invention relates to motorcycle tires. Background Technology

[0002] Patent Document 1 describes a motorcycle tire having a tread portion having alternating first and second inclined main grooves that are inclined in opposite directions. The tread portion includes a first region surrounded by the first and second inclined main grooves and a first tread end. The first region includes multiple tread blocks, each tread block including a contact patch with an angle of 45 degrees or more at each vertex. Such a pneumatic tire improves both on-road and off-road performance and exhibits superior resistance to uneven wear.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-111973

[0004] However, there is room for improvement in the transition characteristics and agility of the aforementioned tires when cornering on highways. Summary of the Invention

[0005] The present invention is proposed in view of the above actual situation, and its main purpose is to provide a motorcycle tire that can maintain off-road performance and resistance to uneven wear, and further improve the transition characteristics and agility when cornering.

[0006] This invention provides a motorcycle tire having a tread portion, the tread portion including a first tread end, a second tread end, and a plurality of first inclined main grooves and a plurality of second inclined main grooves extending obliquely between the first tread end and the second tread end in directions opposite to each other relative to the tire circumference. The plurality of first inclined main grooves and the plurality of second inclined main grooves are alternately arranged along the tire circumference and are interconnected. The tread portion is divided into a plurality of generally triangular first regions surrounded by the first inclined main grooves, the second inclined main grooves and the first tread end. The first regions are divided into a plurality of tread blocks by a plurality of secondary grooves. The plurality of tread blocks include a maximum tread block with the largest tread surface area and a minimum tread block with the smallest tread surface area. The ratio A2 / A1 of the tread surface area A1 of the maximum tread block and the tread surface area A2 of the minimum tread block is 40% to 80%.

[0007] The motorcycle tires of the present invention preferably include a first secondary groove extending between the first inclined main groove and the first tread end, and a second secondary groove connected to the first secondary groove.

[0008] The motorcycle tires involved in this invention preferably have a second groove width that is smaller than the first groove width.

[0009] The motorcycle tires involved in this invention preferably have a second groove depth that is less than the first groove depth.

[0010] The motorcycle tire of the present invention preferably includes the first secondary groove, comprising a first portion connected to the first inclined main groove, and a second portion connected to the first portion and having an inclination angle relative to the tire circumference greater than that of the first portion relative to the tire circumference, wherein the length of the second portion is less than the length of the first portion.

[0011] In the motorcycle tires of the present invention, the length of the second secondary groove is preferably greater than the length of the second portion.

[0012] The motorcycle tires involved in this invention preferably have an angle of 40 degrees or more relative to the tire circumference for the first inclined main groove, the second inclined main groove, and the first secondary groove.

[0013] The motorcycle tire of the present invention preferably includes the first inclined main groove comprising: a first main inclined portion extending across the tire equator; and a first secondary inclined portion having an angle larger than that of the first main inclined portion relative to the tire circumference and being disposed at a position closer to the second tread end side than the first main inclined portion. The second inclined main groove comprises: a second main inclined portion extending across the tire equator; and a second secondary inclined portion having an angle larger than that of the second main inclined portion relative to the tire circumference and being disposed at a position closer to the first tread end side than the second main inclined portion. The first main inclined portion and the second secondary inclined portion are connected.

[0014] In the motorcycle tires of the present invention, the second main tilting portion is preferably connected to the first auxiliary tilting portion.

[0015] The motorcycle tires involved in this invention preferably have the first inclined main groove and the second inclined main groove not connected to the first tread end and the second tread end, but forming terminals.

[0016] The motorcycle tires involved in this invention preferably have the largest tread block and the smallest tread block adjacent to each other in the tire circumferential direction.

[0017] The motorcycle tire of the present invention preferably has a second region of approximately triangular shape in the tread area, which is surrounded by the first inclined main groove, the second inclined main groove and the second tread end. The second region is divided into multiple tread blocks by multiple secondary grooves. The multiple tread blocks include the largest tread block with the largest tread surface area and the smallest tread block with the smallest tread surface area. The ratio A2' / A1' of the tread surface area A1' of the largest tread block to the tread surface area A2' of the smallest tread block is 40% to 80%.

[0018] The motorcycle tire of the present invention, by adopting the above-described structure, can maintain off-road performance and resistance to uneven wear, and further improve the transition characteristics and agility when cornering. Attached Figure Description

[0019] Figure 1 This is a cross-sectional view of a motorcycle tire according to one embodiment of the present invention.

[0020] Figure 2 yes Figure 1 A top view of the unfolded tread of the tire.

[0021] Figure 3 yes Figure 2 An enlarged view of region 1.

[0022] Figure 4 yes Figure 2 An enlarged view of region 1.

[0023] Figure 5 yes Figure 1 A top view of the unfolded tread of the tire.

[0024] Explanation of reference numerals in the attached figures

[0025] 1…Motorcycle tire; 2…Tread; 3…First inclined main groove; 4…Second inclined main groove; 5…Secondary groove; 6…Tread block; 7…Largest tread block; 7a…Tread block tread surface; 8…Minimum tread block; 8a…Tread block tread surface; S1…First area; Te1…First tread end. Detailed Implementation

[0026] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0027] Figure 1 This is a cross-sectional view of a motorcycle tire 1 (hereinafter, simply referred to as "tire") in its normal configuration, representing one embodiment of the present invention. Figure 2 This is a top view obtained by unfolding the tread portion 2 of the tire 1. The tire 1 of this embodiment is suitable, for example, for travel on routes where both highways and off-road terrain coexist. The tire 1 of this embodiment is used, for example, as the rear wheel of a motorcycle. Furthermore, the tire 1 can also be used as the front wheel of a motorcycle. Figure 1 yes Figure 2 A-A sectional view.

[0028] The aforementioned "normal condition" refers to the unloaded state in which tire 1 is assembled on a normal rim (not shown) and filled with normal internal pressure. In this specification, unless otherwise specified, the dimensions of tire 1 are values ​​measured under the normal condition.

[0029] "Standard rim" refers to a rim with a specific specification for each tire within a specification system that includes the specifications the tire is based on. For example, JATMA is a "standard rim", TRA is a "Design Rim", and ETRTO is a "Measuring Rim".

[0030] "Standard tire pressure" is the air pressure specified for each tire in the specification system, including the specifications on which the tire is based. If it is JATMA, it is the "maximum air pressure". If it is TRA, it is the maximum value recorded in the table "TIRE LOAD LIMITS ATVARIOUS COLD INFLATION PRESSURES". If it is ETRTO, it is "INFLATION PRESSURE".

[0031] like Figure 1 As shown, in the above-described normal state, the outer surface 2s of the tread portion 2 of the tire 1 in this embodiment is curved into an arc shape that bulges outward radially from the tire. This allows the tire 1 to achieve sufficient contact area even when cornering with a large camber angle.

[0032] The tread portion 2 has a first tread end (right side in the figure) Te1 and a second tread end (left side in the figure) Te2. The first tread end Te1 and the second tread end Te2 correspond to the two ends of the tire axial direction of the tread portion 2, and for example, they can touch the ground when turning at an angle near the maximum camber angle.

[0033] like Figure 2 As shown, the tread 2 includes a plurality of first inclined main grooves 3 and a plurality of second inclined main grooves 4 extending obliquely between the first tread end Te1 and the second tread end Te2 in an orientation opposite to each other relative to the tire circumference.

[0034] Multiple first inclined main grooves 3 and multiple second inclined main grooves 4 are alternately arranged along the circumference of the tire and are connected to each other. As a result, multiple roughly triangular first regions S1 are divided in the tread 2, which are surrounded by the first inclined main grooves 3, the second inclined main grooves 4 and the first tread end Te1.

[0035] The first region S1 is divided into multiple patterned blocks 6 by multiple secondary grooves 5. Preferably, 4 to 8 patterned blocks 6 are provided in the first region S1. The multiple patterned blocks 6 include the largest patterned block 7 with the largest area of ​​the patterned block tread surface 7a, and the smallest patterned block 8 with the smallest area of ​​the patterned block tread surface 8a.

[0036] Furthermore, the ratio (A2 / A1) of the area A1 of the tread surface 7a of the largest tread block 7 to the area A2 of the tread surface 8a of the smallest tread block 8 is 40% to 80%. Since the ratio (A2 / A1) is 40% or more, the stiffness difference between the tread blocks 6 in the first region S1 is reduced. This improves the transition characteristics and agility during the initial to later stages of cornering on the road. Additionally, in the first region S1, the reduced stiffness difference between the tread blocks maintains resistance to uneven wear. Furthermore, since the ratio (A2 / A1) is 80% or less, uneven deformation occurs when the tread blocks 6 contact the ground in the first region S1, thereby improving mud removal from the first inclined main ditch 3, the second inclined main ditch 4, and the secondary ditch 5, and improving off-road performance. In this specification, "transition characteristics" refers to the smoothness of the vehicle body tilting during the initial to later stages of cornering. Additionally, "nimbleness" refers to the responsiveness of the bike when the rider consciously changes the camber angle. Furthermore, there are instances where transitional characteristics during cornering on public roads and nimbleness are collectively referred to as "road performance."

[0037] In this embodiment, the tire rotation direction R of the tread portion 2 is specified. However, the tread portion 2 of the present invention is not limited to the case where the tire rotation direction R is specified.

[0038] The first inclined main groove 3 is not connected to the first tread end Te1 and the second tread end Te2 (hereinafter, they may be simply referred to as "tread end Te") but forms an end. Similarly, the second inclined main groove 4 is not connected to either of the two tread ends Te but forms an end. Such first inclined main grooves 3 and second inclined main grooves 4 suppress the reduction in rigidity of the tread ends Te with large lateral forces, thereby improving road performance. Although not particularly limited, the tire axial distance La between each tread end Te and the first end 3e of the first inclined main groove 3 or the first end 4e of the second inclined main groove 4 is preferably 1 mm or more, more preferably 2 mm or more, more preferably 5 mm or less, and more preferably 4 mm or less. The first ends 3e and 4e refer to the ends that are not connected to other grooves but are interrupted at the outer surface 2s of the tread 2.

[0039] The first inclined main groove 3 includes a first main inclined portion 3A extending across the tire equator C, and a first secondary inclined portion 3B that is inclined at an angle θ1 greater than that of the first main inclined portion 3A relative to the tire circumference and is located at a position closer to the second tread end Te2 than that of the first main inclined portion 3A. In this embodiment, the first main inclined portion 3A and the first secondary inclined portion 3B are connected via a buckling portion K1 that protrudes to one side (upper side in the figure) in the tire circumference.

[0040] The second inclined main groove 4 includes a second main inclined portion 4A extending across the tire equator C, and a second auxiliary inclined portion 4B that is inclined at an angle θ3 greater than that of the second main inclined portion 4A relative to the tire circumference and is located on the side closer to the first tread end Te1 than the second main inclined portion 4A. In this embodiment, the second main inclined portion 4A and the second auxiliary inclined portion 4B are connected by a buckling portion K2 that protrudes to one side (upper side in the figure) in the tire circumference direction.

[0041] The first main sloping portion 3A is connected to the second auxiliary sloping portion 4B. Furthermore, the second main sloping portion 4A is connected to the first auxiliary sloping portion 3B. Therefore, the tire axial length L1 of the first sloping main groove 3 and the second sloping main groove 4 is ensured to be large, thus improving the shear force relative to mud. Therefore, superior off-road performance can be achieved. In this embodiment, the first main sloping portion 3A is not connected to the bend K2 of the second sloping main groove 4, but is connected to the second auxiliary sloping portion 4B at a position closer to the first tread end Te1 than the bend K2. In this embodiment, the second main sloping portion 4A is not connected to the bend K1 of the first sloping main groove 3, but is connected to the first auxiliary sloping portion 3B at a position closer to the second tread end Te2 than the bend K1.

[0042] While not particularly limited, the angles θ1 of the first main tilting portion 3A and θ3 of the second main tilting portion 4A are preferably 30 degrees or more, more preferably 40 degrees or more, more preferably 60 degrees or less, and more preferably 50 degrees or less. Furthermore, the angles θ2 of the first auxiliary tilting portion 3B relative to the tire circumference and θ4 of the second auxiliary tilting portion 4B relative to the tire circumference are preferably 35 degrees or more, more preferably 45 degrees or more, more preferably 65 degrees or less, and more preferably 55 degrees or less.

[0043] Figure 3 yes Figure 2 An enlarged view of region S1, number 1. Figure 3 As shown, the secondary groove 5 extends obliquely relative to the tire circumference. Such a secondary groove 5, having a tire axial component, exerts shear force relative to the mud, thus improving off-road performance.

[0044] The secondary groove 5 includes a first secondary groove 11 extending between the first inclined main groove 3 and the first tread end Te1, and a second secondary groove 12 connected to the first secondary groove 11. For the first secondary groove 11, for example, its outer end 11e on the side of the first tread end Te1 is not connected to the first tread end Te1, but forms a terminal within the tread portion 2. The two ends of the second secondary groove 12 are connected to the groove. In this specification, "groove" refers to a groove with a width of 1.5 mm or more.

[0045] The tire axial distance Lb between the outer end 11e of the first secondary groove 11 and the first tread end Te1 is preferably the same as the distance La. The distance Lb is preferably 1 mm or more, more preferably 2 mm or more, more preferably 5 mm or less, and more preferably 4 mm or less.

[0046] The first secondary groove 11 includes a first portion 11A connected to the first inclined main groove 3, and a second portion 11B connected to the first portion 11A, wherein the angle θ6 is larger than the angle θ5 of the inclination of the first portion 11A relative to the tire circumference. This first secondary groove 11 maintains high axial stiffness of the tire near the first tread end Te1, where the aforementioned lateral force acts. The first portion 11A and the second portion 11B are connected via a buckling portion K3 protruding to one side in the tire circumference. The difference (θ6 - θ5) between the angle θ5 of the first portion 11A and the angle θ6 of the second portion 11B is preferably 20 degrees or more, more preferably 25 degrees or more, more preferably 50 degrees or less, and more preferably 45 degrees or less.

[0047] In this embodiment, the first secondary groove 11 includes a first short secondary groove 13 with a shorter axial length than the tire and a first long secondary groove 14 with a longer axial length than the first short secondary groove 13. In this embodiment, the first long secondary groove 14 is positioned closer to the second inclined main groove 4 than the first short secondary groove 13. The first portion 11A of the first long secondary groove 14 is inclined at an angle θ3 closer to the second main inclined portion 4A than the first portion 11A of the first short secondary groove 13.

[0048] Part 11A extends along the second main inclined portion 4A of the second inclined main groove 4. As a result, the stiffness difference in the direction orthogonal to Part 11A between the patterned blocks 6 separated by Part 11A and the second main inclined portion 4A, and between the patterned blocks 6 separated by the first part 11A, decreases, thereby improving resistance to eccentric wear. In this specification, "extends along..." refers to the angle θ5 of Part 11A and the angle θ3 of the second main inclined portion 4A. Figure 2 The absolute value of the difference (as shown) is less than 20 degrees.

[0049] The length Ld of the second part 11B is smaller than the length Lc of the first part 11A. This maintains traction performance and allows the soil within the first part 11A to be smoothly expelled towards the rearward side in the tire rotation direction R by utilizing the rotation of the tire 1. While not particularly limited, the length Ld of the second part 11B is preferably half the width TWh of the unfolded tread. Figure 2The percentage of the tire tread width (as shown) is 35% or more, more preferably 40% or more, more preferably 55% or less, and more preferably 50% or less. The half-width TWh of the tread is the length along the outer surface 2s of the tread portion 2 from the tire equator C to each tread end Te. Furthermore, the length of each secondary groove 5 is the length at the center line of each secondary groove 5.

[0050] Figure 4 yes Figure 2 An enlarged view of region S1, number 1. Figure 4 As shown, the groove width W2 of the first secondary groove 11 is preferably 80% or more, more preferably 90% or more, more preferably 120% or less, and more preferably 110% or less, of the groove width W1 of the first inclined main groove 3 and the second inclined main groove 4. In this embodiment, the groove width W2 of the first secondary groove 11 is the same as the groove width W1 of the first inclined main groove 3. The groove width W2 of the first secondary groove 11 is preferably 10% or more, more preferably 15% or more, more preferably 30% or less, and more preferably 25% or less, of the half-width TWh of the tread unfolded.

[0051] The second secondary groove 12 extends in a straight line, for example. Such a second secondary groove 12 suppresses uneven wear generated in each tread block 6.

[0052] The second secondary groove 12 includes, for example, a second secondary groove 17 on the main groove side connecting the first long secondary groove 14 to the second inclined main groove 4, and a second secondary groove 18 on the secondary groove side connecting the first long secondary groove 14 to the first short secondary groove 13. The second secondary groove 17 on the main groove side includes, for example, an outer second secondary groove 19 located on the side of the first tread end Te1, and an inner second secondary groove 20 located on the inner side (side of the second tread end Te2) closer to the tire axial direction than the outer second secondary groove 19.

[0053] Therefore, six tread blocks 6 are formed in region S1. Three tread blocks 6 are formed between the second inclined main groove 4 and the first long secondary groove 14. In addition, two tread blocks 6 are formed between the first long secondary groove 14 and the first short secondary groove 13. One tread block 6 is formed between the first short secondary groove 13, the first inclined main groove 3, and the first tread end Te1.

[0054] In this embodiment, the largest tread block 7 is distinguished by the first long secondary groove 14, the first short secondary groove 13, the second secondary groove 18 on the side of the secondary groove, and the first tread end Te1. In this embodiment, the smallest tread block 8 is distinguished by the second inclined main groove 4, the first long secondary groove 14, the outer second secondary groove 19, and the first tread end Te1. As in this embodiment, when the first inclined main groove 3, the second inclined main groove 4, and the first secondary groove 11 are not connected to the first tread end Te1, the area of ​​the tread block tread surface 6a is defined as follows. The area of ​​the tread block tread surface 6a is defined by the area of ​​an imaginary tread block tread surface 6v formed by extending the groove edges of each groove along the length direction to the first tread end Te1 in the portion not connected to the first tread end Te1. Figure 4 The 6v imaginary patterned tread surface is represented by a shaded line.

[0055] In this embodiment, the largest tread block 7 and the smallest tread block 8 are adjacent to each other along the tire circumference. Thus, since the largest tread block 7, which has the greatest tread block rigidity, and the smallest tread block 8, which has the least tread block rigidity, are adjacent to each other along the tire circumference, the uneven deformation of the largest tread block 7 and the smallest tread block 8 upon contact with the ground is increased, thereby enabling high off-road performance.

[0056] The length Le of the second secondary channel 12 is greater than the length Ld of the second part 11B. Figure 3 (As shown). Such a second secondary groove 12 maintains high circumferential rigidity of the tire tread block 6 formed at the second secondary groove 12, thereby improving resistance to uneven wear. In this embodiment, the length Le of the entire second secondary groove 12 is formed to be greater than the length Ld of the second part 11B.

[0057] The width W3 of the second secondary groove 12 is, for example, smaller than the width W2 of the first secondary groove 11. Such a second secondary groove 12 maintains the rigidity of the tread block and improves the resistance to eccentric wear. The width W3 of the second secondary groove 12 is preferably 30% or more of the width W2 of the first secondary groove 11, more preferably 40% or more, more preferably 80% or less, and more preferably 70% or less.

[0058] The angle θ7 of the second secondary groove 12 relative to the tire circumference is, for example, formed to be smaller than the angle θ5 of the first portion 11A of the first secondary groove 11. Figure 3(As shown). This second secondary groove 12 can utilize the rotation of the tire 1, thus suppressing the reduction in mud discharge caused by the narrowing of the groove width, and suppressing the decrease in rigidity of the tread blocks 6 adjacent to the second secondary groove 12, thereby improving resistance to eccentric wear. According to this viewpoint, the difference (θ5 - θ7) between the angle θ5 of the first part 11A and the angle θ7 of the second secondary groove 12 is preferably 5 degrees or more, more preferably 10 degrees or more, more preferably 25 degrees or less, and more preferably 20 degrees or less. The angle θ7 of the second secondary groove 12 is preferably 5 degrees or more, more preferably 10 degrees or more, more preferably 20 degrees or less, and more preferably 15 degrees or less.

[0059] like Figure 1 As shown, the depth d3 of the second secondary ditch 12 is preferably less than the depth d2 of the first secondary ditch 11. This allows the aforementioned functions to be effectively performed. The depth d3 of the second secondary ditch 12 is preferably 2 mm or more, and preferably 4 mm or less. The depth d2 of the first secondary ditch 11 is preferably 3 mm or more, and preferably 6 mm or less. The depth d1 of the first inclined main ditch 3 and the second inclined main ditch 4 is preferably greater than the depth d3 of the second secondary ditch 12, for example, preferably 3 mm or more, and preferably 6 mm or less.

[0060] Figure 5 This is a top view of the unfolded tread section 2 of this embodiment. (See attached image.) Figure 5 As shown, the tread 2 is divided into several roughly triangular second regions S2, each surrounded by a first inclined main groove 3, a second inclined main groove 4, and a second tread end Te2. The second region S2 is further divided into multiple tread blocks 6 by multiple secondary grooves 5.

[0061] The secondary groove 5 in the second region S2 includes a third secondary groove 23 extending between the second inclined main groove 4 and the second tread end Te2, and a fourth secondary groove 24 connected to the third secondary groove 23. Since the third secondary groove 23 in this embodiment has the same shape as the first secondary groove 11 in this embodiment, its detailed description is omitted. Since the fourth secondary groove 24 in this embodiment has the same shape as the second secondary groove 12 in this embodiment, its detailed description is also omitted.

[0062] Furthermore, the patterned blocks 6 in the second region S2 formed by the third sub-groove 23 and the fourth sub-groove 24 are formed with the same shape as the patterned blocks 6 formed in the first region S1. The plurality of patterned blocks 6 include a maximum patterned block 9 with the largest area of ​​its tread surface 9a and a minimum patterned block 10 with the smallest area of ​​its tread surface 10a. Moreover, the ratio (A2' / A1') of the area A1' of the tread surface 9a of the maximum patterned block 9 to the area A2' of the tread surface 10a of the minimum patterned block 10 is preferably 40% to 80%. In this embodiment, the maximum patterned block 9 has the same shape as the maximum patterned block 7 in the first region S1. In this embodiment, the minimum patterned block 10 has the same shape as the minimum patterned block 8 in the first region S1.

[0063] The angles α1, α2, and α3 of the first inclined main groove 3, the second inclined main groove 4, and the first secondary groove 11 relative to the tire circumference are preferably 40 degrees or more. Such grooves 3, 4, and 11 provide greater traction. These angles α1, α2, and α3 are defined by an imaginary straight line P connecting the two ends of the center lines of grooves 3, 4, and 11.

[0064] The present invention has been described in detail above regarding a motorcycle tire according to one embodiment of the present invention. However, the present invention is not limited to the specific embodiment described above and can be implemented in various ways.

[0065]

Example

[0066] Based on the specifications in Table 1, a prototype with... Figure 1 Basic structure and Figure 2 Motorcycle tires with specific tread patterns. Furthermore, the on-road performance, off-road performance, and resistance to uneven wear of each tire were tested.

[0067] <On-road performance, off-road performance, and resistance to uneven wear>

[0068] The test tires were mounted on the test vehicles described below, and test riders rode them on test tracks on both dry asphalt and dirt surfaces. Road performance was evaluated by the test riders' senses based on the transition characteristics and responsiveness on dry asphalt. Off-road performance was evaluated by the test riders' senses based on the traction and cornering stability on dirt surfaces. Resistance to uneven wear was evaluated by the test riders' visual observation of the degree of uneven wear after the road performance tests. All results are expressed on a 10-point scale.

[0069] Test vehicle: 500cc motorcycle

[0070] Tire sizes (front and rear): 120 / 70R17, 160 / 60R17

[0071] Wheel rim sizes (front and rear): 3.50×17, 4.50×17

[0072] Tire internal pressure (all wheels): 250 kPa

[0073] The test results are shown in Table 1.

[0074] Table 1

[0075]

[0076] The test results show that, compared with the comparative example tires, the tires of the embodiment can maintain off-road performance and resistance to uneven wear, and the transition characteristics and agility during cornering are improved.

Claims

1. A motorcycle tire having a tread pattern, characterized in that, The tread portion includes a first tread end, a second tread end, and a plurality of first inclined main grooves and a plurality of second inclined main grooves extending obliquely to each other in an orientation opposite to the tire circumferential direction between the first tread end and the second tread end. The plurality of first inclined main grooves and the plurality of second inclined main grooves are alternately arranged along the tire circumference and are interconnected. The tread surface is divided into several roughly triangular first regions, each surrounded by the first inclined main groove, the second inclined main groove, and the first tread end. The first region is divided into multiple patterned blocks by multiple secondary grooves. The plurality of patterned blocks includes the largest patterned block with the largest tread area and the smallest patterned block with the smallest tread area. The ratio A2 / A1 of the tread surface area of ​​the largest patterned block to the tread surface area A2 of the smallest patterned block is 40% to 80%. The largest tread block and the smallest tread block are adjacent to each other in the tire circumferential direction. The largest tread block and the smallest tread block are adjacent to each other at the first tread end.

2. The motorcycle tire according to claim 1, characterized in that, The secondary groove includes a first secondary groove extending between the first inclined main groove and the first tread end, and a second secondary groove connected to the first secondary groove.

3. The motorcycle tire according to claim 2, characterized in that, The width of the second secondary ditch is smaller than the width of the first secondary ditch.

4. The motorcycle tire according to claim 2 or 3, characterized in that, The depth of the second secondary ditch is less than the depth of the first secondary ditch.

5. The motorcycle tire according to claim 2 or 3, characterized in that, The first secondary groove includes: a first portion connected to the first inclined main groove; and a second portion connected to the first portion and having an inclination angle relative to the tire circumference that is larger than the inclination angle of the first portion relative to the tire circumference. The length of the second part is less than the length of the first part.

6. The motorcycle tire according to claim 5, characterized in that, The length of the second secondary trench is greater than the length of the second part.

7. The motorcycle tire according to any one of claims 2, 3, and 6, characterized in that, The angles of the first inclined main groove, the second inclined main groove, and the first secondary groove relative to the tire circumference are all greater than 40 degrees.

8. The motorcycle tire according to any one of claims 1 to 3 and 6, characterized in that, The first inclined main groove includes: a first main inclined portion extending across the tire equator; and a first secondary inclined portion that is inclined at an angle greater than that of the first main inclined portion relative to the tire circumference and is positioned closer to the second tread end side than the first main inclined portion. The second inclined main groove includes: a second main inclined portion extending across the tire equator; and a second secondary inclined portion that is inclined at an angle greater than that of the second main inclined portion relative to the tire circumference and is positioned closer to the first tread end side than the second main inclined portion. The first main inclined section is connected to the second auxiliary inclined section.

9. The motorcycle tire according to claim 8, characterized in that, The second main inclined section is connected to the first auxiliary inclined section.

10. The motorcycle tire according to any one of claims 1 to 3, 6, and 9, characterized in that, The first inclined main groove and the second inclined main groove are not connected to the first tread end and the second tread end, respectively, but form terminals.

11. The motorcycle tire according to any one of claims 1 to 3, 6, and 9, characterized in that, The tread surface is divided into several roughly triangular second regions, each surrounded by the first inclined main groove, the second inclined main groove, and the second tread end. The second region is divided into multiple patterned blocks by multiple secondary grooves. The plurality of patterned blocks includes the largest patterned block with the largest tread area and the smallest patterned block with the smallest tread area. The ratio A2' / A1' of the area A1' of the tread surface of the largest patterned block to the area A2' of the tread surface of the smallest patterned block is 40% to 80%.

Images