Pneumatic tire

Abstract

A pneumatic tire according to the present application includes at least one land portion on a tread contact surface, one or more link sipes are arranged on at least one of the land portions, the link sipes include a main portion extending in a first predetermined direction and a side portion extending from the main portion obliquely with respect to the first predetermined direction laterally of the main portion, the side portion includes a first side portion arranged in the side portion on one side of the main portion and a second side portion arranged in the side portion on the other side of the main portion, and the first side portion and the second side portion are alternately arranged in a tire circumferential direction.

Description

Technical Field

[0001] This disclosure relates to pneumatic tires. Background Technology

[0002] Typically, pneumatic tires, especially anti-skid tires, have narrow grooves called sipes on the ground surface of the tread to improve grip on ice. These sipes allow water that seeps onto the tire's contact patch due to melting ice to drain away, thus improving traction on ice.

[0003] Prior art has been proposed (e.g., Patent Document 1) that improves ice grip performance by arranging sipes with high density while minimizing the reduction in rigidity of the land surface.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2005-186827 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] However, the technology in Patent Document 1 is insufficient to balance the rigidity of the land surface and the drainage of the sipes, and there is room for improvement in terms of improving grip performance on ice.

[0009] Therefore, the purpose of this disclosure is to provide an inflatable tire with improved grip on ice.

[0010] Solution for solving the problem

[0011] The main structure of this invention is as follows.

[0012] (1) A pneumatic tire having at least one land portion in the tread surface, wherein

[0013] One or more connecting body grooves are arranged on at least one of the land sections.

[0014] The connecting body groove has a main body portion extending in a first predetermined direction and a side portion extending from the main body portion toward one side of the main body portion at an angle relative to the first predetermined direction.

[0015] The side portion has a first side portion arranged on one side of the main body and a second side portion arranged on the other side of the main body, and

[0016] The first and second side sections are alternately arranged in the tire circumferential direction.

[0017] In this document, the term "tread surface" refers to the outer peripheral surface of a pneumatic tire that contacts the road surface when the tire is mounted on a suitable rim, inflated to a specified internal pressure, and rolling under maximum load. Furthermore, the term "sipe" in "connector sipe" refers to a sipe whose width is less than 1 mm in an area where the tire is mounted on a suitable rim, inflated to a specified internal pressure, and unloaded, at least 50% of the sipe depth. In this document, the sipe depth is measured perpendicular to the tread surface under the aforementioned conditions, and the sipe width is measured parallel to the tread surface in a section perpendicular to the extension direction of the sipe on the tread surface.

[0018] As used herein, "applicable rim" refers to a standard rim of applicable size (measured rim in the ETRTO Standards Manual and designed rim in the TRA Yearbook) that is recorded or may be recorded in the future in an industry standard effective in the region where the tire is produced and used. Such industry standards include, for example, the JATMA Yearbook of Japan's JATMA (Japan Automobile Tire Manufacturers Association), the standards manual of Europe's ETRTO (European Tire and Rim Technology Organization), and the yearbook of the US's TRA (Tire and Rim Association). (That is, the aforementioned "rim" includes current sizes in the aforementioned industry standards as well as future sizes to be listed. An example of "sizes to be recorded in the future" could be sizes listed as "FUTURE DEVELOPMENTS" in the 2013 edition of ETRTO.) For sizes not listed in these industry standards, "applicable rim" refers to a rim whose width corresponds to the tire's bead width. Additionally, "specified internal pressure" refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity of a single wheel at the applicable size and ply rating, as recorded in the aforementioned JATMA, etc. In the case of dimensions not listed in the aforementioned industry standards, "specified internal pressure" refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity specified for each vehicle equipped with tires. Furthermore, "maximum load" refers to the load corresponding to the aforementioned maximum load capacity.

[0019] The effects of the invention

[0020] According to this disclosure, an inflatable tire with improved grip on ice can be provided. Attached Figure Description

[0021] [ Figure 1 ] Figure 1 The tread pattern of a pneumatic tire according to one embodiment of the present disclosure is shown.

[0022] [ Figure 2 ] Figure 2 This is a plan view showing the structure of the connecting body's tool groove.

[0023] [ Figure 3 ] Figure 3The dimensions of the connector's cutter groove are shown.

[0024] [ Figure 4 ] Figure 4 This is a table that provides examples and comparative examples.

[0025] [ Figure 5 ] Figure 5 It provides the relationship between the rigidity of the patterned block and the actual grounding area during shearing.

[0026] [ Figure 6 ] Figure 6 It provides the relationship between edge density and actual grounding area. Detailed Implementation

[0027] The following is a detailed description of embodiments of the present disclosure with reference to the accompanying drawings.

[0028] First, the internal structure of a pneumatic tire (hereinafter referred to as "tire") can be the same as that of a conventional tire. For example, a tire may have a pair of bead portions, a pair of sidewall portions connected to the pair of bead portions, and a tread portion disposed between the pair of sidewall portions. The tire may also have a carcass that is circumferentially spanned between the pair of bead portions, and a belt disposed radially outward on the crown portion of the carcass.

[0029] In the following text, unless otherwise stated, dimensions refer to the dimensions when the tire is mounted on an applicable rim, inflated to the specified internal pressure, and unloaded.

[0030] Figure 1 The tread pattern of a pneumatic tire according to one embodiment of the present disclosure is shown. For example... Figure 1 As shown, the tire has one or more (four in the example shown) circumferential main grooves 2 (2a to 2d) extending along the tire circumference on the tread surface 1. The number of circumferential main grooves 2 is not limited to this example and can be changed as needed.

[0031] The width (opening width) of the circumferential main groove 2 is not particularly limited, for example, it can be 4 to 15 mm, and the depth (maximum depth) of the circumferential main groove 2 is not particularly limited, for example, it can be 6 to 20 mm. In the example shown, the circumferential main groove 2 extends in a straight line in the tire circumference, and it can also extend in a zigzag or curved manner. The circumferential main groove 2 can be inclined at an angle of less than 5° relative to the tire circumference.

[0032] like Figure 1As shown, the circumferential main groove 2 and the tread end TE form multiple (five in the example shown) land portions 3 (3a to 3e). Specifically, land portion 3a is formed by the tread end TE and the circumferential main groove 2a, land portion 3b is formed between the circumferential main grooves 2a and 2b, land portion 3c is formed between the circumferential main grooves 2b and 2c, land portion 3d is formed between the circumferential main grooves 2c and 2d, and land portion 3e is formed by the tread end TE and the circumferential main groove 2d. Therefore, the tire has at least one land portion 3.

[0033] Multiple width-direction grooves 5 extending in the tire width direction are spaced apart on each land section 3a to 3e in the tire circumferential direction. In land sections 3a, 3c, 3d, and 3e, the width-direction grooves 5 connect to two adjacent circumferential main grooves 2, thus dividing land sections 3a, 3c, 3d, and 3e into tread blocks. On the other hand, in land section 3b, the width-direction groove 5 connects to the circumferential main groove 2b at one end and terminates within land section 3b at the other end, thus land section 3b is a ribbed land section (a land section not completely divided by the width-direction grooves 5 in the circumferential direction). The other end of the width-direction groove 5A connects to a width-direction sipe 6 extending in the tire width direction, which extends from the other end of the width-direction groove 5 and connects to the circumferential main groove 2a.

[0034] The width of the width-direction groove 5 (opening width, or maximum width when the groove width varies) is not particularly limited, and can be, for example, 2 to 10 mm. The depth of the width-direction groove 5 (maximum depth) is not limited, and can be, for example, 5 to 20 mm. Furthermore, the width-direction groove 5 preferably extends in the tire width direction or is inclined relative to the tire width direction at an angle greater than 0° and less than or equal to 45°. The width-direction grooves 5 can be arranged at equal intervals in the tire circumferential direction, or can be arranged at various pitch intervals to reduce tread noise.

[0035] The width (opening width) of the sipe 6 in the width direction is not particularly limited and can be from 0.3 to 1 mm. The depth (maximum depth) of the sipe 6 in the width direction is not limited and can be, for example, from 3 to 10 mm. Furthermore, the sipe 6 in the width direction preferably extends in the tire width direction or is inclined at an angle greater than 0° and less than or equal to 45° relative to the tire width direction.

[0036] It should be noted that land sections 3a and 3e are provided with a plurality of width-direction sipes 8 extending from the tread end TE at approximately equal intervals in the tire circumferential direction and terminating in the land section.

[0037] In this document, in the tire, one or more connecting body sipes 4 are arranged on at least one land portion 3 (in this example, all land portions 3). In the illustrated example, one or more connecting body sipes 4 are arranged in each tread block defined by a width-direction groove 5 (or in each portion defined by the width-direction groove 5 and the width-direction sipe 6).

[0038] Figure 2 This is a plan view of the connecting body's tool groove 4. (Example) Figure 1 and Figure 2 As shown, the connecting body groove 4 has a main body portion 4a extending in a first predetermined direction (the tire circumferential direction in the example shown) and side portions 4b1 and 4b2 extending from the main body portion 4a to one side of the main body portion 4a at an angle relative to the first predetermined direction (relative to the tire circumferential direction in the example shown). Therefore, the connecting body groove 4 is a branched groove formed by connecting the main body portion and the side portions together. The connecting body groove 4 is a branched groove including the main body portion and the side portions connected together. The main body portion 4a and the side portions 4b1 and 4b2 are groove portions. The side portions have a first side portion 4b1 arranged on one side of the main body portion 4a and a second side portion 4b2 arranged on the other side of the main body portion 4a. The first side portion 4b1 and the second side portion 4b2 are alternately arranged in the tire circumferential direction. In the example shown, the first side portion 4b1 extends to one side in the tire width direction (left side in the figure) and terminates in the land portion 3, and the second side portion 4b2 extends to the other side in the tire width direction (right side in the figure) and terminates in the land portion 3.

[0039] In the example shown, the main body 4a1 extends in the tire circumferential direction, but can extend at an angle of less than 15° relative to the tire circumferential direction. Additionally, in the example shown, land portions 3a, 3c, 3d, and 3e are tread block land portions, while land portion 3b is defined by a width-direction groove 6, although it is a rib-shaped land portion. Therefore, the extension length of the main body 4a is shorter than the circumferential length of the tread block (or the tread block portion defined by the width-direction groove 6). Furthermore, at least one end of the main body 4a terminates within the land portion 3. In the example shown, only one end e1 of the main body 3a in a first predetermined direction (in this example, the tire circumferential direction) terminates in the land portion 3, while the other end e2 connects to the width-direction groove 5 or the width-direction groove 6. On the other hand, when the land portion 3 is a rib-shaped land portion, the main body 4a can also extend continuously around the tire circumferential direction.

[0040] Side portions 4b1 and 4b2 may extend at an angle of 45° to 90° relative to a first predetermined direction that is the extension direction of the main body portion 4a, for example, but this is not particularly limited. Typically, side portions 4b1 and 4b2 extend in the tire width direction or at an angle relative to the tire width direction (e.g., the angle may be less than 45° relative to the tire width direction). In the illustrated example, both side portions 4b1 and 4b2 extend toward one side (the tire circumferential direction) of the extension direction of the main body portion 4a, while the first side portion 4b1 and the second side portion 4b2 may extend on opposite sides of the extension direction of the main body portion 4a (in this case, side portion 4b1 may extend to one side or the other).

[0041] In this paper, when the length of the connecting body groove 4 in the tire width direction (projected in the tire width direction) is w1 (mm) and the depth (maximum depth) of the micro-grooves (4a, 4b1, 4b2) including the connecting body groove is h (mm), w1×h is preferably 150 (mm). 2 The following is true. This is because by making the connecting body cutter groove 4 smaller, the connecting body cutter grooves 4 can be densely arranged to further improve ice performance. For the same reason, it is more preferable that w1×h is 100 (mm). 2 Below 50 (mm), or even more preferably 50 (mm) 2 )the following.

[0042] Additionally, when the number of connecting grooves 4 in the land section 3 is n, the maximum width of the land section 3 in the tire width direction is BW (mm), and the area of ​​the outer contour of the land section 3 (the area surrounded by the outer contour) (mm) 2 The "equivalent length of the land portion in the tire circumferential direction" obtained by dividing by BW (mm) is BL (mm). The equivalent number of sipes N (converted to the number of lateral sipes completely traversing the land portion) is defined as w1×n / BW. The average sipe spacing in the tire circumferential direction is expressed as BL / (N+1). The sipe density SD is defined as the reciprocal of the average sipe spacing in the tire circumferential direction and expressed as SD=(N+1) / BL=((w1×n / BW)+1) / BL. SD is preferably 0.15 (1 / mm) or higher. This is because a high density of sipes in the connector can further improve ice performance. For the same reason, a sipe density SD of 0.20 (1 / mm) or higher is more preferred, and a sipe density SD of 0.30 (1 / mm) or higher is even more preferred.

[0043] It is important to note that the number of sipes n, the maximum width BW of the land section in the tire width direction, and the outer contour area of ​​the land section are values ​​measured in the unfolded diagram of the tread. "Outer contour area" refers to the area enclosed by the outer contour in the unfolded diagram of the tread. Therefore, even if non-ground parts such as sipes, orifices, and narrow grooves are arranged in the land section, this area does not exclude the area of ​​sipes, orifices, narrow grooves, etc.

[0044] The following is a description of the effects of this pneumatic tire.

[0045] In the pneumatic tire of this embodiment, firstly, one or more connecting grooves 4 are arranged on at least one land portion 3, and the connecting groove 4 has a main body portion 4a extending in a first predetermined direction and side portions 4b1, 4b2 extending from the main body portion 4a toward one side of the main body portion 4b at an angle relative to the first predetermined direction. Therefore, when these groove portions cut the water film, water can be discharged through the main body portion 4a in the first predetermined direction (in this example, the tire circumferential direction), and water can also be discharged to the side through the side portions 4b1 and 4b2 connected to the main body portion 4a, thus enabling efficient removal of the water film. Furthermore, the side portions have a first side portion 4b1 arranged on one side of the main body portion 4a and a second side portion 4b2 arranged on the other side of the main body portion 4a, and the first side portion 4b1 and the second side portion 4b2 are alternately arranged in the tire circumferential direction. Therefore, these side portions can be densely arranged, further increasing the effectiveness of the aforementioned water film removal.

[0046] On the other hand, since the sides 4b1 and 4b2 terminate within the land portion 3, the reduction in rigidity of the land portion 3 can be suppressed, for example, compared to the case where the tread blocks are completely divided in the tire circumferential direction by a width-direction sipe extending between two circumferential main grooves to form tread block pieces.

[0047] As described above, the pneumatic tire of this embodiment can effectively remove the water film without reducing the rigidity of the land portion 3, thereby improving grip performance on ice.

[0048] In particular, in this embodiment, at least one end e1 of the main body 4a terminates within the land portion 3, which further prevents a reduction in the rigidity of the land portion 3 and further improves ice grip performance. From the viewpoint of preventing a reduction in the rigidity of the land portion 3, it is preferable that both ends of the main body 4a terminate within the land portion 3; however, from the viewpoint of effectively removing water film, the other end 4e or both ends can be connected to a width-direction groove or a width-direction cutter groove. In this example, one end terminates within the land portion 3, while the other end is connected to a width-direction groove 5 or a width-direction cutter groove 6, thus ensuring the rigidity of the land portion at one end while providing effective water film removal at the other end.

[0049] Furthermore, if w1×h is within the above range, the connector blade grooves can be arranged more densely, which can further improve ice grip performance. Additionally, if the blade groove density SD is within the above range, the connector blade grooves will be densely configured, which will improve the effectiveness of water film removal and further enhance ice grip performance.

[0050] Furthermore, in this embodiment, the main body 4a extends in the tire circumferential direction, while the side portions 4b1 and 4b2 extend in the tire width direction or at an angle relative to the tire width direction, as in this example. This allows the main body 4a to have an edge component in the tire circumferential direction (an edge component relative to the tire width direction), which improves lateral grip during cornering. Additionally, the side portions 4b1 and 4b2 provide an edge component in the tire width direction (an edge component relative to the tire circumferential direction), which improves straight-line traction and braking performance on ice.

[0051] like Figure 1 As shown, the tire of this embodiment has land portions 3b, 3c, and 3d, wherein multiple rows of connecting body grooves 4 (in the illustrated example, multiple connecting body grooves 4 are arranged at intervals in the tire circumferential direction to form a row) are arranged in a second predetermined direction (in this example, the tire width direction). First, compared to arranging only one row of connecting body grooves 4 on each land portion 3, this will increase the effectiveness of water film removal. It should be noted that one connecting body groove forms a row as the main body portion 4 extends continuously around the tire circumference. In addition, the second predetermined direction can be inclined relative to the tire width direction, and the inclination angle relative to the tire width direction can be, for example, greater than 0° and less than or equal to 30°.

[0052] In addition, such as Figure 1 As shown, two adjacent columns in the second predetermined direction are arranged with a phase offset in the tire circumferential direction, such that the side portions (4b1 or 4b2) of one column of connector grooves 4 and the side portions (4b2 or 4b1) of another column (which serves as an adjacent column adjacent to the first column of connector grooves in the second predetermined direction) are alternately arranged in the tire circumferential direction. This allows for a higher density of connector grooves 4, which is more effective in removing water films and also balances the size of the land area defined by the side portions. Furthermore, as in this example, the side portions (4b1 or 4b2) of one column of connector grooves 4 in the second predetermined direction and the side portions (4b2 or 4b1) of the adjacent column of connector grooves 4 adjacent to the first column of connector grooves are preferably arranged such that they overlap each other when projected in the tire circumferential direction. This allows for a much higher density of connector grooves 4, which is more effective in removing water films.

[0053] It should be noted that in this example, the first side portion 4b1 and the second side portion 4b2 are inclined in the same direction in the tire circumference direction and extend in the tire width direction, and the connecting groove 4 of the column and the adjacent column are symmetrical about the axis along the tire width direction (vertically symmetrical in the figure), so that the size of the land portion to be defined can be uniform when using the above configuration.

[0054] Furthermore, in this embodiment, such as Figure 1As shown, only one end e1 of the main body 4a terminates within the land section 3. Furthermore, the ends e1 terminating within the land section 3 are alternately arranged (on one side and the other side in the tire circumferential direction) between two adjacent rows along the second predetermined direction such that one end 4a of the main body 4a of one row of connector cutter grooves terminates within the land section 3 in the first predetermined direction, while the other end (opposite side) of the main body 4a of another row (which is an adjacent row adjacent to that row of connector cutter grooves in the second predetermined direction) terminates within the land section. This improves ice performance by balancing the location where stiffness reduction is suppressed and avoiding localized areas of stiffness reduction.

[0055] The above effects can be obtained at each land section. Therefore, it is preferable that all land sections 3 (whether they are patterned block land sections or ribbed land sections) have the above-mentioned connecting groove 4.

[0056] In addition to the main body 4b1 extending continuously in the circumferential direction, the connecting body cutter grooves 4 can be arranged side by side in a row in the tire circumferential direction. In this case, as Figure 1 As shown, preferably, one connecting groove 4 is arranged in each patterned block (or the patterned block-shaped landmass defined by the width-direction groove 6) for each column. This is because the high density of the connecting groove 4 can further increase the effectiveness of water film removal.

[0057] like Figure 1As shown, each land portion 3 has multiple secondary cutting grooves 7, which are separately configured from the cutting grooves 4. In this example, the secondary cutting groove 7 is formed by a long side connected to the short side. The long side of the secondary cutting groove 7 has a configuration symmetrical with respect to the sides 4b1 and 4b2 of the connecting body cutting groove 4, and the short side of the secondary cutting groove 7 has a configuration symmetrical with respect to the main body portion 4a of the connecting body cutting groove 4. The long side of the secondary cutting groove 7 extends in the tire width direction or extends at an angle relative to the tire width direction, and the short side of the secondary cutting groove 7 extends in the tire circumferential direction. The secondary cutting groove 7, a portion of the main body portion 4a of the connecting body cutting groove 4, and the sides 4b1 (4b2) are configured to face each other when offset in the tire width direction, forming a pair of opposing cutting grooves. This allows for even higher density cutting grooves. In this example, the angle between the long side and the short side of the secondary cutting groove 7 is an obtuse angle. The ratio of the extension length of the long side to the extension length of the short side is preferably between 1 and 15. If the ratio is 15 or less to ensure the length of the short side, the drainage effect can be sufficient. On the other hand, if the ratio is 1 or more to keep the length of the short side reasonably short, the sipes can be arranged in a high density. As shown, the secondary sipes 7 are arranged in the tire circumferential direction (e.g., at equal intervals), and their short sides are on the same straight line. The ratio of the length of the opposing sipes along the tire circumferential direction to the length of the opposing sipes along the tire width direction is preferably between 0.1 and 2.6. If the ratio is 0.1 or more, the distance between the sipes can be ensured to ensure the rigidity of the tread blocks, while if the ratio is 2.6 or less, ... It is not too large and its length in the width direction is not too short, so that the braking and driving forces can be fully utilized.

[0058] Figure 3 The dimensions of the connector slot 4 are shown.

[0059] like Figure 3 As shown, when the extension length of the side portions 4b1 and 4b2 of the connector cutter groove 4 is a (mm), the length of the side portions 4b1 and 4b2 in the tire width direction (projected length in the tire width direction) is d (mm), the distance between the end of the side portion 4b1 (4b2) of a connector cutter groove (the end terminating in the land portion) and the main body portion 4a of the connector cutter groove adjacent to that connector cutter groove is s (mm), and the inclination angle of the side portions 4b1 and 4b2 relative to the tire width direction is... When, it can be expressed as:

[0060] In this paper, s is preferably 1.5 (mm) or more, because setting s to 1.5 (mm) or more can further suppress the reduction of tread block stiffness. It is also preferred that d > s. This is because the side portions can overlap each other when projected in the tire circumferential direction, thereby further increasing the effectiveness of the sipes formed by the side portions in removing the water film.

[0061] Furthermore, when the circumferential pitch between the side portions 4b1 (or 4b2) is p (mm), and the tire circumferential clearance distance between the side portion 4b1 (4b2) of a connector groove and the side portion 4b2 (4b1) of the connector groove adjacent to that connector groove is q (mm) and r (mm) (q≤r), it can be expressed as: p=q+r. In addition, the tire circumferential clearance distance c (mm) between the connection point of the main body portion 4a and the branch portion 4b1 in a connector groove and the connection point of the main body portion 4a and the branch portion 4b2 in the connector groove adjacent to that connector groove can be expressed as:

[0062]

[0063] Here, when q = α × (d + s), c = 0 and the circumferential positions of the branch points of adjacent sipe rows are aligned in the width direction. This ensures the continuity of the sipe density of the branch relative to the input in the tire width direction, reduces the circumferential variation of tread block stiffness, and provides stable lateral grip performance. Therefore, the range of q = α × (d + s) × 0.8 to α × (d + s) × 1.2 is desirable. In particular, when q = p / 2, r = q, so all sipes in the sipe row are equidistant in the tire circumferential direction. For this purpose, q is preferably in the range of p / 2 × 0.8 to p / 2 × 1.2, and more preferably q is p / 2. This allows for uniform sipe density in the tire circumferential direction within the tread block landmass.

[0064] Example

[0065] The following is for reference Figure 4 Describe the implementation examples. Figure 4 This is a table that provides examples and comparative examples.

[0066] right Figure 4 The tires of Examples 1 to 3 and Comparative Examples 1 to 3 provided herein underwent finite element method (FEM) simulations, and the tread block stiffness and contact patch were evaluated under vertical load conditions. This was obtained by multiplying the contact patch area of ​​the tread block landmass under no-load conditions by the standard contact pressure of 230 kPa for passenger car tires. In Examples 1 to 3 and Comparative Examples 1 to 3, the evaluations were performed under the following conditions: assuming Figure 4 The sipes shown in the schematic diagram are placed on the tread blocks of the tire, with a maximum length of 30 mm in the circumferential direction and a length of 27 mm in the width direction. All sipes are 0.4 mm wide, 6.7 mm deep, and have an end radius (R) of 0.2 mm.

[0067] Figure 5 It provides the relationship between the rigidity of the patterned block and the actual grounding area during shearing. Figure 6The relationship between edge density and actual ground contact area is provided. In this paper, the tread block stiffness Kx (N / mm) is the shear input value in the same direction when the lateral displacement in the tire circumferential direction is 1 mm, and the actual ground contact area Ar (mm²) during shearing is... 2 This refers to the residual ground area with a partial increase when the shear input in the tire circumferential direction is 0.3 times the aforementioned vertical load. For example... Figure 5 As can be seen from the provided examples, compared to Comparative Examples 1 to 3, Examples 1 to 3 are able to balance both the rigidity of the patterned block and the actual grounding area. For example... Figure 6 As can be seen from the provided examples, in Examples 1 to 3, for the same edge density, the actual grounding area increases compared to Comparative Examples 1 to 3.

[0068] Explanation of reference numerals in the attached figures

[0069] 1: Tread surface

[0070] 2: Circumferential main slot

[0071] 3: Land Department

[0072] 4: Connecting body tool groove

[0073] 5: Width direction groove

[0074] 6: Width direction tool groove

[0075] 7: Secondary tool slot

[0076] 8: Width direction tool groove

[0077] CL: Tire equatorial plane

[0078] TE: Tread end

Claims

1. A pneumatic tire having at least one land portion in the tread surface, wherein, One or more connecting body slots are arranged on at least one of the land sections. The connecting body groove has a main body portion extending in a first predetermined direction and a side portion extending from the main body portion toward one side of the main body portion at an angle relative to the first predetermined direction and terminating within the land portion. The side portion has a first side portion arranged on one side of the main body portion and a second side portion arranged on the other side of the main body portion. The first side and the second side are alternately arranged in the tire circumferential direction. The main body extends in the circumferential direction of the tire. The side portion extends in the tire width direction or extends at an angle relative to the tire width direction, and When the length of the connecting body sipe in the tire width direction is w1 and the depth of the micro-sipe constituting the connecting body sipe is h, w1×h is 150 or less. When the number of connecting body sipes in the land portion is n, the maximum width of the land portion in the tire width direction is BW, the equivalent length of the land portion in the tire circumferential direction obtained by dividing the outer contour area of ​​the land portion by BW is BL, the equivalent number of sipes N is defined as w1×n / BW, the average sipe spacing in the tire circumferential direction is expressed as BL / (N+1), and the sipe density SD is defined as the reciprocal of the average sipe spacing in the tire circumferential direction and expressed as SD=(N+1) / BL=((w1×n / BW)+1) / BL, SD is 0.15 or more. The units for w1, h, BW, and BL are all mm, and the units for w1×h and the outer contour area of ​​the landmass are all mm. 2 The unit of SD is 1 / mm.

2. The pneumatic tire according to claim 1, wherein, At least one end of the main body terminates within the land portion.

3. The pneumatic tire according to claim 1 or 2, having a land portion having a plurality of rows of said connecting body slots arranged in a second predetermined direction.

4. The pneumatic tire according to claim 3, wherein, Two adjacent columns of connector cutters in the second predetermined direction are arranged in a phase-off position in the tire circumferential direction, such that the side of one column of connector cutters and the side of another column of connector cutters, which is an adjacent column of connector cutters adjacent to the one column of connector cutters in the second predetermined direction, are alternately arranged in the tire circumferential direction.

5. The pneumatic tire according to claim 3, wherein, Only one end of the main body terminates within the land portion, and The ends terminating within the land portion are alternately arranged between two adjacent columns of connector cutter slots along the second predetermined direction, such that one end of the main body of one column of connector cutter slots terminates within the land portion in the first predetermined direction, and the other end of the main body of another column of connector cutter slots, which is adjacent to the one column of connector cutter slots in the second predetermined direction, terminates within the land portion in the first predetermined direction.

6. The pneumatic tire according to claim 4, wherein, Only one end of the main body terminates within the land portion, and The ends terminating within the land portion are alternately arranged between two adjacent columns of connector cutter slots along the second predetermined direction, such that one end of the main body of one column of connector cutter slots terminates within the land portion in the first predetermined direction, and the other end of the main body of another column of connector cutter slots, which is adjacent to the one column of connector cutter slots in the second predetermined direction, terminates within the land portion in the first predetermined direction.

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