The Yokohama Rubber Co., Ltd.

Masataka Kubota

Yuji Minami

Noboru Kuwahara

Masatoshi Kuwajima

Masataka Koishi

In a pneumatic tire, an inner shoulder land portion includes shoulder lug grooves that extend in the tire lateral direction. Additionally, an inner second land portion includes the through lug groove that extends through the inner second land portion in the tire lateral direction. A center land portion includes a single circumferential narrow groove extending in the tire circumferential direction and center lug grooves that each open at one end portion to the edge portion on the vehicle width direction inner side of the center land portion and terminate at the other end portion, communicating with a circumferential narrow groove. The shoulder lug groove, the through lug groove, and the center lug groove form one communication lug groove extending continuously from a tire ground contact edge toward a tire equatorial plane.

Pneumatic tire

A pneumatic tire includes circumferential main grooves extending in the tire circumferential direction and a land portion defined by the circumferential main grooves. The land portion includes a through lug groove that passes through the land portion in the tire lateral direction and includes first and second chamfered portions formed on left and right edge portions of the through lug groove. The first chamfered portion opens at one end to one of the edge portions of the land portion and terminates at the other end at a central portion in the groove length direction of the through lug groove. The second chamfered portion opens at one end portion to one of the edge portions of the land portion and terminates at the other end portion at a central portion in the groove length direction of the through lug groove.

A pneumatic tire includes a decorative portion on a tire side portion that is an outer surface of a sidewall portion. The decorative portion includes a plurality of ridges that extend along the tire side portion and are arranged side by side in the tire circumferential direction. The plurality of ridges include a common form of an inclination angle in the tire circumferential direction with respect to the tire radial direction and an interval between a pair of the plurality of ridges adjacent. The plurality of ridges constitute a ridge group. Three or more ridge groups are provided and the plurality of ridges of the different ridge groups are arranged intersecting one another. Accordingly, the pneumatic tire can reduce poor appearance of the sidewall portion.

A ratio between the total width (SW) and outer diameter (OD) of a pneumatic tire, which has an asymmetrical pattern formed by grooves formed on a tread part, satisfies SW/OD&#x2264;0.3. Given a ground contact width (CW) in a ground contact region in the tread part, a groove area ratio (GR), and a groove area ratio (GRi) of a tire inner side region (Ai), which spans from a tire equator line (CL) to the vehicle side in the ground contact region, and a groove area ratio (GRo) of a tire outer side region (Ao), which spans from the tire equator line to the opposite side of the vehicle side in the ground contact region, the ground contact region is formed to satisfy 0.75&#x2264;CW/SW&#x2264;0.9, 10&#x2264;GR&#x2264;25%, and GRi&#x3c;GRo.

To provide a pneumatic tire with improved performance and balance in terms of fuel efficiency, steering stability performance and wear life. The total width SW, outside diameter OD, tread groove depth Ga, center groove depth Gc and shoulder groove depth Gs satisfy the relationships SW/OD&#x2264;0.3, Ga&#x2264;0.02&#xd7;SW+2.5 and Gc&#x3e;Gs.

Fuel efficient pneumatic tire

The present technology pertains to a pneumatic tire () comprising: a pair of bead portions (); sidewall portions () connected to the pair of bead portions; and a tread portion () connected to the sidewall portions. A ratio between a total width (SW) and an outer diameter (OD) of the pneumatic tire satisfies the relationship SW/OD&#x2264;0.3. Moreover, if the length along a tread profile () from a first side second reference point (Q) to a second side second reference point (Q) is the developed tread width (TDW), and an angle formed between a straight line that connects the second reference points and the profile center (cc), and a straight line parallel to the tire width direction is an amount of depression (&#x3b8;), the following relationships are satisfied: 0.8&#x2264;TDW/SW&#x3c;1, and 1.5&#xb0;&#x2264;&#x3b8;&#x2264;4.5&#xb0;.

The present technology relates to a pneumatic tire in which the ratio of the total width SW and the outer diameter OD satisfies SW/OD&#x2264;0.3, and grooves are provided on the tread portion. In the ground contact region of the tread portion, when the groove area ratio in the ground contact area is GR, the ground contact width is W, the region having a width of 50% of the ground contact width W and the tire equatorial plane as center is the center region, the groove area ratio in the center region is GCR, the ground contact region on the outer side in the tire width direction of the center region is the shoulder region, and the groove area ratio in the shoulder region is GSR, the ground contact region of the tread portion is formed to satisfy 10%&#x2264;GR&#x2264;25% and GCR&#x3e;GSR.

The present technology relates to a pneumatic tire in which the ratio of the total width SW and the outer diameter OD satisfies SW/OD&#x2264;0.3, and grooves are provided on the tread portion. In the ground contact region of the tread portion, when the groove area ratio with respect to the ground contact area is GR, the ground contact width is W, the region having a width of 50% of the ground contact width W and the tire equatorial line as center is the center region, the groove area ratio in the center region is GCR, the ground contact region on the outer side in the tire width direction of the center region is the shoulder region, and the groove area ratio in the shoulder region is GSR, the ground contact region of the tread portion is formed to satisfy 10%&#x2264;GR&#x2264;25% and GCR&#x2264;GSR.

Automobile tire

The present technology pertains to a pneumatic tire having an asymmetrical pattern, which is formed by grooves, formed on a tread portion. A ratio SW/OD between the total width SW and the outer diameter OD of the pneumatic tire satisfies SW/OD&#x2266;0.3. A groove area ratio in a ground contact region G in the tread portion is GR, and a range from a tire equator line CL to the vehicle side in the ground contact region is a tire inside region Ai and the groove area ratio in the tire inside region Ai is GRi, and a range from the tire equator line CL to the opposite side of the vehicle side in the ground contact region is a tire outside region Ao and the groove area ratio in the tire outside region Ao is GRo, the ground contact region satisfies 10%&#x2266;GR&#x2266;25%, GRo.

An intersection of an extended line of a shoulder side arc and an extended line of a side portion arc is a reference point P, an aspect ratio is &#x3b2;, and an angle &#x3b8; formed by a straight line A joining the reference point P and a center crown CC and a straight line B in a tire width direction that passes through the center crown CC is configured such that 0.025&#xd7;&#x3b2;+1.0&#x2266;&#x3b8;&#x2266;0.045&#xd7;&#x3b2;+2.5. A curvature radius Rc of a center portion arc and a curvature radius Rs of the shoulder side arc are configured such that 12&#x2266;Rc/Rs&#x2266;30. A reference developed width L from a tire equatorial plane CL to an edge of the shoulder side arc on a tire width direction inner side and a developed tread width TDW are configured such that 0.2&#x2266;L/(TDW/2)&#x2266;0.7.

Pneumatic tire with tread having different curvature radii

A tire/wheel assembly includes a wheel having an attaching portion for attaching the wheel to a vehicle and a pneumatic tire that is fit on a periphery of the wheel. The pneumatic tire includes a plurality of tire protrusions and/or a plurality of tire recesses of a tire side portion that constitutes a vehicle outer side, and the wheel includes a plurality of wheel recesses in a surface that constitutes the vehicle outer side.

Tire/wheel assembly

A pneumatic tire unit comprises a front tire to be mounted on a leading side of a vehicle, and a rear tire to be mounted on a trailing side of the vehicle. A plurality of recesses is provided in at least one tire side portion of the front tire, and a plurality of protrusions is provided on at least one tire side portion of the rear tire. A negative pressure region that can be generated at a back surface side of the vehicle is reduced and, therefore, air resistance of the vehicle is reduced and fuel economy is enhanced.

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Hiratsuka, Japan

Masataka Kubota