Patent Description:
For example, as described in Patent Document <NUM>, a tire including a carcass ply is known.

Patent document <NUM> discloses a pneumatic tire has a carcass ply and a side wall rubber provided in outer sides of the carcass ply. The carcass ply has joint portions obtained by overlapping end portions of ply members so as to join. At least one of the joint portions is provided with a rubber tape. The rubber tape is interposed between the end portions of the ply members and is exposed to a surface of the carcass ply. A topping rubber of the carcass ply and the side wall rubber are formed by a nonconductive rubber. The rubber tape is formed by a conductive rubber. A conductive route getting to the rubber tape from a ground-contacting surface is formed in a tread portion. A conductive route getting to the rubber tape from an outer surface of a bead portion is formed in the bead portion.

Patent document <NUM> discloses a tire including a tread portion, a sidewall portion, a bead portion, a bead core provided in the bead portion, and a carcass ply covering at least a portion around the bead core. The carcass ply includes a sewn portion in which a conductive thread is sewn.

Patent document <NUM> discloses a pneumatic tire comprising a carcass as a skeletal structure composed of at least one carcass ply extending toroidally between a pair of bead portions, at least one layer of a belt located on the outer side of the carcass in the tire radial direction of the crown portion. The tire is provided with a cushion rubber and a tread rubber forming a tread portion in turn on the outer side of the belt in the tire radial direction, and a composite fiber containing a conductive fiber and a non-conductive fiber is extended at least from the pair of bead portions to portions in contact with the cushion rubber or a pair of belt under cushions, so as to expose the composite fiber to both surfaces of the carcass at the outer and inner sides of the tire.

Patent document <NUM> discloses a pneumatic tire that is provided with a belt layer arranged on the outside of a carcass in the radial direction of a crown part, and a rubber chafer is disposed on the external surface of a bead part in the width direction of the tire. A cushion rubber and a tread rubber are sequentially disposed on the outside of the belt layer in the radial direction of the tire. Composite fibers that include conductive fibers and nonconductive fibers are disposed at least from the bead part up to the position of contact with the cushion rubber or the position of contact with a belt under-cushion disposed on the outer end of the belt layer in the width direction of the tire, so as to be exposed on at least one surface on the outside or inside of the tire. The rubber chafer contains carbon black having a nitrogen adsorption specific surface area of <NUM>-<NUM> m2/g.

In the above-described tire, it is required to reduce rolling resistance. In order to reduce the rolling resistance, for example, the amount of carbon contained in a carcass rubber of a carcass ply is decreased. However, when the amount of carbon contained in the carcass rubber is decreased, the volume resistivity of the carcass rubber increases and a conductive path from the bead portion to the tread surface portion may be blocked by the carcass ply. Therefore, static electricity transmitted from the vehicle to the bead portion may not be easily released from the tread surface portion to the ground.

In view of the above-described circumstances, an object of an aspect of the present invention is to provide a tire having a structure in which static electricity from a vehicle is easily released to a ground regardless of conductivity of a carcass ply.

According to a first aspect of the invention there is provided a tire as specified in claim <NUM>.

According to a second aspect of the invention there is provided a tire as specified in claim <NUM>.

According to an aspect of the present invention, there is provided a tire having a structure in which static electricity from a vehicle is easily released to a ground regardless of conductivity of a carcass ply.

Hereinafter, a tire according to an embodiment of the present invention will be described with reference to the drawings. In the drawings below, the scale and number of each structure may be different from the scale and number of the actual structure in order to make each configuration easy to understand.

The Z-axis direction shown in each drawing is a direction parallel to the tire radial direction centered on the tire rotation axis. In each drawing, the tire radial direction is the up and down direction. In a part of the tire shown in each drawing, the positive side in the Z-axis direction, that is, the upper side in each drawing is the outside in the tire radial direction and the negative side in the Z-axis direction, that is, the lower side in each drawing is the inside in the tire radial direction.

The Y-axis direction in each drawing is a direction parallel to the tire width direction. In <FIG>, <FIG>, and <FIG>, the tire width direction is the left and right direction. In the following description, for a certain object, the side closer to the tire equatorial portion CL in the tire width direction is referred to as the "inside in the tire width direction" and the side far from the tire equatorial portion CL in the tire width direction is referred to as the "outside in the tire width direction". The tire equatorial portion CL is the center of the tire of each embodiment in the tire width direction. In a part of the tire shown in each drawing, the negative side in the Y-axis direction, that is, for example, the right side in <FIG>, <FIG>, and <FIG> is the inside in the tire width direction and the positive side in the Y-axis direction, that is, for example, the left side in <FIG>, <FIG>, and <FIG> is the outside in the tire width direction.

Further, the circumferential direction around the center axis (that is not shown) of the tire of each embodiment is referred to as the tire circumferential direction. The X-axis direction shown in each drawing is a direction orthogonal to both the Z-axis direction and the Y-axis direction and indicates the circumferential direction in the cross-section of the tire shown in each drawing.

In <FIG>, only a portion located on one side in the tire width direction from the tire equatorial portion CL is shown in the cross-section of a part of the tire <NUM> of this embodiment in the tire circumferential direction. In the cross-section of a part of the tire <NUM> in the tire circumferential direction, a portion located on the other side in the tire width direction from the tire equatorial portion CL is disposed symmetrically with respect to the portion shown in <FIG> in the tire width direction with the tire equatorial portion CL interposed therebetween. In the following description, a portion shown in <FIG> of the tire <NUM> will be described and a portion located on the other side in the tire width direction from the tire equatorial portion CL in the tire <NUM> will not be described.

The tire <NUM> of this embodiment includes, as shown in <FIG>, a tread portion <NUM>, a sidewall portion <NUM>, and a bead portion <NUM>.

The tread portion <NUM> is disposed on the outside in the tire radial direction in relation to the bead portion <NUM> and is located at the outer end portion of the tire <NUM> in the tire radial direction. The tread portion <NUM> has an annular shape extending in the tire circumferential direction. The tread portion <NUM> includes a tread surface portion 11a which is a ground contact surface of the tire <NUM>. The tread surface portion 11a is a part of the outer surface of the tread portion <NUM> in the tire radial direction.

The tread surface portion 11a is, for example, a ground contact surface of the tread portion <NUM> in a state in which the tire <NUM> is attached to a standard rim specified in "JATMA Year Book" and the tire <NUM> is filled with <NUM>% of the internal pressure (hereinafter, referred to as the specified internal pressure) of the air pressure (i.e., maximum air pressure) corresponding to the maximum load capacity (i.e., the bold load in the internal pressure-load capacity correspondence table) in the applicable size and ply rating in "JATMA Year Book" so that the maximum load corresponding to the maximum load capacity is loaded.

Additionally, when the area where the tire <NUM> is produced or used is other than Japan, the tread surface portion 11a is, for example, a ground contact surface of the tread portion <NUM> in a state conforming to the industrial standards applying to the area (for example, "TRA Year Book" in the United States, "ETRTO Standard Manual" in Europe, etc.).

The sidewall portion <NUM> extends inward in the tire radial direction from the outer end portion of the tread portion <NUM> in the tire width direction. The sidewall portion <NUM> connects the outer end portion of the tread portion <NUM> in the tire width direction and the bead portion <NUM>.

The bead portion <NUM> is connected to the inner end portion of the sidewall portion <NUM> in the tire radial direction. A bead core <NUM> is provided in the bead portion <NUM>. More specifically, the bead core <NUM> is embedded in the bead portion <NUM>.

The tire <NUM> is provided with a carcass layer <NUM> which is a skeleton. For example, the tire <NUM> is formed by assembling a first chafer portion <NUM>, a tire main body <NUM>, a belt layer <NUM>, and a belt reinforcing layer <NUM> to the carcass layer <NUM>. The carcass layer <NUM> is provided to straddle the tread portion <NUM>, the sidewall portion <NUM>, and the bead portion <NUM>. The carcass layer <NUM> has an annular shape extending in the tire circumferential direction. As shown in <FIG> and <FIG>, the carcass layer <NUM> includes a carcass ply <NUM> and a conductive portion <NUM>.

The carcass ply <NUM> covers at least a part around the core axis of the bead core <NUM>. In this embodiment, the carcass ply <NUM> extends from the tread portion <NUM> to the bead portion <NUM> through the sidewall portion <NUM> and is folded outward around the bead core <NUM> in the tire width direction. The carcass ply <NUM> has an annular shape extending in the tire circumferential direction. As shown in <FIG>, the carcass ply <NUM> includes a carcass rubber 51a and a plurality of ply cords 51b. The carcass ply <NUM> is formed by embedding the plurality of ply cords 51b in the carcass rubber 51a.

In this embodiment, the loss tangent tan δ of the carcass rubber 51a is relatively small. The loss tangent tan δ becomes smaller as the content of carbon contained in the carcass rubber 51a becomes smaller. The rolling resistance of the tire <NUM> becomes smaller as the loss tangent tan δ of the carcass rubber 51a becomes smaller. In this embodiment, the carcass rubber 51a is relatively difficult to conduct electricity. Accordingly, in this embodiment, the conductivity of the carcass ply <NUM> is relatively low.

The plurality of ply cords 51b extend from the tread portion <NUM> to the bead portion <NUM> through the sidewall portion <NUM> and are folded outward in the tire width direction around the bead core <NUM> while being embedded in the carcass rubber 51a. The plurality of ply cords 51b are arranged at intervals in the tire circumferential direction. The ply cord 51b is, for example, an organic fiber cord or the like.

The carcass ply <NUM> includes a main body of which at least a part is located on the inside in the tire width direction of the bead core <NUM> and a folded portion which is folded outward in the tire width direction around the bead core <NUM> from the main body. The main body is a portion which extends from the tread portion <NUM> to the inside in the tire width direction of the bead portion <NUM> through the sidewall portion <NUM> in the carcass ply <NUM>. The folded portion is a portion which is folded outward in the tire width direction around the bead core <NUM> and extends in the tire radial direction on the outside in the tire width direction of the bead core <NUM>.

The conductive portion <NUM> is provided on the outer surface of the carcass ply <NUM>. The conductive portion <NUM> extends along the carcass ply <NUM> as shown in <FIG>. The conductive portion <NUM> is located on the outside in the tire radial direction of the carcass ply <NUM> in the tread portion <NUM>. In this embodiment, the conductive portion <NUM> extends from the tread portion <NUM> to the inside in the tire width direction of at least the bead core <NUM>. In this embodiment, the conductive portion <NUM> extends from the tread portion <NUM> to the bead portion <NUM> through the sidewall portion <NUM>, is folded outward in the tire width direction around the bead core <NUM>, and extends to the outside in the tire width direction of the bead core <NUM>.

The outer end portion in the tire radial direction of the portion folded around the bead core <NUM> in the conductive portion <NUM> is disposed at the same position in the tire radial direction as the outer end portion in the tire radial direction of the portion folded around the bead core <NUM> in the carcass ply <NUM>. At least a part of the conductive portion <NUM> is located between the carcass ply <NUM> and the bead core <NUM>. In this embodiment, in the conductive portion <NUM>, a portion which is located on the inside in the tire radial direction of the bead core <NUM> and portions which are located on both sides of the bead core <NUM> in the tire width direction are located between the carcass ply <NUM> and the bead core <NUM>. In this embodiment, the conductive portion <NUM> is connected to a conductive rubber portion <NUM> to be described later. The conductive portion <NUM> in the bead portion <NUM> is provided inside the carcass ply <NUM> folded around the bead core <NUM>. As shown in <FIG>, the plurality of conductive portions <NUM> are attached to the outer surface of the carcass rubber 51a in the tire radial direction on the inside in the tire radial direction of the bead core <NUM>.

In this embodiment, the conductive portion <NUM> is a thread-shaped member containing metal. The conductive portion <NUM> is, for example, a conductive thread in which a metal fiber such as stainless steel is wound around an organic fiber. A plurality of the conductive portions <NUM> are provided at intervals in the tire circumferential direction.

Additionally, <FIG> shows a state in which the plurality of conductive portions <NUM> are respectively located on the outside in the tire radial direction of the plurality of ply cords 51b as an example, but the present invention is not limited thereto. The positional relationship between the plurality of conductive portions <NUM> and the plurality of ply cords 51b in the tire circumferential direction is not particularly limited. That is, in <FIG>, the position of the conductive portion <NUM> in the left and right direction may deviate from the position of the ply cord 51b in the left and right direction. Further, the number of the conductive portions <NUM> and the number of the ply cords 51b may be the same or different.

The conductive portion <NUM> has conductivity. The volume resistivity of the conductive portion <NUM> is smaller than the volume resistivity of the conductive rubber portion <NUM> to be described later.

In the present specification, "a member has conductivity" and "a member is relatively easy to conduct electricity" means that the volume resistivity of a member is low enough to allow static electricity from the vehicle to flow.

The first chafer portion <NUM> has conductivity. The first chafer portion <NUM> is a rubber member or a composite member of fibers and rubber. As shown in <FIG>, the first chafer portion <NUM> covers a portion provided in the bead portion <NUM> in the carcass ply <NUM> from the inside in the tire radial direction and both sides in the tire width direction. The portion provided in the bead portion <NUM> in the carcass ply <NUM> includes a portion which covers the bead core <NUM> in the carcass ply <NUM> from the inside in the tire radial direction and both sides in the tire width direction. In the following description, the portion provided in the bead portion <NUM> in the carcass ply <NUM> is referred to as a core covering portion <NUM>. The core covering portion <NUM> passes through the bead core <NUM> in the tire radial direction from the inside in the tire width direction of the bead core <NUM> and extends to the outside in the tire width direction of the bead core <NUM>. The first chafer portion <NUM> has an annular shape extending in the tire circumferential direction.

The first chafer portion <NUM> includes a radial covering portion <NUM> and lateral covering portions <NUM> and <NUM>. The radial covering portion <NUM> is a portion which covers the core covering portion <NUM> in the carcass ply <NUM> from the inside in the tire radial direction. The radial covering portion <NUM> extends in the tire width direction. The lateral covering portions <NUM> and <NUM> are portions which cover the core covering portion <NUM> in the carcass ply <NUM> from both sides in the tire width direction. The lateral covering portion <NUM> extends from the outer end portion of the radial covering portion <NUM> in the tire width direction to the outside in the tire radial direction and covers the core covering portion <NUM> from the outside in the tire width direction. The lateral covering portion <NUM> extends from the inner end portion of the radial covering portion <NUM> in the tire width direction to the outside in the tire radial direction and covers the core covering portion <NUM> from the inside in the tire width direction. The outer end portions of the lateral covering portions <NUM> and <NUM> in the tire radial direction are located on the inside in the tire radial direction in relation to the outer end portion in the tire radial direction of the portion folded around the bead core <NUM> in the carcass ply <NUM>.

The tire main body <NUM> includes, as shown in <FIG>, a tread rubber <NUM> and a sidewall rubber <NUM>.

The tread rubber <NUM> is a portion that constitutes a part of the tread portion <NUM> and has an annular shape extending in the tire circumferential direction. The tread rubber <NUM> is provided on the outside in the tire radial direction of the carcass layer <NUM>. The tread rubber <NUM> is connected to the carcass layer <NUM> through the belt layer <NUM> and the belt reinforcing layer <NUM>. In <FIG>, in order to easily and schematically understand each portion, the carcass layer <NUM>, the tread rubber <NUM>, the belt layer <NUM>, and the belt reinforcing layer <NUM> are separated.

The tread rubber <NUM> includes a tread under cushion <NUM>, a base layer <NUM>, a cap layer <NUM>, a mini side <NUM>, and an antenna rubber <NUM>.

The tread under cushion <NUM>, the base layer <NUM>, and the cap layer <NUM> are laminated in this order from the inside in the tire radial direction toward the outside in the tire radial direction. The outer surface of the cap layer <NUM> in the tire radial direction constitutes the tread surface portion 11a. The mini side <NUM> is connected to the outer end portions of the tread under cushion <NUM>, the base layer <NUM>, and the cap layer <NUM> in the laminated state in the tire width direction.

The antenna rubber <NUM> is embedded to straddle the base layer <NUM> and the cap layer <NUM>. The antenna rubber <NUM> penetrates the base layer <NUM> and the cap layer <NUM> in the tire radial direction. The inner end portion of the antenna rubber <NUM> in the tire radial direction is connected to the outer surface of the tread under cushion <NUM> in the tire radial direction. The outer end portion of the antenna rubber <NUM> in the tire radial direction is exposed to the outer surface of the cap layer <NUM> in the tire radial direction and constitutes a part of the tread surface portion 11a. The antenna rubber <NUM> may extend intermittently, may extend continuously, or may be scattered in the tire circumferential direction.

The base layer <NUM>, the cap layer <NUM>, and the mini side <NUM> are relatively difficult to conduct electricity, and the base layer <NUM>, the cap layer <NUM>, and the mini side <NUM> have low conductivity. The tread under cushion <NUM> and the antenna rubber <NUM> are relatively easy to conduct electricity and have conductivity.

The sidewall rubber <NUM> is a portion that constitutes a part of the sidewall portion <NUM> and a part of the bead portion <NUM> and has an annular shape extending in the tire circumferential direction. The sidewall rubber <NUM> is provided on the outside in the tire width direction of the carcass layer <NUM>. The sidewall rubber <NUM> is connected to the carcass layer <NUM>. The outer end portion of the sidewall rubber <NUM> in the tire radial direction is connected to the outer end portion of the tread rubber <NUM> in the tire width direction. In <FIG>, in order to easily and schematically understand each portion, the sidewall rubber <NUM> and the carcass layer <NUM> are separated and the sidewall rubber <NUM> and the tread rubber <NUM> are separated.

The sidewall rubber <NUM> includes a sidewall rubber main body <NUM> and a second chafer portion <NUM>.

The sidewall rubber main body <NUM> is a portion that constitutes a part of the sidewall portion <NUM>. The outer end portion of the sidewall rubber main body <NUM> in the tire radial direction extends inward in the tire width direction and is located between the carcass layer <NUM> and the tread rubber <NUM>, the belt layer <NUM>, and the belt reinforcing layer <NUM>.

The second chafer portion <NUM> is a portion that constitutes a part of the bead portion <NUM>. The second chafer portion <NUM> is connected to the inner end portion of the sidewall rubber main body <NUM> in the tire radial direction. The second chafer portion <NUM> covers the core covering portion <NUM> of the carcass layer <NUM> from the outside in the tire width direction. The second chafer portion <NUM> is connected to the core covering portion <NUM> and the lateral covering portion <NUM> of the first chafer portion <NUM> from the outside in the tire width direction. Additionally, in <FIG> and <FIG>, in order to easily and schematically understand each portion, the second chafer portion <NUM> and the core covering portion <NUM> are separated and the second chafer portion <NUM> and the lateral covering portion <NUM> are separated.

The rubber material constituting the sidewall rubber main body <NUM> and the rubber material constituting the second chafer portion <NUM> have different volume resistivities. The sidewall rubber main body <NUM> is relatively difficult to conduct electricity. The second chafer portion <NUM> is relatively easy to conduct electricity and has conductivity.

In this embodiment, the first chafer portion <NUM> and the second chafer portion <NUM> constitute a chafer portion <NUM>. That is, in this embodiment, the tire <NUM> includes the chafer portion <NUM> which covers at least a part around the carcass ply <NUM>. In this embodiment, the chafer portion <NUM> covers at least the outside in the tire width direction of the core covering portion <NUM>. The chafer portion <NUM> has conductivity. In the chafer portion <NUM>, the volume resistivity of the first chafer portion <NUM> and the volume resistivity of the second chafer portion <NUM> may be the same or different. In this embodiment, the chafer portion <NUM> covers the inside in the tire radial direction and both sides in the tire width direction of the core covering portion <NUM> and is connected to the core covering portion <NUM>. The chafer portion <NUM> is a portion which protects the carcass layer <NUM> from the friction with the rim to which the tire <NUM> is attached.

The belt layer <NUM> is embedded in the tread portion <NUM>. The belt layer <NUM> is laminated on the outside in the tire radial direction of the carcass layer <NUM>. The belt layer <NUM> is connected to the carcass ply <NUM> and the conductive portion <NUM>. The belt layer <NUM> is located between the tread rubber <NUM> and the carcass layer <NUM> in the tire radial direction. Although not shown in the drawings, the belt layer <NUM> is formed by embedding a plurality of steel cords in the belt rubber. The belt rubber of the belt layer <NUM> is relatively easy to conduct electricity and has conductivity. Accordingly, the belt layer <NUM> has conductivity.

The belt reinforcing layer <NUM> is laminated on the outside in the tire radial direction of the belt layer <NUM>. The belt reinforcing layer <NUM> is located between the tread rubber <NUM> and the belt layer <NUM> in the tire radial direction. The outer surface of the belt reinforcing layer <NUM> in the tire radial direction is connected to the inner surface of the tread under cushion <NUM> in the tread rubber <NUM> in the tire radial direction.

The belt reinforcing layer <NUM> is formed by, for example, winding a composite cord made of rubber and nylon around the outer peripheral portion of the belt layer <NUM> a plurality of times. These rolls of the composite cord constituting the belt reinforcing layer <NUM> are arranged with a gap <NUM> therebetween in the tire width direction. Although not shown in the drawings, the tread under cushion <NUM> and the belt layer <NUM> which sandwich the belt reinforcing layer <NUM> in the tire radial direction are connected to each other in the gap <NUM> between these rolls of the belt reinforcing layer <NUM>. The belt reinforcing layer <NUM> is relatively difficult to conduct electricity.

As shown in <FIG>, the bead portion <NUM> is provided with the conductive rubber portion <NUM>. The conductive rubber portion <NUM> is relatively easy to conduct electricity and has conductivity. The volume resistivity of the conductive rubber portion <NUM> is smaller than the volume resistivity of the carcass rubber 51a. The volume resistivity of the conductive rubber portion <NUM> is smaller than, for example, the volume resistivity of the first chafer portion <NUM> and the volume resistivity of the second chafer portion <NUM>. The volume resistivity of the conductive rubber portion <NUM> is different from, for example, the volume resistivity of the other rubber material constituting the bead portion <NUM>.

Additionally, the volume resistivity of the conductive rubber portion <NUM> may be the same as the volume resistivity of the first chafer portion <NUM> and the volume resistivity of the second chafer portion <NUM> or may be larger than the volume resistivity of the first chafer portion <NUM> and the volume resistivity of the second chafer portion <NUM>.

The conductive rubber portion <NUM> is disposed to penetrate the core covering portion <NUM> from the inside of the core covering portion <NUM> and straddle the outside of the core covering portion <NUM>. The conductive rubber portion <NUM> has an annular shape extending in the tire circumferential direction. The conductive rubber portion <NUM> includes a first portion <NUM>, a second portion <NUM>, and a third portion <NUM>.

The first portion <NUM> is located on the inside in the tire radial direction of the bead core <NUM>. The first portion <NUM> extends in the tire width direction. The first portion <NUM> is disposed to penetrate the carcass layer <NUM> in the tire radial direction. The outer end portion of the first portion <NUM> in the tire radial direction contacts the bead core <NUM>. The inner end portion of the first portion <NUM> in the tire radial direction is connected to the first chafer portion <NUM>. More specifically, the inner end portion of the first portion <NUM> in the tire radial direction is connected to the radial covering portion <NUM> of the first chafer portion <NUM>. The first portion <NUM> includes, as shown in <FIG>, a base portion (i.e., intervening portion) <NUM> and a through-portion <NUM>.

The base portion <NUM> is laminated on the outside in the tire radial direction of the carcass ply <NUM>. The conductive portion <NUM> is embedded in the base portion <NUM>. Accordingly, the first portion <NUM> is connected to the conductive portion <NUM>. In this embodiment, the base portion <NUM> corresponds to an intervening portion which is located between the bead core <NUM> and the carcass ply <NUM>.

The through-portion <NUM> extends inward in the tire radial direction from the base portion <NUM>. For example, a plurality of the through-portions <NUM> are provided in the tire circumferential direction. The through-portion <NUM> penetrates a portion located between the ply cords 51b in the carcass rubber 51a in the tire radial direction. In this embodiment, the through-portion <NUM> divides the carcass rubber 51a in the tire circumferential direction. The inner end portion of the through-portion <NUM> in the tire radial direction is connected to the radial covering portion <NUM> of the first chafer portion <NUM>. The dimension of the through-portion <NUM> in the tire radial direction is larger than the dimension of the base portion <NUM> in the tire radial direction.

As described above, since the first portion <NUM> connects the conductive portion <NUM> and the first chafer portion <NUM> on the inside in the tire radial direction of the bead core <NUM>, the conductive rubber portion <NUM> is disposed to penetrate the carcass ply <NUM> in the tire radial direction on the inside in the tire radial direction of the bead core <NUM> and connects the conductive portion <NUM> and the chafer portion <NUM>. Further, the conductive rubber portion <NUM> penetrates a gap between the ply cords 51b, which are adjacent to each other in the tire circumferential direction, in the tire radial direction and connects the conductive portion <NUM> and the chafer portion <NUM>.

As shown in <FIG>, the second portion <NUM> is located on the outside in the tire width direction of the bead core <NUM>. The second portion <NUM> extends outward in the tire radial direction from the outer end portion of the first portion <NUM> in the tire width direction. More specifically, the second portion <NUM> is located on the outside in the tire radial direction from the outer end portion of the first portion <NUM> in the tire width direction and obliquely extends inward in the tire width direction. The outer end portion of the second portion <NUM> in the tire radial direction is located on the outside in the tire radial direction in relation to the first chafer portion <NUM>. The conductive portion <NUM> is embedded in the second portion <NUM>. Accordingly, the second portion <NUM> is connected to the conductive portion <NUM>.

The second portion <NUM> is disposed to penetrate the carcass layer <NUM> in the tire width direction. The second portion <NUM> includes a base portion (i.e., intervening portion) 82a and a through-portion (i.e., embedded portion) 82b. In this embodiment, the base portion 82a corresponds to an intervening portion which is located between the bead core <NUM> and the carcass ply <NUM>. The base portion 82a is a portion which is located on the inside in the tire width direction in relation to the carcass ply <NUM> in the second portion <NUM>. In this embodiment, the through-portion 82b corresponds to an embedded portion which is embedded in the carcass ply <NUM>. More specifically, the through-portion 82b corresponds to a first embedded portion which is embedded in the folded portion of the carcass ply <NUM>. The through-portion 82b penetrates a portion located at the folded portion in the carcass rubber 51a in the tire width direction.

The outer portion of the through-portion 82b in the tire radial direction is located on the outside in the tire radial direction in relation to the bead core <NUM>. That is, at least a part of the through-portion 82b which is the embedded portion is located on the outside in the tire radial direction in relation to the bead core <NUM>. The distance from the outer end portion of the bead core <NUM> in the tire radial direction to the outer end portion of the through-portion 82b which is the embedded portion in the tire radial direction is equal to or shorter than the dimension of the bead core <NUM> in the tire radial direction.

In the present specification, the "embedded portion is embedded in the carcass ply" includes that the embedded portion is embedded in the carcass rubber of the carcass ply. In this embodiment, the through-portion 82b which is the embedded portion is embedded in the carcass rubber 51a.

Since the base portion 82a and the through-portion 82b are provided, the inner end portion of the second portion <NUM> in the tire width direction contacts the bead core <NUM>. The outer end portion of the second portion <NUM> in the tire width direction is connected to the first chafer portion <NUM>. More specifically, the outer end portion of the second portion <NUM> in the tire width direction is connected to the lateral covering portion <NUM> of the first chafer portion <NUM>. Similarly to the first portion <NUM> shown in <FIG>, the second portion <NUM> penetrates a gap between the ply cords 51b, which are adjacent to each other in the tire circumferential direction, in the tire width direction and connects the conductive portion <NUM> and the chafer portion <NUM>.

The dimension of the portion located on the inside in the tire width direction in relation to the carcass ply <NUM> in the second portion <NUM>, that is, the dimension of the base portion 82a which is the intervening portion in the tire width direction becomes smaller inward in the tire radial direction at the inner portion in the tire radial direction.

The third portion <NUM> is located on the inside in the tire width direction of the bead core <NUM>. The third portion <NUM> extends outward in the tire radial direction from the inner end portion of the first portion <NUM> in the tire width direction. The outer end portion of the third portion <NUM> in the tire radial direction is located on the outside in the tire radial direction in relation to the first chafer portion <NUM>. The conductive portion <NUM> is embedded in the third portion <NUM>. Accordingly, the third portion <NUM> is connected to the conductive portion <NUM>.

The third portion <NUM> is disposed to penetrate the carcass layer <NUM> in the tire width direction. The third portion <NUM> includes a base portion (i.e., intervening portion) 83a and a through-portion (i.e., embedded portion) 83b. In this embodiment, the base portion 83a corresponds to an intervening portion which is located between the bead core <NUM> and the carcass ply <NUM>. The base portion 83a is a portion which is located on the outside in the tire width direction in relation to the carcass ply <NUM> in the third portion <NUM>. In this embodiment, the through-portion 83b corresponds to an embedded portion which is embedded in the carcass ply <NUM>. More specifically, the through-portion 83b corresponds to a second embedded portion which is embedded in the main body of the carcass ply <NUM>. The through-portion 83b penetrates a portion located between the ply cords 51b in the carcass rubber 51a in the tire width direction.

The outer portion of the through-portion 83b in the tire radial direction is located on the outside in the tire radial direction in relation to the bead core <NUM>. That is, at least a part of the through-portion 83b which is the embedded portion is located on the outside in the tire radial direction in relation to the bead core <NUM>. The distance from the outer end portion of the bead core <NUM> in the tire radial direction to the outer end portion of the through-portion 83b which is the embedded portion in the tire radial direction is equal to or shorter than the dimension of the bead core <NUM> in the tire radial direction.

Since the base portion 83a and the through-portion 83b are provided, the outer end portion of the third portion <NUM> in the tire width direction contacts the bead core <NUM>. The inner end portion of the third portion <NUM> in the tire width direction is connected to the first chafer portion <NUM>. More specifically, the inner end portion of the third portion <NUM> in the tire width direction is connected to the lateral covering portion <NUM> of the first chafer portion <NUM>. Similarly to the first portion <NUM> shown in <FIG>, the third portion <NUM> penetrates a gap between the ply cords 51b, which are adjacent to each other in the tire circumferential direction, in the tire width direction and connects the conductive portion <NUM> and the chafer portion <NUM>.

The dimension of the portion which is located on the outside in the tire width direction in relation to the carcass ply <NUM> in the third portion <NUM>, that is, the dimension of the base portion 83a which is the intervening portion in the tire width direction becomes smaller inward in the tire radial direction at the inner portion in the tire width direction.

As described above, since the second portion <NUM> connects the conductive portion <NUM> and the first chafer portion <NUM> on the outside in the tire width direction of the bead core <NUM>, the conductive rubber portion <NUM> is disposed to penetrate the carcass ply <NUM> in the tire width direction on the outside in the tire width direction of the bead core <NUM> and connects the conductive portion <NUM> and the chafer portion <NUM>. Further, since the third portion <NUM> connects the conductive portion <NUM> and the first chafer portion <NUM> on the inside in the tire width direction of the bead core <NUM>, the conductive rubber portion <NUM> is disposed to penetrate the carcass ply <NUM> in the tire width direction on the inside in the tire width direction of the bead core <NUM> and connects the conductive portion <NUM> and the chafer portion <NUM>. Further, the conductive rubber portion <NUM> penetrates a gap between the ply cords 51b, which are adjacent to each other in the tire circumferential direction, in the tire width direction and connects the conductive portion <NUM> and the chafer portion <NUM>.

In this embodiment, the dimension of the conductive rubber portion <NUM> in the tire width direction becomes larger inward in the tire radial direction. That is, the dimension in the tire width direction of the inner portion of the conductive rubber portion <NUM> in the tire radial direction increases.

As shown in <FIG>, the tire <NUM> is provided with a conductive path CP along which static electricity from the vehicle is released from the rim to which the tire <NUM> is attached to the ground. The conductive path CP is a path through which static electricity transmitted from the rim in the tire <NUM> passes and extends from the second chafer portion <NUM> to the tread surface portion 11a while passing through the first chafer portion <NUM>, the conductive rubber portion <NUM>, the conductive portion <NUM>, the belt layer <NUM>, the gap <NUM> of the belt reinforcing layer <NUM>, the tread under cushion <NUM>, and the antenna rubber <NUM> in this order. Accordingly, static electricity of the vehicle transmitted from the rim can be released from the tread surface portion 11a to the ground.

Additionally, as shown in <FIG>, in this embodiment, the conductive path CP from the first chafer portion <NUM> to the conductive portion <NUM> through the conductive rubber portion <NUM> includes, for example, a path through which static electricity flows from the radial covering portion <NUM> to the conductive portion <NUM> through the first portion <NUM> and a path through which static electricity flows from the lateral covering portion <NUM> to the conductive portion <NUM> through the second portion <NUM>.

Further, as described above, the tread under cushion <NUM> and the belt layer <NUM> are connected to each other in the gap <NUM> of the belt reinforcing layer <NUM>. Therefore, static electricity flowing from the conductive portion <NUM> to the belt layer <NUM> flows from the gap <NUM> to the tread under cushion <NUM>.

According to this embodiment, the through-portions 82b and 83b which are the embedded portions in the conductive rubber portion <NUM> are embedded in the carcass ply <NUM>. That is, a part of the conductive rubber portion <NUM> is embedded in the carcass ply <NUM>. Therefore, electricity can be easily conducted through the conductive rubber portion <NUM> in the portion in which the conductive rubber portion <NUM> is embedded in the carcass ply <NUM>. Accordingly, even when the conductivity of the carcass ply <NUM> is low, static electricity from the vehicle can pass through the carcass ply <NUM> by the conductive rubber portion <NUM>. Thus, it is possible to obtain the tire <NUM> having a structure in which static electricity from the vehicle is easily released to the ground regardless of the conductivity of the carcass ply <NUM>. Therefore, it is possible to preferably release static electricity of the vehicle to the ground while reducing the rolling resistance of the tire <NUM> by decreasing the amount of carbon contained in the carcass rubber 51a of the carcass ply <NUM>.

Further, according to this embodiment, the through-portion 82b which is the first embedded portion is embedded in the folded portion which is located on the outside in the tire width direction of the bead core <NUM> in the carcass ply <NUM>. Therefore, a portion in which the conductive rubber portion <NUM> is embedded in the carcass ply <NUM> easily contacts the lateral covering portion <NUM> of the first chafer portion <NUM>. Accordingly, static electricity from the vehicle transmitted from the rim to the chafer portion <NUM> can be easily passed through the carcass ply <NUM> by the conductive rubber portion <NUM> (the through-portion 82b). Thus, static electricity from the vehicle is more preferably easily released to the ground.

Further, according to this embodiment, the through-portion 83b which is the second embedded portion is embedded in the main body which is located on the inside in the tire width direction of the bead core <NUM> in the carcass ply <NUM>. Therefore, a portion in which the conductive rubber portion <NUM> is embedded in the carcass ply <NUM> easily contacts the lateral covering portion <NUM> of the first chafer portion <NUM>. Accordingly, static electricity from the vehicle transmitted from the rim to the chafer portion <NUM> can be easily passed through the carcass ply <NUM> by the conductive rubber portion <NUM> (the through-portion 83b). Thus, static electricity from the vehicle is more preferably easily released to the ground.

Further, according to this embodiment, the distance from the outer end portion of the bead core <NUM> in the tire radial direction to the outer end portions of the through-portions 82b and 83b which are the embedded portions in the tire radial direction is equal to or shorter than the dimension of the bead core <NUM> in the tire radial direction. Therefore, it is possible to decrease the volume of the conductive rubber portion <NUM>.

Further, according to this embodiment, the conductive portion <NUM> is provided to extend along the carcass ply <NUM> and to be located between the carcass ply <NUM> and the bead core <NUM>. Further, the conductive portion <NUM> is connected to the conductive rubber portion <NUM>. Therefore, static electricity transmitted to the conductive rubber portion <NUM> can be transmitted to the conductive portion <NUM>. Accordingly, even when the volume resistivity of the carcass rubber 51a of the carcass ply <NUM> is relatively large and the conductivity of the carcass ply <NUM> is low, static electricity from the vehicle transmitted from the rim to the chafer portion <NUM> can be transmitted to the conductive portion <NUM> through the conductive rubber portion <NUM>. Accordingly, static electricity from the vehicle can be sent to the tread portion <NUM> through the conductive portion <NUM> and the static electricity can be released from the tread surface portion 11a of the tread portion <NUM> to the ground. Thus, static electricity from the vehicle is more preferably easily released to the ground.

Further, according to this embodiment, the volume resistivity of the conductive portion <NUM> is smaller than the volume resistivity of the conductive rubber portion <NUM>. Therefore, it is easy to preferably decrease the volume resistivity of the conductive portion <NUM>. Accordingly, static electricity can preferably flow to the conductive portion <NUM> that makes the relatively long conductive path CP from the bead portion <NUM> to the tread portion <NUM>. Thus, static electricity from the vehicle is more easily released to the ground.

Further, according to this embodiment, the conductive portion <NUM> is a thread-shaped member containing metal. Therefore, the volume resistivity of the conductive portion <NUM> is more preferably easily decreased and static electricity more easily flows from the bead portion <NUM> to the tread portion <NUM> by the conductive portion <NUM>. Accordingly, static electricity from the vehicle is more easily released to the ground. Further, according to this embodiment, the plurality of conductive portions <NUM> are arranged at intervals in the tire circumferential direction. Therefore, the conductive path CP through which static electricity flows from the bead portion <NUM> to the tread portion <NUM> can be increased and static electricity more easily flows from the bead portion <NUM> to the tread portion <NUM> by the conductive portion <NUM>. Accordingly, static electricity from the vehicle is more easily released to the ground.

Further, according to this embodiment, the through-portions 82b and 83b which are the embedded portions are located between the ply cords 51b which are adjacent to each other in the tire circumferential direction. Therefore, a part of the conductive rubber portion <NUM> is easily disposed to be embedded in the carcass ply <NUM>. Further, the through-portions 82b and 83b are easily arranged to penetrate the carcass ply <NUM> and the conductive portion <NUM> and the chafer portion <NUM> are more preferably easily connected by the conductive rubber portion <NUM>.

According to this embodiment, the bead portion <NUM> is provided with the conductive rubber portion <NUM> which penetrates the carcass ply <NUM> in the tire width direction and connects the conductive portion <NUM> and the chafer portion <NUM>. Therefore, even when the volume resistivity of the carcass rubber 51a of the carcass ply <NUM> is relatively large and the conductivity of the carcass ply <NUM> is low, static electricity from the vehicle transmitted from the rim to the chafer portion <NUM> can be transmitted to the conductive portion <NUM> through the conductive rubber portion <NUM>. Accordingly, static electricity from the vehicle can be sent to the tread portion <NUM> through the conductive portion <NUM> and the static electricity can be released from the tread surface portion 11a of the tread portion <NUM> to the ground. Thus, according to this embodiment, it is possible to obtain the tire <NUM> having a structure in which static electricity from the vehicle is easily released to the ground regardless of the conductivity of the carcass ply <NUM>. Accordingly, it is possible to more preferably release static electricity of the vehicle to the ground while reducing the rolling resistance of the tire <NUM> by decreasing the amount of carbon contained in the carcass rubber 51a of the carcass ply <NUM>.

Further, according to this embodiment, the conductive rubber portion <NUM> is disposed to penetrate the carcass ply <NUM> in the tire width direction on the outside and the inside in the tire width direction of the bead core <NUM> and connects the conductive portion <NUM> and the chafer portion <NUM>. Therefore, the connection area between the chafer portion <NUM> and the conductive portion <NUM> through the conductive rubber portion <NUM> can be increased and static electricity from the chafer portion <NUM> can more preferably flow to the conductive portion <NUM> through the conductive rubber portion <NUM>. Thus, static electricity from the vehicle is more easily released to the ground.

Further, according to this embodiment, the conductive rubber portion <NUM> penetrates a gap between the ply cords 51b which are adjacent to each other in the tire circumferential direction and connects the conductive portion <NUM> and the chafer portion <NUM>. Therefore, the conductive rubber portion <NUM> can be easily disposed to penetrate the carcass ply <NUM> and more preferably connect the conductive portion <NUM> and the chafer portion <NUM> by the conductive rubber portion <NUM>.

Further, according to this embodiment, the carcass rubber 51a is relatively difficult to conduct electricity. Therefore, it is difficult for static electricity from the vehicle to pass through the carcass ply <NUM>. However, as described above, according to this embodiment, static electricity from the vehicle is easily released to the ground regardless of the conductivity of the carcass ply <NUM>. That is, the effect that static electricity is easily released to the ground regardless of the conductivity of the carcass ply <NUM> can be obtained more usefully in a configuration in which the carcass rubber 51a is relatively difficult to conduct electricity.

Further, according to this embodiment, the conductive rubber portion <NUM> is disposed to penetrate the carcass ply <NUM> in the tire radial direction on the inside in the tire radial direction of the bead core <NUM> and connects the conductive portion <NUM> and the chafer portion <NUM>. Therefore, the conductive rubber portion <NUM> is disposed to penetrate the carcass ply <NUM> on the inside in the tire radial direction and both sides in the tire width direction of the bead core <NUM> and connects the conductive portion <NUM> and the chafer portion <NUM>. Accordingly, a connection area between the chafer portion <NUM> and the conductive portion <NUM> through the conductive rubber portion <NUM> can be further increased and static electricity from the chafer portion <NUM> can more preferably flow to the conductive portion <NUM> through the conductive rubber portion <NUM>. Thus, static electricity from the vehicle is more easily released to the ground.

Further, according to this embodiment, the dimension in the tire width direction of the inner portion of the conductive rubber portion <NUM> in the tire radial direction increases. Therefore, a portion connected to the chafer portion <NUM> at the inner end portion of the conductive rubber portion <NUM> in the tire radial direction can be increased in the tire width direction. Accordingly, the conductive rubber portion <NUM> and the chafer portion <NUM> are more preferably connected and static electricity easily flows from the chafer portion <NUM> to the conductive portion <NUM> through the conductive rubber portion <NUM>. Thus, static electricity from the vehicle is more easily released to the ground.

Further, according to this embodiment, the conductive rubber portion <NUM> connects the conductive portion <NUM> and the first chafer portion <NUM>. The first chafer portion <NUM> covers a portion provided in the bead portion <NUM> in the carcass ply <NUM> from the inside in the tire radial direction and both sides in the tire width direction. Therefore, it is easy to adopt the above-described configuration in which the conductive rubber portion <NUM> is disposed to penetrate the carcass ply <NUM> on the inside in the tire radial direction and both sides in the tire width direction of the bead core <NUM> and connects the conductive portion <NUM> and the chafer portion <NUM>. That is, as in this embodiment, the lateral covering portions <NUM> and <NUM> and the conductive portion <NUM> are easily connected by the second portion <NUM> and the third portion <NUM> of the conductive rubber portion <NUM> while connecting the radial covering portion <NUM> and the conductive portion <NUM> by the first portion <NUM> of the conductive rubber portion <NUM>.

In this embodiment, the configuration of the conductive rubber portion is different from that of the first embodiment. In addition, the same configuration as the above-described embodiment is appropriately denoted by the same reference numeral and the description may be omitted.

In a tire <NUM> of this embodiment, a chafer portion <NUM> includes a first chafer portion <NUM> and the second chafer portion <NUM> as shown in <FIG>.

The first chafer portion <NUM> includes the radial covering portion <NUM> and lateral covering portions <NUM> and <NUM>.

The outer end portions of the lateral covering portions <NUM> and <NUM> in the tire radial direction are located on the inside in the tire radial direction in relation to the outer end portions of the lateral covering portions <NUM> and <NUM> in the tire radial direction of the first embodiment. The outer end portions of the lateral covering portions <NUM> and <NUM> in the tire radial direction are located on the inside in the tire radial direction in relation to the outer end portion of the bead core <NUM> in the tire radial direction.

A conductive rubber portion <NUM> of this embodiment extends in the tire radial direction on the outside in the tire width direction of the bead core <NUM>. An outer portion <NUM> of the conductive rubber portion <NUM> in the tire radial direction is the same as the base portion 82a of the second portion <NUM> of the conductive rubber portion <NUM> of the first embodiment.

An inner portion <NUM> of the conductive rubber portion <NUM> in the tire radial direction is disposed to penetrate the carcass ply <NUM> in the tire width direction on the outside in the tire width direction of the bead core <NUM>. The outer end portion of the inner portion <NUM> in the tire width direction is connected to the second chafer portion <NUM>. The inner end portion in the tire radial direction at the outer end portion of the inner portion <NUM> in the tire width direction is connected to the outer end portion of the lateral covering portion <NUM> of the first chafer portion <NUM> in the tire radial direction.

In <FIG>, in order to easily and schematically understand each portion, the second chafer portion <NUM> and the inner portion <NUM> of the conductive rubber portion <NUM> are separated and the inner portion <NUM> and the lateral covering portion <NUM> are separated.

With the above-described arrangement, the conductive rubber portion <NUM> is disposed to penetrate the carcass ply <NUM> in the tire width direction on the outside in the tire width direction of the bead core <NUM> and connects the conductive portion <NUM> and the chafer portion <NUM>. Additionally, the conductive rubber portion <NUM> is different from the conductive rubber portion <NUM> of the first embodiment in that the conductive rubber portion does not penetrate the carcass ply <NUM> and does not connect the conductive portion <NUM> and the chafer portion <NUM> on the inside in the tire radial direction and the inside in the tire width direction of the bead core <NUM>.

In this embodiment, the conductive path CP along which static electricity from the vehicle flows includes a path through which static electricity flows from the second chafer portion <NUM> to the conductive portion <NUM> through the conductive rubber portion <NUM> and a path through which static electricity flows from the second chafer portion <NUM> to the conductive portion <NUM> through the lateral covering portion <NUM> of the first chafer portion <NUM> and the conductive rubber portion <NUM>.

The other configurations of the tire <NUM> are the same as the other configurations of the tire <NUM> of the first embodiment.

The present invention is not limited to the above-described embodiments, and the following configurations can also be adopted.

The conductive rubber portion includes a through-portion corresponding to an embedded portion embedded in the carcass ply and has conductivity. The conductive rubber portion may not be connected to the conductive portion. The conductive rubber portion may not be connected to the chafer portion. The installation position of the embedded portion is not particularly limited if at least a part of the portion embedded in the carcass ply is located on the outside in the tire radial direction in relation to the bead core and wherein a distance from an outer end portion of the bead core in the tire radial direction to an outer end portion of the through-portion being the embedded portion in the tire radial direction is equal to or shorter than a dimension of the bead core in the tire radial direction. The embedded portion may not penetrate the carcass ply. The embedded portion may not be exposed to the surface of the carcass layer. The embedded portion may not be connected to the intervening portion. The intervening portion may not be provided.

The conductive rubber portion may not penetrate the carcass ply in the tire radial direction. That is, for example, in the first embodiment, the conductive rubber portion <NUM> may not include the first portion <NUM>. Further, in the first embodiment, the conductive rubber portion <NUM> may not include any one of the second portion <NUM> and the third portion <NUM>. The shape of the conductive rubber portion is not particularly limited. For example, in the first embodiment, the conductive rubber portion <NUM> may be formed such that the dimension in the tire width direction at the inner portion in the tire radial direction does not increase. The conductive rubber portion may not divide the carcass rubber of the carcass ply if the conductive rubber portion penetrates the carcass ply in the tire width direction.

Further, the conductive rubber portion may be a part of the carcass rubber in the carcass ply. In this case, the carcass rubber includes a first rubber portion and a second rubber portion of which volume resistivity is smaller than that of the first rubber portion. The second rubber portion is a portion corresponding to the conductive rubber portion. The first rubber portion is a portion other than the second rubber portion in the carcass rubber. In this case, at least a part of the second rubber portion is located on the outside in the tire radial direction in relation to the bead core. Also in this case, as described above, static electricity from the vehicle is more easily released to the ground regardless of the conductivity of the carcass ply.

The conductive portion is not particularly limited if the conductive portion extends along the carcass ply so that at least a part is located between the carcass ply and the bead core and has conductivity. The conductive portion may not contain metal. The conductive portion may be made of, for example, rubber having conductivity. The conductive portion may not be a thread-shaped member and may be a layered member laminated on the carcass ply. The volume resistivity of the conductive portion may be the same as the volume resistivity of the conductive rubber portion and may be larger than the volume resistivity of the conductive rubber portion. The conductive portion may not be provided.

The chafer portion is not particularly limited if the chafer portion has conductivity and covers at least a part around the carcass ply. For example, in the first embodiment, the first chafer portion <NUM> may not be provided. In this case, the conductive rubber portion <NUM> may connect the second chafer portion <NUM> and the conductive portion <NUM>. In the first embodiment, the first chafer portion <NUM> and the second chafer portion <NUM> may be integrally molded with each other. The chafer portion may not be provided.

The carcass layer may include two or more carcass plies. In this case, the conductive rubber portion penetrates the plurality of carcass plies in the tire width direction and connects the chafer portion and the conductive portion. The carcass layer may include an inner liner attached to the inner surface of the carcass ply.

The configuration of the tread portion is not particularly limited if the tread portion can allow static electricity to flow from the conductive portion extending to the tread portion to the tread surface portion.

The tire of the above-described embodiment may be used in any vehicle.

Additionally, the configurations described in the present specification can be appropriately combined within a range that does not contradict each other.

According to an aspect of the tire of the present invention, a part of the conductive rubber portion is embedded in the carcass ply. Therefore, it is possible to easily conduct electricity through the conductive rubber portion in the portion of the carcass ply in which the conductive rubber portion is embedded. Accordingly, static electricity from the vehicle can pass through the carcass ply by the conductive rubber portion even when the conductivity of the carcass ply is low. Thus, it is possible to obtain the tire having a structure in which static electricity from the vehicle can be easily released to the ground regardless of the conductivity of the carcass ply. Therefore, it is possible to preferably release static electricity of the vehicle to the ground while reducing the rolling resistance of the tire by decreasing the amount of carbon contained in the carcass rubber of the carcass ply.

The carcass ply may include a main body of which at least a part is located on the inside in a tire width direction of the bead core and a folded portion which is folded outward in the tire width direction around the bead core from the main body, and the embedded portion may include a first embedded portion embedded in the folded portion.

According to this configuration, a portion in which the conductive rubber portion is embedded in the carcass ply easily contacts the chafer portion. Accordingly, static electricity from the vehicle transmitted from the rim to the chafer portion can be easily passed through the carcass ply by the first embedded portion. Thus, static electricity from the vehicle is more preferably easily released to the ground.

The carcass ply may include a main body of which at least a part is located on the inside in a tire width direction of the bead core and a folded portion which is folded outward in the tire width direction around the bead core from the main body, and the embedded portion may include a second embedded portion embedded in the main body.

According to this configuration, a portion in which the conductive rubber portion is embedded in the carcass ply easily contacts the chafer portion. Accordingly, static electricity from the vehicle transmitted from the rim to the chafer portion can be easily passed through the carcass ply by the second embedded portion. Thus, static electricity from the vehicle is more preferably easily released to the ground.

A distance from an outer end portion of the bead core in a tire radial direction to an outer end portion of the embedded portion in the tire radial direction may be equal to or shorter than a dimension of the bead core in the tire radial direction.

According to this configuration, it is possible to decrease the volume of the conductive rubber portion.

The tire may include a conductive portion which is located between the carcass ply and the bead core and the conductive portion may be a thread-shaped member containing metal and may be connected to the conductive rubber portion.

According to this configuration, static electricity transmitted to the conductive rubber portion can be transmitted to the conductive portion. Accordingly, even when the volume resistivity of the carcass rubber in the carcass ply is relatively large and the conductivity of the carcass ply is low, static electricity from the vehicle transmitted from the rim to the chafer portion can be transmitted to the conductive portion through the conductive rubber portion. Accordingly, static electricity from the vehicle can be sent to the tread portion through the conductive portion and the static electricity can be released from the tread surface portion to the ground at the tread portion. Thus, static electricity from the vehicle is more preferably easily released to the ground.

A volume resistivity of the conductive portion may be smaller than a volume resistivity of the conductive rubber portion.

According to this configuration, the volume resistivity of the conductive portion is preferably easily decreased. Accordingly, static electricity can more preferably flow to the conductive portion that makes a relatively long conductive path CP from the bead portion to the tread portion. Thus, static electricity from the vehicle is more easily released to the ground.

The carcass ply may include a carcass rubber and a plurality of ply cords which are embedded in the carcass rubber and are arranged at intervals in a tire circumferential direction, and the embedded portion may be located between the ply cords.

According to this configuration, a part of the conductive rubber portion is easily disposed to be embedded in the carcass ply. Further, the embedded portion is easily disposed to penetrate the carcass ply and the conductive portion and the chafer portion are more preferably connected to each other by the conductive rubber portion.

Another aspect of the tire of the present invention includes a bead core which is provided in the bead portion, and a carcass ply which covers at least a part around the bead core, wherein the carcass ply includes a carcass rubber, wherein the carcass rubber includes a first rubber portion and a second rubber portion of which a volume resistivity is smaller than that of the first rubber portion, and wherein at least a part of the second rubber portion is located on the outside in a tire radial direction in relation to the bead core.

According to another aspect of the tire of the present invention, it is possible to obtain the tire having a structure in which static electricity from the vehicle is easily released to the ground regardless of the conductivity of the carcass ply as described above. Therefore, it is possible to preferably release static electricity of the vehicle to the ground while reducing the rolling resistance of the tire by decreasing the amount of carbon contained in the carcass rubber of the carcass ply.

Claim 1:
A tire (<NUM>) provided with a tread portion (<NUM>), a sidewall portion (<NUM>), and a bead portion (<NUM>), comprising:
a bead core (<NUM>) which is provided in the bead portion (<NUM>);
a carcass ply (<NUM>) which covers at least a part around a core axis of the bead core (<NUM>); and
a conductive rubber portion (<NUM>) which includes a through-portion (82b, 83b) corresponding to an embedded portion embedded in the carcass ply (<NUM>),
wherein at least a part of the through portion (82b, 83b) being the embedded portion is located on an outside in a tire radial direction in relation to the bead core, and
wherein a distance from an outer end portion of the bead core (<NUM>) in the tire radial direction to an outer end portion of the through-portion (82b, 83b) being the embedded portion in the tire radial direction is equal to or shorter than a dimension of the bead core (<NUM>) in the tire radial direction.