JP6413910B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire.

  The rolling resistance of tires contributes to the improvement of vehicle fuel efficiency. One of the factors of tire rolling resistance is energy loss due to repeated deformation during running. Tire energy loss is said to correlate with tire temperature. When the tire temperature rises, the rolling resistance decreases (see, for example, Patent Document 1).

JP 05-016623 A

  The technique disclosed in Patent Document 1 increases the temperature of the tire by providing heat generating means on the outer periphery of the wheel in the tire and increasing the temperature of the air inside the tire. There is room for improvement in order to increase the tire temperature efficiently.

  An object of an aspect of the present invention is to provide a pneumatic tire that can reduce rolling resistance and contribute to improvement in fuel consumption of a vehicle.

  According to an aspect of the present invention, a pneumatic tire mounted on a tire wheel, provided on the inner surface of the tire, provided on the inner surface of the tire, and a conductive member connected to a wheel electric wire supported by the tire wheel. There is provided a pneumatic tire comprising: a sheet-like heater that generates heat by electric power supplied through the wheel electric wire and the conductive member.

  According to the aspect of the present invention, since the sheet-like heater is directly provided on the tire inner surface, the rubber and the cord of the pneumatic tire are efficiently heated. By increasing the temperature of the rubber and the cord, energy loss during traveling is reduced, and rolling resistance is reduced. By reducing the rolling resistance, the fuel consumption of a vehicle equipped with a pneumatic tire is improved. Further, when the pneumatic tire travels, centrifugal force or repeated bending acts on the conductive member and the heater. Since the conductive member and the heater are directly provided on the inner surface of the tire, the conductive member and the heater continue to be supported on the inner surface of the tire even when the pneumatic tire is running. Therefore, the durability of the conductive member and the heater is improved.

  In the aspect of the present invention, the conductive member may include a conductive paint applied to the inner surface of the tire. By using a conductive paint as the conductive member, even when centrifugal force or repeated bending acts on the conductive member during the running of a pneumatic tire, the deterioration of the conductive member is suppressed and the durability of the conductive member is improved. .

  In the aspect of the present invention, the conductive member may include a conductive yarn bonded to the inner surface of the tire. Even when conductive yarn is used as the conductive member, deterioration of the conductive member is suppressed, and durability of the conductive member is improved.

  An aspect of the present invention may include a carcass and a belt provided on the outer side in the tire radial direction than the carcass, and the heater may be provided on the inner side in the tire width direction from the end of the belt. Accordingly, the tread rubber in the tread portion, the belt cord, and the carcass cord are efficiently heated.

  In the aspect of the present invention, at least a part of the heater may be provided at a center portion of the tire inner surface in the tire width direction. At least the center part in the tire width direction is heated, and the tread part is uniformly heated by spreading the heat in the tire width direction.

  In the aspect of the present invention, the heater may extend in the tire circumferential direction. By providing the heater so as to extend in the tire circumferential direction, the tread portion is uniformly heated in the tire circumferential direction, and the rolling resistance is effectively reduced.

  In an aspect of the present invention, a tread portion having a circumferential groove extending in the tire circumferential direction and a rib having a ground contact surface and provided between the circumferential grooves, the heater includes the rib and the tire width direction. Provided in the same range, and may be provided in different ranges in the circumferential groove and the tire width direction. The portion where the circumferential groove is provided is a portion where the thickness of the rubber is thin and bending deformation is large. If a heater is provided at a portion corresponding to the circumferential groove, the heater may be greatly bent and deteriorated, or the durability of adhesion between the heater and the tire inner surface may be reduced, and the heater may be peeled off from the tire inner surface. The portion of the tread portion that requires heating to reduce rolling resistance is exclusively a rib having a ground plane. Therefore, no heater is provided in the portion corresponding to the circumferential groove, and the heater is provided only in the portion corresponding to the rib, thereby suppressing the decrease in the durability of the adhesion between the heater and the tire inner surface, while rolling in the tread portion. Only a portion necessary for reducing the resistance can be efficiently heated.

  In an aspect of the present invention, a tread portion having a groove and a grounding surface provided between the grooves may be provided, and the heater may be patterned in accordance with the shape of the grounding surface. The portion where the groove is provided is a portion where bending deformation increases. A portion of the tread portion that needs to be heated to reduce rolling resistance is a portion that has a ground contact surface. Therefore, by patterning the heater according to the shape of the ground contact surface, only the portion of the tread that is necessary to reduce rolling resistance is efficiently controlled while suppressing the decrease in the durability of adhesion between the heater and the tire inner surface. It can be heated well.

  In an aspect of the present invention, the heater includes a linear heating element that is formed of a conductive material and generates heat due to electric power supplied from the conductive member, and a sheet member that is formed of a non-conductive material and covers the heating element. You may have. Since the heater is unitized by the heating element and the sheet member, the operation of providing the heater on the tire inner surface is smoothly performed. Moreover, the occurrence of a short circuit is suppressed by covering the heating element with a sheet member made of a non-conductive material.

  In the aspect of the present invention, the heating element may include a conductive fiber. The use of conductive fibers as the heating elements provides a lightweight and thin heater. The light and thin heater exhibits high adhesion durability with the tire inner surface. In addition, since conductive fibers such as carbon fibers have a high tensile strength, thin conductive fibers can be used. Therefore, a plurality of conductive fibers can be arranged uniformly at narrow intervals, adhesion durability is further improved, and the tread portion is heated uniformly.

  In the aspect of the present invention, the heater includes a first electrode line extending in a tire circumferential direction, and a second electrode line provided in a position different from the first electrode line in the tire width direction and extending in the tire circumferential direction. One end of the heating element is connected to the first electrode line, the other end of the heating element is connected to the second electrode line, and the heating element is connected to the first electrode line. And it is connected with the said electrically-conductive member through the said 2nd electrode wire, and two or more may be provided in the tire circumferential direction between the said 1st electrode wire and the said 2nd electrode wire. Thereby, electric power is supplied to the heating element via the first electrode line and the second electrode line, and the tread portion is heated uniformly.

  In the aspect of the present invention, at least a part of the intermediate portion of the heat generating element between the one end portion and the other end portion may be bent. When the tread rubber extends in the tire width direction by arranging a part of the heating element to be bent, the bent part of the heating element can be extended together with the tread rubber. Is suppressed.

  In the aspect of the present invention, each of the first electrode line and the second electrode line may have a bent portion. When the tread rubber extends in the tire circumferential direction by arranging a part of the first electrode line and the second electrode line to be bent, the bent part of the first electrode line and the second electrode line is the tread. Since it can extend together with the rubber, breakage of the first electrode line and the second electrode line is suppressed.

  In the aspect of the present invention, the heat generating element may be in contact with the tire inner surface, and the sheet member may be bonded to the tire inner surface in a state of covering the heat generating element. When the heat generating element comes into contact with the tire facing surface, the heat of the heat generating element is directly transmitted to the tire inner surface, so that the rubber and the cord in the tread portion are efficiently heated.

  In the aspect of the present invention, the heating element may include an adhesive layer embedded in the sheet member and provided between the sheet member and the tire inner surface. Since the heating element is embedded in the sheet member, the heater can be handled smoothly. The non-conductive material sheet member exhibits high adhesion durability with the tire inner surface through the adhesive layer.

  In the aspect of the present invention, a heat conductive member that is provided between the heater and the tire inner surface, has a higher thermal conductivity than the sheet member, and has a larger outer shape than the sheet member may be provided. The heat generated by the heat generating element is supplied to a wide range of the tread portion by the heat conducting member. Thereby, the tread portion is efficiently heated in a wide range.

  In the aspect of the present invention, a heat insulating member that is provided so as to cover the heater provided on the inner surface of the tire and has a lower thermal conductivity than the sheet member may be provided. By covering the heater provided on the tire inner surface with the heat insulating member, it is possible to suppress the heat generated by the heater from being radiated to the tire interior space filled with air. Thereby, a tread part is heated efficiently.

  The aspect of this invention WHEREIN: You may provide the cover member which adhere | attaches the said tire inner surface in the state which covered the said heater, and fixes the said heater to the said tire inner surface. By using the cover member, the heater is smoothly fixed to the tire inner surface. Further, by using a cover member having various functions such as an insulating function and a waterproof function, the heater is sufficiently protected by the cover member.

  In the aspect of the present invention, a temperature sensor provided on the inner surface of the tire may be provided, and heat generation of the heater may be controlled based on a detection result of the temperature sensor. The tread portion is adjusted to the target temperature by controlling the heat generation of the heater based on the detection result of the temperature sensor.

  According to the aspect of the present invention, there is provided a pneumatic tire that can reduce rolling resistance and contribute to improvement of vehicle fuel efficiency.

FIG. 1 is a cross-sectional view illustrating an example of a pneumatic tire according to the first embodiment. FIG. 2 is a diagram illustrating an example of a tread portion of the pneumatic tire according to the first embodiment. FIG. 3 is a cross-sectional view showing an example of a pneumatic tire mounted on the tire wheel according to the first embodiment. FIG. 4 is an enlarged view of a part of FIG. FIG. 5 is a cutaway perspective view of an example of the pneumatic tire according to the first embodiment. FIG. 6 is a perspective view schematically showing an example of the heater according to the first embodiment. FIG. 7 is an enlarged plan view of a part of FIG. FIG. 8 is a diagram schematically illustrating an example of a connection structure between the heater and the tire inner surface according to the first embodiment. FIG. 9 is a perspective view schematically showing a modification of the heater according to the first embodiment. FIG. 10 is a perspective view in which a modified example of the pneumatic tire according to the first embodiment is broken. FIG. 11 is a plan view schematically showing a part of the heater according to the second embodiment. FIG. 12 is a plan view schematically showing a part of the heater according to the second embodiment. FIG. 13 is a plan view schematically showing a part of the heater according to the second embodiment. FIG. 14 is a plan view schematically showing a part of the heater according to the second embodiment. FIG. 15 is a diagram illustrating an example of a connection structure between the heater and the tire inner surface according to the third embodiment. FIG. 16 is a diagram schematically illustrating an example of a connection structure between the heater and the tire inner surface according to the third embodiment. FIG. 17 is a diagram schematically illustrating an example of a connection structure between the heater and the tire inner surface according to the third embodiment. FIG. 18 is a diagram schematically illustrating an example of a connection structure between the heater and the tire inner surface according to the third embodiment. FIG. 19 is a diagram schematically illustrating an example of a heater according to the fourth embodiment. FIG. 20 is a cutaway perspective view of an example of a pneumatic tire according to the fifth embodiment. FIG. 21 is a cutaway perspective view of an example of a pneumatic tire according to the fifth embodiment. FIG. 22 is a cutaway perspective view of an example of a pneumatic tire according to the fifth embodiment. FIG. 23 is a cutaway perspective view of an example of a pneumatic tire according to the fifth embodiment. FIG. 24 is a perspective view in which an example of a pneumatic tire according to the fifth embodiment is broken. FIG. 25 is a diagram schematically illustrating an example of a tread portion according to the sixth embodiment. FIG. 26 is a diagram schematically illustrating an example of the tire inner surface according to the sixth embodiment. FIG. 27 is a diagram schematically illustrating an example of a tire inner surface according to the seventh embodiment.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings, but the present invention is not limited thereto. The components of the embodiments described below can be combined as appropriate. Some components may not be used.

<First Embodiment>
A first embodiment will be described. FIG. 1 is an enlarged cross-sectional view of a part of a tire 1 according to this embodiment. The tire 1 is a pneumatic tire. The tire 1 is rotatable about the central axis AX while being attached to the tire wheel 100. FIG. 1 shows a meridional section passing through the central axis AX of the tire 1.

  In the following description, the positional relationship of each part will be described using the terms tire circumferential direction, tire radial direction, and tire width direction. The tire 1 rotates around the central axis AX and is arranged around the central axis AX. The tire circumferential direction is a rotation direction around the center axis AX of the tire 1. The tire radial direction is a radial direction with respect to the central axis AX of the tire 1. The tire width direction is a direction parallel to the central axis AX of the tire 1.

  A center axis AX of the tire 1 is orthogonal to the equator plane CL of the tire 1. The equatorial plane CL is a plane that passes through the center of the tire 1 in the tire width direction.

  The inner side in the tire radial direction is the side close to the central axis AX. The outer side in the tire radial direction is the side far from the central axis AX. The inner side in the tire width direction is the side closer to the equator plane CL. The outer side in the tire width direction is the side far from the equator plane CL.

  The tire 1 includes a carcass 2, a belt 3, a belt cover 4, a bead portion 5, a tread rubber 6, a side rubber 7, an inner liner 8, a conductive member 30 provided on the tire inner surface 13, and a tire inner surface. 13 is provided with a sheet-like heater 50 provided at 13.

  Each of the carcass 2, the belt 3, and the belt cover 4 includes a cord of organic fiber, synthetic resin fiber, or metal fiber. Layers including cords such as the carcass 2, the belt 3, and the belt cover 4 are collectively referred to as a cord layer. The cord layer is embedded in the tread rubber 6.

  The tire 1 includes a tread portion 10 having a ground contact surface 14 that contacts a road surface, and side portions 9 disposed on both sides of the tread portion 10 in the tire width direction. The tread portion 10 includes a tread rubber 6 and a cord layer embedded in the tread rubber 6. The side portion 9 includes a side rubber 8 and a carcass 2.

  The carcass 2 is a strength member that forms the skeleton of the tire 1, and functions as a pressure vessel when the internal space 15 of the tire 1 is filled with air. The carcass 2 is supported by the bead portion 5. The bead portions 5 are disposed on both sides of the carcass portion 2 in the tire width direction. The carcass 2 is folded back at the bead portion 5. The carcass 2 includes a carcass cord of organic fiber, synthetic resin fiber, or metal fiber, and rubber covering the carcass cord. The carcass cord may be made of polyester, nylon, aramid, or rayon.

  The belt 3 is a strength member that holds the shape of the tire 1, and is provided outside the carcass 2 in the tire radial direction. The belt 3 includes a belt cord made of organic fiber, synthetic resin fiber, or metal fiber, and rubber covering the belt cord. The belt 3 includes a first belt ply 3A and a second belt ply 3B. The first belt ply 3A and the second belt ply 3B are laminated so that the belt cord of the first belt ply 3A and the belt cord of the second belt ply 3B intersect. The belt cord may be made of steel.

  The belt cover 4 is a strength member that protects and reinforces the belt 3, and is provided outside the belt 3 in the tire radial direction. The belt cover 4 includes a cover cord made of organic fiber, synthetic resin fiber, or metal fiber, and rubber that covers the cover cord. The cover cord may be made of steel.

  The bead portion 5 is a strength member that fixes both ends of the carcass 2, and fixes the tire 1 to the rim 101 of the tire wheel 100. The bead portion 5 is a bundle of steel wires or carbon steel wires.

  The tread rubber 6 protects the carcass 2. The tread rubber 6 includes a plurality of grooves 20 and a grounding surface 14 provided between the grooves 20. The ground plane 14 includes a land surface between the grooves 20 and contacts the road surface.

  The side rubber 7 protects the carcass 2. The side rubber 7 is provided on both sides of the tread rubber 6 in the tire width direction.

  The inner liner 8 is a rubber sheet attached to the inner surface of the tread rubber 6 and the inner surface of the side rubber 7. The tire inner surface 13 is the inner surface of the inner liner 8.

  The internal space 15 is formed between the tire wheel 100 and the tire 1 attached to the tire wheel 100. An internal space 15 is defined by the tire inner surface 13 and the outer peripheral surface of the tire wheel 100. The tire inner surface 13 is provided so as to face the inner space 15. The internal space 15 is filled with air having an appropriate internal pressure.

  The conductive member 30 and the heater 50 are bonded to the tire inner surface 13. The heater 50 is provided on the inner side in the tire width direction than the conductive member 30.

  The heater 50 is provided on the inner side in the tire width direction than the one end 3Ea and the other end 3Eb of the belt 3 in the tire width direction. At least a part of the heater 50 is provided at the center of the tire inner surface 13 in the tire width direction.

  FIG. 2 is a diagram illustrating an example of the tread portion 10 of the tire 1. As shown in FIG. 2, the tread portion 10 includes a groove 20 and a grounding surface 14 provided between the grooves 20. The groove 20 includes a main groove (circumferential groove) 21 extending in the tire circumferential direction, a lug groove (lateral groove) 22 extending at least partially in the tire width direction, and at least partially extending in the tire width direction. Sipe 23 to be included.

  A land portion is provided around the groove 20. The land portion is provided between the groove 20 and the groove 20 adjacent to the groove 20. The ground plane 14 is disposed on the land. The tread portion 10 has a plurality of land portions. Of the plurality of land portions, the land portion provided between the main groove 21 and the main groove 21 adjacent to the main groove 21 is referred to as a rib 16. The rib 16 has a ground contact surface 14 and extends in the tire circumferential direction.

  The main groove 21 extends in the tire circumferential direction. The main groove 21 has a slip sign (tread wear indicator) inside. The slip sign indicates the end of wear. The main groove 21 has a width of 4.0 [mm] or more and a depth of 5.0 [mm] or more. In the example shown in FIG. 2, the main groove 21 includes four main grooves 21A, 21B, 21C, and 21D, and the rib 16 includes three ribs 16A, 16B, and 16C. The rib 16B including the tire equatorial plane CL is called a center rib 16B. The ribs 16A and 16C on both sides of the center rib 16B in the tire width direction are called second ribs 16A and 16C.

  At least a part of the lug groove 22 extends in the tire width direction. The lug groove 22 has a width of 1.5 [mm] or more and a depth of 4.0 [mm] or more. The lug groove 22 may partially have a depth of less than 4.0 [mm].

  At least a part of the sipe 23 extends in the tire width direction. The sipe 23 is formed on the land portion of the tire 1. In the present embodiment, the sipe 23 has a width of less than 1.5 [mm].

  The tread portion 10 includes a center portion 11 including a tire equatorial plane CL and shoulder portions 12 provided on both sides of the center portion 11 in the tire width direction. The center portion 11 of the tread portion 10 includes a tire equatorial plane CL. The shoulder portion 12 of the tread portion 10 is provided on both sides of the center portion 11 in the tire width direction. In the present embodiment, the main groove 21 is provided in the center portion 11. The lug groove 22 is provided in each of the center portion 11 and the shoulder portion 12. The sipe 23 is provided on the shoulder portion 12.

  In the present embodiment, of the shoulder portions 12 provided on both sides of the center portion 11 in the tire width direction, one shoulder portion 12A is a ground contact width of the tread portion 10 from the tire equatorial plane CL toward one side in the tire width direction. This is a region on one side in the tire width direction from the first main groove 21 existing at a distance of 15% to 40%. One shoulder portion 12A includes one grounding end.

  The other shoulder portion 12B is from the second main groove 21 present at a distance of 15 [%] to 40 [%] of the contact width of the tread portion 10 from the tire equatorial plane CL toward the other side in the tire width direction. Also refers to the region on the other side in the tire width direction. The other shoulder portion 12B includes the other ground contact end.

  The center portion 11 refers to a region between the first main groove 21 and the second main groove 21.

  In the example shown in FIG. 2, the main groove 21A is the first main groove 21, and one shoulder portion 12A is defined with the main groove 21A as a boundary. The main groove 21D is the second main groove 21, and the other shoulder portion 12B is defined with the main groove 21D as a boundary.

  The tread portion 10 is in contact with the grounded end when the tire 1 is assembled on a regular rim, filled with regular internal pressure, placed vertically on a flat surface, and the tread portion 10 is grounded in a loaded state with a regular load applied. This refers to the end of the portion in the tire width direction.

  The “regular rim” is a rim that is defined for each tire 1 in the standard system including the standard on which the tire 1 is based, and is a standard rim for JATMA, “Design Rim” for TRA, and ETRTO. If there is, it is “Measuring Rim”. However, when the tire 1 is a tire mounted on a new vehicle, a genuine wheel on which the tire 1 is assembled is used.

  The “normal internal pressure” is the air pressure determined for each tire 1 in the standard system including the standard on which the tire 1 is based. The maximum air pressure is JATMA, and the table “TIRE LOAD LIMITS AT VARIOUS” is TRA. In the case of ETRTO, the maximum value described in “COLD INFORATION PRESSURES” is “INFLATION PRESSURE”. However, when the tire 1 is a tire mounted on a new vehicle, the air pressure displayed on the vehicle is used.

  The “regular load” is a load determined by the standard for each tire 1 in the standard system including the standard on which the tire 1 is based. The maximum load capacity is set for JATMA, and the table “TIRE LOAD LIMITS AT” is set for TRA. If it is ETRTO, the maximum value described in “VARIOUS COLD INFRATION PRESURES” is “LOAD CAPACITY”. However, when the tire 1 is a passenger car, the load is equivalent to 88% of the load. When the tire 1 is a tire mounted on a new vehicle, the wheel load is obtained by dividing the longitudinal axle weight described in the vehicle verification of the vehicle by the number of tires.

  FIG. 3 is a cross-sectional view showing the tire 1 mounted on the tire wheel 100. FIG. 4 is an enlarged view of a part of FIG. As shown in FIGS. 3 and 4, the wheel electric wire 102 is supported on the tire wheel 100. The wheel electric wire 102 is disposed on the spoke 103 of the tire wheel 100. The conductive member 30 of the tire 1 is connected to the wheel electric wire 102. Electric power (current) is supplied to the wheel electric wire 102 from a power source provided in the vehicle. The electric power supplied to the wheel electric wire 102 is supplied to the conductive member 30. The electric power supplied to the conductive member 30 is supplied to the heater 50. The heater 50 generates heat by electric power supplied via the wheel electric wire 102 and the conductive member 30.

  As shown in FIG. 3, the vehicle is provided between the knuckle 104 of the suspension device, the hub 106 supported by the axle 105, and the knuckle 104 and the hub 106, and the axle 105 and the hub 106 are centered on the central axis AX. And a bearing device 107 that rotatably supports the motor. The spokes 103 of the tire wheel 100 are fixed to the hub 106. A rotary connector such as a slip ring is provided on the hub 106. The electric power output from the power source provided in the vehicle is supplied to the wheel electric wire 102 of the tire wheel 100 through the wiring provided in the knuckle 104 and the rotary connector (not shown) provided in the hub 106. The

  FIG. 5 is a perspective view in which the tire 1 according to the present embodiment is broken, and is a view showing the tire inner surface 13. As shown in FIG. 5, the heater 50 has a sheet shape and is fixed to the tire inner surface 13.

  The heater 50 having a sheet shape means that the size of the heater 50 in the tire radial direction is smaller than the size of the heater 50 in the tire width direction and the size of the heater 50 in the tire circumferential direction. The dimension of the heater 50 in the tire radial direction means the thickness of the heater 50. The thickness of the heater 50 is preferably 0.2 [mm] or more and 1.0 [mm] or less.

  The heater 50 extends in the tire circumferential direction. In the present embodiment, the heater 50 is an annular member that is continuously provided in the tire circumferential direction.

  In the present embodiment, the size of the heater 50 in the tire width direction is equal to the size of the center portion 11 of the tread portion 10 in the tire width direction. The heater 5 is provided in the same range as the center portion 11 and the tire width direction. That is, the heater 50 is provided in a region corresponding to the center portion 11 (directly below the center portion 11).

The conductive member 30 is linear and is fixed to the tire inner surface 13. The conductive member 30 is a conductive yarn bonded to the tire inner surface 13. The conductive member 30 is, for example, a thread cord obtained by twisting a plurality of conductive fibers such as metal fibers. The linear resistivity of the conductive member 30 is preferably less than 1 × 10 ⁷ [Ω / cm]. The total fineness of the conductive member 30 is preferably 20 [dtex] or more and 5000 [dtex] or less. When the total fineness of the conductive member 30 is smaller than 20 [dtex], there is a high possibility that the conductive member 30 will be cut when the conductive member 30 is manufactured or when the conductive member 30 is bonded to the tire inner surface 13. This is because, when the total fineness of the member 30 is larger than 5000 [dtex], there is a high possibility that the conductive member 30 is cut while the tire 1 is traveling. Moreover, it is preferable that the elongation rate of the electrically-conductive member 30 is 1.0 [%] or more and 70.0 [%] or less. The elongation is measured in accordance with JIS L 1017 Chemical Fiber Tire Cord Test Method 8.5 Tensile Strength and Elongation.

  FIG. 6 is a perspective view schematically showing an example of the heater 50 according to the present embodiment. FIG. 7 is an enlarged plan view of a part of the heater 50 shown in FIG. 6, and corresponds to a portion A in FIG. As shown in FIGS. 6 and 7, the heater 50 is formed of a conductive material, and is formed of a linear heating element 53 that generates heat by power supplied from the conductive member 30 and a non-conductive material. And a sheet member 54 covering 53.

  The linear heating element 53 is a conductive fiber. In the present embodiment, the heating element 53 is a carbon fiber having conductivity. The conductive fiber may be a single fiber or a bundle of a plurality of fibers.

  The sheet member 54 has sufficiently lower conductivity than the heat generating element 53. The sheet member 54 is formed of an insulating material such as rubber. In the present embodiment, the sheet member 54 is silicon rubber. The sheet member 54 may be made of synthetic resin or non-woven fabric.

  The heating element 53 is embedded in the sheet member 54. In the present embodiment, the surface of the heater 50 is the surface of the sheet member 54. The heater 50 may be formed by sandwiching the heat generating element 53 between the two sheet members 54.

  The heater 50 includes a first electrode line 51 extending in the tire circumferential direction, and a second electrode line 52 provided at a position different from the first electrode line 51 in the tire width direction and extending in the tire circumferential direction. . The first electrode wire 51 is an annular member provided continuously in the tire circumferential direction. The second electrode line 52 is also an annular member provided continuously in the tire circumferential direction.

  The sheet member 54 covers not only the heating element 53 but also the first electrode line 51 and the second electrode line 52. The first electrode line 51 and the second electrode line 52 may be embedded in the sheet member 54 or may be sandwiched between the two sheet members 54.

  In the present embodiment, the first electrode line 51 and the second electrode line 52 are arranged in parallel. The heating element 53 is disposed between the first electrode line 51 and the second electrode line 52 so as to be orthogonal to the first electrode line 51 and the second electrode line 52. One end of the heating element 53 is connected to the first electrode line 51. The other end of the heating element 53 is connected to the second electrode line 52. A plurality of heating elements 53 are provided in the tire circumferential direction between the first electrode line 51 and the second electrode line 52. The plurality of heating elements 53 are arranged in parallel.

  In the present embodiment, the conductive member 30 includes a first conductive member 30 </ b> A connected to the first electrode line 51 and a second conductive member 30 </ b> B connected to the second electrode line 52.

  The heating element 53 is connected to the conductive member 30 (30A, 30B) via the first electrode line 51 and the second electrode line 52. The heating element 53 generates heat by the electric power supplied from the first conductive member 30A and the second conductive member 30B via the first electrode line 51 and the second electrode line 52.

Similar to the conductive member 30, the first electrode line 51 and the second electrode line 52 may be conductive yarns that are thread-like cords obtained by twisting a plurality of conductive fibers such as metal fibers. The line resistivity of the first electrode line 51 and the second electrode line 52 is preferably less than 1 × 10 ⁸ [Ω / cm], and the total fineness is 20 [dtex] or more and 5000 [dtex] or less. The elongation is preferably 1.0 [%] or more and 70.0 [%] or less.

  FIG. 8 is a diagram schematically illustrating an example of a connection structure between the heater 50 and the tire inner surface 13 of the inner liner 8 according to the present embodiment. The heater 50 is disposed so as to contact the tire inner surface 13. In the present embodiment, a cover member 55 that covers the heater 50 that contacts the tire inner surface 13 is provided. The cover member 55 is a sheet-like member. The cover member 55 has an insulating function and a waterproof function. The cover member 55 may be made of rubber or synthetic resin.

  The dimension of the cover member 55 in the tire width direction is larger than the dimension of the heater 50 in the tire width direction. A part of the cover member 55 is in contact with the tire inner surface 13. A part of the cover member 55 and the tire inner surface 13 are bonded through an adhesive layer containing an adhesive. The cover member 55 adheres to the tire inner surface 13 while covering the heater 50 that contacts the tire inner surface 13, and fixes the heater 50 to the tire inner surface 13.

  Next, the operation of the heater 50 according to this embodiment will be described. In winter or early morning, the temperature of the tire 1 before running is lowered. After the engine of the vehicle is started, power is supplied from the power source to the heater 50. Thereby, the heat generating element 53 generates heat, and the inner liner 8 having the tire inner surface 13 is heated. When the tire inner surface 13 is heated, the carcass 2, the belt 3, the belt cover 4, and the tread rubber 6 of the tread portion 10 are heated. In the present embodiment, since the heater 50 is provided directly below the tread portion 10, the tread portion 10 is efficiently heated.

  In the present embodiment, when the temperature of the tire 1 or the temperature of the outside air is 5 [° C.] or less, the heater 50 is activated and the tire 1 is heated by the heater 50. The heater 50 may operate when the temperature of the tire 1 or the outside air is 0 [° C.] or less, or may operate when the temperature is −5 [° C.] or less. A temperature sensor capable of detecting the temperature of the tire 1 or the temperature of the outside air may be provided, and the operation of the heater 50 may be started based on the detection result of the temperature sensor.

  As described above, according to the present embodiment, since the sheet-like heater 50 is provided directly on the tire inner surface 13, the tread rubber 6 of the tire 1 and the cord of the cord layer are efficiently heated. As the temperature of the tread rubber 6 of the tire 1 and the cord of the cord layer increases, the rolling resistance of the tire 1 is reduced. Therefore, the fuel efficiency of the vehicle equipped with the tire 1 is improved.

  Further, when the temperature of the tire 1 or the temperature of the outside air is 5 [° C.] or less, preferably 0 [° C.] or less, more preferably −5 [° C.] or less, the heater 50 is operated, so that the low temperature tire 1 is obtained. It is warmed and the rolling resistance of the tire 1 is reduced.

  Further, during traveling of the tire 1, centrifugal force or repeated bending acts on the conductive member 30 and the heater 50. Since the conductive member 30 and the heater 50 are directly provided on the tire inner surface 13, the conductive member 30 and the heater 50 are continuously supported by the tire inner surface 13 even when the tire 1 is traveling. Therefore, deterioration of the conductive member 30 and the heater 50 is suppressed, and durability is improved.

  In the present embodiment, a conductive yarn is used as the conductive member 30. Thereby, even if a centrifugal force or repeated bending acts on the conductive member 30 during traveling of the tire 1, deterioration of the conductive member 30 is suppressed, and durability is improved.

  In the present embodiment, the heater 50 is provided on the inner side in the tire width direction than the end portion 3Ea and the end portion 3Eb of the belt 3. Thereby, the tread rubber 6 of the tread portion 10, the belt cord of the belt 3, and the carcass cord of the carcass 2 are efficiently heated.

  In the present embodiment, at least a part of the heater 50 is provided at the center of the tire inner surface 13 in the tire width direction. Thereby, after the center part of the tire width direction is heated among the tread parts 10, heat spreads in the tire width direction, and the tread part 10 is heated uniformly.

  In the present embodiment, the heater 50 extends in the tire circumferential direction. Thereby, since the tread part 10 is heated uniformly in the tire circumferential direction, the rolling resistance is effectively reduced.

  In the present embodiment, the heater 50 includes a linear heating element 53 formed of a conductive material and a sheet member 54 formed of a nonconductive material that covers the heating element 53. Since the heater 50 is unitized by the heating element 53 and the sheet member 54, the operation of bonding the heater 50 to the tire inner surface 13 is smoothly performed. In addition, the occurrence of a short circuit is suppressed by covering the heat generating element 53 with the sheet member 54 of a non-conductive material.

  In the present embodiment, the heating element 53 is a conductive fiber such as carbon fiber. By using a conductive fiber as the heating element 53, a lightweight and thin heater 50 is provided. The provision of the lightweight and thin heater 50 improves the durability of bonding between the heater 50 and the tire inner surface 13. In addition, since carbon fibers have high tensile strength, thin carbon fibers can be used, and a plurality of carbon fibers can be arranged uniformly at narrow intervals. Thereby, the adhesion durability between the heater 50 and the tire inner surface 13 is further improved, and the tread portion 10 is heated uniformly.

  In the present embodiment, the heater 50 includes a first electrode line 51 and a second electrode line 52 extending in the tire circumferential direction, and the heating element 53 includes the first electrode line 51 and the second electrode line 52. Are provided in the tire circumferential direction. Thereby, electric power can be smoothly supplied to the plurality of heating elements 53 via the first electrode line 51 and the second electrode line 52, and the tread portion 10 can be heated uniformly.

  In the present embodiment, the heater 50 is fixed to the tire inner surface 53 by the cover member 55 in a state of being covered by the cover member 55. By using the cover member 55 having an adhesive function, the heater 50 is smoothly fixed to the tire inner surface 13. Further, since the cover member 55 has various functions such as an insulating function and a waterproof function, the heater 50 is sufficiently protected by the cover member 55.

  When the tire 1 is heated by the heater 50 and the temperature of the tire 1 reaches a specified temperature (for example, 10 [° C.]), the heating of the tire 1 by the heater 50 may be terminated. Alternatively, when the temperature of the outside air reaches the specified temperature, the heating of the tire 1 by the heater 50 may be terminated. A temperature sensor capable of detecting the temperature of the tire 1 or the temperature of the outside air may be provided, and the operation of the heater 50 may be terminated based on the detection result of the temperature sensor.

(Modification of conductive member)
In the present embodiment, the conductive member 30 is a conductive yarn. The conductive member 30 may be a conductive paint applied to the tire inner surface 13. Even when a conductive paint is used as the conductive member 30, even if centrifugal force or repeated bending acts on the conductive member 30 during running of the tire 1, deterioration of the conductive member 30 is suppressed and durability is improved. The same applies to the following embodiments.

(Modification of heater)
In the present embodiment, the heater 50 is annular. As shown in FIG. 9, the heater 50 may not be annular. That is, there may be an interval portion 50N of the heater 50 where the heater 50 is not provided in the tire circumferential direction. The angle of the spacing portion 50N in the tire circumferential direction is preferably 8 [°] or less. This is because if the angle of the spacing portion 50N is larger than 8 [°], uneven wear due to deformation may occur in the tread portion 10.

  Further, when the heater 50 is not annular, as shown in FIG. 10, the inner liner 8 or the splice portion 60 of the carcass 2 may be disposed in the interval portion 50N of the heater 50. There is a possibility that a part of the tire inner surface 13 has a convex shape in the splice portion 60. By disposing the heater 50 so as to avoid the splice portion 60, the durability of bonding between the heater 50 and the tire inner surface 13 is improved.

Second Embodiment
A second embodiment will be described. In the present embodiment, a modified example of the heater 50 having the first electrode line 51, the second electrode line 52, and the heating element 53 will be described.

  11 and 12 are diagrams showing a modification of the heat generating element 53. The heat generating element 53 has one end connected to the first electrode line 51, the other end connected to the second electrode line 52, and an intermediate part between the one end and the other end. At least a part of the intermediate portion of the heating element 53 is bent. In the example shown in FIG. 11, the heat generating element 53 has a bent portion 56 that is provided at the center in the tire width direction and protrudes in the tire circumferential direction. The bent portions 56 of the plurality of heating elements 53 are bent in the same direction in the tire circumferential direction. Further, the positions of the apexes of the bent portions 56 of the plurality of heating elements 53 in the tire width direction are the same. In other words, the shape of the plurality of heating elements 53 is the same (congruent).

  In the example shown in FIG. 12, the heating element 53 includes a first bent portion 56A that protrudes in one direction with respect to the tire circumferential direction and a second bent portion 56B that protrudes in the other direction with respect to the tire circumferential direction. The positions of the first protrusion 56A and the second protrusion 56B in the tire width direction are different, and the protrusion direction of the first protrusion 56A and the protrusion direction of the second protrusion 56B are opposite directions. The plurality of heating elements 53 have the same shape.

  Thus, when at least a part of the heat generating element 53 is bent, when the tread rubber 6 and the inner liner 8 extend in the tire width direction, the bent part of the heat generating element 53 becomes the tread rubber 6 and the inner liner 8. It can extend in the tire width direction together with the liner 8. Therefore, breakage of the heating element 53 is suppressed. Further, the sheet member 54 is formed of a nonconductive material such as elastic rubber, so that the heater 50 can sufficiently follow the elongation of the tread rubber 6 and the inner liner 8 in the tire width direction. .

  FIG. 13 and FIG. 14 are diagrams showing modifications of the first electrode line 51 and the second electrode line 52. In the example shown in FIG. 13, each of the first electrode line 51 and the second electrode line 52 has a bent portion 57. The bent portion 57 includes a first bent portion 57A that protrudes outward in the tire width direction with respect to the center of the heater 50 in the tire width direction, and a second bent portion 57B that protrudes inward in the tire width direction. The first bent portions 57A and the second bent portions 57B are provided alternately in the tire circumferential direction. The pitch (interval) of the first bent portions 57A in the tire circumferential direction is equal to the pitch of the second bent portions 57B in the tire circumferential direction.

  In the example shown in FIG. 14, each of the first electrode line 51 and the second electrode line 52 has a straight part 58 extending in the tire circumferential direction and a bent part 59 provided at regular intervals in the tire circumferential direction. The bent portion 59 is bent so as to protrude inward in the tire width direction with respect to the center of the heater 50 in the tire width direction.

  Note that the thickness of the electrode line of the bent portion 59 may be the same as the thickness of the electrode line of the straight portion 58 or may be smaller than the thickness of the electrode line of the straight portion 58.

  Thus, when at least a part of the first electrode line 51 and the second electrode line 52 is bent, when the tread rubber 6 and the inner liner 8 extend in the tire circumferential direction, the first electrode line 51 and the second electrode line 51 The bent portion of the two-electrode line 52 can extend in the tire circumferential direction together with the tread rubber 6 and the inner liner 8. Therefore, the breakage of the first electrode line 51 and the second electrode line 52 is suppressed. Further, by forming the sheet member 54 from a non-conductive material such as elastic rubber, the heater 50 can sufficiently follow the elongation of the tread rubber 6 and the inner liner 8 in the tire circumferential direction. .

<Third Embodiment>
A third embodiment will be described. In the present embodiment, a modified example of the connection structure for connecting the heater 50 to the tire inner surface 13 of the inner liner 8 will be described.

  FIG. 15 is a perspective view schematically showing a connection structure between the heater 50 and the tire inner surface 13 according to the present embodiment. The heater 50 includes a sheet member 54, a first electrode line 51, a second electrode line 52, and a heating element 53 embedded in the sheet member 54. In the example shown in FIG. 15, the cover member (55) as described in the above embodiment is not provided, and the heater 50 is connected via the adhesive layer 61 provided between the sheet member 54 and the tire inner surface 13. The tire inner surface 13 is connected.

  When the sheet member 54 has an insulating function, a waterproof function, and a weather resistance function, the heater 50 may not be protected by the cover member (55).

  For example, the vulcanization process is performed in a state where a resin layer such as a nylon resin layer that is easily vulcanized and bonded to the tire inner surface 13 (rubber) is disposed as the adhesive layer 61 between the seat member 54 and the tire inner surface 13. As a result, the heater 50 and the tire inner surface 13 of the tire 1 may be vulcanized and bonded.

  Note that the adhesive layer 61 may not be provided. A sheet member 54 in which the first electrode line 51, the second electrode line 52, and the heating element 53 are embedded is formed of a synthetic resin such as a nylon resin that is easily vulcanized and bonded to the tire inner surface 13 (rubber). The heater 50 and the tire inner surface 13 of the tire 1 may be vulcanized and bonded by performing the vulcanization process in a state where the heater 50 having the sheet member 54 is in contact with the tire inner surface of the green tire (raw tire). . Thereby, the number of members to be used is suppressed.

  FIG. 16 shows an example in which the first electrode line 51, the second electrode line 52, and the heating element 53 are held by a sheet member 54A having an adhesive function. When the sheet member 54A is a material having an adhesive function and an insulating function, the heating element 53 is in contact with the tire inner surface 13, and the first electrode line 51, the second electrode line 52, and the heating element 53 are covered with the sheet member 54A. Thus, the sheet member 54 </ b> A may be bonded to the tire inner surface 13.

  The sheet member 54A is formed of a resin layer such as a nylon resin layer that is easily vulcanized and bonded to the tire inner surface 13 (rubber). The first electrode line 51, the second electrode line 52, and the heating element 53 are disposed between the seat member 54A and the tire inner surface of the green tire, and the sheet member 54A is in contact with the tire inner surface of the green tire. By performing the vulcanization process, the first electrode wire 51, the second electrode wire 52, the heating element 53, and the sheet member 54A are vulcanized and fixed to the tire inner surface 13.

  In the example shown in FIG. 16, the heat generating element 53 is in direct contact with the tire inner surface 13, so that the heat of the heat generating element 53 is directly transmitted to the tire inner surface 13. Therefore, the tread rubber 6 of the tread portion 10 and the cord of the cord layer are efficiently heated.

  The material that forms the sheet member 54 (54A) that is easily vulcanized and bonded may not be a synthetic resin such as a nylon resin, but may be a rubber such as butyl rubber. Rubber is used as the sheet member 54 (54A), and the sheet member 54 (54A) is vulcanized and bonded to the tire inner surface 13, thereby ensuring waterproofness and weather resistance.

  FIG. 17 shows an example in which a heat conduction member 62 having a higher thermal conductivity than the sheet member 54 and a larger outer shape than the sheet member 54 is provided between the heater 50 and the tire inner surface 13. The heat conducting member 62 is a sheet-like member.

  An adhesive layer may be provided between the heat conducting member 62 and the tire inner surface 13. An adhesive layer may be provided between the heat conducting member 62 and the sheet member 54 of the heater 50.

  The heat generated by the heat generating element 53 is supplied to a wide range of the tread portion 10 by the heat conducting member 62. Thereby, the tread part 10 is efficiently heated in a wide range.

  The heat conduction member 62 has a heat conductivity of 10 [W / (m · K)] or more, more preferably 20 [W / (m · K)] or more and 500 [W / (m · K)] or less. It is preferable to include a functional material. Since the heat conductivity of general rubber is 0.1 [W / (m · K)] or more and 0.2 [W / (m · K)] or less, the heat conduction member 62 has the above-described heat conductivity. By including a thermally conductive material having a good heat transfer effect, it is possible to obtain a good heat transfer effect. The thermal conductivity of the entire heat conducting member 62 is preferably 0.2 [W / (m · K)] or more. The thermal conductivity is calculated on the basis of ASTM E1530.

The heat conducting member 62 may include a metal film, for example. For example, the heat conducting member 62 may be a laminate of a metal film such as an aluminum foil and a pair of resin layers laminated on both sides of the metal film. The resin layer may be a resin layer mainly composed of polypropylene or polyester. The laminate of the metal film and the resin layer has a thermal diffusivity at 100 [° C.] of 0.2 × 10 ⁻⁷ [m2 / s] or more, more preferably 0.5 × 10 ⁻⁷ [m2 / s] or more. Good to have. Although the metal film is excellent in thermal conductivity, the metal film alone may break or peel off as the tire 1 travels. The heat conductive member 62 is composed of a laminate of a metal film and a resin layer, thereby improving the adhesion of the heat conductive member 62 based on the resin layer having excellent adhesion while maintaining good heat conductivity. And breakage of the metal film can be prevented.

  The heat conductive member 62 may be a material in which a powder of a heat conductive material is dispersed in a matrix. The matrix can be composed of a resin or rubber composition. The heat conductive material which comprises powder is not specifically limited. The heat conductive member 62 in which the powder of the heat conductive material is dispersed in the matrix also exhibits a good heat dissipation effect.

  When an adhesive layer is provided between the tire inner surface 13 and the heat conductive member 62, the thermal conductivity of the adhesive layer is 0.2 in order to ensure thermal conductivity from the heat conductive member 62 to the tire inner surface 13. [W / (m · K)] or more, preferably 0.3 [W / (m · K)] or more, more preferably 0.5 [W / (m · K)] or more. Is good.

  The thickness of the sheet-like heat conducting member 62 is preferably 30 [μm] or more and 150 [μm]. Thereby, the heat conductivity and durability of the heat conducting member 62 can be ensured. This is because if the thickness of the heat conducting member 62 is smaller than 30 [μm], the heat dissipation performance is lowered, and if it is larger than 150 [μm], the durability against out-of-plane bending stress is lowered.

  FIG. 18 shows an example in which a heat insulating member 63 having a lower thermal conductivity than the sheet member 54 is provided so as to cover the heater 50 provided on the tire inner surface 13. The thickness of the heat insulating member 63 is thicker than the thickness of the heater 50 and the thickness of the heat conducting member 62. The heat insulating member 63 is a porous member having open cells such as foamed urethane resin.

  By covering the heater 50 with the heat insulating member 63, it is possible to suppress the heat generated by the heater 50 from being radiated to the internal space 15 of the tire 1 filled with air. Thereby, the tread part 10 is heated efficiently.

  The heat insulating member 63 made of a porous member also functions as a sound absorbing member. In the traveling tire 1, one of the causes for generating noise is cavity resonance sound caused by vibration of air filled in the internal space 15 of the tire 1. The cavity resonance sound is generated when the tread portion 10 vibrates due to road surface unevenness when the tire 1 rolls, and the vibration of the tread portion 19 vibrates the air in the internal space 15 of the tire 1. The heat insulating member 63 made of a porous member functions as a sound absorbing member that reduces cavity resonance noise and suppresses noise.

  Further, in the example shown in FIG. 18, a sheet-like heat conducting member 62 is disposed between the heat insulating member 63 and the tire inner surface 13. In the example shown in FIG. 18, the size of the heat insulating member 63 in the tire width direction is equal to the size of the heat conducting member 62 in the tire width direction.

  Note that the dimension of the heat conducting member 62 in the tire width direction may be larger than the dimension of the heat insulating member 63 in the tire width direction. By providing the heat conducting member 62 so as to protrude from the heat insulating member 63, a part of the protruding heat conducting member 62 functions as a heat radiating portion. When the temperature of the tread portion 10 is raised from the set temperature by the heater 50, the supply of electric power to the heater 50 is stopped, and the heating process of the tire inner surface 13 by the heater 50 is stopped. If the temperature of the tread portion 10 rises above the set temperature and the heat generation of the tire 1 increases as the tire 1 travels at a high speed, the temperature of the tread portion 10 may increase excessively. When the temperature of the tread portion 10 rises excessively, there is a possibility that a problem that the high-speed durability of the tire 1 is lowered may occur. During heating by the heater 50, the heat insulating member 63 suppresses heat radiation to the internal space 15 and contributes to efficient heating of the tread portion 10. On the other hand, when the temperature of the tread portion 10 rises excessively, the heat insulating member 63 inhibits heat radiation from the tread portion 10 to the internal space 15, and heat is accumulated in the tread portion 10. By making the outer shape of the heat conductive member 62 larger than the outer shape of the heat insulating member 63 and providing a part of the heat conductive member 62 so as to protrude from the heat insulating member 63, the heat of the tread portion 10 protruded from the heat insulating member 63. The heat radiation member 62 is a part of the heat conduction member 62 and is radiated to the internal space 15. Thereby, it is suppressed that the temperature of the tread part 10 rises excessively.

(Modification of adhesive structure)
In the above-described embodiment, the heater 50 is bonded to the tire inner surface 13 by an adhesive layer containing an adhesive or by vulcanization adhesion. The heater 50 and the tire inner surface 13 may be fixed by a mechanical connection such as a fastener or a button. The same applies to the following embodiments.

<Fourth embodiment>
A fourth embodiment will be described. In the present embodiment, a modified example of the heater 50 will be described.

  FIG. 19 is a diagram illustrating an example of the heater 502 according to the present embodiment. As shown in FIG. 19, the heater 502 includes a heating element 53B made of a wire such as a nichrome wire, and a sheet member 54B formed of a non-conductive material and covering the heating element 53B. The heat generating element 53 </ b> B is connected to the conductive member 30 and generates heat by the power supplied through the conductive member 30. The heating element 53B may be embedded in the sheet member 54B, or may be sandwiched between the two sheet members 54B. The sheet member 54B may be made of rubber, rigid resin, or non-woven fabric.

  The thickness of the heater 502 is preferably 0.5 [mm] or more and 1.5 [mm] or less. The heater 502 may be annular or may be provided with an interval portion.

  According to this embodiment, since the heating element 53B is an electric wire such as a nichrome wire, the heater 502 can be manufactured at low cost.

<Fifth Embodiment>
A fifth embodiment will be described. In the present embodiment, a modified example of the arrangement of the heater 50 will be described. FIG. 20 is a diagram illustrating an example of the heater 50 according to the present embodiment. In the following description, an example in which the heater 50 having the first electrode line 51, the second electrode line 52, the heating element 53, and the sheet member 54 is provided on the tire inner surface 13 will be described. In addition, the heater 502 which has an electric wire demonstrated with reference to FIG. 19 may be provided in the tire inner surface 13. FIG.

  In the above-described embodiment, the heater 50 is provided directly below the center portion 11 of the tread portion 10. As shown in FIG. 20, the heater 50 may be provided both directly below the center portion 11 of the tread portion 10 and directly below the shoulder portion 12. In other words, the heater 50 corresponds to a part of the tire inner surface 13 corresponding to the center portion 11 (behind the center portion 11) and the tire inner surface 13 corresponding to the shoulder portion 12 (behind the shoulder portion 12). It may be provided in some areas. Further, a gap may be provided between the heater 50 provided immediately below the center portion 11 and the heater 50 provided immediately below the shoulder portion 12.

  FIG. 21 shows an example in which the heater 50 is provided immediately below the center portion 11 of the tread portion 10 and is not provided immediately below the shoulder portion 12. In the example shown in FIG. 21, the heater 50 is provided in the same range in the tire width direction as the rib 16, and is provided in a different range in the tire width direction from the main groove (circumferential groove) 21. That is, the heater 50 is provided immediately below the rib 16, but is not provided immediately below the main groove 21. In other words, the heater 50 is provided in a partial region of the tire inner surface 13 corresponding to the rib 16 (directly behind the rib 16), but corresponds to the main groove 21 (directly behind the main groove 21). It is not provided in some areas.

  A portion where the main groove 21 is provided in the tread portion 10 is a portion where the thickness of the tread rubber 6 is thin, and a portion where bending deformation becomes large. When the heater 50 is provided in a portion corresponding to the main groove 21, the heater 50 is bent greatly, the heater 50 is deteriorated, or the durability of bonding between the heater 50 and the tire inner surface 13 is reduced, so that the heater 50 extends from the tire inner surface 13. May peel off.

  The portion of the tread portion 10 that needs to be heated to reduce rolling resistance is exclusively a rib 16 having a ground contact surface 14. Therefore, the heater 50 is provided only in the portion corresponding to the rib 16 without providing the heater 50 in the portion corresponding to the main groove 21, thereby suppressing a decrease in the durability of adhesion between the heater 50 and the tire inner surface 13. Only the portion of the tread portion 10 that is necessary for reducing the rolling resistance can be efficiently heated to reduce the rolling resistance.

  FIG. 22 shows an example in which the heater 50 is provided only directly below the center rib 16B. Also in the example shown in FIG. 22, the heater 50 is not provided immediately below the main groove 21. In the example shown in FIG. 22 as well, only the portion of the tread portion 10 necessary to reduce the rolling resistance is efficiently heated while suppressing the decrease in the durability of adhesion between the heater 50 and the tire inner surface 13, thereby reducing the rolling resistance. Can be reduced.

  FIG. 23 shows an example in which the heater 50 is provided directly below the center portion 11 and directly below the shoulder portion 12. Also in the example shown in FIG. 23, the heater 50 is provided so as to avoid a position directly below the main groove 21. In the example shown in FIG. 23 as well, only the portion of the tread portion 10 necessary for reducing the rolling resistance is efficiently heated while suppressing the decrease in the adhesion durability between the heater 50 and the tire inner surface 13, thereby reducing the rolling resistance. Can be reduced.

  As shown in FIG. 24, the heater 50 may be provided directly below the shoulder portion 12 and may not be provided directly below the center portion 11.

<Sixth Embodiment>
A sixth embodiment will be described. FIG. 25 is a diagram schematically illustrating an example of the tread portion 10 according to the present embodiment. FIG. 26 is a diagram schematically illustrating an example of the heater 50 according to the present embodiment.

  As shown in FIG. 25, when the tread portion 10 has a tread pattern having a groove 20 and a ground contact surface 14 provided between the grooves 20, the heater 50 is provided on the tread portion 10 as shown in FIG. 26. You may provide in the tire inner surface 13 in the state patterned according to the tread pattern. The heater 50 is provided directly below the ground plane 14 and is not provided directly below the groove 20. That is, the heater 50 is provided in a partial region of the tire inner surface 13 corresponding to the ground contact surface 14 (directly behind the ground contact surface 14), and a portion of the tire inner surface 13 corresponding to the groove 20 (directly behind the groove 20). This area is not provided.

  A portion where the groove 20 is provided in the tread portion 10 is a portion where bending deformation is increased. The portion of the tread portion 10 that needs to be heated to reduce rolling resistance is exclusively the portion (block or rib) having the ground plane 14. Therefore, the heater 50 is patterned in accordance with the shape of the ground contact surface 14 to reduce the rolling resistance of the tread portion 10 while suppressing a decrease in the durability of adhesion between the heater 50 and the tire inner surface 13. Only the necessary part can be efficiently heated to reduce the rolling resistance.

<Seventh embodiment>
A seventh embodiment will be described. FIG. 27 is a view schematically showing the tire inner surface 13 according to the present embodiment. In the present embodiment, an example in which the temperature sensor 70 is provided on the tire inner surface 13 will be described.

  As shown in FIG. 27, a plurality of heaters 50 are arranged at intervals on the tire inner surface 13. In the example shown in FIG. 27, the heater 50 includes a first heater 50A provided on the tire inner surface 13 and a second heater 50B provided on the tire inner surface 13 with a space from the first heater 50A.

  The temperature sensor 70 is in contact with the first region of the tire inner surface 13 where the first heater 50A is provided, and the tire provided with the first temperature sensor 70A for detecting the temperature of the first region and the second heater 50B. A second temperature sensor 70B that contacts the second region of the inner surface 13 and detects the temperature of the second region.

  The detection result of the first temperature sensor 70A and the detection result of the second temperature sensor 70B are output to a control device provided in the vehicle. The control device controls the heat generation of the first heater 50A and the heat generation of the second heater 50B based on the detection result of the first temperature sensor 70A and the detection result of the second temperature sensor 70B.

  For example, when the first region is a region immediately below the center portion 11 and the second region is a region immediately below the shoulder portion 12, the temperature of the center portion 11 and the temperature of the shoulder 12 may be different. Based on the detection result of the first temperature sensor 70A and the detection result of the second temperature sensor 70B, the control device causes each of the center portion 11 and the shoulder portion 12 to have a predetermined set temperature (target temperature). Furthermore, the power supplied to the first heater 50A and the power supplied to the second heater 50B can be controlled to control the heat generation of the first heater 50A and the heat generation of the second heater 50B.

  In general, a plurality of (for example, four) tires 1 are mounted on the vehicle. When a plurality of tires 1 are mounted on the vehicle, each tire 1 may be provided with a heater 50 and a temperature sensor 70. The control device provided in the vehicle controls the heat generation of the heater 50 provided in each of the plurality of tires 1 based on the detection result of the temperature sensor 70 provided in each of the plurality of tires 1. Good. For example, the temperature of the plurality of tires 1 may differ depending on the irradiation angle of sunlight with respect to the vehicle and the arrangement state of the vehicle in the garage. In the control device, each of the plurality of tires 1 has a predetermined set temperature (target temperature) based on the detection result of the temperature sensor 70 provided in each of the plurality of tires 1. Thus, the electric power supplied to the heater 50 provided in each of the plurality of tires 1 can be controlled, and the heat generation of the plurality of heaters 50 can be controlled. For example, the control device can control the heat generation of each of the plurality of heaters 50 based on the detection result of the temperature sensor 70 so that the temperatures of the plurality of tires 1 are uniform.

1 tire (pneumatic tire)
2 carcass 3 belt 3A first belt ply 3B second belt ply 3Ea end 3Eb end 4 belt cover 5 bead 6 tread rubber 7 side rubber 8 inner liner 9 side 10 tread 11 center 12 shoulder 13 tire inner surface 14 Ground surface 15 Internal space 16 Rib 20 Groove 21 Main groove 22 Lug groove 23 Sipe 30 Conductive member 50 Heater 50B Heater 51 First electrode wire 52 Second electrode wire 53 Heating element 53B Heating element 54 Sheet member 54A Sheet member 54B Sheet member 55 Cover member 56 bent portion 56A first bent portion 56B second bent portion 57 bent portion 57A first bent portion 57B second bent portion 58 straight portion 59 bent portion 60 splice portion 61 adhesive layer 62 heat conducting member 63 heat insulating member 70 temperature sensor 100 tire wheel 101 rim A X Center axis

Claims (19)

A pneumatic tire mounted on a tire wheel,
A conductive member provided on a tire inner surface and connected to a wheel electric wire supported by the tire wheel;
A pneumatic tire comprising: a sheet-like heater provided on an inner surface of the tire and generating heat by electric power supplied via the wheel electric wire and the conductive member.   The pneumatic tire according to claim 1, wherein the conductive member includes a conductive paint applied to the inner surface of the tire.   The pneumatic tire according to claim 1, wherein the conductive member includes a conductive yarn bonded to the tire inner surface. With carcass,
A belt provided on the outer side in the tire radial direction than the carcass,
The pneumatic tire according to any one of claims 1 to 3, wherein the heater is provided on an inner side in a tire width direction than an end portion of the belt.   The pneumatic tire according to any one of claims 1 to 4, wherein at least a part of the heater is provided at a center portion of the tire inner surface in the tire width direction.   The pneumatic tire according to any one of claims 1 to 5, wherein the heater extends in a tire circumferential direction. A tread portion having a circumferential groove extending in the tire circumferential direction and a rib having a ground contact surface and provided between the circumferential grooves;
The pneumatic tire according to claim 6, wherein the heater is provided in the same range in the tire width direction with the rib, and is provided in a different range in the circumferential groove and the tire width direction. A tread portion having a groove and a grounding surface provided between the grooves,
The pneumatic tire according to any one of claims 1 to 5, wherein the heater is patterned in accordance with a shape of the ground contact surface.   The heater includes a linear heating element that is formed of a conductive material and generates heat by electric power supplied from the conductive member, and a sheet member that is formed of a non-conductive material and covers the heating element. The pneumatic tire according to claim 8.   The pneumatic tire according to claim 9, wherein the heating element includes a conductive fiber. The heater has a first electrode line extending in the tire circumferential direction, and a second electrode line provided at a position different from the first electrode line in the tire width direction and extending in the tire circumferential direction,
One end of the heating element is connected to the first electrode line, and the other end of the heating element is connected to the second electrode line,
The heat generating element is connected to the conductive member via the first electrode line and the second electrode line, and a plurality of the heat generating elements are provided in the tire circumferential direction between the first electrode line and the second electrode line. The pneumatic tire according to claim 9 or claim 10.   The pneumatic tire according to claim 11, wherein at least a part of an intermediate portion of the heat generating element between the one end portion and the other end portion is bent.   The pneumatic tire according to claim 11 or 12, wherein each of the first electrode line and the second electrode line has a bent portion. The heating element is in contact with the tire inner surface;
The pneumatic tire according to any one of claims 9 to 13, wherein the sheet member is adhered to the tire inner surface in a state of covering the heating element. The heating element is embedded in the sheet member,
The pneumatic tire as described in any one of Claims 9-13 provided with the contact bonding layer provided between the said sheet | seat member and the said tire inner surface.   The heat conduction member provided between the said heater and the said tire inner surface, heat conductivity higher than the said sheet member, and a larger external shape than the said sheet member is provided in any one of Claims 9-15. The described pneumatic tire.   The pneumatic tire according to any one of claims 9 to 16, further comprising a heat insulating member provided so as to cover the heater provided on the inner surface of the tire and having a lower thermal conductivity than the sheet member.   The pneumatic tire according to any one of claims 1 to 17, further comprising a cover member that adheres to the inner surface of the tire in a state of covering the heater and fixes the heater to the inner surface of the tire. A temperature sensor provided on the tire inner surface;
The pneumatic tire according to any one of claims 1 to 18, wherein heat generation of the heater is controlled based on a detection result of the temperature sensor.

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