JP5462900B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire capable of ensuring tire conductivity while improving low rolling resistance performance.

  Patent Document 1 listed below discloses a pneumatic tire in which the electrical resistance of the tire is reduced while using an insulating rubber material for a rubber member of 90% or more of the total mass of rubber among the rubber members used in the tire. Proposed.

  As shown in FIG. 7, the proposed tire has a carcass a forming a tire frame, a belt layer b superposed on the outer side in the radial direction of the carcass a, and superposed on the outer side in the radial direction of the belt layer b. Band layer c, cushion rubber d interposed between the outer end of the belt layer b and the carcass, edge cover rubber e covering the outer end of the belt layer b in a U shape, radius of the band layer c A tread rubber f disposed on the outer side in the direction and forming a tread ground surface, an under tread rubber g extending between the tread rubber f and the band layer c in the tire axial direction, and the tread rubber f inward and outward in the radial direction A terminal rubber portion h that penetrates and connects the tread ground surface and the undertread rubber g is provided. The topping rubber of the carcass a, the belt layer b, and the band layer c, and the tread rubber f are formed of an insulating rubber material, and the terminal rubber portion h, the under tread rubber g, the edge cover rubber e, and the cushion. The rubber d is formed of a conductive rubber material.

  Here, as shown in FIG. 8 (A), the band layer c is a band obtained by spirally winding a band strip ca having a narrow band shape in which a plurality of band cords c1 aligned in parallel and covered with a topping c2. Formed by ply. In the overlap region where the edge cover rubber e is overlapped during spiral winding, as shown in FIG. 8B, a separation portion j is formed between the band strips ca. As a result, the under tread rubber g and the edge cover rubber e can enter and come into contact with each other in the space j, and the terminal rubber portion h, the under tread rubber g, the edge cover rubber e, and the cushion rubber d A first conductive path that is electrically conductive can be formed.

  However, in the structure in which the separation portion j is formed by the spiral winding of the band strip ca, the width of the separation portion j may vary from tire to tire and the reliability is inferior. Also, when the band layer c is formed by two band plies, it is difficult to align the position of the separation portion j of each band ply up and down, and the step becomes large, so that rubber can enter the separation portion j. However, there is a problem that an air pocket is generated and durability is lowered.

JP 2010-159017 A

  Therefore, the present invention is based on the fact that the band layer is formed by a grid-like band ply in which rubber-coated cords coated with coating rubber around the band cords are arranged in a grid, and rubber is easily formed between the rubber-coated cords. An object of the present invention is to provide a pneumatic tire that can stably form an invading gap and can improve the durability by suppressing air accumulation in the gap.

In order to solve the above-mentioned problem, the invention of claim 1 of the present application includes a carcass that extends from the tread portion to the bead core of the bead portion through the sidewall portion,
A belt layer disposed radially outside the carcass and inside the tread;
A pneumatic tire comprising a band layer disposed on a radially outer side of the belt layer and covering an outer surface of the belt layer,
The band layer includes a vertical arrangement portion in which a rubber-coated cord having a band cord coated with a coating rubber is arranged with a gap Pa in the tire axial direction, and the rubber-coated cord has a gap Pb in the tire circumferential direction. It is characterized by comprising a lattice band ply which is arranged and has a horizontal arrangement portion which is overlapped with the vertical arrangement portion on the inside or outside in the radial direction.

  Further, in claim 2, the band layer is composed of two lattice band plies, and each lattice band ply has a band cord diameter of 0.7 mm or less, and the gap Pa is 0.8 to 0.8 mm. It is characterized by 1.5 mm and the gap Pb being 0.8 to 5.0 mm.

According to a third aspect of the present invention, the lattice band ply is formed by continuously winding a narrow band lattice band strip in a spiral shape,
This grid-like band strip has a vertical array of a plurality of vertical rubber-coated cords extending along the length direction and a horizontal array of a plurality of horizontal rubber-coated cords extending along the width direction. In addition, the vertical and horizontal arrangement portions are connected by adhesion between the coating rubbers of the vertical and horizontal rubber-coated cords.

  According to a fourth aspect of the present invention, the outer end portion of the belt layer has an outer piece portion that covers a radially outer surface of the outer end portion and an inner piece portion that covers a radially inner surface, and covers the outer end portion. A letter-shaped edge cover rubber is disposed, and the band layer includes an overlapping region overlapping the outer piece portion.

Further, in claim 5, a cushion rubber having a triangular cross section interposed between the outer end portion of the belt layer and the carcass,
A tread rubber which is arranged on the radially outer side of the band layer and forms a tread ground surface;
An under tread rubber that forms a sheet extending between the tread rubber and the band layer in the tire axial direction;
And a terminal rubber portion that penetrates the tread rubber inward and outward in the radial direction, an outer end portion in the radial direction is exposed to the ground contact surface of the tread, and an inner end portion in the radial direction contacts the undertread rubber, and the topping of the carcass Rubber, belt layer topping rubber, band layer coating rubber and tread rubber are formed of an insulating rubber material having a volume resistivity of 1 × 10 ⁸ Ωcm or more, and the terminal rubber part, undertread rubber and edge cover rubber And the cushion rubber are formed of a conductive rubber material having a volume resistivity of less than 1 × 10 ⁸ Ωcm,
The under-tread rubber and edge cover rubber disposed inside and outside in the radial direction of the band layer enter the gaps Pa and Pb between the rubber-coated cords and come into contact with each other, and the terminal rubber portion and the under-tread rubber The edge cover rubber and the cushion rubber are electrically connected to form a first conductive path from the tread ground surface to the cushion rubber.

According to a sixth aspect of the present invention, a sidewall rubber that is connected to an outer end in the tire axial direction of the tread rubber and that forms an outer surface of the sidewall portion on an outer side in the tire axial direction of the carcass, and an inner end in the radial direction of the sidewall rubber And a clinch rubber for preventing rim displacement that forms the outer surface of the bead portion.
Moreover, the sidewall rubber is formed of an insulating rubber material, and the clinch rubber is formed of a conductive rubber material,
By disposing a conductive rubber layer made of the conductive rubber material and having an upper end in contact with the cushion rubber and a lower end in contact with the clinch rubber between the sidewall rubber and the carcass, A second conductive path from the rubber to the outer surface of the bead portion is formed.

  As described above, according to the present invention, a vertical arrangement portion in which rubber-coated cords are arranged with a gap in the tire axial direction and a horizontal arrangement portion in which rubber-coated cords are arranged with a gap in the tire circumferential direction are arranged in the radial direction. It has a grid band ply placed inside and outside. Accordingly, the lattice-shaped band ply is uniformly formed with a rectangular gap having four sides surrounded by rubber-coated cords over the entire surface. In addition, the rubber-coated cord is coated with the coating rubber around the band cord, so when the vertical and horizontal array portions are overlapped, the overlapping coating rubbers adhere to each other and the lattice-like cord array, that is, the gap portion, is stabilized. Can be maintained.

  Therefore, when forming a raw tire and vulcanizing the tire, rubbers arranged inside and outside in the radial direction of the band layer, for example, an under tread rubber and an edge cover rubber can easily enter the gap portion and come into contact with each other. . Therefore, it is possible to prevent a decrease in durability by suppressing air accumulation in the gap. When the under tread rubber and the edge cover rubber are formed of a conductive rubber material, the under tread rubber and the edge cover rubber pass through the band layer even when the band layer is insulative. It can be made conductive.

It is sectional drawing which shows one Example of the pneumatic tire of this invention. It is sectional drawing which expands and shows the tread part. (A) is a cross-sectional view showing a rubber-coated cord, (B) is a perspective view showing a lattice band strip, (A), (B) is the top view and sectional drawing which show a grid | lattice-like band ply. (A), (B) is the top view and sectional drawing in case a band layer is formed from two grid | lattice-like band plies. 1 is a schematic cross-sectional view conceptually showing a tire electrical resistance measuring device. It is sectional drawing which shows the conventional pneumatic tire. (A) is a perspective view of the band strip used for formation of a band ply, (B) is an expanded view which shows the winding state of a band strip.

Hereinafter, embodiments of the present invention will be described in detail.
In FIG. 1, a pneumatic tire 1 according to this embodiment includes a carcass 6 that extends from a tread portion 2 through a sidewall portion 3 to a bead core 5 of a bead portion 4, a radially outer side of the carcass 6, and an inside of the tread portion 2. And a band layer 9 disposed on the outer side in the radial direction of the belt layer 7.

  The carcass 6 is formed by one or more carcass plies 6A in this example, in which an array of carcass cords arranged at an angle of, for example, 70 to 90 ° with respect to the tire circumferential direction is covered with a topping rubber. . This carcass ply 6A is provided with a series of ply folded portions 6b folded around the bead core 5 from the inner side to the outer side in the tire axial direction on both sides of the toroidal ply main body portion 6a straddling the bead cores 5 and 5. Yeah. A bead apex rubber 8 is provided between the ply body portion 6a and the ply turn-up portion 6b so as to taper outward from the bead core 5 in the radial direction. Yes.

  The belt layer 7 is composed of two or more belt plies 7A and 7B in this example, in which an array of belt cords arranged at an angle of, for example, 15 to 40 ° with respect to the tire circumferential direction is covered with a topping rubber. It is formed. The belt layer 7 enhances the belt rigidity by crossing the belt cords between the plies, and reinforces the tread portion 2 with a tagging effect. The ply width of the belt ply 7A on the radially inner side is, for example, about 7 to 15 mm wider than the ply width of the outer belt ply 7B, thereby reducing the stress concentration at the ply end.

  Further, as shown in FIG. 2, the outer end portion 7E of the belt layer 7 is gradually separated from the carcass 6 toward the outer side in the tire axial direction, and a cushion rubber 14 having a triangular cross section is disposed in the separated portion Y. Is done. The cushion rubber 14 is made of a relatively soft rubber, and suppresses the cord end peeling starting from the belt cord end by relaxing the shear stress concentrated on the outer end portion 7E.

  The outer end portion 7E is further covered with a U-shaped edge cover rubber 13. The edge cover rubber 13 is formed by folding a thin rubber sheet having a thickness of 0.5 to 1.0 mm into a U shape, and specifically, an outer piece portion covering the outer surface in the radial direction of the outer end portion 7E. 13o and an inner piece portion 13i that covers the inner surface in the radial direction and covers the outer end portion 7E. The edge cover rubber is conventionally used for covering and protecting the end portions of the carcass ply and the belt ply in heavy load tires and the like, and suppressing cord end peeling. However, the present invention is different from the conventional edge cover rubber in that it is used for forming a conductive path in the tire.

  Next, the band layer 9 is formed to have substantially the same width as the belt layer 7 in this example, and covers the entire outer surface of the belt layer 7 in the radial direction. Accordingly, an overlapping region Q is formed in the band layer 9 so as to overlap the outer piece portion 13o of the edge cover rubber 13. The band layer 9 restrains the movement of the belt layer 7 and improves the high-speed durability like the conventional band layer. The band layer 9 may be formed with a band extending portion extending beyond the outer end in the tire axial direction of the belt layer 7 and extending outward in the tire axial direction. In such a case, the restraining force on the belt layer 7 can be further increased, and the high-speed durability can be further improved. In addition, when providing a band extension part, it is preferable that the protrusion width | variety from the belt layer 7 shall be 2 mm or more.

  As shown in FIGS. 4A and 4B, the band layer 9 includes a vertical array portion 21A in which rubber-coated cords 20 are arranged with a gap Pa in the tire axial direction, and the rubber-coated cord 20 It is formed of one or more (in this example, one) lattice band ply 10 composed of horizontal array portions 21B arrayed with a gap Pb in the tire circumferential direction. Therefore, a rectangular gap G having four sides surrounded by the rubber-coated cord 20 is uniformly formed on the entire surface of the lattice band ply 10. The gaps Pa and Pb are at least larger than the diameter D of the band cord 22.

  The vertical array portion 21A and the horizontal array portion 21B overlap each other on the inside and outside in the radial direction. At this time, it is more preferable to arrange the vertical array portion 21A on the radially outer side of the horizontal array portion 21B. This is preferable from the viewpoint of high-speed durability. However, the vertical array portion 21A can be arranged radially inward of the horizontal array portion 21B as required.

  Further, as conceptually shown in FIG. 3A, the rubber-coated cord 20 is composed of a band cord 22 and a coating rubber 23 covering the periphery thereof. As the band cord 22, for example, a conventional organic fiber band cord such as nylon can be suitably used. The coating thickness of the coating rubber 23 is preferably in the range of 0.03 to 0.2 mm, for example.

  In this example, such a lattice band ply 10 is formed by continuously winding a narrow band lattice band strip 24 in a spiral shape. As shown in FIG. 3 (B), the grid-like band strip 24 extends in the vertical direction with a vertical array portion 25A composed of a plurality of vertical rubber-coated cords 20A extending in the length direction and in the width direction. It is formed of a plurality of short horizontal rubber-coated cords 20B and a horizontal array portion 25B. The vertical and horizontal arrangement portions 25A and 25B are integrally connected by adhesion between the coating rubbers 23 of the vertical and horizontal rubber-coated cords 20A and 20B that are in contact with each other, and the lattice state is stably maintained. Therefore, when the coating thickness of the coating rubber 23 is less than the above range, the adhesion is insufficient and it is difficult to maintain the lattice state, and the winding workability of the lattice band strip 24 is impaired.

  Next, as shown in FIG. 1, the tread rubber 2 </ b> G, the under tread rubber 16, and the terminal rubber portion 17 are disposed outside the band layer 9 in the radial direction.

  As the tread rubber 2G, in this example, a cap rubber portion 2G1 forming the tread ground surface 2S, a base rubber portion 2G2 on the radially inner side thereof, and a triangular cross section disposed on both outer sides in the tire axial direction. The thing of the four-layer structure which consists of wing rubber part 2G3 is illustrated. However, other conventional structures such as a three-layer structure excluding the base rubber portion 2G2 can be employed.

  The under tread rubber 16 is a rubber that enhances adhesion to the tread rubber 2G, and extends between the tread rubber 2G and the band layer 9 in the tire axial direction. Form a thin sheet of 0 mm. In this example, the undertread rubber 16 is formed over the entire width between the wing rubber portions 2G3 and 2G3.

  The terminal rubber portion 17 extends through the tread rubber 2G inward and outward in the radial direction, and the outer end in the radial direction is exposed to the tread ground surface 2S and the inner end in the radial direction extends to the undertread rubber 16. Connected. In this example, the terminal rubber portion 17 is formed as a rib-like body extending in the tire circumferential direction. For example, the terminal rubber portion 17 may be interspersed in the tread portion 2 as a columnar body.

  Further, on the outer side in the tire axial direction of the carcass 6, a side wall rubber 3 </ b> G connected to the outer end in the tire axial direction of the tread rubber 2 </ b> G and forming the outer side surface of the side wall portion 3, A rim rubber 4 </ b> G for preventing rim displacement that is connected to the end and forms the outer surface of the bead portion 4 is disposed.

And in the pneumatic tire 1 of this example, in order to improve the low rolling resistance performance, the topping rubber of the carcass 6, the topping rubber of the belt layer 7, the coating rubber 23 of the band layer 9, the tread rubber 2G, The sidewall rubber 3G is formed of an insulating rubber material having a volume specific resistance of 1 × 10 ⁸ Ωcm or more. Further, in order to secure a conductive path, the terminal rubber portion 17, the under tread rubber 16, the edge cover rubber 13, the cushion rubber 14 and the clinch rubber 4G are each electrically conductive with a volume specific resistance of less than 1 × 10 ⁸ Ωcm. It is made of a functional rubber material.

  Here, in the pneumatic tire 1, when the band layer has a conventional structure, direct contact between the undertread rubber 16 and the cushion rubber 14 is cut off. However, the band layer 9 of the present embodiment is formed by a lattice band ply 10 in which a rectangular gap G is uniformly formed over the entire surface.

  Therefore, when forming the raw tire and vulcanizing the tire, the outer tread rubber 16 and a part of the outer piece portion 13o of the edge cover rubber 13 can easily enter the gap G and come into contact with each other. The edge cover rubber 13 can be in contact with the cushion rubber 14 at its inner piece 13i. Accordingly, the terminal rubber portion 17, the under tread rubber 16, the edge cover rubber 13 and the cushion rubber 14 can be electrically connected through the gap portion G, whereby the first rubber extending from the tread ground surface 2S to the cushion rubber 14 is obtained. One conductive path can be formed.

  If the thickness of the edge cover rubber 13 is less than 0.5 mm, the edge cover rubber 13 tends to enter into the gap G and cause an air pocket. In the under tread rubber 16, the tread rubber 2G having a large volume is adjacent to the outer side in the radial direction, so that even if it is thin, there is no problem in entering the gap G, that is, the occurrence of air accumulation, but 0.3 mm. If it is less than this, conductivity becomes a problem. The upper limits of the thicknesses of the edge cover rubber 13 and the under tread rubber 16 are preferably set to 1.0 mm or less from the viewpoint of increasing the rolling resistance performance by reducing the amount of conductive rubber material used.

  As shown in FIGS. 5A and 5B, when the band layer 9 is formed by two lattice band plies 10U and 10L, that is, in the case of a two-layer structure, the band cord 22 It is preferable that the diameter D is 0.7 mm or less, the gap Pa is 0.8 to 1.5 mm, and the gap Pb is 0.8 to 5.0 mm. This is because if the gaps Pa and Pb are less than 0.8 mm, the rubber-coated cord 20 of the upper grid band ply 10U becomes an obstacle, and the gap G of the lower grid band ply 10L This is because the rubber is less likely to enter the air and tends to cause air pockets. Similarly, when the diameter D exceeds 0.7 mm, it is difficult for the rubber to enter the gap G, and an air trap tends to occur. From such a viewpoint, in the case of a two-layer structure, it is preferable that the gaps Pa, Pb and the diameter D are within the above ranges, and further, the difference between the gaps Pa, Pb and the diameter D (Pa−D), (Pb -D) is more preferably 0.1 m or more, and further preferably 0.2 mm or more. When the gap Pa exceeds 1.5 mm and when the gap Pb exceeds 5.0 mm, the restraining force is reduced and the high-speed durability tends to be lowered.

  When the band layer 9 is formed by a single lattice band ply 10, that is, in the case of a single layer structure, the gap Pa is 0.1 to 1.5 mm, and the gap Pb is 0.1 to 5. It is preferably 0 mm. When the gaps Pa and Pb are lower than the lower limit value, the rubber does not easily enter the gap portion G and a tendency of air accumulation occurs. On the contrary, when the upper limit value is exceeded, the binding force is reduced and high speed durability is achieved. Invite the tendency to lower. The diameter D of the band cord 22 is not particularly restricted, but if the diameter D is too large, the bending rigidity of the cord increases, and the rubber-coated cord 20 is disconnected when the lattice band strip 24 is wound. From such a viewpoint, the diameter D is preferably 1.2 mm or less.

  In this example, a conductive rubber layer 18 is formed between the sidewall rubber 3G and the carcass 6 so that the upper end portion is in contact with the cushion rubber 14 and the lower end portion is in contact with the clinch rubber 4G. The conductive rubber layer 18 has a thin sheet shape with a thickness of about 0.3 to 2.0 mm and is made of the conductive rubber material so that the cushion rubber 14 reaches the outer surface of the bead portion 4. A second conductive path is formed.

  As described above, the pneumatic tire 1 is made of an insulating rubber material except for the terminal rubber portion 17, the under tread rubber 16, the edge cover rubber 13, the cushion rubber 14, the clinch rubber 4G, and the conductive rubber layer 18 therein. Can also form the first and second conductive paths from the tread contact surface 2S to the rim R, and can ensure the conductivity of the tire while improving the low rolling resistance performance and the high speed durability. It becomes possible to prevent accumulation of static electricity. Further, it is possible to suppress the occurrence of air accumulation in the band layer 9 and prevent the durability from being lowered.

  It is also possible to increase the usage rate of the insulating rubber material to 90% or more of the total mass of the rubber material used in the tire, and further improvement in rolling resistance performance can be expected. This also greatly reduces the use of carbon black made up of limited petroleum resources, which can reduce dependence on petroleum resources and can greatly contribute to the promotion of eco-friendly tires.

  As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.

  A pneumatic tire (size 195 / 65R15) having the basic structure shown in FIG. 1 was prototyped, and the electrical resistance, high-speed durability, general durability, and occurrence of air accumulation in the band layer of each test tire were tested. The results are shown in Tables 1 and 2.

Except as described in Tables 1 and 2, the specifications are substantially the same. In each tire, the terminal rubber portion, the under tread rubber, the edge cover rubber, the cushion rubber, the clinch rubber, and the inner conductive rubber layer have a volume specific resistance of 1. A conductive rubber material of less than 0 × 10 ⁸ Ωcm was used, and an insulating rubber material having a volume resistivity of 1.0 × 10 ⁸ Ωcm or more was used for the other rubber members. In each tire, the width of the belt layer was 156 mm, the width of the band layer was 156 mm, and the width of the overlapping region Q by the edge cover rubber was 25.0 mm. The thickness of the under tread rubber was 0.30 mm, and the thickness of the conductive rubber layer was 0.75 mm.

The band layers of Comparative Examples 1 and 2 are obtained by spirally winding the band strip ca in FIG. 8A. The band strip ca has a width of 10.0 mm and the number of band cords is 10. Nylon cord is used. Further, in the overlapping region with the edge cover rubber, a separation portion j of 2.0 mm is formed between the band strips ca. Nylon cords of the same material are used for the band cords of the comparative example and the example, and only the diameters are different.

<Electric resistance of tire>
As shown in FIG. 6, an insulating plate 51 a metal plate 52 which is disposed surface is polished on the (electric resistance than 10 ¹² Omega) (electric resistance 10Ω or less), tire rim assembly The electrical resistance value of the tire and rim assembly was measured in accordance with JATMA regulations using a measuring device including a conductive tire mounting shaft 53 for holding the tire and an electrical resistance measuring instrument 54. Each of the test tires was a tire in which the surface release agent and dirt were sufficiently removed in advance and were sufficiently dried. Other conditions are as follows.
Rim: Aluminum alloy 15 × 6JJ
Internal pressure: 200 kPa
Load: 5.3kN
Test environment temperature (test room temperature): 25 ° C
Humidity: 50%
Measuring range of electric resistance measuring device: 10 ^{3 to} 1.6 × 10 ¹⁶ Ω
Test voltage (applied voltage): 1000V

The test procedure is as follows.
(1) Mount the test tire on the rim and prepare a tire / rim assembly. At this time, soapy water is used as a lubricant at the contact portion between the two.
(2) The tire / rim assembly is allowed to stand in the test room for 2 hours and then attached to the tire mounting shaft 53.
(3) The tire / rim assembly is loaded with the load for 0.5 minutes, and further for 0.5 minutes after being released and for 2 minutes after being released.
(4) When the test voltage is applied and 5 minutes have passed, the electrical resistance value between the tire mounting shaft 53 and the metal plate 52 is measured by the electrical resistance measuring instrument 54. The measurement is performed at four positions at 90 ° intervals in the tire circumferential direction, and the maximum value among them is taken as the electrical resistance value (measured value) of the tire.

<High speed durability>
In accordance with the ECE30 standard, a sample tire is tested using a drum tester at a speed of 170 km / h to 10 km / h-20 minutes under a rim (15 × 6JJ), internal pressure (280 kPa), and load (5.0 KN). Step up the speed and drive until the tire breaks. Then, the speed and time (minute) when the tire was damaged were measured.

<General durability>
A sample tire is run at a speed of 100 km / h (constant) under a rim (15 × 6 JJ), internal pressure (250 kPa), and load (8.15 KN) using a drum testing machine. And the travel distance when the tire broke was measured and evaluated by an index with Comparative Example 1 as 100. A larger value is better.

<Air pocket>
The tire was disassembled and visually inspected for the presence of air accumulation due to the band layer.
The number of dismantled tires was 50, and even if one tire had air pockets, “Yes” was set.

DESCRIPTION OF SYMBOLS 1 Pneumatic tire 2 Tread part 2G Tread rubber 2S Tread ground surface 3 Side wall part 3G Side wall rubber 4 Bead part 4G Clinch rubber 5 Bead core 6 Carcass 7 Belt layer 7E Outer end part 9 Band layers 10, 10U, 10L Grid band ply 13 Edge cover rubber 13i Inner piece portion 13o Outer piece portion 14 Cushion rubber 16 Under tread rubber 17 Conductive rubber layer 20 in terminal rubber portion 18 Rubber coated cord 21A Vertical arrangement portion 21B Horizontal arrangement portion 22 Band cord 23 Coating rubber 24 Lattice-shaped band strip 25A Vertical arrangement part 25B Horizontal arrangement part

Claims (6)

A carcass from the tread part through the sidewall part to the bead core of the bead part,
A belt layer disposed radially outside the carcass and inside the tread;
A pneumatic tire comprising a band layer disposed on a radially outer side of the belt layer and covering an outer surface of the belt layer,
The band layer includes a vertical arrangement portion in which a rubber-coated cord having a band cord coated with a coating rubber is arranged with a gap Pa in the tire axial direction, and the rubber-coated cord has a gap Pb in the tire circumferential direction. It consists of a grid-like band ply consisting of a horizontal array portion arranged in the radial direction inside or outside with the vertical array portion ,
The lattice band ply is formed by continuously winding a narrow band lattice band strip spirally,
This grid-like band strip has a vertical array of a plurality of vertical rubber-coated cords extending along the length direction and a horizontal array of a plurality of horizontal rubber-coated cords extending along the width direction. Formed from and
In addition , the pneumatic tire is characterized in that the vertical and horizontal arrangement portions are connected by adhesion between the coating rubbers of the vertical and horizontal rubber-coated cords .   The band layer is composed of two lattice band plies, and each lattice band ply has a band cord diameter of 0.7 mm or less, and the gap Pa is 0.8 to 1.5 mm. The pneumatic tire according to claim 1, wherein the gap Pb is 0.8 to 5.0 mm. A U-shaped edge cover rubber which has an outer piece portion covering the outer surface in the radial direction of the outer end portion and an inner piece portion covering the inner surface in the radial direction at the outer end portion of the belt layer and covers the outer end portion. The pneumatic tire according to claim 1 , wherein the band layer further includes an overlapping region that overlaps with the outer piece portion . A carcass from the tread part through the sidewall part to the bead core of the bead part,
A belt layer disposed radially outside the carcass and inside the tread;
A pneumatic tire comprising a band layer disposed on a radially outer side of the belt layer and covering an outer surface of the belt layer,
The band layer includes a vertical arrangement portion in which a rubber-coated cord having a band cord coated with a coating rubber is arranged with a gap Pa in the tire axial direction, and the rubber-coated cord has a gap Pb in the tire circumferential direction. It consists of a grid-like band ply consisting of a horizontal array portion arranged in the radial direction inside or outside with the vertical array portion,
The lattice band ply is formed by continuously winding a narrow band lattice band strip spirally,
Cushion rubber having a triangular cross section interposed between the outer end of the belt layer and the carcass,
A tread rubber which is arranged on the radially outer side of the band layer and forms a tread ground surface;
An under tread rubber that forms a sheet extending between the tread rubber and the band layer in the tire axial direction;
And a terminal rubber portion that penetrates the tread rubber inward and outward in the radial direction, an outer end portion in the radial direction is exposed to the ground contact surface of the tread, and an inner end portion in the radial direction contacts the undertread rubber, and the topping of the carcass Rubber, belt layer topping rubber, band layer coating rubber and tread rubber are formed of an insulating rubber material having a volume resistivity of 1 × 10 ⁸ Ωcm or more, and the terminal rubber part, undertread rubber and edge cover rubber And the cushion rubber are formed of a conductive rubber material having a volume resistivity of less than 1 × 10 ⁸ Ωcm,
The under-tread rubber and edge cover rubber disposed inside and outside in the radial direction of the band layer enter the gaps Pa and Pb between the rubber-coated cords and come into contact with each other, and the terminal rubber portion and the under-tread rubber A pneumatic tire characterized in that a first conductive path from the tread ground surface to the cushion rubber is formed by electrical conduction between the edge cover rubber and the cushion rubber . A sidewall rubber that is continuous with a tire axial direction outer end of the tread rubber and that forms an outer surface of the sidewall portion, and a bead portion that is continuous with a radially inner end of the sidewall rubber, on the outer side in the tire axial direction of the carcass. With clinch rubber to prevent rim slippage that forms the outer surface of
Moreover, the sidewall rubber is formed of an insulating rubber material, and the clinch rubber is formed of a conductive rubber material,
By disposing a conductive rubber layer made of the conductive rubber material and having an upper end in contact with the cushion rubber and a lower end in contact with the clinch rubber between the sidewall rubber and the carcass, The pneumatic tire according to claim 4, wherein a second conductive path extending from rubber to the outer surface of the bead portion is formed . The lattice band ply is formed by continuously winding a narrow band lattice band strip spirally,
This grid-like band strip has a vertical array of a plurality of vertical rubber-coated cords extending along the length direction and a horizontal array of a plurality of horizontal rubber-coated cords extending along the width direction. 6. The pneumatic tire according to claim 4 or 5 , wherein the vertical and horizontal array portions are connected by adhesion between the coating rubbers of the vertical and horizontal rubber-coated cords .

Images