JP4977144B2 - How to install a pneumatic tire - Google Patents

Description

  The present invention relates to a method for mounting a pneumatic tire, and more particularly to a method for mounting a pneumatic tire that can reliably discharge static electricity charged on a vehicle to a road surface.

  In order to improve rolling resistance and running performance on wet road surfaces (wet performance), a technique for blending silica as a reinforcing agent in a rubber composition of a tread is known. By the way, the static electricity charged in the vehicle is discharged to the road surface from the rim to the tread part through the bead part and the sidewall part in the tire using the conventional carbon black composition. Conductivity deteriorates and static electricity can not flow on the road surface, and when the tire passes over the manhole etc., the static electricity charged on the vehicle causes a discharge phenomenon, adverse effects on radio noise and electronic circuit components, The occurrence of short circuit is a problem.

Conventionally, in order to solve such a problem, a technique has been proposed in which a conductive member in which carbon black is blended in a part of a tread structure is provided to ensure the conductivity of the tire. For example, Patent Documents 1 and 2 below are techniques in which a conductive strip is provided on a part of a tire tread from the tread surface to the bottom surface, and discharge is performed through the conductive strip. Patent Document 3 is a technique in which a conductive thin film containing carbon black is laid on the outer surfaces of a tread and sidewalls and discharged through this conductive layer. Further, in Patent Document 4, a tread wing having good conductivity is arranged on both sides of a tread containing silica, and an outer top tread cap layer having good conductivity covering the tread surface from the tread wing is integrally formed by extrusion with the tread wing. A tread member is formed, and a tire is molded using the tread member. Electric discharge is performed through the outer skin of the outer top tread cap layer.
JP-A-8-34204 JP 2006-143208 A JP-A-8-230407 Japanese Patent Laid-Open No. 9-30212

  However, in the techniques of Patent Documents 1 and 2, since it is necessary to separately provide a conductive strip from the surface to the bottom of the tread strip, the number of parts increases and a special manufacturing method is required. In addition, since the conductive strip is disposed in a large volume, the contact area of the silica-containing tread is reduced, and the rolling resistance and wet performance are not effectively improved.

  In the technique of Patent Document 3, the effect of improving the rolling resistance and wet performance of the tread due to the silica blending is lowered by laying the conductive thin film containing the carbon black, and the original effect is hardly exhibited. In addition, a process of laying a conductive thin film containing carbon black on the outer surface of the tread and the sidewall is separately required.

  Since the technology of Patent Document 4 has a structure in which the tread surface is covered with a conductive outer top tread cap layer as a tread skin, the effect of improving the rolling resistance and wet performance of the tread by silica blending is the above-described conductive outer top tread. Reduced by the tread cap layer, and a conductive outer top tread cap layer as a tread skin must be separately manufactured by extrusion as a separate member on the outer surface of the tread, increasing the number of parts and manufacturing It is hard to say that the structure is easy to do.

  As described above, none of the tires according to the above-described prior arts can ensure electrical conductivity and can be easily manufactured while sufficiently securing the effect of improving the tread rolling resistance and wet performance by silica blending.

  The problem of the present invention is that it is possible to reliably discharge the static electricity charged to the vehicle to the road surface without requiring a special tire manufacturing method while obtaining the effect of improving the rolling resistance and wet performance of the tire by silica blending or the like. It is in providing the mounting method of a pneumatic tire.

  As a result of intensive studies on the above problem, the present inventor does not require a conductive tire by a special tire manufacturing method as described above, and uses a non-conductive tire by an existing general method while using a vehicle. The inventors have found a method for mounting a pneumatic tire that can reliably discharge static electricity to the road surface, and have reached the present invention.

The present invention relates to a pneumatic tire mounting method in which a plurality of pneumatic tires are mounted on a vehicle. An electric resistance in which one tire continuously uses conductive rubber from a rim contact portion of the tire to a tread grounding portion. A pneumatic tire characterized in that it is a conductive tire of less than 10 ⁹ Ω, and the remaining tire is a non-conductive tire using non-conductive rubber at least in the tread ground portion and having an electric resistance of 10 ⁹ Ω or more. It is a mounting method.

  In the present invention, it is effective that the conductive tire is mounted on an axle having the largest axle weight.

  According to the mounting method of the pneumatic tire of the present invention, the static electricity of the vehicle can be surely discharged from one conductive tire among the vehicle mounting tires, so that the remaining mounting tires are based on an existing general construction method. By using a non-conductive tire, features such as rolling resistance and wet performance of the non-conductive tire can be utilized. Therefore, since the conductive tire according to the special method described in the prior art is not necessary, the above problem is solved by the tire manufactured by the existing manufacturing process, and the above-mentioned disadvantage of the tire performance due to the special method is also solved. Can do.

  Hereinafter, embodiments of the present invention will be described.

  FIG. 1 is a schematic view showing a pneumatic tire mounting method according to an embodiment of the present invention.

  The vehicle A shown in the figure is a domestic passenger car of 1600 cc class displacement of the FF system, the size of the mounted tire is 195 / 65R15 88S, and the rim used is a standard rim 15 × 6JJ made of steel.

  As shown in the figure, the tire mounted on the vehicle A is mounted on the same three tires, the left front shaft (FL) and the rear rear shafts (RR, RL), and the front right shaft (FR). ) Is equipped with a tire T2 having a different specification from the tire T1. The tires T1 and T2 differ only in the rubber composition applied to the tread grounding portion of the tire. The tire internal structure, the reinforcing material such as a tire cord, the tread pattern, and the rubber material used in each part other than the tread are Are the same.

  Both the tires T1 and T2 are radial tires having a general internal structure. The tires T1 and T2 are organic fibers such as polyester and rayon, which are folded and locked around the bead cores 5 embedded in the pair of bead portions 4 from the inside to the outside as shown in the tire half-sectional view of FIG. A carcass 6 composed of a single carcass ply using a cord; a tread portion 2 of a cap / base structure composed of a cap rubber 21 and a base rubber 22 located on the outer periphery of the crown portion of the carcass 6; and a side portion of the carcass 6 A belt 7 composed of two belt plies using a steel cord disposed between the side wall portion 3 located on the inner side of the tread portion 2 and the carcass 6 inside the tread portion 2, and a tire circumferential direction on the outer periphery of the belt 7 A cap ply 8 made of a nylon cord wound in a helical shape is provided, and an inner liner 10 for holding air pressure is provided on the inner surface of the tire. It is.

  For the tire T1, the rubber composition that contributes to the improvement of the rolling resistance and the wet performance is used for the cap rubber 21 of the tread portion 2 for the purpose of improving the rolling resistance and the wet performance.

  As such a rubber composition, instead of conventional carbon black as a main reinforcing agent, silica such as precipitated silica, anhydrous silicic acid, synthetic silicate, clay such as calcined clay and hard clay, calcium carbonate A rubber composition containing a non-carbon black non-conductive reinforcing agent such as is used. Among them, the silica described in the above prior art is often used as a main reinforcing agent in place of carbon black because it has a large effect of improving rolling resistance and wet performance.

  In order to improve rolling resistance and wet performance, the rubber composition containing this non-carbon black reinforcing agent is usually 30 to 100 parts by weight of silica with respect to 100 parts by weight of the rubber component in the case of silica compounding, Preferably 40-80 weight part is mix | blended.

For example, as the silica, silica having a nitrogen adsorption specific surface area (BET) of 100 to 250 m ² / g and a DBP oil absorption of 100 ml / 100 g or more is preferable from the viewpoint of the reinforcing effect and workability, and Tosoh Silica Industry Co., Ltd. Commercially available products such as Nipseal AQ and VN3 manufactured by Ultraman VN3 manufactured by Degussa Corporation.

A rubber composition such as the above-mentioned silica compounded with a non-conductive non-carbon black reinforcing agent in place of carbon black having conductive properties has a rubber composition with an electrical resistivity of 10 ⁸ Ω · cm or more and is non-conductive. Shows sex. When this non-conductive rubber is used for the cap rubber 21 of the tread portion 2, the tread grounding portion becomes non-conductive, so that the tire T1 is a non-conductive tire having an electric resistance of 10 ⁹ Ω or more.

  Therefore, the tire T1 can improve rolling resistance and wet performance, but the tread grounding portion becomes non-conductive, and static electricity charged on the vehicle passes through the rubber material of the bead portion 4 and the sidewall portion 3 from the rim to the tread portion. When the tire T1 is mounted on the four wheels of the vehicle A because it is no longer possible to discharge from 2 to the road surface, the radio noise and electronic circuit components are adversely affected.

  Further, in order to further improve the rolling resistance and wet performance of the tire, non-conductive rubber is used not only in the tread portion 2 but also in each portion of the tire such as the sidewall portion 3 and the bead portion 4. There is an increasing tendency to become non-conductive.

Therefore, in the present invention, the tire T2 mounted on the FR is a conductive tire having an electrical resistance of less than 10 ⁹ Ω, so that static electricity charged on the vehicle is discharged to the road surface through the tire T2.

The tire T2 has at least a bead portion 4 in contact with a rim serving as a static electricity conduction path in each portion constituting the tire, and at least a ground end portion of the sidewall portion 3 and the cap rubber 21 following the bead portion 4. Conductive rubber having an electrical resistivity of less than 10 ⁸ Ω · cm is continuously used.

  The form of the energization path is not particularly limited. For example, conductive rubber may be applied to the entire tire T2. Further, a ribbon-like conductive strip rubber may be continuously disposed from the rim contact portion of the bead portion 4 to the grounding portion of the tread portion 2 through the sidewall portion 3, and any means capable of securing a static electricity conduction path. There are no restrictions.

  Thereby, static electricity charged on the vehicle through the tire T2 can be discharged to the road surface, so that problems such as radio noise and adverse effects on electronic circuit components can be solved.

As the conductive rubber used for the tire T2, a rubber composition containing conventional carbon black as a main reinforcing agent can be used, and a rubber composition containing other conductive materials may be used. The resistivity may be less than 10 ⁸ Ω · cm. More preferably, the electrical resistivity is 10 ⁷ Ω · cm or less.

  That is, as the tire T2, a tire using a conventional rubber composition containing a general carbon black can be used. Various grades such as SAF, ISAF, HAF, GPF, and FEF can be used as the grade of carbon black.

Therefore, in the present embodiment, the static electricity charged in the vehicle is discharged to the road surface through the conductive tire T2 in which one of the four tires mounted on the vehicle has an electric resistance of less than 10 ⁹ Ω. In order to further ensure the conductivity of the tire, the electrical resistance of the tire T2 is more preferably less than 10 ⁸ Ω.

  Here, when the conductive tire T2 is mounted on two of the four axes of the vehicle A, the effect of improving the rolling resistance and wet performance provided by the tire T1 is reduced, and the discharge effect of one tire T2 is sufficient. The effect of can be demonstrated.

  The rubber composition used for each part of the tires T1 and T2 is a natural rubber (NR), isoprene rubber (IR), styrene butadiene rubber (SBR), which has been conventionally used for pneumatic tires as a rubber component. Diene rubbers such as butadiene rubber (BR) are used alone or in a blend. As rubber compounding agents, softeners such as oil and wax, stearic acid, zinc white, resins, anti-aging agents, vulcanizing agents such as sulfur, vulcanization accelerators, and the like are appropriately blended. In addition, a silane coupling agent can be used in combination with silica.

  In the present invention, the mounting position of the conductive tire T2 is not particularly limited, but it is preferably mounted on the axle with the heaviest axle weight of the vehicle. This is because, in an axle with a large axle load, the load applied to the tire is increased and the contact area of the tread portion is increased, so that the discharge effect can be enhanced.

  The pneumatic tire mounting method of the present invention includes a plurality of motorcycles, two-wheeled vehicles such as motorcycles, three-wheeled vehicles, five-wheeled or more buses, trucks, trailers, and industrial vehicles. It can be applied to a vehicle equipped with a pneumatic tire.

  The electrical resistivity of the rubber composition is measured according to JIS K6911. The measurement conditions are an applied voltage of 1000 V, an air temperature of 25 ° C., and a humidity of 50%.

  In addition, the electrical resistance of the tire is defined by German WDK, Blatt 3, after running the actual tire for 3 hours at 100 km / h with the tire 1 mounted on the standard rim R at an air pressure of 200 kPa. The measurement was performed based on the “measurement procedure of tire electrical resistance under load”. That is, as shown in FIG. 3, the rim-assembled tire 1 is vertically grounded with a load of 450 kg on a copper plate 31 installed in an insulated state with respect to the base plate 30, and the central portion of the standard rim R and the copper plate 31 are Was measured using a resistance measuring device 32 having an applied voltage of 1000 volts. The temperature at the time of measurement is 25 ° C., and the humidity is 50%.

  The present invention will be specifically described below based on examples.

  Two types of cap tread rubber compounded with silica (compound 1) and carbon black (compound 2) were prepared by kneading in a conventional manner using a Banbury mixer with a capacity of 200 liters according to the formulation shown in Table 1 below. The resistivity was measured according to the above JIS K6911.

  Two types of radial tires (195 / 65R15 88S) having the structure shown in FIG. 2 in which only the cap rubber 21 was changed to Formulation 1 and Formulation 2 were manufactured. The following rubber composition containing carbon black was commonly used for each part of the tire other than the cap rubber.

  Also, the carcass 6 has a polyester cord of 1670 dtex / 2, a ply density of 22 cords / 25 mm, one ply, the belt 7 has a steel cord of 2 + 2 × 0.25, a ply density of 18 cords / 25 mm, two plies (crossing angle 45 °), The cap ply 8 commonly used was a one-piece structure having a nylon 66 cord of 940 dtex / 2 and a driving density of 28 pieces / 25 mm.

  The blending contents and electrical resistivity of the base tread rubber, sidewall rubber and bead rubber are as follows.

Base tread rubber: 80 parts by weight of NR (RSS # 3) / 20 parts by weight of SBR (JSR Co., Ltd. 1502), 45 parts by weight of carbon black FEF (Tokai Carbon Co., Ltd. Seast SO), aroma oil (Japan Energy Co., Ltd.) ) X-140) 5 parts by weight, zinc white (Mitsui Kinzoku Mining Co., Ltd., Zinc Hua 1) 3 parts by weight, stearic acid (Kao Co., Ltd. Lunac S-20) 2 parts by weight, anti-aging agent 6C (Ouchi) Shinku Chemical Co., Ltd. Nocrack 6C) 1.5 parts by weight, sulfur (Hosoi Chemical Co., Ltd. powder sulfur) 2 parts by weight, vulcanization accelerator CZ (Ouchi Shinsei Chemical Co., Ltd. Noxeller CZ) 1.5 parts by weight ..Electric resistivity = 5 × 10 ⁷ Ω · cm
-Side wall rubber: NR (RSS # 3) 40 parts by weight / BR (Ube Industries, Ltd. BR150B) 60 parts by weight, carbon black FEF (Tokai Carbon Co., Ltd. Seast SO) 50 parts by weight, aroma oil (Japan Energy ( X-140) 10 parts by weight, paraffin wax (Nippon Seiwa Co., Ltd. OZOACE-0355) 1 part by weight, zinc white (Mitsui Metal Mining Co., Ltd. zinc white No. 1) 3 parts by weight, stearic acid (Kao ( LUNAC S-20 Co., Ltd. 2 parts by weight, anti-aging agent 6C (Ouchi Shinsei Chemical Co., Ltd. Nocrack 6C) 2 parts by weight, sulfur (Hosoi Chemical Co., Ltd. powder sulfur) 2 parts by weight, vulcanization accelerator NS ( Ouchi Shinsei Chemical Co., Ltd. Noxeller NS-P) 1.5 parts by weight Electric resistivity = 7 × 10 ⁷ Ω · cm
-Bead part rubber: NR (RSS # 3) 100 parts by weight, carbon black FEF (Tokai Carbon Co., Ltd. Seast SO) 70 parts by weight, aroma oil (Japan Energy Co., Ltd. X-140) 3 parts by weight, zinc white ( 3 parts by weight of Mitsui Mining Co., Ltd. Zinc Hua 1), 2 parts by weight of stearic acid (Kao Co., Ltd. Lunac S-20), 2 parts by weight of anti-aging agent 6C (Ouchi Shinsei Chemical Co., Ltd. Nocrack 6C), Sulfur (Hosoi Chemical Co., Ltd. powder sulfur) 2 parts by weight, Vulcanization accelerator NS (Ouchi Shinsei Chemical Co., Ltd. Noxeller NS-P) 1.5 parts by weight Electric resistivity = 7 × 10 ⁶ Ω cm

The electrical resistance of the tire T1 using the blend 1 of Table 1 as the cap rubber is 5 × 10 ¹⁰ Ω (non-conductive tire), and the electrical resistance of the tire T2 using the blend 2 as the cap rubber is 2 × 10 ⁶ Ω. (Conductive tire). The measurement of the electrical resistance of the tire was based on the method shown in FIG.

  After the tires T1 and T2 were incorporated into a 15 × 16 JJ steel rim, the air pressure was adjusted to 200 kPa and mounted on a 1600cc FF domestic passenger car as shown in FIG. 1 to test fuel consumption and noise generation. In the embodiment, the tire T2 is mounted on the FR having the heaviest axle load, and the tire T1 is mounted on the remaining three shafts. In Comparative Examples 1 and 2, the same tires T1 and T2 were mounted on all four axes. In Comparative Example 3, two tires T2 were mounted on the front shaft, and two tires T1 were mounted on the rear shaft.

  The fuel consumption was measured by measuring the distance traveled per liter when the same amount of gasoline was loaded and the vehicle traveled at a constant speed. Table 2 shows an index with Comparative Example 1 as 100. Larger values indicate better fuel economy.

As for noise, we investigated the occurrence of noise such as radio noise and car TV reception interference when passing over metal installations (manholes, etc.) installed on the road surface while traveling on general roads.

  The pneumatic tire mounting method of the present invention mounts a plurality of pneumatic tires such as a motorcycle, a two-wheeled vehicle such as a motorcycle, a three-wheeled vehicle, a five-wheeled bus, a truck, and a trailer in addition to a four-wheeled vehicle such as a passenger car. It can be applied to vehicles.

It is a schematic diagram which shows the mounting method of the pneumatic tire of embodiment. It is a half sectional view of a pneumatic tire. It is the schematic which shows the measuring method of the electrical resistance of a tire.

A …… Vehicle FR …… Front right axle T1 …… Non-conductive tire T2 …… Conductive tire

Claims (2)

In the mounting method of the pneumatic tire for mounting a plurality of pneumatic tires on the vehicle,
One tire is a conductive tire having an electrical resistance of less than 10 ⁹ Ω using a conductive rubber continuously from the rim contact portion of the tire to the tread grounding portion, and the remaining tire is a tread having at least a non-conductive rubber. A method for mounting a pneumatic tire, wherein the tire is a non-conductive tire having an electrical resistance of 10 ⁹ Ω or more used for a grounding portion. The method for mounting a pneumatic tire according to claim 1, wherein the conductive tire is mounted on an axle having the largest axle load.

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