JP2013071368A - Method for manufacturing pneumatic tire and pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a pneumatic tire making lighter weight compatible with cutting resistance at high precision and high quality.SOLUTION: A method for manufacturing the pneumatic tire that includes a side protection layer arranged between a sidewall rubber and a carcass. includes a raw tire forming process for forming a raw tire by pasting one by one tire component members on a rigid core and a vulcanizing process for vulcanization-molding the raw tire by feeding the same into a vulcanization mold together with the rigid core. The raw tire forming process includes a side protection layer forming process for forming the side protection layer by winding into a spiral shape on the rigid core a narrow belt-like net shaped fabric tape in which a net shaped fabric woven with warp yarns and weft yarns is covered with a topping rubber.

Description

  The present invention relates to a method for manufacturing a pneumatic tire capable of improving cut resistance while reducing weight, and a pneumatic tire.

  In order to save energy, there is a strong demand for tires to reduce rolling resistance and improve fuel efficiency, and as one of them, a thinner sidewall rubber has been proposed. However, when the rubber thickness of the side wall rubber is reduced, the cut resistance is reduced, and when the side wall part comes into contact with or collides with the curb or the like during running, cut scratches occur and the tire life is reduced. There's a problem.

  Therefore, Patent Document 1 below proposes a tire in which a protective layer made of rubberized canvas cloth (net-like woven fabric) is provided between a carcass and sidewall rubber. Since this protective layer is excellent in cut resistance, it is possible to effectively prevent the occurrence of deep trauma leading to the carcass and to suppress the reduction in cut resistance due to the thinning of the sidewall rubber.

  And in the said patent document 1, in order to form the tire which has such a protective layer, in the said protective layer, it arrange | positions so that the direction of the warp and the weft which comprise a canvas cloth may cross | intersect with respect to a tire circumferential direction. Yes. Thereby, in the unvulcanized state, the warp and weft can be deformed into a pantograph shape, so that the canvas cloth can be expanded and contracted. As a result, it is possible to form a tire by a conventional method, such as a shaping step in the conventional method and a vulcanization stretch in a vulcanization mold.

  However, although the canvas cloth can expand and contract, when the protective layer extends in the tire circumferential direction, the width inevitably decreases. As a result, the tire is also deformed due to the protective layer at the time of forming the tire, leading to a tendency to deteriorate uniformity and tire quality. Also, there is a limit to the amount of expansion, and there is a great limitation in implementation, for example, shaping is insufficient for tires with a large flatness.

JP 2006-160106 A

  Therefore, the present invention is a pneumatic tire that has a protective layer using a rubberized canvas cloth (net-like woven fabric) and can form a pneumatic tire that achieves both weight reduction and cut resistance with high accuracy and high quality. An object of the present invention is to provide a tire manufacturing method and a pneumatic tire.

In order to solve the above-mentioned problems, the invention of claim 1 of the present application provides a carcass extending from a tread portion to a bead portion on both sides through a side wall portion, and between the side wall rubber forming the outer surface of the side wall portion and the carcass. A pneumatic tire manufacturing method comprising a side protective layer disposed on
A raw tire forming step of forming a raw tire by sequentially pasting unvulcanized tire constituent members on a rigid core;
A vulcanization step of vulcanizing and molding the raw tire together with the rigid core into a vulcanization mold,
And the raw tire forming step is a method for forming a narrow belt-shaped net fabric tape covered with a topping rubber by a net fabric made by weaving warps and wefts made of organic fibers on the rigid core and outside the carcass. It includes a side protective layer forming step of forming a side protective layer by winding in a spiral around the tire axis.

  According to a second aspect of the present invention, the reticulated textile tape is characterized in that one of the warp yarns or the weft yarns extends continuously in the tape length direction.

  According to a third aspect of the present invention, the reticulated woven tape has a tape width in the range of 3 to 25 mm.

  According to a fourth aspect of the present invention, the topping rubber of the reticulated textile tape contains short fibers.

  Further, in claim 5, the side protective layer has a gap between the tightly wound portion where the side edges of the mesh fabric tape adjacent in the radial direction are joined together and the side edge of the mesh fabric tape adjacent in the radius direction. It is characterized by including at least two of the provided loosely wound portion and the overlappingly wound portion in which the side edge portions of the reticulated fabric tape adjacent in the radial direction are overlapped.

  According to a sixth aspect of the present invention, in the green tire forming step, a strip sheet-shaped strip ply piece in which an array of carcass cords aligned in the tire axial direction is covered with a topping rubber and the ply width in the tire circumferential direction is reduced. And a carcass forming step of forming a carcass by sequentially sticking in the tire circumferential direction.

  A seventh aspect of the present invention is a pneumatic tire invention, which is formed by the manufacturing method according to any one of the first to sixth aspects.

  In the present specification, unless otherwise specified, the dimensions and the like of each part of the tire are values specified in a normal internal pressure state in which a normal rim is assembled and filled with a normal internal pressure. The “regular rim” is a rim determined for each tire in the standard system including the standard on which the tire is based, for example, a standard rim for JATMA, “Design Rim” for TRA, or ETRTO means "Measuring Rim". The “regular internal pressure” is the air pressure defined by the standard for each tire. If JATMA, the maximum air pressure, if TRA, the maximum value described in the table “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” In the case of ETRTO, it means “INFLATION PRESSURE”, but in the case of passenger car tires, it is 200 kPa.

  As described above, the present invention includes a raw tire forming step of forming a raw tire by sequentially pasting unvulcanized tire components on a rigid core, and the raw tire together with the rigid core in a vulcanization mold. It adopts a core method that includes a vulcanization process in which the vulcanization process is carried out.

  The side protective layer is formed by winding a mesh woven tape in a spiral shape in the green tire forming step. Therefore, the side protective layer can be formed at a free position in the side wall portion with a free width. The side protective layer can also be formed by tightly winding the side edges of the mesh fabric tape, loose winding with a gap between the side edges, or lap winding with the side edges overlapped, Various side protective layers having different physical properties can be formed while using the same reticulated fabric tape.

  Moreover, in the core method, the raw tire is directly formed on the rigid core in a shape close to the finished tire. For this reason, shaping (expansion deformation from a cylindrical shape to a toroidal shape) and vulcanization stretch in the vulcanization mold do not occur when forming a raw tire in the conventional method. Therefore, even when the side protective layer is formed by spiral winding of the mesh fabric tape, the deformation of the side protective layer after the formation, the deterioration of the tire uniformity due to the side protective layer, the deterioration of the quality Furthermore, restrictions on the size of the tire to be formed can be eliminated.

  In addition, since the side protective layer includes a net-like woven fabric in which warp yarns and weft yarns are woven together, it is possible to uniformly reinforce all directions including the circumferential direction, the radial direction, and the middle direction thereof, and the occurrence of deep trauma to the carcass. It can be effectively prevented, and a reduction in cut resistance can be suppressed even when the sidewall rubber is thinned.

It is sectional drawing which shows one Example of the pneumatic tire formed by the manufacturing method of this invention. It is sectional drawing which shows a raw tire formation process. It is sectional drawing which shows a vulcanization | cure process. (A) is a perspective view which shows the strip ply piece used for a carcass formation process, (B) is a perspective view which shows the reticulated textile tape used for a side protective layer formation process. (A), (B) is sectional drawing and a side view explaining a carcass formation process. (A), (B) is the side view explaining the side protection layer formation process, and the one part enlarged view. (A)-(C) are sectional drawings which show an adhesion winding, a loose winding, and a lap winding notionally.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a cross-sectional view showing an example of a pneumatic tire 1 formed by the manufacturing method of the present invention. The pneumatic tire 1 has bead portions 4 on both sides through a sidewall portion 3 from a tread portion 2. And a side protective layer 10 disposed between the carcass 6 and the side wall rubber 3G forming the outer surface 3S of the side wall portion 3. In this example, the pneumatic tire 1 is a radial tire for a passenger car, and a case where a tough belt layer 7 is disposed radially outside the carcass 6 and inside the tread portion 2 is shown.

  The carcass 6 is formed of a carcass ply 6A in which organic fiber carcass cords are radially arranged. The carcass ply 6 </ b> A has a toroidal shape straddling the bead portions 4 and 4. In the case of this example, both end portions of the carcass ply 6A are sandwiched and locked in the bead core 5 without being folded around the bead core 5 disposed in each bead portion 4. Specifically, the bead core 5 is composed of inner and outer core pieces 5i and 5o in the tire axial direction, and both ends of the carcass ply 6A are sandwiched between the inner and outer core pieces 5i and 5o.

  The inner and outer core pieces 5i, 5o are formed by winding an inextensible bead wire a plurality of times in the tire circumferential direction. At this time, in the outer core piece 5o, the number of windings of the bead wire 5a is, for example, about 1.2 to 2.0 times larger than that of the inner core piece 5i, and the rigidity is larger than that of the inner core piece 5i. Is preferred. As a result, the bending rigidity of the bead portion 4 can be relatively increased while restricting the total number of turns of the bead wire 5a, which is useful for improving the steering stability. In addition, the code | symbol 8 in a figure is a bead apex which consists of hard rubber | gum whose rubber hardness is 80-100 degree | times, for example, rises from each core piece 5i, 5o in a taper shape, and raises bead rigidity. In this specification, rubber hardness means durometer A hardness measured in a 23 ° C. environment by durometer type A based on JIS-K6253.

  The belt layer 7 is formed of two or more belt plies 7A and 7B in this example, in which high-elasticity belt cords such as steel cords are arranged at, for example, about 10 to 35 ° with respect to the tire circumferential direction. . This belt layer 7 has a belt cord that crosses between plies to increase belt rigidity, and substantially reinforces substantially the entire width of the tread portion 2 with a tagging effect. In this example, a band layer in which a band cord such as a nylon cord is spirally wound at an angle of 5 degrees or less with respect to the circumferential direction for the purpose of enhancing high-speed durability on the outer side in the radial direction of the belt layer 7. 9 is provided. As the band layer 9, a pair of left and right edge band plies that covers only the outer end of the belt layer 7 in the tire axial direction, and a full band ply that covers substantially the entire width of the belt layer 7 are used alone or in appropriate combination. Can be used. In this example, the band layer 9 is composed of one full band ply.

  A side wall rubber 3G forming the outer surface 3S of the side wall portion 3 is disposed outside the carcass 6, and a side protective layer 10 is disposed between the side wall rubber 3G and the carcass 6. Is done.

  In the side protective layer 10, as shown in FIG. 4 (B), a narrow band-like net-like fabric tape in which a net-like fabric 11 in which warp yarns 11 a and weft yarns 11 b made of organic fibers are woven together is covered with a topping rubber 12. As shown in FIG. 6, the side protective layer 10 is formed in an endless shape by winding the mesh woven tape 13 in a spiral around the tire axis.

  Since the side protective layer 10 includes the reticulated fabric 11 as a reinforcing member, the side protective layer 10 can uniformly reinforce all directions including the circumferential direction, the radial direction, and the intermediate direction, and prevents the occurrence of deep trauma to the carcass 6. Cut resistance can be improved.

The side protective layer 10, as illustrated in FIG. 1, the distance the distance of 10% of the tire section height H from the bead base line BL from 10% height position P ₁₀ of spaced radially 85% preferably a is formed in the side region Y from the bead base line BL up to 85% the height position P ₈₅ of spaced radially.

  In particular, in order to protect the buttress portion that is easily contacted with a curbstone and prevent the occurrence of cut scratches more effectively, the radial height Ho from the bead base line BL to the outer end of the side protective layer 10 (referred to as the outer end height Ho). May be 75% or more of the tire cross-section height H, and the radial height Hi from the bead base line BL to the inner end of the side protective layer 10 (may be referred to as the inner end height Hi). It is preferable to be 60% or less of the height H.

  Furthermore, the side protective layer 10 can increase the in-plane rigidity because the warp yarn 11a and the weft yarn 11b are constrained and restrained from moving, and is effective in improving steering stability. Therefore, in order to improve the steering stability in addition to the cut resistance, the inner end height Hi of the side protective layer 10 is set to 50% or less, further 30% or less of the tire cross-section height H, It is preferable to make it 15% or less.

  Here, in the side protective layer 10, as a method for winding the mesh fabric tape 13, as shown in FIGS. 7 (A) to (C), the tightly wound ka with the side edges of the mesh fabric tape 13 attached to each other, A loose winding kb having a gap g between the side edges and an overlapping winding kc in which the side edges are overlapped with each other can be adopted. At this time, the loosely wound kb has a smaller reinforcing effect than the closely wound ka and is inferior in an improvement effect on cut resistance and steering stability, but is excellent in weight reduction. In addition, the overlap winding kc is inferior in weight reduction as compared to the tight winding ka, but has a characteristic that the reinforcing effect is large and the improvement effect on cut resistance and steering stability is excellent. Therefore, the tire can be tuned according to the required characteristics by selecting the winding method of the mesh fabric tape 13.

Further, as shown in FIG. 1, the side region Y is divided into three as follows, a radially outer side region YU, an intermediate side region YM, and a radially inner side region YL. When
(A) The radially outer side region YU has a large effect on cut resistance, a large effect on steering stability, and a small effect on ride comfort.
(B) The middle side region YM has a small effect on cut resistance, a small effect on steering stability, and a large effect on ride comfort.
(C) The radially inner side region YL has a small effect on cut resistance, a large effect on steering stability, and a small effect on ride comfort.
It can be said that it is an important area range.

  Therefore, in one tire, more advanced tuning can be performed by changing the winding method of the mesh fabric tape 13 between the side region portions YU, YM, YL. Specifically, in the present example, the side protective layer 10 is formed as a tightly wound portion KA in which the reticulated fabric tape 13 is tightly wound ka in the radially outer and inner side region portions YU and YL, In the side region YM, a case where the mesh fabric tape 13 is formed as a loosely wound portion KB obtained by loosely winding kb is shown. In this case, it is possible to enhance ride comfort and promote weight reduction while exhibiting substantially the same cut resistance and steering stability as the tire having the entire side protective layer 10 as the tightly wound portion KA.

  Here, the side region portions YU, YM, and YL are a height position Pa that separates a distance of 55 to 65% of the tire cross-section height H from the bead base line BL in a radial direction, and a distance of 40 to 30%. The side region Y is divided into three regions by a height position Pb separated from the bead base line BL in the radial direction, and the radially outer side region portion YU is radially outward from the height position Pa. The intermediate side region YM means a region range between the height positions Pa and Pb (including height positions Pa and Pb), and the radially inner side region portion. YL means a region range radially inward from the height position Pb.

  When the outer end height Ho of the side protective layer 10 exceeds 85% of the tire cross-sectional height H, the outer end 10E of the side protective layer 10 is too close to the outer end 7E of the belt layer 7, and stress is concentrated. However, the durability performance tends to deteriorate, such as causing damage starting from the outer end 7E or 10E. In addition, when the inner end height Hi is less than 10% of the tire cross-section height H, the material cost, mass, and process time are unnecessarily increased although there is no adverse effect on cut resistance and steering stability. Incurs a disadvantage.

  Further, a thin inner liner 14 that forms a tire cavity surface is disposed inside the carcass 6. The inner liner 14 is made of a non-air permeable rubber such as butyl rubber or halogenated butyl rubber, for example, and holds the air filled in the tire lumen in an airtight manner. Further, tread rubber 2 </ b> G forming the outer surface 2 </ b> S of the tread portion 2 is disposed on the radially outer side of the band layer 9.

  Next, a method for manufacturing the pneumatic tire 1 will be described. In this manufacturing method, as schematically shown in FIG. 2, a raw tire forming step J1 for forming a raw tire 1N by sequentially pasting unvulcanized tire constituent members on the outer surface of the rigid core 20, and FIG. 3, the raw tire 1 </ b> N is put together with the rigid core 20 into a vulcanization mold 21 and is vulcanized and formed. The rigid core 20 has an outer shape that substantially matches the tire lumen shape of the pneumatic tire 1.

  The raw tire forming step J1 includes an inner liner forming step of attaching a member for forming the inner liner 14 to the rigid core 20, a carcass forming step of attaching a member for forming the carcass 6, and a member for forming the side protective layer 10. Adhering side protective layer forming step, bead core forming step for attaching bead core 5 forming member, bead core forming step for attaching bead apex 8 forming member, belt forming step for attaching belt layer 7 forming member, band It includes a band forming step for attaching a member for forming the layer 9, a sidewall forming step for attaching a member for forming the sidewall rubber 3G, a tread forming step for attaching a member for forming the tread rubber 2G, and the like.

  Among these, well-known various things using the rigid core 20 can be suitably employed for the steps other than the carcass forming step and the side protective layer forming step in the raw tire forming step J1 and the vulcanizing step J2. Therefore, in the present specification, only the carcass forming step and the side protective layer forming step will be described below.

  In the carcass forming step, as shown in FIG. 4A, an array 31 of carcass cords 30 aligned in the tire axial direction is covered with a topping rubber 32, and the ply width W1 in the tire circumferential direction is reduced. A plurality of strip ply pieces 16 in the form of strip sheets are used. Then, as shown in FIGS. 5A and 5B, the strip ply pieces 16 are sequentially attached in the tire circumferential direction on the rigid core 20 and outside the inner liner 14, thereby forming the carcass ply 6A. To do. 5A and 5B, the inner liner 14 is omitted to simplify the drawing.

  At this time, in this example, in the tire equator Co, the strip ply pieces 16 adjacent in the circumferential direction are arranged with their side edges attached to each other or close to each other. Thereby, in the said side area | region Y, the overlap part D where the side edge parts of the strip ply piece 16 mutually overlap is formed. The ply width W1 is preferably in the range of 10 to 50 mm. If the ply width W1 exceeds 50 mm, the overlapping portion D becomes large, which may cause a decrease in uniformity. On the other hand, if the thickness is less than 10 mm, the number of the strip ply pieces 16 becomes excessive, and it takes time for pasting.

  Next, in the side protective layer forming step, as described above, the narrow belt-like mesh fabric tape 13 (shown in FIG. 4B) is used, and the mesh fabric tape 13 is formed as shown in FIGS. As shown in B), the side protective layer 10 is formed in an endless shape by winding it around the tire core on the rigid core 20 and outside the carcass ply 6A. In the side protective layer forming step, the tight winding ka, loose winding kb, and lap winding kc can be freely selected. Further, in one side protective layer forming step, by performing at least two of a close winding step for tightly winding the mesh fabric tape 13, a loose winding step for loose winding, and an overlapping winding step for overlapping winding, In one tire 1, the side protective layer 10 including at least two of the tightly wound portion KA, the loosely wound portion KB, and the overlapped winding portion KC can be formed.

  In such a core method, shaping at the time of green tire formation in the conventional method and vulcanization stretch in the vulcanization mold do not occur. Therefore, even when the side protective layer 10 is formed by the side protective layer forming step, the deformation of the side protective layer 10 after the formation, the deformation of the tire due to the deformation of the side protective layer 10, the decrease in uniformity, etc. Can prevent every time. Also, restrictions on tire size and the like can be eliminated. In addition, as the net-like woven fabric tape 13, it is possible to use a non-stretchable one in which one of the warp yarn 11a or the weft yarn 11b extends continuously in the tape length direction.

  The side protective layer 10 formed by the side protective layer forming step can cover the overlapping portion D in the carcass ply 6A formed by the carcass forming step. That is, the unevenness in the side region Y that is repeated in the circumferential direction due to the overlapping portion D can be hidden, which can contribute to the improvement of the appearance performance.

  Here, in the reticulated textile tape 13, the tape width W2 is preferably in the range of 3 to 25 mm. When the tape width W2 is less than 3 mm, the side region portion YU on the outer side in the radial direction, such as an increase in the number of windings for forming the side protective layer 10, causes a decrease in productivity. On the contrary, if it exceeds 25 mm, the rigidity difference becomes excessive at the winding start end and the winding end of the reticulated woven tape 13 and stress tends to concentrate. Incurs a tendency to decline. Therefore, the lower limit value of the tape width W2 is more preferably 5 mm or more, and the upper limit value is more preferably 15 mm or less.

  Further, as the warp yarn 11a and the weft yarn 11b used for the net-like woven fabric 11, for example, organic fiber yarns such as nylon, polyester, rayon, aramid, etc. can be suitably used, and the thickness thereof is 300 to 800 dtex (for example, 490 dtex). The range is suitable, and the pitch interval of the warp yarns 11a and the pitch interval of the weft yarns 11b in the mesh fabric 11 are each preferably in the range of 20 to 50 / 5cm (for example, 38 / 5cm). The mesh fabric tape 13 obtained by coating the mesh fabric 11 with the topping rubber 12 has a thickness of about 0.5 to 1.0 mm, more preferably 0.7 to 0.9 mm.

  Further, in the mesh woven tape 13, short fibers can be contained in the topping rubber 12 in order to enhance the reinforcement in the side protective layer 10 and further improve the cut resistance and steering stability of the tire. About content of the said short fiber, 10-60 mass parts (phr) with respect to 100 mass parts of rubber | gum, Furthermore, 25-45 mass parts (phr) are preferable. When the content of the short fiber is less than 10 parts by mass (phr), the reinforcing effect by the short fiber is hardly exhibited. Conversely, when the content exceeds 60 parts by mass (phr), looseness occurs and durability tends to deteriorate. Become.

  The types of short fibers are not particularly restricted, and are, for example, organic fibers such as nylon, polyester, aramid, rayon, vinylon, cotton, cellulose resin, crystalline polybutadiene, metal fibers, such as whisker, boron, glass fiber. Inorganic fibers such as can be suitably used. Although the size of the short fiber is not particularly restricted, the average fiber length L is preferably 20 to 5000 μm, and the average fiber length L and the fiber diameter d are preferably 10 to 500 in aspect ratio L / d. Can be adopted.

  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 various aspects.

  A tire for a passenger car (tire size 195 / 65R15) having the structure shown in FIG. 1 was manufactured using the manufacturing method according to the present invention and based on the specifications shown in Table 1, and the cut resistance, general durability, and steering of each tire were manufactured. Stability, ride comfort and tire productivity were tested and compared to each other. Further, the mass of the side protective layer in each tire, the sidewall thicknesses t1 and t2 from the carcass at a predetermined position of the sidewall portion, and the mass of the sidewall portion were measured and compared with each other.

  In each tire, the mesh fabric used for the mesh fabric tape has the same configuration, and organic fiber yarns (6 nylon, 490 dtex) with a thickness of 0.5 mm are used as warp yarns and weft yarns, and they are woven together at a pitch interval of 38 / 5cm. Reticulated fabric is used. The reticulated fabric was dipped in a dipping solution (RFL) for adhesion and then covered with a topping rubber with a calendar roll to obtain a reticulated fabric tape having a total thickness of 0.8 mm.

  The side region Y includes a height position Pa separating a distance of 57% of the tire cross-section height H from the bead base line BL in the radial direction and a height separating a distance of 37% from the bead base line BL in the radial direction. According to the position Pb, it is divided into three parts: a radially outer side region YU, an intermediate side region YU, and an inner side region YL. In Examples 12 to 19, the side regions YU, YM, YL uses a different method for winding the mesh fabric tape.

  For comparison, a conventional tire having no side protective layer was produced as Comparative Examples 1 and 2. In Comparative Example 2, the cut resistance is improved by increasing the thickness of the sidewall rubber in the outer side region YU as compared with Comparative Example 1.

(1) Cut resistance:
Tires are mounted on all wheels of a passenger car (displacement of 2000 cc) under the conditions of rim (15 x 6 J) and internal pressure (200 kPa), and the speed is stepped up by 1 km / H from 5 km / h. Was hit against the curb and the speed at which the side wall was cut was indicated by an index with Comparative Example 1 taken as 100. The larger the value, the better the cut resistance.

(2) General durability:
Using a drum tester, based on the conditions of rim (15 × 6J), internal pressure (200 kPa), load load (7.0 kN), run at a speed of 80 km / h, and determine the mileage when the tire is damaged. It was measured. The complete run is 25,000 km.

(3) Steering stability and ride comfort:
Using the vehicle used in (1) above, a test course on a dry paved road was run on an actual vehicle, and steering stability and ride comfort were evaluated by a sensory evaluation by a professional driver using a 10-point method. The larger the value, the better.

(4) Tire productivity:
The time required to form a green tire was displayed as an index with Comparative Example 1 taken as 100. The smaller the value, the lower the productivity.

(5) Mass of side protective layer:
The total mass of the side protective layer per raw tire was measured and displayed as an index with Example 1 as 100.

(6) Side wall thickness t1, t2:
As shown in FIG. 1, 85% of the tire cross-section height H is radially spaced from the bead base line BL by 85% height position P ₈₅ , and 50% of the distance is radially from the bead base line BL. sidewall from the measured carcass to the sidewall outer surface in spaced 50% height position P ₅₀ is the thickness t1, t2.

(7) Mass of the sidewall part:
The sum of the mass of the side protective layer per raw tire and the mass of the side wall rubber was determined and displayed as an index with Comparative Example 1 taken as 100.

  As shown in the table, it can be confirmed that the tires of the examples can improve the cut resistance while suppressing an increase in the tire weight.

DESCRIPTION OF SYMBOLS 1 Pneumatic tire 2 Tread part 3 Side wall part 3G Side wall rubber 4 Bead part 6 Carcass 10 Side protective layer 11 Reticulated fabric 11a Warp thread 11b Weft 12 Topping rubber 13 Reticulated fabric tape 16 Strip ply piece 20 Rigid core 21 Vulcanized gold Mold 30 Carcass cord 31 Array 32 Topping rubber KA Adhesion winding part KB Loose winding part KC Overlap winding part J1 Raw tire formation process J2 Vulcanization process

Claims (7)

A pneumatic tire manufacturing method including a carcass extending from a tread portion to a bead portion on both sides through a sidewall portion, and a side wall rubber forming an outer surface of the sidewall portion and a side protective layer disposed between the carcass. Because
A raw tire forming step of forming a raw tire by sequentially pasting unvulcanized tire constituent members on a rigid core;
A vulcanization step of vulcanizing and molding the raw tire together with the rigid core into a vulcanization mold,
And the raw tire forming step is a method for forming a narrow belt-shaped net fabric tape covered with a topping rubber by a net fabric made by weaving warps and wefts made of organic fibers on the rigid core and outside the carcass. A method for producing a pneumatic tire, comprising a step of forming a side protective layer by forming a side protective layer by winding it in a spiral around the tire axis.   2. The method for producing a pneumatic tire according to claim 1, wherein one of the warp yarn or the weft yarn extends continuously in the tape length direction.   The method for producing a pneumatic tire according to claim 1 or 2, wherein the reticulated woven tape has a tape width of 3 to 25 mm.   The method for manufacturing a pneumatic tire according to any one of claims 1 to 3, wherein the topping rubber of the mesh fabric tape contains short fibers.   The side protective layer includes a tightly wound portion in which side edges of the mesh fabric tape adjacent in the radial direction are attached to each other, and a loosely wound portion in which a gap is provided between the side edges of the mesh fabric tape adjacent in the radius direction. The air according to any one of claims 1 to 4, comprising at least two of a lap winding portion in which side edges of adjacent mesh-like woven fabric tapes that are adjacent inside and outside in the radial direction are overlapped with each other. A method for manufacturing a tire.   In the green tire forming step, strip ply pieces in the form of strip sheets, in which an array of carcass cords aligned in the tire axial direction is covered with a topping rubber and the ply width in the tire circumferential direction is reduced, are sequentially formed in the tire circumferential direction. The method for manufacturing a pneumatic tire according to any one of claims 1 to 5, further comprising a carcass forming step of forming a carcass by pasting.   A pneumatic tire formed by the manufacturing method according to claim 1.

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