JP2009034924A - Method of manufacturing pneumatic tire, and pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the occurrence of peeling and drop out of a sound absorption layer composed of a porous material by achieving the uniformization of the height of the sound absorption layer in particular relating to a method of manufacturing a pneumatic tire having the sound absorption layer on an inner surface of an inner liner. <P>SOLUTION: The method for manufacturing the pneumatic tire comprises constituting the sound absorption layer by pasting at least one band-shaped member consisting of the porous material and having a notched part onto a molding drum along a drum peripheral direction, The pneumatic tire 1 has the sound absorption layer composed of the porous material on the inner surface of the inner liner. Such sound absorption layer has the notched part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a pneumatic tire having a sound absorbing layer made of a porous material on the inner surface of an inner liner, and in particular, while making the height of the sound absorbing layer uniform, It is intended to suppress the occurrence of peeling and dropping. The present invention also relates to a pneumatic tire having a sound-absorbing layer made of a porous material on the inner surface of the inner liner, and in particular, suppresses cavity resonance of the pneumatic tire to reduce road noise. However, the height of the sound absorbing layer is made uniform, and the occurrence of peeling and dropping of the sound absorbing layer is suppressed, thereby suppressing the peeling and dropping of the sound absorbing layer at the time of tire load rolling.

  In a pneumatic tire assembled in a rim and attached to a vehicle, the tread portion oscillates against the road surface unevenness while the vehicle is running, so that air filled in the tire cavity resonates. This cavity resonance is a main cause of so-called road noise, and many of the resonance frequencies exist in the range of 180 to 300 Hz. When the road noise is transmitted to the vehicle interior, unlike a noise in other frequency bands, it takes a sharp and high peak value, which is annoying noise for passengers in the vehicle interior.

  In order to suppress such cavity resonance and reduce road noise, Patent Document 1 discloses a ring for sound control made of a porous material in a tire lumen formed by a rim and a pneumatic tire attached to the rim. A pneumatic tire having a sound absorbing layer fixed in the tire circumferential direction has been proposed. However, in the invention described in Patent Document 1, although road noise during traveling can be effectively reduced, a belt-like sheet made of foam or the like obtained by foaming rubber or synthetic resin is used as an inner liner on the inner peripheral side of the tread portion. In addition, the belt-like sheet extends in the circumferential direction and is firmly attached, and the heat insulating function is also exhibited. Therefore, the heat generated in the tread portion is smoothly transferred into the lumen defined by the pneumatic tire and the rim. There was an inconvenience that it was impossible to dissipate.

Japanese Patent No. 3622957

  In order to solve such problems of the prior art, the applicant of the present application, in Japanese Patent Application No. 2007-009062, suppresses cavity resonance by attaching a sound absorbing layer on the inner liner of the pneumatic tire. While reducing road noise, providing at least one through hole that reaches the inner liner in the sound absorbing layer allows heat to be dissipated from the through hole in the sound absorbing layer when the tread part generates heat, thereby suppressing thermal destruction of the tread part. Proposed tires. However, although such a pneumatic tire has reduced road noise due to cavity resonance, the height of the sound absorbing layer becomes non-uniform during production, or the sound absorbing layer is peeled off or dropped off. There is a risk that the sound absorbing layer may be peeled off and dropped off from the tire body during rolling. Further, in manufacturing such a pneumatic tire, when forming a raw tire having a sound absorbing layer by affixing a strip-shaped member on a molding drum, a raw case with a sound absorbing layer is attached. When expanding with a bladder or the like, the expansion ratio in the vicinity of the central portion in the axial direction of the raw case is high, and the expansion is performed uniformly. For this reason, the sound absorbing layer attached to the inner surface in the vicinity of the central portion in the axial direction of the raw case cannot be expanded following such expansion, and the height becomes nonuniform due to being pulled. There is a risk of peeling or dropping off from the inner surface of the raw case. On the other hand, the sound absorption layer attached to the inner surface near the edge of the raw case has a smaller expansion rate as it is closer to the edge of the raw case, and an expansion difference occurs during expansion. If it is pulled farther away, the height becomes non-uniform, or in extreme cases, the sound absorbing layer may peel off or fall off. Pneumatic tires such as those described above, where the sound absorbing layer has a non-uniform height or the sound absorbing layer is peeled off, are deteriorated in uniformity due to the above reasons, resulting in a decrease in running performance. There is a possibility that the sound absorption layer may be peeled off and dropped during tire load rolling, and road noise due to cavity resonance cannot be reduced. The “height of the sound absorbing layer” here refers to the length of the sound absorbing layer measured along the normal line standing on the inner surface of the tire.

  Accordingly, an object of the present invention is to solve these problems. The purpose of the present invention is to reduce the road noise due to the cavity resonance of the pneumatic tire while keeping the height of the sound absorbing layer uniform. Another object of the present invention is to provide a pneumatic tire that suppresses the occurrence of peeling and dropping of the sound absorbing layer by suppressing the occurrence of peeling and dropping of the sound absorbing layer. Moreover, the objective of this invention is providing the manufacturing method of such a pneumatic tire.

  In order to achieve the above object, the first invention is a method for producing a pneumatic tire comprising a sound absorbing layer made of a porous material on the inner surface of an inner liner. The pneumatic tire manufacturing method is characterized in that at least one belt-like member having a portion is attached along the circumferential direction of the drum to constitute a sound absorbing layer. By adopting such a manufacturing method, when a strip-like member is attached in the vicinity of the central portion of the raw case in the axial direction, when the raw case is expanded by a bladder or the like, the center of the raw case in the axial direction is used. Even if the vicinity of the part is evenly expanded at a high expansion rate, the band-shaped member is provided with a cut portion, so that the cut portion opens following the expansion of the raw case, so that the height of the sound absorbing layer is uniform. Thus, it is possible to suppress the occurrence of peeling and dropping of the sound absorbing layer. In addition, as the raw case gets closer to the end of the raw case, the expansion rate decreases, and the closer to the end of the raw case, the expansion difference occurs without expansion. When a band-shaped member having a portion is attached, the cut portion opens following such expansion, so that the sound absorbing layer is not pulled excessively and the height of the sound absorbing layer becomes uniform, and the sound absorbing layer is peeled off. The occurrence of dropout can be suppressed. The “cut portion” here refers to a strip-shaped porous member provided with a linear cut or a partially cut portion. Further, a portion in which a porous member having a cut portion is attached to the inside of the tire and the cut portion is open is referred to as a “cut portion” of the sound absorbing layer.

  Further, it is preferable to use a belt-like member having a cut portion extending in a direction crossing the longitudinal direction of the belt-like member from at least one of the short-side ends of the belt-like member.

  Furthermore, it is preferable that the width | variety of a notch part exists in the range of 5-80% of the width | variety of a strip | belt-shaped member, More preferably, it exists in the range of 10-40%.

  A second invention is a pneumatic tire having a sound absorbing layer made of a porous material on an inner surface of an inner liner, wherein the sound absorbing layer is composed of at least one strip member extending along the tire circumferential direction. Is a pneumatic tire characterized by having a notch extending from at least one of the tire width direction ends in a direction crossing the tire circumferential direction. Since such a pneumatic tire is provided with a sound absorbing layer, road noise due to cavity resonance can be reduced, and since this tire can be manufactured according to the first invention, the height of the sound absorbing layer can be reduced. While ensuring the uniformity of the sound, it is possible to suppress the occurrence of peeling and dropping of the sound absorbing layer, and it is possible to suppress the occurrence of peeling and dropping of the sound absorbing layer at the time of tire load rolling.

  According to the present invention, when producing a pneumatic tire having a sound absorbing layer made of a porous material on the inner surface of the inner liner, the height of the sound absorbing layer becomes uniform, and the sound absorbing layer is peeled off and dropped off. It is possible to provide a method for manufacturing a suppressed pneumatic tire. In addition, according to the present invention, it is possible to provide a pneumatic tire in which road noise due to cavity resonance is reduced, the height of the sound absorbing layer is made uniform, and the occurrence of peeling and dropping of the sound absorbing layer is suppressed. .

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a cross section in the tire width direction of an assembly of a tire and a rim formed by mounting a typical pneumatic tire (hereinafter referred to as “tire”) according to the present invention on a rim. FIG. 2 is a partial development view of the tire inner surface of the tire shown in FIG.

  A tire 1 according to the present invention includes a tread portion 2 that contacts a road surface, a pair of sidewall portions 3 that extend inward in the tire radial direction from both side portions of the tread portion 2, and a tire radial direction of each sidewall portion 3. A tire body 5 is configured by a pair of bead portions 4 provided on the inner side and fitted to the rim R. Inside the tire body 5, a bead core 6, 6 embedded in each bead portion 4 extends in a toroidal shape to form a skeleton structure of the tire body 5, for example, a radial structure carcass 7, and a crown area of the carcass 7. A belt 8 that reinforces the tread portion 2 is provided. An air-impermeable inner liner 10 is disposed on the inner surface side of the tire body 5, that is, on the side facing the tire lumen 9 defined by the tire 1 and the rim R. Further, as shown in FIGS. 1 and 2, the tire according to the present invention is formed of a porous material on the inner surface of the inner liner 10 and has a single strip-shaped member 12 having a cut portion 11 along the tire circumferential direction. An annular sound absorbing layer 13 is provided which is formed by pasting.

  In the case of manufacturing such a tire 1, as shown in the perspective view shown in FIG. 3A and the cross-sectional view shown in FIG. The sound absorbing layer 13 is formed by adhering three rows of strip-shaped members 12 adjacent to each other in the drum width direction. Next, tire constituent members such as the inner liner 10, the bead core 6, the carcass 7, and the sidewall rubber are pasted on the sound absorbing layer 13, and the perspective view shown in FIG. 4 (A) and that shown in FIG. 4 (B) are shown. The raw case 15 as shown in the sectional view is formed. By inflating the raw case 15 with a bladder or the like, the raw case 15 is deformed into an expanded raw case 16 having a shape as shown in the perspective view of FIG. 5A and the cross-sectional view of FIG. 5B. At this time, the belt-like member 12 attached near the central portion in the axial direction of the raw case 15 is cut into the belt-like member 12 even if the vicinity of the central portion in the axial direction of the raw case 15 is evenly expanded at a high expansion rate. Since the cut portion 11 is opened following the expansion of the raw case 15 since the portion 11 is provided, the height of the sound absorbing layer 13 is uniform, and the separation of the joint portion 17 is suppressed while being separated. It becomes possible to suppress the occurrence of dropout. Further, since the expansion rate of the raw case 15 decreases as it approaches the end of the raw case 15, an expansion difference occurs without being expanded as the end of the raw case 15 is closer. In the belt-like member 12 affixed to the inner surface in the vicinity of the portion, the cut portion 11 is provided on the side away from the end portion of the raw case 15, so that the cut portion 11 opens following the expansion. Therefore, the sound absorbing layer 13 is not pulled excessively, and the height of the sound absorbing layer 13 becomes uniform, the detachment of the joint portion 17 of the sound absorbing layer 13 is suppressed, and the occurrence of peeling and dropping of the sound absorbing layer 13 can be suppressed. It becomes possible. Further, when a raw tire in which tire constituent members such as the belt layer 8 and the tread portion 2 are attached to the expanded raw case 16 configured as described above is vulcanized with a vulcanization mold, the sound absorbing layer 13 is provided. Tire 1 is obtained.

  In addition, it is preferable to use the band-shaped member 12 having the cut portions 11 extending from at least one of the short-side ends of the band-shaped member 12 in a direction crossing the longitudinal direction of the band-shaped member 12. This is because when the cut-out portions 11 are provided at both ends of the strip-shaped member 12 attached in the vicinity of the central portion of the raw case 15 in the axial direction, the raw case 15 follows the expansion. When the cut portion 11 is opened, the height of the strip-shaped member 12 in the vicinity of the short-side end becomes uniform without being pulled, as compared with the case where the strip-shaped member 12 has the cut-out portion 11. It is easy to suppress the peeling and dropping of the sound absorbing layer 13. On the other hand, in the case where such a cut portion 11 is provided at the lateral short side end that is separated from the end of the band-like member 12 that is attached to the inner surface near the end of the raw case 15, the raw case 15 Since an expansion difference occurs during expansion of the belt-shaped member 12, the cut-off portion 11 can be easily expanded following the expansion as compared with the case where the band-shaped member 12 has the cut-out portion 11. This is because the height of the sound absorbing layer 13 becomes uniform, and the sound absorbing layer 13 can be prevented from peeling off and falling off.

  Furthermore, on the inner surface of the inner liner 10, the width of the cut portion 11 is preferably in the range of 5 to 80% of the width of the band-shaped member 12, and more preferably in the range of 10 to 40%. Because, when the width of the cut portion 11 is less than 5% of the width of the strip-like member 12, the width ratio of the cut portion 11 is too small. The notch portion 11 cannot be sufficiently opened, the height of the sound absorbing layer 13 may become uneven, the joint portion 17 may come off, and the sound absorbing layer 13 may be peeled off or dropped off. On the other hand, when the width of the cut portion 11 exceeds 80% of the width of the band-like member 12, the width ratio of the cut portion 11 becomes too large, so that the cut portion 11 opens when the raw case 15 is expanded. This is because the sound absorption layer 13 may be torn due to that.

  The strip member 12 is chemically bonded to the inner surface of the inner liner 10 using a styrene-butadiene rubber latex adhesive, an aqueous polymer-isocyanate adhesive, or an acrylic or synthetic resin adhesive tape. Moreover, after temporarily fixing with such an adhesive tape or adhesive, the inner surface of the inner liner 10 can be impregnated into the inner surface of the inner liner 10 and then physically fixed by vulcanization molding by heating and pressurization. .

  The tire 1 thus formed includes a sound absorbing layer 13 having a notch 18 extending in a direction crossing the longitudinal direction of the belt-like member 12 from at least one of the short-side ends of the belt-like member 12. Since the tire 1 has the sound absorbing layer 13 disposed thereon, road noise due to cavity resonance can be reduced, and when the tire 1 is manufactured by the above manufacturing method, the uniformity of the height of the sound absorbing layer 13 is ensured. In addition, the disengagement of the joint portion 17 is suppressed, and the occurrence of peeling and dropping of the sound absorbing layer 13 is suppressed, and the occurrence of peeling and dropping of the sound absorbing layer 13 during tire load rolling can be suppressed. Moreover, although it is a secondary effect, since the tire 1 has the notch portion 18, even if heat is generated from a region where heat is likely to be generated when the tire is loaded and rolled, the tire 1 is effectively effective from the notch portion 18. The heat is dissipated and the durability of the tire 1 can be effectively improved. Specifically, the region that easily generates heat at the time of tire load rolling is the vicinity of the end 19 in the tire width direction of the innermost layer of the belt layer 8 that tends to be sheared and deformed at the time of tire load rolling, and the tire load. For example, the tire maximum width position 20 is easily collapsed repeatedly during rolling. From those viewpoints, for example, as shown in FIG. 7, the sound absorbing layer 13 is attached to the inner surface of the shoulder portion 21, and the notch portion 18 is pasted so as to overlap the inner surface of the innermost layer 19 of the belt layer 8 in the tire width direction. Therefore, heat dissipation can be improved and the durability of the tire 1 can be improved. Further, for example, as shown in FIG. 8, the sound absorbing layer 13 is the inner surface of the sidewall portion 3, and the notch portion 18 is attached so as to overlap the inner surface of the tire maximum width position 20, thereby improving heat dissipation. The durability of the tire 1 can be improved. Here, “the tire width direction end 19 of the belt layer 8” means that the tire 1 is attached to a standard rim R (or “Applied Rim” or “Recommended Rim”) in an applicable size described in the following standard. Assembling and tires in the tire width direction cross section in the ground contact state under the condition of applying the maximum load (maximum load capacity) and the air pressure corresponding to the maximum load in the application size described in the following standards The edge in the tire width direction of the innermost belt layer which is the innermost belt layer 8 in the radial direction shall be said. “Tire maximum width position 20” is a condition in which the tire 1 is assembled to the standard rim R in the above-described application size, and the maximum load (maximum load capacity) of the single wheel in the application size and the air pressure corresponding to the maximum load are applied. The position where the cross-sectional width in the cross-section in the tire width direction becomes the maximum in the ground contact state at. The standard refers to an industrial standard effective in an area where the tire 1 is produced or used. For example, in the United States, the Tire and Rim Association Inc. “Year Book” in Europe, “Standard Manual” of The European Tire and Rim Technical Organization in Europe, and “JATMA Year Book” of Japan Automobile Association in Japan. The air here can be replaced with an inert gas such as nitrogen gas.

  Moreover, as shown in FIG. 6, when the sound absorbing layer is fixed to the inner surface of the tread portion by impregnation of the inner surface of the adhesive tape, adhesive, or inner liner, it takes time and labor to remove the sound absorbing member. When a failure occurs, there is a possibility that the failed part cannot be repaired quickly. Specifically, when a puncture occurs in the tread part, the range corresponding to the failure location and the sound absorbing layer in the vicinity thereof are removed by hand, and the grinder is used to evenly buff until the inner liner is exposed. Scold. Next, the surface is smoothed with a scratcher to remove scraps. Only then will it be possible to repair punctures using plug patches as usual. Moreover, after the normal puncture repair is completed, it is necessary to attach the sound absorbing layer again to the portion from which the sound absorbing layer has been removed. As described above, the tire 1 including the sound absorbing layer 13 on the inner surface of the tread portion 2 requires time and labor for repairing a failure portion such as a puncture as compared with a tire not including the sound absorbing layer. Therefore, from these viewpoints, it is preferable that the sound absorbing layer 13 is attached not within the inner surface of the tread portion 2 but within a predetermined range between the bead toe position of the bead portion 4 and the inner surface position of the tread grounding end. Specifically, for example, as shown in FIGS. 7 and 8, the sound absorbing layer 13 is preferably attached to the inner surface of the sidewall portion 3 or the inner surface of the shoulder portion 21. Because many failures such as punctures are caused by stepping on foreign matter in the tread portion 2 that is in contact with the road surface, the sound absorbing layer 13 is not attached to the inner surface of the tread portion 2 but within the predetermined range. This is because it is possible to quickly repair punctures generated in the tread portion 2 while suppressing cavity resonance and reducing road noise. The “inner surface position of the tread grounding end” here means that a tire is assembled to a standard rim (or “Approved Rim” or “Recommended Rim”) at an applicable size described in the following standard, When applying the maximum air pressure specified in the same standard to a flat plate in a stationary state and applying a maximum load load (a load corresponding to 88% of the maximum load capacity), look at the cross section in the tire width direction. The position corresponding to the intersection of the inner surface of the tire with the perpendicular line extending from the outermost end in the tire width direction on the contact surface with the flat plate to the inner surface of the inner liner 10 shall be said.

  Furthermore, the height of the sound absorbing layer 13 is preferably 1 to 50 mm. This is because if less than 1 mm, the sound absorption effect may be reduced, while if exceeding 50 mm, deformation due to centrifugal force during high-speed rotation of the tire 1 increases due to an increase in mass. This is because there is a possibility that problems such as peeling and dropping of the sound absorbing layer 13 may occur. The size, shape, number, etc. of the notches 18 can be appropriately increased or decreased according to the tire size, the internal pressure during use, the curved shape of the tire inner surface, the strength of the nonwoven fabric, and the like. Further, when a plurality of the cutout portions 18 are provided as described above, it is preferable that the cutout portions 18 are arranged at a substantially equal pitch in the tire circumferential direction from the viewpoint of uniformity of the tire 1.

  Furthermore, the band-shaped member 12 constituting the sound absorbing layer 13 can be constituted by an open cell structure or closed cell structure foam of rubber or synthetic resin, or a nonwoven fabric made of synthetic fiber, plant fiber or animal fiber. . And when comprising the strip | belt-shaped member 12 with a nonwoven fabric, in order to exhibit a required sound-absorbing effect, it shall make the specific gravity into the range of 0.1-2.0, and the average diameter of a fiber. It is preferable to set it as 0.1-200 micrometers.

  The above description shows only a part of the embodiment of the present invention, and these configurations can be combined alternately or various changes can be made without departing from the gist of the present invention. For example, the expansion method of the raw case 15 is not limited to the method of applying the internal pressure while using the bladder as described above, and the method of directly filling the tire inner surface with the gas or the method of mechanically expanding with the core Etc.

  Next, a conventional tire having no sound absorbing layer (conventional tire), a comparative tire having a sound absorbing layer on the inner surface of the tread portion (comparative tire), and a tire having a sound absorbing layer according to the present invention (Example tire 1) Since 2) to 2) were manufactured as radial tires for passenger cars having a tire size of 215 / 45R17 and evaluated for suppressing the cavity resonance of the tire, they will be described below.

The conventional example tire, the comparative example tire, the example tire 1 and the example tire 2 have the specifications shown in Table 1, respectively. In addition, the sound absorption layer of the comparative example tire, the example tire 1 and the example tire 2 is composed of a PET nonwoven fabric having a fineness of 6 dtex and a basis weight of 500 g / m ² .

  Each of these test tires is attached to a rim of size 17 × 7JJ to form a tire wheel. The tire wheel is mounted on the vehicle, and the air pressure is 210 kPa (relative pressure) and the tire load load is 3.92 kN. It was used for evaluation of resonance suppression.

  The vehicle traveled on an asphalt road surface at 60 km / h, and the in-vehicle noise at the driver's seat was measured. This measurement result was subjected to frequency analysis, and the suppression effect of the cavity resonance was evaluated based on the peak sound pressure level seen near 230 kHz. The evaluation results are shown in Table 2. In addition, the evaluation result in a table | surface is represented by the exponential ratio when the cavity resonance suppression effect of the comparative example tire 1 which provided the sound absorption layer which does not provide the notch part with respect to the conventional example tire which does not have a sound absorption layer is set to 100. The larger the value, the greater the effect of suppressing cavity resonance.

  As is apparent from the results in Table 2, the tires 1-2 of the present invention having the sound absorbing layer having the notched portion of the present invention are compared with the comparative tire having the sound absorbing layer not having the notched portion. The cavity resonance suppression effect is substantially the same.

  Further, a tire having a sound absorbing layer manufactured by a manufacturing method of the prior art (Comparative Example Tires 2 to 3) and a tire having a sound absorbing layer manufactured by a manufacturing method according to the present invention (Example Tires 3 to 4). ) Were manufactured as 10 radial tires for passenger cars of tire size 215 / 45R17, and the uniformity of the sound-absorbing layer height, disengagement of the joint, peeling of the sound-absorbing layer, and occurrence of dropout were evaluated. Explained.

When manufacturing the tire, the comparative tire 2 is a tire in which a single belt-like member not having a cut portion is attached on a molding drum, and a sound absorbing layer centering on the tire equatorial plane is disposed on the inner surface of the tread portion. In the comparative example tire 3, a single band-shaped member having no cut portion is pasted on the molding drum, and a sound absorbing layer is disposed on the inner surface of the sidewall portion around the tire inner surface position of the tire maximum width position. Tire. The example tire 3 is a tire in which a plurality of band-like members having cut portions are attached on a molding drum, and a sound absorbing layer centering on the tire equatorial plane is disposed on the inner surface of the tread portion. Is a tire in which a plurality of belt-like members are attached on a molding drum, and a sound absorbing layer is disposed on the inner surface of the sidewall portion in the tire circumferential direction centering on the tire inner surface position of the tire maximum width position. In addition, the one strip | belt-shaped member in the comparative example tires 2-3 and the example tires 3-4 sticks the both ends with the overlap allowance of 20 mm, and forms the joint part. Moreover, the belt-shaped member in Comparative Example Tires 2 to 3 and Example Tires 3 to 4 is composed of a PET nonwoven fabric having a sound absorbing layer fineness of 6 dtex and a basis weight of 500 g / m ^2. The tires have the specifications shown in Table 3, respectively.

  As a result, in the comparative tire 2, all the ten sound absorbing layers were peeled off and dropped off, and the joint part was also detached. Moreover, in the comparative example tire 3, the height of the sound absorbing layer was not uniform for all ten tires, and the joint part was also detached. On the other hand, in each of the tires 3 to 4, the sound absorbing layer was not peeled off or dropped off in any of the tires, the height was uniform, and the joint part was not detached.

  As is clear from the above, according to the present invention, when manufacturing a pneumatic tire having a sound absorbing layer made of a porous material on the inner surface of the inner liner, the height of the sound absorbing layer is made uniform, and the sound absorbing layer is made uniform. It has become possible to provide a production method that suppresses the occurrence of peeling and dropping of layers. Furthermore, according to the present invention, it is possible to provide a pneumatic tire in which road noise due to cavity resonance is reduced, the height of the sound absorbing layer is made uniform, and the occurrence of peeling and dropping of the sound absorbing layer is suppressed.

1 is a sectional view in the tire width direction of a typical tire according to the present invention assembled with a rim. FIG. FIG. 2 is a partial development view of the tire inner surface of the tire shown in FIG. 1. (A) is the perspective view which showed the state before and behind sticking a strip | belt-shaped member on a shaping | molding drum, (B) is the sectional drawing. (A) is a perspective view of the raw case provided with the strip | belt-shaped member according to this invention, (B) is the sectional drawing. (A) is a perspective view of the raw tire which extended the raw case, (B) is the sectional drawing. It is a partial development view of the tire inner surface of another tire according to the present invention. It is a partial development view of the tire inner surface of another tire according to the present invention. It is a partial development view of the tire inner surface of another tire according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tire 2 Tread part 3 Side wall part 4 Bead part 5 Tire main body 6 Bead core 7 Carcass 8 Belt layer 9 Tire inner cavity 10 Inner liner 11 Cut part 12 Band-shaped member 13 Sound absorption layer 14 Molding drum 15 Raw case 16 Expanded raw case 17 Joint part 18 Notch part 19 Tire width direction end 20 of belt layer Tire maximum width position 21 Shoulder part R Rim CL Tire equatorial plane

Claims (4)

In the method of manufacturing a pneumatic tire having a sound absorbing layer made of a porous material on the inner surface of the inner liner,
A method for producing a pneumatic tire, characterized in that a sound absorbing layer is formed by attaching at least one strip-shaped member made of a porous material and having a cut portion along a circumferential direction of a drum on a molding drum.   The method for manufacturing a pneumatic tire according to claim 1, wherein the belt-shaped member having the cut portion extending in a direction crossing the longitudinal direction of the belt-shaped member from at least one of the lateral ends of the belt-shaped member is used.   The method of manufacturing a pneumatic tire according to claim 2, wherein a width of the cut portion is in a range of 5 to 80% of a width of the belt-shaped member. In a pneumatic tire having a sound absorbing layer made of a porous material on the inner surface of the inner liner,
The sound absorbing layer is composed of at least one strip-shaped member extending along the tire circumferential direction, and the strip-shaped member has a cutout portion extending in a direction transverse to the tire circumferential direction from at least one of the tire width direction ends. Pneumatic tire characterized by.

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