JP5144981B2 - Pneumatic tire manufacturing method and pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire manufacturing method and a pneumatic tire in which a sound absorbing layer made of a band-shaped sound absorbing member is disposed on an inner liner inner surface.

  A pneumatic tire assembled in a rim and attached to a vehicle generates a cavity resonance of air filled in the tire lumen when the tread portion vibrates against the road surface unevenness while the vehicle is running. 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 road noise is transmitted to the vehicle interior, it takes a sharp and high peak value, unlike noise in other frequency bands, and thus becomes annoying noise for passengers in the vehicle interior.

  In order to suppress such cavity resonance and reduce road noise, Patent Document 1 discloses a non-ring-shaped sound absorbing material using a sponge material in a tire lumen formed by a rim and a pneumatic tire bonded to the rim. The belt-like sheet has a volume V2 in which the ratio V2 / V1 to the total volume V1 of the tire lumen is 0.4% or more, and the sponge material is The surface of the belt-shaped sheet facing the tire lumen is an uneven surface, and the uneven surface has a protruding convex portion and a concave concave portion. An assembly of a pneumatic tire and a rim has been proposed in which the unevenness is repeated by being scattered without aligning the position in the direction or the tire axial direction.

  Conventionally, in manufacturing a pneumatic tire in which a sound absorbing layer composed of at least one strip-shaped sound absorbing member is disposed on the inner surface of the inner liner as described above, FIGS. 9 (a) and 9 (b) As shown in the figure, the band-shaped sound absorbing member 113 having a rectangular planar shape is wound around the outer peripheral surface of the molding drum D, and the longitudinal end portions 115 of the sound absorbing member 113 are mutually butted or overlapped with each other. The sound absorbing layer 111 is formed on the outer peripheral surface of the molding drum, and the inner liner member, the chafer member, the bead ring, the carcass ply formed by covering the ply cord with rubber through the sound absorbing layer 111, and the like. 9 (c), a green case is formed by sequentially stacking the tire constituent members, and the green case is expanded into a toroidal shape using a bladder or the like. Production method and a step of molding a green tire 119, as shown in has been used.

Japanese Patent No. 3622957

  However, according to such a method, when the green case is expanded, the sound absorbing layer 111 on the inner liner inner surface cannot follow the expansion, and as shown in FIG. There is a problem that the joint 120 formed by joining the portions 115 is released. As a result, the amount of deformation of the tire constituent member at the time of expansion differs between the region where the sound absorbing layer 111 is present and the region where the sound absorbing layer 111 is not present on the inner liner inner surface. The problem was that the quality varied.

  Further, in a pneumatic tire in which a sound absorbing layer made of a band-shaped sound absorbing member is disposed on the inner liner inner surface, when the sound absorbing layer 111 is configured, the end portion 115 of the band-shaped sound absorbing member 113 having a rectangular planar shape is used. Although the joint 120 is overlapped and joined to each other, the mass of the joint 120 is locally increased, that is, the mass of the sound absorbing layer 111 is not uniform in the circumferential direction, so that the uniformity may be deteriorated. It was.

  Accordingly, it is an object of the present invention to solve these problems. The object of the present invention is to manufacture a green case having a sound absorbing layer over the entire circumference on the inner liner inner surface. It is an object of the present invention to provide a method for manufacturing a pneumatic tire that can ensure a certain quality by suppressing the release of the joint portion of the sound absorbing layer on the inner surface of the inner liner that occurs when expanding the inner surface of the inner liner. Another object is to provide a pneumatic tire that is superior in uniformity compared to the conventional tires on the premise of effective reduction of road noise.

To achieve the object, the first invention comprises comprises a backing layer over the entire circumference on the inner liner inner surface, the sound absorbing layer, each other longitudinal end of the at least one belt-shaped sound absorbing member Ri Na joined to the sound-absorbing member is a woven fabric, in the manufacturing method of a pneumatic tire according to an non-woven or knitted fabric, longitudinal edges, respectively, range of 85 degrees 15 degrees with respect to the width direction The sound-absorbing member that is inclined at the outer periphery of the molding drum is wound on the outer peripheral surface of the molding drum, and the end portions are overlapped with each other in the circumferential direction of the molding drum and bonded using a rubber-based adhesive. Forming a layer, forming a green case by sequentially stacking tire constituent members on the outer peripheral surface of the molding drum via the sound absorbing layer, and expanding the green case. Special It is a pneumatic tire manufacturing method to be. By adopting such a configuration, the sound absorbing layer can be easily and accurately disposed as compared with the case where the sound absorbing layer is directly attached on the inner liner inner surface of the product tire. Further, the extending distance in the circumferential direction of the joining portion formed by superposing and joining the end portions in the longitudinal direction of the sound absorbing member in the circumferential direction of the molding drum is increased while maintaining the same area of the joining portion. Therefore, the tensile stress applied to the joint when the green case is expanded is more widely dispersed. Therefore, there is no possibility that the joint portion of the sound absorbing member is released when the green case is expanded.

  Furthermore, the thickness of the sound absorbing member is preferably 1 mm or more and 50 mm or less.

  In addition, it is preferable that the edges of the two end portions overlapped and joined to each other are parallel to each other.

In order to achieve the above object, the second invention provides a pneumatic tire in which a sound absorbing layer made of a band-like sound absorbing member is disposed on the inner liner inner surface, wherein the sound absorbing member is a woven fabric, a nonwoven fabric or a knitted fabric. The sound absorbing layer has at least one joint portion formed by superposing the longitudinal ends of the sound absorbing member on each other in the tire circumferential direction and joining them using a rubber-based adhesive , at the junction, a longitudinal edge of the sound absorbing members each are pneumatic tire characterized by being inclined in the acoustical range below 85 degrees 15 degrees with respect to the width direction of the member . By adopting such a configuration, the extension distance in the tire circumferential direction of the joint portion can be increased compared to the case where the end of the sound absorbing member is not inclined, so that the weight distribution of the joint portion is dispersed in the tire circumferential direction. Can be made.

  Furthermore, the thickness of the sound absorbing layer is preferably 1 mm or more and 50 mm or less.

  Moreover, it is preferable that the edges of the two end portions are parallel to each other at the joint portion.

  According to the first invention, when manufacturing a pneumatic tire having a sound absorbing layer disposed on the inner surface of the inner liner, the joining between the ends of the sound absorbing members constituting the sound absorbing layer is maintained when the green case is expanded. It is possible to provide a method of manufacturing a pneumatic tire that can ensure a certain quality. Further, according to the second invention, since the mass concentrated at the joint portion of the sound absorbing layer can be dispersed in the tire circumferential direction, it is possible to provide a pneumatic tire excellent in uniformity as compared with the related art.

  Hereinafter, an embodiment of the first invention will be described with reference to the drawings. Here, FIG. 1 is a view showing a sound absorbing member, which will be described later, used for manufacturing a pneumatic tire (hereinafter referred to as “tire”) according to the present invention, wherein (a) is a plan view and (b) is a rear view. , (C) is a side view, FIGS. 2 (a) to 2 (c) are diagrams for explaining the method of manufacturing a tire according to the present invention, and FIG. 3 is manufactured by the manufacturing method according to the present invention. 4 is a cross-sectional view showing the cross section of the tire in the tire width direction, and FIG. 4 is a view for explaining the effect of suppressing the release of the joined portion of the sound absorbing layer brought about by the manufacturing method of the present invention. The joining part of the sound absorption layer comprised using the manufacturing method of the tire of invention is shown, (b) shows the joining part of the sound absorption layer comprised using the manufacturing method of the conventional tire.

  As illustrated in FIG. 3, a tire 1 manufactured according to the method for manufacturing a tire of the present invention includes a tread portion 2 and a pair of sidewall portions extending inward in the tire radial direction from both side portions of the tread portion 2 in accordance with the custom. 3 and a pair of bead portions 4 provided in the tire radial direction of each sidewall portion 3 and fitted to a rim (not shown) constitute a tire main body portion 5. Inside the tire body 5 is a toroidal structure between the bead cores 6 and 6 embedded in each bead to form a skeleton structure of the tire body 5, for example, a radial carcass 7 and a crown of the carcass 7. A belt 8 that reinforces the tread portion 2 is disposed on the outer peripheral side of the region. An air impermeable inner liner 10 is disposed on the inner surface side of the tire body 5.

  A sound absorbing layer 11 composed of at least one band-like sound absorbing member is disposed on the inner surface of the inner liner 10 over the entire circumference, and thereby vibration of the filled air caused by cavity resonance generated in the tire lumen. The energy is converted into the internal vibration energy of the porous material constituting the sound absorbing layer 11 and is consumed as heat energy, thereby reducing the cavity resonance sound.

  Here, the porous material constituting the sound absorbing layer 11 is integrally formed by intertwining a foam material having open cells or closed cells, or animal fibers, plant fibers, synthetic fibers, etc., formed by foaming rubber or synthetic resin. A woven fabric, a nonwoven fabric, a knitted fabric or the like can be used. If, for example, synthetic rubber is used as the porous material, the heat-absorbing layer 11 can also be provided with excellent heat resistance and water resistance, and if an ether-based polyurethane foam is used, the foamed material is hardly hydrolyzed. it can. The sound absorbing layer 11 needs to be able to withstand pressure and heat during vulcanization molding.

  In constructing the sound absorbing layer 11 in the tire body 5, first, the sound absorbing member 13 having the shape shown in FIGS. 1A to 1C is prepared. The sound absorbing member 13 has a strip shape and has a rectangular cross section as shown in FIG. Further, the edge 14 in the longitudinal direction is inclined at a predetermined angle θ with respect to the width direction. Here, the “longitudinal direction” of the sound absorbing member 13 is a direction parallel to the direction indicated by the arrow L in FIG. 1A, and the “width direction” of the sound absorbing member 13 is the direction of the sound absorbing member 13. The direction is perpendicular to the longitudinal direction and is parallel to the direction indicated by the arrow W in FIG. The sound absorbing member 13 having such a shape may be formed by obliquely cutting out a porous material having a rectangular cross section wound in a roll shape with a cutter or the like, or the shape of the porous material shown in FIG. 1 in advance. It may be formed into a shape. When the sound absorbing layer 11 is composed of one sound absorbing member 13, the sound absorbing member 13 is a long ring that joins the end 15 in the longitudinal direction when wound around a molding drum D described later in the following process. Need to be.

  Next, as shown in FIG. 2A, the sound absorbing member 13 is wound around a predetermined position on the outer peripheral surface of the molding drum D, and the end 15 in the longitudinal direction of the sound absorbing member 13 is moved in the circumferential direction of the molding drum D. The sound absorbing layer 11 is formed by superimposing them on each other and bonding them using a rubber adhesive or the like.

  Next, other tire configurations such as a carcass ply formed by rubber-coating an inner liner member, a chafer member, a bead ring, and a ply cord on the outer peripheral surface of the molding drum D through the sound absorbing layer 11 in accordance with a conventional manufacturing method. The members are sequentially stacked to form a green case 17 schematically shown in FIG.

  Then, according to a conventional manufacturing method, this green case 17 is expanded into a toroidal shape using a bladder or the like, a green tire as shown in FIG. 2 (c) is molded, and after a predetermined vulcanization / finishing process, The tire 1 shown in FIG. 3 having the sound absorbing layer 11 on the entire inner surface of the liner 10 is completed. The expansion of the green case 17 is performed using a bladder as described above, and a gas pressure is directly applied to the inner surface of the green case 17 or the diameter can be mechanically expanded on the inner surface side of the green case 17. It is also possible to carry out by providing a core and expanding the diameter of the core, and it is not limited to these methods.

  That is, the main feature of the configuration of the present invention is that, in the above manufacturing method, in particular, when the sound absorbing layer 11 is configured, the sound absorbing member 13 having a shape in which the edge 14 in the longitudinal direction is inclined with respect to the width direction is used. Further, prior to winding the inner liner member on the outer peripheral surface of the molding drum D, the sound absorbing member 13 is wound on the outer peripheral surface of the molding drum D, and the end 15 in the longitudinal direction thereof is connected to the periphery of the molding drum D. It is to overlap and join each other in the direction.

  According to this, the sound absorbing layer can be easily and accurately disposed as compared with the case where the sound absorbing layer is directly attached to the inner liner inner surface of the product tire by hand or the like. In addition, the extension distance in the circumferential direction of the joining portion formed by joining the end portions 15 in the longitudinal direction of the sound absorbing member 13 in the circumferential direction of the molding drum D and maintaining the same area of the joining portion is maintained. Can be enlarged. That is, according to the conventional method, as shown in FIG. 4 (b), the sound absorbing layer 111 is configured by joining the band-shaped sound absorbing member 113 having a rectangular plane in the circumferential direction of the molding drum D (the tire circumferential direction). Then, the area of the joint portion is S2, and the length of the joint portion in the tire circumferential direction is L2. On the other hand, according to the present invention, as shown in FIG. 4 (a), the edge S14 in the longitudinal direction of the sound absorbing member 13 is inclined with respect to the width direction so that the area S1 of the joint is the same (S1 = S2). While maintained, the length L1 in the tire circumferential direction of the joint portion increases (L1> L2). Accordingly, the tensile stress applied to the joint portion when the green case 17 is expanded is dispersed in a wider range, and there is no possibility that the joining of the sound absorbing member 13 is released when the green case 17 is expanded.

  Further, as shown in FIG. 1A, each end edge 14 in the longitudinal direction of the sound absorbing member 13 may be inclined with respect to the width direction of the sound absorbing member 13. It is preferably in the range of not less than 85 degrees and not more than 85 degrees. When the inclination angle θ of the edge 14 with respect to the width direction of the sound absorbing member 13 is less than 15 degrees, the effect of suppressing the release of the joint portion when the green case 17 is expanded is not sufficient. This is because the end portions 15 are extremely tapered, and it may be difficult to manufacture the end portions 15 on each other.

  Furthermore, the thickness d of the sound absorbing member 13 is preferably 1 mm or more and 50 mm or less. According to this, an excellent sound absorbing effect can be exhibited, and at the same time, cracking, tearing, peeling, etc. of the sound absorbing layer 11 can be prevented. If the thickness d is less than 1 mm, the sound absorption effect is insufficient, and if it exceeds 50 mm, deformation due to centrifugal force during high-speed rotation increases due to an increase in weight, and the possibility of occurrence of peeling or the like increases.

  Moreover, as shown in FIG. 4A, it is preferable that the end edges 14 of the two end portions 15 overlapped and joined to each other are parallel to each other. According to this, since the tensile tension applied to the joint portion when the green case 17 is expanded can be uniformly dispersed, the effect of suppressing the release of the joint portion can be further enhanced. And since the mass distribution over the tire width direction of a junction part can be made uniform, a uniformity can be improved.

  The above description shows only a part of the embodiment of the first invention, and these configurations may be combined with each other or various changes may be made without departing from the gist of the present invention. it can. For example, the sound-absorbing layer 11 can also be configured using a plurality of strip-shaped sound-absorbing members 13 whose longitudinal edges 14 are inclined with respect to the width direction.

  Next, an embodiment of the second invention will be described with reference to the drawings. Here, FIG. 5 is a cross-sectional view showing a tire width direction cross-section of a typical tire according to the present invention, FIG. 6 is a schematic diagram showing a state where a sound absorbing layer described later is extracted from the tire according to the present invention, 7 (a) is a development view of the joint portion of the sound absorbing layer shown in FIG. 6, FIG. 7 (b) is a side view of the joint portion shown in FIG. 7 (a), and FIG. It is the schematic which shows the state which extracted the sound absorption layer mentioned later from the other tire according to this.

  As illustrated in FIG. 5, the tire 1 of the present invention includes a tread portion 2, a pair of sidewall portions 3 that extend inward in the tire radial direction from both side portions of the tread portion 2, and each sidewall portion 3 in accordance with common practice. The tire body 5 is composed of a pair of bead portions 4 provided in the tire radial direction and fitted to a rim (not shown). Inside the tire body 5 is a toroidal structure between the bead cores 6 and 6 embedded in each bead to form a skeleton structure of the tire body 5, for example, a radial carcass 7 and a crown of the carcass 7. A belt 8 that reinforces the tread portion 2 is disposed on the outer peripheral side of the region. An air impermeable inner liner 10 is disposed on the inner surface side of the tire body 5.

  In addition, a sound absorbing layer 11 made of at least one band-like sound absorbing member is disposed on the inner surface of the inner liner 10 over the entire circumference, and thereby vibration of the filled air accompanying cavity resonance generated in the tire lumen. The energy is converted into the internal vibration energy of the porous material constituting the sound absorbing layer 11 and is consumed as heat energy, thereby reducing the cavity resonance sound.

  Here, the sound absorbing layer 11 is made of a porous material, and as the porous material, foamed material having open cells or closed cells formed by foaming rubber or synthetic resin, animal fibers, plant fibers, synthetic fibers, or the like. A woven fabric, a nonwoven fabric, a knitted fabric, or the like that is intertwined and integrated can be used. If, for example, synthetic rubber is used as the porous material, the heat-absorbing layer 11 can also be provided with excellent heat resistance and water resistance, and if an ether-based polyurethane foam is used, the foamed material is hardly hydrolyzed. it can.

  And, as shown in FIG. 6, the main feature of the configuration of the present invention is that the sound absorbing layer 11 is formed by joining the end portions in the longitudinal direction of the sound absorbing member 13 so as to overlap each other in the tire circumferential direction. As shown in FIGS. 6 and 7, the longitudinal edges 14 of the sound absorbing member 13 are inclined with respect to the width direction of the sound absorbing member 13. It is that. Here, the “longitudinal direction” of the sound absorbing member 13 is a direction orthogonal to the tire width direction, and the “width direction” of the sound absorbing member 13 is a direction parallel to the tire width direction.

  According to this, compared with the case where the end edge 14 of the sound absorbing member 13 is not inclined, the extension distance in the tire circumferential direction of the joint portion 20, that is, the portion where the end 15 of the sound absorbing member 13 overlaps in the tire circumferential direction is increased. Since the weight distribution of the joint portion 20 can be dispersed in the tire circumferential direction, the uniformity can be improved as compared with the conventional case.

  Further, as shown in FIG. 7A, each end edge 14 in the longitudinal direction of the sound absorbing member 13 may be inclined with respect to the width direction of the sound absorbing member 13, but the inclination angle θ is 15 It is preferably in the range of not less than 85 degrees and not more than 85 degrees. If the inclination angle θ of the edge 14 with respect to the width direction of the sound absorbing member 13 is less than 15 degrees, the uniformity improving effect may not be sufficient, and if it exceeds 85 degrees, the end of the sound absorbing member is extremely This is because it becomes difficult to superimpose these end portions on each other because they become tapered.

  Furthermore, as shown in FIG.7 (b), it is preferable that the thickness d of the sound absorption layer 11 is 1 mm or more and 50 mm or less. According to this, an excellent sound absorbing effect can be exhibited, and at the same time, cracking, tearing, peeling, etc. of the sound absorbing layer 11 can be prevented. If the thickness is less than 1 mm, the sound absorbing effect is insufficient, and if it exceeds 50 mm, deformation due to centrifugal force during high-speed rotation increases due to an increase in weight, and the possibility of occurrence of peeling or the like increases.

  Moreover, as shown in FIG. 7A, it is preferable that the end edges 14 of the two end portions 15 are parallel to each other at the joint portion 20. According to this, since the mass distribution over the width direction of the joint portion 20 can be made uniform, the uniformity can be further improved.

  Note that the above description shows only a part of the embodiment of the second invention, and these configurations may be combined with each other or various changes may be made without departing from the spirit of the invention. it can. For example, there may be a plurality of joints 20 formed by joining the end portions 15 in the longitudinal direction of the sound absorbing member 13 as shown in FIG. It may be arranged discontinuously in the direction.

  Next, tires according to the present invention were prototyped and performance evaluations were performed, which will be described below.

  The tire of Example 1 is a radial tire having a tire size of 215 / 45R17, and has a fineness of 6 dtex, a thickness of 14 mm, and a width of 100 mm on the inner peripheral surface of the inner liner immediately below the tread portion. A nonwoven fabric is provided as a sound absorbing layer. The sound-absorbing layer has a joint portion formed by joining the end portions of the band-shaped sound-absorbing member between the both ends of the belt-shaped sound-absorbing member as shown in FIGS. Also, the two edges of the joint are parallel to each other.

  The tire of Example 2 is a tire having the same configuration as the tire of Example 1 except that the end portion of the sound absorbing member in the longitudinal direction is inclined by 30 degrees with respect to the width direction at the joint portion. is there.

  The tire of Example 3 is a tire having the same configuration as the tire of Example 1 except that the position and size of the sound absorbing layer are different. The sound absorbing layer of the tire of Example 3 is disposed on the inner liner inner surface immediately below the sidewall portion, and the width of the sound absorbing layer is 50 mm.

  The tire of Example 4 is a tire having the same configuration as the tire of Example 2 except that the position and size of the sound absorbing layer are different. The sound absorbing layer of the tire of Example 4 is disposed on the inner liner inner surface directly below the sidewall portion, and the width of the sound absorbing layer is 50 mm.

  For comparison, the edge of the sound absorbing member in the longitudinal direction of the tire of Conventional Example 1 having the same configuration as the tires of Examples 1 to 4 except that the sound absorbing layer is not provided, and the joint of the sound absorbing layer The edge of the sound-absorbing member in the longitudinal direction of the tire of Comparative Example 1 having the same configuration as the tires of Examples 1 and 2 and the sound-absorbing layer joint is formed, except that is not inclined with respect to the width direction. A tire of Comparative Example 2 having the same configuration as the tires of Examples 3 and 4 was also prototyped except that it was not inclined with respect to the width direction.

  Each of the test tires is attached to a rim of size 17 × 7JJ to be a tire wheel, and is attached to a test vehicle on the tire wheel, an air pressure of 210 kPa (relative pressure) and a tire load of 3.92 kN are applied, and a speed of 60 km / The room noise when traveling on an asphalt road under the condition of h 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 1. In addition, the evaluation result in the table is an exponential ratio when the cavity resonance suppression effect of Comparative Example 1 and Comparative Example 2 in which the sound absorbing layer is provided is 100 with respect to the sound pressure level of Conventional Example 1 having no sound absorbing layer. The larger the numerical value, the greater the effect of suppressing cavity resonance.

  Each of the test tires is mounted on a rim of size 17 × 7JJ to form a tire wheel, and an RFV value (radial force variation value) is measured with an internal pressure of 210 kPa (relative pressure) applied to the tire wheel. Then, each test tire was index-evaluated with the value of the tire of Conventional Example 1 having no sound absorbing layer as 100. The evaluation results are shown in Table 1. In addition, the numerical value of uniformity in the table indicates that the smaller the value is, the better the uniformity is.

  From the results shown in Table 1, the cavity resonance suppressing effect was confirmed in any tire provided with a sound absorbing layer. Further, it was confirmed that the uniformity of the sound absorbing member is improved by inclining the longitudinal edge of the sound absorbing member with respect to the width direction at the joining portion of the sound absorbing layer, and the uniformity is further improved as the inclination angle is increased. It was.

  Furthermore, in order to confirm the effect of the method for manufacturing a tire according to the present invention, 10 types of green cases 1 to 12 having different shapes and arrangement positions of the sound absorbing members constituting the sound absorbing layer were prototyped and tested as follows. This is explained. In addition, all are green cases for radial tires having a tire size of 215 / 45R17.

  The green case 1 has a shape shown in FIGS. 1 (a) to 1 (c), a sound absorbing member made of a non-woven polyethylene terephthalate (PET) nonwoven fabric having a fineness of 6 dtex, a thickness of 14 mm, and a width of 100 mm. A sound absorbing layer is formed by winding the sound absorbing member on the outer circumferential surface of the molding drum and overlapping and joining the longitudinal ends of the sound absorbing member in the circumferential direction of the molding drum. The tire constituent members are sequentially laminated and molded through layers. The sound absorbing layer is disposed on the inner liner inner surface corresponding to the tread portion of the product tire. In addition, the inclination angle of the edge in the longitudinal direction of the sound absorbing member with respect to the width direction is 85 degrees. Furthermore, the two edges of the joint portion of the sound absorbing layer are parallel to each other.

  The green case 2 has the same configuration as the green case 1 except that the edge of the sound absorbing member in the longitudinal direction has an inclination angle of 60 degrees with respect to the width direction.

  The green case 3 has the same configuration as the green case 1 except that the edge of the sound absorbing member in the longitudinal direction has an inclination angle of 30 degrees with respect to the width direction.

  The green case 4 has the same configuration as the green case 1 except that the edge of the sound absorbing member in the longitudinal direction has an inclination angle with respect to the width direction of 15 degrees.

  The green case 5 has the same configuration as the green case 1 except that the edge of the sound absorbing member in the longitudinal direction has an inclination angle of 5 degrees with respect to the width direction.

  The green case 6 has the same configuration as the green case 1 except that the sound absorbing layer is disposed on the inner liner inner surface corresponding to the sidewall portion of the product tire.

  The green case 7 has the same configuration as the green case 2 except that the sound absorbing layer is disposed on the inner liner inner surface corresponding to the sidewall portion of the product tire.

  The green case 8 has the same configuration as the green case 3 except that the sound absorbing layer is disposed on the inner liner inner surface corresponding to the sidewall portion of the product tire.

  The green case 9 has the same configuration as the green case 4 except that the sound absorbing layer is disposed on the inner liner inner surface corresponding to the sidewall portion of the product tire.

  The green case 10 has the same configuration as the green case 5 except that the sound absorbing layer is disposed on the inner liner inner surface corresponding to the sidewall portion of the product tire.

  For comparison, the green case 11 having the same configuration as the green cases 1 to 5 except that the longitudinal edge of the sound absorbing member is not inclined with respect to the width direction, and the longitudinal edge of the sound absorbing member A green case 12 having the same configuration as that of the green cases 6 to 10 was also prototyped except that is not inclined with respect to the width direction.

  These green cases 1 to 12 were expanded using a bladder so that the expansion ratio on the tire equatorial plane was 60%, and it was confirmed and evaluated whether or not the joint portion of the sound absorbing layer was released at that time. The evaluation results are shown in Table 2. The values in the table indicate the number of green cases released by the sound absorbing layer joints, and the smaller the number, the harder the sound absorbing layer joints are released.

  From the results shown in Table 2, it was confirmed that the release of the joint portion is suppressed when the green case is expanded by inclining the longitudinal edge of the sound absorbing member with respect to the width direction.

  As is clear from the above description, according to the first invention, even when the green case is expanded, by maintaining the bonding between the longitudinal ends of the sound absorbing member constituting the sound absorbing layer, a certain quality is ensured. It is possible to provide a method for manufacturing a pneumatic tire to be obtained, and in a pneumatic tire in which a sound absorbing layer made of a band-shaped sound absorbing member is disposed on the inner surface of the inner liner according to the second invention, road noise is effectively obtained. Based on the premise of reduction, it has become possible to provide pneumatic tires with better uniformity than before.

It is a figure which each shows the sound-absorbing member mentioned later used for manufacture of the pneumatic tire according to 1st invention, (a) is a top view, (b) is a rear view, (c) is a side view. (A)-(c) is a figure for demonstrating the manufacturing method of the pneumatic tire of 1st invention, respectively. It is sectional drawing which shows the tire width direction cross section of the pneumatic tire manufactured by the manufacturing method according to 1st invention. It is a figure for demonstrating the release suppression effect of the junction part of a sound absorption layer which the manufacturing method of 1st invention brings about, (a) is joining of the sound absorption layer comprised using the manufacturing method of the pneumatic tire of this invention (B) shows the joint part of the sound absorption layer comprised using the manufacturing method of the conventional tire. It is sectional drawing which shows the tire width direction cross section of the typical pneumatic tire according to 2nd invention. It is the schematic which shows the state which extracted the sound absorption layer mentioned later from the pneumatic tire according to 2nd invention. (A) is an expanded view of the junction part of the sound absorption layer shown in FIG. 6, (b) is a side view of the junction part shown to Fig.7 (a). It is the schematic which shows the state which extracted the sound absorption layer mentioned later from the other pneumatic tire according to 2nd invention. It is a figure for demonstrating the manufacturing method of the pneumatic tire according to a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tire 2 Tread part 3 Side wall part 4 Bead part 5 Tire main-body part 6 Bead core 7 Carcass 8 Belt 10 Inner liner 11 Sound absorption layer 13 Sound absorbing member 14 End edge of the sound absorbing member in the longitudinal direction 15 End part 17 in the longitudinal direction of the sound absorbing member 17 Green Case 19 Green Tire 20 Joint

Claims (6)

It comprises a backing layer over the entire circumference on the inner liner inner surface, the sound absorbing layer, Ri Na joined to each other in the longitudinal direction of the end portion of at least one belt-shaped sound absorbing member, wherein the sound-absorbing member is a woven fabric In the method for producing a pneumatic tire made of a nonwoven fabric or a knitted fabric ,
The sound absorbing member whose longitudinal edges are inclined in the range of 15 degrees or more and 85 degrees or less with respect to the width direction is wound around the outer peripheral surface of the molding drum, and the end portion is circumferentially disposed on the molding drum. Forming the sound absorbing layer by superimposing them on each other and joining them using a rubber adhesive ,
A step of sequentially stacking tire constituent members on the outer peripheral surface of the molding drum via the sound absorbing layer and molding a green case;
And a step of expanding the green case. The method of manufacturing a pneumatic tire according to claim 1 , wherein the thickness of the sound absorbing member is 1 mm or more and 50 mm or less. The manufacturing method of a pneumatic tire according to claim 1 or 2 , wherein edges of the two end portions that are overlapped and joined to each other are parallel to each other. In the pneumatic tire formed by disposing a sound absorbing layer made of a band-shaped sound absorbing member on the inner liner inner surface,
The sound absorbing member is made of woven fabric, non-woven fabric or knitted fabric,
The sound-absorbing layer has at least one joint portion formed by superposing the longitudinal ends of the sound-absorbing member on each other in the tire circumferential direction and joining them using a rubber-based adhesive ,
Wherein at junctions, said longitudinal edges of the sound absorbing members each said pneumatic tire, characterized in that the width direction of the sound absorbing member is inclined in a range below 85 degrees 15 degrees. The pneumatic tire according to claim 4 , wherein the sound absorbing layer has a thickness of 1 mm or more and 50 mm or less. The pneumatic tire according to claim 4 or 5 , wherein at the joint portion, edges of the two end portions are parallel to each other.

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