Pneumatic tires and methods for their manufacture

Abstract

Pneumatic tires, including: an indicator (10) made from a projecting section (10a) or a recessed section (10b) extending in a circumferential direction on an inner surface (4) of the tire; and a sound-absorbing element (5) or a sealing layer (6) applied to the inner surface of the tire (4) along the indicator (10), wherein the indicator (10) is expressed as a marking (12) for identification, which is made up of a letter, number, symbol or graphic.

Description

Technical area

[0001] The present invention relates to a pneumatic tire and a method for its manufacture, and in particular relates to a pneumatic tire and a method for its manufacture which can provide improved productivity in applying a sound-absorbing element or a sealant layer to an inner tire surface. State of the art

[0002] In general, the outer surface of a bellows used in the vulcanization of a tire blank is formed with a multitude of outlet grooves (depressions) extending radially. These grooves are provided for evacuating air from between the inner tire surface and the bellows (see, e.g., JP 2014-84007 A). Consequently, a multitude of protrusions are formed on the inner surface of a vulcanized pneumatic tire, corresponding to the depressions in the outer surface of the bellows.

[0003] Since the inner surface of the tire lacks markings to indicate the appropriate position for applying a sound-absorbing element or sealant layer, applying such an element or sealant layer to the inner surface of such a vulcanized pneumatic tire is time-consuming and labor-intensive, thus reducing productivity. The prior art also includes publications JP 2015-20731 A and JP 2015-128893 A. Brief description of the inventionTechnical problem

[0004] One object of the present invention is to provide a pneumatic tire and a method for its manufacture which can provide improved productivity in applying a sound-absorbing element or a sealant layer to a tire inner surface. Solution to the problem

[0005] To achieve the above-described objective, a pneumatic tire according to an embodiment of the present invention includes an indicator, which is made from a projecting section or a recessed section extending in a circumferential direction on an inner surface of the tire, a sound-absorbing element or a sealing layer applied to the inner surface of the tire along the indicator, wherein the indicator is expressed as a marking for identification made from a letter, a number, a symbol or a graphic.

[0006] A method for manufacturing a pneumatic tire according to an embodiment of the present invention comprises the steps of: vulcanizing a tire blank using a bellows having an outer bellows surface formed with a recessed section or a projecting section extending in a circumferential direction of the bellows; forming an indicator formed from a projecting section or a recessed section extending in a circumferential direction of the tire on an inner surface of the vulcanized pneumatic tire; and applying a sound-absorbing element or a sealant layer to the inner surface of the pneumatic tire along the indicator, wherein the indicator is expressed as a marking for identification made from a letter, a number, a symbol, or a graphic. Advantageous effects of the invention

[0007] In the present invention, an inner tire surface is formed with an indicator, which is made from a projecting section or a recessed section extending in a circumferential direction of the tire, and a sound-absorbing element or a sealant layer is applied to the inner tire surface along the indicator. Thus, the sound-absorbing element or sealant layer can be applied precisely and efficiently. This configuration can improve productivity in a pneumatic tire in which a sound-absorbing element or sealant layer is applied to the inner tire surface.

[0008] In the present invention, the angle of the indicator with respect to the tire's circumferential direction is preferably between 0° and 10°. With this configuration, the indicator is continuously formed on the inner surface of the tire in the circumferential direction.

[0009] In the present invention, the projecting section or the recessed section forming the indicator preferably has a height or depth of 0.3 mm to 2.0 mm and a width of 0.5 mm to 5.0 mm. With this configuration, the dimensions of the projecting section or the recessed section forming the indicator can be suitably adjusted to prevent a deterioration of the air permeability of an inner lining layer.

[0010] In the present invention, preferably at least one region of the indicator in the circumferential direction of the tire includes a recessed section. With this configuration, for example, the recessed section can be used as a starting position for applying the sound-absorbing element, and the sound-absorbing element or the sealant layer can be applied even more efficiently.

[0011] In the present invention, at least two of the indicators are preferably formed on the inner surface of the pneumatic tire. With this configuration, the same bellows can be used to apply sound-absorbing elements or sealant layers in a variety of sizes.

[0012] In the present invention, the indicator is expressed as an identification mark consisting of a letter, number, symbol, or graphic. Consequently, in a configuration where a plurality of indicators are formed on the inner surface of the tire, for example, the sound-absorbing element or the sealant layer can be applied precisely. Brief description of the drawings Fig. Figure 1 is a perspective cross-sectional view of a pneumatic tire according to an embodiment of the present invention. Fig. 2A and Fig. 2B are enlarged views of the X section in Fig. 1 and cross-sectional views along a plane orthogonal to the extension direction of an indicator, wherein Fig. 2A illustrates a case where the indicator is a leading section and Fig. 2B illustrates a case in which the indicator is an in-depth section. Fig. Figure 3 is a perspective cross-sectional view of a modification example of a pneumatic tire according to an embodiment of the present invention. Fig. 4 is a perspective view of a bellows that is part of the vulcanization molding process for the pneumatic tire in Fig. 1 is used. Fig. 5A and Fig. 5B are enlarged views of the Y-section in Fig. 4 and cross-sectional views along a plane orthogonal to the extension direction of a recess portion or a projection portion formed on a bladder outer surface, wherein Fig. 5A the deepening section and Fig. 5B illustrates the projection portion. Fig. Figure 6 is a perspective cross-sectional view of another modification example of a pneumatic tire according to an embodiment of the present invention. Description of embodiments

[0013] Configurations of embodiments of the present invention are described in detail below with reference to the accompanying drawings. Fig. Figure 1 shows a pneumatic tire according to an embodiment of the present invention. Fig. 1. According to the present embodiment, the pneumatic tire comprises an annular tread section 1 extending in the circumferential direction of the tire, a pair of sidewall sections 2 arranged on both sides of the tread section 1, and a pair of bead sections 3 arranged inwards from the sidewall sections 2 in the radial direction of the tire. An inner lining layer (not shown) is arranged on an inner surface 4 of the tire.

[0014] In the pneumatic tire described above, a sound-absorbing element 5 is applied to an area of ​​the inner tire surface 4 that corresponds to the tread section 1 along the tire's circumference. The sound-absorbing element 5 can be bonded to the inner tire surface 4 using an adhesive or double-sided adhesive tape. The sound-absorbing element 5 consists of a porous, open-cell material and exhibits predetermined sound absorption properties based on its porous structure. Preferably, polyurethane foam is used as the porous material of the sound-absorbing element 5.

[0015] As in the Fig. 1, Fig. 2A and Fig. As illustrated in Figure 2B, an indicator 10 is formed on the inner surface 4 of the tire, consisting of a projecting section 10a or a recessed section 10b extending in the circumferential direction of the tire. The indicator 10 serves as a marker to indicate the suitable position for applying the sound-absorbing element 5. As shown in Fig. 2A, the projection portion 10a forming the indicator 10 protrudes inward in the radial direction of the tire, and as shown in Fig. As illustrated in Figure 2B, the recessed section 10b forming the indicator 10 is recessed outwards in the radial direction of the tire. The projecting section 10a or the recessed section 10b is formed by compressing the inner surface of the tire 4 with a bellows B (described later). The sound-absorbing element 5 is applied along the projecting section 10a or the recessed section 10b formed in this way.

[0016] In the pneumatic tire described above, the indicator 10, which is formed from the circumferentially extending projecting section 10a or recessed section 10b, is located on the inner surface 4 of the tire, and the sound-absorbing element 5 is applied to the inner surface 4 of the tire along the indicator 10. This allows the sound-absorbing element 5 to be applied precisely and efficiently. Consequently, productivity can be improved in a pneumatic tire where the sound-absorbing element 5 is applied to the inner surface 4.

[0017] In the pneumatic tire described above, the angle of the indicator 10 with respect to the tire circumferential direction is preferably between 0° and 10°. By appropriately setting the angle of the indicator 10 with respect to the tire circumferential direction within the above-described range, the indicator 10 is formed continuously in the tire circumferential direction on the tire inner surface 4. Therefore, the indicator 10 does not end at a central position on the tire circumference. It should be noted that in the Fig. In the embodiment shown in Figure 1, the angle of indicator 10 with respect to the tire circumference direction is 0°.

[0018] In the protrusion portion 10a or the recessed portion 10b constituting the indicator 10, a height h of the protrusion portion 10a or a depth d of the recessed portion 10b is preferably 0.3 mm to 2.0 mm, and a width w of the protrusion portion 10a or the recessed portion 10b is preferably 0.5 mm to 5.0 mm. By appropriately setting the dimensions of the protrusion portion 10a or the recessed portion 10b constituting the indicator within the above-described ranges, it is possible to prevent deterioration of the air permeability of the inner liner layer disposed on the tire inner surface 4.In a configuration in which the recessed portion 10b is formed, if the depth d of the recessed portion 10b exceeds 2.0 mm, the thickness of the inner lining layer cannot be sufficiently ensured, and it becomes more difficult to prevent the air permeability of the inner lining layer from deteriorating.

[0019] Fig. 3 illustrates a modification example of a pneumatic tire according to an embodiment of the present invention. In Fig. 3. At least one area of ​​the indicator 10 in the circumferential direction of the tire includes a recessed section 11. The recessed section 11 is a section where the projecting section 10a or the recessed section 10b is not present on the tire circumference. By providing the recessed section 11, for example, the recessed section 11 can be used as a starting position for applying the sound-absorbing element 5, and thus the sound-absorbing element 5 can be applied even more efficiently.

[0020] As in Fig. As illustrated in point 3, at least two indicators are 10 (four are in Fig. 3) on the tire inner surface 4. By forming a plurality of indicators 10 on the tire inner surface 4, the same bellows B can be used to apply the sound-absorbing elements 5 in a variety of different sizes.

[0021] Furthermore, indicator 10, as in Fig. 3, expressed as a marking 12 for identification, which is made up of a letter, a number, a symbol or a graphic. Fig. The embodiment illustrated in Fig. 3 is an example case where the mark 12 is a letter (letter of the alphabet) combined with a number and is located at the recessed portion 11 of the indicator 10. However, in a configuration in which the recessed portion 11 is not included, the identification mark 12 may be positioned adjacent to the indicator 10. By applying the identification mark 12 to the indicator 10, the sound absorbing member 5 can be precisely applied in a configuration in which the tire inner surface 4 includes, for example, the plurality of indicators 10, without confusing the indicators 10 with each other. Specifically, the identification mark 12 is preferably formed as the recessed portion 10b in the tire inner surface 4.

[0022] Next, a method for manufacturing a pneumatic tire according to an embodiment of the present invention will be described. As shown in the Fig. 4, Fig. 5A and Fig. 5B, in the method for manufacturing a pneumatic tire according to an embodiment of the present invention, a green tire is vulcanized using the bladder B having a bladder outer surface 21 formed with a recessed portion 20a or a projection portion 20b extending in the bladder circumferential direction. In the vulcanization molding step, the inner surface of the tire is pressed by the bladder B to form the indicator 10 made of the projection portion 10a or the recessed portion 10b extending in the tire circumferential direction on the inner surface of the vulcanized pneumatic tire. At this time, the projection portion 10a and the recessed portion 10b formed on the tire inner surface 4 correspond to the recessed portion 20a and the projection portion 20b formed on the bladder outer surface 21, as shown in FIGS. Fig. 5A and 5B are illustrated. After forming the pneumatic tire, in which the indicator 10 is formed on the inner surface 4 of the tire, the sound-absorbing element 5 is applied to the inner surface 4 of the tire along the indicator 10.

[0023] Consequently, it is possible to obtain a pneumatic tire in which the sound-absorbing element 5 is applied to the inner surface of the tire 4 along the indicator 10. According to this method for manufacturing a pneumatic tire, the sound-absorbing element 5 can be applied precisely and efficiently, thereby improving productivity.

[0024] In the pneumatic tire described above, the indicator 10 is the projecting section 10a or the recessed section 10b extending in the circumferential direction of the tire, but the indicator 10 is not specifically limited as such. From the perspective of increasing tire productivity, the indicator 10 is preferably the projecting section 10a. In the embodiment described above, a case was described in which the indicator 10 extends continuously in the circumferential direction of the tire along a section without the recessed section 11. However, the indicator 10 can, for example, be a dashed line or a dotted line extending intermittently in the circumferential direction of the tire.

[0025] In the Fig. In the embodiment illustrated in Figures 1 to 5, a case was described in which the sound-absorbing member 5 is applied to the tire inner surface 4. However, the present invention can also be applied to a pneumatic tire in which a sealant layer 6 is applied to the tire inner surface 4 instead of the sound-absorbing member 5. In particular, as shown in Fig. As illustrated in Figure 6, the sealant layer 6 is bonded to a region of the tire inner surface 4 in the tire circumferential direction that corresponds to the tread portion 1. The sealant layer 6 is formed from an adhesive sealant material. Any adhesive composition can be used as the sealant material. By using such a sealant material, the sealant material can bond to the tire inner surface 4 due to the adhesive properties of the sealant material. List of reference symbols 1 tread section 2 side wall section 3 bead section 4 Tire inner surface 5 Sound-absorbing element 6 Sealant layer 10 Indicator 10a projection section 10b Advanced section 11 Recessed section 12 Marking 20a Advanced section 20b projection section 21 Bellows outer surface B bellows

Claims

[1] Pneumatic tyres comprising: an indicator (10) made of a projection portion (10a) or a recess portion (10b) extending in a tire circumferential direction on a tire inner surface (4); and a sound-absorbing element (5) or a sealant layer (6) applied to the tire inner surface (4) along the indicator (10), wherein the indicator (10) is expressed as a marking (12) for identification made of a letter, a number, a symbol or a graphic. [2] A pneumatic tire according to claim 1, wherein an angle of the display with respect to the tire circumferential direction is between 0° and 10°. [3] A pneumatic tire according to claim 1 or 2, wherein the protrusion portion (10a) or the recess portion (10b) constituting the indicator (10) has a height or depth of 0.3 mm to 2.0 mm and a width of 0.5 mm to 5.0 mm. [4] A pneumatic tire according to any one of claims 1 to 3, wherein at least a portion of the indicator (10) in the tire circumferential direction includes a recessed portion (11). [5] A pneumatic tire according to any one of claims 1 to 4, wherein at least two of the indicators (10) are formed on the tire inner surface (4). [6] A method for manufacturing a pneumatic tire, comprising the following steps: Vulcanizing a green tire using a bladder (B) having a bladder outer surface (21) formed with a recessed portion (20a) or a protrusion portion (20b) extending in a bladder circumferential direction; Forming an indicator (10) made of a protrusion portion (10a) or a recess portion (10b) extending in a tire circumferential direction on an inner surface (4) of the vulcanized pneumatic tire; and Applying a sound-absorbing element (5) or a sealant layer (6) to the inner surface (4) of the pneumatic tire along the indicator (10), wherein the indicator (10) is expressed as a marking (12) for identification made of a letter, a number, a symbol or a graphic. [7] A method for manufacturing a pneumatic tire according to claim 6, wherein an angle of the indicator (10) with respect to the tire circumferential direction is between 0° and 10°. [8] A method of manufacturing a pneumatic tire according to claim 6 or 7, wherein the protrusion portion (10a) or recess portion (10b) constituting the indicator (10) has a height or depth of 0.3 mm to 2.0 mm and a width of 0.5 mm to 5.0 mm. [9] A method of manufacturing a pneumatic tire according to any one of claims 6 to 8, wherein at least a portion of the indicator (10) in the tire circumferential direction includes a recessed portion (11). [10] A method of manufacturing a pneumatic tire according to any one of claims 6 to 9, wherein at least two of the indicators (10) are formed on the inner surface (4) of the pneumatic tire.

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