Patent Publication Number: US-2022227184-A1

Title: Pneumatic tire and method of manufacturing pneumatic tire

Description:
TECHNICAL FIELD 
     The present invention relates to a pneumatic tire and a method of manufacturing a pneumatic tire. 
     BACKGROUND ART 
     Tires (particularly aircraft tires) are known that are provided with balance patches on the inner surface to adjust a weight balance of the tires (Patent Literature 1). A balance patch disclosed in Patent Literature 1 has a flat sheet-like shape, and is attached to the inner surface of the tire with an adhesive. The balance patch disclosed in Patent Literature 1 is used such that the entire surface of the balance patch on one side is sticked to the inner surface of the tire, and thus has the following problems. 
     When a tire reused, a tread rubber of the spent tire is scraped off, and a new tread rubber is attached to the tire. The balance patch, when provided on the inner surface of the tire, is often temporarily removed and again attached to the inner surface of the tire so as to adjust the weight balance. Since the balance patch needs to be scraped off by use of a hand grinder and the like when removed, the scraping operation leads to a reduction in productivity of manufacturing retread tires. To deal with this, a technique is disclosed that provides a balance patch with a projection so as to facilitate the removal of the balance patch to save the time during the manufacture of retread tires (Patent Literature 2). 
     CITATION LIST 
     Patent Literature 
     
         
         Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2012-121561 
         Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2014-133504 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     The demand for appropriate management of tires has grown according to information such as used situations or traveling distances of the tires acquired from a RFID tag (a functional component) attached to the inner surface of each tire. When both the balance patch and the RFID tag are attached to the inner surface of the tire, there is a risk of unintentionally causing damage to the RFID tag in the process of removing the balance patch during the manufacture of the retread tire. Patent Literature 2 does not mention this issue, which still needs to be improved. 
     To solve the conventional problems described above, the present invention provides a pneumatic tire and a method of manufacturing a pneumatic tire capable of preventing damage to a functional component in a process of removing a balance patch during the manufacture of a retread tire. 
     Technical Solution 
     A pneumatic tire according to an aspect of the present invention includes at least one balance patch (balance patch  40 ) arranged on a tire inner surface (tire inner surface  30 ) that is a surface on an inner side of the tire (tire  10 ), and a functional component (functional component  50 ) having a communication function and arranged on the tire inner surface at a position separated at a predetermined angle (predetermined angle θ) from the at least one balance patch in a tire circumferential direction. 
     Advantageous Effects 
     The present invention can prevent damage to the functional component. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a cross-sectional view taken along a width direction and a radial direction of a pneumatic tire. 
         FIG. 2  is a cross-sectional view taken along a circumferential direction of the pneumatic tire. 
         FIG. 3A  is a perspective view illustrating a balance patch according to the present embodiment. 
         FIG. 3B  is a perspective view illustrating a functional component according to the present embodiment. 
         FIG. 4  is a cross-sectional view taken along the circumferential direction of the pneumatic tire. 
         FIG. 5  is a cross-sectional view taken along the circumferential direction of the pneumatic tire. 
         FIG. 6  is a cross-sectional view taken along the circumferential direction of the pneumatic tire. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, some embodiments according to the present invention are described with reference to the drawings. The same elements illustrated in the drawings are denoted by the same reference numerals, and overlapping explanations are not made below. 
     1. Configuration of Pneumatic Tire 
     A configuration of a pneumatic tire  10  (referred to also simply as a “tire”) according to the present embodiment is described below with reference to  FIG. 1 . 
     As illustrated in  FIG. 1 , the tire  10  is used in a state of being attached to a rim hole  60 . The inner space of the tire  10  attached to the rim hole  60  is filled with gas such as air. The tire  10  according to the present embodiment is illustrated with an aircraft tire mounted to an aircraft. The tire  10  is not limited to the use as the aircraft tire, and may be used for automobiles, trucks (including off-road dump trucks), and buses, for example. 
     A tread  20 , which comes into contact with a road surface, is provided on the rear surface with a balance patch  40 . The balance patch  40  is attached to the surface on the inner side of the tire  10 , which is a tire inner surface  30 . The balance patch  40  is a member used for improving uniformity of the tire  10 , and is typically used for aircraft tires. 
     As illustrated in  FIG. 2 , the tire inner surface  30  is also provided with a functional component  50  in addition to the balance patch  40 . The functional component  50  is attached to the tire inner surface  30  at a position separated at a predetermined angle θ from the balance patch  40  in the tire circumferential direction. The predetermined angle θ is 90 degrees or greater when the single balance patch  40  is attached to the tire inner surface  30 . 
     A gap between the balance patch  40  and the functional component  50  in the tire circumferential direction is longer than a length of the balance patch  40  in the tire circumferential direction, as illustrated in  FIG. 2 . 
     The balance patch  40  and the functional component  50  are described in more detail below with reference to  FIG. 3A  and  FIG. 3B . As illustrated in  FIG. 3A , the balance patch  40  has a flat sheet-like shape. The balance patch  40  is sticked to the tire inner surface  30  with an adhesive. The balance patch  40  is formed from a rubber composition having a large mass in view of the adjustment of the weight balance of the tire  10 . 
     As illustrated in  FIG. 3B , the functional component  50  has an oval shape. The functional component  50  has a configuration in which an electronic component such as a radio frequency identifier (RFID) tag  51  is covered with a rubber member. The material used for the functional component  50  is not limited to the rubber member, and may be a metal member or a resin member. The functional component  50  is also sticked to the tire inner surface  30  with an adhesive, as in the case of the balance patch  40 . The balance patch  40  and the functional component  50  are both attached on the tire equator line. 
     The RFID tag  51  includes an antenna, and an IC chip having a communication function and operated by dielectric power generated by weak radio waves received by the antenna. The RFID tag  51  stores data on used conditions and traveling distances of aircraft tires, for example. The data stored in the RFID tag  51  is read out by use of a reader/writer, and is used for the management of the aircraft tires. 
     As illustrated in  FIG. 3A  and  FIG. 3B , the functional component  50  is shorter in the tire circumferential direction and lighter than the balance patch  40  when attached. 
     The functional component  50  is attached to the tire inner surface  30  after the attachment of the balance patch  40 . 
     2. Operational Effects 
     The operations and effects of the tire  10  are described below. 
     According to the present embodiment, at least one balance patch  40  is arranged on the tire inner surface  30  that is the surface on the inner side of the tire  10 . The functional component  50  having the communication function is arranged on the tire inner surface  30  at a position separated at the predetermined angle θ from the balance patch  40  in the tire circumferential direction. The predetermined angle θ is 90 degrees or greater when the single balance patch  40  is provided (refer to  FIG. 2 ). The arrangement of the balance patch  40  and the functional component  50  separated from each other at 90 degrees or greater in the tire circumferential direction avoids unintentional damage to the functional component  50  in the process of removing the balance patch  40  during the manufacture of the retread tire. This prevents the functional component  50  from being broken up accordingly. 
     The balance patch  40  provided for adjusting the weight balance of the tire  10  inevitably makes the circumference around the arrangement position slightly heavier. According to the present embodiment, the arrangement of the smaller and lighter functional component  50  than the balance patch  40  separated from each other at 90 degrees or greater in the tire circumferential direction can improve the uniformity of the tire  10 . 
     The functional component  50  may be arranged at a position separated from the balance patch  40  at 180 degrees in the tire circumferential direction, as illustrated in  FIG. 4 . This arrangement leads the functional component  50  to be located at a position furthest from the balance patch  40 , so as to prevent damage to the functional component  50  and improve the uniformity of the tire  10 . 
     As illustrated in  FIG. 5 , two balance patches (balance patches  40  and  41 ) may be provided. The functional component  50  in this case only needs to be arranged in a region having a wider gap between the balance patch  40  and the balance patch  41  in the tire circumferential direction.  FIG. 5  illustrates the case in which the balance patch  40  and the balance patch  41  define two gaps (regions R 1  and R 2 ) in the tire circumferential direction. The functional component  50  is thus led to be arranged in the region R 1  wider than the region R 2 . This arrangement can also achieve the same effects as described above. 
     As illustrated in  FIG. 6 , three balance patches (balance patches  40  to  42 ) may be provided. The functional component  50  in this case only needs to be arranged in a region having the widest gap between the balance patches in the tire circumferential direction.  FIG. 6  illustrates the case in which the respective balance patches define three gaps (regions R 1  to R 3 ) in the tire circumferential direction. The functional component  50  is thus led to be arranged in the region R 1  wider than the region R 2  and the region R 3 . This arrangement can also achieve the same effects as described above. 
     When the two or more balance patches are provided, as illustrated in  FIG. 5  and  FIG. 6 , the predetermined angle θ between the functional component  50  and the respective balance patches is not necessarily 90 degrees or greater, and may be set to be less than 90 degrees. The angle between the functional component  50  and the respective balance patches is, however, preferably set to be larger in view of the prevention of damage to the functional component  50 . 
     The tire  10  according to the present embodiment is manufactured by the process described below. At least the single balance patch  40  is attached to the tire inner surface  30 , and the functional component  50  is then attached to the tire inner surface  30  at a position separated at the predetermined angle from the balance patch  40  in the circumferential direction, so as to manufacture the tire  10 . If this process is reversed, in particular, if the functional component  50  is attached to the tire  10  first, and a test for examining the uniformity is executed so as to determine the position at which the balance patch  40  should be attached, the attachment position of the balance patch  40  could overlap with the position at which the RFID tag is attached. The manufacturing method according to the present embodiment can avoid such a problem, so as to not only lead the balance patch  40  and the functional component  50  to be separated from each other at a predetermined angle, but also improve the uniformity of the tire  10 . 
     While the present invention has been described above by reference to the embodiment, it should be understood that the present invention is not intended to be limited to the descriptions and the drawings composing part of this disclosure. Various alternative embodiments, examples, and technical applications will be apparent to those skilled in the art according to this disclosure. 
     For example, the functional component  50  may be arranged at the lightest point of the tire  10 . The term “lightest point” refers to a position at which the tire  10  has the lightest weight. 
     The embodiment has been illustrated above with the case in which the balance patch  40  and the functional component  50  are each arranged in the middle on the tire equator line on the rear side of the tread  20 , but is not limited to this case. The balance patch  40  and the functional component  50  only need to be arranged on the tire inner surface  30 , and may be arranged on the rear side of the side part, for example. 
     In view of the operating efficiency in the steps of attaching and removing the balance patch  40 , at least a part of the balance patch  40  is preferably located on the tire equator line. Avoiding arranging the functional component  50  on the equator line in this case can further reduce a risk of unintentionally causing damage to the RFID in the step of removing the balance patch  40 . 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2019-109532, filed on Jun. 12, 2019, the entire contents of which are incorporated herein by reference. 
     REFERENCE SIGNS LIST 
     
         
         
           
               10  PNEUMATIC TIRE 
               20  TREAD 
               30  TIRE INNER SURFACE 
               40 ,  41 ,  42  BALANCE PATCH 
               50  FUNCTIONAL COMPONENT 
               51  RFID TAG 
               60  RIM HOLE