JP6506612B2 - Motorcycle tire and method of manufacturing motorcycle tire - Google Patents

Description

  The present invention relates to a motorcycle tire having a tread reinforcement layer compatible with durability and steering stability, and a method of manufacturing the motorcycle tire.

  The following Patent Document 1 proposes a motorcycle tire having a tread reinforcing layer. The tread reinforcing layer includes a plurality of reinforcing cords aligned in parallel with the tire circumferential direction, and reinforcing cords adjacent to each other are separated from each other. Such a tread reinforcing layer makes it difficult to disperse the tension acting on the reinforcing cord in a portion of the tread portion throughout the tread reinforcing layer.

JP-A-9-118109

  For this reason, the conventional tread reinforcing layer needs many reinforcing cords in order to obtain the strength of the tread portion having sufficient durability. Such a tread reinforcing layer has the disadvantages of heavy mass, excessive tire rigidity, and poor steering stability.

  The present invention has been made in view of the above-described actual situation, and a crown reinforcing portion in which a belt-like ply is wound at an angle of 5 degrees or less with respect to the tire circumferential direction and a belt-like ply are wound in a zigzag manner It is a main object of the present invention to provide a motorcycle tire including a tread reinforcing layer which can achieve both durability and steering stability on the basis of including a shoulder reinforcing portion, and a method of manufacturing the same.

  According to a first aspect of the present invention, there is provided a motorcycle tire having a tread portion curved in a convex arc shape on the outer side in the tire radial direction, the toroidal carcass and the tire radial direction outer side of the carcass and the inner portion of the tread portion. And a tread reinforcement layer disposed on the tread reinforcement layer, the tread reinforcement layer including a crown reinforcement portion disposed in a tread crown portion including the tire equator, and a pair of shoulder reinforcement portions disposed in tread shoulder portions on both sides thereof And the crown reinforcing portion is formed by winding a long strip-like ply in which one or more reinforcing cords are covered with topping rubber at an angle of 5 degrees or less with respect to the tire circumferential direction. And said shoulder reinforcements are inclined in a first direction at a first angle greater than 5 degrees with respect to the circumferential direction of the tire. A second inclined portion wound in a second direction opposite to the first direction at a second angle larger than 5 degrees with respect to the circumferential direction of the tire; By winding in a zigzag shape including the belt-like ply, and by winding so that the side edges of the strip-like ply do not contact each other, a mesh having a substantially rhombic space surrounded by the first inclined portion and the second inclined portion It is characterized in that it is formed in a shape.

  In the motorcycle tire according to the first aspect of the present invention, it is preferable that the crown reinforcing portion be wound such that the side edges of the strip-like ply adjacent in the axial direction of the tire contact or overlap each other.

  In the motorcycle tire according to the first aspect of the present invention, it is desirable that the first angle and the second angle be substantially the same.

  In the motorcycle tire according to the first aspect of the present invention, it is desirable that the crown reinforcing portion and the pair of shoulder reinforcing portions be formed by one continuous band-like ply.

  In the motorcycle tire according to the first aspect of the present invention, it is preferable that the spread width of the crown reinforcing portion be 5% to 13% of the spread width of the tread reinforcing layer.

  A second invention of the present invention is a method of manufacturing a motorcycle tire having a tread portion curved in a convex arc shape on the outer side in the tire radial direction, and for forming a tread reinforcing layer disposed in the tread portion. The tread reinforcing layer forming step includes a tread reinforcing layer forming step, wherein the tread reinforcing layer forming step includes one or more reinforcements on the outer peripheral surface of the profile deck, which is a rotating body having an outer peripheral surface curved in a convex arc shape radially outward The winding step includes winding a long strip ply covered with a topping rubber with a cord directly or through a carcass ply, wherein the winding step includes the step of rolling the strip ply in a tread crown portion including a tire equator. A crown winding step of forming a crown reinforcement by winding at an angle of 5 degrees or less with respect to the circumferential direction; The first shoulder winding step of forming the first shoulder reinforcing portion by winding the strip-like ply around the doddle portion, and forming the second shoulder reinforcing portion by winding the strip-like ply around the other tread shoulder portion of the tread crown portion And a second shoulder winding step, the first shoulder winding step and the second shoulder winding step respectively forming the strip ply at a first angle greater than 5 degrees with respect to the tire circumferential direction. A first inclined portion wound in a first direction, and a second angle inclined in a second direction opposite to the first direction at a second angle larger than 5 degrees with respect to the tire circumferential direction. The first inclined portion and the second inclined portion are wound by winding in a zigzag shape including the inclined portion and winding so that the side edges of the strip-like ply do not contact each other. And forming a mesh shape having a space portion of the substantially rhombic surrounded by the.

  In the method of manufacturing a motorcycle tire according to the second aspect of the invention, the crown winding step, the first shoulder winding step, and the second shoulder winding step use one continuous strip ply It is desirable to be done.

  In the method for manufacturing a motorcycle tire according to the second aspect of the invention, in the winding step, after the first shoulder winding step is performed, the crown winding step is performed, and then the second shoulder winding step is performed. It is desirable to be done.

  In the method for manufacturing a motorcycle tire according to the second invention, the first shoulder winding step is a step of fixing the winding end of the belt-like ply to the first inner end portion on the tire equator side of the first shoulder reinforcing portion. And the outer circumferential surface of the profile deck while reciprocating the strip ply between the first inner end and a first outer end which is an end on the tread end side of the first shoulder reinforcement portion. Preferably, the method comprises the steps of: feeding the strip ply and positioning the winding of the strip ply at the first inner end to finish.

  In the method of manufacturing a motorcycle tire according to the second invention, the crown winding step spirally winds the strip-like ply from the first inner end toward the second shoulder reinforcing portion, and Preferably, the step of positioning the winding of the strip-like ply at the second inner end which is the end on the tire equator side of the second shoulder reinforcing portion is completed.

  In the method for manufacturing a motorcycle tire according to the second invention, in the second shoulder winding step, the strip-like ply is formed at the second inner end and the end on the tread end side of the second shoulder reinforcing portion. It is desirable to include the steps of: supplying the outer peripheral surface of the profile deck while reciprocating between the second outer end and the second outer end.

  In the method for manufacturing a motorcycle tire according to the second invention, in the second shoulder winding step, the strip-like ply has a small length along the tire circumferential direction at the second inner end and the second outer end. It is desirable to include a winding step.

  In the method for manufacturing a motorcycle tire according to the second invention, in the first shoulder winding step, the strip-like ply has a small length along the tire circumferential direction at the first inner end and the first outer end. It is desirable to include a winding step.

  The motorcycle tire according to the present invention includes a toroidal carcass and a tread reinforcing layer disposed radially outward of the carcass and inside the tread portion. The tread reinforcing layer includes a crown reinforcing portion disposed in a tread crown portion including the tire equator, and a pair of shoulder reinforcing portions disposed in tread shoulder portions on both outer sides thereof.

  The crown reinforcing portion is formed by winding a long strip ply in which one or more reinforcing cords are covered with topping rubber at an angle of 5 degrees or less with respect to the tire circumferential direction. Such a crown reinforcement can improve the strength of the tread crown, in particular the penetration strength, and in turn improve the durability of the motorcycle tire.

  Each shoulder reinforcing portion is formed in a mesh shape having substantially rhombic spaces by winding the strip-like ply in a zigzag shape and winding the side edges of the strip-like ply so as not to contact each other. Such a shoulder reinforcement can distribute the tension acting on a part of the shoulder reinforcement over the entire shoulder reinforcement via the strip plies crossing each other. For this reason, in the shoulder reinforcing portion, the amount of use of the strip-like ply for obtaining the necessary strength can be reduced. Therefore, weight reduction and rigidity optimization of the motorcycle tire can be realized, and in turn, the steering stability of the motorcycle tire can be improved.

  The method of manufacturing a motorcycle tire according to the present invention includes a winding step of winding a long strip ply directly or through a carcass ply. The winding step includes a crown winding step of winding the strip-like ply at an angle of 5 degrees or less with respect to the circumferential direction of the tire to form a crown reinforcing portion around a tread crown portion including a tire equator. Such a crown winding step can form a crown reinforcement portion capable of improving the penetration strength of the tread crown portion, which in turn enables the manufacture of a highly durable motorcycle tire.

  The winding step includes a first shoulder winding step and a second shoulder winding step, and the first shoulder winding step and the second shoulder winding step respectively form the strip ply in a zigzag shape. By winding and winding so that the side edges of the strip-like ply do not contact each other, it is formed in a mesh shape having a substantially rhombic space portion. Such a first shoulder winding process and a second shoulder winding process can disperse the tension acting on a part of the shoulder reinforcing portion over the entire shoulder reinforcing portion and the second shoulder reinforcing portion. The reinforcement portion can be formed, which in turn makes it possible to manufacture a motorcycle tire with high steering stability.

  As described above, the tread reinforcing layer of the motorcycle tire of the present invention can achieve both durability and steering stability.

FIG. 1 is a cross-sectional view showing an embodiment of a motorcycle tire of the present invention. It is a perspective view of a strip | belt-shaped ply. It is an expanded plan view of a tread reinforcement layer. It is a schematic diagram which shows the 1st shoulder winding process notionally. It is an enlarged plan view showing the winding start and the winding end of the strip ply. It is a schematic diagram which shows a crown winding process notionally. It is a schematic diagram which shows the 2nd shoulder winding process notionally.

Hereinafter, an embodiment of the present invention will be described based on the drawings.
FIG. 1 shows a tire meridional cross-sectional view including a tire rotation axis in a normal state of a motorcycle tire (hereinafter, may be simply referred to as “tire”) 1 of the present embodiment.

  The “normal state” is a state in which the tire 1 is rim-assembled on a normal rim (not shown), filled with normal internal pressure, and unloaded. Unless otherwise noted in the present specification, the dimensions of each part of the tire 1 are values measured in a normal state.

  In the standard system including the standard to which the tire 1 is based, the above-mentioned "regular rim" is a rim which is defined for each tire in the standard, for example, "standard rim" in the case of JATMA, "Design Rim in the case of TRA "If it's ETRTO, it's" Measuring Rim ".

  The above-mentioned "normal internal pressure" is the air pressure specified by each standard in the standard system including the standard to which the tire 1 is based, and in the case of JATMA, "maximum air pressure", and in the case of TRA, the table "TIRE LOAD LIMITS AT VARIOUS The maximum value described in COLD INFLATIONS PRESSURES. In the case of ETRTO, it is "INFLATION PRESSURE".

  As shown in FIG. 1, the tire 1 according to the present embodiment includes a tread portion 2, a toroidal carcass 6, and a tread reinforcing layer 7 disposed outside the carcass 6 in the tire radial direction and inside the tread portion 2. have.

  The tread portion 2 is curved in a circular arc shape convex outward in the tire radial direction, and the tread ends Te, Te are positioned on the outermost side in the tire axial direction of the tire 1. The tread portion 2 of the present embodiment includes a tread crown portion 2C including a tire equator C, and a pair of tread shoulder portions 2S on both outer sides thereof. The tread crown portion 2C is located in a straight contact area where a normal load is applied to the tire 1 in a normal state and the tire is grounded at a camber angle of 0 degrees. The tread shoulder portion 2S is a range from the end portion of the tread crown portion 2C in the straight contact area to the tread end Te.

  In the standard system including the standard on which the tire 1 is based, the above-mentioned "normal load" is a load which each standard is determined for each tire, and in the case of JATMA, "maximum load capacity", in the case of TRA TIRE LOAD LIMITS The maximum value described in AT VARIOUS COLD INFlation PRESSURES. In the case of ETRTO, it is "LOAD CAPACITY".

  The carcass 6 is formed of, for example, at least one carcass ply 6A. The carcass ply 6A is formed, for example, by covering carcass cords arranged at an angle of 75 to 90 ° with respect to the tire equator C with unvulcanized topping rubber. For the carcass cord, for example, an organic fiber cord such as nylon, polyester or rayon, etc. is suitably adopted.

  The carcass ply 6A includes, for example, a body portion 6a and a pair of folded portions 6b. The main body portion 6 a extends from the tread portion 2 through the side wall portions 3 on both sides to the bead cores 5 of the bead portions 4 on both sides. The folded back portion 6b is continuous with the main body portion 6a, and the circumference of the bead core 5 is folded back from the inside in the tire axial direction.

  The bead apex rubber 8 is disposed between the main body 6a and the folded back portion 6b. The bead apex rubber 8 is made of hard rubber and extends outward from the bead core 5 in the tire radial direction.

  The tread reinforcing layer 7 extends along the curvature of the tread portion 2 in the tire meridian section, and is formed over substantially the entire width of the tread portion 2. Thereby, the tread reinforcing layer 7 can increase the strength of the tread portion 2 over the entire area of the tread portion 2.

  The tread reinforcing layer 7 of the present embodiment is formed by winding the strip-like ply 9, and is disposed on the crown reinforcing portion 7C disposed on the tread crown portion 2C and the tread shoulder portions 2S on both outer sides thereof. And a pair of shoulder reinforcements 7S. The crown reinforcing portion 7C and the pair of shoulder reinforcing portions 7S are preferably formed of, for example, one continuous band-like ply 9. Such a tread reinforcing layer 7 can be produced efficiently. However, the crown reinforcing portion 7 </ b> C and the pair of shoulder reinforcing portions 7 </ b> S may be formed of band-like plies 9 which are different from each other.

  A perspective view of the strip ply 9 is shown in FIG. As shown in FIG. 2, the belt-like ply 9 is ribbon-shaped, and one or a plurality of, in this embodiment, three reinforcing cords 10 arranged in parallel at substantially equal intervals are unvulcanized toppings It is formed by coating with a rubber 11. Since both the carcass ply 6A (shown in FIG. 1) and the strip-like ply 9 contain unvulcanized rubber, one end of the strip-like ply 9 is pressed against the carcass ply 6A and stuck by using their adhesive force. Will be attached.

  The strip ply 9 of the present embodiment includes both side edges 9s, 9s and has a substantially rectangular cross section. In order to reduce the amount of use while securing the strength of the strip ply 9, the width W1 of the strip ply 9 is preferably, for example, in the range of 2.5 to 12.0 mm. From the same point of view, the thickness t1 of the strip ply 9 is desirably, for example, in the range of 0.6 to 3.0 mm.

  FIG. 3 shows a development plan view of the tread reinforcing layer 7. As shown in FIG. 3, the crown reinforcing portion 7C of this embodiment is formed by winding the strip ply 9 preferably at an angle of 5 degrees or less with respect to the tire circumferential direction. Such a crown reinforcing portion 7C can improve the strength of the tread crown portion 2C, in particular, the penetration strength, and in turn can improve the durability of the tire 1.

  In the crown reinforcing portion 7C, it is desirable that side edges 9s (shown in FIG. 2) of the strip-like ply 9 adjacent in the tire axial direction be wound in contact with each other. Such a crown reinforcement 7C can further improve the penetration strength of the tread crown 2C. In the crown reinforcing portion 7C, the side edges 9s of the strip-like plys 9 adjacent in the tire axial direction may be wound on each other.

  The development width Wc of the crown reinforcement portion 7C is preferably 5% to 13% of the development width Wt of the tread reinforcement layer 7. If the development width Wc is smaller than 5% of the development width Wt, there is a possibility that the strength of the tread crown portion 2C can not be sufficiently secured. If the deployment width Wc is larger than 13% of the deployment width Wt, the amount of use of the strip ply 9 may increase, which may adversely affect the steering stability of the tire 1.

  In each shoulder reinforcing portion 7S of the present embodiment, the first inclined portion 9a in which the strip ply 9 is wound in a first direction at a first angle θ1 and the first direction at a second angle θ2 are It is formed by being wound in a zigzag shape including the second inclined portion 9b wound in an inclined manner in the opposite second direction.

  Furthermore, each shoulder reinforcing portion 7S is substantially wound surrounded by the first inclined portion 9a and the second inclined portion 9b by being wound so that the side edges 9s (shown in FIG. 2) of the strip-like ply 9 do not contact each other. It is formed in a mesh shape having a rhombic space 12. Such a shoulder reinforcing portion 7S can disperse the tension acting on a part of the shoulder reinforcing portion 7S over the entire shoulder reinforcing portion 7S via the strip-like plies 9 crossing each other. Therefore, in the shoulder reinforcing portion 7S, the amount of use of the strip ply 9 for obtaining the necessary strength can be reduced. Therefore, weight reduction and rigidity optimization of the tire 1 can be realized, and in turn, the steering stability of the tire 1 can be improved.

  Preferably, the first angle θ1 and the second angle θ2 are larger than 5 degrees with respect to the tire circumferential direction. The first inclined portion 9a and the second inclined portion 9b having such a first angle θ1 and a second angle θ2 efficiently distribute the tension acting on a part of the shoulder reinforcing portion 7S over the entire shoulder reinforcing portion 7S. It can be done. Furthermore, it is desirable that the first angle θ1 and the second angle θ2 be substantially the same angle.

  Each shoulder reinforcing portion 7S is a first shoulder reinforcing portion 7S1 formed in the tread shoulder portion 2S on one side of the tread crown portion 2C, and a second shoulder formed in the tread shoulder portion 2S on the other side of the tread crown portion 2C. And the reinforcing portion 7S2.

  In the first shoulder reinforcing portion 7S1 of the present embodiment, the strip-like ply 9 includes the non-inclined portion 9c connecting the first inclined portion 9a and the second inclined portion 9b. The non-inclined portion 9c is, for example, a first outer end Ee1 that is a first inner end Ei1 on the tire equator C side of the first shoulder reinforcement 7S1 and an end on the tread end Te of the first shoulder reinforcement 7S1. And are provided.

  In the second shoulder reinforcing portion 7S2 of the present embodiment, the strip-like ply 9 includes the non-inclined portion 9c connecting the first inclined portion 9a and the second inclined portion 9b. The non-inclined portion 9c is, for example, a second outer end Ee2 that is an end on the tire equatorial C side of the second shoulder reinforcing portion 7S2 and an end on the tread end Te side of the second shoulder reinforcing portion 7S2. And are provided.

  Each non-inclined portion 9c described above is wound in a small length along the tire circumferential direction, for example, at an angle of 5 degrees or less with respect to the tire circumferential direction. Such a non-inclined portion 9 c smoothly connects the first inclined portion 9 a and the second inclined portion 9 b, and suppresses the change in angle when winding the strip-like ply 9 small. For this reason, the bending stress acting on the strip ply 9 is suppressed to a low level, which in turn helps to prevent the winding ply 9 from being broken.

  The non-inclined portions 9c of the first inner end Ei1 and the second inner end Ei2 have side edges 9s (shown in FIG. 2) of the strip ply 9 adjacent in the tire axial direction to the strip ply 9 of the crown reinforcement 7C. It is desirable to be wound in contact with or in layers. Such a non-inclined portion 9c can reinforce the crown reinforcing portion 7C to further improve the strength of the straight contact area.

  The tire 1 of the present embodiment is manufactured through the steps of forming a green tire and the steps of vulcanizing and forming the green tire. The step of forming the green tire includes a step of forming a tread reinforcing layer for forming the above-described tread reinforcing layer 7. The tread reinforcing layer forming step includes a winding step of winding the long strip ply 9.

  In the winding process of the present embodiment, first, a first shoulder winding process is performed in which the first shoulder reinforcing portion 7S1 is formed on the tread shoulder portion 2S on one side of the tread crown portion 2C. FIG. 4 is a schematic view conceptually showing a first shoulder winding step. As shown in FIG. 4, in the winding step including the first shoulder winding step, the long strip ply 9 is wound around the outer peripheral surface 13a of the profile deck 13 directly or through the carcass ply 6A.

  The strip ply 9 is, for example, continuously supplied to the profile deck 13 by the applicator 14. The applicator 14 is configured, for example, in the form of a conveyor, for delivering the strip ply 9 along its longitudinal direction. Furthermore, it is desirable that the applicator 14 be configured to guide the strip ply 9 so as not to shift in the width direction.

  Such an applicator 14 can reciprocate the strip-like ply 9 by following it along the outer peripheral surface 13a of the profile deck 13 in a circular arc, for example. The reciprocating movement of the applicator 14 is realized by, for example, a three-dimensional movement device (not shown) or the like.

  The applicator 14 of the present embodiment can supply the strip ply 9 along the tangential direction of the outer peripheral surface 13 a by moving along the outer peripheral surface 13 a of the profile deck 13. As a result, it is possible to prevent, as much as possible, the distortion of the strip-like ply 9 and the distortion at the time of sticking.

  The profile deck 13 of the present embodiment is a rotating body having an outer circumferential surface 13 a that curves in a circular arc shape that is convex outward in the radial direction. The profile deck 13 includes, for example, a plurality of segment-like members, and the outer peripheral surface 13a is configured to be able to expand and contract in diameter by moving these in the radial direction. The expansion / contraction diameter of the profile deck 13 is performed, for example, using expansion or contraction of the expansion body 15 accommodated inside the profile deck 13.

  For example, a pair of carcass holding devices 16 are disposed on both sides of the profile deck 13. The carcass holding device 16 is a ring-shaped member movable in the axial direction, and is mounted on the support shaft 17. Thereby, the carcass holding device 16 can also rotate concentrically and integrally with the profile deck 13. The carcass holding device 16 can hold the cylindrical carcass ply 6A, into which the bead core 5 is inserted and whose end is folded back, from the inner peripheral surface side.

  In the winding step of the present embodiment, the diameter of the profile deck 13 is expanded in a state where the carcass ply 6A is held in advance by the carcass holding device 16 before the first shoulder winding step, and a pair of carcass holding devices Bring 16 close to each other. Thus, a toroidal carcass ply 6A is formed on the profile deck 13.

  Next, in the first shoulder winding process of the present embodiment, winding of the strip ply 9 is started on the toroidal carcass ply 6A. FIG. 5 is an enlarged plan view showing the winding start position and the winding end position of the strip ply 9. As shown in FIG. 5, in the first shoulder winding step, the winding end 9d at the start of winding of the strip ply 9 is fixed to the first inner end Ei1 of the first shoulder reinforcing portion 7S1.

  As shown in FIG. 4, thereafter, the first shoulder winding step reciprocates the strip ply 9 between the first inner end Ei1 and the first outer end Ee1 by the applicator 14. It supplies to the outer peripheral surface 13a of the profile deck 13 which is rotating. In this step, as shown in FIG. 3, the strip ply 9 is wound in a zigzag shape including the first inclined portion 9a and the second slope 9b, and the side edge 9s of the strip ply 9 (shown in FIG. 2). ) So that they do not touch each other. By this process, the strip-like ply 9 can be formed in a mesh shape having the substantially rhombus-shaped space portion 12 surrounded by the first inclined portion 9a and the second inclined portion 9b.

  Such a first shoulder winding process can form the first shoulder reinforcing portion 7S1 capable of dispersing the tension acting on a part of the first shoulder reinforcing portion 7S1 over the entire first shoulder reinforcing portion 7S1. For this reason, the first shoulder winding step makes it possible to manufacture the tire 1 with high steering stability.

  The first shoulder winding step includes the step of winding the strip ply 9 in a small length along the tire circumferential direction at the first inner end Ei1 and the first outer end Ee1. By this process, the non-inclined portion 9 c of the strip ply 9 is formed.

  As shown in FIG. 5, it is desirable that the first shoulder winding process be finished by positioning the winding of the strip ply 9 at the first inner end Ei1. Such a first shoulder winding process can be smoothly transferred to the next crown winding process.

  Next, as a winding step, a crown winding step of forming a crown reinforcing portion 7C in the tread crown portion 2C is performed. It is desirable that the crown winding process be performed following the first shoulder winding process using one continuous strip ply 9 without interruption of the strip ply 9. For this reason, the time which transfers to a crown winding process from a 1st shoulder winding process can be shortened, and it can manufacture efficiently.

  FIG. 6 is a schematic view conceptually showing a crown winding step. As shown in FIG. 6, in the crown winding step of the present embodiment, the strip ply 9 is spirally wound from the first inner end Ei1 toward the second shoulder reinforcing portion 7S2. Such a crown winding process can form a crown reinforcing portion 7C that can improve the penetration strength of the tread crown portion 2C, and thus, the tire 1 with high durability can be manufactured.

  In this step, the strip-like ply 9 is moved by the applicator 14 from the first inner end Ei1 toward the second shoulder reinforcement 7S2 at a low speed, and the outer circumferential surface 13a of the rotating profile deck 13 is Supplied. By this process, the side edges 9s (shown in FIG. 2) of the strip-like plys 9 adjacent in the axial direction of the tire contact each other or are overlapped at an angle of 5 degrees or less with respect to the tire circumferential direction. It is done.

  As shown in FIG. 5, it is desirable that the crown winding process be finished by positioning the winding of the strip ply 9 at the second inner end Ei2. Such a crown winding process can be smoothly transferred to the next second shoulder winding process.

  Next, as a winding process, a second shoulder winding process is performed in which a second shoulder reinforcing portion 7S2 is formed on the tread shoulder portion 2S on the other side of the tread crown portion 2C. It is desirable that the second shoulder winding process is performed following the crown winding process using one continuous strip ply 9 without interruption of the strip ply 9. For this reason, the time which transfers to a 2nd shoulder winding process from a crown winding process can be shortened, and it can manufacture efficiently.

  FIG. 7 is a schematic view conceptually showing a second shoulder winding step. As shown in FIG. 7, in the second shoulder winding process, the applicator 14 rotates the strip ply 9 while reciprocating between the second inner end Ei2 and the second outer end Ee2. The outer peripheral surface 13a of the profile deck 13 is supplied. In this step, as shown in FIG. 3, the strip ply 9 is wound in a zigzag shape including the first inclined portion 9a and the second slope 9b, and the side edge 9s of the strip ply 9 (shown in FIG. 2). ) So that they do not touch each other. By this process, the strip-like ply 9 can be formed in a mesh shape having the substantially rhombus-shaped space portion 12 surrounded by the first inclined portion 9a and the second inclined portion 9b.

  Such a second shoulder winding process can form the second shoulder reinforcing portion 7S2 capable of distributing the tension acting on a part of the second shoulder reinforcing portion 7S2 over the entire second shoulder reinforcing portion 7S2. For this reason, the second shoulder winding process makes it possible to manufacture the tire 1 with high steering stability.

  The second shoulder winding step includes the step of winding the strip ply 9 at a small length along the tire circumferential direction at the second inner end Ei2 and the second outer end Ee2. By this process, the non-inclined portion 9 c of the strip ply 9 is formed.

  As shown in FIG. 5, it is desirable that the second shoulder winding process is finished by positioning the winding of the strip ply 9 at the second inner end Ei2.

  In the above-described winding process, preferably, the circumferential position of the winding end 9e of the strip ply 9 at the end of the winding is substantially equal to the circumferential position of the winding end 9d of the strip ply 9 at the start of the winding. Therefore, in the tread reinforcing layer 7, the strip ply 9 can be wound substantially uniformly in the tire circumferential direction.

  As mentioned above, although the especially preferable embodiment of this invention was explained in full detail, this invention can be deform | transformed into a various aspect, and can be implemented, without being limited to embodiment shown.

  In the above-mentioned embodiment, after performing the 1st shoulder winding process, the above-mentioned crown winding process was performed and the 2nd shoulder winding process was performed after the 1st shoulder winding process. For example, the winding process may be performed by first performing a crown winding process, and then simultaneously performing a first shoulder winding process and a second shoulder winding process. Also, in the winding process, for example, a crown winding process, a first shoulder winding process and a second shoulder winding process may be performed simultaneously.

  A motorcycle tire having the basic structure shown in FIG. 1 was prototyped based on the specifications of Table 1. The penetration strength of the straight contact area of these tires and the steering stability of the test vehicle equipped with these tires on the rear wheels were evaluated. The common specifications of each tire and the test method are as follows.

Tire size: 190/50 ZR 17
Striped ply: Width 4.0 mm, thickness 1.0 mm, 3 reinforcement cords Deployment width of tread reinforcement layer: 200 mm
Test vehicle: Sport type large motorcycle Rear wheel air pressure: 290 kPa

<Penetration strength>
Each test tire was tested by a plunger test according to Japanese Industrial Standard JIS K6366. The results are shown in destructive energy, and the larger the value, the better.

Steering stability
With the above test vehicle, the steering stability when going around the circuit course was tested by the driver's sense. The steering stability was comprehensively evaluated on the stability of the test vehicle when traveling at low and high speeds. A result is shown by the score which sets comparative example 1 to 100, and it shows that it is so good that a numerical value is large.

  The results of the test are shown in Table 1.

  As a result of the test, in each example, it was confirmed that penetration strength and steering stability were improved in a well-balanced manner with respect to the comparative example.

2 Tread portion 7 Tread reinforcement layer 7C Crown reinforcement portion 7S Shoulder reinforcement portion 9 Striped ply

Claims (13)

A motorcycle tire having a tread portion curved in a convex arc shape on the outer side in the tire radial direction.
A toroidal carcass and a tread reinforcing layer disposed radially outward of the carcass and inside the tread portion,
The tread reinforcing layer includes a crown reinforcing portion disposed in a tread crown portion including a tire equator, and a pair of shoulder reinforcing portions disposed in tread shoulder portions on both outer sides thereof.
The crown reinforcing portion is formed by winding a long strip-like ply in which one or more reinforcing cords are coated with topping rubber at an angle of 5 degrees or less with respect to the tire circumferential direction,
In each shoulder reinforcing portion, the belt-like ply is wound in a first direction at a first angle larger than 5 degrees with respect to the tire circumferential direction, and the first inclined portion is wound in the tire circumferential direction And zig-zag winding including a second inclined portion wound at a second angle larger than 5 degrees and inclined in a second direction opposite to the first direction;
By winding so that the side edges of the strip-like ply do not contact each other, it is formed in a mesh shape having a substantially rhombic space portion surrounded by the first inclined portion and the second inclined portion. Motorcycle tires.   2. The motorcycle tire according to claim 1, wherein the crown reinforcements are wound in such a manner that side edges of the strip-like ply adjacent in the tire axial direction are in contact with each other or are overlapped. Wherein the first angle and the second angle claim 1 or 2 motorcycle tire according a same angle.   The motorcycle tire according to any one of claims 1 to 3, wherein the crown reinforcing portion and the pair of shoulder reinforcing portions are formed of a single continuous strip ply.   The motorcycle tire according to any one of claims 1 to 4, wherein a development width of the crown reinforcement portion is 5% to 13% of a development width of the tread reinforcement layer. A manufacturing method of a motorcycle tire having a tread portion curving in an arc shape convex outward in the tire radial direction,
Including a tread reinforcing layer forming step for forming a tread reinforcing layer disposed in the tread portion,
In the tread reinforcing layer forming step, one or a plurality of reinforcing cords are coated with topping rubber on the outer peripheral surface of a profile deck which is a rotating body having an outer peripheral surface curving in a circular arc shape convex outward in the radial direction. Including a winding step of winding the long strip ply directly or through a carcass ply,
The winding step includes a crown winding step of winding the strip-like ply at an angle of 5 degrees or less with respect to the tire circumferential direction around a tread crown portion including a tire equator to form a crown reinforcing portion;
A first shoulder winding step of winding the strip-like ply around the tread shoulder portion on one side of the tread crown portion to form a first shoulder reinforcing portion;
And a second shoulder winding step of winding the strip-like ply around the tread shoulder portion on the other side of the tread crown portion to form a second shoulder reinforcing portion,
In each of the first shoulder winding step and the second shoulder winding step, the strip ply is wound in a first direction at a first angle larger than 5 degrees with respect to the tire circumferential direction. Winding in a zigzag including a first inclined portion and a second inclined portion inclined in a second direction opposite to the first direction at a second angle larger than 5 degrees with respect to the tire circumferential direction; The motor is characterized in that the side edges of the strip-like ply are wound so as not to contact each other, thereby forming a mesh shape having a substantially rhombic space portion surrounded by the first inclined portion and the second inclined portion. Method of manufacturing a cycle tire.   The manufacturing of a motorcycle tire according to claim 6, wherein the crown winding step, the first shoulder winding step, and the second shoulder winding step are performed using one continuous strip ply. Method.   8. The motorcycle tire according to claim 7, wherein in the winding step, the crown winding step is performed after the first shoulder winding step is performed, and then the second shoulder winding step is performed. Method. Fixing the winding end of the strip-like ply to the first inner end of the first shoulder reinforcing portion on the tire equator side of the first shoulder reinforcing step;
The strip ply is supplied to the outer peripheral surface of the profile deck while being reciprocated between the first inner end and a first outer end which is an end on the tread end side of the first shoulder reinforcing portion. The process to
9. A method of manufacturing a motorcycle tire according to claim 8, further comprising the steps of: positioning the winding of the strip-like ply at the first inner end and terminating the winding. The crown winding step spirally winds the strip-like ply from the first inner end toward the second shoulder reinforcing portion side;
10. The method according to claim 9, further comprising the steps of: positioning the winding of the strip-like ply at a second inner end portion which is an end portion of the second shoulder reinforcing portion on the tire equator side; In the second shoulder winding process,
The strip ply is supplied to the outer peripheral surface of the profile deck while being reciprocated between the second inner end and the second outer end which is the end on the tread end side of the second shoulder reinforcing portion. A method of manufacturing a motorcycle tire according to claim 10, comprising the steps of:   The motorcycle according to claim 11, wherein the second shoulder winding step includes the step of winding the strip ply in a small length along the tire circumferential direction at the second inner end and the second outer end. Tire manufacturing method.   The method according to any one of claims 9 to 12, wherein the first shoulder winding step includes the step of winding the strip-like ply at a small length along the tire circumferential direction at the first inner end and the first outer end. The manufacturing method of the tire for motorcycles as described.

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