JP5351705B2 - Motorcycle tire manufacturing method and motorcycle tire manufactured thereby - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a motorcycle tire that inhibits a winding collapse of a band-like ply. <P>SOLUTION: In a band forming process, a feed roller 21 of a band-like ply 10 is laterally moved in a drum axial direction along a roller traveling line L in accordance with rotation of a profile drum 20 so that the band-like ply 10 is spirally wound around on a band molding surface 20S. The interval D between the roller traveling line L and the contour line J of the band molding surface 20S is sequentially increased from the side of the drum equator toward the axial outside. Consequently, an angle &alpha; on the axial inside formed by a normal line N of the roller traveling line L at a point P on the roller traveling line L together with the contour line J is sequentially reduced from the drum equator side toward the axial outside. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a method for manufacturing a tire for a motorcycle that can suppress winding collapse of the belt-shaped ply when the belt-shaped ply is wound spirally on the outer peripheral surface of the convex arc-shaped profile drum, And a motorcycle tire manufactured thereby.

  In motorcycle tires, the tread portion is formed of a convex arc-shaped tread profile with a small radius of curvature because of the characteristic of turning the vehicle body into a large bank. Therefore, when this type of tire is formed, conventionally, as shown in FIG. 7 (A), a profile drum a whose outer peripheral surface a1 is curved according to the tread profile is used, and a long band shape in which a band cord is rubberized. The band ply c is formed by spirally winding the belt-like ply b on the outer peripheral surface a1 of the profile drum a (see, for example, Patent Document 1).

  Specifically, as shown in FIG. 7B, as the profile drum a rotates, the feed roller e that feeds the belt-like ply b is wound spirally by moving laterally along the roller travel line f. ing. At this time, the distance d between the roller travel line f and the contour line j of the outer peripheral surface a1 of the profile drum a is constant, and therefore the belt-like ply b is substantially perpendicular to the outer peripheral surface a1 without twisting. It is pasted.

JP 2004-74647 A

  However, the contour line j of the profile drum a is inclined at a steep angle on the outer end side in the axial direction. For this reason, the belt-like ply b tends to collapse on the outer end side, and it becomes difficult to form the band ply itself, or even if it can be formed, the code arrangement is disturbed and the uniformity is impaired.

  Conventionally, the rotational speed of the profile drum a is suppressed and the winding work is carefully performed to suppress the collapse of the winding. However, this has a limit and hinders the improvement of the production efficiency. .

  Therefore, the present invention is based on the principle that the feed roller is moved laterally along the roller travel line in which the distance from the profile line of the profile drum increases sequentially from the drum equator side toward the axial center side. An object of the present invention is to provide a method for manufacturing a tire for a motorcycle that can suppress the collapse and contribute to an improvement in production efficiency due to an increase in the rotational speed of the profile drum, and a motorcycle tire manufactured thereby. Yes.

In order to solve the above problems, the invention of claim 1 of the present application is directed to a motorcycle tire comprising a band ply radially outside the carcass extending from the tread portion through the sidewall portion to the bead core of the bead portion and inside the tread portion. A manufacturing method of
On the band forming surface of the profile drum having a band forming surface whose outer peripheral surface forms a convex arcuate contour line in the meridional section including the drum axis, a long band shape in which a band cord is rubberized and a feed roller A band forming step of forming the band ply by spirally winding the band-shaped ply delivered by
In addition, in the band forming step, as the profile drum rotates, the feed roller is moved laterally in the drum axial direction along the roller travel line, and the band-like ply is wound spirally on the band forming surface. While turning
The roller running line has a normal N of the roller running line at a point P on the roller running line as the distance from the contour line of the band forming surface sequentially increases from the drum equator side toward the outer side in the axial direction. Is gradually decreased from the drum equator side toward the axial direction outer side, the angle α on the axial center side formed by the contour line.
The feeding roller is characterized in that the roller shaft runs while circumscribing the roller running line at the central point of the length of the roller shaft.

  According to a second aspect of the present invention, in the tire for a motorcycle according to the first aspect, the roller running line has the angle α at the outer end in the axial direction of the band forming surface in a range of 70 to 85 °. Manufacturing method.

  In the invention of claim 3, the band forming step is characterized in that a single band-like ply is used and the band forming surface is continuously wound from one end to the other end in the axial direction.

  A fourth aspect of the present invention is a motorcycle tire, which is manufactured by the manufacturing method according to any one of the first to third aspects.

  In the present invention, in the band forming process, the roller travel line through which the feed roller passes is defined as follows. That is, the distance between the roller travel line and the contour line of the band forming surface increases sequentially from the drum equator side toward the outer side in the axial direction, whereby the normal line N of the roller travel line at the point P on the roller travel line is The angle α on the inner side in the axial direction that forms the contour line is sequentially decreased from the drum equator side toward the outer side in the axial direction.

  Thus, when the belt-like ply is spirally wound, the belt-like ply has a relatively high tension force on the side edge on the outer side in the axial direction, that is, on the side edge facing inward in the radial direction. Make strong contact. As a result, the belt-like ply is difficult to slip and curling can be suppressed. Further, by suppressing the collapse, it is possible to increase the rotational speed of the profile drum, which can contribute to the improvement of production efficiency.

1 is a cross-sectional view showing an embodiment of a motorcycle tire manufactured by the manufacturing method of the present invention. It is a perspective view which shows an example of a strip | belt-shaped ply. It is sectional drawing which shows a band formation process notionally. It is drawing which shows notionally a roller running line with the outline of a band formation surface. It is drawing which shows notionally the motion of the sending roller along a roller running line. (A), (B) is the top view which illustrates a press-contact roller, and a schematic side view. (A), (B) is sectional drawing explaining the conventional band formation process.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing an example of a motorcycle tire 1 manufactured by the manufacturing method of the present invention, including a carcass 6 extending from a tread portion 2 through a sidewall portion 3 to a bead core 5 of a bead portion 4. The carcass 6 includes a band layer 7 disposed radially outside and inside the tread portion 2.

  The tread portion 2 is characteristic of a tire for a motorcycle in which the tread surface 2S is curved in a convex arc shape from the tire equator C to the tread end Te, and the width between the tread ends Te and Te forms the maximum tire width. Tread profile 2P. In this example, the case where the camber value h1 / L1 of the tread profile 2P is 0.3 to 0.7 is shown, and thereby higher turning performance is ensured. The camber value h1 / L1 means the ratio between the tire axial direction width L1 and the radial height h1 between the tire equator point Tc on the tread surface 2S and the tread end Te.

  The carcass 6 is formed of one or more carcass plies 6A in this example, in which carcass cords are arranged at an angle of, for example, 75 ° to 90 ° with respect to the tire circumferential direction. The carcass ply 6A includes a series of ply turn-up portions 6b that are turned back from the inner side in the tire axial direction around the bead core 5 to both ends of the ply main body portion 6a straddling the bead cores 5 and 5. A bead apex rubber 8 for bead reinforcement extending in a tapered manner from the bead core 5 toward the outer side in the tire radial direction is disposed between the ply main body portion 6a and the ply turn-up portion 6b.

  The band layer 7 is formed of at least one band ply 7A, in this example, one band ply 7A, in which the band cord 9 is spirally wound at an angle of 5 degrees or less with respect to the tire circumferential direction. Reinforce almost the whole width with a tagging effect. A tread rubber 2G is laminated outside the band layer 7 in the radial direction to form the tread portion 2.

  Next, in this motorcycle tire manufacturing method, as shown in FIG. 3, a profile drum 20 is used, and a belt-like ply 10 is spirally wound on a band forming surface 20S provided on the outer peripheral surface of the profile drum 20. A band forming step S for forming an unvulcanized band ply 7A by turning is provided.

  As shown in FIG. 2, the band-like ply 10 is obtained by rubber-drawing the band cord 9, that is, a band cord 9 or an array of a plurality of (for example, 2 to 6) band cords 9 is used as a topping rubber G. The figure is a long band-shaped body covered with a rubber band, for example, in which three band cords 9 are rubberized.

  As the profile drum 20, a conventional drum having a known structure in which a plurality of deck segments divided in the circumferential direction is held by a known diameter reducing means so as to be reduced in diameter is used. The profile drum 20 includes a band forming surface 20S whose outer peripheral surface forms a contour line J having a convex arc shape in a meridional section including the drum axis. The contour line J is set according to the tread profile. In this example, the contour line J is approximated to a curved shape obtained by subtracting the thickness t of the tread rubber 2G from the tread profile 2P (shown in FIG. 1). Formed.

  In the band forming step S, as shown in FIG. 4, as the profile drum 20 rotates, the feed roller 21 is laterally moved along the roller travel line L in the drum axial direction, thereby The belt-like ply 10 is wound spirally on the band forming surface 20S. The delivery roller 21 is a roller for delivering the belt-like ply 10 to the profile drum 20, and as shown in FIG. 5, the axial center of the belt-like ply 10 is provided at both ends of a cylindrical body portion 21a that receives the belt-like ply 10. The flange part 21b which prevents the position shift of a direction is provided.

  The roller travel line L is formed as a convex arcuate curve in which the distance D between the band forming surface 20S and the contour line J increases sequentially from the drum equator Cd side toward the outer side in the axial direction. When an arbitrary point on the roller travel line is P, an angle α on the inner side in the axial direction formed by the normal line N of the roller travel line L at the point P and the contour line J is defined as an axial center from the drum equator Cd side. It is decreased sequentially toward the outside in the direction. Strictly speaking, the angle α means an angle on the inner side in the axial direction of the normal line N with respect to the tangent line K of the contour line J at the intersection where the normal line N intersects the contour line J. In the conventional roller travel line, as shown in FIG. 7B, the distance d from the contour line j is constant, that is, the angle α is set to 90 °. In the present embodiment, the interval Dc in the drum equator Cd is set in a range of 10 to 50 mm, like the conventional interval d.

  The delivery roller 21 moves laterally along the roller travel line L so that the roller shaft center 21i and the roller travel line L are in contact with each other at the center point ic of the length of the roller shaft center 21i. Such lateral movement includes, for example, lateral movement means along the X-axis direction parallel to the drum axis, and vertical movement means for moving back and forth toward the profile drum 20 along the Y-axis direction perpendicular to the X-axis direction. This is performed by using an appropriate device including tilting means for tilting the feed roller 21 around the axis in the Z-axis direction perpendicular to the X-axis direction and the Y-axis direction and passing through the center point ic. it can.

  Here, when the feed roller 21 is moved laterally along the roller travel line L, the distance from the band forming surface 20S of the side edge Eo of the belt-like ply 10 on the outer side in the axial direction becomes the side edge Ei on the inner side in the axial direction. The distance is larger than the distance from the band forming surface 20S. That is, since the tension force of the outer side edge Eo is relatively increased, the edge on the side edge Eo side can be brought into strong contact with the band forming surface 20S, so that the belt-like ply 10 becomes less slippery and the roll collapses. Can be suppressed. Further, by suppressing the collapse, it is possible to increase the rotation speed of the profile drum 20 by the amount of the effect without deteriorating the collapse, which can contribute to the improvement of the production efficiency.

  At this time, the angle α (sometimes referred to as an angle αe) at the axially outer end Qe of the band forming surface 20S is preferably in the range of 70 to 85 °. The effect of suppressing the collapse is not fully exhibited. On the other hand, when the angle αe is less than 70 °, the belt-like ply 10 is excessively twisted during winding, making it difficult to cleanly wind and tending to adversely affect the code arrangement accuracy. Therefore, the upper limit of the angle αe is preferably 83 ° or less, and the lower limit is preferably 77 ° or more. The angle α (sometimes referred to as angle αc) at the drum equator point Qc of the band forming surface 20S is substantially 90 °. In addition, when the area from the drum equator Qc to the outer end Qe is virtually divided into three regions yi, ym, and ye at equal widths by the inner and outer dividing points Q1, Q2, in the region yi on the drum equator side, in particular, the winding Since there is no fear of collapsing, it is preferable to place an emphasis on clean winding. Therefore, the angle α (sometimes referred to as angle α1) at the dividing point Q1 is 85 ° or more, further 87 ° or more, Is preferably 89 ° or more.

  The angle α can be smoothly changed from the angle αc to the angle αe. However, for example, the angle α in the region yi on the drum equator side is constant at 90 ° (= αc), and the region yo on the outer end side. The angle α is changed stepwise such that the angle α is constant at 80 ° (= αe) and the angle α in the intermediate region ym is constant at an intermediate angle between the angles αc and αe (for example, 85 °). You can also

  In the band forming step S, it is preferable to use a single band-like ply 10 and continuously wind the band forming surface from one end Qe1 in the axial direction to the other end Qe2. In the case where two strip plies 10 are used, the number of operations for fixing the winding start end of each strip ply 10 to the profile drum 20 and the cutting operation at the end of the winding increase. Thus, compared with the case where the winding speed is increased by preventing the collapse, there is no great difference in the process time. Rather, it is advantageous in productivity because the number of work steps such as fixing work is reduced. When two strip plies 10 are used, for example, it is difficult to accurately align the winding start end of one strip ply 10 and the winding end end of the other strip ply 10, and there is a gap or overlap between them. Since the winding condition is different between the two, the quality of the band ply 7A can be reduced. However, this problem can be solved by using only one belt-like ply 10. Further, by using one belt-like ply 10, the structure of the winding device including the delivery roller 21 and the control thereof can be simplified.

  In this example, as conceptually shown in FIGS. 6A and 6B, the profile drum 20 moves laterally along the contour line J while substantially contacting the profile drum 20, A pressure contact roller 22 that presses the belt-like ply 10 from the feed roller 21 against the profile drum 20 is attached. In this case, since the belt-like ply 10 is restrained between the feeding roller 21 and the pressure roller 22, the tension force on the side edge Eo side can be more reliably increased, which is advantageous due to the effect of suppressing the collapse. .

  In the method for manufacturing a tire for a motorcycle according to the present invention, processes similar to the conventional processes can be adopted except for the band forming process S, and therefore the description thereof is omitted in this specification.

  As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.

  A band ply for a motorcycle tire (195 / 65R420) was prototyped based on the specifications shown in Table 1 using the band forming process according to the present invention, and the state of the collapse of the belt-like ply at that time was measured as the rotational speed of the profile drum. Compared with.

  In the band forming process, the same profile drum is used, and only the shape of the roller travel line is made different. As the belt-like ply, a rubber band with a width of 4.0 mm and a thickness of 1.0 mm was used.

  In the conventional example, the angle α of the roller travel line is constant at 90 °. In Examples 1 to 5, the angle α of the roller travel line is changed in three stages. Specifically, the band forming surface is divided into three equal parts, a drum equator side region yi, an intermediate region ym, and an outer end side region yo, and the angle α is changed between the regions ii, ym, and ye. In the first to fifth embodiments, the inner dividing point Q1 is included in the region yi, and the outer dividing point Q2 is included in the region yo. In the sixth embodiment, the angle α of the roller travel line is smoothly changed.

  The rotational speed (rpm) of the profile drum is indicated by an index with the conventional example being 100, and the larger the index is, the higher the rotational speed V is.

  Further, the state of the belt-like ply collapse was indicated by the number of occurrences of the collapse when 100 band plies were formed.

DESCRIPTION OF SYMBOLS 1 Tire for motorcycles 2 Tread part 3 Side wall part 4 Bead part 5 Bead core 6 Carcass 7A Band ply 9 Band cord 10 Band-like ply 20 Profile drum 20S Band molding surface 21 Feed roller 21i Roller axis 21ic Length of roller axis Center point D Interval J Contour line L Roller travel line S Band forming process

Claims (4)

A method of manufacturing a tire for a motorcycle having a band ply on the radially outer side of the carcass extending from the tread portion through the sidewall portion to the bead core of the bead portion and inside the tread portion,
On the band forming surface of the profile drum having a band forming surface whose outer peripheral surface forms a convex arcuate contour line in the meridional section including the drum axis, a long band shape in which a band cord is rubberized and a feed roller A band forming step of forming the band ply by spirally winding the band-shaped ply delivered by
In addition, in the band forming step, as the profile drum rotates, the feed roller is moved laterally in the drum axial direction along the roller travel line, and the band-like ply is wound spirally on the band forming surface. While turning
The roller running line has a normal N of the roller running line at a point P on the roller running line as the distance from the contour line of the band forming surface sequentially increases from the drum equator side toward the outer side in the axial direction. Is gradually decreased from the drum equator side toward the axial direction outer side, the angle α on the axial center side formed by the contour line.
The method of manufacturing a tire for a motorcycle, wherein the feed roller travels while the roller axis is circumscribed with the roller travel line at a center point of the length of the roller axis.   The method for manufacturing a tire for a motorcycle according to claim 1, wherein the roller running line has an angle α of 70 to 85 ° at an axially outer end of a band forming surface.   3. The motorcycle tire according to claim 1, wherein the band forming step uses a single band-shaped ply and is continuously wound from one end to the other end in the axial direction of the band forming surface. 4. Production method   A motorcycle tire manufactured by the manufacturing method according to claim 1.

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