JP4365678B2 - Cord ply for tire and method for manufacturing tire - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a tire cord ply and a tire manufacturing method that are useful for improving tire uniformity and reducing vibration noise without impairing productivity.

  As a carcass ply and a belt ply of a pneumatic tire, a tire cord ply is used. The manufacturing method of this cord ply is as follows. First, as shown in FIG. 13, an array b of tire cords arranged in parallel is covered with a thin rubber sheet to form a long strip c having a width W. FIG. 14A shows an example of a cross-sectional view of the strip strip c (II cross section in FIG. 13). On both or one (both in this example) of the non-cut side edges e and e of the strip-shaped strip c, ears k formed obliquely for the joint are provided.

  Next, the belt-like strip c is bias-cut at an angle θ, and the cut ply-cut piece f is aligned and the non-cut side edges e are sequentially joined to form a cord ply g for a long tire. Is done. For example, as shown in FIG. 14B, the joint first overlaps the ears k and k and presses this part. As a result, as shown in FIG. 14C, a cord ply g in which the bias cut pieces f and f are joined at the joint portion j is formed.

  In the cord ply g, the tire cord a is inclined at the angle θ with respect to the tire circumferential direction. For example, in a cord ply for a belt of a radial tire, the angle θ is usually set to about 17 to 23 °. The width w of the cord ply g can be determined by h · sin θ, where h is the bias cut pitch.

  The cord ply g formed in a long shape is once wound around a roll body or the like. In the next raw cover forming step, the cord ply g is cut out by a required length L according to the tire size. The cut cord ply g is supplied to a drum for forming a raw cover. The following prior art is known as a technique related to the manufacture of such a cord ply g.

JP 2001-121622 A JP-A-11-165360

  Incidentally, the cord ply g used for one tire includes a plurality of bias cut pieces f in its length L, in other words, a plurality of joint portions j. As a result of various experiments, the inventors have obtained knowledge that the joint portion j affects the tire uniformity and vibration noise during running. That is, as shown in FIG. 14C, the joint portion j has an arrangement pitch P2 between the tire cords a and a that is larger than the arrangement pitch P1 of other portions due to tension, an external force at the time of joint, and the like. Alternatively, the thickness Q of the rubber portion tends to decrease due to the influence of the ear portion k. Such a joint portion j functions as a factor for making the rigidity of the ply non-uniform in the tire circumferential direction even after vulcanization.

  As an example, when the width W of the strip strip c is 4 inches (101.6 mm), the bias cut angle θ is 21 °, and the cut pitch h is 140 mm, one radial tire for a 175 / 70R13 passenger car tire is used. Seven to eight joints j are included in the length L of the minute belt ply. When the force variation of such a tire is examined, the 7th to 8th largest peaks appear. That is, the order of the noise peak and the number of joint portions j of the ply match. Furthermore, as a result of further analysis, such order components of the 7th to 8th noises are likely to resonate with the engine explosion cycle of the vehicle, and the so-called beat noise phenomenon “warn” and “warn” occurs during vehicle travel. I found it to cause.

  In order to remove such high-order peak order components of vibration noise, it is conceivable to increase the width W of the strip strip c and reduce the number of joints of one cord ply. However, increasing the width of the strip-like strip c causes an increase in production facilities. In addition, the reduction in the number of joints tends to cause low-order noise component peaks and deteriorate uniformity. Conversely, it is conceivable to reduce the width W and increase the number of joint portions. However, in this method, the joint work for jointing the bias cut pieces f is doubled, and the productivity is significantly reduced.

  The present invention has been devised in view of the above circumstances, and is based on the provision of at least one pseudo-joint portion, which has the same shape as the joint portion and extends in the length direction, in advance on the strip. A cord ply for tires that is useful for improving tire uniformity and reducing vibration noise without sacrificing productivity by artificially increasing the number of joints included in the hit and manufacturing the cord ply It aims to provide a method.

  The invention according to claim 1 of the present invention is formed by joining bias strips of a long strip-shaped strip, in which tire cords arranged in parallel are covered with rubber, by aligning the direction and jointing non-cut side edges. A cord ply for a tire, wherein the belt-like strip is provided with at least one pseudo-joint portion having the same shape and extending in the length direction as the jointed portion. is there.

  According to a second aspect of the present invention, in the cord ply for tire according to the first aspect, the pseudo joint portion is formed by changing an arrangement pitch of the adjacent tire cords in a strip-shaped strip. is there.

  According to a third aspect of the present invention, there is provided the cord ply for tire according to the second aspect, wherein the pseudo joint portion has a tire cord arrangement pitch substantially equal to a tire cord arrangement pitch of the joint portion. It is.

  The invention according to claim 4 is characterized in that the pseudo joint portion is provided at a position at which the width of the strip is substantially equally divided. It is a cord ply.

  According to a fifth aspect of the present invention, in the cord ply for tire according to any one of the first to third aspects, the pseudo joint portion is provided at a position where the width of the strip-like strip is divided non-uniformly. It is.

  The invention according to claim 6 is the cord ply for tire according to any one of claims 1 to 5, wherein the tire cord is a steel cord and the cord ply is a belt ply.

  According to a seventh aspect of the present invention, there is provided a strip-shaped strip forming step in which a tire cord arranged in parallel is covered with rubber to form a strip-shaped strip having a constant width and a length on both sides parallel to each other. A bias cutting step of forming a quadrilateral bias cut piece by bias cutting at an angle θ and a fixed length, and a joint step of forming a cord ply by jointing the non-cut side edges of the bias cut piece A tire manufacturing method for manufacturing a tire using a cord ply for the formed tire, wherein the strip-like strip forming step extends in the strip-like strip in the same shape and length direction as the jointed portion. It is a tire manufacturing method characterized by forming at least one pseudo joint portion.

  In the present invention, the strip-like strip is provided with at least one pseudo-joint portion having the same shape as the jointed joint portion and extending in the length direction. For this reason, the cord ply used per tire jointed with the bias cut pieces (per tire circumference) has a pseudo joint portion at least twice the number of bias cut pieces. As a result, the number of joint portions increases in a pseudo manner, which helps to improve tire uniformity. Further, when the number of pseudo joints is set appropriately, it is possible to prevent the vibration peak noise component during traveling from resonating with the engine explosion sound. Since the present invention artificially increases the joint part, it is not necessary to widen the width of the strip-like strip, and there is no increase in physical joint work. And the deterioration of productivity can be prevented.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows an overall conceptual diagram of the present invention. The cord ply 1 for tires of the present embodiment (hereinafter sometimes simply referred to as “code ply”) includes a bias cut piece 4 of a long strip strip 3 in which tire cords 2 arranged in parallel are covered with rubber. , By aligning and jointing the non-cut side edges e.

  Examples of the cord ply 1 include a belt ply, a carcass ply, a band ply, or a reinforcing ply arranged in a bead portion. The cord ply 1 of this embodiment is a belt ply of a radial tire for a passenger car. In the case of a belt ply, a steel cord having a wire diameter of, for example, about 0.5 to 1.2 mm is preferably used for the tire cord 2. It goes without saying that the material and wire diameter of the tire cord 2 used are different depending on the type of ply. Moreover, the strip | belt-shaped strip 3 of this embodiment shows what is formed, for example with the width W about 4-8 inches (101.6-203.2 mm).

  In the present invention, the strip-like strip 3 is provided with at least one pseudo joint portion 5 having the same shape as the joint portion j previously jointed and extending in the length direction. The pseudo joint portion 5 corresponds to the shape of the joint portion j and is determined to have substantially the same shape as the joint portion j.

  2A is a cross-sectional view taken along line AA of the strip-shaped strip 3 of FIG. 1, and FIG. 2B is a cross-sectional view taken along line BB of the cord ply 1 of FIG. 1 (cross-sectional view of the joint portion j). Show. The joint j of the cord ply 1 of the present embodiment has a rubber thickness tb that is smaller than the rubber thickness ta of the other part by having the concave portion 6 having a substantially triangular cross section as shown in FIG. And the aspect that the arrangement pitch Pb of the tire cord 2 is larger than the arrangement pitch Pa of the other part is exemplified.

  The basic rubber thickness ta of the cord ply 1 is finished to about 1.0 to 1.4 mm in this example, although it depends on the outer diameter of the tire cord 2. Further, the minimum rubber thickness tb of the joint portion j is about 0.4 to 0.8 times the rubber thickness ta. The recess width m of the joint portion j is about 2 to 3 mm. Further, in the cord ply 1, the arrangement pitch Pa of the basic tire cord 2 (the distance between the centers of the tire cord 2) is about 1.2 to 2.0 mm, and the arrangement pitch of the tire cord 2 at the joint portion j. Pb is enlarged to about 1.4 to 2.0 times the arrangement pitch Pa.

  The pseudo joint part 5 provided in the strip | belt-shaped strip 3 is formed in the substantially same shape as the said joint part j like FIG. 2 (A). That is, the pseudo joint portion 5 of the present embodiment is provided with a recess 7 in which the rubber portion has a triangular cross section and the minimum thickness is equal to the rubber thickness tb of the joint portion j, and the tire cord 2 is arranged. The pitch is set substantially equal to the arrangement pitch Pb of the tire cord 2 of the joint portion j. In the strip-like strip 3, the arrangement pitch of the tire cords 2 other than the pseudo joint portion 5 is set equal to the arrangement pitch Pa of the cord ply 1. The pseudo joint portion 5 extends continuously in the length direction of the strip 3. Further, ears k are provided on the side edges e on both sides of the strip 3 as in the conventional case.

  Moreover, in this embodiment, the pseudo joint part 5 shows the aspect provided in two places at intervals in the strip | belt-shaped strip 3. As shown in FIG. Moreover, the pseudo joint part 5 has shown what was provided in the position which divides | segments the width | variety W of the strip | belt-shaped strip 3 substantially equally, and is divided into 3 parts in this example.

  Such a strip-shaped strip 3 is cut into a bias cut piece 4, and the cord ply 1 is formed by joining the non-cut side edges e in the same manner as in FIGS. 14B to 14C. As shown in FIGS. 1 and 3, the pseudo-joint portion 5 of the strip 3 remains on the bias cut piece 4. That is, the bias cut piece 4 includes at least one pseudo joint portion 5 (in this example, two locations) extending in parallel with the non-cut side edges e and e. For this reason, the cord ply 1 in which the bias cut pieces 4 are jointed can include at least one (two in this example) pseudo joint portions 5 between the joint portions j and j.

  FIG. 3 shows an enlarged plan view of the cord ply, and FIG. 4 shows a CC sectional view of the cord ply 1 shown in FIG. In the cord ply 1 formed using the bias cut piece 4 as described above, the joint portion j and the pseudo joint portion 5 have substantially the same shape, and are arranged at substantially equal intervals in this embodiment. . Since the joint portion j and the pseudo joint portion 5 have similar rigidity, the cord ply 1 is substantially equivalent to a case where the number of the joint portions j is increased three times. Therefore, when such a cord ply 1 is used for a tire, the peak component of vibration noise is increased and the uniformity of the tire is improved. In particular, when the number of pseudo-joint parts 5 is set appropriately, the 7th to 8th order vibration peaks that have been regarded as problems can be easily reduced, and resonance with the engine explosion sound is prevented and vibration ride comfort is excellent. Useful for manufacturing pneumatic tires.

  The rigidity of the cord ply 1 is determined by the rubber (topping rubber) and the tire cord. Compared to the arrangement pitch of the tire cord 2, the contribution ratio of the rubber is very small. Therefore, it is sufficient for the pseudo joint portion 5 to have the same arrangement pitch of the adjacent tire cords 2 as that of the joint portion j in the strip 3. In other words, “the pseudo joint portion 5 and the joint portion j have the same shape” means that at least the arrangement pitch Pb of the tire cords 2 is set to be substantially equal. Therefore, it is not always necessary that the rubber thickness is the same or approximated as in this embodiment. FIG. 5 shows another example of the strip 3 that falls within the scope of the present invention. In the pseudo joint portion 5 of this example, the arrangement pitch of the tire cord 2 is set to be the same as the arrangement pitch of the tire cord 2 of the joint portion j, but the rubber thickness is different.

  Moreover, although the joint part j of this embodiment has shown the example from which the arrangement | sequence pitch of the tire cord 2 becomes larger than another part, conversely to this, the arrangement pitch of the tire cord 2 may become small. . In this case, needless to say, the arrangement pitch of the tire cords 2 is set so that the pseudo-joint portion 5 also matches this. Also, when the arrangement pitch of the tire cord 2 of the joint portion j is the same as the other portions and only the rubber thickness is different, the rubber thickness of the pseudo joint portion 5 is adjusted accordingly. Will do. Thus, the cord ply 1 of the present embodiment is based on the premise that the joint portion j has a rigid portion different from other portions, and the pseudo joint portion 5 has substantially the same rigidity as the joint portion j. Have. As a result, the cord plies of the cord ply are approximately equal in pitch between the joint portion j and the pseudo joint portion 5 due to tension during vulcanization.

  In the present invention, since the joint portion j of the cord ply 1 is increased in a pseudo manner, the width W of the strip-like strip 2 is reduced and the physical joint operation is not increased. Therefore, the deterioration of the productivity of the cord ply can be prevented. Further, it is not necessary to increase the width of the strip strip by using a large topping facility or the like and reduce the number of joint portions. Therefore, it is possible to use a so-called stylusic small-sized topping device that arranges and tops the tire cord 2 without using a weft. This helps to prevent an increase in production facilities.

  The number of pseudo-joint portions 5 formed on the strip-shaped strip 3 is not particularly limited, but is preferably 1 to 5 locations, and more preferably 1 to 3 locations. In particular, when the arrangement pitch of the tire cords 2 in the joint portion j is larger than the other portions, if the number of the pseudo joint portions 5 included in the belt-like strip 3 is excessively increased, so-called skipping of the tire cord 2 may be increased. There is a tendency that it is disadvantageous in terms of uneven wear and durability when used in a tire. Preferably, the pitch between the adjacent pseudo joint portions 5 and 5 or the pitch between the pseudo joint portion 5 and the adjacent joint j is 10 to 50 mm, more preferably 20 to 50 mm.

  In addition, the pseudo joint portion 5 of the present embodiment is exemplified by a portion provided at a position where the width W of the strip-like strip 3 is divided substantially evenly (in this example, a position where the width W is substantially divided into three). However, in addition to such a mode, for example, as shown in FIGS. 6 to 7, the width W of the strip-shaped strip 3 can be provided at a position where it is divided non-uniformly.

Next, a method for manufacturing such a cord ply 1 will be described.
FIG. 8 is a plan view of the manufacturing apparatus 1 for manufacturing the cord ply for a tire according to the present embodiment, and FIG. 9 is a side view of a part thereof. The manufacturing apparatus 11 according to the present embodiment includes a strip supply device 12, a festoon 13 that can temporarily store the strip strip 3 supplied from the strip supply device 12, and the strip strip 3 supplied through the festoon 13. A conveying device 14 that conveys in the length direction, a cutting device 15 that cuts the strip 3 into the bias cut pieces 4, a supply conveyor 16 that conveys the bias cut pieces 4, and a supply conveyor 16 And a pasting conveyor 17 for sequentially forming the cord ply 1 by jointing the bias cut pieces 4 together.

  In the present embodiment, the strip supply device 2 includes a cord stand 12A that supplies a plurality of tire cords 2 arranged in parallel, and a topping device 12B that covers the supplied tire cord 2 with rubber. Is done. For example, as shown in FIG. 10, the topping device 12B includes a screw-type rubber extruder main body 20 and an extrusion head 21 for extruding rubber provided at the tip thereof. The extrusion head 21 is provided with a die 22 on one side surface thereof. The die 22 can cover the tire cord 2 supplied from the other side surface with unvulcanized topping rubber fed from the rubber extruder body 20 and discharge the tire cord 2 from its discharge port 24. The discharge port 24 is provided with convex portions 24 a and 24 a for forming the concave portion 7 of the pseudo joint portion 5 in the strip 3.

  The tire cord 2 is passed through a die 22 through a cord alignment baffle (not shown) provided on the other side surface of the extrusion head 21. The baffle can send out the plurality of tire cords 10 in parallel and in parallel with a cord interval without using a weft. That is, in this embodiment, the stylusic topping device 12B is used. The tire cord 2 includes a reference arrangement portion Z arranged at a constant arrangement pitch Pa, and a thinning arrangement portion X which forms an arrangement pitch Pb larger than the arrangement pitch Pa and forms the pseudo joint portion 5. Are arranged and supplied to the die 22.

  The festoon 13 is composed of a plurality of rollers having a horizontal axis perpendicular to the longitudinal direction of the strip 13. These rollers serve to absorb the difference in feeding speed of the strip strip 3 between the devices before and after the strip strip 3 is temporarily retained.

  The transport device 14 is composed of, for example, a belt conveyor, and includes a first conveyor 14A arranged on the upstream side and a second conveyor 14B arranged continuously on the downstream side, and between these, a cutting is performed. A device 15 is provided.

  For example, as shown in FIG. 11, the cutting device 15 of the present embodiment is pivotally attached to a portal frame 26 disposed across the transport device 14 and an upper frame member 26 </ b> U of the portal frame 26. The support shaft 27, guide means 28 fixed to the lower end of the support shaft 27, and a cutting tool 29 provided so as to be able to travel along the guide means 28.

  Torque of a motor M1 such as a step motor fixed to the upper frame member 26U is transmitted to the support shaft 27 through a speed reduction means 30 using, for example, gears. As a result, the support shaft 27 can change its direction and stop at a predetermined angle around the axis with respect to the portal frame 26. In the present embodiment, the guide means 28 includes a horizontally extending groove-shaped guide rail 28A and a traveling piece 28B that can travel horizontally along the guide groove of the guide rail 28A. The power of the drive motor M2 is linked to the travel piece 28B via a chain or the like (not shown) so that the travel piece 28B can travel in a predetermined direction. Further, the cutting tool 29 is fixed to the traveling piece 28B and extends downward, and in this embodiment pivotally attached to the cutter holder 29A, a disc-like shape having a cutting edge on the outer peripheral surface. And cutter 29B.

  Such a cutting device 15 can set the direction of the guide means 28, that is, the angle θ at which the cutter 29B can bias-cut the strip 3 to a desired value by driving and stopping the motor M1 at a predetermined angle. . Thereafter, the belt-like strip 3 can be bias-cut by running the running piece 28B along the guide rail 28A. The cutter 21B may have a guillotine shape that pushes down the strip 3 when lowered. The pitch for bias-cutting the strip 3 can be adjusted by appropriately adjusting the feed amount of the strip 3 in the first conveyor 14A.

  For example, as shown in FIG. 12, the supply conveyor 16 is a belt conveyor having a conveyance surface facing downward, and is arranged in a straight line with the conveyance device 14. A magnet (not shown) is attached to the conveyor belt 16a of the supply conveyor 16 on the inner peripheral surface side, and this magnetic force attracts the tire cord 2 of the bias cut piece 4 via the conveyor belt 16a. In addition, the supply conveyor 16 is attached to a table-like frame 30 that straddles the sticking conveyor 17 and is located on the upper part thereof via an elevating means 31.

  In the present embodiment, the elevating means 31 is fixed to the frame 30 and is provided on the frame 30 and rises from an upper surface of the supply conveyor 16 and a lifting tool 31a such as a cylinder having the supply conveyor 16 attached to the lower end of the rod. An example is shown which comprises a guide shaft 31b slidably inserted into the bearing portion 30a.

  In the initial state of the supply conveyor 16, the conveying surface of the conveyor belt 16a is at a position Y1 that is substantially the same height as the upper surface of the bias cut piece 4 on the second conveyor 4B. At this position Y1, the end of the bias cut piece 4 sent onto the second conveyor 14B is adsorbed and the conveyor belt 16a is driven so that the bias cut piece 4 is removed from the second conveyor 14B. It can be connected to the lower surface of the conveyor belt 16a.

  Then, the supply conveyor 16 descends to the lowered position Y <b> 2 where the bias cut piece 4 contacts the pasting conveyor 7, and delivers the bias cut piece 4 onto the pasting conveyor 7. This transfer can be performed, for example, by moving the magnet in a direction away from the inner peripheral surface of the conveyor belt 16a by a cylinder or the like and releasing the adsorption to the bias cut piece 4, but when the magnet is an electromagnet, The energization may be turned on and off. In this way, the supply conveyor 16 can supply the bias cut piece 4 from the second conveyor 4B to a predetermined position of the sticking conveyor 17.

  The affixing conveyor 17 is constituted by a belt conveyor that intersects the supply conveyor 16 at the same angle as the angle θ, for example. As shown in FIG. 14B, the non-cut side edge e (side edge without the ear portion k) of the bias cut piece 4 sent to the affixing conveyor 17 is a standby bias. It is placed on the ear part k of the cut piece 4 and pressed as shown in FIG. After the joint, for example, the sticking conveyor 17 is intermittently sent a distance corresponding to the length S in the joining direction of the bias cut piece 4. By repeating such an operation, the long cord ply 1 can be manufactured. The cord ply 1 may be wound around a roll pair as appropriate, or may be appropriately cut off.

  The cord ply 1 thus formed is affixed to the outside of the carcass ply with the longitudinal direction as the tire circumferential direction in the raw cover forming step. The formed green cover is vulcanized to produce a pneumatic tire.

  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.

  As a cord ply for a tire, a belt ply was prototyped based on the specifications shown in Table 1. As common specifications for the belt ply, the width W of the strip-like strip was 4 inches, and the bias cut angle θ was 21 °. Table 1 shows the specifications of the cord ply.

  Next, a pneumatic radial tire for passenger cars having a tire size of 175 / 70R1382S was prototyped using each cord ply. And it tested about noise performance and uniformity. The test method is as follows.

<Noise performance>
1. Sensory evaluation All the wheels of a domestic FF passenger car with a displacement of 1300cm ³ are fitted with test tires under the conditions of a rim of 13x5J and an air pressure of 200kPa, and one driver rides on the asphalt road test track. The magnitude of noise was evaluated by a 10-point method with the comparative example 1 as 6 points by sensory evaluation. The larger the value, the better.
2. Road noise performance Under the above vehicle conditions, the vehicle travels on rough asphalt roads at a speed of 50 km / H, and a noise level dB (A) is measured by installing a microphone at the right ear of the driver's seat. Displayed as noise difference. Negative display is preferable.

<Uniformity>
In accordance with JASO C607-2000, 7th and 8th order components of RFV (radial force variation) of 7 test tires under rim (13 × 5J), internal pressure (200kPa), load (3.54kN) Compared. The smaller the value, the better. Table 2 shows the test results.

  As a result of the test, it was confirmed that each of the example tires D to F using the cord ply of the example had a significant effect on road noise and RFV.

It is a conceptual diagram explaining the manufacturing method of the cord ply for tires of this invention. (A) is an AA expanded sectional view of FIG. 1, (B) is the BB expanded sectional view. It is a partial top view of the cord ply for tires. It is the CC expanded sectional view. It is sectional drawing which shows the other form of a strip | belt-shaped strip. It is sectional drawing which shows the other form of a strip | belt-shaped strip. It is sectional drawing which shows the other form of a strip | belt-shaped strip. It is a top view which shows one Example of the cord ply manufacturing apparatus of this invention. It is a side view which shows the one part. It is a fragmentary perspective view which shows an example of a topping apparatus. It is a fragmentary perspective view which shows an example of a cutting device. It is a fragmentary perspective view which shows an example of a supply conveyor. It is a conceptual diagram which shows the manufacturing method of the conventional cord ply for tires. (A) is an II expanded sectional view of FIG. 13, (B), (C) is an expanded sectional view explaining the joint of a bias cut piece.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cord ply 2 Tire cord 3 Strip strip 4 Bias cut piece 5 Pseudo joint part

Claims (7)

A cord ply for a tire formed by jointing a bias cut piece of a long belt-like strip in which rubber cords of tire cords arranged in parallel are aligned, and side edges that are aligned and not cut,
A cord ply for tire, wherein the strip-like strip is provided with at least one pseudo-joint portion having the same shape and extending in the length direction as the jointed joint portion.   The cord ply for tire according to claim 1, wherein the pseudo joint portion is formed by changing an arrangement pitch of the adjacent tire cords in a belt-shaped strip.   The cord ply for tire according to claim 2, wherein the pseudo joint portion has a tire cord arrangement pitch substantially equal to a tire cord arrangement pitch of the joint portion.   The cord ply for tire according to any one of claims 1 to 3, wherein the pseudo joint portion is provided at a position where the width of the strip-like strip is divided substantially evenly.   The cord ply for tire according to any one of claims 1 to 3, wherein the pseudo-joint portion is provided at a position where the width of the strip is divided non-uniformly.   6. The cord ply for tire according to claim 1, wherein the tire cord is a steel cord, and the cord ply is a belt ply. A belt-strip forming step of forming a constant-width and long strip-like strip with rubber covering the tire cords arranged in parallel and having both side edges parallel to each other;
A bias cutting step of bias-cutting the belt-like strip at an angle θ and a fixed length with respect to the length direction to form a quadrilateral bias cut piece; and a cord by jointing the non-cut side edges of the bias cut piece A tire manufacturing method for manufacturing a tire using a cord ply for a tire formed including a joint process for forming a ply,
The method for manufacturing a tire is characterized in that the strip-shaped strip forming step includes forming at least one pseudo joint portion having the same shape and extending in the length direction as the jointed portion on the strip strip.

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