JP5690231B2 - Code path variation judgment method between carcass ply bead cores - Google Patents

Description

  The present invention relates to a cord path variation determination method between carcass ply bead cores that can easily and accurately determine a variation in cord path between bead cores of a carcass ply for each raw tire in a green tire forming step.

In the raw tire forming process of the pneumatic tire, as shown in FIG.
(A) A carcass ply c is wound on the central drum a1 of the raw tire forming former a having a cylindrical central drum a1 and side drums a2 arranged on both outer sides in the axial direction. A carcass winding step of forming a winding body of a straight cylindrical carcass ply c forming a ply protruding portion c1 protruding outward in the axial direction from the central drum a1;
(A) a carcass squeezing step that uses a finger d that can be freely opened and closed, and that narrows the ply protrusion c1 to a smaller diameter than the inner diameter of the bead core e by having a step surface c1s along the outer end surface of the central drum a1;
(C) Using the bead core retaining ring b1, the bead core e is moved inward in the axial direction, and the inner surface in the axial direction of the bead core e is pressed against and adhered to the stepped surface c1s of the carcass ply c. And (d) expansion of the turn-up bladder g provided on the side drum a2, and pressing the expanding turn-up bladder g inward in the axial direction by the pusher tube b2, thereby protruding the ply. Winding up and pressing the part c1 around the bead core e and pressing it against the carcass ply body part c2;
(For example, refer to Patent Documents 1 and 2).

  At this time, in the raw tire forming apparatus, if the axial center of the central drum a1 and the axial center of the bead core holding ring b1 are misaligned or the axial centers are inclined, the carcass ply c As a result, the cord path between the bead cores e and e (the length of the carcass cord between the bead cores) varies, causing a problem that the uniformity of the tire is lowered. The positional deviation and the inclination between the shaft centers may be collectively referred to as core deviation.

  Therefore, conventionally, as a preliminary test, a bead core e having a coating agent (for example, chalk) applied to the bottom surface of the bead is used to form, for example, a raw tire that has finished the above-described winding and pressing step, and the raw tire is disassembled. By deploying in the circumferential direction, a developed tire h as shown in FIG. 10 (A) is obtained. Based on the coating mark f on the bottom surface of the bead left on the developed tire h, the carcass cord path m was measured at a plurality of positions to evaluate the variation.

  When the variation exceeds a reference value, it is determined that a setting failure of the raw tire forming device, that is, a center misalignment between the center drum a1 and the bead core holding ring b1, has occurred. Setting adjustment is performed.

  As the setting adjustment, as shown in FIG. 10B, a measuring instrument p such as a dial gauge is installed on the outer peripheral surface of the central drum a1, and the radius from the measuring instrument p to the bead core holding ring b1 is set. The directional distance hy and the axial distance hx are measured over one circumference of the bead core holding ring b1. Based on this measurement value, setting adjustment is performed.

  As described above, since the determination of the code path of the conventional carcass is performed by a destructive test, much time and labor are required. Moreover, it is difficult to determine for each raw tire, for example, when the core misalignment occurs in the raw tire forming device during the manufacture of the tire, and a large code path variation occurs in the tire formed thereafter. However, it becomes a hindrance to advanced quality control, such as being unable to detect it early. In addition, it takes a lot of time for the process of “destructive test” → “determination of code path” → “measurement of distance hx and hy (measurement of misalignment)” → “setting adjustment based on measurement result of distance hx and hy”. For this reason, it may cause a decrease in production efficiency.

JP 2001-260247 A JP 2004-175030 A

  Accordingly, the present invention can accurately and quickly determine the variation in the carcass cord path for each raw tire in the green tire forming step, and can perform high-quality quality control, and can perform the process from the determination. It is an object of the present invention to provide a method for determining the variation in the code path between the bead cores of the carcass ply, which can significantly reduce the time required for adjusting the setting of the tire forming apparatus and also improves the production efficiency.

In order to solve the above-mentioned problems, the invention of claim 1 of the present application provides a living room comprising a cylindrical central drum and a pair of side drums disposed on both outer sides in the axial direction of the central drum and having a turn-up bladder. A carcass winding step of forming a cylindrical carcass ply by winding a carcass ply on the central drum using a tire forming former;
Among the cylindrical carcass plies, a carcass throttle that narrows a ply protruding portion protruding outward in the axial direction from the central drum to a smaller diameter than the inner diameter of the bead core having a step surface along the outer end surface of the central drum. Stage,
A bead core holding ring that holds the bead core and can move inward and outward in the axial direction, and a cylindrical pusher tube that presses the expanded turn-up bladder inward in the axial direction. A bead core setting stage in which the bead core is set by pressing the axially inner side surface of the bead core held by the bead core holding ring against the step surface of the carcass ply using a setter;
And the turn-up bladder expands the ply protruding portion around the bead core, and then moves the pusher tube inward in the axial center direction so that the rolled-up ply protruding portion is positioned axially inward of the bead core. In a raw tire forming process including a roll-up pressing stage that presses against a carcass ply main body part, a determination method for determining variations in a cord path between bead cores of a carcass ply,
The n laser distance sensors Sa1 to San are attached to the pusher tube on one side in the axial direction at equal intervals in the circumferential direction, and the n laser distance sensors Sb1 to Sbn are attached to the pusher tube on the other side in the axial direction. Attach it to the position facing the laser distance sensors Sa1 to San,
Prior to the green tire forming step, a round sensor correction ring is attached to the bead core holding ring on one side and the other side in the axial direction, respectively, and the sensor is detected from the laser distance sensors Sa1 to San on the one side in the axial direction. The radial distances La1 to Lan to the outer peripheral surface of the correction ring are measured, the display values A1 to An of the laser distance sensors Sa1 to San at that time are corrected to 0, and the laser distance sensor Sb1 on the other side in the axial direction is corrected. A sensor correction step of measuring radial distances Lb1 to Lbn from Sbn to the outer peripheral surface of the sensor correction ring and correcting the display values B1 to Bn of the laser distance sensors Sb1 to Sbn to 0 at that time,
Using the corrected laser distance sensors Sa1 to San and Sb1 to Sbn, the radial direction from the laser distance sensors Sa1 to San on one side in the axial direction to the outer peripheral surface of the carcass ply on the central drum after the carcass winding stage. The distances Ka1 to Kan are measured, the display values A′1 to A′n of the laser distance sensors Sa1 to San at that time are obtained, and the carcass on the central drum is obtained from the laser distance sensors Sb1 to Sbn on the other side in the axial direction. A measurement step of measuring radial distances Kb1 to Kbn to the outer peripheral surface of the ply and obtaining display values B′1 to B′n of the laser distance sensors Sb1 to Sbn at that time;
Among the display values A′1 to A′n and B′1 to B′n, the sum (A′1 + B′1) to (A′n + B′n) of the display values obtained at the positions facing each other. And determining a code path variation between the bead cores of the carcass ply based on the sums (A′1 + B′1) to (A′n + B′n).

  The invention of claim 2 is characterized in that the number n of the laser distance sensors attached on one side and the other side in the axial direction is 3 or more.

  Since the present invention is configured as described above, it is possible to accurately and quickly determine the variation in the carcass cord path for each raw tire in the raw tire forming process, and to perform advanced quality control. Yes. In addition, the time from determination to adjustment of the setting of the raw tire forming apparatus can be greatly shortened, which is useful for improving production efficiency.

It is a conceptual diagram which shows an example of the raw tire formation apparatus which implements the variation determination method of the code path between the bead cores of the carcass ply of this invention. (A) is a cross-sectional view perpendicular to the axis of the central drum, and (B) is a cross-sectional view of the main part of the green tire forming former in the axial direction. It is sectional drawing of the axial center direction of a bead setter. It is sectional drawing of the axial direction which expands and shows a bead core set stage. (A)-(D) is a fragmentary sectional view explaining a green tire formation process with operation of a bead setter. (A), (B) is sectional drawing explaining the arrangement | positioning of a laser distance sensor, and a sensor correction | amendment step, and a front view. (A), (B) is sectional drawing explaining a measurement step, and a front view. It is the schematic which illustrates the dispersion | variation in the display value after correction. It is a conceptual diagram which shows the conventional green tire formation process. (A) is the conceptual diagram of the circumferential direction body of a raw tire explaining the variation determination method of the conventional code path, (B) is a conceptual diagram which shows the measuring method of the core shift | offset | difference in a raw tire formation apparatus.

  Hereinafter, embodiments of the present invention will be described in detail. FIG. 1 is a conceptual diagram illustrating an example of a raw tire forming apparatus that performs a code path variation determination method (hereinafter referred to as a code path variation determination method) between bead cores of a carcass ply of the present invention.

  In FIG. 1, a raw tire forming apparatus 1 includes a raw tire forming former 2 and bead setters 3A and 3B arranged on one side and the other side in the axial direction thereof.

  As the raw tire forming former 2, a conventional molding former having a well-known structure can be adopted. Specifically, the raw tire forming former 2 includes a cylindrical central drum 4 and a pair of side drums 5 arranged on both outer sides in the axial direction of the central drum 4, and each can be rotated by a support shaft 6. Supported by In the present example, the central drum 4 is composed of a pair of left and right drum portions 4A that are arranged so as to be movable toward and away from each other in the axial direction. Each of the drum portions 4A is composed of a plurality of segments 4a divided in the circumferential direction as shown in FIGS. 2A and 2B. Each segment 4a has a diameter-reducing means having a well-known structure using a cylinder or the like ( (Not shown) can move inward and outward in the radial direction between the reduced diameter state Y1 and the expanded diameter state Y2, and the carcass ply 30 is wound in the expanded diameter state Y2 and the raw formed in the reduced diameter state Y1. The tire is removed. The side drum 5 has a turn-up bladder 5b folded and held on the outer peripheral surface of a cylindrical base 5a supported by the support shaft 6. As is well known, the turn-up bladder 5b can be expanded by internal pressure filling.

  Further, as shown in FIG. 1, the bead setters 3A and 3B are respectively provided with a moving table 19 that can move in the axial direction along a guide rail 18 laid on the floor surface, for example. And a cylindrical support 9 attached so as to be movable together. The support body 9 includes a cylindrical body portion 9A concentric with the support shaft 6, and a disk-shaped side plate portion 9B disposed at an outer end portion in the axial direction of the body portion 9A. In this example, a bead core holding ring 14 is attached to the inner end of the trunk portion 9A in the axial center direction, and a carcass narrowing means 13 having openable / closable fingers 13b is provided in the inner cavity 9H of the trunk portion 9A. Arranged.

  As shown in FIG. 3, the carcass narrowing means 13 has a disc-shaped substrate portion 13A concentric with the support shaft 6, and a rear end portion in the axial direction is supported by the substrate portion 13A so as to be tiltable at a fulcrum P. A plurality of fingers 13B. In this example, the board portion 13A is attached to the rod end of the cylinder 20 fixed to the side plate portion 9B, and can move in and out in the axial direction by the extension of the cylinder 20. Each finger 13B is made of an elastic plate such as a leaf spring material, and is urged in the direction of rising due to its spring property, and the rising is regulated by abutting against the tip of the bead core holding ring 14. Is done. Accordingly, the carcass narrowing means 13 becomes substantially horizontal from the open state Ya in which each finger 13B is inclined forward about the fulcrum P by the movement of the base plate portion 13A in and out of the axial direction by the cylinder 20. Between the closed state Yb can be opened and closed.

  As shown in FIG. 4, the bead core holding ring 14 has a seating surface 17s1 for seating the inner peripheral surface 31S1 (bottom surface) of the bead core 31 and an axially outer side surface 31S2 of the bead core 31 at its inner end in the axial direction. And a step-shaped seating portion 17 having a side wall surface 17s2 for supporting the. In this example, the inner surface in the radial direction of the bead core holding ring 14 is made of a rigid resin material having excellent wear resistance such as nylon resin, and a contact plate 21 for preventing damage due to rubbing with the finger 13B is disposed. The As is well known, a bead apex rubber 32 having a triangular cross section is integrally joined to the outer peripheral surface of the bead core 31 in advance.

  A pusher tube 15 is integrally attached to the support 9. The pusher tube 15 has a cylindrical shape that is concentric with the support shaft 6. In this example, the pusher tube 15 is attached to the support body 9 via a side wall portion 23 that rises radially outward from the body portion 9 </ b> A. In this example, a cylinder 24 is attached to the side wall portion 23, and the rod end is brought into contact with the bead apex rubber 32 by the extension of the cylinder 24, and the bead apex rubber 32 is attached to the outer periphery of the central drum 4. A tilting tool 26 that is tilted toward the surface is arranged.

  Next, as conceptually shown in FIG. 6, there are n laser distance sensors Sa1 to San (collectively referred to as laser distance sensors) on the outer peripheral surface of the pusher cylinder 15A disposed on the bead setter 3A on the one axial side. Sa) are attached at equal intervals in the circumferential direction, and n laser distance sensors Sb1 to Sbn (generally referred to) are arranged on the outer peripheral surface of the pusher tube 15B disposed on the bead setter 3B on the other side in the axial direction. Sometimes referred to as laser distance sensor Sb) is attached to the same phase position facing the laser distance sensors Sa1 to San. Each laser distance sensor Sa, Sb has the same configuration, and various types of reflection type can be adopted. The number n of the laser distance sensors Sa and Sb attached is 3 or more, and if it is less than that, it is difficult to determine the variation in the code path due to the misalignment. Further, if the number exceeds 4, no further improvement in determination accuracy is expected, and conversely the measurement data processing becomes complicated and the cost is increased unnecessarily, so the number n is preferably 4.

  Then, using the raw tire forming former 2, a green tire forming process including a carcass winding stage, a carcass drawing stage, a bead core setting stage, and a winding and pressing stage is performed as in the prior art.

  In the carcass winding stage, as shown in FIG. 5A, the carcass ply 30 is wound on the central drum 4, and both ends form a ply protruding portion 30a that protrudes outward from the central drum 4 in the axial direction. A winding body of the right cylindrical carcass ply 30 is formed. At this time, the bead setters 3A and 3B are retracted to the outside in the axial direction and stand by.

  In the carcass throttling stage, as shown in FIG. 5B, the cylinder 20 is operated and the carcass throttling means 13 is advanced to raise the finger 13b from the closed state Yb to the open state Ya. As a result, the finger 13b is positioned on the radially outer side of the ply protrusion 30a. Thereafter, as shown in FIG. 5C, the cylinder 20 is contracted while the bead setters 3A and 3B are advanced. Along with this, the finger 13b is pushed down by the tip of the bead core holding ring 14, and the ply protrusion 30a is formed on the outer end surface 4s of the central drum 4 as shown in FIG. It has a stepped surface 30S along which it is narrowed down to a smaller diameter than the inner diameter of the bead core 31.

  As shown in FIG. 4, the inner side surface 31S3 in the axial direction of the bead core 31 held by the bead core holding ring 14 is pressed against the stepped surface 30S of the carcass ply 30 simultaneously with the narrowing of the ply protrusion 30a. Thus, the bead core setting step of setting the bead core 31 by adhering it to the carcass ply 30 is performed. In this example, after setting the bead core 31, the bead apex rubber 32 is tilted toward the outer peripheral surface of the central drum 4 by advancing the tilting tool 26 by operating the cylinder 24. Thereafter, each of the bead setters 3A and 3B moves back to the standby position on the outer side in the axial direction.

  In the winding and pressing stage, as shown in FIG. 5 (D), the ply protrusion 30a is wound around the bead core 31 by the expansion of the turn-up bladder 5b, and then the pusher cylinder 15 is advanced to move the pusher cylinder 15 forward. The ply protruding portion 30 a thus pressed is pressed against the carcass ply main body portion 30 b on the inner side in the axial center direction than the bead core 31.

  In the cord path variation determination method of the present invention, the variation in the carcass cord path of the green tire formed by the green tire forming process is determined for each green tire using the laser distance sensors Sa and Sb. To do. The code path variation determination method includes a sensor correction step, a measurement step, and a determination step.

  In the sensor correction step, as shown in FIG. 6, prior to the raw tire forming step, the bead core holding ring 14 </ b> A disposed on the bead setter 3 </ b> A on one axial direction and the bead setter 3 </ b> B on the other axial direction. Are attached to the bead core holding ring 14B arranged in the circle. Then, the radial distances La1 to Lan from the laser distance sensors Sa1 to San on one side in the axial direction to the outer peripheral surface X of the sensor correction ring 25 are measured, and the display values A1 of the laser distance sensors Sa1 to San at that time are measured. ˜An is corrected to 0, and the radial distances Lb1 to Lbn from the laser distance sensors Sb1 to Sbn on the other side in the axial direction to the outer peripheral surface X of the sensor correcting ring are measured, and the laser distance sensors Sb1 to Sb1 at that time are measured. The display values B1 to Bn of Sbn are corrected to 0.

  This sensor correction step is not performed every time one raw tire is formed, but is performed, for example, when the raw tire forming apparatus 1 is set. On the other hand, the measurement step and the determination step are performed every time one raw tire is formed in this example.

  In the measurement step, as shown in FIG. 7, after the carcass winding stage, for example, at the bead core setting stage, the carcass ply 30 on the central drum 4 from the laser distance sensors Sa1 to San on one side in the axial direction. Are measured, and display values A′1 to A′n of the laser distance sensors Sa1 to San at that time are obtained. Similarly, radial distances Kb1 to Kbn from the laser distance sensors Sb1 to Sbn on the other side in the axial direction to the outer peripheral surface of the carcass ply 30 on the central drum 4 are measured, and the laser distance sensors Sb1 to Sbn at that time are measured. Display values B′1 to B′n.

  Here, when the display values A1 to An and B1 to Bn are corrected to 0 by the sensor correction step, the values displayed by the corrected laser distance sensors Sa1 to San and Sb1 to Sbn (display values after the correction) These show the measured value of the distance from the outer peripheral surface X of the sensor correction ring 25. Therefore, the display values A′1 to A′n and B′1 to B′n after correction are respectively from the outer peripheral surface X of the sensor correction ring 25 to the outer peripheral surface of the carcass ply 30 on the central drum 4. Corresponds to the distance measurement.

  Next, in the determination step, among the display values A′1 to A′n and B′1 to B′n, the sum of the display values obtained at positions facing each other (A′1 + B′1) to (A′n + B′n) is obtained, and code path variation is determined based on the sum (A′1 + B′1) to (A′n + B′n).

  As conceptually shown in FIG. 8, the variation of the display values A′1 to A′n after the correction and the variation of the display values B′1 to B′n are respectively from the outer peripheral surface X of the sensor correction ring 25. It means a variation in the distance to the outer peripheral surface of the carcass ply 30 on the central drum 4, that is, a misalignment between the bead core holding ring 14 and the central drum 4. Further, the variation of the sums (A′1 + B′1) to (A′n + B′n) of the display values obtained at the opposing positions coincides with the variation of the code path m of the carcass ply 30 between the bead cores 31 and 31. . Accordingly, the code path variation can be determined based on the sums (A′1 + B′1) to (A′n + B′n).

  As a determination method, for example, the variation ΔD of the sum (A′1 + B′1) to (A′n + B′n), for example, the maximum value Mmax and the minimum of the sum (A′1 + B′1) to (A′n + B′n) The difference ΔD (= Mmax−Dmin) from the value Dmin can be compared with a preset reference value to determine variation. At this time, it is possible to provide a single reference value and determine whether it is large or small, or to provide a plurality of reference values and rank a plurality of variations.

  Note that if the variation in the display values A′1 to A′n after the correction and the variation in the display values B′1 to B′n are too large, the determination accuracy tends to be lowered. Therefore, it is preferable to manage the variation ΔA ′ of the display values A′1 to A′n and the variation ΔB ′ of the display values B′1 to B′n to 1.0 mm or less, respectively. When the variations ΔA ′ and ΔB ′ exceed the upper limit, it is preferable to adjust the setting of the raw tire forming apparatus 1 so as to be equal to or lower than the upper limit. The variations ΔA ′ and ΔB ′ are caused by the misalignment between the bead core holding ring 14 and the central drum 4. Therefore, the misalignment can be easily adjusted based on the values of the variations ΔA ′ and ΔB ′.

  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.

2 Raw tire forming former 3A, 3B Bead setter 4 Central drum 4s Outer end face 5 Side drum 5b Turn-up bladders 14, 14A, 14B Bead core holding rings 15, 15A, 15B Pusher cylinder 25 Sensor correction ring 30 Carcass ply 30a Ply protrusion 30b Carcass ply main body 30S Step surface 31 Bead core

Claims (2)

A carcass ply is wound on the central drum using a green tire forming former comprising a cylindrical central drum and a pair of side drums arranged on both outer sides in the axial direction of the central drum and having a turn-up bladder. Carcass winding stage to form a cylindrical carcass ply,
Among the cylindrical carcass plies, a carcass throttle that narrows a ply protruding portion protruding outward in the axial direction from the central drum to a smaller diameter than the inner diameter of the bead core having a step surface along the outer end surface of the central drum. Stage,
A bead core holding ring that holds the bead core and can move inward and outward in the axial direction, and a cylindrical pusher tube that presses the expanded turn-up bladder inward in the axial direction. A bead core setting stage in which the bead core is set by pressing the axially inner side surface of the bead core held by the bead core holding ring against the step surface of the carcass ply using a setter;
And the turn-up bladder expands the ply protruding portion around the bead core, and then moves the pusher tube inward in the axial center direction so that the rolled-up ply protruding portion is positioned axially inward of the bead core. In a raw tire forming process including a roll-up pressing stage that presses against a carcass ply main body part, a determination method for determining variations in a cord path between bead cores of a carcass ply,
The n laser distance sensors Sa1 to San are attached to the pusher tube on one side in the axial direction at equal intervals in the circumferential direction, and the n laser distance sensors Sb1 to Sbn are attached to the pusher tube on the other side in the axial direction. Attach it to the position facing the laser distance sensors Sa1 to San,
Prior to the green tire forming step, a round sensor correction ring is attached to the bead core holding ring on one side and the other side in the axial direction, respectively, and the sensor is detected from the laser distance sensors Sa1 to San on the one side in the axial direction. The radial distances La1 to Lan to the outer peripheral surface of the correction ring are measured, the display values A1 to An of the laser distance sensors Sa1 to San at that time are corrected to 0, and the laser distance sensor Sb1 on the other side in the axial direction is corrected. A sensor correction step of measuring radial distances Lb1 to Lbn from Sbn to the outer peripheral surface of the sensor correction ring and correcting the display values B1 to Bn of the laser distance sensors Sb1 to Sbn to 0 at that time,
Using the corrected laser distance sensors Sa1 to San and Sb1 to Sbn, the radial direction from the laser distance sensors Sa1 to San on one side in the axial direction to the outer peripheral surface of the carcass ply on the central drum after the carcass winding stage. The distances Ka1 to Kan are measured, the display values A′1 to A′n of the laser distance sensors Sa1 to San at that time are obtained, and the carcass on the central drum is obtained from the laser distance sensors Sb1 to Sbn on the other side in the axial direction. A measurement step of measuring radial distances Kb1 to Kbn to the outer peripheral surface of the ply and obtaining display values B′1 to B′n of the laser distance sensors Sb1 to Sbn at that time;
Among the display values A′1 to A′n and B′1 to B′n, the sum (A′1 + B′1) to (A′n + B′n) of the display values obtained at the positions facing each other. And determining a code path variation between the bead cores of the carcass ply based on the sums (A′1 + B′1) to (A′n + B′n). Code path variation judgment method.   2. The method of determining variation in a code path between bead cores of a carcass ply according to claim 1, wherein the number n of the laser distance sensors attached on one side and the other side in the axial direction is three or more.

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