JP2004249496A - Method and apparatus for manufacturing pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the meandering of a carcass cord under a breaker. <P>SOLUTION: A profile deck 21 is expanded in its diameter accompanied by the approach movement of a bead core 5 due to a clamp ring 20 to push up a body cover 9 including a carcass ply 6A in the shape along the profile deck 21 to expand the same. By this constitution, the outer peripheral surface of the body cover 9 having the pushed-up shape due to the profile deck 21 is pasted on the inner peripheral surface of an annular tread ring 15. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００４９】
【発明の効果】
叙上の如く本発明は、高圧空気に代えてプロフアイルデッキの拡径によってカーカスを膨出せしめ、トレッドリングの内周面にカーカスを押し付けて貼着しているため、ブレーカ下でのカーカスコードの蛇行を抑制できる。その結果、加硫成形の際のカーカスの動きを抑えるとともにコードテンションの均一化を図ることができ、操縦安定性、乗り心地性、およびユニフォミティー等を向上しうる。
【図面の簡単な説明】
【図１】本発明のタイヤの製造方法によって形成された空気入りタイヤの一実施例を示す断面図である。
【図２】本発明の製造方法の一実施例を概念的に示す線図である。
【図３】本体カバー形成工程を説明する線図である。
【図４】タイヤの製造装置の構造の一例を説明する断面図である。
【図５】クランプリングを拡大して示す断面図である。
【図６】プロファイルデッキの拡径及び縮径の状態を示す周方向断面図である。
【図７】プロファイルデッキの輪郭形状を示す子午断面図である。
【図８】従来技術を説明する線図である。
【符号の説明】
２Ｇ トレッドゴム
５ ビードコア
６Ａ カーカスプライ
７ ブレーカ
９ 本体カバー
１５ トレッドリング
２０ クランプリング
２１ プロフアイルデッキ
２２ 膨出貼着手段[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention can prevent the carcass cord from meandering under the breaker when joining the carcass and the tread ring, and can make the carcass cord tension uniform in the finished tire, and can improve the steering stability and uniformity. The present invention relates to a method and an apparatus for manufacturing a pneumatic tire.
[0002]
2. Description of the Related Art
Generally, in a raw tire manufacturing process for a radial tire, as shown in FIG. 8, a cylindrical main body cover c including a carcass ply b locked on both sides by a bead core a is formed, and a bead core a approaching in the axial direction is formed. The raw tire in which the tread ring d and the main body cover c are integrated with each other by pressing the main body cover c in a toroidal shape between the a and the inner peripheral surface of the tread ring d waiting on the radial outside thereof. Is formed. At this time, the swelling of the main body cover c is conventionally performed by filling with high-pressure air.
[0003]
However, the joining of the tread ring d and the main body cover c by the filling of the high-pressure air has a problem that the carcass cords meander under the breaker d1. As a result, during vulcanization molding, sufficient tension does not act on the carcass cord under the breaker d1, causing uneven cord tension, impairing steering stability and riding comfort, and causing the carcass to move during vulcanization molding. And it has a negative impact on uniformity.
[0004]
The meandering of the carcass cord is caused by the fact that the carcass cord b1 (indicated by a dashed line in FIG. 1) that is about to bulge in an arc shape due to the internal pressure filling is linearly restrained by the tread ring d. Only, the carcass cord b1 meanders under compression in the length direction. This meandering occurs more remarkably in a tire having a smaller inner diameter of the tread ring d, that is, a tire having a smaller flatness.
[0005]
Patent Document 1 discloses a technique in which a main body cover is bulged by a low internal pressure of 100 kPa or less and a core whose diameter can be reduced is expanded to adhere to the inner peripheral surface of a tread ring d.
[0006]
[Patent Document 1]
JP, 2002-67184, A
The present invention provides a carcass cord under a breaker based on expanding a carcass by expanding the diameter of a profile deck, and attaching a carcass in a push-up shape by the profile deck to an inner peripheral surface of a tread ring. To provide a method and apparatus for manufacturing a pneumatic tire that can suppress the meandering of the tire, suppress the movement of the carcass during vulcanization molding, make the cord tension uniform, and improve the steering stability and uniformity. And
[0008]
[Means for Solving the Problems]
In order to achieve the above object, claim 1 of the present application is an invention of a method for manufacturing a pneumatic tire, wherein a cylindrical main body cover including a carcass ply locked on both sides by a pair of bead cores can be enlarged and reduced in diameter. Around the profile deck,
The bead core of the body cover is clamped by a pair of clamp rings that can be approached in the axial direction,
And, with the approaching movement of the clamp ring, the profile deck is expanded in diameter to push up the main body cover in a shape along the profile deck to swell between the bead cores,
The present invention is characterized in that an outer peripheral surface of a push-up main body cover formed by the profile deck is adhered to a radially inner peripheral surface of an annular tread ring made of a tread member including a breaker and a tread rubber.
[0009]
According to the second aspect of the present invention, in the meridional section including the tire axis, the radially outer peripheral surface of the profile deck has a radius of curvature R1 and a finished radius of curvature R2 of a radially inner peripheral surface of the breaker of the tread ring. The difference is 200 mm or less, and the width W1 in the tire axial direction is larger than the width W2 in the tire axial direction of the radially inner peripheral surface of the breaker in the range of 10 to 50 mm.
[0010]
Claim 3 is an invention of a pneumatic tire manufacturing apparatus, wherein a pair of bead cores of a cylindrical main body cover including a carcass ply locked on both sides by a pair of bead cores so that the bead cores can be approached in the axial direction. Of the clamp ring,
A swelling and sticking means having a profile deck capable of expanding and reducing the diameter and pushing up the main body cover to swell between the bead cores,
The present invention is characterized in that an outer peripheral surface of a push-up main body cover formed by the profile deck is adhered to a radially inner peripheral surface of an annular tread ring made of a tread member including a breaker and a tread rubber.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a method for manufacturing a pneumatic tire of the present invention will be described with reference to the drawings together with a manufacturing apparatus used for the method. FIG. 1 is a meridional sectional view of a pneumatic tire formed by the manufacturing method of the present invention, and FIG. 2 is a schematic view conceptually showing the manufacturing method.
[0012]
In FIG. 1, a pneumatic tire T is a tire for a passenger car in this example, and a carcass 6 extending from a tread portion 2 to a bead core 5 of a bead portion 4 through a sidewall portion 3 and an inner portion of the tread portion 2. And a breaker 7 placed radially outside of the carcass 6.
[0013]
The carcass 6 is formed from one or more carcass plies 6A in which carcass cords are arranged at an angle of 75 to 90 ° with respect to the tire circumferential direction, in this example, one carcass ply 6A. The carcass ply 6A is integrally provided with a ply folded portion 6b which is folded back from the inside to the outside around the bead core 5 and is locked at both ends of the ply body portion 6a straddling the bead cores 5, 5. A bead apex rubber 8 for reinforcing a bead extending radially outward from the bead core 5 is provided.
[0014]
The breaker 7 includes two or more breaker plies 7A and 7B in which breaker cords are arranged at an angle of, for example, 10 to 35 degrees with respect to the tire circumferential direction. Each breaker ply 7A, 7B has its cord crossed between the plies to increase the breaker stiffness, and substantially reinforces substantially the entire width of the tread portion 2 with a tag effect.
[0015]
In the meridional section including the tire shaft, the tread portion 2 extends in a convex arc shape from the tire equator C toward the tread end E, and in the present example, in a finished state in a vulcanization mold, A radially inner peripheral surface 7S of the breaker 7 (hereinafter sometimes referred to as a "breaker inner peripheral surface 7S") has a curvature radius R2 formed in a convex arc-shaped profile. The radius of curvature R2 is measured as the radius of curvature of a three-point arc that passes through the center point in the tire axial direction of the breaker inner peripheral surface 7S and both outer end points when the breaker inner peripheral surface 7S has a shape other than a single arc.
[0016]
Next, as shown in FIG.
(1) A main body cover forming step S1 (shown in FIG. 3) for forming a cylindrical main body cover 9 including a carcass ply 6A locked on both sides by a pair of bead cores 5;
(2) a clamping step S2 of disposing the main body cover 9 around a profile deck 21 whose diameter can be enlarged and reduced, and then clamping the bead core 5 with a clamp ring 20;
{Circle around (3)} As the profile deck 21 expands in diameter as the clamp ring 20 approaches, the main body cover 9 is pushed up in a shape along the profile deck 21 and swells between the bead cores 5, 5. A swelling / adhering step S3 for adhering the outer peripheral surface of the body cover 9 having a push-up shape formed by the profile deck 21 to the radially inner peripheral surface of the annular tread ring 15 formed in advance. :
It is comprised including.
[0017]
Here, in the present embodiment, the main body cover forming step S1 is carried out in substantially the same manner as in the related art, using a well-known former 10, as schematically shown in FIG. The former 10 has a cylindrical forming drum 11 whose diameter can be expanded, and forms the main body cover 9 in the following sequence of steps. That is,
(A) winding a main body cover constituting member including the carcass ply 6A around the outer peripheral surface of the forming drum 11 to form a straight cylindrical wound body 12;
(B) inserting the bead cores 5 from both outer ends in the axial direction of the winding body 12 and setting the bead cores 5 outside the winding body 12 in the radial direction;
(C) A step S1c of folding back both end portions 12a of the winding body 12 around the bead core 5, thereby locking both ends of the carcass ply 6A.
[0018]
In addition, the main body cover component member is generally composed of the carcass ply 6A and an inner liner rubber disposed radially inward of the carcass ply 6A, but may further include a sidewall rubber, a clinch rubber or the like as required.
[0019]
The tread ring 15 is also formed by substantially the same method as that of the related art, that is, by sequentially winding a tread member including the breaker 7 and the tread rubber 2G on a belt drum having a known structure. In this example, the tread ring 15 is formed in a substantially trapezoidal cross section in which the inner peripheral surface is linear in the meridional cross section. The diameter Dt of the inner peripheral surface of the tread ring 15 is greater than the diameter D2 of the inner peripheral surface 7S of the breaker on the tire equator C in the finished state (shown in FIG. 1) in the vulcanization stretch ratio (1 to 5%). Only set to small.
[0020]
In this example, the main body cover 9 formed in the main body cover forming step S1 is removed from the former 10 by reducing the diameter of the forming drum 11, and then transferred to the manufacturing apparatus 1 of the second invention of the present application. 1 to perform the clamping step S2 and the swelling / sticking step S3.
[0021]
As shown in FIG. 4, the manufacturing apparatus 1 includes a pair of clamp rings 20 for clamping the transferred bead cores 5, 5 of the main body cover 9 so that the bead cores 5, 5 can be approached in the axial direction. And a swelling and sticking means 22 having a profile deck 21 for swelling therebetween.
[0022]
In this example, as shown in FIG. 5, the clamp ring 20 includes a seating portion 23A which sits and receives the bottom surface of the bead core 5 via a carcass ply 6A or the like, and an axial inner end of the seating portion 23A. A locking portion 23B that locks and positions the axial inner surface of the bead core 5 by rising at a small height, and an inclined portion 23C for guiding the bead core that extends downward in a cone shape from the axially outer end of the seating portion 23A. And formed.
[0023]
In this example, one (the right-hand side in FIG. 4) clamp ring 20A is fixed to, for example, the tip of the drum shaft 26 using the first mounting bracket 24 so as to be integrally rotatable with the drum shaft 26. You. The other (left side in FIG. 4) clamp ring 20B is rotatable integrally with the drum shaft 26 via a sleeve tube 27 externally inserted into the drum shaft 26 using a second mounting bracket 25. It is slidably held in the direction.
[0024]
The first mounting member 24 has a disk-shaped side wall portion 24A that rises radially outward from a fixing portion fixed to the drum shaft 26, and the radially outer edge portion of the side wall portion 24A holds the clamp ring 20A. Bolts are connected.
[0025]
The second mounting member 25 includes a slidable slide tube 29 that is slidably inserted into the sleeve tube 27, and a mounting member body 30 that is fixed to an inner end of the slide tube 29 in the axial direction. The mounting bracket body 30 has a cylindrical body 30A having a diameter larger than that of the slide cylinder 29 to form a piston chamber H with the sleeve tube 27, and the axial direction of the body 30A. A first side wall portion 30B connected to the slide cylinder 29 by bolts is formed at the outer end, and a second side wall portion 30C connected to the clamp ring 20B by bolts is formed integrally at the inner end in the axial direction. You.
[0026]
A case portion 32 is rotatably mounted on the axially outer end side of the slide cylinder 29 via a bearing piece 31 such as a ball bearing, and a ball screw mechanism or the like is used for the case portion 32, for example. The slide moving means 33 is linked.
[0027]
Therefore, the parallel movement of the case portion 32 by the slide moving means 33 allows the clamp rings 20A and 20B to relatively move toward and away from each other, and at each position of the close and move movement, the mounting brackets 24 and 25 and the clamp ring 20A, 20B can rotate integrally with the drum shaft 26.
[0028]
Next, in this example, in the profile deck 21 in this example, in a section perpendicular to the axial direction (circumferential section), as shown in FIG. 6, both side surfaces sa in the circumferential direction asymptotically inward in the radial direction. The first segment 21A having a tapered shape and the small second segment 21B whose opposite side surfaces sb gradually approach outward in the radial direction are alternately formed.
[0029]
The segments 21A and 21B can be moved radially outward by a diameter-enlarging / reducing means 34, which will be described later. Is formed in a perfect circle. When reducing the diameter, the profile deck 21 can be reduced in diameter by configuring the moving distance of the second segment 21B inward in the radial direction to be larger than the moving distance of the first segment 21A. .
[0030]
It is preferable that the profile deck 21 be composed of 8 to 16 segments in order to smoothly perform the operation of the expansion and contraction diameter and to ensure a sufficient radius difference between the expansion and contraction diameters. The diameter D1 of the profile deck 21 on the equator of the tire in the enlarged diameter state Y1 substantially matches the value obtained by subtracting the thickness of the main body cover 9 from the diameter D2 of the breaker inner peripheral surface 7S in the finished state. .
[0031]
What is particularly important for the present invention is that, as shown in FIG. 7, in a meridional section including the tire axis, the deck outer peripheral surface 21S has a convex arc-shaped profile similar to the breaker inner peripheral surface 7S in the finished state. Is to have.
[0032]
Specifically, in the meridional section, the deck outer peripheral surface 21S is formed of a single arc in this example, and the difference (R1-R2) between the curvature radius R1 and the curvature radius R2 of the breaker inner peripheral surface 7S in the finished state. Is set to a shape close to the breaker inner peripheral surface 7S of 200 mm or less. Preferably, the difference (R1−R2) is set to 150 mm or less, more preferably 100 mm or less, so as to approximate the breaker inner peripheral surface 7S. When the deck outer peripheral surface 21S is not a single arc, the radius of curvature of a three-point arc passing through the center point and both outer end points of the deck outer peripheral surface 21S is defined as R1. The outer peripheral surface 21S of the deck has a width W1 in the tire axial direction larger than the width W2 (shown in FIG. 1) of the inner peripheral surface 7S in the tire axial direction in the finished state in the range of 10 to 50 mm.
[0033]
Next, the expanding / contracting means 34 includes a guiding means 34A for guiding the segments 21A, 21B in and out in the radial direction, and a moving means 34B for moving the segments 21A, 21B along the guiding means 34A.
[0034]
The guide means 34A includes a plurality of guide shafts 36 extending radially outward from the drum shaft 26, and the guide shafts 36 are fitted with guide holes provided in the respective segments 21A and 21B. , Each segment 21A, 21B can be guided inward and outward in the radial direction.
[0035]
The moving means 34B includes a cylindrical reciprocating member 39 disposed in the piston chamber H and capable of sliding on the sleeve tube 27 in the axial direction, the reciprocating member 39, the first segment 21A, And a second link body 41 connecting between the reciprocating member 39 and the second segment 21A. Here, the link length of the second link body 41 is larger than the link length of the first link body 40, thereby reducing the amount of diameter reduction of the second segment 21B from the expanded state Y1. It can be set smaller than the diameter reduction amount of the first segment 21A.
[0036]
In this example, the reciprocating member 39 can slide in and out in the axial direction by a linear actuator 42 which is an air cylinder fixed to the frame F in this example. The linear actuator 42 is connected to the reciprocating member 39 via a rod member 43 including a joint shaft 43A that extends through the first side wall 30B in the axial direction.
[0037]
In the present embodiment, the case where the moving means 34B is arranged only on one side (the left side in FIG. 3) of the profile deck 21 is exemplified, but it is also possible to arrange the moving means 34B on both sides of the profile deck 21 as required.
[0038]
However, as shown in FIG. 2, the cylindrical main body cover 9 transferred to the manufacturing apparatus 1 is held with the bead core 5 seated on the clamp ring 20 (clamping step S2).
[0039]
Thereafter, a swelling / sticking step S3 is performed. In this step, the slide moving means 33 is operated, the bead cores 5 are slid in the directions approaching each other to a predetermined position J where a predetermined bead distance is obtained, and the profile deck 21 is expanded by the operation of the linear actuator 42. Diameter. As a result, the body cover 9 can be pushed up and bulged in the shape along the profile deck 21, and the body cover 9 pushed up by the profile deck 21 is attached to the inner peripheral surface of the tread ring 15 which has been waiting in advance. It can be stuck by pressing the outer peripheral surface.
[0040]
At this time,
A sufficient tension can be imparted to the carcass cord by expanding the diameter of the profile deck 21; and since the deck outer peripheral surface 21S has a convex arc-shaped profile similar to the finished breaker inner peripheral surface 7S, The tread ring 15 can be attached to the body cover 9 while being deformed into a profile close to the finished state;
Thereby, the meandering of the carcass cord under the breaker can be reliably suppressed. In addition, since the carcass cord under the breaker can be given a tension close to the finished state at the time of sticking, the carcass cord tension during vulcanization molding can be made more uniform, and the movement of the carcass during vulcanization molding can be improved. Can be suppressed. Therefore, it is possible to improve the steering performance, the tire performance such as the riding comfort, and the uniformity of the finished tire.
[0041]
Conventionally, both ends of the tread ring 15 are rolled down inward in the radial direction using a stitcher and attached to the body cover 9, so that wrinkles and the like occur at the rolled-down portion, and the cord arrangement is disordered at the breaker end. are doing. However, in the present invention, since the main body cover 9 is firmly held in the push-up shape by the profile deck 21, the amount of lowering the tread ring at both ends can be significantly reduced, and wrinkles and irregularities in the cord arrangement can be obtained. And uniformity and the like can be further improved.
[0042]
Although the preferred embodiment of the present invention has been described in detail above, the main body cover 9 is formed directly around the profile deck 21 without transferring the main body cover 9 from the former 10 according to, for example, a single-stage molding method. The present invention is not limited to the illustrated embodiment, and may be implemented in various forms.
[0043]
【Example】
Based on the manufacturing method of the present invention, a tire for a passenger car having a tire size of 225 / 60R16 is prototyped with the specifications shown in Table 1, and the steering stability, riding comfort, road noise, and uniformity (RFV ) And the like, and compared with a conventional example in which the main body cover was swollen by high-pressure air. The tires were formed under the same conditions except for the method of expanding the body cover.
[0044]
(1) steering stability and ride comfort;
The test tires were mounted on all wheels of a vehicle (2500 cc) under the conditions of a rim (16 × 6.5) and an internal pressure (200 kPa), and were driven on a dry asphalt test course, and at the same time, steering stability and riding The comfort is indicated by an index based on a sensory evaluation of the driver, with the conventional example being 100. The larger the index, the better.
[0045]
(2) Road noise properties;
Using the vehicle, the vehicle travels on a smooth road surface at a speed of 50 km / h, and the overall noise level dB (A) is measured at the driver's seat. The larger the index, the better.
[0046]
(3) Uniformity (RFV);
Using a uniformity tester, RFV was measured for each of 100 tires, and the average value was evaluated.
[0047]
(4) tire finish;
The tire before vulcanization was disassembled, and the presence or absence of meandering of the carcass cord under the breaker and the presence or absence of the breaker cord arrangement disorder at the breaker end were observed.
[0048]
[Table 1]

[0049]
【The invention's effect】
As described above, according to the present invention, the carcass is expanded by expanding the diameter of the profile deck instead of the high-pressure air, and the carcass is pressed and adhered to the inner peripheral surface of the tread ring. Meandering can be suppressed. As a result, the movement of the carcass during vulcanization molding can be suppressed, and the cord tension can be made uniform, so that steering stability, ride comfort, uniformity, and the like can be improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing one embodiment of a pneumatic tire formed by the tire manufacturing method of the present invention.
FIG. 2 is a diagram conceptually showing one embodiment of a manufacturing method of the present invention.
FIG. 3 is a diagram illustrating a main body cover forming step.
FIG. 4 is a cross-sectional view illustrating an example of a structure of a tire manufacturing apparatus.
FIG. 5 is an enlarged sectional view showing a clamp ring.
FIG. 6 is a circumferential sectional view showing a state where the diameter of the profile deck is increased and reduced.
FIG. 7 is a meridional sectional view showing a profile shape of a profile deck.
FIG. 8 is a diagram illustrating a conventional technique.
[Explanation of symbols]
2G Tread rubber 5 Bead core 6A Carcass ply 7 Breaker 9 Main body cover 15 Tread ring 20 Clamp ring 21 Profile deck 22 Swelling sticking means

Claims (3)

Along with disposing a tubular main body cover including a carcass ply locked on both sides with a pair of bead cores around a profile deck that can be enlarged and reduced in diameter,
Clamping the bead core of the body cover by a pair of clamp rings that can be approached in the axial direction,
And, with the approach movement of the clamp ring, the profile deck is expanded in diameter, thereby pushing up the main body cover in a shape along the profile deck and expanding between the bead cores,
A pneumatic tire characterized in that an outer peripheral surface of a body cover having a push-up shape formed by the profile deck is attached to a radial inner peripheral surface of an annular tread ring made of a tread member including a breaker and a tread rubber. Production method. In a meridional section including a tire axis, a radial outer peripheral surface of the profile deck has a difference between its curvature radius R1 and a finished curvature radius R2 of a radial inner peripheral surface of the breaker of the tread ring of 200 mm or less, and The pneumatic tire manufacturing method according to claim 1, wherein the width (W1) in the tire axial direction is set to be larger than the width (W2) in the tire axial direction of the inner circumferential surface of the breaker in the range of 10 to 50 mm. A pair of clamp rings for clamping the bead core of the tubular body cover including the carcass ply locked on both sides with a pair of bead cores so as to be able to approach in the axial direction;
A swelling and sticking means having a profile deck capable of expanding and reducing the diameter and pushing up the main body cover to swell between the bead cores,
A pneumatic tire characterized in that an outer peripheral surface of a body cover having a push-up shape formed by the profile deck is attached to a radial inner peripheral surface of an annular tread ring made of a tread member including a breaker and a tread rubber. manufacturing device.

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