JP6701985B2 - Raw tire manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a raw tire capable of suppressing the occurrence of air accumulation when a carcass ply is folded back around a bead assembly.

  In a raw tire manufacturing method, generally, a bead delivery step, a bead setting step, and a carcass folding step are performed.

  In the bead delivery step, as shown in FIG. 8, the bead assembly a in which the bead core and the bead apex rubber are integrally joined is received from the bead supply ring b1 of the bead supply device b to the bead set ring c1 of the bead transfer c. Passed. As a result, the bead assembly a is put into the green tire production line.

  In the bead setting step, the bead assembly a is carried into the set position p of the carcass ply e on the drum d by the movement of the bead transfer c. On the drum d, as shown in FIG. 9, the bead lock f is expanded in diameter, and the bead assembly a carried in is joined to the carcass ply e.

  Further, in the carcass folding step, the turn-up bladder g expands after the drum portion di inside the bead lock f in the tire axial direction expands radially outward from the bead core a1 of the bead assembly a. As a result, the outer portion eo (the portion protruding from the bead core a1) of the carcass ply e is folded back inward in the tire axial direction together with the bead apex rubber a2 of the bead assembly a and joined to the inner portion ei of the carcass ply e ( See, for example, Patent Documents 1 and 2.).

  However, in the conventional tire manufacturing method, the bead apex rubber a2 of the bead assembly a is transferred from the bead supply ring b1 to the bead set ring c1 and is carried to the drum d while being substantially upright outward in the radial direction. To be done. Therefore, in the carcass folding step, the bead apex rubber a2 tends not to be bent sufficiently along the inner drum portion di. As a result, air accumulates in the folded portion of the carcass ply, which causes a problem that tire quality is deteriorated.

JP, 2010-036420, A JP2012-236359A

  Therefore, the present invention is to provide a method for manufacturing a raw tire that improves the tire quality by suppressing air accumulation in the folded portion of the carcass ply on the basis of bending and deforming the bead apex rubber in the bead delivery step. I am trying.

The present invention provides a bead assembly in which a bead core and a bead apex rubber are integrally joined, and a bead delivery step of delivering from a bead supply ring of a bead supply device to a bead set ring of a bead transfer,
By moving the bead transfer, the bead assembly held by the bead set ring is carried into a set position on the tire axially outer end side of a carcass ply wound on a drum for forming a raw tire, and Including a bead setting step of joining to
The bead supply ring has a seating surface for seating an inner peripheral surface of a bead core, a first core receiving surface for receiving an inner side surface of the bead core in the tire axial direction, and a first apex for receiving an inner side surface of the bead apex rubber in the tire axial direction. With a receiving surface,
Further, the bead set ring includes a second core receiving surface made of a magnet capable of adsorbing the tire axially outer side surface of the bead core, and a second apex receiving surface receiving the tire axially outer side surface of the bead apex rubber. With
The first and second apex receiving surfaces each include a bending surface that bends inward in the tire axial direction,
In the bead delivery step, when the bead assembly is delivered, the bead apex rubber is bent inward in the tire axial direction by sandwiching the bead apex rubber of the bead assembly between the first and second apex receiving surfaces. It is characterized by including a deformation step of deforming.

  In the method for manufacturing a green tire according to the present invention, it is preferable that at least one of the bead supply ring and the bead set ring includes a heater that heats and softens the bead apex rubber when the bead assembly is delivered.

  In the present specification, "inside" and "outside" in the tire axial direction are a direction toward the tire equator when a raw tire is formed, or a direction corresponding to this is "inside" and the opposite is "outside". Is defined.

  In the present invention, the bead delivery step includes a step of sandwiching the bead apex rubber of the bead assembly between the first apex receiving surface of the bead supply ring and the second apex receiving surface of the bead set ring.

  The first and second apex receiving surfaces are each formed by a bent surface that is bent inward in the tire axial direction. Therefore, in the above step, the bead apex rubber can be bent and deformed inward in the tire axial direction by sandwiching the first and second apex receiving surfaces.

  Therefore, in the carcass folding step, the amount of bending into the bead apex rubber can be reduced. As a result, the accumulation of air in the folded portion of the carcass ply can be suppressed, and the tire quality can be improved. Further, since the amount of bending can be reduced, it is possible to increase the degree of freedom in tire design, such as using a hard rubber material for the bead apex rubber and increasing the rubber thickness.

It is a side view which shows an example of the raw tire forming apparatus for implementing the manufacturing method of the raw tire of this invention. It is a side view which shows a bead supply apparatus and a bead transfer. It is an expanded sectional view which shows a bead delivery process. It is an expanded sectional view which shows the modification step of a bead delivery process. It is a fragmentary sectional view of the drum for green tire formation. It is a fragmentary sectional view showing a bead setting process. It is a fragmentary sectional view showing a carcass folding back process. It is a side view which shows the manufacturing method of the conventional green tire. It is a fragmentary sectional view showing the conventional carcass turn back process.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a side view of a raw tire forming apparatus 1 for carrying out the raw tire producing method of the present invention. The raw tire producing method will be described along the raw tire forming apparatus 1.

  As shown in FIG. 1, a raw tire forming apparatus 1 of the present embodiment carries a bead assembly 61 into a set position P of a raw tire forming drum 2 and a carcass ply 60 wound on the drum 2. The bead transfer 3 and the bead supply device 5 for delivering the bead assembly 61 to the bead set ring 4 of the bead transfer 3 are provided.

  As shown in the enlarged view of FIG. 3, the bead assembly 61 is an assembly in which a bead core 62 and a bead apex rubber 63 are integrally joined. In this example, the bead assembly 61 is formed by a line other than a raw tire manufacturing line. And stored in the stockyard.

  As shown in FIG. 1, the bead transfer 3 moves from a receiving position Q1 for receiving the bead assembly 61 from the bead supply device 5 to a loading position Q2 for loading the bead assembly 61 to the set position P. , Move in the axial direction X of the drum 2.

  The bead supply device 5 moves from the stockyard of the bead assembly 61 to the receiving position Q1 in a horizontal Y direction (not shown) perpendicular to the axial direction X.

  As shown in FIG. 2, the bead supply device 5 of the present example is, for example, a movable base 28 which is guided by a guide rail 30a of a pedestal 30 and movable in the Y direction, and a bead core transfer means supported by the movable base 28. 29 and 29.

  The bead core transfer means 29 includes disk-shaped frames 32 and 32 that are parallel to each other and are attached to the moving base 28 via, for example, columns 31, and a bead supply ring 34 that is supported on each frame 32 via expansion/contraction diameter means 33. Equipped with. Each bead supply ring 34 is concentric with the drum 2 at the receiving position Q1.

  The bead supply ring 34 is composed of a plurality of segments 35 that are divided in the circumferential direction. Each segment 35 can be moved in and out in the radial direction by the expansion/contraction diameter means 33. As a result, the bead supply ring 34 can expand/contract between the expanded state YC2 (shown in FIG. 3) that holds the bead assembly 61 and the contracted state YC1 (not shown) that opens the bead assembly 61. ..

  Although not particularly limited, the expansion/contraction diameter means 33 includes a guide 36 arranged on the side surface of the frame 32 and a moving piece 37 guided by the guide 36 in this example. Each moving piece 37 is driven by, for example, a cylinder (not shown) or the like, and can move in the radial direction. The segment 35 is attached to each moving piece 37.

  As shown in FIG. 3, the segment 35 (bead supply ring 34) includes a seating surface 34a on which the inner peripheral surface 62a of the bead core 62 is seated, and a first core receiving surface that receives the tire axial direction inner surface 62b of the bead core 62. 34b and a first apex receiving surface 34c for receiving the inner surface 63c of the bead apex rubber 63 in the tire axial direction.

  The segment 35 (bead supply ring 34) of the present example includes a base portion 38 having the seating surface 34a and the first core receiving surface 34b, and an apex holder portion 39 having a first apex receiving surface 34c. The apex holder portion 39 is replaceably attached to the base portion 38.

  Then, the first apex receiving surface 34c is formed as a bent surface 41 that is bent inward in the tire axial direction. The "bend" also includes an arcuate curve. Before the bead assembly 61 is delivered to the bead set ring 4, the bead apex rubber 63 is substantially upright toward the outside in the radial direction as in the conventional case. Therefore, before being delivered, the bead apex rubber 63 of the bead assembly 61 held by the bead supply ring 34 is separated from the first apex receiving surface 34c.

  Next, as shown in FIG. 2, the bead transfer 3 includes a first moving base 16 and a pair of second moving bases supported by the first moving base 16 and capable of moving close to each other in the axial direction X. A bead set ring 18 is supported on each of 17, 17, and the second moving table 17.

  The first movable table 16 can be moved in the axial direction X by being guided by a groove 15a on the bed plate 15, for example. The first moving table 16 of this example includes a guide 19 extending in the axial direction X, and a screw shaft 20 connected to M having one end. The screw shaft 20 has a right screw portion 20a and a left screw portion 20b on one side and the other side of the axial direction X, respectively.

  Each second movable table 17 includes a base 21 guided by the guide rail 19 and a ring-shaped frame 22 provided upright on the base 21. One of the bases 21 is screwed into the right-hand screw portion 20a, and the other base 21 is screwed into the left-hand screw portion 20b. Therefore, the second moving bases 17 and 17 can move closer to the desired distance in the axial direction X by controlling the rotation direction and the number of rotations (including the rotation angle) of the screw shaft 20.

  The bead set ring 18 is composed of a plurality of segments 23 that are divided in the circumferential direction. By moving each segment 23 in and out in the radial direction by the expansion/contraction diameter means 24, the bead set ring 18 can be expanded/contracted.

  The expansion/contraction means 24 is not particularly specified, but in this example, it comprises a guide 25 attached to the side surface of the ring-shaped frame 22 and a moving piece 25a guided by the guide 25. Each moving piece 25a is driven by, for example, a cylinder 27, and can move in the radial direction. The segment 23 is attached to each moving piece 25a.

  As shown in FIG. 3, the segment 23 (bead set ring 18) includes a second core receiving surface 18d made of a magnet capable of adsorbing the tire axially outer surface 62d of the bead core 62 and a tire shaft of the bead apex rubber 63. A second apex receiving surface 18e for receiving the direction outer surface 63e. The segment 23 (bead set ring 18) in this example is formed of a base portion 26 having a second apex receiving surface 18e and a magnet 27 attached to the base portion 26.

  Further, the second apex receiving surface 18e is formed as a bending surface 40 that is bent inward in the tire axial direction, like the first apex receiving surface 34c.

  Then, the bead delivery step S1 of the bead assembly 61 from the bead supply ring 34 to the bead set ring 18 is performed as follows.

  The second moving bases 17, 17 of the bead transfer 3 are moved toward each other with respect to the bead supply device 5 standing by at the receiving position Q1. As a result, the bead set ring 18 is moved toward the bead assembly 61 held by each bead supply ring 34. Then, as shown in FIG. 4, when the second core receiving surface 18d of the bead set ring 18 abuts and adsorbs to the bead core 62, the bead apex is formed between the first and second apex receiving surfaces 34c and 18e. The rubber 63 is sandwiched. Thereby, the bead apex rubber 63 can be bent and deformed in a predetermined shape toward the inner side in the tire axial direction.

  Here, in order to easily perform the bending deformation, it is preferable to provide a heater 42 that heats and softens the bead apex rubber 63 when the bead assembly 61 is delivered. The heater 42 is arranged on at least one of the bead supply ring 34 and the bead set ring 18, preferably both. The heater 42 is not particularly limited, but an electric heater is preferable from the viewpoint of ease of control.

  Further, after the bending deformation, for example, the diameters of the bead supply ring 34 are reduced, and the second moving bases 17, 17 are moved in directions away from each other. Accordingly, the bead assembly 61 can be transferred from the bead supply ring 34 to the bead set ring 18. That is, the bead delivery step S1 is performed, and at the same time, the deformation step S1a for bending and deforming the bead apex rubber 63 is performed.

  Next, as shown in FIG. 1, the bead transfer 3 is moved in the axial direction X from the receiving position Q1 to the loading position Q2. As a result, a bead setting step S3 of carrying in the bead assembly 61 held by the bead set ring 18 to the setting position P of the carcass ply 60 on the drum 2 and joining it to the carcass ply 60 is performed.

  In this example, the drum 2 is a single-stage type tire forming former having a conventionally well-known structure. In this example, a pair of drum portions 2A and 2A are rotatably supported by the support shaft 7. The drum portions 2A and 2A can move toward and away from each other in the tire axial direction. As shown in FIG. 5, each drum portion 2A is composed of a drum portion 8 on the inner side in the tire axial direction and a drum portion 9 on the outer side.

  The inner drum portion 8 has a plurality of segments 8a that are circumferentially divided. Each segment 8a has a diameter-reduced state YA1 in which the carcass ply 60 is wound in a cylindrical shape, and a diameter-enlarged state YA2 in which the wound carcass ply 60 is stretched by the diameter-expanding/contracting means 10 having a known structure (see FIG. (Shown) and can move radially in and out.

  The outer drum part 9 comprises a ring-shaped bead lock 11 and winding means 12. The bead lock 11 has a plurality of segments 11a that are divided in the circumferential direction. Each segment 11a can be moved inward and outward in the radial direction between the diameter-reduced state YB1 (shown in FIG. 5) and the diameter-enlarged state YB2 (shown in FIGS. 6 and 7) by the diameter-expansion and expansion means 13 having a known structure. ..

  The bead lock 11 in the reduced diameter state YB1 and the inner drum portion 8 in the reduced diameter state YA1 have substantially the same diameter. In this state, the carcass ply 60 is wound in a cylindrical shape while straddling the bead locks 11 and 11. Thus, the carcass winding step S2 is performed.

  When the bead assembly 61 is carried into the set position P by the bead set ring 18, the bead lock 11 is expanded in diameter as shown in FIG. As a result, the carcass ply 60 can be pressed against the radially inner peripheral surface of the bead assembly 61 and joined to the carcass ply 60. That is, the bead setting step S3 is performed. After joining, the bead transfer 3 is returned to the receiving position Q1.

  Further, as shown in FIG. 7, after the bead setting step S3, the diameter of the inner drum portion 8 (segment 8a) is expanded, and the inner side surface of the bead assembly 61 is disposed on the inner drum portion 8 via the carcass ply 60. The outer drum portion 9 moves inward in the tire axial direction until it abuts the outer side surface of the tire. Then, in this state J, the carcass folding step (not shown) by the hoisting means 12 is performed.

  The winding means 12 has a turn-up bladder 12a in this example. In the non-expanded state YD1, the turn-up bladder 12a is folded into a cylindrical shape having substantially the same diameter as the inner drum portion 8. Further, the bead assembly 61 is a portion 60a of the carcass ply 60, which is expanded by the turn-up bladder 12a and is filled with compressed air, and protrudes outward from the bead assembly 61 in the axial direction of the tire (hereinafter sometimes referred to as an outer portion 60a). While being folded back around, the protruding portion 60a (outer portion 60a) is overlapped and joined to the tire axially inner portion 60b of the carcass ply 60.

  At this time, the bead apex rubber 63 is preliminarily bent and deformed inward in the tire axial direction by the deforming step S3a. Therefore, in the carcass folding step, the amount of bending of the bead apex rubber 63 can be reduced, and the occurrence of air accumulation can be suppressed.

  Although the particularly preferred embodiments of the present invention have been described above in detail, the present invention is not limited to the illustrated embodiments and can be modified into various modes.

1 Raw Tire Forming Device 2 Drum 3 Bead Transfer 5 Bead Supply Device 18 Bead Set Ring 18d Second Core Receiving Surface 18e Second Apex Receiving Surface 34 Bead Supply Ring 34a Seating Surface 34b First Core Receiving Surface 34c First Apex receiving surface 40, 41 Bending surface 42 Heater 60 Carcass ply 61 Bead assembly 62 Bead core 63 Bead apex rubber P set position S1 bead delivery step S1a deformation step S3 bead setting step

Claims (2)

A bead assembly in which a bead core and a bead apex rubber are integrally joined, and a bead delivery step of delivering a bead set ring of a bead transfer from a bead supply ring of a bead supply device,
By moving the bead transfer, the bead assembly held by the bead set ring is carried into a set position on the tire axially outer end side of a carcass ply wound on a drum for forming a raw tire, and Including a bead setting step of joining to
The bead supply ring has a seating surface for seating an inner peripheral surface of a bead core, a first core receiving surface for receiving an inner side surface of the bead core in the tire axial direction, and a first apex for receiving an inner side surface of the bead apex rubber in the tire axial direction. With a receiving surface,
Further, the bead set ring includes a second core receiving surface made of a magnet capable of adsorbing the tire axially outer side surface of the bead core, and a second apex receiving surface receiving the tire axially outer side surface of the bead apex rubber. With
The first and second apex receiving surfaces each include a bending surface that bends inward in the tire axial direction,
In the bead delivery step, when the bead assembly is delivered, the bead apex rubber is bent inward in the tire axial direction by sandwiching the bead apex rubber of the bead assembly between the first and second apex receiving surfaces. A method of manufacturing a raw tire, comprising a deforming step of deforming.   The method for manufacturing a raw tire according to claim 1, wherein at least one of the bead supply ring and the bead set ring includes a heater that heats and softens the bead apex rubber during delivery of the bead assembly. ..

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