JP5576633B2 - Raw tire molding apparatus and method for manufacturing pneumatic tire - Google Patents

Description

  The present invention relates to an apparatus for rolling a case protruding from the bead core outward in the axial direction when molding a raw tire, and using a winding arm to press and join to a toroidal case main body. The present invention relates to a raw tire molding apparatus capable of reducing the undulation generated on the outer surface of a rolled-up case and improving the appearance and uniformity of a pneumatic tire, and a pneumatic tire manufacturing method using the same.

  When forming the raw tire, as shown in FIG. 11, a plurality of winding arms a spaced apart in the circumferential direction are used, and the case protruding from the bead core b outward in the axial direction is rolled up and expanded in a toroidal shape. A so-called mechanical winding method has been proposed in which the case body portion c2 is pressed and joined (see, for example, Patent Documents 1 and 2).

  The hoisting arm a used in this mechanical system has an axially inner end from a substantially horizontal reference state Y by pivotally supporting an axially rearward end on a slide cylinder d movable inward and outward in the axial direction. The arm main body a1 which can rise up radially toward the outer side in the radial direction and a pressing roller a2 pivotally attached to the inner end in the axial center direction are provided. As the slide cylinder d moves inward in the axial direction, each pressing roller a2 moves from the inside in the radial direction along the case main body portion c2, and the case protruding portion c1 can be wound up in the process. .

  Reference numeral e in the figure is an annular contraction band having rubber elasticity, and is wound around the plurality of winding arms a in the circumferential direction so that each winding arm a is attached radially inward. At the time of winding, the case protruding portion c1 is pressed against the case main body portion c2 to be joined, and each winding arm a is returned to the reference state Y after the winding is completed.

JP 2004-268371 A JP 2004-9298 A

  However, in the mechanical system, the pressing roller a2 strongly presses the case protruding portion c1 against the case main body portion c2 by the contraction band e. For this reason, as shown in FIG. 12, an uneven undulation such as a groove-shaped roller mark f is generated on the outer surface of the sidewall portion which is the outer surface of the case protruding portion c1 at the portion where the pressing roller a2 contacts. Occurs. This undulation has a problem that the appearance of the tire is deteriorated, the tire is unbalanced, and the uniformity is lowered.

  The undulation can be reduced by reducing the tightening force of the contraction band e and weakening the pressing force by the pressing roller a2. However, in such a case, since the force for returning the winding arm a to the reference state Y also decreases at the same time, as shown in FIG. 13, the winding arm ai located below the axis of the support shaft g hangs down by its own weight as shown in FIG. For example, the winding arm a cannot be held in the reference state Y. As a result, there is a limit to reducing the tightening force of the contraction band e, such that the next cylindrical tire case cannot be mounted on the shaping drum.

  In view of this, the present invention provides a shaping of a cylindrical tire case based on the provision of a contact ring that comes into contact with the hoisting arm by the relative movement of the slide cylinder in the axial direction and returns each hoisting arm to the reference state. The tightening force of the shrink band can be sufficiently reduced while securing the mounting property to the drum, reducing the undulation caused by the pressing roller generated on the outer surface of the side wall, and improving the appearance and uniformity of the pneumatic tire. An object of the present invention is to provide a raw tire molding apparatus and a method for producing a pneumatic tire using the same.

In order to solve the above-mentioned problems, the invention of claim 1 of the present application holds a cylindrical tire case including a carcass and a side wall rubber, and a case main body portion between bead cores arranged on both sides in the axial center direction. Is a raw tire molding apparatus including a shaping drum that expands a case protruding outside the bead core in an axial direction outside the bead core,
The shaping drum has a pair of drum portions each having a cylindrical support tube that can move relative to and away from the same axis, and the cylindrical tire straddles the pair of drum portions. Hold the case concentrically ,
Each of the drum portions is connected to the support cylinder,
A bead lock means capable of expanding and reducing the diameter and holding the bead core externally inserted into the tire case by the expansion;
The bead lock means is disposed on the outer side in the axial center direction, and is provided with hoisting means for hoisting the case protruding part around the bead core and pressing and joining the toroidal case main body part ,
The winding means is
A slide cylinder that is extrapolated to the support cylinder and is movable relative to the support cylinder in and out of the axial direction;
An approximately L comprising a rising portion that is pivotally supported by the slide cylinder at a pivot point Q and rises radially outward from the pivot point Q, and an arm main body that extends axially inward from the radially outer end of the rising portion. An arm body that is shaped like a letter and can be raised radially from the reference state in which the arm body main part is substantially horizontal centered on the pivot point radially outward in the axial direction, and the arm body main A plurality of hoisting arms having a pressing roller pivotally attached to an inner end in the axial direction of the section are spaced apart in the circumferential direction, and each pressing roller is moved by the relative movement inward in the axial direction of the slide cylinder. A winding arm group that moves from the inside to the outside in the radial direction along the case main body portion to wind up the case protruding portion,
In addition, each winding arm is made of an annular body having rubber elasticity, and is wound in the circumferential direction so as to surround the winding arm group, so that each case arm can be urged radially inward. It has a shrink band that presses and joins the parts ,
A mounting bracket extending radially outward is fixed to the outer end of the support cylinder ,
While the mounting bracket has a receiving piece protruding inward in the axial direction,
Abutting rings that abut against the rising portion by relative movement outward in the axial direction of the slide cylinder and return the hoisting arms to the reference state ;
The abutting ring has an inner circumferential surface in the radial direction supported by the receiving piece, and is fixed to the mounting bracket by a bolt that is screwed inwardly in the axial direction from the outer surface in the axial center direction. It is characterized by that.

  According to a second aspect of the present invention, the winding arm group includes a first winding arm having a large axial length and a second winding arm having a small axial length. The second winding arms are alternately arranged in the circumferential direction.

  The invention according to claim 3 is an invention of a method for manufacturing a pneumatic tire, and includes a step of winding up a protruding portion of the tire case using the winding means of the raw tire forming apparatus according to claim 1 or 2. It is a feature.

  As described above, according to the present invention, a support ring that holds a slide cylinder so as to be relatively movable in the axial direction is contacted with a rising portion of each winding arm by relative movement of the slide cylinder in the axial direction outside. Is provided. The abutment ring abuts against the rising portion, so that a moment in a return direction around the pivot point Q can be applied to the winding arm, and each of the winding arms can be returned to the reference state. Therefore, even when the tightening force of the contraction band is sufficiently reduced, the hoisting arm can be returned to the standard state after the hoisting is finished and the mounting property of the cylindrical tire case to the shaping drum can be ensured. . In addition, since the undulation caused by the pressing roller generated on the outer surface of the sidewall portion can be reduced by reducing the tightening force of the contraction band, it is possible to improve the appearance and uniformity of the pneumatic tire.

1 is a side view conceptually showing an example of a raw tire molding line in which a raw tire molding apparatus of the present invention is adopted. It is sectional drawing which shows a shaping drum. It is a side view explaining the drive device of a shaping drum. It is sectional drawing which expands and shows a drum part. It is sectional drawing which expands and shows a bead lock means further. (A), (B) is sectional drawing which shows a bead lock process and a shaping process. It is a perspective view which shows arrangement | positioning of a winding arm. (A), (B) is sectional drawing which shows the contact state of an arm main body and a contact ring. It is sectional drawing which shows a winding process. It is the side view seen from the axial direction outer side which shows a motion of a pressing roller. It is sectional drawing explaining the winding method of a mechanical system. It is a perspective view explaining the problem in a mechanical system. It is sectional drawing explaining the further problem in a mechanical system.

  Hereinafter, embodiments of the present invention will be described in detail. FIG. 1 is a side view conceptually showing an example of a raw tire molding line in which the raw tire molding apparatus of the present invention is employed.

  In FIG. 1, a raw tire molding apparatus 1 according to the present embodiment holds a cylindrical tire case 2 including a carcass and sidewall rubber, and is a case between bead cores 50 and 50 arranged on both sides in the axial direction. The main body portion 2A is inflated in a toroidal shape, and includes a shaping drum 3 that winds up the case protruding portion 2B that is axially outer than the bead core 50.

  Reference numeral 5 in FIG. 1 is a so-called belt drum. For example, a tread reinforcing cord such as a belt ply and a band ply, and a tread constituent member including a tread rubber are sequentially wound on the outer peripheral surface of the belt drum 5. By doing so, an annular tread ring 6 is formed. Reference numeral 7 denotes a so-called band drum. In this example, a cylindrical tire is formed by sequentially winding tire case constituent members including a carcass and sidewall rubber on the outer peripheral surface of the band drum 7. Case 2 is formed. In addition, as the tire case constituent member, an inner liner rubber, a bead reinforcing layer, a clinch rubber, and the like can be appropriately included depending on the tire structure.

  Reference numeral 8 denotes a tread transport device that receives the tread ring 6 formed on the belt drum 5 from the belt drum 5 and carries it to a standby position P1 radially outside the shaping drum 3. Reference numeral 9 denotes a tire case conveying device that receives the tire case 2 formed on the band drum 7 from the band drum 7 and transfers it onto the shaping drum 3.

  Next, as schematically shown in FIG. 2, the shaping drum 3 includes a pair of drum portions 10 and 10 that can move relative to each other on the same axis, and the cylindrical tire case 2 includes The pair of drum portions 10 and 10 are held concentrically across the pair. Each of the drum portions 10 has a bead lock means 11 that can be expanded and contracted and holds the bead core 50 that is externally inserted into the tire case 2 through the diameter expansion, and an axis of the bead lock means 11. Winding means 12 is disposed on the outer side in the direction and the case protruding portion 2B is wound around the bead core 50 and pressed against the case main body portion 2A expanded in a toroidal shape to be joined.

  Each of the drum portions 10 has a cylindrical support cylinder 14 that is externally held on the support shaft 13 of the shaping drum 3, and the bead lock means 11 and the winding means 12 are provided on the support cylinder 14. ing. In this example, the support cylinder 14 of the drum portion 10R on one side (for example, the right side of the drawing) is integrally fixed to the support shaft 13 via the fixing sleeve 15R, and the support cylinder of the drum portion 10L on the other side (for example, the left side of the drawing). 14 is attached to the support shaft 13 via a slide sleeve 15L so as to be movable in the axial direction and to be rotatable integrally with the support shaft 13.

  The support shaft 13 is rotationally driven by a first drive motor M1 as shown in FIG. In addition, the slide sleeve 15L which is externally attached to the support shaft 13 is connected to a moving means 16 using a ball screw mechanism in this example. The moving means 16 has a moving table 16b that is guided by the guide rail 16a and can move in the axial direction, and one end of the slide sleeve 15L is attached to the upper end of the moving table 16b via a bearing. The moving means 16 has a screw shaft 16c that is parallel to the guide rail 16a and is rotationally driven by the second drive motor M2, and this screw shaft 16c is screwed into a screw hole 16b1 provided in the moving table 16b. Accordingly, the rotation of the screw shaft 16c by the second drive motor M2 allows the other support cylinder 14 to be moved toward and away from the one support cylinder 14 via the movable table 16b and the slide sleeve 15L. That is, both the support cylinders 14 and 14 (that is, both the drum portions 10L and 10R) can be relatively moved toward and away from each other on the same axis, and by the rotation of the support shaft 13 by the first drive motor M1, Both supporting cylinders 14 and 14 (that is, both drum portions 10L and 10R) can be rotated in the same direction.

  As shown in FIGS. 4 and 5, the bead lock means 11 is provided between a pair of guide wall portions 17A and 17B rising from the support cylinder 14 at a right angle to the axial direction, and between the guide wall portions 17A and 17B. A plurality of bead lock segments 18 disposed. The bead lock segments 18 are radially arranged around the axis and guided by a guide portion (not shown) provided on the guide wall portions 17A and 17B so as to be movable inward and outward in the radial direction. In this example, a cylinder chamber 19 is provided in a space surrounded by the support cylinder 14, the guide wall portion 17 </ b> B on the outer side in the axial direction and the bead lock segment 18, and the cylinder chamber 19 is extrapolated to the support cylinder 14. Thus, a conical piston 20 that can move in the axial direction is arranged. And the conical surface of this piston 20 pushes up the slope 18a provided in the radial direction inner end of each bead lock segment 18, and can move each bead lock segment 18 to a radial direction outer side. Further, the bead core 50 extrapolated to the tire case 2 can be held via the tire case 2 by the outward movement in the radial direction, that is, the diameter expansion. A rubber seat 18b for stably seating the bead core 50 via the tire case 2 is attached to the radially outer end of the bead lock segment 18.

  In the tire case 2, a portion between the bead cores 50 and 50 is referred to as a case main body portion 2A, and a portion outside the bead core 50 in the axial direction is referred to as a case protruding portion 2B.

  In the shaping drum 3, as shown in FIGS. 6 (A) and 6 (B), the case main body portion 2A is expanded in a toroidal shape by filling the inside of the bead cores 50 and 50 while approaching each other. The bulging portion of the case main body portion 2A is pressed and joined to the inner peripheral surface of the tread ring 6 carried into the standby position P1. The hoisting means 12 is activated, and the case protruding portion 2B is wound around the bead core 50 and pressed against the toroidal case main body portion 2A.

  As shown in FIG. 4, the hoisting means 12 is inserted into the support cylinder 14 and is movable relative to the support cylinder 14 in and out of the axial direction. A winding arm group 22G composed of a plurality of winding arms 22 attached at intervals in the circumferential direction and extending in the axial direction, and an annular body having rubber elasticity, surrounding the winding arm group 22G and winding in the circumferential direction And the contraction band 23 to be formed.

  In this example, the slide cylinder 21 is inserted on the outer peripheral surface of the support cylinder 14 through an O-ring or other sealing material so as to be slidably movable in and out in the axial direction. A cylinder integrally including plate portions 21a and 21b and an outer cylindrical portion 21c that connects between the outer ends in the radial direction of the end plate portions 21a and 21b, and the end plate portions 21a and 21b and the outer cylindrical portion 21c A cylinder chamber 24 is formed between the support cylinder 14 and the support cylinder 14.

  The support cylinder 14 is integrally formed with a partition wall body 26 that rises from the outer peripheral surface and divides the cylinder chamber 24 into cylinder chambers 24a and 24b in the axial direction. Accordingly, by alternately supplying working air to the cylinder chambers 24a and 24b, the slide cylinder 21 is moved from the retracted position K1 (shown in FIGS. 4 and 6A) in the reference state Y to the advanced position K2 ( It can move inward and outward in the axial direction until it is shown in FIG.

  Next, as shown in FIG. 7, the plurality of winding arms 22 are attached to the ride cylinder 21 at a constant circumferential pitch. As shown in FIG. 4, each winding arm 22 extends in the axial direction through the radially inner side of the case protruding portion 2B, and the axially outer end side is pivotally supported by the slide cylinder 21 at the pivot point Q. It has a main body 27 and a pressing roller 28 pivotally attached to the axially inner end of the arm main body 27.

  As shown in FIGS. 8A and 8B, the arm body 27 has a rising portion 27a that rises radially outward from the pivot point Q, and a substantially L-shape from the radially outer end of the rising portion 27a. A substantially L-shaped arm main body 27b that is bent inward and extends inward in the axial direction along the outer peripheral surface of the slide cylinder 21. Then, the arm body 27 tilts around the pivot point Q from the reference state Y in which the arm body main portion 27b is substantially horizontal in a direction in which the inner end in the axial direction rises radially outward in the radial direction. sell.

  In the present example, the rising portion 27a includes an arc-shaped portion 27a1 centered on the pivot point Q and a rising main body 27a2 extending radially outward from the arc-shaped portion 27a1. The periphery of the arc-shaped portion 27a1 is pivotally supported at the pivot point Q by being held in an arc-shaped pivot hole 35H provided in the support member 35. The support member 35 has a ring shape extending in the circumferential direction, is fixed to the outer end plate portion 21b, and can be divided into inner and outer divided pieces 35a and 35b. By comprising in this way, the some winding arm 22 can be comprised simply and efficiently, and replacement | exchange operation | work can be made easy.

  In this example, the winding arm group 22G includes the first winding arm 22A having a large axial length and the second winding arm having a small axial length, as shown in FIG. The first and second winding arms 22A and 22B are alternately arranged in the circumferential direction. In this example, the pressing roller 28A pivotally attached to the first winding arm 22A is exemplified as having a larger diameter than the pressing roller 28B pivotally attached to the second winding arm 22B. It can also be made small diameter.

  In the first and second winding arms 22A and 22B, the length of the arm main body 27b is different from each other, and the position of the pivot point Q is the same. That is, each pivot point Q is arranged on one circumferential line around the axis of the support shaft 13. In addition, the difference L (shown in FIG. 5) of the length of the arm main body 27b between the first and second winding arms 22A and 22B is larger than the sum of the radius of the pressing roller 28A and the radius of the pressing roller 28B. Thus, the second winding arm 22B can be disposed so that the pressing roller 28B is kept on the outer side in the axial direction without colliding with the pressing roller 28A attached to the first winding arm 22A. .

  The contraction band 23 urges each winding arm 22 inward in the radial direction, and at the time of winding, the case protruding portion 2B is pressed against the case main body portion 2A to be joined. In this example, the first contraction band 23A is wound around the group of the first winding arms 22A in the circumferential direction, and the group is wound around the group of the second winding arms 22B in the circumferential direction. It consists of the second contraction band 23B. The first and second hoisting arms 22A and 22B are formed with mounting recesses 29A and 29B for holding the shrink bands 23A and 23B to be wound and preventing the positional displacement, respectively. The attachment recess 29B is formed radially inward of the first winding arm 22, thereby preventing the contraction band 23B from abutting against the first winding arm 22A.

  Here, in the reference state Y, as shown in FIG. 5, the pressing rollers 28A and 28B are placed on the horizontal holding surface S1 provided on the outer periphery of the outer guide wall portion 7B, and each arm main body main portion. 27b is regulated substantially horizontally. Further, as the slide cylinder 21 moves inward in the axial direction, the first and second winding arms 22A and 22B have their respective pressing rollers 28A and 28B ascend the cone-shaped slope S2 connected to the holding surface S1. At the same time, it rises in the direction of spreading radially while stretching the contraction band 23.

  At this time, as shown in FIG. 9, the pressing rollers 28A and 28B move from the inside in the radial direction along the case main body portion 2A to wind up the case protruding portion 2B, and the shrink band 23A, The case protruding portion 2B is pressed against the case body portion 2A and joined by the tightening force of 23B. In particular, in this example, as shown in FIG. 10 in which the movement of the pressing rollers 28A and 28B is viewed from the axial direction outside, the pressing rollers 28A and 28B are made to interfere with each other by using the long and short winding arms 22A and 22B. And more densely arranged. That is, the pressing unevenness can be reduced.

  When the slide cylinder 21 moves outward in the axial direction, the winding arms 22A and 22B are urged radially inward by the tightening force of the contraction bands 23A and 23B, so that the pressing rollers 28A and 28B pass through the slope S2. To return to the reference state Y.

  Next, it is desirable to reduce the tightening force of the contraction band 23 in order to suppress the concave groove-shaped roller marks (uneven undulation) generated on the outer surface of the tire by the pressing of the pressing roller 28. However, in such a case, the return force to the reference state Y also decreases, so that the lift arm 22 positioned below the axis of the support shaft 13 causes the return force to hang down under its own weight. There is a problem that it is impossible to return and hold the state Y. In this case, when the cylindrical tire case 2 formed by the band drum 7 (shown in FIG. 1) is transferred to the shaping drum 3, the hoisting arm 22 hangs down on the tire case 2 and is transferred. become unable.

  Therefore, in the winding means 12 of the present embodiment, as shown in FIGS. 7, 8 (A), (B), the rising of the rising cylinder 12 is caused by relative movement of the slide cylinder 21 outward in the axial direction. An abutment ring 36 that abuts the portion 27a and returns each of the hoisting arms 22 to the reference state Y is attached.

  The contact ring 36 is a rigid ring having a substantially rectangular cross section made of, for example, metal or synthetic resin, and is fixed to the support cylinder 14 via a mounting bracket 37. In this example, the mounting bracket 37 includes a first mounting plate 38 having a T-shaped cross section in which a radial flange 38b is raised on a base 38a that is bolted to the outer end of the support cylinder 14, and the It comprises a disk-like second mounting plate 39 that is bolted to the flange 38 b, and the contact ring 36 is bolted to the second mounting plate 39. The second mounting plate 39 has a receiving piece 39a protruding on the inner side surface in the axial center direction for receiving the inner peripheral surface of the contact ring 36 and stably supporting the contact ring 36.

  The contact ring 36 is formed with a screw hole 36H for screwing on the outer side surface in the axial direction, and is in contact with the rising portion 27a of each winding arm 22 on the inner side surface in the axial direction. A surface 36A is formed. The angle α formed with the outer peripheral surface of the abutting ring 36 is desirably an obtuse angle of 90 ° or more, preferably 95 ° or more, and more preferably 100 ° or more. And the deformation due to contact with the rising portion 27a can be prevented.

  Then, after the end of the winding, when the slide cylinder 21 relatively moves axially outward from the forward movement position K2 (shown in FIG. 9) and approaches the backward movement position K1, as shown in FIG. 8 (B), The rising portion 27 a of the winding arm 22 contacts the contact ring 36. By this contact, a moment M in the return direction around the pivot point Q is applied to the winding arm 22 and the opening angle β of the winding arm 22 with respect to the reference state Y is constrained. Then, as the retracted position K1 is approached, the opening angle β decreases, and at the retracted position K1, the opening angle β becomes 0 ° as shown in FIG. 8A, and the winding arm 22 is returned to the reference state Y. Can do.

  Therefore, even when the tightening force of the contraction band 23 is sufficiently reduced, the winding arm 22 can be smoothly returned to the reference state Y after the winding is completed, and the cylindrical tire case 2 is attached to the shaping drum 3. Sex can be secured. Moreover, the undulation by the pressing roller generated on the outer surface of the sidewall portion can be reduced by reducing the tightening force of the shrink band 23.

  The axially outer edge of the rising portion 27a has the same inclined portion 30 that has the same diameter inclination as the contact surface 36A in the reference state Y. Accordingly, the contact length La in the radial direction between the rising portion 27a and the contact surface 36A in the reference state Y can be increased, and the winding arm 22 can be stably held in the reference state Y. For this purpose, the contact length La is preferably 15 mm or more. The contact ring 36 is preferably made of nylon resin for smooth contact with the rising portion 27a and wear suppression.

  Next, the process (formation method of a raw tire) which forms a raw tire using the said raw tire shaping | molding apparatus 1 is demonstrated.

  First, as shown in FIG. 1, a band drum 7 is used as in the prior art, and tire case components including carcass and sidewall rubber are sequentially wound on the outer peripheral surface of the band drum 7 to form a cylinder. A tire case forming step for forming the tire case 2 is performed. In addition to the above, the tire case constituting member may be appropriately included depending on the tire structure, such as an inner liner rubber, a bead reinforcing layer, a clinch rubber, or the like. At the same time, in the belt drum 5, a tread reinforcing cord such as a belt ply and a band ply and a tread constituent member including a tread rubber are sequentially wound on the outer peripheral surface of the belt drum 5 to thereby form an annular tread. A tread ring forming step for forming the ring 6 is performed. Then, the tire case conveying device 9 is used to receive the cylindrical tire case 2 from the band drum 7 and transfer it to the shaping drum 3, and the tread conveying device 8 is used to connect the tread ring 6 to the belt drum. 5 is carried into a standby position P1 radially outside the shaping drum 3.

  Next, a pair of bead cores 50 are disposed on the radially outer side of the cylindrical tire case 2 held by the shaping drum 3 and at the position of the bead lock means 11, and the bead lock means 11 is operated, and FIG. As shown in FIG. 6 (A), a bead lock step of fixing the bead core 50 via the tire case 2 by expanding the bead lock segment 18 is performed. In this example, on the outer peripheral surface of the bead core 50, for example, a ring-shaped bead apex rubber 51 having a substantially crescent cross section is attached integrally in advance.

  Next, as shown in FIG. 6 (B), a shaping step is performed in which the case body portion 2A is expanded in a toroidal shape by filling the bead cores 50 and 50 with each other close to each other. At this time, a joining step is performed in which the bulging portion of the case main body portion 2A is pressed against and joined to the inner peripheral surface of the tread ring 6 previously carried into the standby position P1. Note that the joined tread ring 6 is pressed against the case body portion 2A using a stitch roller or the like so that both ends thereof are closely joined to the case body portion 2A.

  Next, using the winding means 12, a winding process for winding the case protruding portion 2B is performed. In this winding process, as shown in FIG. 9, each pressing roller 28 moves up the slope S2 and then has a radius along the case main body portion 2A by moving the slide cylinder 21 in the axial center direction. In this process, the case protruding portion 2B is rolled up and pressed against the case main body portion 2A.

  Then, after winding up the entire case protruding portion 2B, the winding arm 22 is returned to the reference state Y by moving the slide cylinder 21 outward in the axial direction. At this time, when the contraction band 23 having a weak tightening force is employed, the hoisting arm 22 is positioned below the axis of the support shaft 13 and the hoisting arm 22 is in the reference state Y such that the returning force is lost by its own weight. However, in the hoisting means 12 of the present embodiment, the abutment ring 36 that abuts the rising portion 27a is provided on the support cylinder 14, so that the hoisting arm 22 can be smoothly moved. The reference state Y can be returned.

  Then, the green tire formed by obtaining the winding process is then vulcanized in a mold to produce a pneumatic tire.

In addition, in this example, although the case where the cylindrical tire case 2 is formed on the band drum 7 is illustrated,
(1) Using the band drum 7, a semi-complete main tire case is formed by a part of a tire case constituent member such as a carcass or an inner liner rubber, and the semi-complete main tire case is formed into the shaping drum 3. After the transfer to, a cylindrical tire case is formed on the shaping drum 3 by sticking the remainder of the tire case components such as sidewall rubber, bead reinforcement layer, clinch rubber, etc. to the semi-finished main tire case. Complete 2: or
(2) Using the band drum 7, a semi-finished main tire case is formed by a part of a tire case constituent member such as a carcass or an inner liner rubber, and a sidewall rubber, a bead reinforcing layer, a clinch rubber, or the like, for example. A semi-finished sub-tire case consisting of the remainder of the tire case components is formed on the shaping drum 3 and the transferred semi-finished main tire case is combined with the sub-tire case, thereby forming the shaping drum 3. Complete the cylindrical tire case 2 above:
(3) The cylindrical tire case 2 can also be formed by winding each tire case constituent member on the shaping drum 3.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments illustrated, and it is needless to say that various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Raw tire shaping | molding apparatus 2 Tire case 2A Case main-body part 2B Case protrusion part 3 Shaping drum 10 Drum part 11 Bead lock means 12 Winding means 14 Support cylinder 21 Slide cylinder 22 Winding arm 22A 1st winding arm 22B 2nd winding arm 22G Winding arm group 23 Contraction band 27 Arm main body 27a Rising part 27b Main arm main part 28 Pressing roller 35 Contact ring 50 Bead core Y Reference state

Claims (3)

Holds a cylindrical tire case containing carcass and sidewall rubber, and expands the case body part between the bead cores arranged on both sides in the axial direction in a toroidal shape, and is axially outer than the bead core. A raw tire molding apparatus including a shaping drum that winds the protruding portion of the case,
The shaping drum has a pair of drum portions each having a cylindrical support tube that can move relative to and away from the same axis, and the cylindrical tire straddles the pair of drum portions. Hold the case concentrically ,
Each of the drum portions is connected to the support cylinder,
A bead lock means capable of expanding and reducing the diameter and holding the bead core externally inserted into the tire case by the expansion;
The bead lock means is disposed on the outer side in the axial center direction, and is provided with hoisting means for hoisting the case protruding part around the bead core and pressing and joining the toroidal case main body part ,
The winding means is
A slide cylinder that is extrapolated to the support cylinder and is movable relative to the support cylinder in and out of the axial direction;
An approximately L comprising a rising portion that is pivotally supported by the slide cylinder at a pivot point Q and rises radially outward from the pivot point Q, and an arm main body that extends axially inward from the radially outer end of the rising portion. An arm body that is shaped like a letter and can be raised radially from the reference state in which the arm body main part is substantially horizontal centered on the pivot point radially outward in the axial direction, and the arm body main A plurality of hoisting arms having a pressing roller pivotally attached to an inner end in the axial direction of the section are spaced apart in the circumferential direction, and each pressing roller is moved by the relative movement inward in the axial direction of the slide cylinder. A winding arm group that moves from the inside to the outside in the radial direction along the case main body portion to wind up the case protruding portion,
In addition, each winding arm is made of an annular body having rubber elasticity, and is wound in the circumferential direction so as to surround the winding arm group, so that each case arm can be urged radially inward. It has a shrink band that presses and joins the parts ,
A mounting bracket extending radially outward is fixed to the outer end of the support cylinder ,
While the mounting bracket has a receiving piece protruding inward in the axial direction,
Abutting rings that abut against the rising portion by relative movement outward in the axial direction of the slide cylinder and return the hoisting arms to the reference state ;
The abutting ring has an inner circumferential surface in the radial direction supported by the receiving piece, and is fixed to the mounting bracket by a bolt that is screwed inwardly in the axial direction from the outer surface in the axial center direction. A raw tire molding apparatus characterized by the above.   The hoisting arm group includes a first hoisting arm having a large axial length and a second hoisting arm having a small axial length, and the first and second hoisting arms are circumferential. The raw tire forming apparatus according to claim 1, wherein the raw tire forming apparatus is alternately arranged in a direction. A method for manufacturing a pneumatic tire, comprising the step of winding up the protruding portion of the tire case using the winding means of the green tire molding apparatus according to claim 1.

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