JP5632715B2 - Raw cover molding equipment - Google Patents

Description

  The present invention relates to a raw cover molding apparatus capable of providing a bead core with high accuracy in a core method for molding a raw tire cover using a core.

  In recent years, as shown in FIG. 6, a method for manufacturing a pneumatic tire 1 (core method) using a core 11 having an outer peripheral surface 11 a approximate to the tire inner surface shape at the time of internal pressure filling has been proposed (core method). See Patent Document 1 below). In this type of manufacturing method, the inner cover 9, the carcass ply 6A, the bead wire 5a, the belt layer 7, the tread rubber 2G, the side wall rubber 3G, and the like are sequentially attached to the outer side of the core 11, thereby forming the raw cover 1a. Usually, the raw cover 1 a is vulcanized together with the core 11. This method has an advantage that the uniformity of the pneumatic tire is improved because the stretch acting on the carcass and the belt during vulcanization can be kept small.

JP 2006-160236 A

  By the way, in the above-described core method, both ends of the carcass ply 6A cannot be folded back. For this reason, on the bead core 5 of the raw cover 1a formed by the core method, the wire wound body 15 in which the bead wire 5a is spirally wound in the tire radial direction is arranged on both sides of the carcass ply 6A, and the carcass ply 6A. The structure which sandwiches is adopted. However, since such a bead core 5 is conventionally formed by spirally winding the bead wire 5a on the outer side of the inner liner 9 or the carcass ply 6A attached to the core 11, the molding accuracy is poor. In addition, there is a problem that positional deviation of the wire is likely to occur.

  The present invention has been devised in view of the above problems, and provides a raw cover molding apparatus capable of providing a bead core with a simple configuration and high accuracy in a core method using a core. The main purpose.

The invention according to claim 1 of the present invention is a raw cover molding device for molding a raw cover of a pneumatic tire, and a core having an outer surface capable of molding a lumen surface of the pneumatic tire; A wire wound body in which bead wires arranged on both outer sides of the outer surface of the core so as to face a bead forming surface for forming a bead portion and covered with unvulcanized rubber are spirally wound. Holding means for holding, and moving means capable of moving the holding means toward and away from the bead forming surface, the bead forming surface being smoothly outward in the tire axial direction toward the outer side in the tire radial direction. The holding means includes an outer ring that forms a winding surface of the bead wire that faces the bead forming surface and extends outward in the tire radial direction with an inclination along the bead forming surface . T And a ring inner constituting a support surface for supporting the innermost layer of the bead wire by projecting arranged and having core side ya radially inward movement, the outer ring, in the tire axial direction with respect to the inner ring The moving means is arranged such that the moving means moves the holding means composed of the inner ring and the outer ring in the tire axial direction, and the outer ring moves in the tire axial direction with respect to the inner ring. Second moving means for moving the inner ring to the inner side in the tire radial direction of an unvulcanized rubber member or cord member affixed to the bead molding surface. The holding means is moved to a position where it comes into contact, and the second moving means moves the outer ring toward the core with respect to the inner ring, and affixes the wire winding body to the bead molding surface. Unadded Wherein the by pressing the rubber member or code member is transferred to the core side.

  In the raw cover molding device of the present invention, a core having an outer surface capable of molding the inner cavity surface of a pneumatic tire, and both outer sides thereof facing a bead molding surface for molding a bead portion of the outer surface of the core. And holding means for holding a wire wound body in which a bead wire covered with unvulcanized rubber is spirally wound, and the holding means is moved toward and away from the bead molding surface. And moving means to obtain. Further, the bead molding surface smoothly inclines and extends outward in the tire axial direction toward the outer side in the tire radial direction.

  The holding means includes a winding surface of the bead wire facing the bead molding surface and extending outward in the tire radial direction with an inclination along the bead molding surface, and the bead molding surface from an inner end in the tire radial direction of the winding surface. And a support surface that supports the innermost bead wire by protruding to the side. Such a holding means can accurately wind and fix the bead wire in a spiral shape and can hold the shape. Further, the moving means pushes the wound body of the bead wire wound around the holding means against the unvulcanized rubber member or the cord member attached to the bead forming surface of the core so as to move toward the core side. Can be transferred. Therefore, the wire wound body wound with high precision is transferred to the core side as it is. Therefore, the bead core can be provided at an accurate position in addition to improving the forming accuracy of the bead core in the raw cover. And the outer surface of a wire winding body inclines along a bead molding surface. Therefore, when the wire wound body is transferred to the core side, the wire wound body can be pressed evenly, and the transfer is performed reliably.

It is a right half surface sectional view of the pneumatic tire obtained with the manufacturing device of the present invention. It is sectional drawing of the raw cover shaping | molding apparatus of this embodiment. It is a fragmentary perspective view of a raw cover molding apparatus. (A) thru | or (c) is sectional drawing explaining the process of shape | molding a raw cover. (A) And (c) is sectional drawing explaining the process following FIG. 4 which shape | molds a raw cover. It is a right half sectional view of the raw cover obtained by the core method.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a cross-sectional view of a pneumatic tire (hereinafter sometimes simply referred to as “tire”) 1 obtained by the raw cover molding apparatus 10 (shown in FIGS. 2 and 3) of the present embodiment. The pneumatic tire 1 includes a carcass 6 extending from the tread portion 2 through the sidewall portion 3 to the bead core 5 of the bead portion 4, and a belt layer 7 disposed on the outer side in the tire radial direction of the carcass 6 and inside the tread portion 2. And an inner liner 9 made of rubber that is arranged on the tire cavity surface of the carcass 6 and is excellent in air impermeability.

  The pneumatic tire 1 in FIG. 1 shows a normal state in which a normal rim (not shown) is assembled with a rim and filled with a normal internal pressure and is in an unloaded state.

  Here, the “regular rim” is a rim determined for each tire in the standard system including the standard on which the tire is based, for example, a standard rim for JATMA, “Design Rim” for TRA, For ETRTO, use “Measuring Rim”. In addition, “regular internal pressure” is the air pressure that each standard defines for each tire in the standard system including the standard on which the tire is based. The maximum air pressure for JATMA and the table “TIRE LOAD LIMITS AT for TRA” Maximum value described in “VARIOUS COLD INFLATION PRESSURES”, “INFLATION PRESSURE” for ETRTO, but 180 kPa for tires for passenger cars.

  The carcass 6 is composed of at least one carcass ply 6A having a carcass cord extending from the tread portion 2 through the sidewall portion 3 to the bead core 5 of the bead portion 4. In the carcass ply 6A, carcass cords made of, for example, organic fibers are arranged at an angle of, for example, 75 to 90 ° with respect to the tire equator C direction. The carcass ply 6 </ b> A of the present embodiment straddles between the bead portions 4, 4 in a toroidal shape, and end portions 6 e on both sides thereof are terminated in the bead core 5 without being folded back by the bead core 5.

  The belt layer 7 is composed of at least two belt plies 7A and 7B, in the present embodiment, in the tire radial direction, and in the outer two. Each of the belt plies 7A and 7B has a highly elastic belt cord such as a steel cord inclined at an angle of 15 to 40 ° with respect to the tire equator C. The belt plies 7A and 7B are overlapped so that the belt cords cross each other.

  In this embodiment, the bead core 5 includes an inner core piece 5i disposed on the inner side in the tire axial direction of the carcass ply 6A and an outer core piece 5o disposed on the outer side in the tire axial direction of the carcass ply 6A. Have. The end 6e of the carcass ply 6A is held between the inner and outer core pieces 5i and 5o. Further, in the present embodiment, chafer rubber 4g made of hard rubber is disposed in the region in contact with the rim (not shown) of the bead core 5 in the tire radial direction inner side and the outer core piece 5o in the tire axial direction outer side. Yes.

  The bead portion 4 includes inner and outer apexes 8i and 8o that taper from the inner side in the tire axial direction of the inner core piece 5i and from the outer side in the tire axial direction of the outer core piece 5o to the radially outer side of the tire, respectively. Is provided. Such apex 8i, 8o is useful for increasing the bending rigidity of the bead portion 4 and improving the steering stability.

  The pneumatic tire 1 configured as described above is manufactured by vulcanizing a raw cover 1a as shown in FIG.

  2 and 3 show an embodiment of a raw cover forming apparatus 10 for forming the raw cover 1a.

  The raw cover molding apparatus 10 of the present embodiment includes a core 11 having an outer surface 14 that can mold a lumen surface M (shown in FIG. 1) of a pneumatic tire 1, and a bead wire covered with unvulcanized rubber. 5a is configured to include a holding means 12 that holds the wire wound body 15 wound in a spiral shape, and a moving means 13 that can move the holding means 12.

  The core 11 of this embodiment is a pair of three-dimensional outer surfaces 14 that approximate the inner shape of a tire in a 5% internal pressure state, for example, and a bead-side end portion of the outer surface 14 that protrudes outward in the tire axial direction. The flange surface 26 is provided. The inner shape of the tire here is the inner shape of the tire 1 to be manufactured. The “5% internal pressure state” refers to a state in which the internal pressure is reduced from the normal state to an internal pressure of 5% of the normal internal pressure. Since the cross-sectional shape of the tire in the 5% internal pressure state is similar to the cross-sectional shape of the tire in the vulcanization mold, it is particularly effective for reducing the stretch, which is the elongation of the raw cover during vulcanization molding. is there. However, the outer surface 14 of the core is not necessarily limited to such a shape.

  The core 11 of this embodiment is an assembly type which becomes an annular body continuous in the tire circumferential direction by assembling a plurality of divided pieces (not shown) divided in the tire circumferential direction, for example. Thereby, after the raw cover 1a is formed outside the core 11 and vulcanized to obtain a vulcanized tire, the divided pieces can be disassembled and taken out from the tire in a predetermined order. The core 11 is preferably made of a metal material or heat resistant resin that can withstand heat and pressure during vulcanization.

  The core 11 of the present embodiment is assembled outside the wheel-shaped rim-shaped member J, and is held by the support shaft D via the rim-shaped member J. The rim-shaped member J can fix the core 11 on the rim portion Ja by being fitted to the rim portion Ja of the main body J1 having the rim portion Ja, the disk portion Jb and the bearing portion Jc, and the rim portion ja of the main body J1. And a ring piece J2. Therefore, the core 11 can be removed from the rim-shaped member J by removing the ring piece J2 from the main body J1.

  The support shaft D is supported in a cantilevered manner by a frame (not shown), for example, at one end side in the axial direction. Further, the support shaft D is supported so as to be rotationally driven by, for example, an electric motor.

  The outer surface 14 of the core 11 includes a tread molding surface 14a that molds the lumen surface of the tread portion 2 of the tire 1, a pair of sidewall molding surfaces 14b that mold the lumen surface of the sidewall portion 3, and a bead. And a pair of bead molding surfaces 14 c for molding the tire lumen surface of the portion 4.

The bead molding surface 14c is smoothly inclined from the bead toe point t toward the outer side in the tire radial direction toward the outer side in the tire axial direction , and is smoothly connected to the side wall portion molding surface 14b. In the present embodiment, the bead toe point t and the flange surface 26 are formed apart from each other.

  2 and 3, the holding means 12 is disposed on both outer sides in the axial direction so as to face the bead molding surface 14c. Each holding means 12 includes an annular outer ring 17 that forms a winding surface 16a of the bead wire 5a, and an annular inner ring 19 that is provided inside the outer ring 17 in the tire radial direction. In the present embodiment, the moving means 13 is connected to the inner ring 19 via the fixing portion 20.

  The outer ring 17 is formed in a ring shape having the same central axis as the central axis (tire rotation axis) n of the core 11. Further, the outer ring 17 includes an inner side extending in the tire axial direction from the winding surface 16a facing the core 11 side and the inner end 16a1 in the tire radial direction of the winding surface 16a in the cross section including the central axis. It includes an end face 16b and a rear end face 16c extending outward in the tire radial direction from the outer end 16b1 in the tire axial direction of the inner end face 16b.

The winding surface 16a is provided at a position facing the bead forming surface 14c and extends outward in the tire radial direction with an inclination along the bead forming surface 14c. That is, the winding surface 16a is inclined smoothly and outwardly in the tire axial direction toward the outer side in the tire radial direction.

  The inner ring 19 is also formed in a cylindrical shape having the same central axis as the central axis (tire rotation axis) n of the core 11. An outer ring 17 is mounted on the outer peripheral surface of the inner ring 19 so as to be slidable in the tire axial direction.

  In the present embodiment, the fixed portion 20 is integrally fixed to the outer end side of the inner ring 19 in the tire axial direction and extends inward and outward in the tire radial direction, and the radial direction of the disk portion 20a in the tire radial direction. Is formed of an annular body having a substantially L-shaped cross section including a cylindrical portion 20b extending from the inner edge to the outer side in the tire axial direction (the side opposite to the core 11). In the present embodiment, the support shaft D extends through the holding means 12 formed on one side (left side in FIG. 2) of the core 11 in the axial direction.

  As shown in FIGS. 2 and 3, the moving means 13 includes a first moving means 21 for moving the holding means 12 in the tire axial direction, and an outer ring 17 in the tire axial direction with respect to the inner ring 19. And a second moving means 22 to be moved.

  The first moving means 21 includes, for example, an actuator or an electric motor (both not shown) that moves the cylindrical portion 20b and the like in the tire axial direction. The second moving means 22 includes an actuator such as a cylinder. For example, the main body portion is fixed to the disk portion 20a, and a rod that expands and contracts is connected to the rear end surface 16c of the outer ring 17. By the second moving means 22, the outer ring 17 can move in the tire axial direction with respect to the inner ring 19.

  A method of manufacturing the raw cover 1a (shown in FIG. 6) using the raw cover forming apparatus 10 configured as described above will be described.

  First, as shown in FIG. 4A, the holding means 12 is positioned away from the core 11 as an initial state. The holding means 12 is positioned in a state where the inner ring 19 protrudes from the inner end 16a1 in the tire radial direction of the winding surface 16a of the outer ring 17 toward the core. For this reason, the holding means 12 supports the innermost layer bead wire by protruding from the winding surface 16a of the bead wire and the inner end 16a1 in the tire radial direction of the winding surface 16 toward the bead forming surface side of the core 11. A support surface 18 is formed.

  Next, in the present embodiment, the base 4ga of the chafer rubber 4g, the inner liner 9, and the inner apex 8i are attached.

  The base portion 4ga of the chafer rubber 4g has, for example, an elongated cross section, and is wound around the bead toe point t of the core 11 in a small length ring shape outward in the tire radial direction.

  Further, the inner liner 9 is formed by, for example, unvulcanized and ribbon-shaped rubber strip G from the outer side in the tire radial direction of the base portion 4ga with the side edge along the outer surface 14 of the core 11 and the circumferential direction thereof. It is formed by winding while shifting. For example, the rubber strip G preferably has a width W of about 5 to 35 mm and a thickness t of about 0.5 to 2.0 mm. Note that the winding is performed, for example, by fixing one end of the rubber strip G to the outer surface 14 of the core 11 and then rotating the core 11 via the support shaft D and preliminarily moving the rubber strip G along the outer surface of the core. It is performed by moving at a pitch of. As a result, as shown in FIG. 4A, the inner liner 9 made of the rubber strip G is formed on a part (for example, the entire region) of the outer surface 14 of the core body N.

  Further, the inner apex 8i is disposed on the inner side of the inner core piece 5i in the tire axial direction, and prevents the bead wire 5a of the core piece 5i from damaging the inner liner 9.

  Next, in this embodiment, the process of forming the inner core piece 5i on the outer side in the tire axial direction of the apex 8i in the bead molding surface 14c is performed.

  The process includes a step of forming the wire wound body 15 on the holding means 12. The wire wound body 15 is shown in FIG. 4B by rotating the holding means 12 after pressing and fixing a single bead wire 5a covered with a topping rubber on the support surface 18, for example. As described above, the bead wire 5a is spirally wound along the winding surface 16a. At this time, since the innermost bead wire 5a1 is supported by the support surface 18, the wire wound body 15 can be accurately formed in a ring shape. Further, since the winding surface 16a is inclined along the bead molding surface 14c, the wire winding body 15 with high accuracy can be easily formed simply by winding along the winding surface 16a.

  When the wire wound body 15 is formed on the winding surface 16, the holding means 12 is moved to the core 11 side by driving the first moving means 21 as shown in FIG. 4 (c). Let At this time, the holding means 12 is stopped, for example, at a position where the inner ring 19 comes into contact with the base portion 4ga of the chafer rubber 4g. During this movement, the wire wound body 15 is supported by the winding surface 16a and the support surface 18 of the holding means 12, and the shape thereof is maintained.

  Next, as shown in FIG. 5A, the second moving body tool 22 is driven to move the wire wound body 15 together with the outer ring 17 to the core side. Thereby, the wire wound body 15 is pressed by the apex 8i in the unvulcanized affixed to the bead molding surface 14c. And the wire wound body 15 is firmly affixed to the inside apex 8i using the adhesiveness of a mutual unvulcanized rubber.

  As shown in FIG. 5B, when the wire wound body 15 and the inner apex 8i (core 11 side) are sufficiently pressed, the rod of the second moving means 22 is contracted to Only the ring 17 is separated from the core 11. Thereby, the transfer to the core side of the wire wound body 15 is completed, and the inner core piece 5i is formed. Thereafter, the holding means 12 and the moving means 13 move to the initial state shown in FIG.

  Next, the carcass ply 6A is disposed on the outer side of the inner core piece 5i in the tire radial direction. In the step of arranging the carcass ply 6A, for example, a plurality of strip-shaped strip pieces (not shown) that are longer in the radial direction of the tire than the length in the tire circumferential direction are used to connect the outer surface 14 of the core 11 and the tire circumference. A three-dimensional carcass ply 6A is formed with high accuracy by being connected in the direction.

  Next, after the carcass is formed, a transfer process of the outer core piece 5o is performed. As shown in FIG. 5C, similarly to the transfer step of the inner core piece 5i, the wire wound body 15 formed and held in advance on the holding means 12 is moved by the moving means 13 so that the carcass 6 on the bead molding surface 14c. It is pressed and attached to the outside.

  As shown in FIG. 6, the sub-portion 4gb, the belt layer 7, the side wall rubber 3G, the tread rubber 2G, etc., which are connected to the outer apex 8o, the base 4ga of the chafer rubber 4g and form the bead outer surface, Each is pasted. In this way, the raw cover 1 a is formed on the outer surface 14 of the core 11.

  As mentioned above, although the 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. For example, the length of the support surface 18 in the tire axial direction is set to be slightly shorter than the diameter of the bead wire 5a. Thereby, when the inner ring 19 reaches the position where the inner ring 19 comes into contact with the base portion 4ga of the chafer rubber 4g by the movement of the first moving means 21, the wire wound body 15 is operated without operating the second moving means 22. Is transferred to the core 11 side. According to this embodiment, the second moving means 22 can be reduced.

DESCRIPTION OF SYMBOLS 1 Pneumatic tire 2 Tread part 4 Bead part 10 Raw cover shaping | molding apparatus 11 Core 12 Holding means 13 Moving means 14 Outer surface 14c of a core Bead forming surface 15 Wire wound body 16 Winding surface 18 Support surface M of a pneumatic tire Lumen surface

Claims (1)

A raw cover molding device for molding a raw cover of a pneumatic tire,
A core having an outer surface capable of forming a lumen surface of the pneumatic tire;
Holds a wire wound body in which bead wires arranged on both outer sides and coated with unvulcanized rubber are spirally wound in opposition to a bead forming surface for forming a bead portion of the outer surface of the core. Holding means to
Moving means capable of moving the holding means toward and away from the bead molding surface;
The bead molding surface smoothly inclines outward in the tire axial direction toward the outer side in the tire radial direction,
The holding means includes an outer ring that forms a winding surface of the bead wire that faces the bead forming surface and extends outward in the tire radial direction with an inclination along the bead forming surface, and an inner side in the tire radial direction of the outer ring. And an inner ring that constitutes a support surface that supports the innermost bead wire by projecting to the core side ,
The outer ring is arranged to be movable in the tire axial direction with respect to the inner ring,
The moving means includes: a first moving means for moving the holding means including the inner ring and the outer ring in the tire axial direction; and a second moving means for moving the outer ring in the tire axial direction with respect to the inner ring. And moving means,
The first moving means moves the holding means to a position where the inner ring comes into contact with the inner side in the tire radial direction of an unvulcanized rubber member or cord member attached to the bead molding surface,
The second moving means moves the outer ring to the core side with respect to the inner ring, and the wire wound body is unvulcanized rubber member or cord member attached to a bead molding surface. A raw cover molding apparatus, which is transferred to the core side by being pressed against the core.

Images