JP2008246878A - Bead filler manufacturing apparatus and bead filler manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bead filler manufacturing apparatus capable of molding a bead filler not having a joined part causing the non-uniformity of wall thickness without taking time. <P>SOLUTION: The bead filler manufacturing apparatus includes an extruder or injection molding machine for discharging rubber 4, a lower mold 3 rotated so as to discharge and mold the rubber 4 into an annular shape, an upper mold 2 having a rotary shaft 5 crossing the rotary shaft 6 of the lower mold 3, and the molding space 9 constituted of recessed parts 7 and 8 respectively provided to the upper mold 2 and the lower mold 3 in an annular shape. The upper mold 2 is rotated at the same speed as the lower mold 3 and the rubber 4 adhered to the lower mold 3 is molded while held between the two molds 3 and 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a bead filler manufacturing apparatus and a bead filler manufacturing method.

  Generally, when manufacturing a pneumatic tire, each tire component such as an inner liner, sidewall, bead, and tread is bonded together in an unvulcanized state to form a green tire, which is used as a mold. It is manufactured by placing and vulcanizing.

  A bead is comprised from the bead wire which becomes a reinforcing material, and the bead filler which consists of a rubber whose cross section is a triangle. Conventionally, an annular bead filler is formed by extruding a band-shaped rubber having the above-mentioned cross-sectional shape from an extruder, winding it into a roll shape, cutting it into a certain length, and joining its end portions together. . However, in such a conventional method for forming a bead filler, since the ends of the cut rubber strips are joined to form an annular shape, the bead filler thus formed is thick at the joint, and is thick in the circumferential direction. There was a problem of non-uniformity. Such non-uniform thickness results in a decrease in tire uniformity.

  In order to solve such a problem, the following Patent Document 1 discloses that an unvulcanized linear rubber body is attached to a molding disk rotating about an axis while moving in a radial direction on the molding disk. A method of forming a bead filler by laminating a plurality of spiral linear rubber bodies is disclosed. According to this method, the molded bead filler has no thickened joints anywhere on the circumference, and there are no breaks in the members that occur at the beginning and end of the linear rubber body. Since the linear rubber body is thin, it hardly affects the thickness of the bead filler, so that the thickness of the bead filler can be made substantially uniform in the circumferential direction.

JP-A-11-105155

  However, since the method for producing a bead filler disclosed in Patent Document 1 is formed by laminating a plurality of layers of linear rubber bodies, it takes time to laminate them. There is also a problem that a gap is formed between the linear rubber bodies and air easily enters.

  The present invention has been made in view of the above circumstances, and the problem is that a bead filler manufacturing apparatus capable of forming a bead filler without a joint that causes uneven thickness without taking time, and It is to provide a bead filler manufacturing method.

In order to solve the above problems, the bead filler manufacturing apparatus according to the present invention is:
An extruder or an injection molding machine for discharging rubber;
A rotating lower mold in which the rubber is annularly molded;
An upper mold having a rotation axis that intersects the rotation axis of the lower mold;
A molding space constituted by a recess provided annularly in each of the upper mold and the lower mold,
The upper mold is rotated at the same speed as the lower mold, and the rubber attached to the lower mold is molded while being sandwiched between the lower mold.

  The operation and effect of the bead filler manufacturing apparatus having such a configuration will be described. By an extruder or an injection molding machine, rubber is discharged and molded so as to form an annular shape on the surface of the lower mold that rotates around the rotation axis. At this time, a recess is provided in an annular shape on the surface of the lower mold, and discharge molding is performed so that the rubber becomes annular along the recess. The upper mold has a rotation axis that intersects the rotation axis of the lower mold, and rotates around this rotation axis. The upper die surface is also provided with an annular recess. The upper die and the lower die are rotated at the same speed, and the rubber adhered to the lower die is sandwiched between the upper die recess and the lower die recess. While forming the bead filler. Therefore, unlike the prior art, it is not necessary to laminate and form a plurality of linear rubber bodies, and the bead filler can be formed in a short time. Moreover, since it shape | molds by inserting | pinching rubber | gum with the upper mold | type and lower mold | type which rotate, it can press down the edge parts of the rubber | gum which carried out one round and overlapped slightly, and a bead filler without a junction part can be shape | molded.

  In the bead filler manufacturing apparatus according to the present invention, it is preferable that the inclination of the upper mold rotating shaft and the lower mold rotating shaft is in the range of 1 to 60 °.

  Further, the inclination of the rotation axis of the upper mold and the rotation axis of the lower mold is configured to be in a range of 1 to 60 °, and thereby the respective annular recesses of the upper mold and the lower mold are brought into contact with each other in a pressed state. Therefore, the bead filler can be molded while sandwiching the rubber with a large force.

  Furthermore, it is preferable that the bead filler manufacturing apparatus according to the present invention is provided with an external space that is adjacent to the molding space and that discharges excess rubber during molding.

  The recesses provided in the upper mold and the lower mold respectively constitute a molding space so that the rubber has a desired cross-sectional shape with the upper mold and the lower mold being closed, and an external space adjacent to the molding space. Is configured. By configuring in this way, excess rubber protruding from the concave portion can be discharged to the external space while molding the rubber into a desired cross-sectional shape at the concave portion, so that a process such as removal of burrs is not required, and the time is short. The bead filler can be formed with.

In order to solve the above problems, the bead filler manufacturing method according to the present invention is:
A process of annularly molding the rubber discharged from the extruder or the injection molding machine into a rotating lower mold;
A process in which an upper mold having a rotation axis that intersects the rotation axis of the lower mold rotates at the same speed as the lower mold, thereby forming the rubber adhered to the lower mold while sandwiching between the lower mold and the lower mold; Consists of

  In the bead filler manufacturing method according to the present invention, it is preferable that the inclination of the upper mold rotating shaft and the lower mold rotating shaft is in the range of 1 to 60 °.

  The operations and effects of the bead filler manufacturing method with such a configuration are as described above, and by using the bead filler manufacturing method according to the present invention, a bead filler without a joint that causes uneven thickness can be obtained. It can be molded without taking time.

  Furthermore, in the bead filler manufacturing method according to the present invention, it is preferable that a bead wire is disposed in advance in the lower mold, and the bead filler and the bead wire are integrally formed. By arranging the bead wire in the lower mold in advance, the bead filler integrated with the bead wire can be molded without taking time.

<Configuration>
A bead filler manufacturing apparatus and a bead filler manufacturing method according to the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of a bead filler manufacturing apparatus. The bead filler manufacturing apparatus according to the present embodiment mainly includes a discharge port 1, an upper mold 2, and a lower mold 3 of an extruder or an injection molding machine. A cross-sectional view of the upper mold 2 and the lower mold 3 is shown in FIG.

  From the discharge port 1, unvulcanized rubber 4 plasticized by an unillustrated extruder or injection molding machine is discharged. The rotation axis 5 of the upper mold 2 and the rotation axis 6 of the lower mold 3 intersect each other, and the upper mold 2 is attached to a movable arm so that the inclination θ of the rotation axis can be adjusted to 1 to 60 °. . The lower die 3 can be moved up and down so that the completed bead filler 12 can be taken out from the lower die 3. The upper mold 2 and the lower mold 3 are rotated by a motor.

  As shown in FIG. 2, the upper mold 2 and the lower mold 3 are respectively provided with recesses 7 and 8 in an annular shape. The concave portions 7 and 8 face each other to form a molding space 9, and an external space 10 is adjacent to the molding space 9. The shape of the recesses 7 and 8 is configured such that the finished bead filler 12 has a cross-sectional shape with the recess 7 of the upper mold 2 and the recess 8 of the lower mold 3 closed.

<Operation>
The operation of the bead filler manufacturing apparatus and the bead filler manufacturing method according to the present invention will be described with reference to FIG.

  First, as shown in FIG. 3A, the bead wire 11 is previously annularly arranged at a position near the rotating shaft 6 of the recess 8 of the lower mold 3, and the rubber 4 is annularly formed along the recess 8 of the lower mold 3. Thus, the rubber 4 is discharged from the discharge port 1 while rotating the lower mold 3 around the rotation axis 6. In the present embodiment, the rubber 4 has a quadrangular cross-sectional shape, but may be any other shape, and can be arbitrarily set by changing the cross-sectional shape of the discharge port 1 through which the rubber 4 is discharged. Since the molding is performed while being pressed by the upper mold 2 and the lower mold 3 in the subsequent process, it is not necessary to discharge the rubber 4 accurately in the cross-sectional shape of the bead filler 12.

  Next, as shown in FIG. 3B, a recess 7 is also provided in an annular shape on the surface of the upper mold 2. The upper mold 2 and the lower mold 3 are rotated at the same speed, and the recess 8 of the lower mold 3 is rotated. The bead filler 12 is molded while sandwiching the rubber 4 that has been discharged and molded into the molding space 9. At this time, the molding space 9 composed of the recesses 7 and 8 is adjacent to the external space 10, and excess rubber that protrudes from the recesses 7 and 8 while the rubber 4 is molded into a desired cross-sectional shape by the recesses 7 and 8. 4 is discharged to the external space 10.

  This operation is performed until the cross-sectional shape of the rubber 4 reaches the desired cross-sectional shape of the bead filler 12 over the entire circumference as shown in FIG. In addition, since the bead wire 11 is previously arrange | positioned in the recessed part 8 of the lower mold | type 3, the bead filler 12 and the bead wire 11 are shape | molded integrally.

  Finally, as shown in FIG. 3D, the upper die 2 and the lower die 3 are pulled apart, and the completed bead filler 12 is taken out from the manufacturing apparatus and the process is completed.

  Therefore, it is not necessary to laminate and mold a plurality of linear rubber bodies as in the prior art, and the necessary rubber 4 can be discharged and molded only during at least one rotation of the lower mold 3, so that the bead can be formed in a short time. The filler 12 can be molded. Further, since the excess rubber 4 protruding from the molding space 9 can be discharged to the external space 10 while molding the rubber 4 into a desired cross-sectional shape in the molding space 9, a process such as removal of burrs is not required, and the time is short. Thus, the bead filler 12 can be formed.

  Furthermore, since the rubber 4 is sandwiched between the rotating upper mold 2 and the lower mold 3, the ends of the rubber 4 that have made a round and slightly overlapped can be pressed, and a bead filler 12 without a joint is molded. Can do.

Schematic configuration diagram of bead filler manufacturing equipment Cross section of upper and lower molds Diagram showing the operation of the bead filler manufacturing method

Explanation of symbols

1 Discharge port 2 Upper mold 3 Lower mold 4 Rubber 5 Upper mold rotating shaft 6 Lower mold rotating shaft 7 Upper mold recess 8 Lower mold recess 9 Molding space 10 External space 11 Bead wire 12 Bead filler

Claims (6)

An extruder or an injection molding machine for discharging rubber;
A rotating lower mold in which the rubber is annularly molded;
An upper mold having a rotation axis that intersects the rotation axis of the lower mold;
A molding space constituted by a recess provided annularly in each of the upper mold and the lower mold,
A bead filler manufacturing apparatus that rotates an upper mold at the same speed as the lower mold and molds the rubber adhered to the lower mold while being sandwiched between the lower mold and the lower mold.   The bead filler manufacturing apparatus according to claim 1, wherein the inclination of the rotation axis of the upper mold and the rotation axis of the lower mold is in a range of 1 to 60 °.   The bead filler manufacturing apparatus according to claim 1, wherein an external space is provided adjacent to the molding space for discharging excess rubber during molding. A process of annularly molding the rubber discharged from the extruder or the injection molding machine into a rotating lower mold;
A process in which an upper mold having a rotation axis that intersects the rotation axis of the lower mold rotates at the same speed as the lower mold, thereby forming the rubber adhered to the lower mold while sandwiching between the lower mold and the lower mold; The bead filler manufacturing method characterized by comprising.   The bead filler manufacturing method according to claim 4, wherein the inclination of the rotation axis of the upper mold and the rotation axis of the lower mold is in the range of 1 to 60 °.   The bead filler manufacturing method according to claim 4 or 5, wherein a bead wire is disposed in advance in the lower mold, and the bead filler and the bead wire are integrally formed.

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