JP4010611B2 - Molding method of bead filler - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
This invention relates to molding how to mold a bead filler chromatography (annular member).
[0002]
[Prior art]
Conventionally, a bead filler made of unvulcanized rubber , for example, used in the manufacture of pneumatic tires, extrudes a thin band-shaped rubber from the die of the extruder toward one side in the width direction, and then the band-shaped rubber Is then wound into a roll, and then the belt-like rubber is unwound from the roll and supplied to the outside in the radial direction of the bead core so that the other end in the width direction, which is the thick wall side, is in close contact with the outer peripheral surface of the bead core. The bead core is cut by approximately one circumference, and then the start and end of the cut rubber piece are butt-joined to form.
[0003]
[Problems to be solved by the invention]
However, in such conventional forming shape how the excised beginning of rubber pieces, since the annular by butt joining the end to each other, shaped bi Dofira chromatography on circumferential one place, namely There is a problem that the thickness is increased at the joint, and as a result, the thickness becomes uneven in the circumferential direction. Further, when shaping the strip-shaped rubber by extrusion as described above, although the thickness of the strip rubber is changed slightly by a longitudinal position, the remainder such changes in its or Mabi Dofira over a wall thickness in the circumferential direction not There is also a problem that it becomes uniform. If the bead filler having a non-uniform thickness in the circumferential direction as described above is used for manufacturing a pneumatic tire, the uniformity of the pneumatic tire is reduced. Furthermore, when deforming the bi Dofira over from a substantially cylindrical to a final shape of substantially frustoconical, since the radially outer portion of the 該Bi Dofira chromatography (one widthwise side portion of the rubber strip) is stretched significantly, initial There is also a problem that the shape becomes unstable when trying to return to a substantially cylindrical shape.
[0004]
The present invention, wall thickness substantially uniform in the circumferential direction, moreover, an object of the invention to provide a molded how that can be easily molded to geometrically stable and annular member.
[0005]
[Means for Solving the Problems]
The purpose of this is to form a linear rubber made of unvulcanized rubber at the end face when a molding disk having a conical surface inclined downward toward the outside in the radial direction is rotating about its axis. by the body attaching and supplies while moving in a radial direction to the attachment surface, the molding of the bead filler so as to mold a bead filler linear rubber body in which a spiral to said attachment surface with a plurality of layers stacked In the method, it can be achieved by a bead filler molding method in which a linear rubber body immediately after being injected from an injection molding machine that injects unvulcanized rubber into a continuous linear shape is supplied to the adhesion surface .
[0006]
The linear rubber body is supplied to the molding disk by the supplying means while rotating the molding disk around the axis, and the linear rubber body is adhered to the adhesion surface. At this time, the linear rubber body is moved in the radial direction by the supply means, and the linear rubber body adhered to the adhesion surface is formed into a spiral shape, and such a spiral linear rubber body is formed on the adhesion surface. A plurality of layers are laminated to form an annular member. Here, in the annular member formed in this way, the thickened joint portion does not exist anywhere on the circumference, and the members generated at the beginning and end of the linear rubber body are interrupted. Since the linear rubber body is thin, it hardly affects the thickness of the annular member, and thereby the thickness of the annular member can be made substantially uniform in the circumferential direction. In addition, even if the thickness, thickness, etc. of the linear rubber body supplied to the molding disk changes slightly depending on the position in the longitudinal direction, the linear rubber body is wound around the molding disk many times, so such a change is Dispersed in the circumferential direction and averaged, whereby the thickness of the molded annular member becomes substantially uniform in the circumferential direction. For this reason, the bi Dofira over this when used in the manufacture of a pneumatic tire, it is possible to improve the uniformity of the pneumatic tire. Furthermore, because of the so with the linear rubber body is attached to the spiral on the end face of the molded disc (attachment surface) for molding the bi Dofira chromatography, 該Bi Dofira over becomes a flange-like approximate to the final shape, the result It is stable in shape and easy to handle.
[0007]
In addition , it is possible to reduce the change in weight (thickness, thickness, etc.) in the longitudinal direction in the linear rubber body, and to make the amount of rubber injected in one shot uniform, thereby The wall thickness can be made uniform. In addition, since the linear rubber body having a high temperature immediately after the injection molding is supplied to the adhesion surface, the adhesion is strong and the adhesion is ensured.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
In FIGS. 1 and 2, reference numeral 11 denotes a support case, and a rotary shaft 12 extending in the vertical direction is rotatably supported by the support case 11, and a horizontal disk-shaped support plate 13 is provided at the upper end of the rotary shaft 12. Is fixed. A molding disk 14 having a substantially ring shape coaxial with the rotary shaft 12 is fixed to the support plate 13, and the molding disk 14 has an adhesion surface 15 on the upper end surface. Then, the attachment surface 15, and has a shape which approximates to one side of the bead filler over to be described later to a final shape, slightly inclined shape downward toward the radially outward here, i.e. a conical surface. Thereby, the shape of the bead filler at the end of molding becomes substantially the same as the final shape, and as a result, the deformation amount when the bead filler is deformed to the final shape is reduced and the shape is stabilized. Reference numeral 16 denotes a bead chuck supported at the radially inner end of the molding disk 14. The bead chuck 16 is composed of a plurality of arc-shaped chuck segments 17 movable in the radial direction, and has a cylindrical shape as a whole. Yes. The bead chuck 16 grips the bead core 18 placed on the inner end in the radial direction of the molding disk 14 from the inner side in the radial direction while the chuck segment 17 moves in the radial direction synchronously. . 19 is a servo motor as a rotating means built in the support case 11, the rotation of the output shaft 20 of this servo motor 19 is transmitted to the rotating shaft 12 via a belt or the like (not shown), the rotating shaft 12, The support plate 13, the molding disk 14, and the bead chuck 16 are integrally rotated around the axis (rotary shaft 12).
[0009]
Reference numeral 25 denotes a flat base installed on the side of the support case 11. On the base 25, a pair of horizontal guide rails 26 extending in parallel to a plane including the axis of the molding disk 14 are laid. Reference numeral 27 denotes a movable base installed immediately above the base 25. The movable base 27 is slidably supported on the base 25 via a plurality of slide bearings 28 attached to the lower surface and the guide rail 26. . As a result, the movable base 27 can be moved along the guide rail 26 by the operation of a servo motor (not shown). A lift table 29 is supported on the movable table 27 so as to be movable up and down, and the lift table 29 is moved up and down by the operation of a servo motor (not shown). The operation of the servo motors that drive the servo motor 19, the movable base 27, and the lifting base 29 is controlled by control means (not shown).
[0010]
An injection molding machine 30 as supply means is attached to the upper surface of the elevator 29, and this injection molding machine 30 extends in a direction orthogonal to the guide rail 26. The injection molding machine 30 injects unvulcanized rubber supplied to the heating cylinder 32 through the hopper 31 from a nozzle 33 with a plunger (not shown), and forms a continuous high-temperature linear rubber body 34. The linear rubber body 34 immediately after the injection is supplied to the adhesion surface 15 of the molding disk 14 and pressed and adhered. At this time, when the movable table 27 is moved along the guide rail 26 together with the lifting platform 29 and the injection molding machine 30, the nozzle 33 moves in the radial direction along the normal line directly above the adhesion surface 15, and as a result, the adhesion The linear rubber body 34 attached to the surface 15 has a spiral shape. Further, as described above, the attachment surface 15 of the molding disk 14 is slightly inclined downward toward the outer side in the radial direction, but when the linear rubber body 34 is attached to the attachment surface 15, the lifting platform is adjusted according to the inclination. 29. The injection molding machine 30 is moved up and down so that the linear rubber body 34 is always adhered to the adhesion surface 15. In this embodiment, the cross section of the linear rubber body 34 is a quadrangular prism, but it may be a square plate, a polygonal column, or a cylinder. If the linear rubber body 34 supplied to the molding disk 14 is molded by the injection molding machine 30 as described above, the longitudinal weight (thickness, thickness, etc.) of the linear rubber body 34 changes. Since the amount of rubber injected in one shot can be made uniform, the thickness of the bead filler described later can be made uniform in the circumferential direction. . In addition, if the linear rubber body 34 having a high temperature immediately after being injected from the injection molding machine 30 is supplied to the adhesion surface 15 for adhesion, the adhesion is strong and the adhesion is ensured.
[0011]
Next, the operation of the first embodiment of the present invention will be described.
First, the bead core 18 is supplied to the molding disk 14 and placed on the radially inner end thereof, and then the chuck segment 17 of the bead chuck 16 is synchronously moved radially outward. Gripping from the inside in the radial direction while centering. Next, the servo motor is operated to move the movable base 27 and the lift base 29, and the nozzle 33 is moved to the vicinity of the intersection between the outer peripheral surface of the bead core 18 and the attachment surface 15 of the forming disk 14. Next, the molding motor 14 is rotated around the axis by the servo motor 19 and the injection molding machine 30 is operated to inject the unvulcanized rubber from the nozzle 33 into a continuous linear shape. The body 34 is supplied to the attachment surface 15 to be adhered (attached). At this time, the movable base 27 is moved along the guide rail 26 by a servo motor, so that the nozzle 33 and the linear rubber body 34 are radially equal to the width of the linear rubber body 34 per rotation of the molding disk 14. The linear rubber body 34 attached to the attachment surface 15 is spirally moved to the outside. At this time, the adhering surface 15 of the molding disk 14 is slightly inclined downward toward the outer side in the radial direction. Therefore, the elevator 29 and the injection molding machine 30 are lowered by the servo motor, and the linear rubber body 34 is Always adhere to the adhesion surface 15. Here, as the attachment position of the linear rubber body 34 to the attachment surface 15 is displaced outward in the radial direction, the length of one circumference of the linear rubber body 34 becomes longer. Accordingly, the control means rotates the molding disk 14 correspondingly. The speed is gradually decreased or the molding speed of the linear rubber body 34 is gradually increased so that the linear rubber body 34 having the same cross-sectional shape is always attached to the molding disk 14. When the spiral rubber line 34 in the first layer is attached to the molding disk 14 in this way, the injection molding machine 30 is moved by the servo motor, and the nozzle 33 is moved from the outer peripheral surface of the bead core 18 to the first surface. It is moved to the vicinity of the intersection with the linear rubber body 34 of the layer. Thereafter, the linear rubber body 34 is injected from the nozzle 33 of the injection molding machine 30 while rotating the molding disk 14 in the same manner as described above, and the second layer linear shape is formed on the first layer linear rubber body 34. The rubber body 34 is laminated. When a plurality of layers of the linear rubber body 34 are laminated on the attachment surface 15 as shown in FIG. 2, the inner end in the radial direction is attached to the bead core 18 and gradually increases toward the outer side in the radial direction. wall thickness becomes thinner cross section bi Dofira 35 of a predetermined shape is formed.
[0012]
Here, in the bead filler 35 molded in this way, the thickened joint portion does not exist anywhere on the circumference, and the members generated at the beginning and end of the linear rubber body 34 Since the linear rubber body 34 is thin, the discontinuity hardly affects the thickness of the bead filler 35, and thereby the thickness of the bead filler 35 becomes substantially uniform in the circumferential direction. Further, even if the thickness, thickness, etc. of the linear rubber body 34 supplied to the molding disk 14 slightly change depending on the position in the longitudinal direction, the linear rubber body 34 is wound around the molding disk 14 many times. Such changes in thickness and the like are dispersed and averaged in the circumferential direction, whereby the thickness of the molded bead filler 35 becomes substantially uniform in the circumferential direction. For this reason, when this bead filler 35 is used for manufacturing a pneumatic tire, the uniformity of the pneumatic tire can be improved. Furthermore, since the bead filler 35 is formed by adhering the linear rubber body 34 spirally to the end surface (attachment surface 15) of the molding disk 14, the bead filler 35 has a bowl shape approximating the final shape. As a result, it is stable in shape and easy to handle.
[0013]
FIG. 3 is a diagram showing a second embodiment of the present invention. In this embodiment, the linear rubber body 37 attached to the radially inner portion of the molding disk 14 is composed of a certain type (for example, high hardness) of unvulcanized rubber, while being attached to the radially outer portion. The linear rubber body 38 is made of unvulcanized rubber of different types (for example, low in hardness). As a result, the molded bead filler 39 is composed of two types of rubber with the central portion in the radial direction as the boundary 40. And when molding such a bead filler 39, it is preferable to install another injection molding machine in order to inject two types of linear rubber bodies 37 and 38. In addition, when comprising a bead filler from three types of rubber, it is good to provide three injection molding machines.
[0014]
In the above-described embodiment, the linear rubber body 34 is spirally attached to the outer side in the radial direction on the molding disk 14, but in the present invention, the inner side in the radial direction, or You may make it adhere, repeating a radial direction outer side and an inner side alternately. In the embodiment described before mentioned, but were allowed to attach to supply linear rubber body 34 immediately after being injected from the injection molding machine 30 in the molded disc 14, in the present invention, an injection molding machine, extrusion A linear rubber body molded by a machine or the like may be temporarily wound on a roll, and may be unwound from the roll and attached to a molding disk as necessary.
[0015]
【The invention's effect】
As described above, according to the present invention, an annular member having a substantially uniform thickness in the circumferential direction and having a stable shape can be easily formed.
[Brief description of the drawings]
FIG. 1 is a partially broken overall perspective view showing a first embodiment of the present invention.
2 is a cross-sectional view taken along arrows II in FIG.
FIG. 3 is a cross-sectional view similar to FIG. 2, showing a second embodiment of the present invention.
[Explanation of symbols]
14 ... Molding disk 15 ... Adhesion surface
30 ... Supply means 34 ... Linear rubber body
35 ... annular member

Claims (2)

A linear rubber body made of unvulcanized rubber is formed on the adhering surface when a molding disk having an adhering surface that exhibits a conical surface inclined downward toward the outer side in the radial direction is rotating around the axis. In the method of forming a bead filler in which a plurality of layers of spiral-shaped linear rubber bodies are laminated on the attachment surface to form a bead filler by supplying and adhering while moving in the radial direction, unvulcanized A method for molding a bead filler, characterized in that a linear rubber body immediately after being injected from an injection molding machine that injects rubber into a continuous linear shape is supplied to an adhesion surface . After the bead core placed on the radially inner end of the molding disk is gripped from the radially inner side while being centered by the bead chuck supported on the radially inner end of the molding disk, the molding disk is attached. method of forming a bead filler of claim 1 Symbol placement were allowed to attach to supply linear rubber body surface.

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