JP2009061691A - Method of manufacturing annular rubber member and apparatus for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an annular rubber member, in which an extruded belt-like rubber member is bent in a state of small residual stress and the curvature is freely changed, and an apparatus for manufacturing the same. <P>SOLUTION: In the method of manufacturing the annular rubber member provided with a step for extruding a rubber through a mouth ring 15 belt-like by extruders 20 and 30 and laminating and pasting the end parts of the belt-like rubbers to each other to form into an annular shape, the extruded belt-like rubber 1b is bent by making the rubber flow rate in an outer peripheral side flow passage 12o larger than that in the inner peripheral part 12i using a mouth ring 15 having the opening 11 shaped to correspond to the cross-sectional shape of the belt-like rubber 1b, an outer periphery side flow passage 12o to feed the rubber to the outer peripheral part 11o of the opening 11 and an inner periphery side flow passage 12i to feed the rubber to the inner peripheral part 11i of the opening 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an annular rubber member typified by a bead filler as a tire constituent member, and a manufacturing apparatus therefor.

  As shown in FIG. 4, the tire is configured by combining various rubber members such as a sidewall rubber 2, a tread rubber 3, a carcass ply 4, and an inner liner rubber 5. The bead member 10 is disposed in each of the pair of bead portions 1, and the end portion in the width direction of the carcass ply 4 is wound back so as to sandwich the bead portion 10. As shown in FIG. 5, the bead member 10 has an annular bead filler 1b made of hard rubber having a triangular cross section and a bead core 1a made of a convergent body such as a rubber-coated steel wire.

  For example, as shown in FIG. 6, the bead member 10 supplies the bead filler 1 b extruded in a band shape by the extruder 81 via the base 82 to the bead core 1 a formed in an annular shape in advance, and is placed on the inner periphery of the bead filler 1 b. It is manufactured by bonding the bead core 1a (see Patent Document 1 below). The bead core 1a is supported so as to be rotatable in the r direction, and the rotation speed is controlled so as to correspond to the extrusion speed of the bead filler 1b. The bead filler 1b is cut into a predetermined length, and then the ends thereof are bonded together to form an annular shape.

  However, when the belt-shaped bead filler 1b is formed into an annular shape as described above, a circumferential tensile stress acts on the outer peripheral portion of the bead filler 1b due to the difference between the inner and outer peripheries thereof, and thus the bead filler 1b becomes the bead core 1a. It may be deformed in the opposite direction (X direction) and hinder the pasting of the ends. In particular, in the case of the bead filler 1b, since the outer peripheral portion is thin, the rubber flow in the outer peripheral portion tends to be worse than the inner peripheral portion in the rubber flow path inside the base 82, and the above-described problems are remarkable. there were.

Patent Document 2 listed below describes a method in which a die having a curvature matching the curvature of a bead filler is used, and rubber is molded into an annular shape along the die. However, in this method, tensile or compressive stress remains in the bead filler, which may cause deformation after molding. Further, when changing the size of the bead filler, another die having a curvature corresponding to the size must be used.
JP-A-6-297603 JP 2004-17400 A

  The present invention has been made in view of the above circumstances, and an object thereof is to form an annular rubber member that can bend the extruded belt-like rubber with a small residual stress and can freely change its curvature. And a manufacturing apparatus thereof.

  The above object can be achieved by the present invention as described below. That is, the manufacturing method of the annular rubber member according to the present invention includes a step of extruding rubber into a belt shape through a die by an extruder, and bonding the ends of the belt rubber to form an annular rubber. In the member manufacturing method, an opening having a shape corresponding to the cross-sectional shape of the belt-shaped rubber, an outer peripheral flow path for sending rubber into the outer peripheral portion of the opening, and an inner portion for sending rubber into the inner peripheral portion of the opening And a peripheral side flow path, and the rubber flow rate in the outer peripheral side flow path is made larger than the rubber flow rate in the inner peripheral flow path, thereby curving the extruded rubber band. .

  According to the manufacturing method of the annular rubber member according to the present invention, the rubber flow rate in the outer peripheral side flow path of the base is made larger than the rubber flow rate in the inner peripheral side flow path, thereby making the outer peripheral portion of the opening more A lot of rubber can be fed and the extruded belt-like rubber can be bent with little residual stress. Thereby, a deformation | transformation of a strip | belt-shaped rubber | gum can be suppressed, and edge parts can be bonded together appropriately and it can shape | mold accurately in a ring shape. Further, since the curvature of the belt-shaped rubber can be freely changed by adjusting the balance of the rubber flow rate between the outer peripheral side flow path and the inner peripheral side flow path, various sizes of annular rubber members are easily and reliably manufactured. be able to.

  The present invention is particularly useful for producing a bead filler having a triangular cross-section with a tapered outer peripheral portion. The reason for this is that in the bead filler having a triangular cross-section, the rubber flow at the outer peripheral portion of the base tends to be particularly bad, and the end-to-end bonding tends to be hindered. This is because such a problem can be solved according to the invention.

  The annular rubber member manufacturing apparatus according to the present invention is an annular rubber member manufacturing apparatus including an extruder for extruding rubber in a band shape through a base, wherein the base corresponds to a cross-sectional shape of the band rubber. An outer peripheral flow path for sending rubber into the outer peripheral portion of the opening, and an inner peripheral flow path for sending rubber into the inner peripheral portion of the opening, By making the rubber flow rate larger than the rubber flow rate in the inner peripheral flow path, the extruded belt-like rubber is configured to be bendable.

  According to the manufacturing apparatus of the annular rubber member according to the present invention, the rubber flow rate in the outer peripheral side channel of the base is made larger than the rubber flow rate in the inner peripheral side channel, so that the outer peripheral portion of the opening A lot of rubber can be fed and the extruded belt-like rubber can be bent with little residual stress. Therefore, deformation of the belt-like rubber can be suppressed, and the end portions can be appropriately bonded to each other and accurately formed into an annular shape. Further, since the curvature of the belt-shaped rubber can be freely changed by adjusting the balance of the rubber flow rate between the outer peripheral side flow path and the inner peripheral side flow path, various sizes of annular rubber members are easily and reliably manufactured. be able to.

  As an embodiment of the manufacturing apparatus of the annular rubber member according to the present invention, an extruder for supplying rubber to the outer peripheral side flow path and an extruder for supplying rubber to the inner peripheral flow path are separately configured. Things. According to such a configuration, by appropriately controlling the operation of each extruder, it is possible to easily and appropriately adjust the balance of the rubber flow rate between the outer peripheral side channel and the inner peripheral side channel, and to simplify the curvature of the belt-like rubber. Can be changed.

  As an embodiment of the manufacturing apparatus of the annular rubber member according to the present invention, rubber is supplied from the same extruder to the outer peripheral side channel and the inner peripheral side channel, and the cross-sectional area of the outer peripheral channel is Examples include a configuration in which at least one of the outer peripheral side flow path and the inner peripheral side flow path is variably configured so as to be larger than the cross-sectional area of the inner peripheral flow path. According to such a configuration, while the outer peripheral side flow path and the inner peripheral side flow path share the extruder, the outer peripheral side flow path is changed by changing the cross-sectional area of at least one of the outer peripheral side flow path and the inner peripheral side flow path. By making the cross-sectional area of the inner side larger than the cross-sectional area of the inner peripheral flow path, the rubber flow rate in the outer peripheral flow path can be made larger than the rubber flow rate in the inner peripheral flow path.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, an example in which the annular rubber member is a bead filler 1b having a triangular cross-section with a tapered outer peripheral portion as shown in FIGS. FIG. 1 is a schematic configuration diagram illustrating an example of an annular rubber member manufacturing apparatus according to the present invention. FIG. 2 is a front view of an opening formed in the base.

  This apparatus includes a base 15, an extruder that extrudes rubber in a band shape via the base 15 (in this embodiment, two extruders 20 and 30), and a control device 40. The extruder 20 includes a hopper 21 into which a rubber material is charged, a screw 22 that feeds the rubber material forward, a cylindrical barrel 23 that contains the screw 22, and a drive device 24 that drives the screw 22. Is provided. The extruder 30 is configured in the same manner as the extruder 20 and includes a hopper 31, a screw 32, a barrel 33, and a drive device 34. The control device 40 controls the amount of driving and rotation of the screws 22 and 32.

  The base 15 is connected to the front end side of the barrels 23 and 33 of the extruders 20 and 30, and the bead filler 1 b as a belt-like rubber is extruded from the opening 11 formed on the front surface thereof. The extruded bead filler 1b curves in the direction of arrow R as will be described later. As shown in FIG. 2, the opening 11 has a shape corresponding to the cross-sectional shape of the bead filler 1 b, and the tapered upper part is the outer peripheral part 11 o of the opening 11 and the lower part is the inner peripheral part 11 i of the opening 11.

  Inside the base 15, a rubber flow path through which the rubber supplied from the extruders 20 and 30 passes is provided, and an opening 11 is formed on the downstream side thereof. The rubber flow path includes a branch portion 12 that communicates with the inside of the barrels 23 and 33, and a junction portion 13 that communicates with the opening 11. The branch part 12 has an outer peripheral side flow path 12 o and an inner peripheral side flow path 12 i, which join at the junction part 13. The outer peripheral flow path 12 o communicates with the outer peripheral side of the merging portion 13 and feeds the rubber supplied by the extruder 20 into the outer peripheral portion 11 o of the opening 11. The inner peripheral flow path 12 i communicates with the inner peripheral side of the merging portion 13 and feeds the rubber supplied by the extruder 30 into the inner peripheral portion 11 i of the opening 11. In this embodiment, the outer peripheral side flow path 12o and the inner peripheral side flow path 12i have the same cross-sectional area.

  When manufacturing the bead filler 1b as an annular rubber member, first, rubber materials are put into the hoppers 21 and 31 and fed forward while being kneaded by the screws 22 and 32 and supplied to the base 15. The rubber supplied to the base 15 merges at the merge section 13 through the outer peripheral flow path 12o and the inner peripheral flow path 12i, and is integrally extruded from the opening 11 as a belt-shaped bead filler 1b having a triangular cross section. . At this time, the rubber mainly sent via the outer peripheral side flow path 12o is fed into the outer peripheral part 11o of the opening 11, and the rubber mainly sent via the inner peripheral side flow path 12i is sent into the inner peripheral part 11i of the opening 11. .

  And in this invention, when extruding the strip | belt-shaped bead filler 1b, the rubber | gum flow rate in the outer peripheral side flow path 12o is made larger than the rubber | gum flow rate in the inner peripheral side flow path 12i. Thereby, more rubber | gum can be sent with respect to the outer peripheral part 11o of the opening 11, and the bead filler 1b extruded as shown in FIG. 1 can be curved. Since this bead filler 1b is not bent by pulling, the occurrence of residual stress is suppressed.

  As a specific method for making the rubber flow rate in the outer peripheral flow path 12o larger than the rubber flow rate in the inner peripheral flow path 12i, the rotation amount of the screw 22 is made larger than that of the screw 32, or the capacity of the barrel 23 is increased. It is mentioned that it is larger than the barrel 33. In addition to these, means that can provide a difference in the amount of rubber in each flow path that flows per unit time can be appropriately employed. Furthermore, it is effective to increase the fluidity by lowering the viscosity of the rubber passing through the outer peripheral flow path 12o than that of the rubber passing through the inner peripheral flow path 12i.

  The extruded bead filler 1b is cut into a predetermined length, and then its ends are bonded together to form an annular shape. Since the curvature of the bead filler 1b is determined by the balance of the rubber flow rate between the outer peripheral flow path 12o and the inner peripheral flow path 12i, by appropriately controlling the balance of the rubber flow rate, distortion having a desired curvature can be obtained. A small number of annular bead fillers 1b can be produced. Moreover, the bead filler 1b of various sizes can be easily manufactured by adjusting the balance of the rubber flow rate and changing the curvature.

  In the present embodiment, the extruder 20 that supplies rubber to the outer peripheral side flow path 12o and the extruder 30 that supplies rubber to the inner peripheral side flow path 12i are configured separately. By appropriately controlling the operation, the balance of the rubber flow rate can be easily adjusted.

  When the bead filler 1b having a triangular cross-section with a tapered outer peripheral portion is manufactured as an annular rubber member as in this embodiment, the flow of rubber at the outer peripheral portion 11o of the opening 11 is caused by the shape. Easy to get worse. However, according to the present invention, as described above, more rubber can be fed to the outer peripheral portion 11o of the opening 11, so that the poor flow of rubber in the outer peripheral portion 11o is eliminated, and the bead filler 1b Residual stress at the outer peripheral portion can be suppressed.

  Although not shown in FIG. 1, a bead core formed in advance in an annular shape is disposed in front of the base 15 (right side in FIG. 1). The extruded bead filler 1b is supplied to the bead core, and the bead core is bonded to the inner periphery of the bead filler 1b to form a bead member. In such a case, a structure similar to the structure shown in FIG. 6 can be employed. It is also possible to extrude the bead filler 1b one or more times into a spiral belt-like rubber, cut it at a predetermined length, and shape it into an annular shape.

  FIG. 3 is a schematic configuration diagram showing another example of the manufacturing apparatus for the annular rubber member according to the present invention. This apparatus has substantially the same configuration as that of the apparatus shown in FIG. 1 except that one extruder 50 is used and the shape of the die 60 is used. The extruder 50 is configured in the same manner as the extruder 20 described above, and includes a hopper 51, a screw 52, a barrel 53, and a drive device 54. The control device 40 controls the driving and braking of the screw 52 and the amount of rotation.

  In the apparatus of FIG. 1, the extruder for supplying rubber to both the flow paths 12o and 12i of the base 15 is configured separately. However, in the apparatus of FIG. 3, the outer peripheral side flow path 62o and the inner peripheral flow path 62i are provided. On the other hand, rubber is supplied from the same extruder 50. In this device, the cross-sectional area of the inner peripheral flow path 62i is configured to be variable, whereby the rubber flow rate in the outer peripheral flow path 62o can be made larger than the rubber flow rate in the inner peripheral flow path 62i. It is configured as follows.

  Specifically, a choke portion 70 for reducing the cross-sectional area is provided in the downstream portion of the inner peripheral flow path 62i. The choke portion 70 includes a choke bolt 71 attached so as to be displaceable in the axial direction, and a choke bar 72 arranged at a position facing the inner peripheral flow path 62 i and attached to the tip of the choke bolt 71. According to this configuration, the choke bolt 71 is operated to advance the choke bar 72 toward the inner peripheral flow path 62i, thereby reducing the cross-sectional area of the inner peripheral flow path 62i and disconnecting the outer peripheral flow path 62o. The area can be made larger than the cross-sectional area of the inner circumferential flow path 62i.

  The rubber passing through the outer peripheral side channel 62o is sent to the outer peripheral part 61o of the opening 61, and the rubber passing through the inner peripheral side channel 62i in a state where the cross-sectional area is reduced is sent to the inner peripheral part 61i of the opening 61. Thereby, the rubber flow rate in the outer peripheral flow path 62o can be made larger than the rubber flow rate in the inner peripheral flow path 62i, so that more rubber can be fed into the outer peripheral portion 61o of the opening 61. As a result, FIG. The bead filler 1b extruded can be curved as shown in FIG.

  In this embodiment, by reducing the cross-sectional area of the inner peripheral flow path 62i, the rubber flow rate in the outer peripheral flow path 62o is made larger than the rubber flow rate in the inner peripheral flow path 62i. Instead of or in addition, the same operational effects can be obtained by expanding the cross-sectional area of the outer peripheral flow path 62o.

[Another embodiment]
In the above-described embodiment, an example in which a bead filler is manufactured as an annular rubber member has been described. However, the present invention is not limited to this, and can be applied to other annular rubber members such as sidewall rubber. Further, a gear pump may be connected to the front end side of the extruder, and a fixed amount of rubber may be supplied to the die based on the function of the gear pump.

The schematic block diagram which shows an example of the manufacturing apparatus of the annular | circular shaped rubber member which concerns on this invention Front view of the opening formed in the base The schematic block diagram which shows another example of the manufacturing apparatus of the annular | circular shaped rubber member which concerns on this invention Sectional drawing which shows an example of a pneumatic tire Perspective view showing a partially broken bead member The figure which shows a mode that an annular | circular shaped rubber member is manufactured by the conventional method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Bead core 1b Bead filler 10 Bead member 11 Opening 11i Inner peripheral part 11o Outer peripheral part 12 Branch part 12i Inner peripheral side flow path 12o Outer peripheral side flow path 13 Merge part 15 Base 20 Extruder 30 Extruder 60 Base 61 Opening 61i Inner peripheral part 61o Outer peripheral part 62i Inner peripheral flow path 62o Outer peripheral flow path 70 Choke part

Claims (5)

In a method for producing an annular rubber member comprising a step of extruding rubber through a base by an extruder and bonding the ends of the belt rubber together to form an annular shape,
An opening having a shape corresponding to the cross-sectional shape of the belt-shaped rubber, an outer peripheral side channel for sending rubber to the outer peripheral part of the opening, an inner peripheral side channel for sending rubber to the inner peripheral part of the opening, Using a base with
A method for producing an annular rubber member, wherein the extruded rubber band is curved by making the rubber flow rate in the outer peripheral flow path larger than the rubber flow rate in the inner peripheral flow path.   The method for producing an annular rubber member according to claim 1, wherein the annular rubber member is a bead filler having a triangular cross-section with a tapered outer peripheral portion. In an apparatus for producing an annular rubber member provided with an extruder for extruding rubber in a band shape through a base,
The base has an opening corresponding to the cross-sectional shape of the belt-like rubber, an outer peripheral flow path for feeding rubber into the outer peripheral portion of the opening, and an inner peripheral side flow for feeding rubber into the inner peripheral portion of the opening Road and
An apparatus for manufacturing an annular rubber member, wherein the rubber band flow rate in the outer peripheral side flow path is made larger than the rubber flow rate in the inner peripheral side flow path so that the extruded belt-like rubber can be bent.   The manufacturing apparatus of the annular | circular shaped rubber member of Claim 3 with which the extruder which supplies rubber | gum to the said outer peripheral side flow path, and the extruder which supplies rubber | gum to the said inner peripheral side flow path are comprised separately.   Rubber is supplied from the same extruder to the outer peripheral side flow path and the inner peripheral side flow path, and the cross sectional area of the outer peripheral side flow path is larger than the cross sectional area of the inner peripheral side flow path. The manufacturing apparatus of the annular | circular shaped rubber member of Claim 3 which comprised the cross-sectional area of at least one of the outer peripheral side flow path and the said inner peripheral side flow path variably.

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