JP2011178030A - Method for manufacturing rubber member and device for manufacturing rubber member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a rubber member capable of inhibiting the fall of a belt-like rubber when moving the belt-like rubber extruded from an extruder, by suction of a sucking pad, as well as a device for manufacturing the rubber member. <P>SOLUTION: This method for manufacturing a rubber member involves the following procedures: first, a rubber is extruded from a mouthpiece 8 of the extruder 1 in a belt-like form, then the apex part of this belt-like rubber 2 is sucked by the sucking pad 5 and conveyed to a molding machine 7, and the belt-like rubber 2 is molded using the molding machine 7. When the belt-like rubber 2 is extruded from the mouthpiece 8, the mouthpiece part corresponding with the suction surface, of the belt-like rubber 2, which is sucked by the sucking pad 5 is heated at least a rubber temperature immediately after extrusion of the belt-like rubber 2 from the extruder 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method and apparatus for producing a rubber member obtained by molding an unvulcanized belt-like rubber extruded from an extruder.

  Generally, a tire is composed of various members such as a tread rubber, a carcass ply, an inner rubber, and a bead member, and is manufactured by combining these tire constituent members and vulcanizing and molding them. Among the tire constituent members, a bead member formed in advance in an annular shape is used.

  Specifically, as shown in FIGS. 5 and 6, the bead member 21 includes a bead core 22 and a bead filler 23 having a substantially triangular cross section joined to the outer peripheral side thereof. The bead core 2 is composed of a convergent body such as a steel wire coated with rubber.

  For example, the bead member having the above-described configuration is obtained by cutting rubber extruded into a belt shape from an extruder into a predetermined length and winding the belt rubber around the outer periphery of a drum-shaped molding machine as shown in Patent Document 1. In addition to being formed into an annular shape, it can be formed by joining with a bead core.

  In the above method, it is required to accurately convey the rubber band extruded from the extruder to a predetermined position of the molding machine. For this purpose, it is preferable to use a conveying device that adsorbs the leading end portion of the belt-like rubber extruded from the extruder to the molding machine by adsorbing it with an adsorption pad.

JP-A-3-164232

  However, when the belt-shaped rubber is sucked and transported by the suction pad as in the above-described transport device, the belt-shaped rubber may fall during the transport, and there is a problem that productivity is lowered.

  Therefore, in the present invention, in view of the above problems, a rubber member manufacturing method and a manufacturing apparatus capable of suppressing the dropping of the band-shaped rubber when the band-shaped rubber extruded from the extruder is sucked and moved by the suction pad are provided. Objective.

  In general, when extruding unvulcanized rubber with an extruder, if the temperature of the unvulcanized rubber is raised too much, bloom may occur due to an antioxidant, a processing aid, or the like contained in the unvulcanized rubber. The presence of blooms may reduce the adhesive strength at the rubber member interface in the subsequent vulcanization treatment, and the content of anti-aging agents, processing aids, etc. in the rubber will decrease. There is a risk of deterioration of characteristics.

  Therefore, the rubber temperature in the extruder is preferably as low as possible. However, the present inventor has found that the lower the temperature of the rubber extruded from the extruder, the lower the tackiness (adhesiveness) of the belt-like rubber at room temperature, and thus the higher the fall rate of the belt-like rubber. It was.

  And based on that knowledge, the present inventor is able to suppress the occurrence of bloom while improving the tackiness by heating only the rubber surface when extruding the strip rubber from the extruder. It has been found and completed the present invention.

  That is, in the present invention, a rubber member for extruding unvulcanized rubber in a band shape from a die of an extruder, adsorbing the leading end portion of the band rubber with a suction pad and conveying it to a molding machine, and molding the band rubber with the molding machine When the rubber strip is extruded from the base, the base portion corresponding to the suction pad suction surface of the belt rubber is heated to a temperature equal to or higher than the belt rubber temperature (T ° C.) immediately after being extruded from the extruder. It is characterized by doing.

  This suppresses the occurrence of blooming rubber band rubber, while suppressing the deterioration of the rubber properties after vulcanization, while improving the tackiness of the adsorption pad adsorption surface of the belt rubber at room temperature, increasing the adsorption force of the adsorption pad, It becomes possible to suppress the fall of the belt-like rubber during the conveyance.

  Usually, the temperature of the die is lower than the belt rubber temperature (T ° C.) immediately after being extruded from the extruder. Therefore, the tackiness of the belt-like rubber can be improved only by heating the base temperature to T ° C.

  It is preferable to heat so that the temperature of the base portion corresponding to the suction pad suction surface of the belt-like rubber is T ° C. or higher and (T + 25) ° C. or lower. In the present invention, the strip rubber is instantaneously heated at the final die portion extruded from the extruder, so that the strip rubber is pressed without causing bloom even at a high temperature of (T + 25) ° C. and without causing deformation due to softening. It becomes possible to put out. In addition, when heating a nozzle | cap | die, what is necessary is just to heat a nozzle | cap | die part corresponding to the suction pad suction surface of a strip | belt-shaped rubber | gum, and can also heat the surface opposite to a suction pad suction surface together.

  However, it is easier to control the temperature by heating only the base part corresponding to the suction pad suction surface of the belt rubber, and the belt rubber extruded from the extruder as described later is opposite to the suction pad suction surface. Since the surface is in contact with the roller, it is preferable that the tackiness is low. Therefore, it is preferable to heat only the portion of the base corresponding to the suction pad suction surface of the belt-like rubber.

  The rubber member manufacturing method of the present invention can be suitably applied to a belt-like rubber having a substantially triangular cross section such as a bead filler. That is, the band-shaped rubber having a substantially triangular cross-section has a weight deviation in the width direction, and the suction pad is easily detached.In the present invention, the adsorption state of the suction pad is stabilized by improving the tackiness of the band-shaped rubber. Can be maintained.

  In order to manufacture the rubber member according to the present invention, an extruder for extruding rubber in a band shape, a conveying device that adsorbs a leading end portion of the band rubber extruded from the extruder with an adsorption pad and conveys it to a molding machine, A manufacturing apparatus having a molding machine for molding a belt-like rubber and provided with a heater for heating the mouthpiece portion corresponding to the suction pad suction surface of the belt-like rubber in the die of the extruder can be used.

  In the present invention, it is possible to improve the tackiness of the belt-like rubber by heating the base portion corresponding to the suction pad suction surface of the belt-like rubber to a temperature equal to or higher than the belt-like rubber temperature immediately after being extruded from the extruder. It is possible to provide a method and an apparatus for manufacturing a rubber member capable of suppressing the fall of rubber and thus improving the productivity.

Schematic showing a rubber member manufacturing apparatus according to the present invention Front view showing the base The figure which shows the state where the belt rubber was wound around the molding machine The figure which shows the state where the standing rubber was raised by wrapping the rubber band around the molding machine Plan view showing a bead member FIG. 5 is a sectional view taken along the arrow.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view showing a rubber member manufacturing apparatus according to the present invention. This embodiment demonstrates the case where the bead member which is a tire structural member is manufactured as a rubber member.

  The rubber member manufacturing apparatus of the present invention includes an extruder 1 for extruding unvulcanized rubber in a strip shape, a water tank 3 as a cooling device for cooling the strip rubber 2 extruded from the extruder 1, and a belt rubber 2 having a predetermined length. A moving apparatus that cuts the sheet and sends it forward; a conveying apparatus 6 that adsorbs the leading end of the belt-shaped rubber 2 (bead filler) by the suction pad 5 and transports it to the molding machine; and a molding machine 7 that molds the belt-shaped rubber 2 It has.

  A method of manufacturing a rubber member using the rubber member manufacturing apparatus having the above configuration will be described. A base 8 is attached to the tip of the extruder 1, and unvulcanized rubber is extruded from the opening 9 in a band shape. On the outer surface of the base 8, as shown in FIG. 2, a heater 10 (electric heater) for heating a portion (upper edge portion of the substantially triangular opening 9) corresponding to the suction pad 5 suction surface of the rubber band 2. Is provided. The heater 10 is attached along the upper edge of the triangular shape of the opening 9.

  First, the rubber band 2 is extruded from the die 8 of the extruder 1. At this time, the heater 10 is heated so that the temperature of the upper edge portion of the opening 9 of the base 8 becomes equal to or higher than the rubber temperature (T ° C.) immediately after being extruded from the extruder 1.

  The belt-like rubber 2 extruded from the extruder 1 is introduced into the water tank 3 by a roller 3a, cooled, and sent to the moving device. The moving device includes a conveyor 11 and a cutting device (not shown) disposed above the rear portion of the conveyor 11, and the belt-like rubber 2 is cut by a predetermined length by the cutting device.

  The suction pad 5 of the transport device 6 is disposed above the front portion of the conveyor 10. The suction pad 5 can be moved up and down and is movable to the molding machine 7. The suction pad 5 is attracted to the top end of the upper surface of the belt-like rubber 2 and lifted up and conveyed to the molding machine 7 according to the moving speed of the conveyor 11. To do.

  The molding machine 7 includes a cylindrical rotating drum 7a. As shown in FIG. 3, a disk-shaped bead core support portion 7b having a smaller diameter than the rotating drum 7a is attached to one end side of the rotating drum 7a in the rotation axis direction. The bead core 12 is placed on the outer periphery of the bead core support portion 7b, and is arranged so that the outer peripheral surface of the bead core 12 is flush with the outer periphery of the rotating drum 7a. Then, the belt-like rubber 2 is wound around the drum outer periphery, and the lengthwise ends of the belt-like rubber 2 are joined to each other. On the drum outer periphery, a plurality of upright pieces 13 are arranged in a lying state.

  Then, as shown in FIG. 4, the standing piece 13 is erected with the thick side of the belt-like rubber 2 as the base end, and the bead filler 14 is formed by raising the annular belt-like rubber accordingly. At the same time, the base end portion of the bead filler 14 is pressed against the bead core 12 to join the two, thereby forming the bead member 15. In this way, by raising the belt-shaped rubber 2 formed in an annular shape while being laid on the outer periphery of the rotating drum 7a, a uniform force is applied to the entire outer periphery of the belt-shaped rubber when expanding the diameter. An annular bead filler 14 having no annular shape can be obtained.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further in detail, unless this invention exceeds the summary, it is not limited to these Examples.

  Using the rubber member manufacturing apparatus described in the embodiment, a bead member was manufactured as a rubber member. First, 100 parts of natural rubber (RSS # 3), 50 parts of carbon black (HAF), 4 parts of sulfur, 2 parts of anti-aging agent, and 1 part of accelerator are blended as a rubber composition constituting the belt-like rubber (bead filler). Then, this was supplied to an extruder and extruded into a strip shape. The belt-like rubber temperature T immediately after extrusion from the extruder was 85 ° C., and the temperature D of the die 8 was 80 ° C. without being heated by the heater 10.

  Then, by controlling the output of the heater 10, the temperature of the base portion corresponding to the suction surface of the suction pad 5 of the belt-like rubber 2 is changed variously, and the ratio of the belt-like rubber falling from the suction pad and the bloom material on the belt-like rubber surface The presence or absence of was evaluated. Details of the evaluation are as follows.

[Falling rate of strip rubber]
While 900 bead members were manufactured, the number of times the belt-like rubber dropped from the suction pad was displayed in%.

[Presence of bloom objects]
Whether or not a bloom was present on the surface of the rubber strip extruded from the extruder was visually confirmed and evaluated according to the following criteria.
○: No bloom object ×: Bloom object

[Evaluation results]
Table 1 shows the evaluation results of the drop rate of the belt-like rubber (bead filler) and the presence or absence of blooms. In the table, the base temperature D indicates the temperature of the portion corresponding to the suction surface of the suction pad 5 of the belt-like rubber 2 (the upper edge portion of the substantially triangular opening 9). Further, the value of D−T indicates a value obtained by subtracting the rubber temperature T (85 ° C.) immediately after extrusion from the die temperature D.

  From the results of Table 1, when the temperature of the base 8 is in the range of the rubber temperature T (85) ° C. immediately after extrusion and (T + 25) ° C. or less (Examples 1 to 3), the drop rate of the rubber band is Low and no bloom was observed.

  On the other hand, when the temperature of the die 8 was lower than the rubber temperature T (85 ° C.) immediately after extrusion (Comparative Example 1), the drop rate increased due to the decrease in tackiness at room temperature of the belt-shaped rubber. When the temperature of the base 8 was higher than T + 25 ° C. (Comparative Example 2), blooming was observed, and the drop rate of the belt-like rubber was also high. This is considered to be because the adhesion between the suction pad and the belt-like rubber is lowered due to the bloom material adhering to the suction pad.

DESCRIPTION OF SYMBOLS 1 Extruder 2 Band-shaped rubber 3 Water tank 5 Suction pad 6 Conveying device 7 Molding machine 8 Base 9 Opening 10 Heater 11 Conveyor 12 Bead core 13 Standing piece 14 Bead filler 15 Bead member

Claims (4)

A rubber member manufacturing method for extruding rubber from a die of an extruder into a belt shape, adsorbing a leading end portion of the belt rubber with a suction pad and conveying it to a molding machine, and molding the belt rubber with the molding machine. When extruding the belt-shaped rubber from the base, the base portion corresponding to the suction pad suction surface of the belt-shaped rubber is heated to a temperature equal to or higher than the belt rubber temperature (T ° C) immediately after being extruded from the extruder. Production method. The method for producing a rubber member according to claim 1, wherein the base portion corresponding to the suction pad suction surface of the belt-like rubber is heated so as to be at least T ° C (T + 25) ° C. The method for producing a rubber member according to claim 1, wherein the belt-like rubber is a bead filler having a substantially triangular cross section. An extruder for extruding rubber in a strip shape, a conveying device for adsorbing the tip of the rubber strip extruded from the extruder with a suction pad and conveying it to a molding machine, and a molding machine for molding the belt rubber, An apparatus for manufacturing a rubber member, characterized in that a heater for heating a base portion corresponding to the suction pad suction surface of the belt-like rubber is provided in the base of the extruder.

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