JP4475459B2 - Rubber coated head - Google Patents

Description

  The present invention relates to an extruder that coats and extrudes a cord such as a belt layer cord, and particularly relates to an extruder that suppresses a temperature rise of rubber in a rubber-coated head.

  For example, a tire belt is formed by sandwiching a thin rubber layer on both sides of a plurality of belt layer cords that are aligned. Conventionally, as a device for coating rubber on such a plurality of aligned cords, when these cords are passed through the cord passage in the rubber coating head of the extruder, both sides of the cord passage, For example, rubber is supplied to a rubber flow path that joins from above and below to coat the rubber on both sides of the cord, and then the size of the cord is determined by the size of the passage formed between a pair of dies arranged above and below the front end of the rubber-coated head. There is a so-called insulation type extruder configured to determine the thickness of rubber coated on both surfaces (see Patent Document 1).

  FIG. 3A is a perspective view of a conventional extruder using an insulation system, and FIG. 3B is a cross-sectional view taken along line AA of the rubber-coated head 4. In addition, in FIG.2 (b), let the direction in which the several cord 5 is transferred be the front.

  As shown in FIG. 3 (a), the extruder is connected to a rubber generating unit 1 that generates rubber by stirring a rubber material introduced from a hopper 2 provided on an upper surface, and a side surface of the rubber generating unit 1. In addition, a screw is built in, and a cylinder 3 for transferring the rubber delivered from the rubber generating unit 1 forward while kneading and heating is connected to a tip of the cylinder 3 and tension is given by a transfer means not shown. A plurality of cords 5 to be transferred are introduced in a predetermined relative arrangement, for example, held in parallel, and a belt 6 formed by covering the upper and lower surfaces with rubber transferred from the cylinder 3 is sent to the outside. And a rubber-coated head 4.

  As shown in FIG. 3B, the rubber-coated head 4 is configured so that the AA cross section is vertically symmetrical, and includes an inserter 31 and an inserter holder 32 that holds the inserter 31. The inserter 31 includes a cord passage 33 that penetrates the center in the vertical direction back and forth, and can pass a plurality of cords 5 supplied from the rear while maintaining a predetermined relative arrangement. An upper die 34 and a lower die 35 that are symmetrical in the vertical direction are disposed in front of the inserter holder 32 with a space from the front surface of the inserter holder 32.

  On the front surface of the inserter holder 32, tapered inclined surfaces 36 and 37 are extended from the upper and lower ends to the front lower side and the front upper side, respectively, and the inclined surface is extended to the front lower side from the rear upper end of the upper die 34. 38 and the inclined surfaces 39 extending from the lower end of the lower part of the lower die 35 to the front upper side are formed with vertically tapered rubber flow paths 40 and 41 having a tapered tip. Further, it is formed between a downward horizontal plane extending in front of the lower end of the inclined surface 38 of the upper die 34 and an upward horizontal plane extending in front of the upper end of the inclined surface 39 of the lower die 35. The upper and lower thicknesses of the belt 6 are determined by the height of the flat passage 43.

  In the extruder configured as described above, the rubber supplied from the rubber generating unit 1 to the cylinder 3 is transferred to the tip of the cylinder 3 while being kneaded and melted under the action of the screw of the cylinder 3, and the rubber-coated head 4. And injected into the rubber flow paths 40 and 41 from the back side of the paper surface. On the other hand, a plurality of cords 5 which are transferred with tension applied by a cord transfer means (not shown) are introduced into the inserter 31 from the rear end of the rubber-coated head 4 and are held in a predetermined relative arrangement. It is transferred from the front end to the intersection 42 between the cord passage 33 and the rubber passages 40 and 41, and the upper and lower surfaces are covered with rubber. The plurality of cords (belts) 6 covered with rubber have their upper and lower thicknesses determined when passing through the passage 43 between the upper and lower dies 34 and 35, and are fed forward from the front ends of the upper and lower dies 34 and 35. It is.

JP 2002-113793 A

  In the rubber-coated head described above, the rubber flow paths 40 and 41 are increased by increasing the transfer speed of the cord 5 and increasing the delivery speed of the rubber delivered from the cylinder 3 in order to increase the amount of rubber coating / extrusion per unit time. Friction heat between the flowing rubber and the inclined surfaces 36, 37, 38, 39, and friction heat between the rubber on the upper and lower surfaces of the belt 6 passing through the passage 43 between the upper and lower dies 34, 35 and the dies 34, 35. Therefore, the temperature of the rubber flowing through the rubber flow paths 40 and 41 and the temperature of the rubber on the surface of the belt 6 passing through the passage 43 rise, and the rubber on the surface of the belt 6 blooms (bloom of chemicals on the rubber surface). Out) will occur. Further, when the operation of the apparatus is suddenly stopped, the temperature of the rubber and the belt surface further increases, and the rubber is burnt.

  The present invention has been made to solve such a problem, and the object thereof is to pass through a rubber-coated head in an extruder that coats and extrudes rubber on both surfaces of a plurality of aligned cords. It is to suppress the temperature rise of the rubber due to frictional heat between the rubber and the passage.

The invention according to claim 1 is a rubber-coated head that covers rubber on both surfaces of a plurality of aligned cords, and includes a passage of the cord and a rubber flow path that merges on both surfaces of the passage, the rubber flow path is closed and the upstream portion substantially perpendicular to passage of said cord, and a downstream portion that extends in the upstream portion, and joins the oblique to passage of the cord, the The downstream wall surface is a rubber-coated head characterized by having a curved surface that changes the direction of rubber flow .
The invention according to claim 2 is the rubber-coated head according to claim 1, wherein the downstream portion is a rubber-coated head, characterized in slimming Rukoto toward the passage of the cord.
The invention according to claim 3 is the rubber-coated head according to claim 1, wherein both surfaces are rubber-coated head, wherein upper and lower surfaces der Rukoto.
Passage invention according to claim 4, in the rubber coating head according to claim 1, further comprising a through passageway after before, and inserter passing holds a plurality of cords in a predetermined relative arrangement, which penetrates back and forth And a die that passes through the inserter and passes a cord coated with rubber, and the front surface of the inserter and the rear surface of the die are the rubber. A rubber-coated head characterized by partitioning a flow path .
A fifth aspect of the present invention is an extruder comprising the rubber-coated head according to any one of the first to fourth aspects .

According to the present invention, compared with the case where the entire rubber flow path is inclined with respect to the cord passage, the rubber flow is improved by making the upstream portion of the rubber flow passage substantially perpendicular to the cord passage. The overall length of the rubber flow path can be shortened without changing the slope of the downstream portion of the path from the slope when the entire rubber flow path is inclined with respect to the path of the cord. Rubber temperature rise due to frictional heat can be reduced. Further, by forming the curved surface (R) in the downstream portion of the rubber flow path, the frictional resistance between the downstream portion and the rubber can be reduced, so that the temperature rise of the rubber due to frictional heat can be reduced.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1A is a perspective view of an extruder according to an embodiment of the present invention, and FIG. 1B is a BB cross-sectional view of the rubber-coated head. In FIG. 1A, the same parts as those in FIG. 3A are denoted by the same reference numerals as those in FIG. Here, since the extruder according to the present embodiment is the same as the conventional apparatus except for the rubber-coated head 7, description regarding the configuration and functions other than the rubber-coated head 7 is omitted.

  As shown in FIG. 1B, the rubber-coated head 7 is configured so that the BB cross section is vertically symmetrical, and includes an inserter 11 and an inserter holder 12 that holds the inserter 11. The inserter 11 includes a cord passage 13 that penetrates the center in the up-down direction back and forth, and can pass a plurality of cords 5 supplied from the rear in a predetermined relative arrangement. An upper die 14 and a lower die 15 that are vertically symmetric are disposed in front of the inserter holder 12 with a space from the front surface of the inserter holder 12.

  A vertical surface 16 extends downward from the upper end of the front surface of the inserter holder 12, and an inclined surface 17 formed of a curved surface extends to the front end of the inserter 12 at the front lower portion thereof. A vertical surface 18 extends upward from the lower end, and an inclined surface 19 formed of a curved surface extends to the front end of the inserter 12 at the front lower side. A vertical surface 20 extends downward from the upper end on the rear surface of the upper die 14, and an inclined surface 21 made of a curved surface extends to the lower end in front of the upper die 14. Further, a vertical surface 22 extends upward from the lower end on the rear surface of the lower die 15, and an inclined surface 23 formed of a curved surface extends to the upper end in front of the lower die 15.

  The space between the upper vertical surface 16 and the inclined surface 17 on the front surface of the inserter holder 12 and the vertical surface 20 and the inclined surface 21 on the rear surface of the upper die 14 facing them forms an upper rubber flow path 24. ing. Similarly, the space between the lower vertical surface 18 and the inclined surface 19 on the lower surface of the inserter holder 12 and the vertical surface 22 and the inclined surface 23 on the rear surface of the lower die 15 facing them is lower rubber. A flow path 25 is formed. Each inclined surface is curved in order to gently change the direction of rubber flow from the vertical direction by reducing the frictional resistance in the downstream portion where the rubber flow paths 24 and 25 join the cord transfer path. Further, the interval between the inclined surfaces 17 and 21 is gradually narrowed so that the downstream portion of the rubber flow path 24 is tapered, and similarly, the interval between the inclined surfaces 19 and 23 is also the downstream portion of the rubber flow channel 25. It gradually becomes narrower so that it tapers off.

  A downward horizontal plane extends in front of the lower end of the inclined surface 21 of the upper die 14, and an upward horizontal plane extends in front of the upper end of the inclined surface 23 of the lower die 15. The upper and lower thicknesses of the belt 6 are determined by the height of the flat passage 27 formed between these horizontal planes.

  In the extruder configured as described above, the rubber supplied from the rubber generating unit 1 to the cylinder 3 is transferred to the tip of the cylinder 3 while being kneaded and melted under the action of the screw of the cylinder 3, and the rubber-coated head 7. And is injected into the rubber flow paths 24 and 25 from the back side of the paper surface. On the other hand, a plurality of cords 5 which are transferred with tension applied by a cord transfer means (not shown) are introduced into the inserter 11 from the rear end of the rubber-coated head 7 and held in a predetermined relative arrangement. It is transferred from the front end to the intersection 26 between the cord passage 13 and the rubber passages 24 and 25, and the upper and lower surfaces are covered with rubber. The alignment cord (belt) 6 covered with rubber is determined in thickness when passing through the passage 27 between the upper and lower dies 14, 15, and is sent forward from the front ends of the upper and lower dies 14, 15. .

  Here, according to the present embodiment, a vertical rubber flow path is formed by the upper and lower vertical surfaces 16 and 18 on the front surface of the inserter holder 12 and the vertical surfaces 20 and 22 on the rear surfaces of the upper and lower dies 14 and 15. Therefore, the rubber flow path from the upper and lower ends of the inserter holder 12 to the intersecting portion 26 is shorter than that of the conventional device that forms an inclined rubber flow path. The frictional heat between them is reduced. In addition, since the frictional resistance is reduced by the roundness (R) of the curved surfaces of the inclined surfaces 17, 19, 21, and 23 extending to the vertical surfaces 16, 18, 20, and 22, the rubber channels 24 and 25 The direction of rubber flow does not change suddenly but changes slowly. For this reason, the frictional heat of the rubber in the downstream part of the rubber flow paths 24 and 25 is reduced. Actually, the temperature of the surface of the belt 6 formed by coating the cord 5 with rubber by the extruder according to this embodiment was measured and found to be 115 ° C., which was 7 ° C. lower than the conventional apparatus (122 ° C.). Bloom was not generated. Furthermore, when the extruder was stopped suddenly under the same conditions as in the conventional apparatus, the scorching of rubber did not occur as in the conventional apparatus.

  FIG. 2 is a longitudinal sectional view of a modified example of the rubber-coated head. This rubber-coated head is provided with inclined surfaces 17A, 19A, 21A, and 23A made of flat surfaces instead of the curved inclined surfaces 17, 19, 21, and 23 of the rubber-coated head shown in FIG. . Also in this modified example, since the vertical rubber flow paths are formed by the vertical surfaces 16 and 18 of the inserter holder and the vertical surfaces 20 and 22 of the rear surfaces of the upper and lower dies, the inserter holder and the upper and lower ends are formed. Since the rubber flow path from the crossing portion 26 to the intersection 26 is shorter than that of the conventional device, the frictional heat between the rubber flow path and the rubber is reduced.

In addition to the two configuration examples described above, for example, the following modifications (1) and (2) are possible.
(1) In FIG. 1B, all of the inclined surfaces 17, 19, 21, 23 from the upper end to the lower end are curved surfaces, and in FIG. 2, from the upper end to the lower end of each of the inclined surfaces 17A, 19A, 21A, 23A. Although all are flat, a part from the upper end to the lower end of each inclined surface (for example, a portion from the upper end to the lower end of the inserter 11 in FIG. 1B) may be a flat surface, and both upper and lower sides may be curved.
(2) In FIG. 1 (b) and FIG. 2, the rubber flow paths 24, 25 are formed vertically from their upper and lower ends to about ½ of their heights. For example, you may extend to the upper and lower ends of the inserter 11.

It is a longitudinal cross-sectional view of the rubber-coated head which concerns on embodiment of this invention. It is a longitudinal cross-sectional view of the modification of the rubber-coated head which concerns on embodiment of this invention. It is the perspective view of the conventional extruder, and the longitudinal cross-sectional view of the rubber coating head.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Inserter, 12 ... Inserter holder, 13 ... Cord path, 14 ... Upper die, 15 ... Lower die, 16, 18, 20, 22 ... Vertical surface, 17, 19, 21, 23... Inclined surfaces composed of curved surfaces, 24, 25.

Claims (5)

A rubber-coated head that covers rubber on both surfaces of a plurality of cords that are aligned, and includes: a path for the cord; and a rubber channel that merges on both sides of the path. an upstream portion substantially perpendicular to the passageway, to extend in the upstream section, and possess a downstream portion which joins the oblique to passage of the cord, the wall surface of the downstream part, of rubber A rubber-coated head having a curved surface that changes a flow direction . Rubber coating head according to claim 1, wherein said downstream portion is characterized by a thin Rukoto toward the passage of the cord. The double-sided rubber coating head according to claim 1, wherein the upper and lower surfaces der Rukoto. Has a passage extending through the post before has a inserter passing holds a plurality of cords in a predetermined relative arrangement, a passage extending through the front and rear, are spaced in front of the inserter, and the 2. The rubber-coated head according to claim 1 , further comprising a die that passes through the inserter and allows a rubber-coated cord to pass therethrough, and a front surface of the inserter and a rear surface of the die define the rubber flow path. . An extruder comprising the rubber-coated head according to any one of claims 1 to 4 .

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