JP2021008086A - Rubber coating head, and apparatus for manufacturing rubber coated cord - Google Patents

Abstract

To improve rubber adhesion performance to a cord.SOLUTION: Provided are a rubber coating head 7 for coating at least one cord 2, which is continuously supplied, with an unvulcanized rubber, and an apparatus for manufacturing a rubber coated cord. The rubber coating head 7 includes a casing 26. The casing 26 includes: a rubber fill-up space 28 in which an unvulcanized rubber supplied from a rubber supply port 27 is filled; and a cord supply port 29 for supplying the cord 2 to the rubber fill-up space 28. The rubber fill-up space 28 includes: a main portion 31 that is connected to the rubber supply port 27 and extends in a first direction D1; and a sub space 32 that localizedly protrudes from the main portion 31 in a second direction D2 that crosses the first direction D1. The cord supply port 29 is formed in the sub space 32.SELECTED DRAWING: Figure 5

Description

The present invention relates to a rubber-coated head or the like for coating a cord with unvulcanized rubber.

The following Patent Document 1 proposes an apparatus for coating a steel cord with rubber. This device includes a baffle with multiple through holes for the steel cord to pass through, a die plate attached to the tip of the baffle, and an extrusion head that supplies unvulcanized rubber to the steel cord that passes through the die plate. Is configured to include.

Japanese Unexamined Patent Publication No. 2018-27648

In the above device, the steel cord can be coated with rubber, but there is room for further improvement in improving the rubber-attached performance of the steel cord.

The present invention has been devised in view of the above circumstances, and a main object of the present invention is to provide a rubber-coated head or the like capable of improving the performance of attaching rubber to a cord.

The present invention is a rubber-coated head for coating at least one continuously supplied cord with unvulverized rubber, and includes a casing, the casing being supplied from a rubber supply port and the rubber supply port. The cord coated with the unvulvered rubber through the rubber filling space filled with the unvulgarized rubber, the cord supply port for supplying the cord to the rubber filling space, and the rubber filling space. The rubber filling space includes a main portion extending in the first direction connected to the rubber supply port and a second direction intersecting the first direction from the main portion, including a cord discharge port for taking out the rubber from the casing. It is characterized in that the cord supply port is formed in the sub-space, including a sub-space that protrudes locally.

In the rubber-coated head according to the present invention, the cord supply port and the cord discharge port may position the cord along the second direction.

In the rubber-coated head according to the present invention, the cross-sectional area of the subspace orthogonal to the second direction may be smaller than the cross-sectional area of the main portion orthogonal to the first direction.

In the rubber-coated head according to the present invention, the cross-sectional area of the subspace orthogonal to the second direction may be 25 times or more the cross-sectional area of the cord.

In the rubber-coated head according to the present invention, the subspace may project in a columnar shape from the main portion.

In the rubber-coated head according to the present invention, the subspace may include a portion protruding from the main portion while maintaining a predetermined inner diameter.

In the rubber-coated head according to the present invention, the cord supply port may be formed on the axial center line of the subspace.

In the rubber-coated head according to the present invention, the cord may be a wire for reinforcing a tire.

The present invention is a rubber-coated cord manufacturing apparatus for coating at least one continuously supplied cord with unvulcanized rubber, and is a rubber extruder for extruding the unvulcanized rubber from a rubber extrusion port. , A cord supply device for continuously supplying the cord to the rubber-coated head according to any one of claims 1 to 8 connected to the rubber extrusion port and the cord supply port of the rubber-coated head. It is characterized by including and.

The rubber-coated head of the present invention has a main portion extending in the first direction connected to the rubber supply port and a second direction intersecting the first direction from the main portion as a rubber filling space filled with unvulcanized rubber. Includes a subspace that protrudes locally. The cord supply port for supplying the cord to the rubber filling space is formed in the subspace. In such a subspace, the cord supplied from the cord supply port is continuously coated with the unvulcanized rubber, so that the pressure of the unvulcanized rubber in the subspace is relatively low. Become. Since the unvulcanized rubber has a property of flowing toward a lower pressure side, in the rubber filling space, a flow toward the second direction is added to the main flow of the unvulcanized rubber along the first direction. It can be generated continuously. As a result, the rubber-coated head of the present invention can bring the cord into contact with the unvulcanized rubber that continuously flows in the subspace, so that the rubber-attached performance of the unvulcanized rubber to the cord can be obtained. Can be improved.

It is a perspective view which shows an example of the manufacturing apparatus of the rubber-coated cord of this invention. It is a perspective view which shows an example of a rubber extruder and a rubber coating head. FIG. 2 is a sectional view taken along the line AA of FIG. It is a perspective view which shows an example of a rubber-coated head. FIG. 4 is a cross-sectional view taken along the line BB of FIG. It is sectional drawing which shows an example of the subspace of another embodiment of this invention. It is sectional drawing which shows an example of the subspace of still another Embodiment of this invention. (A) is a diagram showing the streamline of the unvulcanized rubber of Example 1, and (b) is a diagram showing the streamline of the unvulcanized rubber of Comparative Example 1.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing an example of an apparatus for manufacturing a rubber-coated cord of the present invention. The rubber-coated cord manufacturing apparatus 1 of the present embodiment (hereinafter, may be simply referred to as “manufacturing apparatus”) 1 is for coating at least one continuously supplied cord 2 with unvulcanized rubber 3. Is. The code 2 is not particularly limited as long as it is coated with the unvulcanized rubber 3. As the code 2 of this embodiment, a case where it is a wire for reinforcing a tire (for example, a bead wire or the like) is exemplified.

The manufacturing apparatus 1 of the present embodiment includes a rubber extruder 6, a rubber-coated head 7, and a cord feeding apparatus 8. Further, the manufacturing apparatus 1 of the present embodiment includes a code collecting apparatus 9 and a control apparatus 10 composed of a computer or the like. The manufacturing apparatus 1 is not limited to such a configuration. The manufacturing apparatus 1 may include, for example, an apparatus different from these apparatus.

FIG. 2 is a perspective view showing an example of the rubber extruder 6 and the rubber-coated head 7. FIG. 3 is a cross-sectional view taken along the line AA of FIG. The rubber extruder 6 includes a cylinder 11 and a screw shaft 12 (shown in FIG. 3).

The cylinder 11 is formed in a columnar shape. The cylinder 11 is supported, for example, by a base 13 (shown in FIGS. 1 and 2) fixed to the floor. As shown in FIG. 3, a chamber 14 for extruding the unvulcanized rubber 3 is provided inside the cylinder 11. The chamber 14 of the present embodiment extends horizontally along the longitudinal direction of the cylinder 11. On the upstream side of the first direction (direction in which the unvulcanized rubber 3 is extruded) D1 of the cylinder 11, a charging port 15 (shown in FIGS. 1 and 2) into which the unvulcanized rubber 3 is continuously charged is provided. Has been done. On the other hand, as shown in FIG. 3, a rubber extrusion port 16 for extruding (discharging) the unvulcanized rubber 3 is provided on the downstream side of the cylinder 11 in the first direction (extrusion direction) D1. The rubber supply port 27 of the rubber-coated head 7 is connected to the rubber extrusion port 16.

The screw shaft 12 is arranged inside the chamber 14 of the cylinder 11. The screw shaft 12 of the present embodiment is configured to be rotatable around a horizontal axis by a drive device (not shown). By the rotation of the screw shaft 12, the rubber extruder 6 can quantitatively extrude the unvulcanized rubber 3 charged into the charging port 15 (shown in FIGS. 1 and 2) toward the rubber extrusion port 16. it can. The unvulcanized rubber 3 extruded into the rubber extrusion port 16 is supplied to the rubber filling space 28 of the rubber-coated head 7 via the rubber supply port 27 of the rubber-coated head 7. The extrusion speed of the unvulcanized rubber 3 (the number of rotations of the screw shaft 12) is controlled by, for example, a control device 10 (shown in FIG. 1) connected to a drive device.

As shown in FIG. 1, the cord supply device 8 is for continuously supplying the cord 2 to the cord supply port 29 (shown in FIG. 2) of the rubber-coated head 7. The cord supply device 8 includes a first reel (winding frame) 17 and a first support portion 18 that rotatably supports the first reel 17. The cord 2 supplied from the cord supply device 8 is guided to the cord supply port 29 (shown in FIG. 2) of the rubber-coated head 7 via, for example, a guide roller 19.

A cord 2 before being coated with the unvulcanized rubber 3 is wound around the first reel 17 in advance. The number of the first reels 17 can be appropriately set, and can be set according to, for example, the number of cords 2 to be simultaneously coated with the unvulcanized rubber 3. In the present embodiment, the four cords 2 are simultaneously coated with the unvulcanized rubber 3. Therefore, the cord supply device 8 is provided with four first reels 17. These first reels 17 are removably supported by the first support portion 18.

The first reel 17 for which the cord 2 has been supplied is removed from the first support portion 18. Then, a new first reel 17 around which the cord 2 is wound is attached to the first support portion 18.

The cord recovery device 9 is for recovering the cord 2 (that is, the rubber-coated cord 4) coated with the unvulcanized rubber 3. The cord recovery device 9 is a second reel 21 for winding the rubber-coated cord 4, a second support portion 22 that rotatably supports the second reel 21, and a second drive device that rotationally drives the second reel 21. It is configured to include 23.

The number of the second reels 21 can be appropriately set, and can be set according to, for example, the number of cords 2 (that is, rubber-coated cords 4) coated with the unvulcanized rubber 3. In the present embodiment, since the four cords 2 are covered with the unvulcanized rubber 3, four second reels 21 are provided. These second reels 21 are removably supported by the second support portion 22.

The second drive device 23 of the present embodiment is for rotating each second reel 21 and winding the rubber-coated cord 4. The second drive device 23 is provided on the second support portion 22. The rotation speed of the second reel 21 is controlled by the control device 10 (shown in FIG. 1) connected to the second drive device 23.

First, the tip end side of the cord 2 of the first reel 17 is fixed to the second reel 21. Then, the second reel 21 can wind the rubber-coated cord 4 via the guide roller 24 by rotation by the second driving device 23. By winding the rubber-coated cord 4, the cord supply device 8 rotates the first reel 17 to continuously supply the cord 2 to the cord supply port 29 (shown in FIG. 2) of the rubber-coated head 7. be able to.

The second reel 21 in which the rubber-coated cord 4 has been wound up is removed from the second support portion 22 and used for, for example, manufacturing a raw tire. Then, a new second reel 21 before winding the rubber-coated cord 4 is attached to the second support portion 22.

As shown in FIG. 2, the rubber-coated head 7 is for coating at least one continuously supplied cord 2 with the unvulcanized rubber 3. The rubber-coated head 7 is configured to include a casing 26. A plurality of cords 2 (4 cords in this example) arranged in the vertical direction are continuously supplied to the rubber-coated head 7 of the present embodiment, but the plurality of cords 2 arranged horizontally are supplied. May be continuously supplied. FIG. 4 is a perspective view showing an example of the rubber-coated head 7. FIG. 5 is a cross-sectional view taken along the line BB of FIG. In FIG. 5, the advanced cord 2 and the rubber-coated cord 4 are shown by the alternate long and short dash-dotted line on the rubber-coated head 7.

The casing 26 includes a rubber supply port 27, a rubber filling space 28, a cord supply port 29, and a cord discharge port 30.

The rubber supply port 27 opens in the casing 26 on the other side of the first direction D1 (that is, on the upstream side in the extrusion direction of the unvulcanized rubber 3). As shown in FIG. 3, the rubber supply port 27 is connected to the rubber extrusion port 16 of the rubber extruder 6. As a result, the rubber supply port 27 can supply the unvulcanized rubber 3 extruded from the rubber extrusion port 16 to the rubber filling space 28. The shape of the rubber supply port 27 can be formed based on, for example, the shape of the rubber extrusion port 16 of the rubber extruder 6. As shown in FIG. 4, the rubber supply port 27 of the present embodiment is formed in a vertically long rectangular shape having arcs at the top and bottom when viewed from the front.

The rubber filling space 28 is filled with unvulcanized rubber 3 (shown in FIG. 3) supplied from the rubber supply port 27. As shown in FIGS. 4 and 5, the rubber filling space 28 includes a main portion 31 and a sub space 32. The main portion 31 and the subspace 32 are communicated with each other so that the unvulcanized rubber 3 can come and go. The main portion 31 and the subspace 32 may be integrally formed in the casing 26, or may be separably formed by disassembling the casing 26.

The main portion 31 is connected to the rubber supply port 27 and extends in the first direction D1. As shown in FIG. 5, the main portion 31 of the present embodiment is terminated at the end portion 33 on one side of the first direction D1 (that is, the downstream side in the extrusion direction of the unvulcanized rubber 3). As shown in FIGS. 3 and 5, the end portion 33 of the present embodiment has an opening 34 for releasing the unvulcanized rubber 3 (shown in FIG. 3) in the rubber filling space 28 into the atmosphere. A relief valve 35 that can open and close the opening 34 is provided. The opening 34 and the relief valve 35 may be omitted.

As shown in FIGS. 4 and 5, the main portion 31 of the present embodiment includes a first portion 37 and a second portion 38.

The first portion 37 is connected to the rubber supply port 27 and extends to one side of the first direction D1. The cross section 45 (shown in FIG. 4) orthogonal to the first direction D1 of the first portion 37 of the present embodiment is formed in a vertically long rectangular shape having arcs at the top and bottom, similarly to the rubber supply port 27. In general, a fluid (including the unvulcanized rubber 3 shown in FIG. 3) has a property of flowing along the shape of an object (wall). Therefore, since the unvulcanized rubber 3 can be smoothly flowed along the arc of the first portion 37, the retention of the unvulcanized rubber 3 can be suppressed. As a result, the rubber-coated head 7 (manufacturing apparatus 1) of the present embodiment can prevent the unvulcanized rubber 3 from being burnt.

Since the cross section 45 (shown in FIG. 4) of the first portion 37 of the present embodiment is formed in a vertically long rectangular shape having arcs in the vertical direction, the unvulcanized rubber 3 (shown in FIG. 3) covers a wide range in the vertical direction. ) Is supplied. As a result, the first portion 37 can effectively bring the unvulcanized rubber 3 into contact with the plurality of cords 2 (shown in FIG. 2) supplied side by side.

As shown in FIGS. 4 and 5, the second portion 38 is connected to the first portion 37 and extends toward one side of the first direction D1. The second portion 38 of the present embodiment extends from the first portion 37 toward one side of the first direction D1 while gradually reducing the length in the vertical direction and the length in the horizontal direction in the front view. It is terminated at the end 33 (shown in FIG. 5) in one direction D1.

The cross section (not shown) orthogonal to the first direction D1 of the second portion 38 is formed in a vertically long rectangular shape having arcs at the top and bottom, similarly to the cross section 45 (shown in FIG. 4) of the first portion 37. As a result, the second portion 38 can smoothly flow the unvulcanized rubber 3 (shown in FIG. 3) along these arcs, so that the retention of the unvulcanized rubber 3 can be suppressed. Therefore, the rubber-coated head 7 (manufacturing apparatus 1) of the present embodiment can prevent the unvulcanized rubber 3 from being burnt.

As shown in FIGS. 4 and 5, the subspace 32 locally projects from the main portion 31 in the second direction D2 intersecting the first direction D1. The subspace 32 of the present embodiment locally projects from the first portion 37 of the main portion 31 in the second direction D2. As shown in FIG. 5, such a subspace 32 is a new flow S2 toward the second direction D2 in the rubber filling space 28 in the main flow S1 of the unvulcanized rubber 3 along the first direction D1. Can be generated. Then, in the rubber-coated head 7 of the present embodiment, a part of the unvulcanized rubber 3 can be concentrated in the sub-space 32 by flowing into the sub-space 32 in which the unvulcanized rubber 3 locally protrudes.

As shown in FIG. 4, the subspace 32 of the present embodiment projects in a columnar shape from the main portion 31. As a result, the subspace 32 is formed in a circular shape having an arc in the cross section 46 (indicated by the alternate long and short dash line in FIG. 4) orthogonal to the second direction. Therefore, since the unvulcanized rubber 3 (shown in FIG. 3) can be smoothly flowed along the arc in the subspace 32, the retention of the unvulcanized rubber 3 can be suppressed. As a result, the rubber-coated head 7 (manufacturing apparatus 1) of the present embodiment can prevent the unvulcanized rubber 3 from being burnt.

As shown in FIG. 5, the subspace 32 of the present embodiment is a portion protruding from the main portion 31 while maintaining a predetermined inner diameter L1 (hereinafter, may be simply referred to as a “same diameter portion”). Contains 40. In the present specification, it is assumed that slight variation (error) in manufacturing is allowed in "maintaining the inner diameter L1". Such a same-diameter portion 40 can reduce the friction with respect to the flow of the unvulcanized rubber 3 toward the second direction, as compared with the case where the inner diameter L1 gradually decreases (not shown). Therefore, the same diameter portion 40 can suppress the retention of the unvulcanized rubber 3.

The number of sub-spaces 32 can be appropriately set, and can be set according to, for example, the number of cords 2 supplied to the rubber filling space 28. In the present embodiment, since the four cords 2 are supplied to the rubber filling space 28, four subspaces 32 are provided. The subspaces 32 of this embodiment are arranged in the vertical direction like the plurality of cords 2.

As shown in FIGS. 4 and 5, the cord supply port 29 is for supplying the cord 2 to the rubber filling space 28. The cord supply port 29 communicates between the rubber filling space 28 and the outside of the casing 26, and can be formed at an arbitrary position of the casing 26. As shown in FIG. 4, the cord supply port 29 of the present embodiment is formed in a circular shape in a side view, and its inner diameter L2 is formed to be larger than the outer diameter L3 (shown in FIG. 5) of the cord 2. Has been done. For example, a baffle (not shown) capable of aligning and supplying cords 2 may be attached to the cord supply port 29.

As shown in FIG. 5, the cord discharge port 30 is for taking out the cord 2 (rubber-coated cord 4) coated with the unvulcanized rubber 3 from the casing 26 through the rubber filling space 28. .. The cord discharge port 30 communicates between the rubber filling space 28 and the outside of the casing 26, and can be formed at an arbitrary position of the casing 26. As shown in FIG. 4, the cord outlet 30 of the present embodiment is formed in a circular shape in a side view. As shown in FIG. 5, the inner diameter L4 of the cord discharge port 30 is formed to be larger than the outer diameter L3 of the cord 2.

The cord discharge port 30 of the present embodiment is configured as a die (base) for molding the unvulcanized rubber 3 coated with the cord 2 into a constant outer diameter. The inner diameter L4 of the cord discharge port 30 can be appropriately set according to the coating thickness of the unvulcanized rubber 3, and can be set to 1.1 to 1.4 times the outer diameter L3 of the cord 2. it can.

The number of cord supply ports 29 and the number of cord discharge ports 30 are set according to the number of cords 2 supplied to the rubber filling space 28. As shown in FIG. 2, in this embodiment, four cords 2 are supplied to the rubber filling space 28. Therefore, as shown in FIG. 4, four cord supply ports 29 and four cord discharge ports 30 are provided.

Then, in the rubber-coated head 7 of the present embodiment, as shown in FIGS. 4 and 5, the cord supply port 29 is formed in the subspace 32. As a result, in the sub-space 32, the unvulcanized rubber 3 is continuously coated on the cord 2 supplied from the cord supply port 29, so that the pressure of the unvulcanized rubber 3 in the sub-space 32 is relatively high. It gets lower. Since the unvulcanized rubber 3 has a property of flowing to the lower pressure side, in the rubber filling space 28, the main flow S1 of the unvulcanized rubber 3 along the first direction D1 is combined with the second direction D2 (secondary space). The flow S2 toward 32) can be continuously generated. As a result, the rubber-coated head 7 of the present embodiment can bring the cord 2 into contact with the unvulcanized rubber 3 that continuously flows in the subspace 32. Therefore, the rubber-coated head 7 (manufacturing apparatus 1) of the present embodiment can improve the rubber-attaching performance of the unvulcanized rubber 3 to the cord 2.

Further, in the rubber-coated head 7, the subspace 32 into which the unvulcanized rubber 3 continuously flows is upstream of the cord supply port 29 side (that is, the flow direction of the cord 2 (second direction D2)) with respect to the main portion 31. It is provided on the side). Therefore, the rubber-coated head 7 can bring the cord 2 into contact with the unvulcanized rubber 3 flowing into the subspace 32 immediately after the cord 2 is supplied to the rubber filling space 28. Further, the rubber-coated head 7 of the present embodiment is an unvulcanized rubber to the cord 2 as compared with a rubber-coated head (not shown) in which the subspace 32 is not provided (that is, only the main portion 31 is provided). The contact time of 3 can be increased. Therefore, the rubber-coated head 7 of the present embodiment can effectively improve the rubber-attaching performance of the unvulcanized rubber 3 to the cord 2.

In order to effectively exert the above action, it is desirable that the cord supply port 29 and the cord discharge port 30 position the cord 2 along the second direction D2. As a result, the rubber-coated head 7 can pass the cord 2 through the rubber filling space 28 along the second direction D2 in which the unvulcanized rubber 3 flows from the main portion 31 toward the sub-space 32. Therefore, the rubber-coated head 7 can increase the contact time of the unvulcanized rubber 3 with the cord 2, and can further improve the rubber-attaching performance of the unvulcanized rubber 3 with the cord 2.

Further, the cord supply port 29 is preferably formed on the axis center line C1 of the subspace 32 as shown in FIGS. 4 and 5. As a result, as shown in FIG. 5, the rubber-coated head 7 has the flow S2 of the unvulcanized rubber 3 from the main portion 31 toward the sub-space 32 and the cord 2 with the axis center line C1 of the sub-space 32 as a boundary. The flow S3 of the unvulcanized rubber 3 from the subspace 32 to the main portion 31 can be generated in a well-balanced manner. Therefore, since the rubber-coated head 7 (manufacturing apparatus 1) can prevent the unvulcanized rubber 3 from staying, the rubber of the unvulcanized rubber 3 on the cord 2 while preventing the rubber of the unvulcanized rubber 3 from burning. Vulcanization performance can be improved.

The cross-sectional area orthogonal to the second direction D2 of the sub-space 32 (the cross-sectional area of the cross-section 46 shown in FIG. 4, hereinafter, may be simply referred to as “the cross-sectional area of the sub-space 32”) is the main portion 31. It is desirable that it is smaller than the cross-sectional area orthogonal to the first direction (the cross-sectional area of the cross-section 45 shown in FIG. 4, hereinafter may be simply referred to as “the cross-sectional area of the main portion 31”). As a result, the rubber-coated head 7 can increase the ratio of the amount of the unvulcanized rubber 3 coated on the cord 2 to the amount of the unvulcanized rubber 3 flowing into the sub-space 32. The pressure of the unvulcanized rubber 3 can be effectively reduced. Therefore, since the rubber-coated head 7 (manufacturing apparatus 1) can effectively supply the unvulcanized rubber 3 to the subspace 32, the rubber-attaching performance of the unvulcanized rubber 3 to the cord 2 is improved. Can be done.

It is desirable that the cross-sectional area of the subspace 32 is set to 3% to 15% of the cross-sectional area of the main portion 31. By setting the cross-sectional area of the subspace 32 to 15% or less of the cross-sectional area of the main portion 31, the pressure of the unvulcanized rubber 3 is lowered, and the rubber attachment performance of the unvulcanized rubber 3 to the cord 2 is improved. It can be effectively improved. On the other hand, when the cross-sectional area of the sub-space 32 is set to 3% or more of the cross-sectional area of the main portion 31, the rubber-coated head 7 (manufacturing apparatus 1) causes the unvulcanized rubber 3 to stay in the sub-space 32. Since it can be suppressed, it is possible to prevent rubber burning of the unvulcanized rubber 3.

It is desirable that the cross-sectional area of the subspace 32 is set to 25 times or more the cross-sectional area of the cord 2. As a result, the rubber-coated head 7 can supply a large amount of the unvulcanized rubber 3 to the sub-space 32, so that the rubber-attaching performance of the unvulcanized rubber 3 to the cord 2 can be improved. On the other hand, if the cross-sectional area of the sub-space 32 is large, the unvulcanized rubber 3 not coated on the cord 2 may stay in the sub-space 32, causing rubber burning of the unvulcanized rubber 3. From this point of view, it is desirable that the cross-sectional area of the subspace 32 is set to 100 times or less the cross-sectional area of the code 2.

As described above, the cord discharge port 30 of the present embodiment is configured as a die (base) for molding the unvulcanized rubber 3 coated with the cord 2 into a constant outer diameter. Such a cord discharge port 30 tends to apply a shear stress in the direction of peeling the unvulcanized rubber 3 from the cord 2 on the unvulcanized rubber 3 coated with the cord 2. Since the cord discharge port 30 of the present embodiment is formed in the casing 26, it covers the cord 2 as compared with, for example, a conventional die plate (not shown) protruding from the casing (main portion) in the second direction D2. The region where shear stress acts on the unvulcanized rubber 3 can be minimized. Therefore, the rubber-coated head 7 of the present embodiment can prevent deterioration of the rubber-attaching performance of the unvulcanized rubber 3 to the cord 2. In order to effectively exert such an action, it is desirable that the thickness W1 (shown in FIG. 5) of the cord outlet 30 is set to 9.95 to 10.05 mm.

As shown in FIG. 5, the subspace 32 of the conventional embodiment is composed of only the same diameter portion 40 protruding from the main portion 31 while maintaining the inner diameter L1, but is not limited to such an embodiment. FIG. 6 is a cross-sectional view showing an example of the subspace 32 of another embodiment of the present invention. FIG. 7 is a cross-sectional view showing an example of the subspace 32 of still another embodiment of the present invention.

As shown in FIG. 6, the subspace 32 may be composed of only a portion (hereinafter, may be simply referred to as a “gradual reduction portion”) 42 protruding from the main portion 31 while gradually reducing the inner diameter L1. Further, as shown in FIG. 7, the subspace 32 may be configured to include the same diameter portion 40 and the gradually decreasing portion 42 protruding from the same diameter portion 40. Such a subspace 32 can reduce the amount of unvulcanized rubber 3 flowing into the gradual reduction portion 42. As a result, in this embodiment, the ratio of the amount of the unvulcanized rubber 3 coated on the cord 2 to the amount of the unvulcanized rubber 3 flowing into the sub-space 32 (gradual reduction portion 42) can be increased, so that the sub-vulcanization The pressure of the unvulcanized rubber 3 in the space 32 can be effectively reduced. Therefore, the rubber-coated head 7 (manufacturing apparatus 1) of this embodiment can effectively generate the flow of the unvulcanized rubber 3 into the subspace 32 (gradual reduction portion 42), so that the unvulcanized rubber 3 does not flow to the code 2. The rubber-attached performance of the vulcanized rubber 3 can be improved.

Although the particularly preferable embodiments of the present invention have been described in detail above, the present invention is not limited to the illustrated embodiments and can be modified into various embodiments.

A rubber-coated head having the basic structure shown in FIGS. 2 to 5 and an apparatus for manufacturing the rubber-coated cord shown in FIG. 1 were prototyped (Examples 1 to 4). In the rubber-coated heads of Examples 1 to 4, the rubber-filled space filled with unvulcanized rubber has a main portion extending in the first direction connected to the rubber supply port and a first portion intersecting the first direction from the main portion. It was configured to include a subspace that locally protrudes in two directions.

For comparison, a rubber-coated head having a rubber-filled space in which the subspace was omitted and a rubber-coated cord manufacturing apparatus shown in FIG. 1 were prototyped (Comparative Examples 1 and 2). Then, the cord was continuously supplied to the rubber-coated heads of Examples 1 to 4 and Comparative Examples 1 and 2, and a rubber-coated cord in which the cord was coated with unvulcanized rubber was manufactured.

Further, for the rubber-coated heads of Example 1 and Comparative Example 1, the flow of unvulcanized rubber was calculated by simulation. FIG. 8A is a diagram showing a streamline of the unvulcanized rubber of Example 1. FIG. 8B is a diagram showing a streamline of the unvulcanized rubber of Comparative Example 1.

The cord outlets of Examples 1 and 3 to 4 were provided in the casing as shown in FIG. 5, and were set to the following thickness W1. On the other hand, the cord outlets of Example 2 and Comparative Examples 1 and 2 were provided on the conventional die plate 48 protruding from the casing (main portion) as shown in FIG. 8 (b).

Further, in Example 3 and Comparative Example 2, the cord was coated with the unvulcanized rubber while releasing the unvulcanized rubber in the rubber filling space into the atmosphere through the opening. On the other hand, in Examples 1 and 2, Example 4 and Comparative Example 1, the cord was circulated in the rubber-filled space without releasing the unvulcanized rubber in the rubber-filled space into the atmosphere. Was coated with unvulcanized rubber.

Then, the rubber-attached performance of the rubber-coated cords produced in Examples 1 to 4 and Comparative Examples 1 and 2 was evaluated. The rubber-attached performance is evaluated by an index with the rubber-attached condition of Example 1 as 100, and the larger the value, the better. Further, in the rubber filling spaces of Examples 1 to 4 and Comparative Examples 1 and 2, the presence or absence of rubber burning of the unvulcanized rubber was visually confirmed. The common specifications are as follows, and the test results are shown in Table 1.
Rubber coated cord: Wire for tire reinforcement (bead wire)
Outer diameter of cord: 1.20 mm
Cross-sectional area of cord: 1.12 mm ²
Number of cords supplied to the rubber-coated head at the same time: 4 Cord outlet thickness W1: 10.00 mm
Simulation software: STAR-CCM + manufactured by Siemens PLM Software

As a result of the test, in Examples 1 to 4, as compared with Comparative Examples 1 and 2 in which the subspace was omitted, the cord can be brought into contact with the continuously flowing unvulcanized rubber, so that the rubberized performance is improved. I was able to make it. Further, in Examples 1 to 4, the flow of the unvulcanized rubber from the main part to the subspace and the flow of the unvulcanized rubber from the subspace to the main part together with the flow of the cord can be generated in a well-balanced manner. Therefore, rubber burning could be prevented as compared with Comparative Examples 1 and 2 in which the subspace was omitted.

In Example 1, as compared with Example 4, in which the cross-sectional area of the subspace is less than 25 times the cross-sectional area of the cord, more unvulcanized rubber can be supplied to the subspace, so that the cord is unvulcanized. It was possible to improve the rubber-attached performance of rubber.

In Examples 1 and 2, as compared with Example 3 in which the unvulcanized rubber is released into the atmosphere, the unvulcanized rubber can be circulated in the rubber filling space, so that the rubber-attached performance can be further improved. did it. Further, in Example 1, as compared with Example 2 provided on the conventional die plate 48 protruding from the casing (main portion), the region where the shear stress acts on the unvulcanized rubber coated with the cord can be made smaller. , The rubberized performance could be further improved.

Further, in the simulation in which the flow of the unvulcanized rubber was calculated, in the first embodiment shown in FIG. 8A, a new flow toward the second direction was added to the main flow of the unvulcanized rubber along the first direction. It was confirmed that the rubber-attached performance could be improved as compared with Comparative Example 1 shown in FIG. 8 (b).

2 Cord 7 Rubber-coated head 27 Rubber supply port 28 Rubber filling space 29 Cord supply port 31 Main part 32 Sub-space

Claims (9)

A rubber-coated head for coating at least one continuously supplied cord with unvulcanized rubber.
Including casing
The casing is
Rubber supply port and
A rubber filling space filled with unvulcanized rubber supplied from the rubber supply port, and
A cord supply port for supplying the cord to the rubber filling space,
Includes a cord outlet for removing the cord coated with the unvulcanized rubber from the casing through the rubber filling space.
The rubber filling space is
A main part connected to the rubber supply port and extending in the first direction,
Includes a subspace that locally protrudes from the main portion in the second direction intersecting the first direction.
The cord supply port is formed in the subspace.
Rubber coated head. The rubber-coated head according to claim 1, wherein the cord supply port and the cord discharge port are located along the second direction of the cord. The rubber-coated head according to claim 1 or 2, wherein the cross-sectional area of the subspace orthogonal to the second direction is smaller than the cross-sectional area of the main portion orthogonal to the first direction. The rubber-coated head according to any one of claims 1 to 3, wherein the cross-sectional area of the subspace orthogonal to the second direction is 25 times or more the cross-sectional area of the cord. The rubber-coated head according to any one of claims 1 to 4, wherein the subspace projects in a columnar shape from the main portion. The rubber-coated head according to claim 5, wherein the subspace includes a portion protruding from the main portion while maintaining a predetermined inner diameter. The rubber-coated head according to claim 5 or 6, wherein the cord supply port is formed on the axis center line of the subspace. The rubber-coated head according to any one of claims 1 to 7, wherein the cord is a wire for reinforcing a tire. A rubber-coated cord manufacturing apparatus for coating at least one cord continuously supplied with unvulcanized rubber.
A rubber extruder for extruding the unvulcanized rubber from the rubber extrusion port, and
The rubber-coated head according to any one of claims 1 to 8, which is connected to the rubber extrusion port.
A cord supply device for continuously supplying the cord to the cord supply port of the rubber-coated head is included.
Rubber-coated cord manufacturing equipment.