JP7367356B2 - Rubber coated head and rubber coated cord manufacturing equipment - Google Patents

Description

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

Patent Document 1 below proposes an apparatus for coating a steel cord with rubber. This device consists of a baffle with multiple through holes through which the steel cord passes, a die plate attached to the tip of the baffle, and an extrusion head that supplies unvulcanized rubber to the steel cord passing through the die plate. It is composed of:

JP2018-27648A

Although the above-mentioned apparatus can coat the steel cord with rubber, there is still room for further improvement in the performance of applying rubber to the steel cord.

The present invention was devised in view of the above-mentioned circumstances, and its main purpose is to provide a rubber-coated head etc. that can improve the performance of attaching rubber to a cord.

The present invention provides a rubber coating head for coating at least one continuously supplied cord with unvulcanized rubber, including a casing, the casing having a rubber supply port and a rubber coating head supplied from the rubber supply port. a rubber filling space filled with unvulcanized rubber; a cord supply port for supplying the cord to the rubber filling space; and a cord covered with the unvulcanized rubber passing through the rubber filling space. a cord outlet for taking out the rubber from the casing, and the rubber filling space includes a main part extending in a first direction in series with the rubber supply port, and a second direction intersecting the first direction from the main part. and a sub-space that locally projects, and the cord supply port is formed in the sub-space.

In the rubber-covered head according to the present invention, the cord supply port and the cord discharge port may be located along the cord in the second direction.

In the rubber-covered head according to the present invention, a cross-sectional area of the sub-space perpendicular to the second direction may be smaller than a cross-sectional area of the main portion perpendicular to the first direction.

In the rubber-covered head according to the present invention, a cross-sectional area of the sub-space perpendicular 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 protrude from the main portion in a cylindrical shape.

In the rubber-coated head according to the present invention, the subspace may include a portion that protrudes 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 tire reinforcement wire.

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

The rubber-coated head of the present invention includes a main part that is connected to a rubber supply port and extends in a first direction as a rubber filling space filled with unvulcanized rubber, and a second direction that intersects the first direction from the main part. and a locally protruding subspace. A cord supply port for supplying the cord to the rubber filling space is formed in the subspace. In such a subspace, since the unvulcanized rubber is continuously coated on the cord supplied from the cord supply port, the pressure of the unvulcanized rubber in the subspace is relatively low. Become. Since the unvulcanized rubber has a tendency to flow in the direction of lower pressure, 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. Can be generated continuously. Thereby, the rubber-coated head of the present invention can bring the cord into contact with the unvulcanized rubber that continuously flows into the subspace, thereby improving the ability of the unvulcanized rubber to stick to the cord. can be improved.

FIG. 1 is a perspective view showing an example of a rubber-coated cord manufacturing apparatus of the present invention. FIG. 2 is a perspective view showing an example of a rubber extruder and a rubber coating head. 3 is a sectional view taken along line AA in FIG. 2. FIG. FIG. 3 is a perspective view showing an example of a rubber-covered head. 5 is a sectional view taken along line BB in FIG. 4. FIG. It is a sectional view showing an example of the subspace of other embodiments of the present invention. It is a sectional view showing an example of the subspace of yet another embodiment of the present invention. (a) is a diagram showing the streamlines of the unvulcanized rubber of Example 1, and (b) is a diagram showing the streamlines of the unvulcanized rubber of Comparative Example 1.

Hereinafter, one embodiment of the present invention will be described based on the drawings.
FIG. 1 is a perspective view showing an example of a rubber-coated cord manufacturing apparatus of the present invention. A rubber-coated cord manufacturing apparatus (hereinafter sometimes simply referred to as "manufacturing apparatus") 1 of the present embodiment is for coating at least one cord 2 that is continuously supplied with unvulcanized rubber 3. It is. The cord 2 is not particularly limited as long as it is covered with the unvulcanized rubber 3. An example of the cord 2 of this embodiment is a tire reinforcing wire (eg, bead wire, etc.).

The manufacturing device 1 of this embodiment includes a rubber extruder 6, a rubber covering head 7, and a cord feeding device 8. Furthermore, the manufacturing apparatus 1 of this embodiment includes a code collection device 9 and a control device 10 configured with a computer or the like. Note that the manufacturing apparatus 1 is not limited to such a configuration. The manufacturing device 1 may be configured to include, for example, devices different from these devices.

FIG. 2 is a perspective view showing an example of the rubber extruder 6 and the rubber coating head 7. As shown in FIG. FIG. 3 is a cross-sectional view taken along line AA in 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 cylindrical shape. This 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 this embodiment extends horizontally along the longitudinal direction of the cylinder 11. An input port 15 (shown in FIGS. 1 and 2) through which the unvulcanized rubber 3 is continuously introduced is provided on the upstream side of the first direction (the direction in which the unvulcanized rubber 3 is extruded) D1 of the cylinder 11. It is being On the other hand, on the downstream side of the cylinder 11 in the first direction (extrusion direction) D1, as shown in FIG. 3, a rubber extrusion port 16 through which the unvulcanized rubber 3 is extruded (discharged) is provided. A rubber supply port 27 of the rubber covering head 7 is connected to this rubber extrusion port 16 .

The screw shaft 12 is arranged inside the chamber 14 of the cylinder 11. The screw shaft 12 of this embodiment is configured to be rotatable around a horizontal axis by a drive device (not shown). By this rotation of the screw shaft 12, the rubber extruder 6 can quantitatively extrude the unvulcanized rubber 3 charged into the input port 15 (shown in FIGS. 1 and 2) toward the rubber extrusion port 16. can. The unvulcanized rubber 3 extruded into the rubber extrusion port 16 is supplied to the rubber filling space 28 of the rubber covering head 7 via the rubber supply port 27 of the rubber covering head 7 . The extrusion speed of the unvulcanized rubber 3 (the number of rotations of the screw shaft 12) is controlled, for example, by 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 a cord supply port 29 (shown in FIG. 2) of the rubber-covered head 7 via, for example, a guide roller 19.

The cord 2 before being covered with the unvulcanized rubber 3 is wound around the first reel 17 in advance. The number of first reels 17 can be set as appropriate, for example, depending on the number of cords 2 to be covered with unvulcanized rubber 3 at the same time. In this embodiment, four cords 2 are simultaneously coated with unvulcanized rubber 3. For this reason, the cord supply device 8 is provided with four first reels 17. These first reels 17 are removably supported by a first support section 18.

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

The cord recovery device 9 is for recovering the cord 2 coated with the unvulcanized rubber 3 (ie, the rubber-covered cord 4). The cord recovery device 9 includes a second reel 21 for winding up the rubber-coated cord 4, a second support section 22 that rotatably supports the second reel 21, and a second drive device that rotationally drives the second reel 21. 23.

The number of second reels 21 can be set as appropriate, for example, depending on the number of cords 2 coated with unvulcanized rubber 3 (i.e., rubber-coated cords 4). In this embodiment, since the four cords 2 are covered with unvulcanized rubber 3, four second reels 21 are provided. These second reels 21 are removably supported by the second support section 22.

The second drive device 23 of this embodiment is for rotating each second reel 21 and winding up the rubber-covered cord 4. The second drive device 23 is provided on the second support section 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 . The second reel 21 can wind up the rubber-coated cord 4 via the guide roller 24 by rotation by the second drive device 23 . By winding up the rubber-coated cord 4, the cord supply device 8 rotates the first reel 17 and continuously supplies 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, on which the rubber-coated cord 4 has been wound, is removed from the second support portion 22 and used, for example, for manufacturing green tires. Then, a new second reel 21 before winding up the rubber-coated cord 4 is attached to the second support section 22 .

As shown in FIG. 2, the rubber coating head 7 is for coating at least one continuously supplied cord 2 with unvulcanized rubber 3. The rubber-coated head 7 includes a casing 26. A plurality of cords 2 (four in this example) arranged vertically are continuously supplied to the rubber-coated head 7 of this embodiment, but a plurality of cords 2 arranged horizontally 2 may be supplied continuously. FIG. 4 is a perspective view showing an example of the rubber-covered head 7. As shown in FIG. FIG. 5 is a sectional view taken along line BB in FIG. In FIG. 5, the cord 2 attached to the rubber-coated head 7 and the rubber-coated cord 4 are indicated by two-dot chain lines.

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 on the other side of the casing 26 in 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. Thereby, 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 the shape of the rubber extrusion port 16 of the rubber extruder 6, for example. As shown in FIG. 4, the rubber supply port 27 of this embodiment is formed in a vertically elongated rectangular shape having an arc 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. As shown in FIGS. The main portion 31 and the subspace 32 communicate 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 formed so as to be separable by disassembling the casing 26.

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

As shown in FIGS. 4 and 5, the main portion 31 of this 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 in the first direction D1. A cross section 45 (shown in FIG. 4) of the first portion 37 of this embodiment perpendicular to the first direction D1 is formed in a vertically elongated rectangular shape having an arc upward and downward, similarly to the rubber supply port 27. Generally, 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 first portion 37 can smoothly flow the unvulcanized rubber 3 along its arc, it is possible to suppress retention of the unvulcanized rubber 3. Thereby, the rubber covered head 7 (manufacturing apparatus 1) of this embodiment can prevent the unvulcanized rubber 3 from burning.

The first portion 37 of this embodiment has a cross section 45 (shown in FIG. 4) formed in a vertically elongated rectangular shape having an arc at the top and bottom, so that the unvulcanized rubber 3 (as shown in FIG. ) is supplied. Thereby, the first portion 37 can effectively bring the unvulcanized rubber 3 into contact with the plurality of cords 2 (shown in FIG. 2) that are arranged and supplied vertically.

As shown in FIGS. 4 and 5, the second portion 38 is continuous with the first portion 37 and extends toward one side in the first direction D1. The second portion 38 of the present embodiment extends from the first portion 37 toward one side in the first direction D1 while gradually decreasing the length in the vertical direction and the length in the horizontal direction when viewed from the front. It terminates at an end 33 (shown in FIG. 5) in one direction D1.

A cross section (not shown) of the second portion 38 perpendicular to the first direction D1 is formed in a vertically elongated rectangular shape having an arc above and below, similar to the cross section 45 of the first portion 37 (shown in FIG. 4). Thereby, the second portion 38 can smoothly flow the unvulcanized rubber 3 (shown in FIG. 3) along these circular arcs, so that retention of the unvulcanized rubber 3 can be suppressed. Therefore, the rubber-coated head 7 (manufacturing apparatus 1) of this embodiment can prevent the unvulcanized rubber 3 from burning.

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

As shown in FIG. 4, the subspace 32 of this embodiment protrudes from the main portion 31 in a cylindrical shape. Thereby, the subspace 32 is formed into a circular shape having an arc in a cross section 46 (indicated by a two-dot chain line in FIG. 4) perpendicular to the second direction. Therefore, the subspace 32 allows the unvulcanized rubber 3 (shown in FIG. 3) to flow smoothly along the circular arc, so that retention of the unvulcanized rubber 3 can be suppressed. Thereby, the rubber covered head 7 (manufacturing apparatus 1) of this embodiment can prevent the unvulcanized rubber 3 from burning.

As shown in FIG. 5, the sub-space 32 of this embodiment is a portion that protrudes from the main portion 31 while maintaining a predetermined inner diameter L1 (hereinafter sometimes simply referred to as "same-diameter portion"). Contains 40. In this specification, "maintaining the inner diameter L1" means that slight manufacturing variations (errors) are allowed. Such a same-diameter portion 40 can reduce friction against the flow of the unvulcanized rubber 3 in the second direction, compared to, for example, a case where the inner diameter L1 gradually decreases (not shown). Therefore, the same diameter portion 40 can suppress retention of the unvulcanized rubber 3.

The number of sub-spaces 32 can be set as appropriate, for example, depending on the number of cords 2 supplied to the rubber filling space 28. In this embodiment, four cords 2 are supplied to the rubber filling space 28, so four sub-spaces 32 are provided. The sub-spaces 32 of this embodiment are arranged in the vertical direction similarly to 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 any position in the casing 26. As shown in FIG. 4, the cord supply port 29 of this embodiment is formed into a circular shape when viewed from the side, and its inner diameter L2 is larger than the outer diameter L3 of the cord 2 (shown in FIG. 5). has been done. For example, a baffle (not shown) that can line up and supply the cords 2 may be attached to the cord supply port 29 .

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

The cord discharge port 30 of this embodiment is configured as a die (die) that molds the unvulcanized rubber 3 covering the cord 2 to a constant outer diameter. The inner diameter L4 of the cord outlet 30 can be set as appropriate depending on 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, for example. 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.

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

Further, in the rubber-covered head 7, the sub-space 32 into which the unvulcanized rubber 3 continuously flows is located on the cord supply port 29 side with respect to the main portion 31 (i.e., upstream in the flow direction of the cord 2 (second direction D2)). 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 . Furthermore, the rubber-covered head 7 of the present embodiment has a higher resistance to unvulcanized rubber to the cord 2 than a rubber-covered head (not shown) in which the sub-space 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 this embodiment can effectively improve the performance of attaching the unvulcanized rubber 3 to the cord 2.

In order to effectively exhibit the above effect, it is desirable that the cord supply port 29 and the cord discharge port 30 are located along the cord 2 in the second direction D2. Thereby, the rubber-covered head 7 can pass the cord 2 into the rubber filling space 28 along the second direction D2 in which the unvulcanized rubber 3 flows from the main portion 31 toward the subspace 32. Therefore, the rubber-coated head 7 can increase the contact time of the unvulcanized rubber 3 to the cord 2, and can further improve the performance of attaching the unvulcanized rubber 3 to the cord 2.

Furthermore, it is desirable that the cord supply port 29 be formed on the axial center line C1 of the sub-space 32, as shown in FIGS. 4 and 5. As a result, as shown in FIG. It is possible to generate a well-balanced flow of the unvulcanized rubber 3 along with the flow S3 of the unvulcanized rubber 3 from the subspace 32 toward the main portion 31. Therefore, since the rubber covering head 7 (manufacturing device 1) can prevent the unvulcanized rubber 3 from staying, the rubber covering of the unvulcanized rubber 3 to the cord 2 can be prevented while preventing the unvulcanized rubber 3 from burning. It is possible to improve the attachment performance.

The cross-sectional area of the sub-space 32 perpendicular to the second direction D2 (this is the cross-sectional area of the cross-section 46 shown in FIG. 4, hereinafter also simply referred to as "the cross-sectional area of the sub-space 32") is It is desirable that the cross-sectional area is smaller than the cross-sectional area perpendicular to the first direction (this is the cross-sectional area of the cross-section 45 shown in FIG. 4, and hereinafter may simply be referred to as "the cross-sectional area of the main portion 31"). As a result, the rubber covering head 7 can increase the ratio of the amount of unvulcanized rubber 3 coated on the cord 2 to the amount of unvulcanized rubber 3 flowing into the sub space 32, so that the amount of unvulcanized rubber 3 in the sub space 32 can be increased. The pressure of the unvulcanized rubber 3 can be effectively lowered. Therefore, the rubber coating head 7 (manufacturing device 1) can effectively supply the unvulcanized rubber 3 to the subspace 32, thereby improving the performance of attaching the unvulcanized rubber 3 to the cord 2. I can do it.

The cross-sectional area of the sub-space 32 is desirably set to 3% to 15% of the cross-sectional area of the main portion 31. By setting the cross-sectional area of the sub-space 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 performance of rubber attachment of the unvulcanized rubber 3 to the cord 2 is improved. can be effectively improved. On the other hand, by setting the cross-sectional area of the sub-space 32 to 3% or more of the cross-sectional area of the main portion 31, the rubber coating head 7 (manufacturing apparatus 1) prevents the unvulcanized rubber 3 from remaining in the sub-space 32. Since this can be suppressed, rubber burning of the unvulcanized rubber 3 can be prevented.

It is desirable that the cross-sectional area of the sub-space 32 is set to be 25 times or more the cross-sectional area of the cord 2. Thereby, the rubber covering head 7 can supply a large amount of unvulcanized rubber 3 to the subspace 32, and thus the performance of attaching 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 that is not covered by the cord 2 may remain in the sub-space 32, causing the unvulcanized rubber 3 to burn. From this point of view, it is desirable that the cross-sectional area of the sub-space 32 be set to 100 times or less the cross-sectional area of the cord 2.

As described above, the cord outlet 30 of the present embodiment is configured as a die (die) that molds the unvulcanized rubber 3 covering the cord 2 to a constant outer diameter. Such a cord discharge port 30 tends to apply shear stress to the unvulcanized rubber 3 covering the cord 2 in a direction that causes the unvulcanized rubber 3 to peel off from the cord 2 . Since the cord discharge port 30 of this embodiment is formed in the casing 26, it covers the cord 2 more easily than a conventional die plate (not shown) that protrudes from the casing (main portion) in the second direction D2. The area where shear stress acts on the unvulcanized rubber 3 can be minimized. Therefore, the rubber-coated head 7 of the present embodiment can prevent the performance of attaching the unvulcanized rubber 3 to the cord 2 from deteriorating. In order to effectively exhibit this effect, the thickness W1 (shown in FIG. 5) of the cord discharge port 30 is desirably set to 9.95 to 10.05 mm.

As shown in FIG. 5, the subspace 32 of the embodiments so far has been configured only with the same-diameter portion 40 that protrudes from the main portion 31 while maintaining the inner diameter L1, but is not limited to such a configuration. FIG. 6 is a sectional view showing an example of the subspace 32 according to another embodiment of the present invention. FIG. 7 is a sectional view showing an example of the subspace 32 according to still another embodiment of the present invention.

As shown in FIG. 6, the sub-space 32 may be comprised only of a portion (hereinafter sometimes simply referred to as a "gradually decreasing portion") 42 that protrudes from the main portion 31 while gradually decreasing the inner diameter L1. Further, as shown in FIG. 7, the subspace 32 may include a portion 40 of the same diameter and a gradually decreasing portion 42 protruding from the portion 40 of the same diameter. Such a subspace 32 can reduce the amount of unvulcanized rubber 3 flowing into the gradually decreasing portion 42. As a result, in this embodiment, the ratio of the amount of unvulcanized rubber 3 coated on the cord 2 to the amount of unvulcanized rubber 3 flowing into the sub space 32 (gradual reduction part 42) can be increased. The pressure of the unvulcanized rubber 3 in the space 32 can be effectively lowered. Therefore, the rubber-covered head 7 (manufacturing device 1) of this embodiment can effectively generate a flow of unvulcanized rubber 3 to the subspace 32 (gradual reduction section 42), so that the unvulcanized rubber 3 flows to the cord 2. The rubber attachment performance of the vulcanized rubber 3 can be improved.

Although particularly preferred 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 and implemented in various ways.

A rubber-covered head having the basic structure shown in FIGS. 2 to 5 and a manufacturing apparatus for the rubber-covered cord shown in FIG. 1 were prototyped (Examples 1 to 4). The rubber-coated heads of Examples 1 to 4 had a main part extending in a first direction connected to the rubber supply port, and a first part extending from the main part to the first direction, in the rubber filling space filled with unvulcanized rubber. The space includes a sub-space that locally protrudes in two directions.

For comparison, a rubber-coated head having a rubber-filled space with no sub-space and a rubber-coated cord manufacturing apparatus shown in FIG. 1 were prototyped (Comparative Examples 1 and 2). Then, the cords were continuously supplied to the rubber-covered heads of Examples 1 to 4 and Comparative Examples 1 to 2 to produce rubber-covered cords in which the cords were coated with unvulcanized rubber.

Furthermore, the flow of unvulcanized rubber for the rubber-coated heads of Example 1 and Comparative Example 1 was calculated by simulation. FIG. 8(a) is a diagram showing streamlines of the unvulcanized rubber of Example 1. FIG. 8(b) is a diagram showing streamlines of the unvulcanized rubber of Comparative Example 1.

The cord outlet in Example 1 and Examples 3 and 4 was provided in the casing, as shown in FIG. 5, and was set to have the following thickness W1. On the other hand, the cord outlet in Example 2 and Comparative Examples 1 and 2 was provided in a 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 unvulcanized rubber while releasing the unvulcanized rubber in the rubber filling space into the atmosphere from the opening. On the other hand, in Examples 1 to 2, Example 4, and Comparative Example 1, the unvulcanized rubber in the rubber filling space was circulated in the rubber filling space without releasing the unvulcanized rubber 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 to 2 was evaluated. The rubber adhesion performance is evaluated by an index taking the degree of rubber adhesion 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 to 2, the presence or absence of rubber burning of 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)
Cord outer diameter: 1.20mm
Cord cross-sectional area: 1.12mm ²
Number of cords supplied to the rubber-covered head at the same time: 4 Cord outlet thickness W1: 10.00mm
Simulation software: STAR-CCM+ manufactured by Siemens PLM Software

As a result of the test, compared to Comparative Examples 1 and 2 in which the subspace was omitted, Examples 1 to 4 had improved rubber attachment performance because the cord could be brought into contact with the continuously flowing unvulcanized rubber. I was able to do it. Furthermore, in Examples 1 to 4, it is possible to generate a well-balanced flow of unvulcanized rubber from the main part to the subspace, and a flow of unvulcanized rubber from the subspace to the main part together with the flow of the cord. Therefore, compared to Comparative Examples 1 and 2 in which the subspace was omitted, rubber burning could be prevented.

In Example 1, more unvulcanized rubber can be supplied to the sub-space than in Example 4, in which the cross-sectional area of the sub-space is less than 25 times the cross-sectional area of the cord. It was possible to improve the rubber adhesion performance of the rubber.

In Examples 1 and 2, compared to Example 3 in which unvulcanized rubber is released into the atmosphere, unvulcanized rubber can be circulated in the rubber filling space, so that the rubber attachment performance can be further improved. did it. Furthermore, in Embodiment 1, compared to Embodiment 2, which is provided on the conventional die plate 48 protruding from the casing (main part), the area where shear stress acts on the unvulcanized rubber covering the cord can be made smaller. , we were able to further improve the rubber attachment performance.

Furthermore, in a simulation that calculated the flow of unvulcanized rubber, Example 1 shown in FIG. It was confirmed that the rubber attachment performance could be improved compared to Comparative Example 1 shown in FIG. 8(b).

2 Cord 7 Rubber covered head 27 Rubber supply port 28 Rubber filling space 29 Cord supply port 31 Main part 32 Subspace

Claims (9)

A rubber coating head for coating at least one continuously supplied cord with unvulcanized rubber, the head comprising:
including the casing,
The casing is
a rubber supply port;
a rubber filling space filled with unvulcanized rubber supplied from the rubber supply port;
a cord supply port for supplying the cord to the rubber filling space;
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 portion that extends in a first direction and is connected to the rubber supply port;
a subspace locally protruding from the main part in a second direction intersecting the first direction,
the cord supply port protrudes from the subspace;
Rubber coated head. The rubber-covered head according to claim 1, wherein the cord supply port and the cord discharge port are located along the cord in the second direction. The rubber-covered head according to claim 1 or 2, wherein a cross-sectional area of the sub-space perpendicular to the second direction is smaller than a cross-sectional area of the main portion perpendicular to the first direction. 4. The rubber-coated head according to claim 1, wherein a cross-sectional area of the sub-space perpendicular to the second direction is 25 times or more larger than a cross-sectional area of the cord. The rubber-covered head according to any one of claims 1 to 4, wherein the subspace projects in a cylindrical shape from the main portion. The rubber-coated head according to claim 5, wherein the subspace includes a portion that protrudes from the main portion while maintaining a predetermined inner diameter. The rubber-covered head according to claim 5 or 6, wherein the cord supply port is formed on the axial center line of the subspace. The rubber-coated head according to any one of claims 1 to 7, wherein the cord is a tire reinforcing wire. A rubber-coated cord manufacturing device for coating at least one continuously supplied cord with unvulcanized rubber,
a rubber extruder for extruding the unvulcanized rubber from a rubber extrusion port;
The rubber covered head according to any one of claims 1 to 8, 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;
Rubber coated cord manufacturing equipment.

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