Extrusion molding die

Abstract

To provide an extrusion molding mouthpiece capable of preventing exposure of side ends of a second rubber layer in a rubber ribbon.SOLUTION: An extrusion molding mouthpiece attached to an end of an extrusion molding apparatus that continuously discharges a rubber ribbon provided with a first rubber layer located on one side of a ribbon thickness direction and a second rubber layer located on the other side of the ribbon thickness direction of the first rubber layer includes: a first rubber inflow passage into which a first rubber forming the first rubber layer flows; a second rubber inflow passage extending in a direction crossing the first rubber inflow passage and into which a second rubber forming the second rubber layer flows; and a rubber ribbon discharge passage extending from a confluence position of the first rubber inflow passage and the second rubber inflow passage. The first rubber inflow passage intersects one side of the second rubber inflow passage in the ribbon thickness direction, including a side end of the second rubber inflow passage in a ribbon width direction.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to an extrusion die. [Background technology]

[0002] Patent Document 1 discloses an extrusion molding device that continuously extrudes a rubber ribbon whose cross section is partitioned into a first rubber layer made of a first rubber and a second rubber layer made of a second rubber. The extrusion molding device combines the first rubber that forms the first rubber layer and the second rubber that forms the second rubber layer in a rubber combining section of the extrusion molding device, and discharges the combined rubber as a rubber ribbon from an extrusion molding die.

[0003] The rubber ribbon discharged from the extrusion die is spirally wound around a molding drum to form a rubber member. In this process, a rubber member such as an inner liner rubber is molded so that the second rubber layer is not exposed on the molding drum side. However, if the side edge of the second rubber layer in the rubber ribbon in the ribbon width direction is exposed, the second rubber layer of the rubber member may be exposed on the molding drum side. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2008 / 7420 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present disclosure is to provide an extrusion die that can prevent the side edge of the second rubber layer in the rubber ribbon from being exposed. [Means for solving the problem]

[0006] The extrusion molding die of the present disclosure is an extrusion molding die attached to the tip of an extrusion molding device that continuously discharges a rubber ribbon having a first rubber layer arranged on one side in the ribbon thickness direction and a second rubber layer arranged on the other side in the ribbon thickness direction of the first rubber layer, and is equipped with a first rubber inlet channel into which the first rubber that forms the first rubber layer flows, a second rubber inlet channel that extends in a direction intersecting with the first rubber inlet channel and into which the second rubber that forms the second rubber layer flows, and a rubber ribbon discharge channel that extends from a position where the first rubber inlet channel and the second rubber inlet channel join, and the first rubber inlet channel intersects with one side in the ribbon thickness direction of the second rubber inlet channel which includes a side end portion in the ribbon width direction of the second rubber inlet channel. [Brief explanation of the drawings]

[0007] [Figure 1A] 1 is a cross-sectional view of a rubber ribbon formed by an extrusion molding device according to an embodiment; [Figure 1B] 10 is a cross-sectional view of a rubber ribbon formed by an extrusion molding device according to another embodiment. [Figure 2] Cross-sectional view showing the rubber ribbon wound around the forming drum [Figure 3] Schematic diagram of an extrusion molding device according to one embodiment. [Figure 4] FIG. 10 is an enlarged front view of a main part of the extrusion molding device according to the embodiment; [Figure 5] Cross section of line VV in Figure 4 [Figure 6] FIG. 10 is a cross-sectional view illustrating a molding method for a rubber ribbon in the embodiment. [Figure 7] FIG. 10 is an enlarged front view of a main part of an extrusion molding device according to another embodiment. [Figure 8] Cross section of Figure 7 along line VIII-VIII DETAILED DESCRIPTION OF THE INVENTION

[0008] [Rubber ribbon] First, an example of a rubber ribbon molded by an extrusion molding apparatus will be described with reference to Figures 1A to 2. Note that in each figure (Figures 1A to 8), the dimensional ratios in the drawings do not necessarily match the actual dimensional ratios, and the dimensional ratios between the drawings do not necessarily match either.

[0009] As shown in FIG. 1A, a rubber ribbon 100 is continuously discharged by an extrusion molding device 1, which will be described later, and formed into a long plate. The thickness of the rubber ribbon 100 gradually decreases from the center toward the side edges in the ribbon width direction D2. This allows the thickness of the rubber member 500 formed by the rubber ribbon 100 to be made nearly uniform when the rubber ribbon 100 is spirally wound around a molding drum 400, as shown in FIG. 2. In this embodiment, the rubber ribbon 100 is formed into a substantially triangular cross section, but this is not limited to this. For example, the rubber ribbon 100 may be formed into a substantially trapezoidal cross section, a substantially crescent cross section, or the like.

[0010] 1A, the rubber ribbon 100 includes a first rubber layer 101 disposed on one side in the ribbon thickness direction D1 (first ribbon thickness direction D11), and a second rubber layer 102 disposed on the other side in the ribbon thickness direction D1 (second ribbon thickness direction D12) of the first rubber layer 101. In this embodiment, the one side in the ribbon thickness direction D1 corresponds to the inner side in the tire radial direction, and the other side in the ribbon thickness direction D1 corresponds to the outer side in the tire radial direction.

[0011] The side end portions 102a, 102a of the second rubber layer 102 in the ribbon width direction D2 are covered by the first rubber layer 101. This prevents the second rubber layer 102 from being exposed on the forming drum 400 side when the rubber ribbon 100 is spirally wound around the forming drum 400, as shown in FIG. 2 . The second rubber layer 102 is exposed at the center of the rubber ribbon 100 in the ribbon width direction D2. In this embodiment, as shown in FIG. 1A , the first rubber layer 101 covers the second rubber layer 102 from the side end portions 102a, 102a of the second rubber layer 102 to the second ribbon thickness direction D12 side, but this is not limited to this. For example, as shown in FIG. 1B , the first rubber layer 101 may cover the side end portions 102a, 102a of the second rubber layer 102.

[0012] As shown in Fig. 2, the rubber member 500 is formed by spirally winding the rubber ribbon 100 around the forming drum 400. By forming the rubber member 500 using the rubber ribbon 100 in which the rubber layers 101, 102 are integrated, it is possible to shorten the time required to form the rubber member 500 and reduce errors in attaching the first rubber layer 101 and the second rubber layer 102 compared to when the rubber layers 101, 102 are wound separately. In addition, it becomes easier to adjust the proportions of the rubber layers 101, 102 in the rubber member 500, which makes it possible to reduce the weight of pneumatic tires (hereinafter simply referred to as "tires") and improve tire performance such as rolling resistance.

[0013] In this embodiment, the rubber member 500 is an inner liner rubber of a tire, but is not limited to this. The first rubber layer 101 forms the innermost surface of the tire. The second rubber layer 102 is disposed between the first rubber layer 101 and a carcass ply disposed on the radially outer side of the inner liner rubber.

[0014] The first rubber layer 101 is formed of a first rubber, and the second rubber layer 102 is formed of a second rubber different from the first rubber. In this embodiment, the first rubber is butyl rubber, which has excellent air permeability prevention properties. The second rubber is squeegee rubber, which prevents the carcass ply from being exposed to the innermost surface of the tire when the unvulcanized tire is expanded by the bladder. The squeegee rubber is a rubber material harder than butyl rubber. Note that the first rubber and the second rubber are not limited to those described above.

[0015] If the side end portions 102a, 102a of the second rubber layer 102 in the rubber ribbon 100 were exposed, the second rubber layer 102 would be exposed on the innermost surface of the tire of the inner liner rubber (the forming drum 400 side of the rubber member 500), and there is a risk that air inside the tire would pass through the exposed portion of the second rubber layer 102. For this reason, it is necessary to suppress exposure of the second rubber layer 102 on the innermost surface of the inner liner rubber of the tire by suppressing exposure of the side end portions 102a, 102a of the second rubber layer 102 in the rubber ribbon 100.

[0016] [Extrusion molding equipment] Next, an example of an extrusion molding device will be described with reference to FIGS.

[0017] As shown in Figure 3, the extrusion molding device 1 includes a first rubber extruder 8 that extrudes a first rubber, a first rubber supply section 2 that supplies the first rubber, a second rubber extruder 9 that extrudes a second rubber, a second rubber supply section 3 that supplies the second rubber, and an extrusion molding die (hereinafter simply referred to as the "die") 4 that molds the supplied first rubber and second rubber into a rubber ribbon 100 and discharges it in the ribbon discharge direction D3.

[0018] The rubber ribbon 100 discharged from the die 4 is transported by a plurality of transport rollers 200 and pressed onto the forming drum 400 by a pressure roller 300. The forming drum 400 is configured to be movable in its axial direction (a direction perpendicular to the paper surface of FIG. 3) and to be rotatable around its axis. By moving the forming drum 400, into which the rubber ribbon 100 has been fed, in the axial direction while rotating, the rubber ribbon 100 is wound spirally around the forming drum 400.

[0019] The first rubber supply unit 2 is attached to the first rubber extruder 8. As shown in FIGS. 3 and 5 , the first rubber supply unit 2 includes a first rubber supply path 21 that supplies the first rubber extruded from the first rubber extruder 8 to the die 4. In this embodiment, the first rubber supply path 21 is formed to have a substantially circular cross section and is arranged on the first ribbon thickness direction D11 side of the die 4, but is not limited to this. In this embodiment, the first rubber supply unit 2 is separate from the second rubber supply unit 3, but may be integrated with the second rubber supply unit 3.

[0020] As shown in Fig. 3, the second rubber supply unit 3 is attached to the second rubber extruder 9. As shown in Figs. 3 and 5, the second rubber supply unit 3 includes a second rubber supply path 31 that supplies the second rubber extruded from the second rubber extruder 9 to the die 4. In this embodiment, the second rubber supply path 31 is formed to have a substantially circular cross section, but is not limited to this. The second rubber supply path 31 is arranged upstream of the die 4 in the ribbon discharge direction D3.

[0021] [Extrusion molding die] As shown in FIGS. 4 and 5, the die 4 is disposed at the tip of the extrusion molding device 1 and attached (for example, by bolting) to the first rubber supply unit 2 and the second rubber supply unit 3. In this embodiment, the die 4 is formed in a substantially rectangular parallelepiped shape, but is not limited to this. The die 4 includes a first die 5 disposed downstream in the ribbon discharge direction D3 and a second die 6 disposed upstream in the ribbon discharge direction D3. In this embodiment, the first die 5 and the second die 6 are separate bodies and fixed to the first rubber supply unit 2 and the second rubber supply unit 3 by fixing members (for example, bolting), not shown. The first die 5 may be formed integrally with the second die 6.

[0022] The nozzle 4 includes a first rubber inlet path 41 through which the first rubber flows, a second rubber inlet path 42 through which the second rubber flows, and a rubber ribbon outlet path 43 through which the first rubber and the second rubber are formed into a rubber ribbon 100 and discharged in a ribbon discharge direction D3.

[0023] The second rubber inlet path 42 extends from the second rubber supply path 31 to the rubber ribbon discharge path 43. In this embodiment, the second rubber inlet path 42 is a through hole that penetrates the second die 6. The second rubber inlet path 42 is formed in a substantially triangular shape when viewed in the ribbon discharge direction D3. Note that the second rubber inlet path 42 is not limited to the above.

[0024] The second rubber inlet channel 42 extends in a direction intersecting with the first rubber inlet channel 41. In the present embodiment, the second rubber inlet channel 42 extends in the same direction as the rubber ribbon discharge channel 43 (ribbon discharge direction D3), but is not limited to this. For example, the second rubber inlet channel 42 may extend in a direction intersecting with the rubber ribbon discharge channel 43. From the viewpoint of improving the rubber flow of the second rubber, it is preferable that the second rubber inlet channel 42 extends in the same direction as the second rubber supply channel 31.

[0025] In the present embodiment, the thickness T2 of the second rubber inlet channel 42 is constant, but is not limited to this. For example, the thickness T2 may decrease toward the joining position P1 of the first rubber inlet channel 41 and the second rubber inlet channel 42. Furthermore, the width W2 of the second rubber inlet channel 42 in the ribbon width direction D2 is constant, but is not limited to this. For example, the width W2 may decrease toward the joining position P1.

[0026] The junction position P1 is a position on the upstream side in the ribbon discharge direction D3 where the first rubber inlet channel 41 and the second rubber inlet channel 42 join together. In this embodiment, the junction position P1 is located on the upstream end surface 51 of the first die 5 (the downstream end surface 61 of the second die 6).

[0027] The first rubber inlet path 41 extends from the first rubber supply path 21 to the rubber ribbon discharge path 43. In this embodiment, the first rubber inlet path 41 is formed by the first die 5 and the second die 6, but is not limited to this.

[0028] The first die 5 has a recess 51a on its upstream end face 51 in the ribbon discharge direction D3. The recess 51a extends from the position where it intersects with the rubber ribbon discharge path 43 to an end face 53 of the first die 5 in the first ribbon thickness direction D11. By attaching the first die 5 to the second die 6, the recess 51a and the downstream end face 61 of the second die 6 in the ribbon discharge direction D3 form the first rubber inlet path 41.

[0029] According to this configuration, by changing the shape of the recess 51a, it is possible to easily change the shape of the first rubber inlet channel 41. In other words, by replacing the first mouthpiece 5 with one having a different shape of the recess 51a, it is possible to easily change the shape of the first rubber inlet channel 41.

[0030] The first rubber inlet passage 41 may be, for example, a hole extending from the outside to the inside of the first nozzle 5, or may be a hole consisting of a through hole penetrating the second nozzle 6 and a hole extending from the through hole to the inside of the first nozzle 5.

[0031] From the viewpoint of improving the flow of the first rubber, it is preferable that the first rubber inlet channel 41 extend in the same direction as the first rubber supply channel 21. From the viewpoint of improving the merging of the first rubber and the second rubber, it is preferable that the merging angle between the first rubber inlet channel 41 and the second rubber inlet channel 42 be 90 degrees or less. The merging angle is the angle between the center line of the first rubber inlet channel 41 and the center line of the second rubber inlet channel 42.

[0032] In this embodiment, the first rubber inlet channel 41 is formed in a flat plate shape. That is, the thickness T1 of the first rubber inlet channel 41 is constant. The thickness T1 may decrease toward the joining position P1. That is, the thickness T11 on the joining position side of the thickness T1 may be smaller than the thickness T12 on the supply channel side of the thickness T1.

[0033] The first rubber inlet channel 41 intersects with one side (first ribbon thickness direction D11) of the second rubber inlet channel 42 in the ribbon thickness direction D1, including the side end portions 421, 421 of the second rubber inlet channel 42 in the ribbon width direction D2. From the viewpoint of reliably covering the side end portions 102a, 102a of the second rubber layer 102 in FIG. 1A with the first rubber layer 101, it is preferable that the first rubber inlet channel 41 intersects with 50% or more of the thickness in the ribbon thickness direction D1 between the side end portions 421, 421 of the second rubber inlet channel 42 to the central portion 422. Note that the first rubber inlet channel 41 may cover the entire circumference of the second rubber inlet channel 42.

[0034] The width W1 of the first rubber inlet channel 41 in the ribbon width direction D2 is larger than the width W2 of the second rubber inlet channel 42. From the viewpoint of improving the flow of rubber downstream of the first rubber inlet channel 41, it is preferable that the width W1 be formed to narrow toward the joining position P1. In this embodiment, the downstream end portions 411, 411 of the first rubber inlet channel 41 are formed in an arc shape, but this is not limited to this.

[0035] In order to improve the flow of the first rubber to the downstream ends 411, 411, the first rubber inlet channel 41 may be formed in a shape in which the thickness T1 at the central portion in the ribbon width direction D2 is narrowed or in which the thickness T1 at the side ends in the ribbon width direction D2 is widened.

[0036] The rubber ribbon discharge path 43 extends from the joining position P1 toward the outside of the die 4. In the present embodiment, the rubber ribbon discharge path 43 is a through hole that penetrates the first die 5. The rubber ribbon discharge path 43 is formed in a substantially triangular shape when viewed in the ribbon discharge direction D3, but is not limited to this.

[0037] The area of ​​the cross section perpendicular to the rubber ribbon discharge path 43 is preferably larger than the area of ​​the cross section perpendicular to the second rubber inlet path 42. In this embodiment, the thickness T3 of the rubber ribbon discharge path 43 in the ribbon thickness direction D1 is larger than the thickness T2 of the second rubber inlet path 42, and the width W3 of the rubber ribbon discharge path 43 in the ribbon width direction D2 is larger than the width W2 of the second rubber inlet path 42.

[0038] The thickness T1 of the first rubber inlet channel 41 at the junction P1 (thickness T11 on the junction side) is preferably smaller than the thickness T3 of the rubber ribbon discharge channel 43. From the viewpoint of reliably covering the side ends 102a, 102a of the second rubber layer 102 in FIG. 1A with the first rubber layer 101, the width W3 is preferably 90% to 110% of the width W1 of the first rubber inlet channel 41.

[0039] The rubber ribbon discharge path 43 has a discharge opening 43a through which the rubber ribbon 100 is discharged. The discharge opening 43a is arranged on the downstream end face 52 of the first die 5 in the ribbon discharge direction D3. The minimum length Lmin from the first rubber inlet path 41 to the discharge opening 43a is preferably 2 mm or more. From the viewpoint of preventing deformation of the rubber ribbon 100 due to contact with the rubber ribbon discharge path 43, the length Lmax of the rubber ribbon discharge path 43 (from the junction position P1 to the discharge opening 43a) is preferably 10 times or less the thickness T3 of the rubber ribbon discharge path 43, and more preferably 5 times or less the thickness T3.

[0040] The thicknesses of the first rubber layer 101 and the second rubber layer 102 in FIG. 1A are set appropriately depending on the thickness T1 of the first rubber inlet channel 41, the thickness T2 of the second rubber inlet channel 42, the thickness T3 of the rubber ribbon outlet channel 43, the inflow speed of the first rubber, and the inflow speed of the second rubber, etc.

[0041] [Rubber ribbon molding method] Next, an example of a method for molding the rubber ribbon 100 using the extrusion molding device 1 will be described with reference to FIG.

[0042] First, as shown in Fig. 6(a), the second nozzle 6 is attached to the second rubber supply unit 3, and the second rubber R2 is supplied from the second rubber supply path 31 to fill the second rubber R2 into the second rubber inlet path 42. Then, the supply of the second rubber R2 is stopped, and the second rubber R2 that has protruded outside the second rubber inlet path 42 (second nozzle 6) is removed.

[0043] Next, as shown in Fig. 6(b), the first die 5 is attached to the second die 6, and the first rubber supply unit 2 is attached to the first die 5 and the second die 6. Then, the first rubber R1 is supplied from the first rubber supply path 21, and the first rubber R1 is filled into the first rubber inlet path 41 and the rubber ribbon outlet path 43.

[0044] 6(c), after stopping the supply of the first rubber R1, the second rubber R2 is supplied again, and the second rubber R2 is filled into the rubber ribbon discharge path 43. At that time, the first rubber R1 that had been filled into the rubber ribbon discharge path 43 is pushed out of the rubber ribbon discharge path 43 (first die 5) by the second rubber R2, and only a part of the first rubber R1 that has flown out from the first rubber inlet path 41 into the rubber ribbon discharge path 43 remains in the rubber ribbon discharge path 43.

[0045] Then, by stopping the supply of the second rubber R2, preparation for molding the rubber ribbon 100 is completed. By performing the above-mentioned preparation for molding, it is possible to prevent the second rubber R2 from flowing into the first rubber inlet channel 41. Furthermore, even if the rubbers R1, R2 are the same color, it is possible to reliably confirm whether or not the rubbers R1, R2 have been discharged from the die 4. Note that the above-mentioned preparation for molding is preferably performed when the die 4 is attached or after maintenance of the extrusion molding device 1.

[0046] After the above molding preparation is completed, as shown in Figure 6(d), by simultaneously supplying the first rubber R1 and the second rubber R2, the first rubber R1 flowing in from the first rubber inlet channel 41 and the second rubber R2 flowing in from the second rubber inlet channel 42 merge at the merge position P1, a rubber ribbon 100 is molded, and the rubber ribbon 100 is discharged from the discharge outlet 43a.

[0047] As described above, in this embodiment, the extrusion die 4 is an extrusion die 4 attached to the tip of the extrusion device 1 that continuously discharges the rubber ribbon 100, which includes the first rubber layer 101 arranged on one side (first ribbon thickness direction D11) of the ribbon thickness direction D1 and the second rubber layer 102 arranged on the other side (second ribbon thickness direction D12) of the first rubber layer 101 in the ribbon thickness direction D1, and includes a first rubber inflow path 41 into which the first rubber R1 that forms the first rubber layer 101 flows, It is preferable that the rubber ribbon discharge passage 43 includes a second rubber inlet passage 42 extending in a direction intersecting with the first rubber inlet passage 41 and into which the second rubber R2 forming the second rubber layer 102 flows, and a rubber ribbon discharge passage 43 extending from a joining position P1 of the first rubber inlet passage 41 and the second rubber inlet passage 42, and that the first rubber inlet passage 41 intersects with one side (first ribbon thickness direction D11) of the second rubber inlet passage 42 in the ribbon thickness direction D1, which includes side end portions 421, 421 of the second rubber inlet passage 42 in the ribbon width direction D2.

[0048] According to this configuration, the first rubber R1 flowing in from the first rubber inlet channel 41 can cover the side end portions in the ribbon width direction D2 of the second rubber R2 flowing in from the second rubber inlet channel 42. This allows the side end portions 102a, 102a of the second rubber layer 102 to be covered by the first rubber layer 101, and prevents the side end portions 102a, 102a of the second rubber layer 102 in the rubber ribbon 100 from being exposed.

[0049] Furthermore, like the extrusion die 4 according to this embodiment, it is preferable that the area of ​​the cross section perpendicular to the rubber ribbon discharge channel 43 is larger than the area of ​​the cross section perpendicular to the second rubber inlet channel .

[0050] With this configuration, space can be secured in the rubber ribbon discharge path 43 for the first rubber R1 and the second rubber R2 to merge, and the rubber ribbon 100 can be formed while maintaining the state in which the first rubber layer 101 covers the side end portions 102a, 102a of the second rubber layer 102.

[0051] Furthermore, as in the extrusion molding die 4 of this embodiment, it is preferable that the thickness T1 (thickness T11 on the confluence side) of the first rubber inlet channel 41 at the confluence position P1 is smaller than the thickness T3 of the rubber ribbon discharge channel 43 in the ribbon thickness direction D1.

[0052] According to this configuration, the second rubber R2 can easily flow into the rubber ribbon discharge path 43, and the second rubber R2 can be prevented from flowing into the first rubber inlet path 41.

[0053] Furthermore, like the extrusion die 4 according to this embodiment, it is preferable that the minimum length Lmin from the first rubber inlet channel 41 to the outlet 43a of the rubber ribbon outlet channel 43 is 2 mm or more.

[0054] With this configuration, the rubber flow can be stabilized after the first rubber R1 and the second rubber R2 join together, and the rubber ribbon 100 can be formed while maintaining the state in which the first rubber layer 101 covers the side ends 102a, 102a of the second rubber layer 102.

[0055] The extrusion die 4 is not limited to the configuration of the embodiment described above, nor is it limited to the effects and advantages described above. Furthermore, various modifications can be made to the extrusion die 4 without departing from the spirit of the present invention. For example, it is possible to arbitrarily select one or more of the configurations and methods according to the various modified examples described below and employ them in the configurations and methods according to the embodiment described above.

[0056] 7 and 8, the extrusion die 4 may be configured to include a rubber flow adjusting unit 7 that adjusts the rubber flow of the first rubber. With such a configuration, the rubber flow adjusting unit 7 can adjust the rubber flow of the first rubber in response to changes in the rubber flow of the first rubber due to the molding environment of the rubber ribbon 100, variations in viscosity of the first rubber, and the like. Note that the extrusion die 4 may be configured to include multiple rubber flow adjusting units 7.

[0057] From the viewpoint of improving the rubber flow of the first rubber toward the downstream ends 411, 411 of the first rubber inlet channel 41, the rubber flow adjuster 7 is preferably disposed in the center of the first rubber inlet channel 41 in the ribbon width direction D2. For example, a male screw such as a bolt can be used as the rubber flow adjuster 7. In the case of a male screw, it is necessary to provide a female screw that penetrates all the way to the first rubber inlet channel 41 on the first mouthpiece 5 or the second mouthpiece 6. Then, by rotating the male screw, the insertion length T4 of the male screw into the first rubber inlet channel 41 can be adjusted, and the rubber flow of the first rubber can be adjusted. [Explanation of symbols]

[0058] DESCRIPTION OF SYMBOLS 1...Extrusion molding device, 2...First rubber supply section, 21...First rubber supply path, 3...Second rubber supply section, 31...Second rubber supply path, 4...Extrusion molding die, 41...First rubber inlet path, 411...Downstream end, 42...Second rubber inlet path, 421...Side end, 422...Central section, 43...Rubber ribbon discharge path, 43a...Discharge port, 5...First die, 51a...Recess, 6...Second die, 7...Adjustment section, 8...First rubber extruder, 9...Second rubber extruder, 100...Rubber ribbon, 101...First rubber layer, 102...Second rubber layer, 102a...Side end, 200...Conveying roller, 300...Pressing roller, 400...Molding drum, 500...Rubber member, P1...Joining position, R1...First rubber, R2...Second rubber, T4...Pathway penetration length

Claims

1. An extrusion die attached to a tip of an extrusion molding device that continuously discharges a rubber ribbon including a first rubber layer disposed on one side of the ribbon in a thickness direction and a second rubber layer disposed on the other side of the first rubber layer in the thickness direction of the ribbon, a first rubber inflow path into which a first rubber forming the first rubber layer flows; a second rubber inlet passage extending in a direction intersecting the first rubber inlet passage and into which a second rubber forming the second rubber layer flows; a rubber ribbon discharge path extending from a joining position of the first rubber inlet path and the second rubber inlet path, the first rubber inlet channel intersects with one side of the second rubber inlet channel in the ribbon thickness direction, the side including the side end of the second rubber inlet channel in the ribbon width direction, The second rubber inlet passage is formed in a substantially triangular shape when viewed in the ribbon discharge direction, The width of the first rubber inlet channel in the ribbon width direction is larger than the width of the second rubber inlet channel in the ribbon width direction, an extrusion molding die, wherein the first rubber inlet passage intersects with a portion of the second rubber inlet passage between a side end portion and an upper central portion thereof;

2. An extrusion molding nozzle as described in Claim 1, wherein the first rubber inlet passage intersects with more than 50% of the thickness in the ribbon thickness direction between the side end of the second rubber inlet passage and the central upper portion.

3. An extrusion molding nozzle attached to the tip of an extrusion molding device that continuously discharges a rubber ribbon having a first rubber layer arranged on one side of the ribbon thickness direction and a second rubber layer arranged on the other side of the first rubber layer in the ribbon thickness direction, a first rubber inflow path into which a first rubber forming the first rubber layer flows; a second rubber inlet passage extending in a direction intersecting the first rubber inlet passage and into which a second rubber forming the second rubber layer flows; a rubber ribbon discharge path extending from a joining position of the first rubber inlet path and the second rubber inlet path, the first rubber inlet channel intersects with one side of the second rubber inlet channel in the ribbon thickness direction, the side including the side end of the second rubber inlet channel in the ribbon width direction, The width of the first rubber inlet channel in the ribbon width direction is larger than the width of the second rubber inlet channel in the ribbon width direction, The first rubber inlet passage is formed to narrow toward the joining position.

4. The extrusion die according to claim 1 , wherein the area of ​​a cross section perpendicular to the rubber ribbon discharge passage is larger than the area of ​​a cross section perpendicular to the second rubber inlet passage.

5. The extrusion die according to any one of claims 1 to 4, wherein a thickness of the first rubber inlet channel at the joining position is smaller than a thickness of the rubber ribbon outlet channel in a ribbon thickness direction.

6. The extrusion die according to any one of claims 1 to 5, wherein a minimum length from the first rubber inlet channel to the outlet of the rubber ribbon outlet channel is 2 mm or more.

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