JP6199537B2 - Inner liner manufacturing method - Google Patents

Description

The present invention relates to the production how Lee emissions toner liner of a pneumatic tire such as a passenger car.

  An inner liner is provided inside the pneumatic tire for the purpose of preventing air leakage and keeping the tire air pressure constant.

  And the conventional inner liner is formed in uniform thickness over the full length in the width direction using a calendar roll (refer to patent documents 1 and 2).

JP 2008-37156 A JP 2002-144445 A

  The inner liner is arranged for the purpose of keeping the tire pressure constant. However, when the inner liner having a uniform thickness as described above is used, the rubber volume is insufficient, so that the bead ring and the green tire are not separated. There was a possibility that a gap was generated in the air and the remaining air was generated. This point will be specifically described with reference to FIG.

  FIG. 8 is a view showing a state before and after vulcanization of a tire using a conventional inner liner, in which (A) is a cross-sectional view showing a state before tire vulcanization, and (B) is a state after tire vulcanization. FIG.

  In the vulcanization molding process, when the green tire T is set in the mold, a bead ring 100 that holds the bead portion of the green tire T and a bead portion of the green tire T as shown in FIG. There may be a gap S1 between them.

  When the raw tire T is vulcanized, since the raw tire T is heated while being pressed against the inner surface of the mold by the bladder 102, the rubber of the inner liner 50 of the raw tire T is directed in the direction of arrow F. To flow.

  However, in such a case, there is a case where the rubber volume is insufficient and the gap S1 cannot be filled, and as shown in FIG. 8B, an air remaining 58 may occur in the vicinity of the toe end point 101. is there. In FIG. 8, 52 is a chafer, 54 is a carcass ply, and 56 is a bead core.

In view of the above, and an object thereof is to provide a manufacturing how Louis emission toner liner can prevent the air remaining caused by poor flow of the rubber of the innerliner in the tire vulcanization.

The invention described in claim 1
An inner portion characterized in that a thick portion larger in thickness than a central portion is formed by folding both end portions in the width direction of the unvulcanized rubber sheet having a uniform thickness over the entire length in the width direction with a predetermined width. It is a manufacturing method of a liner.

According to the present invention, it is possible to provide a manufacturing how Louis emission toner liner it is possible to prevent the occurrence of air remaining due to defective flow of the rubber of the innerliner in the tire vulcanization.

It is sectional drawing which shows the inner liner which concerns on the 1st Embodiment of this invention. It is a figure which shows typically the manufacturing apparatus used for manufacture of the inner liner which concerns on the 1st Embodiment of this invention. It is a figure which shows typically the slitter apparatus of the manufacturing apparatus of FIG. It is sectional drawing which shows the inner liner which concerns on the 2nd Embodiment of this invention. It is a figure which shows typically the manufacturing apparatus used for manufacture of the inner liner which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the inner liner which concerns on the 3rd Embodiment of this invention. It is a figure which shows the state before and behind vulcanization | cure of the tire which concerns on embodiment of this invention. It is a figure which shows the state before and behind the vulcanization | cure of the tire using the conventional inner liner.

  Hereinafter, the present invention will be described based on embodiments.

A. Inner liner and manufacturing method thereof (first embodiment)
1. Inner Liner FIG. 1 is a cross-sectional view showing an inner liner according to the first embodiment, and FIG. 2 is a view schematically showing a manufacturing apparatus used for manufacturing the inner liner according to the first embodiment. .

  As shown in FIGS. 1 and 2, the inner liner 10 </ b> A according to the present embodiment is obtained by cutting both ends of an unvulcanized rubber sheet 12 having a uniform thickness over the entire length in the width direction with a slitter device 34. Are laminated and attached to both ends of the cut unvulcanized rubber sheet 12, and thick portions 14, 16 having a thickness larger than the thickness of the central portion are formed on both sides in the width direction. .

  As a result, the thickness H2 of the thick portions 14 and 16 formed at both ends of the inner liner 10A is set to twice the thickness H1 of the central portion. About the level | step difference of the thick parts 14 and 16 and a center part, since the air remainder by a level | step difference will generate | occur | produce easily if a level | step difference exceeds 1.0 mm, it is preferable to set to 0.5-1.0 mm. For this reason, the thickness H1 of the central portion is preferably 0.5 to 1.0 mm, and the thickness H2 of the thick portions 14 and 16 is preferably 1.0 to 2.0 mm.

  Further, the widths D1 and D2 of the thick portions 14 and 16 are preferably set to 10 to 30 mm because a thickness shortage occurs when the thickness is less than 10 mm, and the cost increases when the thickness exceeds 30 mm.

2. 2. Inner Liner Manufacturing Method As shown in FIG. 2, the manufacturing apparatus used in the inner liner 10A manufacturing method includes a calender device 30 having a pair of calender rolls 30a and 30b and a transport roller having a plurality of transport rollers 32a and 32a. A series 32, a slitter device 34 disposed above the conveyance roller series 32, and a pair of press sponge rollers 36a and 36b are provided.

  The slitter device 34 is provided with slitter blades 34a and 34b at the tips of a pair of arms (not shown). The slitter blades 34a and 34b are arranged at predetermined intervals in the roller width direction of the transport roller 32a, and can be horizontally adjusted in the width direction of the transport roller train 32 to adjust the position. .

  The calendar device 30 feeds the inner liner rubber G from between a pair of calendar rolls 30a, 30a, and forms an unvulcanized rubber sheet 12 having a predetermined width dimension and thickness dimension.

  While the unvulcanized rubber sheet 12 delivered from the calendar device 30 is conveyed by the conveying roller train 32, both sides of the unvulcanized rubber sheet 12 have slitter blades 34a of the slitter device 34, as shown in FIG. It is cut into a predetermined width (10 to 30 mm) by 34b. The end piece formed by cutting is overlaid on the end of the unvulcanized rubber sheet 12 after cutting, and the end piece is passed between the pair of press sponge rollers 36a and 36b so that the end piece is cut. The inner liner 10A is manufactured by being affixed to the unvulcanized rubber sheet 12.

  As described above, according to the present embodiment, the thick portion can secure a sufficient rubber volume around the bead, and prevents the occurrence of air residue due to poor rubber flow of the inner liner during tire vulcanization. can do. Moreover, a thick part can be easily formed and an inner liner can be manufactured only by cut | judging both sides and sticking with an unvulcanized rubber sheet.

(Second Embodiment)
1. Inner Liner FIG. 4 is a cross-sectional view showing an inner liner 10B according to the second embodiment. FIG. 5 is a diagram schematically showing a manufacturing apparatus used for manufacturing the inner liner 10B according to the second embodiment.

  As shown in FIGS. 4 and 5, the inner liner 10 </ b> B of the present embodiment is an unvulcanized rubber sheet without cutting the unvulcanized rubber sheet 12 having a uniform thickness over the entire length in the width direction as described above. 12 are formed by folding both end portions, and thick portions 14 and 16 having a thickness larger than the thickness of the central portion are formed on both side portions.

  The thickness H2 of the thick portions 14 and 16 of the inner liner 10B, the thickness H1 of the central portion, and the widths D1 and D2 of the thick portions 14 and 16 are set similarly to the inner liner 10A of the first embodiment. .

2. Inner liner manufacturing method

  As shown in FIG. 5, the manufacturing apparatus used in the method for manufacturing the inner liner 10B includes a calender apparatus 40 having a pair of calender rolls 40a and 40b, a transport roller series 42 having a plurality of transport rollers 42a, and a transport roller series. 42, and a pair of presser sponge rollers 46a, 46b. The inner liner 10A manufacturing apparatus according to the first embodiment is bent instead of the slitter apparatus 34. The difference is that the device 44 is provided.

  The bending device 44 includes a pair of arms 44a and 44b with a bending mechanism, and the arms 44a and 44b are arranged at predetermined intervals in the roller width direction of the conveying roller 42a. The position can be adjusted by moving horizontally in the width direction of the series 42.

  The unvulcanized rubber sheet 12 delivered from the calendar device 40 is bent by a predetermined width dimension (10 to 30 mm) at both ends of the unvulcanized rubber sheet 12 while being conveyed by the conveying roller train 42. The inner liner 10B is manufactured by being folded and folded and passing between the pair of presser sponge rollers 46a and 46b.

  As described above, according to the present embodiment, it is possible to easily produce an inner liner that can sufficiently suppress the generation of remaining air by simply folding both sides and folding the uncured rubber sheet. can do.

(Third embodiment)
FIG. 6 is a sectional view showing an inner liner 10C according to the third embodiment of the present invention.

  As shown in FIG. 6, the inner liner 10C is formed by sticking reinforcing material chafers (canvas chafers) 22 and 23 to both end portions 14 and 16 of the inner liner 10B of the second embodiment. ing.

  For this reason, it becomes possible to protect the part which rubs hard with a tire rim, and it is preferable.

B. FIG. 7 is a diagram illustrating a state before and after vulcanization of a tire according to an embodiment of the present invention, and FIG. 7 (A) is a diagram of a raw tire manufactured using an inner liner 10C before vulcanization. It is sectional drawing which shows the state of (B), (B) is sectional drawing which shows the state after vulcanization | cure.

  As shown in FIG. 7A, in the vulcanization molding process, when the raw tire T is set in the mold, the bead portion 1b of the raw tire T is removed as in the case of using the conventional inner liner. A gap S2 is generated between the bead ring 100 to be held and the bead portion 1b of the green tire T.

  When the tire is vulcanized, the green tire T is heated while being pressed against the inner surface of the mold by the bladder 102. In the present embodiment, as shown in FIG. The rubber of the inner liner 10 </ b> C can flow in the direction of arrow F to reliably fill the gap S <b> 2.

  That is, the inner liner 10 </ b> C is arranged so that the thick portions 16 are provided on both side pieces as described above, and a portion 16 a of the thick portion 16 faces the toe end point 6 b of the bead portion 1 b of the tire T. For this reason, the rubber volume around the bead portion 1b can be secured. As a result, sufficient rubber flows in the gap S2, so that the gap S2 can be filled as shown in FIG. As a result, in the vicinity of the toe end point 6b of the bead portion 1b, the occurrence of remaining air due to insufficient rubber volume of the inner liner is suppressed, and the tire T with less occurrence of remaining air can be manufactured.

  In FIG. 7, 2 is a carcass ply, 3b is a bead core, 4b is a bead filler, 12 is a vulcanized rubber sheet, 16 is a thick part, 16a is a part of the thick part, and 23 is a chafer.

1. Examples and Comparative Examples Using an unvulcanized rubber sheet having the thickness shown in Table 1, an inner liner (Examples 1 to 6) in which both ends are folded and folded at the folding amount shown in Table 1, and an inner with a uniform thickness A tire having a tire size of 195/65 R15 was produced using the liner (Comparative Examples 1 and 2).

2. Evaluation of Examples and Comparative Examples For each of the manufactured tires, an air remaining rate was evaluated and a tire cost index was evaluated. The air remaining generation rate was evaluated by observing a cross section of the bead portion of the manufactured tire. The tire cost index was evaluated assuming that the manufacturing cost of the tire of Comparative Example 1 was 100. The evaluation results are shown in Table 1.

  From Table 1, the tire (Comparative Example 2) using a uniform inner liner having a thickness of 2.0 mm has a sufficient amount of rubber, so that the occurrence of residual air is reduced compared to Comparative Example 1, but the cost is low. It turns out that it improves greatly.

  On the other hand, tires (Examples 5 and 6) using an inner liner made of unvulcanized rubber sheet having a thickness of 1.0 mm and bent at 10 mm and 30 mm have a sufficient amount of rubber. It can be seen that the tire cost index is 101, 102, which is almost the same as that of the comparative example, although the remaining air generation rate is as small as 0.02% and 0.00%.

  Further, in Example 1 (a tire using an unvulcanized rubber sheet having a thickness of 1.5 mm and an inner liner having a bending amount of 30 mm), a sufficient amount of rubber could be secured, but the level difference of the inner liner was 1. Since it is as large as 5 mm, it is easy to generate air residue due to a step, and the air residue generation rate deteriorated to 1.20%.

  In Example 2 (a tire using an unvulcanized rubber sheet having a thickness of 1.0 mm and an inner liner having a bending amount of 50 mm), the amount of rubber is sufficient, and the air remaining due to poor rubber flow of the inner liner The incidence was 0.00%. However, since the amount of bending of the left and right thick portions is large, the cost increases.

  In Example 3 (a tire using an unvulcanized rubber sheet having a thickness of 0.5 mm and an inner liner having a bending amount of 30 mm), the thickness of the left and right thick portions is small, so the amount of rubber is insufficient. The remaining air generation rate deteriorated to 1.10%.

  In Example 4 (a tire using an unvulcanized rubber sheet having a thickness of 1.0 mm and an inner liner having a bending amount of 5 mm), the amount of rubber is insufficient because the bending amount of the left and right thick portions is small. The air remaining rate was close to that of Comparative Example 1.

  As described above, according to the present embodiment, it is possible to prevent the occurrence of remaining air due to insufficient rubber volume of the inner liner during tire vulcanization, and further, the thickness of the thick part and the central part of the inner liner, By appropriately setting the width, it is possible to suppress an increase in tire weight and material cost.

  While the present invention has been described based on the embodiments, the present invention is not limited to the above embodiments. Various modifications can be made to the above-described embodiments within the same and equivalent scope as the present invention.

1a, 1b, 51 Bead portion 2, 54 Carcass ply 3a, 3b, 56 Bead core 4a, 4b Bead filler
6a, 6b, 101 Toe end points 10A, 10B, 10C, 50 Unvulcanized inner liner 12 Unvulcanized rubber sheet 14, 16 Thick portion 16a Thick portion 22, 23, 52 Chafer 30 Calendar device 30a, 30b Calender rolls 32, 42 Conveying roller series 32a, 42a Conveying roller 34 Slitter device 34a, 34b Slitter blades 36a, 36b, 46a, 46b Pressing sponge roller 40 Calender device 44 Bending device 44a, 44b Arm 58 Air remaining 100 Bead ring 102 Bladder D1, D2 Width of left and right thick parts (bending amount)
F Flow direction of rubber G Rubber for inner liner H1 Thickness of central portion of inner liner H2 Thickness of end of inner liner S1, S2 Clearance T Raw tire

Claims (1)

An inner portion characterized in that a thick portion larger in thickness than a central portion is formed by folding both end portions in the width direction of the unvulcanized rubber sheet having a uniform thickness over the entire length in the width direction with a predetermined width. Liner manufacturing method.

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