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JP-7857096-B2 - Pneumatic tires with sealant

JP7857096B2JP 7857096 B2JP7857096 B2JP 7857096B2JP-7857096-B2

Inventors

  • ジャン－クロード パトリス フィリップ グリフォイン
  • モーリッツ ブルックナー
  • ローマン ゴール
  • サメル ギュプタ
  • ケヴィン エリク エム ピエレ

Assignees

  • ザ・グッドイヤー・タイヤ・アンド・ラバー・カンパニー

Dates

Publication Date
20260512
Application Date
20211215
Priority Date
20201218

Claims (14)

  1. (i) a tread portion (10) having circumferential grooves (9) and (ii) rows of circumferential ribs (8) or tread blocks, an inner surface defining a tire cavity (6), and a sealant layer (5) that at least partially covers the inner surface radially below the tread portion (10) within the tire cavity (6), wherein the sealant layer (5) includes raised sealant portions (19), the raised sealant portions (19) are provided radially below each of at least two of the circumferential grooves (9), and the sealant layer (5) has a radial thickness greater in the raised portions (19) than in the radially below region (18) of the rows of circumferential ribs (8) or tread blocks . Each of the aforementioned raised portions (19) has an axial width within the range of 70% to 130% of the axial width of the bottom of the circumferential groove (9) located radially above each of the aforementioned raised portions (19). At least one foam member (7) is attached to the radially inner surface of at least two axially adjacent raised portions (19), thereby forming at least one air cavity (16) between the axially adjacent raised portions (19), the radially outer surface of the foam member (7), and the radially inner surface of the sealant layer (5) between the axially adjacent raised portions (19). The pneumatic tire (1, 11) is characterized in that the foam member (7) is optionally a foam strip extending in the circumferential direction (c) along a circumferential length corresponding to at least 50% of the inner circumference of the tire (11), measured along the inner surface at the axial center of the tire (11).
  2. The pneumatic tire according to claim 1, wherein the foam member (7) is optionally a foam strip extending in the circumferential direction (c) along a circumferential length corresponding to at least 80% of the inner circumference of the tire (11), measured along the inner surface at the axial center of the tire (11).
  3. The pneumatic tire according to claim 1 or 2, characterized in that the radial thickness of one of two adjacent raised portions (19), measured from the inner surface of the tire (1, 11) to the innermost surface in the radial direction of each raised portion (19), is at least 15% greater than the radial thickness of the sealant layer (5) midway between the two adjacent raised portions (19), or at most 100% greater than the radial thickness of the sealant layer (5) midway between the two adjacent raised portions (19), or both.
  4. The pneumatic tire according to any one of claims 1 to 3, characterized in that the tire (1, 11) includes at least three circumferential grooves (8) and at least four rows of circumferential ribs (9) or tread blocks.
  5. The pneumatic tire according to any one of claims 1 to 4, characterized in that the raised portion (19) of the sealant is provided radially below each of the circumferential grooves (9).
  6. The pneumatic tire according to any one of claims 1 to 5, characterized in that the maximum radial thickness of the raised portion (19), measured from the inner surface of the tire (1, 11) to the innermost surface in the radial direction of each raised portion (19), is in the range of 3 mm to 9 mm, and/or the radial thickness of the sealant layer (5) between two adjacent raised portions (19) is in the range of 2 mm to 6 mm.
  7. i) the difference between the radial thickness of the sealant layer (5) in the middle between two adjacent raised portions (19) and ii) the maximum radial thickness of one of the adjacent raised portions (19) is at least 0.5 mm, and/or The pneumatic tire according to any one of claims 1 to 6, characterized in that the sealant layer (5) extends axially over at least 90% of the width of the tread portion (10).
  8. The pneumatic tire according to any one of claims 1 to 7, characterized in that the sealant agent comprises one or more of the following: a butyl rubber composition, a polyisoprene composition, a natural rubber composition, a polyurethane composition, a polybutene composition, an emulsion styrene-butadiene rubber composition, an EPDM composition, and a silicone composition.
  9. The sealant layer is (i) A sealant strip that extends circumferentially along the inner surface of the tire (1, 11) with respect to the axis of the tire (1, 11), and is adjacent to the axial surface of the tire (1, 11), (ii) One or more sealant strips wound spirally along the inner surface of the tire (1, 11) with respect to the axle of the tire (1, 11), A pneumatic tire according to any one of claims 1 to 8, characterized in that it includes one of the following.
  10. The sealant strip forms the raised portion (19) and the region of the sealant layer (5) radially below the circumferential rib (9) or the row of tread blocks, At least a number of the sealant strips are In order to form the raised portion in the sealant layer (5), the region radially below the circumferential groove (8) is radially thicker than the region (18) radially below the circumferential rib (9) or the row of tread blocks, The sealant layer (5) is arranged so as to form the raised portion (19) on it, with the layers overlapping each other vertically. The pneumatic tire according to claim 9, characterized by having one or both of the above.
  11. The tread portion (10) has two shoulder portions and a central portion between the two shoulder portions in the axial direction, each of the shoulder portions includes a row of circumferential shoulder ribs or shoulder tread blocks, the central portion includes at least three circumferential ribs and at least four circumferential grooves, and each of the shoulder ribs is defined by one of the at least four circumferential grooves . The raised portion (19) of the sealant layer (5) and the region (18) of the sealant layer having a radial thickness smaller than the radial thickness of the raised portion (19) are alternately located along the axial direction (a) of the tire (1, 11). The pneumatic tire according to any one of claims 1 to 10, characterized in that the region (18) of the sealant layer (5), having a radial thickness smaller than the radial thickness of the raised portion (19), has an axial width in the range of 60% to 120% of the radially outermost surface of each row of ribs or tread blocks radially upward.
  12. The axial width of the foamed member (7) is within the range of 20% to 50% of the maximum axial width of the sealant layer (5). The pneumatic tire according to any one of claims 1 to 11 , characterized in that the foam member (7) does not contain a coating or foil facing the sealant layer (5).
  13. The foamed member (7) Noise attenuation material and Polymer foam material, Polyurethane foam material, Strip shape and, Materials with a density in the range of 0.01 g/ cm³ to 1 g/ cm³ , A pneumatic tire according to any one of claims 1 to 12 , characterized by including one or more of the following.
  14. A method for manufacturing a tire according to any one of claims 1 to 13 , The step of hardening the tire (1,11), The steps include: forming a sealant layer (5) on the inner surface of a hardened tire (1, 11) by attaching one or more sealant strips to the inner surface, and forming a raised portion (19) in the sealant layer (5) in the region radially below the circumferential groove (9) of the tire tread portion (10); The optional step of attaching at least one foam member (7) to the innermost radial portion of two adjacent raised portions (19), A method that includes this.

Description

This invention relates particularly to pneumatic tires, and more specifically to pneumatic tires having a sealant layer on their inner surface that optionally supports at least one foamed member. Self-sealing pneumatic tires typically delay or prevent the loss of air pressure and the resulting tire deflation after a tire has been punctured by a sharp object such as a nail or screw. Several methods, sealants, and tire structures have been proposed for puncture-sealant pneumatic tires. However, most of these approaches have drawbacks. Strength rating 4,895,610U.S. Patent No. 9,802,446U.S. Patent No. 8,360,122 A schematic cross-sectional view of a conventional tire including a sealant layer is shown.A schematic cross-sectional view of one embodiment of a sealant tire according to the present invention is shown.A schematic cross-sectional view of a conventional tire, including a foaming strip attached to the sealant layer, is shown.A schematic cross-sectional view of a noise-damping sealant tire according to one embodiment of the present invention is shown. The structure, function, and advantages of this invention will become clearer upon consideration of the following description in conjunction with the accompanying drawings. Figure 1 is a schematic cross-sectional view of a conventional tire 1'. This example of tire 1' has a tread portion 10, two bead portions 3, and two sidewalls 2 that join the axial outer edges of the tread portion 10 to the respective bead portions 3. The tread portion 10 has a plurality of circumferential grooves 9 and ribs 8. Such a pneumatic tire structure is generally known in the tire industry. Tire 1' has an inner surface defining a tire cavity 6. A sealant layer 5' is provided on the inner surface of tire 1' in the region opposite the tread portion 10. The thickness of the sealant layer 5' is essentially constant across the axial width and outer circumference of tire 1'. For ease of understanding, reference numerals 2, 3, 6, 8, 9, and 10 are used in the description of Figures 2-4 to refer to the same components described below. Figure 2 shows a tire 1 according to the first embodiment of the present invention. Similar to tire 1' shown in Figure 1, tire 1 has a sidewall 2, a bead portion 3, a tread portion 10, a tire cavity 6 arbitrarily separated by the inner liner of tire 1, circumferential grooves 9 (i.e., circumferential main grooves), and circumferential ribs 8. The sealant layer 5 according to the embodiment shown in Figure 2 extends along the inner surface of the tire 1 in the circumferential direction c and the axial direction a. The sealant layer 5 has four raised portions 19, each of which is located radially below the groove 9 in the axial direction. In other words, the sealant layer 5 has a portion that is thicker in the axial position of the groove 9 than the region 18 located radially below the rib 8, where the radial thickness is smaller. As a result, the thicker sealant in the radially inner region of the groove improves the sealing performance of the tire 1 in the region where the tread rubber material is relatively thin compared to the region where the tread rubber material is relatively thick in the axial position of the rib 8. This configuration strikes a good balance between the sealing properties of the sealant and weight impact. In particular, a large amount of sealant can increase the weight of the tire 1, which may lead to a decrease in ride comfort and handling characteristics. As shown in Figure 1, this configuration is more cost-effective compared to tire 1'. Furthermore, having a thinner sealant layer in the radially downward region of the rib 8 improves thermal conductivity and/or avoids heat generation in these regions, particularly for improved high-speed performance and frequent cornering operations. It should be noted that the relative thickness of the illustrated raised portion 19, or in other words, the radially inward projection or ridge of the sealant layer, is schematically shown in Figure 1. Preferred absolute and relative thicknesses are described herein. In non-limiting embodiments, the thickness of the sealant layer 5 is approximately 3.6 mm in the region 18 between the raised portions 19, while the maximum thickness of the sealant layer 5 in the raised portion 19 is approximately 4.5 mm. For clarity, the axial direction a, circumferential direction c, and radial direction r are shown in Figure 2, as is commonly used in descriptions of tire geometry. The term "direction" is not limited to specific orientations unless otherwise specified herein. The axial direction a can be understood as the direction parallel to the axis of rotation of tire 1. The circumferential direction c is concentric with the axis of rotation of tire 1, and the radial direction r extends radially from the axis of rotation, as is commonly understood in the tire industry. Figure 3 shows a conventional tire 1" having members 2, 3, 6, 8, 9, and 10, as previously described