JP2005231577A - Reinforcing air envelope for safety tire and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reinforcing air envelope reducing a defective generation rate at the time of a manufacturing by preventing intrusion of air between a tube and a reinforcing layer by optimizing the reinforcing layer, and its manufacturing method. <P>SOLUTION: This air envelope 1 is formed into a hollow annular shape and is stored into a tire 2. When prescribed internal pressure is filled, a space S<SB>1</SB>is formed between the envelope 1 and an internal surface of the tire 2. When internal pressure of the space S<SB>1</SB>is lowered by puncture, etc., the envelope 1 performs enlarged diameter deformation and takes over supporting of load from the tire 2. The envelope 1 has a hollow circular tubular tube 9 provided with a crown part 6, a pair of side parts 7 extended toward the radial inward from both the end parts, and a base part 8 extended to face the crown part 6 over both the side parts 7, and a reinforcing layer 10 for surrounding the outer periphery of at least the crown part 6 of the tube 9 over the entire periphery. The reinforcing layer 10 has a plurality of through holes 11 extended in the thickness direction. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is housed in a tire, filled with gas at an internal pressure set in relation to a predetermined internal pressure of the tire, and forms a space between at least the tire inner surface when the tire internal pressure is normal, TECHNICAL FIELD The present invention relates to a hollow tubular safety tire reinforced air bladder that expands and deforms as the internal pressure of the tire changes to support the load from the tire, and a method for manufacturing the same. Reduce the incidence of

  There are various types of safety tires that can be safely and continuously run to a place with equipment that can be replaced or repaired even if the tire internal pressure drops or disappears due to tire puncture, air valve damage, etc. Things have been proposed.

  For example, Patent Document 1 discloses a reinforced air bladder for safety tires formed by vulcanizing and joining a reinforcing layer made of a composite material of a fiber member and rubber on the outer circumference of an air bladder having a hollow annular shape. . Such reinforced air bladder is stored in a tire, filled with gas at an internal pressure set in relation to the predetermined internal pressure of the tire, and when the internal pressure of the tire is normal, at least due to the shape retaining action of the reinforcing layer, A space is formed between the inner surface of the tire, and the diameter of the tire is increased and deformed as the internal pressure of the tire decreases due to puncture or the like, so that the load is supported from the tire.

  Such a reinforced air bag is generally manufactured by a method as shown in FIGS. That is, a rubber member composed of a single material made of unvulcanized rubber and / or a composite material made of unvulcanized rubber and fibers is attached on a molding drum (not shown) to form a ring shape for a reinforcing layer. The sheet 101 is formed, and the crown region 102 of the reinforcing layer ring-shaped sheet 101 is held by the positioning holding member 103 as shown in FIG. Next, a semi-vulcanized or vulcanized tube 104 formed separately is filled with gas at a predetermined internal pressure and expanded, and the positioning holding member 103 and the sheet 101 held thereon are moved thereon. As shown in FIG. 5 (b), the tube 104 is disposed in close contact with the outer surface of the crown portion so that the inner surface of the central portion 102 of the sheet 101 matches. Thereafter, the side portion 105 of the sheet 101 is bent radially inward along the outer surface of the tube 104, and as shown in FIG. 5C, the tube 104 is tightly surrounded by the sheet 101 to form an annular support containing the tube. To do. And this annular support body containing a tube is vulcanized and molded in a mold (not shown) to obtain a reinforced air bag.

International Publication No. 02/96678 Pamphlet

  In such a conventional manufacturing method, it is difficult to completely exhaust the gas existing between the tube and the reinforcing layer because the reinforcing layer is pasted on the outer periphery of the tube having an unstable shape. In some cases, a residual gas, that is, so-called air entry may occur between the reinforced air bladder tube and the reinforcing layer. If the reinforced air bag that has entered the air is vulcanized, the gas may expand and cause product defects. Further, if a reinforced air bag containing air is used as it is, the reinforcing layer may be peeled off. However, it is difficult to find such air entering from the outer surface of the tube-containing annular support before vulcanization, and countermeasures have been desired.

  Accordingly, an object of the present invention is to provide a reinforced air bag and its manufacture in which the reinforcement layer is optimized to prevent air from entering between the tube and the reinforcement layer and to reduce the occurrence rate of defective products during production. It is to provide a method.

  In order to achieve the above object, the first invention is housed in a tire, filled with gas at an internal pressure set in relation to a predetermined internal pressure of the tire, and at least the tire inner surface when the internal pressure of the tire is normal In the reinforcing air bladder for a hollow circular safety tire that forms a space between the tires and expands and deforms with a decrease in the internal pressure of the tire to replace the load from the tire, the reinforcing air bladder is A hollow circular tube comprising a crown portion, a pair of side portions extending radially inward from both end portions thereof, and a base portion extending opposite to the crown portion between both side portions, and at least the tube And a reinforcing layer that surrounds the outer periphery of the crown portion over the entire circumference, and the reinforcing layer is a reinforced air bag for safety tires having a plurality of through holes extending in the thickness direction.

  In the present specification, the “predetermined internal pressure” is an industrial standard effective in an area where the tire is manufactured, sold, or used, such as JATMA, TRA, ETRTO, etc. It shall be the internal pressure specified by the standard and specified according to the load capacity. The “internal pressure set in relation to the predetermined internal pressure” means that a space is formed between the outer surface of the reinforced air bladder and the inner surface of the tire in a gas-filled state where the predetermined internal pressure is applied to the tire. On the other hand, in the run-flat state where the internal pressure of the tire is reduced, it means the internal pressure at which the reinforced air bladder expands and deforms as the tire internal pressure decreases and can replace the load support from the tire. The internal pressure is in the range of +0 to 20%.

  Moreover, it is preferable that the diameter of a through-hole exists in the range of 0.3-2.0 mm.

Furthermore, it is preferable to arrange 1 to 5 through holes per 100 cm ² .

  Furthermore, it is preferable that the reinforcing layer further surrounds both side portions of the tube.

  Further, the second invention is a reinforcing layer ring in which a single member made of unvulcanized rubber and / or a rubber member made of a composite material made of unvulcanized rubber and fibers is pasted on a molding drum. A gas-impermeable semi-vulcanized or vulcanized tube filled with a gas at a predetermined internal pressure is brought into close contact with the outer surface of the crown portion so that the inner surface of the central portion of the sheet is aligned. Bend the side of the sheet along the outer surface of the tube, tightly surround the tube with the sheet to form an annular support with a tube, and vulcanize the annular support with the tube in a mold In the method for producing a reinforced pneumatic bladder for a safety tire, the sheet is provided with a plurality of through-holes extending in the thickness direction using a perforation means prior to disposing the sheet in the tube. Safety tie to A method for producing a sac use reinforcing air.

  At this time, in the vulcanization molding step, the space between the tube and the sheet constituting the tube-containing annular support can be simultaneously degassed by degassing the tube-supported annular support in the mold and the mold. preferable.

  According to the present invention, there is provided a reinforced air bag and a method for manufacturing the same that prevent air from entering between the tube and the reinforcing layer by reducing the amount of defective products during manufacturing by optimizing the reinforcing layer. It becomes possible to provide.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view in the width direction showing a safety tire containing a reinforced air bladder for a typical safety tire according to the present invention (hereinafter referred to as “reinforced air bladder”) mounted on a rim and filled with a predetermined internal pressure. FIG. 2 is an enlarged view of a main part of the reinforced air bladder of FIG.

The reinforced air bladder 1 has a hollow annular shape and is housed in the tire 2 to form a safety tire. This safety tire is mounted on the rim 3 to form a tire assembly. The tire 2 is filled with a predetermined internal pressure via a gas filling valve 4, and the reinforced air bladder 1 is filled with a gas at an internal pressure set in relation to the predetermined internal pressure of the tire 2 via a gas filling valve 5. As a result, as shown in FIG. 1, a space S ₁ is formed in the tire 2 and a space S ₂ is formed in the reinforcing air bladder 1. On the other hand, when the inner pressure of the space S ₁ of the tire 2 is rapidly lowered by puncture or the like, results internal pressure difference between the space S ₁ and the space S ₂ is increased, eventually reinforced air bladder 1 is diametrically enlarged deformed The tire 2 reaches the inner surface of the tire 2, and supports the load from the tire 2.

  The main feature of the present invention is that the reinforced air bladder 1 has a crown portion 6, a pair of side portions 7 extending radially inward from both ends thereof, and a crown extending between both side portions 7. A hollow circular tube 9 having a base portion 8 extending opposite to the portion 6, and at least a crown portion 6 of the tube 9, and a reinforcing layer 10 that surrounds only the outer periphery of the crown portion 6 in FIG. The reinforcing layer 10 has a plurality of through holes 11 extending in the thickness direction as shown in FIG.

  As described above, in manufacturing a conventional reinforced air bladder, a ring-shaped sheet for reinforcing layer is stuck on the outer peripheral surface of a tube expanded by gas. At this time, in order to prevent air from entering between the tube and the sheet, the tube and the sheet are usually brought into close contact with each other sequentially from the center of the width of the sheet toward both ends. However, since the tube does not have a reinforcing structure and is merely expanded and supported by internal pressure by a gas filled therein, the shape thereof is unstable. For this reason, if a strong force is applied to make the tube and the sheet completely adhere, the tube will be deformed. Conversely, if the force is weak, the tube and the sheet cannot be adhered completely. If there is a gas between the two, it is difficult to completely exhaust the gas. When the annular support body with a tube in which an air-filled space exists between the tube and the reinforcing layer thus formed is vulcanized and molded, the air in the space expands as the temperature rises. However, since the tube around the air-filled space and the reinforcing layer are in close contact with each other, the air-filled space forms a closed space. As a result of the internal pressure rising due to the expanded air, the gas is annular. It expands in the radial direction of the support and causes damage to the reinforcing layer, which increases the incidence of defective products during production.

  On the other hand, in the reinforced air bladder of the first invention, since the reinforcing layer 10 has a plurality of through holes 11, even if air is present between the tube 9 and the reinforcing layer 10, The air in the air-filled space passes through the through-hole 11 by utilizing the deaeration performed in the mold during the vulcanization molding and the expansion action of the gas in the air-filled space generated by the heat during vulcanization. Since it can be easily discharged out of the reinforced air bag, the above-described reinforcing layer 10 is not damaged, and the occurrence rate of defective products during manufacturing can be reduced.

  Moreover, it is preferable that the diameter d of the through-hole 11 exists in the range of 0.3-2.0 mm. The ring-shaped sheet for the unvulcanized reinforcing layer is soft, and even if a minute through-hole is opened, the through-hole is closed again due to plastic deformation of the sheet. This is because it is difficult to form a through-hole having a diameter d of less than 0.3 mm because it flows into the inside. On the other hand, when the diameter d is greater than 2.0 mm, the strength of the reinforcing layer 10 is reduced, and during normal running This is because the through-hole 11 may become a nucleus of crack generation.

Furthermore, it is preferable to arrange 1 to 5 through holes 11 per 100 cm ² . When the number of through holes 11 is less than 1 per 100 cm ² , the gas discharge speed through the through holes 11 is smaller than the expansion speed of the air in the air, which causes deformation of the reinforcing layer 10 and the tube 9. This is because if there are more than five, the gas discharge rate through the through-hole 11 is hardly improved, but the strength of the reinforcing layer 10 is reduced.

  FIG. 3 is a cross-sectional view in the width direction showing a state in which a safety tire containing another reinforced air bladder according to the present invention is mounted on a rim and filled with a predetermined internal pressure. As shown in FIG. 3, the reinforcing layer 10 preferably further surrounds both side portions 7 of the tube 9. According to this, when the internal pressure of the tire decreases due to puncture or the like, the reinforced air bladder uniformly expands and deforms, so that stable run-flat traveling is possible.

  In addition, the part which arrange | positions the through-hole 11 is not specifically limited, The through-hole 11 can be arrange | positioned in the part corresponding to at least 1 of the crown part 6, both the side parts 7, and the base part 8. FIG.

  Next, a method for manufacturing a reinforced air bladder for a safety tire according to the second invention will be described.

  FIG. 4 is a perspective view of a typical drilling device used in the method for manufacturing a reinforced pneumatic bladder for a safety tire according to the second invention. As shown in FIG. 4, a rubber member 13 composed of a single material made of unvulcanized rubber and / or a composite material made of unvulcanized rubber and fibers extruded from an extruder (not shown). , Conveyed on the conveyor 14. A punching device 15 is provided above the conveyor 14. The punching device 15 is connected to driving means (not shown) such as a cylinder or a motor via a driving shaft 16 and can be driven to reciprocate in the vertical direction.

  The punching device 15 is provided with a plurality of punching means 17 along a direction orthogonal to the flow direction of the rubber member 13. The diameter of the punching means 17 is preferably 0.3 to 2.0 mm. The perforating means 17 is formed of, for example, stainless steel in a cone shape, and has a length that can penetrate the rubber member 13 in the thickness direction.

  A support base 18 that receives the lower surface of the rubber member 13 is provided below the punching device 15, and a hole 19 into which the tip of the punching means 17 enters is formed in the support base 18.

When the rubber member 13 is conveyed on the conveyor 14, the punching device 15 is driven to reciprocate in the vertical direction with respect to the hole 19, whereby the through hole 11 is formed in the rubber member 13. The number of the through holes 11 per 100 cm ² can be adjusted by changing the mounting pitch of the punching means 17 or by controlling the relationship between the conveying speed of the rubber member 13 and the reciprocating speed of the punching device 15. it can. Further, the through hole 11 can be formed only in a desired region of the rubber member 13 by changing the mounting position of the punching means 17.

  In this way, the rubber member 13 provided with the through holes 11 in advance is stuck on a molding drum (not shown) to form a reinforcing layer ring-shaped sheet. Thereafter, a reinforced air bladder for a safety tire is obtained by a manufacturing method similar to the conventional method for producing a reinforced air bladder for a safety tire (FIGS. 5A to 5C).

  Or although illustration is abbreviate | omitted, instead of the rubber member 13 extruded from the extruder, the ring-shaped sheet | seat for reinforcement layers formed by sticking a rubber member on a molding drum is set to the punching apparatus 15 shown in FIG. And a through-hole can also be formed like the above. Also in this case, a reinforced air bag for a safety tire is obtained by performing the subsequent steps in the same manner as in the conventional manufacturing method.

  If a through hole is provided in this way, even if a gas remains between the tube and the reinforcing layer at the time of attachment, the gas is easily discharged out of the reinforcing air through the through hole. For this reason, the reinforcing layer is not damaged due to gas expansion during vulcanization molding, and the rate of defective products during production can be reduced.

  At this time, in the vulcanization molding step, in particular, the tube-containing annular support is set in the mold, and the tube-containing annular support in the mold is partly or wholly between immediately after the mold is closed and during the vulcanization molding. It is preferable that the space between the tube and the sheet constituting the tube-shaped annular support is simultaneously degassed by deaeration between the support and the mold. According to this, the air in the air-containing space remaining when the reinforcing layer is attached to the tube can be easily discharged out of the reinforcing air bag through the through hole, and during vulcanization molding Since the problem caused by the expansion of the air in the air-filled space between the tube and the reinforcing layer is eliminated, the incidence of defective products due to the damage of the reinforcing layer can be further reduced.

In addition, the place mentioned above only showed a part of embodiment of this invention, and can change a various change in a claim.

  Next, a safety tire reinforcing air bladder according to the present invention was prototyped and performance evaluation was performed, which will be described below.

The reinforced air bladder of the example is a reinforced air bladder for a safety tire having a tire size of 495 / 45R22.5, and has the structure shown in FIG. 6 and is made of butyl rubber having a thickness of 3 to 5 mm. The outer peripheral surface of the conductive tube has a thickness of 2 to 10 mm and is tightly surrounded by a reinforcing layer formed by rubber-coating an aramid nonwoven fabric. In the side portion of the reinforcing layer, three through holes having a diameter of 1.0 mm are formed at a rate of three per 100 cm ² .

  For comparison, the tire size is a 495 / 45R22.5 safety tire reinforced air bag, has the structure shown in FIG. 3, and has the same outer peripheral surface of the tube as in the embodiment, but no through holes. A reinforced air bladder (conventional example) formed by tightly enclosing with the same reinforcing layer as in the example except for the above was also manufactured.

  100 each of the above-mentioned reinforcing air bladders using the same mold and under the same vulcanization conditions, make a trial production, visually inspect the appearance and check for damage to the reinforcing layer, and generate defective products Rate was evaluated. As a result, the incidence of defective products was 2% for the reinforced air bladder of the example and 20% for the reinforced air bladder of the comparative example.

  From this evaluation result, it can be seen that the reinforced air bag of the example has a significantly reduced incidence of defective products compared to the reinforced air bag of the comparative example.

  According to the present invention, it is possible to provide a reinforced air bag and a method for manufacturing the same, which optimizes the reinforcing layer, prevents air from entering between the tube and the reinforcing layer, and reduces the occurrence rate of defective products during manufacturing. It has become possible.

FIG. 3 is a cross-sectional view in the width direction showing a state in which a safety tire containing a representative reinforced air bladder for a safety tire according to the present invention is mounted on a rim and filled with a predetermined internal pressure. It is a perspective view of the cut sample which cut | disconnected the reinforced air bag shown in FIG. 1 in the width direction. FIG. 5 is a cross-sectional view in the width direction showing a state where a safety tire containing a reinforced air bladder for another safety tire according to the present invention is mounted on a rim and filled with a predetermined internal pressure. 1 is a perspective view of a typical drilling device used in a method for producing a reinforced pneumatic bladder for a safety tire according to the present invention. (A)-(c) is a figure for demonstrating the manufacturing method of the conventional reinforced air bladder for safety tires. It is sectional drawing of the width direction shown in the state which mounted | wore the rim with the safety tire which accommodated the reinforced air bladder for safety tires of the Example, and was filled with the predetermined | prescribed internal pressure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reinforcement air cylinder 2 Tire 3 Rim 4, 5 Air filling valve 6 Tube crown part 7 Tube side part 8 Tube base part 9 Tube 10 Reinforcement layer 11 Through-hole 12 Reinforcement layer crown part 13 Rubber member 14 Conveyor 15 Drilling device 16 Drive shaft 17 Drilling means 18 Support base 19 Hole

Claims (6)

The gas is filled with the internal pressure set in relation to the predetermined internal pressure of the tire and stored in the tire, and when the internal pressure of the tire is normal, a space is formed between at least the tire inner surface and the internal pressure of the tire is reduced. In the reinforced air bladder for a hollow circular safety tire that expands and deforms along with the load and supports the load from the tire,
The reinforced air bladder has a hollow circular tubular shape including a crown portion, a pair of side portions extending radially inward from both ends thereof, and a base portion extending opposite the crown portion between both side portions. A tube, and a reinforcing layer that surrounds at least the outer periphery of the crown portion of the tube over the entire circumference,
The reinforcing layer is a safety tire reinforcing air bladder having a plurality of through holes extending in the thickness direction.   The reinforced air bladder for a safety tire according to claim 1, wherein the diameter of the through hole is in a range of 0.3 to 2.0 mm. Wherein a through hole is formed by 1-5 disposed per 100 cm ^2, according to claim 1 or 2 reinforcing air safety tire according to.   The reinforcing air bag for safety tires according to any one of claims 1 to 3, wherein the reinforcing layer further surrounds both side portions of the tube. A rubber member composed of a single material made of unvulcanized rubber and / or a composite material made of unvulcanized rubber and fibers is pasted on the molding drum to form a ring-shaped sheet for a reinforcing layer,
A gas-impermeable semi-vulcanized or vulcanized tube filled with gas at a predetermined internal pressure is disposed in close contact with the outer surface of the crown portion so that the inner surface of the central portion of the sheet matches,
Bend the side of the sheet along the outer surface of the tube, tightly surround the tube with the sheet to form an annular support with a tube,
In the method for producing a reinforced air bladder for a safety tire in which the annular support with tube is vulcanized in a mold,
Prior to disposing the sheet on the tube, a method for producing a reinforced air bladder for a safety tire is provided, wherein a plurality of through holes extending in the thickness direction are provided in the sheet using perforation means.   The said vulcanization molding process WHEREIN: By deaeration between the annular support body containing a tube in the said mold and a mold, between the tube which comprises the annular support body containing a tube, and the said sheet | seat is also deaerated simultaneously. A method for producing a reinforced pneumatic bladder for a safety tire according to claim 1.

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