JP2009000971A - Device and method for manufacturing air bladder for safety tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and a method for manufacturing an air bladder for a safety tire increased in production efficiency while maintaining the durability of the air bladder for the safety tire. <P>SOLUTION: This air bladder manufacturing device 1 comprises a main forming drum 2, an auxiliary forming drum 3 larger in diameter than the main forming drum 2, and a transfer means 4. The main forming drum 2 comprises an expansion means 5 and a pair of fixing means 6a, 6b positioned on both sides of the expansion means. A sheet-like extension support member is wrapped around the main forming drum 2 to form a ring-like tension support member 7. A sheet-like reinforcing material is wrapped around the auxiliary forming drum 3 to form a ring-like reinforcing member 8. The transfer means 4 transfers the reinforcing member 8 of the auxiliary forming drum 3 onto the outer periphery of the main forming drum 2. The expansion means 5 of the main forming drum 2 is expandable and contractible in the radial direction, and expands the crown part of the formed extension support member in the radial direction. The fixing means 6a, 6b are movable in the lateral direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a safety tire air comprising a gas-impermeable tube, a tension support layer that tightly surrounds the entire outer surface of the tube, and a reinforcing layer disposed on the outer periphery of the crown portion of the tension support layer. The present invention relates to an apparatus and a method for manufacturing a sulfur.

  Reinforcing members such as a reinforcing tube, reinforcing rubber, and reinforcing belt, or a foam, elastic body, medium, and the like as a safety tire that can travel a certain distance even in a run-flat state in which the tire internal pressure has suddenly decreased due to puncture or the like There are known tires that support the load of the tire on the shoulder, tires that are coated or filled with a sealant agent, block damaged parts such as holes formed in the tire, and prevent a decrease in internal pressure, and the like. However, these conventional safety tires often have a high defect rate and a low manufacturing efficiency due to the complicated manufacturing method.

  In order to solve such a problem, for example, in Patent Document 1, in a run-flat state in which a tension support member is disposed on the outer peripheral surface of a tube and is housed in a safety tire and the internal pressure of the tire decreases, the tire A hollow cylindrical air bladder is described that expands and deforms as the internal pressure decreases and replaces the load support from the tire. In manufacturing such an air bladder, after attaching a tension support member to the outer peripheral surface of an unvulcanized tube while controlling the shape of the tube as expected, vulcanize both. Are joined. However, since the tube is flexible and its shape is unstable, it is difficult to accurately dispose the tension support member.

  In order to solve such problems in production, Patent Document 2 discloses a tension support member in which a narrow strip made of a composite material of a fiber member and rubber is attached to a hard support having a required outer contour shape. Is described, and a method of sticking this on a tube is described. According to this, since the shape on the hard support is stable, the tension support member can be easily molded with high accuracy as expected.

International Publication No. 02/43975 Pamphlet International Publication No. 02/96678 Pamphlet

  In the air bladder described in Patent Documents 1 and 2, it is preferable to use a high-strength fiber such as an aramid fiber for the tension support member. However, such high-strength fibers have low extensibility, and it takes time to apply them to those having a diameter difference such as a hard support. Therefore, development of a more rapid molding method is desired.

  The object of the present invention is to solve such problems of the prior art, and its purpose is to improve manufacturing efficiency on the premise of maintaining the durability of the air bladder for safety tires. An object of the present invention is to provide a manufacturing apparatus and a manufacturing method for a safety tire pneumatic bladder.

  In order to achieve the above object, a manufacturing apparatus according to the present invention is provided on a gas-impermeable tube, a tension support layer that tightly surrounds the entire outer surface of the tube, and an outer periphery of the crown portion of the tension support layer. An apparatus for manufacturing a pneumatic tire bladder for a safety tire comprising a reinforcing layer and a main molding drum for forming a ring-shaped tension supporting member from a sheet-shaped tension supporting material, and the main molding drum An auxiliary molding drum for forming a ring-shaped reinforcing member from a sheet-shaped reinforcing material having a larger diameter and a reinforcing member formed on the auxiliary molding drum are transferred onto the outer periphery of the main molding drum. The main molding drum includes: expansion means for expanding the crown portion of the tension support member in the radial direction; and a width direction for fixing the bead portion of the tension support member located on both sides of the expansion means. Move to It is characterized in that it has a capacity of a pair of fixing means.

  The “crown part” and “bead part” of the tension support member referred to here are air pressures facing the crown part, sidewall part, bead part and rim of the tire when the safety tire is assembled to the rim. The parts to be placed in the crown part, side part, bead part, and base part in order, the portion of the tension support member that should be placed in the crown part of the air bladder is the “crown part”, and the bead part in the air bladder The part that should be called "bead part".

  The expansion means is preferably a core having a plurality of air ejection holes spaced in the circumferential direction, a divided core formed by aligning a plurality of segments in the circumferential direction, a bladder, or a combination thereof. In particular, when the expansion means includes a split core, the split core is preferably composed of at least 16 segments.

  The method of manufacturing a pneumatic tire for a safety tire according to the present invention includes a gas-impermeable tube, a tension support layer that tightly surrounds the entire outer surface of the tube, and an outer periphery of the crown portion of the tension support layer. In a method for manufacturing a safety tire pneumatic bladder comprising a reinforcing layer formed, a sheet-like tension supporting material is attached to a main molding drum to form a ring-shaped tension supporting member, and a sheet-like reinforcing material is formed. Affixed to the auxiliary molding drum to form a ring-shaped reinforcing member having a larger diameter than the tension supporting member, and the reinforcing member is disposed radially outside the crown portion of the tension supporting member. While moving both bead portions inward in the width direction, the crown portion of the tension support member is expanded radially outward to join the tension support member and the reinforcement member, and the inner surface side of the crown portion of the tension support member joined to the reinforcement member In addition, The tube is inserted, and the tension support member is bent along the outer surface of the tube to form a circular tubular body formed by tightly enclosing the tube with the tensile support member. It is characterized by obtaining nou.

  In addition, it is preferable that the peripheral length, which is a distance measured along the outer surface of the tension support member, between the width of the tension support member before expansion and the width ends of the tension support member after expansion is substantially the same. Here, “substantially the same” means that the width of the tension support member before expansion is 100 and the peripheral length of the tension support member after expansion is in the range of 90 to 110.

  Furthermore, it is preferable that the maximum value of the circumferential extension rate before and after expansion of the tension support member is 50% or less.

  According to the present invention, it is possible to provide a manufacturing apparatus and a manufacturing method for a safety tire for a pneumatic tire with improved production efficiency on the premise of maintaining the durability of the pneumatic bladder.

  Next, embodiments of the present invention will be described with reference to the drawings. 1 and 2 schematically show an entire typical manufacturing apparatus for a pneumatic tire bladder (hereinafter referred to as “air bladder”) according to the present invention.

  The apparatus 1 shown in FIG. 1 includes a main molding drum 2, an auxiliary molding drum 3 having a larger diameter than the main molding drum 2, and a transfer unit 4. The main molding drum 2 has expansion means 5 and a pair of fixing means 6a and 6b located on both sides thereof. A sheet-like tension support material such as a composite of rubber and a highly extensible fiber member is wound around the main molding drum 2, and both ends in the circumferential direction are joined to form a ring-shaped tension support member 7. . A sheet-like reinforcing material such as a composite of rubber and a low-extension fiber member is wound around the auxiliary molding drum 3, and both ends in the circumferential direction are joined to form a ring-shaped reinforcing member 8. The transfer means 4 can remove and hold the reinforcing member 8 of the auxiliary molding drum 3 and can reciprocate between the main molding drum 2 and the auxiliary molding drum 3. The expansion means 5 of the main molding drum 2 can be expanded and contracted in the radial direction, and the crown portion of the tension support member formed thereon is expanded in the radial direction. The fixing means 6a and 6b are movable in the width direction of the drum.

  Next, a method for manufacturing an air bladder using the manufacturing apparatus 1 configured as described above will be described. First, as shown in FIG. 2, a ring-shaped tension supporting member 7 is formed on the main molding drum 2, and a ring-shaped reinforcing member 8 is formed on the auxiliary molding drum 3. Next, the bead portion of the tension support member 7 is fixed by the fixing means 6a and 6b. Further, after the transfer means 4 is moved onto the auxiliary molding drum 3 and the reinforcing member 8 is detached and held from the auxiliary molding drum 3, the transfer means 4 is shown in FIG. Thus, it moves to the outer periphery of the main molding drum 2. Here, by moving the fixing means 6a, 6b inward in the width direction, that is, in a direction approaching each other, both bead portions of the tension support member 7 fixed thereto are brought closer inward in the width direction. At the same time, by expanding the expansion means 5 in the radial direction, the crown portion of the tension support member 7 is expanded outward in the radial direction, so that the tension support member 7 and the reinforcing member 8 are connected as shown in FIG. Join. Next, the transfer means 4 is moved again toward the auxiliary molding drum 3, the tension supporting member 7 joined to the reinforcing member 8 is removed from the main molding drum 2, and vulcanized on the inner surface side as shown in FIG. Insert the finished tube 9. After that, when both width ends 10a and 10b of the tension support member 7 are bent along the outer surface of the tube 9, both width ends 10a and 10b are joined to each other, and the tube 9 is tightly surrounded by the tension support member 7, FIG. An unvulcanized circular tubular body 11 as shown in FIG. And if this tubular body 11 is removed from the apparatus 1 and vulcanized in a vulcanization mold (not shown), a gas-impermeable tube and a tension support layer that tightly surrounds the entire outer surface of the tube, A hollow air bladder having a reinforcing layer disposed on the outer periphery of the crown portion is obtained.

  In general, in safety tires containing pneumatic bladders, the internal pressure of the pneumatic bladder is set higher than the inner pressure of the tire, and the tension generated in the pneumatic bladder is borne by the tension support layer and the reinforcing layer due to this differential pressure. This prevents the air bladder from expanding and deforming when the tire internal pressure is normal. High tensile strength fibers such as aramid fibers are used as the material for the tension support layer and the reinforcement layer in order to exert the effect of preventing expansion deformation even when the centrifugal force due to rolling of the tire acts in addition to the tension due to the internal pressure. Is generally used. Since such high strength fibers have low extensibility and are difficult to be deformed after pasting, in the conventional method for producing air bladder, the outer surface close to the final shape of the tube or the air bladder to which internal pressure is applied. A narrow strip is spirally wound and pasted onto a rigid support having a shape. The reason for this is that the side portion of the tube and the rigid support has a large diameter difference, and if a wide strip with low elongation is used for this, the diameter difference cannot be absorbed by the extension of the strip, and wrinkles occur. Since such a kite impairs the strength of the air bladder, it is intended to prevent the generation of the kite by narrowing the width of the strip. However, prior to the strip application, it is necessary to determine the attachment posture and position. When a narrow strip is used, the number of attachments increases, which increases the number of attachment postures and positions. There was a problem that the attaching work required time.

  In order to shorten the time required for the pasting operation, constituent members are sequentially pasted on a flat drum like a general pneumatic tire to form a tension support member, and this crown portion is expanded and expanded. Therefore, it is considered effective to apply a manufacturing method for forming a desired shape, that is, a so-called shaping method. This is because, in the shaping method, it is only necessary to stick a wide sheet once on a flat drum, and there is no possibility of wrinkles while reducing the time required for the sticking operation, and the strength is not impaired. However, if the crown part is simply expanded and expanded, the crown part is greatly stretched in both the circumferential direction and the width direction, so the strength of this part is significantly reduced. There is a risk that deformation cannot be prevented. Therefore, the inventor reduces the elongation in the width direction and reduces the strength of the crown portion by expanding the crown portion of the tension support layer if both bead portions approach each other in the width direction so as to approach each other. As a result, the inventors have found that the present invention can be suppressed, and have completed the present invention.

  From the viewpoint of suppressing a decrease in the strength of the crown portion, it is preferable that the elongation in the width direction when the crown portion is expanded is as small as possible. Specifically, when the crown portion is expanded, the width of the tension support member 7 before expansion is set to 100, and the peripheral length of the tension support member 7 after expansion is preferably 110 or less, more preferably 105 or less, even more preferably. The bead portions are brought close to each other so that the ratio is 101 or less.

  Further, in the shaping method, as the tension support member 7 is expanded in the radial direction, the peripheral length also increases. The stretch rate in the circumferential direction of the tension support member 7 is preferably the same as the expansion rate in the radial direction in any part. If this is uneven, the stretch rate in the circumferential direction is high when used as an air bladder. The part is easily broken. Therefore, it is preferable that the maximum value of the circumferential expansion rate of the tension support member 7 before and after expansion is within 1.5 times the radial expansion rate, and the radial expansion rate is 25% in the production of normal air bladder. Since it is before and after, it is preferable that the maximum value of the elongation rate in the circumferential direction is 50% or less.

  Thus, in order to make the circumferential extension rate of the tension support member 7 uniform, the expansion means 5 of the manufacturing apparatus 1 includes a core having a plurality of air ejection holes spaced apart in the circumferential direction, and a plurality of segments. It is preferable to use any one of divided cores, bladders, and combinations thereof that are aligned in the circumferential direction.

  FIGS. 7A and 7B are schematic cross-sectional views in the width direction when the expansion means is the core 13 including the air ejection holes 12 spaced in the circumferential direction, and FIG. The state before expansion, (b) shows the state after expansion of the tension support member 7. As shown in FIG. 7A, after the ring-shaped tension support member 7 is formed on the core 13 and the fixing means 6a and 6b, the bead portion of the tension support member 7 is fixed by the fixing means 6a and 6b. Next, when air is ejected from the air ejection holes 12 toward the tension support member 7, the crown portion of the tension support member 7 can be expanded as shown in FIG. 7B. In this case, since the elongation ratio in the circumferential direction of the portion of the tension support member 7 located immediately above the air ejection holes 12 tends to increase, a large number of the air ejection holes 12 are dispersed in the circumferential direction and the width direction. It is preferable to arrange.

  FIGS. 8A and 8B are schematic cross-sectional views in the width direction when the expanding means is a split core 14 in which a plurality of segments are aligned in the circumferential direction. FIG. (B) shows a state after the tension support member 7 is expanded. FIG. 9 is a cross-sectional view taken along the line AA in FIGS. 8A and 8B, in which the right half shows a state before expansion and the left half shows a state after expansion. As shown in FIG. 8A, after the ring-shaped tension support member 7 is formed on the split core 14 and the fixing means 6a and 6b, the bead portion of the tension support member 7 is fixed by the fixing means 6a and 6b. . Next, when the divided core 14 is moved radially outward, the crown portion of the tension support member 7 can be expanded as shown in FIG. Such a split core 14 can have the same configuration as that of a split core used in a normal tire molding apparatus. For example, as shown in FIG. 9, a large segment 15a having a large peripheral length and a small segment having a small peripheral length. The segments 15b can be alternately arranged in the circumferential direction. In the state before expansion, the small segment 15b is stored inside the large segment 15a in the radial direction, and when expanding, the large segment 15a and the small segment 15b are moved outward in the radial direction using hydraulic pressure, pneumatic pressure, servo motor, or the like. Move to match these peripheral surfaces. In this case, the frictional force from the large segment 15a acts on the portion of the tension support member 7 that is in contact with the large segment 15a, and the portion that is not in contact with any of the segments Such frictional force does not act. For this reason, in expansion, the circumferential extension rate of the portion that is not in contact with any segment tends to be larger than that of the portion that is in contact with the large segment 15a. From the viewpoint of reducing the deviation in the circumferential extension rate, it is preferable to reduce the frictional force between the large segment 15a and the tension support member 7. For example, the number of segments constituting the split core 14 is increased to increase the large segment 15a. The perimeter can be reduced. The number of segments is preferably 16 or more, but is preferably 48 or less, and more preferably 32 or less, from the viewpoint of manufacturing cost, control and maintenance management of the split core 14.

  FIGS. 10A and 10B are schematic cross-sectional views in the width direction when the expansion means is the bladder 16. FIG. 10A is a state before the tension support member 7 is expanded, and FIG. 10B is a tension support member 7. The state after expansion is shown. As shown in FIG. 10A, after the ring-shaped tension support member 7 is formed on the bladder 16 and the fixing means 6a and 6b, the bead portion of the tension support member 7 is fixed by the fixing means 6a and 6b. Next, when the bladder 16 is filled with air and expanded, the crown portion of the tension support member 7 can be expanded as shown in FIG. This expansion means is particularly advantageous in that the variation in the circumferential expansion rate is small.

  The core, the split core, and the bladder having the air ejection holes described above can be used alone or in combination. For example, when the tension support member 7 is expanded with air or a bladder, it is difficult to make the contour shape of the tension support member 7 after expansion, particularly the shape of the shoulder portion, a desired shape. It is advantageous. FIGS. 11A to 11C are schematic cross-sectional views in the width direction when the expansion means is a split core 14 including a plurality of air ejection holes 12 spaced in the circumferential direction, and FIG. The state before expansion of the support member 7, (b) shows the state during expansion of the tension support member 7, and (c) shows the state after expansion of the tension support member 7. When using such expansion means, first, as shown in FIG. 11 (a), after forming the ring-shaped tension support member 7 on the core 14 and the fixing means 6a, 6b, the tension is applied by the fixing means 6a, 6b. The bead portion of the support member 7 is fixed. Next, when air is ejected from the air ejection hole 12 toward the tension support member 7, the crown portion of the tension support member 7 expands as shown in FIG. When the split core 14 is moved radially outward in this state, the tension support member 7 comes into contact with the split core 14 as shown in FIG.

  FIGS. 12A to 12C are schematic cross-sectional views in the width direction when the expansion means is a combination of the bladder 16 and the split cores 14 arranged on the radially inner side, and FIG. The state before expansion of the member 7, (b) shows the state during expansion of the tension support member 7, and (c) shows the state after expansion of the tension support member 7. When using such expansion means, first, as shown in FIG. 12 (a), after forming the ring-shaped tension support member 7 on the core 14 and the fixing means 6a, 6b, tension is applied by the fixing means 6a, 6b. The bead portion of the support member 7 is fixed. Next, when the bladder 16 is filled with air and expanded, the crown portion of the tension support member 7 expands as shown in FIG. When the split core 14 is moved radially outward in this state, the tension support member 7 comes into contact with the split core 14 as shown in FIG.

  Even when these divided cores are combined with other expansion means, the number of segments constituting the divided core is preferably 16 or more, and the reason is as described above.

  Note that the above description shows only a part of the embodiment of the present invention, and these configurations can be combined with each other or various modifications can be made without departing from the gist of the present invention. .

  A pneumatic tire for a safety tire having a tire size of 495 / 45R22.5 was manufactured using the manufacturing apparatus of the present invention in which the expansion means is a combination of a split core consisting of 16 segments and a bladder. This pneumatic support member was expanded by 27% in the radial direction, and the circumferential expansion rate before and after expansion was 29% at the maximum. There was no damage to the tension support member of the obtained air bladder, and when the specified internal pressure was applied to the tire and the air bladder, the diameter growth of the air bladder was suppressed satisfactorily.

  For comparison, a pneumatic tire for a safety tire having a tire size of 495 / 45R22.5 is formed by sticking a narrow strip on a hard support to mold a tension support member and sticking it on a tube. Manufactured.

  The number of air bladders produced per unit time by the production method of the present invention was compared with the number of air bladders produced per unit time by the conventional production method. As a result, compared to the conventional manufacturing method, the present invention was able to manufacture 8.3 times as many air bags per unit time.

  According to the present invention, it is possible to provide a manufacturing apparatus and a manufacturing method for a safety tire pneumatic bladder with improved manufacturing efficiency on the premise of maintaining the durability of the safety tire pneumatic bladder.

1 is a schematic overall view of a typical production apparatus for a safety tire pneumatic bladder according to the present invention. It is a figure for demonstrating the process of forming an air bladder using the apparatus shown in FIG. It is a figure for demonstrating the process of forming an air bladder using the apparatus shown in FIG. It is a figure for demonstrating the process of forming an air bladder using the apparatus shown in FIG. It is a figure for demonstrating the process of forming an air bladder using the apparatus shown in FIG. It is a figure for demonstrating the process of forming an air bladder using the apparatus shown in FIG. It is a width direction schematic sectional drawing in case an expansion means is a core provided with the air ejection hole spaced apart in the circumferential direction, (a) is the state before expansion of a tension support member, (b) is expansion of a tension support member Shown later. It is a width direction schematic sectional drawing in case an expansion means is a division | segmentation core formed by aligning several segments to the circumferential direction, (a) is the state before expansion of a tension support member, (b) is a tension support member The state after expansion is shown. FIGS. 8A and 8B are cross-sectional views taken along the line A-A in FIG. 8A, in which the right half shows a state before expansion, and the left half shows a state after expansion. It is a width direction schematic sectional drawing in case an expansion means is a bladder, (a) shows the state before expansion of a tension support member, (b) shows the state after expansion of a tension support member. It is a width direction schematic sectional drawing in case an expansion means is a division | segmentation core provided with several air ejection holes spaced apart in the circumferential direction, (a) is the state before expansion of a tension support member, (b) is tension The state in the middle of expansion of a support member, (c) shows the state after expansion of a tension support member. It is a width direction schematic sectional drawing in case an expansion means is a combination of a bladder and the division | segmentation core arrange | positioned at the radial inside, (a) is the state before expansion of a tension support member, (b) is tension support. The state in the middle of expansion of a member and (c) show the state after expansion of a tension support member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pneumatic apparatus 2 Main molding drum 3 Auxiliary molding drum 4 Transfer means 5 Expansion means 6a, 6b Fixing means 7 Tension support member 8 Reinforcement member 9 Tube 10a, 10b Both ends of tension support member 11 Circular tubular body 12 Air ejection Hole 13 Core 14 Split core 15a, 15b Segment constituting the split core 16 Bladder

Claims (6)

Manufacturing a pneumatic tire for a safety tire comprising a gas-impermeable tube, a tension support layer that tightly surrounds the entire outer surface of the tube, and a reinforcing layer disposed on the outer periphery of the crown portion of the tension support layer In the device to
The apparatus has a main molding drum for forming a ring-shaped tension supporting member from a sheet-like tension supporting material, and a larger diameter than the main molding drum, and forms a ring-shaped reinforcing member from the sheet-shaped reinforcing material. An auxiliary molding drum for carrying out, and a transfer means for transferring a reinforcing member formed on the auxiliary molding drum onto the outer periphery of the main molding drum,
The main molding drum has a pair of movable means extending in the width direction, and extending means for expanding the crown portion of the tension supporting member in the radial direction, and fixing the bead portions of the tension supporting member located on both sides of the expanding means. A pneumatic tire manufacturing apparatus for a safety tire, comprising a fixing means.   2. The expansion means according to claim 1, wherein the expansion means is a core having a plurality of air ejection holes spaced apart in the circumferential direction, a divided core formed by aligning a plurality of segments in the circumferential direction, a bladder, or a combination thereof. Manufacturing equipment.   The manufacturing apparatus according to claim 2, wherein the expansion means includes a split core composed of at least 16 segments. Manufacturing a pneumatic tire for a safety tire comprising a gas-impermeable tube, a tension support layer that tightly surrounds the entire outer surface of the tube, and a reinforcing layer disposed on the outer periphery of the crown portion of the tension support layer In the way to
A sheet-like tension support material is attached to the main molding drum to form a ring-shaped tension support member,
Affixing a sheet-like reinforcing material on an auxiliary molding drum to form a ring-shaped reinforcing member having a diameter larger than that of the tension supporting member,
Arranging the reinforcing member on the radially outer side of the crown portion of the tension support member;
While bringing both bead portions of the tension support member to the inside in the width direction, expanding the crown portion of the tension support member radially outward, joining the tension support member and the reinforcing member,
Insert the vulcanized tube into the inner surface side of the crown portion of the tension support member joined to the reinforcing member,
Bending the tension support member along the outer surface of the tube to form a tubular body formed by tightly enclosing the tube with the tension support member,
A manufacturing method characterized in that an air bladder is obtained by vulcanization molding of this circular tubular body.   The manufacturing method according to claim 4, wherein the width of the tension support member before expansion and the peripheral length of the tension support member after expansion are substantially the same.   The said tension support member is a manufacturing method of Claim 4 or 5 whose maximum value of the circumferential direction expansion rate before and behind expansion is 50% or less.

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