JP2006193005A - Assembly of pneumatic tire and rim and assembling method for pneumatic tire and rim - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an assembly of a pneumatic tire and a rim and an assembling method for a pneumatic tire and a rim, assembling the pneumatic tire and the rim with a fitting strength at a higher level than that in the prior art when the pneumatic tire and the rim are fitted and assembled. <P>SOLUTION: This assembly is composed of the rim 3 and the pneumatic tire provided with a groove 12 extended substantially in the radial direction on the bead part surface coming into contact with the rim. In the assembly of the pneumatic tire and the rim, the groove is extended at least from the bead heal part to the separating part between the rim flanges 4, 5 and the tire, and a liquid elastomer composition is interposed in a gap 7 between the tire bead part and the rim flange of the fitting part where the rim and the flange come into contact at the time of assembling the tire and the rim. According to this assembling method of the pneumatic tire and the rim, the air in the fitting part is evacuated through the liquid elastomer composition from the fitting part where the tire bead part 1 and the ring and flange 4, 5 come into contact with each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pneumatic tire and rim assembly and an assembling method.

  More particularly, the present invention relates to a pneumatic tire and rim assembly in which the pneumatic tire and the rim are assembled with high fitting strength, and a pneumatic tire and rim assembly method for realizing the assembly. .

  Conventionally, when a pneumatic tire and a rim are assembled, that is, when a pneumatic tire is fitted to the rim, the bead portion of the tire and the flange portion of the rim do not completely adhere to each other, and a gap is generated in part. In some cases, a pneumatic tire and a rim are assembled while air is accumulated in the gap.

  This state will be described with reference to FIG. 5. As shown in FIG. 5, the bead base surface 2 of the bead portion 1 of the pneumatic tire fits strongly in the rim flange lower portion 4 of the rim 3 without causing a gap. Is ideal, the bead outer surface 6 guided by the flange upper portion 5 of the rim 3 is positioned below the outer surface 6 by the outer surface 6 being in close contact with the flange upper portion 5 during rim assembly. In many cases, a gap 7 is formed between the rim 3 and the flange of the rim 3.

  The presence of such a gap portion and the accumulation of air in the portion is a portion where the tire bead portion and the rim flange portion are supposed to be in contact with each other and should not be in contact with each other. Therefore, since the contact pressure between the two is not uniform throughout the pneumatic tire, it is difficult to obtain a sufficiently high fitting strength between the pneumatic tire and the rim as a whole.

  If it is not possible to realize a sufficiently high value as the fitting strength, it may adversely affect the steering stability of the vehicle, may induce rim deviation, or this may occur when the tire rolls. There is a possibility of causing inconveniences in various points such as that air leaks from the non-contact area and may adversely affect the decrease in the internal pressure of the tire.

  The gap 7 described above gradually decreases due to the familiarity of the bead outer surface 6 with the use of the tire. However, with the decrease in the gap 7, the accuracy of the initial rim assembly changes, and the roundness of the tire is reduced. Longitudinal run-out caused by inferiority, and force variation due to poor tire balance become large, vibration may be induced in actual vehicle running, and further, the braking area is reduced by reducing the contact area between the bead part and the rim. , There is a possibility that a rim shift occurs between the bead portion and the rim flange, affecting the straight running performance and reducing the durability.

  Such a problem can be said to be a problem based on the assembly accuracy when assembling the rim, but the user of the pneumatic tire (the tire / rim assembler) has no long experience and careful attention to the tire. -Even if the rim is assembled, it is desired to realize a pneumatic tire that can produce the best rim assembly without causing the above-described gap.

Therefore, such a problem has been studied conventionally, for example, on the outer surface of the tire bead, on the outer side of the tire radial direction with reference to the separation point at which the outer surface of the bead is separated from the rim flange. Four or more extending air vent grooves are provided, and the air vent groove has an inner end at a position of 4 to 10 mm from the separation point, a length of 15 to 50 mm, and a groove cross-sectional area of 0.1 to 2.5 mm ^2. When the rim is assembled, air intervening between the outer surface of the bead and the rim flange passes through the air vent groove and is discharged to the outside of the tire so that air remains in the gap. There has been proposed a pneumatic tire that is not used (Patent Document 1).

  However, this proposal is able to draw air through the air groove moderately, but even if the gap amount is small, it still remains as the gap itself, and even if the problem is reduced, there is still room for improvement. There was something.

  Further, on the tire bead surface, there is a bulge height that reduces the gap between the rim arc surface on the bead corner surface, which is a range facing the rim arc surface of the rim by being assembled to the rim and filled with internal pressure. It has been proposed that a bulging portion of 0.3 to 1.0 mm is provided and the tightening force of the bead portion with respect to the rim is increased by the bulging portion to improve the fitting force (Patent Document 2).

  However, this proposal also needs to remain as the gap itself even if the gap amount is reduced, and there is still room for improvement even if the problem is reduced.

  In addition, after assembling the tire to the rim, a filler is injected into the gap, particularly from a through-hole formed in the rim, and the gap interposed between the bead and the rim is filled with the filler. It has been proposed to obtain a tire / rim assembly in which the bead portion and the rim are firmly fitted by solidifying the agent (Patent Document 3).

However, in this proposal, there is a case where a gap remains and the filler is solidified without being completely filled, and there is still room for improvement even if the problem is reduced.
JP-A-5-139124 JP 11-291723 A JP 2001-294026 A

  In view of the above-described points, the object of the present invention is that when a pneumatic tire and a rim are assembled and assembled, the bead portion of the tire and the flange portion of the rim are not completely adhered to each other at the fitting portion. A novel pneumatic tire that realizes that the pneumatic tire and the rim can be assembled with a higher level of fitting strength than the prior art even when they are in a member relationship that creates a gap in part. A rim assembly and assembly method is to be provided.

The pneumatic tire and rim assembly of the present invention that achieves the above object has a configuration described in any one of the following (1) to (3).
(1) An assembly of a rim and a pneumatic tire in which a radially extending groove is provided on a bead portion surface in contact with the rim, wherein the groove extends from a bead heel portion to a spaced portion between the rim flange and the tire. A pneumatic tire and rim characterized by comprising an elastomer composition that is at least in a liquid state at the time of tire / rim assembly at least in a fitting portion that extends and a tire bead portion and a rim flange contact each other. Assembly.
(2) An assembly of a pneumatic tire and a rim in which a rim flange portion is provided with a groove extending in a substantially radial direction, and at least a tire / rim at a fitting portion where the tire bead portion and the rim flange contact each other A pneumatic tire and rim assembly comprising an elastomer composition that is liquid when assembled.
(3) An assembly of a pneumatic tire having a radially extending groove in the bead portion and a rim having a substantially radial groove in the rim flange portion, wherein the tire bead portion and the rim flange are in contact with each other A pneumatic tire and rim assembly characterized in that a liquid elastomer composition is present at least at the time of tire / rim assembly in the fitting portion.

Furthermore, the pneumatic tire and rim assembly of the present invention preferably has the following specific configuration (4).
(4) The pneumatic tire and rim set according to any one of (1) to (3) above, wherein the liquid elastomer composition is liquid butyl rubber at least when the tire / rim is assembled. Solid.

In addition, the pneumatic tire and rim assembly method of the present invention that achieves the above-described object has the following configuration (5).
(5) A method for assembling a tire and a rim by fitting a pneumatic tire and a rim flange to assemble the tire and the rim. As the pneumatic tire and the rim flange, either or both of the grooves for venting air And the air in the fitting portion from the fitting portion where the tire bead portion and the rim flange are in contact with each other through the elastomer composition which is liquid when the tire / rim is assembled. A method for assembling a pneumatic tire and a rim, wherein the tire / rim is assembled by removing the tire.

  According to the present invention according to the above (1), (2), (3) or (4), it is possible to suppress rim displacement and improve air leakage resistance without impairing workability during rim assembly. A new pneumatic tire and rim assembly can be realized.

  In addition, according to the present invention according to the above (5), a novel pneumatic tire and rim that achieve both the suppression of rim displacement and the improvement of air leakage resistance performance without compromising workability when assembling the rim. A novel pneumatic tire and rim assembling method capable of obtaining the assembly can be realized.

  More specifically, according to the pneumatic tire and rim assembly of the present invention, a groove that extends in the radial direction of the tire is provided on the outer surface of the bead or / and the rim flange portion. Since the air existing in the gap can be discharged from the air, it is possible to reduce the air remaining in the gap formed along the outer surface of the bead near the bottom of the bead. After being fitted to the rim, the elastomer composition is injected into a gap formed between the bead portion and the rim from a hole provided in the rim, and the elastomer composition is further solidified from the liquid state at the time of the injection. As a result, the gap between the bead portion and the rim is filled with the elastomer composition, and the gap between the rim and the bead portion (air accumulation) is eliminated, so that the fit between the bead portion and the rim is strong. Ri, can be solved various problems described above.

  Hereinafter, the pneumatic tire and rim assembly of the present invention will be described in more detail.

  The pneumatic tire and rim assembly of the present invention is an assembly of a rim and a pneumatic tire in which a groove extending in a radial direction is provided on a bead portion surface in contact with the rim, the groove being a bead heel portion. The groove extends at least from the rim flange to the separation portion of the tire, and the groove serves as an air discharge groove for discharging air in the gap. This configuration is the configuration of the present invention according to the above (1).

  This groove only needs to be formed so that the air in the gap can be effectively discharged during the assembly of the pneumatic tire and the rim, and is not necessarily provided on the side surface of the bead portion of the tire. A configuration using a rim provided with a groove extending substantially in the radial direction in the rim flange portion may be used, and this configuration is the configuration of the present invention according to the above (2).

  Furthermore, it is good also as a structure by which the groove | channel extended in a substantially radial direction is provided in both a tire bead part surface and a rim flange, and this structure is a structure of this invention concerning said (3).

  The above-mentioned groove is not particularly limited as long as the above-described air can be effectively discharged, and the installation position, the number of installations, the groove depth, the groove length, and the like are not particularly limited. According to these findings, the position of the groove center side end (start position D) in the radial direction of the groove starts near the bottom of the bead, and the position of the outer periphery end (end position F) is a position where the bead and rim are separated from each other. It is preferable that (B) be within a range of about 5 mm to 30 mm. Preferably, in order to further improve the air leakage resistance, it is preferable to start from the vicinity of the bottom of the bead which is directly below the center in the width direction of the bead wire and extend to the rim cushion (separated position (B)).

  However, if the air can be vented as intended, the length L of the groove may be shorter, and in consideration of problems such as a decrease in the strength of the bead, the purpose is to vent the air in the gap. What is necessary is just to make it the required length.

The cross sectional area of the air vent groove is preferably in the range of 0.1 to ^2.5 mm ² . If the groove cross-sectional area is 0.1 mm ² or less, the air venting action may be insufficient or may take time, and if it exceeds 2.5 mm ² , the air seal effect may be impaired, which is not preferable.

  According to various studies by the present inventors, the number of grooves depends on the size of the tire, but at least three grooves are necessary, and the upper limit is about 35. This is because the effect does not increase corresponding to the number of lines beyond that.

  In the present invention, after the bead portion is fitted to the rim, an elastomer composition as a filler is injected into the gap between the bead portion and the rim from the hole of the rim, and the gap is filled with the filler. .

  By the injection of the elastomer composition, air that has been in the gap is discharged through the above-described groove portion, and the elastomer composition that is in a liquid state at the time of injection is cured, so that the rim and the bead portion are cured. There is no gap (air pool) between them, and the bead portion and the rim are firmly fitted, and the inconvenience caused by the presence of the gap can be solved.

  Although it does not specifically limit as this elastomer composition, For example, a liquid butyl rubber etc. can be used as a preferable thing.

  Hereinafter, an assembly of a pneumatic tire and a rim according to an embodiment of the present invention will be described with reference to the drawings. 1-4, the pneumatic tire 10 is demonstrated below as what is in the normal state with which the normal rim 11 was mounted | worn and the normal internal pressure was filled.

  FIG. 1 shows an embodiment according to claim 1 of the present invention. In a pneumatic tire 10, a bead portion 1 is disposed on a bead outer surface 4 facing a rim flange 11 on the outer side in the tire axial direction. Three or more air vent grooves 12 extending inward and outward in the tire radial direction and spaced apart in the circumferential direction are provided.

  The rim 10 is formed by raising the rim flange from the outer end in the tire axial direction of the bead base on which the bead base surface 2 of the bead portion 1 is seated, and the rim 11 is normally attached to the pneumatic tire 10. It is a rim. 13 is a bead core, 16 is a bead filler.

  Further, the tire bead portion 1 is provided with a reinforcing layer 15 that wraps the carcass 14, and the reinforcing layer 15 has a direction in which an organic fiber cord having strength such as a steel cord or an aromatic polyamide crosses the carcass cord of the carcass. The rigidity of the bead portion 1 can be increased by the reinforcing layer 15. However, the reinforcing layer 15 is not necessarily used, and the present invention can be applied to any pneumatic tire having any basic structure as long as the configuration (1) or (2) can be realized. Can also be adopted.

  The bead outer surface 6 extends inward and outward in the tire radial direction and has at least three air vent grooves 12 in the circumferential direction, and adjacent air grooves are arranged at positions separated from each other.

  As described above, the air vent groove 12 extends inward and outward in the tire radial direction from the separation point B where the bead outer surface 6 is separated from the rim flange 11 when the pneumatic tire 10 is in a normal state. As described above, the inner end D of the air vent groove 12 is preferably positioned in the vicinity of the bead base surface, and the radial length L along the bead surface is preferably about 30 mm to 70 mm. . The air vent groove 12 is preferably formed such that the outer end F thereof is located slightly outside the separation point B.

  The air vent groove 12 may have various cross-sectional shapes such as a circular shape, a square shape, and a trapezoidal shape, but the groove depth H is preferably at least 0.1 mm or more, more preferably 0. .2 mm or more. On the other hand, if the depth H of the groove exceeds 1 mm, the liquid elastomer to be filled may leak, which is not preferable.

  When the air vent groove 12 is set to such a groove depth H, the air in the gap 7 formed between the rim flange 11 and the bead outer surface 6 is used as the air vent groove 12 during the rim assembly operation. The bead outer surface 6 is pressed toward the rim flange 11 by the internal pressure when the tire is filled with a normal internal pressure, and the air vent groove 12 is deformed by the press, and the groove wall The air vent groove 12 is closed by contacting the rim flange 11.

  Therefore, at the time of rim assembly work, the air staying in the gap (air pool) between the bead outer surface 6 and the rim flange 11 is excluded from the air vent groove 12 and the bead portion 1 is brought close to the rim flange 11. While improving the rim assembly accuracy, the air vent groove 12 is pushed and closed during internal pressure filling, and the ventilation of the air vent groove 12 is blocked, thereby preventing air from being diffused in the tire lumen and improving airtightness.

  In addition, as shown in FIG. 3, the adjacent air vent grooves 12 and 12 are connected by providing a bypass groove 16 extending radially inward of the separation point B in the tire circumferential direction, as shown in FIG. It is preferable because the exhaust can be performed uniformly and the uniformity of the rim assembly accuracy can be improved.

  In the present invention, as shown in FIG. 4, the elastomer composition is injected as a filler 19 from the through hole 18 of the rim 11 using the injection device 17. According to the knowledge of the present inventors, the through holes 18 are provided at appropriate numbers and intervals over the entire circumference of the bent portion of the rim corresponding to the position where the gap is formed. It is preferable to provide them at regular intervals, and it is practical to correspond to the number of air vent grooves.

  It is important for the elastomer composition to be liquid at least upon injection. After the injection, a solidified one is preferably used, but a certain liquid state or elastomer state may be maintained even after the injection is completed. This is because the intended purpose and effect of the present invention can be achieved even in a liquid state or an elastomer state. As the elastomer composition, for example, liquid butyl rubber or the like can be preferably used, and as the injection device 17, for example, a piston type such as a syringe can be used.

  The elastomer composition 19 is injected until the elastomer composition 19 leaks from the air vent groove 12 or from the other through hole 18 adjacent to the through hole 18 used to inject the elastomer composition 19. What is necessary is just to apply pressure until the thing 19 leaks out. This is performed for all the through holes 18. Thereby, the air accumulated between the rim 11 and the bead part 1 is pushed out to the outside through the air vent groove 12 or the adjacent through hole 18 by the entry of the elastomer composition 19, and the rim 10 and the bead part 1. The gap between is eliminated.

  The method of filling the gap with the elastomer composition does not have to be a piston type such as a syringe as shown in the figure, and is expected in advance in the rim depression where the gap is expected to be formed. It is also possible to apply a liquid elastomer composition equal to or larger than the gap volume to be applied. In that case, the liquid elastomer composition can be temporarily held when it is applied to the recessed portion of the rim with a viscosity increased to some extent so that the application form can be temporarily held. You should choose something like this.

  Immediately after the injection of the elastomer composition 19 or after the rim assembly after pre-coating, a normal internal pressure (for example, an internal pressure prescribed in JATMA) is filled, and if the elastomer protrudes from the through hole 18 or the air vent groove 12, etc. If composition 19 is present, it is removed. Thereafter, since the elastomer composition 19 is solidified, the fitting between the rim 11 and the bead portion 1 becomes strong, and high steering stability as desired can be ensured.

  In this rim assembly, the filled elastomer composition 19 remains inside, and the friction coefficient of the filled elastomer composition is higher than that of soapy water or bead wax used during normal rim assembly. Any numerical value may be used, and by using such a value, there is no adverse effect on rim displacement.

  In the above description, the case where the air vent groove 12 is provided exclusively on the tire bead surface 1 has been mainly described, but the same air vent groove 12 may be provided on the flange portion of the rim. Moreover, you may provide the same air vent groove 12 in both the bead surface of a tire, and the flange part of a rim | limb. When the air vent grooves 12 are provided on both the tire bead surface and the rim flange, the number and pitch may be the same or different.

  Pneumatic tires and rim assemblies having an evaluation tire size of 205 / 65R15 94H were actually created and evaluated.

  At that time, as shown in Table 1, the evaluation tire was provided with a groove for venting air in the bead and / or rim flange, and liquid butyl rubber was used as a filler. As an assembly (Examples 1 to 4), as Comparative Examples 1 and 2, no air vent groove was provided, and as Comparative Example 3, an air vent groove was provided in the bead but no filler was used. Created and evaluated for each.

  That is, each assembly was evaluated by performing an air leak test and a rim displacement test described below.

(1) Air leak test:
Compare the air leak rate after running the indoor drum.
As the rim, a JATMA standard rim was used. The internal pressure was 120 kPa, the load was 88% at 200 kPa, and the speed was 81 km / h. The drum diameter was 1700 mm and the ambient temperature was 38 ° C.

  Under this condition, run 60,000 km and measure the internal pressure difference before and after running. The ratio of reduced pressure to the initial internal pressure (120 kPa) was calculated as a percentage, and the air leakage rate of the moon was obtained.

  Evaluation is carried out by relative evaluation when the value of one comparative example is 100, and the larger the number, the less air leakage and the better the performance.

(2) Rim displacement test:
As the rim, a JATMA standard rim was used. The internal pressure was set to 200 kPa, and a passenger car with a displacement of 2500 cc was used as an evaluation vehicle.

  In the rim displacement test, soap water (MT-1000) was applied from the tire rim cushion part to the bead base part to assemble the rim. After the rim was assembled, it was left for 2 hours or more, then attached to the vehicle, After repeating the braking test from the initial speed of 50 km / h five times, the amount of deviation between the tire and the rim at the rim flange portion was measured.

  In the evaluation, the product of Comparative Example 1 was used as an evaluation criterion, and if the amount of rim deviation was smaller than that of Comparative Example 1, it was expressed as “◯” for pass, and if it was equivalent to Comparative Example 1, it was expressed as “Fail” for failure. .

  Details of each example and comparative example are as follows.

Example 1
A groove for venting air was provided in the bead portion, and liquid rubber was applied to a predetermined recess portion of the rim to perform rim assembly.

Example 2
A groove for venting air was provided in the rim, and liquid rubber was applied to a predetermined recess of the rim to form a rim assembly.

Example 3
A groove for venting air was provided in the bead portion, a groove for venting air was also provided in the rim, and liquid rubber was applied to a predetermined recess of the rim to form a rim assembly.

Example 4
A groove for venting air was provided in the bead portion, and liquid butyl rubber was applied to a predetermined recess portion of the rim to perform rim assembly.

Comparative Example 1
This is a conventional tire / rim assembly, which is not provided with any groove for venting air. No filler was used.

Comparative Example 2
This is a conventional tire / rim assembly, which is not provided with any groove for venting air. However, the rim assembly was performed by applying liquid butyl rubber to a predetermined depression of the rim.

Comparative Example 3
The bead portion is provided with the same groove as that provided in the first embodiment. No filler was used.

  Table 1 shows the results of evaluation for each of the above-described Examples and Comparative Examples.

FIG. 1 is a schematic cross-sectional view for explaining an assembly of a pneumatic tire and a rim according to the present invention. FIG. 2 is a partially enlarged schematic sectional view for explaining an assembly of a pneumatic tire and a rim according to the present invention. FIG. 3 is a schematic side view for explaining an assembly of a pneumatic tire and a rim according to the present invention. FIG. 4 is a schematic sectional view for explaining an assembly of a pneumatic tire and a rim according to the present invention. FIG. 5 shows that when a conventional pneumatic tire is fitted to a rim, the bead portion of the tire and the flange portion of the rim do not completely adhere to each other, and a gap is formed in a part, and air is accumulated in the gap portion. It is the model conceptual diagram which showed the state.

Explanation of symbols

1: bead part 2: bead base surface 3: rim 4: rim flange lower part 5: rim flange upper part 6: bead outer face 7: gap between rim flanges 10: pneumatic tire 11: rim body 12: air vent groove 13: Bead core 14: Carcass 15: Reinforcement layer 16: Bead filler 17: Bypass groove 18: Injection device 19: Through hole 20: Elastomer composition B: Separation point between bead and rim D: Inner end F of the air vent groove F: Air vent Outer edge of groove

Claims (5)

  An assembly of a rim and a pneumatic tire provided with a groove extending in a substantially radial direction on a surface of a bead portion in contact with the rim, wherein the groove extends at least from a bead heel portion to a rim flange and a separation portion of the tire. A pneumatic tire and rim assembly characterized in that an elastomer composition that is liquid at least in a tire / rim assembly is present in a fitting portion where the tire bead portion and the rim flange are in contact with each other. .   An assembly of a pneumatic tire and a rim in which a rim flange portion is provided with a groove extending in a substantially radial direction, and a fitting portion where the tire bead portion and the rim flange come into contact with each other at least when the tire / rim is assembled. A pneumatic tire and rim assembly characterized by comprising a liquid elastomer composition.   An assembly of a pneumatic tire in which a groove extending in a substantially radial direction is provided in a bead part and a rim in which a groove in a substantially radial direction is provided in a rim flange part, wherein the tire bead part and the rim flange are in contact with each other A pneumatic tire and rim assembly characterized in that an elastomer composition that is liquid at least when the tire / rim is assembled is present in the joint.   The pneumatic tire and rim assembly according to any one of claims 1 to 3, wherein the elastomer composition that is liquid at least when assembling the tire / rim is liquid butyl rubber.   A method of assembling a tire and a rim by assembling a tire and a rim by fitting a pneumatic tire and a rim flange, and either or both of the pneumatic tire and the rim flange are provided with a groove for venting air. Using the tire and the rim, and the tire / rim assembly by removing air from the fitting portion through a liquid elastomer composition from the fitting portion where the tire bead portion and the rim flange are in contact with each other. A method for assembling a pneumatic tire and a rim which are characteristic.

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