JP4384508B2 - rim - Google Patents

Description

  The present invention relates to a rim for mounting a pneumatic tire that forms a plurality of air chambers in the tire axial direction.

    There is one tire chamber that can be filled with air obtained by mounting a conventional tire on a rim.

  For this reason, when the tire is punctured by nailing, curb side cut, or the like, traveling is significantly difficult due to a decrease in internal pressure, and it is necessary to immediately replace the spare tire, resulting in a complicated replacement operation.

  Also, in the situation where there are snowy and snowy roads in some places while running on a continuous curve on a mountain road in winter, grip performance is improved by lowering the internal pressure and increasing the ground contact area in a conventional tire with one tire chamber. Although it is desired to increase the steering stability, it is disadvantageous from the viewpoint that the tire rigidity decreases as the internal pressure decreases.

  In addition, in a situation where the vehicle is running on a continuous curve on a mountain road that is not paved and has large irregularities, the conventional tire with one tire chamber reduces the internal pressure and lowers the longitudinal rigidity of the tire to reduce vibration ride performance. However, as the internal pressure is reduced, the lateral stiffness and the longitudinal stiffness of the tire are also lowered, which is disadvantageous for steering stability.

In order to solve these problems, a tire / rim assembly having a plurality of air chambers in the width direction has been proposed (see Patent Document 1).
JP 2003-39914 A

  By the way, in the tire / rim assembly described in Japanese Patent Laid-Open No. 2003-39914, the inner diameter of the outer bead portion and the inner diameter of the inner partition wall portion are set to be the same in the pneumatic tire, and the diameter of the outer bead seat in the rim is set. And the inner bead sheet had the same diameter, there were the following problems.

  In the rim 12 having the shape shown in FIG. 3, since the bead sheet has a constant diameter in the width direction, the partition wall 24 may move and cause air leakage, for example, when the internal pressures of adjacent air chambers are different.

  Therefore, in practice, in order to fix the partition wall portion 24, the rim 12 having a constant diameter must be fixed using an adhesive, and when the adhesive is not used, as shown in FIG. A specially shaped rim 12 in which a tall hump portion 44 for preventing movement of the partition wall portion 24 is disposed beside the partition wall portion 24 must be used, and the partition wall portion 24 becomes the hump portion 44 when the rim is assembled. In addition, since the inside of the tire is not visible, it is difficult to place the partition wall 24 at a predetermined position, and the rim assembling work is very difficult.

  In view of the above facts, an object of the present invention is to provide a rim capable of improving the work of assembling a pneumatic tire.

  The invention according to claim 1 includes a pair of left and right bead portions, a sidewall portion extending outward in the tire radial direction from the bead portion, a tire radial outer end of one sidewall portion, and a tire in the other sidewall portion. Between the tread portion that connects the radially outer end and the pair of left and right bead portions, the bead portion is provided to be spaced apart inward in the tire axial direction, and at least one tire of the sidewall portion and the tread portion A pair of tires extending inward in the tire radial direction from the inner surface side, the inner end in the tire radial direction being in contact with the rim, and forming three independent tire air chambers in the tire width direction between the rim and the rim when mounted on the rim. A rim for mounting a pneumatic tire including a partition wall, wherein the outer bead seat is in contact with an inner peripheral surface of the bead portion, and an outer side in the rim axial direction of the outer bead seat. A flange to be disposed; an outer hump portion disposed on the inner side in the rim axial direction of the outer bead seat; and a step portion provided on the inner side in the rim axial direction of the outer bead seat, and having a smaller diameter than the outer bead seat An inner bead sheet that is set and contacts the inner peripheral surface of the partition wall, an inner hump disposed on the inner side in the rim axial direction of the inner bead sheet, one inner hump and the other inner hump And a drop set to be smaller in diameter than the inner bead sheet, and when the diameter of the outer bead sheet is Do and the diameter of the inner bead sheet is D, 0.02 < (Do-D) / Do <0.12 is satisfied.

  Next, the operation of the rim according to claim 1 will be described.

  A tire / rim assembly comprising three tire air chambers that are independent in the tire axial direction by mounting a pneumatic tire having a pair of bead portions and a pair of partition walls on the rim according to claim 1. A solid can be obtained.

  Hereinafter, an example of the rim assembly will be described.

  When a pneumatic tire having a pair of bead portions and a pair of partition walls is mounted on the rim, first, one bead portion and the partition wall are passed over one flange and dropped into a drop, and then the other bead portion. , And over the other flange over the partition wall.

  In order to dispose both partition walls inside both stepped portions, both side portions may be pressed.

  The work of dropping the bulkhead part over the flange and dropping it into the drop and the work of placing both bulkhead parts inside both stepped parts are different from the normal rim assembly, but otherwise a normal tire is assembled to the rim. It can be done in much the same way as work.

  After mounting a pneumatic tire on the rim, each tire chamber is filled with air.

  By filling the central tire chamber with air, the partition wall portion is pressed outward in the rim axis direction, and the side surface abuts on the stepped portion.

  Thereby, the inner peripheral part of a partition part is supported on the inner side bead sheet between a step part and an inner hump part. Further, the inner hump portion can suppress movement of the partition wall portion on the inner side in the rim axis direction.

  Further, by filling the tire chambers on both sides with air, the bead portion is pressed outward in the rim axial direction, and the side surfaces abut against the flange.

  Thereby, the inner peripheral part of a bead part is supported on the outer side bead sheet between a flange and an outer side hump part. Further, the outer hump portion can suppress movement of the bead portion on the inner side in the rim axis direction.

  In this way, a tire / rim assembly for running is obtained.

  This tire / rim assembly has a problem because other unpunctured tire air chambers support the load in either puncture on the ground contact surface due to nailing or other side puncture due to curb rubbing, etc. You can continue driving safely without any problems.

  If 0.02> (Do-D) / Do, it becomes impossible to secure the height of the step portion that suppresses the movement of the partition wall, and a tall protrusion must be provided separately. In this case, the rim assembly work becomes difficult, and in some cases, the rim assembly becomes impossible.

  On the other hand, when (Do−D) / Do> 0.12, the inner diameter of the rim becomes smaller, and as a result, the diameter of the brake that can be mounted inside the rim becomes smaller. This is not preferable because there is a possibility that the vehicle motion performance is deteriorated.

  The invention described in claim 2 is characterized in that, in the rim described in claim 1, 0.04 <(Do−D) / Do <0.08 is satisfied.

  Next, the operation of the rim according to claim 2 will be described.

  By satisfying 0.04 <(Do−D) / Do <0.08, (1) the assembly work of the tire to the rim is facilitated, (2) the rim fit property of the tire is facilitated ( 3) A good balance can be achieved with respect to the three points that the rim diameter does not become so small as to cause a problem.

  According to a third aspect of the present invention, in the rim according to the first or second aspect, when the drop amount of the outer hump portion and the inner hump portion is h, 0 <h ≦ 0.5 mm It is characterized by satisfying.

  Next, the operation of the rim according to claim 3 will be described.

  If the amount h of depression of the inner hump part and the outer hump part exceeds 0.5 mm, the movement of the partition wall part and the bead part inward in the rim axis direction cannot be suppressed.

  On the other hand, when the drop amount of the inner hump portion and the outer hump portion becomes 0, the partition wall portion and the bead portion are caught during air fitting, and it is difficult to dispose them at predetermined positions.

  As described above, according to the rim of the present invention, there is an excellent effect that the assembling work of a pneumatic tire provided with a pair of left and right bead portions and a partition wall portion can be improved.

  Hereinafter, an embodiment of a tire / rim assembly using a rim of the present invention will be described with reference to FIGS. 1 and 2.

FIG. 2 shows a cross section along the tire rotation axis of a tire / rim assembly 14 in which a pneumatic tire 10 (size: 225 / 55R17) is mounted on the rim 12.
(Composition of pneumatic tire)
As shown in FIG. 2, the pneumatic tire 10 according to this embodiment includes a pair of bead portions 16 for mounting on the rim 12, as in a general pneumatic tire.

  A bead core 18 is embedded in the bead portion 16.

  A sidewall portion 20 is integrally provided outside the bead portion 16 in the tire radial direction.

  A tread portion 22 is provided between a tire radial direction outer end of one sidewall portion 20 and a tire radial direction outer end of the other sidewall portion 20 across the tire equatorial plane CL.

  In the present embodiment, a pair of partition walls 24 that are inclined and extended inward in the tire radial direction from the tire inner surfaces of both shoulder portions are provided spaced apart from each other on the inner side in the tire width direction of the bead portion 16.

  The inner portion of the partition wall portion 24 in the tire radial direction is hereinafter referred to as an inner bead portion 25.

  A bead core 31 and a bead filler 33 are embedded in the inner bead portion 25.

  Between the pneumatic tire 10 and the rim 12, there is a main air chamber 26 between the partition wall portion 24 and the partition wall portion 24, and a first auxiliary air chamber between the bead portion 16 and the partition wall portion 24 on the arrow L direction side. 28, a second auxiliary air chamber 30 is formed between the bead portion 16 and the partition wall portion 24 on the arrow R direction side.

  Since the inner end of the inner bead portion 25 in the tire radial direction is in close contact with the rim 12, the main air chamber 26, the first sub air chamber 28, and the second sub air chamber 30 are independent of each other.

  A first carcass ply 32 straddling the toroidal shape from one bead core 18 to the other bead core 18 is embedded in the pneumatic tire 10.

  The first carcass ply 32 has one end in the width direction wound around one bead core 18 from the inside of the tire to the outside, and the other end in the width direction is wound around the other bead core 18 from the inside to the outside of the tire. .

  In the bead portion 16, a bead filler 34 extending from the bead core 18 to the outer side in the tire radial direction is embedded between the winding portion 32 </ b> A of the first carcass ply 32 and the main body portion 32 </ b> B.

  The first carcass ply 32 is a normal one in which a plurality of organic fiber cords arranged in parallel with each other such as a polyester cord and a nylon cord arranged in a radial array are rubber-coated, and the bead portion 16, the sidewall portion 20, And the tread part 22 is reinforced.

  Furthermore, a second carcass ply 37 straddling in a toroidal shape from one bead core 31 toward the other bead core 31 is embedded inside the pneumatic tire 10 on the inner side in the tire radial direction of the first carcass ply 32. Yes.

  The second carcass ply 37 has one end in the width direction wound around one bead core 31 from the inside of the tire toward the outside, and the other end in the width direction is wound around the other bead core 31 from the inside to the outside of the tire. .

  In the inner bead portion 25, a bead filler 33 extending from the bead core 31 to the outer side in the tire radial direction is embedded between the winding portion 37 </ b> A of the second carcass ply 37 and the main body portion 37 </ b> B.

  Similar to the first carcass ply 32, the second carcass ply 37 is a normal one in which a plurality of organic fiber cords arranged in parallel with each other such as a polyester cord and a nylon cord arranged in a radial arrangement are rubber-coated. The partition wall 24 and the tread portion 22 are reinforced.

  A belt 36 is disposed on the outer side in the tire radial direction of the first carcass ply 32.

The belt 36 is composed of, for example, two or more steel cord crossing layers.
(Rim structure)
As shown in FIG. 2, the rim 12 of the present embodiment is composed of an outer rim portion 12A arranged on the vehicle outer side when the vehicle is mounted and an inner rim portion 12B arranged on the vehicle inner side.

  The disk portion 60B integrally connected to the inner rim portion 12B is formed with a plurality of screw holes 62 and holes 64 for inserting bolts attached to the vehicle axle.

  On the other hand, the disk portion 60A integrally connected to the outer rim portion 12A is formed with a hole 66 at a position facing the screw hole 62, and on the side surface on the inner rim portion 12B side, radially outward of the hole 66. An annular groove 68 is formed.

  The outer rim portion 12 </ b> A and the inner rim portion 12 </ b> B are fixed to each other by screwing a bolt 70 inserted through the through hole 66 into the screw hole 62 and tightening.

  An O-ring 72 is fitted in the groove 68, and the O-ring 72 is in close contact with the groove wall surface and the side surface of the inner rim portion 12B, thereby sealing between the outer rim portion 12A and the inner rim portion 12B. ing.

  The outer rim portion 12A and the inner rim portion 12B include an outer bead seat 46 in which the bead portion 16 is disposed, and an inner bead seat 48 in which the bead portion 25 is disposed, which is disposed on the inner side in the tire axial direction of the outer bead seat 46. Is formed.

  Here, when the diameter of the outer bead sheet 46 is Do and the diameter of the inner bead sheet 48 is D, 0.02 <(Do−D) / Do <0.12 needs to be satisfied. It is preferable that 04 <(Do−D) / Do <0.08 is satisfied.

  For example, when a tire for a passenger car having a tire size of 225 / 55R17 is mounted, Do-D is 9 mm <Do-D <50 mm in actual dimensions, and preferably 17 mm <Do-D <35 mm.

  In the pneumatic tire 10, the inner diameter of the bead portion 16 is the same as the diameter Do of the outer bead seat 46 and the inner diameter of the inner bead portion 25 is the same as the diameter D of the inner bead seat 48 according to the dimensions of the rim 12. The diameter is set.

  A flange 50 is formed on the outer side of the outer bead sheet 46 in the axial direction, and a gentle mountain-shaped outer hump 72 is formed on the inner side in the axial direction.

  Further, a step 52 having the same function as the flange 50 is formed between the inner bead sheet 48 and the outer bead sheet 46, and a gentle mountain-shaped inner side is formed on the inner side in the axial direction of the inner bead sheet 48. A hump 74 is formed.

  A large-diameter hole 76 is formed in the center of the disk portion 60A.

Here, the distance from the line (parallel to the rotation axis) indicating the amount of depression of the outer hump 72 h (the diameter D ₀ of the outer bead sheet 46 (equivalent to the rim diameter in JATMA standards)) to the top of the outer hump 72 Measured in the radial direction.), The amount of depression of the inner hump 74 was h (measured from the line indicating the diameter D of the inner bead sheet 48 (parallel to the rotation axis) to the top of the inner hump 74 in the rim radial direction). In some cases, 0 <h ≦ 0.5 mm is satisfied.

  Further, a drop portion (well) 54 in which the diameter of the groove bottom is set smaller than that of the inner bead sheet 48 is formed on the inner side in the axial direction of the pair of inner humps 74.

As shown in FIGS. 1 and 2, the rim 12 has a first valve hole 78, a second valve hole 80, and a third valve hole 82, and the first valve hole 78 has a first valve hole 78. The first air valve 38 for filling the first sub-air chamber 28 with gas and the second valve hole 80 have the second air valve 40 for filling the second sub-air chamber 30 with gas, and the third valve hole 82. Is attached with a third air valve 42 for filling the main air chamber 26 with gas.
(Function)
First, in the rim 12 of the present embodiment, a small-diameter inner bead sheet 48 is provided on the inner side of the large-diameter outer bead sheet 46 via a stepped portion 52, and dropped on the middle part of the pair of inner bead sheets 48. 54 is provided, the inner diameter R _O of the bead portion 16 and the inner diameter R _I of the inner bead portion 25 are set corresponding to the diameter of the inner bead sheet 48 and the outer bead sheet 46. When the tire 10 is assembled to the rim 12, the bead portion 16 and the inner bead portion 25 of the pneumatic tire 10 can be dropped into the drop 54, and the rim of the pneumatic tire 10 is assembled in the same manner as a conventional pneumatic tire assembly. Assembling work to 12 becomes easy.

  An example of the rim assembly will be described below.

  When the pneumatic tire 10 is mounted on the rim 12, first, the one bead portion 16 and the partition wall portion 24 are moved over the one flange 50 and dropped into the drop 54, and then the other bead portion 16 and the partition wall portion. 24 is moved over the other flange 50.

  In order to dispose both the partition walls 24 inside both the step portions 52, both the side portions 20 may be pressed.

  The operation of dropping the partition wall portion 24 over the flange 50 into the drop 54 and the operation of disposing both partition wall portions 24 inside both the step portions 52 are different from the normal rim assembly, but otherwise the normal operation This can be done in much the same way as attaching the tire to the rim.

  After the pneumatic tire 10 is mounted on the rim 12, air flows from the first air valve 38, the second air valve 40, and the third air valve 42 to the first sub air chamber 28, the second sub air chamber 30, and the main air chamber 26. And so on.

  Here, by filling the central main air chamber 26 with gas, the partition wall portion 24 is pressed outward in the rim axis direction, and the side surface comes into contact with the stepped portion 52.

  Accordingly, the inner peripheral portion of the partition wall portion 24 is supported on the inner bead sheet 48 between the step portion 52 and the inner hump portion 74. Further, the inner hump portion 74 can suppress the movement of the partition wall portion 24 inside the rim axis direction.

  Further, by filling the first auxiliary air chamber 28 and the second auxiliary air chamber 30 on both sides with gas, the bead portion 16 is pressed outward in the rim axial direction, and the side surfaces abut against the flange 50.

  Thereby, the inner peripheral part of the bead part 16 is supported on the outer bead sheet 46 between the flange 50 and the outer hump part 72. Further, the outer hump portion 72 can suppress the movement of the bead portion 16 on the inner side in the rim axis direction.

  In this way, the tire / rim assembly 14 used for traveling is obtained.

  The tire / rim assembly 14 supports the load by the other non-punctured tire chambers in any case such as puncture on the ground contact surface due to nailing or the like, or side puncture due to curb rubbing or the like. So you can continue to drive safely without problems.

  Here, if 0.02> (Do-D) / Do, the height of the stepped portion 52 that suppresses the movement of the partition wall portion 24 cannot be secured, and a tall protrusion (flange) must be provided separately. The projections are caught when the rim is assembled, and the workability of the rim assembly becomes difficult, or in some cases, the rim assembly becomes impossible.

  On the other hand, when (Do−D) / Do> 0.12, the inner diameter of the rim 12 becomes smaller, and as a result, the diameter of the brake that can be mounted inside the rim becomes smaller. This is not preferable because there is a possibility that the vehicle motion performance is deteriorated.

  Further, if the amount of drop h of the inner hump portion 74 and the outer hump portion 72 exceeds 0.5 mm, the movement of the partition wall portion 24 and the bead portion 16 inward in the rim axis direction cannot be suppressed.

On the other hand, when the drop amount h of the inner hump portion 74 and the outer hump portion 72 becomes 0, the bead portion 25 is caught by the inner hump portion 74 and the bead portion 16 is caught by the outer hump portion 72 at the time of air fitting. It becomes difficult to place in the position.
(Test example)
In order to confirm the effect of the present invention, one type of tire / rim assembly of a conventional example, three types of tire / rim assemblies of examples to which the present invention is applied, and a tire / rim assembly according to a comparative example Two types were prepared and compared for each item of rim assembly workability and wheel volume retention.

  The test tire is for passenger cars and has a size of 225 / 55R17.

The rim assembly workability and the wheel internal volume retention were evaluated in four stages.
-Rim assembly workability: A case where a normal rim assembly machine can be used to assemble the rim in the same manner as normal tires was evaluated as “good”. If it is inferior, it will be “poor”, if it is superior, “excellent”, impossible with a commercially available rim assembling machine, or even if it is somehow assembled, it will be “difficult” if damage that causes safety problems occurs. did.
-Wheel volume retention: “Good” when the wheel is equivalent to a 17-inch normal wheel (less than about 10% as a guide). If it becomes narrower than that, it will be “poor”, if it becomes wider than the normal wheel, it will be “excellent”, if compared with the normal wheel of 17 inches, it will be “difficult” if it is very small (20% or more lower as a guide). .

  The results were as shown in Table 1 below.

試験の結果、実施例１〜３は、リム組み作業性、及びホイール内容積保持性の何れも問題となる事項は無かった。

As a result of the test, in Examples 1 to 3, there was no matter in which both the rim assembly workability and the wheel volume retention were problematic.

It is sectional drawing of the rim which concerns on one Embodiment of this invention. 1 is a cross-sectional view of a tire / rim assembly using a rim according to an embodiment of the present invention. FIG. 10 is a cross-sectional view of a tire / rim assembly according to Conventional Example 2. 1 is a cross-sectional view of a typical tire / rim assembly having one tire chamber.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Pneumatic tire 12 Rim 14 Tire / rim assembly 16 Bead part 20 Side wall part 20 Tire side wall part 22 Tread part 24 Partition part 25 Inner bead part 26 Main air chamber 28 1st sub air chamber 30 2nd sub air chamber 46 Outer bead sheet 48 Inner bead sheet 50 Flange (outer flange)
52 steps 54 drops

Claims (3)

A tread connecting a pair of left and right bead portions, a sidewall portion extending outward in the tire radial direction from the bead portion, and a tire radial outer end of one sidewall portion and a tire radial outer end of the other sidewall portion Between the pair of left and right bead portions and the bead portion spaced apart from the inner side in the tire axial direction, and extends inward in the tire radial direction from at least one tire inner surface side of the sidewall portion and the tread portion. And a pair of partition walls that form three independent tire air chambers in the tire width direction between the rim and an inner end in the tire radial direction in contact with the rim and when mounted on the rim. A rim for mounting a tire,
An outer bead sheet in contact with the inner peripheral surface of the bead portion;
A flange disposed on the outer side in the rim axial direction of the outer bead seat;
An outer hump portion disposed on the inner side in the rim axial direction of the outer bead seat;
An inner bead sheet that is provided on the inner side in the rim axial direction of the outer bead sheet, is set to have a smaller diameter than the outer bead sheet, and contacts the inner peripheral surface of the partition wall;
An inner hump portion disposed on the inner side in the rim axial direction of the inner bead sheet;
A drop that is provided between one inner hump portion and the other inner hump portion, and has a smaller diameter than the inner bead sheet;
A rim satisfying 0.02 <(Do-D) / Do <0.12, where Do is a diameter of the outer bead sheet and D is a diameter of the inner bead sheet. The rim according to claim 1, wherein 0.04 <(Do−D) / Do <0.08 is satisfied. 3. The rim according to claim 1, wherein 0 <h ≦ 0.5 mm is satisfied, where h is a drop amount of the outer hump portion and the inner hump portion.

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