JP2007069753A - Tire wheel assembly and support for run flat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire wheel assembly and a support for a run flat capable of realizing a light weight while maintaining durability. <P>SOLUTION: This tire wheel assembly comprises a pair of elastic rings 5 arranged around a rim 1 and an annular shell 4 between the elastic rings 5, 5 at a cavity of a pneumatic tire 2, and supports 3 for a run flat provided with two lines of swelling parts 4a, 4a swollen toward the outside in a radial direction and extending in a peripheral direction are inserted on both sides at an axial center position E of the annular shell 4. A distance W is from the axial center position E of the annular shell 4 to peaks of the respective swelling parts 4a, and a processed area X is set within a range of 10%-65% of the distance W from the axial center position E of the annular shell 4, so that the annular shell 4 is selectively lightened in the processed area X. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a tire wheel assembly that enables run-flat running and a run-flat support body used therefor, and more particularly, a tire-wheel assembly and run-flat support that can achieve both weight reduction and durability. About the body.

  Many technologies for enabling a certain degree of emergency traveling have been proposed in response to market demands even when a pneumatic tire punctures while the vehicle is traveling. Among these many proposals, there is one that enables run-flat running by mounting a core on a rim in a hollow portion of a pneumatic tire and supporting the punctured tire with the core (for example, Patent Document 1). To 3).

  This run-flat support is composed of a pair of elastic rings and an annular shell straddling the elastic rings, and is mounted on the rim via the elastic rings. The run-flat support has the advantage that it can be used without causing any disruption to the market because it can be used as it is without any special modifications to existing wheels and rims.

  By the way, the run-flat support body is required to give a predetermined strength to the annular shell in order to withstand an external force applied when assembling the rim and further support a load during run-flat travel. However, when the annular shell is given high strength, there is a problem that its weight increases.

In view of such a problem, in order to reduce the weight while maintaining the durability of the run-flat support body, a plurality of reinforcing ribs are provided over the entire area of the annular shell, or a plurality of areas are provided over the entire area of the annular shell. Providing a through hole has been proposed (see, for example, Patent Document 4 and Patent Document 5). However, when reinforcing ribs and through-holes are provided over the entire area of the annular shell, the current situation is that the weight reduction and durability cannot always be fully satisfied.
JP-T-2001-519279 JP 2001-163020 A JP-A-10-297226 JP 2004-149013 A JP 2004-51088 A

  An object of the present invention is to provide a tire wheel assembly and a run-flat support body that can be reduced in weight while maintaining durability.

  In order to achieve the above object, a tire wheel assembly of the present invention comprises a pair of elastic rings arranged around a rim in a hollow portion of a pneumatic tire, and an annular shell straddling the elastic rings. And a wheel / wheel assembly in which run-flat supports having two rows of bulging portions extending in the circumferential direction while bulging outward in the radial direction on both sides of the axial center position of the annular shell are inserted. In a three-dimensional object, a range of 10% to 65% of the distance W from the axial center position of the annular shell with respect to the distance W from the axial center position of the annular shell to the apex of each bulging portion. In addition, the annular shell is selectively lightened in the region to be processed.

  The run-flat support of the present invention comprises a pair of elastic rings arranged around the rim and an annular shell straddling the elastic rings, and the axial center position of the annular shell. In the run-flat support body provided with two rows of bulges extending in the circumferential direction while bulging outward in the radial direction on both sides of the annular shell, from the axial center position of the annular shell to the apex of each bulge With respect to the distance W, a range of 10% to 65% of the distance W from the axial center position of the annular shell is set as a processing target region, and the weight reduction processing is selectively performed in the processing target region with respect to the annular shell. It is characterized by having been subjected to.

  In the present invention, the run-flat support body is formed with an outer diameter smaller than the inner diameter of the tread portion of the pneumatic tire so as to maintain a certain distance from the pneumatic tire, and the inner diameter of the bead portion of the pneumatic tire. It is formed to have substantially the same dimensions as the inner diameter. The run-flat support body is assembled to the rim of the wheel together with the pneumatic tire in a state where the run-flat support body is inserted into the hollow portion of the pneumatic tire, thereby constituting a tire wheel assembly. When the pneumatic tire is punctured while the tire / wheel assembly is mounted on the vehicle, the punctured and crushed tire is supported by the run-flat support body, so that run-flat travel is possible.

  In such a run-flat support body, it is necessary to withstand the external force applied when assembling the rim while minimizing the weight. It is desirable to give the strength of.

  In view of this, the present inventor has proposed a rim assembly for a run-flat support body provided with two rows of bulging portions extending in the circumferential direction while bulging outward in the radial direction on both sides of the axial center position of the annular shell. When analyzing in detail the stress generated in the annular shell during running and run-flat running, we found that the stress distribution is very small in a specific region from the axial center position of the annular shell to the top of each bulge, The present invention has been reached.

  That is, in the present invention, the range of 10% to 65% of the distance W from the axial center position of the annular shell to the distance W from the axial center position of the annular shell to the apex of each bulging portion. In addition, by selectively reducing the weight of the annular shell in the region to be processed, it is possible to reduce the weight while maintaining sufficient durability.

  The weight reduction processing means processing that locally reduces the amount of constituent materials used. As this weight reduction processing, the region to be processed of the annular shell can be made thinner than other regions. In this case, the thickness of the region to be processed of the annular shell is preferably 75% to 90% of the thickness of the other region. Moreover, in order to avoid stress concentration, it is preferable that the reduction rate of the thickness of the annular shell by the weight reduction processing is 10% / mm or less. Furthermore, as a weight reduction process, it is possible to provide a plurality of through holes in the processing target area of the annular shell, or to provide a plurality of dimples in the processing target area of the annular shell.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a meridian cross-sectional view showing the main part of a tire wheel assembly (wheel) according to an embodiment of the present invention, wherein 1 is a wheel rim, 2 is a pneumatic tire, and 3 is a run-flat support. The rim 1, the pneumatic tire 2, and the run-flat support body 3 are formed in an annular shape around a wheel rotation shaft (not shown). That is, the run-flat support 3 is inserted into a cavity formed between the pneumatic tire 2 and the wheel rim 1.

  The pneumatic tire 2 includes a tread portion 21, a pair of sidewall portions 22 and 22, and a pair of bead portions 23 and 23. A carcass layer 24 is mounted between the pair of bead portions 23 and 23. In addition, two belt layers 25 are embedded on the outer peripheral side of the carcass layer 24 in the tread portion 21. These belt layers 25 include a plurality of reinforcing cords inclined with respect to the tire circumferential direction, and are arranged so that the reinforcing cords cross each other between the layers. Further, a belt cover layer 26 formed by winding an organic fiber cord in the tire circumferential direction is embedded on the outer peripheral side of the belt layer 25.

  The run-flat support 3 includes an annular shell 4 and an elastic ring 5 as main parts. The run-flat support 3 is spaced apart from the inner surface of the pneumatic tire 2 during normal running, but supports the collapsed pneumatic tire 2 from the inside during puncture.

  The annular shell 4 includes two rows of bulging portions 4a and 4a extending in the circumferential direction while bulging outward in the radial direction on both sides of the axial center position E (tire equator line). It has an open leg structure including leg portions 4b and 4b extending along the portions 4a and 4a. The annular shell 4 including the bulging part 4a and the leg part 4b forms a contour consisting of a smooth curve in the meridian cross section. By providing two rows of bulging portions 4a on the annular shell 4 in this way, the contact location with respect to the tire inner surface is dispersed into two or more, and the local wear given to the tire inner surface is reduced. Can be extended.

  The annular shell 4 is thin with a thickness of 0.5 to 5.0 mm, and is made of a highly rigid material for supporting the vehicle weight via the punctured pneumatic tire 2. A metal, resin, or the like can be used as the constituent material. Among these, steel, aluminum, etc. can be illustrated as a metal. On the other hand, the resin may be either a thermoplastic resin or a thermosetting resin. Examples of the thermoplastic resin include nylon, polyester, polyethylene, polypropylene, polystyrene, polyphenylene sulfide, and ABS. Examples of the thermosetting resin include an epoxy resin and an unsaturated polyester resin. The resin may be used alone, or may be used as a fiber reinforced resin by blending reinforcing fibers.

  The elastic rings 5 are attached to the leg portions 4b and 4b of the annular shell 4, respectively, and support the annular shell 4 while abutting on the left and right rim seats. The elastic ring 5 reduces the impact and vibration received by the annular shell 4 from the punctured pneumatic tire 2, and prevents the slip against the rim seat to stably support the annular shell 4.

  As a constituent material of the elastic ring 5, rubber or resin can be used, and rubber is particularly preferable. As rubber, natural rubber (NR), isoprene rubber (IR), styrene-butadiene rubber (SBR), butadiene rubber (BR), hydrogenated NBR, hydrogenated SBR, ethylene propylene rubber (EPDM, EPM), butyl rubber (IIR) ), Acrylic rubber (ACM), chloroprene rubber (CR), silicone rubber, fluorine rubber and the like. Of course, additives such as a filler, a vulcanizing agent, a vulcanization accelerator, a softening agent, and an anti-aging agent can be appropriately blended with these rubbers. And a desired elasticity modulus can be obtained based on the mixing | blending of a rubber composition.

  In the tire-wheel assembly configured as described above, when the pneumatic tire 2 is punctured during traveling, the collapsed pneumatic tire 2 is supported by the run-flat support body 3, so that run-flat traveling is possible. become.

  FIG. 2 shows an annular shell constituting the run-flat support. As shown in FIG. 2, when the axial distance from the axial center position E of the annular shell 4 to the apex of each bulging portion 4 a is W, the distance W is 10 from the axial center position E of the annular shell 4. The range of% to 65% is the processing target region X. In the region X to be processed, the annular shell 4 is selectively lightened. The processing part may be the entire surface of the processing target region X or may be partial.

  FIG. 3 shows an annular shell subjected to a thinning process as a lightening process. As shown in FIG. 3, the thickness t1 of the processing target region X of the annular shell 4 is thinner than the thickness t2 of other regions. As a processing method to change the thickness of the annular shell 4, an overhanging process that expands the material radially outward is adopted when forming a thin portion, and the material is moved from the surroundings when forming other portions. Bending such as collecting can be employed.

  Thus, by making the processing target region X of the annular shell 4 thinner than other regions, it is possible to obtain the annular shell 4 of the run-flat support body 3 that is light and has sufficient strength. The processing target region X is a region in which the distribution of stress generated in the annular shell is extremely small when assembling the rim and during the run-flat running. However, if lightening processing is performed in other regions, the durability may be insufficient. .

  The thickness t1 of the processing target region X of the annular shell 4 is preferably 75% to 90% of the thickness t2 of the other region. Thereby, durability and weight reduction can be made compatible. If the thickness t1 of the processing target region X of the annular shell 4 is less than 75% of the thickness t2 of the other region, it tends to cause breakage starting from that portion, and conversely if it exceeds 90%, weight reduction is not possible. It will be enough. Moreover, the reduction rate of the thickness of the annular shell 4 due to the weight reduction processing is preferably 10% / mm or less. That is, stress concentration due to a sudden change in thickness can be avoided by gradually decreasing the thickness of the annular shell 4 from the thicker portion toward the thinner portion.

  FIG. 4 shows an annular shell subjected to punching as a weight reduction process. In FIG. 4, a plurality of through holes 41 are formed in the processing target region X of the annular shell 4. In this way, by providing the through hole 41 only in the processing target region X of the annular shell 4, it is possible to reduce the weight while sufficiently maintaining the durability. The ratio of the total opening area of the through holes 41 to the area of the processing target region X is preferably 10% to 25%. Thereby, durability and weight reduction can be made compatible.

  FIG. 5 shows an annular shell subjected to dimple processing as a weight reduction processing. In FIG. 5, a plurality of dimples 42 are formed in the processing target region X of the annular shell 4. Thus, by providing the dimple 42 only in the processing target region X of the annular shell 4, it is possible to reduce the weight while sufficiently maintaining the durability. The ratio of the sum of the opening areas of the dimples 42 to the area of the processing target region X is preferably 10% to 75%. Thereby, durability and weight reduction can be made compatible.

  In a tire-wheel assembly (Examples 1 to 3) of a pneumatic tire having a tire size of 205 / 55R16 and a wheel having a rim size of 16 × 6 1 / 2JJ, an annular shell is processed from a steel plate having a thickness of 1.2 mm. Then, an elastic ring was attached to each leg portion of the annular shell to produce a run-flat support body, and the run-flat support body was inserted into the hollow portion of the pneumatic tire.

  In Examples 1 to 3, the range of 10% to 65% of the distance W from the axial center position of the annular shell to the distance W from the axial center position of the annular shell to the apex of each bulging portion An area was selected, and an annular shell was selectively lightened in the area to be processed. That is, in Example 1, the thickness of the region to be processed of the annular shell was set to 0.9 mm and was made thinner than other regions (thinning processing). In Example 2, a plurality of through holes were provided in the region to be processed of the annular shell (punching processing). In Example 3, a plurality of dimples were provided in the region to be processed of the annular shell (dimple processing).

  For comparison, a tire-wheel assembly having the same structure as in Examples 1 to 3 except that a run-flat support body in which the annular shell is not lightened is manufactured and the run-flat support body is used. A solid (conventional example) was obtained.

  The durability and mass of the above four types of tire wheel assemblies were evaluated by the following measurement methods, and the results are shown in Table 1.

durability:
Each tire / wheel assembly is mounted on the right side of the front wheel of the rear-wheel drive vehicle with the air pressure of 0 kPa with the valve core removed, and the test driver runs abnormally at a speed of 90 km / h on the elliptical course. I measured the distance to stop driving. The evaluation results are shown as an index with the conventional example being 100. The larger the index value, the better the durability.

mass:
For each tire wheel assembly, the mass of the annular shell was measured. The evaluation results are shown as an index with the conventional example being 100. A smaller index value means a lighter weight.

  As shown in Table 1, the tire wheel assemblies of Examples 1 to 3 were able to achieve weight reduction while maintaining good durability in comparison with the conventional example.

It is meridian sectional drawing which shows the principal part of the tire wheel assembly which consists of embodiment of this invention. It is meridian sectional drawing which shows the cyclic | annular shell which comprises the support body for run flats of FIG. It is a perspective view which cuts and shows the annular shell which gave the thinning process as a weight reduction process partially. It is a perspective view which cuts and shows the annular shell which gave punching as lightening process partially. It is a perspective view which cuts out and shows the annular shell which performed the dimple process as a weight reduction process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wheel rim 2 Pneumatic tire 3 Run-flat support body 4 Annular shell 4a Expansion part 4b Leg part 5 Elastic ring 41 Through-hole 42 Dimple

Claims (12)

  The pneumatic tire is composed of a pair of elastic rings arranged around the rim in the hollow portion of the pneumatic tire and an annular shell straddling the elastic rings, and has diameters on both sides of the axial center position of the annular shell. In the tire-wheel assembly in which the run-flat support body provided with two rows of bulging portions extending in the circumferential direction while bulging outward in the direction of the direction is inserted, each bulging portion from the axial center position of the annular shell A range of 10% to 65% of the distance W from the axial center position of the annular shell with respect to the distance W to the apex of Lightweight tire wheel assembly.   The tire / wheel assembly according to claim 1, wherein, as the weight reduction processing, the region to be processed of the annular shell is made thinner than other regions.   The tire / wheel assembly according to claim 2, wherein a thickness of the region to be processed of the annular shell is 75% to 90% of a thickness of another region.   The tire wheel assembly according to claim 2 or 3 which made the reduction rate of the thickness of said annular shell by said weight reduction processing 10% / mm or less.   The tire / wheel assembly according to claim 1, wherein a plurality of through holes are provided in the region to be processed of the annular shell as the weight reduction processing.   The tire / wheel assembly according to claim 1, wherein a plurality of dimples are provided in the region to be processed of the annular shell as the lightening processing.   A pair of elastic rings arranged around the rim and an annular shell straddling the elastic rings, and bulging radially outward on both sides of the axial center position of the annular shell. In the run-flat support body provided with two rows of bulging portions extending in the circumferential direction, the axis of the annular shell with respect to the distance W from the axial center position of the annular shell to the apex of each bulging portion. A run-flat support body in which a range of 10% to 65% of the distance W from a central position in the direction is a processing target region, and the annular shell is selectively lightened in the processing target region.   The run-flat support body according to claim 7, wherein the processing target area of the annular shell is made thinner than other areas as the lightening process.   The run-flat support body according to claim 8, wherein a thickness of the region to be processed of the annular shell is 75% to 90% of a thickness of another region.   The run-flat support body according to claim 8 or 9, wherein a reduction rate of the thickness of the annular shell by the lightening process is 10% / mm or less.   The run-flat support body according to claim 7, wherein a plurality of through holes are provided in the region to be processed of the annular shell as the lightening processing. The run-flat support body according to claim 7, wherein a plurality of dimples are provided in the region to be processed of the annular shell as the weight reduction processing.

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