JP4445303B2 - Tire and rim assembly - Google Patents

Description

  The present invention relates to an assembly of a tire and a rim that can relieve impact energy received from a contact surface during run-flat running.

  2. Description of the Related Art A run-flat tire having a core installed in a tire lumen is known in order to enable run-flat running for a certain distance when the tire internal pressure is reduced due to puncture or the like during running. In such run-flat tires, it is indispensable to absorb vibrations from the road surface during run-flat driving. The core uses a cushioning material such as rubber or elastic plastic. A laminate of more than one type of buffer material has also been proposed.

  However, these conventional run-flat tires also have poor shock-absorbing functions and transmit shocks from the road surface directly to the vehicle or damage the suspension. The handling stability and ride comfort were poor.

Therefore, the applicant, in tire cavity, by mounting the run-flat member made of a coil spring receives a load in the radial direction around the Trim, greatly alleviating steering stability impacts from the road surface during run-flat driving It has been proposed to improve the performance and ride comfort and reduce the influence on vehicle damage (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 7-17221

  However, although the run flat member of Patent Document 1 is excellent in impact relaxation resistance, the load bearing ability may be insufficient, and further improvement is desired.

  The present invention is based on the use of a core composed of an elastic annular body having a spring plate corrugated in a tire lumen and a ring-shaped body that is externally fitted to the elastic annular body. An object of the present invention is to provide a tire and rim assembly capable of improving the ride comfort and suppressing the decrease in steering stability.

In order to achieve the above object, the invention according to claim 1 includes a tire and a rim for assembling the tire, and supports the tire load when the internal pressure is reduced in a tire lumen surrounded by the rim and the tire. the assembly of tire and rim arranged annular core, said core comprises a resilient annular member you continuously mounted and the tire circumferential direction on the rim, the annular member fitted around the resilient annular member The elastic annular body has a waveform that revolves around the rim and repeats entering and exiting in the tire radial direction at a constant pitch in the tire circumferential direction, and an impact through the ring-shaped body during run-flat running is a tire having the waveform It forms a ring with a spring plate to relieve the radial elastic deformation, yet the elastic annular body, while being detent fitted in one position of the rim in the circumferential direction, other than the fitting point The minute characterized in that the relative slip between the rim is allowed.

According to a second aspect of the present invention, the elastic annular body has a spring plate thickness t of 2 to 6 mm, a corrugated tire circumferential pitch P of 50 to 100 mm, and a total height Ha of 20 in the tire radial direction. The invention according to claim 3 is characterized in that the elastic annular body has a height ratio (Ha / Hb) between a total height Ha of the corrugated tire radial direction and a tire cross-section height Hb of 10 to 35. In the invention according to claim 4, the rim is provided with a rotation-preventing portion formed of a recess, and the elastic annular body has a protruding piece, and the protruding piece is connected to the rotating-stopping portion. It is characterized in that it is prevented from rotating with respect to the rim by being fitted to the rim .

  In the invention according to claim 1, the elastic annular body has a waveform that goes in and out in the tire radial direction at a constant pitch in the tire circumferential direction, and forms an annular body ring shape using a spring plate. When an impact received from the road surface, such as when riding over unevenness, is transmitted to the elastic annular body via a ring-shaped body that is externally fitted to the elastic annular body, the waveform is buffered by elastic deformation in the tire radial direction.

  As a result, impact transmission to the vehicle is suppressed, and damage to the vehicle, such as breakage of the suspension, can be prevented, and run flat travel durability can be improved and travel distance can be extended. Prevents a significant decrease in ride comfort. Further, since the elastic annular body has a ring shape with the spring plate being waved, it is easy to manufacture and can suppress an increase in weight.

  In the invention according to claim 2, the thickness t of the spring plate of the elastic annular body is 2 to 6 mm, the pitch P in the tire circumferential direction of the waveform is 50 to 100 mm, and the height Ha in the tire radial direction is 20 to 40 mm. Therefore, it can be suitably used for a radial tire for a passenger car, and, as in the invention according to claim 3, by setting the height ratio (Ha / Hb) to 10 to 35%, By improving the balance with the body, it is possible to prevent a decrease in normal running performance and to improve run-flat running performance.

  As in the invention according to claim 4, the elastic annular body fits in the rim well, so that the core can be easily attached and fixed, and the impact of the run-flat running can be stably reduced.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a tire / rim assembly 1 (hereinafter, simply referred to as an assembly 1) includes a tire T and a rim R that assembles the tire T. The rim R and the tire T An annular core 3 that supports the tire load when the internal pressure decreases is disposed in the tire lumen 2 that is surrounded by.

  In the present embodiment, the tire T includes a tread portion 12, sidewall portions 13 and 13 extending inward in the tire radial direction from both ends thereof, and bead cores positioned on the radially inner side of the sidewall portions 13 and 13. The toroid which has a pair of bead parts 14 and 14 which provided 15 is made. In addition, a carcass 16 is bridged between the bead portions 14 and 14 on the tire T, and a belt layer 17 is wound in the circumferential direction outside the carcass 16 and inside the tread portion 12.

  The carcass 16 includes one or more radial or semi-radial carcass plies in which the carcass cord is arranged at an angle of, for example, about 70 to 90 ° with respect to the tire equator C, and the belt layer 17 includes the belt cord. While the tire equator C is arranged at an angle of about 0 to 30 degrees, for example, it is formed from two belt plies 17A and 17B in this embodiment, each of which has a well-known configuration. On the toe side, a protrusion 14a is formed that projects obliquely downward in the radial direction and projects toward the center.

  The rim R supports a pair of rim seat portions Ra and Ra on which a bead bottom surface 14A of the bead portion 14 of the tire T is seated, and a tire axial direction outer surface 14B of the bead portion 14 and has an outwardly curved portion at an upper end. It has a rim body in which tire receiving portions R1 and R1 including flanges Rb and Rb are connected by a joint ring R2. The joint ring R2 is held on the axle via a disk (not shown) to form a tire wheel. The rim seat portion Ra has a hump groove Rc extending into the inner end portion in the tire axial direction, into which the protrusion 14a is fitted. The joint ring R2 is joined by connecting a bottom rim-like rim well Re by the groove wall Rf between the two spaced-apart portions Rd connected to the upper end of the groove wall of the hump groove Rc. .

  Further, in this embodiment, as shown in FIG. 3, the groove wall Rf is formed with a rotation stopper Rg consisting of a recess, preferably at one place, at most about 3 to 5 places in the circumferential direction, and the rim well Re The groove width Wrf is about 3/5 to 1/4 times the rim width, and the groove depth Drf is about 0.5 to 3.0 mm. The rim width is the nominal width of the regular rim R, and the regular rim is a rim determined by the standard for each tire in the standard system on which the tire is based. If so, "Design Rim" or if ETRTO, "Measuring Rim".

  2 to 4, the elastic annular body 4 is provided with a wave portion 4 a that repeatedly enters and exits the tire in the radial direction of the tire at a constant pitch P, and is provided in a ring shape using a spring plate 6. Make. In this embodiment, the spring plate 6 has a thickness t in the range of 2 to 6 mm. If it is less than 2 mm, the elastic modulus in the radial direction of the elastic annular body 4 tends to be insufficient, and if it exceeds 6 mm, the elastic modulus is excessive and the impact absorbing ability is reduced. The thickness t is preferably 2.5 mm or more for the lower limit, and more preferably 3.5 mm or less for the upper limit.

  The pitch P in the circumferential direction of the wave portion 4a of the elastic annular body 4 is in the range of 50 to 100 mm. If it is less than 50 mm, the rigidity in the tire radial direction becomes excessive, so that the elastic deformation corresponding to the impact force from the road surface is insufficient. Inferior. More preferably, the lower limit is 65 mm or more. More preferably, the upper limit is 85 mm or less.

  The waveform of the elastic annular body 4 is such that the total height Ha from the bottom point to the ceiling point in the tire radial direction is in the range of 20 to 40 mm. If it is less than 20 mm, the shock-damping capacity is insufficient because the elastic deformation stroke is short. Conversely, if it exceeds 40 mm, the weight of the elastic annular body 4 increases.

  Further, the height ratio (Ha / Hb) between the total height Ha and the tire cross-section height Hb is set to a range of 10 to 35%. If it is less than 10%, the buffering stroke of the elastic annular body 4 is insufficient, and the buffer relaxation effect is not sufficient. Conversely, if it exceeds 35%, the weight of the elastic annular body 4 becomes excessive. More preferably, the lower limit is 15% or more. More preferably, the upper limit is 30% or less. The cross-sectional height Hb is a “cross-sectional height” defined in JIS4202. In addition, each value of thickness t, pitch P, total height Ha, and Ha / Hb is what is called a radial tire for passenger cars, and is set to a preferable value for a tire having a flatness ratio of about 0.5 to 0.8. Yes.

The spring plate 6 has a width wb of about 3/5 to 1/4 times the rim width, that is, fits into the groove width of the rim well Re, thereby preventing deviation in the tire axial direction. Yes. Further, as shown in FIG. 3, a locking portion 6p made of a protruding piece that can be fitted to the rotation stopping portion Rg made of the dent of the rim R is projected at a position that becomes the wave bottom 6a1 of the wave portion 6a. Yes. By inserting the locking portion 6p into the rotation stop portion Rg, it is possible to prevent the elastic annular body 4 from being displaced from the rim R in the circumferential direction and prevent rotation. Further, by setting the fitting portion to one place, it is possible to allow relative sliding between the elastic annular body 4 and the rim R at the other part due to the deformation of the elastic annular body 4 while preventing rotation. In this embodiment, as shown in FIG. 2, a positioning portion 6 b is formed which is a recess formed by cutting out the position to be the wave front 6 a 2.

  The spring plate 6 is made of a stainless steel material such as SUS304WP-8, SUS304WP-9, or SUS316WP-A, a piano wire steel material such as SWP-A or SWP-B, or a copper alloy such as brass, phosphor bronze, or beryllium copper. Various other spring materials with excellent spring properties, preferably high-strength spring materials such as stainless spring steel materials and piano wire steel materials can be used. The spring plate 6 is subjected to a die forming process, and both ends thereof are connected by welding, rivets, caulking, or the like to form a ring shape. It is also possible to corrugate after forming a ring-shaped body in advance. The wave portion 6a includes not only the pitch P having the same length but also a constant pitch in the sense that it is repeated in a constant cycle.

  In this embodiment, as shown in FIGS. 1 and 2, the ring-shaped body 5 that is externally fitted to the elastic ring-shaped body 4 includes an inner ring body 5 </ b> A attached to the elastic ring-shaped body 4 and a support wall portion on the outer peripheral surface thereof. 5B and the ring body 5C outside the outer peripheral surface are integrally formed. In the present embodiment, the inner ring body 5A is a flat plate wound body having substantially the same width as the elastic annular body 4 (about 0.8 to 1.2 times the width w6 of the elastic annular body 4). A flip-up piece 5 </ b> A <b> 1 radially outward is formed at the edge, and is guided when relatively moving laterally in the tire axial direction so as to be externally fitted to the elastic annular body 4. Further, on the inner circumferential surface of the ring body 5A, an engaging portion 5A2 made of a convex strip shown in FIGS. 1 and 2 is formed in the circumferential direction. As shown in FIGS. 1 and 2, the engaging portion 5A2 has a shape that can be fitted to the positioning portion 6b of the elastic annular body 4, and by fitting the positioning portion 6b, the ring-like body 5 A lateral shift in the tire axial direction can be prevented.

  Further, in this embodiment, the support wall portion 5B revolves around the circumferential direction by repeatedly entering and exiting the V shape in the tire axial direction, and the outer ring body 5C has the same width as the inner ring body 5A. The support wall portion 5B and the outer ring body 5C are integrated with the inner ring body 5A, and the outer peripheral surface of the outer ring body 5C is the tread portion 12 during run-flat running. The ring-shaped body 5 is loaded by contacting the inner surface. For this reason, the ring-shaped body 5 requires moderate flexibility that can support a load from the road surface and can provide a certain amount of buffering, and rigidity that transmits the deformation to the elastic annular body 4 when excessive deformation occurs. .

  Therefore, rubber and synthetic resin can be used as the material used for the ring-shaped body 5, but nylon, polyester, polyacetal, and other high-strength industrial synthetic resins can be preferably employed from the viewpoint of weight reduction. In order to obtain flexibility, various rubbers can be used, and those having a durometer JISA hardness of about 55 to 85 can be used. It is also possible to use composite materials of various fibers including steel, inorganic and organic fiber cords, short fibers, metals, organic and inorganic powders. “Durometer A hardness” means rubber hardness according to durometer type A based on JIS-K6253.

  In such a core 3, first, the elastic annular body 4 is extended to the rim well Re of the rim R and is seated on the groove bottom of the rim flange Rb while extending over the rim flange Rb. Prevent misalignment in the direction. In addition, by engaging the locking portion 6p with the rotation stopping portion Rg of the rim R, the elastic annular body 4 can be prevented from being displaced in the circumferential direction while preventing the displacement of the elastic annular body 4 with respect to the circumferential direction. As described above, the number of fitting points is set to a small number of about one, so that the elastic annular body 4 and the rim R are prevented from rotating while the elastic annular body 4 and the rim R between the other portions are not rotated. The relative slip accompanying the deformation of the elastic annular body 4 can be allowed.

  Further, the tire T in which the ring-shaped body 5 is housed is dropped between the tire receiving portions R1 and R1 together with the ring-shaped body 5 over one rim flange Rb. By pushing the side wall portion 13 on one side in the tire axial direction and using a gap that can be generated between the bead portion 14 and the elastic annular body 4, the inner ring-shaped body 5 is moved up by using the flip-up piece 5 </ b> A <b> 1. The outer periphery of the elastic annular body 4 can be manually fitted only at the entrance portion. Further, by controlling the tire pushing distance in advance and fitting the engaging portion 5A2 of the annular body 5 to the positioning portion 6b of the elastic annular body 4 as shown in FIGS. Thus, it is possible to prevent the displacement of the tire in the tire axial direction during the run-flat running with the rotation of the tire. The ring-shaped body 5 is elastically fitted around and fixed to the outer periphery of the elastic annular body 4. Thereafter, the internal pressure is filled and the tire T is mounted at the normal position of the rim R.

  In such an assembly 1, when the tire lumen pressure is reduced to 0 due to puncture during traveling, the outer peripheral surface of the annular body 5 of the core 3 receives the inner surface of the tread portion 12 and travels. Further, when the tread portion 12 gets over the convex portion of the road surface during traveling, the inner surface of the tread portion 12 impacts the ring-shaped body 5 in a radially inward direction. The elastic annular body 4 also receives an impact force in the radial direction through the ring-shaped body 5, and reduces the height Ha of the wave portion 6a of that portion together with the adjacent wave portions Ha. Changes to be tall, that is, the elastic annular body 4 stores energy therein, absorbs and relaxes the impact force, and transmits it to the rim R. As a result, it is possible to reduce the feeling of bottoming when riding over the protrusion, prevent the vehicle body such as the suspension from being damaged, and maintain steering stability. During run-flat traveling, when the bumpy surface of the road surface is overcome, such as when overcoming the road surface, the spring plate 6 forming the elastic annular body 4 is elastically deformed in the tire axial direction. As a result, the impact energy is absorbed and the impact force F is reduced from the road surface. As a result, the impact on the vehicle due to the impact of the run-flat running can be reduced, the run-flat running distance can be extended, and the high-speed run-flat running can be achieved. Make possible. In addition, the driving stability can be maintained by the shock relaxation, and the riding comfort equivalent to that of normal driving can be obtained. Further, the up-and-down movement of the tire in the run-flat traveling when traveling on a normal road surface can be absorbed by the annular body 5.

  In the present invention, in order to facilitate the rim assembly work, the elastic annular body 4 may be formed by winding and connecting a belt-shaped spring plate 6 having a corrugated shape to a rim well Re of the rim R. Furthermore, the ring-shaped elastic annular body 4 can be divided into a plurality of parts and connected around the rim well Re to form an annular shape. Further, the rim well Re, the groove wall Rf, the rotation stopper Rg, the locking Instead of the positioning structure of the portion 6p, the engaging portion 5A2, and the positioning portion 6b, various types that can prevent relative movement can be used. Also, for example, a recess that fits each wave part can be shifted by using rubber, synthetic resin, or directly formed on the rim, but it is possible to adopt a configuration that can be returned and positioned. It is.

  As shown in Table 1, examples of tire and rim assemblies using a core 3 having an elastic annular body 4 and a ring-shaped body 5 of various dimensions and materials were prepared. Further, a conventional example product having a core 3 having only a ring-shaped body 5 without using the elastic annular body 4 shown in FIG. 6 was evaluated for durability performance, steering stability performance, and riding comfort performance during run-flat travel. Each test method is as follows.

<Durability>
The tire assembly with an internal pressure of 0 kPa was continuously run on an iron drum wafer having a diameter of 1.7 m at a speed of 80 km / h and a load of 6.86 kN, and the running time until the running became impossible due to breakage of the core 3 was measured. A result is displayed by the index | exponent which made the conventional example the standard value 100, and it is so favorable that a numerical value is large.

<Steering stability and ride performance>
The test assembly was mounted on four wheels of a domestic FF passenger car with a displacement of 2000 cm ³ , and the internal pressure of the right front wheel assembly was set to 0 kPa. Using the test vehicle, drive on a stepped road on dry asphalt road, Berjaso road (cobblestone road), Bitzmann road (road surface covered with pebbles), etc., driving stability performance and ruggedness, pushing up In addition, sensory evaluation was performed by 10-point method for ride comfort performance related to damping. The result is shown as an average value of 10 drivers, and the larger the value, the better.

<Shock absorption energy>
The integrated value of the displacement was measured when the load was changed from ON to 3920 N with air removed from the assembly to be tested. A result is displayed by the index | exponent which made the conventional example the standard value 100, and it is so favorable that a numerical value is large.

It is a meridian cross-sectional view illustrating an embodiment of the present invention. FIG. It is the principal part disassembled perspective view. It is the tire equatorial plane sectional view. It is a tire equatorial plane sectional view showing a run flat running state. It is meridian sectional drawing which illustrates a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Assembly of tire and rim 2 Tire lumen 3 Core 4 Elastic annular body 5 Ring-shaped body 6 Spring plate R Rim T Tire

Claims (4)

A tire and rim assembly comprising a tire and a rim for assembling the tire, and an annular core for supporting the tire load when the internal pressure is reduced in a tire lumen surrounded by the rim and the tire. ,
The core consists of an elastic annular member you continuously mounted and the tire circumferential direction on the rim, the annular body fitted on the elastic ring-shaped member,
The elastic annular body has a waveform that circulates around the rim and repeats entering and exiting in the tire radial direction at a constant pitch in the tire circumferential direction, and impacts through the ring-shaped body during run-flat running in the tire radial direction of the waveform. It has a ring shape using a spring plate that relaxes by elastic deformation , and
The elastic annular body is fitted to the rim at one location in the circumferential direction and is prevented from rotating, and a relative slip with respect to the rim is allowed at a portion other than the fitting location. Rim assembly.
  In the elastic annular body, the thickness t of the spring plate is in the range of 2 to 6 mm, the corrugated tire circumferential pitch P is 50 to 100 mm, and the total height Ha in the tire radial direction is 20 to 40 mm. The tire and rim assembly according to claim 1.   2. The elastic annular body according to claim 1, wherein a height ratio (Ha / Hb) between a total height Ha of the corrugated tire radial direction and a tire cross-sectional height Hb is in a range of 10 to 35%. Or the tire and rim assembly according to 2. The rim is provided with a detent portion made of a dent,
The said elastic annular body has a projecting piece, The rotation is stopped with respect to a rim by fitting this projecting piece to the said rotation stop part, The Claim 1 characterized by the above-mentioned. Tire and rim assembly.

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