JP2005075294A - Vehicular wheel rim - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire rim suppressing the lateral displacement amount of a tire when turning, improving steering stability when turning, and having a good shock absorbing property and good riding comfort when traveling straight. <P>SOLUTION: In the vehicular wheel rim 1 attached to a vehicle, the height h2 of an inner flange 4i positioned on the inside of a vehicle when attached to the vehicle is larger than the height h1 of an outer flange 4o positioned on the outside of the vehicle. A difference h2-h1 between the height h2 of the inner flange 4i positioned on the inside of the vehicle when attached to the vehicle and the height h1 of the outer flange 4o positioned on the outside of the vehicle is set 4 to 25 mm. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle wheel rim that can improve steering stability during turning.

  2. Description of the Related Art Conventionally, various attempts have been made to improve steering stability during turning in a four-wheeled vehicle. In general, by providing a high modulus reinforcing cord layer and hard rubber layer on the sidewalls and bead portions of the tire, the lateral stiffness of the tire is improved and the lateral deformation of the tire during turning is suppressed. It has been broken. However, increasing the lateral stiffness of the tire tends to improve the longitudinal stiffness at the same time. For this reason, it is inferior to vibration absorption at the time of straight running, and the malfunction of impairing riding comfort tends to occur.

  The inventors paid attention to a wheel rim on which a tire is mounted and tried to improve steering stability by improving the shape of the wheel rim. In general, the wheel rim is formed with an outer flange on the both ends of the bead seat portion on which the bead portion of the tire is seated, while rising in the radial direction. The inner and outer flanges are all set to the same height (for example, usually 17.5 mm or 18.0 mm for passenger cars), but paying attention to the deformation behavior of the tire when turning, It has been found that if the height of the inner flange located on the inner side of the vehicle is larger than the height of the outer flange located on the outer side of the vehicle, it is possible to suppress a large lateral deformation of the tire without significantly deteriorating the riding comfort. It came to complete.

  As described above, an object of the present invention is to provide a vehicle wheel rim that can improve steering stability during turning without impairing riding comfort.

  The invention according to claim 1 of the present invention is a vehicle wheel rim mounted on a vehicle, and the height of the inner flange located on the inner side of the vehicle when the vehicle is mounted is the same as that of the outer flange positioned on the outer side of the vehicle. It is characterized by being larger than the height.

  The invention according to claim 2 is characterized in that a difference (h2−h1) between a height h2 of the inner flange and a height h1 of the outer flange is 4 to 25 mm. This is a vehicle wheel rim.

Further, in the invention according to claim 3, the inner flange has a vertical surface that extends continuously in the radial direction of the bead seat surface via a small arc, and has a flange outer end and a radius of curvature R1. An end arc surface that protrudes radially outward in a small arc, and a joint surface that connects between the vertical surface and the end arc surface, and from the rim diameter line, the vertical surface and the joint surface A height H1 up to the intersection point A, a height H2 from the rim diameter line to the intersection point B between the joint surface and the end arc surface, and a distance D in the tire axial direction between the intersection point A and the intersection point B. The vehicle wheel rim according to claim 1, wherein the following formula is satisfied.
0.2 ≦ D / (H2−H1) ≦ 1.2

  According to a fourth aspect of the present invention, in the vehicle wheel rim according to the third aspect, the joint surface includes an arc surface that is convex outward in the tire axial direction and has a radius of curvature R2 of 2 to 20 mm. It is.

  As described above, according to the first aspect of the present invention, since the height of the inner flange located on the inner side of the vehicle is larger than the height of the outer flange located on the outer side of the vehicle when the vehicle is mounted, the slip angle is given. When this is done, the flange having a large height functions as a wall that suppresses the lateral deformation of the bead portion, and the large lateral deformation of the bead portion can be prevented. Therefore, responsiveness when a slip angle is applied can be improved, and as a result, steering stability can be improved. Further, since the structure of the tire is not changed, the original riding comfort of the tire can be maintained by adjusting the height of the inner flange, for example.

  Further, when the difference (h2−h1) between the height h2 of the inner flange and the height h1 of the outer flange is limited to a certain range as in the second aspect of the invention, the riding comfort performance is more reliably achieved. In addition, the steering stability can be improved while preventing the deterioration of the rim assembly performance.

  As in the third aspect of the invention, the inner flange has a vertical surface that extends continuously in the tire axial direction of the bead seat surface via a small arc and extends in the radial direction, an outer end of the flange, and a radius of curvature R1. An end arc surface that protrudes radially outward in a small arc, and a joint surface that connects between the vertical surface and the end arc surface, and an intersection of the vertical surface and the joint surface from a rim diameter line A height h1 up to A, a height h2 from the rim diameter line to the intersection B of the joint surface and the end arc surface, and a distance D in the tire axial direction between the intersection A and the intersection B are constant. When regulated by the relational expression, the slope of the joint surface can be appropriately formed in accordance with the bead portion of a standard tire. As a result, while ensuring a large contact area with the bead part, it is possible to prevent the contact pressure with the bead part from becoming excessive and to maintain bead durability.

  When the joint surface has an arc surface having a center on the center line side of the rim width and a radius of curvature R2 of 2 to 20 mm as in the invention according to claim 4, the bead portion has an outer side in the tire axial direction. It can be suitably matched to the bead shape of the tire provided with the raised bulge portion, and it is useful for securing a large contact area with the bead portion to prevent bead heat generation and the deterioration of durability performance.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a partial end view of a vehicle wheel rim 1 of the present embodiment. The vehicle wheel rim (hereinafter sometimes simply referred to as “wheel rim”) 1 is integrally provided with a rim portion 1A for supporting a tire and a disc portion 1B having a hub (not shown), for example, steel or aluminum. It is formed of a metal material such as an alloy. The wheel rim 1 of the present embodiment is for a passenger car, and the disc portion 1B is not particularly limited according to customary practice, and various structures are employed.

  The rim portion 1A has a groove-like well portion 2 extending in the circumferential direction with a depth and width for dropping the bead portion 8 (both shown in FIG. 3) when the tire T is attached and detached. A bead seat portion 3 having a bead seat surface 3a formed on both sides in the axial direction and on which the bead portion 8 is seated; and the bead seat portion 3 extending continuously outward in the tire radial direction and connected to the bead seat portion 3. And a flange portion 4 that supports the outer surface in the tire axial direction.

  In the present embodiment, the well portion 2 and the bead seat portion 3 are formed based on the contour shape of a so-called 5 ° deep bottom rim for a passenger car. The flange portion 4 includes an inner flange 4i located on the inner side of the vehicle when the vehicle is mounted, and an outer flange 4o located on the outer side of the vehicle. In the present invention, the height h2 of the inner flange 4i is the outer flange. It is formed larger than the height h1 of 4o. The heights h1 and h2 of the flanges are radii from the rim diameter line RL, which is an axial line passing through the position of the rim diameter, to the outermost position in the tire radial direction of the flanges 4i and 4o in the meridian section including the rim rotation axis. The height in the direction, both of which are formed at a constant height in the circumferential direction.

  FIG. 2 shows the behavior of the tire T located outside the turn when the four-wheeled vehicle is turning. When a slip angle θ is given to the tire T, a deviation occurs between the traveling direction a of the vehicle and the rotational direction b of the tire. As a result, the tread rubber in the contact surface indicated by hatching in the figure undergoes shear deformation that is dragged inward of the vehicle due to friction with the ground. As a result, a lateral force Y is generated in the tire T. The magnitude of the lateral force Y generated at this time is the product of the lateral elastic modulus (axial direction) per unit length of the tread rubber and the amount of deformation of the tread rubber.

  The bead portion on the vehicle inner side of the tire T is deformed so as to fall to the flange 4i side in the wheel rim 1 along with the shear deformation of the tread rubber when passing through the contact surface. At this time, by increasing the height h2 of the inner flange 4i, the inner flange 4i becomes a wall that suppresses large lateral deformation of the bead portion, and the lateral elastic modulus per unit length of the tread rubber is increased. Increase in appearance. Therefore, by using the vehicle wheel rim 1 of the present invention, a large lateral force Y can be obtained even at the same slip angle. In addition, such an action significantly improves the turning response of the vehicle when a slip angle is given, and improves steering stability. Therefore, when the driver turns the steering wheel, the vehicle can react quickly. Further, in the vehicle wheel rim 1, for example, by adjusting the height h2 of the inner flange 4i or the like, it is possible to easily prevent deterioration in riding comfort.

  The height h1 of the outer flange 4o is preferably set to a flange height (for example, 17.5 mm or 18.0 mm for passenger cars) defined in a standard such as JATMA. If the height h1 of the outer flange 4o is less than the height defined in the standard, the tire T is likely to be detached from the wheel rim 1 during turning, and conversely, if the height h1 exceeds the height defined in the standard, the height However, because of the synergistic action with the flange 4i, the rim assembly of the tire becomes difficult and the ride comfort tends to be deteriorated.

  In addition, if the difference (h2−h1) between the height h2 of the inner flange 4i and the height h1 of the outer flange 4o is too large, the stability during straight traveling tends to be impaired, and the riding comfort tends to deteriorate. On the contrary, even if it is too small, there is a tendency that improvement in handling stability cannot be expected sufficiently. From such a viewpoint, although not particularly limited, it is desirable that the height difference (h2−h1) is 4 to 25 mm, more preferably 6 to 25 mm, and still more preferably 10 to 18 mm.

  In the present embodiment, as shown in an enlarged view in FIG. 3, the inner flange 4i is connected to the outer side in the tire axial direction of the bead seat surface 3a via a small circular arc surface 5, and the vertical surface 6 and the outermost flange. An example is shown in which an end arc surface 7 forming an end and a joint surface 9 that connects the end arc surface 7 and the vertical surface 6 have a contour shape.

  The small arc portion 5 is formed by, for example, an arc having a curvature radius R0 of about 4.0 to 6.5 mm. Further, as shown in FIG. 1, the vertical surface 6 of the flange 4 i can define the rim width RW with the vertical portion 6 of the flange 4 o that rises outside in the tire radial direction. In the present embodiment, the inner and outer flanges 4i and 4o are illustrated in which the length of the vertical surface 6 in the tire radial direction is set to be substantially the same. The end arc surface 7 is formed as a small arc having a radius of curvature R1 of about 7 to 12 mm, for example, which is convex outward in the radial direction. The end arc surface 7 can effectively prevent the bead portion 8 from being bent excessively at the end portion of the flange even when the bead portion 8 of the tire is greatly deformed outward in the axial direction. In addition, about the shape etc. of these small circular arc surfaces 5, the vertical surface 6, or an end circular arc surface 7, it can determine according to the dimension described in standards, such as JATMA.

  In the present embodiment, the joint surface 9 is connected to the vertical surface 6 at the intersection A, and the inner arc surface 9a is convex toward the inside in the axial direction, and the outer end of the arc surface 9a and the intersection C are at the intersection C. Examples include a continuous arc extending outward in the radial direction and an inner arc end surface of the end arc surface 7 and an outer arc surface 9b protruding at the intersection B and protruding outward in the axial direction.

  The inner arc surface 9a is preferably formed by an arc having a curvature radius R2 of 1 to 40 mm, more preferably 2 to 20 mm, for example. When the radius of curvature R2 is less than 1 mm or exceeds 40 mm, the contour shape of the inner flange 4i is far from the outer surface shape of the bead portion 8 in the tire axial direction, and large heat generation and wear are caused by friction with the bead portion 8. This is not preferable because it tends to cause Similarly, it is desirable that the outer arc surface 9b is formed by an arc having a radius of curvature R3 of 10 mm or more, more preferably 20 to 100 mm, and still more preferably 30 to 80 mm. Thereby, the outline of the flange can be made closer to the outer surface shape of the bead portion or the sidewall portion of the tire T.

Moreover, it is desirable to limit the gradient of the joint surface 9 in the inner flange 4i. Specifically, the height H1 from the rim diameter line RL to the intersection A between the vertical surface 6 and the joint surface 9 and the height from the rim diameter line RL to the intersection B between the joint surface 9 and the end arc surface 7 are shown. It is desirable that H2 and the axial distance D between the intersection A and the intersection B satisfy the following expression.
0.2 ≦ D / (H2−H1) ≦ 1.2

  As a result of various experiments by the inventors, when the gradient {D / (H2-H1)} is less than 0.2, the joint surface 9 rises with a so-called steep gradient, and the inner flange 4i is not used during turning. It has been found that a large contact pressure tends to act between the bead portion 8 and the bead portion 8. For this reason, riding comfort is deteriorated, and a large amount of heat is easily generated in the bead portion 8 during traveling, thereby reducing durability. On the other hand, when the gradient {D / (H2-H1)} exceeds 1.2, the joint surface 9 has a so-called gentle inclination, and it is difficult to obtain an effect of suppressing the deformation amount of the bead portion 8 even during turning. Particularly preferably, the gradient {D / (H2-H1)} is set to 0.4 to 0.8. In the inner flange 4i, the length L in the radial direction of the outer arcuate surface 9b is particularly preferably set to, for example, 50 to 90%, more preferably about 60 to 85% of the length (H2-H1). .

FIG. 4 shows another embodiment of the present invention.
In this embodiment, the bead portion 8 is formed to be suitable for a tire having a raised portion 10 raised outward in the tire axial direction. In this embodiment, the inner flange 4 i has a contour shape comprising a vertical surface 6, an end arc surface 7 forming the flange end, and a joint surface 11 connecting the end arc surface 7 and the vertical surface 6. Consists of.

  The joint surface 11 of this embodiment is connected to the vertical surface 6 at an intersection A and is an arc B 11a that is convex toward the inner side in the axial direction, and an intersection B on an end arc surface 7 that is located on the outermost side in the radial direction. And the outer arc portion 11b that protrudes inward in the axial direction, the inner end in the tire radial direction is connected to the inner arc surface 11a at the intersection C, and the outer end in the tire radial direction is the outer arc surface 11b. And an arcuate surface 11c that is continuous at the intersection E and is convex outward in the axial direction. The inner arc surface 11a and the outer arc surface 11b are preferably formed by small arcs having curvature radii R2i and R2o of, for example, 4 to 60 mm, more preferably 6 to 30 mm. On the other hand, it is desirable that the inner circular arc surface 11c be formed with an arc having a radius of curvature R4 of 2 to 20 mm, more preferably 6 to 12 mm, for example.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. For example, as a rim, it goes without saying that it can be implemented as various wheel rims such as for heavy-duty vehicles as well as for passenger cars.

  A wheel rim for a passenger car with a rim size of 5-1 / 2J × 14 was prototyped based on the specifications in Table 1 and tested for lateral displacement, steering stability, and riding comfort during turning, and the performance was compared. For the outer flange, standardized dimensions (J type flange height 17.5 mm) were standardized. The test method is as follows.

<Horizontal displacement during turning>
Running on a flat belt test machine under the following conditions, the tire center is extracted by laser scanning the running center of contact, and the tire axial distance from the rim flange position to the cross-section tire maximum width as shown in FIG. W was measured.
・ Tire size: 185 / 65R14
・ Internal pressure: 200kPa
・ Longitudinal load: 400kgf (3.92KN)
・ Slip angle: 6 °
・ Speed: 80km / h

<Steering stability>
A 1800cm ³ domestic FF vehicle is fitted with four test wheel rims, 185 / 65R14 radial tires for passenger cars, and an internal pressure of 200 kPa, driving on a dry asphalt road test course with one driver. In addition, characteristics relating to handle response, rigidity, grip, etc. were evaluated by sensory evaluation of the driver. The results are displayed as an index with Comparative Example 1 as 100. The larger the value, the better.

<Ride comfort>
Under the same vehicle conditions as described above, sensory evaluations were made regarding ruggedness, push-up, and damping on stepped roads on dry asphalt roads, Berjaso roads (cobblestone roads), Bitzmann roads (roads covered with pebbles), and the like. The results are indicated by an index with Comparative Example 1 being 100, and the larger the value, the better.
The test results are shown in Table 1.

  As a result of the test, in the example, the lateral displacement amount is reduced as compared with the comparative example, and a remarkable performance improvement effect is seen also in the steering stability. It was also confirmed that there was no difference in ride comfort when the difference in height between the inner flange and the outer flange was within 6 cm. In Example 3 where the difference was 18 cm, it was at a level where there was no practical problem.

It is a fragmentary sectional view of a wheel rim showing one embodiment of the present invention. It is a top view explaining the tire in turning. It is a partial expanded sectional view of a wheel rim. It is a partial expanded sectional view of the rim | limb which shows other embodiment of this invention. It is sectional drawing of the tire and rim assembly explaining a lateral displacement amount.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle wheel rim 2 Rim part 3 Flange 4B in disk part 4A Outer flange 9 Joint surface RL Height of flange in rim diameter line h2 Height of outer flange h1

Claims (4)

  A vehicle wheel rim mounted on a vehicle, wherein a height of an inner flange positioned on the inner side of the vehicle when the vehicle is mounted is greater than a height of an outer flange positioned on the outer side of the vehicle. Wheel rim for   The vehicle wheel rim according to claim 1, wherein a difference (h2-h1) between a height h2 of the inner flange and a height h1 of the outer flange is 4 to 25 mm. The inner flange is connected to the outer side in the tire axial direction of the bead seat surface through a small arc and extends in the radial direction, and has a flange outer end and a small arc having a radius of curvature R1 toward the outer side in the radial direction. A convex end arc surface, and a joint surface connecting between the vertical surface and the end arc surface,
And a height H1 from the rim diameter line to the intersection A of the vertical surface and the joint surface;
A height H2 from the rim diameter line to the intersection B of the joint surface and the end arc surface;
3. The vehicle wheel rim according to claim 1, wherein the following expression is satisfied at a distance D in the tire axial direction between the intersection point A and the intersection point B. 4.
0.2 ≦ D / (H2−H1) ≦ 1.2   4. The vehicle wheel rim according to claim 3, wherein the joint surface includes an arc surface that is convex outward in the tire axial direction and has a curvature radius R2 of 2 to 20 mm.

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